Ratcheting hydraulic chain tensioner with rotational reset and locking means

摘要

A hydraulic chain or belt tensioner includes a ratchet-pawl interface on the piston skirt that can be reset to a locked position by rotating the piston and compressing it until locked. The tensioner preferably includes at least one flat on the piston. The flat prevents the piston from rotating axially and locks the piston into place. The locked position is especially useful for shipping the tensioner.