Patent ID: 8398513

Claim:
A plate-link chain for a motor vehicle drive system, the chain including a large number of link plates connected by rocker members to allow relative pivotal movement of successive chain links, wherein the rocker members extend transversely to the longitudinal direction of the plate-link chain, said chain comprising: a plurality of link plates interconnected by rocker members, wherein pairs of rocker members are positioned opposite each other and pairs of rocker members are received in respective rocker-member-receiving openings in the link plates, the pairs of rocker members each including two rocker members in surface-to-surface contact with each other at respective rocker member rolling surfaces to roll relative to each other as the chain bends, curved contact surfaces formed on the rocker members and on surfaces of rocker-member-receiving openings in the link plates, over which contact surfaces respective rocker members and link plates are in contact with each other to transmit force when the chain is pulled and wherein the rocker members are pivotable about their respective longitudinal axes and the curved contact surfaces formed on the rocker members are slidable relative to contacting rocker-member-receiving openings in the link plates when the chain bends, the respective contact surfaces each being arc-shaped and having a width that extends transversely to the longitudinal direction of the plate-link chain and having at least three sequentially-arranged arc-shaped regions with different curvatures along respective arc lengths of the regions, wherein the at least three regions include convexly-curved contact surfaces on the rocker members and concavely-curved contact surfaces on the rocker-member-receiving openings in the link plates, wherein pairs of the curved contact surfaces are provided at spaced surface contact regions on the rocker members and on the link plates and lie on respective opposite sides of a longitudinal axis of the chain, and wherein at least one contact surface region has a curved segment along the contact surface arc length whose smallest radius of curvature is located substantially in the middle of the contact surface arc length, and wherein pivotal movement of the rocker members within the link plate openings is resisted and local stress spikes are avoided at transition regions from one radius of curvature to another radius of curvature in the contact regions of the contact surfaces of the rocker members that are in contact with and are opposite to the contact regions of the link plate openings and resulting from relative pivotal movement of the rocker members relative to the rocker-member-receiving openings in the link plates.