Controlled severing of a continuous web

摘要

Apparatus for severing a continuous web at preselected locations spaced lengthwise of the web which includes a first drive for advancing the web at substantially uniform velocity in the direction of its length through a predetermined fixed path. A circular mandrel is mounted for rotation adjacent to the web path and has a plurality of cutter blades at uniform angular intervals around the periphery thereof. A differential transmission couples the mandrel to the web drive and is controlled by a stepper motor to advance or retard angular velocity of the cutter mandrel as compared with linear velocity of the web. A pair of sensors are respectively responsive to motion of the web and rotation of the cutter blades toward the position of cutting engagement. A control circuit receives signals from the sensors and from a tachometer responsive to web velocity to control the stepper motor and thus to advance or retard rotation of the cutter mandrel so that the cutter blades engage and sever the webs at the preselected and desired web-sever locations.