Eastman-kodak Company

James W Gunn

James Douglas Shifley

Douglas J Pfaff

Richard H Berg

A variable torque device for maintaining constant tension in a web of material as the web is unwound from a supply roll. The variable torque device includes a lead screw attached to the shaft of the supply roll via an appropriate gear ratio. A coil spring is located between a hub on the lead screw and a set of rings and friction pads. As the lead screw rotates, the hub translates, thus changing the displacement of the coil spring, which in turn changes the loading of the rings and friction pads. With a full supply roll the coil spring is compressed so as to create an amount of torque to create the desired web tension. As the supply roll unwinds, the rotation of the lead screw translates the hub to expand the coil spring, reducing the torque and maintaining the web tension constant.

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Holley, NY, United States of America

James W Gunn