Patent ID: 7878439

Claim:
An assembly for a seat belt restraining system for restraining an occupant of a vehicle, the assembly comprising: a retractor having a spool receiving a portion of the seat belt and a locking mechanism operatively connected to the spool; a pretensioner having a drive mechanism including a plurality of pretensioner balls sized to engage a pinion, the pinion operatively connected to the spool through a force limiting element, the pretensioner defining a guide surface structured to guide the pretensioner balls along a ball path around the pinion, the guide surface including a notch sized to engage at least one of the plurality of pretensioner balls, the pretensioner balls engaging the pinion along an engagement section of the guide surface, the notch being located along the engagement section; and the pretensioner operable in two modes including, a first mode wherein the drive mechanism of the pretensioner is activated to force the pretensioner balls around the pinion to wind-up seat belt onto the spool, and a second mode wherein the spool is rotated to pay-out seat belt from the spool and one of the plurality of pretensioner balls engages the notch in the guide surface to block rotation of the pinion and limit force through the force limiting element.