ACTIVE CENTER PIVOT DEVICE FOR CONTROLLING SHEET TENSION AND METHOD OF USING SAME

摘要

A device for controlling web tension is disclosed. The device includes a carriage in which a first guide roller is spaced from a second guide roller by a frame. The carriage or frame pivots about a pivot location. A moving web is threaded through the carriage in a serpentine path. Rotation of the carriage or frame causes web displacement. When tension disturbances occur in the moving web, the device rotates for accumulating or releasing the web material and thereby dampening tension variations downstream. The pivot dancer device can be placed in a communication with a controller for open loop control or closed loop feedback control.