FI72465B - TRYCKVERK FOER FOERAENDERLIGA FORMAT. - Google Patents

Description

1 72465

Printing machine for variable sizes

The invention relates to a method for conveying a paper web in a printing machine and to an apparatus for carrying out the method according to the preambles of claims 1 and 2.

DE-2 617 418 discloses a rotary printing machine for a variable paper size in which it is not necessary to change the cylinder to change the size. The paper web to be printed is conveyed through a nip between two cylinders and then back. However, this printing machine requires torn printing brackets due to the plug conveyor belt fitted before and after the printing part, which, however, is not desirable in many printing jobs.

It is an object of the invention to provide a method and an apparatus for carrying out a method which makes it possible to carry out continuous printing, unwinding and further processing with adjustable size, in which case only a short piece of paper web has to be moved forwards and backwards, without the need for any reciprocating paper web slots. machine elements.

The task is solved according to the invention by means of the object of claim 1.

The advantages achieved by the invention consist in particular in that the device can be arranged immediately before or after the printing cylinder or cylinders, so that. only a short piece of paper path needs to be moved back and forth. This has a favorable effect on the alignment quality of the full print 2 72465 or equivalent, the cutting alignment. Production speed and smooth running of the machine can be substantially improved because no reciprocating machine parts are required. Resizing is substantially simplified. The paper web tension of the web passing through the printing machine can be easily changed by means of the adjusted groups of drive rollers.

An embodiment of the invention is shown in the drawing and will be explained in more detail below. The drawing shows a printing machine equipped with a device according to the invention.

From the paper storage roll (not shown), the paper web 1 is fed to the printing machine 2 by means of a drawing roller group 4 used by the main drive device 3. From the traction roll group 4, the paper web 1 is led to the first paper web collector 6. The paper web collector 6 consists of a roll 7 fixed to two arms 8. Both arms 8 are connected to the shaft tightly, which shaft is rotatably mounted on the side racks of the printing machine 2. An operating pin 5 of the electric rotating magnet 5 is connected to the other shaft end of the shaft. The housing of the rotating magnet 5 is attached to a side holder. The torque of the rotating magnet 5 can be infinitely adjusted in a known manner and acts in such a way that the paper web 1 is held tightly between the traction roll group 4 and the roll 7 of the paper web collector 6 with a predetermined force. The tension of the paper web is adjusted between the roll 7 and the traction roll group 4 in a known manner and is kept constant.

The paper web 1 rotates around the roll 7 from above by about 180 ° and then around two of it and at a distance to the left or counterclockwise of the turn rollers 9 and 11 arranged therefrom and mounted on the side supports. From the turntable 11, the paper web 1 is fed to a second group of drive rollers 12 driven by an electric motor. It first rotates around the press roll 13 and then around the drive roll 14 of the drive roll group 12 practically without play. From the traction roll 14, the paper web 1 passes through the pivot roll 16 horizontally through the printing nip 3 72465 between opposing printing cylinders 17 and 18 to a third traction roll group 19. The third traction roll group 19 consists of an electric motor driven traction roll 21 and a press roll 22 mounted thereon. through the second paper web collector 23. The second paper web collector 23 consists of the same structural elements as the first paper web collector 6, namely a roll 24, two arms 26 and an electric rotating magnet 27. From the second paper web collector 23 the paper web 1 travels to the fourth traction machine group 28 and one or more which process, for example, press or cut across a steady speed paper web 1.

The traction rollers 14 and 21 of the second and third groups of traction rollers 12, 19 are each provided with an encoder plate which acts as an actual value sensor, and the rollers are in each case driven by a DC motor.

An encoder is connected to the second printing cylinder 17, 18 as a holding value sensor. The encoder has high accuracy and they give their impulse to the digital reference field. The second and third traction roller groups 12, 19 each have their own control circuits for their DC motor, so that the desired paper web tension can be adjusted and maintained between the first and third traction roller groups 12, 19.

When printing, the paper web 1 is conveyed in double-sided printing through the printing nip of the heavy printing cylinders 17, 18, as long as they are affected by the printing plates. When conveyed through the tension means 10 of both printing cylinders 17, 18 through the nip, the second and third sets of traction rollers 12, 19 undertake the paper web 1 further, and in particular as follows: 4 72465 Step 1: braking the paper web 1 from production speed with constant deceleration or blue function 0 on the way to a stop; Step 2: reversing the paper web 1 from a stop with constant acceleration or according to a sine function e.g.

At a distance of 60.0 mm; Step 3: braking the reverse of the paper web 1 with a constant deceleration or according to a blue function, e.g. at a distance of 60.0 mm until stopping; Step 4: advancing the paper web 1 from a stop at a constant acceleration or according to a blue function to a production speed of e.g. 60.0 mm.

In the maximum size, the durations of all four stages can be the same, in the minimum size the durations of the first and second stages are the same, and also the same as in the maximum size; the durations of the second and third stages are likewise the same, but correspondingly longer compared to the maximum size.

Or the following could also be done:

The first and second stages are the same size, the third and fourth stages are the same size but different (longer) compared to the first and second stages.

However, instead of stopping the paper web 1 as it passes through the clamping means channels 10 through the press nip, stopping may also occur as it passes through the weight-free surface bounded by the end and beginning of the weight cylinder 17 and / 18 through both press cylinders 17 and 18.

The first paper web collector 6 in front of the printing machine 2 and the second paper web collector 23 behind the printing machine 2

II

6 72465

Sub-strip 1 paper web 2 printing machinery 3 main drive device 4 traction roller group, first 5 rotating magnet 6 paper web size and, first 7 roll 8 arm 9 swivel roller 10 tensioning channel 11 swivel roller 12 traction roller group, second 13 press roll 14 traction roller 15 16 swivel roller 17 traction cylinder 19 traction cylinder 18 22 press roll 23 paper web collector, second 24 roll 25 26 arm (23) 27 rotating magnet 28 traction roll group, fourth

II

Claims (2)

7 72465 A method of conveying a web in a rotary printing press by means of two traction devices for printing a web of variable, interlocking sizes between two non-replaceable cylinders, the web being pulled back and forth through the nip between the cylinders after printing and held therein, characterized by a web without tension holes ( 1) is guided to travel forwards or backwards by means of a pair of traction rollers (12, 19) arranged in front of and backwards of the weight nip, respectively. Printing machine for carrying out a method according to claim 1 for printing variable, interconnected sizes with a traction device and a track collector arranged in front of and behind the press nip, characterized in that the track traction devices are two pairs of electrically driven traction devices (12, 19) arranged inside the printing mechanism (2). .