US2234832A - Photoelectric transmitter - Google Patents

Description

March 11, 1941:. L, M. POTTS PHbTOELECTRIC TRANSMITTER Filed Jan. '10, 193B 2 Sheets-Sheet l FIG.

INVENTOR. LOU I S M. P0 T T S A ORNEY.

March 11, 1941. ,L. M. I=OTTS 2,234,532

PHOTOELECTRIC TRANSMITTER Filed Jan. 10, 1.938 2 Sheets-Sheet 2 I I46 I v I42 .5 FIG. 8 I43 6| '32 g 7 I44 I37 l I I I I I I I I I I I I I I I I I l l l l I I I l l INVENTOR. LOUIS M. POTTS F I G I 3 ATTORNEY.

Cil.

Patented Mar. 11, 1941 UNITED STATES 2.234.832 PHOTOELECTRIG TRANSMITTER Louis M. Potts, Evanston, Ill., assignor to Teletype Corporation, Chicago, 111., a corporation of Delaware Application January 10, 1938, Serial No. 184,138

37 Claims.

This invention relates to printing telegraph apparatus, and particularly to keyboard controlled signal transmitting mechanism. I

An object of the invention is to generate telegraph signals in a photoelectronic device through the cooperation of a distributor controlled from a keyboard.

Another object oi. the invention is to provide overlap between keyboard and distributor operations in a keyboard transmitter.

Briefly, the invention contemplates a keyboard mechanism including a set of code bars to be positioned characteristically according to the key lever depressed. Each of the code bars controls the corresponding positionment of an apertured slide bar. A beam of light from a source of i1- lumination is directed toward a photoelectronic device, and generally disposed in the path of the beam are the slide bars and two coaxial cylinders which house the photoelectronic device. The wall of the inner cylinder contains a slot parallel to the axis of the cylinder and somewhat longer than the span of the slide bars, this slot being in the light path.

The outer cylinder is rotatable under the control of a single revolution clutch, and is provided with a'plurality of peripheral apertures so positioned that they traverse the slot in the inner cylinder successively as the outer cylinder rotates. The apertures in the outer cylinder are aligned with the slide bars and particularly with the apertures therein. The slide'bars rest on a stationary slotted member, and their range of movement is to position their apertures in or out of registry with the slot in the stationary member. When an aperture is in registry, it permits a portion of the beam of light to impinge upon the surface of the rotatable cylinder. Thereafter, as the peripheral slot of the rotatable cylinder, which is aligned with the particular slide bar, traverses the slot in the stationary cylinder, the beam of light transmitted through the aperture in the slide bar is also transmitted through the slots in the two cylinders and impinges upon the photosensitive element. in the photocell, thus increasing the conductivity of the cell and generating a Signal impulse of a particular kind. When, however, the aperture in a slide bar is positioned out of registry with the slot in the stationary support, light is prevented from passing through the corresponding slot in the rotatable cylinder, and

the conductivity of the cell remains unchanged during traversal of the slot in the inner cylinder by the particular slot in the outer cylinder, thus generating a signal impulse of a different kind. The rotatable cylinder is released for one cycle of operation upon each depression of a key lever and is arrested automatically at the end of the cycle initiated by that key lever.

With regard to the arrangement of the light being set by the code bars, are locked during the cycle of rotation of the distributor, but an instant after the start of the cycle, the code bars which had also been locked are unlocked and may be reset by the operation of another key lever. At the completion of the cycle of the distributor, the new setting of the code bars is transferred to the slide bars by the yield mechanism. A clutch release condition having been stored upon the operation of the key lever to reset the code bars, the distributor is not arrested but proceeds into the cycle contemplated by the resetting of the code bars.

According to another embodiment of the invention, the linkage between the code bars and the slide bars includes no yield, so that when the slide bars are locked, the code bars are also locked, and they cannot be reset until the distributor closely approaches its rest position.

For a complete understanding of the invention and of the manner in which the same may be accomplished, reference may be had to the following detailed description to be interpreted in the light of the accompanying drawings wherein,

Fig. 1 is a perspective view of one embodiment of theinvention having portions broken away to show structural details;

Fig. 2 is a side elevational View of the apparatus shown in Fig. 1;

Fig. 3 is a plan view of the apparatus shown in Fig. 2;

Fig. 4 is a perspective of one detail of the transmitter shown in Figs. 1 to 3, inclusive;

Fig. 5 is a development of cylindrical scanning elements shown in Figs. 1 to 3, inclusive;

Fig. 6 is a plan view of another embodiment of the invention;

Fig. 7 is a vertical sectional view taken approximately on the line 1-1 of Fig. 6;

Fig. 8 is a diagrammatic showing of an electrical circuit;

Fig. 9 is an elevational view of the clutch tripping mechanism of the embodiment shown in Figs. 6 and 7;

Fig. 10 is an elevatlonal view partly broken away showing a modified keyboard mechanism at one stage of operation; and

Fig. 11 is a view similar to Fig. 10 showing the same mechanism at a later stage of operation.

Referring now to the drawings in which corresponding reference characters designate identical parts throughout the several views and particularly to Figs. 1 and 2, reference numeral H indicates a keyboard base casting to the front of which is secured a slotted comb l2. Keylevers l3 extend through the slots in comb l2 to the interior of keyboard base casting H and are there pivotally supported on a common pivot rod (not shown) and are spring urged to their uppermost positions with respect to the slots in comb l2 by individual springs (also not shown). Each of the key levers I3 is provided with a keytop [4 by means of which manual operation of the several key levers may be performed.

Inside the base casting II a plurality of code bars it are slidably supported, Code bars l6 extend transversely ofthe keyboard mechanism directly below the entire set of key levers l3. The code bars are provided at their upper edges with notches which may be defined by one vertical edge and one oblique edge or by two oblique edges, the notching of the several code bars being variable with respect to the several key levers in accordance with the code which, in the preferred embodiment of the invention, is a permutation code comprising various combinations of marking and spacing signals. Code bars I6 are slidable transversely of the keyboard base H from one to the other of two positions, and the sliding movement of the code bars is effected by the camming action exerted by a key lever.l3 upon the oblique edge of a notch during the operation of depressing the key lever. The notching of the code bars I6 is such that for each permutational setting of code bars l6 by a key lever, no other key lever may be fully depressed, the reason for this being that the simultaneous depression of two key levers involves the inconsistent condition of attempting to present at least one of the code bars in both of its possible positions.

Each of the code bars l6 supports on one face thereof a pair of spaced pins l1 between which is disposed the lower end of a lock lever it! which is pivotally mounted upon a pivot pin l9 intermediate the ends of lock lever l8. Keyboard base casting H is provided with a slot 2| through which the several lock levers l8 extend to be presented between the pins ll carried by the corresponding code bars 86.

