DE1223871B - Line switching mechanism for teletyping machines - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

H041

German class: 21 al -17

Number: 1223 871

File number: St 23719 VIII a / 21 al

Filing date: April 22, 1965

Opening day: September 1, 1966

The invention relates to a line switching mechanism for teleprinting machines to achieve an exact one Line advance at high speeds of sound, where the line feed is changed by changing Leverage ratios due to the pawl which is out of engagement with the ratchet wheel in the rest position can be pre-set and is fixed by a locking device that locks the pawl with the ratchet wheel Stop finds a defined limit.

With the condition set in telex technology to be carried out within a character Carrying out the line interchange is at higher clock speeds using conventional Line switching units no longer guarantee an exact line advancement, since the occurring high mass acceleration no longer allows reliable curve control.

So is z. B. a line switching device is known in which the by adjusting a stop lever The pawl performs a more or less large idle stroke before it comes into engagement with the ratchet wheel. At the end of the switching stroke, the switching pawl hits a stationary stop a lock acting in the feed direction between the pawl and the ratchet wheel which is prevented from being thrown overhead. This device has the disadvantages that the pawl on the one hand due to the 'idle stroke suddenly comes into engagement with the ratchet wheel, whereby an increased Material stress and unnecessary noise generation occurs, on the other hand only in the case of the maximum Line spacing uses the full switching stroke.

Another line feed device known from German patent specification 1033 245 avoids these disadvantages by providing an idle stroke due to the constant engagement with the ratchet wheel Switching pawl is avoided and an adjustment of the line feed by changing lever ratios full utilization of the entire stroke is permitted in every setting. On the other hand is liable this device has the disadvantage that there is no way to prevent over-throwing, because different end positions of the pawls are assigned to the different feed positions are. Furthermore, the pawl constantly engaged with the ratchet wheel has the disadvantage that turning the pressure roller back by hand is only possible after the pawl has also been lifted out.

All of these disadvantages are avoided by the line switching mechanism according to the invention. It enables on the one hand, when the latch is raised in the idle state, maximum utilization of the switching

Line switching mechanism for teletyping machines

Applicant:

Standard Elektrik Lorenz Aktiengesellschaft,

Stuttgart-Zuffenhausen, Hellmuth-Hirth-Str. 42

Named as inventor:

Heinz Gaissert,. '■

Johannes Hiller, Pforzheim

hubs, while on the other hand it is ensured that the intended line feed is adhered to exactly

- Will. This is achieved according to the invention in that the change in the lever ratio, which determines the degree of line advancement, is associated with a concentric adjustment of the pawl corresponding to the resulting line feed relative to the defined end position, in which the pawl interacts with a stationary catch pawl for the time of Reversal of direction establishes a positive connection between the ratchet wheel and stationary device parts.
The invention will be explained in more detail using an exemplary embodiment in conjunction with the drawings.

F i g. 1 shows a perspective illustration of the design of a line switching mechanism according to FIG Invention;

F i g. 1 a shows the lower part of the FIG. 1 only partially shown pull tab and associated operating mechanism;

2a and 2b show schematically the line switching mechanism of Fig. 1 in the idle state and at the time of the latch end position.

In the case of the in FIG. 1 in an exploded view for a better overview Form, shown in perspective, embodiment of a line switching mechanism according to FIG Invention is shown a part of the machine frame 1, in which, among other things, the shaft 2 of the pressure roller 3 and the axis 5 of the paper pressure rollers 4 are mounted. The shaft 2 and the axis 5 protrude accordingly the representation out of the frame part 1 and are used to store the most essential parts the line switching mechanism, the ratchet wheel 7 is fixedly arranged on the shaft 2, followed by a free one rotatable adjustment bracket 11, between which on the

609 658/270

Shaft a rocker arm 9 is also freely rotatable. The conclusion is formed by a rotary knob 6, which is fixedly arranged on the shaft 2, for setting lines by hand. A hand lever 17 is pivotably mounted on the axle 5 beyond the frame part 1, the lower part of which is angled like a bow and grips around the frame part in order to find the end of the protruding axle 5 for a further mounting. Between this end of the bracket and the frame wall, a catch pawl 20 and an index lever 18 are pivotably arranged on the axis 5 in alignment with the ratchet wheel 7. A spring 22 is also provided, by means of which the hand lever 17 is held in contact with the inside of the frame part 1. The hand lever 17 is used to set the line spacing marked by numbers la, to which locking holes 1 & in the frame part 1 are assigned, with which the hand lever engages in the corresponding settings via its locking bolt 17 a. About its bow-like part of the hand lever 17 determines on the one hand by a form-fitting guide 17b, 14b the position of the machine stroke on the rocker 9 transferring pull tab 14, which is rotatably connected via a bolt 15α with a pull lever 15 according to FIG Triggering of the line switching function carries out an always constant pivoting movement h. On the other hand, the hand lever 17 is also with. the adjustment bracket 11 via a slot guide 17 c, 116 in a form-fitting connection. The bracket 11, which can thus be adjusted into several positions via the hand lever 17, is provided with a stop bolt 11a, which serves as an abutment for the switching rocker 9, which is under the action of a spring 19. Furthermore, the adjusting bracket 11 is aligned with the switching pawl 8 a run-on bevel 12 is provided, through which the pivot on KlinkenaTm 9 a of the rocker arm 9 arranged pawl 8 is held against the action of a spring 8a in the rest position out of engagement with the ratchet. 7 a fixedly arranged in the frame part 1 stop 10 is used to stroke limiting lock the pawl 8 with the ratchet wheel 7 to avoid skidding effects.

