Patent ID: 8287410

Claim:
A device for placing a looped belt under tension, the device comprising: a tension arm moveably mounted on a base, said tension arm lying substantially in a first plane; a pulley mounted on said tension arm for rotation about an axis substantially perpendicular to said first plane, said pulley adapted to be engaged by the looped belt; wherein said tension arm is formed with a slot and said base is formed with a threaded hole; a screw passing through said slot and into said threaded hole and formed with a screw head; and first and second interchangeable bushings having different axial lengths, either of which can be interposed between said screw head and said tension arm such that said screw passes through a selected one of said first and second bushings and into said base, wherein, upon tightening said screw, said first bushing enables said screw head to clamp said tension arm to said base, thereby establishing a static mode wherein said tension arm is held stationary relative to said base, and said second mounting bushing prevents said screw head from clamping said tension arm to said base, thereby establishing a dynamic mode wherein, in response to a changing force applied between said pulley and the looped belt, said tension arm moves relative to said base in such a manner as to maintain the force substantially constant.