Takata Corporation

Yasushi Kanamori

Masahiro Shiotani

Joji Mishina

Koji Hiramatsu

Muneo Nishizawa

Miwa Morimoto

Isamu Mizuno

Masao Hisaki

The disclosed seat belt retractor may include a spool for retracting a seat belt, a torsion bar, a pre-tensioner, and a locking device. The torsion bar may disposed inside the spool, wherein one side of the torsion bar is connected to the spool, and configured to absorb energy of movement of an occupant while being deformed under torsion. The pre-tensioner may be positioned at one side of the spool and configured to generate a rotating drive force for rotating the spool in a retracting direction in a condition of rapid deceleration of a motor vehicle. The locking device may be capable of locking another side of the spool such that a rotation of the spool in a withdrawal direction is suppressed at both an operating time of the pre-tensioner and a non-operating time of the pre-tensioner.

Seat belt retractor

A seat belt retractor which achieves stable performance of a pretensioner. The seat belt retractor includes a spool for winding up a belt thereon. The spool has a shaft portion, a spool gear, and a spring-biased shaft projection which are disposed to project from a face of the spool. A spool bearing (or ring-like collar) is fitted around the shaft portion of the spool. The spool bearing is made of a material having high hardness and high rigidity such as SUS or SC. By this spool bearing, the spool is prevented from being directly subjected to load, like a bearing.

A seat belt retractor configured to prevent the occurrence of backlash between the torsion bar and a member to which the same is fitted even when a force is applied to the torsion bar when rotation of the retractor is locked. Backlash preventing ribs are provided on the inner peripheral surfaces of the axial hole of the reel on the sides which not subject to a large force between the reel and the torsion bar. Therefore, since a large force generated when rotation of the locking base of the locking mechanism in the webbing unwinding direction is locked is not applied to these backlash preventing ribs the collapse of the backlash preventing ribs caused by such a force can be prevented.

Seatbelt retractor

A seat belt retractor including a torsion bar is provided. A second torque transmitting portion of the torsion bar is clamped between a reel and a holder member press-fitted radially in the reel without backlash in the axial direction. A first torque transmitting portion is strictly fixed to a pawl holder without backlash in the axial direction by radially crimping an internal periphery of a left end portion of the pawl holder of a locking means. Therefore, the first and second torque transmitting portions conventionally formed in a torsion bar are effectively used, thereby eliminating a groove for an E-ring as conventionally used and thus simplifying the configuration of the torsion bar. In addition, since the first and second torque transmitting portions can operate without backlash, the occurrence of jarring noise due to vibrations of the seat belt retractor can be prevented.

A seat belt retractor having a structure preventing a gear or pinion having external teeth from being improperly assembled to a spool gear. The pinion includes concave portions on its inner periphery and the spool gear includes corresponding convex portions on its outer periphery. The concave and convex portions are configured to be fit together may be inclined in the circumferential direction and thus have no symmetrical plane. If during assembly the pinion is positioned adjacent the spool gear with the wrong side out, the pinion and the spool gear would not fit together and the mistake would be noticed and, therefore, prevented.

A seat belt retractor with a torsion bar which can receive a large torque and can be easily formed by forging is provided. A reel assembly of the seat belt retractor includes a reel, a torsion bar, and a locking member. A first connection part of the torsion bar non-rotatably couples with concavities of a locking base of the locking member. A second connection part non-rotatably couples with concavities of the reel. The outer peripheries of the connection parts and are torx-shaped having a plurality of concavities and convexities formed in a wave-shape. A ratio R /R of the distance between the tops of the wave-shaped convexities of the connection parts and the axial center of the torsion bar (radius R ) to the distance between the bottoms of the concavities and the axial center of the torsion bar (radius R ) is set to 1.2 to 1.3.

To provide a torsion bar for the use of a seat belt retractor which can be manufactured without a spheroidizing annealing process. A torsion bar to be used as a load limiter in a seat belt retractor is characterized in that the torsion bar is made of steel of which the carbon content is 0.04% or less.

Torsion bar for seat belt retractor

A torsion bar in a seat belt retractor includes a torsion portion to be twisted. The torsion portion has an outer portion, and a center portion inside the outer portion. The outer portion has a hardness lower than that at the center portion to thereby increase energy absorption in twisting the torsion portion. Therefore, even if higher stress is applied to the outer portion of the torsion portion when the torsion bar is twisted, the number of turns until the torsion bar is broken can be increased as compared to the conventional one. Accordingly, the belt withdrawing amount is ensured enough after the twisting of the torsion portion is started, thereby improving the energy absorbing capacity.

Growing community of inventors

Tokyo, Japan

Yasushi Kanamori