US 4,538,774 AGranted

Webbing tension device

AssigneeKabushiki Kaisha Tokai-Rika-Denki-Seisakushao

InventorsTeruhiko Kawaguchi, Yuji Nishimura, Akinori Fujiwara

Life of this patent

Estimating the term…

Loading patent…

Abstract

In a webbing tension device adapted for use in a seatbelt system for protecting an occupant in an emergency situation of a vehicle, comprising a wheel supported by a webbing takeup shaft, a pawl latched to the wheel to prevent the wheel from rotating and trigger means detecting an acceleration and deceleration acting upon the vehicle in the emergency situation thereof to release the pawl from the wheel, cam means is caused to abut on the pawl and the trigger means. Accordingly, the wheel is surely prevented from the rotation in an ordinary running situation of the vehicle, and in the emergency situation of the vehicle the trigger means moves the cam means to release the pawl reliably from the wheel. In the present webbing tension device, thus, latching and releasing performances between the pawl and the wheel are improved.

Claims16

Dependent claims

A webbing tension device adapted for use in a webbing retractor for protecting an occupant in an emergency situation of a vehicle, which comprises:

(a) a wheel supported by a webbing takeup shaft of the webbing retractor;
(b) first resilient means biasing the wheel in a direction of a retraction of an occupant restraining webbing;
(c) a pawl caused to latch to a portion of the wheel, thereby preventing the wheel from its rotation;
(d) cam means abutting on the pawl to support it, thereby maintaining a latching situation of the pawl and the wheel, the cam means allowing the pawl to be released from the wheel when the cam means is rotated in one direction;
(e) trigger means causing the cam means to rotate in the one direction to release the pawl from the wheel in the emergency situation of the vehicle, the trigger means having a reversible structure including an acceleration sensor detecting the emergency situation of the vehicle, a trigger member opposed to the cam means and rotated by the acceleration sensor in the emergency situation of the vehicle and second resilient means biasing the trigger member, the direction of the biasing force of the second resilient means being reversed at a pedetermined rotated position of the trigger member;
and
(f) clutch means connecting the wheel to the takeup shaft to transmit a biasing force of the first resilient means to the takeup shaft when the wheel is rotated,
whereby the pawl and the wheel are securely latched to and released from each other.

5 more elements

A webbing tension device adapted for use in a webbing retractor for protecting an occupant in an emergency situation of a vehicle, which comprises:

(a) a wheel supported by a webbing takeup shaft, the takeup shaft being rotatably supported by a frame fixed to a vehicle body and retracting an occupant restraining webbing thereon;
(b) first resilient means biasing the wheel in a direction that will cause the retraction of the webbing;
(c) a pawl caused to latch to a portion of the wheel, thereby preventing the wheel from its rotation;
(d) cam means abutting on the pawl to support it, thereby maintaining a latching situation of the pawl and the wheel, the cam means allowing the pawl to be released from the wheel when the cam means is rotated in one direction;
(e) trigger means causing the cam means to rotate in one direction to release the pawl from the wheel in an emergency situation of the vehicle, the trigger means having a reversible structure including an acceleration sensor detecting the emergency situation of the vehicle, a trigger member opposed to the cam means and rotated by the acceleration sensor in the emergency situation of the vehicle and second resilient means biasing the trigger member, the direction of the biasing force of the second resilient means being reversed at a predetermined rotated position of the trigger member;
(f) clutch means connecting the wheel to the takeup shaft to transmit a biasing force of the first resilient means to the takeup shaft when the wheel is rotated;
and
(g) third resilient means biasing the takeup shaft in the direction that will cause the retraction of the webbing, the biasing force of the third resilient means being weaker than that of the first resilient means,
whereby the pawl and the wheel are securely latched to and released from each other.

6 more elements

A webbing tension device adaped for use in a webbing retractor for protecting an occupant in an emergency situation of a vehicle, which comprises:

(a) a frame fixed to a vehicle body;
(b) a takeup shaft rotatably supported by the frame and retracting an occupant restraining webbing thereon;
(c) a wheel supported by the takeup shaft;
(d) a first spring biasing the wheel rotatively in a direction that will cause the retraction of the webbing;
(e) a pawl caused to latch to a portion of the wheel, thereby preventing the wheel from rotating in an ordinary running situation of the vehicle;
(f) trigger means detecting an acceleration and deceleration acting upon the vehicle to act to release the pawl from the wheel in the emergency situation of the vehicle and having a reversible structure including an acceleration sensor having a head portion and a trigger member abutting on said head portion of the acceleration sensor, the trigger member comprising a trigger lever and a second spring biasing said lever and the biasing force of the second spring to the trigger lever being reversed when the trigger lever is rotated across a predetermined position;
(g) cam means abutting on the pawl to support it, thereby maintaining a latching situation of the pawl and the wheel in the ordinary running situation of the vehicle, the cam means being rotatively pressed on to the acceleration sensor by the first spring through the pawl in the ordinary running situation of the vehicle and in the emergency situation of the vehicle the cam means being rotated to release the pawl from the wheel by the acceleration sensor through the trigger lever;
and
(h) clutch means connecting the wheel to the takeup shaft to transmit a biasing force of the first spring to the takeup shaft when the wheel is rotated.

6 more elements

Dependencies are inferred from the claim text.