Patent ID: 6042042
Filing Date: 2000-03-28
Classification: B60R

Abstract:
A seat belt retractor comprising:a reel for winding a webbing,a frame for supporting the reel,a spring for biasing the reel in a direction for winding the webbing,a locking mechanism for stopping rotation of the reel in a direction for unwinding the webbing in an event of a vehicle emergency, andan impact absorbing mechanism for allowing the rotation of the reel in the webbing unwinding direction with keeping a predetermined tensile load on the webbing when tension exceeding a predetermined value is exerted on the webbing when the locking mechanism stops the rotation of the reel,wherein an annular lock base for stopping the rotation of said reel in the event of the vehicle emergency is provided coaxially with said reel,said impact absorbing mechanism is provided with a spiral roll formed of a spiral metallic band wound on an outer periphery of the lock base,a winding direction of said spiral roll from its outer end toward its inner end is identical with a webbing winding direction of said reel,an outer end of said spiral roll is secured to said frame and an inner end of said roll is connected to an outer periphery of said lock base, andwhen said locking mechanism stops the rotation of the reel, the lock base and the reel are coupled to each other and the roll is reversely rolled up from the inner end of the roll so as to be wound onto the lock base because of the rotation of the reel in the webbing unwinding direction, thereby absorbing the impact.