DE1082601B - Devices for tensioning the rubber blanket on printing cylinders - Google Patents

Description

GERMAN

LIBRARY

OF THE GERMAN PATENT OFFICE

The invention relates to devices for tensioning the rubber blanket on printing cylinders.

It is known that the elevators used for printing cylinders in the form of rubber blankets by clamping devices of various types to be attached to the printing cylinder and to be clamped on this.

One of the known devices provides for one end of the rubber blanket to be attached to a tensioning shaft attach, on which a gear is arranged, which is in engagement with a rack. In the Slidable guide of a pivoting console, this rack is slidably received, so that at Pivoting the console the rack can be quickly brought into engagement with the gear. That Adjustment and automatic locking of the console in the position of engagement of the rack with the gear is carried out by a single machine part, for example by an eccentric. The tensioning of the Rubber blanket takes place in such a way that after pivoting the rack into the engagement position of the Gear made the adjustment of a threaded spindle connected to the rack which triggers a longitudinal movement of the rack in the sliding guide of the pivoting console and at the same time that which is arranged on the tensioning shaft of the rubber blanket and is in engagement with the rack gear located a rotary movement in the clamping direction granted.

With this device, the tensioning of the rubber blanket around the impression cylinder is only carried out by one End of the blanket, made from the end attached to the expansion shaft. this has the consequence that the clamping mode is inelastic, in which the unequal tension on the printing cylinder the blanket does not experience any tension compensation. The tightening of the rubber blanket happens on one side and leads to an uneven tension of the rubber blanket on the impression cylinder.

The same disadvantage occurs in another known device in which the tensioning of the Rubber blanket is made by three movable jaw members attached to racks, which over distributed across the width of the printing cylinder, releasably connected to one end of the rubber blanket. on a drive shaft leading longitudinally through the printing cylinder are at the intervals of the racks Gears arranged, which are in engagement with the racks and the adjustment of the jaw members bring about.

Furthermore, a device is known in which both ends of a rubber blanket by means of tensioning rails be clamped on two opposite surfaces of an expansion shaft with a square cross-section.

Tensioning devices
of the blanket on printing cylinders

Applicant:

VEB Kartonagenmaschinenwerk KAMA, Dresden-A 16, Blasewitzer Str. 21/25

Helmut Gottschald, Werner Heller
and Erich Leichsenring, Dresden,
have been named as inventors

The rubber blanket is tensioned here by putting a key on one side of the tensioning shaft located square. On the opposite end of the expansion shaft is a Ratchet wheel attached, in which a pawl mounted on the side wall of the printing cylinder engages.

The rubber blanket clamped on the printing cylinder is in its clamping position by means of the locking gear secured.

Although with this device the clamping of the rubber blanket on the impression cylinder takes place at the same time is made at both ends of the blanket, there is also a uniform contact tension of the Rubber blankets cannot be achieved, as this is independent of the different blanket tension on the printing cylinder When turning the expansion shaft, both ends of the rubber blanket are exposed to the same tensioning effect are. A voltage equalization cannot therefore be achieved with this device.

The same also applies to a further known device in which one end of each of the two clamping spindles is provided with a square to push through once with a square key Turning one of the clamping spindles or both clamping spindles at the same time, the blanket on the Tighten pressure cylinder.

Further disadvantages of these known devices consist on the one hand in the lack of fine adjustment because the tensioning of the rubber blanket is carried out directly on the tensioning shaft, on the other hand in the Limitation of the clamping possibility by the arrangement of a locking gear with which a clamping of the rubber blanket is only possible in the area of one tooth pitch of the ratchet wheel.

Another possibility of tensioning the rubber blanket on the circumference of a printing cylinder is through

009528/57

Devices known, on the expansion shafts worm gears are attached, which with transverse to the screw spindles arranged in the pressure cylinder are in engagement with the expansion shafts. One of these Devices is also provided with clamping spindles, which span the width of the printing cylinder are distributed in order to ensure even tensioning of the rubber blanket only over the width of the impression cylinder enable.

