Patent ID: 7097206

Claim:
A belt-buckle tightener for a seat belt system in a vehicle, comprising: a rotatable spindle which is connected to a belt buckle via a draw-in cable; and a drive for rotation of the spindle, wherein the spindle and draw-in cable are arranged so that rotation of the spindle results in the draw-in cable being rolled up on the spindle and movement of the belt buckle in a direction that tightens the seat belt, the drive being integrated in the spindle; and a coupling sleeve which is connected in a rotationally fixed manner to a frame of the vehicle chassis, wherein the spindle is mounted rotatably on the coupling sleeve, and the drive includes a gas generator fastened to the spindle and a driving belt fastened at both ends to the coupling sleeve, and wherein the driving belt is partially wound up on the coupling sleeve and runs around the gas generator when the belt-buckle tightener is not operating, to form a space for receiving gas which is produced by the gas generator so that when gas from the gas generator enters the space the space is enlarged and the driving belt is unwound from the coupling sleeve, thereby producing a driving force and causing the spindle to rotate.