US2382251A - Telegraph perforator-transmitter - Google Patents

Description

Augfl l an. PARKER "HA1.

TELEGRAPH PERFORATOR-TRANSMITTER -2 sheetssheet '1 MR w Kw R v u 0 mm W a W I l' Q vwmrons BY 02 i- 1945- -R., D. PARKER ETAL 2,332,251

TELEGRAPH PERFQRATOR-TRANSMITTER Filed Aug. 25, 1943 2 Sheets-Sheet 2 m m m m mR U o w a @n M 0 M w A 0 M K T F O l T O 1 6 W A m HU mm m 2 I J j m x a it U. R 0 m 4 h m n I w w w w n y o L @Q- m 6 [UH IHI O V L E MB H W 5 H M w a r u q l N F 0 25 Q 2 ll: 1 5.: mg m Patented Aug. 14, 1945 UNITED STATES PATENT OFFICE TELEGRAPH PERiFORATOR-TRANSMITTER Italzemond D. Parker, Brooklyn, and -Allan Weaver, Port Washington, N. Y., assignors to Bell Telephone Laboratories,

Incorporated,

New York, N. Y., a corporation of New York Application August 25, 1943, Serial N... 499,936

the over-all width of the tape is inch approxi- Claims.

This invention relates to printing telegraph apparatus and more particularly to telegraph transmitters for the transmission of character identifying signals.

Transmission of character identifying signals in telegraph systems is frequently achieved in accordance with a paper tape including control indicia formed in varying combinations. Specifically the control indicia may be in the form of transverse rows of perforations formed in the tape either by a keyboard perforator or by a signal controlled perforator which is commonly referred to as a reperforator. 'The tape thus' prepared passes through a transmitter or sensing mechanism to control the transmission, in succession, of signals respectively identified with the transverse rows" of perforations.

The prime object of the invention is to control photoelectrically the transmission of permutation code signals, each of which may be identified as a single transverse row of perforations in the tape. I

Another object is to successively translate the transverse rows of perforations in the tape into corresponding combinations of beams of light and to transmit these beams of light through light conducting rods, these beams of light after passing through the rods activating-photoelectric cells for producing the signal impulses in combination respectively corresponding to the transverse rows of perforations.

Another object is to successively sense, or scan, by means of a light source, signals corresponding to each transverse row of perforations in the tape and to photoelectrically transmit the current impulses of each signal so sensed, to a storing circuit for transmission over a, start-stop distributor to an outgoing line.

Another object is to reduce the number of mechanically operated parts heretofore ,required in the perforated tape transmitter wherein operable metallic pins were employed for sensing.

ployed to transmit charactersusesfive selecting impulses in various combinations of fcurrentf and no current intervals (or other current o'r W K p voltage differentiated intervals) and each coma th us -=-th w d s n may be p fe a ly bination appears on the ordinary telegraph tape as a row or group of perforations, each perforation representing in a common case a "current" impulse of a combination, andv each space provided for a possible perforation but not perforated, representing a no current impulse. In a transverse row the possibleperforations appear on a basis of about 0.1 inch center to center and The. permutation-signal code generally em tape which is operated in the usual manner for I transmission over an outgoing line.- The signals appear in transverse rows in the tape, each row comprising a distinctive arrangement of perforations to correspond to the current impulses of the signal, in permutation code, which it represents. Immediately below the transverse row, that is being sensed, are five narrow rods of light conducting material to correspond to the five selecting impulses of a signal combination andthese rods maybe molded to conduct light in any desired direction or directions. The light passes through each of the perforations in the transverse row being sensed and then through the corresponding rods of light'conducting material substantially without spreading laterally, even though the rod may be bent to a considerable extent, to a' photoelectric cell-which becomes activated to operate a relayin a 'signal storing circuit. A start-stop rotary distributor transmits to the line each signal in turn as it is prepared by the operated and unoperated relays of the signal storing circuit.

A feature of the invention is the use of photoelectric cells for transmitting telegraph signals perforated in a narrow telegraph tape.

Another feature is the elimination of metallic pins for sensing and the numerous operable mechanical parts required with metallic pin sensing. Another feature is that the perforated telegraph tape is not subjected to tearing as in tape,

transmitters wherein metallc pins are employed for sensing.

In a mechanism using sensing pins or sensing levers the controlled contacts are physically related to the sensing elements; in the arrangement of,. t he present invention there is great latitude ably with it herein in referring to the same function.

