US2435035A - Simultaneous plural frequency start-stop telegraph system - Google Patents

Description

Jan. 27, 194s. DEVAUX f 2,435,035

SIMULTANEOUS PLURAL FREQUENCY START-STOP TELEGRAPH SYSTEM Filed Jan. 28, 1943 2 Sheets-Sheet 1 INVENTOR zuc/s/v DEVAUX I BY ATTORNEY Jan. 27, 1948. LQDEVAUX 2,435,035

SIMULTANEOUS PLURAL FREQUENCY START-STOP TELEGRAPH SYSTEM Filed Jan. 28, 1943 2 Sheets-Sheet 2 INVENTOR LUCIE/V DEVAUX ATTORNEY Patented Jan. 27, 1948 SIMULTAN EOU S PLURA'L FREQUENCY START-STOP TELEGRAPH SYSTEM Lucien Devaux, Lyon, France, assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application January 28, 1943, Serial No. 473,885 In France January 31; 1942 23 Claims.

The present invention printing telegraphs and particularly systems adapted for transmission of messages, by means of radio;

In ordinary transmission, utilizing very short code signals, it is known that parasitic influencescause addition or suppression of signals, whereby errors in reception are produced. For instance, one letter is printed instead of another, .etc.

An object. of the present invention is the reduction or elimination of parasitic disturbances in the transmission of code signals. by means: of. a printing telegram In brief, I accomplish this result in the follow.- ing manner: Garbl-ing'of' code signals dueto-para: sitic influences is. appreciably reducectby lengthening the duration of the signals" while using alow resonance frequency having a. large time constant. However, a disadvantage; of this arrangement resides: in the fact that lengthening of the duration or the signals brings about an unacceptable slowedown in-tra-nsmission.

It is. therefore a further object of; the. invention to provide means for preventing a slow-down in transmission, of the: code signals while permitting, nevertheless, lengthening of. the duration of the signals to such a degree that gambling, due to parasitic action on the. radio connection, is reduced or practically eliminated.

This result is obtained, according to certain characteristic features of: the invention, in the following manner: A. frequency of different: mod,- ulation of a single carrier wave is assigned: to each code signal and the total number of these frequencies for: a. code of five: elements for ex.- ample is six; namely, one frequency for each code signal plus one, additional frequency for the signal for starting the printing telegraph at the receiving station. It thus becomes possible to transmit each code signal not just during, a very short. period of time, which is but a fraction of the: total; period of time allotted to the complete signab combination (comprising the starting signal and the following signals: making up the code symbol of a. particular character) but during the totality of that. periodof time. For instance, if the system is adapted to operate at a, speed of seven characters per second. or approximately 140 milli-seconds for each character, the transmission of various frequencies, including the: starting signal. and the: code; signal, will; last 150' milli-seconds. Upon reception, the signals are separated by filters and act upon the respective relays which register the combinations of the code; Durin the next period of. 14:0: milk-seconds, which i relates to systems for.

consumed by the transmission of the next character, the registered signals of the-former character set up the combination upon the receiving translator and printing takes place thereafter during transmission of the next following or a third character. Thus, the total time allotted for the transmission and printing of a character is 420 mint-seconds, of which 280 milli-se'conds are used for the transmission of a second and third.

character which are stored by the receiving apparatus to be printed successively as following character are received.

Inasmuch as the starting signal is sent alone, its intensity must be such that the modulation of the sending station is a maximum. The signals of the code are sent in permutations of 5 in the present embodiment of the invention which contemplates a code of five elements, the intensity of each signal being Such that the total of five signals produces maximum modulation of the sending station. As a result, one obtains a variation of the modulation ranging from 0 to the maximum, according to the number of the marking signals of the code, Due-to this arrangement, it would become impossible to use devices for attenuating parasitic influences such as for instance limiting means. The present invention overcomes this drawback by sending a code signal not just by direct transmission of a frequency, but by variation of this frequency which is being transmitted continuously.

Thus, during the time reserved for transmission of signals, the transmitter is modulated by the combined code frequencies fl, f2, f3, f4, and I5, for; instance. The sending of a marking signal consists in causing a slight variation of the corresponding frequency in a fractional amount thereof, for instance. by slightly increasing the capacity of the resonant circuit relating thereto; Frequency f l becomesfl-Afl for the sending of the first code signal etc. Similarly, while awaiting the starting signal, the transmitter is modulated at the frequency f6 and the sending of the starting signal is produced by varying the frequency from JSto Iii-M6. The modulation of the transmitter by means of frequencies it to f6 may be produced by any known method, for instance by means of simple modulation while transmitting a carrier and two lateral bands. or, preferably, by means of modulation without carrier while sending a single lateral band, or by means of frequency modulation etc.

