VEHICLE SEAT PRETENSIONER AND PRETENSIONER ASSEMBLING METHOD

摘要

A pretensioner (10) has a cylinder (11) and a piston (12) which moves within the cylinder (11). The piston has an inclined stopper face (37) increasing in diameter in the first direction. In a space (H) between the stopper face (37) and the inner peripheral face of the cylinder (11), there attached are steel balls (35) which abut on the stopper face (37) and the inner peripheral face of the cylinder (11) to suppress the movement of the piston (12) in the second direction. The steel balls (35) fit into a fit-in groove (21) of a retainer (18), which is attached to the piston (12).