LEE os GY OL LE BY _ EAR 19017 R.A (TUTE OF TEC r INS’ C ove . Ky f J UM KMOL Ea 7 r i K XN 537 ‘ JIRA MC AT 445 Earle, R. H. The Morkrum system of printing telegraphy ; Mk ra i ne a matt ‘ THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY A THESIS PRESENTED BY RALPH H. EARLE AWOL she PRESIDENT AND FACULTY OF ARMOUR INSTITUTE OF TECHNOLOGY FOR THE DEGREE OF BACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING MAY SY, S17 ie Tne e aa of Ce etri LA AAAL Engineering, ILLINOIS INSTITUTE OF TECHNOLOGY Dean of Engineering Studies PAUL V. GALVIN LIBRARY 35 WEST 33RD STREET ae CHICAGO, IL 60616 is RP Ci Ong Wicgieg saa f ME : a, yoowOniss STUART ane ee RANE ii ae rele te 10 waray 2 iaisitNe: aH YEIASO OaLaT OMITATAT | ey THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY OBJECT, The object of this thesis is the composition of a detailed descrip- tion of the Morkrum System of Printing Te- legraphy. weed’? "i ie 6 YSTARVERIZT DUITMIAL WO METCYe MUAAAOM FET .TORGLEO ateedd atdt to toetdo edT ~qitsash fhetiateb s to nottteoqmoes edt at -eT agittaizvi to meteye mrrdroM ext to sort “qstael TTS THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY FOREWORD. The material for this thesis was obtained from the Morkrum Company, al- though the wording and arrangement is orig- inal with the writer. A number of the draw- ings of this thesis were also obtsined from that company. R.H.E. YHIAADSINT DMITMIAT TO METAY MUAAAOM AH? . THOWEAOT eteeds atdt tot [strotam oft -f[8 ,yaeqmod aurrvtroM edt mott heatstdo saw -gito at tmemegnatia bas anthrow edt dgyodt -wath edt to tedmum A .tetiaw edt ditw [sat mort bentetdo oefe stow atesdt atdt to egat -Yasqmoo tat 2.8.8 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Table of Contents Part I - Introductory GENERAL - = = = = = = PRELIMINARY SYSTMM - - - - SECOND SYSTEM - = = = «= THIRD SYSTEM - - = = = = FOURTH SYSTEM - = - = = FIFTH SYSTEM - - = = = = SIXTH SYSTEM - - - = = «= Part II - THE TAPE = = = = = © «= THE CODE - -© = = = = = THE PERFORATOR - © - = = GENERAL LAYOUT - - - = = THE PUNCH PINS - - = = = THR HAMMER - - - = = = THE PUNCH LEVERS - = - = SELECTIVE MECHANISM - = - TAPE FEED - - = = - = = p.3 pe? p.8 p.ll pe2l pe25s pee? Perforator p35 p.37 p.39 p42 p42 p47 p.49 p.50 p.56 YHTARDSIST OMITUIAT IO METeYe MUSDINOM FHT &.q Y.g 8.9 {[l.q [s.q as. TS.q rsotatottel Shed TS. e5.9 Sh. Sh.q VS.q es.g 03.q aa. atoaetmod to afdet yrotoubottal - I trsf Be Or ee ee a net) a a SOLE SD MPC YE YHARTMLISAL oP oO a ee “PETS “MOORE Se Be Va Se Oke oe Nee fide oe le Ee eee ET aha ie) ey ie EE SEES - = «= « = = = MaTeYe HIXIC bas ,ebod ,eqeT - II traf ae we we Se wy ee ep a oe ta aD et ke i er =~ = = « s s §ORAROTIET Tat ~ - = = «= = QUOYAL CATHWRS - + « = « = @NI¢ HONGT BHF - = = = «© = = SEMMAR DHT - = = = © @SHVEI HOWUL FET - = «= = M@IWAROSM BVITORIAG we wee ee ee ae THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Table of Contents (Cont'd) BAM OPUARR RO ea oe ok ee END-OF-THE-LINE INDICATOR - - - p.60 Part III - The Distribution System GENERAL - - - - - = = - = p.68 MOTOR - - - - - = = = = = p.69 TAPE CONTACTS - - - - = - = p.71 TAPE FEED - - - = - - - = p.73 WOANGULGSION). 4 =. 4 je = =. = p.78 AUTOMATIC STOP - = = - = = = pe79 CUT-OUT - - =- = = = = = = p.85 TRANSMITTING DISK - - = = = = p.87 POLE CHANGER RELAYS - - - - = p.90 RECEIVER DISK «© - - = = = = p.92 TRANSMISSION SHAFT = - - - = = p.93 SYNCHRONIZER - - - - = = = = pe94 DISTRIBUTOR CIRCUITS - = - = = pyl04 VHUAAORINT QUITUIRI TO MET eYe MUAXFOM FET (a'taxod) ataetnod to aldaT S8.q - - soe oe el = (om emoAde wOoAT Odiqg - =- = HOTADICHT SUL I-HH?-TO-Cuz moteye mottadiutet® ed? - IIT treT Ric - > + < 2s > Cana ae be ae el at a ee ne HR [Vi@se ou we ab <u oo 24 eo BRASRORLETES Mie «+ = # e = 8 ORE RT QViqh io seheD <oyet + Ie sWOTeeTMemART Videc- «= + = + = SOR8 DRTARORE BORG. «nm ce be we ne! omy ew ae TOsa.y- - = - = = RelG OULTrrMmenant OCsq.. - -- = + o= -CYAISH SHDMAHO STOF S03@.4 < «= ce as om ue -e) SO RCNSRVERORE S0sq.- - = = + om PEARS MOTCETMEMANT DQsq.- = oe oe oe o+ n= OR RS TMOMMONYE bOLiq--. -. -. <» = SMIVORTO! RoTUaIATeRG THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Table of Contents (Cont'd) MOTOR CIRCUIT - - - = = = = = p.104 TRANSMITTER DISK CIRCUITS =~ = - = p.105 AUTOMATIC STOP CIRCUITS = - = - p.110 RECEIVER CIRCUITS = = = = = = p.1il POLAR DUPLEX OPERATION - - - - - p.114 WHEATSTONE DIFFERENTIAL RELAY - - =- p.122 Part IV - The Printer GEWERATARLNCHORCIACUETI. -. -— ~- |b. pQLse SYPEWHRESY GIGS" -- -- -» =» =~ =p. ptags PRAERNND«PTATE-NALAY-CLRCULTS. -- --p.p213s TYPEWHEEL MOVEMENTS - - - - = = p.135 GUMNRWAEKTS < 2 2 se tt cl ps HQd37 ROTATOR) STRIKER, AND SHIFT LINKS - p.146 ROTATOR LINKS “5 - = = = = = = p.147 STRIKER LINKS - - - = - = = = pel5S YHIAADATE?T OMITVIAL To METLYS MUANHOM FET (S'tx00) etnxetmod to efdet t t $ 1 { ' t S0f.¢ @Olr.eg- - = = &TIVOAID Meld ARTTIMEMART Off{.q¢ - = = = efITyosIS LoTe SITAMOTUA ({[fl.q e's = ee = he) 6BETUDRIS AEVISORA B{fleq - - = = = HOITAMHTO XHITUT AATOT SSl.q - ~- = YAITH TAITURATATIA AMOTeTASHW rotated ef? - VI trel BEIiq’= <9 27 a7 2h a7 =? =” 2S @8l.q - - - - + -' -° - = JagnvEcyY? rig - “~~ - "s “+ "= "= “e 72 “es MEPATT QSlL.g = = “= “= “= “= “Q2HEMEVOM IRSHVTIYT VEf.g? <9 a7 6 oo wt Ss SR abl.q - OMIT VIIHC CUA |ANHINTE | HOTATOR TOL.G sw" 3 A” 6 a” 2 OS BATE HORROR eatigis .-° a2" 2% 3t 2° oo Ra - TTUOATS A0TOM THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Table of Contents (Cont'd) SHrye RS AO CLRCI TL - oo 266 SHIN WOT TONS + we ee hy SELECTOR MECHANISM - - - = = -p.159 SELECTOR DISKS =< = = = = = - 'p.161 SELECTOR DRUM - = - - - - - - .167 WOtdeds BOGE S 4. -.- et DO SPACER AND BACKER - - - - - p.173 PLATEN AND LINER - - - - - = p.185 PRINTER CIRCUITS - - - - = = p.190 ACTUAL SELECTOR CIRCUITS - - - p.193 LOCK RELAY CIRCUITS - - - - - p.194 LOCK AND PLATE RELAY CIRCUITS - - p.19” FINAL SELECTOR CIRCUITS - - - - p.200 INSTRUMENTS - - - - - = = p.209 OPERATING CIRCUITS - - - - - p.212 ROTATOR CIRCUITS - - - = - - p.2l14 CENTER LETTER CIRCUIT - - - - p.216 SPACER AND STRIKER CIRCUIT - - - p.217 YATATOMTNT OMITMUIAL FO METCYe MUASAOM THT {A'troD) etmetmod to aeldeT Oia a a ee a a ee Yatid + = » sftenqeo kohe sepeRenie Cal.q-. -. -. -. - > = ¢MOIMAHOEM moTOmITze atic se » + s » SPOON MOTOMIEE Yal.q - <= = STs oero MERE mOTORETS OFq a+ .-raeegere er Pecee ROME ROTATOR avi.g 4 - - - - = AMHOAG GMA ABDATE Glia - = <etwert <n . RENTS CUA BATATS Oefliq << + = =) = = BRIUOETD atTETAT SCl.q .- .- + STIUOMID. AOTOMIBEe TAUTOA MOEiq. <<. =. — <. BOTUDRTS YALE Roos fef.q - - -ORIUOHID YAIEH FTAIT cm EDOE 008.q -. -. = = enIUDEID sovomTme TAUTT CO8iq. « + =» = = = & SOMRMDRTERT Qi8.q +S) Sefer S) BRTUOMTO: OMTTARTTO bIg¢.q - = - + «= - SMTUDSTO soTATOR alkeq - .- - = -TIUOMID ANTPET AeTMEO WIS.q - = - TIUORIO AEXIATA CMA AMOATE THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Table of Contents (Cont'd) PRINTER DISTRIBUTION CIRCUIT - - p.2z0 OPERATING CIRCUITS - - - - = pe223 MAIN BREAK CONTROL - - - = = p22 SPACING CIRCUIT - = = = = = pe225 BACKING CIRCUIT - - - -- - - p.227 SHIFT CIRCUITS - - = = = = = p.228 RUB-OUT CIRCUIT - - - = = = p.231 DISTRIBUTION CIRCUIT - = = = = p.232 YHTAROMINT DRLTMIAT TO METOYe MUAAHOM HT (A'da0d) ataetaod to eldel OSS.q -. -. TIUDATO MOITUAIATEIG AATMIAT ONG Mae BTIUOATD PMITAAETO | B8.q = - - - = GOMMMOD AABRE MEA | asa. - - - = = = MUUORTS omrDace : NS8.q .- - == - -.-. TTUOSIO MMTHOME as O88ig -.- 9. -.- eS ORION | Se on a a - MIUORIO TUO-aUA ; ii S88.q - - - =, ~ MIVOATO woImuarRTera THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Illustrations Introduction Figs. 1 - 6 Impulse Diagram Code, Tape, and Perforator Figs. 7 - 15 Plates 1 - 2 Distribution System Figs. 16 = 30 Plates III - Viii Printer Figs. 30 -64 Plates IX - XII. YATAADAIST OMITUIAT FO METSve MUAZAOM FHT esottsrtes I [I neottosbortal a3 - If .agtt matastd eefyamt totatotret fas ,eqeT ,ebod 6g - T .eett S$ - I estelt metaye nolttudi¢rtetd CS ~ df .ant® EEFEFVY - III esetelt tetatrt hd- OF ant? .IIX - EL aetalt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Part I - Introductory. GENERAL, In the operation of the Morkrum System of Printing Telegraphy, the message to be transmitted is first transcribed onto a perforated paper tape according to a eode of perforations. This operation is perform- ed on a keyboard perferator, just as though the message were being typewritten. The tape is then run through an automatic transmitter. This device, termed the transmitting distributor, sends out a series of electrical impulses over the line; the character of these impulses is determined by the perforstions in the tape. At the receiving station, the line impulses enter an automatic receiver, call- ed the receiving distributor. Through the agen- ey of this distributor, the incoming impulses control a series of receiving relays, which re- lays, in turn, control the action of a print- ing device. This printer is an automatic type- YATAADEIAT QUITMIAT WO MeTsve WustaoM aut -vrotosbortal - I tral to mottereqo edt aI .cANEAUS oft ,ydqernzefeT satinixt to geteve surrarol edd bedivoenettd texrit ef hbettimanstt ed of ageegem 8 ot smtbrooos eqet teqaq beterotreq se odmo emrotres at mottereqo six? Jerottsrotred %d “eboo edt devodt es taut ,totavetreq Brsodyext s mo be at eqst of? .mettixrweqy? ated otew esescom wid? .rettimenert oltemotve né dysordd nvr nedt ~totudinderb gatddimemerd edt “bomred ,ooltved novo aoelugmt [sotrtoele ‘to astres s ¢#o ebnes at seafnamt saedt to tetostade edt senil edt -oqat oft at enoiterotreq eit yd bemtarreteb eft ,mottete gatvieser edt tA! : -ffIso ,revitesetr oftemotve as retmse esaluqmt oatf -cops edt desordT .rotedinteth satvieser edt be boaluqmt aatmoort edt ,rotlueditteth eaetdt to yo -~or dotdw ,eyslet aniviteset to asirea s L[ortacs -tattg s to mottos edt Lortnoo ,atst oi ,eyel ~oqyt ottemotys as at tetatirqa sid? .sotveb nat THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY writer which prints, or typewrites, the message onto a standard message blank. Printing telegraph systems in general possess distinct advantages over Morse systems, especially on heavy traffic lines. Printing telegraphs do not demand the services of skilled operators, whereas Morse systems are entirely dependent upon such services. This circumstance is becoming more and more impor- tant by reason of the growing scarcity of Morse operators and the consequent increase in wages demanded by them. Furthermore, the printing telegraph is able to maintain for the entire day, a speed of transmission somewhat greater then the maximum speed obtainable by manual operation. Consequently, fuller service from the equipment as well as a decrease in operat- ing costs is gained when a printing system is {1s YHIATORIET DPUITHILI IC MATCY?e MUSAEOM SAT egszseom edt .eettiweqyt +o ,atatiq dotiw tetirw etnafid sgeseeom Sreinete s otmo at emeteye dqstaelet srttatst eatoM revo sogsinsybs tonttefh aeearog L[atoneg Jegune olttstt yrsed mo y{istoeqee .smeteye gootvree edt Sasmeh tom ob adqsrgefet antiniazd ameteye esitoll essiedw ,atoteteqo heLfive to eidT ,aeotvtar fone moqy trebmeqeS vlertioe ers -roqgml siom Base etom aximooed at esnstemvotto eexrol to yitotace gutwots edt to moaser yd tast aensw at casetont taevpeaaoo adt Bas etotateqo gaitaixng edt .stomredtro® .medt yd bebnsmeh eritne edt trot ofateteam ot efde at fqetaotet tetasrs teadwenmoe notseimenast to Seeqa 8 ,yeb feuaam YI sidentstdo beeqe mumixen, edt nedt Be NY ie mont soivrea toliot ,yltmospeenod -foltetego ~tsteqo af sesetoeS s es Ifew aa taomgtups edt et metaya gattaitq 8 monw bomieg at etsoo ant 5: © eee THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY substituted for Morse. Béfore taking up a detailed study of the Morkrum System of Printing Teleg- raphy, we must establish the principle upon which the line signals are transmitted. This operation is performed by the machines before referred to as distributors. In order that their operation may be clearly understood, a simple device will be chosen which possesses certain features in common with the distribu- tors. This device will gradually be developed until it finally embodies the main features of the actual distributing apparatus. After this preliminary treatment, we can take up a study of the Morkrum System in its practical form. PRELIMINARY SYSTEM, Certain of the underlying principles of the Morkrum System of Printing Telegraphy are embodied YHIASOALAT OWLTMIRT TO MATeYe MUAAHOM FHT se tol tot betutivedse beftsteh s qu gridet exobdd -geloT sanitaiscl to meteye muritoM edt to thste nogy elqtontrq edt det{detee tes ow .ydqst eid? .bottimenett ots efanete onti edt doisdw etoted eenidesm edt yd bemrottog ek mottatreqo tad? sefto al .erotudittatbh a2 ot berretet s ,bootatebas. yfitselo ed yem sotteteqo tioeit eeseseeog foltiw nenode ed {ftw esotveb efqmte -uoditteth edt dtiw commoo at geruvtast alstreo heqoleveb ed yilevberg {fiw eotveb ets? sexot setutest ofsw edt eeibodmas yilsait dt Lede sotiA .antsteqqs gotindiuteth Levtos adt to & git exes mao ev ~tsomtacrd yrediniferq eist faottosxq att of meteye. murarol erit to yhinte earrot ghedred .METeYe YHAUIMIIAAT surrayoM eft to selqtonizrq guiyfirebas edd to Sethodms ota ydasreeleT antininl to msteye © THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY in the telegraphic scheme of Fig. 1. D and D' are two stationary wooden disks or bases, fit- ted with bearings at their centers. A shaft, S, runs in these bearings, and at each end of the shaft is mounted a metal brush arm, A. These brush arms are in the same angular po- sitions with respect to the shaft; in other words, they are in line. At its outer end, each arm carries a brush, which trails or wipes over its disk when the shaft is revolved. On each disk, and in the path of the brush, is located a series of five contact buttons, thesé contacts being similarly placed on each disk. Since the spacing of the arms and contacts on each disk are the same, the two brushes will always make contact with corresponding buttons. For example, if the brush at the left rests on the top contact, 1, the brush on the right will rest on the top contact, 1, at that end of YHTARDS IAT DMITHIAT TO METeye MUSAROM GHT 'C bos T .f weit to emedse otdgatselet ont mt -tit .seesd to evelth mehoow yisnotiste ows ets “ ttade A .erotaso tledt ts egnitsed dttw Bet to bre dose ts bas aguitaed seeds at enor .é .A lowe deotd fatem e Setnuom ef ttede ent -o7 taelyanrs ouee wits ct ers amve deustd osedT redto mi ;ttade edd ot toeqeet dtiw anoitie ibe tetso ett gA 2 egte at eva yedd ,ebtow seqiw to aftert dotdw ,devtd @ eeitres mre Mose “0 .bovfover et stadea edt medw tetb edt revo et demrd ent to tea oar at bxe ,xeth dose aeedt ,anotiud doataos evit to dettee = beteoor ery Hoke ‘xo beoa lay yltalinte aptted atoatsod mo atogtnoo Bae ears ott %o attosae eat eonte Iitw seteired owt adt ,emee oft ots Yetb dons -anoditod gatisogeertos déiw tostmos sAsam ayawls eter Mel odt te deurd odd tt ,efqmaxe tot tigty ef mo deoxd edt |. T .dbethos qed eat Be to Bas tadt te ,f ,toetmoe got ent mo teot [Eby ‘ e LP ee Pat ok Wiig ee Pie Bae y a od / eee yy THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the shaft. As for the électrical arrange- ment, at the transmitting station the contact buttons,l, 2, 3, 4, and 5, are connected re- spectively to the keys, Ki, Kp, Kg, Ka, and Ks, thence through the battery, B, to ground at G. Therefore, when a key is depressed, the corresponding button will be connected to the battery. At the receiving station, each of the buttons is connected through its own re- lay to ground at G', The operation of the apparatus is as follows: Rotate the shaft, S, by some means in the direction indicated by the arrow. The brushes will then wipe over the buttons in the order 2.25.5. 4. 5.3. 2. ---, Mere. fore, if key K, be depressed, the negative Side of the battery will be connected to but- ton 1, and while the transmittimg brush is YHIARDAIAT QUITMIAT FO MATEYe MURAHOM FHT ettade oft -egrarrts L[eotirtoelé edd rot eA : tostroe edt cottete gaitdimanert ed? ts ,taom -et bstoommoo sts .3 hos i. eas Eenotese has .pX .et poh «ph .ayod odd ot YLovitoege fbasorg of .,2£@ ,wresvtad edt davordt eomedt , ad edt ,beeeotqeh et ye a nedw ,erotetesT .» ts odt o¢ betoennoo of Lftw motied gatbmoqaerr0e to dose ,cottste anivieoet ott tA sqrettad ~or mwo att aneene Beteonnon at saottud oft .'D te busorg ‘ot we eytersyqs. edt to mottarsqo oT omoe yd ,2 ,ttate oft otetol :awolfot es at eworrs add yd bedsotbat mottoorth ett ot ate ony ) anotésd odt ttevo eatw modt tiiw eddessd ont eotodT .--- .$ ,f 1a ,S «8 8 .f Tebt0 odt at | ovitegen edt _beaaetyob od P yor ti “ore? ads ot ‘Sedbeaties od ftiw credited edt ‘to obte ak segad gai tt tneaett ost ‘etkity ba8 .I mot a THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY passing over the button, a circuit will be completed through the shaft, S, contact but- ton 1 on the receiver disk, through the re- lay Rj, to ground at G', and thence to bat- tery, B. The resultant current will operate relay Ry. Likewise, if any other key or com- bination of keys be depressed, the corres- ponding relays will be operated at the receiv- ing end, One method of carrying on com- munication with this device would be to arrange & code, assigning a combination of key-depres- sions (or relay movements) to each desired character or letter of the alphabet. In all, thirty-one combinations might thus be obtained. One complete combination or letter would be sent out for each revolution of the shaft, By depressing a different set of keys for each revolution, we could send out the successive YHTAROAIAT OQUITMINT TO MATEYe MURAAROM FHT ed [ftw tivetto s ,aotiud oft revo anteesq — -tsd togtnos ,@ ,ttade eft dacordt betelqmoo -9t ent davotmdt ,detbh rovisoer edd wo L mot -ted ot sonedt foe .'D te bavora of +r ysl etsteqo [fiw tnorto tastiveet efT .€ .yret -moo To yex tetto yrs tk ,eetwettl .fh yelor -eetxr09 oft ,beasexceh ed eyeX to aotisatd -visoer eit te Setateqo ad [fiw eyelet antbhnog ebose act -mo0o mo gntyrrss to bodtem end | egast1s ot ed blyow soivob etdt dtiw motteotanm -perqeb-yex to nxoftentdmoo s gniagteas ,eboo 8 betteed fose ot (staomevom yelet to) agote {fa ol .tedsiqls oft to tettel 10 tetsatsdo wbomtatdo of sect tiatm erottantdmos omo-yittdt ed hilrow rottel 10 sottsatdmos etelgaoo ead .ttats oft to aottsfover dose rot tro troe tome tot syex to tea tnetettr6 s antaeergsb vai evinespove oft tuo Baoe bio ew ,aottslovet iva aes THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY letters of a word or message, and an observer at the receiving end could read off the mes- sage by the relay movements. The system just deseribed is of course impractical because it is necessary to connect the two stations by the shaft, S. Fig.2, however, illustrates a plan without this defect. SECOND SYSTEM, In this second scheme, the two brush arms are not on the same shaft, but are rotated in unison by separate driving mechanisms not shown in Fig. 2. The electrical connection between the two points is maintained by the wire marked "Line", which may be an ordinary telegraph line. Hence, we may have the transmission of signals over @ considerable distance. Messages are transmitted in this scheme in exactly the same manner as in YHIAAOSIAT OMITHIAT YO METSYS MUAAAOM FHT sertesdo ms bes ,easeasem 10 brow s to atottel -sem sit tto beer bLooo bro anivisoer edt ts -einomovom yaler edt yd egee et bediroeed text metaye edt yrasesoen ef ¢i sensoed Laottostqml eetses to se°Se¥sde edt yd exottate owt edt tosdnoo ot tcodtiw asfq a setartes{{l ,tevewod ,&.atT etootob etdt Brooes alit mI .muTeYe awooze | emse eit ao ton ets emrs destd owt oft , omedoa efsisies yd nostas ot Setstor era tud’ .dtade en? .& .gkF af woe ton emetasdoem gaivith atatoq owt odd moowted mofteennoo [soirtosle dotdw ,"extl" betrsm etiw edt yd hbeatstatem ef ew ,99meH .onil fyatgelet yreathro me ed aor 2 tevo afsagte to coteatmenett edt oevad yam -oonstelbh efdsrebtenos mrt bottinenert ere senseeel tar at es tenis euse odt yitoexe at emenfoe etdt © THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the first case. The two driving mechanisms and the means for keeping the two arms in step of course introduce new features, but it is not necessary to discuss these features at this point. A great improvement in the scheme of Fig. 2 would be effected if some other means of transmission were used instead of the five keys; these keys are too slow and cumbersome. Consequently, an automatic trans- mitter has been devised and applied to the system; the new system appears in Fig. 3. THIRD SYSTEM. In the scheme of Fig. 3, the contacts and vertical contact pins, 1, 2, 3, 4, and 5, have been substituted for the corresponding keys of Fig. 2. These pins are mounted loosely, near their ends, on & common horizontal shaft or fulcrum, and have & lever action, through a small range, about YHFAADLINT OQUITUINI TO MATeYe MUAAHOM FHT ametusdoom gaivith owt efT soess tetit edt ot emre owd oft gatqesx rot ensem sit Sas tr tud ,nerstset wem sosbotint serros to qota eetsseot sasdt earoeth of y1rseessen for ef ~tetog afdt vs ett at tmremevotgmt teerTg A emoe tt hetoette ed Bilyow & .3tt to emonoe Sestenmt bees erew cotestmensrt to emsem tedito bare wolfe oot ets eyed seedt jayex ovit edt to -enstt ottametue me ,yltnempeanod .emoetedmro edd ot betiaqgs bne beatved meed erxd tottia ~& .git of erssags metaye wor odd ;meta ze emedoe edt aI .MiTcYe CHInT teostroo L[acttrevy ine atorinoo edt ,o .agtt to betstitedse seed eved ,¢@ faa yh .8& ,S Lf .eatg geod? .S .gil to eyot antinoqeserres: edt tot “no ,eine tledt tse YLesool betavom ore enta evad bas ,morofet to ttiede Latnosirod mommoo a trodes ,ogmex flame 2 dgvotdd ,coltos tevel 8 “ae Latte 2 we x Dl ar THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY this shaft. The contact is made at one end of the lever, so that a slight movement of the other end makes or breaks the contact. The movement of the levers, with the consequent opening and closing of the contacts, is effected by means of a perforated paper tape. This tape is pulled along flatways under the free ends of the pins. At intervals, holes are punched in the tape, and when one of these holes comes under a pin, the end of the pin drops through the hole. This movement of the pin or lever closes the contact; this con- dition corresponds to a closed key in Fig. 2. The tape must move along at such a speed, that the combinations of contacts, corresponding to the individual letters, are maintained throughout a complete revolution of the brush arm. That is, there is always a definite rela- tion between the speed of the tape and the speed 0 YHTAAOGINT PAITUIAT TO MATEY MURAHOM FHT to bas eno ss obam ef tostmoo efT . Stade efdt edt to tromovom tdatfe es tedt o@ .tevel ent etoatnoo oft exsetd to eouvlsm bas tedto ~etevefl edt to tremevom ofT efit to anteole bas gaineqo tnavpeanos eft dtiw betstotreq s to exsem yd Betostts et ,atostnos ayewielt gmofe belinq et eqst eid? .eqat teqeg -elavrotart tA .entg edt to ebae sert edd tebnr to exo nedw bas ,eqat edt mt bedonavg ers eolod edt to bee edt .awiq @ rebar eemoo eslod esodt to tmemevom etal .ofod eft deworilt eqorh wtg -moo etdt ;tostnoos edt aseofo revel to atq edt -S .3fT at yox beeols gs of ebmoqeetios cottth tedt ,Beeqa s dove te anofs evomt teom eqst eXT gatbaoqgestros ,etostnos to enmottantdmos edt fentatatam ers ,erettel Ieawbiviirl odd ot feoxrd sit to aefttrLovet etefqmoo s tvodauordt -siet etintteb s evawis ef eredt ,et tad? Jmre heeqea oft fas oqet oft to besqe oft meewhod wott 10 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY of the brush arm. If the tape is punched proper- ly, line impulses corresponding to a message can be sent out. Furthermore, the rate of trans- mission can be increased over the rate of the old system by the operator raising the speed of the tape, and at the same time raising the speed of the brusharms in the proper proportion. By these means, any transmission speed is obtain- able, ranging from zero to seventy-five or more words per minute. However, the rapid transmission made possible by the tape control introduces a new and serious problem, viz., the distortion of the line impulse. This distortion is carried to such an extent that inaccurate receiving is the result. This matter of distortion can be better understood, and a solution devised, through @ study of a aoukca of current impulses; we will, therefore, now take up such a study. OL YHIAAOMICT QOULTUIAT TO MATeYe MUAHHOM GET -tegotq fedoung ef eqet odt tI .mre devrd edt to nso egsasem s of ai Fiieuhetres sestnemt emit eet | otro dace od -snev? to etat edt ,eromredtirs eid fo ever oft tevo hergsetoni ed ase molteetm to heeqe edt guiatset stotereqo edt yd meteye flo beoqe edt yateiet emit omse odd te brea ,eged ent YI .mottxrogorq teqotg oft mt eurredieutd eds to -ntstdo et heege noteetmener? Ure .ensem eaont etom TO axibscéaeren 6 otes mort ‘galgaet elds strata 18q ghxee soleeimacetd biqet edt etevewod ; 2 eoorbortat fordmes sqat edd yd efdteser ébei sotireteth edt as8iv coldotg evobros bra west beitise et soltrovals aid? ,eelvqmt eati edt to ai aniviteoer otetvooedt vars tnotxe as dove ot ed aso sotdsoteth to setten eid? .tisees edt dgyoudt , .5eeiveb notin loe s hee ebootetobar, retted ow sese Lirqmt Tee TTe to eeitee s to ubute 2 -Ybute 2 dove qe oxst wor iecitionane yet | ae pe ree ment eae aba I THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY CURRENT IMPULSES. A series of ideal current impulses is represented in dia- gram (a). Such impulses occur only under perfect operating conditions. This particular series would be sent out by the transmitter during one revolution of the brush arm, with pins 1, 2, 4, and 5; in the closed contact position, and contact 3 open. In an analysis of the diagran, assume a certain instant, 0, from which to measure time. After a fraction of a second, represent- ed by the length Ot j, the transmitter brush strikes button No. 1; since pin contact 1 is connected to the battery and is closed, the button is connected to the battery. Immediately, the line current rises to its full value, Ij, shown as the distance OIj, and it maintains this value throughout the duration of contact. At the instant te, the transmitter brush leaves [£ YHTAHORIAT DULITMIAZG TO MATeYe MUAAAOM THT to sefree A. ,cfartvIMT TUPAAVO ~Sith wt fhotmeeetqer ef eceluqmt tnetrro [sobt teostteg tebos ylao rwose eeelsqmt dowe .{a) mers esttes tefvotitag afd? .enottthnoo antisreqo saith tettimenert edd yd tro taee od Bbilsow antg ctiw ,ore destd edt to mottrfovet ero mottteog tostnoo heeofo odt at 4d Bae dS .S Lf -feqo & toatroo bas _ aMetsefb edt to eleylane os ol eiseaom ot doftdw mort .O testent nistres 8 empresa ~tnseotqet ebuooes s to mottoett e tettéA .omtt ‘dasxd tettimenett edt . tO atesel edt yd be ef [ voatmon aniq somte 3f .of% mottud eexatxrte edd ,beseolfo et bos yrettsd eft of betoonmos eUlstetbeaml .yrettsd ost ot betesinon et motted egl ,emtav [Ist ett ot aseta taetres omtl edt extatntem ti bas ,pI0 eomstaib edt es awode etoetooo to cottésteb eft tuonguoitt esfev efdt aevesl deuxd toddinenett oft ygt tustent edt th. Bn tne 12 THE MORERUM SYSTEM OF PRINTING TELEGRAPHY the button, and the current immediately falls to zero. This time of contact, represented by tit2, is called a marking interval, and during this entire time, an impulse is being sent out over the line. As for the succeeding periods, te-tz indicates the time necessary for the brush to go from one button to the next. The space t3-t4 stands for the time of brush passage o- ver the second button; it is a marking or pulse interval, since the second pin contact is as- sumed to be closed and its contact button ener- gized. Next, ta-t5 is the intermediate space between the second and third contact buttons. The next interval, however, is different from any of the preceding ones. Dur- ing this time, t5-ts, the brush is passing over the third button. It will be remembered that the third pin contact was assumed to be open; hence, the third button is not connected to YHIAADELAT PUITHIAT TO METeYe MUSANAOM FHT effet ylétsthbemmt taertus edt bas ,nottnd edt wd betneecerqer ,tostnos to emtt etd? .ores of aafro6 bos ,fevretnt gaidtem 8 bel{se ef .gtrt too tree gited ef oefegqmt as ,smit ertine etdt | emit edt sz0evo eebhotreq grtbesoore odd tot eA feuxd oft rot yrseessen omtt outs setsothat st-st sosge efT tren oft ot sottud eno mort on ot -o egssesq desxd to omtt soit tot ebsete pt-at eelog to anidvam s at tt ynottod frooes edt tov -es at vostmoo aig broose edt eorte ,Leviotat «zene mottud foatios ati bith honele od 09 Saat eosqe otstheeretct ent Bt ateat -txel -bosig -exotiod tostnoo Bridt bas brosoe ent postop ef ,tevewors fevretat dxXen od? or -eeno githeserg edt to yas mort doorett rs revo goteesq et sesud edt ,at-at omit obit get tari? Setodmomor sd Iftw tl .wotted brbdt edt iseqo od o¢ bomrses sew tostmos aig Said ot ot betoennoo tom et sotdud Sridd edt .eorted THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the battery; therefore, no current or line impulse appears during this interval. This is known as a spacing interval, as opposed to mrking interval. Following this period are the two marking intervals as shown, properly spaced and in every way similar to the first two marking intervals. A series of impulses such as these is desirable in every respect. The marking and spacing intervals are regular and sharply defined; the current always as- sumes the same value for each pulse.A proper- ly constructed receiver should respond per- fectly to such signals. However, it is not practical nor even possible to produce such impulses under actual operating conditions. Instead, the series takes the shape indicated in (b). Here, the sharply defined impulses of (a) become wavey, with rounded corners and no 13 éL YHIAADEINT OUITMIAT FO METSY2 MUSNAOM SHT enti ro deerme on ,stoteredd iyretisd edt etd? .Isvretat efdt antush exseaqqe seloqmt hesogyo as ,favretat gatesya s a8 mwond et wfsvretat gurivtem ot ets .botreq efdt antrolfot ylteqerg ,mwode es efsvretat anidtem owt oct tertt odt ot walimte yew yrove at bose beoaze -efavrstit arctizvean owt es dove eeeluamt to setrea-A” edt .dosqaet Yrove ff efdsartesi et saedt teinget ets alsviotat gxteaqe fre get bron -28 syewis toetrve eft {beriteh ¥fatede bre -teqotg A.eefuq does tot eufav emed sit eéuve . -req fooqeet Sivode rovfeoet beatorrsanos YL ~eLetats dove ot yitost | ‘ Isotsostq tom et tk ,revewoll” © Fe Se esaluqat dose essbony of efdtaeor move ton ‘beetentl .emokstbaoo amitearesqo Lsutés “tobas Cd) at betesthat eqetie odt worst aettes ott ‘(s) to ese Luque bediteds yiqrede ond ore om bua eredtoo bebavot dtiw .veven ont i Ku 14 THE MORKRUM SYSTEM OF PRINTING. TELEGRAPHY definite line between succeeding pulses. The middle or spacing interval is bridged over so that it appears as a weak marking pulse. Or, the pulses may be still further distorted and assume the form of those shown in (c); this latter, in fact, more nearly represents the true form of the working pulses. As for the causes of this dis- tortion of the impulses, there are two prin- cipal ones. The change from the regular im- pulses shown in (a) to the wavey form shown in (b) is caused by the phenomenom known as cur- rent lag. In brief, due to the inductance of the telegraph circuit, the line current does not rise to its full value the instant the cir- euit is closed by the brush arm contact. In- stead, it rises gradually, requiring a very ap- preciable time to reach its full value. This time of rise for the first impulse is shown as ti-te in (b). In the same way, the current does i YHIAASDAINT OMITHIAT FO MATeYe MURUHOM ART ed? .ecelug antissooue asowted eatl etiattedb og tevo begbixd at ([svretat antoesqe to of bbim .<O .esisq gaititen Hsew 8 es erseqqe tr tadt fas betroteth recdtrst [f[tte od yam aeelug ext atdt ;(0) mt oworle eaodt to mrot edt omvane edt etasserqet yirsem stom ,tost at ,rottsl .80elug sian edt to mrot enrt ~eatbh eldt to seanse edt rot eA mcebre ows ers eredt ,eeeluaqmt edt to mottrot mort welyget edt mort eymeto edT .eeno LEqto at swore mot yovsw edt ot (a) mt oworle eoelaq -tio es cwoowt momemomadg ent yd boesso et (d) to sonsteubat ot ot ofS ,tetrd al .gealf toer ee0b taortys ent edt ,tivetto dyersefet edt -tto edt tustent edt oxfav {Iut ett of eatx tom -ol ,tostaoo mrs destd edt yd besolo et tio -{8 Yrev s gutvinoet ,ylfavbets eoalt +r /haotes efdT .,oulev {wt ett dosot ot omttd efdatoerq as mwota ef selaqat tertt edd tot eatt to omit aeob theriro edd ,yew omee edt mI .(d) at gt-ct =p Soh) HOE Ree 15 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY not fall to zero the instant the transmit- ting brush leaves a contact button, but, on account of the capacity of the line, requires an appreciable time to do so. This time of fall is shown as t3-t4 in (b). Thus, the cur- rent does not obey the makes and breaks of the circuit immedietely, but is said to lag. When the impulses follow each other rapidly, one does not die away before another begins. The result is that the impulses run together; two marking intervals, separated by a spac- ing interval, often do this, thereby obli- terating the spacing interval. The saw-tooxth form of the wave, as shown in (ce), is caused by induc- tion. The neighboring telegrapg wires induce small varying currents in the line, so that the resulting current, made up of the induc- ed and working currents, is of the irregular form shown, The induced currents have the af YHZARORIAT QUITUIAI TO MATeYe MUSAAOM FHT -Simens:d edt taatent efit orex ot [fst ton no ,tud ,aottud tostnoe s eevsel deutd Seed sorinpet ,eattl edt to ytfosqss edt to tasools to omit efaT .oe ob ot emit efdatoetgqqs aa -rso sat ,estT .(d) ot at-st es mwodea et [fst To eiserd bas beats edd vedo tox Boob trex -a8l ot bise et tud ,yfetstbemmt tieotto edt eUlbiqer tetito dose wollot eselnqmt edt ced¥ -etised tedtone etoted yewa eth tom ecb oo stedtegzod mvt eesiugmt eft gedd et tiveot od? -osge s td betarsqes wefavretat gritzem ows -tfdo yderedt ,etdt ob metto ,favretnt gat slevretmt ssthecs ont gattared i edt to mrrot aygood-was of? ‘“mosbat yd beaxso et ,{o) mt ‘ueda ee ota eoubat eettw aqatgefet gutrodigtom ed -aoks tedt oe ,entl eft ai eteettwos uaheder Ltene | -ovbni od? to qu ebam ,tnetts. aati topes ee relogettt edd to et ,etmetiss gatziow bas Fa ‘ed? evad etsorirs Beoebat ont wormoria wrot THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY greatest effect during the early growth of the impulse; they may even be large enough to reverse the direction of the line cur- rent while the impulse is till very smell. When the impulse has grown to a reasonable size, the induced currents are absorbed. A consideration of the caus- es of distortion will shown that since cur- rent lag and induction increase nearly di- rectly with an increase in length of line, the amount of distortion varies nearly di- rectly with the length of line. The effect of impulse dis- tortion on accurate receiving of signals is apparent. Not only does confusion result from the bridging over of the spacing inter- vals, but also from the fact that the re- ceiver lags behind the transmitter. This lag occurs because the receiver does not respond until the impulse has grown to a working 16 af YHQARDAIRT OMITUIAT TO MaTeYe MUAAHOM HHT to dtworg ylrse edt snttyb sootts testsers dayone earsl ed mevs yem yedt ;saluqmt edt -tw5 omit eft to mottoertth edt eetever ot -{fems vrev [fit et saluqmt edt olfidw taet efdanogeset s ot mworg aad safuqmt eft cmet¥ -bedtroeds eta sinerrss boeorbal edd ,ssia _-ayso eft to mottstebleanoo A ‘=t%9 oonte tedt mvode [L[tw moldrotetbh to es -t6 ywfrsem sesotont mnottovbat bas sel tnet ,ontfl to désgmef nt sasetont as dtiw ¢itesr -f5 ylrsex eettevy mottroterh to tavome edt eoatf to dtanel oft ditiw yitost -atbh selwqmt to tosette edT at esf{erate to. antvieset etatseos mo moltrod tiseet mofentnos seoh yino tol ,tmeteqqs -tednt actosqe sit to revo gaighitd edt. mort -et edt tadt toat edt mort oafs tod ,elsy gel etdT .retdimanert edt Suotded easel revise baoqest ton eo0b teviooor eft savesed srs600 guiidtow s ot aswors asd eeluqmt edt [tian THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY value. The induced currents do not, as a rule, reach sufficient magnitude to oper- ate the receiving relays; their usual ef- fect is to distort the impulse by destroy- ing the early part, and thereby still fur- ther retard the receiver. Since the amount of distortion depends upon the length of line, the longer the line is, the more dif- ficult becomes operation; satisfactory opera- tion cannot be maintained over lines of any practical length. With the underlying causes of distortion in mind, we are now prepared to take up the solution of the problem. A study of the impulse diagram will show that the question becomes one of causing the im- pulses to grow to their final working value very rapidly. If the impulses should rise quickly, they would not tend to spread out aT ¥I YHTAROAIAT QUITUIAT GO MaTeYe MUAAHOM FHT ees ,tos ob efnertis beowbat eft .onfav -teqo ot obstinasm taotofttse dosst ,eint -te fsves ttodt reyelet anivtese: edt ots -yortesd yd ealuqmt edt troteth ot ef toot -rut [{f[tte yderedt bas ,iveq yliss eid aut tasome oft eomic .rovleser ont drake todt to dtamelf edt smoquy ehmeqeh mottroterb to -tib stom edd ~et eatr eft regcol out entl -ateqo yrotostetise ;aottarsqo aemooed sivott was to sontl tevo Seatatelthc ‘a tonneo mots .% -ditgnel feottos tq BORED aniy ft obas anit saty bersqetg won ers ew ,fintm at mottroteth to 4 .mel[dorq eft to moftuloe odt qu exst ot tedt woth Iibw merasth eeluqert edt te vhuve -mt edd soxtasso to emo eemooed nofttesno ont eslev gittalow Lenk? ateds of wor ot eeeleg oelx Bisoie eesivqmt edt $1 -Yibtges Yrev iso haoree ot baet ton blirow yodt walotsp 18 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY so much, so that there would be a sharp di- viding line between marking and spacing in- tervals. Furthermore, the effect of the in- duced currents would be minimized, since their greatest effect occurs during the ear- ly growth of the pulse, which period would be short. The solution which has given the most satisfaction is what is known as double current operation. In this scheme, there is a marking pulse as before. However, instead of a space interval being indicated by a current pulse of no magnitude, that is, by an absence of current, it is indicated by a current pulse in the opposite direction. For convenience, the spacing pulse is called positive, whereas the marking pulse is called negative. The terms positive and negative merely indicate that the line currents are BL YHLAASALIAT PULTHIAL TO METCYS MUAMHOM SHT -rh grade 2s od Hhisrow stedt tadt oe ,doum oe -at grtosqe Sos sotitsm meowled entl gathiv -«t eft to toette ont ,oromredir! .elevrot gonte ,beximinia sd blyow einertye heovh -tse eft satrsbh etrvooo toette tastseta rredt biyow botreq dotdw ,seisq sft to dtworg vi trode ed stevia eat dotdw mottaloe ont ag awonwt et tedw ef nottostattee teoa oft ~ottedoe etdt al .moftereqo tnetris ofdivob ~TOvewOH .etoted as ealuq gatirsm s at oredt Betaothat anted Lavrstat soaye 2 to bsetant et ted? ,sbhotingesm om to seafuq tnerrg9 8s yd yd Setsotiat ei tt ,tasrxs0o to esnesds as yd .ftottoetth otteoqgo eft at eefuq tmetitse s befiso et ssisq gntosqa edt ,sometmevaoo toF belfao at oefnq umtidram edt esotedw ,evitteog evitages fas evitteog earret ed? .evitesen ets sinerrye efi edt tadt oteotbhat Vetem | THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY opposite directions in the two cases. The use of both marking and spacing impulses of course necessitates some changes in the equipment, but these changes will be taken up a little later. The reason for the more sat \kisfactory operation of the double current eatin ean be more clearly understood after that explanation of certain principles of current rise in a circuit. It was just shown how, when there is current in a circuit, the current legs or falls to zero gradually when the circuit is opened. If an e.m.f. be ap- plied, opposite in direction to the one which established the current, the current will fall much quicker than it otherwise would. If the e.m.f. be maintained, the current will decrease, pass through zero, and build up in the other direction. 19 ef YHIAADATIRT QUITHIAL TO METeYe MUSAHOM THT eit .dseso owt oft mf errottoerld efieoqqo eoefluqmt agtosqe bos gnetitsa dtod to sev eit mt aegaedo emoe eetstissesen eerson to nevtat od [ftw eegrato scaedt tud ,taemgiups wtetel efttil se gi ase stom odt tot moaser oefT dxsrrso efdvoh edt to nottatsero wretostaty tetts Sootetebus yltaefo etom ed mso mod ave to eslqtonizq ntstrso to motteanslgxe tect mwode test esw tl .tivoerto ea mt eett tnetmw9S eft’ ,tiverte ew mt tnetime et eredt nedw ,wod sodw yffevbers ores ot effet to eaef teeter -qs od .t.m.o ma tI .betoqé at timortes edd doltdw emo edt ot cotteettb at etteodqo ,betIq [Ltw trove od¢ teers eft Bedelfdatee | -bivow satwredto ti madd redetitp donm [fat {ftw tmetyvo edt .beatatatam od .t.m.e edd tI at qu blind bas ,otes davotdd easy ,oesetoeb | ,mottesrib redto edt -'y a ee ee Se 20 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY to illustrate the application of this prin- ciple to our own problem, consider the same impulse series as was used in the previous discussion, except with both mrking and spac- ing pulses. The intervals of this series are marking, marking, spacing, marking, marking, or, in terms of current direction, negative, negative, positive, negative, negative. This series is pictured in (da). ‘An observation of diagram (4a) shows that the two negative or marking pulses which come first are the same as in diagram (ec). But at the beginning of the third or spacing interval, a positive e.m.f. is applied, which action causes the line current to fall almost instantly to zero and start to rise in the positive direction. Likewise, st the be- ginning of the fourth interval, which is mark- ing, the line current quickly reverses and builds up in the negative direction. The last YATAADAIRT OQUITUIAL TO MATEY MUAAHOM FHT -ning efdt to nottestiags edt eterdesl£t of emse eit tehtexoo ,mefdorg mro to ot elgto ssoiverg edt at bees eaw es aciree salnqut -oeqe bos sotdxeam dtod ditw tqeoxe ,aoteevoetbh ers settee etdt to elavrotat edi? hepiie got .acizism ,anidzam ,gotosqe eaaitract Pen ,ovitsgen ,sottoerrh tneriso to enmret at ,10 ein? .evitszen ,evissnen ,svitieog voviteger -(5) at berstetq ef settee (5) margetb to nottevreedo mA‘ gealug goivzren to evitsgen owt edt sade awors mstgsth ct es emse eft ote tetit emoo do kw TO butdt odd to gatautged edt ts tof .