Irrespectiye; of. the modulating method chosen, after; reception the frequencies fl to iii are furnished by the receiver. It is possible to arbitrarily choose frequencies ii to 16 according to the present invention, the frequencies assigned to the code signals should preferably be contained in an octave in order to avoid intermodulation frequencies. For example, one may use for the code signals the harmonics II, I3, I5, I I, and I9 of such basic frequency as may be desired. For instance, 50 cycles per second would give the following frequencies: 550, 650, 750, 850 and 950. Moreover, in order to assure a more uniform filtering action, this invention also provides for the determination of each frequency in such manner that the spacing between two adjacent frequencies is a constant fraction of one of the two frequencies; with a spacing of approximately 15% of the lowest frequency, the following values are obtained:' 550, 628, 722, 830 and 955.

The frequency of the starting signal, which'is sentalone may be of any desired value but the same is preferably superior to the highest signalling frequency in order to prevent the harmonics from falling Within the range of the code signal frequencies. In the example given above, this frequency could for instance be 1100 cycles per second.

The factor which characterizes the variation of frequencies for producing marking signals is made as small as possible in order not to render separation of frequencies difficult. With resonant circuits of good quality one may use a factor of 0.02.

The invention also provides means for producing the transmission of frequencies according to the method described above and uses a radio transmitter controlled by a printing telegraph transmitter. Moreover, the present invention uses the various frequencies obtained from the output of a radio receiver in order to operate a printing telegraph receiver.

With these and other objects in view, as will be more apparent hereinafter, the present invention is fully described in the following specification and illustrated, by way of example, in the accompanying drawings, inwhich- Fig. l is a schematic view of a printing telegraph transmitter;

Fig. 2 shows schematically a printing telegraph receiver, designed for cooperation with radio receiving apparatus.

In the drawings, Fig. 1 illustrates the transmitter comprising five key bars I, 2, 3, 4, 5, whose movement is controlled by keys such as 6, I, 8, and 9. Transmitting keyboards of this type are well known in the printing telegraph art, for example, the present Teletype and Creed keyboards. The connection between the keys and the bars is conventional and not shown in the drawing. When a key is depressed, shaft I is connected by a clutch, not shown, to motor t l and performs one revolution and is then stopped in well known manner by the disengaging of the clutch members. Shaft Ill carries two cams I2, I3 which operate contact springs I4 and I5, respectively. Bars I to 5 close combinations of contacts I6 to 20 when moved toward the right in response to the operation of any key, the combinations depending on the particular permutation of the five unit code assigned to the operated key. For the purpose of explanation it is assumed that any closed contact will cause the transmission of a marking impulse while the open contacts cause the transmission of a spacing impulse. The transmitter E produces modulation by means of oscillators OI to 05 which are connected to contacts I4 to 2D and to one contact of spring I5, as

shown in the drawings. A sixth oscillator 05 is connected to contact I4 and to one contact of spring I5. It will be noted from the shape of cams I2 and I3 that the duration of the start signal occupies about one third of the rotarycycle of shaft III while the remainder of the cycle, that is, during the time cam I3 holds contact lever I5 against its upper contact, is used for the simultaneous transmission of the frequencies assigned to the particular character being trans-- mitted. In rest position, oscillator 06 operates alone, one of its circuits being closed by contact I5a. Thus a frequency I6 is produced and the transmitter sends a modulated wave at this frequency. When a key is depressed, the clutch, not shown, engages and shaft I0 is connected and turns, whereupon cam I2 immediately closes contact l4 which serves for changing the frequency of oscillator 05. The frequency thus becomes fG-Affi and the transmitter sends a modulated wave at this frequency. It is this Wave which serves as the starting signal. This wave is of relatively very long duration, during which time shaft l0 turns approximately degrees. Thereafter cam I2 moves out of engagement with contact lever I4 removing the ground from the oscillator 06, and at the same time cam I3 acts upon spring I5 and contact I5a is opened and oscillator 06 is completely stopped, while contact I512 is closed and puts oscillators OI and 05 into operation. The latter act upon the transmitter so as to send five frequencies simultaneously. The value of each of these frequencies depends upon the position of bars I to 5, that is to say opening and clos ing contacts I6 to 20 which, when closed, cause the frequency of the corresponding oscillator to change from f to f-Af.

