Retractor having a single sided energy absorbing spool

An energy absorbing seat belt retractor comprising:

• a frame;
• a spool rotatably mounted relatively to the frame for protracting and retracting a safety belt wound thereabout,
• a lock wheel operatively coupled to the spool, including a plurality of lock teeth associated therewith;
• first means for engaging the spool upon sensing a one of a vehicle deceleration and seat belt extraction above certain determinable levels;
• second means located within the spool joining the lock wheel to the spool for probe biting relative movement therebetween below a threshold input force level generated in part by occupant load on the seat belt and for generating a controlled energy dissipating reaction force on the seat belt after the input force exceeds the threshold level to permit a controlled rotation of the spool and the controlled payout of the seat belt from the spool, the second means includes:
• an axle assembly (50) including third means (90, 90', 90") movably disposed therein for dissipating energy as it moves by extruding adjacent material, including a splined and threaded carrier translationally movable relative to one of the lock wheel and spool, wherein the carrier includes a plurality of hardened balls (96) proximate its periphery, movable against material of an inner bore of the spool to extrude such material as the balls move with the carrier.

An energy absorbing seat belt retractor comprising:

• a frame;
• a spool rotatably mounted relatively to the frame for protracting and retracting a safety belt wound thereabout,
• a lock wheel operatively coupled to the spool, including a plurality of lock teeth associated therewith;
• first means for engaging the spool upon sensing a one of a vehicle deceleration and seat belt extraction above certain determinable levels;
• second means located within the spool joining the lock wheel to the spool for prohibiting relative movement therebetween below a threshold input force level generated in part by occupant load on the seat belt and for generating a controlled energy dissipating reaction force on the seat belt after the input force exceeds the threshold level to permit a controlled rotation of the spool and the controlled payout of the seat belt from the spool, wherein the second means includes an axle assembly (50) including third means (90, 90', 90") movably disposed therein for dissipating energy as it moves by cutting adjacent spool material internal to the spool, wherein the third means includes a splined and threaded carrier translationally movable relative to one of the lock wheel and spool, the carrier includes at least one cutting edge (124) proximate its periphery, movable against material of an inner bore of the spool to sever such material as the edge moves with the carrier.