US2768233A - Teleprinter for automatic telex service - Google Patents

Description

Oct; 23, 1956 o. MOSER TELEPRINTER FOR AUTOMATIC TELEX SERVICE v 5 Sheds-Sheet 1 Filed April 5, 1952 1956 o. MOSER 2,768,233

TELEPRINTER FOR AUTOMATIC TELEX SERVICE United States Patent TELEPRINTER FOR AUTOMATiC TELEX SERVICE Otto Moser, Bern, Switzerland Application April 5, 1952, Serial No. 280,843 Claims priority, application Switzerland April 6, 1951 8 Claims. (Cl. 178-79) In automatic teleprinter service number dials like those generally used in automatic telephone service are employed for calling the desired subscriber although the teleprinters themselves have keys with letters and with the digits from to 9.

This invention refers to a teleprinter for automatic service in which no special number dial is needed for calling subscribers inasmuch as in accordance with the invention the teleprinter is equipped with a selector impulse generator operated by the teleprinter keys.

it is therefore an important object of the invention to provide means affording a greatly simplified construction and operation of a teleprinter, in which transmission means transfer the movements of the key levers and are coordinated to the keys, whereby upon actuation of a single key the remaining keys become inoperative by common locking means.

Another object of the invention resides in the provision of means avoiding the possibility of simultaneous actuation of several keys during operation of the teleprinter.

These and other objects of the invention will become further apparent from the following detailed description, reference being made to the accompanying drawings. The accompanying drawings represent by way of example one embodiment of the teleprinteraccording to the invention, wherein:

Fig. 1 shows a side view of the transmitter unit of the teleprinter (with drive means omitted), in partial section;

Fig. 2 shows a front view of the number selector impulse generator;

Fig. 3 shows a section taken along line III-III of Fig.2; i

Fig. 4 shows a section taken along line IVIV of Fig. 2;

Fig. 5 shows an elevational view of the number selector impulse generator, as seen from the right of Fig. 2;

Figs 6 and 7 show the circuiting of the electrical parts of the number selector impulse generator.

The number selector impulse generator, hereinafter sometimes called numeral impulse generating meansfis mounted on a cast frame 1 attached to the side walls'2 and 3 of the transmitter unit. The cast frame 1, extending parallel to the front of the transmitter unit, has two forwardly directed brackets 1a and 1b. In these brackets is mounted the drive shaft 4, to which, during operation, a torque is continuously transmitted inthe direction'indicated by arrows by the drive motor via a friction clutch (not shown in the drawing), and on these brackets is I further journalled the trigger or release shaft 5. On the drive shaft 4, between the two brackets 1a and 1b, ten control cams 6 (only three are shown in Fig. 1) are rigidly mounted side by side, each associated with oneof the numeral keys 1, 2, 9, 0. Each cam is provided with a spiral groove whose turns are divided .into two groups. The number of turns in the inner group 6a corresponds to the number of numeral selecting impulses to be emitted with the corresponding numeral key.

ice

2 The number of turns in the outer group 6b is the same for all cams. Each pair of groups of turns 6a and 6b is joined by a portion of groove 6c with increased pitch (sharp transition). The inner approach to the groove is marked 6d and the end of the groove 6e (Fig. 4).

Each cam 6 is associated with a two-arm transmission lever 7 freely rotatable on the trigger shaft 5. One arm 7a of this transmission lever is provided with a perpendicularly set and pointed style or follower 7b, which is guided along the groove as the corresponding cam 6 revolves. To prevent the style 711 from escaping from the groove during operation, each transmission lever 7 is provided with an abutment 22 attached to the cast frame 1. The same arm 7a has a spring 8 attached which draws the transmission lever and style towards the center of the cam 6 and against the latter. All springs 8 are hooked to a continuous bar 9. Each transmission lever 7 operates in conjunction with a trigger or release lever 10 having a hub 10a and a tab 1012. All triggers 10 are non-rotatably and alignedly mounted on the trigger shaft 5.

