Patent ID: 9302648
Filing Date: 2016-04-05
CPC Classification: B60R

Claim Text:
1. A belt pretensioner comprising a belt shaft, a force limitation arrangement connected with the belt shaft, and a pretensioner drive wheel coupled with the belt shaft so as to be locked against relative rotation, a retaining element is provided for coupling the pretensioner drive wheel to the belt shaft enabling the pretensioner drive wheel to drive the belt shaft in a pretensioning direction by a pretensioning direction movement, and the retaining element is releasable to uncouple the pretensioner drive wheel from the belt shaft by the rotation of the belt shaft in a belt webbing withdrawal direction after the pretensioning direction movement has taken place, the retaining element being formed by a spring plate with an inner toothing configured to be keyed with an outer toothing of the belt shaft while the pretensioner drive wheel moves in the pretensioning direction and to be unkeyed from the outer toothing of the belt shaft by the rotation of the belt shaft relative to the spring plate in the webbing withdrawal direction, wherein the pretensioner drive wheel and the belt shaft interact with each other via a ramp contour formed on the pretensioner drive wheel, and the retaining element is axially moved by an axial movement of the pretensioner drive wheel relative to the belt shaft forced by the ramp contour.