US2274737A - Photoelectric transmitter - Google Patents

Description

March 3, 1942.

FIG; l4

L. M. POTTS 2,274,737.

PHOTOELECTRIC TRANSMITTER Filed Dec. 20, 195'? FIG. I

6 Sheets-Sheet 1 INVENTOR LOUIS M. POTTS BY I v 7 vfi March 3, 1942 T L. M. POTTS PHOTOELECTRIC TRANSMITTER I Filed Dec. 20, 1957 6 Sheets-Sheet 2 INVENTOR. LOUIS M. POTTS ATTORNEY.

March 3, E942. L. M POTTS 2,274,737

PHOTOELECTRIC TRANSMITTER Filed Dec, 20, 1937 6 SheetSF-Shee-t 3 62 g 5 59 58 57 :2 2 fl i- I I a 231 v 2n INVENTOR.

20s LOUIS 'MwPOTTS I If BY I ORNEY. I

L. M. Po'rfs .YPHOTOELECTRIC TRANSMITTER Filed Deg. 20, 1937 6 Sheets-Sheet 4 FIG. 5

INVENTOR.

POTTS LOUIS M.

F IG.

Filed Dec. 20, 1957 6 Sheets-Sheet) 5 F l C5. 7

s I l RT-HQ m m m 8 EM 0 w BIG F IG

Patented Mar. 3, 1942 v 2,214,731 .rno'rocmc'rmc TRANSll/IITTER Louis M. Potts. Evanston,

- Corporation, Chicago, 111.,

Delaware Ill., assignor to Teletype a. corporation of Application December 20, 1937, Serial No. 180,'71

38 Claims.

This invention relates to printing telegraph machines and-particularlyfto transmitting ap-- paratus for impressing-telegraph signals upon a communication channel.

Morespecifically, the invention pertains to the scanning of message indicia byphoto-electronic means and the initiation of telegraph impulse conditions in accordance with the message indicia scanned.

An object of the invention is to scan message indicia arranged on page form paper in linesaccording to the arrangement of, and if desired,

in conjunction with the printed message which the indicia represent.

Another object or the invention is to control theprogress of the message page through the scanning transmitter by' electrical impulse conditions generated thereby.

Another object of the invention is tosupplement the impulse conditions originated by the page scanner by impulse conditions introduced by an auxiliary photo-electronic mechanism.

Another object of, the invention is to receive and store a plurality of message pages for delivery successively to the page scanner mechanism and to deliver the pages thereto in succession automatically. v

The invention features a photo-electric scanning system in which the scanning of message index elements successively is accomplished by shutters comprising apertured endless flexible bands similar in structure to photographic focal-plane shutters arranged to travel at right angle to the direction of travel of the message The invention also features a selector mechani'sm local to the transmitter to which all of the signals generated therein areapplied and which is effective in response to certain ofsaid signalstocontrcl the handling of the message page and the admission of stored pages into the transmitter. a a I A. rel'ated invention, which contemplates the transmission of impulses corresponding to signals carried by a tape and scannedpby photoelectronic means, is disclosed in copending application Serial No. 48,098, filed November 4,

1935, by Louis M..Potts.

Briefly, in accordance with the preferred embodimentoi the present invention, thereis pro-. vided a pair of. endless .bands spaced'apart a 7 distance depending upon the vwidth of apage upon which signals to be transmittedlhave been impressed, and supported for movement in ,par-

allel paths by two pairs of sprockets or pulleys carried by two shafts. provided with feed pins for receiving and holding in proper alignment 9. message page. 'A' pair of endless scanning belts extend transversely of the page supporting belts. One of the'scanning belts is provided'with an aperture arranged to register with all of the signal-impulse elements of a code-signal combination simultaneously, and the belt is moved step, by step to bring the aperture into registry with the code-signal come binations successively. The other belt is provided with a plurality of apertures in stepped or staggered arrangement so that the signalimpulse elements of 'a code-signal combination may be scanned successively by the several apertures of the'set. This'belt receives continuous movement when operating. A photo-electric system comprising'a source of light and a photo electric cell is arranged in proximity to the scanning belts so that impulses may be generated in accordance with the signaleimpulse elements scanned. The impulses thus-generated may be amplified and impressedupo'n a 'communication channel. I

. The code-signal combinations generated, in addition to being impressed upon'a-cornmunication channel, are impressed upon the windings I of the selector magnet of a selector mechanism local to" the transmitter. The selector mechanism may be similar to that employed'in printing telegraph receiving units and provlded'for controlling certain functions that "require perfor advancement simultaneously and delivery successively to the page handling bands of the I storage magazine is actuated by the page-han lines of signal formance in the transmitter mechanism. The advancement of, the page step by step through the transmitter to eflect'the transmission'ofthe v combinations and the feeding o from thetransmitter after the,

I has been transmitted, are 7 controlled by the selector mechanism.

out of the page complete message Aimesage storage sprocket feed mechanism for engaging a plurality of message pages arranged overlapping transmitter.

v The feed mechanismof the page dling band mechanism of the transmitter; The message storage and "message transmitting mechanism is automatically arrested when the last page of message materiahhas been trans mitted and is automatically restartedlby the placing of a page in the storage magazine.

inventiomreferen'ce may belh ad to thesfollow: I

The belts or bands. are

magazine is mounted adjacfent to the transmitter'and is provided with' a fulland-complete, understanding of the Fig. 2 is a fragmentary front elevational view having detailed portions at the right side there-- of broken away and in section;

Fig. 3 is a fragmentary side elevational view with the assembly of shafts 3| and 92 in quarter section as best indicated by line 33 of Fig. 2;

Fig. 4 is a sectional view taken approximately on line 4-4 of Fig. 3;

Fig. 5 is a sectional view takenapproximately on the line 5-5 of Fig. 2;

, Fig. 6 is a sectional view.v taken approximately on the line 66 of Fig. 3;

Fig. 7 is a fragmentary rear elevational view showing the selector mechanism in an opposite direction from that of Fig. 2;

Fig. 8 is a fragmentary plan view of a message storage magazine having portions broken away to reveal structural details;

Fig. 9 is an elevatlonal view of the message storage magazine shown in Fig. 8 with certain parts broken away or in section to show structural details;

Fig. 10 is a detail view of the magazine operating mechanism appearing at the right of Fig. 9, showing the mechanism at a different tionally supported by brackets 26 above shaft 24. Sprockets 41 are likewise provided with feed pins 50. Endless bands 49 extend from each of the sprockets 44 to the corresponding sprockets 41. Bands 49 may be fabricated from any durable thin sheet material, such as sheet steel, and each. provided with feed perforations 5| spaced in accordance with the spacing of feed pins 46 and of sprockets 44 and 41. so that when shaft 42 is permitted to rotate, bands 49 travel in endless paths. Bands 49 are provided with feed pins 52 similar to sprocket feed pins 46, and these pins are disposed intermediate each two feed perforations 5|. Endless bands 49 serve to support and feed, through the transmitting mechanism, a page-width paper which carries the code signal combinations to be transmitted. One such page is indicatedby the reference numeral Y53 and it will be observed that this page is provided with perforations arranged along the margins thereof to be fitted over and engaged by pins 46, 48 and 52. A similar message page for controlling a transmitter is described in Patent 1,060,939 granted May 6, 1913, to Louis M. Potts.

Retaining strips 54, having tunnels through which feed pins 46 and'52 may pass, are mounted above bands 49 in close proximity thereto to prevent page 53 from shifting out of position on band 49.

Shaft 3| supports and imparts continuous rotation to gear 56 and the driving element 51 of a jaw clutch. Driven element 58 of the Jaw clutch is slidable axially of shaft 3| and is urged toward driving element 51 by compression spring 59. The jaw clutch of elements 51 and 56 is of the single revolution type, and disengagement is effected by clutch throwout lever' 6| cooperating with flange 62 carried by driven element 56.

on the line I5-l5 of Fig. 1, showing two different operative conditions; and,

Fig. 16 is a sectional view taken approximately on the line |6|6 of Fig. 3.

Referring now to the drawingsin which like reference numerals designate corresponding parts throughout the several views and particu-- larly to Figs. 1 and 2, the reference numeral 2| designates an electric motor, therotor shaft 22 of which carries a pinion 23. A shaft 24 journaled in brackets 26 has gear 21 meshing with pinion .23 whereby continuous rotation is imparted to shaft 24. Shaft'24 carries a gear 23 which is engaged 'by a gear 29 secured to a shaft 3| joumaled in brackets 32 and 33. Ad-

jacent to the end journaled in bracket 33, shaft 3| has secured thereto a pinion 34 (Fig. 3) which is engaged-by a gear 36 secured to a'short shaft 31 that is journaled in bracket 38 carried by bracket 33. Shaft 31 supports and drives, through a-spring loaded friction clutch, a gear 39 with which is meshed a gear 4| secured to shaft 42 which is rotatably supported by brackets 43. Shaft 42 is normally restrained from rotating in response to the torque continuously applied by the spring loaded friction clutch of shaft 31 by'an escapement mechanism which will be described later.

Shaft 42 has fixed thereto inspaced relation a pair of sprockets 44 each of which has the In alignment with the two sprockets 44 are periphery thereof provided withfeed pins 46.

Driven element 58 of the clutch mechanism is splined to sleeve 63 which is mounted on shaft II and isfree' of the shaft so as to be capable of remaining stationary while the shaft rotates and which constitutes the element that is driven intermittently by the clutch mechanism.