The five frequencies transmitted thus depend upon the position of the bars I to 5, or in other words, upon the combination of the code corresponding to the letter to be transmitted.

The simultaneous transmission of the five impulses lasts a relatively long time, that is for substantially all of the remainder of the rotary cycle of shaft I0 while the raised portion of cam I3 holds contact lever I5 against its upper contact b.

At the end of the revolution of shaft I0 contact I5b is opened and contact I-5a closed, The transmitter thereupon emits the rest position wave which is modulated at a frequency f6, this being analogous to a constant spacing signal being sent to the line, which practice is well known in the start stop printer art. Bars I to 5 are then restored to rest position in the well known manner thereby opening any of the contacts Hi to 2B which may have been closed. The apparatus is thus restored to starting position and is ready again for transmitting anew character.

It should be noted that the transmitter keyboard mechanism is simpler than that used in conventional start stop systems in that no distributor is required for sending the selecting impulses in succession, because the selecting impulses are transmitted simultaneously after the start signal has been sent. Cams l2 and I3 serve to separate and time the transmission of the start impulse and the selecting impulses.

An example of a receiving circuit is schematically shown in Fig. 2.

The invention contemplates the use of a start stop receiving printer preferably of the kind known in the art as a single magnet printer wherein one magnet serves as a start magnet and also responds to selecting impulses received after the start impulse to control the operation of a mechanical selector. Printers of this :kind lane provided with '.a wonstaniy nperatingmotor which furnishes :power for the :pneration the printer.

Between the ;'motor :shaft and .a power ishattrnf the printer is a clutch whose driving and dt'iven members are normally disengaged tinder lQQRiiXQl of :the start :magnet 1 armature. When :a :startrimpulse is ,areceived, the :start magnet operates :releasing the shafit 'Which'inakes 0118 revolution and then ntops yon engaging the startmagnet :armae ture. Theshaftremains stationaryiuntilreleased when the :start signal :for the :next :character is received. The power :shait usually carries 101' drives ca :mechanical distributor arrangement vimich cooperatesmithzthe.startmagnetawhen the latter is receivingzselectingsimpulsesto controlithe selecting mechanism of the printer. .There are many variations of this unechanism, allao'f which, however, :have ithezsame vgeneral principle :of operation. In thiszcountry the -T.eletype;is:the best known of the :single magnet printers, while in Europe the C1teed:single magnet commonly used.

itswillihe understood thatthe printer motorrand the :keyboard motors are controlled ;by suitable governors set so the motors'turn atzalmost the same .speed', :that :of zprinter being 12. :trifle higher ;to=ensure that :theprinter mot-or wi'lltcome toaa stop with-each reuolution so :that when the next start signal is neceived, theiprinternnqtor will start off iin unison with :the incoming signals 28.6- cording totthe usual practice.

In 'Fig. 2 .of v-the trimmings, printer rmotor 1k! is.

shown 'as :being aconmected to shaft :In :actual .practice,;however,:it will zbe'innderstood that nhait 22 is connected icy suitable :gears to the printer power :shait, irather than directly to the motor, and in :this wayzthermagnet-indiczitedibyreference character :2! :serves as .a start magnet for -hoth shafts as well as functioning as a selectingmrage net for the printer. ,It should heikept .in mind that in :the presentinuentionrmagnet 21! does not receive the .aselecting :impulses niirectly from an incoming .circuit "for the .:reason that all selecting impulses are :received simultaneously which makes it necessary to first separate :the frequencies by suitable .ifilters and register them on melays "when so separated, and :later by means .;of :a cam arrangement on shaitq25. zofwvhichcnlythose cams 2-9 and an required to :controlathe ifirstimpulse are :shown, :the impulses stored n .a .'g11OuD of :relays :-are :sent one at ;a time to magnet ':24 via \a second distributor .arran'gement including cam 12.4 and :a series :of contacts "which separate the impulses and sends them properly itimedtto magnet 12 ,l, so that the flatter operates :at just the right time :to contnol the respective mechanical selectors withinithezprinter. There isinoizdifiicnlty in this :because shait $22 :and the printer .shait are driven from :a common ;s0.u11ce :of :power :and turning in fixed relati'onship mitheach-zothenrand cam 124;andithe:'contactszcontroliedthenebyxcan be spaced to :secure the optimum "result.

