US2327369A - Telegraph signal translating system and apparatus - Google Patents

Description

L. M. POT-rs 2,327,369

TELEGRAPH SIGNAL TRANSLATING SYSTEM AND APPARATUS Aug. 24, 1943.

Filed Nov. 15, 1940 5 Sheets-Sheet l mOw INVENTOR. LOUIS M. POTTS Aug. 24, 1943. L M. POTTS 2,327,359

TELEGRAPH SIGNAL 'I'RANSLATING SYSTEM AND APPARATUS Filed Nov. 15, 1 9407 5 Sheets-Sheet? INVENTOR. LOUIS M. POTTS ATTORNEY.

Aug. 24, 194-3. M. PoTTs 2,327,369

TELEGRAPH SI GNAL TRANSLATING SYSTEM AND APPARATUS Filed Nov. 15, 1940 5 Sheets-Sheet 5 INVENTOR. LOUIS M. POTTS f I42 BY '93 FIG. 6

' ATTORNEY.

5 Sheets-Sheet 4 L. M. POTTS Filed Nov. 15, 1940 TELEGRAPH SIGNAL TRANSLA'I'ING SYSTEM ANb APPARATUS POTTS INVENTOR.

A ORNEY.

LOUIS M.

NON. w N. 5383 5.2.35. mmhtimzsmk N N was 222 525. a EN EN |...i :N 1% N3 6N munmoowm Aug. 24, 1943.

I Aug. 24, 1943. PQTTs 2,327,369

TELEGRAPH SIGNAL TRANSLATING SYSTEM AND APPARATUS INVENTOR. LOUIS M. P OTTS Flea ATTORNEY.

Patented Aug. 24, 1943 TELEGRAPH SIGNAL TRANSLATING SYSTEDI- AND APPARATUS Louis M. Pctts, E va.nstcn, Ill., assigncr to Teletype v.

Corporation, Chicago; Ill a corporation of Delaware 1 Appiication November 15, 1940, Eei'ial No. 365,730

7 I "21Glaims. This invention relates to printing telegraph apparatus and systems and particularly to translating mechanisms for translating signal combinations according to one code into signalcombinations according to another code.

An objectof this invention is to make possible the use 'of a keyboard transmitter operable according to one telegraph code and a-recorder operable acoordingto a different telegraph code tion to produce selectively apertures between a source of 'light and a scanning cylinder Which houses a photoelectric cell and which has circurnierential combinations of light transmitting and opaque areas according to the facsimile signaling code. Upon the reception of a permutation code signal combination-and the setting of the slides k the scanning cylinder is set in rotation for one revolution. Facsimile telegraph signals are then generated according to the activation of the photoelectric cell under ning cylinder.

According to another embodiment of the invention the permutation code signals arereceived by a multiple magnet receiving selector mechanism which has a selector magnet corresponding to each element of the code; Each of the selector magnets controls the positioning of one of the slides which co-operatively establish individual apertures for a light beam to be scanned by the scanning cylinder. As in the case of the first mentioned embodiment of the invention, the scanning cylinder is set in rotation for one revolution upon the reception of a permutation code signal combination by the multiple magnet receiving selector mechanism.

In the practice of the invention a communicatic-n system is featured which includestranslating devices of the single magnet or multiplemagnet controlled type whereby intercbmmunication may had betweena subscriber having a permutation code transmitter and facsimile recorder and a subscriber having permutation code transmitter the control of the scan and recorder, or between two subscribers having permutation code transmitters and facsimile recorders. Also featured are communication systerms for providing intercom'rn'unication between a central station'and a plurality of subordinate stations ando-per'able over rnetallic cc-nductors or radio channels, said communicationsystems including translating devices as hereinbefore described generally and to be described hereinafter in detailfor translating permutationcode signals into-facsimile signals. r g V For a complete understanding'oi the invention reference may be had to the following detailed description to be interpreted in the light of the accompanyingdrawings wherein, Fig. l is'a plan view partly broken away showing a signal translating device operable un'denthe control of magnets individual to each impulse of a received signal combinati n;

Fig. 2 is a perspective viewpartly broken away showing structural details of the signal translating device shown in Fig. 1; V

Fi 3 is an eleVational view of thetranslating device shown in Fig.1; V e

Fig. 4 is a plan view partly broken away showing a modified form of signal translating device which operable under the control of a single receiving magnet; g

Fig. 5 is anelevaticnal viewpartlybroken away taken at the rig t hand side of Fig'. 4;

Fig. 6 is an ele onal view taken at the lower edge of Fig.

Figs. 7 and 8, when placed end to end with.

Fig. 8 at the right of .7, show a complete corrmiunication system including signal translating devices according to the previously identified figures; 7 V

Fig. 9 is a schematic wiring diagram of a communication system including signal translating d vices and having a metallic communication channel in one direction and a radio channel in the other direction; and

i 10 is ,a schematic wiring diagram of a communication system similar to that of Fig. 9 but having metallic channels in both directions.

Referring now to the drawings and particularl y to Figs. 1 to 3, inclusive, the reference numeral IE; indicates generally the signal generating mechanism of a photoelectric facsimil trans- 'mitter such as that shown in applicationserial No.'261,418 filed March 13, B939, by L. M. Potts, which matured Nov. 25, 1941, into Patent No. 2,263,592. The patent discloses akeyboard controlled transmitter and keyboard control is not 'of interest in connectionwith the present invention. However, reference may be had to th patent for a detailed description of the photoelectric scanning and facsimile signal generating mechanism.

The signal generating mechanism It includes a housing I! into which extends from one end a rotatable shaft I8. The end of shaft 18 presented inside cylindrical housing ll supports and has secured thereto by means of set screw [9 a rotatable canning cylinder 2? A shown in the patent, cylinder 20 has circumferential rows of light transmitting apertures or windows arranged according to the facsimile code of impulses for letters, figures, and symbols. The opposite ends of scanning cylinder 26 and housing cylinder 11 from that where shaft l8 enters is open and the base of a photoelectric cell 2i is stationarily supported in the open end of the housing cylinder l7. Photoelectric cell 2! is of the elongated cylindrical type and has its cathode and anode at least coextensive with the portion of scanning cylinder 2!] which has circumferential bands of scanning apertures.

At apoint just clear of the surface of scanning cylinder 23 the housing cylinder H is cut away on a verticalplane and to the fiat surfaces .resulting from the cutting away of the portion surfaces provided by cutting away a portion of Retainer. plate 26 is providedthe cylinder ll. 7 with light transmitting apertures 21, there being an aperture 21 in alignment with each of the circumferential rows of light transmitting windows or apertures of rotatably scanning cylinder 20.

The apertures 21 are arranged in two rows in staggered formation in order to minimize the space required for the full set of apertures.

The slides 24 are movable endwise individually into either of two positions which may be designated as a marking and spa c ng position. They are provided with apertures 23 arranged in two roWS spaced according to the spacing of the rows of apertures 27, and the spacing ofthe apertures 28 from each other in each row is such that cer tain of the apertures will register with'apertures 2'! when the slide is in the marking position and others will register with apertures 21 when the The arrangeslide 24 is in spacing position. ment of apertures 21' in all of the slides 24 is such that for each permutational setting of .the slideszd an alignment of apertures 28 willregister with one onlyof the apertures 21 in the plates 25.

At the opposite side .of frame 22 from that which supports. apertured plate 23 there is a longitudinally eXtending slot, 29 across whichis disposed a plurality of vertically positionedpartitions 3!. The spacing ofthepartitions 3i corresponds to the spacing of apertures 21 longitudinally of'plate 26 so that the partitions 3i define the entrances of li ht passages which may be. completed through alignment of apertures 28.in 1slides 24 and through apertures 21. A lamp-.32 having a long filament 33 is mounted in close proximity to the slot 29' in 'framel22 (Fig. 1) and servesas a source of light to be ment 3-8 is urged by compression spring 39 to move longitudinally of shaft l8 to engage driving element 4| which is sleeved on shaft IS. A g'ear' 42 is secured to driving clutch element 4| and'a motor driven pinion 43 meshes with and imparts continuous rotation to gear 42 and through it to driving clutch element 4|.

Driven clutch element 38 is normally restrained from engagement with driving element 4| by clutch throwout lever 44 urged by tension spring 46 into the path of clutch-throwout cam 41 associated with flange 48 of driven clutch element Sleeve 37 has secured thereto a cam 5| which is engaged by a roller 52 carried by a lever arm 53 which is spring biased to maintain roller 52 in engagement with cam 5!. When the clutch mechanism is in rest condition the roller 52 is resting upon cam 51 near the top of a descending slope thereof, and thusimparts a torque to the cam and thus to sleeve 3'1 and driven clutch element to hold them in such angular position that clutch throwout-lever 44 pulls driven clutch element 38 entirely out of engagement with driving element li and rubbing of the teeth of one clutch element upon those of the other is avoided.

