Method and device for controlling the tape overrun in folding machines

摘要

The invention relates to a method and a device for controlling the tape overrun at the first blade folder of a folding machine. The object of the invention is to detect the slip occurring of a sheet between the sheet feed and the first blade folder for a correction of the tape overrun at any desired clock speed and under any desired slip conditions of the machine in order to achieve a high degree of folding accuracy. For this purpose, when the machine is running the phase shift in the movement cycle of a blade folder which is set in a defined manner is determined at the associated movement cycle of the front edge of the sheet within a working clock at the first blade folder of a folding machine for a number "n" of work cycles, the average value is formed and preferably output in cm/per working clock. The deceleration occurring when slip arises is determined in an electronic evaluation device and output as a characteristic variable for the deviation of the setting value of the optimum tape overrun, and the movement cycle of the front edge of the subsequent sheets is changed via an actuation element by controlling the feed time so that the slip is compensated.