Kabushiki Kaisha Tokai Rika Denki Seisakusho

Hironori Sasaki

Tatsushi Kubota

Kenji Matsui

Hisao Yamada

Akio Numazawa

Yoshihiro Oka

A tension reducer used in a webbing retractor is provided with a weak coil spring, a strong coil spring, and a connecting member all connected in series, the rotation of the connecting member in the webbing winding direction being stopped at a predetermined time after the webbing has been pulled out from the winding shaft when a passenger puts on the webbing. The inner end of the weak coil spring is connected to the connecting member so that, after the rotation of the connecting member has stopped, the urging force of the spring is released as the spring unwinds from its outer end.

Tension reducer

Disclosed herein is a tension reducer suitable for use in a webbing retractor, which comprises a weak resilient spiral spring whose one end is connected to a webbing take-up spindle of the webbing retractor and which exerts an urging force in a webbing winding direction, a connecting member connected to the other end of the weak resilient spiral spring and disposed rotatably about the take-up spindle, a strong resilient spiral spring whose one end is connected to the connecting member and which exerts an urging force in the webbing winding direction greater than the urging force of the weak resilient spiral spring, a device for stopping the rotation of the connecting member in the webbing winding direction so as to avoid the exertion of the urging force of the strong resilient spiral spring on a webbing at the time that the webbing is pulled out of the take-up spindle to be fastened to an occupant, and a device disposed about the take-up spindle for controlling the degree of tightening of the windings of the weak resilient spiral spring so as to prevent the torque thereof from exceeding a predetermined range.

A webbing retractor for taking up an occupant-restraining webbing used in a seat belt apparatus for a vehicle has a takeup shaft held by a frame, and the webbing is wound around the takeup shaft. The takeup shaft is pivotally held at a substantially intermediate portion of each of a pair of arms. One end of each arm is pivotally supported by a support shaft, and the arms are adapted to rotate about the support shaft. At the time of a sudden deceleration of the vehicle, a clamp plate held at a distal end of a clamp lever is pushed upward by an actuating device including the arms to cause the webbing to be clamped, and when a clamping force exceeding a predetermined value is applied to the webbing, a projection formed at a proximal end of the clamp lever presses a thin-walled portion toward a rectangular hole so as to deform the thin-walled portion, which in turn causes the clamp plate to move in a direction in which the clamped state of the webbing is canceled, thereby setting a webbing-clamping force at a predetermined level or below.

Webbing retractor

A tension reducer for use in a webbing retractor having a webbing take-up spindle for winding a webbing thereon having two types of flat spiral springs, one with strong and the other with weak resilient characteristics connected in series to each other through a gear wheel is urged in a webbing winding direction. The gear wheel is locked to avoid the urging force of the strong flat spiral spring on an occupant. The tension reducer comprises inertial mass bodies movable when the gear wheel is unlocked and a C-shaped friction spring whose diameter is enlarged by the movement of the inertial mass bodies for avoiding an abrupt rotation of the gear wheel relative to the take-up spindle. Thus, the abrupt tension of the strong flat spiral spring is prevented so that the occurrence of an improper sound is reduced.

In a support construction of securing member for securing an occupant restraining webbing applied to a vehicle and adapted for supporting the securing member to a vehicle body through an extension member, an intermediate portion of the extension member is connected to the securing member through connecting means, therewith a forward end portion of the extension member formed in a portal shape is received in a support hole formed on the securing member, and the back portion of the portal shape portion is caused to abut on a peripheral portion of the support hole and a pair of receiving portions are formed on both sides of the portal shape portion. Accordingly, the receiving portions are latched to a peripheral portion of the support hole and a large tension load acting between the securing member and the extension member can surely be sustained in an emergency situation of the vehicle.

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Aichi, Japan

Hironori Sasaki