Patent ID: 7963872

Claim:
A traveling transmission chain for use in an engine, comprising first and second sets of plates interconnected in overlapping relationship and forming an elongated, endless loop disposed in a path of travel lying substantially in a plane, the loop surrounding an inside region of said plane and being surrounded by an outside region in said plane; wherein each plate has a pair of holes for receiving a connecting pin; the chain has a chain pitch equal to the distance from the center of one of the holes in each plate to the center of the other hole in the same plate; each plate of both sets has a guide-engaging portion for sliding contact with a chain guide; the guide-engaging portion of each plate of at least one of the first and second sets comprises a pair of front and rear flat surfaces, spaced from each other in the direction of elongation of the chain, for sliding contact with a flat guide surface of a chain guide; the guide-engaging portion of each plate of said at least one of the first and second sets also comprises a pair of front and rear convex curved surfaces for sliding contact with a convex guide surface a chain guide; each said convex curved surface of each plate being continuous with one of said flat surfaces of the same plate and meeting said one of said flat surfaces at a boundary, and said convex curved surfaces of each said plate being disposed between the flat surfaces of the same plate in the direction of elongation of the chain; each plate of said at least one of the first and second sets has a concave surface, extending from one of the convex curved surfaces of the same plate to the other convex curved surface of the same plate, for forming a lubricating oil-retaining clearance between the plate and a flat guide surface and for also forming a lubricating oil-retaining clearance between the plate and a convex guide surface; the distance between the boundaries between the flat and convex surfaces of each plate of said at least one of the first and second sets is shorter than the chain pitch; and the radius of curvature of each said convex curved surface gradually increases in the direction from the boundary at which it meets a flat surface toward the concave surface of the same plate.