US2110260A - Telegraph system - Google Patents

Description

March s, 1938.

M. S. BURGESS ET AL TELEGRAPH SYSTEM Filed Dec'. 17

, 1935 5 sheets-Sheet 1 March s, 193s. M. s. BURGESS ET AL v 2,110,260

' TELEGRAPH SYSTEM -l Filed Dec. 7, 1955 s sneets-sheet 2 POL AR/ZED Masi/,4655.5

/NVEA/wRS ,4, 5 CLARK A 7' TORNEV March 8, 1938. M. s. BURGEss r-:r Al.)

TELEGRAPH SYS TEM Filed Dec. 1.7, 1955 5 Sheets-Sheet 5 M. 5. BURG j 1.5. CLARK NI/E/VTORS' March 8, 1938. M. s. BURGl-:ss x-:r Al. 2,110,260

TELEGRAPH SYSTEM Filed Dec. l?. 1935 5 Sheets-Sheet 4 wkrm D M. s. u/ecfss NVE/V70 ,4.5. CLA/wr ATTORNEY March 8, 193s. MSBURGESgH AL y 2,110,260

TELEGRAPH SYSTEM Filed Dec. L7', 1955 5 sheets-sheet '5 .Mael/@655s I V WVENRS'AacLAR/r ATT ORNE V Patented Mar. 8, 1938 UNITED STATES PATENT OFFICE TELEGRAPH SYSTEM Telegraph Company,

York

a corporation of New Application December 17, 1935, Serial No. 54,886

9 Claims.

This invention relates to a telegraph system, and more particularly to a picture transmission system arranged for the transmission of teletypewriter characters.

The message content of a telegraph type of signal depends upon the number of individual discrete current values that may be discerned at the receiving end. this number usually is two and in ordinary submarine cable telegraphy it is usually three. As-

vsuming the same amount of intelligence transmitted in a given time, the invariable relation between the quantities involved is C11-:constant Where C equals the number of discrete current values, and n equals the signal speed. Theequation indicates that a given message content can be transmitted over a shorter time with the same available frequency band Width as the number of discernible current values is increased. Heretofore, there have been conceived picture transmission systems employing a large number of discernible current values that might be adapted for the transmission of teletypewriter characters. It is an object of this invention to provide a telephotographic system arranged for the transmission of teletypewriter characters.

The invention comprises a system in which a five-unit twoielement permutation code combination representing a character to be transmitted, is translated into a telephotographic permutation code selected from a two-unit six-element combination and recorded on a film. Thereafter, the telephotographic code is transmitted over a picture transmission system. At a receiving station, the telephotographic code is decoded and retranslated into the original five-unit two-element code which is passed into a suitable teletypewriter apparatus to effect a printing of the transmitted character.

In the preferred embodiment as herein described and illustrated, perforate representations of characters to be transmitted actuate a transmitter which passes corresponding ve-unit twoelement permutation code combinations into a translating arrangement to effect telephotographic permutation code combinations. The latter are recorded on a lm as combinations of two elemental areas, each of which may assume any one of six different shade intensities. The film is thereafter advanced into a photoelectric device in which currents corresponding to they shade intensities are produced for transmission over a lino circuit. At a receiving station the line currents effect a reproduction of the original telephotographic code combinations on another In ordinary telegraphyy film. A receiving photoelectric apparatus transforms the shade intensities into corresponding currents which are decoded and translated into the original five-unit two-element permutation code combinations. The latter effect a reproduction of the perforate representations appearing initially in the transmitting apparatus. The perforate reproduction may be employed with a suitable teletypewriter device to accomplish a printing of the transmitted character.

Figure 1 is a block representation of a telephotographic system arranged for the transmission of .teletypewriter characters;

Fig. 2 shows the method of arranging the succeeding figures of the drawing; and' Figs. 3 to 6, inclusive, when arranged as indicated in Fig. 2, delineate diagrammatically a telephotographic system adapted for the transmission of teletypewriter characters.

