Patent ID: 6497379
Filing Date: 2002-12-24
Classification: B60R

Abstract:
A seat belt retractor which, in a normal situation, allows a free extraction and retraction of a webbing which is wound around a spool, and which, in an emergency, restrains an occupant by stopping the extraction of the webbing, said seat belt retractor comprising:an energy absorbing mechanism configured to limit a load applied to the webbing within a load limit in the emergency, wherein said energy absorbing mechanism is configured to gradually reduce the load applied to the webbing after the load limit is reached; wherein said energy absorbing mechanism comprises a torsion bar which is twisted by a torque caused by an extraction force applied to said webbing in the emergency, and which absorbs an impact energy which occurs in the emergency, and wherein the energy absorbing mechanism is configured so that the torque applied to the torsion bar is gradually reduced so that the load applied to the webbing is gradually reduced after reaching the load limit; further comprising a circular pulley attached to said torsion bar in a decentered manner and a wire wound around said circular pulley, and wherein said wire is configured to be pulled by a force caused by the extraction force applied to the webbing, so that the torque applied to the torsion bar is gradually reduced.