US2913517A - Automatic stop for telegraph printer - Google Patents

Description

Nov. 17, 1959 B. HOWARD ,91 17 AUTOMATIC STOP FOR TELEGRAPH PRINTER Filed Feb. 18, 1957 FIGZ FIGI JNVEN TOR. BERNARD HOWARD BY M; I

ATTORNEYS Unite AUTOMATIC STOP FOR TELEGRAPH PRINTER Bernard Howard, Ramsey, Nl, assignor to Teleprinter Corporation, Hackensack, N.J., a corporation of New Jersey Application February 18, 1957, Serial No. 640,806

r 7 Claims- (Cl. 178-41) This invention relates to telegraph printers, and more particularly to an automatic stop mechanism for the same.

The primary object of the present invention is to generally improve telegraph printers, and a more particular object is to provide an automatic stop mechanism for the same. A still more particular object is to provide such a mechanism arranged for use with a telegraph printer of the general character shown in my Patent No. 2,769,029, granted October 30, 1956, and entitled Telegraph Printer.

In telegraph printers, it is common to employ a local drive motor which runs in synchronism with a like motor at the remote transmitter. This drive motor operates much of the mechanism continuously even when no signal pulses are being received, which increases the wear of the mechanism. Moreover, in the case of portable equipment operated by a battery, it is wasteful of battery current.

To overcome this difficulty, I provide automatic stop mechanism which stops the local motor and consequently all of the printer mechanism, if no signal is received for a predetermined desired time. The motor and associated mechanism are restarted, however, upon the reception of a starting signal pulse. The term pulse is here used broadly, and applies to interruption of telegraph line current, because the usual practice is to maintain current on the line when no signal is being transmitted. (This insures discovery and recognition of a possible break in the line.) Thus, in the present case, the motor will be restarted and energized by the local current source if the telegraph line current is interrupted upon resumption of signalling. I

Another object of the invention is to make the predetermined non-signal time which stops the motor, readily adjustable. In the present case, the mechanism includes a scale and pointer which may be adjusted for a non-signal time ranging anywhere from one-half to two minutes. A still further object of the invention is is provide multiple scales which differ in length, and one or another of which maybe used, depending on the rate of signal transmission.

To accomplish the foregoing general objects, and other more specific objects which will hereinafter appear, my invention resides in the telegraph printer and automatic stop elements, and their relation one to another, as are hereinafter more particularly described in the following specification. The specification is accompanied by a drawing in which:

Fig. 1 is an edge view of an automatic stop mechanism embodying features of my invention;

Fig. 2 is a front elevation of the same;

Fig. 3 is a schematic wiring diagram explanatory of the invention;

Fig. 4 is a fragmentary vertical section showing the hammer shaft and main cam shaft in one particular telegraph printer;

Patented Nov. 17, 1959 Fig. 5 shows how the present automatic stop mechanism is applied to such a printer; I

Fig. 6 is a fragmentary view showing a minor modification of the mechanism; and

Fig. 7 shows a modified arrangement of telegraph printer embodying my invention.

Referring to the draw n Fig. 4 is a vertical section corresponding to the upper part of Fig. 13 in my aforesaid Patent No 2,769,029. Paper 194 enters a paper slot at 192, and is fed upwardadjacent a type body T. This operatesthrough an inked ribbon 200 when the paper is struck by a hammer 196. The hammer 196 is normally retracted by a spring, except when operated by a hammer bar 212 carried by a hammer shaft 216. The paper 194 is moved by means of a feed drum 202, and thence around a roller 204, and upward at 206.

The shaft is a main cam shaft which is driven by the local motor of the telegraph printer. The motor is not shown in Fig. 4, but is indicated at M in Fig. 3. It will be understood that shaft 90 is a continuously rotating shaft, whether or not a signal is received, while the hammer shaft 216 oscillates only upon receipt of a signal.

Referring now to Fig. 2, the continuously rotating shaft is indicated at 90, while the intermittently oscillated shaft is indicated at 216. The stop mechanism includes speed reduction gearing driven by shaft 90 and therefore by the motor, and terminating in a movable means 12, 34 controlled bya releasable clutch 14 to operate a switch 16. There is also a resilient restoring means 18 urging the movable means 12 in a direction oppositeto that in which it is urged by the motor and shaft 90.

Considered more specifically, the speed reduction means includes a worm 20 driving a worm gear 22which drives a pinion 24 meshing with a gear 26. The latter drives a pinion 28 meshing with a gear 30. The latter drives a friction wheel 34. The movable means 12 is a strip or link which is connected to an operating finger 36 pivoted at 38. This finger when moved down by the link 12 operates the switch 16. The switch 16 ispreferably a sensitive precision switch, a common commercial example of which is the so-called Microswitch.