Sleeve 63 has secured thereto a cam 64 which is engaged by a spring biaseddetent 66. Detent 66 operates through cam 64 to apply a torque to sleeve 63 at the instant of disengagement of clutch elements 51 and 58 by clutch throwout lever 6| to effect complete separationof the clutch elements and prevent clutch teeth chattering in the stop. position.

Sleeve 63 supportsfor rotation independently thereof a drum 61 (Fig. 3) having sprocket pins 66 uniformly spaced around the periphery thereof. A ratchet 69 is secured to drum 61. At a point remote from drums 61 and 8|, opposed brackets 10 and 1| the bases of the brackets and clamping the brackets to the base of the transmitter. Bracket "supports stud 12 in the same horizontal plane as clutch driven sleeve 63. Stud 12 supports freely rotatable drum -13 which is similar to drum 61 and is provided with similar sprocket feed pins 14. An endless flexible band 16 .of"

ter'just below the upper tangent run ofjmessage page feed bands 49 and is arranged to move, as will be set forth in detail later, in the direction (Fig. 1) are adjustably mounted by screws extending through slots in.

The .upper tangent run indicated by the arrow. Band 16 is provided Y the length of the longest line of signal combinations which the message page 53 is expected to accommodate plus the width of one code-signal supported in brackets 32 and 33 below shaft 3|,

has loosely mounted thereon gear 9| which meshes with continuously driven gear 56 carried byshaft 3|. 'A positive drive jaw clutch mechanism similar to that previously. described and comprising driving element 93, axially movable element 94; compression spring 96, and clutch throwout lever 91 (Fig. 2) is associated with shaft 92. Driving element 93 issecured to gear 9|-soas to be continuouslyrotatable therewith, and

driven element 94 is positively connected to shaft 92 so that, when clutch elements 93 and 94 are combination. The spacing of slots 18' along band,

16 is equal to the circumference of drums 61 and I 13. These relationships facilitate the resetting of band 16, in a manner which will be described later, to bring a slot 18 into position to scan a line beginning with the first signal combination.

Clutch driven sleeve 63 supports, in spaced relation to drum 81, a freely rotatable drum 8| .provided with sprocket feed pins 82 in the periphery thereof. Drum 8| has secured thereto ratchet 83 which is also rotatable independently of sleeve 63 by which it is supported. A stud 85' carriedby bracket 18 rotatably supports a drum 84 similar to 'drum 8| and spaced from drum 13 in accordance with the spacing between drums '61 and 8| carried by sleeve 63. Drum 84 is provided in the periphery thereof with sprocket feed pins 86,

and drums 8| and 84 are just enough larger'in engaged, shaft92 is rotated .and, when clutch elements 93 and 94 are held apart by clutch throwout lever'91, shaft 92 is stationary although gear .9| continues to rotate. Cam 98 secured'to shaft 92 and detent 99 cooperate in'themanner set forth with reference to cam 64' and detent 66 to effect complete separation of- clutch elements 93 and 94. 'The gear ratio of gears 56 and 9| is unity so that shaft 92, when driven, rotates Y at the same velocity asshaft 3|.

diameter than drums 61 and 13 to enable an endless flexible band 81 of opaque material to overlie and overlap band 16. Band 81 is 'prov vided adjacent to one edge with spaced feed perforations 88 that are entered by sprocket feed pins 82 and 86. Band 81 is provided with a plu-' rality of sets of longitudinally extending slots each set consisting of a number of slots 89 equal in number to the signal elements of a signal combination and preferably disposed in obliquely offset arrangement so that as band81 travels in the direction indicated by the arrow, the slots 89 of a set register successively with transversely extending slots 18 of band 16. The distance from the beginning of one set of slots 89 to the beginning of the next set is equal to the circumference of drums 8| and 84, andband 81 is equal in length to'an integral multiple .of the circumference of drums 8| and 84 so that as the drums make one complete revolution any; one

of the sets of slots 89 will be brought exactly A gear |8| fixed to shaft 92 meshes with a gear |82 carried-loosely by sleeve 63'andfreely rotatable thereupon. On the face'which is presented toward ratchet 83;- gear |82 carries a stud I83 upon which is pivotallymounted a pawl I84 urged into engagement/with the teeth of ratchet 83 by a spring, (not shown) The pawl |84and ratchet 83- serve as a driving connection between gear |82 and drum 8|, whereby band 81 is continuously moved in the direction'indicated by the arrow when shaft 92.is rotated. As previously stated, the circumference of drum 8| equals the distance between the corresponding parts of any two adjacent sets of slots 89in band 81. Thus it will be apparent that if the first slot 89 of a set is about to come into registry with a signal combination on message page 53 as drum 8 l begins to rotate, the first slot of the next set will be about to come into registry with the same signal comb nation at the completion of one revolutionof drum 8|. The ratio between gears IM and |82 is such that gear |8| in one revolution will im-' into the position occupied by the preceding set i at the beginning of the revolution.

' As set forth in the preceding paragraphs. each of the scanning bands 16 and 81 is equal in length to an integralmultiple of the circumference of the sprockets by which it will be supported. If

both bands are proportioned according to the same multiple, the outer band, which is supported on the larger sprockets, must have the axes of its sprockets farther apart than those of the sprockets supporting the inner band, if

the outer band is to be drawn taut between its sprockets. The slots in brackets 18 and 1| permit both bands to be drawn taut and permit Y studs 12 and 85 to be disposed in different vertical planes. 7

The driving of drums 61 and 8| to effect signal scanning movement of bands 16 and 81 will now be described. Ash'aft'92 (Fig.3), rotatably part to gear |82 slightly more than one revolution. the excess representing, in peripheral movement of drum 8|, the distance from a vertical edge of one signal combination to the. corresponding edge of the next signalcombination in a line.

Thus for a single revolution of shaft 92, one entire set of slots 89 will scan a signal combination; and the first-slot of the next set will be presented inreadiness to scan the next signal combination.

The advancement of successive setsof-slots 89 into posit on to scan successive'signal combinations is automatically controlledand effected through the small difference between angular ved locities of 'ge'ars |-8| andl82, thev'elocity of the latter of which is the higher. Theslots 89 in band 81 should be so proportioned in relation to the velocity of travel of the band that a signal impulse of the desired length is generated while a slot traverses a fixed point, .such as a signal 7 start impulses, by which properphasi'ng is main I el ment on the message page.

The slots 1n'band'81 represent the elements of. permutation code signal combinationaand the impulses initiated during scanningmaybe marking or spacing depending upon thefnat-ure of code impressions on the message page scanned by the'slots. The space between sets cf slots also represents impulses. preferably" the rest and tained in a start-stop'system Theportionls of band '81 representing both of these signaljimpulses'are blank, due to-th'e provision of 'a', sepa rate scanning system for generating the rest im pulse, as will presently appear. pulse might, however, be represented by a slot,

since it is ordinarily of marking nature, in which case each signal combinationcarried bythe mess ge page would have a marking element to be scanned'by the rest impulse slot. Theauxiliary scanning system to be described later could then 'be dispensed with, but extra space wouldbeoccupied on'ea ch page by the rest impulse elements.

The transmitter herein disclosed may be arranged to generate impulses for five or six unit code but preferably generates six unit code com- The rest imthe zone traversed by.slots'18"and 89, a slot 18 will register successively with the signal combinations, and that while the slot 18 is in registry with'each of the'signai combinations; a set of slots 89 will passacross slot I8 and thus scan successively the several signal elements of a Sig-- nal combination. As shown in, Figs. 1, 2, and 5,

b'inations. The reason for this preference is that when a five unit code is employed, code combi nations are assigned to shift and unshift functions to efiect letters or figures printing. These shift and unshift combinationsare not representative of characters to be printed, and their employment in a. message page might result in the.

introduction of extra spaces in the printed message accompanying the ignal combinations, and in order .totr'ansmit lines of standard length, excessively wide message pages with-longer than 7 average lines ofsignal combinations might be.,

required.

I is mounted a housing ll 8;(Figs. 2 and 5) whichcontains a photo-electric celllls'and a reflector [2| (Fig.5). Reflector l2! isgset at such The" six unit code afiords amplenumber of signal combinations for letters'and'figures selection without a shift. ,It thus permits the code,

combinations and associated message characters to be arranged exactly in accordance with' the normal spacing of typewritten reading rnatter. The transmitter may operate directly a six unit permutationprinter, or it may be employed to operate afive-unit code'printer if there beinterposed between the transmitter and the printer a code translating system such. as thatdisclosed in Patent 2,152,772, granted April 4, 1939,.130 L.

Y M. Potts.

Shaft-92 has secured thereto a cam IM (Figs.

- 2, 3, and 6); which is disposed in an elongated aperture Him a lever I07 pivoted on and suspended from sleeve 63 carried by shaft 3|; Lever I01 carries a stud I 08 which pivotaliy supports pawl I09. Pawl I09 isalignedwith and is spring urged into engagement .with ratchet 69 secured to'drum 6'1; The oscillation of lever ill! by cam 104, as shaft 92 rotates, causes ratchettilto be advanced step by step, to ,efiect advancement of transverse slot" in band 16 from one to an- :other of the signal combinations successively each time shaft 92 performs one revolution. A Y spring- -liased check pawl HI (Fig. 6) is pivotally moulfie 7 mitter mechanism. and engages, ratchet B9 to.