(0) -boltiqqs et ate. ® evitteog i favretat ecipace {fet ot tnertHe earl | eit acanmse polities dotdw ob eetz ot frete bes ores of vitaetest teomfe nod edt te catwoxtd scottoot hs evitisog edt - raat at dotdw fevrodat atwot edt to , setaats bas eeetevet thiletep tnerts9 ontf ed? vant” teel edT .gwottostibh evitsagens edt at qn ebfinud 21 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY two intervals are marking, similar to the first two. A further observation of the diagram shows that the marking and spacing pulses are clearly defined. Furthermore, the pulses are at high values throughout nearly all of their existance, so that the induced currents from other lines are soon absorbed. Thus, the problem of producing definite pulses, little affected by induced currents, is ap- parently solved. FOURTH SYSTEM. The applica- tion of the principle of double current oper- ation to the telegraphic system which was de- veloped earlier in this discussion appears in Fig. 4. However, before the system as a whole is explained, two new pieces of apparatus should be described. The first of the new devices YHTAADRIEZT DUITHIALT TO MeTeye MUSAHOM THT ef} of reltmte -poitdvem ets efsvietat owt ows text? edt to moitsvreedo redtrst A gntosqe bas goitram edd tsdit awode marnerb eit ,stomroftimt .bomttob ylteslo STS soe lua yirsen tuodesonsdt seotay datd ts ets ascing beoubat edt tedt of ,soceteixe xriedt to [fs bedtceds moog eta eentl tedto mort etmeruuro ,2eaelog etiniteb antosborq to mef{dorq edt ,erdT -gs et ,etnerro boorbat qd hetostte eLstLe | " ,bovfoe ¢ltaetsa -seotfqgqs edT .METeYe HTHU0F | ~teqo toerxys eldsob to ele tantee edt to mrott ~oh een fotdw meteye otiqetgefet eit of notte mt eTaeqas mofeevoels etdt me tetftse heqolev - eLodtw s ee meteyea ent etoted .Tovowol > sat entetaqcs to peoetg wert ‘ow? Dentelqne et | .Dedtressh od biedte eookveb wen “ott 0 text oat 22 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY is a relay pole chenger. This is an ordinary Felay.equipped with both front and back con- tacts. When the relay coil is not energized, the armature remains against the back contact, but when the coil is energized, the armature is drawn forward against the front contact. The other new device is a polarized relay. This relay has an armature which plays between two contacts, but has no retractile spring. When the coils of the re- lay carry current in one direction, the ar- mature takes position against one contact. If the coil current is reversed, the armature goes over to the other contact. Since there is no retractile spring, when there is no current in the coils, the armature remains against whichever contact it happens to be. With this understanding of these new instruments, we can take up an ex- Ss YEIAROAIAT OQUITMIAL 20 MeTeye MUSAHOM FHT yrsenibro mea ef aftdl .teansdo efog yeler a at -~aoo dosd bas sgaort dtod dttw beqdtups, ysiet Sesisrene tom et [foo ysfer oft medW¥ .etost eTostaon Moad edt tenters eantamet ovetamre oft ersteants. oft ,.besigrtone et ftos eft sodw tod ,toataoo txort edt taniess brawrot ovatd et s ef sotveb wen teito ext evutemrs me eat yelor eifT .yaelort besirelog on sad sud ,etsstaos owt neowted eyslq doidw ~9t edt to eftoo edt aefY .anitrqe olitosrtet -rs edt ,mottosrt5 eno mt tieriso yriso ysl tI .toetnos eno tantegs coftteog eevest eryteam ermteacre eft ,berrevet ef tasiis9 [too ait otedt esatt .testmos sedto eft ot tavo ae0g on ef etent sorw ,gnizrqe eLitosrter om at eniamet ettanre edd ,altoe eft at trerise od ot snogqad tt testnoo revetotdiw tentays f to gatineterobang eidd Atty ~-xe fs qy eist mso ow ,eineswittant wen evedt - BD gd a (Lg THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY planation of the new scheme, As in the pre- ceeding system, there are the tape contacts. These contacts do not, in this case, control the line impulses directly, but do so through five of the relay pole changers just describ- ed, one pole changer being provided for each of the five tape contacts. Each set of relay coils is connected to the local battery by means of its own tape contact, so that when the contact is open, the relay is not ener- gized and the arm ture remains against the back point; when the tape contact is closed, the relay is energized so that the armture is drawn over to the front point. The current path from the back point of the relay pole changer is to the negative side of the mrk- ing battery and through the battery to ground. The front contact is connected to the positive side of the spacing battery, the negative side 23 és YHIALOLITT HPUITHIAI TO METeYe MUSMAOM HT -erq edd at eA .emonoe wer eft to notiansi¢ .eteostaos oqat oft ets etedt ,meteye anthes fortmeoos ,saso etht at ,tom ob etostmnoo seodT _figsorlt of ob ted ,.yftoertS seeInqmt oentl edt -diroeeh tant etesmsdo efoq yelet edt te ovit dése tet bebtvorg ented texzmedo efog sro ,be yelet to tee dos® .etoaetmon eqet evit edt to yd yrottead Isool edt ot Hotoonnoo ef elroo nodw tsdd og ,tostnoo eqst mwo efi *o ensom «teme tom ef yvafer ef? ,.mego ef toatnoo eit ext tentage ertemer eroterrs oft bee bests ebesols eat sostmoo erat oft todw ,tatog aoad emtenre oft tedt oe bestarene et yslet edt tasrtys of? .tetog taort edd ot revo mwerh et eLoqg yalet eit to tatog xoad oft mort Atsq -tzam eft to obta evitagea edt ot ef teanado Aavors of yrettad ont davordt Bas profiad gat evittnog edt ot Betooktroe et toatmoo tnort ed? ebte evisazen edt ,yrotted grteaqe edt to ebte THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY of which goes to ground. The armature is con- nected to one contact button of the transmit- ting disk. The revolving brush arm is connect- ed to the line. A consideration of the trans- mitter circuit shows that with a tape contact open, @ negative or marking line impulse is sent out, and with a tape contact closed, a positive or spacing impulse is sent out. Thus, the tape contacts control the character of the line impulses. At the receiving station, the line is connected through the operating coils of a polarized relay to ground. Therefore, a positive current pulse throws the armature to one side or point, whereas a negative pulse throws the armature to the other point. One point is dead, the other point is connected to one side of the local battery, and the ar- 24 .RAE on ee Sey eee De | Tomer SS YHIAROAIGT OUITMIRI TO MATAYe MUAAHOM RAT -f09 eft erstemrs 6X? .foayora oF goog dotdw to -timenett odt to nottud tostmos. emo ot hotsoen -toentos et ore devid entvfover edt .welb satt ~oait oft ot bo -ecstt ot to cotiarsbienos A tostiros eqat es ditiw tent ewore tinotto tett ta ef eeluqmt satl antvren to evitenen s ,asdo s ,boeofo tostros saat s dtiw ins , tro tree end? .dso tase af eafmamt sxtésqe to ovitteog to totosrads odd L[ortmoo atostado sqst edt -boaluqmk exrfl edt eft ,acottate satvieser eft tA aftoo gattsteqo edt dasotdt hetoonnos et enlkl ‘8 ,9toteted? .bavors ot esler BSositefog s to ot erstemrs eft ewortt saluq tnevttyo svitteog seflouq evitsgen es agsetedw ,tatog xo shite emo em0 .tatog teddo edt ot srutemrs oft ewordt hetsonroo at tatog tedto edd ,beeb et! tatog | ~-ts edt bra ,ytettad [sool edt to obta emo ot 25 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY mature is connected to the receiver brush arm. The receiver relays are connected between their respective control buttons and the free side of? the local battery. As for the operation of the receiving apparatus, suppose a spacing or po- sitive line impulse appears. The armature of the polarized relay goes to its dead contact, so that no local relay is affected. Suppose a negative or marking interval next appears. The armature of the polarized relay goes over to the opposite point, which is connected to the battery. The local relay is energized, and in- dicates a signal. Thus, in this system, the local receiving relays respond only to the marking intervals, just as was the case in the former system. FIFTH SYSTEM. Fig. -5 shows a still further development of the system. This 3s YHCAADATET OUITMIAG TO MATSYe MUSAHOM GHP ars desxd tevteost edt ot hSetoonmog al etutam tlad¢ meewted betooamoo ota ayslet tevieoss edT ebte sett oft bus enottad Lottaoo evitoeaaet -Yiretisd L[seol edd to edt to aottareqo edt tot eA -“O¢ £0. uttosqe = esogare ,astarsqgs.3anivisset to eretsore edT .etseqqs salfuqmt eati evitte -tostmoo baeb att ot e903 yslet bestisloq edt ‘8 esoggue ,betoetts at yslet Leool om tedd o@ edt ,etaeqqs txen [sevietat gatizrem to ovitegen ot tevo sesog yeflot besirsiog edt to etetamta edt ot Betoonnoo et dotdw .tatog sttaoqqo edt -xt Bue ,bosigrens ef qelot Leool of? .eretted odt ,meteye sid ot ,erdT .feagte es eetsoth edt ot ylmo Dbaoqeet eyslor goiviooet [anol edd mt ezeo edt sew es.taut ,alavretat gottrem eit smeteye temtot 8 ewore a..ght .METEYE BTWIE, oo op dey oy eka? smoteye odd to tmemgoleved tedéuut [Lite - Reale Pipe "ete tege re 6 AA 8 ea 26 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY scheme is the same as that of Fig. 4, except that the line signals are sent out by a main- line pole changer, controlled by the relay pole changers, instead of being sent out by the relay pole changers themselves. This main line pole changer is merely a polarized relay with its operating coils connected to the bat- tery through the relay pole changer contacts, its armature connected to the line, and its two points connected respectively to the spac- ing and marking batteries. The other sides of the batteries are grounded. The operation of the system is apparent from the diagram. This system possesses two ad- vantages over the former one. The first is that the number of contacts in the main line eirecuit is reduced to one, viz., the one at the main line polechanger. Under adverse con- ditions of operation, this feature is of no YHIAMOSIAT DUITUIAL TO MATeYe MUAAKOM AAT tqooxe ,$..9f% to gedtd es emee odt et emesioe -ntea s yd two tooe ore efengte enti edt tert yelor edt vd beflertaos .,tegmads efoq omit yd tuo tase aniesd to hastack ,etrenasde efog xten efdl .eevicemedt eregmanio efog yelfst edt yeler besitalog 2 yletom at tegaarto efog entl -tsd eft ot Betoonmoo eftos aniiatsqo eth activ eevostaco tegnsio slog yalst edd dgvordt yret att Bers .,ertl ett ot betoernoo srstanre ett -osge edd ot ylovitoeqass betoonmoo sitmtoq ort to ashtea redto sf? .eetrettad ertiem bre ant to motteteqo eft .bobnsorg ers seitotiad ent msigeib eft mort tnersqqe et moteye oendft -bg owd eeaeoacog motera etal. eb tenit edf .eno semrol edt revo segadasy entl nism edd at etostnos to tedmua sdit tedt ts emo oft ..siv ,esmo ot heouber et timorte ~mfoo setevbse refhsU .teudadosfog entl atam ent om to et etwitsst etd? ,cotteree to anoltis | ne THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY little importance. The other improvement appears when & number of marking or of spacing inter- vals are transmitted in succession. The main- line-pole-changer armature retains the same position throughout the series; hence, the line current is msintained constant at its full value throughout the series. Current lag therefore does not oceur except when succes- sive impulses are of different signs. SEXTH SYSTEM. The final de- velopment of the system is shown in Fig. 6. The scheme of Fig. 6 is the same as that of Fig. 5 except for two changes in the receiv- ing apparatus. These changes still further decrease the possibilities of wrong inter- pretation of the incoming impulses by the receiving apparatus. The first change is the fact 27 RIAU a on ¥ ¥ +S YHIASOAIAT OULITHIAL TO MITeYea MURAHOM FHT ~eomatroqmt eftrit aveeqys tromsvorqmt refto ex? -rotait satosqe to +o satvtem to tedsaur 8s nedw -ittem efT .moteseoone at betttmeratt ore elev amsa edt entater otvtamra rsanedo-elog-ontl edy ,esonead :eetrsa edt tuodasotdt soréieoq ett ts tuatenoo heatetrtam at toerryo entl gal twermy) .eetres edt teorgcordt eslav Lint -seooua medw tqeoxe rwo90 tom Beob etotetadtt -erate dustottibh to sts eselsqmt ovte ~9h [entt eff .MaTeYe HTzre .o gli mr awonde et moteve edt to taemgolev to tadt es omee oft at 3 .gtl to emofoe eT -viesot oft nf asanredto ovt tot tqesoxe & .2tF tentryt [ftte eogreto eaedt vewdereqas ant -totot acotw to asttilitdiseog sit sasstoob ont ™ ag gntmoont edt to nottatera ,artevag¢s aatvtsoeT tost eft ef egmeads tarit’ edt °° Gris 28 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY that the receiving polarized relay does not control the five simple relays directly, but instead, controls an exactly similar polar- ized relay, which, in turn, controls the five simple relays. This working is plain from Fig. 6. The second change is shown sthematically: It consists of an adjustment by which the receiver disk can be moved for- ward in the direction of rotetion of the brush arm, or can be retarded against the direction of rotation of the brush arm. The total angle through which the disk may be turned is perhaps forty degrees. The reason for this modifi- cation may best be studied from Diagram (e). This diagrem is the same as (a) as far as the wave form of the impulse is concerned. It will be noticed from the diagrams that the o or.) YHTARDALAT OMITAIRY TO MATeYe MUAMHOM AAT tom ee0b ysfer bestrsfoq grnivieost eft tedd tod ,vftoorth ayelet efqmte evit edt L[ortmoo -telog tafimie yitosxe os efottmoo ,Ssetent evit edt afortmoo ,mivt af ,doitdw ,yelor best mort atefq at anttxow efd?..aysfor olqmte od 2 Blt awode alt eanesdo Bboooee edt tohemtesths os to atetasoo ti ehiab hdomeche =Tot bevou ed aso welh xevieoet edt cotdw yd oft, to gottstor to mottoetlh edd at braw edy tantsss bebrster ed mae to ,mts deotd eft .mte davrd edt to mottator to mottoortb ed yam delb odd dotdw davords ofens [stot .8eetgebh ytiot aqedteq at heawt -fithbom eldt trol noeser off | a (a) mesnelt, aoxt hetbute ed jisili tena pakie as ist a2 (5) ee omsa, eft at merasth atdT -beateonros at salngqmt odd to mot evew edt odd tadd amatgetb edd mott beotton of Lftw tT THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY impulses are quite jagged and irregular. The irregularities may produce a slight flutter- ing of the armature of the receiving poler- ized relay, especially near the transition period between positive and negative pulses. This fluttering is not of sufficient magni- tude to throw the armature from one point to the other, but it is great enough to produce @ poor contact. Such a contact would not be desirable in the circuit of the simple re- lays. A remedy for the uncertain contact in the circuit of the five relays is provided when the second polerized relay is added to the scheme of Fig. 5. This relay does not change its position unless the main line relay first changes; any fluctuation of the armature of the main line relay less than a complete movement from one point to ao YHIAAOAIAT: DUITMIAT TO MITeYe: MUSAAOM SAT eit .xsisgetrt bas begast stiup ers sealngmt -totiolt tigtfe e soyborq vem esititelsgetts -tsfoq anivieser edt to exsteagre edt To gat cotétenart edt rsem ylistoeqes ,yslert best -2oeling evittegon bus ovitteog neswied botreq ~ hagent dnetorttwe to toa at gitretiolt etdt: ot tetog emo mott etutenrsa oft wordt ot ebst eosborg ot agvone testa et tt tud ,zredto eft ed ton bisow tomtnoo e dowd .tostmoo to0g # -ot efqmte edt to ttvorto edt mt efdarteeh 2ayst mistroons eft trot chenen A et ayslet evit edt to tiverto oft af tostnoo- et yeler beaiteloq baosee edt sodw bebivorg ysfer etd? .¢ .gft to -omadoe oft ot bobbs tem edd eaotar moitkeod ett egaaedo tom aeoh rottevtor ft wae jgooguedo text ysfer extl seel yeler onfl aten eit to ervteanrts eft to. ot totog exo mort tmemevom etof[qmoo s aadt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the other does not affect the second relay. The armature of the second relay possesses sufficient residual magnetism so that the contact is kept firm. Hence, any flutterings of the main-line-relay armature do not af- fect the local relays. The impulses in the local ecireuit, with the plan just described, are shown by the rectangular full-line pulses in (e). The transmitted pulses are shown dot- ted. It will be noticed that the received pulses are fair reconstructions of the trans- mitted pulses, but occur at a slightly later time because of current leg. The second change in the sys- tem, viz., the angular adjustment of the re- eeiver disk, allows the middle, or fullest portion of the pulse to be utilized. This fact may be understood by a reference to (e). 30 YAUAASIIAT DUITMIAL TO MTeYe MUAAAGM, EXT -yslert baoose edt tootts tom seoh tedto seit seeeoceeg yelet Baoosa edt to otstants.edT suit tedtt of mattengsm [evbleer taotottise eativedtult yas ,eomeH smrtt tqed.ef tosiaos ~te ton of etrtanre yelor-onti-ntam odt to -aysiet.fsool edt toot [sool sndt of eselvqmt odT ete ,Sedirecebh text melq odt dtig,,divotis seelua enti-[ist realugnestoet oft yd owode -tob.owode ere esalug bettimanet? ef? .(e) ot hevteset edt tedt beotton od I[ffw tl. .het -~anett edd To anottiouttesooer riat ots seelugq totel vltdatia se ts.rs990 dud ,,sceluq.hbottim +3al daettso to eaueced omit eye odt af egdedo broooe, eff ¢ -ot sdt to.tnomtartbs telwgne edd ,.atv ,mot teaelint +o ,ofhbim edt ewolls.,veth.revieo etdT ,boalliss ed ot eelsq eit. to nobdrod -(9) ot eonsreter s yd booterehny od yam toet. rei dak RN aly et Bet, 31 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY This diagram shows the puls- es, and also shows the buttons of the receiv- er disk developed, or rolled out, just below. The buttons are drawn in to such a scale that the diameter of each button represents the time of brush-passage over that button, and the dis- ‘iste between buttons represents the time re- quired by the brush to pass from one button to the next, The buttons are small compared to the pulses, and that portion of the pulse ly- ing directly above each button is the only portion utilized; the remainder of the pulse occurs while the brush is between buttons. By sliding the entire row of buttons along under the row of impulses, we can make any button receive any part of the impulse series. This condition can be actually duplicated in practice by the revolution of the the disk upon which the buttons are mount- ed. However, in practice it is never desired VEO SN eee Nae “ aot ta ee Lé YHUARPRLIGT SYITMIANG TO MITSYE MUHAROM FHT -elyg edt ewode mergsths etd? ~visset etd to exotiud edt ewodea oels bre ,.ee -wofed teug ,vso beffor to ,.beqofeveh wetbh re tadd efsoe s dove ot wk mrerh ete enotinud sa? enmtt eft trosetqet cottud dose to tetemsibh oft -elb edt fase ,mottud tsdt sevo spseasa-deuxd to -9t omt? edt etroeetasr enottud seswied deuau mottod ero mort sesq of Senid sit yd berfoo od heteqmoo fIsme ers eoottud ent? .txen edd ot ~vl sefoq oft to mottroq teintt bee ,ssetuq oft yino ett ef sottud dose evods ylteerth ant selug edt to tshotemer elt ;bost Lita noftrog ya .enottnd meewted et deurd eft elidw ersooo tebas gnofe snotiud to wor ertine edt satbita _tottud ye ever mao ew ,seatuqmt to wor odt esettse sefuqmt odd to treaq yas evteser qvifisotos od neo cotifinoos eid? } to sottsefovet edit ydiseltsatq at hetsotiqnb -tayom era esotdud edt dotrlw soquy dath ett oft _ betig0es teven ef tf eottoestq at ,tevewoH .be 32 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY that an impulse be received on any but its own button. Hence, the angle through which the disk turns is only sufficient as to al- low each button to receive any part of its own Lhpelee: with a little added leeway in both directions of rotation. The results of such an ad- justment of the disk are two in number. The first is that the disk can be adjusted so as to admit only the peaks of the impulses. Hence, with the aid of the two relays on the line side of the disk, greatly distorted im- pulses can be correctly interpreted. The se- eond result is that on long lines, where the current lag may produce quite a lag of re- ceived pulses behind the transmitted pulses, the receiver disk can be rotated backward un- til the brush-and-button contact occurs at the same time as the reception of the pulse. St YATASOAIAT OUITMILI LO MATeYe MUAAAOM FHT eti gud yne mo bevitsoet 6d eelfsqmt os tadt doidw desotit efane ett ;,sorol .motiud mwo -f3 ot es toetotttue yino ef anit weth edt eti to dteq yas eviesset ot mottud dose wol ct yswoet bohbs efttil s dAtiv aetnent Fea se) nokteter to anottoorib dtodd -ba ae dove to atiueet off edit .tedmua mt ows ors Heih ont to toomtent oa betarthe od aso death edt tedd ef terlt -goniuqmt oft to etesq edt vino timbe ot as edd mo eysiet owt ett to Ste ent dtinw ,eonel -mt hetroteth yfteerg ,deth edt to ebte enti ~e3 ed? .betetagtetat yiteerroo ed sao eselig edd eredw ,eentl smof mo tedd ef diveet bros -et to gel s etimp souborq yee asl trerivo ,eeciug bottinenert edt Satded easeinq bevies -ms hrawNoed hotsator od mao Heth revieser oft te exrsooo toatmoo nottud-bos-deotd eft Ift -cafeq edt to morttqeoor eft es emtt omse ont _ aie tare) 33 THE. MORKRUM SYSTEM OF PRINTING TELEGRAPHY Another way of looking at the ¢ondition is that the two brush arms are revolving at ex- actly the same speed, but the receiving arm stays a little behind the trahsmitting arn, the distance behind depending upon the cur- rent lag. This last described system constitutes the Morkrum System of Printing Telegraphy reduced to its simplest form. The scheme includes the essential features of the Morkrum distributors. (These are so called because they take the five character elements of position, which are found on the tape, distribute them as impulses or elements of time, and then, at the receiving station, re- transform the elements back into those of po- sition, that is, relay positions.) This dis- tributing apparatus, together with the tape perforator and automatic printer, makes up the commercial Morkrum System. ES YHTAMDETET DUITUIAZG TO METeYe MUSXAOM ANT et moftrbaod edt ts antadool to ysw tedtomA -xe te goiviover ots emre decid ows odd tadt mre sofvisost edt ted ,fseqa omse sit yitos ,urs enttivimatett odd iotded slitil ses eyste -ire edt coqy antimeqeb butded sonstelh oft nel trot moteye hediroseb tesl atdT opt tated to metaye mrraxoM ont) coturtitenos ed? .orot teelfqmie ett ot boouber ydostzefe? edt to eexrstset [etinesre eft aebrulont emodoe, heliso oe ets evenT) .erotudiaterh suxdrolf ginemele tretostsdo evit sat svet yort. sevsood ,eqet edt mo Bosot ere. dotdw ,mottituog to to avaemele to seetraqmt es medt etudtttalh . ~et ,mottete saiviesoot eft tea ,cedt ime ,omtt -og to eeodt otnt atosd. etremefe edt mrotenatt. -eth eid? (.anottteeq yelor ,eb sed? ,cottte eqat edt dtiw ratheans eestetsqqs anitedizt. qe sexen ,tedaing oltsnoisa bas rotetotteq — emetearcé mortroM [stetemmos edt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY With this preliminary survey of the plan, we are ready to take up a de- tailed description of the commercial system. There are a number of different types, dif- fering in the minor details, but the one de- seribed in the following pages is the one commonly used on commercial duplex telegraph lines. 34 YHTAAOSIAT OUITWIAT LO MATEYe MUSSAOM FHT Yevive Yrenimifstq add Ati -96 8 oss exet of Theer eta ow ,melq eft to -meteve [stotemmoo edt to mottqixroveh bolfist 2%ib ,eeqyut tnerettth to tedmsmt s srs evedT -eb oso oft tud ,efieteb tontm oft at anttet eto oft et sexsq saetwolfot ont af bediroe dqetsefét xelquh fetotommos mo hoes yinomes “P'S Seenel ” i 35 THE MORKRUM SYSTEM OF PRINTING THLEGRAPHY Part II - Tape, Code, and Perforator. THE TAPE. As was said before, the message to be transmitted by the Morkrum System of Printing Telegraphy is first punch- ed onto a paper tape, the number and arrange- ment of punched holes depending upon the let- ter or character which the holes represent. Samples of the tape are shown below. SHIFT @ E RD I SN PMR, EN Fh Le D Te ta ZR SS Fe 42 B The holes for any one letter or character are arrenged in a row across the tape, with the proper blank or unpunched spac- pha Lei ber i ae a A ! Bae HA TRS ee SORA te, Ee in) ees £ ra , ems £9 0) 09 ‘ y * YETAAOMIAT DLITUIAT TO METAYS MUSHHOM THT stotstotrel bas .,ebod ,eqsT - II tref ,ototed bise asw eA .ETAT AAT. . TS day mrritoM edd yd bottinenart ed ot eseaeem edt -doanq terit et ydqergefe? anitatr1t to meteye ~opierts brs tedmor edt ,eqst reqsq 6 otme he | -tof edt moqs anthaeqeh esfod betonuq to taom * stoeverqer eefod edt dotdw tetoartsds to, rot pee | iid en mote ers eqet oft to eelqmet ie 36 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY es between holes. The rows are separated a distance of about one-tenth of an inch, this being sufficient to produce clear distinction between successive letters. Notice that the rows of holes are not exactly perpendiculer to the length of the tape, but that they Slant backward a little. The reason for this Slant will be explained in connection with the transmitting distributor. Besides the holes used in combinations to represent letters, a con-. tinuous row of holes runs the full length of the prepared or pundhed tape. Theses holes are used in feeding the tape through the ap- paratus. The teeth of » small spur wheel en- gage the holes, so that the tape is draw a- long as the wheel revolves. This system of feeding affords a positive and definite tape movement; the tape cannot slip without the et ie me ee. Be YETAROMITT PUITHIAT TO METCYS MUSAHOM SHT s betatsqse eta ewot edt .asfor meewted eo ettit dont mae to dtnet-ero tvods to sonsterh nottontteth tsefs ssrborg ot tastofitsue anted edt tent oottol .erettel evtaassove moewiod telcotbaeqie, ¢ltosxe tom ste eoelod to ewot yedt tedt ted .scaet edd to dtamel edt of etd? rot nogser edT .oftdil s Stawfosd taale dtiw mottoenmos at bemtsfqre ed [ftw trate »votudizxters setitimenert edt mf hoes eolond edt asbiteod .-f09 # ,erettel taoeerqar ot anoitsaidmos dtamel fist edd anor aeLorl to wor evoumit eelod esred? .eqet bedhasq to bexeqorg ext to -qe eft detromt eqat edt gctboet at beam ers -te foedw roqe [feme 2 to dteet edT -estorag -s mwarb et eqst oft tedt 08 eotod ‘edt 9389. es) motene etat seevloves. feedw eft as gaol oaat othnttes boa evitteog 8 ebrotte Batbeot fit, PRON Em aC, Sonne: eat, ot: RCE THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY feed holes being torn out. If such trouble occurs, it is at once noticed by the opera- tor and can be remedied. THE CODE. The perforations f follow the plan of the five-unit code, which is given on the sample of tape, p.35. This is called a five-unit code because for each letter or character, there is a total of five intervals, either holes or blanks; "blank" is used for want of a better term, and denotes évery location where no hole is punched. The intervals or elements are numbered for refer- ence 1, 2, 3, 4, and 5, across the tape. The five elements allow of thirty-one combinations; hence, thirty-one characters are available. By the use of a shift, similer to a typewriter shift, thiry-one new meanings may be assigned to the combinations, so that a total of six- ty-two characters or signals are available. 37 4225 2 ao PN 0 Se eae Vay) 7" cn vé YHIAAPAINT YPULTHIEI TO MaTeye MUSAGOM FHT {dsort fovea tI tro mrot. gated eefod feet -steqo edt yd heottom esno ts ef ti: ,ertmeo0 -bethemor od aso bre tot t emottarotreq oft .8000 AAT detdw ,ebos tinu-evit edt to msfq sdt wolflot aid? .28.q ,eqst to elqmse odt mo movig at fose tot oenssoed shoo tins-evit s belfse af evtt to Latot s at eredt. ,xetostado to.tetiel af notre td yeunsld to eefed redtte ,elevretat eetonebh bas ,mret tretted a to tasw tot bees at eiT. .bedonuq et ofod om ototw noftsool ytevs) -tetet tot bevedmrc eis atwemele 19 alevrotat ed? .egat odt agotos (@ Bas ,.4.48 8). £ some janoktsaidmoo eme-ytitdt to wolfe elnemole evit sefdslteave ers eretostads smo+yiridd , eomed totixrwegyt s’ot ralimte ,tiide es to sen edt yf bedtgtees ed yan esalnecom wen emo-yridd ,ttide -xfe to Ietot es tadt os ,enottsnidmoo edt ot -oldsitsyvs ers afsngie to sistosrado owt-yi - THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Besides the actual charac- ters which are to be transmitted and print- ed at the receving station, the code algo includes several operating signals, which govern certain functions of the printer a- side from its regular printing movements. These signals are: space, carriage return, lining, shift, and rub-out. The space sig- nal causes a space to be left between suc- cessive words of the printed messace. The carriage return is used when a new printed line is to be started. The lining signal causes the printer to turn up a new line, just as is done in the operation of a type- writer. The shift signal causes shift char- acters to be printed instead of the normal characters; the printing of the normal char- acters is restored by the space or the car- riage return signal. The rub-out is used 38 YHTAROSIET OUITUIALT TO META Ye MUSUIOM aaT -oateulo L[estoe oft aeebteod -tattq has bettimenars od ot ote foftdw atet oels eboo odd ,cobtste gatveoer odt ta he dotdw ,elenstea setisreqo [ateves eobsfont -8 totairg et. to enoktonst aisitos arevog -atnomevrom gattateq tafsser ett wort obte : stutter ensinrmo ,soasqe cers aleanate seed? -gte sesqe eT .tuo-dort Sas ,ttide ,»sototl -ore moewted ttef od ot onmtet ie absien fen ed? ,egsacem betaitq oft to ebrow evisseo hetaitq wen & cenw bees af atuter sgsivsso fergte gatetl eff .betrate od ot eb ombt in . ,emkl wen sa qe mot ot. totairg eft mosses + a) oeqyt-s: tor ROLMATATO edt mb enoh at as tent | | -tedo titde asaueo Langte ‘Wide ed? teem io (¢ Lemrom ect to, besteqk betaiyg od: ot anotee ree a tnefe, Lene ost, ett 20, anttabeg ot, am a THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY 39 when a mistake has been made in perforating the tape. The tape is run through the perforator again, and the erroneous letters are punched out. Note that the rub-out combination of hole is the only one comprising all five intervals; hence, any other character contains fewer hole and can be punched out. When the printer re- ceives the rub-out signal, it remains inopera- tive or "marks time” until a different sienel is received; the printer then performs its us- ual functions, just as it did before the rub- out signal was received. THE PERFORATOR. The tape is punched by means of a keyboard perforator. The general performance of the machine is as follows: The actual punching of the tape is done by a row of six pin punches which face a die; the tape passes between the punches and the die. Five of the punches are for the five S s, YHTAAPRIR?T PLITHIAL {TO METEY2 MUSAAOM EAT eit satterotreq ot sbsm meed sant odatetm 2 coeriw sotstotireg edt daugorit ocr af oqst edT .oqst boedoasq ots etottel exsosnorre oft bas ,aisaus eeLlod to mottsatdmos two-dur edt Tadd otoll .ts0 seleviotnk evit [fs antettqmos emo yimo edt et ,20fod tewet entsinoo tetoasredo tedto ya’ ,soned -et tetmixng ont med% stwo fofenng of mao bia ~stoqomt amisner di .,fergte tyvo-dst edt eevteos {srgte tastesttib e [tian "omttd axlrean”" ro evit -en edi enrotreq nedt retnira edt yhevisset ef -doxr odt ototed S5rb tf es taut ,emottonst Lar ebevieosr esw L[eagta Tso eit eget et? ,fOTAROTAET BHT stotatotres hSrsodyet s to ensem yd herfonsg as at ontdoam eft to eomamrotreq [steaes edT ef ogst sdt to gnidonsq Isetoe edT vewolLlot s eset dotdw sedonng atq xte to wor ‘ vd ectob bra esdonugq eft coowlsd eosesg eget edt jofb evit oft rot exs eedomnq edt to evil sath odd es esyu ik: * : tie 40 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY code holes, whereas the sixth is for the feed holes. An electro-magnetic hammer forc- es the punches through the tape; on the back or return stroke of the hammer, the tape is advanced one feed hole, so that a fresh sec- tion is ready to receive the next series of perforations. Different combinations of holes are selected for the different characters by a selective mechanism worked from the key- board. This mechanism operates as follows: Between the hammer-head and the punch pins exists a small clearance, in and out of which five rods or punch levers slide independent- ly. One punch lever is provided for each of the five code punches, but none is provided for the feed punch. When certain holes are to be punched, the corresponding punch levers are left between the hammer head and punches, filling up the clearance. On the forward stroke Ob YHIAHOTIZT OMITUIAT TO MRTEYe WIARAOM FHT eft tot et dixte edt esstedw ,selod oboo -srot otmed ottemasm-ortosfe aA .aeLlod’ beet Noed odt mo pedst edt davouwlt eerdomeq edt es et east odt ,temmed edit to exotte orrtet to -96e deett « tedt o8 afoul best emo BSesnsvbs to settee txen oft eviteost of yhset ef nott aefod to enottsatdmos tasetettric senordsrotreg yd erotoarsds drorettib edd tot hotberee ove Lyed oft movt bettow meinedoem svttesrea 8 tewolfot a8 eetaredo metnedtoom etd? .htacd oe «s eat douva oct ae basd-tommed oft moowted dotdw to two bas mt ,soneteeld [lama s ateaixe -trebteqobat obife atevel deovg to abot evit to dese tot hebivowq at revel Sousa end ee Bebivotc et omon tud podonng ae et ott 3 eee ‘ore eofodt atetrtso mod sons Boot eft tot 3 a erevel donug acfBrogesrtos éat ,Setfoanq ed of , eotomng baa feed remmect edt aeewled ster basis eforte brewtot edd m0 Lesneteefo bail eid went 41 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY of the hammer, the pins are pushed through the paper. If a hole is not to be punched, the punch lever corresponding to that hole is withdrawn from the clearance between the hammer and punches; then, on the forward stroke, the hammer enters the clearance, but not far enough to strike the pin. Hence, no hole is punched by that particular pin. The feed holes are always punched; the selec- tive mechanism has no contol over the pin which punches the feed holes. The rods or punch levers are controlled through a series of levers from a keyboard, similar to that of an ordinary typewriter. The keyboard also automatically control the electro-magnetic hammer, With the idea of the general functions of the perforator in mind, we can now take up a discussion of the machine in its ie PEE eo fs YHTAROAIAT DUITHIAG FO MATEYe MUAAHOM TAT devouwdt Sbodewa ote eaie sft .,tommadt eft to bedonug ed ot tom st olfod e tI iseqsq edt ofod tedt ot antbooceet1ros revel donuq odt eft neswisd sonerselo oft mort mwstidtinv et Sterrot edd mo ,nodt :esdouug fae tommsd ,somerssf[o edt eretme remmead edt ,eforte ,e0meH .mitgq edd exitte ot davone rst ton tud iq tefsolireag.tadt yd bedeasq st efod on -oolfee edt ;hedonsg eyswie ere sefod beet odT aig edt tsvo Lotion om ead me imedo om evit 10 ehor off .eslod hest odd eedomuq dotdw esiree. 8 dasordit Belfottaon ere etevel dong ted? ot telimte ,Srsodyex a mott erevel to cele breodyex en. .retirweqyt yrantizo as te ettengsm-orteele edt Lortaes ylfeottanciss tate it eT emmedt Leveneg ent to sebt edt MtkW 0 yey neo ew ,batm mt roterotieq edt to poston i) ett mt eidoam oft To eakone gets 8 Waitara 3 ron THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY practical form. In this entire discussion, rough sketches will be used to show the gen- eral construction of the parts, but these sketches are not intended to represent the apparatus in detail; the accompanying photo- graphs of the machine show the details of construction. GENERAL LAYOUT. The perfora- tor consists of a hollow cast iron base, on the top of which are located the hammer and punch mechanisms and the tape reel. The key- board overhangs the front of the base. Some of the connecting levers between the keyboard and punch pins are inside the base, whereas some are on top. Fig. 7 shows a top veiw of the perforator; the different parts are iden- tified in the sketch. THE FUNCH PINS. At the lower left-hand corner of the base are the punch 42 ss YHIAHORIAT DEITHIAI AO Mateye MUAAHOM aT -toteavoeth etitas etdt al. .mrot Leottoarg -~neg edt wode ot hDsev ed [fitw eedotete. darort eaedt tod ,etreq edt to ootteutdedos [arte eit tasserqsr ot hebrotnat ton ers eeslotede -otodg goiynsqroces eft :{isteh at extstsqqs to aftsteb edt, wode satdosm edt to efgerg »coftonrtedos -stoiteg edT .TUOYAL TASm URS ae} mo ,9aed moti teso wolfod s to etetenos zo¢ bas tremmed edt Setsool ets. dotdw to got. edd -you ofl .[ee% oqat edt bas, enalasdoom Hoos emoe .oasd edt to taoxrt edt agasditevo hisod Srsodyoxt edt seewied erovel grttoeinos..edt to esotodw ,csasd eft ebient ers eatg donug bas to whev, got s awode ¥ .gtt .got mo erg moe -mebt sis satis tooerettts edt jrote rot req oat » 9 -etotete eft at betttt tewol oth th, .2UTT BOUOE ABB oy won che eee: Honig, edd. ets. oasd, nity shcndbase boedetteL 4 43 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY pins and die. The punches are of steel, about one-tenth inch in diameter by one and one- fourth inches long. There are five of such pins for the tape contact holes, and an ad- ditional smaller pin for the feed holes. All six pins slide back and forth in guide holes bored through the face of a small block. The idea is illustrated by Fig. 8, where B denotes the guide block. The block is[_-shaped, and across the open face extends a cover plate, HE, also bored with guide holes for the pins. The die, D, lays over this cover plate. The two are channelled out slightly so that the tape can be drawn along between them. The pins ordinarily project behibd the back face of the block, and also extend, at their op- posite ends, nearly through the end plate, E; they do not, however, extend into the tape channel. The hammer strikes the projecting eh YHIAADHITT QUMITAIAT TO METCYe MUASHOM HHT trods .Leets to evs eedoonq ofT woth Sas ent -ero bas emo yd rtetemeafh at dont ditnet-oeno foxa to evit ets ered? .smol eodont dirsot -5a ms bas ,aefod fordabe eget edt rot eat [LAiseelod boot edt tot miq telfeme L[anottrs eefod ebies mt dtrot Bas aosd obife entq xfa edit .woofd f[feme s to goxt odt dgrorit hetod astomeb G& etedw .8 art yd botertes{[t et sebt bas’ ,beqede- jet xoold ed? .footd ebtag edt ,eteala "ovoo 2 Bbaetxe eset meqo edt eeotros -anig edd tot gefod situg dit berod oefs ,f edT .6telg tevoo efdt revo eysl .c¢ .9tb ext edt tedt of yltdatla tso bolfLennsdos e212 owt ‘edT .modt asowted aoole swath of neo eqat eset dosd edt Sdided toetota ylitenthro emt «go ttedt ts ,baotxe cafe bas ,foold edt to, otela fre edt davon} yfrsen ,ebae dtteod eqst at? otat bratxs ,tevewod ,tom ob yedt 32% aatioetor odt eoxttte roomed od? .feamede aa. eae THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ends of the pins, and drives the pins across the channel into suitable recesses in the die; if the tape is in place between the die and end plate, it is of course punched. The punch ends of the pins are slightly hollow-ground so as to give better cutting edges. The method of returning the pins to their original positions, on the back stroke of the hammer, is also indicated in Fig. 8. The feed-hole pin, F, is rigidly at- tached to af -shaped crosshead, C, which slides back and forth in the guide block; the crosshead is normally held at the rear of the guide block by the spring, S. The for- ward stroke of the crosshead is limited by its lug (the stem of the "1") striking the end plate, E. The croddhead is also bored with holes for the punch pins, but the fit between the crosshead and pins is so loose 44 AL YHUAROAIAT: MMITMICL TO METEYS MUSAZOM ANT eeotos aniq ont eevith bre ,emtq. edt to ebro ;9L5 eft at eeeecost sldetinog otnat Iennsento oft has efb ett isowted seefd mt at sqet oAtT TE domuq off .bedoanq oersoo to af ti ,etslq bao Brsorg-wollod yitdatle ete antgq edt to ebas. -cogbe anifive tetted evig ot as 08 ed? gartarstexr to bodtem ext dosd edit mo ,exottieaoq Leniygiro tredt ot anmiq’ at Betsofiat oels st ,temmed edt to sdorta’ -ts yibtatt et .& ,atq efond-beet ed? .8 ait ffotdw .0 .bsedeeoto beqede-~ 8 ot betoat “ytooltd ebbing edd ot dtrot Sas dosd eaebile rast oft ts bled qflemrom et Ssentehoto oft -tot of? .2 ,antrtqe edt yd Moold ebtusa sft to wd Betimtr at baadecors eit to eslovte brew edt gatutxvte ("I" edd to mote ont) ‘anf att Betod oafe at beedtibors ef? .f ,etesla bas Fit edd stud ,ento devrg eft tot eoefot Atiw geool oa Bt enty Bae heedesoto ett asewted hh SPS rare gel BS 1 ee NRE 45 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY that the crosshead slides forward freely, without pulling any of the pins along with it. Each of the five pins is fitted with a small collar, which rests against the twck face of the crosshead. The crosshead ordin- arily bears against these collars, so that the pins are held in their extreme back po- sistion clear of the tape. In the operation of the ar- rangement, after the crosshead has started on its forward stroke, any of the pins can follow, in case they too have been struck by the hammer. The crosshead stays ahead of the pins until the end of the stroke, and the pins go through a punching movement the same as though the crosshead were not pre- sent.On the back stroke, however, the cross- head strikes the collars on the pins and carries all the pins back to their original os YHIARDELST PUITUIAL FO METEYS MUARHOM AHT .YLeert brewiot goebife Ssenleeoros efit tadt dtiw anoles entq eft to yas amifl(uq. truodttw 8 Atiw hottit et eatq evitt edt to dosi .tt wo sf odd tanteses eteert dotdw ,relloo [lame -aibxo beedegoto efT .fsedesors edt to esst Jadt of ,atalf[oo saedt temiszs ataed yLite -og Zoed omertxe x tedt ot Bled ors entg ont -eqsy edt to reefo mottete -18 eft to mottareqo edt al Hhetiste ead Ssedesoro. edt totts ,trome'gcet meg ant edt to yre .exorte brawrot ett mo dovite need eved oot yedt caso at ,wollet to beeds.eyste bsedezoro edl,.commsd-edt.yd Sas eodotte ect to bne edd [ives anigq edt edt tmemovom,guidonng s dgsormt og aentq edt -9tq tom etew bsedesoto edt dguodd as omse “spore edd .tevewod ,giorte aosd odt a0, tn08 Snes acta edt mo areifloo edt eeiirte beed featgtto tled? of toad eatq edt [fs aetriso - | : , 46 THE MORKRUM SYSTEM OF PRINTING TEIRGRAPHY positions. A feature which should be noticed here is that at the end of the forward stroke, the pin collars strike the crosshead, and their travel is thereby limited; otherwise, the pins would drive into the die and soon loose their cutting edges. The method of starting the crosshead on its forward stroke is also ap- parent from Fig. 8. It will be remembered that the five contact-hole pins are not struck directly by the hammer, but instead, small interference rods are inserted between the hammer and the pins, so that the rods are struck by the hammer. A feed hole, on the o- ther hand, must be punched at every stroke of the hammer, and hence no punch lever is provided for the feed pin. Instead, this pin projects beyond the others a distance slight- ly in excess of the thickness of a punch lev- ob YHCAADEILT DUITMMIAT TO MeTeYe MUMAOM TA? heoiton ed Si{yode do tdw esriteset A semoftieog ,otorte hrewrot edt to Bas odt ts tad? at erod ttedt Bas ,bsedesoro odd otttte arsf[Lloo mig odt eatg edt ,setwredto ;betimil yderedd er Lovett ttedt seool mooe baa ef5 edt otmit evith bisow . -2ogbe gaitiso edt enitvate to Bbodtem sdT' -qs oelfs at etorte Sreawrot ati mo bsedeasots heredmemet od £[fiw tf .8 .gtt mort tneteq fourte tom srs entq eLod-tostmoe evit edd. tadt If{eme ,hbestent sud .remmed edit yd yitoorth eit oasewhled betreent srs ebor sonsretretat ets ebot edt tedt oe ,satq ond Sas cremmed -o eft mo {efod best A .rommed edt yd aourte exorte yrove ts bedonuq ed tenm bead redt et revel deonvq om eonmed bae ,tommed ,odt to tigq etdt ,bsetenl .atq hset atid tot Sshtvorg -trigife senateth s etedto edd broyed -etoetorq -refl domuq s to esemsoidt edt to seeoxe at yl. 47 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY er. Therefore, the feed pin is struck by the hammer before any of the punch levers, so that the feed pin and crosshead lead the other pins throughout the stroke. It is ap- parent that with this method, the proper movement of the pins is not interfered with by the crosshead. THE HAMMER. The hammer mag- net consists of two solenoids, designed for 110 volts, direct current. The solenoids are placed horizontally at some distance behind the punch pins and in line with them. The arrangement is clear from Fig. 7. The two coils are supported from the base by 4 brack- et, which is attached to those ends of the Goils adjacent to the punch pins. The solen- oids are fitted with movable cores or plung- ers, which slide in and out of the rear ends of the coils. A yoke connects the cores, and Th YETAROTIET DUITHISY GO. Maeve WURAAOe ERT eft yd Momrte ef miq) best edd YototeredT .19 . oB! ,etevel donug eft to yaa stoted roamed edt haa! hsedesots bas atq beet odd tedt -qz at tI ,exotte odd tuodasordt entg tredto teqorg oft .bodtem efdd ditw stadt Jasteg dttw berettetat tom st satq odd to tremevom » .Beedeeoto ett yd -gam-tommed eT. .HEMMAR: ART: TOt.Bomgtesh ,sbifonelLoe owt to etetanoos ter ets ebtonefloe od? stmstiso gosrih ,atfov Off baitded somaterh omoe $s yifatadstromd Soosl¢ edt ..medt dtiw eatl at baa extq dontq sdf owt of? .V.2hT mort tselo at tasmegratta -toatd « yd saad edd mort botroyquae eta eftoo eit. te shas oa0dt ot hedosits et dotdw te -seloa edd .amtq donag edt ot tnenshbe @: : : -gariq to eetoo sldsvom détw bettit. en shee, seamen feo nahn mk ehte: SPOR SF 4 bos ,eeroe edt atsennoo exoy A. sltoovedt to" . 