its alreadyz-statei-thesshafttofzthezreceiver :tnot shown) :is adapted to make :one involution-tor each character. Thi shaft is associated with a second shaft .22 marrying :two'cams r28, 24 which act upon certain contact springs referred 'to.:furzthcr .on. fih it 22 in turn :rotates ishatt 125 103 meansofa reduction gear ;2i|,.having1a:ratio of i1 :2. its a -result,\;shaft :2 :makesza ;half:i:evolutiOni r-each character r eceived. Shaft '25 carries thr cams :28, '29,, .30 acting :uDQn certain contact spring des ribed below. tithe receiving :circuit \QQQPIEEQS mescnant circuits eior th selection f III)v frequencies, :reiays 11.01 the irecepticn L91 signals, registering.relays:andswitchnQntactsactuatedhy the :cams 538 more fiully described hereafter.

iltadio receiuerflzieeds {the detected modulat ng currents to :thc :gnid of tube Eitl iof ,lowfimpedance, whereby a 'it n i cr :Mxmay be interpo ed i c the mucosa 10f ibri-nging the amplitudeiof the currentsaogsuch za valueathat the :tube 3:! acts 34, 2? limiter. The plate ,:is Ffed across a new resistance 33,. 1A condenserza tofigreat capaeity-connectsithe plate :to spring 2315 which {is actuated hycam -23,

irest zpositicn of the apparatus While awaitineathestartinastena .the raised por ionscfc m ficanshnnspri gzw lo cccntactc- Them ic circuit ,cf :tuhe .34 is; c nfiqt d to zazrescnent circuit :clc ed .iby nnden .35 and selfndu tance 3:1. 7 Ennis circuit :is :ada'us e i r weso ance at t inecuency l'fB"" [2Af 1&n, i damped a t e a pessibl provided that the resistance .33 is zoi low taluenndu erm ts frequencies .f6 and ;f6- -M6 t pass with dik cific ency. T i first resonant c r- Quit ser es as a educing 'i te for the s a t si nal... Th i Q l between theseIf-inductance g3"! and th ca citance 5. "Wh e t e su t n is ;pro duced, is connected to the grid of a second 1 tulce 43 8 \tgheseiplete is ,fediacrossza resistanceds and connected thy means :OfffiGOIJ-dEHSBI to two sncols'et, flz er r ei r h item nt-c the two resqnant circuitsdhl and 43. \Circuit 43. is ad usted to a freguenoy slightly higher than fiandcincuit 4 to .ireeucnc s i tly o th n it -M Beth t ere a hi h sce fic ent =0 pe -tens n -=end hei t m -.ccn t n can .be e at v la d to the du a ion c heam na nal. 4t an M a e =0 n d.. in kn n mine, as a to c iiie acr oppoitely ccnnecteo rectifiers 45 46 and resistances 41, 48 upon :the molanized [relay 4.9. Fig. 2 shows a idirect tconnecticn with relay- 49, however, in order to p reserye the full .ef ficienc y of the inesona nt circuits 43, .44,';prov-ision is also made for inse itionpf a tube, During the waiting-period, the ifirequcncyjfi .is received and the resonant ciecuit 43 .is excited more than circuit 44. The current i polarized relay .49 has such a direction that the v atter :opens .its contact. When ireqns c tit-1M6 is .-.rcc d ci cu is re .ex itediand rel y 1& h c i t rs y ecutent inhnpcs te dit ct cn. o s h co t 1 shc ld be me ed thatth r a r n em n c cc netoth pre ent e n i ha ns tivezat all t o;parasitic influences. 'If-such-occur, they are reduced by the first resonant circuit and act 'uponicircuit .43 and .44 with equal inten itras a re t. the e ay 11 not affected attain.