It is also known to have a rotary movement transmitted at the end of the printing cylinder via a worm drive to be transmitted to a tensioning shaft by a spur gear drive on the second tensioning shaft, so that too in this device a simultaneous tensioning of the rubber blanket made from both ends of the blanket can be.

In the known embodiments, the disadvantages outlined above are not eliminated, and the long-standing demand for a tension-equalizing effect on that with unequal tension to achieve on the circumference of a printing cylinder resting rubber blanket, is also with a Adjustment of both expansion shafts not fulfilled at the same time.

In the following, an apparatus will be described according to the invention, which the known apparatus inherent disadvantages eliminated. To tighten the with different tension on the circumference of the printing cylinder resting rubber blanket in elastic and tension-compensating To make self-regulating way of both ends of the rubber blanket is the one for a reciprocal Adjustment of the two expansion shafts provided worm spindles assigned a pivot lever arrangement.

The invention is described in more detail using an exemplary embodiment shown in the drawing. It shows

Fig. 1 the front view of the device,

Fig. 2 shows the side view of the device in the direction of arrow A in Fig. 1,

Fig. 3 shows the side view of the device in the direction of arrow B of Fig. 1,

Fig. 4 the clamping of the rubber blanket according to section line CD in Fig. 1.

Both ends of a blanket 2 placed around a printing cylinder 1 are clamped onto the surfaces 5 of the two tensioning shafts 6, 7 by tightening the clamping screws 3 by means of the clamping strips 4 that extend over the width of the printing cylinder. These are passed through the channels 8, 9 of the printing cylinder 1 and stored in the side walls 10 of the printing cylinder. At both ends of the tensioning shaft 6 a worm wheel 11 is attached, which meshes with its teeth in the thread of a worm spindle 12. The worm spindles 12 are supported in one guide bearings 13 each arranged on the two side walls 10 of the printing cylinder 1, in which the worm spindles 12 are only loosely guided. By placing the hemispherical ends 14 of the two worm spindles 12 on the inclined surface 15 of the clamping levers 17 mounted in the pivot point 16, when the worm spindles 12 are adjusted, they are pressed against the contact pins 18 of the pivoting levers 19 arranged at the two ends of the clamping shaft 7 and thus a pivoting movement of the Swivel lever and the expansion shaft achieved in the tensioning direction of the rubber blanket. The two pivot levers 19 are secured against the dead center position by the two stop pins 20. The lifting of the tensioning lever 17 and the simultaneous pivoting of the pivoting lever 19 by adjusting the worm spindles 12 only occurs when the rubber blanket 2 attached to the tensioning shaft 6 is already tensioned so tight that both worm gears 11 by blocking the tensioning shaft on the with the worm gears engaged worm spindles 12 exert the action of a nut, so that the worm spindles are moved against the inclined surface 15 of the clamping lever during a further adjustment. In this way, depending on the tension of the rubber blanket 2 on the printing cylinder Ij, either the two tensioning shafts 6, 7 are simultaneously given a rotary movement in the tensioning direction, or their rotary movement takes place in a self-regulating interaction, in order to equalize tension with simultaneous tensioning of the blanket bring about the pressure cylinder. After the cloth has been tensioned, the screw spindles 12 loosely guided in the clamping bearings 13 are also locked in their tensioned position by means of the locking screw 21 for self-locking of the screw spindles 12.

Claims (1)

Claim: Device for tensioning the rubber blanket on a printing cylinder, with which the tensioning of the Rubber blanket, the ends of which are each attached to a tension shaft, from both ends of the blanket an adjustment of the worm spindles which are in mesh with worm gears is carried out is, characterized in that the two worm spindles (12) for a reciprocal Adjustment of both expansion shafts (6, 7) is assigned a pivot lever arrangement (17, 18, 19). Considered publications:
German patents Nos. 387 696, 475 170, 480103; U.S. Patent Nos. 1215 344, 1414104, 2,541,254, 2,778,307. 1 sheet of drawings © .00 »528/57 5.60