A better understanding of theinvention may be had from'the following description takentin conjunction with the accompanying drawings wherein like reference characters designate simi-;

lar parts throughout the several views, and which:

Fig. 1 snows a typewriter sending and receiving station in diagrammatic form wherein one station is shown schematically and includes provisions for transmissiorfby (1) sensing a perforated telegraph tape with light from a common mitter'wherein the rods of light conducting material are mounted in 'a'oarricrcapable of oscillation' about a fixed pivot away from and toward the exit tape channel of a tape perforator. Each oi. the rods of light conducting material is shown in two sections interconnected by a tube coated internally with reflecting material and arranged to extend in directionsat; right angles to each other, the-five selecting rods of a groupforming a square having a cross-section with one rod in each corner and one in the center. The position of the carrier displaced from the perforator is shown in dot and dash lines;

Fig. 4 is an elevation viewltaken along line 44 of Fig. 3; r

Fig. is a side elevation view of another alternative of the sensing device wherein the rods f source and (2) impinging the light from such of light conducting material are bent to form a different arrangement from that shown in Figs. 3 and 4. Similar to that shown in Fig. 3, the position of the carrier displaced from the perforator is shown in dot and dash lines;

Fig. 6'is an elevation view taken along lines 6-5 of Fig. 5;Figs. 4, 5 and 6 being somewhat schematic.

The system shown in Fig. 1 may be considered as including three principal units, namely, a tape perforator il, a tape sensing unit l2, and a transmitting unit l3, these units are at one station which is connected by the conductors of outgoing line H to central oilice II where the transmission signaling current of source I6 is furnished for a connection extended to a remote subscriber station ll.

Referring to Fig. l perforator II which may beof the type disclosed in United States Patent 2,262,012 granted to R. A. Lake on November 11, 1941, prepares the controlling perforated paper tape which is advanced in steps by a tape feed mechanism (not shown) in the perforator. Tape l3 passes taut-tape operated bar I3, to the tape feed wheel 20 of the automatic tape transmitter. Tape feed wheel 20 is operated in steps by stepping magnet 2|, each operation of the stepping magnet being effective to attract armature 22 which in its movement causes pawl 23 to rotate ratchet wheel 24 one step.

Transmitting tape 8 in being advanced stepby-step passes through tape channel 25 in a hinged blockhead 25, the upper member of which has a cut-out portion indicated by dotted lines 21 for permitting radiant energy or light from an exciter element, say lamp 28, to sense the current impulses of a signal in each transverse row of perforations in tape I3. Each transverse row in tape it may be said to be an area of different light controlling abilities, or a combination of transparent and/or opaque portions, the transparent portion represents "current impulses and the opaque, no current impulses. Immediately below the tape and in direct alignment with lamp 23 are five rods of light conducting material. These rods designated 29, 30, 3|, 32 and 33 are positioned below the tape to corre spond to the five selecting pulses of a signal combination and are of a suificiently narrow width to be positioned on the basis of 0.1 inch center to center. Rods '29 to 33 are premolded to fan out sufficiently to conduct light to five photoelectric cells 34, 35, 35, 31 and 33 respectively. Except for the light conducting rods, the transmitter or scanning unit l2 may be of the type disclosed in United States Patent 2,262,012, supra.

When lamp 28 in its lighted condition illuminates or senses a perforation in tape l8, the corresponding rod conducts light to its assoelated photoelectric cell which is thereby activated to set up a current which is amplified by a corresponding amplifier of those designated 39, 40, 4|, 42 and 43, sufficiently to operate the corresponding relay of storing relays 44, 45, 46, 41 and 43.

A distributor l3 comprises an inner solid commutator ring 49 and an outer commutator ring 53, both of which are suitably attached to the upper surface of an insulating disc 8|. The outer commutator ring is divided into seven insulated segments which includes the five segments corresponding to the five selecting units of the "Baudot code, a. "stop segment and a start" segment. A distributor brush 82 wiping on the stop segment closes a line circuit |4 connecting therewith a remote subscriber station I! preferably through a. central oflice IS. The remote subscribers station is provided with the usual sending contacts 52 and receiving printer magnet 53. It will be understood that while central oflice l5 may be used for connecting the local distributor and the remote subscriber station, the system shown is not necessarily limited thereto and may be readily applied to include a private wire or direct wire system, wherein a-central office is not employed.