Clutch 'throwout lever 44 is provided with a leftwardly extending arm 56 which terminates belowand in the path of one arm of a clutch tripping lever 51' pivoted at 58. A downwardly extending arm EiQ-of clutch tripping lever 57 is disposed in thepath of a hooked portion El of a link. 432 which is movable rightwardly to rock clutchtrippinglever 5T counterclockwise to effect the, withdrawal of clutch throwout lever 44 from engagement with clutch throwout cam 41 whereby compression spring 39 may move driven clutch elementiiiinto engagement with driving element d! to receive rotation therefrom and thus impart rotation to shaft 13- and scanning cylinder 29. Shaft i8 is rotated through one revolution whereupon driven clutch element 38 is disengaged from driving element il by the reengagement ofclutch throwout lever 45 with cam s? and shaft I8 and scanning cylinder 23 are brought to rest. The co-operation of link 62 with clutch tripping lever 51 is of the nonrepcat species due to the downward camming of link 6?. as it is moved rightwardly by virtue of engagementof an upwardly sloping cam portion of anorexic ceiv'e and each selector magnet :isprovided with a pivoted armature I58- Each ofv -the armaturcs 68 is provided at its liree end with adjustable abutment screw 59 whichv is aligned with the right-hand end of associated-slide H. l Slides which carries cam follower roile'r E52 supports a1 locking ballblade 1B which spans the slides 11 adjacent to the locking projections is, H "which arein spacing or rightd'land positions have their locking proiections -ill resented to the r ht of locldng bail'blade If, and ti as that are ilresentei their marking or =lei -=lia;nd

ciieir locking proiectio'ns presented position have to the left of the locking bail blade 3%. 'When shaft i3 begins to rotate, cam 51 lowers arm 53 so that the locking blade 2 6 is presented between those of the locking projections 1 1 that to theright'oi it and those are tot 1 Thus, the slides il are blocked against movement until near the end ofa cycle of rotation ofshaft 58 when cam 51 lifts arm 53' to lift locking bail bladel't clear or the top of locking projection 7 Each-of the slides l a lug T! on th lower edge thereof 3), and disposed in .e'- oi the lugs TI is a bail i3 jioivoted at is.

end of clutch tripping link 62 is pivotally connected. When any of the slides H is moved. to its marking positi'on'by its associated selector magnet El the lug T? will engage b'ai-i 7-8 and rock the bail in counterclockwise direction, thus he tripping of the clutch comorising'driven element 53 and drivingelement M. From tliis'i't wil be E1310 are to be energized for any given permutation code signal combination must be energize-doubstarltielly simultaneously rather than insuccession from a receiving distributor. The-reason for this is that the first slideli to be operwouid effect tripping of the clutch for dr ding shaft to iirough the operation of bail link 62, clutch tripping lever 53, and clutch throwout lever 5 and the slides H would be, come locked by the lowering of locking bail blade 75 before the remaining marking impulses 1...: he code combination could be received and perform their selective functions; The translating d vice shown in Figs; 1 to 3, inclusive, particularly eration of the photoelectric permutation code 1 The photoelectric scanning and transmitter. facsimile signal generating mechanrm is identical with that shown in Figs. l to 3, inclusive, and the same reference characters have been applied thereto. Also, the driving mechanism for the scanning drum and the combined clutch Bail it'- has a depending arm ill-to which the rl-g'ht-han'-d sent that all of the selector-magnets all teat ported in bracket 36.

; assembly ic-undation a plate 185. 111 a plate m by means of pivot screw carried with it! by means of rew anti-singing device and lock bail for the slides which control the .lightvalve slides are identical .with those heretofore described and lareidentified by the same reference numerals.

The receiving selector mechanism for controliing the operation of the lightvalve slides 24' is similar to that shown in Patent No. 1,937,376 grantedNovember 28, 1933, to W. J. Zenner. The reference numeral 8'] designates a mounting plate for the selector mechanism. A selector-magnet assem-biy comprises a bracket 52, to which is secured by means of screws 83 a magnet core 8i .Core 84 has two arms, each of which supports a winding 86, which is connected to a telegraph line. At their outer end, the arms of core 84 terminate in pole faces 81. Bracket 82 supports opposed pivot screws 88,

in turn .pivota'l'ly support an armature 'lever 82. Armature lever 89 has rigidly secured thereto armature M which is disposed in alignment with the pole races 81. The other end of armature lever '89 terminates a cam follower portion (notshown), which co-operates with an armature lever cam '32 included in a receiving :selector cam assembly 3.- Selector cam assemmy 93 is driven from gear" 42 through a sleeve 94, which has a reduced oortionirota'ta'bly sup- "Cam assembly '93 is sleeved on sleeve 9'4 and is provided'at its opp-osite ends with discs 95. To the right of cam assembly 93 sleeve 34 has disc $9! secured the-reto, and to the left of cam assembly 93 disc or is "splined on sleeve 94 and is 'slidable thereon. A friction disc resilient material, such as felt; is interposed between the disc and the disc 9.! at the right of receivlr: carnassembly 53, and another friction disc is= interposed between the discs 9'4 and it; at the left of camassemciy 93, the friction] discs idcn'tified byviilhfi .numeral S8, .A com-pres :on spring H3! urges disc 35 rightwardly of sleeve 94 and compresses friction discs 98;. between t adjacent cs. Discs 323, 52', 8-3 and Q formea iri'c 1 clutch through which rotation be .rted to front contimlcusly driven sleeve 94. l I Selectorcem assembly includes stop Hi2 which is arranged-to be a r ested released for rotation alternatively un the control of a stop gate Hi" n'cluded in s es- Sto-p -g. .te ass mbly 1M- has asxits pivoted below y slet-e l-ili, W'sch supported by pcstsim moonted on mounting plate El. 1-H,

exile thereto the ed screw 1 !2 which. threadedlv e sic mounting'plate lilo; be ed. piv-otally for orien it -t p vot screw ms and may be clamped in sired'position of by 52% and arm Mi 'i'nto Stop is 4 carried by plate of stop arm by a s mg (no wn). gate 5&3 may be latch-edin blccl relatioi stop arm iii-2 by shomdcredlatch 1e ver 5 i3 is pivotally mounted on ti of plate and. is'urged by so rig. latching engagement with stoo Latch lever. l-i-ES is rocked once of. compression spring 1 M. to lift its shoulder out; of latching engagement with the stop provided, which indicates that the apparatus is operable in response to the very commonly employed five unit permutation code. This code affords a maximum thirty-two primary "selective combination. However, as is well known, by allotting two or the code combinations to shift and unshift function, the code may be ex valve slide in the embodiment of the invention shown in Figs l to 6. inclusive, functions exactly the same manner, as far as the transmission of facsimile combinations is concerned,

as does the sixth light valve slide in Fi'g'sQQl to 3. The difference is only in the 'rzi' thokior controlling the sixth light valve slide and this difierence is that i Figs. 1 to 3, the sixth slide presented in one or the otherof its two pQsitions in accordance with the presence or ab sence in a signal combination of animpul set'o operate the sixth magnet, whereas in the em' b'odiment of the inventionshown in Figs. 4110 6, inclusive, the sixth light valve slide is presented in one or the other of its two positions under the control ofshift and unshift permut'ation code signal combinations. p I Referring to Fig. 6, it will be noted that 'in the lower edge of the foremost of the slide bars I ll controlled by the bail-shaped levers I4 I two notches are provided. Each of the other oi t h e five slide bars I47 is notched and the positioning of the notches on the bars is according to' the permutation code so that when slide bars I4"! have been positioned under the control of the receiving selector mechanism in accordance with a shift code combination, an alignment of notches will result in one position and, when the slide bars Ml have been set in accordance with the unshift code combination, n alignment of notches will result in the other position. Be-

low the slide bars I41, and in" registry with the position in which the alignments of notches may result, are selectable bails I6I and IE2 carried by levers I63 and I54, respectively, pivoted at IE5 and IE'i respectively. Each of the levers I63 and I 64 has a downwardly extending aini and the extremities of the two arms are inter} connected by a tension spring I63 which biases lever I63 in counterclockwise direction andl'ever I64 in clockwise direction. The levers I63 a'nd I64 have fingers I69 extending toward, each other and the extremities of the fingers its are dis,- posed under oppositely extending flanges II I; carried by a retracting lever H2, pivoted at I13. Retracting lever I'I2 has an arm I14; extending upwardly from the point'of the pivotal mount ing, with its extremities disposed in the path of arm lid of locking baillever 53.