{Ehecontactof relay 4-9 isconnectedtotheelectmmaenei :24 by m a s o :sp in c n t 50 ch. is actu ted by the ra e p r ion 1 c 24.

s s on a the e cctromaenet .24 operates, the printer power shaft not shown-andalsoshaft :22 tarts torcvolvei neaee c s r g 35 which-opensnts cQntact-wandcloses its contact :31. {Fire mlate oitube 31 :is 'now connected in par.- ellelito five rcsona t ircuits amt-. 5 ach of whichacircu ts is adjusted 'fcrrtheicnowing freei is 2M hes i cuits are as little dam ed as; pos sib.1e :and each of them permits the apesis fed by resistances 51 and connected across con denser 58 to the exciting windings 59 and 60 of. the two resonant circuits GI and 62. Circuit 6| has a resonance for a frequency slightly higher than fl and circuit 62 has a resonance for a frequency slightly lower than fl -Afl The two circuits are. difierentially connected across rectifiers 63, 64 and resistances 65, 6G to polarized relay Bl, exactly as is the case for the reception of the starting signal as above described. If the first-code signal is a spacing signal, the frequency fl is received and the contact of relay 6'! is open. If the signal is a marking signal, the frequency f|-Afl is received and relay 61 closes its contact which is then connected to ground. The contact of relay 6'! is connected to the contact terminals of springs 68, 69 which are actuated by cam 29. It will be understood that the circuit including tube 56, relays 61, 10 and 12 as well as cams 29 and 30 and the contacts operated thereby are only for the reception, storage and retransmission of the first impulse to the printer. There are four other identical circuits operated in the same manner for impulses, or frequencies two, three, four and five, controlled respectively from circuits 52, 53, 54 and 55 and each of these circuits ha an individual pair of earns 29 and 30 associated therewith. Since these circuits are identical and operate in the same manner they have been omitted for the sake of clarity.

, In the present embodiment, each cam 29 has associated with it a relay HI and a relay 12. These relays are for the purpose of storing received impulses. Cams 29 which control the operation of relays 10 or 12 depending on which half cycle of shaft 25 is effective, all have the same angular position on shaft 25, because immediately on receipt of a start signal shaft 25 starts to move and-either contact H or 8! closes an operating circuit for the group of-relays- Ill or 12 and immediately thereafter cams 29 close either contact 68 or 69 which causes either relay group ill or "to store simultaneously any impulses registered by any operated relay 61 leavingthe latter ready to register the simultaneously transmitted code impulses which follow immediately after the start impulse which initiated the operation'just described. It should be noted that shaft 25 moves an appreciable distance before the transmission of the long start impulse has terminated, and therefore relays 61 are ready for a new'oode combination before the expiration of the start impulse. The relays in when operated lockto battery from contact II when the apparatus is just be yond the position shown in Fig. 2 after a start pulse has been received and the shaft has turned a trifle from its normal position, and the relays of the group just referred to remain so locked until two further characters have been received, including the impulses for the character whose start impulse initiated the operation, during which time shaft 25 has made a complete revolution and then the cam again opens contacts H and releases the five relays 10 connected thereto making this group of relays ready to receive another group of impulses after the start impulse preceding this group has been received. Contact 8| operates in the same manner but 180'degrees after contact If. This contact controls the locking circuit for a group of five relays 12, identical with relays 10 and operating in the same manner but 180 degrees, or one letter thereafter; 1

The respective cams 30 are mounted on shaft 25 in the-same angular position, the effective length of the cams and their angular position on the shaft being such that the respective wires from contacts 14 or leading to contacts 15, I6, l7, l8 and 19 of cam 24 which control the operation of magnet 2| when the latter is receiving selecting impulses will be simultaneously connected by the respective contacts 14 or B0 to individual ones of the relays in the group denoted by reference characters 10 or 12 depending on which half cycle of the shaft 25 is effective for this operation. The relay circuits will now be described in more detail. While the shaft 25 makes a half revolution upon rotation of shaft 22, spring 68 closes its contact and the registering relay ill is connected to contact 68. If relay 61 has been operated, relay I0 is likewise operatedfrom battery, contact H, winding of relay lll, contact 68, armature of relay 6! to ground, and it becomes locked by its grounded tongue to battery at the spring contact H which is closed due to rotation of cam 28. At the end of the half revolution of shaft 25, contact 68 is open but relay 10 remains in the position where it finds itself as a result of the operation or non-operation of relay 61.

During the following half revolution, the contact of relay 6'! is connected to a registering relay 12 of a second group of five relays, only one of which is shown by means of springs 59 disposed on the other side of cam 29. At the same time, the contact of relay ill is connected by means of spring 14, which is operated by cam 35, to the first spring I5 of the distributor which in turn is actuated by cam 24. The indication registered by relay i0 is transmitted to the electromagnet 2| by means of contact 15 which is closed during the period of time when the reception of the first signal takes place in the telegraph receiver.

