Device and method for positioning a cross cut on printing material and web-fed press having the device

1. A device for positioning a cross cut relative to printed images on at least one printing material web in a web-fed press having at least one printing unit, the device comprising:

a cross cutter;

a computing device for generating at least a first control signal for changing a phase angle of the printing unit and of the cross cutter relative to one another; and

a path length variation device for changing a path length through which the printing material web runs between the printing unit and said cross cutter;

said computing device also generating a second control signal for changing said path length and adjusting a positioning of the cross cut on the printing material web by interaction of the change in said relative phase angle and the change in said path length.

2. The cross-cut positioning device according to claim 1 , further comprising a longitudinal cutting device disposed downstream from the printing unit in travel direction of the printing material web past the printing unit and to said longitudinal cutting device, said longitudinal cutting device cutting the printing material web into a plurality of partial webs, said path length variation device being provided for at least one of the partial webs, said computing device generating said second control signal for changing the path length of the at least one partial web, the partial webs to be combined in mutually superimposed position at a gathering point located upstream of said cross cutter.

3. The cross-cut positioning device according to claim 2 , further comprising a sensor associated with the path length of said length variation device of the at least one partial web for detecting one of at least part of a printed image and markings applied to the printing material, the second control signal associated with the at least one partial web to be generated as a function of a signal from said sensor.

4. The cross-cut positioning device according to claim 2 , further comprising a first sensor disposed upstream and a second sensor disposed downstream from said path length variation device of the at least one partial web for detecting one of at least part of a printed image and markings applied to the printing material, the second control signal associated with the at least one partial web to be generated as a function of signals from said first and said second sensors.

5. The cross-cut positioning device according to claim 1 , further comprising:

a transmitter associated with the at least one printing unit for determining the phase angle thereof; and

a transmitter associated with said cross cutter for determining the phase angle thereof, said computing device generating said first control signal as a function of signals from said transmitters.

6. The cross-cut positioning device according to claim 1 , wherein the web-fed press has individual drives for at least one of at least one printing unit, said cross cutter, and said path length variation device.

7. A web-fed printing press, comprising at least one printing unit, a folder disposed downstream of said at least one printing unit, and at least one device for positioning a cross cut relative to printed images on at least one printing material web, the at least one device for positioning including:

a cross cutter for making a cross cut in the at least one material web;

a computing device for generating at least a first control signal for changing a phase angle of the printing unit and the cross cutter relative to one another; and

a path length variation device for changing a path length through which the printing material web runs between the printing unit and the cross cutter;

said computing device also generating a second control signal for changing said path length and adjusting a positioning of the cross cut on the printing material web by interaction of the change in said relative phase angle and the change in said path length.

8. A method of positioning a cross cut relative to printed images on at least one printing material web in a web-fed press having at least one printing unit and a cross cutter, the method which comprises the steps of:

determining a phase angle of the printing unit and the cross cutter relative to one another;

changing the phase angle of the printing unit and the cross cutter relative to one another;

changing a path length through which the printing material web runs between the printing unit and the cross cutter; and

adjusting the position of the cross cut on the printing material by interaction of the changed relative phase angle and the changed path length.

9. The method for positioning a cross cut according to claim 8 , which further comprises the additional steps of:

cutting up the printing material web into a plurality of partial webs;

combining the partial webs into a mutually superimposed form at a gathering point located upstream of the cross cutter;

changing at least one path length through which a partial web of the printing material web runs between the printing unit and the cross cutter; and

adjusting the position of the cross cut on the partial web by interaction of the changed relative phase angle and the changed path length of the partial web.

10. The method for positioning a cross cut according to claim 9 , which further comprises detecting at least one of at least part of the printed image and markings applied to the printing material on at least one partial web.