The rocker arm 9 consists of a freely rotatable guide bushing 9d on the shaft 2, which is provided on the side facing the ratchet wheel 7 with a double lever consisting of the ratchet arm 9 α and a double lever consisting of the lifting arm 9 b and on the opposite side with a switching arm 9 c . The lifting arm 9 & is angled at the end. Through the free leg, the catch pawl 20 is held out of engagement with the ratchet wheel 7 via its pin 20 a in the rest position of the shift rocker 9 and during a certain part of each indexing stroke. The spring 19 acting on the lifting arm 9 b also serves as its suspension through its counter-suspension on the index lever 18.

Via the switching arm 9 c of the rocker 9, the pull tab 14 acts on the line switching mechanism. For this purpose, the switching arm is provided with a smooth sliding surface which runs obliquely to the pulling direction in accordance with the stroke h and via which the pull tab 14 acts with its sliding roller 14 a. The inclination and design of the surface is chosen so that when the tab 14 (Fig. 2b) is pulled, the entire length of the sliding surface profile lies on or approximately on the arc around the tab pivot point 15 a passing through the point of contact between the roller 14 a and the sliding surface , wherein the sliding surface can be straight if the pull tab 14 has a certain minimum length. This ensures that in all. Line switching positions of; Hand lever-17, the displacement of the roller 14 a -on the Geitfläche of the arm 9 c and thereby 'a the switching stroke changing effective lever length of the switching arm 9 c to result in, the rocker arm 9 and thus the pawl 8 is a constantly

ίο Assume constant stroke end position.

When the line feed setting is changed, the interlocking guide 17 b, 14 b causes an angular adjustment of the pull tab 14 in the idle state of the line switching mechanism, which is directed from the maximum value towards the minimum value against the sliding surface, which is inclined in the rest position. In order to keep the necessary play between the sliding surface and the roller, the adjusting bracket 11 is also adjusted with the pull tab via the form-fitting slot guide 17 c, 11 b by the hand lever 17 in such a way that it pivots the rocker arm 9 resting on the stop 11a in such a way that the points of the sliding surface located opposite the sliding roller 14 α all lie on an arc around the tab pivot point 15 a, the radius of which is less than or at most equal to that of the circle through the point of contact between roller 14 a and the sliding surface in the unloaded state. With the stiffening of the Sehaltschwinge 9, the pawl 8 is tracked by the ramp 12 attached to the bracket 11. Their position is chosen so that, although free turning back and forth of the roller 3 by hand is guaranteed, the idle stroke which inevitably results therefrom is, however, as small as possible.

The latching positions of the hand lever 17 result from those matched to the tooth pitch of the ratchet wheel 7 Adjustment positions of the adjustment bracket 11, the adjustment angles being equal to one another and in each case correspond to one or a multiple of a tooth pitch of the ratchet wheel 7.

In order to have a defined and secured To ensure the position of the pressure roller 3, the index lever 18, which pierces under the action of the springs 19 and 20 έ and which is about to be provided, is provided

-45 Adjustment purposes vertically adjustable locking piece 18g is in constant engagement with the ratchet wheel 7.

With reference to FIGS. 2a and 2b, the functional sequence of a switching cycle will now be explained in connection with what has been described above. ^;

In the two schematic representations, the setting for a double line feed is strongly drawn out, while the settings for one and a half line feed are indicated by dash-dotted lines.
Based on the in F i g. 2 a shown rest position, in which the pawl 8 is held by the counter-position of the rocker arm 9 on the stop 11a by the ramp 12 out of engagement with the ratchet wheel 7, when the line switching function is activated, the pull tab 14 is actuated by the pull lever 15 On the roller 14 a on the switching arm 9 c acting pull tab 14 pivots the rocker arm 9 clockwise, whereby the pulled pawl 8 in sliding from the remaining in its position run-up slope 12 in engagement with the ratchet wheel 7 and this for the from the point of application of Roller 14a with the switching arm 9 c given effective lever length and

the constant machine stroke h takes along the resulting angular path.