' prevent backward rotation ofratchetBS and to 1 upon a stationarymortion of the transinsertion are. simplified.

a source of illumination comprising an elongated lamp H6 ofsullicient length toilluminatea full line. of signal combinations is stationarily mount-.

ed just above hands and bands 16 and '81 so that message'page 53 may pass betweenlamp I I6 and bands 16and 81 and may be illuminated thereby. A cover ll! isfitted over lamp I 16 and confines the illumination. to message page 53. Below the upper runs of bands 16 and 8'! there 'the'upperl and lowerrunsof bands I 6 and 81. I jThe'mounting of the'cell andits removal and rev by having thecelloffset with'respectto the scanning bands.

The message page 53 may beopaque to light supplied by lamp H6, and the signal elements "perforating the page in accordance with the sigcontained therein may be of a light transmitting nature They may comprise apertures 'made'by nal combinations to betran'smitted, or they may comprise portions or the page rendered translucent by treatment with oil or other suitable material. With this arrangement the lighttransmitting portions of the signal combinations rep-' resent marking conditions and permit thephotoelectric c'ell'to be activated toinitiate marking impulses.- 1 According to anjalternative arrangement, 1 the message page may be translucentfand.

the signal combinations may be printed thereon so to render the; marking signal elements I opaque. The photo 'electric cell willfthen be non.

responsive to marking signal elements, and it maybe soconnected electrically to the telegraph line that marking signals are initiated in response to an inert condition of the photoe'electric cell.

insure that pawl. I09 picksup successive teeth 7 7 thereof upon each operation by cam I04. I

.As shown in Fig. '6, a considerable amount of overtravel is provided in the return movement -of pawl I09 to pick up theizext tooth in ratchet 69, and thisresults in lost motion-in the forward movement, whereby the pawl does'not advance ratchet 69,until ,-near the-end of its'forward movement. The reason forthis is that bandit must remainstationary until all of the character'code slots of. a set in band-81 have scanned a signal combination, and must then be stepped to its next position into registry with "the next signal combination during the interval it is being traversed bya blank-.portionrof band -8l between two sets of slots.

1 It will be apparent from the description thus far that with a message page supported on hands Q9 with a line of signal combinations disposed in.

-As still anotheralternativathe signal cbmbinations may be printed in an opposite arrangement;

namely,fprinting the spacingeleme'nts withink so asto render them opaque, leaving unprinted areas of the translucentpage to represent marking conditions; Whenjmarking areas arelight transmitting, the initiation of impulses by the photo-electric cell is direct, an activatedicondition oi. the cellresulting in, marking impulses; and an'finert condition resulting in' spacing impulses. When marking areas are opaque, a reversal of control conditionbetween the cell and th telegraph line isinecess'ary, ,sO that a mark ing'impulse may beinitiated in response to an The characters rep inert condition of the; cell. resented by; the signal combinationsjfmay be printed directly above" the signal combination,

so thatthe message page constitutes legible copy as well as a transmittercontrolling form.

Each of the s10ts.89 in, band. 81. is arranged to signal 'combinationjwhile slot register' with one not ftl'ie sl gn alf elements of a 18; is" in" registry with an'en'tire signal combination, and those of f slots 89 which register with a perforation ortranslucent area of pageESpermit lightito pass 7 I through to photo-electric cell IIBto' effect activation of the cell. The transmitting mechanism,

: as disclosedherein, is arranged to transmit startstop permutation code signals-which, as is well :known, are equallength combinations. of marking and spacing signals preceded by astart sig-' inn, which is of spacing nature, and followed by a stop or rest signal, which is of marking nature. Assuming that translucent areas'represent marking signals and spacing signals are generated by permitting no light to reach photo-electric cell H9, the start signal may be considered as rep- 7 resented by a portion, of the blank space in band 81 between any two sets. of scanning slots 89.

provided to permit'light to reach photo-electric cell H9 to effect the generation of the rest im- -The stop or rest impulse involves the generation I of a markingsignahand if no apertures in bands I6 and 81 and marking elements on the page are pulse, a separate optical system, as heretofore Y mentioned, may beprovided for the generation of the restimpulse. I n g This system, as shown in Fig. 3, comprises an auxiliary lamp I23, auxiliary photo-electric cell I24, and a disc I26 fixed to shaft 92 and provided with an aperture I2' I throughlwhich, light ,may be transmitted from lamp I23 to photoa cell I24. Since scanning bands and 81 are driven by shaftg92 through gearIIlI and cam I04, and since the scanning of one signal combination is accomplished by one revolution of,

shaft ,92, perfect timing of the generation of the .stop or rest impulse under the control of disc I28 can be maintained so that after the last slot 83 of a set has scanned the last signal element of a signal combination, aperture I21 in disc 5 I26 can come into the path of light from lamp I23 to photo-electric cell I24 to effect generation of the stop impulse. vThe time requiredfor the first slot, 890i a set to come into registry lwith in Patent 1,937,376. granted November 28, 1933,

to, Walter J.Z enner and comprises a selector magnet I3! having an armature I32,'-an armature lever I33 for controllingthe'setting of selector lever "I34, and a s'wordi'and T-selector mechanism which includes swordlevers I31 and T-levers I38 and which is controlled jointly by selector lever I34 and by selector cam assembly I39 carried by shaft 92;toeflfect the setting or T-levers I38 in accordance with the signal combination impressed upon selector-magnet I3I..

dinarily {employed in receiving selector mechanisms as exemplified in Patents, 1,145,633 and 937,376, in that itis thei'usual'custom to'drive theselector cam assemblythrough a friction clutch mechanism; so that itmay be arrested when Ysig'nalcombinationsare not being received while permitting its driving 'shaft' to rotate continuojusly in order'that rotation may be imparted tojthe selector cam; assembly as soon as the start impulse of the signalcornbination is received byy the selector. magnet. Selector'cam'assembliesin start-stop receiving; printers are usually driven at'ia slightly faster rate'ithan are transmitter shafts, iniorder that attire-end ofeach cycle the cam assembly may be 'sync'hronized with the transmitter by arresting itbrieflywhich not only makes desirablethe frictionclutch connection,-

but also necessitates an; angular'sequence of re- 7 ceiving cams diiferentfrom that of transmitting V cams. In the-present structure; the selector cam assembly rotatesat the speed'of transmitting shaft 92, and therefore theangular setting of cams thereon may be comparable withthat of transmitting cams,rathe'r than with'those of the first signal elementaftertransmissionof the rest impulse has ceased represents the start impulse as does also that portion of the blank space in band 81 between two sets of slots 89, which traverses an arbitrarily selected point during the 7 time interval mentioned. I

There are certain functions to be performed in the transmitter whichcorrespond to functions in the receiving printer which may be responding to W the signals generated in the transmitter.- For example. after a complete line ,ofsignal combi- 3 nations hasbeen scanned, it is necessary to advance bands 49 to bring a, new line of signal S combinations into;position to be scanned, and

it is also necessary to reset bands 16 and 81' corresponding toa carriage return operation, so that a slot 18 in band 16 shallbe presented in position to scan the first signal combination of be'prepared to scan that signal combination in timed relation to the presentation of slot I8. It

is, therefore, necessary that there shall be,,local trol those functionsin the transmitter itself.

As shown in'Fig. 7, there is associatedwith shaft 92 a selector mechanism responsive to all of the signal combinations generated in the trans-- mitter. This selector mechanism maybe generally similar to that disclosed in Patent-1,745,633

printer receiving cam assemblies shown"in 'Pat-. ents 1,745,633 and '1,937,376; It will be'found by whensignal combinations are not being generated inthe photo-electric cells and appliedtoselector magnet. I3I, and therefore that a frictiondrive and magnet controlled stop meme-error selector cainassembly I39 are not required. 'T-levers I38' are connectedby intermediate levers I l-I to endwise slidable notchedcode bars I42,'so1 that for each characteristic setting I ofT-levers I38 in accordance with a signal combination, a corresponding settingiofco'de, bars I42 is effected, Code. bars Hi2- areprovided. withgnotches 'as at I43 arranged,along'an edgeof each code bar in accordanceL with thesignaling code upon. which the mechanism isfijperated. For certairisettings I of the: code bars, "these being the settings representative" of function selections, one ,or more alignments of notches; extending transversely. of the'group'of codebars I42 is effected. j- ,7 thenew line, and one of the sets of slots 89 shall 1 One of the functions that a printingtelegraph apparatus operating 'on signals transmittedffrom the herein disclosed photoielectrictransmitter is required to perform periodically is the carriage return operation by which the carriage is restored to abeginning of line position for the printin'gof anewliner Corresponding to the carriageiretu'rn" ffunction inaprinter is a .functionjrequired' to be performed in the transmitting mechanism involving the resetting' of scanning ",bandsf'lfi and v 81in proper relation to scan a new lineiof signal combinationsb'e'ginriing :with thefirst combinaftion in' the'line, For; the performariceof this granted February 4, 1930, to srMorton et al. r 7 5 function, there" is provided a function bar I44 (Figs; 2, 4,1 5; and which has .aportion exthese a notch. m.

tending across the set of notched codebars I42 and in alignment with which a clearance of notches maybe presented for the selection of bar'l44. Bar I44 is. translatably supported on pivot-pin I45 (Fig. movable in slot I41'and V is biased for engagement with the edges of code bars |42.by tension spring I48. A universal opall of the positions in which alignments of notches in code bars I42 may be effected, has an arm'I59 (Fig. 1) engaging. a lever I 54 operated by cam I55 carried by shaft 92.