A universal ball 22 is contained within keyboard base casting i I and extends transversely thereof below all of the key levers I 3 and in close proximity thereto. Universal bail 22 is pivotally supported at its opposite ends upon pivot pins 23 and is provided near one end with a bracket 24 which includes an arm 26 that pro- :Iects upwardly from within the keyboard base I 6 through a slot 21. The purpose of universal bail 22 is to trip a distributor clutch, and the manner in which this may be accomplished will be de scribed later. It may-be stated, however, at this point that upon the depression of any key lever I3, the universal ball 22 is rocked downwardly about its pivot pins 23, and the upper end of arm 26 which it supports is' thereby rocked outwardly.

Upon the upper surface of keyboard base It there is secured a bracket 3| the upper surface of which supports a plurality of flat slide bars 32. Each of the slide bars 32 is provided with a single aperture 33 which, when sliding ovement is imparted to slide bars 32. is movable into or out of registration with a narrow slot 34 in the upper part of bracket 3|. Each of the slide bars 32 is articulated to an individual lever 36 pivoted on pivot pin [9 adjacent to a corresponding one of the lock levers l8. The number of slide bars 32, levers 36, lock levers l8, and code bars I6 is equal to the number of code elements involved in each of the permutation code combinations, which is preferably five, but which may, under conditions requiring a more extensive code. be six or more. Each of the levers 36 has reed springs 31 secured to the opposite edges thereof, and the free ends of the reed springs are of sufficient width to engage the edges of the slide bar operating lever 36 and also the edges of the adjacent and associated lock lever I8, as is clearly disclosed in Fig. 4. Reed springs 31 are so ten-' sioned that they seek engagement with both edges of slide bar operating lever 33 and associated lock lever l8, and it will be apparent from this that if a lock lever is rocked upon pivot pin i9 while the associated slide bar operating lever 36 is held stationary, one of the reed springs 31 will be moved by the lock lever out of engagement with the slide bar operating lever 36 which, in turn, will prevent the other reed spring from following the motion of lock lever l8. A condition of unbalance is thus created as between the two springs 31, so that each spring seeks to shift the lever which it alone is engaging in such direction as to restore engagement of both springs to both levers. Thus, when the restraint upon the slide bar operating lever 36 is removed, it is immediately shifted by one of the springs 31 in the same direction in which look lever l8 was rocked.

Keyboard base I I has secured to the upper surface thereof a cylindrical housing 4| in which is slidably fitted a cylindrical support 42 for an electric lamp 43. Within cylinder 4| are supported a spherical lens 44 and cylindrical lens 45, the function of which is to focus an elongated beam of light from lamp 43 upon reflector 46, so positioned as to reflect the beam upwardly through elongated slot 34 in bracket 3|. The focusing of the beam upon the reflector may be accomplished by moving cylindrical lamp support 42 within cylinder 4i to vary the distance between lamp 43 and lens 44 and reflector 46, the latter being stationarily supported.

Keyboard base ll supports, just forward of bracket 3!, a bracket 48 which is provided near its upper end with a circular aperture ifito which is fitted, to be stationarily supported thereby, a cylinder 49 having both ends open. Cylinder 49 is provided, in the lower portion thereof, with an elongated slot) 5| parallel to its a'tis and in a vertical plane with respect to slot 34 in bracket 3|. Slot 5| is of sufflcient length to span all of the slide bars 32 and to extend a short distance beyond the slide bars at one end. Slots 34 and 5! may be of substantially the same length. On. its forward wall, bracket 48 supports an adapter 52 which, in turn, supports the'base 53 of a photoelectronic device 54 that extends into stationary cylinder 49 and has its light sensitive cathode 56 substantially coextensive with slots 34 and 5|. Upon the basis of the description thus far presented, it will be apparent that when any one of slide bars 32 is so positioned that its aperture 33 is presented in the vertical plane defined by slots 34 and'5l, light from lamp 43 will pass through condensing lens 44 and will be directed by reflector 46 through slot 34, slide bar aperture ill ill

llll

amines and slot bl to impinge upon light sensitive cathode lit. Likewise, those of the slide bars 32 which have been so positioned, under the control ofloclr lever l8 and code bars is that their apertures ll are out of registry with slots 3t and bl, will intercept light transmitted through slot dd.

Keyboard base it supports electric motor ti to the rotor shaft of which is secured pinion bl. llhis pinion meshes with a gear bl secured to signal distributor shaft 64 which is rotatably supported in bearings 66 carried by braclret t'l supported by keyboard base ll. Shaft tt has secured thereto the driving element tl (Figs. 2 and 3) of a positive drive single revolution clutch mechanism, the driven portion bl of which is supported by shaft 64 but is not secured thereto, is urged by compression spring ll into engagement with driving member W, and is normally restrained from such engagement by clutch throw-out lever l2 cooperating with clutch throw-out lug ll formed on the periphery of driven clutch member 69l Clutch throw-out lever lll is pivotally supported at it and is urged by the tension spring I5 (Fig. 2) into the path of clutch throw-out lug I3. When clutch throwout lever ll is rocked away fromthe throw-out lug ill, compression spring ll urges driven memher llll into engagement with member bl whereby rotation is imparted to driven member ll from shaft Toward the end of a revolution, clutch throw-out lever iii, if permitted to respond to the influence of its biasingspring, returns to its positionin the path of clutch throw-out lug ll, shifts driven clutch member 69 axially of shaft t l by a camrning actiomand thus adects disengagement of the clutch members and arrestment of driven member td.

lllrlven clutch member Ell, is slidably lreyed to a sleeve it which is also supported by shaft t l. lit its forward end, sleeve l6 engages and supports a cylinder ll which is closed at its rear most end, at which point it is supported by sleeve lll, and which is open at its foremost end, the words foremost and rearmost as used herein be ing related to the'front of the keyboard, the foremost and rearmost ends of cylinder ll being the left and right ends, respectively, as viewed in Fig. 2. Cylinder ll is slightly larger than cylinder and is fitted over the latter in coaxial relation with respect thereto and bears the same relation; namely, coaxial, with respect to sleeve lit by which it is supported. It will be apparent from this that when sleeve 76 is rotated upon the tripping of clutch throw-out lever ll, cylinder ll is also rotated.

As indicated in Fig. ,1, and in complete detail in Fig. 5, cylinder ll is provided with a plurality of circumferentially extending apertures that are oflset both axially andcircumferentially with respect to each other successively. There is an aperture lid to correspond to each of the slide bars lit, and the slots 18 and mounting of cylinder ll are such that as cylinder W is rotated, each of the slots lid traverses the position occupied by the aperture of the corresponding slide bar ll when the latter is presented in position to transmit light. In addition to the slots it, cylinder fl is provided with a. slot it beyond the rearm-ost of the slide bars 32 but within the range of slots lit and El, so that as cylinder ll is rotated, light may be transmitted invariably through slot is to cathode 56 of the photoelectric cell bl. It maybe added that cylinder W is so mounted upon the sleeve It that when the latter is in its rest position, due to the separation of the clutch elements tt and bl by clutch throw-out lever ll, slot "ll is in registry with slots ll and bl so that light impinges continuously upon cathode ht during the rest interval. The blanll portion of cylinder ll between the end of slot ld and the beginning of the first of the slots lt provides for the complete exclusion. of light from photoelectric cell ht during a portion of a cycle of rotation of cylinder ll.