When cam 5i operates lever 53 to lift look: ing bail I6 out of locking position it accom' plishes this by rocking lever 53 clockwise. and arm Ilt thereof rocks retracting leverIIZ counterclockwise with the result that the flanges 'I'II engage fingers or IE3 and I64 and drawv the se lectable bails IiiI' and :62 clear of the loiwer edges of the slide bars M1; Thus, the selectable bails IiiI and IE2 are prevented from interfering with settingeof theslide bars I41 according to received signal combinations. When lookpgp n lever is returns to normal pojsiitior which i's the ex r m counterclockwise po tco es viewed in Fig. 6, it permits lever ilz to rotate in, clockwise direction, this rotatibn being parted l; 'y s pring I 53 operatinglthrough levers Hi3 one i i and 7 their op'eosj o ngers open fl e ii .1? s in le he sli eleer re r sents neither the shif nor til e lln slliit cert hina'tion, both of the selectable tens :il and IE2 will come to rest against the lower e'dges oi the slide bars I41. However, if either o f th e st te bails flees an e 'se efi fb' were. it will enter the a ignment o ffnotch'es, thus moving lever IIZ their clockwise 'directionthan it is stove hen neither 'qrt'ne' selectable Hails arrangem nt, of notches.

pair of spaced lugs I83fat upper ed e between which the laterally extending portion or ant} IQ] of IeverJIS QR is disposed. Similarly, slideISI is provided with sii aced lugs I 811 between which the laterally extendingportioncf e n I32 or lever "it is disposed. When lever Hi3 oo'ou ies its extreme counterclockwise position it's sensing b' i iGI ioai aiig ineht or 'jri ie ii'; ith s ic s i' t hel i i li m' e ii of i s a m i essh's e he 1 'en1 i t e mg' ts and'h as snirt'eo' iiee l site its left-hand position "whereby the associated light valve Slide is] shifted toexti 'e'ine left-h and bositiori to hlo'ck out light fro m one entire set of circn mierential rows :oi gc'olde apertures cylinder 29', s ich set of rows of apertures being those assigned either alignment or'oot he in the slides on, the'tr'a 'versely extending portion of, its 'arm l8 l will have engagedthe righthand bne of the and Willhzivies'hiited slide I51 to its extre right-handpojsition, wh by the sixth liht valveslide will be 'pres'entedin extreme righthand po it o tobio ek 'oiit' light rroreh or the circumferential rows of apertures which were r i l kedwh ffi es ifi Films n e tr m ef hand position and to unbloek those sets of apertures which were then blocked. V g H 'Levei" I'I2 is biased in counterclockwise di ection by a light tension spring I38 so that w locking bail lever 53 is in extreme counterclock wise position, as viewed in Fig. 6, and its de'plend ing arm We at the right-handend has re 'e the upper end of lever I'I2,.the right-hand end of lever H2 will be under the control o eoge s' we of levers IE3 an use aecwin ,r oe ise higher than either of those fingers move it, it being understood that spring I58 stronger than s ring its so that spring lea wiii control the move-merit of lever I I2.

At the oop'er eno' of the em tale e eig'iieed end or lever :12 a slide I81 is pivotaliy ooflr'ui ted thereto. Slide lfil is 'connected tea seventh light valve sl d 188,. Thus; when lev r [i2 is rocked sponding to that which is employed when char acters are printed by typed elements. Accordingly, no signal is to be transmitted in a cycle of operation of scanning cylinder 28 initiated as a result of the reception of a shift or unshift permutation code combination.

As disclosed in the copending application hereinbefore identified, the scanning cylinder 22 is provided with a light transmitting slot for the generation of a start signal located in an area on the periphery of the cylinder which includes no portion of any of the character signal transmitting code slots. Upon release of the scanning cylinder 22 for the transmission of any facsimile signal, the starting signal slot first scans the light beam and causes the photoelectric cell to generate a signal for starting the receiving printer. Since no signal is to be transmitted in response to the shift and unshift permutation code combinations, it is preferred that the scanning cylinder, which is released for rotation in response to the shift and unshift signal combinations in the same manner as for any other permutation code combinations, shall not effect the generation'of a start signal, since this would set the printer in operation and effect spacing of the receiving tape without recording anything in the space. The function of the slide l8? and its associated light valve slide N38 is to block the light path in registry with the start signal slot of the scanning cylinder 25 when either of the selectable bails lfil or I62 is in the selected position. The blocking occurs when lever I22 is in extreme clockwise position, thus presenting slide I87 and light valve slide I88 in extreme right-hand position. At the points where apertures in the light valve slides 24 align when the slides are set according to the shift and unshift permutation code signals, there are no circumferential rows of apertures in the scanning cylinder 20. Thus, light is prevented from passing through the alignment of apertures in the light valve slides 24 when the slides are set in accordance with the shift and unshift signals and no impulses are generated in the photoelectric cell, the rotation of the scanning cylinder 29 being merely an idle operation applying no signals to the telegraph line and, therefore, having no effect on the receiving printer.

Referring now to Figs. '7 and 8, which, fitted together with Fig. 8 placed at the right of Fig. 7, show a complete telegraphic communication system, the reference letters A and B indicate subscribers stations. Subscribers stations A and B are identical and only one will be described in detail, which is the A station. At the subscribers station a facsimile recorder Edi is connected through the winding of relay 262 local to the station A to one end of telegraph line 263, the other of the motor 261 is connected directly to one side of a powerline and the other terminal may be connected to the other side of the power line through conductor 2228, contact and tongue 229 01 relay 262 and conductor 2| I. Thus, when relay 222 is energized due to the transmission of facsimile signals from the central oifice over telegraph line 223, the circuit of motorZll] will be closed and facsimile recorder 2m will be -driven. Relay 2 32 is preferably of the slcw-to release type so that its contact tongue will not operate in accordance with facsimile signalsbut will remain closed during the reception of signals to apply steady current to motor 201.

Station A is provided with a permutation code transmitter 2 2 which may be connected to a telegraph line 2! 3 through tongue 2M of key 2H5,

Tongue 2!? of key 2l6 completes the circuit for motor 207 which drives permutation code trans mitter 2i2 as well as facsimile recorder 20!.

The other end of telegraph line 213 is connected to one end of one winding-of a differential relay 218 and this winding will be described for the sake of convenience as the upper winding. The other end of the upper Winding of relay 218 is connected to tongue 2H of a relay 22l. The relays 2i8 and 22! are located at the central station. When the system is idle, relay 22! is deenergized and its contact tongu 219 engages its back contact which is connected to one end of battery 222, the other end of which is connected to ground. Battery 222 supplies power for energizing the upper winding relay 2l8 upon the closure of key 2H5 at subscribers station A. Key 2 Iii is closed manually when the subscriber desiresv to operate permutation code transmitter 212 to. transmit a message.

Upon the energization of the upper winding of; relay 2H3, its tongue 223 which is connected to ground is brought into engagement with its front contact which is connected to one end of the winding of relay 225, the other end of which is connected to outer tongue 228 of relay 22L Tongue 226 normally engages a back contact which is connected to a grounded battery 221.

Upon the closure of energizing circuit for relay end of which is connected to tip contact spring I 224 of answering jack 286 at a central ofiice.

At th station A, a motor 26"! is provided for driving the facsimile recorder 29!. One terminal 225 at tongue of relay 2|8, relay 224 attracts its contact tongue 228 which engages its front contact "and completes a circuit for lamp 229 from battery 23L Lamp 229 is associated with jack 256 and indicates to an operator at the central office that the subscriber at station A desires to transmit a message. The answering operator thereupon inserts plug 232 into jack 286. It will be understood that the operator could answer station B by inserting the sam plug 232 into the jack associated with station ".8 had the subscriber at station E closed his key l2l6 to effect the illumination of his jack lamp [229.

Upon the insertion of plug 232 into jack 206, plug tip 233 engages tip spring 2554, outer ring 234 engages ring contact spring 236 of jack 206, inner ring 23'! engages ring contact spring 238 of jack 2%, and sleeve 229 engages bushing 2 H of 'jack 2%.

The bushing 22! of jack 208 is connected to one end of the winding of relay 22!, theother end of which is connected to ground. Sleeve 2320f the plug, which engages bushing 24], is connected by a conductor'2 i2 to one end of the Winding 243,

the other end of which is connected-to one terminal of a grounded battery 244. Thus, upon the insertion of plug 232 into jack 263, relays 22I and 223 are energized in series.

Relay 22 l attracts its contact'tongue 2l9 frompengage'ment with back contact to" engagementswith front contact,

attracts contact tongue 22% out of engagement with its back contact, thus interrupting the circuit for jack lamp controllingrelay .224, and attracts: its contact tongue 245 into engagement with-a front contact; Contact tongue 2 15, upon engagingits front contact, completes, the energizing circuit for the lower Winding of 218 which neutralizes the effect of the upper winding and releases contact tongue 228. l

A further eifect of theenergization of relay 22| is that permutation code transmitter H2 is disconnected irom battery 222 and is connectedinstead to outer ring contact spring 238 or" jack286.

Since contact spring 236 is engaged by the outer ring 234 of plug 232, the circuit of, the permutation code transmitter is extended to the operators cord circuit. This circuit includes 001 ductor 245, winding of relay 247, key 255, cone ductor i, winding of repeater relay 252, contact tongue 253 of repeater relays 254 and 256, front contact with which tongue 253 is normally engaged since relay 252 is normally energized, and

grounded battery 251.

