Web tensioning device with plural control inputs

摘要

A web tensioning device utilizes a dancer arm which can be positioned by a controlled servo motor. In a preferred embodiment, the controller for the servo motor receives an input signal based on the acceleration (positive or negative) of the dancer arm and implements a torque component necessary to maintain predetermined web tension, for example, an applied torque component that changes the position of the dancer arm. The controller may also receive additional input signals indicative of the acceleration of the web itself.