48 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY from the center of this yoke, = plunger rod goes forward between the solendids, through a guide hole in the bracket, and terminates in a round-headed nut, N,. A hammer spring, acting against the magnet, normally keeps the cores drawn partially out of the coils and the plunger rod in its extreme back po- sition. When the coils are energized, the cores are drawn into the coils, and the plun- ger rod thrusts forward toward the punch pins. The hammer solenoids are controlled automatically from the keyboard. The hammer itself is a hori- zontal steel lever, pivoted at A (see Fig. 7), and extends into the clearance between the end of the plunger rod and the punch pins. Thus, when the plunger rod comes forward, it thrusts the hammer on ahead of itself. The construction of the ham- Ob YHLAHOALTET DULTUIAT TO METeYe MUSAHOM HHT hor tegmutaq s ,ovoy etht to retas0 ent mort davorts yebtonafoe edt seewted brawict seog eetentarre? bus ,tefoard eft xt efod ehiva’s ,adince vemmed A.W , tum bebsed-hnsot e@ mt eqeer yilamron , tenga odd tencisas uitios aftoo edd to tuo ylisttisg twerb dstoo edt -og Hosd emexrtxe ett at hor tegneiq odd bas ext ,bostarere ers effoo oft sodY .aottte | -onlq edt bas ,efioo ‘edt otth mwath sts eerde ne doasq odd Brawot Brawrot aveutdd hor res 3 bellortice ere eblodelod tenkied ed? sant -5xaodyex edt mort yLlsottamotys Pie es: ~tiod @ et tfowt! tommed ed? © 9° * | ae o( .Qlt cee) A te botoviq ,revel Leote Istnos : ‘eit meowted sorersefo ent otmt ehmetxe Bae “lemtq donsq odt ae bot tosasfa edt Yo bme | )) .brawrot evemos Bor regax tg att aedw esd? ( \Sfeadt to beeds no remax odd eteotdt $2 oe ‘smad edd to nottowttenos edt) 8 te tig 49 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY mer is shown in Fig. 9. As indicated, the hammer is channelled out along its length. The channel faces the punch pins. In line with the pins is cut the rectangular notch, B (see Figs. 7 and 9). When the end of the hammer is pushed forward by the plunger rod, the ends of the punch pins enter the notch, B, The channel and notch furnish the clear- ance, before referred to, between the punch pins and hammer. Note that the bearing at A, upon which the hammer is pivoted, is offset from the center-line, so that the bearing stud is well clear of the middle of the chan- nel. " THE PUNCH LEVERS. The five interference pins or punch levers, which slide in and out of the clearance between the ham- mer and the punch pins, are merely square steel rods; they move lengthways of the hammer through a") ' Ve) ore! <> a ae eh YHIAADEIAT DUITHIAG TO MATCYa MUAAZOM HRT edt .fetsotint eh .& «ett of awode ef rem Ateool ath gaolea tuo bellomnsdo ei temmad entt al .antq dogsagq edt esoet Lormedo oT doton taleanstosr sft two ef ent ot dtiw eft to bre edt mod! .(2 bas Y .egtt ese) & ,bor tegaulg edt yd brewrot bedeng al remmed dotom edd tetne antgq doasq oft To ebme ont -tsefo edt detotyt dotom bas fonneado edit .& sonugq oft meowted ,ot bertetet stoted , eons A te guitsed oft tedt eto jrommat bas eniq dogito ef ,betoviq ef temmed edt dotdw nogr antteed ofirtedd of ,enti-retaso edt mort | -nado eft to efhbim edt to tsefe Liew ab bute =~ e aera: 7 fer He evit ef? .etiVal HO“UT HHT efile dotdw ,erevel doauq to amt eonetetrotat. -med ont noowtod eonstselo edt to two Bas, at Teste erempe:xforem ets ,emiq omg odt bre tom dgrotdd renamed edd to eyewdieael evom yedt jebot ~ 50 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the channel. They are arranged in a vertical row or pile, so that each one is in the hori- zontal plane of a punch pin. The levers are numbered from 1 at the bottom to 5 at the top, corresponding to the same numbers of the code elements. The punch levers extend just far enough along the channel that their ends cross the notch in the channel, and thereby fill up the clearance space at the tack of the pins. However, each lever may be withdrawn from the channel for about half an inch; this movement is sufficient to re-establish clearance. SELECTIVE MECHANISM. The meth- od of moving the punch levers from the key- board is illustrated in the isometric sketch of Fig. 10; this sketch, for simplicity, shows the complete links for only one punch lever, and shows only one key. Hach key is the ter- minal of a long arm, K, the back end of which O38 YUTAMDAINT AMITUIAT LO Maree MUAAOM ABT feotsirev s af besnstre ots rod? -fomisdo edt ~frod.oft mt et ono, dose tedt oe ,eltq.1o wor ete erovel off .miq donuq s to onelq Isitnos got edt ters ot mottod edt te £ mort botedmia eboo edt to eredgum omae odt ot anibmoqesetios _ st test baotxe exovel donsq edt .etmomefe 2B0TD abtre wiodd tedt Lonnedo oft gaols devote qu.[fftt yderedd bas ,fennedo edt of doton oft -egtq ent to aoa edt. ts .cosqe eouatsslo edt edd siott, owerbdtiw ed yem revel, tose . TevewoH taemevom etdt jdont os iled twods tot Lonnsido -eoretselo delidetas-et of daoototitue ef -ddem eiT .MeIMAHORM SVITOMIAE . fo -yor odd sort exevel donsq eft aatvom to bo dotese otutemoat edd mt beterteu[{t et braod awode ,qtiotlamie tot .dotexe, atdhj;0L sett 20 <tevel sonsq emo Yoo tot exatt otelqaos, edt _) *tet edt ef yor dost «yout eno Yao aworia beta” he P | dotite to bas oad oni .X jure gxol 2 to fecta ret 51 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY is mounted on a shaft, S. The key lever, or arm, has a projection, P, which rests on a large rectangular strap-iron loop, L; the loop has no back side, but instead, the two ends of the strap are supported by two bear- ings, BB, as shown, The arm, F, is attached to one end of the loop, and rises vertical- ly. The upper end of the arm, F, is slotted, and engages the short end of the bell crank, D, The crank has a suitable bearing at =E. The long arm runs forward to the punch lever, and is pivoted to that lever at A. Tracing through the link movements, we find that if the key lever is pushed down, ss it would be by the depression of a key, the front of the loop, IL, is also pushed down; this movement brings the upper end of F forward, and with it, the short arm of the bell crank. The long arm of the bell crank is thereby drawn toward YHTARORILT DEITUINI IO METeYS MUSXHOM HHT to ,tevel yet eT .c ,ttede s no botvasom ef 8 mo ateer dotdw .2 ,nottvestorq s esd ,mre edt if ,qool mott-qette tefesastoer estel owt oft ,isetemt tud .,eblta Axoed om esd qool -teed owt yd hetroqqve ers qatte oft to ebae bedostiea et ,F ,orrea 6d? .awode se ,74 ,egat -[sotixey seett bas .qooL edt to Bre smo of bottolea at .f ,mra- eft to Soe sreqqy ed? st ~Mnato [fed sit to Bae trode edt eesgescs Sas 2 te scttrsed efdatise s ged Hoero eit sc tevel donvd odd ot Srawrot earr ors anol dT grtosxT .A te tevel tadd ot betovtq at bre tf tedt Bott ow ,etasmevom satl edt Agro? ed Bblyow tt ea ,mwoh bedeugq ei revel yer odt oft to trort sit ,yo! s to moteeerqeb sit yd tnemevom eidd ;awob.bedenq oe@fa et ,f .qoot dtiw bose (brewrot I to boe reqqs edt egaind gaol ed? .Aneto [led edt to mre trode edt , tt brswot nweth ydetedd ct vaste fLed eft to ars 52 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the right, and it pulls the punch lever with it. This movement of the punch lever is the one de- sired. All parts are returned to their original positions by springs, not shown in the figure. The controls for all the punch levers are the same: each punch lever has its own bell crank and loop movement. In Fig. 11 is shown the complete selective mechanism with the exception of some of the keyboard keys and levers which are left out to simplify the sketch. The method of nest- ing the six loops and the arrangement of the bell cranks should be noted especially. The sketch also shows the several fingers which each key le- ver carries. These fingers point downward, and each rests on one of the loops; hence, the depres- sion of a key simaltaneously depresses several loops, and, at the same time, withdraws several punch levers. By this action, a key controls such 3d YHIARZORIAT DUMITUIAL TO METSYe MUSAHOM DHT ti adtiw-vevel donq edt ellinuq th bos | tigty oft -9b ono oft et revel donug sit fo taemevom ata fantakro tted? ot bBenruter ots etraq [LA .berta -stsgit edt af mwote gon ,e2gnirga yd aeaottheog adt sts eatovel doroq edt £f2 tot efLortmoo: oi? : Unsto ffed owo etl asd tovel doacq dose > emae ~tmomevom qool hrs stelqmoo edt mwode et LL .ght aly, meets | emoe to amoisqeoxe edd dtiw metasdoem avitoelee tTtel ere dotdy etevel fora eyed brsodyed eft to -taen to hodtem sit .dotefe sdt vitiqate ot tro edt to tmomegasits edt bas aqool xte edt gat fotede eft .yf{stosqes betom ed bivorle axneto [led Rat vow fore to £ chy: exogalt: fsvsvee oft awode osfe . faa ,brewnwob tatoq etegalh oseXt ssotttes Tov - -aetqeb est ,eonedt :2aqool edt to Ofr0, HO: eteon, soe, Latevea asaeenyed ufesoonst fente: yet! to ee r farevee ewsrhdttw |, omtt omae: oft te: bee ay sa : dove efLortnoo, yet sy, mottos eld yh s erevel 7 Da 53 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY punch levers as will cause the proper holes to be punched in the tape. The hammer control is indi- cated in the same figure. In addition to the five bell cranks, there is a sixth lever mounted with them and similarly controlled. This lever is the top one of the bell crank group, and is operated from the outside loop. The top lever has no long arm extending to a punch lever, but instead, consists of a single arm, identical with the short arms of the bell eranks. This arm controls the hammer magnet through the series contact shown. One point of the contact is stationary, whereas the oth- er is carried by the lever just mentioned. The contact is normally open, but when the arm is moved forward, by a depression of the front loop, the contact closes and connects the solenoids to the source of current sup- YHTAMDAIAT DAITMIAL TO METeYe MUSAAOM FHT aefok tecorq eft eeseo [ftw es arevel donnug -ogst eft at bedonug ed of ~Ehat at Lortaos trommad ait edt ot mobtifis aI .statt omee edt mt betsoe vtevol dixta es at eredt ,edimeto [fed oevit eSellortaos yfralimts bas medt dttw betarvom Aneto [fod eft to exo got oft et revel etdAT -qool ebtatro edt mort betsteqo at Bae ,quorty 8 ot antinetxe mrs srof om ead tovel qot eT efgste s te etetenoo ,fhsetent tud ,revel donuq {fed oft to amrs trode odt dtiw Isottmwedt ,mrs temgsm temned edt eLfortmoo mra eidT .etinsto tatog enO .mvwote tostnoo sasirea edt davordt -dto edt essredw ,yrscottate at tostaon eit to eSemotinem test revel edt yd Betttras et te eft monty ted ,neqo yflamton et tostnoo ed? edt to moftasetqeS s yd ,fSreawrot Bevom ef mrs etosanos Bas esects tostmoo eft ,qoof taort -que taertso to servoe edt ot ebtomefos edt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ply. The contact is adjusted to close just after the punch levers have been withdrawn by the bell cranks. As for the location and mount- ing of the link mechanism on the machine, the bell cranks and contact are situated an the top of the base, as indicated in Fig. 7, where- as the loops and keylevers are inside the hol- low base of the machine; the levers F of Fig. 10, connecting the loops and bell cranks, ex- tend upward through slots of the grid, G, as indiested in Fig. 7. The mounting of the bell cranks on the vertical studs is also apparent from Fig. 7. The method of suspending the loops and key levers in the base is illustrat- ed in Fig. 12, which is a veiw upwards at the bottom of the machine. The six free ends of the two sides of the loops are mounted in the 54 YEIAAOAIRT DALTHIAT TO METCYe MUARAOM HHT test asofo ot betesths et tostaoo edT .yla awethditw seed evad erevel donsq edt retts -aineto [fed edd yd -iasom Baa aotssoof edt rot #2 edt ,eatdosm edd no matnadoem eat{ oct to amt edt om betsutte ets tostmoo has exnete {Led -otedw ,." .nti at betsotbat es ,seaad eft to got -fod edt ehbtent ete erevelyed bae scoot edt as aft to % erevsl odd jeatdosm eit to casd wolf -xe ,avesro [fed has eqool edt anttoennoo ,OL es .© ,bixvg aid to stole danotdt Srawgs bast {fed edt to gattavom of? .¥ .att at botaoliat tastaggs oasis at ebsta [sottrev edt ao etnats eV. .gtt mort edd gatbhneqese to hodtem dT -tettas([l?t st eesd odt at atevel yet bas sqool ed? ta shtawqy wrev a ef dotdw ,&f .@tt at be to alae sett xte ed? .entdoam oft to mottod edt mt hetavom ets aqoot edd to eohts ows odd pf A oe ee a fae! 3 * 4 a4 wy THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY two bearings as shown. Washers or spacers are pleced between adjacent straps in order that there shall be no interference between them. The loops are held up snugly against their backstop on the under side of the base by return springs. The idea is eleear from Fig. 13, and needs little comment. The rod, R, of Fig. 13, runs the full length of the loops. This spring support allows the front of the loop to be pushed down by a key lever, but immediately returns the lever to its normal position when the pressure is released. The mounting of the key levers is similar to that of the loops, and is shown in Fig. 12. The back ends of all the levers are strung loosely on a shaft, 8; the levers are kept separated on the shafts by spacers. The key levers have spring returns, similar to those of the loops. All springs, both of 55 ou Cs YHCATOLINT OUTTAIAI FO MATSYS MUAAHOM ANT eTs ateosqe to ersdesW .mwode es eanttsed ovt seit teSro at agarte tnesestis moewted beoslq emendt moowted sonetetretar om ed [fade eredt tteit tveateas ylaune qu bfed ere eqool eft qd eead edt to eshte tebas ods mo qotexosd est? mort reafo et sebt ofT .eantiqe arustet to ,f ,hor edT .tnemmoo s{ttiil aboom bas ,éf -2eqool edt to dtanel [fut eft env cL att edd to taott edt ewolfa troqaze aairce ald? txud ,tovef yout a yd mwoh bedsersq ed of qool fenrrom ett ot tevef odt eaanruetor yiststbhemnt | eDbosseler st orteeetq sdt aodw nottteog atevel yet edt to sattarom eT ) mwode at bas ,aqool adt to tsdt ot tafiimte at etevel edt {fe to aime doad ofT .SI .utt at arevel edt ;& ,ttede s mo y{ssool anurte ets ~eteosqe yd eftedea edt mo hetersqes tqex ors ‘siimte ,anruter anitxgea evad erovel yex siT to diod ,sgaitqs [fA .eqool edt to saodt ot THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the loops and key levers, are anchored to the rod, R, of Fig. 13. THE KEYBOARD. The key levers terminate at the front of the machine, have key buttons attached to the front ends, and thereby form the keyboard, The plen of the keyboard is cleer from Fig. 7. In a general way, it follows the plan of the standard typewriter keyboard, but as only upper case letters are used in telegraphic work, addi- tional characters are supplied instead of the two separate styles of letters. Notice that besides the actual printing characters, the keys include the operating signals, such as carriage return (CARRET), lining, and oth- ers. THE TAPE FEED. The method of feeding the tape may be seen in Fig. 7. The tape reel is normally supported horizontally on the top of the base to the right of the 56 ad YHTAROEIRT OMITAINA TO MATSYe MUSAHOM FHT ot betodons ete ,atevel vei Bas eqoolt edt -8f£ .2tt to .f , bot edt etovel yew ofT .CHAOSYaA HT eved ,emtdosam oft to tnortt oft ts etsainret bos ,eise tnootrt edt ot bedostts anotind yox edt to asfgq eiT .fraecdyei sft mrot yderedt feteneg a ml .S .att mort <nele at breodyext Busbastea edt to malq edt ewoffot tf . Yaw ease teqas ylno ae ted ,brsodyet retliveqyt -tihbe ,trow ofdaatastet at pie ete etettel to beetent Sbetfarrea ere aetatostade [anctt sotto .atettel to nétete, piotcauie owt eft ~atetosrado arttcitq Isutos edt eehteed tact fove ,eafarnta anttateqo eff obsfomt eyed ent efto bae ,aatatt ,.{TEAHAD) mrvter onstytas 3s 879 to bodtem ef? .CanY FIAT ERT odT .¥ .g9f% ot mooa od yen sqat edt gathest yliataostrod Setroqque yiismrom at feet sqst eit to tdgit edt of saad edt to qot edd no 5” THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY bell cranks. The tape unwinds from the reel, passes between the punch pins and die, and then passes between an idler or tension rol- ler and the feed roller. The idler is pressed against the feed roller by a spring. The idler and feed roller may be seen in Fig. 7 at the left of the punch pins and die. The feed rol- ler is a vertical cylinder, slightly higher than the tape is wide. It has projecting pins or teeth which engage the feed holes in the tape, so that the tape is pulled along as the feed roller turns. The idler is a second cyl- inder which serves to keep the tape close-up against the feed roller. The driving of the feed rol- ler is accomplished by a ratchet and pawl movement, a part of which movement may be seen in Fig. 7. At the bottom of the feed roller, and rigidly mounted with it, is a ve YHLALTHSIET PUITHIAG TO MATEY MUSIAOM FHT ~leet edt mott ebatwoau east efT .axmato [fed bas ,9tb bee extq donve oft meswted eaeaag -foxr aotere? ro talht as seowted sesesq not Heseetq at relSt edT .reffot best edt bas rel telbt eft .grirtqe 2 yd tefflor best edt tantsas edt ta VT .gtl at nese ed yam refLor Beet Sra ~fot Beet efT .sth Bas entg donsgq eft to Hel svedatd yitdatfe ,rebatiyo Isofirev s at rel amntq axtteetora ead $I .eftw et oqet edt nadt edt mt seltod beet edt ousgnto dotdw dtoe? to edt se anofe beffreq at eqat edt tadt oa ,eqet -I[yo baoosee s et telit ofT wanted reffor heet qu-oa0lo ayat edt gqsex ot sevros dotdw tebat eteol[flot beet edd tantagea -fot boet edt to anitvirh eT | « Ivaqg bee tedotet #2 yd hedatiqmosos st tefl ed yeu tacmovom detiw to traq a ,tnemevonm beet edt to mottod eft t4 .v watt aot neue 8 ak ,tt adtiw Setmrom yfbtatr See ,reLfor THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ratchet wheel. A long pawl attached to the end of the hammer comes forward with the hammer on the forward stroke; the pawl hooks over a tooth on the ratchet, and on the back stroke of the hammer, pulls back the ratchet one tooth. This movement of the ratchet ad- vances the feed roller and tape one step. These steps are about one-tenth inch long, measured on the tape, which distance is suf- ficient to produce clear distinction between successive letters on the tape. The punching, feeding, and selective mechanisms, so far described, con- stitute the essential parts of the perfora- tor. Experience, however, has shown the de- sirability of adding two more features. THE BACK SPACER. The first of these new elements is the back spacer; by means of this device, in case the wrong 58 83 YELAMORIZT OUILTUIALT TO MET2YS MUAAAHOM FHT sit ot bedortisa [waq gnof A .{sorw tedotst edt -ditw 6Sreawrot asmos rtemmed edt to bas axood (waq edt ;esdorte brawrot edt mo tommed dosd edt so Bas ,tedoter sedi mo dicot & t9¥v0 tsedotat edt voad alluaq ,r9smmed edt to exorta -he teflotat edt to taomerom eidT .dioot emo etota enc eqat Sus ref{lor beet edt esoray ~amol domi dinet-eno tuods ets agete saedT “tse st soneteltbh doidw ,sqst oft mo bersesen meowted moktentteth tssfo eouborq ot tastott -9qet edt mo arettel avieasoorus hae ,antbest ,agidonsq edT -foo ,S5edirogeb rat ce ,smetmadoen evitoelea -sxotreq edt to attey Iatinesae edt stuitte -o6 edt awode oad ,revewod ,eonstreqx= .rot .s9tstset stom owt untibe to yttitdarts tetit ed? .AHOAIe BOAT FHT stecsqs unsd edd at atmemefe wena szedt to ancotw eft sesso mt ,eotveh stadt to ensem yd 59 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY letter has been punched onto the tape, the tape can be backed up until the incorrect letter is again in the punch. Then the let- ter may be cancelled by the "Rub out" key. Thus, the purpose of the back spacer on the perforator is exactly the same as its pur- pose on a typewriter. The movement is illustrated in Fig. 14(a), which is a veiw of the under side of the base. The stud which carries the feed roller extends through the base, and terminates in a star wheel. A lever and pawl, as indicated in the figure, are mounted so that the pawl engages the star wheel. Hence, when the lever is salen to the right, the star wheel is turned through a small angle. The star wheel assumes a definite position under the action of the jockey roller which rests upon it. The movement of the star wheel YHZAROGIET SMITUIZT YO MATCYe MURAHOM ART eit ,eqst edt otmo bedossy, seed asd rettel toenroont eft (tins qu hezosad ed mao eqsat -tal eit moilT .donsg edd? at atreas el rottel -you “tno dof” edt vd beifeoaas od yeu tet edd mo ressede Xned edt to seogrsg edt , asd? ~tog att se omas edt yitoaxe et totsiotieq etotirwoqys 8. m0 920g betartan{f[r at taemevom edt vehus edd to wrey sa at dotdw ,(a)Sl. .gtl at edt selirse doidw Bote eff .snsd eft Yo obta Bas ,seed edt davordt ehnotxe telfor heet .lweq Sas xrsvel A .feedw tata 2 at seteaturet os Setmcom ems ,otegtt edt at botsotiat as .eomel .foodw tetea odt eoasane {weq edt stadt edt ,tdaty edt ot bedeng ef tevel sit asdw -olats [lems s dysordd Semxut at feoedw tste sottteog efiatteh s asemmeae Leedw rste edt dotdw teflor yexsot edt te mottos oft tebas feedw tate ed? %o txsmevom oAT .tt moqs ataer 60 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY turns the feed roller and tape back one step. The lever and pawl are returned to their originel positions by a spring. The lever projects from the base at the lower left- hand corner. THE END-OF-THE-LINE INDICA- TOR. The next of the new features is the end-of-the-line indicator. This device gives warning when approximately sixty-five char- acters have been punched onto the tape; six- ty-five characters are assumed to constitute a printed line. When the signal is given, the carriage return key is depressed, so that at this point in the message, the printer will begin a new line. The device is there- fore seen to perform the same function as a warning bell on a typewriter. Before a mes- sage is started, the carriage return key is depressed; this action assures the perfora- 08 YHIALORIET SAITUIAL TO MUTZYe MUSAAOM FHT -qete exo aosd eqat bus reffor beet edd emit xtedt ot bomrutex ets Iweq Sne8 tevel eAT tevef ef? .anitqe e yd soottieco [anigize -ttel rewol edt te oasd edt mort atostorq etomros Sasd -ADIQWI HNTI-RHT-T0-cue See edt et serstset wen sit to xem of? HOT eevia eotveb ald? .rotsotfat emt{-edt-To-bae -redo ovit-yvexte zletamixorg¢s asiw gotatsyw -xie j;eqst edt otmo bedonsg aeed saved aratos stgtivenos of bemsaaa sta aretostario eritexy? esovis at Lemste edt set’ .enti bstaira s tadt on ,beaserqed et you arvter ensirtas edt toeltatiq odt ,oasecom edt at tatog etdt ta -stedt ef ectveb ef! eat wea s miged [ftw 8 eg sottonut smsa edit crrotteq ot meee stot -eom & ototed ,tetitweqysd es mo [fed antatsw at yet ariter onsittas edt ,bedistea et ease -stotieq ed? eetwees sottos atid ;beeeetced 61 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY tor and the printer being in phase as regards the lines. The indicator is located in the base of the machine; the details of its construction are presented in Fig. 14(a). In this figure, the parts are in the beginning- of-a-line position. As shown, on the feed roller shaft is a small pinion, which drives a 65-tooth gear through the medium of an eaux- iliary or idler pinion. At each stroke of the hammer, the large gear is turned through the angle of one tooth, so that at the end of a line of sixty-five characters or signals, the large gear will have turned through one complete revolution. The gear turns against the action of a spring, U; this is a flat spiral spring, similar to a small clock spring. The large gear carries a small cam or disk, D, concentric with it. A lever, I, fa YHIAROAIAT SUITUIAT TO MATeYe MUKAHOM HHT eitesret as eesdiq at gnited tetattg edt bas tot -sentl ent mi betsool st totsetiat exT etl to eltsteb edt yemtdoam ett to eaad aft mI .{e)bf .gt! at betaecerq ots mottorrtenco -getnotaed eft at sre atray edt ,etsalt atid? beet edd no ,mwodea eA .motitaocg eat{[-a-to eevirh dotdw .aotnta {femme s et Itade refLlot -xss as to mrifen edt derovdt ssen dtoot-d3 8 edd to etortea dose tA .wotmtq tefhi to yretit edt darordt hentot ef tae, estrsf edd ,rommed es to Bus odt te tadt on ,dtoos omo to ofgna ,efencate ro erstoarado eviteyixta to satl exo dasotdd bhearvt evead ({tw rasp egtal edt santsae enrst tees efT .moltinlLover stefqmos telt s at atdt 3U .aairge sto nottes sit eaatrqe doofo f[Iame s of taltmte .anixqe Latiqe {{eme # 2eelttss tseg ontel edT el ,tevel A wtt dtiw otutnesroo ,T¢ ,tetb to mso 62 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY is held against the edge of the disk by a spring. An interference pin or stud projects from the face of the large gear in such a manner, that, as the end of the printed line is approached, the stud travels under the lever, lifts it off the disk, and raises it still farther till the contact spring of the lever strikes the fixed point of the contact. This condition is shown in Fig. 14(b). The contact is in series with an indicator lamp and source of current supply, so that when the contact’ closes, the lamp lights. The lighting of the lamp serves as a warning to the operator that the end of a line is near. The contact is so adjusted that the warning oceurs at about the fifty-eighth character of the line. Special construction of the large gear is shown in the figure, viz., the iy) YHIARDEINT ORITMILI TO MATCYe MUANAOM AT g yd wetbh edt to sabe edt tentages bled et etoetotg Sute to aiq eonotetretat mA .gaitge s dose xt tsen ontel edt to soad edt mort entf£ Betatxq edt to Bre oft es ,tadt ,tennam edd to brs afevert bute edt ,fetosorgqs at tt aseeteax brea .xeth edt tto tt attkce ,revel edt to aniztqe gosigoo edt [Ltt tediret {ftite etestinos edt to tatog bextt ed} aotints tovel od? JG)SL ght xk wore st sotdtbaos eld qus{ totsotint as Attw sotres sf ef tostaoo “ade tedt of ,yfaaue toeriso To eotvoe bas eft .etdeil quel edt ,eeeols Sostiroo edt ot natntrsw a as eovrce qmal edt to gatidell taem St omtf a to Sne oft tedt trotsreqo edt gatorrew edt tadt betestbs os at tostaoo edT totostsio dtdate-ywtlt edt troda ts sivese eoxtf edd To edt to mottouttenxos Lstoeqe | edt ,.stv ,orsglt adv at owode et tseg eatel 63 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY lest four teeth of the gear are cut out; the last four teeth are mentioned with the under- standing that the teeth are numbered from the one in contact with the idler when all parts are in the initial or beginning-cf-a-line position. The reason for this construction of the gear is as follows; if all the teeth were in the gear, there would be no means of stopping rotation at the sixty-fifth charac- ter, and the operator might continue punch- ing. The rotation of the gear would continue, so that presently, the interference stud would turn from under the end of the contact lever, thereby releasing that lever and des- troying the warning signal. Hence, the last four teeth of the gear are cut out, so that when these spaces reach the idler, any fur- ther punchine of characters has no effect on the large gear; hence, the warning signal is YHTARDEIET SAITHIAT FO METeYe MUAAHOM FHT eff ;tuo Tyo ota teen edt to dteet rset fteslf -rebay edt diiw benotinom ers dteet rs0ot teal edt mort hersdmuena ete dtost eft tsdit actiaste attrag [fs medwrofht sdt dtiw tostmoo at ano ent f-a-to-gatnntsed to [sttint edd mi ets softosrtesxoo satdt rot mosgser ef? snotttesg dteet edt [fs ti gewolfot es et rses edt to to smasem om od Blyow stodt . T8238 edit mt stow ~ostads ditit-ytrte edt ts noltistor gatqqote -donasq enattroo tigtm rotereqe edt Bas ,tet eouxttaoe bilrow tees oft to nottetor edT want bste soneretretat edt ,yltmeserq ted? oe tosiaco adt to bao edt tehoas mort aret bixsow -seb bea tevel tadit sntsesfer yderedt ,rovel veal add ,someH .[angte zatareaw eft satyort sedt oe ,tso tuo ets teeq edt to dteet rot -mpt yrs ,telbit edt doset seosqe esoedt nediw ao tootte om esd eretoerane to aatdensq tedt et fenate antorew edt ,eonmed itsen surel edt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY maintained. The release of the warning signal is effected simaltaneously with the punching of the carriage return signal. The carriage return key operates the selector punching mechanism in the same manner as any other key, but in addition, the key strikes the end of a small bell crank, B, of Fig. 14 (a), at the right end of the base. Through the agency of this bell crank, the key push- es a rod, called the release rod, through a small distance toward the left. The release rod is connected at the left to an arm, H, which carries the idler pinion. This arm is centered on the stud that carries the large gear, and is kept in such a position by &@ spring, T, that the idler pinion is nor- mally in mesh with the driving pinion and the large gear. But when the release rod is push- 64 hd YHLAROAIST QDUITMIAT TO MATEY MURAXOM FHT Fentetatsm gntatew eft to easefet edT edt dtiw ylavoscatfamte hetostts et Lacate efit .fangte oroter eastrreo edt to satdongg sotoefer eft estarsqo yet aroter esaetrrsas vie as tenray omee oft at metsaedoenm antdonnsg eeticrte yet edd ,gotttibe at tod ,yext tsdte Bf .att to ,&@ ,axmetrs [fed (fame s to Bae edt davord? .easd edt to bre tdsatr edt te ,{8s) -fasg yeu edt ,x¥asio [fed atdt to yonsss edt & davord? ,50r seselfer edt Beffso .hor 8s e9 easefer ofl .ttel edt Brawot oonmateth Cfeme eH ,mxs ms ot Mol sit ts betoennoo ef bor mrs etd? .wotatq refht edt aetrrso dotdw eit getrrso ted? byte edt no Bbetetmeo et moltisog # dove dit tqext ef bas ,1sen eatal -tom gt sotatq tefbt edt tadd .T ,aattqs « yd ont Bue mointg gaivith edd dittw deem at yifam ~feog eat bor easolor odt sedw tnd .rseg earal 65 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ed to the left, it carries the idler lever and pinion with it. The idler is thereby thrown out of mesh with the feed roller pin- ion. This condition is illustrated in Fig. 14(¢). The large is now free, and runs back- ward, under the action of the spring, U, un- til it reaches its original position; i.e., it turns back approximately one revolution. This movement of the large gear turns the interfernce pin out from under the contact lever and allows that lever to drop back onto the cam; the lamp contact is broken, and the warning therefore ceases. The backward movement of the large gear is stopped by the interference pin striking the end of the contact lever. Such a condition of the parts is shorm in Fig. 14(a). In order that the carriage return key need not be held down until the 3 YHIAMDE INT DAITHINI TO METeYe MUAAHOM FHT revel terfht eft setarao tt ,stel eft of be ydetont at refit efTl .ct ditw motatq Sas -ata teffor Boet oft ditw deem to tro mwrorit alt ot Batartaus({[t at mottihmoo etd? .mot -tosd ents bre ,estt worn at ental ofT .{o)dir -or .U ,gairqe edt to mottoa edd tebas ,b1av e-O-L ;nottisog [artatro sti eedoser tk Itt aottrfover exo yLletemtxorgqqs wosd exret tr egtsl edt to tnomovom altAT tebas mort tuo miq eorretretet edt amrst tases ot tevel tact awolla bra revel teatmos odd et tostmoo qmef eft ymso edt otmo doad qorh 8928800 StTotereds satntsw edt dae .-fetord bt teen ontal edt to tnemevom brewioad eT edt uaxtticta otq somerstretat edt rd beqyota motstinos s dove .reref tostmoo edt to Bae w(@)dr eutt mt mvode at etre; edt to eusierse eft tadt tebro al eit {tins mwob bled ed ton beer vex amretet THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY indication mechanism has assumed the start- ing position, a pawl, P, has been provided, This pawl drops into a notch, N, cut in the release lever, when the lever is in the re- lease or full-left position. The release le- ver is threrfore held in the extreme left position, after it has once assumed that po- sition, by the pawl. The carriage return key need, therefore, not be held down in order that the release lever maintain its position. The pewl is thrown out of the notch, and the lever freed, by a stud or trip pin on the lower face of the large gear. This stud is so placed that just as the lerge gear reach- es its starting position, the stud strikes the pawl and trips it out of the notch. The release rod then returns to its normal posi- tion. We have now completed the 66 30 YHIAAOLLIGT QUITUIAL FO MATeYe MUAAHOM HHT -trete edt fomusss ead metasdoom motisotiat Seblvorg aoed esd .f ,f[waq 8s ,sotttaogd ant est at tzo .% ,dotom a otat ecoth [weq etdt ~ay edt af et revel sdi modw ,revel ossolet -9f sesefer edT .motttecq ttel-f[int to sasel tel emetixs edd at Sled erotretdd ef tev -og tad? Bemyese somo cad tt retts ,aottteog yet muster ensitras efT .Iweq edt yd ,nottte tefro at amwob Sfer ed ton ,srotetred? ,boom emottiaoqg ett atetntem tevel sesofor edt tant edt Bas ,dotor odd to tuo mwordd at Iweq od? edit mo mtg git? ro fute e yd ,boert revel eb bota etd? .tsee egtel ent to esst rewol -foser tees satel edt es tent vedd fesriq oa eexiuve bute ett ,moktteoq sattrate ett Bo ed? .doton sft to tgo tL aqixt base fweq oxi? -teog famitor ett ot emintsy mott bow oseefer Mot? edt betefqmos wor svat oe” 67 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY description of the Morkrum perforator, and will next take up a discussion of the dis- tribution system, the general theory of which was developed in the Introduction. Vs YUTALPEITT OUITMIAL FO METeYe MUSAROM AAT baa ,totetotreg morvro! edd to sottqitceeb ~efh.edit to anoteenoerth s qu eat tren [iiw doldw to yroedd L[etoenmer oft ,meteaye nottudizt exolioubortal edt at beqefeveh eaw 68 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Part III- The Distribution System. GENERAL. The distribution system of the Morkrum System of Printing Telegraphy is the same as that of the last introductory system, viz., that of Fig. 6. There are a number of auxiliary devices add- ed to assist in operation, but the general plan and theory are identical with the plan and theory of Fig. 6. For communication in both directions, the apparatus of Fig. 6 must be in duplicate at the two stations; that is, each station must have both transmitting and receiving equipment. It has been found advan- tageous, therefore, to mount the transmitting and receiving disks of one station, together with their auxiliary equipment, on one base; the complete set of apparatus is called the é@istributor. By this means, compact construc- tion is obtained, and both receiving and trans- mitting brush arms may be driven by a single 638 YEIAHPALST OWITHIAL TO MeTeYe MUASHOM BHT smeteye noltudixtetd ed? -III tral sottudixntels edT .TASHMED eottats? to matey? mrdroM edd to meteye tasl edd to ted? ee emse oft ef yigargefeT .9 .2tl to tad? ,..atv .meteye yrotonhoriat -bbe eestveb yietlixse to tedmux @ era stedT fetonen oft tud ,notieteqo at teteee ot be mefg edt dtiw [sottmeht ete yroedd bas nelq oft gotteotasamoo trol .d .gtt to yroodt Sas gesm 39 .zit to extatsqqs eft ,anoltoerth dtod eet teadd senottsate owt edt ta etasotiqnh at ed Bue untttioenert dtod evad tenm motista doae -sevbs Savot need sad tl .tmemqiops antvieset gaittiinenert eft tnvom ot ,eroteted? ,asoenst rettexzot ,soltiate emo to avtath umtvteoer haa ;oasd emo no ,tmomalope yratiixses tledt diiw est hefiIso ef antereqgs to tes etelqnoo eft -ovitesco tosqmoo ,emsaem efdt yt .rotedixtatd -erert Bae univisoet dtod Sne ,hentstdo et mott efaste s yd mevith od yer eorre deord satition THE MORKRUM SYSTEM OF PRINTING TELEGRAPEY electric motor. In the following description of the distributor, the general action of the apparatus will be explained with the aid of rough sketches; the accompanying photographs of the actual machine show the details of construction. The general order of treatment will follow the path of a current pulse through the machine. The general layout of the dis- tributor is presented in Fig. 15, which is a top or plan veiw of the apparatus. The figure shows the positions of the various parts, but is schematic as far as their construction is concerned. THE MOTOR. The motor, which drives both brush arms and the tape feed mech- anism, is a 1/10 H.P., 1800 R.P.M., 110 volt, D.C., series machine, manufactured by the Gen- 69 ea YHTAAOST IAT DULTMIAT TO METeYe MUSAAOM FHT .rotom ofrtoele mottqttoash snlbwoffot ext alt edt to mottos [srores sft ,rotudivters eit to to Bts odt Attw hentel[qxe ed Iflw evtersecs adqataotodg aniynsqmosos edt yseiotete dayot to eftstei efit wode enttosm {aftoa ont To tromtaerd to tobro L[atetes efT .notvourtenoce siaguvorsit eafog taorrso a to dtaq est wolflot [fiw -enidoan eft -eth eft to tuoyesl [srenen odT gs et ito betw .OL .giT at betneeerqg ef rotudiat exsett efi? .entsrecaes oft to wlev malg ro got tad vetreg esotrav oft to exoltteog edt ewode elt nottorrtenoo ttedt es rst ee ottamoroe et . besrranso9 dotdw ,rotod efT .HOTOM HHT -foem fost eqet edt bre emrs deord tod sevirh effov OIL , M208 008L, .T.H OL\£ Bs et “metas -sef ect yd berutostunam ,extitoam celtod ,.0.0 70 THE MORERUM SYSTEM OF PRINTING TELEGRAPHY eral Electric Company. The speed regulating device, shown at the left of the motor, is applied, since it is essential that the machine run at constant speed. As is indicated, the de- vice is merely a fly-ball governor, driven by the motor, and arranged to open a contact when the spead becomes excessive. The con- tact is placed between the motor and the source of current supply; across the contact is shunt- ed a 1000-ohm resistance. If the motor speeds up, the governor opens the contact, and there- by places the 1000-ohm resistance between the motor and line. The motor therefore slows down until the contact closes again, snd shunts the resistance, By means of this governor, large changes may be made in the load or ap- plied voltage without any great effect on the spped of the motor. In Fig. 16 is given a detailed oT YHIAROEIET DLITWIAG TO METeYe NUSIHOM FHT eUnsqaod olrtoelt [ere ,eolvel natiefinseer beogs edAT botiqqs at ,tovom edt to tief oft ta mwore sox ontdosm oft tedt fatincase et ti eonte -95 eft ,feotsotint et eA .ioedqe tuatenco ta mevirh ,iostevog I[f[sd-yft eae Ylerem et esty tostncs 8 aeqo ot bentesta Bae ,totom sft yd ~09 edT .esviteesexes semooed kseqea. edt norlw eerroe edd bas rotom edt meewted Beseltq at toat -toode ef teatmoo eft evorcos 3ylqque terry to ebeeqa totom eft tI .eonsteteet mio-000L & be -erTeit bas ,tostmoo edt anego tomrevog edt .ax edd seewied eometates t mico-000f edt eooaltaq yd ewola exrotereds szotom odT .enif Bae sotom etenda foe ,otssae eeseofs teatnos eft Lhitanw mob ,tomtevern efit to exsem Yl .eomateteor ont -q@ tO Beol oft mt sham ed yam cosnado esrel eit mo toette teeta yee tyodtiw enstfLory Setic etotom edt to beqge Beltetedh s sevis et 3f .2tT mI THE MORKRUM SYSTEM OF PRINTING TELEBRAPHY veiw of the governor. The mechanism is sup- ported in a steel "0" frame. This frame is attached to the motor by bolts, as shown. The operation of the governor is apparent from Fig. 16. THE TAPE CONTACTS. The tape contact mechanism is located at the lower right-hend corner of the machine. This mech- anism performs the same function as it did in the introductory system of Fig. 6; that is, it controls the relay pole changers,being it- self controlled by the paper tape. The tape contact pins are five in number, and are held in a vertical plane, as shown in Fig. 17. Hach pin is held ina pin-holder, which is a small,round, brass disk. The pin runs through the disk edgeways, and is fuxed to the disk by a set screw. A bearing hole is bored through the disk from 71 iv YHTARSELET DUITULAT TO MATeYe MURAIOM ART -qvea ef metosdoem ef? .1omrevog edd to whov et emext efdT ,omext "O" Leete se ot betrog sawode e& ,etlod yd rotom efit of bertostis tnersags et ronrevo”_ eft to gcottersre sil OL sgtt mort eqast efT, .cTOATHOO EZAT THT tewol edt te betsoof ef metnerioom tostmoo ~-fioom efdT .sntdosm oft to renreo hited=tiatt mt Bb tk es molttonst emse sot aemrotreq metas et tedd 73 .gfT too meteye yrofesbortat ott -tf golted,erosmedo efog yeafer edt efortcos tt eoqat teqeq eft yd bhelfortroo tlee erft ere ento toninoo ecat of? eeralq L[eottixevy 8 mt Bled ets. bor ,tedmen rt gmt Led et otq dos® .