Seat belt fastening device

摘要

A seat belt fastening device has a seat belt buckle and a single casing in which a compression coil spring for pulling in slack of the seat belt is positioned between a retainer and a flange of a guide member. An inertial mass member is slidably disposed in the guide member. The coil spring is connected by a wire to a pulley unit through the retainer and guide member. The seat belt buckle is connected to the pulley unit by a wire. The wire is usually wound to the pulley unit which is locked by a control lever. When the inertial mass member moves under excessive deceleration, it drives operation levers and the control lever to unlock the pulley unit. As a result, the wire is pulled out from the pulley unit by the released compression spring. Incidentally, the wire is wound to the pulley unit so that the buckle is retracted into the casing and the slack of the seat belt is reduced.