Car safety belt tightener with crash load sensor - utilises inertia of compression spring, which is part of crash load sensor

摘要

The car safety belt tightener has a tubular housing which encloses a compression spring (22) for a crash load sensor (26,27), held between two end plates (12,21). The first end plate (12) is attached to one end of a cable (8), which passes through the spring and has its other end attached to the safety belt. The second end plate (21) is attached to a bolt (5) which is held in place by pawls (36) which have their other ends supported on a disc (18). In the event of a crash, the mass of the spring and its attached fittings causes it to move axially so that the tips of the pawls (36) are pulled clear of the disc and swing inwards about a support ring (17). Thus, the spring is released to apply tension to the safety belt. ADVANTAGE - Small number of components, and reliable function.