11 designates one of the numeral keys of the teleprinter, simultaneously serving as number transmitter key in number selection. It is mounted on one end of a bell crank 13 rotatable on a pivot 12, whose downward arm 13a, when the key 11 is depressed, acts on the arm 7c of the transmission lever 7 so that the style 7b approaches the groove entrance 6d. 7

Brackets 1a and 1b of frame 1 are each prolonged at their lower portions with straps 14 and 15 respectively, rotatably mounted on the trigger shaft 5 and fastened to brackets 1a and 1b with screws 16 and 17 respectively passing through oblong holes in the straps. The straps 14 and 15 bear a rotatably mounted pawl shaft 18 parallel to drive shaft 4 and trigger shaft 5, as well as the aforesaid spring bar 9. On the pawl shaft 18, ten pawls 19 are rotatably mounted, serving to lock the respective numeral keys actuated. For this purpose, the pawls 19 are provided with projections 19a acting in conjunction with the upper edges of extensions 13b on arms, 13a of the corresponding bell crank 13. The hubs 19b of the pawls 19 have radial slots 19c occupied by pins 20 fixed in the pawl shaft 18 to restrict the range of rotation of the pawls 19. The pawls 19 are held in one angular position by springs 21.

A pin 23 on bracket 1a of frame 1 bears two rotatably mounted check levers 24 and 25 (Figs. 1, 2) acting in conjunction with discs 26 and 27, respectively, fixed on the drive shaft 4. The upper arms of the check levers have projections 24a and 25a respectively, engaging notches 26a and 27a in the discs, and are thus able to prevent rotation of the drive shaft 4. A spring 28, when the impulse transmitter system is at rest, holds check lever 25 in engagement with disc 27. Check lever 24 is also subject to the action of a spring 29, and is controlled by a cam 30 mounted on the trigger shaft 5 and having an upper curve 30a and a lower curve 301) acting in conjunction with a pin 31 attached to the lower arm 24b of the check lever 24. At rest, pin 31 lies against the upper curve 30a, so that the check lever 24 is out of engagement with the disc 26 for the time being. Cam 30 also bears a rotatably mounted roller 32. The lower arm 25b of check lever 25 has a track 250 for the roller 32. Alongside the cam 30 a fixed lever 33 is also provided, subject to the action of a spring 34 which holds the trigger shaft 5 in an initial position, with the circumference of the roller 32 resting on the track 250. The pawl shaft 18 carries a fixed crank 35 to which a rod 36 is attached under the action of a spring 37 acting on crank 35 and hooked to the bar 9, so that at rest, the said rod abuts on the lower tip 25d of the check lever 25, thus likewise determining theinitial position of the pawl shaft 18. An-

J other lever 38 fixed on pawl shaft 18 acts in conjunction with a lever 39 fixedly attached to the trigger shaft 5, as will be explained below.

In the location of the bracket 1b, the frame 1 also has an arm Is to which the sets of contact springs comprising spring contacts 40-45 are attached (Figs. 2, The pair of spring contacts 40, 41 making the impulse contact i (Fig. 7) is controlled by an impulse disc 46 mounted on the end of the drive shaft 4. For this purpose, the spring contact 40 is provided with a projection 40a by which the impulse disc 46 lifts it periodically as the drive shaft 4 revolves, so that the impulse contact i is opened twice during one revolution of the impulse disc 46. The pair of spring contacts 42, 43 forms the bypass contact k (Fig. 7) to suppress supernumerary impulses. This is controlled by a switch lever 47 fixed to the trigger shaft 5 and having a beveled projection 47:: at the end, so that when revolved it presses spring contact 43 against spring contact 42 after a certain angle of rotation. In addition, there is a safety contact s (Fig. 6) whose purpose will be described below and which consists of the pair of spring contacts 44, 45. At rest, another switch lever 49 rotatable on the trigger shaft 5 and clamped to switch lever 47 in an adjustable angular position relative to the latter by means of screw 48 keeps the safety contact s closed. However, as soon as the trigger shaft 5 is turned, the switch lever 49 slides off the spring contact 44, which consequently breaks away from the contact 45.

The number selector impulse generator whose structure has been described above is brought out of rest condition into a condition preparatory to number selection by means of the call key 50. The call key 50 and all parts of the number selector impulse generator that are displaced when the call key is operated are shown in preparatory position in the drawing.