The invention operates as follows:

Synchronism of the transmitter and receiver motors is maintained by the well known start stop system. The transmitting station is arranged to send out an unusually long start impulse preceding the code combinations of each character which are sent out as a group of modulated frequencies simultaneously after the transmission of the start pulse. The relatively long start impulse and the still longer interval'used to transmit simultaneously the frequencies corresponding to the selecting impulses permits the use of efficient filter arrangements at the receiving station that effectively eliminate parasitic frequencies.

The selecting frequencies are separated by filters/and immediately on reception operate a combination of relays 61 of which there are five, according to the marking and spacing elements of the characters transmitted. A line signal having the characteristics just described is not adapted to operate any of the standard start stop printers, so accordingly, means are provided at the receiver to alter the received signals so that only a relatively short start signal is sent to the printer followed by suitably timed selecting impulses which are transmitted to the printer in succession.

In order to accomplish this purpose a storing arrangement is'necessary, which in the present embodiment consists of two groups of storing relays 70' and 12 respectively. On receipt of the start impulse for a character, the combination as set up on relays 6'! is transferred to relays lll or 12 depending on the position of shaft 25. The operated: -relays of these; sets remain locked in for substantially an entire revolutionio-t shaft 25. on the receipt of a: start. impulse for a second character, cams 30,103; means of contacts M or 80, depending on which halt cycle of. shaft 25 iseflective, connects the contacts of any operated relays H1 or 12 to the wires extending. from the contact levers of contacts '15, 1.6, 1'], T8. and 1 9 of cam 24. The stationary contacts: associated with the respective contactlevers are connected to the windings Li of the common start and selecting magnet of the printer. It will-be understood thatthe printer shaft, notshown, and shaft 22 driven therefrom. start to rotate when the start signal releases the printer clutch. As soon as the start magnet has released these shafts, contact 50 of cam 24 opens, irrespective of the length of the startsignal, or whether-it has terminated or not, and-cam 24 proceeds to send to magnet 2| a series of impulses one afterthe other properly timed to operate the printerselecting mechanism according to the code combination-for the first character. On recei-pt ofathi-rd startimpulse, the letteris printed.- The startimpulse fora fourth character will cause the printing of the second character, and so on. All-code combinations pass through the steps just describedbefore the printing operation takes place. When a message is ended, it is customary to send a number of impulse combinations tocause the tape or paper web i-n thecase of a-page printer to feed out. Two ormore of thesenon-prin-ting' code combinations. could be sent at the end of each message to-clear the receiver of stored characters;

Although the present invention has been described in connection with a particular. constructiommany modifications and adaptationsmaybe made without departing from the spirit and scope of myinvention and it should. therefore benoted that I do not intendto so limit the same.

1. An alternating-currentstart-stop printing telegraph system, comprising a group of continuously operating wave signal producers corresponding respectively to code signals and start signals, means for modulating and" transmitting first a wave for a start signal and thereafter the waves all at one time fora given code character, so that each of said transmission prolonged beyondsingle signal ti-me butwithin substantially thetime of code charactertransmission bysignal sequence, in combination with a receiver andrecorder comprising devices for translating the received signals pertaining to a given code character to a printed record thereof during a plurality of time periods of operation and means by which such devices are successively controlled by the start signals of succeeding code characters.

2. An alternating current start-stop printing telegraph system, comprising a group of continu-, ously operating wave signal producers corresponding respectively to code signalsand start signals, means for modulating and successively transmitting first a wave-for a start signal and thereafter the waves all at onetime for a given code character, so that each of said transmissions is prolonged beyond single signal time but within substantially the time of code character transmission by'signal'sequence, means for receiving and recording code character signals successively transmitted as aforesaid, ,comprising means including on or more sets of storing relays and responsive to receptio'noia start signal 110 to: registerslmultaneously thecodesignals of. the; transmittedcharacter corresponding to that start. signal: and itoztransier said signalstov a set. of storing relays, and means: responsive to start. signals. corresponding. to subsequent characters for controlling operation. of the printer to print. the first mentioned character from the stored sig- 3. A. telegraph systemv according: .to claim 1 whereinthe waveproducers continuously operate. toprodnce waveirequencies assigned respectively to: the component signals. and means by whlchthe waveszso produced are transmitted in the absenceof: marking and starting signals.

