DE1287109B - Car back button device for a teleprinter - Google Patents

Description

The invention relates to a carriage return sensing device for a teleprinter with a latch-controlled and actuated by a carriage forwarding device Forward switching for gradual advancement of the carriage against a return spring action and with a reverse circuit for releasing the forward circuit in the Sense of the carriage return under the action of the return spring.

Every time an operator presses the keypad of a teleprinter makes a failure, the receiving teletype is connected to the respective one Teletype station a misprint of a character, a number or a other character triggered. The teleprinters' cars in the broadcasting and receiving station are reset to the position of the first missed character, whereupon a deletion code is transmitted in each case, so in the connected station the incorrectly printed characters are deleted. For this backspace are already proposed various carriage return sensing devices for installation in a teleprinter been. However, the same are extremely expensive, complicated in structure and unreliable in operation.

The object of the invention is to create a simply constructed Car back switch, which is only a minor modification of the conventional advance circuit conditional and which works reliably.

To solve the problem, the invention proposes that a backspace switch Backstop includes which the forward circuit upon receipt of a backspace code blocks after a full or partial sound step in the return direction.

A preferred embodiment of the invention relates to a carriage return sensing device with a forward ratchet wheel, a forward push pawl operated in the direction of the carriage forward movement and a retaining pawl, both pawls of a release element of the reverse circuit are acted upon, and is characterized in that the backstop is used as a reset pawl is designed for the forward ratchet wheel, the ratchet tooth by a partial amount the pitch of the forward ratchet wheel offset from the teeth of the pawls is, and that the reset circuit is a levering element for the pawls from the forward ratchet wheel owns.

According to the invention is only the insertion of an additional Back release latch required, which has a similar function as the retaining latch of a known arrangement. The ratchet teeth of the reset pawl is after the Invention to a lesser extent compared to the clinker teeth of the other two pawls offset. The holding pawl and the advancing joint pawl are activated when the carriage is reset excavated so that the ratchet wheel by the amount of said displacement, the one Makes up a fraction of the pitch of the ratchet wheel, runs back. When resetting the advance circuit on hold, where the reset pawl comes out of the ratchet wheel is excavated, the ratchet wheel runs around the remainder of the pitch back, so that a total of one step interval by a backspace process is moved back.

According to another development of the invention, the excavation of the various pawls by means of a single release element. To this Purpose are on the one hand the lifting approaches of the pawls offset from one another and on the other hand the pawl of the reset circuit has a stroke limitation compared to the Ratchet of the advance circuit.

On the basis of a return code, the pawl becomes the return circuit actuated, whereupon the release element all three pawls from the ratchet wheel digs so that the car runs back to the left end of the car track.

The backspace switch device according to the invention can by minor Modification of a known advance circuit can be realized so that the device built into the construction of a teleprinter according to the invention can be. The teleprinter's car can move at exactly one step interval be reset. By having an additional control for the release element built in for a partial movement, this release element can be used in two ways to trigger the carriage return as well as the backspace movement. The backspace circuit to trigger the backspace movement based on a received backspace code be constructed in a manner analogous to the flyback circuit.

Thus, the invention of the carriage return sensing device ensures a great deal Field of application because it works reliably and economically.

The invention will now be referenced in connection with the drawings a preferred embodiment explained.

F i g. Fig. 1 shows a perspective view of the essential elements the switching devices of a teleprinter; F i g. 2 to 6 show consecutive Steps of the operation of the ratchet mechanism of the advance circuit as well as the associated backspace circuit; F i g. 7 to 10 show consecutive Steps in the workflow of the switch pawl of the reset circuit.

In the left part of FIG. 1 you can see a forward ratchet wheel 2, on ' its wedged, in the drawing upwardly directed shaft a drive gear sits. From the same a timing belt 29 is guided to a pulley 50, which are rotatably mounted on a shaft, not shown, at the right end of the frame is. The printing carriage 28 is firmly hinged to the forward toothed belt 29, so that the same when rotating the drive gear in the desired way to the left or to can be moved to the right. One end of a long spring 1 is on the right part of the frame, and the other end of the spring is attached to the left face of the Cart articulated, the spring via a pulley 44 near the forward ratchet wheel 2 is performed so that the print carriage is constantly biased towards the left end of the web is. As a result of the spring force, the forward ratchet wheel 2 acts constantly Counterclockwise torque. However, rotation of the ratchet wheel is blocked, as soon as one of the pawls to be described engages in a tooth of the ratchet wheel.

In the middle of the F i g. 1 shows a code selection rail arrangement 27, where the number of dialing bars corresponds to the number of telex codes used in each case is equal to. When a code signal is received from the transmitting side, the dialing device the receiving station all corresponding Selector rails triggered. Move the selector bars assigned to each character step of the code signal up and to the left at the same time.