The key 50 is set on a bar 51 slidably and vertically mounted in a bearing 54 attached to the outside of the side wall 2 of the transmitter unit by means of screws 52 and 53. The lower end of the bar 51 is acted upon by the opposing compression spring 55. The bar 51 is articulated to a lever 57 rotatable on a pivot 56, its motions being transmitted by a tension member 58 to a crank 59 which in turn is rotatably mounted on pivot 60 on a bracket 61 likewise attached to the outside of the side wall 2.

The crank lever 59 acts in conjunction with an arm 25e of check lever 25 so that upon depression of the call key 50, the crank 59 forces the arm 25 downward, whereby the check lever 25 is disengaged from the disc 27. As a result of this movement of the check lever 25, the track 250 so changes its position that the trigger shaft 5 is able to rotate through a small angle under the action of spring 34. At the same time, the cam 30 rotates far enough so that its lower curve 30b comes opposite the pin. 31. The check lever 24 consequently drops into place, its projection 24a engaging the notch 26a in disc 26, whereby check lever 24 assumes the function of check lever 25. This change of place of the two check levers 24 and 25 is simultaneous, so that the drive shaft 4 cannotbe driven by the drive motor for the time being. At the same time, the tip 25d slips off the rod 36, so that the pawl shaft 13 is rotated under the action of spring 37 until lever 38 touches lever 39. Thus the number selector impulse generator has been brought into the preparatory condition in which it is seen in the drawing.

Lever 57 is extended by a prolongation with tab 57a acting in conjunction with a projection 62a on a pawl 62 by means of which the actuated call key 50 and all parts displaced by it are locked. The pawl 62 is held in locking position by a spring 63. The locked call key 50 and number selector impulse generator are released, after completion of number selection, by means of an electromagnetic relay 64 whose armature 65 is articulated by a bar 66 with pawl 62, so that when relay 64-is actuated, the attracted armature 65 disengages the pawl from tab 57a of lever 57 against the force of spring 63.

Of the actual transmitter of the teleprinter, the drawing (Fig. 1) shows only the more essential parts. A detailed description of the same is to be found in U. S. Patent No. 2,651,676.

The control means associated with the current or code impulse combinations to be emitted and controllable by means of the several character keys are impulse discs 67, of which only one is visible in Fig. l, with a lateral milled groove. They are fixed on a common shaft 68 driven by the aforesaid drive motor and executing one revolution upon actuation of a character key. Each of the impulse discs 67 acts in conjunction with a follower lever 69 pivoted on shaft 70 and provided with a guide pin 71. Upon actuation of a character key, the corresponding follower lever 69, in manner to be described below, enters the said groove and executes a reciprocating motion upon ensuing rotation of the impulse disc 67, which motion is transmitted to the transmitter contact system, not shown, via a bar 73 common to all follower levers and connected to lever 72.

The transmitter unit is also provided with a device containing, firstly, means associated with the several character keys for transmission of their motion to the corresponding control means, and secondly, a locking device common to all of the character keys, which locking device, upon actuation of one character key, automatically locks all the others, and prevents simultaneous actuation of several character keys. This device, for each row of character keys, has a U-shaped rail 74, open upwards and with upwardly directed legs. These rails are so arranged that the bell cranks 13 of a row of keys have their downward extensions 13b between the two flanges of the corresponding rail, which limits the swing of the bell cranks 13. In the rails 74 and an additional rail 75, transverse to their longitudinal direction, there are longitudinally displaceable bars 76 associated with the individual character keys, which bars are in loose mechanical connection with the bell cranks 13 and with the follower levers 69. The bar 76, upon actuation of key 11, transmits the motion of bell crank 13 to the follower lever 69, and after completion of impulse emission, is returned by the latter to its initial position.

The locking device comprises an additional set of bars 77 associated with the individual character keys and displaceably mounted in the rails 74 and 75, which bars act in conjunction with a ball lock as known in the art of typewriter design. This comprises the cage formed by the cavity in rail 75, with balls 78 movable therein, their lateral play being taken up upon entry of a bar 77. The bar 77 abuts loosely against the extension 13b of the bell crank 13 under spring pressure. The spring pressure is supplied by a spring 79 disposed upon bar 77 and acting on a collar 77a thereof.

Fig. 6 diagrammatically shows the circuit for the trigger relay 64. In addition to the trigger relay, this ineludes source of current 80, safety contact s, and additional contact st. operable by means of the lock key 81 of the teleprinter. This diagram shows that the call key 50 cannot be unlocked, nor therefore the number selector impulse generator stopped, by actuation of the lock key 81, during emission of a number selector impulse sequence, since during that operation the safety contact s is always open.

