US2085175A

US2085175A - Teletypewriter

Info

Publication number: US2085175A
Application number: US67380A
Authority: US
Inventors: Thornton Floyd Edwin
Original assignee: American Telephone and Telegraph Co Inc
Current assignee: AT&T Corp
Priority date: 1936-03-05
Filing date: 1936-03-05
Publication date: 1937-06-29
Anticipated expiration: 1954-06-29

Description

June 29, 1937. F. E. THORNTON 2,085,175

TELETYPEWRITER Filed March 5, 1936 INVENTOR F. E. THORNTON ATTORNEY Patented June 29, 1937 UNITED STATES PATENT OFFICE TELETYPEWRITER Application March 5, 1936, Serial No. 67,380

18 Claims.

This invention relates to teletypewriters and, more particularly, to means for suppressing all but the first of several consecutive line feed operations of a teletypewriter.

The invention is especially useful when applied to page teletypewriters monitoring on circuits over which a series of line feed signals are frequently sent, such as when the subscribers are using order forms or when the subscribers are sending press dispatches which usually have a series of line spaces between the different items. Although this is the preferred use of the invention, it is to be understood that the invention is not limited to monitoring teletypewriters, but may be applied to teletypewriters in general. Accordingly, the invention will be described as applied to a teletypewriter similar to the teletypewriter shown and described in Patent 1,904,164 granted April 18, 1933 to S. Morton et al. The disclosure of this Morton et a1 patent is incorporated herein by reference as a part of this specification.

The operation of the invention is based upon the fact that, during line feed operations, the printing bail of the teletypewriter does not move its full length of travel. Accordingly, when the teletypewriter performs a line feed operation in response to the reception by the teletypewriter of the first of a series of successive line feed signals, a latch locks the line feed bell crank in its operated position. Then, when the remainder of the series of successive line feed signals are received by the teletypewriter. they are of no efiect because the line feed push bar of the teletypewriter is held in its operated position which is clear of the function bail. After all the consecutive line feed signals have been received and a space or any character signal is received, the printing bail moves its full length of travel and disengages the latch, thereby restoring the line feed push bar to its normal position.

The preferred embodiment of the invention will now be described in detail with reference to the drawing in which:

Fig. 1 is a side view of part of a teletypewriter, of the type shown in the Morton et a1 patent, as viewed from the left side of the teletypewriter and showing the line feed suppressing mechanism in its normal unoperated position;

Fig. 2 is a view similar to that of Fig. 1 showing the line feed suppressing mechanism locked in its operated position;

Fig. 3 shows the line feed suppressing mechanism being released from the locked position of Fig. 2;

Fig. 4 is a fragmentary sectional view taken along line 44 of Fig. 1 and illustrating details of the catch which holds the line feed mechanism in the locked position shown in Fig. 2; and

Fig. 5 is a fragmentary side view taken along the line 55 of Fig. 1 representing the relation of the locking bar to the line feed bell crank and line feed push bar.

A general description of the various parts of the teletypewriter, described in detail in the Morton et a1 patent, shown in the drawing will now be given. The line feed function lever i, of which a fragmentary view is shown, is one of the socalled function levers. In addition to the printing of characters it is necessary to provide for various functions such as line feed, platen shift, platen unshift, and automatic signaling. To perform these various functions special code, or function, levers'are provided all of which are pivotally mounted on a function lever shaft (not shown) suitably mounted in the teletypewriter.

A fragmentary sectional view of function bail II is shown. This bail is mounted on bail shaft 26 but the mounting details are not shown in the drawing for the sake of simplification as they may be found in the Morton et a1 patent. The purpose of function bail I l is to impart to the bail blade ID, of which a cross-sectional view is shown, the necessary power to actuate the line feed push bar 2 and the other function push bars (not shown). Function bail blade I 0 is arranged to span all of the function push bars and to cooperate therewith as described in the Morton et al patent. Line feed push bar 2 is rotatably joined by the pin 3 to the lower arm of the line feed bell crank 1. Push bar 2 is provided with a projection, or arm, I 3. Attached to the top of arm I3 is one end of a spring l2 the other end of which is mounted on the frame of the teletypewriter. Spring I2 tends to pull line feed push bar 2 to the right.