A function switch bracket 12 is provided with a function switch arm 13 connected by a spring 49, so that the switch bracket 12 upwards and downwards can move down, in each case when the switching leg 13 of a not shown Cam is raised or lowered.

A carriage return lever 21 and a carriage return button 25 are each mounted on one side on a shaft 30 and each extend below the function switch bracket 12 and the selector rail assembly 27 therethrough; the free ends of the two levers are on the back of the machine in the manner shown each on one Carriage return pawl 19 or a carriage return switch pawl 23 aligned, so that they are in engagement with it.

These levers 21 and 23 are each tensioned upwards by springs 31 and 32 so that they are held in contact with the lower edge of the function switch bracket 12. A carriage switch bracket 11 is located in front of the function switch bracket 12 and can be moved back and forth by means of a cam disk (not shown). This carriage switch bracket is used to actuate the pressure device, not shown, which is seated on the carriage 28 , and to actuate a forward push pawl 5 by means of a roller 8, which sits below the carriage switch bracket; as a result, the forward ratchet wheel 2 is indexed by one tooth pitch against the spring tension and the carriage 28 is moved to the right by one step interval.

A pressure blocking rail 26 serves to suppress the release of pressure and at the same time to block the carriage advance to the right. When receiving a Character codes, the print lock rail 26 is moved up and left so that the printing device can be operated on the carriage and an imprint is made. Only when a character has been printed out does the carriage move before each is triggered the following printing process to the right by one step interval. F i g. 3 shows the Type of position of the advance switching when the carriage advances by a step interval shall be.

When the pressure lock rail 26 moves to the left, the left end thereof abuts as shown in FIG. 2 against a stop leg 33 of a forward stop lever 14 for the forward joint pawl 5 according to FIG. 3, whereby the forward lock lever 14 is pivoted counterclockwise against the action of the spring 48. As a result, the toggle joint buckles and the right end of the forward push pawl 5 moves out of the forward lock lever.

At this moment the car gearshift bar 11 is in the first half of its period of movement and swings backwards. Therefore, the toggle lever leg 9, which is pretensioned by a tension spring, pivots about the pivot pin 35 in a clockwise direction, so that it follows the movement of the roller 8. As a result, the right ends of the forward push pawl 5 and the reset pawl 4, which are both rotatably seated on a pivot pin of the toggle lever arm 9, are pivoted counterclockwise (FIG. 3). The toggle joint comprising the pawls 4 and 5, which are articulated to the toggle arm 9 by means of a pivot pin, kinks and both pawls engage the respective following tooth of the ratchet wheel 2 . On the other hand, a holding pawl 6, likewise held pivotably on the pivot pin 35, remains in engagement with the preceding tooth of the leading ratchet wheel 2.

The mutual position between the teeth of the ratchet wheel 2 and the individual pawls 4, 5 and 6 for this working position is shown in FIG. 3 shown.

During the return movement, the car gearshift bracket 11 swings forwards, the toggle lever arm 9 also being pushed forwards by the roller 8. As a result, the advance pawl 5 pushes the advance ratchet wheel 2 by one tooth pitch with respect to the holding pawl 6. The holding pawl 6 returns to the state according to FIG. 2 after it has snapped over the tooth comb in connection with the tooth notch in which the forward thrust pawl 5 engages. As a result, the drive gear is rotated further on the ratchet wheel shaft by an angle corresponding to the tooth pitch, so that the carriage 28 advances to the right by one step interval.

When a function code is received, an associated function lever (for example the carriage return lever 21) is selected, and an attachment (not shown) of the pressure lock rail 26 strikes the side edge of this lever. This stops the print lock rail 26 and locks the printing process. The forward lock lever 14 remains at rest. The stop leg 36 of the advance pawl 5 thus remains in engagement with the notch 37 of the advance locking lever 14, despite the fact that the carriage gearshift bar 11 swings backwards and the toggle lever leg 9 cannot follow the movement of the roller 8. As a result, the toggle lever arm 9 is locked against pivoting in the counterclockwise direction, the forward push pawl 5 and the return pawl 4 cannot engage in the respective following tooth notch of the ratchet wheel, and consequently the carriage is not moved further to the right.

The car thus stops without switching. Upon receipt of the carriage return code, the carriage return lever 21 is raised so that it follows the upward movement of the function switch bracket 12 in contact with the lower edge of the same under the action of the spring tension; the free end of the carriage return lever 21 engages a notch in the carriage return pawl 19 (FIG. 1). The upward movement of the carriage return lever 21 locks the pressure lock rail 26 against movement upwards and to the left, so that the advance circuit for the carriage 28 is locked in the manner described above.