A Arr alternating current start-stop. printing; telegraph system,.comprising. a group of continuously-operating. wave: signal. producers corresponding respectively to: code signals and start. signals, means. .ior: modulating and transmitting firsta. wave forv a start. signal. and thereafter the. waves. all. at. one time. fora. given code character, sothat each of said transmissions is. prolonged. beyond. single. signal tiimebntwithin substantiallytheltimeuof codecharactera transmission by signal; sequence, said modulating..means comprising de-- vices fnr varying, the frequency oitheproduced;

waves, .in combination .with a. receiver and recorder comprisingdevices for translating the. received signals. pertaining to a given. code. character-toaprinted record thereof during aphrrality of. time periods or operation andmeansby whichsuch. devices aresuccessively controlled bythe startsignals. of. succeeding code characters.

15. A. telegraph. system according to claim. 1 wherein the. code. signal frequencies. are contained withinan. octave.

,6.A telegraph system according. to claim. 1 in. which the, code signallrequencies are. chosen. according to harmonically based numbers, a. common basic-frequency being-adopted. and the product ofsaid; basicirequency and each of. the. her: monicv numbersgiving. the. value. of, each code frequency.

;7.. A telegraph signal according to claim ,1. in

whichthe starting si nal frequency is higher tha 11h? code, signal frequencies...

.;.,-A telegraph system according toclaim 4 wherein the receiver translating devices com.- pri-se selective circuits of low damping and freguency. gijcriminating circuits of high efficiency'. 9. A telegraph system according. to claim 31 wherein the receiver translating devices vcomprise-selective circuits otlow dampin and electronic discharge amplitudelim-iters, whereby to redu para it d turbances in transmission.

1.0-- e esrap syste ac ordin to claim .4 hete nth c iver tran latin ev es comprise selecti e ci cu ts. of low dampi an l ni discharge amplitude limiters and wherein the irequency dis i minating circuits are of high cf.- fiQ nG v 1 1. The method of codesignalling. by. alternatingcurrents wherein each code character con- 512. 9 a reqetsre in n mb o o si n ls alon Whin st r si na w ch efin r continuously producingwaves; of low damping and of eme ge ir quen i s P 1 1 mrod a sier s ignels .in dulei e s a d Wave a meer i l .ep e ,ae st t e requiremen by v r nethei qsene esl t nsmittin by r diation the modulated waves in a. succession iofqa s a si nelml ewedb i ce i nals a a one tine-to e r d characte a h s ants en a 9 .-.i. r 1--.oq9upvio h tim p r d t eel- 5 e eragte ..trensm s e re v transmitted waves, deriving therefrom the modulated'signals'by filtering, amplitude limiting and high frequency discrimination, translating and recording each of the code characters over successive time periods and controlling the initiation of operation in said time periods by successive start signals.

12. In a system of the character described for electrically transmitting messages by means of code signals, wherein each character of the message corresponds to a code symbol and each code symbol is composed of a predetermined number of code signals, a plurality of signal bars, the number of the latter being the same as the largest number of signals contained in any one symbol of the code, a contact associated with each of said bars, a plurality of frequency'modulating circuits, each one of said circuits being connected to one of said contacts, operating means associated with and adapted to operate said bars to open and close said circuits, a radio transmitter, all said circuits being connected to said transmitter; an extra modulating circuit connected to said transmitter, make-and-break contacts, connecting means interconnecting said modulating circuits among each other and connecting the same to said malre-and-break contacts, the latter being also connected to said extra modulating circuit, a control contact connected to the latter, and control means associated with said operating means and said control and malre-and-brealr contacts, whereby, upon actuation of said operating means, said control means actuate said control and maKe-and-break contacts, to selectively open and close said circuits, while the respective bars simultaneously close said modulating circuits.

13. The system claimed in claim 12, in which said control means comprises a pair of cams for actuating said contacts;

.14. In a printing telegraph system of the type described, means for simultaneously registering the code impulses of each transmitted character, means for printing said characters, means for transmitting a start impulse for each operation of said printing means, and means for delaying each successive operation of said printing means pending operation of said start impulse transmitting means.

