VORRICHTUNG ZUM ABTRENNEN VON ABSCHNITTEN VON EINER BAHN DURCH QUERTRENNSCHNITTE ENTSPRECHEND AUF DER BAHN BEFINDLICHEN DRUCKMARKEN

摘要

Apparatus for severing sections from a web by transverse severing cuts at locations related to printed marks on the web. The apparatus includes a rotary cutter and pair of feed rollers, a differential transmission by which the feed rollers are operatively connected to a common drive motor for driving the rotary cutter and the feed rolls. A servomotor is provided for imparting a correcting rotation to the transmission. A mark detector for detecting the printed marks, a sensor for detecting the position of the rotary cutter, and a controller for controlling the servomotor in dependence on the deviation of the spacing of the printed marks from the predetermined web section length are also provided. The servomotor is a stepping motor which receives stepping pulses in a number which represents the difference between the theoretical length of each web section and the actual distance between the printed marks.