“f watt nt awode as -eeatd ,boevor,[isme s et doldw )tebfodt-atq -6yavenhe selkh oft Aywordd anor mtg edT .ofeatd &£ .weroe’ tee a yd fetb eft ot hexvt et bre mort Heth est davordd bexod et eLod antrecd THE MORERUM SYSTEM OF PRINTING TELEGRAPHY face to face, but considerably off center. All five of the pin holders are mounted on @ vertical stud rising from the base. The tape-ends of the pins rest against a metal plate called the tape shield. The opposite ends of the pins are fitted with contact points, which are alligned with contact screws. The serews are supported by an insulating bracket, which, in turn, is supported from the base. This bracket insulates the pins from the base and from each other, For ease and compactness of construction, the contact pins are alternately long and short; the con- tact screws are correspondingly staggered. By this construction, more room for lock nuts on the screws is provided than would be if the screws were all mounted in a single ver- tical row. The contacts between the pins and screws are normally held closed by the springs, 72 st YHITARVELIET OUITAYIAI TO METeYe MUSIAOM ART etetmoo tto yidsrehteroce tud.,eomt ot sost no hetavom era eteobfod mty edt to evtt ILA eft .casd eft mort anteta bute Lfaettrey s fatem 2 tentess teet axtq edt to 2ebne-eqst etteoqqo eft .bfeltdte eqat edt hellse staid tostnros dtiv hbediit ere extq edt to ehse .eworoe tostaoo dtiv homelifa eta doitdw ,etntog guitelverct na yd bettoggrva ets avertoa oat mort hetroqqve ef ,arst at ,dotiw.,textoard amiq edd eetelsant texoetd etdl .eead edt sess Tot ,~tedto dese mort Sas sesd eit mort tostaos edt ,sottouytenos to seentoaqmoe bas “08 ott :ttode bas gnol yfetsaret{[s ere entq Seotegsets ywlantiaogesrros ere aweroe tost sda Zool tot moor siom ,woltesrtemos etdy ¢& tL od Sieow cedt bobitvotq et everoe edt mo -itev efgnte 6s at betmvom [fe etew ewetoe odd Saxe entq eit neowted etoastaoo odT .wot Leolt -egaiuge odd yd Asaclo SLod yffsemrom sts ewetoe THE MORKRUM SYSTEM OF PRINTING TELEGRAPEY S, as indicsted, In the operation of the tape- contact mechanism, the tape runs between the ends of the pins and the tape shield, so that the pins are lifted away from the shield a small amount. This displacement of the pins, though very small, is multiplied by the lever action of the pins and pin-holders to such an extent that it is sufficient to open the cen- tacts. When the perforations in the tape oc- cur. the ends of the pins, under the action of the springs, S, drop through the holes and close their respective contacts. THE TAPE PEED. The tape-feed mechanism is also apparent from Fig. 17. The feed-wheel consists of a brass disk, fitted with short, steel, wire teeth; the disk is fixed to the lower end of a vertical shaft called the feed shaft. The wheel and shaft 73 éYv YHTAHOS INT OAITUIAT TO MATeYe MUHAAOM FHT ehbeteothat ca ,f -eqet edt to sokteteqo edt at edt meewted enut eqat eft ,metnedoom voatnoo tadt oa ,Bfetde east oft base entq ott To abso & bletta odd mort yews Hbettil ere antq edt ~ematg edt to treemenosiqeltbh eidT .davome [fame tevel edt yd hbetiqtifom ef ,[feme yiev davodt me ose ot etebfod-nrtq Bae entq oft to nottor -xoo ent meco of tnetotttre et ti tadt tretxe -90 eqed edt at emotdsrotreq edd med? .atost aofies edd tobag vache edfy to ebme sdt .1r0 Sas esfod efit asvordt qord .2 ,agninqe ont to eBtostnoo evitoeqeser treit seols beet-eqst eff .CEEY STAT FHT edt VE entt wort trersqys oefe ef metnadoom Hhestlt ,Heth aserd eg to etetenmos L[eedw-boeet et vetbh edt jdteet extw ,feete , trode dttw ttere [settrey 8 te bue tewol ett ot Sexit tIiade bas feerw of? .ttade Soot edt helleo — THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY are located on the opposite side of the tape shield from the contact pins and tape, but the edge of the wheel projects a slight dis- tance through a slot in the shield, and is thereby enabled to engage the holes of the tape. The upper end of the verti- eal shaft carries a worm wheel which engages @ worm on a horizontal transmission shaft from the motor. The worm drive, as shown, is enclosed in a gear-box. The gear-box cast- ing extends downward to form a casing or col- lar bearing for the vertical feed shaft; it extends to either side to form a sleeve about the transmission shaft. By this arrangement, the vertical shaft and feed-wheel are sus- pended from the transmissi6n shaft. The low- er end of the vertical shaft is normally held against a stop at the bottom of the tape shield 74 SY YHTASDRIAT DPUITUIRI TO MITEYe MUAAAOM TAT eqat edt to site ettaogqe eft mo hetsool ots tud ,eqst Baa satq tostooo eft mort Bbleltide -etb tdsifea e etoetorq Loedw exit to sahe odt st bas .,ifetie sdt ot tole #2 dyvotst soonest edt to eefod sit egeane ot befdane yYdetedt eoqat -titev oft to Bue reqqr edAT eengane dotdw feedw mtow 2 sefitae ttede. [a0 ditede moltsetmanar? [atmosirod 8 mo mrow 8 ecwors aes ,evinb mxrow eft .rotom odd mort -faso xed-tseg efT .xod-tseg 2 ot beeoLlore ef -[oo to gatess sg crot ot Stawmvob sinetxe ant tt gdtede beet Isoldtevy edd tot gritsed tel suods eveela #2 mrot ot ebtea redtie of sbretxe etherognert2 efdt ya ,ttate oofesinanerd ent -ese ets L[eedw-heet fre ttade [eoitrev oft -wol of? .ttete cofeetmensrs eft mort bobaeq Brod yifeuron ef ttade [solttrev eit to bre t6 Sfetds eqst oft to mottod edt ts qotea 2 tentazs 75 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY by a spring, so that the feed-wheel projects through the slot in the tape shield. An attachment which aids in the threading of the tape under the tape con- tact pins is also shown in Fig. 17. This de- vice serves to pull all the contact pins a- way from the shield, and at the same time, withdraw the feed-wheel from its slot. When the parts are in this position, the tape may easily be threaded under the pins. Upon their Telease, the contact pins again rest on the tape, and the feed-wheel engages the feed holes. The attachment is operated by the movement of the lever, L, of Fig. 17. The movement of this lever, through the cam, C, pushes the lower end of the feed-shaft and the feed-wheel away from the shield. The movement of the lever, L, ar YHTAROSIET DUITUIRI TO MATeYe MUAAHOM SHT etoetotq Leedw-hbeet eft tedt of ,aacizrqe s yd ~bletse eqet edt at tele edt Aguordt ot ebts dotdw dnomiostis aA -moo eget edt tebas eget eft to gnthserdt edd “96 eatxT .TI .att ot owode oefs et enxnta toast -s emiq tostaos eis [fe [f{sq ot eavres asotr .omit emae edt ts fos ,bfetda edt mort yew med” ,tofea atl most Leecweboet oft warbditiw ys eqat edd ,cottteod sidt mt ers eatraq ont attedt moqU .ertq edd robau fSebsexrdt ed yitese edt oo test miegs emtq toextaoo odd ,seselet best edt sepeanme Leedw-Seet edt Bas ,ogst : selon Beteatege et taomdoaetia odT TL .gtt to ,< ,sevel edt to tmemevom oft yd emiso oft dasordd ,r9evel sidt to tmemevom adT dtede-heet eft to bas szewol efit eotteng ,9 -bfetdea edd mort yevs Lostiweheet odd bas I ,tevel odt to tmenevom oft THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY also raises the contact pins away from the tape shield, through the agency of another lever. By referring to Fig. 17, we see that between tape pins #3 and #4, there is a free space, due to the fact that the row of feed holes occurs in this space, A bell crank is mounted with the pin-holders between holders #3 and #4, the bearing being at the elbow of the crank. One end of the crank extends along the pins a short distance, and terminates in & vertical cross-rod. The cross-rod extends completely across the row of pins. The other end of the erank is connected to the lever, L. Thus, when the lever, L, is moved to the right, it not only withdraws the feed-wheel from the tape shield, but also lifts all the pins away from the shield. With the parts in these positions, the tape may 76 hy * YELAADEINT DHITHIAL 4O MATEY MUAASOM THT ety mort yawe entq torstooo oft aseter celfs softone to voness oft darordt ,ffetda scet tet ese ow .TL og ot antaseter yi .tevel eert s et otedt . Be bus 8) enta eqet neowted Beet to wor eft tadt fo2et efit ot ob ,cosae ‘et Maero Ifed A .eoaqga etdt at exsooo eefod eresffod soawted sexehfod-atq ent dtiw betnvom to wodfe edt te gnted art+sed ent ,34 Boe 8% gasofs ebaetxe wneto eit to bue emo .xnmetro oft ct eetaniorvet fea ,eenateth trode s antq sift ebsetxe bor-aeoro edT .Sor-saoros {serttrey a tedvo eff .anta to wor eft eecros ¢istefqmos etevel eft ot hetoommon at anero ent to bao ol eft ,f ,tevel edt medw ,endT eit awatbatiw yf[oo ton tt ,tdetr eit ot bevom coals tud ,bfetde eqat eft mort Leedw-best a¢2W .bLetde eft moxt yeve eat oft [fe etttl yam eqet eit ,encotttsoqg oeedt at etrsq edd ‘ THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY be easily threaded under the pins. When the hand lever, L, is moved back to its normal position, the pins and feed-wheel also re- turn to their original positions; they per- form this movement under the action of their return springs. The tape contact and feeding mechanism just deseribed is mounted on a brass plate, fastened to the main base; hence, the entire mechanism may be easily replaced in case repairs are to be made upon it. To facilitate such replace- ments, the worm shaft of the tape-feed is con- nected to the main shaft from the motor through the coupling, D, of Fig. 17. This coupling con- sists of two steel disks, one on each shaft. The two disks are faced together and connect- ed, near their edges, by a single pin. Such a coupling furnishes no impedance to the removal 77 TY YHIARLDEIET DUITVIAI FO METEY2 MUSAHOM FHT eisv condW .entq ent rebsaw bobsordtd yitese od Senros ett ot #wosd fevom ef .1 ,tevel Bred -et osfs fesdw-iset bae entq et ,aolttteoq -teq yest ;enoliteoq [antaito tredt od arst ttedt to ncottes eid tebas taomevom aidtd arot -cunizqe arstet amibeet Sae testsoo eqet e:iT eeetd #2 so betasom st hodtroseb tart melaadoom efit ,soned ;eaad ntem elt ot Semetest ,etely ot BéSRTGét vitesse od yam meteaoom ov tice ott soqs efem ed ot ets attsqet esse -soeiaer dota etstiitesst of -xoo at beet-eqset edt to ttade mtow edt ,elnem dasordt rotom eit mort ttade atem edt of betoor -n09 nat{quos etdT .VI weit to .f ,antiquoo odd ettade dose no ero ,eteth [eetea owt to eteate -tsonmmoo bas tettesot Boost ets etetbh owt edT e dou® satq ofgate 8 yd ,eonbe tiedt ween . fs fevomer eft of comsheqmt om sedatarst gatiqsuoeos 78 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY of the mechanisn. THE TRANSMISSION SHAFT. The transmission for the tape-feed mechanism is shown in Fig. 18. As indicated, the trans- mission shaft is supported in four bearings, B; one is on @ bracket near the motor, the second by the coupling, and the last two on either side of the worm drive of the feed- wheel. These latter two bearings are a part of the bracket whieh supports the tape shield. The general plan of transmission is this; the motor, through a gear train, drives the gear, G; this gear, throughsa clutch, drives the transmission shaft, which, in turn, drives the feed-wheel. None of the transmission parts need further comment with the exception of the elutch. The cluteh forms a part of an automatic stop system which will now be dis- cussed, et YHIARDAIAT DUITUIST FO METCYe MULAAOM SET eustnxasoom edt To edT ,TWAHG WOLGEIMCMART FHT et metnedoem best-ecst exit tot soteetmanstt -enart edt ,betsothat aA .8f .2fF mt. mwode egaiztsed tot at Setroqquva ef ttade ootseta eft ,totom edt teem texeerd a co et emo 3d mo owt teal ost foe ,ant{[quoo eft yd booses ~beet edt to evixh mrow edt to ebte reditts tteq 8 ete egaitsed owt tettel ceed! .l[sedw ~Efetda eqet edt ettogque doldw tevoard edt to eat saidd ef molsetmecart to melq [stones ont .tTees eft eevind ,atart reeg 8 davordt ,rotom eft eovixh ,dotufo a dacort .rseg atdt 32 sevith ,sxret at ,fotdw ,tteda soteetmenstt etteq moleeltmenart eft to enol .feodw-beet ont to mottgeoxe oft dtiw tnemmoo tedttot hoex as to treq s srirot cotufo efT .dotuto edt ~etS ed won [ftw fotdw meotsye cote olttamotve beeen 719 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY THE AUTOMATIC STOP. It has been found necessary to apply an automatic stop or control device to the tape-feed mech- anism. When this device is omitted, diffi- culties arise when the perforator operator does not work fast enough to supply the dis- tributor with tape. The tape tears between the two machines, or else the distributor feed tears the feed holes out of the tape. It is with the idea of overcoming this dif- ficulty that the manufacturer adds the auto- matic stop. The general plan of the de- vice is this: before entering the tape feed of the distributor, the tape loops over a small lever. This lever carries a contact point at its opposite end; a second point is fixed to the base. The opening and elosing of the contact controls a magnet called the er YETALPRIZT QUITUIAT TO METCYe MUAZHOM FHT esd tI .TOTE DITAMOTUA FHT ottanotiss ie ylaqqes ot yrsesecen bavot seed -ceem Beet-eqet eft ot ectveb [ottmoo to qote “itti8S5 ,hettimo et stiveh eidt med¥ ,metas stotexoqgo totstoiieg edt menw eeira estiiue eet edt viqgxe ot deuore test xrow tom seob meewted etest ocst off .oqet dtiw rotudiat sotodtatetb eft oale to ,sentdoam owt edt eoget eit te tro sefod hest odd ereet Best -ti5 efdt gaimoorevo to sebt odd dtiw et tI -otua oft efbea srotutortgonsm oft ted¢d ytivelt yots oitamn -e8 edt to mefq L[stemeg oT Beet eqet oft antretme eroted setnit? ak ootr ® teve eqook eget et ,rotedixtels ent to torgtaoo 8 eeixres revel elf? .tevel Linme tatog Broose eo ;hre etteoqqo ett te taktog anteolo bae prineqo efit .eead odt ot hextt et ent belf2eo towrpgem s afortnoo toadnoo ent to THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY cut-out magnet, which, in turn, controls the feed clutch in the transmission shaft. Ordin- earily, the tape between the perforator and distributor hangs loosely and exerts no pull on the lever; but if the tape tightens up, as it will when the perforator is working Slower than the distributor, it pulls on the lever and opens the contact. The solenoid is de-energized and opens the clutch. The tape feed is thereby stopped before the tape is torn. When the tape again becomes loose, the lever is released, the contact closes, the clutch solenoid is energized, and the clutch re-engages, so that the tape feed pro- eeeds as before. The automatic stop as actually applied to the mohine is shown in Fig. 18(a) and (b). The gear, G, is made in one piece 08 YHILADTIAT PHITHIAT FO MUTeYe MUEAAOM ANT edt afortmoo ,srst at ,dotdw ,texgem tuo-tno -otfitO .ttede noteatmenert edt at dotulo Seet bas totatrotssa edt seewted sqet oft .yfita {f{vug om etrexe bas yleeool egasd totsdirterh a9 enstidatt eqed edt tit ted ;tevel ed? no jn bttow at sotearotreq oft medw [ftw tt as edd vo affegq tt ,rotudiatatb ent ast tewoles bltonefoe eit .toestmoo od? emeqo bane tevel eT .dotufo odt esoqo bas besitgreme-e5 ef eqst edt eroted Beqqota yderodt et hoet sqet ,secol semooed ateza oqad esd med¥ .aerot et eesaofo tortinoon edt ,foeeeler et revel ext eit bas ,bestureme ef Htomefoe dotsio edt -orq fHoet eqet ext tadd oe ,esyszme-et Sotuto -etotsd es abooe vyiisutes es gote ottemotse oT {@)8f wat mt ewode at entdoam et ot betiqas ecoety ono at obem et ,2 ,ts0m eT .{d) Sas 81 THE MORKRUM SYSTEM OF PRINTING TRLEGRAPHY with the sleeve, S', and the disk, A; the sleeve makes a bearing fit with the trans- mission shaft. The disk, A, constitutes a part of the clutch. When the elutch is en- gaged, the gear, G, and the shaft turn in unison; when the clutch is disengaged, the gear, G, the sleeve, 3, and the disk, A, turn idly upon the shaft, whereas the shaft remains stationary. The detailed construction of the cluteh is shown in Fig. 18(a) and (b). On the transmission shaft is mounted the car- rier, B, which carries the elutech dog, D. A spring, S, holds the dog against the edge of the disk, A. In the edge of A is a small notch, N, and at the end of the dog is a tooth which engages the notch. It will be seen, therefore, that as long as the dog, D, bears against the edge of the disk, A, the £8 YHIAAOTIFT PUITMIAT TO METeYe MUASAOM FHT eft 5A ,dwetb oft bae .'2 ,eveele oft stiw -enert eit dtivw tit untreed 8 sexam sveele ea eetutitenoo .A ,WetS ocT .dtsde coteein -se et dotulo edt sei .dotsfo edd To traq ai ocd ttede ett Boe ,0 ,teen edt , Seven etd ,bexsnmeeth et dotulo edt sedw ;moeinns eA ,wakh ed Boe .© ,evecete oft .o ,Ts8eR dterte edt exetordw .ttede edd? noqs YLhE oxi eTrenctiste entanet nottemrtenos beftsteb eit .(d) Besa (s)@L .gtt at mronte st dotefo eft te -teo edd Botmpom si Sieade moteriwanerd odd m0 -C ,305 dotrfo eft celrrao dotdw ,f&@ ,tett ezfe eft tentege gob efit ebfod ,& ,anitqe A Ifeme s et A to esbe ont nl .A , Heth edt To gs ef gob oft To Bro oft ts Sar ,f ,dotox ed [ftw tI .doton edt senzegne dotdw dtoot .¢ ,yob eft es gror es tedt ,stotered? .cees edy ,4 ,xeth oft to exis oft tentens ereed THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Gluteh is engaged. The clutch is disengaged when the dog, D, is held away from the disk, A. The tripping mechanism for disengaging the clutch is also shown in Figs. 18. On the base, and near the ecluteh, is lo- cated the cluteh solenoid, M. The solenoid has an armature, pivoted at the lower end, which carries a stop pin, P. Ordinarily, the solenoid is energized, and therefore holds its armature away from the clutch. However, when the control contact is opened by the tightening of the tape, the solenoid is de- energized, and its armature is drawn away by a spring. This armature movement thrusts the stop pin, P, into the path of the dog, D, so that the dog strikes the pin. The dog is trip- ped out of the noteh, and the clutch is dis- engaged. 82 Ce are &8 YHIZAROAIAT DUITHIAL GO METeYe MUAAAHOM FHT hegaegnesth vi dot#io efT .begegme et dotslo -x8ib edt. mort yewa blod at .C ,gob ext aedw oA tot matnedoem gatqgqixt ed? .eglt mi mwode ovfs ef dotolo est amtaagmeerh -of ef ,detufo oft tsen Soe ,eesd edt a9 1.2L bromefow eiT .M .htomefoe dotulo sit hSetes ~Sre tevof edd ta hetovtq ,etutamre oe eed edt ,yfitestixo .f ,ata gqote s esitras dotriw ebLod erotetredd Boe ,besturene et htoneloa ~tovewoR .dotyfo seat mort yews etstemrs ett ed? wd Bexego at testnroo Lortaoo edt now ~e65 ef hbtomeloe edt ,eaqeat edt to antretiagtt vd yYsve aweth st cxuvteamre ett foe ,bestgrene ad? ateurdt? toomevom sritemrs eld? .actege s oe ,f .g08 edt to dteg odtiotat ~i ,atq qote -qixd at gobi ed? .mitq odd eoxdltnta gob oft tedt -@tb at detufe edt Bae ,dotonm edt to tro beg edegsygre THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Means are provided for the holéing of the dog, D, away from the disk, A, On the transmitting shaft, and beside the carrier, B, is mounted a disk, C. This disk conteins a wide shallow V-notch in its edge. A lever, T, is pivoted at one end to the base plate of the machine; the upper end bears against the cam, C, under the action of a spring. The end of the lever is so shaped as to fit in the notch of the disk, C. In the operation of the device, the shaft and the disk, C, ordinarily revolve so fast that the lever has not time to drop into the noteh of the aH otro wa ow the notch is so shallow that should the lever drop into it, the lever could not hold the disk against the driving force of the shaft, but would be raised out of the noteh as the disk turned. When the stop pin, P, trips out the dog, D, 83 && YHTASSEIAT DLITULAT TO Maeve MUAAHOM FHT edt tot bBebtvorq ere enssli .deth odd mott yews ,f , 305 edt. to antifod edt obteaed Bae ,ttede gatttimensrd edt oO .A Weth ati? .0 .dets a Botavom at .f&@ ,tetrtss onde ati mt dotom-V wolfsde eitw a antsiaoos eft ot Bre emo ts fetoviq st ,f ,tevef A atsed bre tegqs edt ;entdosem edt to etalq saad & to gottes edd rebar .9 .mso odd tentsass as Seqeda oe et revel off to Bae ell .gattge o) ,M8kb edt to dotom edt ab tit ot ,eotved edt to mottareqo edt mI evfovet viitentito ,o ,derh edd dias ttede ont qortS of omtt tom sad toevel edt tadd test oe dotorm atbipoute. viet eit to deton edt otat ovat goth tevel edt Sfrode ted? woffsde oa st tantens Meth edt Hlod tom bLyoo revel edt tt ed bf{vsow tad ,ttsde edt to eotot zatvirh edt -Senmtut dats oft ae doton oft to tro bestar «f ,205 odd tuo ected .f .ata qote eft med® THE MORERUM SYSTEM OF PRINTING TELEGRAPHY the momentum of the carrier causes the parts to assume to position of Fig. 18(b). The dog, D, is now well clear of the disk, but the spring on D tends to rotate the carrier back- ward until the dog drags on the disk, 4A. How- ever, the notch on the disk, C, is cut so that just as the parts come to rest in the position of Fig. 18(b), the notch in C stops under the end of the lever, T. The end of the lever drops into the notch and locks the parts in position. Hence, the dog, D, is kept elear of the disk, A. When the dog, D, is released by the stop pin, P, it drops onto the revolv- ing disk, 4, As the notch in A passes under the dog, the dog drops into the notch, and the clutch is thereby re-engaged. The notch in the cam, C, is shallow, so that the lever easily rises out of the notch and rides on 84 $8 YETAFDAIAT DAITUICL TO METEYA MUMIAOM ANT atrsq edt aeasso tettrse ad? to mutaemom edt e905 edt .(d)8£ .3kF to wotttaog of emuass of eit tod ,weth edt to rasfo [Lew wom et ,T -Noad toltrso edt stator ot einet C mo anttaqe -woH .A ,Hath oft ao -egsth gob edd [tins diaz oa to et .0 ,dath eft ao doton sdt .tevs edi at taot ot emoo atraeq sdt sa tent stadt aqote 0 at doton edd ,(d)Sl waft to mottheoq to hoe eAT .T .tevel oft to ine edt robar edt evool bas dotonm edt otmi egorh tavel ot tqovt ef .f ,g0b odd ,eoneH .mottieocg alt etrag eA ,death edt to reefs beassfer sk .f .g0h oct moni -vyfovet edt otmo egorTh tr ,t .atq gots edt yd teboay eoareg A mt dotom aft eA .A ,detbh ant bas ,dotor eit otmt sqorh gob edt .R0b edt Sotonm ef? .begeuas-er ydetodd at dota ont tevel edd tadd of ,wofiade ef .o ,meo edt mt mo aebit Bree fotom eft to dro seeit yitero THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the edge of the disk, thereby leaving the entire clutch free to rotate. THE CUT-OUT. A so-called cut- out mechanism is also shown in Figs. 18. The purpose of the device is to operate a relay, which operation eauses both front and back contacts of the pole changer relays (identi- cal with the pole changer relays of Fig. 6) to be connected to the positive side of the battery. Hence, when the device operates, on- ly positive line impulses are sent out; this condition is the same as when the "rub out" signal is given, which signal consists of all positive intervals, and it will be remember- ed that the printer does not respond to such signals. When the tape feed stops for any cause, the cut-out device operates, so that the printer is kept inoperetive. If it were not for this device, the printer would print 85 &8 “YHIARVAIET DUITHIAL FO METEYS MUSAOM FET odd astvsel ydeteds ,deth edt to eahe aft -otator ot sett dotsfo ertine -txo Belfse-o8 A .TUO-TUD SHT ef? .8f .astt of mwode osfs et matnedoem tno «Yetfeot 2 staraqo ot Sf sotveb oft to ssoquisg fosd ban trort dtod gessss mottsatreqo notsdiw ~-tianebt) evyaler teareds efog edt to etoztnos (@ .a@f% to ayafer reansio sfoq eft dtiw fa0 edt to sife evittacq ot of betoaenmoo od of -1o ,getareqo estvoeh edt montw ,eonel .tretted efit ;tvo imee ate eeeluamt ontf evitteog yi "tno duit" edt nxedw es emee edd at nwottrbnoo {fa to atetanos [saute dotdw .mevts at I[sogte -tedmomet of (fiw tt ins ,efasvretat evitteog dose ot Burogest tom aeod tetatrq odd tadt be wre sot eqote best eqat adt mo! .afscate tedt oe ,asotereqo estveb tyo-tro edt ,oarao stew ti TI .svitatrecomt tqet ef treatatrq ect tatrq Bluow tetaita edt ,eotveb etdt tot tor THE MORKRUM SYSTEM OF PRINTING TRIEGRAPHY over and over again whatever character hap- pened to be in the tape contact mechanism when the tape feed stopped. The details of this device are also shown in Figs. 18. On the feed shaft is mounted a disk, K, containing a wide noteh, as shown; against the disk bears the lever, H, pivoted at its lower end, and held against the disk by a spring as shown. The lever, H, carries the movable point of the contact, J. When the lever bears against the edge of the disk, the contact is held o- pen, but if the lever drops into the notch, the contact is closed. The details of the cut-out relay and of the eleetrical connec- tions will be given later. The cam, K, is so placed on the feed shaft that when the shaft stops and is held by the disk ¢ and its lev- er, the notch in K will lie under the end of 38 YETAMPRIGT QUITMIRI TO MaTeye MUATAOM eHT -yed tetostado tovetadw mts2s tevo Sms trevo metnadoem baatnds eqst edt at ed ot boneq .Seoqqgote bost eqst edt nedw eotveb etdt to aftsteb sdT feet oft m0 .8f .egtt mt ovoda osfe ots 8 stintstcoo ,X ,zeth s betavom st sede atsed dweth edt tentsse gowode ea ,doton oblr bas ,5ne tewol stt te betovitq .—E ,tevel edt mode as anitge »e yd watd edt tentens Sled to tatog efdsvom ad} as fitz a ,toevel oAT tautisas ataed revel edt aed? .% .toednos edt -o Bled at testmoo odt ,ateth ent to oahe ot eHoton edt otmt sqorb revel edt tL tud ,m9q edd to altstoh edT .Beeofo at tostmnoo edt -eoennos L[rotrtesfe oft to bas vseler tgo-tuo of at ,X .mso oct ,tetel aevia ed [Itw agott tHrede edt modw tedt tede fest edt mo Senate -vef att Bue Y Xeath edt yd bled ef bue sqots to Bas edt tebay eff Cltw I at dotom ot ,t0 87 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the lever, H; hence, during this time of stop, the printer will remain inoperative. When the feed shaft is revolving at its usual speed, the lever, H, does not have time tordrop in- to the notch. THE TRANSMITTING DISK, Next in the order of treatment comes the trans- mitting disk and brush arm. The disk is lo- eated behind the tape-feed mechanism, as is indicated in the general plan of Fig. 15. The driving of the brush arm by the motor is accomplished through the gear train and main shaft, as shown in Fig. 15, the main shaft carrying the brush arm. The main shaft is supported at its ends in bear- ings, B, one being on a bracket near the mot- or, and the other being on the bracket which supports the transmitting disk. The shaft passes through a large hole in the middle of v8 YETAROSIET DUTTMIAT GO MATEYe MUAXHOM THT eqots to omtt atdt gatib ,eomed 3H ,revel scdt eit mofW ,evitsteqont atamex ({[lw totatrtq edt e5esqa L[asey ett ts anxtviover at tiede best -xt goth ot omtt evad ton es0b ,H ,tevel edt eAoton edt of txoH .AeId DALTTINGWART SET -eastt edt aemoo tnaomtsett to tebro ent at -of ef dalb eAT .oms dasrd bos Meth antitio es ,mstnedosem best-sqat edt Batded hotso -Of .ytt to mafq [stones ad? mi SJetsothat et ors deutd edt to axivizrh of? xsen edt dasotd? bedatfaqmooos et sotom edt yd .OL.egt? of mwodea gs.,ttede atem bas atari efiT.,mrs desrd edd gatytiso ttede otem edt -reed at shae att ts betroqgve at ttsde atsm -tom edt taex toxostd s ao gated emo .f ,egat dotdw tetost¢d ed? mo sated todto edt bas ,to ttade ofT .xath gatttimanert edt etroqqye to .efbhtm edt mt efod ental a davordt eosesq 88 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the disk to the bearing at the back side of the disk. The bearing support is shown in Fig. 19. The transmitting disk is of fiber, about two and one-half inches in dia- meter, and is supported from the base by a bracket (see Fig. 19). The disk carries eight brass contact buttons, set flush with the face of the disk. Connection is made to the buttons through leads at the back. The functions of the eight buttons are indicated in Fig. 15. There are the five code buttons, 1, 2, 3, 4, and 5, a lamp button, L, and the two synchronizing buttons, the first positive: and the second negative. The functions of the eode buttons have already been explained. The lamp but- ton is used in the operation of a signal lamp, by which the receiving station signals the 88 YHIATOAIET DUITAIRI TO MATeYS MUMAHOM AAT to ebts dtosd oft ts aoirsed eft of Meth ont at mwode et trogqse antrsed efT .xeth oft oCI alt to et detbh antttinscert sdT ~at5 mt settont tisd-enro bre owt tueods ,tedit se yd easd edt mort betroqqua et bas ,toton tdgte seterss deth ofT «(CL watt sea) todostd odt ditw dexs(t tes ,enottud tostnoo seatd edt otf sham ef molttsenmoD .detbh edt to sost efosd edt ts ebfeasf{ davordt anotind tdgte edt to emottenst edT ems eredT .Gf weil mt betsotbat ete esotitsd ec bos .b .8 .S .f£ ,anottud eboo svit sot gatstmordonya owt odt bas ,l ,mottud qmsf 2 Baosee edt bas evitteog teritt edd ,anotind exotiud sheo ent to saottonst odT .evttsgen -tud qusf ed? .bemtelfqxs aeed ybset{[s eved .qmar fecgte s to moktsteco edt mt bees at stot edd afergte mottste goivisset sdt dotdw yd 89 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY transmitting station or vice versa. The syn- chronizing buttons are used in keeping the transmitting brush arm at’ one station and the receiving brush arm at the other station in step; the synchronizing system will be ex- plained a little later. It suffices to say here that the positive button is connected perm@nently to the positive side of the bat- tery, whereas the negative button is connect- ed permanently to the negative side of the battery. The brush arm and brush are mounted on the main sheft on an insulating bushing. The brush arm is of brass, whereas the brush is a copper strip, bent into a "U"; one end is attached to the brush, the other trailing over the disk. The brush arm also carries a felt wiper, as shown in Fig. 19, which wipes over the disk and keeps it 28 YHQAHVELGT SUITHIAS TO MNTeYe MUSAAOM FAT -mya efT .setov sotvy to motiste anttituedatrt eds antgeex at beas sta enotiod gutstnordo edt bra motiaste sxo ts ots deotrd gatitinenart gt qoftsats redvto edt ts mora dautd anctvtooor -xs od [ftw meteye eniztaordonye edt iqste yse ot eootttse tI .retel efttti s hertsiq Betoonnoe ct sottud ovittaog edt tadt ered -tad edt to eble evitteoqg edt of yitrgnemreg -toemroo elf notvtud evitsgzem edt asetsdw ,yret eid to ebte seviisagen oft ot yfitmemesrre, fe e yrotitad ets deotd bas ove destd eT antvslivedt as go Stade otam edt no betavom esetelw ,sasid to et mrs destd edt .gntdand 8 Otnt taed .qitrtea reqqoo s et destd edt edt ,desrd edt ot bedostts ef bae sro ;"U" orra dewrd of? .deth edt? revo gatitsrtd tredto ost' at awode es ,tectw tflet s eetrrsao osfs df aqesd faa Asth eft t9v0 eeqtw dotdw ,er THE MORKRUM SYSTEM OF PRINTING TLEGRAPHY free from dirt. Contect is made with the brush arm by a wire brush, consisting of a number of vertical wires. This second brush bears against the hub of the brush arm. The support of the brush in its bracket is clearly shown in Fig. 19. THE POLE CHANGER RELAYS. Con- sidering the path of a current impulse through the apparatus as our general order of treat- ment of the subject, we find that the pole changer relays come next in order. The five pole changer relays, whose function is the same as in Fig. 6, are located in a row at the upper left hand corner of the distribu- tor base (see Fig, 15). In addition to the five instruments mentioned, there is an addi- tional one, the cut-out relay, whose function is to connect both front and back contacts of 90 oe YHLAAOALITT DAITMIAI TO METeYS MUSAAOM ERT etttb mort eett fesxd edt dity sbem ai tostxol *o tsdana s to anttatenoo ,deotd etiw s yd ore textegs ersed dastd brooss sid? .aettw f[sottrov sit to txoaqqua oT .orre destd edt to dod odt -at% at owotle yitsel[o at texcostd ett at dauxd ~@f -~f00 .GYAIHA AGDMAHD LOL FHT Savord? esisqmt tasrrso.s to dteq oft gutreita -teert to tebro I[steneg m0 as estateqqds oft afog odt tadd Batt sw ,toefdse edd to taon evit eT .rebro at trem smoo aysflet teamado edy st coftoast seoedw ,ayafor. rexgmsdio efog ts wor sa mat Beteoof ors ,d .all at asa omse -sdirteths edt to rentoo baed tel teqqs edt edt of mottthbe mI .(af .g3tl 998) easd rot -ifbfSs os ak etedt ,59n0ttnom etromertent evit mottonust ssodw ,.ysist tro-txo odt ,emo Ismott. to atostnoo adored Bae taoxrt dtod.toennoo ot at 91 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the others to the positive side of the bat- tery. The sixth pole changer relay is simi- lar in construction to the others. A detailed view of one of the pole changer relays is presented in Fig. 20. The solenoid, as mounted on the distrib- utor is vertieal; it is fitted with strap i- ron pole pieces, Py and Po, The bottom pole piece, Po, is prolonged and bent up along the front of the eoil; the pole piece extends about half way up the coil. The armature is of the same stock as the pole pieces, and is hinged to the armature as shown. The arma- ture carries the eontact lever, C, which is insulated from the armature by a sheet of fiber. A bracket is attached to the lower part of P2, runs up in front of the armature, and carries the fixed relay contacts, The armature is normally kept against the back fe YHTARDALIAT HUITHIAG FO MATeYe MUAAHOM FHT -ted edt to ebte evititeor edt ot etedito out -Imte et yalsr toansdo slog dixts eit .yret earedto edt of molttomurtenoos af taf to emo to wety hefieteb A | ai at Setasastq at aysfer tegmaio elog sat -dixttetS edt so hetnwom ae ,btomefoe eT .08 -t qatte dtitw betstit ef tt :fsottrey et tets efog mottod eT of Boe -T ,se0efq slog sot anoles qu taed bas besnolorq at .of ,esety ebmetxe esetq efog eft ;f[too ext to taort edt et aruteamrs ofdT .ftoo edt qu yaw tfed treds st bas ,eeo9tq sloq adt an woota emse edt to -anrs edT .myroie es stytamrs oft of boantd at doidw .5 ,tevrelt sostaos edd eetrieo erut to teste s yd otutemre odd mort bSetelveant - towol eft ot bedoetta af tedostd A .tedtt sistemas ext to tnott at qu east ,si to traq edt ,atostnoo yefet bextt edt astiures bas wosd edt tentesse tqed yifesrom et etstearrs 92 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY eontact by the flat steel spring, 5S. When the solenoid is ener- gized, the upper part of the armature is drawn toward the upper pole piece, Py, which movement closes the front relay contact. When the solenoid is de-energized, the arma- ture, under the action of the spring, 5S, re- turns to its original position. In Fig. 20(a) is shown the conventional symbol used for such a relay in wiring diagrams. Next in order of discussion occurs the main-line pole changer; however, we will omit this diseussion for a time, and hext consider the receiving apparatus. THE RECEIVER DISK. The receiver disk and brush arm are located behind the trans- mitter disk, as is illustreted in Fig. 15. The construction and mounting of the disk is, in ge YHIASOTIAT OPULTHIAI TO MATeYa MUAAAOM FHT oc ,amtinqe [sete talt ed? yd toataos -tece et btonsfoe edt modi et erstemra edt to trag teqgs edd ,bests dotdw .ft ,seetg sfoq r9eqgs edt biswot aweth etostmos ysfeor trort sdt sesolo Saomevom -emts edt ,fesiateme-e5 2? Stodmefea edt ced -et ,© ,aoivqe edt to actios edt tebas ,esrst ecottisoq [entatto att ot satus edd awode at (8)08 .gtT al ysfer s dowe tot fees Lodmaye I[saoitmavacs eamargsth antitw at mofsesosth to tebto at txeH etavewon ;togdedo efog enti-xatam sit azsoco has ,emit s tot motesseath ealdst timo (fiw ew -eutstaqqs axtvieset odd tebteros trem tevteoot edT .1eId AEVIZORR BHT ~enaty edt Batded Sotsool. ets mrs deord bos. aeth eqT .of .2ti ot beteattev[([t at eae ,weth retin at ,ef Heth edt to antinvom ae nottosstegos THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY general, the same as that of the transmit- ter disk. One difference in the two is that the receiver disk possesses one large but- ton at A, (see Fig. 15) instead of the two synehronizing buttons which the other pos- sesses. The other difference is in the attach- ment of the disk to the bracket. The receiv- er disk is attached to the bracket by thumb- screws if such a manner that after loosen- ing the thumb-screws, one may turn the en- tire disk through a small angle. The theory of such an adjustment was presented on page 30 ff. The disk has a scale marked on its edge, so that its angular movement can be gauged. THE TRANSMISSION SHAFT. The driving of the receiving brush arm from the moter is accomplished through 4 main shaft, carrying the brush arm, and a gear train, as 93 a J 2 YHITAADTIAT OMITUIAT TO MATeYe MULAHOM ANT -timenett odt to tedt es omee edt ,I[stenep tadt et owt edt ot someteTtt& emO death ret -tud estal emo soeasseog Heth tevtesor aft owt edd to hbretemt (8£ .atf eee) ,A te mod -8og tedto sdt dotdw anottsd entstaordonye -dostis edt mt ef eemersttih radfo exT .asaaee -vieser ed? .tetoatd oft of Heth odt to trem -dandt yd teatosrd edt ot feroatis et wets +e -nsesoof tette tad? tenasm 2 dose &t swetos -te odt mut yam somo ,oworne-dandd oct act ‘yroodft ef? .efane [fame s darordd ast ert? ezsg mo betsecerq esw tmomtentis ce dove to ett xo heitsm eL[ses ae ead wath edT .Tt OF ed sso daemevom tafvgae ett tedt oe .eade Segrag ef? .TUAHS WOLCEIMeMART MAT edt mout ora deotrd artvtesor edd To aaivits Stade afem s Asrordt fedet{qmooos st totom es ,atertt tsex3 3 Sas ,area deord edd antyirss 94 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY was the case of the transmitter. The shaft is supported on two bearings, one on a brack- et near the motor:and the other near the disk and on the disk bracket. The drive, however, from the motor to the brush arm is not direct, but is through a so-called synchronizing eluteh. This eluteh constitutes a part of the equipment for keeping the receiver brush at one end of the line in synchronism with the transmitter brush at the opposite end of ‘the line. We will now consider the synehroni- zer, of which the elutch forms a part. THE SYNCHRONIZER. The scheme of the synchronizing apparatus is as follows: The driving motors at the two ends of the line run at approximately the same speeds, but the receiver brush arm is geared to run & little faster than the transmitter arm. The funetion of the synchronizer is to retard the $e YETAHOITHT HAULTMIRT TO METeYa MUAAROM TET ttefe edT .xottinemert eft To sage edt aew -tosrtd # m0 exc ,Banttssd owt mo Bbetroqqss at wet5 edt resem rtedtc edt Bue totom edt teem to etavewod ,ovixS oft .texontd oweth edt mo Sas ~toorTlth tom at mre deoxrd eft ot rotom edt mort giisinordenye heff{se-ce s dasordt et tod to ¢trsq s setutitenos detufo eidl .dotsle dastd tevteser edt antgoeyv rot tnemyispe edt dittw matnordooye at eatf edt to bas exo ta to bre etteogqo edt tea denxrd rettimsenert edt -tuordenye edt tobtanoo wom [f[tw ef enti eat ed1tsq 4 sorot dotsLo edt dotdw to ,.tes emedoe eft .AESIMOAHOUYe SHT tewolfot as et estatecqs antaiaotdemye edd to edt to ehao owd sit ts erotom gaivisS edt -ebooege emse edt vieteamtxortqga ta aur oatl net ot betseg et mrs deaord tevteset oft tod eff .orre rettimenats edt nedd tetest eftti£ s eft hretexs ot alt rexinordenys edt to nottonnt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY receiver brush at suitable intervals, so as te keep the receiver arm sensibly in step with the other. The occurrence of the cor- rection interval is governed by the relative positions of the two arms, so that whenever the receiver brush has attained a definite small angle of advance over the transmitter brush, a correction interval takes place, so that the receiver brush is drawn back into its proper position, This retardation of the receiver brush is accomplished by the syn- ehronizing mechenism, which is controlled by the two synchronizing pulses, the first negative and the second positive, which the transmitter brush sends out between susses- sive letters. The two synchronizing buttons were mentioned in the deseription of the transmitter disk, 95 6e YHLAHDAINT DUITHIAI TO METEeYS MUSNHOM THT ee oe ,Sfavretat efLdattys tn demrd revisser gete at yidtenesa mre toviteser edt qeei ot -roo edt to sometrso90 ed? .1radto odd dtiw evitafer edd yd benrevog ef Lsvretat aolttost tovenoiw tait of ,amrs owt oft to amoltlaog etiniteh s bentsiia esd dautd tevteser edt tottimenasrt odd tevo sonsvd5s to elane [fame oa ,eostg setst [2vtetat sotteerrose 2 ,dartd otmt aoed swath st dasad tertecer ost tadt sit to motisitster atdT .motitacq reqotq att -aye edt ¢d bedetiqmooss at dewsrd tevisoer BSel{fortiace at dotdw ,metnsdoom gaistaotds tert? oft ,seetiuq antstaordomre owt edt yd edt dotdw ,evitteog broosa edt Sac evitsgen -eessaue ssowted tvo abmoe darrd vettimanrsrt anotiud antstnordemye owt edT .atettel ovte edt to mottetroceh eA? mt Serotinoem etow xetb tett tomdart THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY A schematic view of the syn- ehronizing mechanism is presented in Fig. 21. This figure illustrates only the general principal underlying the system: certain mod- ifications are necessary before it can be used in actual operation. The cam mrked cor- reeting cam in Fig. 21 is mounted on the re- eoiver brush arm shaft. A contact arm bears against the cam, under spring tension, so that every revolution of the eam, the end of the lever drops into a notch in the cam face. This movement of the lever close the contact, which is in a circuit composed of the contact itself, the corrector megnet, the marking contact of the main line relay, local battery, and ground. Suppose the transmitter sends out the negative synchronizing pulse; the main line relay closes the mrking sontact. 96 ae YEIAHPALAT OAITUIAI TO METeye MUAYAOM FHT -mys edt toe weiv oltamedse A ofS .3tt at botmosetaq et metasdoem gatstmrords fatsoreg edt yino seterteni{[t atsatt atdt -~hom atstres :mevayea edt satyf[rebas [aqtontrq ed meo ti eroted yrsacsoem sta emottsoltt -ros beslran aso efl .cotistere L[eutor at boas -et edt go Setnvom ef [S .gtl at mae gattoer exsed mre tostnoo A .tisde oa deaurd tevteo es ,foisass gatiqe tebasr .msao edt tontags bre oft ,meo edt to nolttuforst yreve tsds mso edt at doton s otmt eqoth tevel edt to edt esofo revel edt to txomevem aidT .soat te Sesoqmon tiseotto gs at ei dotdw ,tostaooe teagan totoertes edd ,tLoatt tostnoe edt eysiet eatl atam edt to toetaoo gatitam silt ebasors bas ,yretiad L[sool ehbooe tottiogaett edt esoqyse edt j;eefue antstnovstonve evitesen eft tro etostsnoo antititean edt esaofo yeter eatf atsm THE MORERUM SYSTEM OF PRINTING TELEGRAPHY Such a condition is indicated in Fig. 21. Now the notch in the face of the correcting cam is so placed with reference to the re- ceiver brush arm that if the receiver arm is ahead of the transmitter arm, the synchroni- zing pulse will occur while the cam slot is under the end of the contact lever. At this time, therefore, the cam contact is closed, and the main line relay is on its marking contact; hence the corrector magnet is ener- gized, and applies a correction. The next pulse is positive, so that the corrector mag- net is immeidately de-energized by the open- ing of the relay contact. If the correction need be but slight, the corrector magnet may be de-enersized through the opening of the eam contact. When the receiver brush is in step with the other, the cam contact does not 9” ve YEGALMECAT DUITHMIAT TO METEYE MUSDION THT ~fS .3t% wt betsothst ef motttbmee s dove anttoerros edit to sort edt ct deter ent wel -et oft ct ooneretet cttw feoslfq of ef mao el mrs tevieset edd tt tedt ove dentd tevtes -trovrdomze eit ,axs tettimeansrt edt? to heeds et tole mee edt eftdw rose IIftw selsq gnats efdt 3A .rsvel tosinon eft to base edd rebar ,beeolo ef tostnoe meo eft ,etotstait ,omti giivives efi mo et yeler omti ntam oft bas -stene ef temganm totostros aft sened ;toetnoo txes efT .mottoerzros se seilaqgs base bests -pem totesetros edt tedt of ,evitteog ef seis -feqe edt yd bestaremne-e5 yletobtommt ef ten sottoerroo ett tI .toe2tnco yalor oft to ant yam vomgem tothexrco ed? ,triutle tnd ed heen edt to antaeqo eft tayordd hestorense-eh of evoesnoo mso ef sastd tervteset edt cor tom e006 tostanos meo ond ,tente edt Atiw qete at THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY close until after the synehronizing pulse has occurred, so that no correction is ap- plied, As was previously stated, the scheme of Fig. 21 is not the one used in prac- tical operation, since it is necessary to mo- dify the control of the corrector magnet somewhat. However, before taking up these modifications, we will consider the synchron- izing elutch, by which the corrector magnet is enabled to retard the receiver brush arm, The synchronizing cluteh is shown in Fig, 22. The motor drives the re- eeiver shaft through a worm on the the motor shaft and a worm on the receiver shaft. The worm-wheel, and a gear, A, of Fig. 22, are in one piece together with the connecting Sleeve. The sleeve is bored to make a bearing fit with the shaft, but is not fixed to the 98 YHIAADS TET DUITUIRL TO METEYG MUSLIOM HHT eafogq artstaotdonye edd retts I[ittar esolo -qs ef motseertroo om tedd of ,berrsoco ead borig eft ,betate ylevotvergq asw ef -orrq mt Beas eno ext tom ef IS .att to emeifos -om ov yrseeessen et tt esata ,mottetsqo Iseltt tengam totoerios edi to L[ortmoo edd YIEh eeedt qu satvet etoted ,tevewoH .tadwermoe -sordonyea eft toftanoo [[tw ew ,enottsotttbom Fores cofpertoe eit dotdw yd ,fotwle antst ets desid sevtecer add breatet of boefdane et et dotulo antstnordonye eT -er oft sevith totom eft .SS watt at nwode totom eft edt mo arrow & duvordt ttede tevtes emt .ttade tevtesot edt mo mrow s bas ttede ere ,SS .ptt to ,A .teea © Bae , feedw-oiow gattvoonnos edt ditw sedterot esetq eno at anttsed 2 esa o¢ berod et eveela eT ,ovoele edt ot Bextt tom et tud ,¢tede edt dtiw tit 99 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY shaft. To the brush arm shaft is attched the earrier, B, which carries the pinion, P, meshing with the gear, A, and the pinion, Q, meshing with the pinion, P, A star-wheel is mounted with the pinion, Q, and a jockey rol- ler bears against it, under the action of a spring, 3S. By this arrangement, as long as the jockey roller holds the star-wheel lock- ed in position, the carrier, B, the shaft, and the driving gears, A, and C, all revolve together. If however, the star-wheel is turn- ed, the two pinions, Q and FP, are turned, and the carrier, B, rotates with respect to the gear, A, and hence with respect to the driving motor. Whether the brush arm is ad- vaneed or retarded, with respect to the moter, depends upon the direction is which the star- wheel is turned. Below the elutch is the cor- ee YHTAHDELET OUITMIAI TO MATCYe MUSAHOM FHT edt hetotte ef ttede ars desxd edt of .ti ade et -Motatg oft setrteo dotdw ,f ,relttss ef ,Molatq odt bas ,A ,xre98eg eft dviw sotdeem et {[sedw-rste A .f ,motmtq eft tiw antfeem -fot yetook 2 Baa .’ ,moiatq edt dtiw betavom 8 to moltes edt tebas ,tt taxtezs etaed ref es pool ee ,tnemegmerts etst yT .& ,anirge -~fool Leedw-rate edt ebfod rzelf[or yortoot sdt ettede edt ,¢ ,relxres ont sobtteoq ct be evfover [[s ,° Bea ,A ,atses antivir edt bas -nxrst et L[eedw-tesve ont ,tevewod YI .toedtegot efhbeatst era .I bas 2 ,enotatg owt edt , bo ot teeqees ditw eetsiow .4 ,retareas edd ine eit ot teeqeet dtiw oomed base ,A ,tesg odt -be et ore desctd oft todted¥ .totom anitwich .retom edt ot tooceet dttw ,bebrsetet to Seonsy -rete edt dotdw ef nottoerth eit soqn eimeqeb ferret et feedw -roo end ef dotwfo edt wofed THE MORKRUM SYSTEM OF PRINTING TELZGRAPHY recting magnet, to whose armature is attach- ed a small interference pin, P. The magnet is so located that when it becomes energized, it draws the interference pin into the path of the star-wheel. Therefore, if the magnet be energized while the star-wheel is revolv- ing about the central shaft, the pin trips the star-wheel through the angle of one tooth. The result of the movement of the interference pin is the retardation of the brush arm. As was just shown, the clutch loeks the receiver shaft and the driving gears, A and C, together, so that the shaft, elutch, and gears revolve in unison. If however, while they are revolving, the interfernee pin trips the star-wheel, the carrier, B, the star- wheel, and the shaft are stepped back slight- ly. Thus, when the receiver brush gets too far shead of the transmitter brush at the 100 0oL YHIAHOH TAT DEITLIAI 2O Matera MUSAAOM HHT -dosite et erutaors exodw ot ,temasre anttoer tornem eft .f ,otaq eonerotretat ([feme s be Sesitstene eemooced si mendw tadt betsect os at disq edt otat atq eomatetretmt eft eward tt vensgsm od tt ,eroteredT .[eenwerese edt to -vilovert et feedwertste edt eLiiw besinirene od eqis? mtg eit ,ttade {sttmee ext tyoda gat eivooy eno To efans odt dagpotdd feeswetate edt tremevom edt to timeer eT noltsirster sit et mtq sonerettetmt edt to dotefo edt ,mwode taut eeaw eA wore decrd edt To ,erses astvieh edt boe teste tavteses edt exool efotelo ,ttade ott test of ,tedtesot .0 bas A eftdw ,revewod tI .moetns at svfovet arses bas eqist ata senmretretat edt ,anivfover era yodt -rate eft ,2f ,refurss eft ,[sedw-tsate oft -Sdatie wosd beqqets ere Stedea edt baa ,loodw oot etog darnd revteost edd codw .andl .¢uL edit ts deord tottimenart odd to Baede ret 101 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY opposite station, a synchronizing pulse oe- curs, which eauses the corrector magnet to pick-up, and thereby apply a correction to the brush erp. The retardation of the re- ceiver arm is very slight, but the driving motors run at such nearly constant speeds, that the arms turn through several revolu- tions before correction become necessary. As was previously stated, the control of the corrector magnet is some- what different from that shown in Fig. 21. The correétor magnet does not have time to pick-up under the action of the synchroni- zing pulse. It is necessary, therefore, to prolong the influence of the pulse. Two re- lays are added to the scheme, one a quick- acting, and the other a slow-acting instru- ment. The mechanical construction of the re- fol YAUSADTTIST DUITMILI FO MET CYS MUAAAOM FHT -90 eeluq gxtsinordorye s ,nottete ettaoqgo ot gemssm totoettos ect geeveo dotdw ,etie ot moiftoerros s yiqqs yderedt bre qu-dolg -grts desrd oct -et eft to nottairatet eT gaivich est tod ,tdgtie yrev at mora revieo ,eboeqe tastenoe yireen dose ts ant erotom -plovet [stoves davordt arst ere ed? tedt eTrseepoen emosed moltoeriroe etoted anoltt foteate ylesotverq saw eh -emor ef vemgam totosiroo eft to Lortnoo ont ofS .at® wk owode tadt mort diretetttd sade ot emtt evsd tor eo0b tenmsam rotoerros eT -trotdomye eft to mottos edt tebhbav qu-detg ot ,ototetent ,yresesooen at tI .eafsa oats -eT owl .oefsgq edd to somenltat edt sano lotg -fotso s eno ,emedoer eft ot Behbs ors eval -urtest anttea-wols 2 terito oft baa ,gnttor -eT eddy to noltourtenos [sotmexoem efT .trem 102 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY lays is the same as that of the relay pole ehangers, already described. The new scheme, 28 is used in practical operation, is presented in Fig. 23. In this figure, the quick acting relay is marked "X", and the slow-acting is marked "Y", By reference to Fig. 23, we that when the correcting pulse is received, if the cam contact is closed, the current passes from the positive side of the lo¢al battery, through the printer relay and cam contacts, through the windings of X and Y in multiple, to the negative side of the battery. Relay X picks- up and eloses eontact a. The correcting mag- net is now connected across the local battery through the contacts a and b. Also, both re- lay windings are connected in multiple ecross the loeal battery. The slow-acting relay, Y, now picks-up and opens contact b; the open- Sof YATASOARIRT OQUITUIAL TO MITEYS MUAAROM FHT efog yelet eid to tedtd es omec oct ef eval eheditosed yheetlse ,eteanedo feay et se ,emedoa won oT aii aot betmeretg eat ,wottereqo L[eoltioarq at yefer antioe aotep edt ,etuatt eft al .