| 摘要 |
[Object] To allow force transmission members to smoothly move in a pipe, to facilitate setting of a stopper for stopping rotation of a ring gear, and to reduce the cost with a simple structure. [Solution] A ring gear 15 of a pretensioner 8 includes a plurality of levers 17 and one arc-shaped stopper 16. During operation of the pretensioner 8, the levers 17 are sequentially pressed by balls 12a to rotate a pinion 19 and a spool in a seatbelt retracting direction. When the ring gear 15 rotates by a predetermined rotation amount, an outer peripheral edge 16c of the stopper 16 contacts and presses the opposing ball 12a. Since the ball 12a is thereby clamped between the stopper 16 and an inner peripheral surface 10d 1 of a pipe 10, the ring gear 15 is stopped. |
