The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 2006
Filed:
Dec. 14, 2004
Richard H. Berg, Greenville, SC (US);
James D. Shifley, Spencerport, NY (US);
Douglas J. Pfaff, Rochester, NY (US);
James W. Gunn, Holley, NY (US);
Richard H. Berg, Greenville, SC (US);
James D. Shifley, Spencerport, NY (US);
Douglas J. Pfaff, Rochester, NY (US);
James W. Gunn, Holley, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
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.