éS Sexzem ef anties-wole edt bas ,"%" hexzeam et redw tact ew ,eS .sti ot eeseteter yo 9 ee msec edt tt ,bertecer el sealing uattoetros elt mort eeneesq tnetiso eft ,boeofo ef tostnoo fasotdt ,yretisd [sso0f edt to sita evitinec edt dssords ,etostros mao Baus yelet sotaixrq ont edt ot ,elfgttinvum mt Y boa X to eantiatw odd -avolq X yale .yretted edt to site evitsser -ge0 geivserron efT .a sostnce aesolfo has gr yretied [ao00f adt aaores betsennos won st ten -et dtod ,osfA .d basa e etostnoo eft dasordt ‘eeotoe elqitiom mt hatoensoe ers egetiatw yal 3 oY ,yelet yoitos-wole efl ._yretiad fool edt -xeqo eft :d sostsoo ensco bos qu-evotq won THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ing of contact b de-energizes both relay wind- ings, so that the contacts a and b are open- ed. When a and b are open, the correcting mag- net is disconnected from the battery; hence, the magnet is de-energized. But in the mean- time, it has performed its synchronizing function, i.e., it has, through the agency of the synchronizing eluteh, retarded the brush arm. If, when the synchronizing pulse is received, the cam contact is open, (as it will be when the brush arms are in step) there is no current path through the cam contact to the relays X and Y. Hence, the relays are not energized and no correct- ing action occurs. The purpose of the 200-ohm resistance shunted aeross the corrector mag- net is to absorb the inductive kick, present 103 sol YHUARVARIAT SULITMIRT TO MiTeYe NUAAZOM FHT -batw yafeou dted sestoroeme-ef d toetmos to grt -seqo ets d bas se atostroe eit tadd os ,egat -gem gaitoettos edt ,meqo ers d ins s ned .be .eoned ;ytettad edt mort betoennooelh et tan -asem oft mt ted .bestgtens-eb et tengsm edt gpuisisonudomvye ett hemrotreq esd Ti ,emit yorens oft dasordt ,esd tt ,.8.f ,sottonut est fBebrater .detufo antsinorfonyea oft to. eoxs destd antsicorsonzge eft sedw ,tT .teqo et tostnoo mso edt ,bevieost et safug nt ers same deord edt medw ed [ftw tt es) eit desordt dteq tmetiso om et eredt (qete ,ooned .Y Bre X eyelet oct ot toextmoes mao ~tosttos on bas hesigtreme tom eta syster ont eersooo mottos ant mie-008 ent to esogrsg eAT -asu toteetros edt eaxctres betmide constateer tnecet¢ ,forvt evitovbrt edt dtoads ot at ter 104 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY when the circuit of the magnet is opened, If this resistance were not provided, de- structive areing would occur at the eontact b or at the eam contact. We will now complete the dis- cussion of the electrical cireuits of the distributor. THE DISTRIBUTOR CIRCUITS. The complete eircuits of the distributor are shown in Fig. 24. It is obviously impractieal for us to attempt a study of the eireuits as pre- sented in this figure; hence, we will sepa- rate the constituent eireuits from the rest and study them one at a time. THE MOTOR CIRCUIT. The motor eireuit is so simple that it need not be sep- rated from the other circuits of Fig. 24. 4s is indicated, the motor, together with the governor contact and the 1000-ohm resistance aol YHLAAORIAT QMITUIAG TO MITAYe MUEQAOM FHT efenego et tensem edt to ticerto edt sew ~eh ,hebiIvoxrq tom erew eonstetees etdy tI toastaos edd ta «wisso biyow goteve evisvourte etostace mae edd ts to d ~et6 edt etef[qmoo won iftw eV eit to ativzerte [aotrteefe eft to noltsero etovudtaters eft .8TIVOHIO HOTUAIATaIC Har mwode ers totudiyteti edt to etisorte eteflamos rot fselvoeitqmt ylevoivdo et tI .AS wath at -eTg af eatinerio edt to ybute s tqmetts of os -ages [ftw ew ,eoned jetogtt etdt of betase test edt mort etiverte daentitance edd etet eemtt « ts so Modd yhote bas xosvom edT ,TIUSHIO AOTOM RHT -qoe ed gon heem tit teddy ofamte oa eat siverto oSS .8f% To atlserts szedto edt mort betar edt ditw rediegot ,trotom oft ,betsetbat et aad eoneteteer mic-O00L edt Sua toextn00 torreros THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY in multiple, are connected across the 110- volt battery. TRANSMITTER DISK CIRCUITS, The circuits of the tape contacts and relay pole changers are Shown in Fig. 25. The con- nections are similar to those of the intro- ductory system shown in Fig. 6, except for the addition of the 900-ohm resistance, D, in series with the back points of the relay pole changers, and for the addition of the eut-out relay. The purpose of the resistance, D, is to prevent the short-circuit of the battery when one or more of the relay pole changer tongues are on their front contacts and the transmitter brush is on the corres- ponding button. The cut-out relay was dis- cussed before; it is controlled by the tape feed cut-out. As is indicated, when the cut- out relay is de-energized, as is normally the 105 eoL YHLARDEIET QUITMIAI TO MaTeYe MUAAAOM THT ~Off edt seorors hetoernnoo ors ,efattiom at e“retisd tlov eGTIVOAIO HEIGC AATTIMewsnt yalet bas eatogstnos eqet edt to etisorto eT -n09 efT .é& .2tt mt ovoda ors etegnadto slog -ortal edt to eeody of reflimia ers enoltioen sot taqeoxe .3 .2fl ot nwode moteye yrotordh 2 ,eousteteer mio-00@ eft to softtbhbhs odt yelet ect to atatog doad eft dtiw eotres nt eft to mottrbbs eft rot bas ,eteasedes slog ,comatetest edt to eeoqruq ofT .yefot duo-tuoe eds to tiverto-tyoda edt tmevetaq ot at ,C efoq veler edt to erom to eno nedw yretiad etostnos tnort rtedt mo ets eeranot teansdo -sertos eft mo ef devad tetiimenats edt das -8th eaw yelert tso-tso edT .nottod antbhaog eqat edt yd belfortmoo et Tf yeroted hereve -too edt cedw ,fetsothat et eA .tuo-tro boet edt yifsoron ef es ,festareme~-ob at yeLlor tro THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY case,the armature rests against its back point, so that the back points of all the relay pole changers are negative. When the cut-out re- lay is energized, by the closing of the cut- out cam contact, its armature is drawn over to the front point. When the armature is in this position, both the front and back con- tacts of the relay pole changers are posi- tive. Hence, by means of the cut-out mechan- ism, all-positive impulses are transmitted through the line whenever the cut-out is in operation, Fig. 25 also comprises the circuits of the main line pole changer. The buttons of the transmitting disk are connect- ed to the tonguss of the relay pole changers; the brush arm is connected to one terminal of the main line pole changer; the other ter- minal of the main line pole changer is con- 106 YHILADRIAT PULTUIAL TO MFTEYE MUARHOM THT etatog dosd ett tentane sieet erpismts edt,eesso efoq yefor edt [fe to etntog toad ext tadt oe -et tvo-too est cedW .evitexzen ers atoacnesio -tuo ect to anteofo edt yd ,dbestureme ef yal t‘oevo mwath st etutamre ctl ,toestmaoos meo tro ot et exstenrs edt sef#¥ .tatoq snort eit oF -moo Hoed bas trort sdt dtod ,mottisog efst -teoq ete eteanesdo efoq yeler edt To atoat -~fetoem tgo-stuo sit to aensem yd ,someH .evit hettinenert sts seafsemt evititesoq-ifs ,met ot et ¢uo-tyo oft teveneds omti edt duvordt emolttateqo eft eoatrqmon oefs éS .akt edT .tea2meis slog enti atem eft to aeftvotto -tesensoo ers Weth antttinenart eft to eaotiud :etennedo efoq yeler edt to eeugnod edt oF bo faniwtet exo ot Hetoommoo ef ome destd edt -tet tedto ect j;reasado efog enti aism est To “00 ef tegmaio sfog omtl otsem edt to [anita 107 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY nected to the local battery through the 900- ohm resistances, A, B, C, and D. A study of the connections of the main line pole changer and resistances will show that two 900-ohm resistances, A and B or C and D, are always in series with the main line pole changer while it is connected across the local bat- tery. Hence, the current through the coils is limited to a value which the winding will safely carry. The tongue of the main line pole changer is connected to the middle point of the winding of a milammeter; we are not at present concerned with the purpose of the milammeter. At this point of connection, the circuit divides. One path consists of half the winding of the milammeter, one coil of the main line relay, the artificial line, and ground. The other path leads through the Yor YETARDAIET DUITHMIAT FO MUTEYS MURIAOM SAT -00€ eft dasordt yrotted [seo0l exit ot botoon to yhote A .d Bos ,0 .& .A ,eoonsteteet mio seanedo efoq entf£ atem oft to enottosennoo ot mio-O0€ owt text wore (ftw eeoneteteet bas eyewfs ets ,f Sos 9 ro € bos A ,eoorstelteer teagmedo efog enti atam odd dtiw esetres at -Jad fasol odd seotos hetsenaoo et tt eLidw eftoo eft dasouw’t taetrvo edt ,sonelH .yrot [ftw antiaty oft dotdw oslev s ot Bbetimii£ et eY¥TITSO yletee satf stam eft to ssanot oT tatog effbim edt ot fetoenmnoo ef teanerio sfog tom ets ew ;tetemmeallma a to antbatw edt To ent te secarsa ont ditw benresnoe tmeastq ta esd ,sottoennos to tatog atdt tA .tetemmelio tiad to etetenoo dieg em .B@ebivib .tuoerto to [foo ono ,retemmeltm odt to yntbatw odd eonit Latotttixe edt ,yeler enti atam ont edt dgsord? ebsol dteq reito esl .bovora bae THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY other half of the winding of the milammeter, through the other coil of the main line re- lay, and thence to the line. We see, there- fore, that, as in Fig. 6, the armature of the main line pole changer is connected to the line. One point of the main line pole changer is positive, whereas the other is negative; these two points are respectively connected, as before, to the positive and the negative legs of the main line battery. This battery is not shown in Fig. 25. The operation of this much of the transmitting circuit is exactly the same as that of the scheme shown in Pig. 6. The transmitting disk of Fig. 25 has the eight contact buttons, previously discussed. The function of the five code but- tons is apparent. The synchronizing and lemp buttons, however, may require a word of ex- 108 BOL YHLARORIAT PUITUIALI GO METEYea MUHAHOM FHT Totenmelic: efit to gnetbaliw edt to tiad tedto -ef entf atam edd? to [too tonto edt davordt -eteit ,eee eo enti edt ot eonendt? bas ,yal to eruteorre off .a .att xt es ,teit ,.etot ot betsennoo et tearedio efLog entl atam eit efoq sali ateam efit to tatoq emo .onil ont et tedto eft esetedw ,evitiaog et tegmacdio yfevitosqest ete etmtog owt seedt jevtisszen baa evtttaog est ot ,eroted es , Setsenntoo eYretied omtf mtem ent to erst evitssen ort eft .@8 .3t% ot mwode ton et yretiad efdTt gritvioerstys oft? to doum etd? to acltatreqo edt to feat eas eomas oct yiiesxe et tivsotio -d sat at mvode smodoe est to Heth anittimensr? edT ylerotverq ,enotted tostaoo tinte ody sad Gf -tud eboo evit edt to nottonst of? .beaevoets qmsf Sns gatstaordonys eft .tneteqqs ef enot -xe to brow e erivper yam ,tevewod ,anotiud THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY planation. The negative synchronizing button is permanently connected to the nega- tive side of the local battery, so that only marking impulses are sent out by this button. It controls the main line pole changer in ex- actly the same manner as the code buttons do. The positive synchronizing button is the same as the negative, except that it is connected to the positive side of the local battery. Hence, only spacing pulses are sent out by this button. The lamp signal button is marked "L" in the figure. This button mey be either positive or negative, depending upon the position of the break key. Ordinari- ly, the break key connects the lamp button to the positive side of the battery, so that only positive or spacing impulses are sent 109 eor YHLAROTIAT QUITMIAT LO MATEYS MUAXFOM ERT cottenstg anisinordomye evivasen ed? -egen ett of Betoennos yitmenemreg ef sotind yino tedt o8 ,yrettead [sect edt to eshte evtt ecottud etdt yd tro tmee eta sesluqmt antiram -xe mt regneno efoq ontf aiam eft efortnoo ti ob esotitud eboo eft es tenmam omee edt ¥ltos gatstocotdenye evitteog eft tqeoxe ,evitezen edd sa omss sit at notitod to obte evtttesoq edt ot Setoenmoo et tf tadt eeelng aatoata yino ,eenmed .yretied feool ont wtottsd atdt yd tro taoe ets at sottrd [angte qmal edT yam motiod eid? .ercatt edt at "I" besrem antbhbsaeqeh ,evitssen to evitteog rentte ed -ivantb+O .yex deerd eft to aottteog eft soqu sotiud amal edd etoennoo yet weoetd eft , xf vent oe ,ytetted edt to ebte evitteon edt ot toea ets eealfuqat antoage 10 evitteod yimo THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY out by the button. If the break key is de- pressed, however, it connects the button to the negative side of the battery, and hence marking impulses are transmitted. At the re- ceiving station, these pulses control a lamp relay, similar to the other local receiving relays; this lamp relay, in turn, controls a lamp. Normally, the lamp is not lighted, but if the break key be depressed, the lamp at the other station lights. This lamp is used for the transmission of signals between operators at the two station, and does not interfere with the message. AUTOMATIC STOP CIRCUITS. The circuit of the automatic stop for the tape- feed mechanism, comprising the stop lever and cut-out magnet, is clear from Fig. 24. The stop lever contact is in series with the cut-out magnet, and the two are connected a- eross the local battery. 110 OLf YHUAADRLIAT DAITHIAL TO METEYe MUHAAOM THT ~e5 at yeu Heaerd ect tl .nottud edt yd tuo ot sottasd eft atosnmoo tk ,revewod ,heaserc eorens hne ,yrettad edt to ebte evitasen ent ~ex ant th ,bettimanart ors eseloamt sanitrsem quel s Loxrtaoo soefua ssedt ,acttata antvteo arivtecer Leo0f tanto ext of realimte ,yelfert afordnoo ,atwt of ,ystlet qmel eatdt yeyeler ebetdaif tom at qual edt ,yf[femrol .qmel s aqmel ext ,boeserceb od. yor pee act th tud et qmef stil .etdatl sottete rsdto ext ts ceewledafennte to nolseekmane1t edt tot heey vom 2905 bae ,notiate ow? sdt tea earotsteqo eonsasem edt dtiw eretretat edt. .eéTIuosIo Gore DITAMOTUA -oqet edd rot qote oftanotra add to sivorto tevel qote odt antatramos ,matmedoom heet ->S sett mort rsefo at ,temgem tro-tuo bas edt dtiw seltrea at et tostnoo revel qote edT -a betoonnoo ere ovt oft bas ,tonnem tvo-tso eYrotiad [seol eft eeoto pf THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY THE RECEIVER CIRCUITS. The receiver circuits are shown, somewhat simpli- fied, in Fig. 26. The path of the impulse from line to ground is through one coil of the main line relay, through the milammeter, through the other coil of the main line re- lay, and through the artificial line to ground at G', The milammeter is connected in series with the main line relay, so that a more ac- curate idea of the strength of the incoming line impulses may be obtained than would be furnished by the movement of the main line relay armature. The artificial line is merely an adjustable resistance and capacity in par- allel, connected between the main line relay and ground. The function of the artificial line will be taken up during the discussion of the polar duplex. The tongue of the main line fff YATAROEIAT DAITHIS EO MATEYS MUAAROM EAT ent ET IVORTO AHEVIGOEA FHT -fiqnts vedwemoe ,mwode ere etivorto tevtecet eefleqmt oft to die, eAfT dS .nlt mt deft to [too ono dasrordt at Bavora ot entl mort eTetemmelin edt deavord? ,yaflet ontl mtam odt “et enti nism edd to [too tedto eft darordt Besotg of entl LCetotttite oft Agrotdt bas , yal eskres mt betosmnoo et tetommaltm odT..°D ts -o8 eTom a tedt oe ,yafet ontl atem edt atin aittmoont edt to atanette edt to sebt aterso ed Briow read hertstdo od Yea eselugmt entl ent£l satan odt to tromevrom edt yd bedetaret vletom et entf£ [stottitevs ef? .erotsmars slot -tsq at yttosqss bare sonmetelteet ofdstartis as yaler enti mtam edt meowted Setoennoo ,felfs fetolttitre edt to maottonct ef? .Sus0ry fae aoteavsosth edt gritedS qe rotlat ed [ftw omti exefqub refog edt to extf atam edt to sxamot eft ; 112 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY relay is connected to the positive side of the local battery; the two points are connect- ed to the two coils of the printer relay, as was the case in the introductory system. The remaining two terminals of the printer re- lay coils are strapped together, and this point gonnected to the negative side of the local battery through a 2000-ohm resistence, By this arrangement, the printer relay fol- lows the movements of the main line relay. The purpose of the 2000-ohm resistance is to limit the current through the printer relay. One point of the printer re- lay is dead. The other point is connected to the positive side of the local battery. The armature of the relay is connected to the receiver brush arm. Hence, when spacing sig- nals are sent out from the transmitting sta- tion, the tongue of the printer relay goes Sff YHTAAOLIST PUITUIAS TO MiTECYe MUSTAHOM HHT to ebte evytttsec eft of bstoonnoo at ysalet -toemtos ets atatog owt edt syrettad Isce0l ant es ,vafer retattq edt to eltoo ow? ext oF Be ef? .meteye yrotoubottat edt mt eeso edd saw -~st totatrq odt to eferimret owt antntanet efdt boe ,seftegot S5eqqarts ers afioo yal ent to ebte evtisszexn edt of betosnnos tatog ,sonsteatesst mio-000S s davordd yretiad [sool efot ysafer rsteitq edt ,tuagoanarrs aldt ra eYSler eaxll atem edt to etnemevom edt awol ot at sonatetaet mio-0008 edt to ssogqrrq edT ysfet tataing eft davotdt taortwo odd timtl -9r totairvg ent to tmtoq end et Botoonnoe at tatog tadto ofT .hbaeh et ysl edt .yrettad [soof eft to ebta evitiaog odf, eit of bstoennoo et ysler edt to orsteors, -ate gatosqe aedw ,ectel .ars davtd revisoet este gaitttioansrt eit mort too tues ste alan 2903 yelor tataiw edt to sxanot edt ,aott 113 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY to its dead point, and the receiver brush is not energized. When a marking pulse is received, | the tongue of the printer relay goes to the opposite point, which is connected to the po- sitive side of the local battery; hence, the receiver brush arm is energized. The opera- tion, therefore, is exactly the same as the system of Fig. 6. The circuits of the local re- ceiving relays have been omitted; they will be considered during the discussion of the printer, The synchronizing circuit,” as previopsly described, was taken from Fig. 24, Hence, no further explanation is required. As for the buttons on the re- ceiver disk, and the circuits which they con- trol, the buttons are arranged just the same as those of the transmitter disk, except that 3 § YHUAHORIAT DQAITUIANG TO METeye MUANIOM FAT ton ef daurd tevieset edt fas ,tmtog bseb att ot eSovisosy st oe Lire goivram es ment! .bestarene edt of seos yefer totaizng oft to ovanot odt -oq eft ot betoonnoe et dotdw ,tutogq ottaogqo sit ,soned gyrettad Iaoof adt to ebte svitte -ste¢o eff festeremre ef ors deuvrd revteocer edit em emee eft yl[tosxe at ,stoteted? ,moit -O ett to matere -et Ls00f sit to attuyorto exAT {fiw yedt ~hetiimo meed svad eysler aaivioo edt to mofeevostb edt antteb batebtenoo ed etotairg etivorfo gotstrordomye of eatt mort movst eaw ,bedtrosed yLayoltverq es ebortuper ef mottenslaxe teddrut om ,eomel .bS ~or oft mo enotisd edt tot eA -109 yeds doidw eftvorto odd Bas ,Meth zevteo omsa edt test Seararrs ers smottud edt , forte ted? tqeoxe .Natd rettiownstrt oft to seodt as THE MORERUM SYSTEM OF PRINTING TELEGRAPHY the two synchronizing buttons of the trans- mitter have been combined into one large but- ton on the receiver disk. This button is marked "A" in Fig. 26, and is called the re- storing button. The receiver circuits beyond the receiver disk will be taken up in connec- tion with the printer. We will now explain the polar duplex operation of the Morkrum System. POLAR DUPLEX OPERATION. The system of telegraphy as presented in Fig. 24 is capable of duplex operation, that is, capa- ble of simaltaneously transmitting two mes- sages: one in either direction. The plan is that of the polar duplex. As in all duplex @haes, the principal requirement is that the home-main-line relay shall respond only to signels from the distant station, and that the distant-main-line relay shall respond on- 114 Sif YHUAAOVRINT DUITMIAT TO MATAYe MUSMAOM THT -enstd edt to saotiod gotsiaordonye owt edt -tod sarsl enc otat Bbeatdmoos weed ovad tettin at aottod efct .xeth rerteser edt mo not -et ect belfao et Sne .3S .2k% ot "A" Bottom etotiod gatrotea booyed ettyvorto tsviesex eT -oommoo at qr sevtst ed [ftw vatbh tevteosr edt stelqxe wom [ftw oW .tetatirq edt dttw xctt moraroM edd to soitareqo xelfqs5 tafoq edt -meteye ed? .MOITAHITIO. XRIIVG HALOT $8 .stl at dbotnoaeta es ydqataefet To meteya -scso ,at tedt ,mottategoe xefqub toe sideqeso at -zem ows gatitimensrt yissosmetfamts to eld ek asfq ofT .mottoerth redtte at exo :sense xefquh {fs mt sA .xelqubh raloq edt to tadt tedt at tnomertiper [sytontrq edt ,eemmtzre vino Buoqeer [fede valet etti-atam-omod ont tedt Bae ,cottata tratath edt mott efeayte ot -10 Broqeet [fede yalor enrtienxtam-daateth oft 115 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ly to signals from the home station. In other words, each relay registers signals received from the other station, but does not regis- ter signals sent out from its own station. If the relays perform in such a manner, then each station can simaltaneously receive and transmit a message without the interference of the line signals. The circuits essential for a@uplex operation have been separated from the general scheme of Fig. 24, and are pre- sented in Fig. 27. This figure represents two stations, exactly alike. Suppose the main line pole changer at the home station to be on its positive contact, as shown in the fig- ure. A circuit is thereby established from ground at G', through the positive leg of the main line battery, B, through the pole changer contact, to the middle point of the YHCARORIRT OPMITLILI TO METeYe WOM AAT tedvo aI .anottistea emod odt mort pes ot YI Bovteoet afenntea atetatner yatet dose ,ebrow -atget tom asoh ted ,aottste tedto edt mort -fottate awo ett mort tyo tmee afarate tot soft ,rennan s dove at mrotreq eysler edt tI bas evieest yfasoonstiemte nso mottste dose sonerestietmt edt tuodttw sasseem s timanstt wafsmgte emtl aft to tot [sttcease attsorte sit ; mort hetereqsa dood svad mofttateqo xefar5 -9T7 ore bus 228 at to oserfon [steven odt etneszerqet ervalt etdT .¥S .ett at betmee ntam edt? eaoqqueé .etffe yltosxe ,adotisis owt ed ot mottsts emod edt ts teannssio elog oentl -glt edt at mwode es ,tosiaoo ovitteoq stt mo mort foratidstes ydetedt et throrto A .eiw to gel evitteog edt damrordt ,'2 ts brsots ofoqg edt davordd .&€@ .yrettsd entl ateam edt eit to ¢tmtoq elbbtm edt o¢ ,toataoo teqmedo THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY milammeter winding; at this point, the path divides into two branches. One part leads through one coil of the mein line relay, through the artificial line, to ground at G,. The other part goes through the other coil of the main line relay, through the line to the distant station, through one coil of the main line relay, through the entire milammeter winding, then through the second coil of the min line relay to the artificial line, and through that to: ground, Now, return to the middle point of the mil- ammeter at the home station; the current path divides at this point. If the artificial line is properly adjusted, the resistance and capa- eity to ground through the two brenches of the circuit will be the same. Hence, the cur- rent divides here into two equal parts, and, moreover, the two parts build up to their 116 afl YHUAROAIET OAITAIAT TO METeYe MUAWHIOM FHT dteq edt ,tatog aka ts ;yatiatw totemel tm esbsel treq an .2edenard owt ofat sebivts «valor ontf atem odt to [too eno davordt ta baoorts of ,omtl [etotttirts eft davord? tedio oft dasotdt se0g traq tedto ediT . 2 edd davotds ,ysfert eat atem edt to [too exo davordt ,motists tuetetb edt ot enti edt dgsords ,ysfexr eatf{ atam edt to [foo edt davord? sedi ,anthatw rotemmet[tm ertinas edt of yslet enti mtan edt to [toe baoosa ehbavotg of tedt davord? fos ,eatl fatofttizs -fitm edt to tatog ofbbitm edt of axrster ,woll dteq toaerrso edt ggottats omod odt te tetommne exalt (Cstoltiiixs edt TI .tatog atdsd te sehivts -sqso fos eonstateaet eft ,Sstent hea yiteqota alt to aedonstd owt odt davotd? bawora ot yito -rvo edd ,eomeH .omeas edt ed [{[tw thsorto odt ,bas ,stray favpe owt otnt sted sebivth tres xtedt ot qu bitsd atraq owt edd ,rsvootom THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY working values at the same rete. Therefore, one-half of the current goes out over the line to the distant station, and one-half goes to ground at the home station. Hence, there are equal currents in the two coils of the home main line relay; the coils are s0 connected that the two equal currents neutralize each other's magnetic effects. There is, therefore, no resultant movement of the armature. At the receiving or dis- tant station, the currents pass through the relay coils in opposite directions. Hence, the magnetic effects of the currents are ad- ditive, and there is a movement of the relay armature. Of course, if the armature is al- ready in the position to which the line cur- rent ends to move it, there can be no move- ment. Also note that the current at 117 Yit YHIAAORIET PALTHIAI TO METSYe MUMALOM ANT ,etoteted? .stat omee odt tes eoutsy antirow edt tevo to ae0gn tmeturo old to tlaed-seno tled-sno B98 .sotiate tastelb edt ot entlL .oomek .mottsta gmod sit te Bbarota ot seog altos owt edt mt atcexrtso L[aspe ets otedt ets sftoo edd ;ysler omilf ntsm smod edt to stocerrve [ape owt edd tadt hetoenmmoo og -atoette oftenaam a'redte dose estisriven tneaerom tastivesr on ,astotetedt ,st sreAiT -et6h to amivteeeser edt tA .stutamres edt to. edd davordd saszy efaortyo eft ,aotiste tast .o0teH .anxoktoert& etiacoqgo mt aftoe yelor ~bs ots etaetise edt to stostte ottensam edt yaier eft to taxamevom 8 at stedt bas ,evistth -f[e sf eruteorea edd ti ,estsce tO ,otvtsmrrs -to anil edt doftdw ot mottteog edt mt ybser -svom om ed ase etedt ,ti svomw ot ehne toot ot mom ts toe tise edd tadd eton os LA THE MORKRUM SYSTEM OF PRINTING TSLEGRAPHY the home station passes through the milam- meter windings in opposite directions, so that no deflection of the instrument is pro- duced. At the receiving station, however, the current passes through the entire winding in one direction, so that a deflection is produc- ed. Hence, a8 a summary of the operations, we may say that signals trans- mitted by the home station do not affect the receiving apparatus at that station, but are registered by the receiving apparatus at the distant station. In the same way, signals sent out by the distant station affect only the receiving apparatus at the opposite end of the line. The operation of the plan wuld of course have worked out the same had both stations been sending out either positive or negative currents. 118 BLL YHTAHDEIST PALTUIAL 4O MTeYe MUTAAOM TUT -msftm edt dyvordt esersq mottste emod edt oe ,anottosrrdS etteoqqo mt aaugtbatw tevem -org ef toomortemt edt to sottoofteb on tadt edt ,tevewod ,dottsts saivtsser eit tA .heomh xt gatbatw ettine od? danotdt aseesq Ynetti0 -osborg et mottoelteb a tedt of ,mottoerth ono Hs edt to yreame * es ,oomel -soatt efeoate daddy yee yam ow ,anoitsisqo edt footts ton of mottate emod edt yd bettin ere tod ,nottats tadt te exstataqgs antvioser edt ts eutstsqge univteser edt yd beretetser elargte ,ysaw omae edt ol .nxotiste tastelrd yino toetts mottste tieteth edt yd tuo tise Bae etleoqyo edd te autsreqgqa anivieser eit bivow mafy edt to mottateqo edT .entt edt to dtod had sase edt tua beiréw evad eetvoo to to evititeos teitte tvo anthaea meed enottstea eatneriss evitssen 119 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY If both stations are sending out currents of the same sign, say positive for example, we have equal e.m.f's. impressed on both ends of the line. Hence, there is no resultant line current, and of course, no current through those coils of the main line relays which are connected directly to the line. Each relay will, however, register the same as though it were receiving current from the other station. An inspection of the dia- gram will show that the current through the artificial line at the home station will be in the same direction as positive current from the distant station would be. Hence, this current through the one coil of the re- lay produces the same movement of the arme- ture as a positive current from the other station would produce. Likewise, at the dis- tant station, the current through the arti- ert YHUAROAIET QUITHIAL TO MNTEYS MUAAKCOM FHT attbaes ers anottate drod tI evittisog yse ,magte omse ed? to atnerrye to Seesetamt .e't.m.e Lampe evad ew ,efqmsxe tot om si ered? ,eomeH .entl edt to esbae dtod 0 om ,gatveon to bre ,tmetiso emtl trativest entf misnx eft to eftoo exsodt davordd tnettryo eft ot yltoetth betoennoe ete dotdw aysler edt tetetzer ,revowod ,{Iiw yaler dost .antlf mort toetivo satvtsset stew tt davondt es smae -sath edd to aottoeqant aA .sottats rato ent edt dayvordt daexrryo edt tadt words [ftw mara ed [ftw mottate omod edd fae oxif f[stottiias toerryo evitteog as csolttoertsS Adin edt at ,eoneH .ed bilrow cottste tasteth edt mort -ot eft To [foo eno odd dayordt taerrro etdt -serrs edd to tmemavom omae edt ascovborq ysf retito edd mort tnertyo evitteoq s se otut -elb eft ts ,saltwettl .eosborg biyow nottate -tita edt danvordt taerxvo edt ,notiate tast 120 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ficial line and one coil of the main line relay is in the same direction as a posi- tive current from the home station. Hence, the movement of the distant relay armature is the same as though that movement were produced by a positive current from the home station. Therefore, we see that each relay still registers the signal sent out by the other station, but does so by current from its own station. If both stations were send- ing out negetive currents instead of posi- tive, the operations would be exactly the same, except, of course, the relay armatures would take position against the opposite points from the first case. In case both stations are sending out current, but these currents are of different sign, the operation of the re- Osl YAYAAVE INT OQUITHIAT TO MATeYe MUAAHOM NAT exif ateam eft to [too eno basa ont [stott -leoq ¢ ss mottoerth emee oct at eat yelfor ,9o%eH .mottetea emor edt moxt taermv.e evit ervtsmre valet tnateltbh edt to taemervrom edt etew tnomovom gadt dasodt es omen edt et emod edt mott tnerrso evitteoq s yd beowbotq yelet dose ted? see ew ,stotetedT .nottats eit yd tno tuen Lamgte edt aretetaer [{tite mort tnetrss yd oe eeoh gud ,nottatea tedto enoitveta awo ett -brea stew enottate ditod tI -tnog to besteant etnerruvo ovitaazen tro aat edt vitoesxe od floow amottatrsaqo edt ,ovit serstsnres ysfer edt ,eatsoo to ,sdyeoxe ,omss stteoqqo edt tentane notttacg sxat bilnoow ee2e20 garit edd mort etatog ets enottate dtod sesoe al ere atcetiso esedd ted ,tmet«se to satbooe -et edt to acktsreqo edt ,agte tastrett th to THE MORKRUM SYSTEM OF PRINTING TELGRAPHY lays is not changed. The only effect is the doubling of the line currents. We see, therefore, that by using the instruments and connections of Fig. 27, we can establish duplex operation, that is, we can establish simaltaneous com- munication in either direction over a single wire. The Morse sounder and other instruments of Fig. 24 ere used when the two distributors are being first put into opera- tion. By means of these instuments, the oper- ators at the two ends of the line can com- municate with each other. Since these Morse cireuits do not form a part of the printing telegraph system proper, their discussion will be omitted. We will now take up the des- cription of the only remaining element of 121 £sf YHTARDIAT DUITAIAT FO MATCYe MUANHOM FHT eit et tostte yino ef? .boanado ton st eysl -stoatiye exif eit to antiduoh vd vad? ,oroteredt ,cee e¥ to amottoenicoos Bae etmoemerdant edd gatas -‘tokssrero xefanh dalidetee neo ew ,TS .2ft -moo avoexetfemte delbfdstes neo ow ,et tact efaate = tevo noltoert6 tedtte mi nofttssianm -othy todto bas treSaroe satoli exfT owt edt medw bees ors dS .ati to sinemuttent -steqo otat tuq terit anted ors erotediztalrs -teqgo eft ,atnemstent eeedt to ansem yi .aoltt “moo mao eatf edt te efme owt edt te etots eeroM easedt eomt2 .tedto dose dttw etsotaum anttateyq off to traq s mrot von ob atigorto ackeesoeth rledt ,teqorq metaye dystaetst -Settiao ed {fiw -295 eft qu edet wor [ftw e¥ ‘a to taemefe yuakontamet yino odd? to aottqtto 122 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the distribution system, viz., the Wheatstone differential relay. THE WHEATSTONE DIFFERENTIAL RELAY. The main line pole changer, main line relay, and printer reley, although they do not form a part of the distributor itself, yet constitute part of the entire distribu- tion system; all three are adaptations of the Wheatstone differential relay. The three functions are performed by instruments which are exactly alike in mechanical construction, but differ in their electrical connections. The Wheatstone differential relay is primarily the same in its action as any other polarized reley; that is, it in- cludes a moving contact arm, playing between two fixed contact points, and operating solen- eids. The contact arm takes position against one point or the other, depending upon the direction of the current through the operat- ssf YHLAADARINT OMITAIAL TO Meterve MUAATOM TAT exotetsedW eft ,.siv ,metays mottuyditteth edt ystor [attaerett rh TAITUNANTTIC THOTETARHW AHT extf£ mtem ,teagmado efoq ont£ atem ed? YATES oh yedt davodi[s ,ysfer tetaitg baa ,yalst etloatt totudtateth edt to trsq s mrot ton -ydixtetbh ettine edt to trag stutitanoo tox to saottstqgsis eis serdd [fa ;aeteye cnott setdt of? .yefet isttmetettth onotateed® edt fotdw ateemavttent yd fomtotteq ers enattonut efottorrtecos [sotasdoem at extie ylfosre sts esnottoennoo LIsetrtosfe rtedt at rettth tod {atineretttsb emoveatsad® edt e2 mottos ett af omse edt yltramtiq et ysloer -at dt ,st gadt ;yafex bestrsf[oq tedto yas seowted uitvelq ,ore fostmoo anivom # sebslo -mefos anttereqo fae ,atatog sostmoo hextt owt taniages motiteog saedst mrs sostaoo eft .ablto edt moqs antiaeqeS ,redto edt to sateq sao -tateqo edd davordd taetrvo eft to mottoerth 123 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ing coils. The armature, however, is not per- manently polarized, as it is in the usual form of polarized relay, but is polarized by a separate exciting coil. The relay may be used as a differential or cumulative in- strument, depending upon the connections of its operating coils. A relay is said to be differential when the magnetic effects of the currents through its operating coils eoun- ter-balance or oppose each other, and cumula- tive when the magnetic effects of all cur- rents add to each other. The Wheatstone dif- ferential relay in its working form is shown in the accompanying plates. The principal parts of the instrument are shown in Fig. 28. The two cores of the main coils, C and C', are mount- ed vertically and side by side. On these cores are wound the main coils, each coil &sf YETAAORIAT OMITHILT TO MATCYe MUAZHOM SHT -teg ton et ,tevewod ,stutsorre eA? .eftoo ant Iecas edt at et tt as ,bestraefoq yitmeram bostrsfog at tud ,ysfet bestrsfoq to mrot yen ysfer ofT .ftoo antttoxe etataqee a Yd -xt evitalsmo to [attimetettib s a2 beas ed to smottoenmooe oft moqn ancthreyzos ,tremmrvte ed ot Blae et yelot A .eftoo anttateqo att edt to atostte oftemasm edt aedw [sitinetrett tb -msoo aftoo anttsteqo att dgvoris strerivo -sfimso Bae ,tetto dose esogqoe to sonelfad-tet -tso Ife to etoette oltenssm edt modw evit -tt& enotatsed” edt .reito dose of Sha etnet mwora et orrot gnivrow ett mt yeler L[aftrerst aetale gatynsqmooos edt at eft to atrsq [satonitq edT owt oct 1.88 walt mt mrofe ots tromorvent -tosom ere ,'9 bas 0 ,eltoo atan edt to estos esedtd aO .ebtea yd ebie Bae yilfsotirev he Itoo dose ,aftoo atam edt Savow sts setoo 124 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY consisting of two separate windings. The ends of the windings are brought out to binding posts on the base of the instrument. Each core is fitted with pole-pieces, as is in- dicated. The armatures, A and A', play between the pole pieces, one armature being at the top of the cores and the other at the bottom. Zach armature consists of an iron disk with a smell projecting tongue at one edge. The two disks are attached to a bress rod, R, which runs through the centers of the disks; brass is selected for this rod on account of its non-magnetic properties. The rod is supported at the top and bottom in pivots, The tongues af the armatures ex- tend into the space between pole-pieces. The exciting coil may also ast YHTAHOATLIAT OQMITMIAT TO MATcY2 MUSAHOM HHT ebme edT .eantintw etetaqea owt to yattetenoo amxtbetd ot tro tdayord ete enathatw edt to dost ,tromurtent edt to ersd ect no ateog -at et as ,sesetq-efog dttw betttt st eros ehbetsoltb A dos A ,eorstenrs ad? erutamrs sxo ,eesata aflog edt neawied yal redto eit Baa aetos edt to got edt te antod na to atatenco erutamts dos® .mottod edd ts tsa osnsot anttcotorq [fame a dttw datb mort 8 ot S5edosite ers asistb owt sdT .enbo ono etetneo odd davordt anus dotdw .f. ,S0r sesrd fot etdid tot Setoefee st assrd :ateth edt to eeolttoqorg ottompam-aon ati to tasooos mo movdod Bas qed edt te hbetroqqre alt bor edT -xe setwismra sdt te sergarot edt .atoviq at -eecetg-elog meewied ossqe eft otat Aaot oels tam f[too gatitoxe eT 125 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY be seen in Fig. 28, As shown, the coil com- prises an iron core, upon which is placed the exciting winding. The core is mounted vertically, and is of about the same height as the other cores; at the top and bottom, the core is fitted with pole-pieces. The pole-pieces are end piec- es, attached to the core in such a manner that they project from one side of the core. Semi-circles are cut out of the projecting ends of these pole-pieces; in the two semi- circular pockets so formed are placed the two circular disk-ends of the armatures, one disk being placed in each pole-piece. A very small air-gap is left between the armatures and pole-pieces, so that the two armatures end the brass connecting rod by which they are supported can turn freely in their pivots. Just above the upper arma- ture, and mounted on the brass connecting esr YHYAROE INT DLITHIAG TO MATeye MUAAHOM HHT -moo [tos edt ,mvonde aA .8S .atl at sees od Beoalg at dotdw moqy ,eroo aort ns esetra Setasrom ef gtoo eAT .amthatw eantitoxe oft tdated emse efit toda to et Bae ,yiisettrey emosvtod bas qot edt ts :aetcs tedto edd es 200elq-elog ditw beftit at etroe edt -seltg Srne sia sesetq-aefog eT Toomtan s dose mt ezoo edd ot bedortts ,e¢ -eroo eft to eble exo mort toetora yedt tadt anttootora edt to tuo tus ets asforto-tmed -tmes owt eft mt ;sesetq-efoq eeedt To absae efit hessfq ere besrrot on stetoog taivorto eno ,eeTutsare edd to ebpe-dteth teluerts ont yrev A .eseltgeefog dose at bseslg gated teth setvtsmre edt soowted ttel ef qss-tisa [Iane serstenres ows edd tedt of ,eeoetq-elfog hae yeds dotdw yd bot sxivoonnoo eastd edt Sas -atovig tktedt mt yloert arot neo betrocqive eta ~sarme teqqy edt evode test guilteenntoo esesd eft mo fetavom fae ,eist 126 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY rod, R, is a contact arm, 0. This arm is fix- ed to the rod, R, at one end, and carries a contact point at its .other extremity. Two fixed contact points are provided, one on either side of the arm and both in line with the contact point carried by the arm. The arm swings back and forth with the armatures be- tween the two stationary points. 4s for the operation of the relay, suppose the two operating coils car- ry currents which polarize the poles and cores in the manner indicated in Fig. 29. Also, let the current in the armature-exciting coil be of the direction that polarizes the armatures es shown, There is no return path for the ex- citing coil flux between armatures except through the intervening air or through the cores of the operating coils; obviously, the flux chooses the latter path, Hence, in Fig. YHIAHORIST PUITMIAL TO MATeYe MUSAAOM Hat ~xit ef ore eidT .0 .mrs toatmoo a et .f , bor 8S eetties foe ,fne emo ts ,f . bor oft ot bs owT .ysinertxe tenfto; efi ts txtoq toatroo no ero ,febtvorq eta etrtog tostace bextt avtw entfl mt dtod bas orre eft To ehte raitte oxe ef” .wre oft yd beirreo tetoq tortnoo edt -ed setutemre odd dtiw dtrot bas wosd aantwe eetatog yrenottste ows edt reowt eddy to sottereqo edt rot eA -ts9 eftos anrttsreqo owt eft seeogqve ,vyelfeot eeTtoe bea eelog ext estraloq dotdw atneriuro yt vor ,oafA .