Key 255 normally connects conductor 25! directly to the winding of relay 24! and holds relay 258 energized to complete a circuit from grounded local holding battery through operators keyboard transmitter 248 and permutation code printer magnet 229 to ground. Upon the operation of key 255, the circuit of relay 258 is opened so thatthe relay releases its armatures and thus disconnects transmitter 248 and printer magnet 2% from the local holding battery. In make-beiore-break manner with respect to the circuit of relay 241, the key 255, when operated, also connects transmitter 228 and printer magnet 2 59 in series with relay 24'! and with the repeater to which conductor 25! extends. With this arrangement the operator may cut the transmitter 248 and 2:32 into the permutation code communication circuit for setting up cir-- cuits desired. by subscribers or for monitoring message transmission. Under normal conditions, when plug 232 is not inserted into any jack, the ground connection for maintaining holding current upon relay 252 of the repeater is obtained through the outer left-hand contact tongue 259 of a relay 252. lhis holding circuit includes the winding of relay 26?, which as will presently appear, controls the operation of a translator mechanism, such as that shown in Figs. etc 6, inclusive. Upon the energization of relays 22 and 252 the ground connection at the subscribers permutation code transmitter is substituted for the ground connection at the contact tongue 250 of relay 262 so that permutationcode signal transmission is initiated and the transmitter 2 i2 will correspondingly energize and de-er'lergize relay 2M, operators receiving magnet 2 and repeater relay 252. I

. In addition to the tongue 223, differential relay 2l3 has contact tongue 225 connected to ground and engageable with aback contact when neither or both of windings of relay 2H3 are energized. The back contact is connected byconductor 239 to the jack spring 238 which is engaged by inner ring 23'! of plug 232 from which conductor 2% extends to one end of the winding of relay 262,'the other end of which is connected to battery 283. An energizing circuit for relay 262 is completed when both windings of relay 2i8 become energized and neutralize it to cause the release of tongue 225, and the relay 262 attracts its two left-hand and two right-hand tongues. The outer right-hand contact tongue 264 of relay 252 normally engages its backcontact, to which is connected one pole of battery 266, the other pole being connected to ground. The contact tongue 26:! is connected by conductor 25l-to one end of the winding of magnet 263, the other end of which is connected to ground. The broken lined rectangle in the upper righthand corner of Fig. 7, designated 21B, is intended to represent diagrammatically a signal translating mechanism such as that shown in Figsxe to' 6, inclusive, for translating fro-in permutation code signals into facsimile signals. Ehe magnet 268 corresponds to the signal receiving selector.

magnet 86 of Figs..4 to 6, inclusive. Magnet 258 is normally helcl'energized by current supplied from battery 2%. tion of relay 252, contact tongue 254 moves into engagement with its front contact which is connected to the contact tongue 269 of relay 241. The front contact with which contact tongue 259 is engageable is connected to a grounded bate tery 2'. Since in a static condition with the -operators set rendered operative through the actuation of key 2555 relay 2%? is continuously. energized, it being included in the holding circuit for operators receiving magnet 24d, whether the holding circuit be extended from the ground 'at 1 the contact tongue 252 of relay 252 or from the ground at the permutation code transmitter 02 a subscribersstation, battery 2?! will be connected to the front contact of contact tongue 254 of relay 262 through contact tongue 259 of relay 241. From this itwill be apparent that receiving selector magnet 26% is not responsive to oscillation of tongue 2% of relay fi'i'iexcept when relay 262 is energized t:- conne'ct magnet to the tongue 259 through contact tongue .Upon the energization of relay its inner right-hand tongue 2'52 engages its front contact which is connected to conductor 255 and therefore 'is connected to the same ground as the winding of relay 2 52; Contact tongue 2'52 of re- 1 lay 282 is connected to one end of one of the.

windings of a double wound relay 213, the other end of which is connected. to grounded'battery 214. Relay 223 is thus energized in parallel with relay 262, the circuit for the former extending through one of the contact tongues of'the'latter however, and the energizing circuit of both includes the retracted contact tongue 225 of relay2l8.

The inner left-hand contact tongue 276 of re v lay 262 normally engages a back contact which is connected to the front contact associated with the right-hand contact tongue 21! of relay 213; When contacttongue 276 is attracted into engagement with its front contact, a connection is established from ground to a. conductor 218 at tently'or, in other words, will flash for directing the attention of the operator to a particular 012-- crating condition. When contact tongue engages its front contact, lamp 219- will be illu- However, upon the energize-1 7 When contact tongue K to the tip 233 of plug 232.

minated steadily. The left-hand contact tongue 282 of relay 223 completes a locking circuit through the left-hand winding of that relay, said circuit also including contact tongue 283 of relay 243 and normally closed key 285.

Considering now the operation of the portion of the system in Fig. '7 thus far described, upon the closure of key 2i6-by subscriber A, the motor 20! for driving his transmitter 2E2 will be operated and the transmitter 252 will be connected to battery 222 at the central office through one of the windings of relay 218. Relay 2i8 will be energized and will disconnect ground from conductor 230 and close the circuit of relay 22'to connect battery 23! to lamp 223 which will become illuminated to indicate to the operator in charge of transmitter 248 and receiving printer 229 at the central ofi'ice that subscriber A desires to transmit a message. The operator thereupon inserts plug 232 into jack 2% and actuates key 255 placing the operators set in a circuit with relay 24'1. Relays 22! and 223 thus become energized in series to complete the energizing circuit for the second winding of M3, to open the energizing circuit for relay 22 i, and to connect transmitter 2i2 through the upper winding of relay H8 in series with relay 2%! and thus to .op-

erate receiver 239 and interrupt the connection to battery 222, these being the functions of relay 22!. Relay 243 prepares the locking circuit for relay 213. I

Relay 2i8 being a differential relay which is in neutral condition when both windings are en ergized, releases its contact tongues, the lower of which has no immediate effect as the circuit of relay 22E is already opened at contact 228. The release of the upper contact tongue 22% resuits in the connection of ground to conductor 26L whereby relay 262 becomes energized. The relay 262 operates to remove the local ground connection at contact tongue 250 from relay 2%, thus placing the relay under the control of transmitter H2 and subscribers station A, to complete a circuit for the steady illumination of lamp 219; to place the receiving selector magnet 268 in the translator mechanism under the control of relay 24! and to complete the energizing circuit for relay 213. The relay 2T3 upon being energized completes its own holding circuit and prepares for the flashing of lamp 219 by making connection to the sourceof interrupted current,

The circuits are now completed for subscriber A to communicate to the operator at the central oifice the identity of the connection which he wishes and the operator answers subscriber A by operating transmitter 228. The characteristic answer will be recorded on the printer repre sented by the receiving magnet 259 and will'be repeated by the relay 247 to actuate correspondingly the receiving selector magnet of the translator mechanism.

The translator device, such as that shown in Figs. 4 to 6, inclusive, is represented schemati cally by the selector magnet 258 and the photoelectric cell 286. The photoelectric cell 296 is connected to the control grid of the first electron tube of an amplifier shown schematically and in dicated generally by the reference numeral 281. The plate electrode of the last electron tube of the amplifier 231 is connected by conductor 283 Thus, ignals originating at the subscribers transmitter 2E2 or at the operators transmitter 248 are received not only by the operators receiving device 249 but also by the receiving mechanism 268 of the translatorunit and are therein translated into facsimile signals which are impressed upon the conductor 288 and are transmitted through plug tip 233 and plug tip contact spring 204 of jack 206 to facsimile recorder 20! by way of telegraph line 203 and winding of relay 202, which is energized by the facsimile signals but has no direct eif'ect since the motor'circuit has previously been closed by contact pring 2 !'i of key 2H5.

When the subscriber A has informed the op erator at the central office by means of permutation code signals, the identity of the station with which he desires to communicate, which information is recorded by the operators permutation code printer as a typed message and by the subscribers facsimile recorder as a facsimile message, the operator then makes the connection to the called subscriber. This is done by means of the cord plug 29!. The tip 292 of plug 29! is connected to conductor 238 in the same manner as tip 233 of plug 232 so that facsimile signals will be available at that element of the plug. The outer ring 293 of plug 29! is connected by conductors 29 i and 296 to the winding of repeater relay 25d and then through the armature 29'! of repeater relay 252'to battery 298.

The inner ring 299 of plug 29! is connected by conductor 30! to one end of the winding of supervisory circuit relay 302. The other end of the winding of relay 302 is connected to grounded battery 303. The left-hand contact tongue 304 of relay 302 is connected to one end of one of the windings of a double wound relay 366 and the other end of the winding of the relay 306 is connected to grounded battery 30?. The inner righthand contact tongue 303 of relay 362 is connected to one of the terminals of lamp 309, the other terminal of which is connected to grounded battery 3! l. Contact tongue 303 of relay 302 is operable between a front contact which is connected to ground and a back contact which is connected to the front contact engageable by the left-hand contacttonguejiZof relay 306. The contact 350 of relay 302 is connected to conductor 30!, whereby the circuit of conductor 30! may be extended not only to the Winding of relay 302 to battery 303 but also through the left-hand winding of relay 306 to battery 3M. As will presently I appear, inner ring 299 of plug 23! which is connected to conductor 30! is engageable with a jack contact spring which is connected to ground so that relays 322 and 303 will be energized upon insertion of plug 29! into a jack. The outer right-hand contact tongue 305 of relay302 is connected to conductor 230 and its back contact is connected to ground, these connections being comparable withthose of contact tongue 250 and its back contact. Relay 302 corresponds in func tion to relay 262 and relay corresponds in function to relay 273.