Fig. 1 delineates a block representation of a picture transmission system arranged for the transmission of teletypewriter characters. Referring to Fig. 1 an actuation of a character key on a sending keyboard causes an operation of punches in a perforator to effect a perforate representation of a character to be transmitted. The perforated'tape is fed into a transmitter which emits a five-unit two-element code comprising a combination of current and no-current impulses, depending on the positions of the perforations in the tape. The code combination is passed into 'a translating apparatus that changes the current and no-current impulses into a telephotographic code combination. As a sensitized photographic film is fed into an exposing system, the' telephotographic code is recorded thereon 'as a combination of two elemental areas, each of which may assumeany one of six different shade intensities. After development and drying, the iilm is passed into a telephotographic transmitter which transforms the various shade intensities into corresponding currents for transmission over a line circuit shown in heavy lines and controlled by a suitable transmission regulator to obviate external interferences.

At a receiving station, which operates in synchronism with the sending station, the line currents are retranslated by a telephotographic receiver into a telephotographic code which is recorded on another sensitized photographic film as a combination of two elemental areas, each of which may assume any oneA of six different' shade intensities that are identical with those produced initially by the sending station. After.

development, the film is fed through a scanning system wherein the various shade intensities are changed again into corresponding currents. `The latter operate certain translating relays to formulate a code combination of current and nocurrent impulses utilized to actuate a tape perforator to produce a perforate representation which is a. duplication of the one initially set up in the sending apparatus. Finally, the perforated tape is advanced into a teletypewriter device to eiect a printing of the transmitted character.

Figs. 3, 4, 5 and 6 when placed side by side in accordance with Fig. 2 illustrate a picture transmission system modiiled for the transmission of teletypewriter characters. A character, which is to be transmitted, is' initially prepared by striking an appropriate key on a keyboard so 'as to :eifect the closing of certain contacts of a group 400 to 404, inclusive, associated therewith as shown in Fig. 4. For the purpose ofthis illustration, let it be assumed that contacts 466 and 464.are closed. As a result thereof, energization circuits for punch magnets 466 and 439. respectively, associated with the perforator are completed. 'I'he energization circuit for magnet 466 may be traced from ground 4|6, through closed contact 466, lead 4||, winding of magnet 466 to battery 4|2; and the energization circuit for magnet 409 may be traced from ground 4|6, through closed contact 464, lead 4|3, winding of magnet 409 to battery 4|2. Punches 4|1 and 42| associated with magnets 466 and 469, respectively, are actuated to provide two perforations in a tape 422, each ofA which is contiguous with an edge thereof. After withdrawal from a tape supply, not shown, the tape 422 is advanced into a tape transmitter by a toothed wheel 423 engaging longitudinallyaligned perforations 424 provided centrally of the tape 422 to effect its advancement. The feed wheel 423 is driven in a manner that will be explained hereinafter.

As the tape 422 is fed into the transmitter, any one or combination of tape pins 426 to 436, inclusive, may be caused to engage associated contact points 434, 434 depending upon the positions of the perforations existing in the tape 422 as it is ejected from the perforator. Since, for purposes of this illustration but two perforations, positioned as previously indicated, were provided in the tape 422, then only tape pins 426 and 436 will be permitted to project through the perforations to engage their associated contact points 434, 434 each of which has battery 433 connected thereto. Obviously, tape pins 421, 426 and 429 will be prevented from further movement by the absence of perforations in the tape 422 and, consequently, battery 433 will notbe connected thereto. Inv this manner, the transmitter emits -a'code combination comprising. current impulses eifected by tape pins 426 and 430 and no-current impulses eifected by tape pins 421, 426 and 429, respectively. For a more detailed operation of the tape transmitter, reference may be had to the copending application of E. F. Watson, Serial No. 28,332, led June 25, 1935, which issued as Patent No. 2,055,567 on Sept. 29, 1936. In the event that it is desired to make a printed record of the code combinations emitted by the tape t nsmitter, any well-known teletypewriter appara us maybe associated therewith. A suitable device for this purpose is described and illustrated in the patent of Morton et al., No. 1,904,164 issuedApril 18, 1933.