Once in each revolution of shaft 92, cam-I58 I24 so that a stop or rest condition is impressed upon the telegraph line." Each time that-bail I84 erating bail I5I,pivoted at I52 and spanning' operates. lever I54 to permit universal operating bail |5| to rotate counterclockwise from its normal position, as view'edinFig. 5, underthe influence of tension spring I51 andimmediately restores it to extreme clockwiseor normal position against the tension of the spring. Function bar. I44 has, in its upper edge a clearance I58, a'slightlyhigher portion I59, and between I Clearance I58 permits bar I44 to rest against the edges of code bars I42. Higherportion I59 is in the'pathof universal operating bail I5I and together with othersimilar bars is engaged by the bail as it rocks counterclockwise toeffect withdrawal of bar I44 and others from engagement with code bars I42, leav-. ing the code bars free to move. As bail |5| returns to its normal position, it permits bar I44 to return into engagement with code bars. I42, and if an alignment of notches is presented to function bar I44,, the bar entersfthe alignment of notches, its. free end thereby being lifted sufficiently to causenotch I5I' to become hooked on the lower end of operating bail I5I. tinued motion of bail |5I toits normal position I f results in leftward movement (asviewed in Fig.

5) of bar I44. Above function bar I44 there is mounted on bracket I53 a pivot rod I52 which supports a bail I54 that is substantially coextensive with the universal operating bail I5I and also supports a bell crank lever I55. Bell crank is operated, clutch throwout lever 91 is presented in clutch disengaging position and shaft=92 is arrested. A safetyyielding interconnection between link I14 and clutch' throwout lever 91 is afforded by pin I15, slot I11, and tension spring ported by clutch driven sleeve 53, 'none has been identified'asbeing'positively connected to the sleeve except cam '54. Referring now to Figs. 1,

2, and 6, reference numerals I8I and I82 indicate arms secured to sleeve 53 and extending radiallytherefrom between band feeding 'drums'51 and 8| and adjacent the inner 'faces thereof.

Drums 61 and'8l have projections I83 and I84 on the inner faces thereof presented in the path of arms I8I and I82 of sleeve 53. Projections I83 and I84 arewedge shaped, and arms I8I and 82 of sleeve 53 are preferably moderately fiexiblejso that drums 51 and 8| arecapable of continuous rotation in the direction of travel of bands 15 and 81, by the flexingof arms I8I and|82 as the sloping faces of projections I88 and I84 engage them passing. In actualpractice, only drum 8| operates through a plurality of Conrevolutionsduring the scanning of a line, drum 51 never completing a rev01ution before restoration of the drums to line beginning position. Therefore, only projection I84 needsto be wedgeshaped and only arm 'I82 needs'to be flexible; however, it may be convenient to-provide similar arrangements for both drums, for uniformity, and also because there may be occasion,-such as in the making of adjustments, for rotating drum 51 through'sever'al revolutions while arm" I 8| relever I55 comprisestwin arms I51 and I58 in the'operating path of which bail I54 is disposed,

and a single arm I89. Arm I51 of'bell crank I58 depends along the side of function bar I44,

and the barjis provided with lug I1I for engaging'arm I51 and rocking bellcrank I55 clockwise as function bar. I44 is moved to its extreme lefthand position. Arm I59 of bell crank I55 is connected by link I12 to clutch throwout lever 5| associated with the positive drive clutch carried by shaft 3|. The downward movement of link I12, resulting from the rocking of bell crank lever I55, causes clutch throwout lever 5| to be withdrawn from restraining engagement with driven element 58 of the clutch, which is thus permitted to move into engagement with driving element 51 under the influence of compression spring 59. A connection for the driving of sleeve '58 is thus established. Bell crank lever I59, as

it is rocked in clockwise direction, imparts clockwise rocking movement to bail I54. Bail I54 is provided with an arm I15, which is connected by link I14 with clutch throwoutlever 91 associated with the positive drive clutch comprising elements 99 and 94 carried by shaft 92. The downward movement of link I14, as bail I84 is actuated,

results in the rocking of clutch' throwout lever into position todisengage driven element 94 from driving element 98 asthe shaft 92 reaches its rest position in which position aperture I21 in disc I25 is presented in registry. with the light path between lamp in and photo-electric cellit cycle.

ery of flange62.

mains stationary.

The rotation of sleeve 53, when clutch lever5I is tripped by function bar I44, causes arms|8| and I82 to revolve. The'motion is in the same direction as that imparted to'drums 51 and 8| during signal scanning operations, and. as the drums are thenstationary, due to arrestmentof shaft 92 by clutch lever 91, the scanning band restoring arms I8I and I82 revolve idly until they have traversed the distances previously traversed by drums 51 and 8| in scanning the char acters in the line just completed, which in the case of drum 8| is the actual distance traveled,

while in the case of drum 5 1 is an integrated:

distance accumulated in the successive rotations of the drum, whereupon arms I8I'and I82 come In the foregoing description of elements supinto engagement with projections I83 and I84 and rotate the drums through the remaining distance which sleeve 53 rotates in completing one Flange 52 of driven'clutch element 58 base. cam apex I85 (Fig. 4) on the periphery thereof. A lever I81 pivoted at I88 extendssubstantially horizontally below shaft 3| and has upstanding cam follower I89 in engagement with the periph- At.the distal end from the point ofpivotal mounting I 88, lever I81 is pivoted to a link I9| which is guided. in slotted bracket I95 and has near its lower end a laterany extending projection I 92 (Figs. 5 and 15) disposed above function bar I44. Near the end ofthe cycle of operation of driven clutch elelever |81 downwardly to effect downward movement of link I9I.- Link |9I in turn rocks functionbar I44 downwardly toeffect disengagement of notch I5I thereof from universal operating bail I5| Function bar I44, bell crank lever I88,.

" ment 58, cam projection I on flange 52 rocks 'ders I91 in the paths of are thus permitted to return to their and ball I64 normal position. The restoration of bell crank lever I66 to its normal. position results in the restoration of clutch throwout lever M in position to arrest clutch element 58 at end of a complete revolution thereof. The restorationof bail I64 to normal position results in withdrawal of clutch throwout lever 91 from restraining engagement with driven clutch element 94 carried by shaft 92 whereby clutch elements 93 and 94 are permitted to become reengaged and shaft 92 begins to rotate.

In order that drums 61 and BI shall not overtravel, after arms I82 and I83 have been brought to rest, they are provided with stop lugs I93, Fig. 4, extending from the outer or exposed faces for cooperation with two stop levers I94. I94'are pivoted at I96 and are notched at their upper ends to provide shoulders I91 for presentation in the path of stop lugs I93. Since it is essential that shoulders I91 of levers I94 be presented in the path of stop lugs I93 until the end of the cycle of operation of driven clutch element 68, and since it is likewise essential that shoulders I91 be withdrawn from the paths of stop lugs I93 before shaft 92, operating through gear IM and cam I04, can rotate drums 8I and 61 respectively any appreciable distance, it has been found convenient to connect drum stop levers I94 to clutch throwout lever 91 which controls the operation of shaft 92. Accordingly, an arm I98 is added to clutch throwout lever 91' and is connected at its outer end to the lower ends of drums stop levers I94 by link I99. From this it will be observed that when bail I64 is operated to present clutch throwout lever in position to disengage driven elements 94 from driving elements 93, levers I94 are rocked counterclockwise, as viewed in Fig. 4, to present shoulstop lugs I93. Since drum 8|, which is the only one that operates through more than one revolution between resettings, is driven from shaft 92, there is no possibility of interference by lever I94 with the normal operation of drum 8|, shaft 92 now being arrested. Th restoration of levers I94 to unblocking position is effected when clutch throwout lever 91 is withdrawn to permit shaft 92 to not be rocked when function bar I44 to effect disengagement from bail II. The circumstances under which the scanning band resetting function'may require function bars I44 or I will be described later. After the scanning of a line of signal combi-.

nations hasbeen completed, it is also necessary to advance the'message pagetopresent a new line of signal combinations to the scanning bands.

Levers presented This function corresponds to the line feed function in a printing telegraph'receiver and may be responsive to the line feed code combination transmitted for controlling the printing telegraph receiver. For controlling this function, there is provided a line feed function'bar 206 (Figs.'4 and 5) which is similar to function bar I44 and is provided on one face with a lug 201 (Fig. 4). A bell crank lever 208 similar to bell crank lever I66 'is rockably mounted on shaft I62 and has twin arms 209- and 2| I, the former of which is in the path of lug 201. Bell crank lever 208 has an arm 2I2 which is connected by 7 laterally extending arm 22I, which engages the .inneredge of pawl 2I1 and link 2I3 to an arm 2I4, Fig. 5, of a pawl 2 I 6 which,

with pawl 2I1 and ratchet 2I8, constitute an escapement mechanism. Pawls 2I6 and'2I1 are pivoted at 2I9, and pawl 2I6 is provided with a imparts clockwise rotation thereto whenpawl 2I6'is rotated clockwise. A tension spring 222 biases pawl 2I1 coun terclockwise,

and this pawl imparts a corresponding bias to pawl 2I6' through arm 22I. Scape wheel 2I8 is secured to shaft 42, which is constantly under torque and which is effective to advance message-feed bands 49. The spacing of the teeth of escapement wheel 2"! corresponds to the spacing of lines of code signal records on message page-53 so that when scape wheel 2I8 rotates a distance equaling the angle between corresponding edges of adjacent teeth, oneline of signal records is moved out of registry with the scanning bands and'the next line is presented resume operation. Thus, drums 61 and 8I are always arrested in the same position after a band resetting operation and since, as previously It was previously stated that bell crank lever I66 is provided with twin arms I61 andv I68 and the relationship of function operating bar I44 to arm I61 has been set forth. A function bar 20I bears the same relation to arm I68 that function bar I44 bears to I61, so that upon selection of either of function bars I44 or 20I and operation thereof by universal operating bail scanning band resetting operation will be performed. The disengagement from universal operating bail I5l is accomplished by the same means provided for disengaging bar I44; namely, link I9I. Link I9I is provided at its lower end with a slot 202 in which function bar 20I is disposed. Slot 202 is of suflicient depth that when function of function bar 20I' bar m is unselected it will in registry therewith.

