Abstract: A roller chain is provided with the links having extending butt portions to prevent excess inward movement of the chain. The butts may be located on the inner links or outer links. A silent chain with block lacing is also provided with the butt portions on the guide links.

Abstract: A roller chain is provided with links having some rollers of nylon. The nn rollers may be arranged with standard metallic rollers in patterns along the length of a single-strand or double strand roller chain. The nylon is polytetramethylene-adipamide.

Abstract: While chain tensioners are used with chains on the engine of a motor vehicle, conventional blade spring configurations do not apply consistent forces throughout the life of the chain. The chain tensioner comprises two blade springs mechanically interlocked within a shoe, the shoe being adapted to contact the chain of the motor vehicle. The two blade springs each have a minimal form radius that is substantially smaller than the minimal form radius of a single blade spring, the single blade spring being otherwise identical to the two blade springs, and the thickness of the single blade spring being the same as the combined thickness of the two blade springs.