In Fig. 3,y any one or combination of polarized *relays 300 to 304, inclusive, may be energized depending on the combination of engagements eftherefore,

fected between the tape pins 426 to 430, inclusive, and contact points 434, 434. As previously described, only tape pins 426 and 430 were caused to engage contact points 434, 434, therefore, only those relays of group 300 to 304, inclusive, associated therewith will be energized. Accordingly, an energization circuit for relay 300 may be traced from ground 308, through winding of relay 300, lead 309, and, in Fig. 4, through lead 369, tape pin 430, contact point 434 engaged with the latter, to battery 433; and'an energization circuit for relay 304 may be traced from ground 3|0, through Winding of relay 304, lead 3| I, and in Fig. 4 through lead 3| I, tape pin 426, contact point 434 engaged with the latter. to battery 433.

To facilitate a tracing of circuits in the drawings, it should be kept in mind that relay contacts are shown in normal positions assumed when their associated relays are in an unoperated condition. Accordingly, an energization circuit for relay 3|2 may be traced from ground 326, closed contact 32| of operated relay 363, lead 323, winding of relay 3|2 to battery 324; and an energization circuit for relay 3|6 may be traced from ground 323, closed contact 329 of operated relay 364, lead 33|, winding of relay 3| 6 to battery 332. Relays 3|2 and 3|6 operate to pull all contact 'tongues associated therewith to the right,

' while relays 3I3, 3|4 and 3| 5 remain unoperated thereby allowing all contact tongues associated therewith to remain vin their normal positions as seen in Fig. 3. As a consequence of the operation of relay 3| 6, battery 335 is connected through lead 336, contact 331, lead 336, contact 339, lead 346, contact 34|, lead 342, closed contact 343 associated with operated relay 3|6, lead 345, resistance 36| and lead 349, and in Fig. 4, lead 349, light valve 435 to ground 436. As a result of the operation of relay 3|2, battery 356 is connected through lead 351, closed contact 366 associated'with operated relay 3|2, lead 366,'contact 36|, lead 362, contact 363, lead 364, contact 366, lead 366, closed contact 361 associated with operated relay 3| 6, lead 369, resistance 314, lead 316, and in Fig. 4, lead 316, light valve 431 to ground 436.

In Figs. 3 and 4, it is readily seen that the six resistances oi' groups 366 to 355, inclusive, and 316 to 316, inclusive, are of different values, and, in addition, that the resistances oi' each group are arranged to be connected individually in a series circuit extending between their associated light valve and battery in the manner as previously described in connection with resistancesv 36| and 314. The particular resistance selected determines '-the value of the current owing through its associated light valve thereby controlling the size of the aperture in the latter in a manner which will be subsequently explained. The light valves 436 and 431 may be of a suitable type such, for instance. as that disclosed in the patent of E. C. Wente, No. 1,638,555 issued August 9, 1927. In Fig. 4, light from source 4331s focused by lens 440 on a small slot formed by movable elements 444 in an orince 446 provided in the pole pieces ofa permanent magnet 446 Issociated with light valve 435. As previously describe'd, an electric current flows frombattery 335 through light valve 436 and, accordingly.

flows through movable elements 444 thereby occasioning a displacement of the latter by a reaction of the magnetic fields due to the current andthe magnet. 'Ihe image of the orifice of light valve 435 is then focused by lenses 443 and 441 on a sensitized lm 448 moving past the point of exposure. An apertured plate 449 precludes diffused light from interferring with the recording. Likewise, in valve 431 light from source 439 is focused therethrough and onto the sensitized lm 448 under control of a current flowing from battery 356 in a manner similar to that described in connection with valve 435. Referring to Fig. 4, it will be observed that when the images of the orifices of light valves 435 and 431 are recorded on film 448, the image of light valve 431 will always occupy a position in advance of that occupied by the image of light valve 435 due tol the advancement of lm 448 in the direction indicated by the arrow. Accordingly, the combination of two shades, one after the other on two elemental areas of the film 448, represents the character which existed initially as perforations in tape 422. In like manner, therefore, combinations of two shaded areas, cach of which may assume one of six different intensities depending upon the resistances selected from group 35i! to 355, inclusive, and group 310 to 315, inclusive, will provide thirty-six telephotographic code combinations of which thirty-two are suicient to represent the combinations of current and nocurrent impulses eiected by the perforate representations produced by actuations of the character keys on the sending keyboard.