The contact tongue MS of relay 3% is connected to a source of interrupted current indiholding winding of relay 3&5, the other end of which is connected to grounded battery 361. The contact tongue til of relay 3th is connected to a key 368 which may be operated manually to interrupt the holding circuit of relay 33%. Relay 325 has one end of its winding connected to the sleeve 32I of plug 29! and the other end con nected to battery 32". Relay 3I6 corresponds to relay Its purpose is to prepare a holding circuit for relay The plug 29! serves as means for connecting a subscriber, such as A, to whatever station to which he may oesire to transmit a message. For example, he may desire to transmit a message to subscrihens station which is identical with his own station. This is accomplished by inserting plug as: into jack i286 at subscribersstation B. Upon the insertion of plug 22H intojack i205, plug tip 2st connects the output 238 of translator ElS to the tip spring I264 of jack I285 which is connected by conductor through relay to i'acsirnile recorder lEdl at station B. As soon as 'nipulses begin to be transmitted over telegraph line relay becomes en zed to close its contact 52rd, thus completthe circuit of operatingmotor lZt'i which is in operation to drive facsimile recorder EZEI. or plug 295 contacts-with bushing oil, wherecy relays tit and I22! series. The insertion ofv plug also results in the connection to the back contact f relay l2l3 g of plug ZQiand ring conf acl: 52% and the connection 1 of permutation code its extension 294 l5 ring contact springfilia a of jack I266 'he upper front contact of relay Ifll. Relays d lEEl, upon becoming energized, attract everal contact tongues. Contact tongue relay 322i becomes disconnected from tery i222 and engages its front contact,therecnnected to permutation code sigconductor c .i" renti ay iiliil to the'key 2H3 of subhers eta-non B which is open, so that the er wind ng of relay lfllii does not become energized. The attraction of the two lowcrcontact rins of rclaylilfil as the relay becomes en results the closureof the circuit of winding of relay i8 and the disconofbattery from the winding of relay Sin only the lower winding of differencontact tongue 3 tc-connect ground to the winding of elay 3-. However, since battery from that relay by the "nest contact tongue of relay l22l the relay .1; not become w ergized an lamp i229 will not become illuminated.

The energizatlon of only one winding of relay .7 attraction 0 its contact tongues results f in the disconnection of ground from jack spring a and thus from ti e winding of relay 392 at tral office. Thua'the relay 35E, whether it may have been momentarily energized clu; Edi was inserted into jack 52%, re-

' 'ng the time the connection ity itwill have become eniy because relay IEEB is of o-operate variet and its circuit'does become closed until relay 522i has become gized which operation occurs substantially instantaneously upon the insertion of the. plug The circuit of conductor rcay i is en zed, the relay will attract into the jack. Relay 3&2 also operates substantially instantaneously and attracts its contact tongue 3% to complete the energizing circuit for relay 3G6, thereby establishing contact with the source 3I3 of intermittent current for lamp 389 and also preparing the circuit of a the holding Winding of relay 3%. Since relay 355 became energized in series with relay l22i, its contact tongue 3I'I has been attracted to complete the holding circuit for relay 3% and that relay remains energized.

Lamp 359 will be illuminated steadily during the transient interval that relay 352 remains energized due to the connection of the lamp to groundthrough contact tongue When relay I2l8 opens the energizing circmt of relay 392 and also of the relay 3%, lamp 3519 will be transferred to connection with the source 3l3 of in- 29I remains in jacks I255 and subscribers station B is conditioned for Message reception. T -e connection to the source 1H3 of interrupted current is maintained by the holding winding of re-' lay 3% after the operating winding of that relay becomes ole-energized.

The apparatus is now conditioned for the transmission of message material from subsc ibers station A to subscribers station B and the operator may actuate key 255 to remove the operators set from the communication circuit.

, The permutation code signals generated by the transmitter 2 I2 will be repeated by the relay 24! to actuate the selector magnet 258 of the facsimiletranslator 215 and the facsimile signals generated in the photoelectric cell 256 and amplified inthe vacuum tube amplifier 231 will appear at the outputcircuit 288 of the amplifier and will beimpressed upon plug tip 292, jack spring I204, and telegraph line I Slit-3 to operate facsimile recorder I201 at subscribers station 23. The facsimile signals, in reaching the recorder I 25H, traverse the relay 22M and this relay is preferably slow to release in order that the contact I209 shall not be openedand closed corresponding to the facsimile signals to interrupt the circuit of motor I201.

When the subscriber at station A has com- 'pleted the transmission of his message, it is only necessary for him to open key ZIS. This opens the circuit of the upper winding of relay 2!!! which isthe signaling circuit and includes relay 247 and repeater relay 252, all of which become de-energized. The contact tongues of relay 218 are, therefore, attracted due to the rclays becoming unbalanced and although the attraction of contact tongue 223 has no immediate effect, since the circuit of relay 226 is interrupted at contact tongue 226 of relay 22!, the attraction of the other contact 225 results in the de-energization of relay 262 whereby lamp 2'55! is connected to the source of interrupted current RI and flashes until plug 232 is removed from jack 2%. The. operator should also remove plug as: from jack I206, whereupon all of the relays in the supervisory circuit will become tie-energized.

However, if at any time before the subscriber A releases key 2H3, the subscriber at station B desires to transmit a reply he will close his key I2 It, thus completing the permutation code communication circuit from his station through the upper winding of relay I218, which will become neutralized and will release its contact tongues I223 and I225, completing the circuit of relay -3U2 to cause it to attract its'contact tongue 398 and-switch-lamp 389 from condition of intermittent illumination to condition of steady illumination, This will indicate to the operator at the central station that plug 235 should not be removed om jack but that'the connectionto subscrmefs station B should be maintained to permit the subscriber to transmit a reply to subscribers station A. It is to be noted that with the plugs 23! in service in the jacks as efo e identified, the closure of keys 2E5 result in the disconnection ofthe from the windings "of repeater r respectively, due to the energization or the :elays and 352, respectively, and extension. of the circuit to the respective subscribers. Since the subscribers station B is identical with subscribersstation A, the station B may initiate communication with station A in the am we man e that station A init ates communication with station 73; as previously described. In 1 is case the operator at the central station will answer the call of station B by inserting plug into jack and by operating key 255 to place transmitter 2 38 and receiving magnet 2- .8 in connnunication station .E and will complete the call by inserting plug 22! into jack Provision made within the contemplat-i n of the invention for the initiation of communication by station A or B with subscrib-- ers whose stations include permutation code apparatus only, and such stations may initiate communication with the station A orB.

local ground lays 252 and At the extreme right-hand of Fig. '7 is shown a jack 335 which is included in the section of the central offi e previously described and which has its outer plug contact spring connected by an oifice trunk 333 to the plug tip contact of three-circuit jack 335. The in ner plug ring contact spring 33? of'jack'33! is connected to ground and the bushing 333 of jack 33! is connected to one end of the winding of a relay-3i. the other of which is connected to ground.

The contact tongue 5 which is operated by relay engageable with a front contact which. is connected to ground and is connected by conductor to a lamp 333 associated with jack in the section of the central ofice which handles the switching of permutation code telegraph only and is shown in Fig. 8. The plug tipcontact spring of jack 33! is left unconnected because there is no occasion to trans mit facsimile signals into the section of the central cfiice which handles permutation code messages only.

Upon the the permutation. extended t trunk to spri of relay is e t to ground to cause relays 352 t of plug 28! into jack 3 code si aling conductor 2 332 and offi e The circuit 336 to become energized, the former to disconnect the local ground from perinute code signaling conductor and the latter to prepare its own holding circuit and also the circuit for supply ing interrupted current to lamp 383. As a result of the engagement plug sleeve 32! wi .1 jack bushing 338 the relay 333 is energized in series with the relay the former to complete the circuit for lamp 333 associated with jack 33 5 in the permutation. code message switching section of the central office'and thelatter to complete the holding circuit for the relay 386.

When lamp 3 93 becomes illuminated the operator in charge of the section of the central ofiice,

shown in Fig.8, inserts plug 3-5! into jack 336 preparatory to answering the call indicated by lamp 333 for the purpose of completing the communication channel. Plug 35! is a three-circuit plug having tip 352, rin 353, and sleeve 354.

In addition to the plug tip contact spring 334, jack 336 is provided with ring contact spring 346 and bushing 33?. Spring 3 38 is connected to ground and sleeve 34'! is connected to one end of the winding of a lamp controlling relay 356, the other end of which is connected to ground. The contact tongue 3-5! associated with relay 355 is engageable with a grounded front contact and is connected by conductor 358 to one of the terminals of a lamp 359 associated with jack 33L The other terminal of the lamp is connected to a grounded battery i The tip 352 of plug 35! is connected through an operators set 3% which may be identical with the operators set in Fig. '7 which, as previously described, consists of transmitter 248 and receiving printer 23E controlled by key 255, to one of therelays 332 of a telegraph repeater 363 and through the relay 352 and the contact tongue 353 of relay 365 to ground. The plug tip 352 is also connected by conductor 33! to the back contact of a relay The left-hand contact tongue 3&9, winch is engageable with the back contact, is connected to a grounded battery 31!. The winding of relay 338 has one end connected to battery 312 and the other end connected to sleeve 354 of plug 35! in the same manner that the winding of relay (H3 is connected to sleeve 325 of plug 23!. The purpose of relay 363 is to disconnect from the operators set 36! and from the relay 332 of repeater 353 the local battery 31% which holds the operator's receiving printer and repeater relay 362 energized when plug 35! is not in active service in a jack. The relay 368 also prepares a locking circuit for a double wound relay, as will presently appear.