The clutch 14 is simply a pressure roller which presses the link 12, against the friction roller 34. The pressure roller 14 is carried on one arm 40 of an angle lever which is pivoted at 41, and the other arm 42 of which projects beyond the frame 44. Roller 14 is urged against link 12 by a pull spring 46 connected to arm 42. The latter is disposed in the path of movement of an operating finger 50 (Figs. 2 and 5), the hub 52 of which is mounted on the hammer shaft 216 (Figs. 2 and 5).

The link 12 is preferably frictionally surfaced. The frictional surface is needed on only one side, that which engages the friction drive roller 34, but in practice it may be frictionally surfaced on both sides because it is convenient to make the same by dipping a thin metal strip in a liquid rubber compound or similar frictional I material.

Referring now to Fig. 3 of the drawing, the incoming signal is received over conductors connected to a relay coil 152 which operates a relay armature 154 between contacts 156 and 158. When the relay is energized, a circuit is established from a local power supply source through contact 156 to the left-hand magnets at 2, 3, 4 etc. When the relay is de-energized, a circuit is established from local source 160 through contact 158 through the righthand magnets. These magnets control theprinter in a manner which is explained in detail in my aforesaid Patent 2,769,029.

In accordance with the present invention, I provide a circuit across the line 150, that is, in shunt with the relay coil 152. This circuit includes the aforesaid switch 16 and a relay magnet 54 controlling contacts 56 which are normally closed, as indicated by spring 58. The contacts 56 are disposed in the circuit 60, 62 leading from local power supply 160 to the motor M.

The switch 16 is normally open, and thus the relay 54 is not affected by the pulsing of the signal circuit 150. However, if the transmission of signals is interrupted for a substantial period of time, the link 12 (Fig. 2) is pulled downward until the operating finger 36 reaches and operates switch 16. This closes the switch, and inasmuch as the signal line 150 is in normally-energized condition, the relay 54 is operated, thereby opening contacts 56 and stopping the motor M. The motor remains stopped until signalling is resumed by means of a long starting pulse or interruption.

During normal signalling, the motor is not stopped because the switch 16 is open. Referring to Fig. 2, switch 16- remains open because the operating finger 36 cannot reach the switch 16. It keeps beginning to move down, but the incoming signals cause operation of the hammer shaft 216 each time a letter is printed, and this moves the pressure roller 14 away, whereupon restoring spring 18 pulls the link 12 and operating finger 36 upward to their starting point. In practice, the parts vibrate rapidly and almost imperceptibly, and it is only when there is no operation of the shaft 216 for a desired relatively long period of time that the slowly turning friction wheel 34 has an opportunity to move the link 12 and with it the operating finger 36 far enough to affect the switch 16.

The time required before stopping the motor is readily adjustable. For this purpose, the upper or starting position of the operating finger 36 is determined by an adjustable pointer 64, pivoted at 38, and locked in position by suitable means, in this case, a thumb nut 66. In the particular case here shown, the pointer is movable over a scale plate 68' provided with an arcuate slot 70 through which the lock screw passes. The pointer cooperates with a scale 72. In the present case, this scale is marked from /2 to 2, representing a time duration of one i half minute to two minutes. By loosening the thumb nut 66 and moving the pointer 64 to a desired position on the scale, the non-signal time required for shutdown is readily adjusted.

However, the non-signal signal transmission rate, because that determines the speed of rotation of the main cam shaft 90. A number of different signal transmission speeds have been standardized. For example, the American standard is 60 words per minute, the European standard is 66 words per minute, and a high-speed rate which has come into use is 100 words per minute. The scale plate 68 is accordingly provided with two additional scales 74 and 76. In the particular case here illustrated, the scales 72, 74 and 76 correspond respectively to 100, 66 and 60 words per minute.

Referring now to Fig. 5 of the drawing, the main cam shaft is indicated at 90, and the hammer shaft is indicated at 216. These correspond to the same shafts shown in Fig. 4, and to the corresponding shafts shown in Fig. l3 of my Patent 2,769,029. The finger 50 is mounted on hammer shaft 216 and engages arm 42 of the angle lever which carries the pressure roller 14 (Fig. 2). Worm 20 (Fig. 5) meshes with worm gear 22', thus turning a shaft 23 which drives the train of reduction gearing within frame 44, as already described in connection with Fig. 2. From inspection of Fig. 5, it will be understood that each counter clockwise oscillation of shaft 216 to cause the printing of a letter, raises the arm 42 and releases the pressure roller 14 (Fig. 2), and so restores the operating finger 36 to initial position.