When function bar 206 has been selected and moved to its extreme left-handpositionby universal operating bail I5I',' as'viewed in 'Fig. 5,

line feed'function bell "crank lever 208 is -rocked in clockwise direction, thus rocking bail I64 clockwise to effect arrestment of shaft 92,,and

moving link 2I3.upwardly.- The upward movement of link 2I3 causes pawls 2I6 and 2I1 to operate rocked clockwise to present it in the path of the teeth of scape wheel 2I8, and pawl 2I1 being withdrawn. Scape wheel 2I8 is permitted to rotate until pawl 2I6 arrests it, which occurs before the wheel has rotated an angular distance corresponding to the distance between two teeth. The disengagement of function bar 206 from universal operating bail I5I is effected by acam 223 secured to message page band idler shaft 48. Cam 223 is provided witha plurality of lobes 224 corresponding in number and spacing to the teeth of escapement wheel 2I8. A bellcrank lever 226 pivoted at 228 has at the free end of one of its 221-projecting into the path of 9 arms a portion lobes 224, and has at the freeend ofits other arm pivotal connection 229 with a link 23I 'de-- pending therefrom. Link 23I carries at its lower end a transversely extending pin 232, a portion of which extends under the end of function bar 206. Bell crank wise direction by tension spring 233. When pawls 2I6 and 2I1 are actuated to permit page feed ratchet feed wheel to rotate until checked is rocked dual selection by as a true escapement, pawl 2|6 being V 226 is biasedZin counterclockby pawl 2|6, rotation is imparted by bands 7 of pawls 2i6 and 2H to like positions.

49 to shaft 48 through sprockets 41, and cam 223 is rotated an angular distance equal to that of escapement wheel 2|8.. The rotation of cam 223 is sufficient to cause one of the lobes 224 to encounter end 2210f bell crank 226 and rock this lever 243 will also be rockedpclockwise andwill withdraw pawl 2l1 from restraining engagement i with escapement wheel 2|8. Pawl'2l6 is not at this time operated so that escapement wheel 219 bell crank lever clockwise, thus lifting link 23l. Pin 232being'th'us lifted imparts clockwise rocking movement to line feed function bar 206 so is not checked but is permitted to rotate until pawl 21! is again presented in blocking relation thereto.

Tape feed sprocket idler shaft 48 has secured thereto, adjacent to line feed control cam follower 221, a message-feed control cam 246 which v is provided with a single apex 247. 'A cam follower bell crank lever 248 similar to bell crank 226 is rockably mounted at 228 and is connected by a link 252 to the left-hand end of function bar is thus presented in the path of the tooth immediately following the one which has just previously been permitted to. escape, and pawl 216 is withdrawn from escapement wheel checking position so that the escapement wheel 2l8 is per- 7 mitted to rotate the additional distance necessary to bring the next tooth into engagement with J pawl 2 l 'l which holds the ratchet wheel from further rotation. As previously stated, bell crank lever 208 has twin arms 209 and 2| l the former of which is engaged and operated by function bar 206-. A function bar 234 similar to ,bar 206 may be provided for engagement with and operation of arm 2 of bell crank lever 208. Thus theline feed function may be performed in response to either of two signal combinations, and the circumstances under which such control may be desirable will be described later. Function bar 234 is provided with a slot 235' (Fig. through whish pin 232 carried by link 23! extends, so

that when function bar 2134 has been selected, engaged by operating. bali l5l, and operated, it may be released therefrom by link'23l.

' Another function, which has utility in the page transmitter herein described but which has no counterpart in many printing telegraph receivers, is message feed. By means of this function, after all of the lines of signal combinations carried by the page have been transmitted, the entire page may be delivered from the transmitter, a feeding d stance corresponding to a number of line feed operations in a single operation. For the selection of the message-feed function, there is pro vided a function bar 236 (Figs. 4 and 11) similar tofunction bar 206 and similarly provided with a lug 231 in the path of which is disposed arm 238 of a bell crank lever 239 pivoted upon rod I 62. A portion of bail I94 is presented in the path of arm 238 of hell crank lever 239, so that when motion is imparted to the bell crank by function bar 233, clutch element 94, carried by shaft 92, will be disengaged from clutch element-93 and shaft 92 will be arrested to stop scanning. Arm 2 of bell-crank lever 239 is connected by link 242 (Figs. 4 and 5) to one end of a lever 243 which 'is pivoted at 2I9 coaxially with the pivotal mounting of line feed escapement pawls 2H and H8. At the end opposite to that engaged by link 242, lever 243 is provided with a laterally extending arm 244 similar to arm 22i of escapement pawl 2H3 and similarly engaging the inner edge of escapement pawl 2| 1. It will thus be observed that when link 242 is moved upwardly due to clockwise rocking of bell crank lever 239,

236 (concealed by function bars 206 and 234 in Fig. 5) so that, when apex 241 of cam 246 rocks bell crank lever 248 clockwise and moves link 252 upwardly, function bar 236 will be disengaged from universal operating bail l5l, and bell crank lever 239 and bail i 64 will return to their normal position. Pawl 2ll is thenpermitted to respond to the influence of tension spring 222 toiengage and arrest scape wheel 2i8. 5

Referring to. Figs. 2 and 4, consideration will now be given to the circumstances under which the-performance of a function under-the control of either of two function bars may bedesirable. For this consideration it should be borne inmind that bell crank lever l06,:which controls carriage return for scanning bandresetting, may be actuated by either of function bars I44 and 2M, and bell crank lever 208, which controls line feed,

may be operated by either of function bars 205 and 234. In some printing telegraph receiver mechanisms, the line feed and'carriage return function mechanisms are made responsive. to "a single code combination so thatupon the reception of that combination both functions are initiated simultaneously.- In other printers, separate line feed and carriage return code combinations 'are assigned to control the two functions and both combinations must be received inorder to effect the performance of both functions. In receiver mechanisms ,of thelatter class, it is usually customary to transmit the carriage return signal before the line feed signal for the reason that a greaterinterval oftime is usually required.

to accomplish carriage return operation than that requiredfor line'feed andthe time for the completion of the carriage return operation is-aiforded during the performance of line feed The transmitter disclosed herein is particularly adapted to the control of those printingtelegraph receivers in which the line feed and carriage return operations are initiated in response to a single signal combination. It will be apparent that if separate line feed and carriage return signals appear at the end of a line of message material, the first of the two signals will be transmitted and the function corresponding to that signal will be performed in the transmitter. Thus,'if

the carriage return signalis the first of the two function signals andi scanned, the bands will be reset to begin the scanning of a new line and the line feed signal appearing at the end of the line will not be transmitted nor will a line feed 7 function be performed in the transmitter. Conversely, if the line feed signal proceeds the car 'riage return signal, the message page will be advanced in response to the scanning of the line I feed signal and the carriage return signal will than have been moved out of registry with the scanning bands. If a single code combination is I employed in selecting bothcarriage return and line feed operationsmode bars I 42 will be notched indented, without resetting the ejection of the page from of each line of selected when identically with respect to two function bars, such .as I44 and 206, so that upon the setting of the code bars in positions corresponding to the combinedfline feed and carriage return signal function bars I44 and 266 will be selected and simultaneously operated by universal'operating bail that after the portion of the heading in one linehas been scanned, the portion in the next line may be scanned from its beginning. by bringing feed without also resetting it into registry with the scanning belt by a line feed'operation without restoring the scanning band to the beginning of line position. Also where the last line of a paragraph is very short it may be possible to proceed to the scanning of the next line, which would in all probability be scanning bands. Provision for. this situation may be had by cutting selected in response to a signal assignedto line feed only, and bell crank 208 alone will be rocked to effect advancement of the message page without resetting of the scanning band.

Since the message-feed function results in the the transmitter, there is probably no circumstance under which it would be desirable to begin scanning the first line of the next message page at any other positionthan that designated herein as-the beginning of the line position. The simultaneous resetting of the scanning ,bands for the scanning of a new message page would therefore probably be desired invariably. This could be accomplished by cutting the code bar's identically with respect to message-feed function riage return function bar 2! so that both funcfunction bar mitted over the telegraph line and will initiate the carriage return operation in the receiving printer. Following the scanning of the carriage return signal, the line feed signal is scanned and code bars I42 are set in accordance with this signal. The notching of the-code bars I42 must be such that a carriage return function bar shall respond to the line feed signal, and accordingly, I44 is selected simultaneously with either of bars 206 and 234. The two functions are thus initiated simultaneously in the transmitter inresponse to theiine feed'signal and are performed while the line feed operation is being performed'in the receiving printer. The trans-,

,mitter function mechanism'was, howevenidle during the initiation 'of the carriage return'operation in the receiving printer. Since no function is performed by the transmitter in response to the carriage return signal, and scanning band resetting is performed in response to the line feed 7 signal, there can be no independent line feed function which will be effective in the transmitter to accomplish line feed only, unless there be provided in the code shall be bar 236 and dual car- 3 tion bars would be selectedin responseto the message-feed signal and would effect simultaneous rocking of bell crank lever I66 and I.

In the foregoing description of line feed and carriage return operation, a system of function bar selection was described in which, inresponse to a single code combination,

I44 and 206 are selected to initiate line feed and scanning band resetting simultaneously.

