DD203868A1 - DEVICE FOR PRINTING AND DISCONNECTING CYLINDERS - Google Patents

Abstract

The invention relates to a device for Druckanstellen and -abstellen of cylinders in sheetfed offset printing presses, wherein the arrival as well as the stopping of the cylinder takes place successively and in the region of each opposite cylinder channels. The aim of the invention is to increase the print quality and already to print the first sheet after printing in perfect quality. The task is to einzaerben the entire pressure surface of the blanket cylinder with the first machine cycle after the print exhibition. According to the invention, this is achieved by arranging bearing levers pivotable about the center of the plate cylinder, provided with rotatable eccentric bushes, supported in planes of the blanket cylinders, and providing actuating means acting successively to rotate the eccentric bushings and pivot the bearing levers , Application: Printing machines.

Description

Device for pressure on and off of cylinders

Field of application of the invention

The invention relates to a device for printing on and off of cylinders in sheet-fed offset printing machines, wherein the arrival as well as the stopping of the cylinder takes place successively and in the region of the respective opposite cylinder channels.

Characteristic of the known technical solutions

At modern sheetfed offset printing machines, the requirement is made that with the hiring of the print already the first sheet is fully printed, but this is only possible if previously the blanket cylinder was supplied over the entire printing surface with fresh paint.

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By, the DD-PS 86 631 a satisfying this requirement solution is made known.

The on and off operation of the cylinder is completed in several phases. First, the plate cylinder is set in the area of the opposite cylinder channels to the blanket cylinder. Thereafter, the employment of the blanket cylinder to the impression cylinder without the employment of the plate cylinder to the blanket cylinder also takes place in the region of the opposite cylinder channels. The plate cylinder and the blanket cylinder are mounted in eccentric bushings. The rotation of these eccentric bushes is carried by attached to the same arm, which are connected by a coupling and form a parallel-guided four-bar linkage. By hydraulic working cylinder acting on the entire four-bar linkage, as well as on the coupling takes place on and off the blanket cylinder and the plate cylinder sequentially.

Although this device meets the requirement of consistent pressure on and off, but has the disadvantage that when turning on and off relatively large masses must be moved and the actuator has many points of articulation, whereby a high engine performance can not be achieved.

Object of the invention

The invention aims to increase the print quality and already print the first sheet after Druekanstellen in impeccable quality.

Object of the invention

The invention is based on the object, with reasonable effort, a device for turning on and off the pressure

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create with the entire printing surface of the Guminizylinders is already fully colored with the first machine cycle after the pressure setting and to achieve a high machine line, the moving masses are kept as small as possible.

Essence of the invention

According to the invention this is achieved in that pivotable about the center of the plate cylinder bearing levers are arranged, which are provided with rotatable eccentric bushings in which the blanket cylinder is mounted, and that for rotating the eccentric bushings and for pivoting the bearing lever successively becoming effective adjusting means are provided , For pivoting the bearing levers are as, adjusting means arranged hydraulic working cylinder, which are each attached with one end to the Lagerheblen and with the other end on the machine frame. As adjusting means for rotating the eccentric bushings hydraulic working cylinder or in a second construction variant rotary vane motors are arranged, which are fixed to the bearing levers.

Ausführungsbeisρie1

The invention will be explained below in some embodiments.

In the accompanying drawings show:

Pig, 1 the schematic representation of the gearbox for pressure on and off - with the pressure off

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Pig. 2 like Pig. 1-1. Phase of pressure adjustment Pig. 3 like Pig. 1-2. Phase of pressure adjustment

Pig. 4 is a schematic representation of a second construction variant of the transmission for pressure on and off - when the pressure is applied

The printing unit of sheet-fed offset printing machines in Reihenbauart is essentially formed by the plate cylinder 1, the blanket cylinder 2 and the impression cylinder 3. In the inventive device for pressure on and off the plate cylinder 1 and the pressure cylinder 3 is rigidly mounted in the machine frame.