Finally, Fig. 7 shows the circuiting of the impulse contact i and the bypass contact k, which are connected in series with the subscriber line via terminals 82.

The operation of the teleprinter in number selection is as follows: Upon depression of the call key 50, the numeral impulse generating means is mechanically pre pared for ensuing number selection, as has been described above. The numeral impulse generating means is thereby placed in the condition represented in the drawing. At the same time, by otherwise known means (not shown),

the first preselector' in the teleprinter station is actuated.

To select the subscriber number, one of the numeral -keys 11 of the transmitter unit is depressed. This actuates the control system' associated with it, the lower arm 13a of hell crank 13 acting on arm 70 of transmission lever 7 and swinging it so that the style 7b is moved up from the center of cam 6 to the groove entry 6d of the latter. At the same time, switch lever 49 leaves spring contact 44 so that the safety contact s is opened. In the course of its motion, the transmission lever 7 carries along the trigger 10 by its tab 10b, whereby the trigger shaft 5 is rotated clockwise (Fig. 1). The corresponding rotation of cam 30 causes the pin 31 to be picked up on the upper curve 30a of the cam, thereby swinging the check lever 24 against the force of spring 29, so that the'projection 24a disengages. from the notch 26a of the disc 26. In this way, the drive shaft 4 is unlocked, so that it begins to revolve.

Upon rotation of the trigger shaft 5, lever 39 draws away from lever 38, thus also releasing the pawl shaft 18. The latter now revolves under the action of spring 37 upon lever 35, so that the pawls 19 move downward and the actuated numeral key 11 is locked by its associated pawl 19, the projection 19a catching the upper edge of the extension 13b of bell crank 13. By such locking of numeral key 11, completion of the initiated process of selection is ensured. The clearance of pins 20 in slots 190 of pawl hubs 19b is necessary to prevent premature release of the locked actuated numeral key in case, during the process of selection, motion of pawl shaft 18 should inadvertently be produced by means of some other numeral key.

Upon depression of numeral key 11, the transmitter of the teleprinter is simultaneously started via bar 76, produces the code impulse combination symbols corresponding to the numeral selected, and thereby controls the receiver of the calling station, so that the number selected is printed on the control copy. By suitable circuiting procedures, the code impulse combinations are prevented from reaching the subscriber line simultaneously with the number selection impulses. Subsequently, the bell crank 13 of the actuated character key 11, by means of its extension 13b, thrusts the bar 77 between the balls 78 of the ball lock, so that all other numeral keys are locked.

The revolving drive shaft 4 now produces emission of the number selection impulse, the impulse contact i being periodically opened and closed by the impulse disc 46. The number of impulses thus emitted corresponds to the number of turns in the group of groove turns 6a; The transmission lever 7 is guided by the style 7b projecting into the groove. Upon transition of the style 7b from the group of turns 6a to the group of turns 6b along the portion of groove 60, the transmission lever 7 swings more rapidly. The trigger 10 transmits this motion via trigger shaft 5 to switch lever 47, which at that moment actu-ates the spring contact 43, whereby the contact k is closed and the impulse contact i is bypassed (Fig. 7), so that the impulse contact i, which is still actuated by the impulse disc 46, will not carry any additional emitted pulses, despite further rotation of the drive shaft 4. The group of turns of groove 6b, which is the same for all cams 6, ensures the same selection interval for all digits between two successive selector operations. At the end of the group 6e, the style 7b is lifted to the surface of the cam 6. This presses the transmission lever 7 far enough to one side so that, under the action of spring 8, it returned to-its initial position along the outside of .abutment 22. At the same time, the trigger 10, under the action of the spring 34 attached to lever 33 on trigger shaft 5, is also turned back, whereupon the check lever 24 with pin 31 drops back on the lower curve 30b of cam 30 and stops drive shaft 4 after the last revolution by means of its projection 24a, engaging the notch 26a in disc 26. Upon return of the trigger shaft 5, the lever 39 strikes lever 38 a blow which causes the pawl shaft 18 to lift the pawls 19 briefly so that the locked character key 11 is released. Further, switch levers 47 and 49 move back to their initial position, opening the bypass contact k and closing the safety contact s.