The combinations of relays operated and resistances selected in the aforedescribed manner to eiect a telephotographic code combination of a perforate representation of the usual thirty-two teletypewriter characters are as follows:

Table B Light valve current Fig.4 Resistance Fig. 3

350 I 351 1I 352 2l 353 3l 354 n 4I 355 5I 370 I 371 1I 372 2l' 373 3l 374 4I 375 5I' The film 448 and tape 422 are simultaneously advanced one character space at a time by a synchronous motor 450 driving the shaft 425 through meshing bevel gears 45| and 452 in a manner that will now be explained. Also meshing with gear 452 is a bevel gear 453 keyed to one end of a shaft 454which has mounted on its opposite end a drum 455 provided with a pin 456 mounted transversely in an outer periphery thereof. Mounted concentrically with the drum 455 is a second drum 451 having a peripherally recessed portion 458 disposed oppositely to the pin 455. A cross member 459 afxed to one end of a shaft 464 is provided Table A Character sent Perforgatg repre' Relays operated l ResistalIlCgSd Lower Upper se ec e case case 1 2 3 4 5 300 to 304 312 to 310 300-1 312-13 370 352 's -1- 300-3-4 312-15-13 370 353 -1- 301-2-3 3111-14-15 374 352 -1- -1- 30o-3 312-15 375 352 3 300 312 373 350 1 -1- 300-2-3 312-14-15 374 350 & -1- 301-3-4 313-15-15 370 355 -1- -1- -1- 302-4 314-16 375 355 3 -1- -1- 301-2 313-14 372 350 A -1- 300-1-3 31213-15 372 354 300-1-2-3 31243-1445 371 352 -1- 301-4 3-16 374 353 -1- 302-3r4 314-15-16 372 351 e 302-3 314-15 371 350 9 -1- 303-4 315-15 373 353 -1- -l- 301-2-4 313-14-16 373 351 1 300-1-24l 312-13-14-15 370 351 4 -1- 301-3 313-15 375 354 Bell -1- 300-2 312-14 371 354 5 -l- -1- 304 315 371 351 7 300-1-2 312-13-14 375 350 -1- 301-2-3-4 313-14-15-16 375 353 2 300-1-4 312-13-10 371 l353 300-2-3-4 312-14-15-16 375 351 5 -1- 300-2-4 312-14-15 372 355 -1- 300-4 312-15 374 351 301 313 373 352 -l- -1- 302 314 374 354 -1- -1- -1- 303 315 372 352 Figures. 300-1-3-4 312-13-15-16 373 355 Leuersm.. 300-1-2 3-4 312-13-14-15-15 372 353 Blanks1-.-. -1- None None 370 350 The following table shows the current values derived from the use of individual resistances 350 to 355, inclusive, and 310 to 315, inclusive, and utilized to actuate light valves 435 and 431. A

with four radial slots 460 spaced 90 degrees apart and arranged so that the slots in sequence accommodate the pin 455 during each revolution of the drum 455 thereby imparting an intermittent movement to the shaft 464. Apparatus for effecting this movement is well known and is described in the patent of Herbert E. Ives No. 1,738,007 issued December 3, 1929. Fastened to the opposite end of the shaft 464 is a feed sprocket 465 engaging the usual perforations aligned along the longitudinal edges of the film 448 to effect its advancement past the point of exposure before the light valves 435 and 431 in amounts corresponding to the angular movements of the cross member 459. A camera 46| containing the lm 448 and arranged for recording and transmitting the telephotographic code combinations may be of any well-known type such, for example, as that disclosed in the patent of Louis M. Potts No. 1,882,893 issued October 18, 1932. The radial slots 460-are arranged so that the intermittent movement imparted to shaft 464 comprises a one-quarter revolution for each complete revolution of the drum 455 thereby effecting an advancement of the iilm 448 before the point of exposure in an amount equal to the space required for the telephotographic code combination to represent one character. Se'- cured to the shaft 464 intermediate cross member 459 and film feed sprocket 465 is a gear 490 meshing with gear 49| amxed to one end of a shaft 492 having a gear 493 mounted on its opposite end. Gear 433 meshes with a gear 494 fastened to one end of a shaft 495 which has the tape feed sprocket 423 secured to its opposite end. It is to be understood that the mechanism provided to intermittently advance the film 448 one character space at a time also drives the transmitting tape feed sprocket 423 in a manner that the film 448 and the tape 422 areadvanced simultaneously one character space at a time. With this arrangement, therefOrl?. the sensitized film 448 is advanced for exposure before the light valves 435 and 431 at the-instant the tape transmitter emits the current and no-current combi- .nations effected by the perforations in the tape 422, and after the emission thereof, the tape 422 and lm 448 are.simultaneously advanced one character space at a time to make ready for the transmission and recording of the next character.