During the downward movement of the function switch bracket 12 according to FIG. 1, the carriage return pawl 19 is pressed down by the free end of the carriage return lever 21 against the action of the spring 38. When the carriage return pawl 19 goes down, the free end of the lever 20, which sits with the other end on the shaft 30, is depressed under the action of the driver lug 39. As a result, the angle lever 16 is pivoted about the pivot pin 40 in the counterclockwise direction by a driver attachment on the lower edge of the central part of the lever 20. A coupling rod 15 is articulated to the upper end of the angle lever 16 and is pulled backwards when the angle lever is pivoted counterclockwise. Thus, the coupling rod 15 pivots the lever 41 about the pivot pin 35 in a counterclockwise direction. Since one end of the lever 41 is hinged to the rear end 42 of the lever 3, which carries a release plate 43 at the front end, the lever 3 pivots about the pivot pin 35 in the counterclockwise direction together with the lever 41. The release plate 43 at the front end of the lever 3 lies between the lifting approaches of the respective pawls 4, 5 and 6 and the forward ratchet wheel 2. If the lever 3 is pivoted counterclockwise, the forward pawl 5 and the retaining pawl 6 are lifted out of the ratchet wheel 2 one after the other, and then the return pawl 4 the locking of the forward ratchet wheel 2 is released and the carriage 28 is returned to the left edge under the action of the spring 1.

The lever 3 has a downwardly directed stop leg at one end 47. As soon as the carriage return lever 21 has reached its lowest position, it engages the stop leg 47 in a notch 46 of a pawl 7 below the release plate 43 a, so that the same remains locked in this position until the carriage 28 on the left edge has run back.

The carriage return switch according to the invention must be constructed in such a way that that upon receipt of a backspace code, a backspace of the car by the Length of a step interval.

For this purpose, the invention proposes a device that additionally to the conventional reverse circuit is arranged next to the same and a reset pawl includes for the respective backstop of the ratchet wheel after a tooth pitch. This reset pawl is coupled to the toggle joint in such a way that that the forward thrust pawl has a small linear displacement.

If according to FIG. 1 received a code with the exception of the backspace code is, the lifting movement of the carriage return button 25 by the downward Driver approach blocked at least one code selector bar; if on the other hand the The back touch code is received, the carriage back touch lever 25 can through without hindrance the driver lugs of the code selection rail are raised, the lever 25 together is lifted with the function switch bracket 12.

Then the free end of the lever 25 falls into the recess of the carriage return switch latch 23 a. This adjustment of the carriage return button 25 locks the pressure lock rail 26 against a shift upwards and to the left, as well as when receiving the Carriage return codes. As a result, the advance of the carriage 28 is suppressed.

When the function switch bracket 12 goes down, the lever 25 is pressed down. As a result, the free end of the carriage return switch pawl 23 is taken down against the spring tension. The lowering movement of the pawl 23 presses the free end of the lever 24, which is pivotably seated on the shaft 30, under the action of the driver lug 45 of the pawl 23 downwards. Only when the lever 24 is pressed down does the downwardly directed driver attachment in the central part of the lever 24 pivot the angle lever 18 in a counterclockwise direction with respect to FIG. 1, the plate 17 attached to the left side surface of the angle lever being taken along in the same direction. Since the plate 17 has a small driver attachment 51, the rotary movement of the plate 17 also takes along the angle lever 16 against which the driver attachment 51 abuts in the counterclockwise direction.

The angle lever 16 is used to trigger the carriage return. The coupling rod 15 thus moves backwards, and the lever 3 with the release plate 43 pivots in the counterclockwise direction, just as in the context of the carriage return movement described above. The forward pawl 5 and the retaining pawl 6 are lifted out by the release plate 43 (FIG. 5). The forward ratchet wheel 2, which is connected to the retaining pawl 6 in the state of FIG. 4 was engaged, rotates back a small angular amount until the reset pawl 4 is completely in engagement with the toothed notch of the ratchet wheel on which the retaining pawl was previously placed (see FIG. 5), where the forward thrust pawl 5 and the retaining pawl 6 are excavated. This movement of the Minkenrades is converted into a linear movement of the carriage 28 for back-scanning the same by a small distance to the left. If the reset pawl 4 were also lifted out of the ratchet wheel in this case, the carriage 28 would be returned to the left writing edge in one go.

To suppress this undesirable process, the following trick is used: the lifting approach of the reset pawl 4 is at a somewhat greater distance from the release plate 43 than the lifting approach of the forward push pawl 5 and the holding pawl 6 based on the waiting state after the end of a work cycle according to FIG. 2, so that the pawls 5 and 6 first come free from the ratchet wheel 2 and only then the reset pawl 4 is lifted. The actuation of the release plate 43 must be carried out in such a way that the disengaging movement stops before the reset pawl 4 is disengaged and after the pawls 5 and 6 have been lifted out.

