Automotive seatbelt take-up device
AssigneesSuncall Corporation, Kabushiki Kaisha Tokai Rika Denki Seisakusho
InventorsSadaaki Mitsuo, Masahito Wakahara, Norikazu Akamatsu, Kazuhiro Osaki
Life of this patent
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Abstract
An automotive seatbelt take-up device has a primary spiral spring biasing a take-up shaft in a seatbelt take-up direction. A spring clutch transfers rotation of the take-up shaft in a seatbelt drawing-out direction to a ring. A secondary spiral spring is capable of generating rotational biasing force on the take-up shaft in a direction opposite that of the primary spiral spring. Thus, the present invention provides an automotive seatbelt take-up device that can reduce both the drawing-out force and the take-up force of a seatbelt when the seatbelt is being worn.
Claims5
An automotive seatbelt take-up device comprising:
- a take-up shaft operatively connected to a seatbelt take-up shaft;
- a primary spiral spring fixed to said take-up shaft, biasing said take-up shaft in a take-up direction;
- a spring clutch, including a ring and a clutch spring, fitted to the outside of take-up shaft, transferring rotation of said take-up shaft in a seatbelt drawing-out direction to said ring;
- a balance spring capable of generating a rotational bias force in a direction opposite to that of said primary spiral spring, one end of said balance spring being fixed to said ring;
- a ratchet wheel fixed to another end of said balance spring;
- restricting means capable of restricting said ratchet wheel, thereby preventing rotation in said seatbelt take-up direction;
- means effective when said ratchet wheel is restricted, for permitting said spring clutch to transfer friction in a direction to wind said balance spring tight, whereby a take-up force on said take-up shaft is reduced;
- and
- means, effective when said ratchet wheel is restricted to permit a release elastic force of said balance spring to assist, by way of said spring clutch, rotation of said take-up shaft in said drawing-out direction.
Dependencies are inferred from the claim text.