DE2156576C2 - Device for changing the type of stroke force in power-driven writing units - Google Patents

Description

The invention relates to a device for changing the stroke force of the individual types in the case of power-driven writing mechanisms with a single, drivable by means of a cam drive for printing against the recording medium and by means of a return spring movable back to the normal position type head on a counter the paper roll movable type head carrier cinsioHbar is arranged.

Various writing mechanisms have become known which have a device for adjusting the impact force according to the number of copies required and the size of the copies to be printed Types own.

For example, from the German Auslegeschrift 1 190 006, a typewriter is known in which the type carrier can be driven by different cam disks. which can be coupled to one for each type stop Shaft are arranged side by side.

ίο The cam disks have different ones Cam height and shape so that the cam follower roller and the parts operated by it are different Get accelerations and speeds, depending on which of the cam disks the roller is in contact with. To control this cam follower element a not small number of control members is required. Would this well known facility also with a device for changing the thickness of the impression according to the number required

so provided with penetration, so are still further levers required, which the whole device complicate it even further.

On the other hand, the German Offenlcgschrift I 052 711 a device for changing Adjustment of the strike energy of type levers is known, in which only those on the type carrier acting force of the return spring, which counteracts the force driving the type carrier, accordingly the desired velocity can be changed. This known arrangement enables No setting of the velocity for a total type carrier according to the type size and the number of copies required.

The invention is based on the object of a type carrier carrying a large number of types the stroke force via a common device according to the type size and number to make the copies to be made divisible.

According to the invention, this object is achieved by that the component of the force of the return spring acting on the carriage is via a two-armed Swivel lever is adjustable, one arm of which is articulated with the slide of the type head carrier is, the pivot point is adjustable in the longitudinal direction of the pivot lever, and the second Arm has a Lagcrbolzen around which a rocker arm to a vertical / to pivot lever lying MitteUage is pivotable to a limited extent. On whose one end engages the return spring.

A preferred embodiment of the object » the invention is illustrated in the drawings and explained in more detail below. It shows

F i g. 1 is a diagrammatic representation of the subject matter of the invention,

F i g. 2 a detail of FIG. 1 with the rocker arm in the position for capital letters and

Fig. 3 shows the detail according to Fig.2 with the Rocker arm in the position for small letters.

In Fig. 1 is movable along a paper roll 1 Carriage 3 is shown, on which a slide 5 movable perpendicular to the paper roll 1 as a type head carrier is arranged. On this slide 5 is a spherical type head? with on its scope arranged in rows and columns arranged characters. A two-armed pivot lever 9 is around a bolt 11 pivotably on the carriage 3

arranged, the first arm 13 articulated at 15 rr.it the carriage 5 is connected and the second arm 17 has a Lagerbolzcn 19 to which a Rocker arm 21 is pivoted to a limited extent.

This rocker arm 21 has a bolt 22 to which a return spring 23 is hinged. This Return spring 23 acts on both sides of a tilted position in the opposite direction on the Rocker arm 21. The pivoting movement of this rocker arm 21 is controlled by stops arranged on it 25 and 27 limited, which one with the arm 17 of the pivot lever? cooperate. The return spring On the other hand, 23 is firmly connected to the carriage 3.

On the other arm 29 of the rocker arm 21 an Ansciilaastift 31 is arranged, which for the purpose of switching this rocker arm 21 with a selector lever! 33 cooperates. This selector lever 33 is arranged pivotably about a bolt 35 on the carriage 3 and in the rest position rests against a stop 39 due to the force of a spring 37. The carriage 3 is driven by a cam 41 which can be triggered when the load is actuated and which interacts with a cam follower element 43 on an arm of a pivot lever 45. This pivot lever 45 is on the balance. 3 pivotably mounted and with its fork-shaped end 47 comprises a bolt 49 on the slide 5. In the rest position of the selector lever 33, the rocker arm 21 rests with its stop 25 on the arm 17 of the pivot lever 9. If the cam 41 is released in this position to act on the carriage 5 to produce an imprint of the type head 7 on the paper roller 1, the return spring 23 is connected to a lever arm "" according to FIG. 2 z. B. effective for large box lobes. If small-area letters / imprints were also made in this tilted position of the rocker arm 21, a perfect imprint cannot be produced. These small, flat letters would smash the paper. In order to prevent this, the selector lever 33 is acted upon in such a way that the rocker arm 21 via its stop pin 31 and the incline 51 of a recess 53 on the selector lever 33 into the other tilted position according to FIG. 3 is brought. In this position the return spring "3 is effective on a larger lever arm " b " . In addition, the return spring 23 is further tensioned in this position, whereby more drive energy is absorbed by the return spring 23. Since the carriage 5 always receives the same impulse via the cam drive, The clear-surface types assigned to this position are imprinted with less energy. Only when the selected key is pressed for small-area letters is a code signal sent via the corresponding key lever to the selection magnet 71, which pivots the selector lever 33 against the spring force 37 about the bearing pin 35 , whereby the stop pin 31 of the rocker arm 21 over the slope 51 of this lever 33