Also, affixed to the shaft 425 is a bevel gear 466` meshing with a bevel gear 461 mounted on one end of a shaft 468 having a feed sprocket 469 secured toA its opposite end. 'I'he feed sprocket 469 engages the usual perforations aligned along the edges of the film 448 to effect the latters withdrawal from iilm supply 410 and, in addition, to advance the exposed film 448 into a fixing apparatus 413 in which the imag on the film 448 are developed. 'I'he diameter of feed sprocket 469 is one-fourth that of feed sprocket 465 so as to move the film at a uniform rate of speed that is equal to the average vrate of speed at which the film is being exposed to the light valves 435 and 431. 'I'he fixing apparatus 413 containing developing tank 462 and fixing tank 463 may be of any suitable type such, for instance, as that disclosed in the copending application of Herbert E. IVeS, Serial No. 291,744 led July 11, 1928 which' issued as Patent 1,989,618 on Jan. 29, 1935.

Also, keyed to an end of the shaft 425 is a bevel gear 41'4 meshing with a bevel gear 415 fastened to one end of a shaft 416 having aflixed to its opposite end a feed sprocket 411 employed to withdraw the developed iilm from the tank 413 and to advance it before a stationary scanning plate 418 onto a take-up 412. 'I'he diameter of4 feed sprocket 411, like that of feed sprocket 489,

is one-fourth that of feed sprocket 465 thereby enabling the developed film 448 to be passed before the scanning plate 418 at a uniform rate of speed which is equal to the average rate of speed at which the sensitized lm 448 is being passed before the point of exposure to the light valves 435 and 4,31.

The various shades of the two elemental areas of the developed film 448 are transmitted by being passed in order before a scanning aperture 418 provided in plate 418, at which point the shades are illuminated by a lamp 480 and condensing lens 48|. A beam of light is focussed on the photoelectric cell 482 and as each portion of the lm 448 is passed before the scanning aperture 419, beams of light of varying intensities are focused on the photoelectric cell 482 to produce varying currents representing the shade intensities of the two elemental areas on the lm 448. An amplier 483 ampliiies the currents before their application to a modulator 485. lOscillator 486, modulator 485, amplifier 481, and filter 488 serve to effect in the well known manner a transmission of a carried wave modulated by the currents produced by the photoelectric cell 482 over the line circuit shown in heavy lines. Filter 500, amplifier 5|0, and demodulator 5| I' receive the modulated carrier and direct the transmitted photoelectric currents to a light valve 502 shown in Fig. 5. Apparatus for transmitting and receiving photoelectric current signals may be of any suitable type such, for example, as that described in the patent of Maurice B. Long, No. 1,706,032, issued March 19, 1929 and in the patent of Herbert E. Ives, No. 1,738,007 issued December 3, 1929. In Fig. 4 it is seen that the image of the orifice of light valve 431 is always recorded on the film. 448 in a position in advance of the image of the orifice of light valve 435 in the manner as hereinbefore described. 'I'herefore, it is obvious that the shade intensity produced by light valve 431 will always be transmitted over the line circuit in advance of the shade intensity produced by light valve 435.

