Patent ID: 7631830

Claim:
A seat belt retractor ( 100 ) having a rotationally mounted spool ( 120 ) with a seat belt wound or windable thereon and a pretensioner ( 300 ) for selectively winding the spool in a belt winding direction to rewind the seat belt upon the spool; the pretensioner comprising: a power transfer mechanism ( 350 ) activated by a pyrotechnic element ( 400 ) for causing a clutch assembly ( 200 ) to change state from a disengaged mode to an engaged mode in which the clutch assembly drivingly engages the spool; the clutch assembly ( 200 ) comprising a clutch housing ( 210 ) having provision to support a plurality of rotationally mounted clutch pawls ( 240 , 240 a - c ), the clutch housing received within a recess ( 202 ) of the spool ( 120 ), each of the clutch pawls configured to be compressively loaded between the spool and the clutch housing when in the engaged mode; wherein the clutch pawls ( 240 ) are symmetrically arranged within the clutch housing for rotation movement from the disengaged position to the engaged position, the clutch housing including an O-ring receiving feature ( 230 ) configured to support portions of an O-ring ( 280 ), the O-ring extending across portions of each pawl, each pawl including an O-ring receiving member ( 252 ) configured to receive an inner wall of the O-ring, the O-ring biasing each clutch pawl via the O-ring receiving member ( 252 ) to the disengaged position.