CYKLISK ELEKTRODRIVANORDNING FOER SKAERMASKIN FOER FIN- OCH BESKIKTAT PAPPER

摘要

A paper cutting machine and method including a double rotary knife consisting of two cylinders geared together each containing a knife which mates with another to form a scissor action to cut a web including a sensor for detecting the speed of the web and including a motor for driving the two cylinders wherein the sheet size can be set to a desired size to provide an input to a microprocessor which is connected to the sheet speed sensor and to a position feedback from the drive motor and which generates a modulated signal for the motor so as to cause the knives to travel at the web speed at the instant of cutting and to modulate the cylinder speed to obtain larger or smaller sheets. Novel rotary drums and drive train system having low inertia are provided to allow the rapid acceleration necessary for the invention. Also, the knives are mounted in a novel manner.