Between the point at which cylinder fl is supported and the end against which compression spring 'llvabuts, sleeve ld is provided with cams ti and hi. it loclr bail til pivotally supported upon screws ll has integral therewith an arm lt supporting at its free end a cam follower roller ll which-may engage cam dl. At their upper ends, the loot: levers it are provided with laterally exte'n'ding protections ll (rightwardly as viewed in Fig. 3) each of which has an upstand ing loclring lug dd. The position of locking bail til with respect to lugs dd is such that when a code bar is shifted to its extreme right-hand position, thus rocking its associated locking lever it to its extreme counterclockwise position, the locking lug ll of that'loclr lever is presented just to the left (as viewed inldlg. 3) of loclr bail bl. When a code bar it is shifted to its extreme lefthand position which results in roclring of its associated loclr lever it to its extreme clockwise position, the loclring lug llll of that loclr lever is presented just to the right of loclr bail ll (also as viewed in Fig. ll). It will be apparent from this that when, after the setting of the code bars in particular permutational positions by the depression of the lrey lever ll loclr bail til is lowered to present its loclrlng blade in the path of movement of inciting lugs til, none of the loclt levers can be roclred whilethe loclr bail is thus lowered, and consequently none of the code bars it can be shifted and no other lrey lever can be depressed.

Loclr bail ill also has integral therewith an arm ll which, when follower roller d'l has been lifted to its'outermost position with respect to cam ti, is engagedand held by a latch dl' secured to a sleeve ill roclrably supported upon a stud t l. at

its opposite end, sleeve til has secured thereto a lever which has an arm llll engageable with a stop screw llt for limiting the counterclockwise motionof lever tt, sleeve ll, and latch ll and which also has or depending arm til the lower end of which is disposed in the path of a shoulder ill integral with a linlr ltl which is articulated at its forward end to arm lt carried by universal bail ll. Linlr ltl has a portion of its upper edge in an oblique plane adjacent to a screw ill-l carried by a stationary braclret supported by lreyboard base ll. Tension spring lll l supports linlr ltl so that its upper edge is in engagement with screw ldll. When linlr ltll is moved forwardly by operation of universal bail lb from a key lever it; its shoulder lll engages arm lll of lever db and imparts cloctzwise rotation thereto, l'his cloclrwise rotation is transmitted through sleeve til to latch arm, at which is also roclred cloclrwise and permits arm ll to loclr bail til to escape. as linlr ltll is moved forwardly by the universal bail, it is also roclred downwardly by the camming action of screw ltl upon the obliquely disposed portion of the upper edge so that the lower end of arm 99 of lever tt is permitted to escape from shoulder ldl, and lover db and latch llll are restored to their normal or extreme countercloclrwise positions by their biasing tension spring (not shown). The surface or link ltl' immediately to llll the rear of shoulder IOI slopes downwardly away from the shoulder, so that as the universal bail 22 returns to its normal position and link I02 is moved rearwardly, it is rocked downwardly about the point of articulation with arm 26 by the camming action of the lower end of arm 39 of lever 96 upon the sloping surface adjacent to shoulder mi, and shoulder IOI is thus restored to its position behind the lower end of arm 99 in which position it is prepared to rock lever 96 and latch 92 clockwise in response to the next operation of universal ball 22.

Looking bail 83 is also provided with a laterally extending projection I06 from which depends an arm E01 terminating directly above an arm I08 integral with clutch throw-out lever 12 and extending rightwardly therefrom (as viewed in Fig. 3). The relationship of depending arm 501 to clutch throw-out lever arm I08 is such that when arm 9| of lock bail 83 is engaged and held by latch 92, the lower end of arm I01 is held lifted sufficiently to permit the clutch throw-out lever to be presented against the periphery of driven clutch member 69 in position to engage clutch throw-out lug 13 and effect disengagement of the clutch. When lock bail lever arm 9| escapes from latch 92 due to operation of link I02 by universal bail 22, arm I01 depresses arm I08 of clutch throw-out lever 12 as lock bail 83 descends to locking relation to lock levers I8, and as clutch throw-out lever arm I08 is depressed, the clutch throw-out lever is rocked out of engagement with lug 13 and engagement of clutch elements 68 and 69 through the action of compression spring 1| is effected. The restoration of arm 9| to latched condition, which is accompanied by the lifting of ball 83 out of the path of movement of lugs 89 carried by lock levers I8, is effected by cam 8|, having a single apex (not shown). This apex,

when clutch driven member 69 and its associated cam 8| by latch 92, and that upon rocking of latch 92 by link I02, lock bail 83 immediately is rocked into locking position under the influence of its biasing tension spring I09, and at the same instant clutch throw-out lever 12 is tripped by arm I01.

' Another lock bail, designated by the reference numeral III, is also pivoted on pivot screws 84 and is so positioned with respect to upstanding lugs 2 carried by leftwardly extending projections H3 of slide bar operating levers 36 (as viewed in Fig. 3) that the lugs N2 of those slide bar levers 36 that are rocked into extreme counterclockwise positions are presented to the left of the locking blade of lock bail III, and the lugs II2 of those slide bar levers that are rocked to their extreme clockwise position are presented to the right of lock bail III. Lock bail III has integral therewith an arm II4 which is provided with a cam follower roller I I6 which continuously engages cam 82. In the rest condition of the apparatus, follower roller II 6 engages the descending slope of the single apex (not shown) of cam 82 slightly below the uppermost portion of that slope so that look bail III is held out of locking relation to the lugs I|2 of slide bar controlling levers 36, and as bail III is biased into engagement with cam 82 by a tension spring 1, it applies a torque to cam sleeve 16 and therefore to driven clutch member 69, which is slidably keyed to it, whereby the clutch elements are maintained fully separated, so that the chattering of the clutch teeth is prevented. As sleeve 16 begins to rotate in response to the tripping of clutch throw-out lever 12, cam follower roller IIG descends to the nadir portion of cam 82, and bail III is thus lowered into locking relation to the slide bar operating levers 36.

The function of bail III is to lock the slide bars 32 in whatever positions they may have been set, so that their setting shall not be disturbed during the scanning of slot 5| in stationary cylinder 39 by rotating cylinder 11. It is, therefore, desirable that bail I shall be lowered before that portion of slot 5| that is coextensive with the first of the slide bars 32 has been scanned by the first of the slots 18, and that it shall not be lifted until after that portion of slot 5|, which registers with the last of the slide bars 32, has .been scanned by the last of the slots 18.

