Abstract: A dual spool retractor device for seat belts in a motor vehicle including a frame, two spools rotatably mounted to the frame, and a pretensioning system providing pretensioning rotation for both the spools. The spools are pretensioning through the activation of a micro-gas generator. The gas generator can provide gas to a single or a pair of gas cylinders. One or more flexible numbers such as a metal band or cable is used which is coupled to one or both spools via a pulley. Activation of the gas generator forces a piston to move in a manner which exerts tension on the flexible member(s) thereby unwinding the flexible member from the spool pulley and providing pretensioning rotation of the respective belt spool.

Abstract: A seat belt retractor for use in seat belt restraint systems. The retractor incorporates dual rotopretensioner units and adaptive load limiting characteristics. Preferably, the rotopretensioners are positioned on opposite ends of a retractor spool for driving the spool for pretensioning rotation. A first pretensioner may be activated alone to provide pretensioning rotation. In one embodiment of the invention, if the second pretensioner is not activated, the system will be engaged to provide a given belt load limiting characteristic. A second rotopretensioner may be fired either after the first pretensioner is fired to increase pay-in capacity or to activate a different load limiting characteristic for the retractor.

Abstract: An assembly having a retractor and a pretensioner whereby the pretensioner can be employed to provide load limitation features. The pretensioner may also be used without the load limitation features. The pretensioner has a drive mechanism including a plurality of pretensioner balls sized to engage a pinion, the pinion operatively connected to the seat belt through a force limiting element. The pretensioner defines a guide surface structured to guide the pretensioner balls along a ball path along the pinion. The guide surface includes features to engage a pretensioner ball and block the pinion.

Abstract: An assembly having a retractor and a pretensioner whereby the pretensioner can be employed to provide load limitation features. The pretensioner may also be used without the load limitation features. The pretensioner has a drive mechanism including a plurality of pretensioner balls sized to engage a pinion, the pinion operatively connected to the seat belt through a force limiting element. The pretensioner defines a guide surface structured to guide the pretensioner balls along a ball path along the pinion. The guide surface includes features to engage a pretensioner ball and block the pinion.