Seat belt retractor with cinch mechanism

摘要

A seat belt retractor includes a spool with seat belt webbing wound thereon. A frame supports the spool for rotation in a belt withdrawal direction or a belt retraction direction. A pawl engages ratchet teeth formed on end portions of the spool to prevent rotation of the spool in the belt withdrawal direction when a predetermined amount of seat belt webbing is withdrawn from the spool. A cam which has a multi-loop cam groove is rotatably driven by a gear train in response to spool rotation. A lever with a cam follower portion in the cam groove is pivoted by the cam to move the pawl into engagement with the ratchet teeth.