DE1272074B - Paper roll changing device, especially for web-fed rotary printing machines - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

B65h

German class: 47 k -3/08

Number: 1272 074

File number: P 12 72 074.0-53 (Sch 40222)

Filing date: February 11, 1967

Open date: 4th July 1968

The invention is concerned with roll changing devices on web-fed rotary printing presses and others Paper processing machines, the control of which is initiated with the rotary movement of the star wheel to the Connection of the running out web with the replacement roll by a speed comparison between the remaining roll and the control pulse given to the machine is triggered.

A known device of this type according to German patent specification 1108 239 gives the star wheel rotation triggering control pulse when one of the path speed in dependent on the machine, d. H. with their larger or smaller residual roll diameter. It is with a single control pulse that can be triggered at any machine speed and that is always roughly constant and the shortest possible time for the sequence of the roll change process achieved that on the remaining roll As waste or waste, roughly the same and very small remnants of the web always remain.

In this known device, the control pulse for the start of the roll change operation triggered when a predetermined constant difference between the speed of the remaining roll and the machine occurs. This principle is based on the fact that the machine speed during the roll change is not changed. Only under this condition can this method be used with a single control pulse in a roughly constant roll change time, a roll remainder that is always roughly the same after expiration of the connection process.

In certain cases it is now desirable in practical operation, the role change with reduced Perform machine speed. The reason for this can be poorly coiled, dented and beating paper rolls or that are to process papers of shorter tearing lengths are. On the other hand, modern high-pressure web presses, for example, allow maximum speeds, some of which are considerably higher than the speeds at which the currently usual devices an automatic roll change can be safely carried out.

In these and other cases it is necessary to keep the machine with the machine during the roll change run at a reduced speed. Appropriately, this happens automatically by that the "slow down" command of the main engines from the switching of the roll changing device is influenced for a long time until the main motors are reduced to an adjustable speed value. If desired, the main motors can after loading paper roll changing device, especially for Web-fed rotary printing machines

Applicant:

Schnellpressenfabrik Koenig & Bauer

Corporation,

8700 Würzburg, Friedrich-Koenig-Str. 4th

Named as inventor:

Dr.-Ing. Engelbert Muth, 8700 Würzburg

at the end of the roll change, it automatically increases to the previous speed setpoint will.

For reducing the engine speed to a predeterminable value in connection with There are now several possible solutions for an automatic role change. The simplest would be first to reduce the machine speed and then the automatic roll change to be carried out at the reduced, but again kept constant machine speed. In this The trap would be a first speed or diameter comparison to trigger the "slower" command of the machine and a second one to start the actual roll change process, whereby the first control pulse would have to be given at a diameter of the remaining roll that is the maximum speed corresponds to the machine. At a production speed below the If the maximum speed is, it would have to be accepted that the machine would have a certain Time runs at reduced speed before the roll change process is initiated. This would be especially a disadvantage where several paper webs run into a machine, since the individual Roll changing devices usually perform the gluing operation at different times and thus the time spans in which the machine works at reduced speed, add.

The invention seeks to avoid these disadvantages. It is based on the suggestion, the impulse for reducing the machine speed to an adjustable setpoint at the same time the start impulse for the roll change process to be initiated with the rotary motion of the roll star

809 568/302

trigger. This means that the time it takes to bring the machine down to a lower running speed a part-time of the roll change process and thus the gluing operation is not extended. However, the three advantages of the known device according to the German patent 1108 239 are preserved. These are namely:

1. a single control pulse that occurs at any machine speed can be triggered,

2. an approximately constant and shortest possible time period for the reel change process to run and

3. a remainder of the roll that is always roughly the same.

For this purpose, the invention proposes that the control pulses for starting the roll change process and reducing the engine speed to an adjustable setpoint at the same time given and each time a predetermined constant difference of the square root of the occurs Residual roll speed and the square root of the machine speed is triggered.

In this way it can be achieved with a single control pulse that for all common Machine speeds even with a continuous downward control of the machine speed an adjustable target value, an approximately equal, smaller roll remainder remains as waste and the entire roll change takes place in an approximately constant time regardless of the web speed. There is therefore no need for a second speed or Diameter comparison and control pulse. One Such a control device automatically selects the one for the beginning of the roll change at each machine speed required residual roll diameter. After the role change has been initiated the process runs continuously with known means.

An embodiment of the invention is explained with reference to the drawing.

The three-armed, motorized rotatable star wheel 1 is shown in the glued position. The running web 2 of the remaining roll 3 is to be glued to the replacement roll 5 driven by the endless belt 4. The belt reel 6 receives its drive from the machine via a gear 7 with a variable drive speed, which also drives a measuring generator 8. Each roller star arm carries one of the measuring generators 9, 10 and 11, which is driven by its roller, for example from the roller cone, at a variable speed depending on the roller diameter. In the position shown, the two measuring generators 8 and 9 are connected to one another. The swivel frame 12, which is mounted in the machine side wall and carries the adhesive brush 13 and the separating knife 14, is part of the other equipment of the usual type.

The two counter-connected measuring generators such. B. 8 and 9, generate electrical voltages, which are proportional to the respective speeds. The automatic control of the gluing process and simultaneously reducing the engine speed to a predetermined setpoint value each triggered as soon as the two counter-connected measuring generators with a predetermined constant difference between the square roots of their speed. Only then do the two work Measuring generators a control pulse. The selected difference corresponds to a remaining roll diameter, that of the forme cylinder circumference of the machine, its running speed, the speed characteristic of the main motors and the adjustable speed value to which the machine is set during the roll change process is downgraded, depends. The speed reduction of the main motors over time is thereby assumed to be linear.

The speed comparison of the two measuring generators can be carried out by any suitable device, that forms the desired mathematical function. The arrangement is to be made so that the Control pulse only if there is a positive difference between the square roots of the two measuring generator voltages is given, so if the speed of the residual roller measuring generator is greater than that of the machine measuring generator.

Claims (1)

Claim: Paper roll changing device, in particular for web-fed rotary printing machines, whose with the Rotary movement of the roller star initiated control for connecting the outgoing web with the replacement roll by a given by a speed comparison between the remaining roll and the machine Control pulse is triggered, characterized in that the control pulses for the start of the roll change process and for reducing the machine speed an adjustable setpoint is given at the same time and each time a predetermined constant occurs Difference between the square root of the residual roller speed and the square root of the Machine speed are triggered. Considered publications:
German patent specification No. 1108239. 1 sheet of drawings 809 568/302 6.63 © Bundesdruckerei Berlin