The tape transmitter assembly I2 is arranged to operate with light sensitive devices, such as photoelectric cells 34 to 38, which correspond to the five segments of the outer commutator ring 50. Assume that the signal combination about to be transmitted is shown on the tape I8 immediately above rods 29, 30, 3|, 32 and 33, and that the signal is made up of a blank space for impulse No. 1 and perforations for impulses Nos. 2 to 5 inclusive, as shown in the drawings. Light from source 23 is therefore conducted through rods 30, 3|, 32 and 33 to activate photoelectric cells 35, 36, 31 and 38. The currents generated by photoelectric cells 35 to 33' are individually amplified by amplifier tubes 40, 4|, 42 and 43 to operate relays 45, 45, 41 and 43 respectively.

During the next rotation of brush 52 over the segments of distributor ring 50, the five selecting impulses transmitted over line l4 will be "no current for the first impulse and current for each of the next four impulses of the signal transmitted.

In connection with the perforated tape, each transverse row representing a signal combination contains five potential perforations. A row of perforations when sensed will permit light from lamp 28 to pass through the tape, but the absence of perforations in the tape will obviously prevent light from passing through. The light passing through perforations in a transverse row is conducted through rods immediately below such perforations and thereby impinged on photoelectric cells. The cells that receive light are momentarily activated to cause a "mark" or "current impulse to be transmitted over the line and the cells that received no light, becauseof no perforation, over the corresponding rods remain inactive and thereby cause to be transmitted to the line a space or no current" impulse condition.

In connection with the start-stop rotary dis tributor, brush 82 comprising metallic portions.

for wiping over the commutator rings 49 and 50, is mounted on one end of a main drive shaft 58 having a gear wheel 60 fixed thereon in mesh with a worm 6| carried on a shaft 62 which is connected through a friction clutch 63 to a mo-, tor 54 employed to drive the main shaft 58. On

riding on the low portion of cam 55, begins now to engage the raised cam portion'66 with the resuit that the contacts 59 become closed and thereby complete a circuit traceable from grounded positive battery 69, through the winding of stepping magnet 2 I, closed contacts 59, conductors 10 and ll, to ground at switch 55 in its operated position. Stepping magnet 2| operates and causes pawl 23 to rotate ratchet wheel 24 an an-v gular distance to an amount equivalent to the distance between contiguous teeth of the ratchet. Accordingly, the tape is advanced to set up the code unit combination for the next; character to be transmitted.

In the normal operation of the transmitterdistributor, it occurs frequently that there is a diiference between the rate at which the character units are transmitted and that at which the tape is fed from the perforator Since the tape is fed directly from the perforator to the transmitter, it will be evident that if for any reason the perforator operation is interrupted the transmitter will use up all of the slack in the tape and thereafter proceed to damage the feed holes used with the feed wheel 20 for advancing the tape, unless a provision is made to stop the transmitterdistributor I3 automatically. For the purpose, therefore, of taking care of the difference between the rates of operation of the transmitter-distributor and the perforator there is'fixedly mounted on the main drive shaft intermediate the gear wheel 60 and the tape feed operating cam 65 a stop cam I2 formed with a peripheral shoulder I3. Associated with the stop cam is a stop arm 14 pivoted at I5 and normally having one end held in engagement with the periphery of the stop cam by coil spring 16. The opposite end of stop arm 14 is operatively associated'with magnet 5| which is employed to rotate the stop arm about its pivot to thereby move the former out of engagement with the stop cam periphery. Grounded negative battery 11 is connected through the winding of magnet 5| to electric contact 54 which is opened and closed under control of an automatic stop lever I8 projecting between the transmitter and perforator. $top' lever 18 is so arranged that the tape passes thereunder. It is supported in vertical slots provided in upright members 19, 19. The contacts 54 are also connected through a manually operated switch 55 in its operated position to ground.