The ring 353 of plug 35! i connected to one end of the winding of a relay 373, the other end of which is connected to grounded battery 3. The contact tongue 376 is connected to one terminal of a lamp 318, the other terminal of which is connected to grounded battery 31?). The front contact with which contact tongue 313 is engageable is connected to ground and the back contact is connected'to one of the front contacts of a double wound relay 38 l which has been previously mentioned. When relay 373 is energr'ed, which condition obtains as long as plug 35! remains inserted in jack 335 whereby plug ring 353 engages grounded jack spring 343, contact tongue 316 will engage the grounded front contact to complete the circuit of lamp 378 whereby the lamp will be steadil illuminated. The front contact with which contact tongue 31'! is engageable is also connected to plug ring 353 and receives ground connection when the plug is inserted into jack 3H5. Contact tongue 31! is connected to one end of the operating winding of relay 38!, the other end of which is connected to grounded battery 332. Thus, when relay 313 is energized, relay 38! is energized in parallel with it.

lfhe relay 38! is provided with two contact tongues identified by the reference numerals 383 and Contact tongue 383 i connected to a front contact of relay 338 which is engageable by a contact tongue 386. The contact tongue 333 is connected through a normally closed key 387 to ground.

The front contact with which contact tongue 383 of relay 38! is engageable is connected to one different y 381 are completed at the contacts of jack 33 and V plug 35L all of the relays become energized upon insertion of the plug into the jack andbecome de-energized upon withdrawal of the plug from the jack. The holding circuit of relay '38! may be interrupted by the opening of the manually operable key 38'! but this will have no effect upon the relay 38! and it will remain energized through its operating winding, since when the relay see is energized so that the holding circuit oi" relay 3 31' is completed. through the contact tongue 386, the relays 313 and Sci are also energized, the latter through its operating winding. Also, it is not possible for the source of interrupted current 388 to be connected to lamp 3'18 when plug 35! is inserted into jack 335.. The circuit conditions necessary for lamp 318 to be operated from source of interrupted current 388 are that relay 3%! be energize-d through its holdirrg circuit and relay 313 be de-energized to permit its contact tongue 315 to engage the back contact. When plug 35! is used in establishing connection between two subscriber stations having permutation code apparatus only, therel'ays 358, 373 and 381' and the lamp 3'58 are operable as will be described later.

p mutation. code communication circuit site side of repeater 53 from that to c "ators set 35! is connected extends ground through the contact tongue 33! of relay and through the winding of relay 3% to the tip of a plug. 3%. Associated with the plug EQB is a supervisory system that is identical L The with the supervisory system associated with the .n s

ti'on of a double wound relay 3%. The relay 388 energizable in parallel with the relay 3% and like the relay 3 3i is arranged to prepare a circuit from source of intermittent current 399to lamp 39.1. The relay also completes its. own holding circuitwhich is prepared by a relay Mil, the circuit of which extends from the sleeve of p u 393. The relay it! also has a contact tongue which normally engages back contact to connect battery to plug tip 355. and thus-to the winding of repeater relay to hold the repeater relay energized when plug is not use.

Plug is adapted to co-operate. with the subscribers jack il i by which connection may be made to a subscribers station, such as the staticn C. Between the subscribers jack 5! l and the i 'subscribers station C, certain supervis ry circuits are needed which will now be described.

Plug tip contact spring 452 of the jack All is connected to the front contact of a relay 3 which corresponds to the relay 22! of Fig.7. The rela tit has one end of its winding connected to ground and the other'en'd of the winding connected to the jackbushing did, so thatwhen plug 3t3 s inserted into 'jack 4, relay M3 becomes energized. in series with relay 4G I. Conto control the continuous or vintermit-.

tact tongueflfi of relay M3 normally engages'the back contact which is connected to grounded battery 41?. Contact tongue 4H3 of relay M3 is connected. to one terminal of one of the windings of the difierential relay 618-, the other terminal of which is connected to conductor Mflwhich is one of: a. pair of conductors forming a metallic circuit for. communication between subscribers station C and the central ofiice at the-station C the conductor M9 is connected to one of the stationary contacts 42! of. a key 422 which is open when station C is idle.

The other winding of diiferentialrelay 428 has one end connected to grounded battery 423. The other end of the: second winding of differential relay M8 is connected to a front contact of relay 413 with which: contact tongue 42 co-operates. Gontact tongue 424' is connected to a conductor 426 which is the other one of the'pair forming the communication circuit between subscribers station C and. the central oiiice. 'At the subscribers end of conductor. 528 the conductor is connected toone endof the winding of t .e receiving selector magnet 42'! of a receiving printer. The other end of the winding of magnet 42? is connectedlthrough transmitter new a movable contactmembcr 429 of key 422. When subscribers station Cis idle, movable contact 429 of key 422 engages a fixed contact i3l which is connected to ground.

The back contact with which contact tongue 424 of relay M3 co-operates is connected to ground so that when relay M3 is de-energizerl and key 422 is open; the conductive path comprising Contact tongue e24, lice conductor 425, receiving selector magnet 32?, transmitter 522, and movable contact 429 of key 522 is grounded at both ends.

Relay 4 l Sis also provided with a contact tongue 4 32' which co-operates with a back contact only.

The back contact-is connected to grounded bat- 44-8 is connected to ground.

Relay 534 has a. single contact tongue 43'! and front contact which is engaged by the contact tongue. Contact tongue. 3 3! is connected to ground. The front contact with which contact tongue 43?; co-onerates is" connected to one te r minal of a lamp 438, the other terminal of which is connected to grounded battery 439.

The operation of the subscribers stations A and B and of the central office equipment has been described up to the point where repeater 353 and operators set 365 have been. placed in condition to receive permutation code signals from the operators set comprising transmitter 2 58 in Fig. '7 or from the subscribers transmitter stations A or B, this being accomplished by insertion of plug l into jack. Upon communication to the operators set as! of the identity of the permutation code station with which station A or B desires to communicate and, it being. assumed that such station is the subscribers station C. the operator inserts plug 393 .into jack 4H. Plug tip- 382 engages jack spring 4.!2 and extends the communication circuit to the front contact with which contact tongue are of relay 4E3 co-operates. Plug sleeve 4&2 engages jack bushing 414 and places reiay M3 in series with relay dill, where upon. both relays become energized. Relay ifil removes local battery from plug tip 352 and prepares locking circuit for double wound relay 398.

Relay 413 moves itscontact tongue H6 into engagement with its fixed contact, thus extending the communication circuit through one of the windings of differential relay A8 and through conductor did to the open key @223. The relay 4l3 also attracts its contact tongues it i and 32. The contact tongue 126 completes a circuit from ground through battery M3, the upper winding of differential relay M8, front contact and contact tongue -32 1, line conductor receivin selector magnet 52?, and transmitter 328 at the subscribers station C to ground through the key 422. Thus, a circuit is completed through the upper winding of relay M8 and through the selector magnet 27 at subscribers station Since the relay M8 is adifferential relay, and only one of its windings is now energized, the contact tongue will be attracted to connect ground to one end of the winding of relay 434 and also to the plug sleeve contact spring 436 of jack 4! G. Since the circuit from battery 4533 to the other end of the winding of relay 434 is open of relay 394 is completed and relay'te i attracts its contact tongues, thus completing the energizing circuit for the double wound relay 3% which becomes energized and completes its holding circuit. The relay 334 also connect lamp 391 to ground so that the lamp becomes continuously illuminated.

The subscribers station C is provided with a ringer 44! connected across the normally open key 422 and having in series therewith a condenser 442 so that the ringer will be responsive to alternating current only. VVell-known means may be provided at the central ofiice for applying alternating current between the line conductors M9 and sat for operating ringer ull to atract the attention of the subscriber at station 0 so that he may place his printing telegraph apparatus in operating condition to receive a message. The subscriber does this by closing the key 422. Movable contact 529 is thus disengaged from grounded fiXCl contact 4-3! and is engaged with contact 125. Also, a movable contact 443 completes the circuit of motor 444 which is set in operation to drive the receiving printer represented by the selector magnet 5-21 and the transmitter mechanism 428.

As the result of closure of the key 29, a communication circuit is completed from battery 423 through the upper winding of relay 4H3, contact tongue sac, line conductor 325, receiving selector magnet 21 transmitter 4-28, movable contact 329 and fixed contact 42! of key 622, line conductor ile, lower winding of relay M8, contact tongue iiii, spring 512 of jack 3H, tip 392 of plug 333, winding of relay 356 of repeater 3%, and contact tongue 39B of relay 352 to ground. It will be observed that the communication circuit includes both windings of the relay M8. Since this is a differential relay, it will release its contact tongue 5-35 and the tongue will remain released as long as key 622 is closed and plug 393 is in the jack 4i i, regardless of changes in the line from marking to spacing or spacing to marking condition.

The release of contact tongue 235 results in the removal of ground connection from relay 4% and tongues M6, 424, and 4232.

relay 4 .34.

relays 394 and 3S8, the latter remaining energized due to its holding winding. The release of the contact tongues of relay 39 3 will result in connection of the source of interrupted current 399 to lamp through the attracted contact tongue of relay S98 and the released right-hand contact tongue of relay 394. This will indicate to the operator at the permutation code switching portion of the central o-fiice, shown in Fig. 8, that station C is in condition to receive a message. The operator thereupon notifies the subscriber at station A by operation of the operators receiving and transmitting set 35! that he may proceed with the transmission of the message. The message will traverse the repeater in Fig. '7 and the repeater 3'63 in Fig. 8 in reaching the subscribers station C and will be transmitted back to subscribers station A for home record purposes as a facsimile mess-age, conversion taking place in the translator 273.