Line feed bell crank i, which is pivotally mounted on pin I4, is also actuated by spring 12 through the pin 3 and tends to revolve around the pivot H in a. counterclockwise direction. The right end of line feed bell crank 1 is connected rotatably by a pin 32 to the line feed vertical link IS, the effective length of which may be adjusted by means of the turnbuckle 33. The line feed vertical link I6 is pivotally joined at its upper end by the pin 34 to the line feed bell crank 31 which is pivotally mounted at IE to the frame of the printer. Attached to the top arm of hell crank 3| by pivot 35 is the line feed pawl l9 which is adapted to cooperate with the line feed ratchet of the Morton et al patent, constitute this invention, will now be given. Pivotally connected v by.

the pin 3 to the line feed bell crank 1 is the line feed locking bar 8 whichais pulled; upward '[bya spring 23 one end of which-is connected to the bar 8 at point 22 and the other end to a pin- 24securcd to the frame of the -printer. The upper and right end of bar 8 is horizontally surfaced and is provided with a shoulder 28. Due :to the upward pull of spring23, this end of bar 8 normally rests against 'the insides'urface of the invertd U member 2| whichis secured to' the detail 3! and the frame of theprinter by thes'crew 29. A fragmentary view of bar 8 in this position is shown inFig. 4. When bar 8 is moved to the left in Fig. 1, as will be hereinafter described, its shoulder 28 latches against the left edge of member 2|, as shown in Fig. 2,'thereby locking bar 8, bell crank I, link Hi, the line feed lever 3|, and pawl IS in their operated positions.

In Fig. 1, let it be assumed that the preassigned combination of significant current variations assigned to operate the line feed mechanism has been received by the teletypewriter and that the line feed function lever I has been selected in response to this code combination. Lever I now revolves in a clockwise direction around the function lever shaft (not shown) of the teletypewriter and engages the lower surface of push bar 2, and causes bar 2 to rotate counterclockwise around pin 3 upon which it is mounted together with the lower arm of the bell crank 1 and bar 8. This counterclockwise rotation of push bar 2 causes the notch 9 of push bar 2 to be placed in the path of blade ll] of the function bail II as shown in Fig. 2.

After selection of push bar 2 has been made in the manner described in the Morton et a1 patent, the function bail causes blade ID to engage notch 9 and move push bar 2 to the left against the tension of spring I 2. Due to the pivotal connection of bell crank lever 1 by means of pin 3 with the push bar 2, line feed bell crank is now forced in a clockwise direction around the shaft i4, against the tension of spring l2. This causes the vertical line feed link IE to be pulled downward thereby imparting to the line feed lever 3| a counterclockwise rotation around pin l8. As a result, the line feed pawl I8 is pulled to the left to effect the counterclockwise rotation of ratchet 36 and platen 28. This causes the paper in the teletypewriter to be fed forward one line space as described in the Morton et al patent.

The clockwise movement of bell crank lever I forces the line feed locking bar 8 to move to the left due to its pivotal connection with bell crank lever by means of pin 3 as shown in Fig. 5. The right end "of bar 8 thus slides to the left under the inverted U-shaped member 2| and is pulled upward by spring 23. After bar 8 has moved a short distance to the left, its shoulder 28 latches with the left outer surface of member 2|, as shown in Fig. 2, thereby holding bar 8, bell crank I, link l6, lever 3|, and pawl I!) in their operated positions. At the same time, the printing ball 25 moves to the right in only a short are which is not sufllcient for bail 25 to touch bar 8. This is because bail 25 is designed, as described in the Morton et al patent, to move in a shorter arc in response to a line feed signal than it moves in response to an ordinary character signal. restricted; movement of ball 25 is necessary iii-order to prevent printing and movement of the carriage at this time.