@S walt at beteotiat tenneam edt at ef LItoo ehkerexe loti? eke edd af treriwo est aerrtenrre oft soxsitsfoq tent mottoerth eft to -xe eft rot dteq aurtet om ef ered? .mwode es tqeoxe serutsars meowted xuft ftoo anttto edt davordd to tre antrevretat edt darvordt eft? ,yfarotvdo saftes anttsreqo edt to setos eatt ot ,conel .dtsq retteal edd seeoods xeI[t THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY 18, the flux between armatures assumes the same direction and path as the operating flux. Such action pulls the armature in the direction of the flux; that is, the armature takes position against the right-hand pole- piece. When the armatures are in this posi- tion, the contact arm lie against the right- hand eontact point. Had the operating current been in the opposite direction, the cores, C and C', and their pole-pieces would have been oppositely polarized. Hence, the arma- tures would have swung toward the left pole- pieces until the swinging contact arm made contact with the stationary point at the left side. Therefore, the direction of the working current, by determining the polari- ty of the pole-pieces, determines to which side the armatures will swing, and therefore 127 YETASORINT QUITHIAG YO METEYe MUAZAOM AAT eid esemrses setotemre neewted xolft edt (or gattereqo edt ss Steg bas sottoettb emes edd at etuteore odt elf{ugq anofios dorée ,xult etutaore edt ,et tant? yxft eft to mottoerts -efog bret-tigtt edt tentage oottteod eexat -teaoqg eldd st eta sewwitsorrs edd oof! .soete ~tisils eft tentage etf mre voatmoo edt ,nott etotoq voetmoo hasd tnetivo aritsteqo eit bell ,eeToo edt ,sottoerts ettacqqo edt at reed event Bitrow seoslg-elog ntedd Bue .'O Bae 9 -esute efit ,somed .bestrsefoq yletteogqo seed -sfoq ttef edt brawot annwe eved bivow serut ebhem srre toetmoo untertwe edd Itinw eeoetdq edd tsa tntog yranottate adt ditw toatmoo edt to mottoertS edt ,etoteredT .obte itel -lrefoq oft anictrreteh yd ,trertwo antdrow doitdw ot eenimreteb ,eesetq-efog ext to yt erctetesd fas ,antwe [ftw eersteora edt ehte THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY determines whether the right- or left-hand contact will be closed. If, instead of the direction of the working current being changed, the direction of the armature exciting current had been changed, the armature would have changed position just the same, This move- ment would be due to the change in the po- larity of the armatures. In practice, how- ever, the exciting current of the armature is not changed. In Fig. 30 are shown the three methods of connecting the relay wind- ings when the instrument is to perform its three respective functions. As was said be- fore, each core carries two independent wind- ings, 811 four windings being the same; the windings on each core are shown separated in Fig, 30, but in reallity, both are distrib- uted over the entire length of the core. 128 8st YHTAAOSTIET DMITMIAL TO METeYe MUSACM SHT Brad-ttef tc -tdstr eft tontedw sontarreted «beaols ed [ftw tostnoo noltoottb est to bastent ,tI ent ,beaneds anted tnertyo gxtdtow edd to tasiivo gattioxe exutsarrs est to nottoorth eved Bloow etuteamts edt ,heamedo mood had -evom efdT .emsea edt tert mottteog beaneris: -oq edt xt ennsdo edt ot eh ed blrow taom -wod ,sottostq al .eerutamrs edt to yttrel erutsora eft to taerrse antttoxe ext ,teve ebegaedo ton ef eit ovote ere OS .att ol -betw yelet est unttoonmos to aboritem ee1dt ett mrotreq ot af taemiriant edt new sant ~ed Sten asew eh .anottvonnt evitoereert setdt -batw taehseqehst owt selyteo eros dose ,e10t edt jemee edt arted aanthoatw root [fs ,eant beteteqera mwode era etoo mses mo anntinatw -diateté ers dtod ,ytiitfeer at ted .0& .att at -exco edt to dtanef etttne oft revo bets 129 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY In Fig. 30(a) is shown the relay as connected for action as a main line pole changer. In this case, all four windings are in series, and in such a way that their magnetic effects are cumulative. The exter- nel connections are to terminals a and b. An Spplication of the cork-screw rule shows that when the coils carry current in the direction indicated by the arrows, the top of the left core becomes a north pole, whereas the top of the right-hand core becomes a south pole, The contact arm, therefore, assumes position against the right-hand contact point. if the operating current is reversed, the polarity of the cores is reversed and the contact arm assumes position against the left point. Hence, the instrument fulfills the requirements of & main line pole changer, In Figs. 30(b and ¢c), we see est YETAROALIET QHITAIAI TO METEYe MUAAAOM FET est owota et (s)08 .aktF al entt gies s es sottos tot Betoencos sea yelst agotintw tvot Ife ,eseso sidt ol .tegnade eLfog tted} tact yew s dose nt bas ,eetten at ors -tolxe ed? .evitelsmue ere avoette oftenssm mA .d bes @ elentoret of ers anolttoenmos fen tact? awode efet weror-dtoo ent to softtsotiage sottoorth edt ot duets yrrse elton edt sedw dtel edd to got edt ,eworrs oft yd beteotbat qot eft eseretw .efog Hdton & semoced exoo eefog divoe ge eemoosd etoo Bbuet-tdatr odt Yo sottieog aemunee ,ototeredt ,mrs tontmos eT edt TE .tntoq toetmoo bued-tintz eft tertese ytluelog edt ,beatever et tnorryso adttereqs ars tostioo edt bea Bearever at setoo edt to some .tatog ¢tel edd tanteaes notttecq eommacs to atnemertsper edt efltt fot tremurtest edt sxegsade efor eatl aten s eee ow ,f{9 Sas d}O8 .eotT al 130 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the instrument arranged for operation as a main line relay. The main line relay is un~ der the action of two operating currents: that passing through the artificial line, and that passing through the min line. These two currents should neutralize each other's effects on the armature. At the same time, the relay should respond to a single operat- ing current passing through all windings in seties. An examination of Fig. 30(b and c) will show that the relay will act in the de- sired manner. Fig. 30(b) shows the relay car- rying currents that neutralize, that is, the currents which it carries when messages are being transmitted from its own station. Fig. 30(¢) shows the instrument carrying a single operating current, as it does when messages are being received, In Fig. 30(a) is shown the OsL YHTAAOSIET QMITUIAL TO MITeYe MUAAHOM THT & a8 coftearteqo tok boaneste Sneourrtent edt -ng ef yefleor onti miam efT .ysfert enti atam satmeriso anttstredo owt to mottes edt reb ,onti Letotttins edt devordt anteesq tadt esed? .entl mtam oct davoult anteesq tad? bae a'tedto done estiettxem bivode efmertse owt ,emts emea eft tA .erxetenrre est ao etooette -tsteqo efacte e ot Buoqeet Siyode velfet edt okt enetiotw (fs davotdt arteesaq taetise got (9 bre d)OS att to mottanimexe oA .eeites ~ef eft mt toa [ftw ysaler otit tadtd wode [ilw -%80 yeler eft eawode (d)O8 watt .tennem borte edt ,et teadt ,estferiven tadt ettiert1i9 aniyr ers eeneerem catw seixvreo tt dotdw etnerrso enti .oottsta mwo att mort bettimenatt acted efanta 2 antyrtso tnenmurtent ost awode {9)08 eexesesen neaiw ee0b ti es ,tnertive anttsteqo ebevieces anied ets ext mwa et (B)0€ watt al 131 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY relay connected for use as a printer relay. In this case, there should be two sets of windings; current through one set should cause the armature to take position against one point, whereas current through the other set should cause the armature to take position against the other point. Two windings are therefore provided, each consisting of two coils, one on each core. The terminals of one winding are a and b; the terminals of the other are b and co. Terminal b goes to one side of the operating battery. Now, if terminal a is connected to the remaining side of the battery, the armature assumes position adjacent to the left pole-piece. If, instead, terminal c is connected to the remaining side of the battery, the armature shifts to the right-hand position. Hence, the position of the armature depends upon which of its two féf YHUAHOLIST QUITMIAT TO METEYE MUAAAOM FHT evsfer tetacitq s es een rot. Bstoentoo ysfot to estea ows ed bisode exedt ,eeso etdtd al essso S{yode tee ono duvordt tnettse jeantbhbalw eno tentese fsolvieog eta? of etuteanra odt tee tedto edt agvonrdd tnertyo esotedw ,intog notttacg etat ot eantenrrs edt cavao hivode ets egatiatw owl .tatog taito edit sentsga owt to anttetsanoo dose ,hebivorq esotetedt to alsniatet of? setos dose mo exo ,ettoo to afsenimires edt 3d hoe e ers gitthatw smo ov aeca d [sntateT .0 Bae d ote recto edt ti ,wol .yrettsd suantisteqo oft to ebtea emo ehte antntemer oft ot Setoenmoo et s Lantatret coltteog senseas stutemre oft ,yrettead eft to ebsotent ,ti .,secetq-sefoq ster eit ot Taecsths ebte anintemer eft ot 5botoontmoo at o Lantmredt ext of ettine orntsares eft ,ytected ent to to noitteog edt ,esmeaH ,nottleoqg Sansd-tdutt owt ett Yo doltdw aoge ebasqed etutears ont 132 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY windings is energized; this is the action de- sired in the printer relay. It should be noted that the windings are not energized simaltan- eously, but only one at a time. In Fig. 24, conventional sym- bols are used for the differential relays in the different functions. In the diagram, each instrument is shown as having two coils, just as the usual type of polarized relay. However, if it is remembered that the Wheatstone dif- ferential relay always has two coils, though they may be on the same or different cores, and that changes in the opgrating currents in these coils produce exactly the same ef- fects as the same changes would produce in an ordinary polar relay, no confusion on the part of the reader will result. In the wiring diagram, the armature-exciting coils are o- mitted for the sake of simplicity. YHIAAFDEINT DHITAIAT AO METSYE MUSAHOM THT -eb cotter eid ef efdd sBosiaiteme et esntieiw beton ed biyode tI .yalet reining and at botte -netisnts bestareces ton ers eagntbatw eis tadt eemttd 8 te exo yino tud ,ylasoe -ayve [snotinevnoo ,s8 watt ol ot ayefer festénerettib edt rot beer ore efod fose ,merneth edt mI .enottonst tmetett th ent tent ,aftos owt geived as nwode st toemmrtect ~tevevoH .¥ysier besixsfog to eqyt I[sver edt as -tth enotetsed” oft saft bersdmemer at tr tt davodt ,sftoo ows eed evyawia yefot Istinetet ,eeTc6o toeTettlb +o emse edt mo ed yam yedt etnertro gantteraqo eft at eegnede tedd Bae -te omes et yiteszxe soubotq altos esedd xt nt ecwbora Bfisow sentado omen oft ee etoest adit ao molestaoo on ,yafer refog Yranifbto as goitiw oft xI .tiveet If tw tebeet eft to t1aq -o ete afioo unittoxe-erctarre eft ,mearasth eyttetiqmte to exse eft tot betiina THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY The last paragraph. concludeg the discussion of the distribution system. Next will come a description of the printer. As in the foregoing material, rough sketches of the printer parts will be used to show the general principle of action, whereas the photographs of the actual machine will be relied upon to show the detailed construcion of the machine. 133 1 YHITAHVEIST OUITHIAT TO MATEYe MURXHOM EET ashulonoo \ dgersgetse¢ teel ed? emetev2a dottediztvath odd to moteesoetb odt etotnizng eit to mottqtreesh a emoo I[I[itw txre® eedotexe dasot ,[stretam gniosetot ent mi eA wore ot boas od {[Itw etteq tetnitq odt to eit esetedw ,tottos to siqtontrq [ereren oft ed [ftw ontioan feutos edt to edqersotodq solomrtenco bellteteh aft wore of noqu hetler onidoar ant to THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Part IV - The Printer. GENERAL. The Morkrum printer is, in reallity, a typewriter, operated by electro-magnets which are controlled by the incoming line impulses. In the following des- cription of the machine, the plan will be to take up first the mechanical movements of the printer, and then to explain the electrical means by which the mechanical movements are operated and controlled. The complete printer may be seen in the accompanying plates. As is indi- cated, the main frams consists of a bed-plate, from each corner of which rises a post; a cov- er-plate is screwed onto the top of these posts. When the machine is completely assem- bled, it is entirely enclosed except for the platen and typewheel carriage. The printing action in this machine is accomplished by the typewheel striking a message blank, which is supported 134 S5L YHLAHDEIOT DMITUINI TO MNTEYe MUSHOM FHT etecaini edi - VI traf tednizg avrdroll efil .TASHWHD yd hetersqe ,tetinweqys s ,ytiifesr at ,et edt yd betfovtnoo era doftdw, stensgsm-orltoele ~b8eb aniwoflot edt aI ,eesfrqmt sotl antmoont ot ed ftw amelq eft ,entisoam oft to nottaire end to etremovom [sotcsdoem ett tertt qu sextet {Isettiosle odd atelfqxe of nodt bas ,tetnizta ets eteomevom [setnsdoom att dotdw yd enasem eAeflortnes bre betareqo ed ysa setaing etefqmoo eft -tbot et eA .eetalg gniyrsqmooos edt at noes .otelq-bed s to etatenco emart atem edd ,botae -voo 8 ;teoq s& sealt doltdw to temros dore mort esedt to got edt otmo Bewotsea at otalq-te «meses tlotefamoo eat satdoam edt nei .eteor est rot tqeoxe beecfone yLeritiae et ti ,beld eexeiyrse [sedweqyt bas cotalq eldt mt mottos anitatra eT feenweaqyt edt yd beratiqmooos et eninosm fetrogqse et dotdw ,ansld ogsseem s anitdizte 135 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY on the platen. These warts are shown in the assembly photographs. THE TYPEWHREL. The typewheel is shown in Fig. 31. It is a fiber drum, a- round the edge of which occur the type in raised characters; the characters are arrang- ed in two rows, one near the top and one near the bottom of the drum, The typewheel has a hub at its center, the hub being bored to fit a shaft called the typewheel shaft. This shaft furnishes the primary support for the wheel. THE PLATEN. The platen is a rubber roller, whose purpose is to hold the message blank or other paper. It is similar to a typewriter platen, and will be taken up in detail a little later. THE TYPEWHEEL MOVEMENTS. There are a number of necessary movements of the typewheel. Primarily, of course, the wheel él YEUASOEIST OUITHIALT YO METEYE MUANAOM FHT edt at awode ets etrar csedl .netel[q et mo -adgaersotodq yidmesas {eedweqyt edT .ISEHVSIYT FHT -s ,muTh todit a ef ti .[8 .2tf of awode et mt ecyt eft tyooe riotdw to egbe edt barot -onsTtts ers exoteastadio eft j;etetssrsdo beater teen exo bas qod ott rsen eno ,awor owt at Be & ead L[esdweqyt eft .motb edt to motitod ent tit oF Horod gated dud edt ,z9etmeo ett tea dod ttede ata? .ttede L[eedweqyt edt helff[so ttade s Leow eft tot troq¢ss yramizrq ed? sedetnrut set netsf[q¢ efT .HETAIT FHT eft Bflod ot et seoqusq seaodw ,telfor teddst tefimte ef tI .reqsq teito ro dnald eagsasem qs sextet ed Iliw bae ,notelq tetirweqyt a ot etetel ealidii se L[tateh at etedT .cTWXMEVOM IESHWALYT HHT edd to atnemevom yreesesen to redmiun s ote foedw edt ,satvoo to ,yfiremixi .Leedweqyt 136 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY must strike the platen so as to print the character. Before this action, however, it must have rotated so that when it strikes, the proper proper raised character will be at the point of contact between the wheel and platen. Also, the typewheel must be in its correct vertical position, that is, the correct position along the axis of its shaft. If the wheel is in its normal position, char- acters of the top row strike the platen; if the wheel be raised a little, characters of the bottom row strike the platen. This lat- ter is called the shift position of the wheel, and is assumed when the shift signal is re- ceived over the line. Furthermore, after the printing of each letter, the typewheel must be spaced, that is, it must be moved along in front of the platen a short distance, so that the next letter pfinted will lie beside él YHTARVEIST QUITHIAI TO METAYe MUAZAOM FHT edt salrq ot es of metelfq eft exixte tearm tr ,tevewod ,mctios etd? esoted .retsaetado ,sosixte 2f sedw tad? oa betator eved teum ed {[iiw tetoetaeto beetaxr teqortq reqotq est feedw eit mneewted toe2etn00 to tatog oft ts ai od tenm L[ooedweqyt efit ,osfA .motaly bae ed? ,ef tadd ,sokttaog [soitrev sooxsroo ett etisde ett to atxe edd qrof[s mottteog toer roe -tedo ,cottleog LIanarrom att at at [sedw ext tI tl ,setelq ext sitrze wor qot sat To etetes to atetoerado ,efitil a boatet ed Leodw odt -tel etd? .netsl[q eft extrte wor mottod ext elvoedw ed? to softtteog tide eft beffen at tet ~-or at fenante titdse ect sedw hemraaa eat hoe ent testa ,ctomrettast .enil ext tevo hevteos term L[oodweqyt edt ,tettefl dose to antinizg giofs bevomw ed tesm tt ,at tadt ,beoage od on ,ecomatetS ttode » setala add to tnort at ebteed otf I[ftw betattq rettel tres ott tedt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the preceeding one. It is important that we note that in this printer, the platen remains stationary, whereas the typewheel travels back and forth in front of the platen, and thereby distributes the successive charac- ters along the printed line; in the ordinary typewriter, the platen carries the paper be- fore the point of printing, but in this case, it is the printing point which moves. And last, when the end of a printed line is reach- ed, the typewheel must be moved back to its starting position. With this idea of the type- wheel movements, we are now ready to study the means by which these movements are accom- plished. THE CARRIAGE. The typewheel is supported on a carriage (see Fig. 32). The carriage travels back and forth before the platen, carrying the typewheel with it. As is indicated in the general views, the car- 137 ver YETALOAIGT DHITHILZA TO METCYe MUAAHOM FHT ew tedt tasizogmt at tI .eno gatbeesstq et exntsmer netelq eft ,rstaitg etdi at teddy eton efevet? [serweqyt edt esetenty ,yrenctiste bas ,metefaq eft to taort at dgrot bas Mord -oxtedo oviesecone aft aetudintels ydetont yrenthiro eft at yentl fetnixc odd amole aro? -ed teqeq eft asetirso nets[q sit ,retirweqyt oes atdt ot ted .getinixg to tartog edt etot Sok ,sevou doltdw totogq smttattg eft af tL -foset et sail Betaitq s to Sas edt nedw , vast att ot siesd Bevom ed teu Isendwegyt edt , be -oqy?t ent to esebk etdt ath’ soottteog satdiretea ybote ot vhseer wom ets ow ,atnomevom Leodw -mooss ers atsemevom seedtt dotdw yd easem eat ebedatiq Ieeiweqyt edT .GWATHHAO SAT ef? ,(S8 .aki een) esetrrso ea mo betrogque et est exoted strot bse soad slevetd esairreo eA .tt dtiw L[eedwoqys odt aatyrise ,netsla -Tao eft ,ewetv [stores eft at betsstbhat ef THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY riage is supported on two square steel rods, which extend clear across the front of the printer just in front of the platen. The car- riage is so constructed that when one of the rods is turned, the typewheel strikes the platen, when the other rod is turned, the typewheel assumes the shift position. Hence, these rods not only form a run-way or track for the carriage, but also serve to transmit energy to the carriage for the typewheel move- ments. Because of this arrangement, the elec- tro-magnets operating the typewheel can re- main stationary, and be rigidly attached to the frame of the machine. A third rod, simi- lar to the other two, but not assisting in the support of the carriage, is located be- low the other two rods. This third rod serves to transmit the motion of rotation to the typewheel. We see, therefore, that the car- ~ 138 asf YETAROUIET OQUITUIAT TO METEYE MUSRAOM SET -8bor L[ecte etanpe owt mo betrogque ef easi2 edd to tnort edd esoror rsefo brotxe dotsdw -7s¢ ed? .wetefq edd to tmort ab tert retnirg ent to emnoj;medw tadt beteusttenco oa at sgeie ect asiixte Leedweqys ect ,bemrst et ebor edt ,bearut ef Bor tendto eft medw ,netala ,eoneH .mottteocad ttide edt sonuaes L[soedweqyt dost xo yaw-owr 8 orrot yimo ton ebor eesdt dimesaert of evres ols tud.,egetrrso edt ref ~8V Onl Leotwoayt ext tot exsixreo et ot yatere -oete ond ,trcomegnetzs etdt to eaveosd .atoem ~et meo L[eedrecyt edd anitareqo etsugem-ort ot bedoatia yilbtate od bas ,yrecofttetes ata -iute ,So% briant & .omtdosm ont To emart odt mt antietass fon ted ,ow? redio edt ot «sl -od Dstscof st ,eneteras edt To droqqua edt eevies Sot hbitdd atd? .,shor owd redto edd wol eft ot mottstor to mottom edt simeaetd ot ~tso. eft tad? ,eroteredd ,eea eV .Leedwoeqyt 139 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY riage serves as a support for the typewheel, and also transmits to the wheel the movements of rotating, striking, and shifting. The complete carriage is shown in Fig. 32. As the mechanism is rather complicated, we will take up, one at a time, its various functions and the parts concern- ed. The carriage frame is shown in Fig. 33. It consists of two parts. The first is a yoke, which is supported by the two steel rods as stated before. The yoke is fitted with round collars, free to turn, which have square holes at their centers; the holes fit the square supporting rods, so that when the rods are turned, the collars turn with them. The second part of the casting is of the form shown; it is attched to the yoke by two small shefts in the bearings. eél YECAADRIGT DAITHIAT FO MATCYe MUATAAOM ANT e{eeiwecys ont tot vroqqye s es eevres enetr atnemevom eit Lfeenw edt ot etimenett oefa base eartttide Sas .grtdicta ,aattator to ef szelitas etefqmoo exAT tedvat at metxadoom edv eA .SE .att of cworlk ,emtd a ts exo ,gu exXat [ftw ow ,botsotfamoo -resioo ettag edt bas amottonst esotrav est - be mvora at omart sastrrso eAT edt .etteq owt to atatemoo tI .88 att ot eit yd bettoqqya eat dotdw ,etoy se et tertt et exioy eff .etoted betsta as aber [oote owt dotdw .arut of sett ,atsf{f[oo basor dtiw hbetttt eefod oft :atetmes ttedt ts sefod srsrpe evad sedw tedt o8 ,ebor amttroqque etaspe edd ttt dtiw arst arsffloo edt ,benrrst ota efor odt to at anttaso edt to trsag baooee oft .modt yd sioy edt of bedotts eft tt jawode mrot edt -eattrsed edt at atisde [fame owt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY In Fig. 34, we see the es- sentiel parts for rotating the typewheel. The bevel gear, B, is mounted on the lower end of a vertical shaft, 3; at the top of the shaft is a universal joint. A sleeve, A, is attached to the upper member of the uni- versal joint, and into this sleeve slides the typewheel shaft, F., The upper end of the shaft carries an arm, called the locating erm, which locates the typewheel. The type- wheel is set onto its shaft with the locat- ing arm extending into one of the holes in the bottom of the wheel. The shaft, F, is at- tached to the collar, C, which fits over the Sleeve, A, The collar, C, and the shaft, F, are joined by a small pin, D, so that the the collar and shaft can move up and down a- long the sleeve, A, This mounting is neces- sary in order that the typewheel may move to 140 ODL YHTARORIAT DAITUIAI TO MATSYe MUTATOM THT -a8 edt cea ew ,d8 walt al -faetiweqys edd anttstor tet atrsq Istines tewol edt ao betavom et .f .tseq Leved eT to qod eft te; ,ttsde [sottrevy s to ine eA ,oveolfs A .tntot fastevtas 3 eat stada edt -tav odd to tedmem tecas eit ot bedostts at aebifs eveel[s etdt otat Bae ,fatot [seater edt to bas taqas ofl .t ,ttade [sedveqy? edd anttesol edd Sef{fao ,orts me setrtss stada -egyt off .feedweqyt adt setssof dotdw ,mrs -tsool edt dttw tSade att ofao tea et [sedw mt ssfod edt to emo ofmt gaotbmetxe ams ant -ts et |, Made of? .feody oadt to mottod edt edt reve stit dotdw ,0 ,teffos edt ot hosdort «% ,ttade oft bar .9 .zslloo ef? .A yovools eft tentt oe ,7 .atq [lame a yd Seato§ ote -8 a7ob bas qu evom mao ttade fos taffoo eft -aecen et anttnvom eid? .A ,eveete eft anof ov svom yeu Loedweaqyt oft tad? tebro mt ree Ss - 3 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the shift position and may still be rotated. The purpose of the universal joint is to al- low the typewheel to strike without disturb- ing the gear, B, and the shaft, S. Fig. 34 also shows the method by which motion is transmitted from the rota- tor shaft to the gear, B. A second gear, =, meshes with the gear, B; this second gear, E, has a square hole cut in its center, so that it fits over the square rotator shaft. Hence, when the rotator shaft is turned, the gear, E, is also turned, so that the typewheel rotates. The gear, E, fits the rotator shaft loosely, so that the gear can slide along the sheft with the carriage, and be in mesh with the gear, B, In Pig. 32, we see the rota- tor parts in place on the carriage frame. As is indicated, the second casting of the car- 141 fat YHIARVAITT DUITMIAL FO MATCYe MUAAROM AHT ehotator ed ([f{tts yem hae cottteoq Hida adt -fa ot st tatot Issteviasw edt to saoqrug edT -dtusvatbh tuodiiw etirte ot [oodwoeqyt edt wol oc ,ttede oft bas ,.f .t898q eft gat Sodtem edt awode oefs £8 .9tt -ad or edt mort botiimanexrt st nsottom dotdw yd 22 41899 baooee A .E ,t892 edd o¢ ttade rot .2 ,t8903 booose aldt :;¢ ,rs9e3 ott dtiw esdaen teadt oe ,tetnes ett at tvo ofod eterpea es aad ,eonsH .ttsda rotstor etsryoe edt tevro atit tt ,2 ,t803 oft ,bearstd et Jiade totstox eit mosh eastator f[senwoqyt edt tad? of ,dentut osf{s af eTleeool ttede totator odd attt ,2 ,1raes eT ttene edit amofe ebtis aso 188g eft tadt of et} dtiw deem at od bas ,easivtas edd dttw ~& ,Tse2 -stor edt o98 ow ,S& .stT al eh .emett essixrse edt mo eosf{q at atraq tof -tso edt to anttaso baooea sit ,Sstsotbri. at THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY riage serves to support the sleeve, whereas the lower casting holds the shaft, F, of Fig. 34. Fig. 32 also shows the gear guide, by which the gear, E, is drawn along with the carriage. As indicated, the lower casting carries an arm extending downward, and this arm supports a collar bearing for the gear E of Fig. 34, The striker movement of the carriage is shown clearly in Fig. 32, left view. To the coller, which fits over the striker shaft, is attached a lever, #25-4, the upper end of which is connected by a link, #25-5, to the upper casting of the car- riage frame. Hence, when the rotator shaft turns (to the left), it turns the lever, #25- 4, which movement pushes the typewheel to the left and downward, The carriage in this latter position is shown in Fig. 39. 142 ear YHIAHOAINT DUITAIAT FO METSYe MUAXHOM FHT asetediyw ,eveele edt trogqqra of sevtes ogait eBtt to ,2 ,ttade sdt ebfod xuattsso towol odt vd ,ebtira tases ed? ewode oefs SS .2tt .d8 edt diiw anofs swath et ,2@ ,rseg edt dotidw anttase towol odd ,Sotsofiat ef .ousiitss eidt bor ,Stawawob anthaetxe mre as eeirrss tees oft rot anitsed raffoo ea atroqqya mrs 35 .a2tt to & edt to smoemevom textrte adfT Itef ,SS .gft wt yltsefo awode at osgatixtrao edt rsvo aftt dotdw ,rsf{foo oft oT .welv »d<dg4 revel s tedoatta at ,ttade tovizta 8 4d boteemnco et dotdw to bre teaqs oft -tso edd to gattceae teqqu oft of ,8-88} .XatLl Stade totetor edt medw ,soneH .omatt oastt -a8h ,revel edt emus tt ,(ttel edt ot) ement og feodweqy? edt sedavq taemevom doftdw ,> aidt mt easttrss od? .Srswtwob bas ttel edt 88 .ght at mwode et xotttescg zetitsl 143 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Note that the joint between the carriaege- frame castings is in line with the univer- sal joint of the typewheel shaft; hence, the carriage can bend over like a hinge. A centering device is added to the striker movement of the carriage in order that the raised characters of the type- wheel will always hit the paper squarely. Onto the typewheel shaft is attached a star- wheel, #25-14 (see Figs. 32, 35, and 36); the star-wheel is so placed that the spaces between its teeth lie directly below the re- spective characters on the typewheel. A cen- tering lever, #25-19, is mounted on the car- riage frame as shown in Fig. 36. This lever is pivoted, near its middle point, to the carriage frame; the lower end carries 4 cross- pin, P (Fig. 36), which fits into the slot of @ transverse cam, This cam is rigidly attached “hed or & YRIAAPRINT DQUITHINT TO MaTeYe MUSAHOM THT -ensirrso edt meewted tntot edt? ted? etot -tovins oft ditv entif at et santtaso emstt edd ,somed ;ttade foodweqyt odt to tmtot [sa eagntd s extl revo bred 129 exetrrss Sebbs et estveb attretmes A at egsitrse eit to taomevom reiatrte edt of -eqyt ait to sretvoertsdo beatat edt tacit teSto eUlotenmps teqeq edd tid ayawle [Itw [seidiw -tate s ferfostts et ttede Lfsedweryt edt ofn0 7(a8 bee ,38 ,SS .aatT oon) AL-38% , Loos seoscge eft tedt Beoslq o2 at Leedw-tsta eft ~et eft wofed qitoerth etl dteet att nsewrted -teo A .[sedweqyt edt mo atetostads eviiseqe -189 edt mo bedavom at ,eL-88 ,revel yatret revel sidT £388 .3tt at mwode ea omert egsit edt ot ,tatog ofbbim ett rsem ,Betoviq eat -ge0ts a eetrtse bae tewol ent jomart easiritso So tole edd ofut atit dotdw , (88 sft) I .ate Sedosttes qlbtalt et mso etdT ,mao earevansrd 2 144 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY to the lower casting of the carriage. Ordin- arily, the centering lever is in the position shown in Fig. 35, but as the carriage is bent over for the striking movement, the relative motion of the cam and centering lever is such that the upper end of the centering lever en- ters one of the spaces between the teeth of the star-wheel. Both the aibee end of the centering lever and the spaces in the star- wheel are slightly V-shaped. Hence, as the lever enters the space, the star-wheel and typewheel are not only brought to center, but are locked in that position until the end of the stroke. The parts are returned to their original positions through a reversal of ro- tation of the striker shaft. The shift mechanism may be understood from Fig. 32. The collar which fits over the shift shaft carries an arm, A. Saf YHTAHPAIAT DHITMIAY TO METeYe MUAAHOM FHT ~aibrO ,eaatrtss edt te anttaso rewol edt ot mrotttsoq edt ai et tovel antretmes ed? ,ylirva toed st sasiznrso eft as tid .d& .3f% at mroda evitsfer edt ,tnoemevom gaidizrta edt tot revo ifoss at revel amtretmeo bas meo edt to nottom ~te tevel gatrotmes sit to bae teqqu edt tadt to dteet odt asewted seosqa edt to ono eret eft to fae xreaqr edt dtod .lesedw-rste ant -tate edt at seoave edt bas tevel antretaeo edt as ,eonmeH .beqadte-¥ yitdetlfe ers foedw bos L[oedw-tate sd? ,eosqa edt arotne revel tod ,teataes ot tdyvord yino ton ets L[sedweadyt te bao oft Ctinuw nottteog tadt nxt Sexool ots xtedt ot hbhemavtet ors eitag ofT .ovorte oft -or to [sersver s dusotdt? srotiteog Lantatro ettade teitrtes eft to nottst ad vem metnadoom tiide od? dotdw raffoo edT .Sé sali mort Sostesokas eA ,mrsa os selrrso ttede ttide odd revo atit THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY By means of a link, this arm connects with the vertical sliding rod mrked "shift plun- ger", This rod slides up and down in the bear- ings on the main casting as is shown in the figure. To this rod is attched the clutch, #25-7, which is merely a flat plate. One end of the plate is attached to the plunger rod; the other end is forked, and fits over the end of the coliar (C of Fig. 34) on the type- wheel shaft. When the shift sheft is turn- ed (to the left), it turns the sleeve and the arm, A, This movement reises the plunger, #25- 42, which movement, in turn, raises the clutch collar, typewheel shaft, and typewheel. The typewheel is thereby moved into the shift po- sition. A return spring on the carriage brings the parts of the shift mechanism, in- cluding the shift shaft, back to their normal 145 GSI YHIAHSRIZT OMITHIAT TO METSYe MUSAAOM FHT dtiw atoomroo mra etd} ,~nvif » to ansom yo -culq Stide"” fextam bot gathtie L[setirev srt -rsed sit at mwob bare qu sebtf{fe bor etdT ."teg edd ot mwode 2t es anttaso xtam edt mo eant efotelo edt hbedotis at hor eitdt oT .otoultt bro enO .etelg talt s ylotem ab dotde , T-884 bor tega Ig edt ot bedoatts et stsfq edt to eiy tevo atit Bus ,bexrot at Bae tedto oft -sayt edt mo (8 watt to 2) seffoo eft to hae ettede Loew -atay at ttede siide odd sod’ edt Bas eveole eft enrud tt ,(dteLl eft ot) Be -a8% ,regaclq eft seatst taemevom etal .A ,ors dotefo edt seetsar .atet mt ,tromevom dofdw ,Sd ei? .feedweqyt fas ,ttste Lesdweqy? ,talfoo -og ttide sit otnt Sevom yderedt at feedweqyd ecottie ensitrtas eft mo gsairqe oxster A . -ti ,aatasdoem dttda edd to ettaq edt agatrd Ismrton ttedt ot Hoad ,ttade dtids edd aatbulo 146 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY inoperative position, This spring is shown in Fig. 32; it is stretched between the spring bracket, #25-10, on the plunger, to the lower part of the carriage casting. The inker is the device by which ink is smeared onto the typewheel face during the striking movement; the ink is applied just before the wheel strikes the platen. The inker consists of a small felt roller, soaked in ink, and mounted on sup- porting levers. These levers are attched to the frame of the carriage. As this device is mechanically simple and unimportant, it is omitted from the detail drawings; it is shown, however, on the assembly photogrephs. THE ROTATOR, STRIKER, AND SHIFT? LINKS. The means for turning the ro- tator, striker, and shift shafts are shown in Pig. 37. This figure also shows the meth- od of supporting the shafts on the main bear- aby VETAZDEIET DAITHIAL TO MaTeye MUAAHOM AT mwode ef antuqe stat ,motiteog evitsteyont gnitqa edt nsewied bedoterse at tt ¢SS .altt at rewol edt ot ,toanulg edt mo ,Of-d8% ,totoard esaiteso ezsiizss edt to Treq yd eotveb ett at revni oT sost Lfoedweqyt edt otro betaema at ast doitdw et Act sdt <tnomevom antdinte edt ga throdb edt eexttxte L[eedw end? oroted tent betiqgs tfLet £fame 2 to atatemon tevtat onT .netsiq -que mo Satavom bas ,att of bexsoe ,reffot ot Bedotts ers etovel seed? .areval axicirog et eotveb etdt sA .eastrtso edt to omaxt edt et tt ,tuetroqminy See efomte yifisotmadoom eMwode st st ;aantwarh ItstedS edt mott Settimo ~adgataotoda yidweseas edt mo ,tsvewod (tA ,AENITTe ,HOTATON ANT -or eft antanet tot anmsem ofT .eXMIT THING mwots ete atteada wtide bas cethete ;<edat ~dtem edt awode orts stvgit eldT .VS «att at -rsed ntem edt no attads eft aritrogqqua to bo THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ing plates. THE ROTATOR LINKS. Consider- ing the rotator mechanism first, we see that the rotator magnets, which furnish the ener- gy for rotating the typewheel, are located at the bottom of the machine near the middle of the base. There are two sets of magnets: one set for left and one set for right rotation of the typewheel., Each set consists of two solenoids, allfour being supported from the base by the magnet bracket. Each solenoid is fitted with a sliding core or plunger; the two plungers of the left rotator magnets are joined by a yoke attached at their ends, and likewise, the two plungers of the right ro- tator mgnets are connected by a similar yoke. From the center of each yoke, a rod, R, comes forward between the two solenoids, passes through a guide hole in the magnet bracket, 147 Tal YHTAHDAIGT OMITUIAI FO MeTeye MUAUHOM SH? aeetsta ant -<teblemod .2@aviT AOTATOH THT fedt oc8 ew ,tarit metnedoom totetor edt art “tenes edt datart detdw ,atemgam totstor odt ve hSstsool ote foeedwaqyst edit antitator rot va to ofbbim oft rsen enxtdoem edt to mattod edt eno :atenmgen to ates owt era ered? .oead edt xottstor ddutr tot des exo bas ttel rot tee owt to ateatasos tee doei ,feendwoqyt edt to edt mort hettoqqse anted twotfifis ,ebtomefos eat Sroxefos dost .sexostd teaaan odd yd easd edt ;regnufa to etoo antbtlfe s ditw betitt ets stengem rofator ttel ext to etegretq owt bare ,eboe ttedt ts bedoastte avtoy s td bentot -or tdstt edt to exreagnelq owt oct ,oaetwoitlf -ofoy rsfinie s yd 5etoennos ete etonagsu totst Bemoo ,f§ ,fort s ,exdoy dose to retaso oft mort aeeasq ,ehtonefoe owd edt neowted hrawrot etodostd tergem et at efod ebtyg s davordt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY and terminates in a rounded end at some dis- tance in front of the bracket. Hach rod is fitted with a collar near its projecting end, and an open-coil compression spring is placed between the collar and the bracket. We come now to the connecting links between the ro- tator magnets and the rotator shaft. The connecting links comprise first, an auxiliary shaft, called the magnet shaft. This shaft is supported at one end in a bearing in the magnet bracket, and at the other end in a bearing in the main right bracket. At the end near the rotator coils, the shaft carries a cross-bar, ©, and near the other end, the sector of a gear. In Fig. 37, this sector is shown considerably to the left of the right main bracket; in reallity, the sector lies very close to that bracket. The crogs-ber, C, extends in front of both 148 Bhi YHSARDAIZT PUITHIAL TO MaTeye MUSAHOM RT -etb emoe ts Bas bebavor a at setsatmtret brs at bot dost .texoatd eft to taort at sonst eboe anttseforq att taea se{[foo = déitw betttt Seosly et anttqa soteserqmoo [fos-neqo ae base emoo oF ,texostd edt bas telfoo oft moswied -or edt aoewted axtmt{£ amttoonmoo eft ot wor etiede totstor eft Sue etenasm rotst estigmoo auzatl amttoenmos edt tomgam edd Holflso ,ttede yratfixnve as ,tertt at Bae enc te botroqqye eat ttatia etal .ttede edit ts bos ,tedostd teagam edt at anitsed s tduit atem edd at gatised e at Bre tedto .eftoo totstor odd taem bae edt tA .tedostd teen Sne ,0 ,tad-asots 8 eselrtse stade edt -3f£% mI .tse3 s to toteese edt ,5ne tedto edt edt ot yfderebleanoo awode st totooa eatdt VS eUtif{f{feot at :texosrd ateam tdatr sft to ttef eJoxdostd tadd o¢ seofe yrev eetf totsse edt stod to toort ot abmetxe ,o .tad-aegoto eri THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY rods, RR; the springs on the rods keep the rods firmly against the cross-bar. The gear sector stands vertically on the magnet shaft, and engeges with a pinion of the rotator shaft. The operation of the scheme is as follows: If the right rotator magnets be energized, they draw their plungers for- ward; this action thrusts the upper rod, R, forward, and with it, the upper end of the cross-bar, ©. Hence, the auxiliary or magnet shaft turns through a small angle, and with it, the gear sector; the movement of the gear sector turns the pinion meshed with it, and in that way turns the rotator shaft. If the left rotator magnets had been enerzized in- stead of the right, the rotator shaft would have been turned in the opposite direction. Means are provided for re- turning the parts to their original positions 149 bf YHIAAOSIAT DAITHIAL FO MATeYS MUSAHOM FHT edt goot shot edt co eamitge edt 38H , shor tse3 eff .rsd-ss0tos eft taniesss yimttt ebor -Jieda teageam eft mo yf{isotiirev sbaste totoes stotetor elit to sotataq s dtiw 2seqgegre bas ttads emedos odd Lo gottsteqo odT atemzem totatot tdatt edt TI :awoffot as at “rot etegautq xstedt wearh yedt ,bostaroeme od 2H. .bot toqqs adt eterrdt mottos ald? ;htaw eit to Bae reqqy edt ,tt ditw bas ,.irewtot vemgam to yrseifixzes odt ,esmeH .9 ,.tad-eeorTe dtiw Bas ,efans [feme s davordts aarst ttede t20g oft to tnmemevom sdt y2rotees tases edt ,tt bas. ,tt dAviw hedeom amotata edt artet totoes ent tI .ttede totator edt enrut yew tadt of -ni Bostovone geed Sat etenaam totstor Stet bivow ttade rotator edt ,tdatt adt to Ssotsa ~mottoorts st aie eit of bomast ased evad -et Tot hehivorq ets siacM anotttaog fantatto ttedt of attaq edt antatet THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY after the rotator magnets have been de-ener- gized. A small arm, called a centering arm, is attched to the magnet shaft at the out- side of the right main bracket. This arm points downward. At its lower end are attach- ed two closed-coil tension springs, called centering springs. The other ends of the springs are attached to anchor lugs on the main bracket, one lug being at the left and one at the right of the arm. The right-hand spring is attched to its lug by means of an adjustable screw, so that the tension of the springs can be varied by the turning of the screw. By this arrangement, the two springs tend to draw the arm in opposite directions, one toward the right, and theother toward the left. Since the springs are equal in strength, there is no displacement of the arm from its central position. If, however, 150 oaL YHILADEIRT QALITAIALT FO MATeYe MUSAHOM FAT -rete-05 meed evad efoagan totstor edt tetts ets antrotaes s befiso ,mares [ieme A .bosts -tiro oct fs ttarie tveogam odd ot hodotta et mrs etaT .tetostd mtan tdzgit sdt To osble -dostts ots Smo tewol stt tA .Brswavob etatoq feffso ,eantrqe aotenest [too-herols ows Be eit to ehne troedto ef? .agritcqe antretmeo edv mo earl vrorffoms of Sedostts ets eantiae bas ttef od? ts ented auf eno ,tetoatd atsm fasd-tdgit efT .mrsa edt to tistr edt ta sito os to ansom yi auf avr of bedotis ef gatige efit to mnotenet oft tadt o8 ,werse efdetarths edt to actaxut edt yd Setrav ed nse agattas agatitqe owt edt ,tmemegnatis etdd yl .weroe ~amottoetth etteogqo wt mrs edt weth of Saot brawot redtoedt bas ,tigtt edt Srswot ame at farpe exs agntrqe eft oomte .ttel edt eit to ¢remeosiguth on 2t eredt ,dtanerta eTevewond ,tI ,wottteog L[atines att mott mrs 151 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY a rotating movement of the typewheel occurs, the centering arp turns with the magnet shaft, thereby drawing out one centering spring and releasing the other. When the rotation mag- nets are de-energized, thus releasing the torque on the magnet shaft and centering arm, the springs draw the centering arm back to its vertical position. This movement of the arm brings all the rotator parts back to their central positions. The centering device just described has proven to be inadequate for rapid working of the printer. All the perts should be centered after one letter has been printed and before the next has begun. When the letters are printed in rapid succession, the centering mechanism does not work fast enough. The action of the springs diminish- es aes the central position of the arm is ap- a ae fel YHIASOAIET OMITMIAL FO METEYC MUSZTOM FHT ,atpooo L[sedwoqyt edt to tromevom satiaetor a ttede temas edt dttw ecrot ors anirotaeo ont base aottge aniretmss exo tyo aniwertS ydeteds -gem sottetor efs nodW .tefto oft grbaselet edd anteseler endt ,hbostgrene-e5 ets sten tea goitretmes Sas ttsde tangam edt mo exprtod ot aoed oms 2atretnes edt wath esantrqa edt edt to tnxemevom etdT .motttacg L[sottrev ett ttodt ot toad streg totator edt [fe saniid ors eenotttaoq Lertaco. test eotveb amitetaes ol tot eteavpehent od ot mevotq aad bediroaed atxeq odd £L4 .tetatrtq oft to antdrow Blast seed ead xettel ono rests baretaso ed blroda sedW .csaed sed txot edt stoted bas hetatra etotseooore Blasr at Setaiza ove etettel edt test atow tom sech mataadoom gaitotmen edt -Salalmib eantiqe eft to sottoe edT .dasone -qs ef axe att to mottteoq [attaso ed? ae ae 152 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY proached, because the working spring is near- ly counter-balanced by the other. Therefore, @ second centering mechanism has been added; this latter device acts on the rotator shaft itself, and does not come into very great action until the parts have nearly reached their central positions, The second centering mechan- ism may be seen in Fig. 37. The rotator shaft projects through the main bracket on the right; the shaft is here fitted with a small semi- circular cam, D. Two small bell cranks are mounted at their elbows on the bracket as shown.One end of each crank bears against the flat face of the cam, whereas the two free ends are connected by an open-coil ten- sion spring. The centering action of the de- vice is apparent from Fig. 37. Note that the action increases as the central position of sar YHTASOF IAT PULTHIAT YO Maeve MULAZOM TT -rsen et eatige anisdrow eit eesssed , hetissorg ,etotered? ,tedteo ait yd beonmalsd-tetavoo yf shefiisa ased esd meinedoem gnivetces buosee £ ttede totator edt ao etoes eoltveb tettel. atdt teera yrev otat emoo ton esol Bae ,tLoatt betloser Ylreen evan eitac sid [linn noltes eenoliteog {[sxrtaeo ttesit -ceadioom anitretmes Buossa eAT ttede totetor sdT .TE att at moose od Ysm met :tigia odd oo texoatd mism edt dawotdt etostorq -tmse [femme se dtiw bessit etext at tHade edt ers exners [fed [fare owl .7 .meo talvotto we dedoacd pdisne-nvaliovwtioss ts bedrssocr tentsae ersed xrero done to bas sn0.cwore owt edt esetodw ,mso edt to essst telt edt -met [foo-neqo as yd betoannxoo ets.ehne sett ~96 eft to oottss zatretmes off .anttaqe note edt ted? efo# .VS .att mort Santana ei eoly to noitieog fertres edt ssa eeesetont cottor 153 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the parts (the position shown in Fig, 37) is approached. This increase is due to an increase of the effective radius of the re- storing torque, which increase accompanies the restoring movement of the parts. A locking cam is also shown on the rotator shaft, just behind the cen- tering cam; the lock, of which this cam forms a part, must be released before the rotation of the shaft can take place. The purpose and ection of this lock will be explained later. THE STRIKER LINKS. The striker rigging is also shown in Fig. 37. The striker magnet is located at the bottom of the machine beside the left main bracket. The armture is suspended from the lever, L, which is pivot- ed ed at its lower end to the left min brack- et, and attached at its upper end to the con- necting rod, E, The upper end of the rod, 3; SéL YHTASPEIST DAITHIAI TO METeyve MUSAHOM FET (VS .af% xt mwode notttaog edt) atiraq ont as ot osb at eaasstont etdT .bedesorqqs et -er ait to estbhar evitsettes edit to sasetont getnsqmooos eeseront dotdw ,erprosy anitote ecitec edt to taomevom snttoteer ent mwote cefe ef mso sittoof 4 -teo eft baided tas, ,ttsate rotator edt co emrot meo ett dotdw to ,Hoolf edt ymso antret mottstor eft sroted hoessfer ed taum ,traq 3s fos esogtug off .esefa etfst nao state eft to etetef heatelaqxe ed [ffw tool efdt to mottos setixte aed? .aamII AEAIATa SUT texiixte edT .TS watt mt mwode oefs ef sutsait entdoam sit to mottod eit ts fetaoot ef sengam et erstents of? .Jexfoard mtam ttef sAt ehteed -govia at softtw ,T ,revel edt mort hebmedere -dtostd otan ttef edt ot Bae sewot ett tsa be be -moo ed? ot bae rteqqs ett ts betostis Eas ,te w= ,bor ett to bre teqay edT 1.2 . bow gatioen THE MORKRUM SYSTEM OF PRINTING TELGRAPHY is joined to a crank, F, en the striker shaft. The connecting rod contains an adjusting link by which the length of the rod can be varied; this adjustment determines the magnitude of the impact as the typewheel strikes the plat- en. When the striker magnet is energized, it draws its armature downward, and with the armature, the lever, L. The move- ment of the lever, L, turns the striker shaft by means of the connecting rod, E, and turns the crank, F. The crank, F, is mounted on the striker shaft, so that the rotation is trans- mitted to this shaft. In order that the striker shaft and other parts shall be restored to their original positions after the stroke, a crank, T, and return spring are provided. The crank is mounted on the right end of the 154 YHTAHOLET PUITUIAT TO METSY2 MUSAKOM FHT -tistea xovttite edt mo .7 ,xmers a ot hemtot et Mnif uttdvesfbs as estetnoo hor satttoennos oedT ebotrev ed aso bor ext to dtanel ent dotdw yd to ebutinseam oft eenioreteh taemecutis etdt -telq est sexinta [eenwegys edd es soequt eit .19 al texsgesm tevixte edt sed? .Srewoved siutsure att ewerh ti ,besisaterce -~evom eft .f ,revel est ,ersteuts edd diitw base ttede rexievte ett sort .J ,tevel esd to taom ectst Basa ,= ,bor auatioennoo ait te ansem yd est mo fhetnsom at ,% .Maeto ofl .