Fig. 2b shows the same end position resulting for all three settings, in which the switching arm 9 c lies with the profile of its sliding surface on the S circular arc around the lug pivot, which runs through the point of contact between the roller 14 a and the switching arm sliding surface. In this end position limited by the machine stroke h , the pawl 8 has not yet fully reached its end position. The last fraction of the path is covered together with the moving rocker arm 9 due to the inertia until the locking of the ratchet wheel 7 via the pawl 8 and the stop 10 of the indexing movement sets a defined limit in which by the in the feed direction effective locking also prevents over-throwing. As the pawl 8 approaches its end position, the lifting arm 9 b of the rocker arm 9 releases the catch pawl 20 (not shown in FIGS. 2a and 2b), which thus engages the ratchet wheel 7 due to its spring 20 b. This is adjusted so that its ratchet tooth, shortly before the pawl 8 has reached its end position, falls behind a ratchet tooth. This position is maintained by the catch pawl 20 up to a certain point in time of the backward movement of the rocker arm 9. Thus, the ratchet wheel 7 and thus the pressure roller 3 is positively connected to the machine frame 1 via the stop 10 on the one hand and via the pawl 20 and the axle 5 on the other hand for the time of the reversal of direction of the moving switching elements 8 and 9. As a result, the skidding and bouncing effects that occur at high line feed speeds in the end position, caused by the kinetic energy stored in the printing roller, are intercepted, so that an exact line break is achieved.

In the course of the return of the rocker arm 9 brought about by the spring 19 to its starting position, the catch pawl 20 is first disengaged from the ratchet wheel 7 by the lifting arm 9 b , which is followed by the pawl 8 sliding back on the run-up bevel 12. Thus, the ratchet 7 is released again, so that a manually operated setting of the pressure roller 3 is possible at any time. Only the index lever 18 acts via its locking piece 18a in a manner that does not influence the free forward and reverse rotation of the roller 3 in order to maintain the selected roller position on the ratchet wheel 7.

Claims (8)

Claims: 55 1. Line switching mechanism for teletypewriters to achieve an exact line advance at high switching speeds, in which the line feed by changing lever ratios due to the rest position is out of engagement with the ratchet pawl can be preset and by a the pawl with the ratchet locking, fixed stop a defined limit finds, characterized in that with the determining the degree of line advancement Change of the leverage ratio according to the resulting line feed concentric adjustment of the pawl (8) connected to the defined end position is, in which the pawl (8) interacts with a stationary catch pawl (20) a positive connection between the ratchet wheel for the time the direction is reversed (7) and stationary device parts (10, 20, 1). 2. Line switching mechanism according to claim 1, characterized in that the pawl (8) with a centrally to the ratchet wheel (7) rotatably arranged shift rocker (9) is positively connected, which on the one hand via a switching arm (9 c) with a pull tab (14) in There is an operative connection and, on the other hand, brings the catch pawl (20) into or out of engagement with the ratchet wheel (7) in relation to the ratchet position via a lifting arm (9 b). 3. line switching mechanism according to claim 1 and 2, characterized in that the concentric Adjustment of the pawl (8) by means of a in the idle state with the rocker arm (9) in Frictionally engaged adjusting bracket (11) takes place, and that the lifting of the pawl (8) in the rest position causing the run-up slope (12) is part of the adjusting bracket (11). 4. line switching mechanism according to claim 1 to 3, characterized in that the adjustment movements of the bracket (11) depending on the change in the position of the pull tab (14) certain effective lever length of the switching arm (9 c) are equal to each other and each correspond to one or a multiple of a tooth pitch of the ratchet wheel (7). 5. line switching mechanism according to claim 4, characterized in that the adjusting bracket (11) is operated via a hand lever (17) which determines the pull tab position. 6. Line switching mechanism according to claims 2, 4 and 5, characterized in that the surface of the switching arm (9 c) in operative connection with the pull tab (14) is smooth and designed so that the points of contact in the mutual adjustment on the corresponding arc about the pivot point (15 a) of the pull tab (14) lie, and that these Schaltarmfläche is in the actuated state of the pull tab (14) with their profile on the line passing through the point of contact arc about the flap pivot point (15 a). 7. line switching mechanism according to claim 6, characterized in that the pull tab (14) so is long that with a straight design of the Schaltarmfläche a sufficient approximation to the Arc curvature is achieved. 8. line switching mechanism according to the preceding claims, characterized in that that a resiliently on the ratchet wheel (7) acting index lever (18) the pressure roller position during of rest periods fixed. Considered publications:
German Patent No. 1033 245;
German utility model No. 1860153. 1 sheet of drawings 609 658/270 8.66 © Bundesdruckerei Berlin