Patent ID: 8910894

Claim:
A seat belt pretensioner comprising: a housing, a belt shaft ( 10 ), a load limiting device ( 70 ) connected with the belt shaft ( 10 ), a pretensioner drive wheel ( 20 ) coupled to the belt shaft ( 10 ) in a rotationally fixed manner, a coupling element ( 60 ) located on the pretensioner drive wheel ( 20 ), which is fixed in the circumferential direction via a detachable connection and can be locked in a housing-fixed manner in the belt webbing extraction direction by a blocking device ( 90 ), and an engagement wheel ( 50 ) is provided for connecting the belt shaft ( 10 ) with the pretensioner drive wheel ( 20 ) having axially directed conical engagement portions ( 51 ) engages into corresponding recesses ( 12 ) on the belt shaft ( 10 ) or on the pretensioner drive wheel ( 20 ) and is fixed in the circumferential direction on the pretensioner drive wheel ( 20 ) by the coupling element ( 60 ), the detachable connection between the coupling element ( 60 ) and the pretensioner drive wheel ( 20 ) can be disconnected by the housing-fixed locking of the coupling element ( 60 ) and a rotation of the belt shaft ( 10 ) in the belt webbing extraction direction, and, thereby, the engagement wheel ( 50 ) is enabled to undergo a relative rotational movement in relation to the pretensioner drive wheel ( 20 ) or in relation to the belt shaft ( 10 ), which relative rotational movement is superimposed with an axial movement by the conical engagement portions ( 51 ), whereby the engagement portions ( 51 ) disengage from the recesses ( 12 ) and the form-closed connection between the pretensioner drive wheel ( 20 ) and the belt shaft ( 10 ) can be released, wherein the coupling element ( 60 ) is connected with the pretensioner drive wheel ( 20 ) via a snap-off lug ( 22 ) which connects the coupling element from the pretensioner drive wheel.