In Fig. 5, the transmitted photoelectric currents actuate movable elements 50| of light valve 502 in the manner explained in connection with light valve 435. The image of the orice in light valve 502 is illuminated by a lamp 503 and condensing legs 504, and focused by a lens 505 through a scanning aperture 508 provided inscanning plate 501 and onto a sensitized film 508. Light valve 502 actuated by photoelectric currents representing the transmitted shade intensities now effects a reproduction of the transmitted shade intensities on the lm 508 exactly in the order of their appearance on the film 448. A suitable line regulating apparatus 484 for maintaining the initial values of the photoelectric currents throughout the entire length of the transmission line may be employed. For example, a regulator of the type illustrated in the copending application of A. D. Dowd, Serial No. 734,179 filed July 7, 1934 and is described in corresponding British Patent 453,462, accepted Sept. 11, 1936 would be satisfactory. 'I'he employment of the line regulator provides a control of the transmission line characteristics so that the shades of the two elemental areas as produced on the transmitting film 448 will be duplicated with identical intensity on the rethrough a tape transmitter is similar to that employed for the identical purposes in connection with camera 46| and tape transmitter of the transmitting station as seen in Fig. 4. The receiving camera 509 may be of any well known type, such as that described in the patent of Louis M. Potts, supra. A synchronous motor 5|3 is employed to drive the receiving mechanism in synchronism with the synchronous motor 450 associated with the transmitting apparatus. A suitable apparatus capable of effecting a synchronization of the transmitting and reproducing mechanisms as employed in the transmission of pictures may be used to synchronize motors 450 and 5I3. For example, the apparatus described and delineated in the patent of Maurice B. Long, supra, would be satisfactory. Film feeding sprockets 5|4, 5|5 and 5|6 of receiving camera 509 are duplications of the film feeding sprockets 411, 469 and 465, respectively, of cam- 4era 46|. Therefore, it is apparent that the film 508 of camera 509 is advanced in identical steps simultaneously with the lm 448 in camera 46|.

The sensitized film 500 is withdrawn from the film supply 5|1 by the sprocket 5|4 and thereafter is exposed to light valve 502 at a uniform rate of speed synchronized with that at which the film 448 is fed past the pho-toelectric cell 482 so that the transmitted shade intensities are reproduced in' succession on the lm 508 in the order of their appearance on the lm 448. Therefore, in each telephotographic code combination eiected by this invention, the shade represent-- ing the orifice of light valve 431 will always occupy on the lm 508 a position in advance of that occupied by the shade, representing the orifice of light valve 435. The lm 508 is then fed into a xing apparatus 5|8 containing a developing tank 5|9 and a xing tank 520. The xing apparatus 5|8 .is identical with fixing apparatus 413. From the xing apparatus 5|8 the developed lm 508 is 'withdrawn by the sprocket 5|5 and passed along to a sprocket 5|6 aixed to one end of a shaft 525 which has a cross member 526 mounted on its opposite end. As previously seen in connection with cross member 459, the cross member 526 imparts an intermittent movement consisting of one-quarter revolutions to the shaft 525, thereby effecting an advancement of the film 508 before a stationary scanning plate 521 one telephotographic code combination at a time. In this manner, therefore, the various shades of the two elemental areas comprising a single telephotographic code combination are again converted into photoelectric currents by the passing of the developed iilm 508 before scanning apertures 528, 528 provided in the plate 521. Through the apertures 528, 528, a lamp 529 and condensing lens 530 illuminate simultaneously the two elemental areas of the lm 508 so that varying beams of light passing therethrough are focused by lenses 53| and 532 upon photoelectric cells 536 and 531. Obviously, the various shadesof the elemental areas of lm 508 will effect variations in the intensities of the beams of light focused onv the photoelectric cells 536 and 531 and, accordingly, the shade variations will be represented by corresponding variations in the currents produced in the photoelectric ycells 536 and 531. Photoelectric cell 536 is connected through amplifier 538 to selecting polar relays 605 to 609, inclusive, by lead 539. Photoelectric cell 531 is connected through amplifier 540 to selecting 600 to 604, inclusive, by lead 54|. The selecting lead 694 and closed contact 681 to lead 693.

polar relays cuits of relays 603 to 600, inclusive, provide successively diminishing biases for these relays which are equal to the successive diminishing biases of relays 608 to 605, respectively.