At any time after the slide bar operating levers 36 have been locked, ball 83 may be lifted by its cam 8| to permit the lock levers I8 to be set in accordance with a new signal combination by operation of a key lever. The lifting of lock ball 83 by the operation of the apex of cam 8| upon cam follower roll 81 results in release of clutch throwout lever 12, so that it returns to the position in which it may effect disengagement of clutch elements 68 and 69, and also results in clockwise rocking of arm 9| into position to be retained by latch 92. In this condition, the lock levers I8 are no longer blocked, and code bars I6 are free to beset in accordance with a new signal combination. However, should a key lever be operated, and through operation of universal ball 22, link I02, lever 98, and sleeve 93, latch 92, be rocked clockwise and restored to normal position atthe instant that lever arm 9| is held in its extreme clockwise position by the apex of cam 8|, lever arm 9| might not escape from latch 92, and the cycle of operation of distributor cylinder 11, intended to be initiated corresponding to the combination established by depression of the key lever, would not be initiated and, therefore, a. sig nal combination would not be transmitted. To guard against the depression of a key lever at the exact instant that cam follower roll 81 is held at the most remote position radially of cam 8|, an additional lock is provided upon the key levers, this lock being effective through the universal bail 22.

Referring particularly to Figs. 2 and 3, it will be observed that a lever pivotally supported on pivot rod I2| has arm I22- extending under the driven sleeve to which driven clutch element 69 is keyed and carrying at its free end a cam follower roll I23, which engages a cam I24 fixed to driven clutch element 69. An arm I28 extends in the opposite direction passing across link I02 near the free or rearmost end thereof, and also passing between upstanding arms I21 of a bifurcated block I28, Fig. 3, secured to keyboard base II. At its free end, link I02 is provided with an upstanding shoulder I29 which must pass through the plane in which lever arm I26 is operable in response to operation of the universal bail 22 suflicient to effect tripping of clutch throw-out lever 12. Cam I24 normally holds lever arm I26 out of the path of shoulder I29. Once during a cycle of rotation of cam I24, cam follower roll I23 rides onto a nadir portion of cam I24 and rocks lever arm I28 into the path of shoulder I29 of link I02, this operation occurring just previous to the restoration of lever arm lIlI till

accuses ti by cam ti into position to be retained by latch 32. Lever arm I26 remains in the path oi shoulder I 29 until after cam follower roll til has descended from the apex of cam ti to the extent that unlatching of lever arm tI by oper ation of link I02 can be effected. Cam follower roll I23 then rides out of the nadir portion of cam IM and lifts lever arm I26 out of the path of shoulder I23. It will be evident from this that during the interval in which lever arm I23 is presented in its extreme clockwise position, link Itt cannot be operated sufiiciently to effect rocking of latch 32. After the apex of cam ti has cleared latch restoring cam follower roll 87, lever arm Itt is lifted and link I62 may then be operated through a full cycle by universal bail it. Bifurcated block ltd serves as a guide for the free end of lever arm Itt and prevents link I02 from operating through a full cycle at a time when such operation is undesirable.

The electrical circuit for the transmitter hereing described is shown schematically in Fig. 8. By reference to this figure, it will be observed that the previously identified lamp l3 and motor ti are connected across conductors ItI and I32 which are intended to be connected to any suitable source of power, as by means of cord plug Iild. Photoelectric cell 54 is connected to the input circuit of an amplifier I34, indicated only symbolically in Fig. 3. For a complete disclosure of an amplifier to which photoelectric cell 54 may be connected, reference may be had to U. S. Patent No. 2,177,077 granted on Oct. 24, 1939, to lb. lI/l. Potts. One of the output terminals of amplirler I34 may be connected to telegraph line I36 and the other may be connected to ground. At the remote terminal of line I36 there may be connected one of the terminals of the selector magnet of a printing telegraph apparatus indicated symbolically at I37, the other terminal of which may be connected to ground as indicated.

'lihe photoelectric telegraph transmitter herein described is adapted to transmit start-stop permutation code signals each signal combina tion representing a character consisting of a, definite number of impulses of marking or spacing nature preceded by a start impulse, usually of spacing nature, and followed by a stop or rest impulse, usually of marking nature. In operation, motor 6| is started, lamp 43 is illuminated, and amplifier I34 is placed in condition to be controlled by photoelectric cell 54. In the rest condition, as previously set forth, slot 19 in cylinder 'I'I registers with slot in cylinder 49 and with slot 34 in bracket 3|, and as there is no slide bar interposed between these slots, light fromlamp 43 impinges upon the cathode 5B of photoelectric cell 54 thus rendering the photoelectric cell conductive, and in response to this condition of the photoelectric cell, amplifier I34 applies to line I36 2. continuous marking signal. Mechanical conditions existing while the rest impulse is being applied to telegraph line I36 are that locking balls 63 and III are held in their uppermost or ineffective positions by latch 92 and cam 82 respectively. The apex of cam 8| is out of the position in which it may prevent the release of lever arm 9| by latch 92, and lever arm I26 is held out of the path of shoulder I29 carried by link I02.

Upon the depression of a key lever, code bars I6 are shifted to a permutational setting characteristic oi. that key lever. This permutational setting is imparted to lock levers I B and near the bottom of the key lever stroke, I111 bail 22 is operated sufiiciently to trip ed lever arm ti from latch 92 which permits lock bail t3 to be drawn downwardly by spring I03 to hold the lock levers I8 in the positions into which they have been moved, and simultaneously de pending arm Ill'll integral with lock ball 33 trips clutch throw-out lever 12 and rotation of cam sleeve It and rotatable cylinder 'II'I begins. as lock bail III was held out of locking position with respect to slide bar operating levers 3% at the time the key lever was depressed, those levers followed the motions of lock levers It by reason of the oppositely presented springs 3I and were therefore positioned correspondingly to the lush levers It. in the first few degrees of rotation of driven clutch element 69, lock bail III is low ered by cam t2 into locking relation to slide bar operating levers 36 to prevent disturbance of the permutational setting of slide bars M as determined by the setting of code bars It, Imu ing the lowering of lock bail I I I, the bla por-=- tion of cylinder Il between slot It and the first til of slots it traverses slot 5i of cylinder td, and

as no illumination reaches the photocell during this traversal, the current through cell ht is re---' duced and possibly entirely interrupted, and the condition on telegraph line I36 is changed from marking to spacing, which is the start condition, and results in starting of printer I3TII.

