SE454663B - PROCEDURES AND PRINTINGS FOR VARIABLE SIZES - Google Patents

Description

454 663 10 15 20 25 30 35 2 and is described in more detail below. The drawing shows a printing unit with the device according to the invention.

From a non-reproduced paper roll a paper web 1 is unrolled and a printing unit 2 is fed by means of a draw roll group 4 driven by a main motor 3. From the draw roll group 4 the paper web 1 is fed to a first paper web magazine 6.

The paper web magazine 6 consists of a roller 7 which is suspended in two arms 8. Both arms 8 are connected to a shaft which is rotatably mounted in the side frame of the printing unit 2. A drive pin is connected to one shaft end of the shaft to an electric rotating magnet 5. The housing of the rotating magnet 5 is attached to the side frame.

The torque of the rotating magnet 5 is infinitely adjustable in a known manner and acts in such a way that the paper web 1 between the drawing roller group 4 and the roller 7 of the paper web magazine 6 is kept taut with a predetermined force. The paper web tension is set and kept constant in a known manner between the roll 7 and the draw roll group 4.

The paper web 1 runs from above about 1800 around the roller 7 and then around two below it and at a distance to the left and right of the same arranged breaking rollers 9 and 11 stored in the side frame. From the breaking roller 11, the paper web 1 is fed to a motor-driven second pull roller group 12. First the paper web goes around a press roll 13 and then around a draw roll 14 which belongs to the draw roll group 12 which takes place practically non-slip. From the draw roll 14 the paper web 1 is guided around a breaking roll 16 and through a pressure gap between the horizontally opposite pressure cylinders 17 and 18 and then to a third draw roll group 19. The third draw roll group 19 consists of an electric motor driven draw roll 21 and a After the press roll 22, the paper web 1 passes a second paper web magazine 23. The second paper web magazine 23 consists of the same elements as the first paper web magazine 6, namely of a roller 24, two arms 26 and an electric rotating magnet. 27. , for example, presses it or cuts it across.

The traction rollers 14 and 21 in the second and third traction roller groups 12, 19 are both equipped with their own encoder disc as actual value sensor and are each driven by a direct current motor.

An encoder such as a setpoint sensor has been connected to one of the pressure cylinders 17, 18. These encoders have a high resolution capability and deliver their impulses to a digital comparison circuit. The second and third draw roller groups 12, 19 each have their own control circuit for their associated DC motor, so that a desired paper voltage can be set and maintained between the second and third draw roller groups 12, 19.

During printing, the paper web 1 is fed through the printing gap between the printing cylinders 17, 18 which are printed at high or low pressure, as long as the printing plates affect the paper web.

When clamping means channels 10 on the two pressure cylinders 17, 18 pass through the pressure gap, the second or third draw roller group 12, 19 takes over the continued transport of the paper web 1, which takes place as follows: Step 1: The paper web 1 is decelerated with constant delay or according to a sine function distance of, for example, 60.0 mm from production speed to standstill; step 2: The paper web 1 is moved from a standstill with constant acceleration or according to a sine function backwards, eg 60.0 mm; step 3: The backward movement of the paper web 1 is decelerated with a constant delay or according to a sine function on a distance of eg 60.0 mm to a standstill; step 4: The paper web 1 is advanced from a standstill with constant acceleration or according to a sine function to a production speed of a distance of, for example, 60.0 mm.

At maximum format, the duration of all four steps 454 663 10 15 20 4 is the same, at minimum formats, the duration of the first and fourth steps is the same and also as large as at maximum format. The duration of the second and third stages is also mutually equal but correspondingly longer compared to the maximum format.

Another alternative is the following: first and second stage equal, third and fourth stage equal but different (longer than) first and second stage.

In the case of smaller formats, however, even instead of the paper web 1 being stopped while passing the clamping channel channels 10 through the printing gap, the stopping takes place while a pressure-free surface limited along the circumference of the printing cylinder 17 and / or 18 passes through the printing gap between the two the pressure cylinders 17 and 18.

The first paper web magazine 6 in front of the printing plant 2 and the second paper web magazine 23 after the printing plant 2 ensure that the paper web 1 is unrolled continuously from the supply roll or can be continuously fed to the processing station after printing.

Claims (2)

A method for transporting a paper web (1) in a printing press (2) of a rotary printing machine by means of two traction means (12, 19) for printing the paper web with different, successive formats between two non-replaceable cylinders (17, 18), the paper web after the printing being pulled back and forth through a pressure gap between the cylinders (17, 18) and stopped, characterized in that the web (1) not provided with transport perforation by means of a front and a Pull roller pairs (12, 19) arranged controllably behind the pressure gap are moved back and forth. Printing unit for carrying out the method according to claim 1 for printing variable, successive formats with a pulling means (12, 19) arranged in front of and after the printing gap and a paper web magazine (6, 23), characterized in that as traction means for the web (1), two cooperating regulated, electromotor driven traction roller pairs (12, 19) are arranged in the printing unit (2), around which the web runs.