This enables functionbar 234 to be selectable for initiating a line feed operation alone but necessitates the use of which the line feed and carriage return operations are jointly responsive to a single signal combination. By cutting code bars I42 differently the transmitter herein described may be arranged to operate a receiving printer in which the carriage return and line feed operations are 7 performed independently each in'response to its own assigned signal combination. For this arrangement a message page may carry at the end the message a carriage return signal followed by a line feed signal. In order that the scanning mechanism may be permitted two function bars a receiving printer in which extends a cam to scan the line feed signal, it is necessary that it shall not respond to the scanning of the carriage return signal with the performance of a function. Accordingly, code bars I42 are so notched that none of the function bars shall be the code bars have been set in position representing the carriage return signal,

however, the carriage .retum signal will be transwhich is mounted to which might be designated as extraordinary to which the line feed mechanism only of the transmitter would be responsive.

In order that the transmitter maybe operated continuously without requiring the manual insertion of page after page of messages as the transmission of signals from each page is completed and the message page is ejected from the transmitter, a message storage magazine is provided.- The construction of the message magazine is shown in Figs. 8 and 9. Referring to Fig. 9, reference numeral 26I designates a' platform. slope downwardly toward message-feed bands 49 and whichter-minates just above message-feed idler sprockets 41. Platform 26I is provided with an integral frame-edge 262 which serves to maintain the message pages in posedin the space between theright-hand end of platform 26I and the right-hand end of frameedge 262. Just below 264, platform 26I is provided with aslot through curedto message-feed idler. shaft 48 and the periphery of the cam is engaged by cam follower arm 266. Cam 261 is provided with a depression" The purpose of bail 264' is to depress into engagement with message-feed bands 49 the foremost endof a message page supported. by platform 26L At equidistant points thro feed two line feed signals, one

263 just inside frame .262, and the transverse. portion of the bail is disoneof the side arms of bail follower arm 266 integral a with one side arm of the ball. A cam 261 is seghout theirlength, message-feed bands 49 are provided with pins 269 whichdifier from'pins 52 in that they 3 are claw-shaped. Aslmilar construction is dis- 7 that their free ends tend to draw away from band 69, whereby pins 269 are normally withdrawn from the outer surface of bands 49. When that portion of a band49 whichcarries a spring 21| passes over one of the sprockets 41, spring 211 is flexed into engagement with the underside of the band and pin269, carried by it, is projected through the aperture in the belt. The arrangement of pins 269 along band 49 is such that when the depression in cam'261 is presented to cam follower 266 so that ball 264 is permitted to'rock clockwise, a claw-shaped pin 269 on each of bands 49 is presented directly beneath the first of the marginal perforations in a message page which has its foremost .end presented adjacent to the right-hand end, Fig. 9, of frame 262- so that the foremost perforations are fitted over claw-shaped pins ass by sea 264 as it rocks clockwise. From this it will be apparent that the spacing between any two claw-shaped pins 269 is equal to the circumference of sprockets 41, and

further that the length of a band- 49 is (aqua-Ito an integral multiple of, that circumference. so that pins 269 are uniformly spacedupon band 49.

permit feed pins 214 to project successively'above secured thereto a ratchet wheel 216 which is engaged by a jockey detent 211 arranged to arrest ratchet wheel I216 predetermined angular positions. The angular disposition of ratchet wheel 216 with respect to sprocket wheel 213 is such'that in each position of arrestment of shaft 212, a pin 214 on each of sprocket wheels 213'pro- The timing of the mechanism is such that bail 264 is restored to its normal position before claw 269 has been carried forward to a point at which it would strike the transverse portion of the bail, and the right-hand end of frame 262 may be provided with clearances-in alignment with the pins carried by bands 49 through which clawshaped pins 269 may pass. Claw-shaped pins 269 carry the message page forward and as soon as they move free of any supporting surfaces,

such as sprockets 41, they are retracted by theirv springs 21l. By the time they are permitted to be retracted, other feedpins carried by bands message page so that engagement of the page by the claw-shaped pins is no longer required. In order that pins 269 shall not be projected through their apertures in bands 49 by message-feed sprockets 44, each of the latter may have a recess 210 in the periphery thereof which will accommodate spring 21! and pins 269 so that the clawshaped pins shallnot interfere with the ejection of a message page from the transmitter. Also, since the upper run of bands 461s very close to the scanning bands, it is desirable to maintain pins 269 projected through their apertures in bands 69 as these pins pass across the scannin bands, as pins in their retractedpositions would interfere with the operation of the scanning bands. Accordingly, pin supporting strips 265 of sufiicient length to accomplish the purpose outlined alcove may be supported between bands 49 and the scanning bands as shown in Fi 1 and ,5; 1

At a point remote from its lowermost edge, platform 26i carries rotatable shaft 212 which may be mounted'in journal brackets (not shown) depending from ,the'underside of platform 26!.

Shaft 212 has secured thereto a pair of sprocket jects through platform 26! approximately normal thereto. Shaft 212 pivotally supports a plate 216 which carries pivotally mounted ratchet 'feed pawl 219. Pawl 2191s biased into engagement with ratchet 216 by tension spring 26I.' A link 262' connects plate 216 tojone end of a lever 263 pivotally mounted'at 264 on a bracket 266 which depends from the underside of platform 26l adjacent to the lowermost end thereof The other end of lever 263 is disposed in the path of a pin 266 extending from the face of a disc 266 fixed to message-feedjdlershaft 46; When pin 269 engages lever 263 during the rotation of disc 266,

it imparts counterclockwise rocking movement to lever263, which in turn moves link 262leftwardly, asviewed in Fig. 9.' Link 282 in turn rocks plate 216 clockwise, which, through pawl 219 and ratchet wheel-216, rotates a sprocket whee1 213 clockwise one ratchet feed step. After pin 269 passes the end of lever 263, the latterand link 262 and plate 216' are restored to normal position by tension spring 291 which engages link 262. The distance'frorn the right-hand end of frame 262, as viewed in Fig. 9, to the point at which a pin 214 of sprocket wheel 213 projects through platform 26! is such that when a stand- 7 am length message page has its foremost end abutting the right-hand end of frame 262', its most remote feed perforations are disposedupon pins 214 of ratchet feed wheel 213. The timing the surface of platform 26!; Shaft 212 also has that at about the time bail 264 rocks clockwise to 49 have entered the marginal perforations in the engage a message page with claw-shaped pins 269 whereby the message begins to be moved forward by bands 46, ratchet 216 is operated to free. the page from engagement with sprocket feed wheels 213, and the peripheral speed of sprockets 213 should be compatible with the peripheral speed of sprockets 41, so that mutilation of the message-feed perforations shall not occur. stored in the message magazine in overlap arrangement, each page being set back from the 296 pivotally mounted onrod 263 and connected together by brace 296 serves to retain a pile-up of message pages in engagement. with sprocket wheels 213. Each time ratchet 216 is operated, all of the message pages are shifteddownwardly along the inclined platform 26I,'the lowermost I message, if in position to be engaged by pins 269,

feed wheels 213 spaced apart in accordance with the spacing between message-feed bands 49 so that their feed pins 214' may register with the marginal perforations in a message page deposited in the message magazine and confined between the sides of itayframe 262. Platform 261 is provided with apertures in alignment with sprocket feed wheels 2'13 and ossuflicient size to is advanced free of sprocket-213 se tha-t iirmarbe advanced by band 49 to the transmitting position,

and the message next above it is brought into position where itsfore'most end is in. position to be next picked up by bands 49.

The spindle which supports one of the pressure rolls 292 also supports a roll 294 which has a. rela.

tively deep annular groove 2'95 intermediate its ends. Below platform 26l a roll 296 thin enough to enter groove 295 of roll 294 is rotatably supported inalignment with said groove by one end A plurality of message pages may .be

of a lever 291 pivoted to bracket 266. A tension spring 299 biases lever 291 in clockwise direction, and platform 26| is provided with an aperture at the point of registry of roll 296 with roll 202 so that when there are no message pages stored on platform 261, lever 291 may rock clockwise and roll 296 may enter groove 295 in roll 204. However, when platform 26| is supporting one or more message pages, rolls 294 and 296 'areheldseparated by the message pages. At its other end, lever 291 engages one of a pair of contact springs 30l and holds the springs engaged when rolls 294 and 296 are maintained separated by a message page. When the supply of message pages is exhausted and lever- 291 rocks clockwise, contact springs 30| separate and open an electrical circuit tobe described later, which remains open tor 331, and conductor 326 to power terminal 3|0.

Electromagnet 334 has amechanical function for an understanding of which reference may be had to Figs. 2 and 5; Armature 330 of magnet 334'is connected by'link339, to the free end of an arm 3 pivotally mounted upon shaft I62 which supports bail I66 and the function bell crank levers. Arm 3 is positioned between until more message pages are placed in the maga- I zine.