The blanket cylinder 2 is mounted in mounted in the machine frame pivotable bearing levers 4, 4 ^T. The fulcrum of the bearing levers 4, 4 ^f coincides with the center of the plate cylinder 1. At the other end of the bearing lever 4, 4 ¹ e is a rotatable eccentric bushing 5, 5 ', in which the blanket cylinder 2 is mounted on both sides, arranged. For turning on and off the blanket cylinder 2 to the plate cylinder 1 and the impression cylinder 3 actuating means 6 are provided. The arranged in the present embodiment for pivoting the bearing levers 4, 4 'on both sides of the machine frame hydraulic working cylinders 7, 7 ^{1 are} formed, which interact with the bearing levers 4, 4 ^f .

In a first construction variant, the same fixed levers 8, 8 ^{T are} connected to rotate the eccentric bushes 5, 5 '. To these levers 8, 8 ^! and the bearing levers 4, 4 ^! is ever a twisting the eccentric bushes 5, 5 'effecting hydraulic cylinder 9, 9' attached.

In a second construction variant, rotary vane motors 10, 10 ^T are fastened to the bearing levers for rotating the eccentric bushings 5, 5 '.

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The regulation of the pressure of the blanket cylinder 2 to the plate cylinder 1 as well as to the pressure cylinder 3 is not shown here but known inside or outside, to the hydraulic cylinder 7,7 ^! 9, 9 'or rotary vane motors 10, 10' provided attacks.

The operation of the device according to the invention for pressure on and off is as follows:

After Pig. 1 is the blanket cylinder 2 to the plate cylinder 1 as well as the impression cylinder 3 in a parked position. In order to ensure the full coloration of the blanket cylinder 2 already on arrival of the first sheet, the first phase of the employment of blanket cylinder 2 to the plate cylinder 1 within the opposing cylinder channels 11, 12 must be performed. This is done by acting on the hydraulic cylinder 9, 9 ', or the rotary wing motors 10, whereby the eccentric bushings 5, 5 ^! to be twisted. The second phase of employment takes place between blanket cylinder 2 and impression cylinder 3 and again in the area of the opposing cylinder channels 12, 13. This is done by acting on the hydraulic cylinder 7, 7 ¹ , whereby the bearing levers 4, 4 'are pivoted counterclockwise and the plate cylinder 2 is turned on to the impression cylinder 3 (Pig. 3, Pig. 4).

The pressure is switched off in exactly the reverse order.

It is particularly advantageous that during the employment of the blanket cylinder 2 to the printing cylinder 3, the previous employment of blanket cylinder 2 to the plate cylinder 1 undergoes no change and thus a duplication is excluded.

Claims (4)

invention claims 1 · A device for printing and parking cylinders in sheet-fed offset printing machines, wherein the arrival as well as the stopping of the cylinder takes place successively and in the region of the respective opposite cylinder channels, characterized in that about the center of the plate cylinder (1) pivotable bearing lever (4, 4 ') are arranged, which are provided with rotatable eccentric bushes (5, 5') in which the blanket cylinder (2) ^ is mounted, and that for rotating the eccentric bushes (5, 5 ') and for pivoting the bearing lever (4, 4 ') successively become effective actuating means (6) are provided. 2. Device according to item 1, characterized in that for pivoting the bearing levers (4, 4 ') as adjusting means (6) hydraulic working cylinders (7, 7 ^f ) are arranged, each with one end to the bearing levers (4, 4 ^! ) and hinged at the other end to the machine frame, 3. Device according to item 1, characterized in that for rotating the eccentric bushes (5, 5 ') as actuating means (6) hydraulic working cylinders (7, 7 ^f ) are arranged, each with one end of bearing lever (4, 4' ) and hinged at the other end to the eccentric bushing (5, 5 ^! ). 4 »device according to point 1, characterized in that for rotating the eccentric bushes (5, 5 ') DrehflugImotore (1.0, 10 ^f ) are arranged, which are attached to the bearing levers (4, 4 ^f )» For this 2 sheets of drawings