.7 Consequently, when the function ball I moves its blade Hi to the left in response to the receptio'n' by the teletypewriter of the second in ,the: series of successive line feed signals, it cannot: again push the line feed push bar 2 to the left because bar 2 is already held to the left by means of the latching engagement of shoulder 28 with member 2|. As a, result, the line feed pawl l9 is'not operated by this second line feed signal. Subsequent successive line feed signalseare likewise ineffective to cause the operation of line feed pawl- |9 Withth result that platen2ll is not rotated further.

However, when a "space or character signal is received, bail 25 moves through its regular length of travel which is 'suflicient for bail 25 to strike against bar 8 at the point 30 as is shown in -Fig. 3. When bail 25 hits against bar 8 at point 30, it does so with force sufiicient to drive bar 8 downward against the tension of the spring 23. This causes shoulder 28 to disengage itself from its latching engagement with the left edge of the stationary member 2|.

After thus being unlatched, bar 8 is moved to the right by the counterclockwise rotation of the bell crank 1 around the shaft H by spring i2. This counterclockwise movement of bell crank I also gives the line feed vertical link IS a vertical upward motion which imparts a clockwise rotation to line{ feed lever 3|. This causes the line feed pawl l9 to move to the right and assume its normal position as shown in the drawing. At the same time, the line feed push bar 2 is also moved to the right by means of spring l2. All of the line feed mechanism is thus restored to the position shown in the drawing and the teletypewriter is ready to respond to the next code signal com bination.

It is to be understood that the above embodiment of the invention has been shown and described to illustrate th features and principles of operation of the invention. Various changes may be made in this specific embodiment without departing from the scope of the invention which is to be limited only by the claims appended hereto.

What is claimed is:

1. In a telegraph printer. printing mechanism, line feed mechanism, operating means for operating the line feed mechanism in response to line feed signals received by the printer, and control means for rendering the operating means inefiective to operate the line feed mechanism, said control means including a latch,

2. A teletypewriter having in combination normally unoperated line feed mechanism, means for operating the line feed mechanism in response'to line feed signals received by the teletypewriter/a normally unoperated latch adapted to lock the line feed mechanism in its operated position, and an instrumentality for operating the latch when the line feed mechanism is operated.

3. A teletypewriter having in combination normally unoperated line feed mechanism, means for operating the line feed mechanism in response to line feed signals received by the teletypewriter, a normally unoperated latch adapted to lock the line feed mechanism in its operated position, operating means for operating the latch, and an instrumentality for restoring the latch to its normally unoperated position.

4. A teletypewriter having a platen, line feed mechanism, said line feed mechanism including a line feed pawl for rotating the platen one space at a time, said line feed pawl having a normally unoperated position and an operated position, a line feed function lever for effecting the movement of the line feed pawl from one position to the other, suppressing means for preventing rotation of the platen by the line feed pawl, said suppressing means comprising holding means for effecting the holding of the line feed pawl in its operated position, and operating means for operating the suppressing means.

5. A teletypewriter having a platen, line feed mechanism, said line feed mechanism including a line feed pawl for rotating the platen one line space at a time, said line feed pawl having a normally unoperated position and an operated position, a line feed function lever for effecting the movement of the line feed pawl from one position to the other, suppressing means for preventing rotation of the platen by the line feed pawl, and operating means for operating the suppressing means.

6. A teletypewriter having a platen, line feed mechanism, said line feed mechanism including a line feed pawl for rotating the platen one line space at a time, said line feed pawl having a normally unoperated position and an operated position, a line feed function lever for effecting the movement of the line feed pawl from one position to the other, suppressing means for preventing rotation of the platen by the line feed pawl, operating means for operating the suppressing means, and control means for discontinuing the operation of the suppressing means.

7. A teletypewriter having a platen, line feed mechanism, said line feed mechanism including a line feed pawl for rotating the platen one line space at a time, said line feed pawl having a normally unoperated position and an operated position, a line feed function lever for effecting the movement of the line feed pawl from one position to the other, a line feed locking bar for preventing rotation of the platen by the line feed pawl, operating means for operating the line feed locking bar, and locking means for latching the line feed locking bar in its operated position.

