Patent ID: 6106013
Filing Date: 2000-08-22
Classification: B60R

Abstract:
A seat belt system having a controlled force energy management system tuned to a vehicle's crash performance characteristics, the seat belt system comprising:a retractor reel carrying a seat belt including a shoulder belt wound thereon for protraction and retraction;a reel shaft mounting the reel for rotation relative to the shaft at tensile forces applied to the seat belt above a predetermined tensile onset force;a lock connected to the reel responsive to a predetermined condition to stop rotation of the reel and shaft up to the predetermined tensile onset force on the seat belt, the reel shaft rotating with the reel to allow the belt to be freely protracted therefrom until the occurrence of the predetermined condition;a thread on the reel shaft;a threaded nut mounted on the thread for axial travel along the reel shaft, the nut rotating with the reel shaft without axial travel thereon during free protraction of the belt until the occurrence of the predetermined condition;a tubular member mounted on the shaft having a wall of a predetermined wall thickness and material to be deformed to dissipate energy in a controlled predetermined manner; anda deforming member movable relative to the tubular member upon application of the onset force to the seat belt and having a profiled surface to cooperate with the tubular member to deform the same in a radially outward direction to dissipate energy in the controlled predetermined manner by limiting the shoulder belt loads and belt extraction to predetermined ranges thereof over a predetermined time period to provide an energy management system tuned to a particular vehicle's crash performance characteristics, the relative movement caused by the locking of the reel shaft against rotation upon occurrence of the predetermined condition and rotation of the reel relative to the locked shaft at forces at and above the onset force with the reel rotation rotating the nut to cause the nut to travel axially along the locked shaft.