Patent ID: 7892127

Claim:
A power transmission chain that undergoes a transition alternately between a linear region and a region wound over a pulley, the chain comprising: plural link plates; and plural coupling members that couple the link plates to each other, the coupling members including a plurality of main power transmission members, and a plurality of counter members each being interposed between a corresponding link plate and a corresponding main power transmission member, each main power transmission member having a counter portion that opposes a corresponding counter member, the counter portion coming into contact with the corresponding counter member in a contact state that includes at least one of rolling contact and sliding contact at a contact portion that displaces in association with a bending of the power transmission chain; and a pair of end faces that oppose each other in a chain width direction, each end face having a contact region that is adapted to come into contact with a corresponding sheave surface of the pulley, the contact region including a center point of contact; wherein the main power transmission members include first and second type main power transmission members, the counter portion of the first type main power transmission member having a first involute curve based on a first base circle having a relatively large radius of curvature, and the counter portion of the second type main power transmission member having a second involute curve based on a second base circle having a relatively small radius of curvature; and wherein a position of the contact portion relative to the center point of contact of the first type main power transmission member in both a first and a second direction is different from a position of the contact portion relative to the center point of contact of the second type main power transmission member in both the first and the second direction, the first direction being orthogonal to the chain width direction and a chain traveling direction, and the second direction being different from the first direction and being in the chain traveling direction, when the linear region of the power transmission chain is viewed in the chain width direction.