Depending upon the setting of slide bars tt, certain of them may be positioned to intercept light transmitted through slot 34 in bracket ti, these being the slide bars that are presented their extreme-left-hand positions, as viewed in Fig. 3, and others may be presented in their ertrerne right-hand positions with their apertures 33 in registry with slots 34 and BI to permit light to impinge uponcathode 56 as the corresponding slots 78 traverse apertures 33. The rotating cylinder I1 thus serves as a transmitting distributor to cause photoelectric cell 54 to be rendered conductive or non-conductive a1- ternatively in accordance with the setting oi the several slide bars 32. Photoelectric cell 54 controls amplifier I34 which, in turn, impresses upon telegraph line I 36 signaling impulses corresponding to the setting of slide bars 32. After the last of slots I8 has traversed slot 5|, slot I9, which represents the rest impulse, comes into registry with slot El, and if no key lever has been depressed during the cycle of operation of distributor cylinder I1, it comes to rest upon completion of one revolution.

In the foregoing paragraph no further reference was made to mechanical operations following mention of the lowering of slide bar lever locking bail I I I, the remainder of the paragraph being devoted to the description of the method of generating signal impulses. After lock ball I II has been lowered, lock bail 63 may be lifted, as resetting of the lock levers l8 cannot have any effect upon the setting of slide bars 32. The

' sooner the lifting of lock ball 83 is eflected the greater is the extent of overlap between the transmission of a signal combination and the setting up of the next signal combination, However, before bail 83 i lifted, cam I24 operates upon its follower roll I23 to lower lever .arrn I26 into the path of shoulder I29 on universal bail link I02 so that the universal bail cannot be operated fully during the critical interval when lever arm 9| is being presented under latch 92 and the apex of cam 6| is being moved dil out of range of cam follower roll 81. As soon as these conditions have been satisfied, cam I24 lifts lever arm, I26 and link I02 is in condition to be operated fully. If at this time another key lever is depressed, the lock levers I8 will be set in a new permutational arrangement in accordance with the signal combination represented by the key lever, but the slide bar levers 36 being at this time locked will not be correspondingly moved and certain of the reed springs 31 will be shifted out of engagement with their slide bar levers 36 thus establishing an unbalanced condition which will result in setting of the slide bar levers 36 in correspondence to the setting of lock-levers I8 when near the end of the cycle of rotation of cylinder 11, lock bail III shall be lifted. Simultaneously with the lowering of lock bail 83 to store the new setting of the lock levers I8, depending arm I81 withdraws clutch throwout lever 12 from the path of clutch throw-out lug 13 so that upon the completion of a revolution cylinder 11 will not be arrested but will continue to rotate to achieve the transmission of the signal combination which had been stored in look levers I8. Just before reaching the position in which cylinder 11 would have been arrested had the additional signal combination not been stored, lock bail III is lifted and the slide bars are permitted to be set in correspondence with the positions of lock levers I8, whereupon bail III is again lowered to lock the slide bars 32 in their new positions. Should another key lever be depressed after the restoration of lever arm 9| and the lifting of lever arm I26, another signal combination will be stored in the lock levers, and the distributing cylinder 11 will not be arrested at the end of the cycle but will continue to rotate to effect the transmission of the signal combination representing the key lever depressed. As long as an operator continues to depress key levers during the rotation of cylinder 11, the cylinder will not be arrested -but will rotate continuously. Cylinder 11 will, however, be arrested after the transmission of the signal combination corresponding to the last key lever depressed.

Another embodiment of the invention is shown in Figs. 6 and 7, this embodiment differing from that already described in the positions of the source of illumination and of the photo-electric cell and in the further fact that there is no provision for overlap as between the transmission I of a signal combination representing one character and the resetting of the code bars to represent another character.

As indicated in Figs. 6 and '7, motor shaft I4I carries pinion I42 meshing with gear I43 fixed to driving clutch portion I44 carried by distributor shaft I46. Driven clutch element I41 is slidably keyed to cam sleeve I48 also mounted on shaft I46 and is urged into engagement with clutch driving element I44 by compression spring I49 but is normally restrained from such engagement and held arrested by clutch throw-out lever I5I. A slotted distributor cylinder I52 identical with cylinder 11 is rotatably supported by cam sleeve I48, and inside cylinder I52 is mounted a stationary cylinder I53 identical with cylinder 49 and having a single slot I54 parallel to its axis. The arrangement of elements thus far described is substantially identical with those appearing in Figs. 1 to 5, inclusive.

As shown in Fig. 7, a long filament lamp I56 and cylindrical lens I55 are mounted inside the stationary cylinder I53, whereby a thin wide beam of light is focussed through slot I58.

Below rotatable cylinder I52 there is mounted a block I51 having a concave cylindrical surface conformed to the contour of rotatable cylinder I52 and presented in close proximity to the external surface of that cylinder. Block I51 has an elongated slot I58 in vertical alignment with slot I54 in stationary cylinder I53. Block I51 also has a concave cylindrical surface presented downwardly in conformity with a stationary cylinder I59 which is supported in engagement with the lower concave surface of block I51 and which has an elongated slot I66 coextensive with slots I58 and I54 and in vertical alignment with those slots. Cylinder I59 houses a photoelectric cell I6I having a cathode I62. It will be apparent that the positions of lamp I56 and photocell I6I could, if desired, be reversed.

Block I51 is provided with a horizontally extending slot of sufficient height and width to-receive, confine, and guide a plurality of apertured slide bars I63 substantially identical with the slide bars 32 shown in Figs. 1 and 3. Slide bars I63 are arranged to be presented in either of two positions to dispose their apertures correspondingly in or out of alignment with slot I58 in block I51. Each of the slide bars I63 is articulated directly to a lock lever I64 pivoted on pivot pin I66 supported by keyboard base casting I61. Lock levers I64 are controllable from permutation code bars (not shown) in the same manner as the previously described lock levers I8 are controlled. There is no yield between lock levers I 64 and slide bars I63 and, therefore, the setting of the lock levers I64 cannot be disturbed until the last of the several slide bars I63 has been scanned by the corresponding peripheral slot in rotatable cylinder I52.

A single lock bail is provided to prevent disturbance of the lock levers I 64 and slide bars I63 during the transmission of a signal combination, this bail being designated by the reference numeral I68 pivoted on screws I69, as shown in Figs, 6 and 7. Bail I68 has integral therewith an arm I12 at the free end of which is supported a cam follower roll I13 which continuously engages a cam I14 secured to cam sleeve I48. In the rest condition of the apparatus, cam I14 holds lock bail I68 out of blocking relation to upstanding lugs I16 carried at the upper ends of lock levers I64. The operation of lock bail I68 is identical with that of lock bail III in the previously described embodiment, the bail being lowered as soon as the distributor cylinder I52 begins to rotate; namely, during the transmission of the start impulse while the blank portion of cylinder I52 is passing across slots I54 and I58 and being lifted after the last of the slide bar conditions has been scanned by the last of the peripheral slots, and while the rest impulse slot is traversing slots I54 and I58.