Number selection can now be continued; that is, the key corresponding to the next digit .can be depressed. Upon completion of number selection, the relay 64 is actuated by an impulse transmitted from the teleprinter station, so that the call key 50 and the mechanism associated with it are released and the number selector impulse generator is thereby returned to rest position. Release can also be eifected by means of lock key 81 during number selection, between two selection operations. By this means, the arm 25e of check lever 25 is relieved from the pressure of crank lever 59, so that the check lever 25 engages the disc 27 under the action of spring 28. The motion of check lever 25 is transmitted to cam 30 via the track 25c on the lower arm 25b of the check lever and the roller 32, which cam, by rotating accordingly, takes the check lever 24 out of the way of the disc 26. At the same time, the rod 36 is caught by the tip 25d of check lever 25, thus fixing the pawl shaft 18. This reliably prevents the pawls 19, upon deflection of check lever 24 with number selector impulse generator not in use, from dropping readily and locking any act-u ated character keys.

Various changes .and modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

1. In an automatic teleprinter having a keyboard; a rotatable main shaft, control means coordinated with and arranged for selective actuation by one of said keys, impulse generating means coordinated with and arranged for selective actuation by said one key and including contact means responsive to said control means for transmitting a plurality of current impulses corresponding to said one key, said control means and said impulse generating means being operatively connected with said main shaft, .an oscillatable release shaft spaced from said main shaft, motion-transmitting means connected with said release shaft and actuatable by said control means for oscillating said release shaft, and locking means disposed between said release shaft and said main shaft, said locking means being rendered inoperative for permitting rotation of said main shaft in response to oscillation of said release shaft by said control means.

2. An automatic teleprinter according to claim 1, wherein said control means includes guide-groove means having an inlet and an outlet thereto, said motion-transmitting means comprising a lever pivotally supported intermediate its ends on said release shaft and actuatable at one end upon depression of said one key for operative engagement of its opposite end by said guide-groove means, and a release element secured to said release shaft and operatively engageable by said lever for transmitting movement to said release shaft.

3. An automatic teleprinter according to claim 2, including means for preventing disengagement of said lever from said guide-groove means, and spring means for restoring said lever and said release element to their respective inoperative positions.

4. An automatic teleprinter according to claim 3, wherein said guide-groove means is provided with a predetermined plurality of convolutions in accordance with the number of impulses desired to be transmitted.

5. An automatic teleprinter according to claim 3, wherein said control means is provided with additional guide-groove means continuous with said first-mentioned guide-groove means, said impulse generating means including short-circuit contact means, said release lever being provided with tripping means for closing said shortcircuit contact means responsive to engagement of said lever by said additional guide-groove means, whereby said impulse generating means is rendered inoperative during a minimum interval of time pending locking of said main shaft.

6. An automatic teleprinter according to claim 2, wherein said guide-groove means is provided with a predetermined plurality of convolutions in accordance with the number of impulses desired to be transmitted.

7. An automatic teleprinter according to claim 2, wherein said control means is provided with additional guide-groove means continuous with said first-mentioned guide-groove means, said impulse generating means including short-circuit contact means, said release lever being provided with tripping means for closing said shortcircuit contact means responsive to engagement of said lever by said additional guide-groove means, whereby said impulse generating means is rendered inoperative during a minimum interval of time pending locking of said main shaft.

8. An automatic teleprinter having a keyboard with separate letter-designating keys and with numeraldesignating keys; control means coordinated with and arranged for selective actuation by said separate keys, contact means responsive to said control means for transmitting code impulse combinations corresponding to said designated letters and numerals, numeral impulse generating means linked for movement with said numeraldesignating keys, means normally locking said numeral impulse generating means, so that upon actuation of a numeral-designating key only code impulse combinations are transmitted, and additional control means arranged for actuation by said numeral-designating keys for transmitting by said generating means a plurality of numeralselecting impulses corresponding to said designated numetals.

References Cited in the file of this patent UNITED STATES PATENTS 1,100,413 Wotton June 16, 1914 1,814,236 Wusteney July 14, 1931 1,954,170 Gibbs et a1. Apr. 10, 1934 1,965,121 Kardorfi July 3, 1934

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