After the motor has been started by closing the switch 56 the manually operated switch 55 I is closed to complete an obvious lighting circuit for lamp 28 and an energization circuit for magnet 5| which was hereinbefore traced. Lamp 28 lights for the purpose of effecting the sensing of each signal combination perforated. in the tape. Magnet 5| operates to disengage stop arm 14 from stop cam 13 to thereby permit the rotation of the main drive shaft 58. So long as the perforator continues to operate, the tape being fed therefrom will have sufficient slack to -allow the stop lever 18 to rest on the upper member of contacts 54 thereby retaining contacts 54 in the closed condition. In the event that the perforator operation is interrupted the tape will be pulled taut to raise the stop lever 18 outof engagement with the upper member of contacts 54 thereby enabling the upper memberof contact 54 under the influence of coil spring 30 to disengage from the lower member, to interrupt the circuit extending through magnet 5|. The upper and lower members of contact 54 are, preferentially, made of spring material so that coil spring 80 is is not necessary in commercial installations. Stop arm 14 actuated by coil spring 15 when magnet 5| becomes deenergized moves into contact with the stop cam periphery and eventually engages shoulder 13 to stop the distributor brush by holding the main drive shaft from rotation. In this event it will be evident that the transmitter is also stopped since it is also driven from the main shaft. It will be understood that the distributor brush will only be stopped on the stop segment of the commutator ring 50 due to the fact that theshoulder 13 of stop cam 12 is predeterminedly positioned with respect to the distributor brush to effect this result. I

. Figs. 3, 4, 5 and 6 show two alternative scanning devices or mechanisms, namely, Figs. 3 and 4,

as illll and Figs. 5 and 6 as |5ll wherein the rods of light conducting material are mounted in a carrier capable of oscillation about a fixed pivot away from and toward the exit tape channel of the keyboard perforator. Normally, the tape entrance channel of the scanning, or sensing, unit is immediately adjacent the exitchannel of the perforator, say perforator |0|. in Fig. 3 and perforator |5| in Fig. 5, and the tape passes directly from the perforator to the sensing unit without exposing .any portion of the tape. When the perforator is operated the tape feed mechanism thereof advances the tape and moves the sensing unit about its pivot a. distance equal. to the distance between the transverse rows of perforations,

to start a transmitting distributonwhich includes means to move the sensing unit toward the perforator to sense the new row of perforations] determined speed whereas the perforator may be operated at a speed dependent upon its inherent limitations and the speed oi. the operator. If the perforator is operated at a higher speed than the speed of rotation of the transmitting distributor shaft 88 (Fig. 1), the tape will be fed at a rate higher than the rate at which it is advancing mechanism thereof. When the loop of the tape has been exhausted and the tape becomes taut between the sensing unit and the perforator and provided operation of the perforator is not resumed, the sensing unit due to the cyclic operation of the tape advancing mechanism and its cooperation with the feed holes in the tape, will be moved in a clockwise direction toward the perforator and in such movement, which is step by step, the transverse rows of perforations will be sensed successively until the sensing head is brought in abutting relation to. the perforator. when the sensing unit abuts the perforator, mechanism is operated for discon- -tinuing the operation of the tape advancing mechanism through arresting the rotation of the transmitting distributor shaft 58.

The tape advancing-mechanism, as shown-in tailed description of-a sensing mechanism carrier capable of oscillation about a flxed pivot away from and toward'lthe exit tape channel of a keyboard periorator, reference may be had to United States Patent 2,262,012 supra.

The light conducting rods, according to the present invention, are shown in Fig. 4 respectively extending through apertures in a plate over which the perforated tape advances. In accordance with the provision of five selecting impulses to a signal combination there are five light conducting rods I04 to I08 arranged to fit into the five apertures respectively, in the tape bearing plate. As the tape advances each'transverse row of perforations in the tape appear immediately about the five light conducting rods, there being a light conducting rod for each of the possible perfora- United States Patent 2,262,012,. supra, includes elements operated practically in accordance with cyclic rotation of transmitter-distributor shaft 58. Included in the sensing unit and constituting a part of; the tape feeding mechanism is a slidably mounted member (not shown) carrying at its upperextremity pins spaced corresponding to the spacing of the feedperforation and operated cyclically by the transmitter-distributor shaft 58 to cause its pin to engage and disengage the feed perforations in the tape. file feeding movement of the noted element is achieved through the provision of a cam operated lever (not shown) carrying at its extremity a pin which cooperates with a cam slot in the element carrying the pins which engage the feed perforations in the tape to cause the rectilinear movement thereof; that is, a movement whereby the pins thereof engage the next succeeding feed perforations in the tape to effect a relative movement between the sensing unit and the perforated tape. If the tape is taut, movement of the element carrying the pins will cause the sensing unit to move about its pivot bearing I03 toward the exit channel of the perforator. However, if the tape between the perforator and the sensing unit is not taut the action of the recited element will be such as to cause the tape to be advanced step by step through the sensing unit until the tape becomes taut when the condition previously described will be repeated; that is, the sensing unit will be moved in a direction whereby its tape entrance channel will approach and abut the tape exit channel of the perforator.