A universal bail link I11 is provided for tripping clutch throw-out lever I5I which is biased to clutch arresting position by spring I15, this link differing from previously described link I02 in that no blocking shoulder corresponding to the shoulder I29 of link I62 is required. Link I11 operates a bell crank lever I18 which is similar to the previously described lever 99 except that it is not associated with a latch controlling sleeve but has instead an arm I19 disposed above and in close proximity to the free end of a rightwardly extending arm I8I of clutch throw-out lever I5I (as viewed In Fig. 6). Bell crank lever H8 is rocked in the same manner as lever 99 and in being so rocked its arm "9 depresses the free end of clutch throw-out lever arm I 6| thus tripping the clutch and initiating rotation of distributor cylinder I52.

The generation of signal impulses under the control of the setting of slidebars I63 acting as shutters to control the transmission of light to photoelectric cell I6I is identical with that dethe cylinder. It follows from this that after cylinder I52 has been set in operation by depression of a key lever, the earliest that the next key lever can be depressed is just before cylinder I52 completes its cycle of rotation and after the impulses controlled by the several slide bars I63 have been generated and transmitted.

No particular disadvantage arises out of the fact that the overlap contemplated by the first described embodiment of the invention is not present in the second as the photo-electric scanning and signal generating mechanism is capable of being operated as rapidly as standard commercially available telegraph printers can receive the signal combinations and execute the operations in accordance with such combinations. The principal difference between the two embodiments of the invention from the standpoint of overlap is that the embodiment disclosed in Figs. 6 and '7, when operated at or near its maximum speed, may require a rhythmic keyboard technique whereas the embodiment shown in Figs. 1 to 5, while not intended to transmit signal combinations any more rapidly, permits of more irregular keyboard technique, and might be preferred by operators who at times operate other kinds of keyboard devices, such as typewriters, andonly occasionally operate a printing telegraph transmitter keyboard, so that they do not acquire the rhythmic touch.

A further embodiment of the invention is shown in Figs. 10 and 11, this being a modification of the overlap mechanism included in the transmitter exemplified in Figs. 1 to 5, inclusive. This embodiment differs from that of Figs. 1 to in that in the overlap mechanism already described, the burden of flexing any number up to five of the springs 31 is directly upon the key levers I4, and due to the varying number of springs to be flexed, according to the sequence of characters, any key will require more effort to operate at one time than at another, and the touch will therefore be irregular, whereas, in the modification to be described, power available within the transmitter is employed for flexing the springs, and none of this labor burdens the keys, so that a uniform touch is afforded.

Referring to Figs. and 11, lock levers I9I, connected to code bars I92 in the same manner as lock levers I8 are connected to code bars I6 in Figs. 1 and 2, are pivoted on pivot rod I98. Also pivoted on rod I93 adjacent to individual lock levers I9I are slide bar controlling levers I94, each of which carries a pin I96 disposed in an elongated slot I91 of a light shutter slide bar l98. Slide bars I98 are provided with individual locl' .ig lugs I99. which are presented on either side of a lock bail 20I as slide bars I98 are moved from one to the other of their two possible positions. Lock bail 20I corresponds to lock bail III inFigs. 1, 2, and 3.

The upper ends of lock levers I 9I are relatively narrow, and the edges are substantially parallel to a center line through the levers. The upper ends of slide bar controlling levers I94 are relatively broad and the edges slope oppositely from a mid-point thus providing opposite camming surfaces. Reed springs 202, similar to reed springs 31, are presented on opposite sides of lock levers I9I and slide bar controlling levers I94, and at the points of engagement of a pair of springs 202 with a lock lever I9I and slide bar controlling lever I94, those levers are of the same width, so that the springs 202 tend to center levers I94 with respect to levers I9I.

A single bail 203, corresponding to bail 83,

serves to block lock levers I9I and to operate 2 levers I94. The movement of a lock lever I9I under control of a code bar I92 need be only suflicient to present its narrow upper end on either side of theblade of bail 293. As bail 203 is held elevated when such movement occurs, there is no restraint on slide bar levers I94, and they follow levers I9I to have their apices presented on either side of bail 203, no flexing of springs 202 occurring during movement of levers I9I and I94 by operation of a key lever. The length of slot I91 in each slide bar I98 is such that when a slide bar is held in'its extreme lefthand position, as in Fig. 10, movement of its associated lever I94 clockwise by a lock lever I9I will result in presentation of its pin I96 substantially in the right-hand end of the slot I91. Conversely, when a slide bar is held in its righthand position and its associated operating lever I94 is presented counterclockwise bya lock lever I9I, the pin I96 is brought substantially into engagement with the left-hand end of the slot.

When a slide bar operating lever I94 has been shifted by its associated lock lever I9I, as for example, in clockwise direction, its associated slide bar I98 being held locked by bail I, as shown in Fig. 10, it comes to rest with its pin I96 substantially prepared to impart rightward movement to slide bar I98 and with a portion of the left-hand sloping surface of its broad head in the path of bail 203. The bail may descend 5 only until it is arrested by lever I94 assuming that lug I99 of slide I98 continues to be blocked by bail 20I. No further clockwise movement is imparted to lock lever I9I by descending bail 203. The tension spring by which bail 203 is urged downwardly, which corresponds to spring I09 of Fig. 1, exerts greater force than the aggregate of force exerted by five or less of the springs 202, and as soon as bail 20I is lifted, bail 293 descends the remainder of the distance it is intended to move. The further descent of nail 203 produces a camming effect upon the sloping surface of the head of lever I94, which is thus moved further clockwise and which, through its pin I96, shifts slide bar I98 to its right-hand position. The further clockwise movement of lever I94 causes it to draw away from left-hand spring 202 and to draw right-hand spring 202 away from lever I9I, thus tensioning the springs, as shown in Fig. 11.

Looking of slide bar I98 in the new position; namely, its right-hand position, as viewed in Fig. 11, is accomplished. when bail 20I is lowered to its dotted line position into the'path of lug I99.

Thereafter bail 203 ma be lifted and when it 75 is lifted, springs 202 restore lever I94 to centered position with respect to lever I 9|, pin I96 thus being moved away from the right-hand end of slot I91. When the slide bar I98 is to be restored to its left-hand position, lever I 9| is rocked counterclockwise, whereby pin I96 is presented in the extreme left end of slot I91, and as bail 293 descends and bail MI is lifted, slide bar I99 is shifted leftwardly by bail 293 operating through lever I94 and pin I96.