A roll 302 similar to roll 294 and-provided with annular groove 303 is rotatably mounted in the free end of an arm 304 that is pivotally mounted on rod 263. A tension spring 306 biases arm 304 in clockwise direction, and arm 304 extends rightwardly well beyond the end of frame 262 so that roll 302 may engage and be supported by a message page adjacent to the scanning position. A thin'roll306 capableof entering groove 303 in roll 302 is rotatably supported by one end of a lever 301, which is pivotally supported by bracket 308. A tension spring 303 biases lever 301 counterclockwise so that roll 306 seeks entrance into groove 303 of roll 302. The'presence of a message page between rolls 302 and 306 prevents counterclockwise rocking movement of lever 301.-

At its other end, lever 301 engages one of a pair springs in engagement when lever 301 is retained in its extreme clockwise position. A pin 3|2 is carried by the underside of lever 301 directly.

above shaft 48, and the pin engages the periphery of a cam 3|3 fixed to shaft 46. Cam 3|3. is pro-' vided with a single depression in the periphery thereof, so that at apredetermined instant in a cycle of operation of shaft 46, cam 3|3 permits lever 301 to. rotate counterclockwise if there is at 'that time no message page interposed between rolls 302' and 306. Thus, it will be observed that lever 301 is not operable to permit opening of contact spring 3||the instant that a message page is withdrawn from between rolls 302 and 306 but that suchopening must await the presentation of the depression in the periphery of cam 2 3|3 to pin 3|2. The timing of the rocking of lever 301 with respect to the operation of other elements associated with shaft 46 or controlled thereby and the function of contact springs 3| in the electrical circuit will be described hereinafter. a

The electrical control systemfor the photoelectric transmitter is indicated diagrammatically in Fig. 12. Power cord 3|6, which may be plugged into any convenient source of power, is

connected to power terminals 3H and 3|8. A cirto its extreme counterclockwise position so'that baiii ISA 'is permitted'to return to its counterclockwise position and the clutch, comprising elements 93 and 96, is tripped oil. Fromthis it will be observed that the operation of the scanof contact springs 3H and maintains those evident from this that when relay 3|9 is deener gized so that its contact tongue 321 engages back ning'bands is supervisedbymessage page fol-' lower lever 301 and cam 3|3 so that the scanning bands cannot perform idle scanning operations when no message page is positioned to be scanned.

Switch 332 affords a manually operable control for stopping the transmitter for any desired purpose. 3

Referring again to Fig. 12, it will be observed that a conductive path may be traced from back contact 342 of relay 3|0 through conductor 343, contact springs 30l, normally closed'switch 344,

conductor 346, winding of electromagnet 341, re-- slstance 348, conductor 349,-conductor 331, and conductor 326" to power terminal 3|8. It will be contact 343 and contact springs 30| are closed,

electromagnet 341 will be energized. Stating the same-condition from the standpoint of the operation of the transmitter, electromagnet 341 will be energized when thereis one ormore message pages in the message magazine awaiting transrhission although therev isno message page} in the transmitter, the presence of-message pages 7 in the magazine being indicated by the closed" n r condition of contact springs 30|.'

Electromagnet 341 also performs a mechanical.

. function, an understanding of which may be had by reference to Figs. 2- and 5; The free end of armature 35| of electromagnet 341 is confined between the main ,body of previously identified link 252 and a hook-shaped finger .352 carried thereby. At its/lower end link 252 is articulated cuit for a switching relay 3| 9 is traced from power terminal 3|1 through conductor 321, conductor 322, contact springs 3| l, conductor 323, winding of switching relay 3|0, resistance 324, conductor 326.

to power terminal 3|8. Thus, when contact springs 3 are engaged, switching relay 3|9 is energized and its contact tongue 321,,which'is connected by conductor, 328. to conductor 132", is

f held in engagement with front contact 1329 from which a conductive path maybe traced through conductor 33l, normally closed switch 332, winding of electromagnet 334, resistance 336, conducto message-feed function bar 236, and upon energization of. electromagnetQ331, function bar 236 is shifted to effect-operation of link 242' and withdrawal of pawl 2|] from blockinge engagement with-scape wheel 2|8 in the same manner as if it had been operated by universaloperating bail |5| upon selection by code bars I42. Switch .344 is provided for preventing the operation of magnet 341 as for convenience in testingrand adjusting the magnet or related apparatus, or

when inserting or rearranging messages in the storage magazine, so that a messagefeedoperation shall not be initiated at-an improper time.

Since magnet=341 remains energized-only as long as switching magnet 3|9 is-deenergized,,and the latter magnetcan' remain deenergized'only as long-as therecess in cam73|3 is presented to the' cam follower of' lever 301, therotation of scape wheel 213, upon withdrawal of message'- feed pawl 2l1, results in rotation of cam 313 and immediate closure of contacts 3| I. Magnet 319 is thus again energizedand magnet 341 be- It is necessary to prolong zine, or the presentation of the first line of signal combinations on a page, received from the magazine, in the scanning position. This can be accomplished by providing a latch to hold messagefeed function bar 236 in operated position. Bar 236 will not at this time become latched on operating'bail I51, because it is not rocked counterclockwise to present its notch in the path of bail I51, there being no selection of function bar 236 'by code bars 142. Therefore, an additional latch must be provided. a

As shown in Fig. 11, the frame of electromagnet 341 has pivoted thereto a latch lever 353 having a shoulder 354 positioned to .drop behind a projection 356 of armature 35l when the armature is in attracted position. Latch lever 353 is biased in operative direction by a spring 351 and extends across link 252 above a pin 358 projecting laterally from one face of link 252. With this arrangement, armature 351, whenattracted, will become latched upon shoulder 354 of lever 353, thus holding function bar 236 in operated position. When thereafter cam projection 241 rocks bell crank 248 clockwise and effects upward movement of link 252, pin 358 rocks latch lever 353 counterclockwise, whereby shoulder 354 is lifted out of engagement with armature projection-356, and function bar 238 is permitted to return to its normal position.

When function bar 236 is operated and held by ball I 5I,' it may shift armature 351 through the rocking of link 252 to such an extent that the armature becomes latched on shoulder 354. This will not interfere with the normal operation and release of the function bar. The lifting of link 252' by cam projection 241 will result in the simultaneous tripping of latch lever 353 and the tripping of function bar 236 from en agement with bail l5l.

Concurrently with the release of armature 351,,

and if no message page has been presented between rolls 302 and 306,.switching magnet 319 .the dimensions of the page storage magazine. The distance fronr'the end of frame 262 to the through platform 26l shall be neither substantially'greater nor less than the distance from the top of a page to the axis of the last feed perfothe recess in cam 3l3 is'presented to its follower,

rested through operation of link 339, lever arm I 341, bail I64, link I14, and clutch throwout lever 91. The energizing circuit formagnet341 is broken at contact spring 301 so that messagefeed function bar 236 remains in its normal position and message-feed bands 49, scanning bands 16 and 81, and shaft 92 are arrested and remain in their nonnal or idle position.

At various points in the foregoing description,

reference has been made to relative dimensions of message-feed bands and sprockets, the dimensions of the message page storage magazine, and the arrangement of feed pins. These characteristics have direct bearing upon the length of page that can be handled conveniently, and upon the timing of the page handling mechanism.-

As previously stated, the spacing of the clawshaped pins 269 on a band 49 is preferably equal to the circumference of the message feeding sprockets of the transmitter. The reason for this is that once in each revolution-of the idler sprockets 41, mechanism actuated by cams carried by the idler sprocket shaft operates to deliver a message page from the magazine. Whenthis occurs, the claw-shaped pins must .be presented in position to accept and advance the message. It follows from this that each message page should not be longer than the distance'between claw-shaped pins 269,.for if they are, two successive claw-shaped pins on aband 49 will engage a single message page, which is of no advantage, and a message freshly delivered from the magazine maybe deposited over a portion of the preceding message page, which is not desirable. Preferably, each page will be substantially equal in length to the spacing between successive claw-shaped pins; There will then be neither overlap nor gap between successive message pages.

The size of page that is to be used determines point at which pins 214, of sprocket 213 'project ration therein. If the pages should be too short, the'sprockets 213 will not advance it into position to be engaged by claw-shaped pins 269. If it energized and its armature 35! will be attracted and latched. Another message-feed operation seeking to present a page to the scanning position will thus be initiated.

Once in each revolution of disc 288- (Figs. 8. and 9) attending the successive message-feed.

function operations initiated by magnet 341, the magazine message-feed mechanism comprising lever 283, link 282, pawl 219, and ratchet 216 will be operated. Magazine message-feed ratchet 213 will thus be operated periodically and any message pages engaged thereby will be advanced 'step by step until the lowermost is presented in position to be engaged by claw-shaped pin 269 upon the next operation of bail 264. The

message page will then be advanced by bands.

tact springs iifll' and 3 both become separated. The energizing'circuitfor magnet 334 is thus broken at front contact329 and shaft 92 is arshould betoo long, it will not be moved clear of sprockets. 213 when the .claw-shaped pins at- .tempt to deliver it to the scanning position ina single operation, 'andthefeed perforations may be torn out. "It will be evident that with the page storage magazine proportioned as outlined above, the right-hand end of frame 282 may serve as a guidefor the positioning of the first of a supply of message pages. With the leading edge f the page abutting the end of frame 262, the

last, feed perforations on the page will be sub stantially in registry with sprocket pins 214.

r In the event that special length message pages .either longer or shorter than those the storage magazine is arranged to handle'are to be used ccasionally, they may be placed in themagazine singly, resting above thepressure rolls 292, as for example upon cross brace 290, and extendi g under rod 263 with the leading edge in positon to be applied to the claw-shapedpins. Thus,

-t1e page will not be engaged by sprocket pins 214. A page of special length may be thus po'si-' tioned for transmissionahead of messages in the magazine without removing those"messa ges. It

is, however, desirable to disable the message-feed mechanism of the magazine in order that mes sages engaged by message-feed pawl in either of its two tion of the shaft. For

contained in the magazine with the lowermost not be advanced during the forwarding of the special size or rush message of any size by bands 49. This may be accomplished by the magazine disabling mechanism shown in Fig. 13. A pawl shifting cam 366 having operating handle'366 is loosely supportedon shaft 212 for rocking movement thereon adjacent to ratchet 216. Ratchet feed pawl 219 is provided with a pin 361 which engages the periphery of cam 366. At the point in its periphery normally presented to pin 361, cam 366 has a radius which permits the pawl to engage ratchet 216. In a clockwise direction from this point, the radius increases until it exceeds the maximum radius of ratchet 216, so that when cam 3661s rotated the magazine sprocket shall counterclockwise by means of handle 368, pawl '219 is cammedaway from ratchet 216 until it is held entirelyclear. The periphery of cam 366 is provided with two notches which a Jockey 369 is adapted to enter'when the cam is presented positions. The jockey is pivoted coaxially with pawl 219 on plate 216,

and when the plate is rocked by'link 282, jockey 369 imparts a corresponding rocking movement to cam 366, so that the cam remains in whatever relation to pawl 219 it has been manually presented.