% ,Mreto odt -enett at cottetotr oft tedt of ,tteise texinte ettadfe atdt ot botdtio rsiixte eit ¢tadt tefto mf od Heroteet od [fede etreq stedto fas Stade ,etotte oft tetts emotttaod Ienitairo rledt ebebivorg ete aaitge mrster boa .T ,ansro s ent to bae tiznit edt mo hetnvom et arero oT 155 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY striker shaft. The return spring is an open- coil tension spring, stretched between the crank, T, and an anchor lug on the main brack- et, The turning of the striker shaft and crank T from the inoperative position stretches the return spring; hence, at the end of each stroke, as soon as thestriker magnets are de-snergiz- ed, the return spring draws the parts back to their original position. THE SHIFT LINKS. The shift mechanism is illustrated in Fig. 37. The shift magnet is attached to a bracket at the left of the rotator bracket. The magnet consists of a sOlenoid with a plunger core; as we shall see later, the magnet is also a relay. A plunger rod is fixed to the core, passes through a guide hole is the bracket, and terminates in a rounded end. This plunger rod bears against @ crank, G, which is mounted on 4 small shaft, aé6f YHTAHOGIET DUITUINS FO MHTeyYe MUADIOM FHT -nego oe el anitaca ormtet eiT .ttede texitte edd meewied betoverte ,unirqe ootene? [toe -isstd miam end amo art toders ms faa .T ,wrero xnato fae ttene texiaxnte ext Lo aninrut edT te efit eefoterta motiteog eviterecomt eft moxt T ,etorte dose to bre oft tea ,eoted :anirgqe arstet -sintone-9b ere storsem texintacsdt ss mo0e eA (ot dosd efteq eit eweth gunitqea cavter edd , be enottteog fantzizro rtedt $tide ed? .e2MVII THING FHT Stine efT LVS watt mt hetertan{[Il ef metredoem to ttef est te tedoerrd es of herosits at tersan s to etatecoo temrasm ed? .gexsatd rotator ent e928 [isde ow es ietoo tenmeltq Bs ditw blonsfoe tegnola A .ysfet 8 o8fs ef tomgan etd ,tetsl 8s dgvowt sesseq ,stoo eft of bextt af bor at ectanimies Bae ,tezoartd eit at efod ebtus tentens ateed Sor tezacf[o elf? .bae bebavort s ettade [fame & mo heteovom et NSotdw .» ,Xasto s THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY H, At the left end of this shaft is mounted the crank, I, bent to clear the striker mag- net as shown. The crank, I, is connected to the crank, J, on the shift shaft, by the con- necting rod, P. When the shift magnet is en- ergized, it draws in its plunger core, and in so doing, thrusts its plunger rod forward. This movement of the plunger rod turns the crank, G, the shaft, H, and the crank, I, Through the agency of the connecting rod, the movement of the crank, I, turns the crank, J, and the shift shaft. As for the return of the parts to their original positions, it will be re- membered that on the carriage, there is a shift return spring. This spring not only acts on the carriage parts, but in so doing, re- turns the shift shaft and all the rigging 156 def YATAMORIET YUITUIAT FO METeYS MUAUAOM HHT heodasom et ttade etd? to Bee ttef odt tA .H -gam revinte eft reefo ot taed ,I ,Anmero ext ot hetoennce st ,I ,awmaro edT .mwode es tor -roo sat yd ,ttede tide edt mo ,.% ,xMmero edd ot , bor neritoonx «te st tomasm ttide oft odd’ mt Brae ,.sT09 reasirtiy ett mi ewetb tf ,bestate eSuawrot bor segnvfg att atestdit .actob os edt enrst bot tesaelgq eit Lo daomevom efAT el ,Mmetro edt Bus .H ,itede oft .D ,dasto bot antteenroo eit to yoross eft dovordT enero edt ecrrt ,T fears att To tromevom ont ettede dtide eft Bae .% ettsq edit to atuter eft rot eA -ot ed [ftw sk ,eanottieog Lentgito riedt of s et etett ,esstireo edt mo Tadd ber)edmem etoe elmo ton arivas atdT .anitqe oroter itide -9T ,amioh oe xt tud ,2traq exsitiss oft mo aulasix edt [fe Soe tede ttide sdt art THE MORKRUM SYSTEM OF PRINTING TELSGRAPHY back to the starting position. THE SHIFT LOCK. A lock, which locks all the parts in the shift position, is also indicated in the figure. This lock consists of a T-shaped double crank, pivot- ed at the point of interseetion of its three arms on & lug attached to the magnet bracket. The stem of the T extends forward, and con- tains a notch on its under side; this notch hooks over the end of a vertical lever, EK, mounted on the shaft, H. The upper arm of the double crank is held away from the mag- net bracket by an open coil compression spring. The lower arm lies in the path of a plunger, which is attached to the plunger core of a solenoid. This solenoid is called the release magnet. In the operation of the de- vice, the notch in the forward lever is or- 157 Tel YHLARO7IRT OQUITMIAG TO MATEY MUANAOM SUF etoltvteoq acttixveate edt ot xosd foldw ,dool A .A001. THING ERT efoitteod tilde edd at etveq edd {fe adtool Aool etc? .etwatt eft at Seteaotbat osle et -toviq ,dmaro eldvob begqate-T a to etelanoo eetn? ett to gottosersint to tatog ent ta be -texoard teamoem oft ot BSedostimme acl s mo emts -m0o bre .ftewrot ebssixe T eit to meta ont dogon atdt ;eblte tebas est xo dotom # anita? eu ,-tevel [sottvey s to Ste oft teve eaxfood to mma regqy ofT .H ,tiads edt mo betorom -gem eft mort yewe Bred ef xmato efdsoh edt euaitgqes sofseserqmoo [tos mego as yd texserd ter ~tTegasto # to dAtaq edd at eetl ere towol oAT 8 to etoo tegastg oft ot betostis ef dotdw saseler odd belleo et Slomefoe eidT ,blonefoe -tenmssmn +98 edt to mottareco oct al -x0 el tevel Srawret oft at sotonm eft ,eotv THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY dinarily not hooked over the end of the le- ver, K; K is too far toward the front of the machine to engage with the notch. The T-crank does, however, bear against the top of the lever, K, under the action of the compres- gion spring. When the parts assume the shift position, the lever, EK, turns back a little, so that the notch \in the @rank drops over the end of the lever. Therefore, when the shift magnet is de-enerzized, the lever, XK, is not free to return to its originel po- sition, but is locked in its new position. Therefore, ali the other shift parts are lock- ed. The release of the mrts is effected by the release magnet. When this magnet is ener- gized, its plunger rod comes forward, strikes the lower end of the T-crank, and thereby raises the notch off the lever, K. The lever, with the other parts, is therefore free to 158 Bel YECARDAIET OUITHLIT TO METCYe MUSAROM HHT -ef ett to Bae est rove bexcod tom yYiitanthb edt to trort edt fsreawot ret oot et AX 3X , tev uinero-7 ef? .doton add Atiw exesme ot entdoam ent to qot edt tentace taedi ,tevervod .ss0b -ees1tqmoo edt to mottes sit treba ,x ,revel ttide edd emrees etrsq eft cof! wantiqe mofe ~eLttif ea dosd eaves .A ,revel edd ,mottteod tevo eqoth dmesd oft mt doton edt tadt oe edd cedw ,ereotered? .tevel eft to bre ot eo ,tovel et ,hextsrens-oeb ef songsm Ttide -og L[antzito ett ot srutet ot sort tor ef emofttvog wom att at hettoof ef tad ,aottte -fool ers etrsq vitdse tedto efit [fs ,ercteredT yd betoetts ef attra; oft to sarefer ofT whe -rete ef temgen ald? ned’ .temeam saselotr ent serints ,irawtet eeroo bor rennulq atk ,bests yderets Snes ,vxrare-T oft to bae towol arid etevel oft .X ,xevel est tio sotom edt soeter o¢ sett etotetedtt et ,stteq sertto edt dtiw 159 THE MORZRUM SYSTEM OF PRINTING TELEGRAPHY return to its original position. When the release magnet is de-energized, the T-crank again drops down onto the lever, K, and the parts are once more in the position indicat- ed in Fig. 37. The purpose of the shift lock is evident when we remember that often sever- al shift characters occur in succession, and it is desirable that the typewheel maintain its shift position throughout the series. THE SELECTOR MECHANISM. We now pass to the selector mechanism, by which the rotation of the typewheel is stopped at any desired point. It will be remembered that the typewheel characters are distributed a- round the entire ciroumference of the wheel, and in order that any particular letter be printed, the typewheel must be stopped in its rotation when that particular letter lies di- eal YHTAROEIET DPUITHIALI FO METEYS MUSSAOM ERT edt sedY .moltttsog Lantgiro ast ot mrvtet doero-7 edt ,hbestareme-ob at temsem seselet ert bos i ,.tevel edt otmo mwoh agoth aisgs -tsetiat mottteoqg eft mt erom eono ets avtTeq SS eatt at bo weol stide edt to escarsgy edT -revee notte tad tedmemer ow aedw inehive et fee ,cnoteeeoose ot swoeo etotoe rade ttide Ir itetotem L[eedweaqyt oft tad? efdartseb et st ecotres edt tsodgsoruds mottteog tiide at! oY .Me@IMAHOEM SOTORITe ANT cotdiw yd ,meateedoem toteefer eft of eaaq wor tea beqqote et Leedweqys ot to nottator ext tedt haredmemet od I[flw tI .tatog herteeb yore -s hetudixteth ers arstosrado L[seenweqys ett efoodw eft to escetetmvotto erfttne ed? harot ed tettiel taluotizraq yas tect tebro mt fae ett at fhecqote od tan L[eedweqyt edt ,bedoira -fh eell rtettefl tefsotitaqg ten? merry moktatotr THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY rectly before the platen. The selector, com- plete and applied to the machine, is shown in Fig. 38; as is indicated, it is located at the front of the machine beside the right main bracket. The selector mechanism proper is shown in Fig. 39. As the mechanism is somewhat complicated, its general principles will be explained before the description of the actual parts is attempted. The fundemental idea in the stopping of the rotator shaft is illustrated in Fig. 40. In this figure, we see the rota- tor shaft carrying an arm or lever, called the index lever. D is a stationary disk con- taining a number of holes. When the rotator shaft turns, it of course turns the index lever with it, so that this lever sweeps 0o- ver the face of the disk, D. If the rotation of the shaft is to be stopped at any desired 160 Oaf YHUAHDAIRT PUITHIAT IO MATCYe MUSAHOM FET -moo ,totoeefes ef? .metela oft erected vitcet awode et ,emidesm eft ot betfaas bra etelg Bevsaool at ti ,betsotbat eat ee ;88 .stt at tdett edd ebtaeed ontdose sit to tmort edt ts tecotg metnerfoom totoefee of? .tendsetd stam et meinedoom oft eA 88 watt mt owode et sefatonixag L[ereten att ,fetsotiqmooe tedwemoe to gotdqinoaeb sdt etroted beatafqxe od [Liw efotqmette ai sttsaq Leutos est edd mt sefbi {[sinemobavt od? betarvesf[{[t ef state rotator eft to antaqcote -stor eft see ow ,atyait eist al .0S watt ot hefIso ,tevel to mre me gniytreas ttsde rot “soo Heth yranctiste we at € .tevel xebni ott totetor sit sed .sefod to tedorn s gointat xrebat aad Comend eetsoo to tf ,entnt ttede -0 aqscewe revel etst tadt oe ,tt dtiw tevel smoitstor edt tI .C ,ofetb eft to soaet. edt tev BerteoS yaa ta beaqote of of al ttede edt to 161 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY point, a small pin is pushed up through one of the holes of the disk,D, into the path of the index lever. When the lever strikes the pin, rotation stops. THE DISKS. Such a disk me- chanism, with some minor changes, is used to limit rotation in the Morkrum machine; the mechanism as applied to the printer is shown in Fig. 4la and b. Here, there are four thin steel disks, called selector plates, each of which is similar to the disk, D, of Fig. 40. The four disks are arranged in a pile, with @ supporting collar running through their centers; this collar is marked "S" in the figures. Bach disk may be turned independent- ly through a small angle on the collar, the turning being limited by the plate stops as indicated. At the bottom of each disk is a lug which carries a small pin, P. An arn, A, fat YHIASHAIET DUITHILT TO METCYe MUAASOM FHT eno dasordsd qu bedesq at atq iene a ,tatog to dtaq est ott .¢,weth ett to vefod edt to eit sevirte revel odt mod .tovel xebrt edd -egote softtstor. at -om Meth se dop& . .2ck21d: ERT ot foau el ,segnedo tonim smos dtvitw ,metrado edd sentdoem merdtroM odd of actistor timilf oworle eat setaita edt ot beliaqgs ss. metnadoom akat reset ers eredd ,eraE .d bas aft watt at to dose ,setely trotcelea beffeo ,exteib feete Oh sail to, ,teth edt of telimte et dotdw cttw ,oftg s at begnerrs ote aslelth suct edT sted¢ davordit actoorr telfoo goidroqqua s edt mt "2" beslyam ef talfoo eldt garetmeo -trebueqeiat berrsd od yew detb seat .eomstt edd ,telfoo edt mo efans [feme a dasordt xt es eqote etelq odd yd betiniti£ ated antoztst s at xeth dose to mottod edt t4 .betsothat A mrs oA .T .ntg {Lame 2 setrtsao dotdw got 162 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY with a forked end, fits over the pin, P, and at its lower end, is attached to a small sup- porting shaft, B. A second arm, C, is also mounted on the shaft, and this second arm lies in the path of a plunger rod which is fixed to the plunger core of the plate solen- oid. By this arrangement, if the plate solen- oid becomes energized, it dtaws its core for- ward, and, through the agency of the two arms, C and A, turns the disk from its normal posi- tion of Fig. 41(a) to its opposite position of Fig. 41(b). When the plate solenoid is de- energized, all parts return to their origin- al positions under the action of a coil spring, ube akewn., wound onto the shaft, B. The method of moving each of the other three disks is identical with the one justvdescribed. The arrangement of the links betw@en the solenoids and disks is shown Sal YHTAAOEIZT DULTUIAL ©O MTeye MUAAEOM FHT Sos ,1 .xtq eft steve etit .bae festxot we diiv ~que [fame s ot bedoetis et ,hme tewol ett tea oefa et ,9 ,mre broees A .o ,tItstie antitog x asta Hoooee eatdt Boe .ttede off mo botasom et dotdw bor tegnuf{q a to stsq oft at sell ~sefos etalq edt to etoo tegnutg eid ot bextt -mefoe etefq edt tt ,tnemegnetre atdt yi .bro -tot etco etl awetS ti ,beata rere esemoced blo ens owt oft to yoregs edt davorit ,Sn8 , Stew -leoq Ismrom ett most Melb ed? anwut .A base 0 nottteod etteoaqo att ot (a)IS .gtT to mott -eb at blonefoe etelq edt medY .(d){2 .gtT to -ataite rtedt ot atetet atraq [Ia ,bostgrens egatvae [too s to sottos edt rebas ancttisog fs ef ,dtade edt otmo hacow somalia deans to dose antvom to bodiem sx? ext ditw [seofinebt et extets eerdt yedto edt edt to tremepnetts edT .bodirorebh text sto mwoda aft extetS bas aebtomefoa ext no@wied etait THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY in Figs. 41(¢) and 42. The plate solenoids, as shown in Fig. 42, together with certain other solenoids of the printer, are mount- ed on the large relay bracket, which is at- tached to the base. The figue is self-ex- planatory. By this arrangement, any disk may be moved by its plate solenoid, inde- pendently of the movements of any of the other disks. As for the manner in which the disks are used, the index lever of the rotator shaft sweeps over the face of the outside disk (the one shown in Figs. 41), just as the lever of Fig. 40 sweeps over the face of the disk,D. Ordinarily, the in- dex lever is in the central vertical posi- tion shown in Fig. 40, but if the rotator shaft be turned, the index lever of course turns with it. The disks are shown in place 163 YETASPEIST QAITUIAT TO METEYe MUSSHOM THT eebtonefoe etslq ed? .Sh Bas (o}fd .extE nt mtetrss dtiw rerctesgot gh esiil of mwode es -trnoom eve ,tetatyq oft to eftomefoe teanto -ts et dotdw ,texoetd yelet extel edt oo bo -xe-tfee af evatt exT .sasd oft ot Bedost weltb yas ,tmemegastts etd? yi .yroteanalq -ebot .Btomefoa etsig att yd hevom od yeu edd to yrs to etmemevom eft to yitnebneq ~exetbh tedto tofdw at tenmean edt sot eA eft To tevefl xebot eft .fean ote evealtb odt edit to eest edt revo ageewe stade totstor (£2 .egit of awode eso eft) Hath obtetwo tevo eqeewe OD .siT to tevel ent sa tent -ot eft .yliranthrO .¢, Hath eft to eost odt -laoq [aottviev Isrtneo edt at ef revel xeb totator oft It tud .Ob .afi ot mwode acl? eervos to tevel xebat edt ,hentot od $t ate seafq at mwode eva exfetbh eT .tt dtiw eaxust 164 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY on the printer in Fig. 38. The construction of the disks is such, as regards the location of the holes, that if each disk is in one extreme angular position or the other, there are two rows of holes through the disks lined up, and only two rows. For instance, if all the plate mag- nets be energized and all the disks, there- fore, turned to the limit of their travel, there will be two rows of holes lined up, each row extending entirely through the set of disks. Furthermore, one row of holes will be on the left side of the index lever and the other row will be on the right. Hence, if a pin be thrust from the back of the disks through each row of holes, so that the ends of the pins extend beyond the face of the outside disk, the index lever, rotator shaft, and typewheel can turn only until the index bat YHIARPRIET QUITUIAT FO METEYe MUSAEOM THT 88 ,att at rtetaitq eft mo eatet& eft to mottorirtenxos edt cefod ext to nottsool ect ebtsset es ,dove et tefirarsa ometixe eno mt at Hath doze Tir tart to ewot owt ers erent ,redto ext ro nottteoq yinxo Bas ,qu boeotl edetbh edd Assrotdt seford -gem etefq eft [fs It ,eomeatant tol .eror ond -eredt ,exetbh edt [fs bas besiaisene ed eten efeovett tlott to timti eft ot hermit ,erot eas bentl esfod to ewor owt ed [fiw eredt tee eft Agvord? ylertioe anticetxe wor dose {fiw easfod to wot eno ,stomreditet .eveth to base rteve{l xefat edt to eblte tteLl ext xo od .e0n6E .tdatt edt no sd [fiw wor refto sed? exeth eft to xeosd edt mort tautad sd ata s tt shine edt tad? os ,eefod to wor dose dssordt edd to eset edt broyed bmetre entq ext to ettade totatot ,tevel xebat edt ,weth ebltetiro xebat oft Lites yIro mut rso L[eedweqyy base THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY lever strikes one of the pins. In case the left rotator magnet be energised, the index lever strikes the pin to the left. Likewise, in case the right rotator magnet be energiz- ed, the index lever strikes the pin to the right. In the same way, if all four disks are in their normal position, that is, if none of the plate solenoids are energized, there are again two rows of holes through all four disks. As before, one row lies to the left of the index lever and the other to the tight. These two rows are different, however, from the rows in the first case. Hence; the rotation of the index lever, rotator shaft, end typewheel is again limited in either di- rection, but the limits are different from whet they were in the first case, Likewise, if only one of the 165 oof YHIALOEIAT OMITUINT LO METeYe MUAAAOM ART edt exec al .enta ett to eno eoxinta tovel xoeirt edt ,beatetens of tongem totator Stel ,eatwenttd .ttef edt of atq edd eexttrts revel -stetens od tengam totator tdgtt edt erso at edt of atq odt aetiute tevel xebat eft , fhe etdalt sot [fs tr ,ysw emae oft al ~ai ted? ,acottteoq Lenrron tledt ot ers arfetd 5estatene ors aftonefoe estalq oft to emon TE [fs davordt aefod to ewor owt aisas ers oxedt edt ot eetl wor eno ,eroted eA .edalh twot edt ot sedto edt Ses revel xoiat edt to ttef etovewon ,taoetettih5 era swor ows osen! Srigit edt ,eemeH .seeo detit edt at awor edt mort etteda totator ,vovel xobat oft to mottstor ~th vredtte at botimti£ atass et L[oedweayt bas mont trervettré ets etimtt£ edt tud ,aottoet .9a8o tetit edt st stew yodt tadw eft to exo ylmo tL ,eatwedltd THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Selector plates be turned, whereas the others remain in their normal positions, a still different row of holes will be established on each side of the index lever. No differ- ence how the disks are placed, provided each be in extreme position or the other, two paths for the stop pins through the disks are pro- vided, one path or row being on the left side of the index lever and the other on the right. As a result of this arrange- ment, we can stop the rotation of the type- wheel at fifteen different points in either direction of rotation or at thirty points in all. Considering also the center position of no rotation, we obtain a total of thirty-one different positions or points which we can assign to the typewheel. It will be remember- ed that we were able to send thirty-one dif- ferent combinations of line impulses; as we shall see later, the first four line impulses 166 aol YHTAHORIZT OAITMINT TO MeReYe MUAXHOM SHT etedto edd esetadw ,Senret od eatelq totoslea [f{tte e ,smottteog L[smrroa thledd «tf ataner hadetidstes od {fiw eefod to wor tmetettrs =rottis of .tevel xebat edt to ebte dose, mo Nose Bebtvorq ,Seselq ors eet edt wod some edteq owt ,redto edt to mottteog emortxe at ed -org 9o%8 etelb edt desordt entq qotea edt trot ebte ttef edt mo umtod wor to dtaq exo ,bebtv .tdgtt odd mo tedto eft Baa tevel xebat odt to -egmatrs aidt to tlieer s eb -eqyt edt to mottator eft gote aso ew ,tmom teditts mt etatog taereltth meotttt ts Leedw at atatog ytrtdt tea ro sottstor to mottoorld to moltteog rtetaeo edt osfa anixrebtemoo .ifs efo-yitids to Istet s atsatde sw ,amoftator os neo ew dotdw etatog to aeaotttsoa saeretTt5 -todmemet od fiw #1 .Loedtweagyt eit of agtsss “Erb emo-yiuidt S5a0ee ot efda erew ew tact be ew es ,;ecelugmt emtl to enottsatdmooe taeret nealnqmt eatf rvot tetit odt ,retel ses [fsda 167 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY determine the positions of the selector plates, whereas the the fifth pulse determines the direction of rotation of the typewheel. We see, therefore, the purpose and action of the selector disks. Furthermore, by the use of the shift movement, the thirty-one type- wheel positions are increased to sixty-two, just as the total number of characters avail- able for transmission was increased to six- ty-two. In the Morkrum system, not all of the sixty-two possible disk combinations are uti- lized. THE DRUM. The next question is how the interference or stop pins pass through the disks, are mounted, and operated. There are, in all, twenty-four of the pins, all supported on a steel frame called the drum; the frame is called the drum because of its general shape. The drum and pins are mae Val YHTAAOSAIST DUITAINT TO METeYe MUHAROM FHT ,estelq rotoelfes ent to amotitteod edt omtmorreteb ot sentmreteb eefuq dittt edt edt sseredyw 9” .feedweqyt edt to mottator to mottoerths to mottos Bae seogrsq edt ,stotetedt ,s028 sex edt yd ,stromredtrut .edelkbh trotoefee sit -eqyt eno-yitidd edt ,tnomevom tide edt to ,owt-ytuie of Asarseroat sts asotttiaoq Isedw -ftavsa aretosrado Yo todmsrn fatot edt as test -xts of Bsoasetont esw nwotaatmenstt rot ofds edd to {fs ton ,metsye merirolf edt nt owt-yi -Itu eva snottentdmoo wath elfdterog owt-yixte -bestl aottaesp txem ed? MURT THT seaq antg gots 10 senetetrotat etd wod at ebetateoqo bee ,betnvom ors ,adetb edt davord? ,enta edt to root-ytmews ,{[f[s at ,ots etedT edt belles emert feete eg mo hetroqare [Is eavaoed muth edt Beffseo ef emartt odt jmurb ers extq bas mrrh eT .eqade [arenes ett to 168 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY shown in Figs. 38 and 39. The drum consists of two circular end-plates, Py and Po, con- nected by supporting rods and space sleeves as shown in the figures. Each plate possesses two projections at diametrically opposite points; the projections sare bored to receive the two horizontal supporting rods. The end plates are kept apart by sleeves which fit over the supporting rods. These sleeves also constitute bearings, so that the entire drum ean slide back and forth on the rods. The two plates, Py and Po, are similarly bored with guide holes for the interferance pins. The pins extend from one plate to the other, and project both at the front and back of the drum. On each pin is mounted a small collar, and between this collar and the left-hand plate is placed an open coil compression spring, #35-14. 8aL YHLAAPRIST PAITAIHI TO MITSYS MUSXHOM FHT atatemoo mrh efT .eS bas 8S .eatt mt mwode =f09 eat Bae 5° ,eetsia-bes ts{yvotts owt to seveels soaqa bas efor aattroqags2 yd SBotoonr eeasesgecg etsiq dost .noeresgtt edd at amwode ea ettsoqqo yifsotrtemsth ta enottostorq owt evisosr ot betod ete anottoetora edt :atatog Bae ocT .ebot 2anttrogquve rabuiab<ée owt sdt ¢it dotdw asvesie yd txsqea sqex ets astelq oefs aeveele seed? .ebor artitogque edd tevo mixh etttme oft taedt of ,aantrsed etutiteaoo eT .ebot edt mo dtrot Sms xoasd ebtfa aso Berod yitsitmis ete ,of base pi ,setsf{q ows © -anktg sonstettetat sdv tot esfod ebireg dttw .tento eft ot stala smo mort baotxe extq oT edt to foed Ses tmort sdt te dtod toetorq has etalfoo (Lame ws betnvom ef atq dose mo .unTb Saad-ttof odd Bae taffos stdt neewted has moteserqmoo [too neqo ms Seoslq at atslq .df-38% ,gotrqa THE MORKUM SYSTEM OF PRINTING TELEGRAPHY If the drum be thrust toward toward the right, the projecting pins strike the pile of selector plates. Two of the pins will be in line with holes in the plates, and will pass through the complete set of plates, as was described before. The other pins, which are not in line with the holes, cannot pass through the series of plates; hence, they strike oneplate and stop. The spring mounting of the pins allows the frame to travel on to its extreme right-hand posi- tion, in which position, the two pins will extend through all four disks and into the path of the index lever. In Fig. 38 we see also the means for thrusting the drum toward the right. Beneath the drum is a magnet called the drum magnet, which is attached to the right main bearing. A view of the drum magnet alone is presented in Fig. 43. The magnet consists of 169 eeL YHTAADELIST DLITHIAI TO MaTeYye MUAHOM AHT Srawot sesrdt ed mrrh eft ti extite enmtaq anttoetorq edd ,tdatr eit brsvwot antg sdt to ow? .setsiq toteeflee to eiiq edt -eetvelq edt mt asfod cttw eat{ at ed {[I[ly to toe otefqmoo ent devordt sesq [fiw bas totte edT .,eroted fedtroeeb esaw. es ,astalq ,eefod edt dttw entI at tom ets dotdw ,antgq ssets([q to seltes edt davotit eseq tonmso edT .gote bas eteafaero sitrte yodtd ,somed easitt edt awolls eato edt to aattavom gaixge -teoq Daed-tdatr smertxe att ot mo Levert of {ltw entq owt edt ,motttaoq dotdw at ,aokt edt otat bos eteltb xrnot [Ls dgvordd baetxe .tevel xebnt edt to diag edit oafa sse ow 8S .2itt al etigty edt brewot corth edt anttesrdt rot ansem murb edt bellao tengem s ait mutbh eit dtsened stam tdatr odt ot fodortia 2t dotdw ,tengam st erofes temasm meth edt to wetv 4 .antreed to etatenoo tongsm off .eS wot! wt botnsaetq 170 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY two solenoids, each fitted with a plunger core. The two cores are attched to a yoke, from the center of which extends a rod, R. This rod joins a connecting rod; the lower end of the connecting rod is mounted in a stationary pivot, whereas the upper end is forked and engages a grooved collar on the face of the drum, When the drum magnet is en- ergized, it draws in its plungers, and, through the linkages just described, forces the drum to‘the right. When the magnet is de-ener- gized, all parts return to their starting positions under the action of the springs on the stop pins. ROTATOR LOCK, Reference was made during the description of the rotator transmission to a lock on the rotator shaft. This is e device which holds the rotator shaft stationary while the selector mechanism is OTe YHTARPAIFT OAITMINI TO MET2LYe MUASHOM FHT sognufgq a ditw bettit dose ,abtomelfoe owt .en0y 8 Ot bedotts ers setos owt sd? .9tT09 oi ,hor a abretxe dotdw to tetmes edt mort sowol odt ;5or anttoenros exe eatot bor atdT e mt Bbetarom at bor anttoennoo edt to baa et bas teqqy edt asersdw ,tovtq yremottates edt mo tsffoo bevoorg s aszaane bas hbextot mrs edt to sost ene ef tengam awrbh edt mod? duavordt ,ina ,stenostg att at awarh tt ,bestate moth ect geotot.,Sediteseb test segsiattl edt? -tere-ebh al tennem edt aedW wtdatt edtiot gilttrstes tkedt of atster atrsq {fa , fests agaizqe edt to aottos od? tobsas enolittaog ~exttq qote edt so asw eometTeteh 4007 HOTATOR totator edt to aoftqitoseb odt artish ebam ottade totator edt ao xaool s ot noteatmanert ¢tede rotator oft esblod dotidw eotveb s at ebdAT st matxedoom totoefee edt allidw yissoltiste THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY being set; the lock is released by the drum as it moves toward the right. The lock on the rotator shaft is shown in Fig. 37. It consists of a semi- circular cam, M, mounted on the rotator shaft, with the flat side of the cam turned upwards. Above the cam are the two bell cranks, J N, pivoted at their elbows to the right main brecket. The lower ends of the cranks rest on the two sides of the cam, as is indicated, so that the cam and rotator shaft cannot turn. The two lower ends of the cranks are joined by a tension spring, so that they are held on the cam, The upper halves of the cranks are bent at right angles so as to lie end- to-end. Above the meeting point of the two arms is the end of a third bell crank, 0. This crank is pivoted at its elbow to a lug on the inner face of the main bearing. One Lx As YHTAHOHIAGT DUITMIALT GO MaTeYe MUSSUIOM ART murbh edt yd beasefer eat Hoof edt jtee antiod etdgirt eft brswot esvom tr as ttade totetor edt mo Hoof en? -Imee s to etetenoo ZI .¥S walt ot avode at ettede totstor edt amo betavom ,M .mso rafsotto -ebysway Senrut mao edt to ebte taft edt dtfw ~a U ,exmeato [fed owe odd ete mao edt evodsé atem tdgtr edt ot ewodle risdt tea betoviq teort eidexe edt to ebxe tewol ofl .texoatd -Detasthat at es ,meo edt to aebte owt edt mo fist tonase tteade totstor 502 mao edt tadd oa hbemtok ets axnato edt to eaboae tewol ows silt Hbfek evs yeds tedt of ,anttqe aotanet s yd exrato eft to aevfad rteqqu eft .meo edt mo -has elf ot as os selans tdatr te treed ats ows adt to tatoq antteem eit evodA .bae-ot 0 ,waato [fed brtdt a to bae edt at amis arf a ot wodlfe ett ts Bbatovitq at anarto efdT etO0 .naitrsed mien edt to sont trenat eat mo 172 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY end of the crank extends through a slot in the bearing, so that it lies above the two cranks, N N, whereas the other end is bent upward. An arm,called the plunger ram, is mounted on the drum in line with the verti- cal arm, 0, When the drum assumes its right-hand position, the plunger ram of the drum strikes the crank, 0, and moves its up- per end toward the right. The horizontal end of the crank is thereby depressed, and, in moving down, strikes the ends of the crenks, NN, The bottom ends of the cranks are spread out so that they clear the locking cam, M. The rotator shaft is now free to turn. When the drum goes back to its original position, after the printing of a letter, the crank, 0, is released, and all parts return to their normal positions. YHTAHOEIST DUITUIAL FO MaTeYe MUAMHOM BAT xt tole gs ifavords shinotxe xAnato ent to bro ows oft avods eeti tt tadd oe .anttsed edt tned sit ime tedto edt easetedw ,2 UW ,edaato st ,sat tegnuty edt belfso,mTs ah. .btswqs -firev edt ditw oatf mt morbh odt no botavom »O ,ars Le9 ati semvess mutd edt aed¥ edit to msi tegmutq oft \coitieoq basd-tdoty -qu stir asvom Bas .0 ,dansto edt eedixte murs bas {[strostrod sAT .tdgizr edt biswot bae req at ,bas ,beseetaed yderedt et Axnato edt to ,eXnaio edt To abas edt setitte ,mwob gatvom Ssetqe ets etmars edd to shae mottod eT .u eM ,mso gaitvool edt raefo yedt tadt oe tro gedW ,.arct ot sett won at ttefe totstor edT “ottteog ltsniatto att of xoad eeon myrrh oft .O ,Aasto eft ,tettel s to arttatrq odt tetts ttedt of mrster attedq {fe Bes ,beesefet eat -ecoittiteor Lanron 173 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY We will now take up the two remaining movements of the typewheel, viz., the movements of spacing and backing. THE SPACER AND BACKER. The spacer is that mechanism by which the carriage and typewheel are moved side-ways after the printing of a letter, so that the next letter will be printed beside the first one. The backing movement is the carriage return. That is, it is the movement by which the carriage, after reaching the end of a printed line, is returned to its starting position at the be- ginning of a line. The spacer is operated au- tomatically by the printer between letters, and is also operated between wordswhen a space signal is received over the line, The backer is operated only when a carriage return sig- nal is received. The spacer and backer mechan- are YATAROSIET DUITHMIFI TO MITeYe MUAAHOM SHAT owt ent qu exst wor [ftw oe ~esitv ,{f[sendweqyt edt to atnemsvom anintener eaatdead Bae antosqe to stnxamevom edt eal .APXOAT GMA AFOATE THT sgsivrso edt dotdw yd metusdoem tadtd at tesaqe edt reste sysw-ebte Sevom ets Loeedweqyt 5ne tettel txen oft tedt of ,tettel sa to anttatrg edt ,axo tattt eft ebleed fetnitq of [ftw teql .arster oasizirss eft et tnomevom antdosd oastirrss off dotdw yd toomoevom oft at sr .at et ,emtl betaita a to bre ett antdoexer tetts ~ed edd ts motstaoq gattiate ett ot benrster -78 hotsteqo ef rteosqe efT .sxtf£ 2 to antnata ~atottel seewied tatming edt yd yllsottamot eosqe 8 metwebtow neowtsd Setatreqo oele et bas tedoed edT ,entil odd tovo bevteoer si Lanate -gle aister esstiree 3 cedw yino Setateqo at -Sevieoer at faa -sedoem texosd S18 tosaqe oT THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ism is shown is Fig. 44(a, b, c, d, and e). Pig. 44(a) is a face view of the left end of the mechanism: that part located on the left main bracket; (b) is a front or edge view of the same portion; (ce) is a top view of the entire mechanism; (4) and (e) are face views of that part of the device located on the right main bracket. As is indicated in the fig- ures, @ small chain is attched to the car- riage, which chain runs to the left end of the printer, over ea pulley on the left main bearing, and winds onto a drum marked "spring barrel #41-3". This drum contains a flat spi- ral spring, which is wound so that it tends to keep the chain wound-up on the barrel. Fig. 44(a) shows an end view of the barrel, and indicates the method of regulating the spring tension, 174 STE YHLAAVEIAT QUITKIAL TO MATEYS MUHAHOM THT .(o Bas ,b .o .d .S)dD .2tT et awode st mat to bao Stel odt to watv sost a at (s)bd att ttef sdt mo betaool tisq teadt :metnedoom ed? to welv esbe to ¢fnott a st (d) ;tedostd atsm ait to watv qot a at (9) gmottrog emse oidt awety sost eta (9) Soe (8) gmetnadoom ottiae edt mo betsocl esotrveh edt to traq tedy to -texserd oteam tdgtr e-git edd at S5eteothat st aA -17189 adv o¢ Sestotts et atiado [fama aw ,eety to Bae ttel ext ot enor ntado dotdw .sgeit atem tefl edt ao yoliug 8 tevo ts ahaa all gaixqe” Sevttam mth s oto hate fea ,anitsed -tqa telt 2 antetnoo mutb atdT ."S-f£a4 Lorired ebuet tf ted? og bavow at dotdw ,antrqe fst -fextad edt mo qu-bmrow atsdo eft qoex of ferried edt to wetv Bae as awode (a) a tt edd gatisiiuget to bodtem edt aetaotbat bas - eutanet gatice THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY The action of the spacer me- chanism is to draw the carriage toward the right, by steps, against the action of the backer spring. The backer mechanism proper is merely a means for releasing the spacer, so that the carriage is free to travel to its extreme left position under the action of the backer spring. We will first describe the spacer mechanism. The spacer is located at the right end of the printer, near the back. Re- ferring to Fig. 44(c), we see that a second chain is attched to the carriage, runs to the right end of the printer, and there winds onto a second drum called the space drum. The space drum consists of @ barrel, at each end of which is a ratchet; the two ratchets are indentical in construc- 175 ore YHYARPRLET DUITULTAL TO MATeYe MUAXHOM THT -om teosqe ent to mokto2e sat ent Srowot oestirss edt wath ot et metnado edt to motion ef? textayges ,sqete yd ,tdsit tocory metnedoom tetoad edT .amtrqe redisad .T99aqge eat grteseler tot ensem se ylotem at ot L[evary o¢ sort at oxysttrso edt tedt oe sotjos edt tebny nottteog tel emortxe att edtroeeh terttt [ftw se” .umtraca rsfoad edt to meatradoem tresaqge edt ed? ta Sstsool at tessya sft -el ,doad edt teea ,retaty edt to bro tdate baooes & tad? ese ew ,(ojSd watt of agatrtet ot ant ,eastirao eft of Sedotts st mtarto ebatw eredt base ,retaire eft to bao tdstr edt emoerh esaqe sit boffao merb broose 3 otno to atatenroo myth eesca od? stonotar sp et dotdw to bae dose ts ,Ietrad a -ourteroo at Isetiaefiant era etenfotsa:y owt sdt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY tion and mounting. The drum is supported from . the space magnet bracket by a stud. The drum is turned, and the chain wound up, by the ac- tion of a pawl which engages the outside ratch- et; the second pawl, which engages the second ratchet, is merely a check pawl. The two pawls are kept in contact with the ratchets by two springs as shown, The outer pawl is mounted on a lever called the space lever. The space le- ver is pivoted, near its middle point, to a stud, wich, in turn, is mounted on the mgnet bracket. A spring, called the space spring, keeps the left end of the spacer lever and pawl in the upper position. At its right end, the lever is connected, through an adjustable link, to the yoke of the space magnet. The space magnets consist of two solenoids with plunger cores. The solen- 176 are YHTAHORIAZT PEITMIRG TO METSYe MUSXHOM FHT mort Betrodqre ef mrbh ofT .anttavom bas aoltt asrbh efT .5ate s yd texoatd temasm sosce ont -o8 odt yd ,qy favow atedo eft Bae ,benrst st -dotar aftetyvo edt eensane deidw Iweq = to mott broose edd esnaane dotdw ,fweq Brosee edt ;te efwac ows eff .Iwsq doedo ws yLletom st ,tedotst ows yd atedots: edt diiw tostaco mt tqext sts eTwote es eantrge xo betavom at Iweq tetro od? -ef essqe eft .tevel ssaqe edt feff{so revel a gs ot ,tntog ofSbinm att teem ,fetovia ef tev tengen oft mo hetavom ef ,axet af .dotw ,Sste eanttaqea eosre eft Selffeo ,aatrae A ,texosid bra tevef rocoags odt to bas ttef edd aqoet e5xe tdatr att tA .mottteog reqqr odd aot [wag eldstest5s as davsotdt ,hetosnnos et revel edt etongam soaqe edt to sdovu edt of ,aotl to tetemoo atenaam soeqe anf? -mefoa ofT .aeToo tesaula dttw ebhtomefoa owt Evy THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY oids are fixed to the magnet bracket as in- dicated. The lower end of the plunger core of each solenoid is attached to the space yoke. As for the action of the spac- er, during the printing of a letter, the space magnet is energized; it draws up its plungers, the space yoke, and the right end of the space lever. This movement of the space lever draws its right end downward, and with it, the pawl; this movement is against the action of the space spring. The pawl engages one of the ratch- et teeth. The check pawl has, in the meantime, kept the space drum from turning backward. When the printing of the letter is completed, the space magnet is de-energized. It therefore re- leases the plungers, yoke, and space lever, and the space spring raises the left end of the space lever and the pawl. This movement of the space pawl turns the ratchet and therefore YVI YHIAAVAIET DAITUIAI. TO MATEYe MUSASOM FHT -xt es tedoatd tomgem odd ot fextt ers ebto etoo tegaulg edt to bre rewol of? .fetaotd -e%0y soace oft of Retioette ef btonefor dose to -o2qe od? Yo mottogn sit tot et esesqe oft ,rettef a to axitmitg sdt ontrsb .t9 estegazta ett qo ewerh tt ;besfarens ef tenasm aoarea edt to Bae tidstr oft Soe ,sdoy esaae odd aweth tevel sosqe eit to tromevom etdT .tevel :iweq edt .¢tf dviw Bye ,Srswewoh base tigi1t att efit to mottos edt tantasa at tromsvom atdt -cdotst eft to omo aeageane Iraq of? .aottge sosqe ,omttnsoem odt mt ,asd [wag wooo si? .diset te sed” ,brswtoad satmrret mott mrh esaqe sdt tqer edt ,Setefqmoo et rettel eft to gaitatrq edt -e% ototetedt tf .5esltsreme-96 ef ftonasm eoaqa etsvel sosye bas ,sroy ,atroann(q edd aesesel to 5x6 iter efit eeeter satrqe esace edt bas to vaemovom efdT .fwaq oft Bae tewel sosqe edt srotetedt Bue tafotert oft earot [wee oosce odt 178 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY winds-up the carriage chain one more step. The device is so adjusted that the carriage is moved the proper distance for the spacing of the letters. We see, therefore, that by this device, the spacing of the carriage is accomplished, and that furthermore, the spac- ing movement does not occur until after the printing of a letter; the operation of print- ing and spacing, therefore, occur at distinct- ly different times, as is desired. The backing mechanism, as was stated before, is a release for the space drum, so that when the backing action takes place, the carriage travels to its left po- sition under the action of the backing spring. The mechanism comprises a tripping lever, which draws the space and check pawls away from their ratchets, a means of operating the trip- ping lever, and the backing drum. ere YHTAHOELET DUITMIAG FO MATEY MUSNHOM ART -cete erom ono Sisds exsirise sdt qe-ebatw essiureo eft tedt hetsufbe ce et estveb sdT antceqe eft rot eomstatbh teqorgq eft bevom at -etettel edt to yd test ,etctotodt .ees oi ef egeiutso edt to uatosqe edt ,eotveh att -oaqe old ,stomredixet teft for ,fedetliqnooos edit tetts [iia anooo tom esch tmomevom ant -taitg to mottsxeqo ext stettel es to antinatra | -~tonttelh ga xse00 ,etoleted? ,antosqe Boe ant ehertseb et se ,semtt trortettib vf be ,metoetoom antioad aft eosge edt rot easefert 2 at ,stoted fetsts azsw eexyat mottos antdoed edt modw fect oe ,murb -~og ttel ett ot sferatt esetrreas edt ,cosla -gitiqe anixosd eft to mottos edt tefrs molttte fotdw gevel agctaqizxt e esainrqmoo metresoom odT mort yews sliwaq woedo bas ssage edt ewexh -qiet edt anittereco to ensom 8 ,atedoter rtedt omerrd gatsiosd ex? fre ,tevel ant 179 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY The tripping arrangement is shown in Fig. 44(a4 and @). The tripping lev- er is a small bell crank, pivoted at its el- bow to the space lever stud, A, One end of the crank extends upward and carries a cross- rod; the cross-rod extends across the front of both pawls. The other arm of the crank terminates under the plunger rod of the back- ing magnet. This magnet is a single solenoid with a plunger core, to which is sttadhett the plunger rod, As for the action of the back- er, when the backing magnet is energized, it draws its plunger and plunger rod downward; the plunger rod pushes down the end of the tripping crank, which movement draws the up- per end to the right. By reason of the cross- rod at the upper end of the arm, the two pawls are also drawn to the right and away from the ere YHTAAORIAT OMITAIAI FO METCYS MUSAHOM FAT at tnemesnertra getaqixt edt -val antaqind eft .(6 bra BAS watt ot ovrode -~fo ett te betovtq ,anero [fed [Lame s eft toe to boe smO .A ,hute tevel eseqe ont ot wod -~eects s settiss bre biewqy efnetxe aneto eft taort eft eezotes ebmetxe hor-eacte sit bor Yearo eft to mrs tredto ofl .elweq diod to -tosd edt to hor reanetq ent tebau eetantmtet Blronefoe slarte es ef tengen efd? .temgen ant : edd ffadoatie eat dotdw ot ,etos teanmela eae dtliw ebor regnastq -fosd oft to mottos eft tot eA tt ,Sestsiese ef tensam antvoad edt aedw ,.16 + Srewenrob for toxneltgq fae teagnelq ett ewerb odd to bue oct cwob eodeug Bor teagnutq edt -qs odt aweth tremevom dotdw amare antoqivt -peote edt to moseet vd .dioty edt of Bre ted elweq owt eit ,mre eft to bee reqqn eft te hot ext mort yYaews fre tdatr edd oF mwvseth osfs ers ; ee van - THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ratchets, as is shown in Fig, 44(e). The space drum is therefore released, and the carriage is drawn back to its starting position, A locking device is added to the becker, which device locks the backer in its operative position of Fig. 44(e). This device is necessary in order that, in case the backer magnet is de-energized before the carriage has reached the left end of its trav- @1, the space pawls will be held away from their ratchets until the carriage does reach the end of its travel. At the end of the back- ing movement, the carriage releases the lock. The details of the device are shown in Fig, 44(c avd 4). In (e) we see & small rod, called the backing rod, extend- ing from the left main bearing to the right main bearing; the rod is supported loogely, so that it is free to turn or to slide end- ways. Near its right end, the rod carries a 180 ost YHTARDHIET DUITHIALT FO METeYe MURAAOM ART eosqs efT .fo)db .akt of ovode et as ,etedoter ezeierso eft bae ,beassfet exroteredt ef moth erottteog anitrate ett ot Hoed nweth eat ot hebhs ef eotvefh antdool A at tetosd edt exool entveb cotdw ,revoesd ott etdT .{e)bd wart to mottteog evitsteqo sett . eeso nt ,teid tebro ot yrseeseom at estved eft eroted bestarene-ob et tensem rexiosd sdt -vert ati to bre ttel eft besioset asd egstrtso mort yswe Blod ed [itw elfweq esaqe edt .fLoe doset ge0h esstrrsas edt Citas etedoter rredt -tosd edt to bae est tA .