From the foregoing, it will be apparent that after the slide bars I98 have been locked, lock levers I9I and slide bar operating levers I94 may be unlocked and reset according to a new signal combination. Slide bar operating levers I94 are not locked during the transmission of a signal combination, as in the embodiment first described but onlyslide bars I99 are so locked. Furthermore, whereas reed springs 91 in the first described embodiment operate to set the slide bars 32 according to the setting of lock levers l8, in the embodiment shown in Figs. 10 and 11, the tension spring (not shown) which lowers bail 203 shifts the slide bars I98, and springs 202 operate subsequently to restore the slide bar operating levers I94 to alignment with the lock levers I9l, such restoration being attended by idle movement of pins I96 within the slots I91 of the then stationary slide bars I98.

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

What is claimed is:

1. In a telegraph transmitter adapted to be controlled by a keyboard device, a key lever op- ,erated selector mechanism, a plurality of light shutters controlled by said selector mechanism. a photoelectronic impulse generator, and means for scanning said light shutters to control said impulse generator.

2. In a telegraph transmitter adapted to be controlled by a keyboard device, a key lever operated selector mechanism, a plurality of light shutters controlled by said selector mechanism, a photoelectronic impulse generator, and a rotatable scanning member having an aperture in alignment with each of said light shutters for controlling said impulse generator.

3. In a telegraph transmitter adapted to be controlled by a keyboard device, a key lever operated selector mechanism, a plurality of light shutters controlled by said selector mechanism, a photoelectronic impulse generator, and a rotatably mounted cylindrical scanning member having a circumferential aperture in alignment with each of said light shutters for controlling said impulse generator.

4. In a telegraph transmitter adapted to be controlled by a keyboard device, a key lever operated selector mechanism, a plurality of light controlled by a keyboard device, a key lever controlled selector mechanism, an impulse generating mechanism, means controlled by said selector mechanism for controlling said impulse generating mechanism, means for locking said selector mechanism upon the operation thereof, means for locking said selector controlled means, and means for unlocking said selector means after the locking of said selector controlled means and during the generation of impulses under the control of said locked selector controlled means.

6. In a transmitting device, a keyboard including a plurality of keys, a set of permutation bars controlled by said keys, 8. transmitting circuit, photoelectric signal generating means connected to said circuit, and means controlled according to the operation of said permutation bars fordetermining the signals to be generated by said photoelectric means.

7. In a transmitting device, a plurality of selectively operable keys, 9. set of permutation bars controlled by said keys, a photoelectric instrumentality, means controlled according to the operation of said permutation bars for controlling the action of the photoelectric instrumentality, and means for transmitting code signals according to the action of the photoelectric instrumentaiity.

8. In a telegraph transmitter, a plurality of selectively operable keys, a plurality of light shutters, a photoelectric device, means controlled by the keys for operating said shutters in varying permutations, and means for controlling said photoelectric device in accordance with the operation of said shutters to eflect the transmission of code signals.

9. In a photoelectric transmitter, a plurality of light shutters, key operated means for effecting the permutational setting of said shutters, and means including a photoelectric device for transmitting start-stop telegraph signals according to the control of said light shutters.

10. In a photoelectric transmitter including a plurality of keys, a master light shutter, a plurality of secondary light shutters, means for operating the master shutter invariably upon the operation of any key, means for operating the secondary shutters variably according to the key operated, and photo-sensitive means for generating code signals according to operation of the secondary shutters.

11. In a photoelectric signal transmitter, a light shutter device for determining the character of the signals, a light shutter device for timing the elements of the signals, selector mechanism for operating the first mentioned shutter device variably, and means for operating the last mentioned shutter device invariably.

12. In a photoelectric signal transmitter, a variably operable light shutter device, an invariably omrable light shutter device, means for variably controlling the flrst mentioned light shutter device, and means associated with the last mentioned means for initiating operation of the second mentioned shutter device.

13. ,In a telegraph transmitter, a keyboard mechanism including a plurality of keys, permutation bars controlled by said keys, primary signal controlling means controlled by said permutation bars, secondary signal controlling means controlled by said primary means, means for locking said primary and secondary means successively, and means for unlocking said primary means substantially immediately after the locking of said secondary means.

lid

ii. In a telegraph transmitter, a keyboard mechanism including a plurality of keys, permutation bars controlled by said keys, primary signal controlling means controlled by said permutation bars, secondary signal controlling means controlled by said primary means, independent 1y operable locking means for said primary and secondary signal controlling means, and yieldable means interconnecting said primary and secondary means for affording movement of either of said primary and secondary means while the other is locked for a particular signal to be transmitted.

15.1111 a telegraph transmitter, a keyboard mechanism including a plurality of keys, code bars controlled by saidkeys, primary signal controlling means controlled by said code bars, secondary signal controlling means controlled by said primary means, and yieldable means for biasing said secondary means to follow the movement of said primary means whereby signals in accordance therewith may be transmitted.

l6. In a telegraph transmitter, a keyboard mechanism including a plurality of keys, code bars controlled by said keys, a rotatable signal distributor, key controlled means for releasing said distributor for rotation to transmit signals in accordance with the setting of said code bars, means for locking said key controlled means upon operation thereof, cam operated means for restoring said locking means to unoperalted condition, and means for locking said key controlled means during the restoration of said first mentloned locking means.

17. In a telegraph transmitter, a keyboard mechanism including a plurality of keys, code bars controlled by said keys, a rotatable signal distributor, a keyoperaited universal bail, means controlled by said bail for releasing said distributor for rotation to transmit signals in accordance with the setting of said'code bars, means for locking said ball upon operation thereof, means associated with said distributor for rest-oring said locking means to unoperated condition, and means also associated with said distributor for imposing a locked condition upon said bail during the restoration of the first mentioned locking means.

18. In a telegraph transmitter, a keyboard mechanism including a plurality of keys, a universal bail operable 'bysaid keys, a plurality of code bars also operable by said keys, means operable by said bail for locking said code bars, a signal distributor, and means operable by said locking means for setting in operation said distributor whereby signals in accordance with the operation of said bars will be transmitted.

19. In a telegraph transmitter, a keyboard mechanism including a plurality of keys, code bars to be set permutatively by said keys, a plurality of levers articulated to said code bars, a.

plurality of levers capable of being held stationary while the first mentioned levers are set by the code bars, a plurality of impulse controlling elements articulated to the second mentioned levers, and flexible members associated with said first and second mentioned levers and adapted to be distorted upon set-ting of the second mentioned levers While the first mentioned levers are held stationary, and to effect movement of said second mentioned levers upon release of the hold thereon.

20. In a telegraph transmitter, a keyboard mechanism including a plurality of keys, code bars to be set permutatively by said keys, a plurality of levers articulated to said code bars, a plurality of levers individually associated with the first mentioned levers, flexible members for causing the second mentioned levers to follow movement of the first mentioned levers, a plurality of impulse controlling elements controlled by said second mentioned levers, and means operable by power independent of said keys and set in operation by said keys for moving said second mentioned levers through distances greater than those imparted by said first mentioned levers.

