Seat belt retractor of automobile

摘要

A seat belt retractor, a reel of which is rotated by a winding spring and a tightening spring when shock is applied on the automobile body. The winding spring is provided to a reel which winds a seat belt, while the tightening spring is provided to a shaft. In a normal condition, the reel is separated from the shaft by a clutch. Resilient force of the tightening spring is stored to the shaft by a stopper. In a normal condition, the seat belt is retracted only by the winding spring. When shock is applied on the automobile body, the stopper releases the shaft, which rotates by the tightening spring. Then, the clutch connects the shaft and the reel, whereby the seat belt is retracted by the winding spring and the tightening spring.