When the subscriber at station A has completed the transmission of the message, he opens his key 2 i 5 and as previously described, lamp 229 becomes illuminated due to removal of energizing current from one of the windings of differential relay 2E8. Thereupon, the operator at the combined permutation and code facsimile switching portion of the central Office withdraws the plugs 23.2 and 29!. The Withdrawal of plug 291 results in de-energization of relay 339 and extinguishment' of lamp 353 associated with jack 336. Thereupon, the operator at the permutation code switching portion of the central ofiice, which is that shown in Fig. 8, withdraws the plugs 35! and 393 from the jacks 335 and i! 1, respectively. The circuit of the relays 363 and dill are thus interrupted and these relays release the holding circuits of the double wound relays 38| and 398, respectively. Also the circuit of relay 373 i interrupted due to the withdrawal of plug 35L The circuits of lamps 39'! and 3'18 are thus interrupted and the lamps are extinguished.

The withdrawal of plug 393 from jack 4! l opens the circuit of relay M3 which releases its contact The contact tongue i-it upon release moves into connection with the battery 4 i 1 and the contact tongue 424 moves out of connection with the upper winding of differential relay 4 I 8, and into connection with ground. Thus, a circuit is completed from battery 4|! through contact tongue H6, lower winding of relay 4E8, line conductor 4!.1, closed key 422, transmitter 428, receiving selector magnet 421, line conductor 42S, and contact tongue 424 of relay M3 to ground. The lower winding of relay H8 is thus energized and since the circuit of the upper winding is interrupted at the contact tongue 424, the relay will attract its contact tongue 35 to connect ground to one end of the The other end of the winding of relay 434 will be connected to battery 33 due to the release of the contact tongue 432 by relay 4|3. Thus, the relay 434 will become energized and will connect ground to its contact tongue 431 to the lamp 438, thus completing the circuit of the lamp which will become illuminated. This will indicate to the operator at the portion of the central ofiice, shown in Fig. 8, that the subscriber at station 0 has not yet opened his key 422. If the lamp 438 does not become extinguished within a reasonable time, the operator may reinsert plug 3% into jack 4H and inquire as to whether the subscriber at station C desires to transmit a message. However, should the subscriber at station C open the key 422 promptly upon the termination of the received message, the lower winding of relay H8 will become de-energized, the contact tongue 435 will be re1eased,'thusinterrupting the circuit of relay 434 which will release its contacttongue 43.1 and extinguish lamp 438.

It may happen'that during reception of a message at station C the subscriber may wish to interrupt the message being transmitted .to him, such as to enable him to transmit a question or comment concerning the message, or a reply to a question contained therein. Also, he may desire to interrupt the message in order to transmit a message to another station which will hecessitate the changing of connections at the central office to connect station C with the desired other station which may,'for example, be the station D.

The interruption of message reception at station C may be accomplished by momentaryopening of key 422. Fixed contact 42! and the lower winding of differential relay 4T8 is thus disconnected from movable contact 429 and the grounded fixed contact MI is contacted by the movable contact 429, :thus causing the upper winding only of the relay 418 to beenergized'and to attract contact tongue 435. Ground is thus connected through jack spring 136 and plug ring 396 to relay-3534 which becomes energized and attracts its right-hand contact tongue out of engagementwith the contact to which the source of interrupted current 399 is connectedand into engagement with a grounded contact, thus changing lamp cs1 from intermittent illumination to momentary steady illumination. This indicates to the operator at the central *office that key 422 has been opened whereupontthe operator actuates set 36 to make in-ju'iry of the subscriber at station C as to the reason for his interruption of the transmissionor the identity of the station with which he desires to communicate.

For purposes of illustration, it is convenient to assume that the subscriber :at station desires :to communicate with station D. The operator at the central ofiice completes the connection by removing plug 35] from jack 335 and inserting it into jack MH. This causes relays 3E8, 373', and 38! at the central office to be energized in the same manner that re1a'ys'394, 398, and 191 were energized when plug 393 was iii-- serted into jack 4! I, and causes relays H3 and the upper winding of relay NIB to be energized. The operator then applies ringing current between the line conductors M19 and N26 to operate ringer 14$! for the purpose of notifying the subscriber at station D 'to close his key M 22. Upon the closure of the key I422 relay [4T8 releases its contact tongue 1435 due to the placing of its :two windings in series and relay '313 is released to cause its contact tongue 316 to move into its engagement with its back contact, whereby lamp 318 is connected to the source of interrupted current 388 and will flash for the duration of the transmission between stations C and D. From this it will be observed that the source 'of interrupted current 388 which does not "become effective at any time during communication between one of the combined stations, such as A or B, with one of the permutation oodestations C MD, does become efiective during com munication between two permutation code stations, such as the stations C and D. a

It is also possible for a permutation code station, such as the station D, to initiate communication with one of the combined stations, such as the station B. The subscriber :at station D closes the key M22 which completes the circuit of the motor MM and also completes a circuit from the battery it! 1 through the flower contact tongue of relay .t'dtlS, through the lower winding of relay 141%, conductor :i kifi, :key i222, transmitter i are, receiving selector magnet .l line conductor 11326., land innermost upper contact tongue of relay It to ground. .Differential relay 141-3 having only one of its win ings :energized attracts its :contact tongue E1435 to .complete the circuit :of relay 165:4 whereby lamp [11'3315 illuminated. The lamp M338 serves ;as .a signal to the operator to answer the station 113 by inserting either the plug 35! or the plug .393 into 'jjaek idiLi, "the two plugs having identical supervisory circuits associated therewith. 1t will he assumed that the operator :answers with the plug 33-3. Relays i394, 3928, and i are energized, as also rrelay Edit, whereupon the lamp controlling' relay M534 is released "and relay 39 i is released to cause lamp Si-i1 to be iil'lumir'i'aited intermittently. NVhen :the operator has a'scertaincdsfromtthesubscriber at station '1) the identity of the station with which he Wishes to communicate, which will be assumed to be station B, plug it! is inserted into ,jack 335, thus causing the supervisory relays 3.76;, 3.58, and 331 to becomeienergized and also thezrelaytfifi whereby lamp 353 is :steadily illuminated.

The .lamp 359 Jserves as a :s'ignal to :the operator who has the receiver 125.9 to :answer the call available at :33], This is accomplished 'by inserting plug 5232 into Jjack 3.3. whereupon the supervisory zreiays 1262, 22:13, and 2%, associated with lplug 2232, operate and the operator's receiving printer, represented by the magnet 2419, and the transmitter 1438 :are connected .to the permutation :code communication :circuit which has ibeen 'entended to plug 2.91. Theoperatorat the central-office of Fig. '7, upon being informed that the subscriber :at station 513 is the called subscribeninsehts plug 'Z-Fii into jack i233. The supervisory -;ci:rcuits associated with the plug 29-! respond to the insertion of the plug into jack i235 :and the supervisory circuits associated with the neck respond .in the same manner :as :previously described for transmission of .a message from station .A to station .3. The permutation code signals repeated by the repeater in Fig. .7 from the signal transmitted from :station D will terminate :at the ground engaged by contact tongue x'lfitil ot-relay .362, due to the fact that relay 392 :does not remain energized because the contact tongue 1225 of differential irelay 12% at station B will be out of engagement with "its back :contact as a result of the energization of the lower Winding only of "relay ii-iiil. Should the subscriber :at station a? close his key liilfi, which he has .no occasion to do unless he desires to :hrea'k in .on :the message being transmitted to him, zt'n'erelay 1218 will release its contact tongue and ground connection will be :extended to the relay i362 to cause it to be energized, thus attracting =its icontact tongue 131.9 and disconnecting ground from the permutation code-signaling circuit at that point, the terminal of the ciroui't then being the ground at the translIlltCEl i i l fi of su'bscr'ibers station E. Since here is no apparatus at the station B responsiv'e to permutation code signals, those signals will 'h ave-no efiect at that point. Facsimile signals for actuating the facsimile recorder i2lll will 'be generated in the photoelectric cell 238 of the translator and will be impressed upon the conductor 28% and the plug tip 292 from which point they will traverse the jack spring 1264, telegraph line i253, and relay E282 terminating at the facsimile recorder I25. The energization of relay 232 will cause the motor circuit to close and remain closed, thus causing the motor IZdl to be actuated for driving the facsimile recorder 9285.

When the subscriber at station D concludes the transmission of the message, he opens the ey I 422. This opens the circuit of one of the windings of the relay M98 which thus becomes unbalanced and attracts its contact tongue M35, connecting ground through jack Hill to the winding of relay 3% which becomes energized and attracts its right-hand contact spring into engagement with the grounded front contact, thus causing lamp 331 to be illuminated steadily. Thereupon, the operator withdraws plug 393 from jack 4H and withdraws plug 35l from jack 3%. All of the supervisory relays associated with jack l4! 1, with plug 3:33, with plug 35!, and with jack 336 become de-energized, whereupon lamp 353 will be extinguished. This is the signal to the operator at that portion of the central office, shown in Fig. 7, to withdraw plug 232 from jack 33! and to withdraw plug 29l from jack 12%. Upon the withdrawal of the plugs, all of the supervisory circuits, namely, those associated with the plug 29!, the plug 232, and the jack 1286, return to normal.

