Patent ID: 7972231
Filing Date: 2011-07-05
Classification: F16F,F16H

Abstract:
1. A pulley assembly comprising: a first member capable of cooperating with a power transmission belt to drive/be driven by the cooperating power transmission belt; a second member, the first member movable guidingly relative to the second member around a first axis; and a coil spring having a length and a circumference and a first portion with an arcuate length extending around the first axis and attached to the first member and a second portion with an arcuate length extending around the first axis and attached to the second member so that a force tending to move the first/second member around the first axis is transmitted through the coil spring to the second/first member, each of the first and second portions defined by a formed, elongate member comprising turns each with a diameter and extending through no more than 360° around the first axis, at least one of the first and second members having a groove that: a) opens axially and has an axial extent; and b) is bounded by a surface into which a respective portion of the coil spring is fit, the respective portion of the coil spring having a curvature around the first axis with the coil spring in a relaxed state that is not matched to the surface bounding the groove, the respective portion of the coil spring within the groove radially elastically deformed from the curvature the respective portion of the coil spring has with the coil spring in the relaxed state so that residual forces in the coil spring cause generation of radial forces acting between the surface bounding the groove and the respective portion that cause the respective portion of the coil spring to be clamped within the groove to thereby cause the respective portion of the coil spring to follow movement of the at least one of the first and second members around the first axis to thereby transmit forces between the first and second members through the coil spring, the groove in the at least one of the first and second members has clamped therein only a single one of the turns on the first and second portions that cooperate with the at least one of the first and second members.