21. In a telegraph transmitter adapted to be controlled by a keyboard device, a photo-electric impulse generator, means for producing a light beam, means controlled variably by said keyboard device for dividing a portion of said beam of light into corresponding individual beams of light, and means operated invariably by said keyboard device for admitting to said photo-electric impulse generator a portion of the remainder of said first mentioned light beam and the individual light beams in predetermined succession.

22. In a telegraph transmitter adapted to be controlled by a keyboard device including a plurality of key levers, a permutation code devicecontrolled by said key levers, a photo-electric impulse generator, means for producing a beam of light, means controlled permutably by said permutation cod device for preparing variable light paths from said beam to said photo-electric impulse generator, and means operated invariably by said keyboard device for completing said light paths.

23. in a telegraph transmitter adapted to be controlledby a keyboarddevice, aperm'utationcode device responsive directly to said keyboard device, means ior producing a light health, a photoelectric impulse generator, means having light transmitting apertures for distributing light to said photo-electric impulse generator, and means permutably controlled by said permutation code device for transmitting to the surface of said distributlng means light from said beam in variably disposed areas.

24-. In a telegraph transmitter adapted .to be controlled by a keyboard device, impulse generating means, impulse distributing means, a timing element controlled by said keyboard device, a timing element controlled by said distributor, and means controlled by said timin elements for coordinating the operation of said keyboard device and said distributingmeans.

25. In a telegraph signaling apparatus, signal transmitting means, a set of elements, a set of selectors corresponding in number to said elemenits, means operated permutably by said selectors for setting said elements correspondingly, a source of light, a power driven rotary mechanism cooperating with said elements in the operation of said transmitting means by light from said source, and means for setting said selectors.

26. In a telegraph signaling apparatus, signal transmitting means, a set of elements, a set of selectors corresponding in number to said elements, means operated permutably by said selectors for setting said elements correspondingly, a source of light, a power driven rotary mechanism arranged for uniformly rendering said source of light effective on said transmitting means to controlthe length of each signal impulse transmitted thereby, and means for setting said selectors.

27. In a telegraph signalling apparatus, signal transmitting means, a set of elements, a set oi selectors corresponding in number to said elements, means operated perm-utably by said selectors for setting said elements correspondingly, a source of light, a power driven rotary mechanism having means for uniformly rendering said source of light efiective at the beginning of each signal, and means for successively rendering the source of light efieotive on said transmitting means as determined by the position of said elements.

28. In a telegraph signaling apparatus, signal transmitting means, a set of elements, a set of selectors corresponding in number to said elements, means operated permutably by said selectors for setting said elements correspondingly, a source of light, a power driven rotary mechanism cooperating with said elements in the operation of said transmitting means by light from said source, means to start said rotary driven mechanism at the beginning of each signal, means to stop the same at the end of each signal, and a keyboard for controlling said starting and stopping means and for setting said selectors.

29. In a telegraph signaling apparatus, signal transmitting means, a set of elements, a set of selectors corresponding in number to said elements, means operated permutably by said selectors for setting said elements correspondingly, a source of light; a rotary power driven mechanism cooperating with said elements in the operation of said transmitting means by light from said source, a start and stop clutch for rotating and timing the operation of said mechanism during each signal period, a keyboard for tripping said clutch and for setting said selectors, and a lock for said keyboard controlled by said mechanism and arranged to release said keyboard for reoperation at the end of each signal period.

30. In a signaling apparatus, signal transmitting means for controlling all transmitted impulses, a set of elements for controlling the operation of said transmitting means, a set of selectors, means operated permutalbly by said se- 5 lectors for setting said elements correspondingly, a source of light, a rotary driven mechanism having a series of successively operating sections cooperating withsaid elements in the operation of said transmitting means by light from said .0 source in accordance with the position of said selectors, a power driven start and stop clutch for continuously advancing and timing the operation of said rotary mechanism during each signal period, a keyboard, and means operated 55 thereby independently of said transmitting means for tripping said clutch and for operating said selectors.

31. In a signaling apparatus, signal transmitting means, a set of selectors, a source of light, a rotary member having a series of successively operative sections for eflecting th operation of said transmitting means by light from said source of light to transmit uniform starting impulses followed by a series of selecting impulses varied 5 in accordance with the setting of said selectors,

a power driven start and stop clutch for rotating said rotary member, and means independent of said transmitting means for tripping said clutch and setting said selectors.

32. In a telegraph transmitter, a keyboard mechanism including a. plurality of keys, code bars controlled by said keys, a rotatable distributor, key controlled means for releasing said distributor for rotation to transmit signals in accordance with the setting of said bars, means controlled by said code bars for controlling the character of the signals transmitted by said distributor, means for locking said key controlled means upon operation of said distributor, and means for thereafter locking said code bar controlled means and releasing said key controlled means whereby they may be reset.

33. In a photo-electric signal transmitter, a light shutter device permanently associated with said transmitter for determining the character of the signals, a light shutter device for timing the elements of the signals, means for operating the first mentioned light shutter device variably, and means for operating the last mentioned shutter device invariably.

34. In a telegraph transmitter, a keyboard mechanism including a plurality of keys, permutation bars controlled by said keys, primary signal con-trolling means controlled by said bars, latch controlled means for locking said signal controlling means, secondary signal controlling means controlled by said primary signal controlling means, cam controlled means for locking said secondary signal controlling means, and means for unlocking and relatching said latch controlled locking means following the locking of said secondary signal controlling means.

35. In a telegraph transmitter, a keyboard mechanism including a plurality of keys, permutation bars controlled by said keys, primary signal controlling means controlled by said bars, means for locking said primary signal controlling means, m-eans for latching said locking means in unlocking position, means controlled by said keys ,for releasing said latching means, secondary signal controlling means controlled by said primary signal controlling means, means for locking said secondary signal controlling means, rotatable cam means for operating said last mentioned locking means, and rotatable cam means for relatching said first mentioned looking means following the operation of the second mentioned locking means to lock said secondary signal controlling means.

36. In a telegraph transmitter adapted to be controlled by a keyboard device, a key lever controlled mechanism, an impulse generating mechanism, means controlled by said key lever controlled mechanism for controlling said impulse generating mechanism, means for locking said key lever controlled mechanism, means for locking said impulse generating mechanism controlling means, and cam controlled means for operating both of said locking means in a predetermined sequential manner whereby said key lever controlled means is released before said impulse generating mechanism controlling means.

37. In a telegraph transmitter adapted to be controlled by a keyboard device, a key lever controlled mechanism, an impulse generating mechanism, means controlled by said key lever controlled mechanism for controlling said impulse generating mechanism, primary means for locking said key lever controlled mechanism, means for locking said impulse generating mechanism controlling means, means for releasing said primary locking means, secondary locking means for said key lever controlled mechanism, and means for operating said secondary locking means prior to the release of said primary means and for releasing said secondary means after the release of said primary means.

LOUIS M. POTTS.

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