The mechanism maybe operated equally well by a downward motion, and Fig. 6 shows a slight modification of the mechanism shown in Fig; 2. Much of the mechanism has been omitted in Fig. 6, to simplify the drawing, but briefly, the operating finger 80 and link 82 are moved time is itself related to the down by a friction roller 84 and a pressure roller 86. The latter is carried on an angle lever pivoted at 88. This pivot is below the pressure roller 86, instead of above as shown in Fig. 2. The pressure roller is therefore released by downward movement of the finger bearing against the arm 102 of the angle lever.

In Fig. 4, the printer is shown in upright position, as in my aforesaid US. Patent 2,769,029. However, the printer may be disposed in horizontal position as illustrated in my copending application Serial No. 596,294, filed July 6, 1956, and entitled Telegraphic Printing Apparatus. Such a horizontal arrangement is shown in Fig. 7 of the drawing, which corresponds generally to Fig. 11 of said copending application. In Fig. 7, paper 104 is taken from a paper roll 106 and fed downward over a guide roll 108 to a feed roll 110. The latter cooperates with a pressure roll 112. The paper then moves upward out of the printer as shown at 114. In its upward movement, it passes between a type wheel or cylinder 116, and a ribbon 118. The latter is struck by a hammer which is operated by a hammer shaft 122. The latter also carries the finger 100 bearing against one arm 102 of the angle lever which carries the pressure roller of the automatic stop mechanism. The arms 100 and 102 correspond to the similarly numbered parts in Fig. 6.

The automatic stop mechanism is mounted on a frame 124, and is driven by means of a worm 126 mounted on the main cam shaft 128, or on any other shaft which is continuously driven by the driving motor of the printer. The worm 126 meshes with a worm gear 130 which in turn drives the reduction gearing and friction roller in the automatic stop unit 124. These parts may correspond exactly to those already described in connection with Figs. 2 and 5.

The initial starting signal from the transmitter should be a longer than normal pulse (opening of'the line circuit). It should be longer than the time needed for a printed character, in order to produce an operation of the hammer shaft, for it is the latter which releases the clutch and link.

. It will be understood that the shaft which keeps releasing the stop mechanism need not necessarily be a hammer shaft. Any intermittently movable part or vibrated part may be used for this purpose. The important thing is that, unlike the main shaft or cam shaft which rotates continuously, it should bea part which works only in response to the reception of signals.

It will also be understood that while I have shown the operating finger 36 moved downward and restored upward by means of a restoring spring 18, the operating finger may be pulled upward by link 12, and fall back to initial position gravitationally. The spring arrangement is preferred, but a gravitational arrangement is operable.

It is believed that the construction and method of operation of my automatic stop for telegraph printer, as well as the advantages thereof, will be apparent from the foregoing detailed description. It will also be apparent that while I have shown and described my invention in several preferred forms, changes may be made 'in the structures shown without departing from the scope of the invention as sought to be defined in the following claims.

I claim:

1. Automatic stop mechanism for a telegraph printer having a driving motor which operates continuously with or without incoming signals, and a reset part which opcrates only in response to incoming signals, said stop mechanism including speed-reduction gearing driven by said motor and terminating in a movable means controlled by a releasable clutch to operate a switch, resilient restoring means urging the movable means in a direction opposite to that inwhich it is urged by the motor, circuitry including the aforesaid switch such that move- "may ment of the movable means for a predetermined desired time operates the switch and stops the motor, and means connecting the aforesaid reset part to said clutch to release the same in response to substantially any incoming signal.

2. Automatic stop mechanism for a telegraph printer having a driving motor which operates continuously with or without incoming signals, and a reset part which operates only in response to incoming signals, said stop mechanism including speed-reduction gearing driven by said motor and terminating in a friction wheel, a link connected to an operating finger to operate a switch, a pressure roller to press the link against the wheel, restoring means to urge the link in a direction opposite to that in which it is rolled by the wheel, circuitry including the aforesaid switch such that movement of the link and finger for a predetermined desired time operates the switch and stops the motor, and means connecting the aforesaid reset part to said pressure roller to move the same away from the link in order to release the link in response to substantially any incoming signal.