15. In a printing telegraph system of the type described, means for simultaneously registering the code elements of a transmitted character, a set of storing relays, means responsive to the start signal of the next following character for transferring the code elements of the first mentioned character to said set of storing relays thereby making said registering means available to register the code elements of said next following character, a' start stop printer, and means responsive to the start signal preceding the transmission of the code elements of a third character for transferring the code elements of the first mentioned character one at a time from said storing relays to said printer, thereby causing th printing of the first mentioned character after the printing operation has been initiated by the start signal of the third character.

16. In a printing telegraph system of the start stop type, means for receiving a starting signal of a predetermined frequency followed by a plurality of different frequencies simultaneously transmitted corresponding to the marking and spacing units of a code character, a printer having a single magnet responsive to start signals followed by successively transmitted selecting impulses, a plurality of registering relays,means 12 for separating said diiferent frequencies and simultaneously operating a combination of said relays thereby, whereby said relays are positioned in'accordance with the marking and spacing units of the code character, means responsive to the receipt of a second start impulse for transferring the code elements registered by said relays to a set of storing relays, and means responsive to a third start signal preceding the transmission of the frequencies for a third character for transmitting the impulses of the first mentioned character one at a time to said printer magnet after said magnet has been actuated by said third start signal whereby said printer prints the first mentioned character.

17. In a printing telegraph system of the start stop type, means for receiving a starting signal of a predetermined frequency followed by a plurality of different frequencies simultaneously transmitted corresponding to the code elements of a character, a printer having a single magnet responsive to start signals followed by successiveiy transmitted, selecting impulses, registering relay means, a plurality of filter means each connected to a relay of said relay means, said filter means being adapted to separate the simultaneously transmitted frequencies and pass the respective frequencies to predetermined ones of said relays whereby the latter are operated in combinations corresponding to the code elements of the received character, a plurality of storing relays, means responsive to the receipt of a second start frequency preceding the frequencies corresponding to the code elements Of a second character for transferring the code elements of the first mentioned character recorded by said registering relays to a set of corresponding storing relays, and -means operable in response to a third start signal preceding the reception of the frequencies for a third character for transmitting impulses one-at a time from the operated ones of said storing relays to said printer'magnet whereby said printer prints the first mentioned character.

18. A telegraph system according to claim 17 wherein said means for transmitting impulses one at a time to said printer comprises a distributor,

19. A telegraph system as claimed in claim 17 wherein sa d means for transmitting impulses one at a time to said printer comprises a distributor having a rotary shaft driven from the printer power shaft. I a 20. A telegraph system as claimed in claim 17 wherein said means 101 transmitting impulses one at a time to said printer comprises a distributor having a rotary shaft driven from and at the same rate as the printer power shaft, and wherein the means for transferring the code combinations from the registering relays to the storing relays comprises a second distributor having a rotary shaft driven from the printer power shaft.

21. A telegraph system as claimed in claim 17 wherein said storing relays comprise two independent sets of storing relays, a second distributor having a rotary shaft driven from said printer power shaft at one half thespeed of said power shaft, said second distributor being adapted to connect the respective sets of storing relays to the contacts of said registering relays alternately, whereby eachstoring relay set stores only alternate letters. 4

22. A telegraph system as claimed in claim 17 'whereinsalid means for transmitting impulses one at a time to said printer comprises a distributor having a rotary shaft driven from and at the same rate as the printer power shaft, and wherein said storing relays comprise two independent sets of storing relays, a second distributor having a rotary shaft driven from said printer power shaft at one half the speed of said power shaft, said second distributor being adapted to connect the respective sets of storing relays to the contacts of said registering relays alternately, whereby each storing relay set stores only alternate letters, and circuit means controlled by said second distributor for connecting the contacts of the respective sets of storing relays alternately to the contacts of the first mentioned distributor.

23. A telegraph system as claimed in claim 17 wherein said storing relays comprise two independent sets of storing relays, and wherein a second distributor having a rotary shaft is driven from the printer power shaft at one half the speed of said power shaft, said second distributor having contacts adapted to connect the respective sets of storing relays to the contacts of said registering relays alternately, one set being thus means for opening the locking circuit of the respective sets alternately comprising contact means in each locking circuit spaced 180 degrees apart about the second distributor shaft and a cam for opening said contact means disposed on the last mentioned shaft.

LUCIEN DEVAUX.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date go 1,960,021 McWhirter May 22, 1934 1,661,962 Robinson Mar. 6, 1928 1,599,445 Watson Sept. 14, 1926 1,975,486

Thomas Oct. 2, 1934

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