Patent ID: 7458534
Filing Date: 2008-12-02
Classification: B60R

Abstract:
1. A pretensioner coupling for a seat belt retractor for a motor vehicle, the retractor having a belt shaft and a pretensioner drive adapted for rotating to wind the belt shaft, the pretensioner coupling comprising: a coupling latch movably arranged between a release position and an engagement position, the coupling latch producing a load-transmitting rotational connection between the belt shaft and the pretensioner drive when in the engagement position and movable out of the engagement position and into the release position to permit relative rotation between the belt shaft and the pretensioner drive, and an inertial mass mounted on the belt shaft and being rotationally arranged in relation to the belt shaft, the coupling latch being coupled with the inertial mass wherein the inertial mass rotates more slowly than the pretensioner drive when the pretensioner drive has been activated to wind the belt shaft thereby moving the coupling latch to the engagement position, and the inertial mass rotating faster than the belt shaft at the conclusion of the winding of the belt shaft by the pretensioner drive, moving the coupling latch to the release position, and wherein the coupling latch is arranged to swing between the release position and engagement position, the coupling latch having a pin which engages a radial cam track formed by the inertial mass.