Patent ID: 8181556
Filing Date: 2012-05-22
Classification: B41F,B65H,Y10T

Abstract:
1. A method for controlling a position of a cutting register on a printed web in a rotary press, comprising the steps of: registering, by a sensor, a cutting register comprising one of a specific item of image information and a measuring mark on a printed web running-through the rotary press, the sensor being arranged at a knife cylinder of the rotary press; supplying a register signal from the sensor to a control device, the register signal being generated by the sensor in response to the cutting register; determining, by the control device, a partial cutting register error from the register signal, the partial cutting register error representing a deviation of the cutting register from its intended position at the time of said step of registering; and influencing the speed of at least one clamping point located upstream of the knife cylinder in the rotary press in response to the partial cutting register error for correcting the partial cutting register error, the at least one clamping point being arranged in a cooling unit; wherein the step of influencing comprises controlling an angular velocity of at least one clamping unit with a first controller, the at least one clamping unit being an existing non-printing draw unit or clamping point arranged in an area of the web course downstream of the last printing unit to the knife cylinder, and during said step of influencing, tracking a web tension of a section of the web between two clamping points in the rotary press and changing one of an input web tension force or the set point for a subordinate controller for the input web tension to restrict the web tension by limiting a speed of the web to a predefined upper and lower limit, so that a force adaptation is effected for dissipating a force change in the section between the two clamping points or a force change in sections between further clamping points which occur as a result of controlling the cutting register error in the rotary press, and during said step of influencing controlling, by a first controller a manipulated variable for correcting the partial cutting register error; wherein the method further comprises: transferring control of the angular velocity of the cooling unit from the first controller to a second controller for tracking a clamping point upstream of the cooling unit and moving the manipulated variable back into a permissible range if the limits of the manipulated variable are exceeded during control of the part register error.