Abstract: A power transmission drive comprising driving and driven sprockets interconnected by a chain consisting of interlaced ranks of links having projecting toes to engage the walls of the sprocket teeth and articulated by two-part pivots disposed transversely through aligned apertures in the links, the cross-section of each pivot part being similar and generally equilateral about axes 120.degree. apart and the apertures being elongated in the direction of the link length. The pivot parts comprise a pin and a rocker each of which has three convex and three concave surfaces which alternate and are joined with one another. A convex surface of the pin and rocker meet in rocking engagement with one another.

Abstract: A synchronous belt and pulley drive in which the drive between spaced pulleys is primarily by frictional contact of a belt on the pulley peripheries; synchronization is insured by providing spaced teeth on the belt which teeth are accommodated by tooth gaps in the periphery of the pulleys. The drive is further characterized by matching the pitch of the driveR pulley with the belt pitch under a first tension and matching the pitch of the driveN pulley with the belt pitch under a second tension, wherein the first tension is different and usually greater than the second tension.

Abstract: A power transmission drive comprising driving and driven sprockets interconnected by a chain consisting of interlaced ranks of links having projecting toes to engage the tooth gaps of said sprockets and articulated by two-part pivots disposed transversely through aligned apertures in the links, the cross-section of each pivot part having generally the shape of a three-lobed convex hypotrochoid and the said apertures having generally the shape of a longitudinal section through a chicken egg.

Abstract: A synchronous belt and pulley drive in which the drive between spaced pulleys is primarily by frictional contact of a belt on the pulley peripheries; synchronization is insured by providing spaced teeth on the belt which teeth are accommodated by tooth gaps in the periphery of the pulleys. The drive is further characterized by matching the pitch of the driveR pulley with the belt pitch under a first tension and matching the pitch of the driveN pulley with the belt pitch under a second tension, wherein the first tension is different and usually greater than the second tension.