3. Automatic stop mechanism for a telegraph printer having a driving motor which operates continuously with or without incoming signals, and an oscillatable print hammer shaft which operates only in response to incoming signals, said stop mechanism including speed-reduction gearing driven by said motor and terminating in a friction wheel, a friction link connected to an operating finger to operate a switch, a pressure roller to press the link against the wheel, resilient means urging the link in a direction opposite to that in which it is rolled by the Wheel, circuitry including the aforesaid switch such that movement of the link and finger for a pre determined desired time operates the switch and stops the motor, and means connecting the print hammer shaft to said pressure roller to move the same away from the link in order to release the link in response to an incoming signal.

4. Automatic stop mechanism for a telegraph printer having a driving motor which operates continuously with or without incoming signals, and another part which operates only in response to incoming signals, said stop mechanism including speed reduction gearing driven by said motor and terminating in a friction wheel, a link connected to an operating finger to operate a switch, a pressure roller to press the link against the wheel, restoring means to urge the link in a direction opposite to that in which it is rolled by the wheel, circuitry including the aforesaid switch such that movement of the link and finger for a predetermined desired time operates the switch and stops the motor, and means connecting the aforesaid part to said pressure roller to move the same away from the link in order to release the link in response to substantially any incoming signal a, normally stationary but adjustable pointer, said pointer having means acting as a stop for said finger when the link is released, whereby the non-signal time after which the motor is stopped is readily adjustable by movement of said pointer.

5. Automatic stop mechanism for a telegraph printer having a driving motor which operates continously with or without incoming signals, and another part which operates only in response to incoming signals, said stop mechanism including speed reduction gearing driven by said motor and terminating in a friction wheel, a link connected to an operating finger to operate a switch, a pressure roller to press the link against the wheel, restoring means to urge the link in a direction opposite to that in which it is rolled by the wheel, circuitry including the aforesaid switch such that movement of the link and finger for a predetermined desired time operates the switch and stops the motor, and means connecting the aforesaid part to said pressure roller to move the same away from the link in order to release the link in response to substantially any incoming signal, a fixed scale plate and a normally stationary but adjustable pointer cooperating with said scale plate, said pointer having means acting as a stop for said finger when the link is released, whereby the non-signal time after which the motor is stopped is readily adjustable by movement of said pointer relative to said scale plate, said scale plate having a plurality of dilferently dimensioned scales corresponding to different rates of signal transmission with their corresponding difr'erent motor speeds.

6. Automatic stop mechanism for a telegraph printer having a driving motor which operates continuously with or without incoming signals, and an oscillatable hammer shaft which operates in response to substantially all incoming signals and only in response to incoming signals, said stop mechanism including speed reduction gearing driven by said motor and terminating in a friction wheel, a friction link connected to an operating finger to operate a switch, a pressure roller to press the link against the wheel, resilient means urging the link in a direction opposite to that in which it is rolled by the wheel, circuitry including the aforesaid switch such that movement of the link and finger for a predetermined desired time operates the switch and stops the motor, and means connecting the hammer shaft to said pressure roller to move the same away from the link in order to release the link in response to substantially any incoming signal, a fixed scale plate and a normally stationary but adjustable pointer cooperating with said scale plate, said pointer having means acting as a stop for said finger when the link is released, whereby the non-signal time after which the motor is stopped is adjustable by movement of said pointer relative to said scale plate.

7. Automatic stop mechanism for a telegraph printer having a driving motor which operates continuously with or without incoming signals, and an oscillatable hammer shaft which operates in response to substantially all incoming signals and only in response to incoming signals, said stop mechanism including speed reduction gearing driven by said motor and terminating in a friction Wheel, a friction link connected to an operating finger to oper ate a switch, a pressure roller to press the link against the wheel, resilient means urging the link in a direction opposite to that in which it is rolled by the wheel, circuitry including the aforesaid switch such that movement of the link and finger for a predetermined desired time operates the switch and stops the motor, and means connecting the hammer shaft to said pressure roller to move the same away from the link in order to release the link in response to substantially any incoming signal, a fixed scale plate and a normally stationary but adjustable pointer cooperating with said scale plate, said pointer having means acting as a stop for said finger when the link is released, whereby the non-signal time after which the motor is stopped is adjustable by movement of said pointer relative to said scale plate, said scale plate having a plurality of difierently dimensioned scales corresponding to different rates of signal transmission with their corresponding different motor speeds.

References Cited in the file of this patent UNITED STATES PATENTS 2,344,792 Swezey Mar. 21, 1944 2,640,873 Moebius June 2, 1953 2,728,811 Gemmel Dec. 27, 1955

Images