[evert att to bae edt eXvof oft soesefet ogstrres edt ,inemeron act eotved ent to efteteh odT een ow (o) af (5 Bye o)SS yet ot nwode ers -baotxe ,bor athdosd edt beliso ,bor [feme 8 tdgtt od? of antrsed ats Hier eit mort ant sYfeeool betrogqrve et bor est sartteed atam -hoo obtfe of to mrst of sett ef tt tends 028 8 eoelzrso bor eit ,bae tidstt ett teell .eyew a * Ma as THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY small collar, called the backing collar; near the left end, the rod carries a somewhat sin- ilar collar, and between the latter collar and the left main bearing is placed an open- coil compression spring. The spring tends to keep the rod in its extreme right position. Referring to (ad) of Fig. 44, we see an end view of the backing rod and collar. It will be further noted that the plunger of the backing magnet extends above the top of that magnet, and is attached to one end of a lever called the backing lock lever. This lever is pivoted at its middle point to the magnet bracket; the other end of the lever extends to the left and termin- ates beside the backing rod collar, Suppose now, that the end of a printed line has been reached by the print- er. The carriage is in its extreme right po- 181 L6f YETARDEIST QUITUIAT TO METeYe MURAAOM FAT teem ;relfon antinoad edt helfeo ,telf[oos [Lame -mte tadwomoe s aeirres hor eft ,Boe tteLl eft seffloo tettsal edt newwied fae ,telfoo telt -ceqgo ma beoslaq et anivsed otsm ttef est bas ot ebhnet sntrqe ofT .antiqe moteeerqmos [fco mottteod ddaix emetixe eti at bor ext qeez Pd egtt to (6) ot anttretet bas bor uatvosd edt to woiv bao ams ese ow edt tenis Seton redtist ed [ftw tl .ralfoo evods ebiretxe temaen antiosd efit to tepartg et fhedosttse et Bae ,sensem tedt to got edt Hoof gatadoaed eft beliso revel 2 to bre emo efbhfhinm att te betovta eal tevel etd? .revel be ranito oft ;texfoard tensan eft ot tntoq -nimret baoe dtef eft ot ebmetxe tevel edd to »rsffoo bor anttosd edt efized aets to bee est tsct ,wom esogqqwe -toixg oft yd ferloset sood set entf£ betattq s -o¢ tdatt emertxo ett of et esnetrtess ed? .t98 182 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY sition. The backing magnet is energized for an instant; it draws its plunger downward, and thereby raises the left end of the back- ing lock lever. Under the action of the spring on the backing rod, the backing rod and col- lar move short distance to the right, .so that the collar is under the backing lock lever. (See Fig. 44-e), Therefore, even though the backing magnet be de-energized, its plunger is held up by the backing lock lever. The carriage travels to its left-hand position; as it reaches this position, it strikes the left-hand collar of the backing rod and moves the rod a short distance toward the left. This movement of the backing rod withdraws its collar from beneath the backing lock lev- er, so that the lever drops to its normal] position of Fig. 44(a), When the lever is in this position, the space pawls engage their YATAAODEITT QUITMIHL TO METeye MUAAHOM FAT xot bestatrere st tensem antiosd oct .mottte eSisvowobh texasfq edt ewath tf ;tastent oe -doad ott to Bro ttel eft ecalat wdereds bas aciege edt to settos edt tebaU .tevel Hoof art -foo bas bor antdoad oft ,bor antidosd edd no ted? o#.,gdgit exit otf somatethS trode evom tal -tevel aoof untiwosd edt robme et rsf[loo edt adt dasodt meva ,etoteredT .{e-bB .2tt 902) seanctq eft ,hestarene-95 od tenasm Bt nef edT .tevel wool antioad ont ud qs Bled aft wxottieoq Baed-dtel att ot alevaty ensixtrso eis gexitite tr ,wotttsoq eldt eedoset JE es sovom bre bor anixoad edt to reaffoo brad-ttef ettel eft Srewot oonsteltb Jxrodea #2 bor ont awarhdsiw Bor gotdoad edt to tnemevom etd? ~vefl doof anitxoed eft dtesned mort rsi[foo ett feorrom att otf sqoth revel ext tadt oe ,+re et revel ett med¥ .(b)S3 wet to nottteog attedd essence afwaq eoage edt ,nolttteog etdt at THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY ratchets; they have not engaged, however, until the carriage has reached its start- ing position. An additional attachment is to be found on the space drum. This attach- ment is a stop pawl whose purpose is to pre- vent the spinning of the space drum after the backing movement is completed. While the carriage is travelling back to its starting position, the space drum is turning back- ward rapidly; it has been found more desir- able to stop the drum at the end of the back- ing movement by a special stop pawl, rather than to allow the check and space pawls to drop onto the ratchets while they are revolv- ing. The lower part of the stop pawl may be seen in Fig. 44(d and e). This pawl is pivoted to a bearing on the base-plate. 183 rrte 5) en bel YHIARSAITT OMITHIAI FO MUTeYe MUPIOM ANT ,1evewod ,foensaatme tom eved yent jatenfotar -Srste evi bedoser esd essittes edt fing acottfaod art af teemfostis [snotstibs aA -Sostts efdT .masrh sesqe edt oo Bbasot ed of -~etg ct ef etogryq esonw [wag qots sa ef tnem tette mth essge edt to aftinntqe ext tnev eit efidy .betef{qmooe et tnemevom anitosd ent sotivete etr ot Mord griflevare ef eastites -foesd aniaryt eat mutrh soaqe exit ,nolttieog -tieef erom Basol meed asd tt :ylitqat basw -xtoad eft To Bre eft ts merh eid qots of elds tentear ,[weq qote [steeqe 2a yd tnemevom ant ot efwaq essqe haa iwseto est wotla od mad? -vfover ets yest efidw etedotet eft ofmo qorh eant qote eft to traeq towol oT eid? .{e Bre B/D att mt asee od yem [weg etafq-ssed edd xo anitesd a2 of betovitq et Iwag 184 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY The upper part of the pawl splits into two fingers; one finger bears on the face of the drum, whereas the other extends slong the back of the rear ratchet. The face of the ratchet carries a small stud or pin. When the carriage is in its starting position, the stud rests on the top of the rear fin- ger of the pawl; as the carriage is drawn toward the right by the winding of the chain onto the space drum, that finger of the pawl which rests on the face of the drum rises onto the chain wound on the drum, and rides on the top of the chain instead of on the face of the drum. Both pawls are thereby lifted away from their former positions, so that the back finger clears the path of the stud on the ratchet. As the drum unwinds, during the backing movement, the pawl assumes its former position, so that just as the car- riage reaches its starting position, the in- bBLI YHIARORIAT DUITHIAG TO METEYS MUANAOM FHT owt otat atiiaqe [weq edt to ttaq teqqs oAT edt to sost oft mo steed reant? enc sereantt ent snofle sebasixe tedvo edd esetedw ,mrd efy To esst eT .tedoter reset eft Ito dosd ced’ .ataqa to Bute [fame © setrrso tesoteat ~nottteog anttrate ett at ef eastrzrso ent -nit xsexr eft to qot ont aco eteet Butea odt | mwerbh ef esstxras eft ea ;iwag edt to teg mitefo eft to anthbatw edt yd tddats edt brewot fwaq oft to tonnit gedd ,orxh5 sosqe edt oto eoett mrxh eft to eost edt ao eteot doldw seblt bas ,mith edt mo Baecw atedo edt cotnao ext mo to Bsetent otacdo edt to qot edt ao yderedt ere afweg dtod .murh oft to cost oe ,encttteogq temrrot risdt mort yaws betttl exit to disq edit arsefo reuntt doad eft tadt -sbhatwan myrh eft BA .tedoter oft mo bute eemmeass [weq odt ,snomevom gatsioed sft anired -1tso eft es taut tadt os .mottteaog temtrot att ~at edt .motttsog antirate ett esdoset egait 185 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY terference stud strikes the stop pawl. The space drum therefore stops, and the space palws drop onto the ratchets. We will now take up a study of the platen, and of the lining mechanism , which is closely associated with the platen. THE PLATEN AND LINER. The complete platen, with the lining mechanism, is shown in Fig. 45. The platen consists of the roller and auxiliary attachments for hold- ing the message blank or other paper. The lining mechanism is the arrangement by which the roller is turned slightly at the end of each line, so that the message blank presents @ new surface for the next printed line. Fig. 45 is a catalogue drawing of the platen; only the main parts will be discussed here. The frame of the platen con- sists of the cover of the printer, casting #1, together with two end plates, marked re- ear YHITAAOAIAT DAITUIAL TO METEYe MUSLIXOM FET ed? .f[weg cote eft soextrte bute esnerstret eoege edt Bae ,eqote etotetedt mirth soece -etedotser eft otmo qorh ewleq yoote es qu ost won [Iiw eo” . metoedoem gataxtl edt to bas ,setsIq silt to -astelq edd ditw fSetatooszes yleeofs ef dofdw edt .feuNII GWA WEPAIT FHT metoedoom urtatf£l edt dttw .netalq steiqnmos to atetenoo setslq eiT .cd .yhh ot awode et -fhfod rot sitnemdostte yretlixee baa teffor edt edT .taqagq tento to wmefd onseeom edd act doitdw yd tcemenoeitie eft et metnsdoem antarl to boe eft ta yitdatfle hemrut et reffor edt etnoeerg wneld eseesem oft tadt oe ,sntl dose emit entf botning trem oft trot eostrve won Bs ufno ;neteale oft to antwerb eszoletsso ae et ch .eted beeesoeth ed Ifiw etraq atem edt -noo mnetefa eft to emert oA? uitteso ,tetnizq eft to tevoo edt to etate -st Sextem ,sotalq bae owt diiw tedtegod , It 186 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY spectively, casting #2 and casting #3. The screws at the four corners of the cover plate screw into the four corners of the main frame of the printer; the end castings are screwed onto the cover plate. The platen, in its restrict- ed sense, is a rubber roller, similar to that of a typewriter. It is mounted on the platen shaft, #5-1, which is supported by the end casting in bearings. At either end of the shaft is a hard-rubber thumb-wheel, by which the platen may be turned. There are a number of auxiliary attachments on the platen, the most important of which attachments is the one for holding the paper against the roller. This latter device consists of the two feed rolls, #14 and #15 respec- tively, and their mountings. These two rolls bear against the roller, and hold the paper snugly against the roller. The two rolls may acl YHTARORIET DUITHIRI TO MHTSYE MUAAFOM. THT eff .8% antteses bona St anitsao .Ylevitoeqe etsfq tevos edd tc arertos rvot eft ta ewetoe ematt mitem eft to aremroo rs0t edt otat werse bewetos ers euniteso fae ods ;retaitq edt to -otefgq teveon edt otnao ~-tofrtest ett at .metela eAT tent ot relimte ,relfor teddyr s et ,eenss bs netela eft no hetrrom at t1I .zetistweqys s to boo edt yd betroqqne et dotdw ,f-8) ,ttade edt to bre redtte tA .eantreed at aniteso cotdw yd ,Lleorw-duvdt reddur-href es alt stede teduum s ete etodT ,benint ed yam aetel[q oct edt ,metalq oft mo atnomiostts yrelfixvs to edt st etoomiosttsa dotdw to tnstroqumt teom -te{for edt tamtess teqsaq ost gathiod rok eno eteteamos sotveb tetisel etdT are -oeqest Sft bas $f) ,efLor beet owt edt to effort owt seedT .eantiavom rtont Bes ,ylevit xeqeq edt blod bas ,telfor oft tentags teed yeu allot owt efT .tellor oft gentase yiguae THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY be drawn away from the platen by the arrange- ment shown in Fig. 45(a). The rolls are mount- ed on a spring rod,as shown, which is screw- ed at its right end to the end casting. The front end of the spring lays across a rod known as the release rod, which extends from one end @sting to the other, and is fitted into bearings at either end. At the point where the spring rod lays across the release rod, the latter is cut down to semi-circular form; the spring rod lays across the flat face thereby secured. The release rod carries a gmall lever, marked #18 Rolls handle, by which it may be turned. The mechanism so far described is duplicated at the left end of the platen. In the operation of the at- tachment, the feed rolls normally lie close against the platen, as in (a). However, if the rolls handle and release rod be turned, 187 Ter YHUTARSAIET DQUITHILI TO MET EYe MUARROM FET -egnarts odt td metela ett mort yews owerh od -tosom ers affor efT ,.(s)d «atl at swode toom -wetes et detdw ,awode es bot aniztqa e mo be ed? .amtteso bre ect of bane tdgix ett ta be Bot 8 seotes evel anitqe eft to Bae taott mont ebnetxe dotcw ,bot sasefer eit es mworx hetsit et bas ,tedto ext ot anitemp bre ono $atog od tA .hbre tocdtie ts esniztsed ovat seaselet oft ezotos eysal fot anitge edt etedw tefsotte-imee ot mwoh tivo alt tettal odt , bot telt oct seotes eysl bor anttqe edt jyorot eetrreo hot seseler eT .bersose ydotedt eost yd ,oLiasdi effoi ely besitam ,revel Liane s tet of matmsacdoom edt .homret od yam tt dotdw to bro ttol eft ts betesti[quB et hediroeeh eMtotsl[q edt -ts edt to moktarsqo ot af eeolo eff ylfsorrom effort beet ont stunted ti.,tevewoH .({(s) mit as ,metela oft tentens eSeait od box sexoler bas elbnad effort edt Treat Su —t sty Aa) oe te iy gee THE MORKRUM SYSTEM OF PRINTING TRELEGRAPHY the spring rod is pushed downward until it finally lays across the round side of the release rod. This movement of the spring rod pull the feed rolls away from the platen. When the rolls handle is pushed back to its original position, all parts return to their usual positions. The purpose of the device is to release the message blank so that it may be withdrawn from the platen or its position adjusted, The lining mechanism can bet- ter be understood from the end view of the platen. Referring to this view, we see the ratchet mounted on the platen shaft. The ratch- et and platen are ordinarily held in posi- tion by the detent roll as shown. At the left of the ratchet is a lever, L, which carries two pawls: the lining pawl and the stop pawl. The lever and pawls are connected with the 188 BBL YHTAHOEIOT OMITAIRGA TO MET? Ye MUSAHOM EHT tt {£ttas brawnwoh beresq at bor antrae odd eft to ebts basor eft asores syel yifentt . gminge odd to toomevom eta? .bot saselfet efetefa oct mort yews effor best edt Ifsq bor ett ot deed hoeresq at efhand effort eft nod’ ttedt ot arutet etreaq [{[e ,cotiteog [aentgizxo .enottteog [eves et estveh est lo eeortsq ed’? yem tt tedd os sinald eaenhed efit seseler ot mottteog att to metsiq edt mort awerbdt-w ed betertbs -ted mao matredoom gotctl eT edt to wetv bae edt mort hootatehbas sd ret eit sea ow ,weitv etdt of amitrete® .metelyq -foter edT .ttade seteiaq oft mo hotastom Terfotet -tesog at bled viitanthiro ore motalq boe te ttel edd JA .mwore en [for tnetob edt yd aott esittas dotdy etevel a et texoter edt to elwaq qote odd bre Iweq antotf est :efwaq owt eit Atiw Betoonxoo ata eiwaq dae revel eT THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY lining magnet as shown. In the operation of the liner, the lining magnet is first ener- gized. The magnet moves the lever, L, to- ward the right, and, through the agency of the lining pawl, turns the ratchet and feed roll toward the left; this turning is the equivalent of either one or two lines on the message blank. The stop pawl serves to stop the turning. The position of the stop pawl may be changed by means of the lever, A. When the stop pawl is in one position, two lines on the message blank are turned up at every stroke of the lining magnet; when the pawl is in the other position, one only is turned up at a time. We have now completed the aiscussion of the principal mechanical fea- tures of the Morkrum printer, and will next take up a study of the electrical circuits and eouipment by which the mechanical devices 189 esl YHIAHOSIET DUITHIRT FO MATCYe MURAAOM ENT te mnottateqo eft al .mwore es tensam gauintl -rene terltt ef tenmasm yotati eft ,reati edt -ot ,< ,tevel edt eevom tomgeam efT .bosta te yoruess ent davordd .bne .tdatr edt Bbraw boet bas tedotet edt enrst ,fwaq artotl oft edt eat antnret atdt ;ttel ont Srewet [for edd mo eentf owt ro emo tedtte to trefsvicve qove o¢ eevros [weq qotvs sil .unald exsseem fiweq qovta est to mottteor ed? wamtnred ont -A ,tevel eft to amsem yd boeamedo ed yam ows ,mottteog eso at eft I[wac qote edt nef¥ vs qx benist ets iinsid easerem ect mo eentl edt nedtw ;fengam untatf edt to sforta Yreve et ¢imo emo ,mottteog tetto ent nt ef [wag omit s ts qv bonrret eft Setelqmoo wor svet oF -s90t Isotnsdoom fsytontrgq edt to notearoethb vxen [fbw bas ,vetaixng murxtrol edt to esrst atinvorto Lsotttoefo odd to ybute s qu oxat eeotveh L[eotasdoem edt dotdw yd tooematyoe baa 190 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY are controlied, THE PRINTER CIRCUITS. In Fig. 46 are given the complete circuits of the Morkrum printer. As the general circuits are too complicated for purposes of explana- tion, the constituent circuits will be sepea- rated from the rest and discussed one at a time. In order that the reader may thoroughly understand the fundamental plan of the con- trol, the main circuit will be developed by stages, as wes done with the distribution system in the introduction. In fact, we will begin with the receiving station of Fig. 6, and develope the printer circuits from that scheme. In Fig, 47, we have the re- ceiving station of Fig. 6, except that the local relays, P-1, P-2, P-3, P-4, and P-5, are connected so as to lock themselves in the energized or closed position, That is, YATAHORIAT OLITAIAG FO METSYS MUSAAOM FAT -beflortnos ete mol J/&TIUSHIO Satnint eH? to attsorto atsIqnos sdt meyita ors 34 .2f eitsotto {atenes ect eh .vetattq mordroll edt -anelaqxe to eesoqts¢ rot hetaetliqmos oot ers -sqea ed [f{lw atituetto taouttianoce edd ,mnoft s ts emo beaavoeth base dveet edt mort hotat yfdacoredt ys tefser ent tadt robro ol .entt ~(o9 edt to mele Istnomebast edt busterobay ud feqoloved ed [ftw tiyorto miamw edd , fort mottudicrterth sdv ditw exob aaw es ,aceqsta [fiw ew ,tost al .mottesbortat edt mi moteye .@ .gtt to mofteate suatvieoet edt détiv mtged tedt mort ativorte retartrq edt ogofeveb baa | -omenoe -9t edt ovad ow . TS ait al edt tads tqooxs .3 .2tt to wolttste satvies ~a-2 Baw ,A-T ,8-F ,S-2 ,f-f ,ayaler Isool mt eevioemeds wool of es oe hetosmmoo ste at tac? .mottteog Seeofo ro bestatene edt 191 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the front points are connected to one side of the battery, and the armatures are connected to their respective operating coils, as shown, If one re- lay is momentarily energized, as it will be by a current pulse, it draws up its armature against its front contact; with this contact closed, the relay remains energized, even after the current pulse has ceased. This locking cireuit is con- nected to the battery through s switch called the main break. A momentary opening of this switch euts off the locking current from the relays for a time sufficient for them to return to their nor- mel condition, As a possible use for the systen, we could establish a printing system with these five relays. The first four relays might act as operating solenoids for the selector plates, and the fifth relay might determine the direction of rotation of the typewheel. Furthermore, by fit- ting the solenoids with relay contacts other than fer YHTAAOLIGT DLITMIAG FO METeYe2 MUAXHOM AAT “ft to ebts omo ot hetoomroo ers etatog taort ed? ttedt ot fetoennoo ete vetstenrs eft fue , rotted ~st oo tI .mvrode es ,eftoo anttereqoe svitoeqeet yd ed {{tw ti es ,bestatens efitsiaemom et ysl gentsess eroteors eft qu ewarh tt ,saluq taerr9 a eit ,besofoe ftostnos etdt dttw ;toatmoo taort ett tsoerrtwe edt tetts asve ,Sestarsie emtamet yalet -m0o at Stirorto antadoofl etd? .beaseo asd ealig feffso dotive s davordt yretitsd eit of boetoor dottwa etdd to yxtmoqo yretmomom A .xeetd atam edt tot eyafert oft mort taerttye axtitool odd tTto atu ~ton ttedt ot arster ot medt tot tmetotttwa emtt s emottitbaoo Lfsm ewetaye edt tot oes efdtaeog a ad seed? ddiw metsya gattatiq ea datidstse Bbisoo aw es tos trigtm eyelet tyot tartt ed? .aysler evtt brea ,eetsiq todcetce eif tot abtomefoe anttateqo to gottoorth eft extmroteb tdato yelot ditt edt “Tit yd ,stomredtxrs® .fsedwegyt edt to nottstor sed? tedto atostxoo ysler ditw ebtomelos edt antt THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY their locking contacts, we arrange the oper- ating circuits, that is, the circuits of the rotator, striker, shift, and other magnets. A control circuit could be developed, and, in fact, some such plan is followed in the Morkrum printer. The cycle of operations for such a machine would be as follows: The re- ceiver brush passes over the receiver but- tons, 1, 2, 3, 4, and 5, and the five plate relays are opersted or else remain inopera- tive, depending upon the nature of the separ- ate impulses. The plate relays set the selec- tor plates, and at the same time, set up the circuits of the operating mechanisms. Hence, efter the fifth pulse, the typewheel rotates, strikes, and spaces. The final printer move- ment is to open the main break for an instant, s0 that the plate relays return to their nor- mal positions. By this time, the brush has 192 Ser YATANDRIAT DUITAIAT FO METeYe MURAHOM THT -teqo edt sansrte ew ,etostnxos gatdool tied? edit to asttverto edt ,alb tad? ,ettocorto antte -atentzem tedto Bae ,itide ,texinte ,.totastor pes .bexoleveb ed ALvoo tiworto L[ordmoo A ent mt bewoffot ef melq dove omoe ,tost at etotatra oomratroll tot emotisreqo to efoyo ont -et edT :awollot ee od biliyow omftdosm s dove -tyd teviteoor edt revo ewaasq devtd tevies eiela evit edt boas ,.& has ,f .o a8 .f ,enot -stoqont miamer sefe ro beteteqo ste eysfet -tsqee edt to ersten edt moqu antbhnsgebh ,evit -oefea edt tee aysafert etsiq od? .e0ealyqmt ots edt qv tea ,omtt emse edt ta Bas ,seteslq tot .9oceH .emetnadoes anttsteqo edt to ativorto .setetor Leedweryt edd ,safeq dtttt edd tetts -evom tetairg Centt edT .eooaqe bos ,eottuts -sostest as trot dasrd atam edt meqo ot alt taom -ron ttedt ot aryter eysfor etalq edt tadt os asd cdesrd oft ,emtt etdt yi .eanottteoq Lam 193 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY again reached the first contact button, and the same cycle of operation occurs for the next letter. In this way, the printer would perform its functions. The great fault of such a system is this: All the movements of the type- wheel must occur during the intervel of time required by the brush arm in passing from contact button #5 to button #1. If The trans- mission of messages is performed at any prac- tical speed, this interval of time is too short for the typewheel to complete its move- ments. We therefore modify the system of Fig. 47 somewhat, so that one letter is being print- ed while the next one is being received over the line, THE ACTUAL SELECTOR CIRCUITS. The new scheme, which is the one used in the Morkrum system, is presented in Fig. 50. In this plan, the plate relays are not connected eer YHTARORIRT DPULTAIAT TO METeYe MUAAAOM HHT bas ,gottnd toataoo terlt eft Sedoset areas edt rot etsoeo mottstreqo to efoyo emae ont Birow tetatra edt ,yaw atdt al .rettel txen saottonst ett mrotred s dose to tiust tsern eT -eryt edt to etmemevom odt [fA :stdd eat meteye emtt to Levretat edt anttob ryc00 teym Loeodw mort guxteeaq oi mrs deotd edt yd bertupet -anetd ofT TI .£% aottud of a4 nottsd tostnos -ostg yas ts Bemrotreq af gegeeaom to nofesia oot st amtt to Lavretnt etdt ,Seeqe Isolt -avom att etefemes ot L[sedweqyt edt tot trode -gfT to metaye edt ytibom etotetedt eV .2inom -tatxq anted ak rettel emo tadt of ,tadwemoa TS tevo bevitesor aatod at emo txen ant oftdw be eontt adt sOTIVOAIO AOTORIZE TAUTOA SHT oid at Seay eno eft at dotdw ,emedoe wort ed? at -OG .afl at betneastq at .moteya avtaroM Setosmmoo ton ete ayafer ots{a oft .aelq etd? 194 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY to the receiver contact buttons. Instead, a second series of relays, called lock relays, are connected to the contact buttons, and the plate relays are controlled from this second set. It seems advisable, for purposes of explanation, to build up the plan of the control circuits between the lock and plate relays. THE LOCK RELAY CIRCUITS. The connections of the lock relays and trans- mitter disk are shown schematically in Fig. 48. Note that the lock relays of Fig. 48 have taken the places of the local relays in the distributing system of Fig. 6. As is indicat- ed, the lock relays lock themselves in the operative position, just as the plate relays do in the preceeding scheme. The locking cur- rent in this case, however, comes through the back contacts of a sixth relay, similar ATAADEIAT OUITUING TO MATCYa MUAXAHOM SHT @ ,beetanl .enottyud tostmoo tevteser oft ot ~eysfer Moofl bofiso ,eysfer to esitea brooes bas ,enottud toatmoo eft o> bstoenmoo ots aidt mort beflortnoo ets aysist otalq ont eseoging tot ,el{daeivbe emese tl .tee baooea edt to nella ett qu b{tsd ot ,woltensl{qxe to etafg Bas Zool sid asewted etiverto Cortncs eayeist .CTIUOHIO YAISH BHOOL ET -artertt bee eyaler dool edt to enottoonnoo edT olf ot yl[{sottamedoe awofe: sta xXeltbh tetsin oved OS .2t% to ayefer aool edt sect eto% .8s edt at aysafer Isool edt to eesrtq edt nedst -tsothat ef eA .8 watt to mateyse gotvediuterb edt wt eev[oemedt Asol ayefer Hooft edt .5e ayelet stafq eff es tes mottiaog avitsteqo -19 anttool ef? .emedoe anthesseta edd at ob davordd eemoo ,tevewod ,saso edd at trot rtaftwte ,yalot dtxtea ew to stostxoo daoad edt 195 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY to the others, and called the selector break. The circuits are so arranged that when the selector break coils are de-energized, and the armature lies against the back point, the locking circuit is closed to the battery; when the coils are energized, the armature is drawn away from the back point, and the locking circuit is separated from the bat- tery. Hence, when the selector break opens, it releases any of the lock relays which have been locked in the operative position. The control of the selector break is through a button on the receiver disk. This button, called the restoring but- ton, is double size, and corresponds to both the positive and negative synchronizing but- tons of the transmitting disk. It will be remembered that once every revolution of the transmitter brush arm, a marking impulse is sent out from the negative synchronizing but- ser YATASORIAT DUITMIAT FO MATSY2 MUAATOM GHT -Msetd totesfee edt befifeo hans ,etedto edt of eit medw tedt begnatrs of ets atinerto edT Bas ,bostareme-of ete eftoo Aserd totoelea ~tatog dosd edt fentsass eet{ eruteanrs edt suytettad edt ot beaofo et ttuoxto aatdool edt erstemre edd ,hestaureme ote eftoo sit nedw edit Bre ,tatoqg wosd odd mort yews awerb ef -tead edt mort beteatsaqes et sitsettoe antxool ~emeqo Xsotd totoslee oft medw ,eoneH .yred even dotdw agsle1 Aaool edt to yms esasefer tt -cottteog evitsisedo ad? at fexool ased totoefee edt to Lortioo eT revieset edt so sottod s dagvord? et deed -tod antrotest edt Beffse ,sottud atdT .vetb ditod of ebmoqesertroo bas ,este ef[dvob ef ,mot -tud antsinorfoaye evitegen bas evitteoq edt ed [ftw tl .deth gatttimenart edt to anot edt to molttuLovet yreve eoso tadt bersdmemet et sefuqmt aytsdxrem s ore david rstiimescatd -tod antstrordeaze evitegen eft mort two sites THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY to; hence, the selector break is energized and operates once every revolution of the brush arms. Furthermore, the opening of the selector break occurs between successive let- ters, so that the lock relays are "restored" after the reception of each impulse combina- tion. The lock relay, L-5, does not lock itself in position with current from the selector break; we will presently see the reason for this fact. It might be well to state here a condition which is general in all the Morkrum circuits, viz., one side of the bat- tery is permanently grounded, and one side of every solenoid or relay is permanently grounded, Therefore, only one additional path need be established between the battery and the magnet in question, 196 eer YHTAAHRIAT OUITMIAL FO MATS Ye MUAAHOM BHT Sestetene et Aserd rotoel[ee oft ,somed yot edt to notgufover yreve somo gotarszo fra eit to antaeqo eft ,stomtedii? .emte devtd ~tel evicesoove meewted erseo0 wee1d tosooelose “fhototsex" ers ayafer wool edd tad o8 ,eted -antdmoo ealuqmt dose to aottqeser edt t6tts molt . geoh ,a-1 .ysfler wool edT txettso dtiw mottteog at tleett soot ton yltnesetq [[lw ow ;ieertd toteefee edt mort etost eid tot moaget sft coe stete ot [Lew od tiatm $I edt £fe wt Lerenes 2! Sotdy mottirbroo s ested -ted edt to ebte omo ,.stv ,stivgorto mrrmdrotf ebte sno boa ,bobavors yltmenaoreq ef yret vitconamtreq et qeist to bhomefoe yreve to dtaq [enotttibea emo ylno ,etoteted?T .bebnavots bes ytetiad edt meowted bedetidstae ed Soen erorteerp at tengam edt ae ah aoe 197 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY THE LOCK AND PLATE RELAY CIR- CUITS. The connection from lock to plate re- lays is shown in Fig. 49. Here we see that the five plate relays are connected in paral- lel with their respective lock relays. The two sets of instruments are connected in par- allel through four back contacts of a relay known as the divide relay. Plate and look relays #5 form an exception to the general arrangement: they are connected directly in parallel. The plate relays lock themselves in the operated position by current through the min break, just as before, although the locking circuit is not shown. By this arrangement, if the contacts of the divide relay are closed, as they are when the divide relay is not ener- gized, the plate and lock relays are in par- @llel. The plate relays will, therefore, fol- low any movements of the lock relays. Since yer VHTAROSIPT DUITHIAT TO METSYe MUSAAOM HT -AT0 YAIGH RTATLT CWA AOCGI FHT -et etstq otf Xool mort mottoenmoo sdT .eTIUD tadt ese ew steH .Od .2atW xt mworte ef ayel -fersg at Sefoonnmoo ete eyelot stsfa evit ont adi .eyefet dool aviteeqesor xiedt dittw [el -raq mt fetoemron ete stnemuttent to eter owt ysier s to atoataoo xoed twot davordt Cells Moot Bae etall .ysfor ebtvt5 edt as avond [aromen edt ot mottceoxe ma oot @ aysfot mt yftoettb bets anos ers yend :tremegcatts eevisemedt dool evefer etelg oct .fel(s1sq dasomnt trevrve yd motttaoq Seteteqo edt at edt devodt(s ,stoted se tes, ,xserd aiem edt eMwode ton at titrvorto anttool edt tt ,tceregnsirs atdd yi es ,Sevolfs ete yeflor ohtvtS edt to etostaoo -trere ton et valet ebitvith edt nedw ete zodt -teg “ai ers eyefer xoof bas etsia sit ,boesta -fot ,etotetent ,{[ftw aysfor stafq oAT .Lolls eonte .eyefer fool ext to atmemevom yos wolf 198 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the lock relays are governed by the incoming line impulses, the plate relays also register the character of the impulses. If the contacts of the divide be opened, as they will be when the instru- ment is energized, the two banks of relays are separated. The first four lock relays act just as before, but the plate relays are not affected by the line impulses. Since the locking circuits of the two sets of relays are independent, the plate relays remain in the position in which they were at the open- ing of the divide contacts; then, when the main break opens, locking current is cut off from the plate relays, and they resume their inoperative position. As for the operating circuits of the divide relay, the relay coils are con- nected to one tongue of the relay. The back point, corresponding to this tongue, is con- beL YHTATHE IST DUITHIFT TO METAYe MUAAAOM ENT anitmoont eft yf hextovon exs eyelet wool ent netarnet oels avelor etsiIq edt ,eeefsgqmt entl -seefugqmt edt to refestaro edt ebivibh edt to sioetmeos adt tI -ortamrt eft nedw od [ftw yodt sa ,beneqo ed eyafer to ered owt eft ,besisrene ef sSnom eyelet Hoof tot terkt esl .botareqea ets ers ayefer etealq oft tud ,cxoted ae tes, tos ext sont? .eealuqmi oatl odt yd betoetts ton eyafat. to etes owt oft to aetisorto antiésol ot ctemet eysier etalg edt ,tinobmoqebot ets -meqo oft te exow ysdt dotdw at aoltteog eft eit nedw ,nedt getostnos ebiIvith edd te ant tto tuo eat torture astvool ,smeqo Aserd ciem tied? omuset yedt foe ,eysfer etelq eft mort noltteca evitetoqont ativorto anttereqe edd rot @A -noo ete altoo valet edt ,esfler ebivih edt to Zosd efT .yafer edd to examot smo oF betoon -coo et ,exgnot etdt ot untbnoqeerroo ,déntog ry THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY nected to the restoring button of the receiv- er disk. When the relay is in its usual po- sition, there is a current path from the re- storing button, through the brush and brush arm, through the divide relay contact to the operating coils, and thence to ground. Hence, when a marking pulse occurs at the restoring button,as it does once every revolution of the brush arm, the divide relay is energized. It therefore draws its armature against the front contact, and thereby cuts itself off from the receiver disk. As we shall see pre- sently, the front contact is connected to the battery through the main break; hence, the divide relay is locked in its operative position until the opening of the main break. At the same time that the divide relay has changed its own circuit, it has separated the lock and plate relays. Ny rf tol , wi +e oy eer YHTARORINAT OMITHIAT TO METCYe MUAAHOM THT -viaoer oft to nottnd untroteer ont of betoon -og I[sver ett at at yafer eft mon .detbh to -et eft mort dteq tnerrss @ ef erodt ,nottte desrd bae deurd edt dasort? ,nottisd antrote edd od teetnoo yalor ebivibh edt dguvordd ,ore ,eoneH .invore o¢ somedt fae ,altoo antiateqo gatteteet aft te eryooo selsq anidtam s ooedw to motdufovet yreve eeno seoh wi as, nodind -Sestateme et yeler ebivib edd ,arra desrd edd eft tentses srutsmres ett ewesth sroteveds #1 tto Yfeati etme ydetedt Bae ,tostnoo taort -etg eee {fate ew ef .xetbh tevteoet oft mort ot betoennoo ef stostnoo tncrt edt ,yiitmes ~soned ;Axserd mitam eit duvordt yretiad oft eviteteqo ett at betsof et yealet ebivib ext etsetd ate efit to gatneqo edt [fttav mottteog ead yelet ebitvitbh eit teds emtt emsae ont tA beterages ead tf ,tlrorte mwo dst heanario eyelet eteafq Ans wool eit THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY When we go a step further, and apply the scheme just described to the scheme of Fig. 47, the result is the circuit presented in Fig. 50. 4s was said before, Fig. 50 shows the lock and plate relay cir- cuits actually used in the Morkum printer. FINAL SELECTOR CIRCUITS. In Fig. 50, the lock relays are connected to the receiver disk just as in Fig. 48, and they receive their locking current through the back contact of the selector break. The first four relays are connected in parallel with their respective plate relays through the back contacts of the divide, just as be- fore. The fifth relays are connected direct- ly in parallel. The five plate relays and the fifth lock relay receive locking current through the main break. The selector break and divide relays are connected to the re- storing button of the receiver disk. The di- 200 OOS YHTAROELST DUITMIAT FO METcYe WUHAHOM FUT erott@t gets 2 os ow rod! eft of hedivroseh gest emoedon edt ylage bas tinotto oft ef tivaert edd ,TA .ett to enonoe ,etoted Brse caw eA .08 walt at betassetyg -tte yefor etefq hae wloct edt awode Od .2tt totatxg modroM edd at bees yl autos ettio aI ,eTIVOsAIO HOTOMIMe LAWMIE ot betesmnoo ers eyefer wool edt ,0d watt hoe ,6S watt at es teut deth revieser ont davordd tastxrso goftool artedt evteser yedt ed? .¥eerd rotesefee edd to vostaoo toad sit fef{fersq nt beteermos sts evefet root tert? dayvordt syafer etslia evitseeqeer iatedt dtinv -ed een test ,ebtvtb eft to etoetros wosd odt -toorlb betoonmoo ere eysfet dgvtiIt odT .erct Bae eyelet otelq evtt oT .feflereq af yt daerzrvo goivool evieoet yefer Yoof dvtit edt ; wsetd totoefee oft .Hserd mtsm edt davordt -~evy edt of betoenmmos ers eyelet ohivith baa -fh edt .teth tevteoet est to nottud satrote = —— poe Ue ne 1 Re YY, moi POF wv Y - * «hip he 7 Vrs 201 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY vide relay receives locking current through the main break. We see, therefore, that al- though the arrangement of the figure has been changed somewhat from that given in Figs. 48 and 49, the electrical connections are just the same. There are, however, two additional devices in Fig, 50. The first of the new devices is the drum magnet and drum switch. The drum magnet is connected to the battery through one of the front contacts of the divide, so that the magnet is energized while the divide relay is closed. Furthermore, the drum mag- net carries oa switch called the drum switch; this switch closes when the drum magnet is energized. The purpose of the switch is to connect the battery into the distribution cireuit, as that circuit is called which serves to operate the rotator magnets or other print- er functions, That is, the drum switch con- £0$8 YHTAHORIET DUITHIAL TO MATCYS MUSAHOM ART fiasordd tuerrve anivosol asvitsssr yelet obtv -fe2 tadt ,eroteredt .ee8 oF .Naeetd ateam sdt mood esd eryatt ocd to tnoamesnerra odd davodt 8) .entt at nevis tadd mort tedwemoe hSeanado vent ets esottoennoo [sotrvoele eft .e) bas Ianotiibhse owt ,tevowod .ets oven! -omse ent -O8 ,at% ot eeotveb eeotveh wer ent to teartt ed? morh oft .dotiwe morb boe veryem murtb oft et davordd yretted edt ot betosmmoo et tongam oe ,eohivts eft to etositnce trort ext to exo ebivth eit eLfdw bestetene ef tesgem edt teadt -gem murh edt ,orormedtrs! .besolfo at yelor efotiwe meth eft Belles dotive se aottrsas ten ef tTergem mtb ede stedw eseofo dotive etdt of et dottwe eft to eeogrsg sd? .bostetomne mottudirterS edt otnt yretted edt toennoo sevies dotdw belfse ef ttvetto tadt as ,titvertto -tnitg tadto to etemgsm rotator eft stareqo ot ~tioo dottwe mab eft ,et tedT .enotsonrt +e THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY nects the battery to the semi-automatic func- tions of the printer. The other additional feature is the signal lamp. As is indicated, the lamp is controlled by an additional lock relay, identical with the other lock relays. “hen a marking pulse is received by the lamp but- ton, the lamp lights, whereas if a spacing pulse is received, the lamp stays dark. The action is apparent from the diagram. We will now trace through the cycle of operations with the system of Fig. 50, remembering that the idea of the scheme is to allow one letter to be printed while the next letter is being received over the line. Suppose, for example, that the signal ++——Hthe letter A) is received. The action of the lock re- lays is for instruments #3, 4, and 5 to oper- ate, since the relays respond only to marking 202 808 YETAROAIZT OLITHIAG TO METEYeS MUARAAHOM FUT -onnt oltsmotys-Imee eft of Yiettsd oft eftoon tetairg ett to erott stxteset L[anctttbhbs tonto ed? qmefl edt ,beteotbat et eA .qmel Ieanste eit et eyvafer wool Ianctitbbse ne yd felfortmoo at rod” ,eyator wool tedto ed? dttw Isottrebt ~tod gual edt vd bevieset eat selinug anidisa s avtosqe @ tr sastedw ,etdsil qmel oft ,not eit «atab eyate qmsf edt ,fhevteoet et safuq smsrgetbh eft mort toerscqs et mottos est dasordt gostt won [fiw sv eatt to metaye oft dttw anotteteqo te eLloyo egetoe et to sebi eit tsdt acitednemet 8 elidw Betnitq ed of rettel emo wolfs ot et eit tevo hevtecer avted el tettel txen ent {sugte edd tedt ,sfqmeaxe tot ,eveogque antl ebeviteoet at (A tettel edt)-—— ++ -et Zool eft to mottos en? -rogo ot @ Boe .d .Si etmomertent rot ar yet. guidtsm o¢ yfoo baoqeer eyelet oft sonia ,sts Pier i ae 204 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY pulses, and #1 and 2 to remain inoperative. Lock relays #3 and 4 lock themselves in the operative position with current from the sel- ector break. The five plate relays duplicate the settings of the lock relays, and #3, 4, and 5 lock themselves in position with cur- rent from the main break. L-5 is also lock- ed by current from the main break. This ac- tion takes place while the receiver brush is passing over the five contact buttons, #1, 2, 3, 4, and’ 5. When the brush reaches the restoring button, the selector break and di- vide relays are operated. The divide relay separates the first four plate relays from the lock relays and locks itself in position. Hence, the separation of the lock and plate relays is maintained after the brush has left the restoring button. At the same time, the Selector break cuts off locking current from 208 YHIAROSINT OUITMIAY TO MATAYe MUSAHOM SHT eoviteteqont nismet otf S fas [% buna ,eeelug est mt sevfecmedt Mool S bana S¥ eyelet wood -fee edt mort tasirxvo Athy noltieog evitereqo etacitfqnuh eyefor otelq evit sXiT .xeerd totoe od ,8% bas ,eyeler wool eft to eanittes ent -10 dtiw cottisog at eevfeemess soot d@ bas -Hool oafe et 4-1 .teerd ates edt movl inet -s2 aint ,aserd otem ont mort daetrso yd be deoxrd tevtsoer ect eftdw esata satst scott f% .erottyd tostaos evit eft tevo sateeag at 2 Soa ,8 ,8-.8 edd sedecet destd edd aedl -ib Bas Heerd sotoel[sea oct ,nottud antroveet vefer ebivifh ed” .beteteqo ota ayalet shiv mort eyelet ovelq twot terit ext eestaraqes cotttaoq at tloet! exool Bree aysfet wool ont etela bos woof adt to nottetaqes edt ,oornell Stel sad decid oft vetta beatstatem ef eyelet ext ,omit emee edt tA .mottad gxtrotver odt mort tnexrrve anttool tto etre xserd rotoelee 205 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY the first four lock relays, and these relays resume the inoperative position. The fifth lock relay remains locked with the fifth plate relay. The selector break remains energized only as long as the brush is in contact with the restoring button, but this time is long enough to allow the relays to unlock and as- sume théir inoperative positions. As a result of these movements, we have lock relays #1, 2, 3, and 4 de-ener- gized, and #5 still energized and locked in position. Plate relays #1 and 2 are inopera- tive, whereas #3, 4, and 5 are energized and are locked in position. The selector plates are therefore set, and ready for the print- ing operations to begin. Besides separating the lock and plate relays, the divide relay has, at this time, completed the circuit of the drum magnet, This magnet draws in its armature, 80S YHTAROAIAT DUITHIAT FO METeYe MUAAAHOM FHT eyefer esedt boa ,eyeie: wool trot terlt edt cid t% ediT .sotttecq evitereqont ext Smrveet etelq Avtit edd dA¢iw bedool antemer yelot dool heatoteme enismer xsexrd totosiIse en” .yelst itiw tgosinoo at ef deutd eft es goof as yino goof al omtd etnct tad ,notted antroteet eft ~es bore Moofos of eyelet edd wolls of Agvone -anottteoc evitsregont riédt ems ,etnemevom eeedt to tinest sp eA -rere-9h 3 boa .& .8 Li eyelet dwool evad or at heslool fas besturene [ftte 3% base , fests -ateqont eta S boe £% ayeler stell .octtteog bos besistene ers @ Bae ,) ,8) aastedw .,evit setslg zosoelee ed? .xottteogq at bsiool ets -tntaq edt rot ybset baa ,tes etoleredt eta eaitged of anotiareqo ant tool eft gniteraqer aebteed ts ,ead ysfer ebivib eds ,eysler etelq bas myx eft to ttnorto ett Setelqmoo ,emtt elnt. ,otutamre att mt ewerth temzsm ald? .temzem THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY and thereby sets the interference pins of the selector. The drum magnet also closes the drum switch. This switch connects the battery to the printing functions, so that the printing action now takes place. In the mesntime, the lock relays have been receiving the first two or three line impulses of the next letter, and have stored these impulses by the locking of the lock relays. The final movement of the printer, during the printing of a letter, momentarily opens the main break. This mo- mentary opening cuts off locking current from the divide and plate relays, together with L-5, for a sufficient intervel of time for these instruments to return to their normal positions. Note that the unlocking of the divide relay restores the drum magnet and 206 a0 YHIALDSRINT PUITMIAG TO METEYE MUAAROM SHT to arta sonetettetrt eft etee ydered? fas eerolfo cafe tenmgem murb ed? .roteefsea edt eat atoenroo dottwe etdT .cottwe morh ont tent of ,emottonet antinixng edt ot yretisd -ecalq sextet wor acites gnaitnaing edt adool edt ,emitnsem ext ni to owt terft edt antvteoet meed evad eyelet Bas .tovtel txen eft to eoalsamt. ont setdt goisiool edt yd eselsqmt eeedt betote evad -eyeflor tool eft to eit to taenevom L[axtt en? tettel as to satinivg edd sntryh ,retnirq -om etd? .deerd mtam erit enoqe yiitetasmom mort tnerxvo sattool tto etno amineqo Yretner dtiw tedsegot ,eyefer otelq Sane obitvih edt stot omit to {Isvretat tnetotitvee a rot ,a-1 femros tledt of oyster of aetnomurtent eaedt att Yo ant¥ootas ext tact stoi! .eaottteor bas venzem murh eft seroteet yefet shivth 207 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY drum switch to their inoperative