Starting device and seat belt tightening apparatus

摘要

A starting device (21, 121, 41) for actuating a gas generator (8) by striking a detonator (10) in response to an acceleration of a predetermined level or more. The starting device includes a firing pin (22), an inertial mass (23), an annular permanent magnet (24) and an erroneous-actuation preventing mechanism (9, 109, 42). The firing pin (22) is capable of igniting the detonator (10) by moving toward and colliding against the detonator (10). The inertial mass (23) is made of a cylindrical permanent magnet for supplying kinetic energy to the firing pin (22). The annular permanent magnet (24) has an inside diameter larger than an outside diameter of the inertial mass (23). The erroneous- actuation preventing mechanism (9,109, 42) prevents the erroneous actuation of the starting device (21, 121, 41). The erroneous-actuation preventing mechanism (9,109, 42) includes a restricting member for selectively setting the inertial mass (23) in a nonmovable state and in a movable state.