If the sensing unit through the operations previously described abuts the perforator and if operation of the perforator is resumed, thesensing unit will be moved about its pivot bearing, say I03,

in a counter-clockwise direction to repeat the operations previously described. For a more detions appearing in a transverse row of perforations. The light conducting rods I04 to I08 are shown in Fig. 3 extending downwardly through an offset to points where they are, respectively connected to tubes I09 to H3 (Fig.4) which are internally coated with alight reflecting material. These tubes are bent to form approximately degree elbows and positioned in the direction of the plane of rods I04 to I 08 to extend to a formation wherein the five light conducting rods form a square in cross-section having one tube in each comer and one in the center. At this point other rods of light conducting material such as those designated I I4 to I I 9 are respectively connected to tubes. I09 to H3 respectively, and extended through block support I20 and then turned through any angle to impinge light upon any desirable arrangement of photoelectric cells in a .manner such as shown in Figs. 3v and 4, for example, rod. II5 impinges light on photoelectric ce1lI2l.

Figs. 5 and 6 showanother alternative arrangement of light conducting rods wherein rods I53 to I51 are brought down through an offset somewhat poses; perforations in a transmitting tape shall, constitute any portions of such tape which are' sumciently transparent, translucent or reflective to passor control the passage of enough light t control a light sensitive element, actual perforations are preferred.

What is claimed is:

1. An impulse transmitter controlled by a strip having areas thereon opaque to light and other areas transparent or translucent thereto comprising a light source progressively movable over a given range with said strip and also movable with respect thereto, fixed position light sensitive elements, and light conveying means for causing light passing said transparent or translucent areas toimpinge upon said elementsv in all posi-, tions of said light source.

2. In a transmitter, a medium'bearing repres sentations of coded signals in physical form, a plurality of light sensitive means, a source of light, a pivotally mounted sensing head for scanning the representations of said medium in succession, means having a pivoted portion for conducting light, interrupted in accordance with said representations, substantially without spreading representin characters, a plurality of photoelectric cells, a source of radiation, a tape having transverse rows of conditions, one row for each character, means for advancing said tape, step by step, through the range of said source whereby each of said rows is sensed by said source to produce permutated beams of radiation, and radiation conveying tubes individual to said photoelectric cells and respectively arranged to transmit said beams of radiation to activate said photoelectric cells, said tubes being jointed to allowfor relative movement between the respective ends thereof.

4. A telegraph tape transmission device comprising two units, one of said units being stationary and the other having a pivot point about which it may move from and toward said one unit, a tape, a perforator in said one unit for applying transverse rows of code conditions and a longitudinal row of feed perforations in said tape, means on said one unit cooperating with said feed perforations for longitudinally moving said tape, step by step, a sensing point on said other unit over which said tape is moved, a source of radiant energy on said other unit immediately above said sensing point, an element provided for each of the possible conditions in any one of said transverse rows for conducting radiant energy, photo-v f'electric cells each fixedly located at the termina" tion of one of saidelements, a flexible radiant energy conducting pivot point in each of said elements, and means included in each of said cell respectively responsive to the radiant energy con- .ducted through one of said elements whereby said cells control the transmission of impulses corresponding to said code conditions as presented successively in said transverse rows at said sensing point.

5. Pulse control transmission means comprising a relatively narrow strip designed to be im pressed with pulse controlling indicia, a sensing head, means for causing said strip to progress relatively to said sensing head, means for supplying radiant energy to said sensing head in a manner to cause a plurality of beams thereof to be modified in accordance with the i dicia upon various portions of said strip, radiant energy 7 sensitive means, light conducting cylinders having one end adjacent said head and positioned to pick up and convey said modified beams to said radiant energy sensitive means respectively, said cylinders being fanned out at their ends adjacent said light sensitive means to positions widely separated as compared with the separations of their ends at said sensing head, said cylinders being provided with flexible joints between their ends.

RALZEMOND D. PARKER. ALLAN WEAVER.

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