JPH0155107B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plate cylinder for an offset rotary printing press, which is provided with a plate tensioning device in the cylinder groove.

A typical plate cylinder used in offset rotary printing presses is covered with a printing plate carrying the print image to be printed. The printing plate, which is stretched onto the plate cylinder, is secured at its ends by a tensioning device, for example a tensioning rail, which is arranged in an axially extending cylinder groove. (See Figure 438, p. 371, 1975).
In this type of so-called single-rotation printing press, the printing plate surrounds almost the entire printing cylinder. However, plate cylinders on which two printing plates are stretched are also already known. The two printing plates are tensioned on the printing form cylinder in longitudinal register by means of a tensioning and adjustment mechanism located in the cylinder groove. In plate cylinders of the above-mentioned type, known for example from German Patent No. 442,934 and German Patent Application Publication No. 1235,953, each revolution of the plate cylinder causes two blanket cylinders of similar size to Two printed images are transferred.

Starting from this known state of the art, the object of the invention is to set up a printing plate with at least two printed images having similar or different subject matter and which can be adjusted individually with respect to length registration. Our goal is to provide a printing cylinder that can.

In order to solve this problem, in the configuration of the present invention,
The forme cylinder is provided with at least one additional groove extending parallel to its axis, in which a groove insert movable outside the outer circumferential surface of the forme cylinder is disposed, and two Length registration of one of the two printed images is carried out using a plate tensioning device provided in the barrel groove, and length registration of the other printed image is carried out using a groove insert in an additional groove. the groove insert is supported within the groove by an eccentrically supported adjustment shaft;
A groove insert is connected to the bottom of the groove via a tension spring.

To provide a multi-rotary printing press in which two or more printed images having the same or different subject matter can be transferred to a blanket cylinder for each rotation of the plate cylinder by using only one plate cylinder. An advantage of the present invention is that it allows for In this case, the length registration of the individual printed images on the form cylinders can be adjusted individually. Compared to known two-turn or multi-turn printing presses with two or more printing plates on the plate cylinder, the invention has the further advantage that the production costs associated with the necessary tensioning devices are low. There is.
Because two or more printed images can be
This is because by arranging the plates on one printing plate, it is only necessary to tighten both ends of this one printing plate using the printing plate tensioning device. The groove may optionally be narrower than the barrel groove with the printing plate tensioning device.

The use of a plate cylinder with two grooves and on which only one printing plate is stretched has already been disclosed in German Patent No.
It is known from specification No. 609099. In this known plate cylinder, a printing plate tensioning device is arranged in one of the grooves, while the other groove is covered by a molded member. However, in contrast to the design of the plate cylinder according to the invention, this profiled element is not movable in the radial direction, so that it can be used to register the length of the printing plate stretched on the known plate cylinder. It is impossible to do so.

Next, embodiments of the present invention will be described with reference to the drawings.

The drawing shows a forme cylinder 1 schematically in a side view. As is well known, the plate cylinder 1 is rotatably supported between both side walls of the printing press, and a dampening device and an inking device are attached to the plate cylinder 1. It is crimped onto a parallel rubber cylinder. A printing plate 2 is attached to the printing cylinder 1, which almost completely surrounds the printing cylinder 1. A printing plate 2 consisting of two parts has printed images A and B.
The subject matter of these printed images A and B may be the same or different.

The plate cylinder 1 is provided with a groove 3 and a cylinder groove 4 located diametrically opposite the groove 3. The trunk groove 4 has a conventional plate tensioning mechanism and a length registration mechanism, for example, plate tensioning devices 5 and 6, and
Both ends of the plate are tightened by these plate tensioning devices 5 and 6. A radially movable groove insert 7 is located in the axially extending groove 3 . The groove insert 7 is supported on an eccentrically supported adjustment shaft 10, which is eccentrically supported on both end faces of the plate cylinder 1 by eccentric supports 11.

The illustrated groove insert 7 is U-shaped. Both legs of the groove insert 7 are each connected to one end of a tension spring 8, 9, the other end of which is fixed to the bottom of the groove 3. This causes the groove insert 7 to be pulled into the groove 3 and the adjustment shaft 1
It is pushed towards 0. By rotating the eccentric bearing 11, for example by means of a lever, the groove insert 7 is moved in the radial direction.

Adjustment of the length registration of the printed images A and B located on the printing plate 2 is carried out as follows: The printed image A is placed on the printing plate placed in the cylinder groove 4, as in the general case. Length registration takes place by means of the tensioning device 5. After the desired length registration of the print image A has been carried out by means of the printing plate setting device 5, the length registration of the print image B is carried out by rotating the eccentric support 11. By raising the groove insert 7, the printing image B or the section of the printing plate 2 which contains the printing image B is shifted in a counterclockwise direction. By a corresponding rotation of the eccentric bearing 11, the tension springs 8, 9
When the groove insert 7 is drawn into the groove 3 as a result of the force action, the length registration of the printed image B is adjusted in the clockwise direction. After adjusting the length registration of the printed image B, the printing plate tensioning device 6 is tightened.

In the illustrated embodiment, two printed images A, B
A printing plate 1 having the following is used. However, within the scope of the invention it is possible to provide the printing plate 2 with a large number of printed images. In this case,
For each additional printed image, it is necessary to provide the form cylinder 1 with a further groove with the illustrated length registration adjustment device in the form of a radially movable member. Furthermore, with regard to the shape, the control device and the configuration of the groove insert 7 can be selected with appropriate dimensions and corresponding components for the radial movement of the groove insert 7, depending on the particular specifications in each case. It is necessary to cover necessary and sometimes unnecessary grooves.

[Brief explanation of drawings]

The drawing is a side view schematically showing the plate cylinder of the present invention. 1... Plate cylinder, 2... Plate plate, 3... Groove, 4... Body groove, 5, 6... Plate tensioning device, 7... Groove inserter,
8, 9...Tension spring, 10...Adjustment shaft, 11...
...Eccentric support, A, B...Printed image.

Claims (1)

[Scope of Claims] 1. A plate cylinder for an offset rotary printing press with a plate tensioning device in the cylinder groove, in which the plate cylinder 1 is provided with at least one additional groove 3 extending parallel to its axis; A groove insert 7 is disposed in the groove 3 so that the plate cylinder 1 can move out of the outer peripheral surface, and the length registration of one of the two printed images A and B provided on the plate 2 is carried out. , by means of a printing plate tensioning device 5 provided in the barrel groove 4, such that the length registration of the other printed image B is carried out by movement of the groove insert 7 in the additional groove 3. A groove insert 7 is supported in the groove 3 on an eccentrically supported adjustment shaft 10, and the groove insert 7 is connected to the bottom of the groove 3 via tension springs 8, 9. A plate cylinder for an offset rotary printing press, which is characterized by: 2. Form cylinder according to claim 1, wherein the groove insert 7 is of U-shaped construction, and a tension spring 8, 9 is connected to each leg of the U-shaped groove insert 7. 3 Plate plate 2 with two printed images A and B is plate cylinder 1
Claim 1, characterized in that the additional groove (3) is arranged diametrically opposite to the body groove (4) with the printing plate tensioning device (5, 6). Print cylinder.