Vehicle seat belt retractor - has torsion spring on shank of double catch, to release it when return spring force prevails over catch spring

摘要

The base side plates have bores (8) in which bearing elements (9) seat the ends of the axle (7) on which the spool (10) rotates. On the external surface of one of the side plates a spring housing (19) accommodating a spiral spring (17) is fitted. Both side plates have shaped slots (32) in which the ends of the catch (30) seat. The shank (34) of the catch has a torsion spring (35) fitted so that normally the spring forces the catch legs (33) to engage with tooth flanks (13) of the ratchet wheels (12). When a length of belt is uncoiled, the tension of the spiral spring increases until it exceeds that of the torsion spring. At this point the housing (19) performs a limited rotary motion forcing the catch to swing out from engagement with the tooth flanks.