8. A teletypewriter having a platen, line feed mechanism, said line feed mechanism including a line feed pawl for rotating the platen one line space at a time, said line feed pawl having a normally unoperated position and an operated position, a line feed function lever for effecting the movement of the line feed pawl from one position to the other, a line feed locking bar for preventing rotation of the platen by the line feed pawl, operating means for operating the line feed locking bar, locking means for latching the line feed locking bar in its operated position, and control means for unlocking the line feed locking bar.

9. A teletypewriter having a platen, line feed mechanism, said line feed mechanism including a line feed pawl for rotating the platen one line space at a time, said line feed pawl having a normally unoperated position and an operated position, a line feed function lever for effecting the movement of the line feed pawl from one position to the other, a line feed locking bar for preventing rotation of the platen by the line feed pawl, operating means for operating the line feed locking bar, locking means for latching the line feed locking bar in its operated position, control means for unlocking the line feed locking bar, said control means being responsive to certain preassigned teletypewriter signals for striking against the line feed locking bar whereby the line feed locking bar becomes unlatched.

10. A teletypewriter having a platen, a printing bail, line feed mechanism, said line feed mechanism including a line feed pawl for rotating the platen one line space at a time, said line feed pawl having a normally unoperated position and an operated position, a line feed function lever for effecting the movement of the line feed pawl from one position to the other, a line feed locking bar for preventing rotation of the platen by the line feed pawl, operating means for operating the line feed locking bar, locking means for latching the line feed locking bar in its operated position, and control means for unlocking the line feed locking bar, said control means including the printing bail, said printing bail being responsive to certain preassigned teletypewriter signals for striking against the line feed locking bar whereby the line feed locking bar becomes unlatched.

11. A teletypewriter having feeding means for feeding stationery through the teletypewriter, operating means for operating the feeding means, and control means for rendering the operating means ineffective to operate the feeding means, said control means including a locking bar.

12. A teletypewriter having feeding means for feeding stationery through the teletypewriter, operating means for operating the feeding means, control means for rendering the operating means ineffective to operate the feeding means, and suppressing. means for preventing the operating means from operating the feeding means, said suppressing means including a U member.

13. A teletypewriter having feeding means for feeding stationery through the teletypewriter, said feeding means having an unoperated position and an operated position, operating means for moving the feeding means from one position to the other, and control means for locking the feeding means in one of its positions, said con- P trol means including a latch.

14. A teletypewriter having feeding means for feeding stationery through the teletypewriter, said feeding means having an unoperated position and an operated position, operating means r for moving the feeding means from one position to the other, control means for locking the feeding means in one of its positions, and releasing means for unlocking the feeding means after it has been locked in one of its positions.

15. A teletypewriter having in combination line feed mechanism, operating meansfor operating the line feed mechanism in response to line feed signals received by the printer, and control means for preventing at least one of a series of successive line feed signals from effecting operation of the line feed mechanism by the operating means, said control means including a locking device.

16. A teletypewriter having in combination line feed mechanism having an unoperated position and an operated position, operating means for means for preventing nput the first 01 8. 'ser i'ea of sncces'siveiine feed signals jfi om efi ecting' operation'ofj the line feed mechanism, Said control' means including a normally unactuated guppressing device for rendering the'opei ating means ineffective jto dpeiate 'theline feed mechanism, and actuating means for actuating the sup pres in n i 18. 'A teletypewrite'r havingin combination line iee'd mechanism, operating nian'sfior ope'iat'in'g the line feed mechanism in ";-esponse to iin'e' 'ieed signals received'by the printer, and control means foi preventing all but theflr st "of ajseries'oi s'iicce'ssive' line feed signals from eifecting operation of the line feed mechanism, said CQ IQtIOI means including normally unoperated 'su'i p fssing means for jrenderingthe operating means ineflective to operate the line feed mechanism; 'said'operating means "being adapted to eiiect'; the operation of the s uripressing means infrepons to the first line feed signal received/ Y the teletypewriter therebypreventinglthe remainder of the line feed signa1s'in"the'seri'es from eflectin'gope 'ati'on of the line ieeqinechanisni by the operating means '15 EDWIN 'noiwron;