ίο is acted upon. NaJi every impression is made the rocker arm 21 automatically returns to its starting position according to FIG. 2 brought as the stop pin 31 of the rocker arm 21 when pivoting the pivot lever 9 back into the starting days runs against the run-up slope 54 of the recess 53 of the selector lever 33. This will make the rocker arm 21 is applied counterclockwise, whereby it returns to its original position (according to Fig. 2).

In order to be able to adjust the spring force of the return spring 23 in the two tilt positions of the rocker arm 21, the stops 25 and 27 are arranged to be adjustable around the rocker arm 21. In addition, the return spring 23 is connected at one end to an adjusting screw 75 which is adjustably arranged on the carriage 3.

In order to adapt the thickness of the individual characters to the number of copies required, the pivot lever 9 is provided with an elongated hole 55 in which the bolt 11 of a bearing lever 57 engages, which is mounted on the carriage 3 (59) and via a pull wire 61 with a lockable, manually adjustable adjustment lever 65 is connected. This adjusting lever 65 has a Bolt 67, which cooperates with a locking toothing 63 in order to adjust its rotational position. The Lapgloch 55 is formed in the shape of a circular arc to allow pivoting of the bearing lever 57 about the bolt 59 to facilitate. Even when adjusting the bearing lever 57 and thus of the bolt 11, the effective lever arm of the return spring 23 is changed. At a Adjustment of the adjustment lever f> 5 for several copies less energy is absorbed by the return spring 23 than when adjusting the adjustment lever 65 for just one copy.

The subject matter of the invention enables an effective change in the stroke force both accordingly the number of copies as well as small and large characters, with an approximately uniform specific surface pressure is achieved for all types in each setting.

1 sheet of drawings

Claims (5)

Patent claims: 1.Device for changing the stroke force of the individual types in power-driven writing units with a single type head which can be driven by means of a Noeken drive to print against the recording medium and which can be moved back into the normal position by means of a return spring, which is arranged adjustably on a type head carrier which can be moved against the paper roller, characterized in that the force acting on the carriage (5) component of the force of the return spring (23) is adjustable via a two-armed pivot lever (9), of which one arm (13) is pivotally connected to the carriage ¹ S) of the Tvpenkopfträgcrs whose Sdiwenkpunkt is adjustable in the longitudinal direction of the pivot lever (9), and the second arm (17) has a position pin (19) around which a toggle lever (21) is pivoted to a limited extent around a center frame perpendicular to the pivot lever (9). at one end of which the return spring (23) engages. 2. Apparatus according to claim 1, characterized in that a pivot point of the The pivot lever (9) forming the bolt (II) can be displaced in a slot '' (55) of the pivot lever (9) is and that the bolt (11) is attached to a Lagerhebcl (57) which on the carriage is mounted and via a Z ".gdraht (61) with a latching adjustment lever that can be adjusted by Hond (65) is connected. 3. Device according to claim 2, characterized in that that the setting lever (65) has a hole (67) which is used for the purpose of setting Rotational position interacts with a Rasl / .ahnung (63). 4. Apparatus according to claim 1, characterized in that the rocker arm (21) with two Stops (25. 27) is provided, which alternately, depending on the tilt position, on the pivot lever (9). 5. Apparatus according to claim 4, characterized in that the rocker arm has a stop pin (31) which cooperates with a selector lever (33) for the purpose of switching the tilt position. (·>. Device according to claim, characterized in that that the selector lever (33) can be adjusted by a magnet (69) and returned to the starting position by a return spring (37) is movable.