Patent ID: 6206314
Filing Date: 2001-03-27
Classification: B60R

Abstract:
A seat belt retractor, comprising:a reel shaft for winding a webbing therearound having a rotational axis,a first reel coaxially connected to the rotational axis of the reel shaft without slippage and having a shape of a cylindrical drum,a second reel including a rotational shaft disposed parallel to the first reel and laterally spaced apart therefrom, a large diameter reel portion with an end surface, a small diameter reel portion having a diameter smaller than that of the large diameter reel portion and situated adjacent to the large diameter reel portion, and a transition portion formed at the end surface and having a curved transition groove for connecting the small diameter reel portion and the large diameter reel portion, said transition groove having a shape of a part of an arc with a radius equivalent to an average of a radius of the small diameter reel portion and a radius of the large diameter reel portion,a rope member having one end fixed to the first reel and wound around the first reel, said rope member extending from the first reel to the large diameter reel portion through the small diameter reel portion and the transition portion and wound therearound including the transition groove so that a rotational ratio of the first reel to the second reel is changed, andurging means disposed inside the second reel for urging the second reel to rotate in a direction of winding of the webbing against a rotation of the second reel resulting from a rotation of the first reel caused by winding of the rope member around the first reel when the webbing is withdrawn from the reel shaft, a force for withdrawing the webbing being decreased in accordance with an amount of withdrawal of the webbing by changing the rotational ratio of the first reel to the second reel.