Therefore, when the lm 508 is advanced one telephotographic code combination at a time before 'the scanning apertures 528, 528, as seen in Fig. 5, the shade representing the orifice of light valve 431 will produce a current in photoelectric cell 536 and the shade representingthe orice in light valve 435 will produce a current in photoelectric cell 531. These current values correspond to the current Values derived for the purpose of actuating the light valves 435 and 431 at the transmitting mechanism, and the latter current values corresponding to the resistances used with light valves 435 and 431 may be seen in Table B. A suitable shutter arrangement may Abe associated with the scanning plate 521 so as to obviate the possibility of producing false currents in the photoelectric cell 531 as the film 508 is advancing into the camera 509. Since, for the purposes of this description, resistance 314 was associated with` light valve 431 and resistance 35| was associated with light valve 435, the current values actuating these light valves are 4I' and |I, respectively, which are obtained by substituting the Vcurrent values of Table B in the resistance column of Table A. The current 4I ows'on lead 539 through the windings a. of polar relays 605 to 609, inclusive, which are connected in series, to overcome the biases on all relays of this group except relay 609 and, accordingly, relays 605 to 600 inclusive are operated while relay 609 continues in the unoperated condition. As a result thereof current from battery 6|5 ows throughy armatures 6|6, lead 6|1, armature 6|8, lead 6|9,-armature 620, lead 62|, armature 622, lead 623, and armature 624 of unoperated relay 609, lead 625, winding of neutral relay 630 to ground 632 thereby completing an energization circuit for neutral relay 630. The latter operates to close contacts 631 to 64|, inclusive. 'I'he current |.I flows over lead 54| through the windings a of polar relays 600 to 604, inclusive, which are connected in series, to overcome the bias on relay 600 only and, accordingly, relay 600 operates while relays 60| to 604, inclusive, remain in the unoperated condition. As a result thereof, current from battery 644 ows through armature 645 of operated relay 600, lead 646, armature 641 of unoperated relay 60|, lead 648, closed contact 638 of operated relay 630, lead 649, winding of neutral relay 616, lead 68|, winding of neutral relay 650 to ground 682 thereby completing an energization circuit for neutral relays 650 and 616. The latter operate to close contact 681 associated with winding 616 and contact 683 associated with relay 650. Battery 688 is connected through closed contact 683 to lead 689, and battery 688 is connected througIl will be noted that battery 688 may be connected through each of contacts 683 to 681 inclusive, to the latters associated leads 689 to 693, respec' tively, depending on the operations of the relays in the group 650 to 680, inclusive.

In Fig. 5, it will be observed that leads 689 to SIS, inclusive, are connected to one end of the windings of punch magnetsSSll to SS4, inclusive. of a well known type of perforator. Inasmuch as battery S88 is now connected to leads SIS and S93, the former will be connected to ground SSS associated with the opposite endy of each ot the windings of punch magnets SSII and SSS thereby eti'ecting an operation of punches SSS associated with the magnets to provide two periorations in tape SI2, each oi' the perforations being contiguous with an edge of the tape SI2. In connection with the receiving tape SI2 it will be noted that the perforations produced therein occupy positions identical with those appearing in the transmitting tape 422. The tape SI2 is advanced by feed wheel S into a tape transmitter in which the tape perforations cause the sending out of current impulses from battery SSI. Obviously, the absence of periorations in the space intervening between the two perforations produced in the manner as described above, eil'ect no-current impulses. 'Ihese current and nocurrent impulses effect an operation of a printer to record the transmitted character. 'I'he tape transmitter may be of a suitable type such as that described in the copending application of E. F. Watson. supra. used 'at the transmitting station. 'Ihe printer may be of a well known teletypewriter printing apparatus such as that disclosed in the patent of Morton et al., supra.

'lhe following table shows how the various values of photoelectric currents eii'ect the operation oi' the translating relays to reproduce the transmitted teletypewriter character in a man- In,Table C, the and signs indicate current and no-current impulses, respectively, with reference to'battery S88 (Fig. 6). Since it has been described that these current impulses energize any one or combination of punch magnets SSII to 554, inclusive, thereby resulting in an actuation of the latters associated punches, the signs may also be construed to indicate the positions of perforations in the tape SI2, while the signs may be construed to indicate an absence of perforations in the tape SI2. Also, it is obvious that and signs may indicate operation and non-operation, respectively, of the punch magnets S50 to SSS, inclusive.