The disablement of pawl 219 'bycam 366 permits shaft 212 to be rotated manually in either direction. Therefore, a knob 31l (Fig. 8) is secured to one end of shaft 212 for manual rotaexample, if messages are presented in position to .be transferred to the transmitter, and it is desired to transmit a rush message of the page size which the magazine accepts, cam 366 may be rocked counterclockwise to disable pawl 219,- shaft 212 may be rotated counterclockwise one step to retract the'messages in the magazine, and the rush message may be placed under pressure rolls 292, on top of the messagesin the magazine, and in position to be next transferred to the transmitter, whereupon pawl 219 is restored tooperative condition by reverse operation of cam 366. In operating to advance the rush message in the transfer operation, the magazine mechanism will advance the messages in the magazine to the position they occupied before being retracted. Should there be several rush message pages, the pages in the magazine may be retracted a number of ratchet steps equaling the number of rush pages, and the rush pages put in the magazine on top, in echelon arrangement, with the lowermost and foremost in position to be transferred. The pawl is then restored to operative condition and the regular messages will follow the rush messages into the transmitter automatically. When; a

message carried bya longpage is to be transmitted, it is desirable not to restore the feed pawl to operative condition after the ratchet has been back-stepped, because the feeding of the long page into the transmitter would not bejcompleted before the next message transfer operation occurs. The pawl should, therefore, remain retracted, and if switch 3 is opened, the trans- I26 are connected in parallel mitter will come to rest after the long page has been ejected therefrom.

As previously stated, the message-feed func: tion mechanism of thetransmitter, whether initiated by selection of function bar 236 or by operation of electromagnet 361, is arrested, by cam 246 at the time that a pair of claw-shaped pins 269 have been advanced nism is arrested under the Fig. 9 wherein lever 283 and follower arm ceding; it continues.

the first line of a message page lnscanning location. It follows from this that lever 301 controlling contact springs 3 should be released to test for the presence or absence of a page in the transmitter at the time that the feed mechation. This operating condition is indicated in the recess in cam 3l3 is shown presented to follower 312, which is. prevented from entering the recess to permit separation of contact springs 3 because rolls 362 and 366 are held apart by a mesage page. As indicated, the message page has not been drawn entirely out of the magazine, thedistance from the message pick-up position to the scanning position being less than a page length. Therefore, clawshaped pins 269 for receiving the next message page have not yet magazinemessage-feed pm 289 and'the recess in' cam. 261 are correspondingly remote from 266 respectively.

In Fig. 10 the message pick-up mechanism is shown with the claw-shaped pins 269 advanced to message receiving position. The message which had been extending into the magazine has been drawn entirely out, and its trailing edge is seen to be just clear of the leading edge of the lowermost page in the magazine; Camfollower 266 has entered the recess in cam 261 and ball 264 has depressed the leading portion of thelowermost page in the magazine into the path of pins 269. Pin 289 isabout to operate the magazine message-feed mechanism, and the recess in cam 3l3 is remote from follower pin 3|2.

Referring again to. Fig. 12, the signal transmitting circuit is shown inthe upper portion thereof. Lamps H6 and I23 for activating photo-electric cells H9 and I24, respectively, are connected to power terminal 3l1 by conductors 361 and32l, and to power terminal 3l8 by conductors 362 and 326. Photo-electriccells H9 and across the input of a power supply and signal amplifier indicated schematically at 363. One terminal of the output of amplifier 363 isconnected through the winding of selector magnet l3! of the transmitter to telegraph line 366 to point, selector magnet 365 of a printing telegraph receiver mechanism may be connected in the usual way. Thus, signaling impulses generated in thephoto-electric cells are amplified and impressed upon the telegraph line through selector imagazine receives and stores messages for delivery successively to the page supporting and advancing bands of the transmitter. The delivery of these message pages is under the control of the bands, so that synchronized operation. results. When the foremost messagepage in the magazine is transferred to the page handling bands, all of the pages in the magazine are advanced one step. After the transfer, the message advances step bystep toward the-scanning position as the transmission of the message pre- When the message-feed signal at end of the message page being sca'nned becomes effective, that page is delivered out of the scanning position, and the page following it to a position to present 7.5 is advanced into position for scanning of the first above outlined 'condi-' reached receiving position, and

which, at a remote the general operation of the line, and is there arrested. Immediately the scanning bands are set in operation and'the first line of signal combinations is scanned combination by combination in succession by continuous motion of the scanning band having sets of longitudinal slots and step-by-step movement of the band having transverse slots.

As each. signal combination is scanned, the im-- pingement of a beam of light upon the 'photoelectric cell is correspondingly controlled and signal impulses are thus generated, including phasing impulses. These impulses are impressed upon a telegraph line, and are also applied to a selector mechanism local to the transmitter. The selector mechanism controls the setting of selector bars, which are set for every code combination transmitted, but which effect only a few actual selections responsive to a few function signals. Line feed, carriage return, and message feed are characteristic functions. In response to a carriage return signal the scanning bands are moved by special means, in the same direction in which they travel for scanning, into position preparatory to scanning the first charac ter of a line and are there arrested momentarily, after which scanning of the line begins. When the line-feed function is selected, the page handling bands are advanced one step to present the next line of signal combinations in position to be scanned by the reset bands.

The final signal in any message page is preferably a message-feed signal, in response to which the message page is advanced outof scanning position by advancement of the message-feed bands, and the next message is brought into position for scanning of the "first line and is there arrested. There is also a magnet control of the message-feed mechanism whereby messages contained in the storage magazine remotely from the transfer position will be advanced step by step, when there is no message in the transmitter, until a message page is delivered to transmitting position. When there are no message pages stored in the magazine, and a message is being transmitted, the scanning, transmitting, and all message feeding mechanisms will come to rest upon the advancement of the page out of scanning position in response to a message-feed signal at the end of the message- From the foregoing description, it will be observed that the photo-electric transmitter in accordance with the invention will transmit signal combinations capable of controlling commer- Although a particular embodiment of the invention has been shown in the drawings and described in the accompanying specification, it will be understood that the invention is not limited to the particular arrangement of parts and details of construction herein disclosed, but that the invention is capable of modification, rearrangement, and substitution of parts and alteration in any other respect within the scope of the appended claims. 7

What is claimed'is: H .1. In a telegraph transmitter adapted to be controlled by record material carrying signaling indicia arranged in successive parallel lines as in ordinary reading matter, means for,photoelectrically scanning each signal combination in a line in succession and each line, in succession, means for generating signaling impulses according to the signal combinations scanned,nand

means for generatingsynchronizing impulses between sets of impulses corresponding to signal combinations.

2. Ina telegraph transmitter adapted to be controlled by record material carrying signaling indicia arranged in successive parallel lines,

photo-electric means for generating signaling impulses, means for illuminating all of the elementary areas of a signal combination simul-- taneously, and means for rendering the illumination of each elementary area'of a signal combination. selectively effective in succession upon said photo-electric means;

3. In a telegraph transmitter adapted to be said scanning means constituting the sole means for determining the sequence of scanning.

4. In a telegraphtransmitter adapted to be controlled by record material carryingcharaccially available printing telegraph receiver .mechanisms under the control of page width fornis having the signal combinations arranged there-, on in lines and will automatically insert neces- The transmitter sary synchronizing impulses. mechanism will interpret the signal combination it is impressing upon the telegraph line and will respond to those signals which represent functional operations by performing functions ter signaling indicia arrangedin successive lines,

means for scanning the signaling indicia for each character in a line successively, and means for generating signaling impulses including a photosensitive device having a different portion of the sensitive surface efl'ective in the generation of E impulses for each successive character signal in a line. v

5. In a telegraph transmitter adapted to be controlled by record material carrying signal I combinations arranged in successive lines, means sens1t1ve means for generating-impulses in acnecessarily incident to the scanning of successive lines of signal combination. The transmitter will automatically eject a message page after the transmission of the signal combinations con- 7 tained therein has'been completed and will automatically receive page after page of message material from a message page storage magazine as rapidly as the transmission of message material from a page is completed. regardless of the length of message material contained upon a page and without delay, so that substantially continuous transmission of signals may be accomplished without continuous supervision.

for illuminating said signal combinations, photocordance with said signal combinations, and a plurality of scanning elements, one of which determines the sequence ofscanning the elements of a signal combination, and another of which determines the succession of scanning of the signal combinations.

6. 'In a telegraph,transmitteradapted tobe *controlled by record material carrying signal combinations-arranged in successive lines, a light beam, scanning means for periodicallyinterrupting the light beamymeans for effecting relative motion between said scanning means and the elements of a'code combination and betweensaid scanning'means and successive codegcombina-

Images