Such a stopping of the trip plate 43 is made possible by the invention obtained in the following way. At the lower end of the carriage return switch pawl 23 is a bevel 52 is formed. When the pawl 23 moves down, comes the inclined edge with a roller 22 into engagement, so that the pawl 23 is pivoted backwards. As a result, the free end of the lever 24 comes from the pawl 23 free. The pawl 23 is, as already said, when Lowering of the carriage return button 25 by pressing down the function switch bar lowered. The inclined edge 52 slides on the roller 22, whereby the switching pawl 23 in the position according to FIG. 9 is pivoted. This then also moves the carriage return button 25 from the section of the pawl 23. As a result, the pawl reverses 23 in the raised starting position according to FIG. 8 back. This is how the Lowering movement of the lever 24 through the driving lug 45 to the end, so that the disengaging movement the release plate 43 stops before the reset pawl 4 disengaged from the ratchet wheel is.

The suspension of the pivoting movement of the lever 3 with the release plate before the reset pawl 4 is disengaged means that the stop leg 47 has not yet engaged in the notch 46 of the switching pawl 7 either. The lever 3 thus begins its return movement in the starting position, and the other switching elements such as the carriage return button switch pawl 23, the carriage return button lever 125 and the reset button switch lever 24 return to the starting position (FIG. 10). As a result of the return movement of the lever 3 with the release plate in the starting position, the forward pawl 5 and the holding pawl 6 fall into the respective following pawl tooth of the ratchet wheel, which is adjacent to the pawl tooth acted upon by the reset pawl (see Fig. 6).

At this point in time, the car control bar 11 is on its return path and swings forward. The roller 8 sitting on the bracket strikes against the toggle lever arm 9 and pivots the same counterclockwise (see FIG. 2), so that it is returned to its starting position. At the point of greatest deflection of the return movement of the carriage switch bracket 11, the right end of the reset pawl 4 hits a release stop 10, so that the reset pawl 4 is pivoted counterclockwise due to the pressure occurring (Fig. 2). As a result, the reset pawl 4 is lifted out of the ratchet wheel. Only when the reset pawl is lifted does the ratchet wheel turn back until the forward push pawl fills the pawl tooth section in question, which is already in engagement with the tooth profile of the pawl.

As a result, the carriage 28 is back-scanned by exactly one step interval. The backspace occurs as many times as a backspace code is received.

Claims (6)

Claims: 1. Car back button device for a teleprinter with a latch-controlled and actuated by a carriage forwarding device Forward switching for gradual advancement of the carriage against a return spring action and with a reverse circuit for releasing the forward circuit in the Sense of the carriage return under the action of the return spring, characterized in that a reset circuit (23, 24) comprises a backstop (4), which the forward circuit when a backspace code is received after a full or partial switching step blocks in the reverse direction. 2. Wagenrückasteinrichtung according to claim 1 with a Forward ratchet wheel, a forward ratchet pawl operated in the direction of the carriage forward movement and a retaining pawl, both pawls of a release element of the reverse circuit are acted upon, characterized in that the backstop is used as a reset pawl (4) is designed for the forward ratchet wheel (2), the ratchet tooth by a partial amount the pitch of the forward ratchet wheel compared to the teeth of the pawls (5, 6) is offset, and that the reset circuit is a lever for the pawls (5, 6) from the forward ratchet wheel. 3. Wagenrückasteinrichtung according to claim 2, characterized in that the lifting approach of the reset pawl (5) opposite the lifting approaches of the pawls (5, 6) is offset and that the lifting element Trigger element (43) of the reverse circuit is used. 4. Wagenrückasteinrichtung according to claim 3, characterized in that the reset circuit comprises a on the actuating linkage (16, 15, 41, 42, 3) of the trigger element (43) acting by a Wagenrückastschaltklinkle (23) actuated carriage return button (25) and that a Stroke limiting element (22) for the carriage return switch pawl (23) is provided so that the working stroke of the carriage return button (25) is smaller than the working stroke of the carriage return lever (21) . 5. Wagenrückasteinrichtung according to claim 4, characterized by a stroke limiter for the carriage return switch pawl (23) in the form of an inclined edge (52) of the carriage resetting latch and a diverting element (22) for the respective disengagement of the carriage return switch latch (23) from the associated Drive lever (24). 6. Wagenrückasteinrichtung according to one of claims 3 to 5, characterized by a frame-fixed release stop (10) for the reset pawl (4) which holds the reset pawl lifted out of the ratchet wheel (2) in the waiting position of the forward circuit.