-Referring to Fig. 6, it is to be understood that grounds S33 to S36, inclusive, are individual to windings of neutral relays B52, SSS, SSS and SSS, respectively.

Also, it is to be understood that the motor SI2 advances the tape SI2 one code combination at a time in unison with the sprocket SIS employed to feed the iilm S08 before lamp S29 exactly in the steps that motor 450 effected the advancement of tape 422 and lm 448 through the sending tape transmitter and camera 4SI, respectively.-

Various modications of the apparatus described and illustrated herein may be made without departing from the scope of the invention deiined in the appended claims.

What is claimed is:

A 1. A telegraph system i'or transmitting characters comprising means for translating the characters into code combinations of impulses of light of more than two diil'erent intensities,

means for producing signaling currents corresponding-thereto, and a circuit for eiecting a v I transmission of the signaling currents.

2. A telegraph system for transmitting characters comprising means for translating the characters into code combinations of more than two shades of unit areas, an instrumentality for eil'ecting signaling currents corresponding thereto, and a circuit for transmitting the signaling currents.

3. A telegraph system -for transmitting symbols comprising means for translating the symboisinto permutation code combinations o! shades of unit areas, an instrumentality for producing signaling currents corresponding thereto,

a circuit for transmitting the signaling currents,v

and receiving apparatus for effecting a printing of symbols corresponding to the signaling currents including a decoder and aprinting device operated thereby.

4., A telegraph system for transmitting symbols comprising means 'for producing permutation code combinations of current and no-current impulses representing the symbols, means for translating the mst-mentioned code combinations into code combinations of impulses oi' light of more than two intensities, means responsive to the second-mentioned code combinations for producing signaling currents corresponding thereto, and a circuit for eil'ecting a transmission of the signaling currents.

g5. A telegraph system for transmitting symbols comprising means for producing perforate representations of the symbols, means vfor translating the perforate representations into permutation code combinations of impulses of light, means responsive to the code combinations for eii'ecting signaling currents corresponding thereto, a transmission circuitA and a receiving instrumentality for accomplishing a printing of symbols corresponding to the signaling currents including a decoder and a printing apparatus operated thereby. l y

6. A telegraph system for transmitting symbols comprising means for producing perforate representations of the symbols, means for producing code combinations of current and no-current impulses corresponding to the perforate representations, means for translating the mst-mentioned code combinations into code combinations of more than two shades of unit areas, means for effecting signaling currents corresponding to the second-mentioned code combinations, a circuit for transmitting the signaling currents, and an instrumentality for accomplishing a printing' of symbols corresponding to the signaling currents including a decoder and a printing apparatus operated thereby.

'1. A telegraph system comprising av communication channel, telephotographic transmitting and receiving apparatus connected to the channel for transmitting and receiving signaling currents representing a plurality of shades of unit areas of photographs, printing telegraph transmitting and receiving apparatus, and means for representing each character transmitted by the telegraph transmitter by a permutation code combination of a plurality of shades of unit areas connected between the telegraph and telephotographic apparatus.

8. A telegraph system for transmitting symbols comprising means for translating the symbols into permutation code combinations of impulses of light of more than two different intensities,

means for producing signaling currents corre-v sponding thereto, a transmission circuit, and a receiving instrumentality for eiecting a printing of symbols corresponding to the signaling currents including means for reproducing the code combinations of impulses of light produced initially Vto represent the symbols, means for eiecting currents corresponding to the reproduced code combinations, a plurality of relays operated selectively by the last-mentioned currents for effecting teletypewriter code combinations of impulses, and a teletypewriter operated by the lastmentioned code combinations.

9. A telegraph system for transmitting symbols comprising means for translating the symbols I into permutation code combinations of shades of unit areas, means for producing signaling currents corresponding thereto, a transmission circuit, and a receiving instrumentality for effecting a printing of symbols corresponding to the signaling currents including means for reproducing the code combinations of shades of unit areas produced initially to represent the symbols, means for eiecting currents corresponding to the reproduced code combinations, a plurality of relays operated selectively by the last-mentioned currents for effecting teletypewriter code combinations of impulses, and a teletypewriter operated by the last-mentioned code combinations.

MONTAGUE STEPHEN BURGEs's, ALvA BENSON CLARK.

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