Referring to Fig. 9, which shows a complete communication system that might be used in an industrial organization or hotel between the Various departments thereof, or in a police intercommunication and broadcast system involving fixed and mobile stationathe reference numeral 56! designates a keyboard transmitter at each of the fixed stations E, F, and G. Keyboard transmitter Sfil may be of very simple form, such as the one disclosed in Patent 1,135,613 granted April 13, 1915, to L. M. Potts, having no transmitting distributor, but having merely transmitting contacts to be closed substantially simultaneously in permutational code combinations under control of a keyboard mechanism. The keyboard is provided with a lock lever 562 controlled by a magnet 553 for locking the keyboard when a key lever has been depressed. The transmitting contacts are connected to conductors contained in a cable 535. The cable terminates in a central ofiice H where the transmitting contact conductors of all of the cables 56 are connected to bus bars or other common conductors 565.

The common conductors 586 are connected to the individual selector magnets 56? of a translator mechanism which may be similar to or identical with that shown in Figs. 1 to 3, the magnets 55? corresponding to the magnets El of Figs. 1 to 3. The armatures 568 of the magnets Eitl are arranged to operate the slides 55!! which control the shutter slides Eli and also effect tripping of a clutch, such as that shown in Figs. 1 and 3, to impart rotation to the scanning drum. Through the rotation of the'scanning drum, signals are generated in photoelectric cell 512, which signals are amplified by amplifier 513 and are transmitted by radio transmitter 514.

The facsimile translator shown in Fig. 9 is provided with a pair of normally open contacts 576 that are closable by a cam operated lever '11.

Lever 51"! may be operated by a cam (not shown) driven along with the scanning cylin der and arranged to close the contacts at the beginning of rotation and to permit them to open near the end of the cycle. One of the contacts is connected to battery and the other is connected to a seventh conductor contained in each of the cables 554. At the stations E, F, and G, the seventh conductors are individually connected to the keyboard lock controlling magnets 563.

Each of the stations E, F, and G is provided with a radio receiver 5'58 for receiving facsimile telegraph signals transmitted by the transmitter 514, and the output of the radio receiver is connected to the signal responsive magnet 5'59 of a facsimile printer 58% for recording facsimile messages received by the radio receiver '518. There may also be stations, such as the station J, from which there is no occasion to transmit messages, which are provided only with a radio receiver 578 and. a facsimile recorder 58!. The station J may, for example, be a police motor vehicle equipped only for one-way communication, as is a common custom; namely, for the reception of information or instructions.

In the system shown in Fig. 9, message transmission from any of the stations E, F, or G may be efiected by depressing the keys to control the permutative closure of contacts 56!. Upon the depression of any key, certain of the contacts 55| at that station will be closed to complete the circuits of corresponding ones of the magnets 561. This will result, a disclosed in Figs. 1 to 3, in the generation of facsimile signals at the photoelectric cell which will be amplified at 573 and broadcast by transmitter 574. At the beginning of the generation of the facsimile signal, contacts 516 are closed, thus completing the circuits of magnets 563 at all of the stations E, F, and G, whereby the magnets become energized and the locks 562 are operated to look all of the keyboards.

As the facsimile signal corresponding to the permutation code is transmitted by radio transmitter 574, it is received by the radio receivers 518 at stations E, F, G, and J and is recorded on the facsimile printers iiSi. Toward the end of the facsimile signal contacts 5'36 are opened and the magnets are released, whereby locks 562 are disabled and a key may be depressed at any of the keyboards. By providing for the looking of all of the keyboards, one keyboard may not be operated to interfere with the registering, upon magnets 56?, or a code combination initiated at another keyboard.

Another communication system employing apparatus according to the present invention is shown in Fig. 10. Referring to that figure, the reference numeral tel designates a keyboard transmitter which may be of the type shown in Patent No. 1,595,472 granted August 10, 1926, to H. L. Krum, which may be considered the equivalent of the transmitters shown in Figs. 7 and 8 having transmitting contacts 632 connected to ground and to a communication conductor 8%. The keyboard transmitter 68!, and a facsimile recorder 6 3 5 which may be similar to the facsimile recorders 2M and i, shown in Fig. '7, make up a subscribers station, such as the station K. The facsimile recorder 664 is connected to one end of a communication conductor 601.

Other subscribers stations L and M are similarly provided with keyboard transmitters 6M and facsimile recorders 6%.

Each of the conductors 663 is connected to one asso /gees terminalof an individual. line relay 668 at a' central oifice station N and the other-terminal of the winding of each relay 608 is connected to battery 559. A series circuit beginning atground at the cen ral onice station N includes the line" relay contacts EH of the line relays 658, and the selector magnet M201 a signal translator G l-3' which may be similar to that shown in Figs. 4 to 6, inclusive, theseries circuit'then extending from the selector magnet 512 to battery 689. The photoelectric cell 6M corresponds to the cell 32 in Fig. i and generates facsimile signals correspondin to permutation Code signals impressed upon the selectormagnet 652. .The facsimile signals generated in th cell 6&4 are amplified in amplifier M5 and are applied tothe communication conductors td'l over which they are transmitted to the'facsimile recorders at'the stations Ii, L, and M.

Upon the operation of an one of the keyboard transmitters at stations KL, and M, its

transmitting contacts 6&2 are operated in accordance with permutation code combinations, and the signals are repeated by the line relays 568 to control correspondingly the circuit of the selector magnet hi2 of the translator 613. The facsimile signals are generated at GM and are transmitted over the conductors 5G! to the station which originated the message to provide a home record and also to all Of the other stations connected to central'oflice station N. Thus, any one of the stations K, L, and M may communicate With each of the other stations in the system. As distinguished from the communication System shown in Fig. 9, the system shown in Fig. 10 involves metallic conductors throughout for interconnecting the several stations and is particularly applicable to industrial installations, hotels, and other business organizations where it is desirable to provide intercommunication' between several locations with the recording of all transmitted material at all stations;

Although certain specific embodiments of the invention have been shown and described herein, it is to be understood that the invention is not limited to such specific embodiments but is capable of modification and rearrangement without departing from the spirit ofthe invention and within the scope of the appended claims.

What is claimed is:

1. In a telegraph apparatus, a permutation code signal receiving mechanism, permutation members positionable by said signal receiving mechanism, permutationally apertured slides in dividually controlled by said permutation mem-,

2.111 a telegraph apparatus, a permutation code signal receiving mechanism, permutationally a ertured slides positionable by said signal receivlng mechanism, a source of light and a photoelectric cell associated with said slides, a rotatable cylinder associated with said slides, said source of light and said photoelectric cell, said cylinder having circumferential rows of apertures arranged according to a facsimile signaling code, means for rotating said cylinder, and means op erated by said signal receivin mechanism for controlling the connection of said cylinder to said rotatin means.

3. In a telegraph apparatus, a code signal receiving mechanism, signal responsive members positionable by said signal receiving mechanism,

4. In a telegraph apparatus, a code signal re-- ceiving mechanism, signal responsive members positionable by said signal receiving. mechanism, light shutter members individually controlled by said signal responsive members, a source of'light and aphotoelectric cell associated with said light shutter members, a rotatable cylinder associated with said light shutter members, said source of light and said photoelectric cell, said cylinder having circumferential rows of apertures are ranged according to a facsimile signaling code, means for rotating said cylinder, and .meansope-n atedby said signal receiving mechanism for con trolling the connection of said cylinder to said rotating means. r

5. In atelegraph apparatus, a code signal re ceiving mechanism, signalresponsive members positionable by said signal receiving mechanism, light shutter members individually controlled by said signal responsive members, a source of li ht andv a light sensitive impulse generator associated with said light shutter members, a rotatable cylinder associated with said light shutter mem, bers, said source of light and said light sensitive impulse generator, said cylinder having circume ferential rows of apertures arranged according to a facsimile signaling code, means for rotating said cylinder, and :means operated by said signal receiving mechanism for controlling the connec tion of said cylinder to said rotating means.

6. In a telegraph apparatus, a code signal re: ceiving mechanism, signal responsive members positionable bysaid signal receiving mechanism, light shutter members individually controlled by j said signal responsive members, a source of light and a light sensitive impulse generator associated with said lightshutter members, a rotatable scanning member associated with said light shutter members, said source of light and said light sensitive impulse generator, means for rotating said scanning member, and means operated by said signal receiving mechanism for controlling the connection or said scanning member to said rotating means. J i s 7. In a telegraph apparatusapluralityof signal responsive electromagnets, a light shutter member individual to and operable by each of said electromagnets, said light shutter members being apertured to establish variou single light paths according to the energization of said electromagnets, a rotatable member having signal combinations of light blocking and transmitting areas in registry with the light path positions, a source of light and alight sensitive impulse generator associated with said-lightshutter members and said rotatable member, means for driving said rotatable member, and means actuated by any of said electromagnets upon the energi-

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