Takata Corporation

Joyson Safety Systems Japan K.k.

Masahiro Shiotani

Yasushi Kanamori

Joji Mishina

Koji Hiramatsu

Yusuke Iura

Isamu Mizuno

Miwa Morimoto

Tetsuya Hamaue

Hiromasa Tanji

Noriyuki Kosugi

Masashi Shimizu

Yoshiteru Sakaguchi

Kunihiro Kamei

Provided are a pretensioner, a retractor, and a seat belt device that can achieve weight reduction of a device by improving slidability of a power transmission member used for the pretensioner. A pretensioner includes a drive wheel for rotating the spool, and a power transmission unit for transmitting power to the drive wheel in an emergency. The power transmission unit includes a power transmission member for rotating the drive wheel, a pipe that contains the power transmission member, a gas generator for supplying a working gas into the pipe, and a housing that defines a passage for the power transmission member on an outer periphery of the drive wheel. The housing has a sliding member that is disposed at an outlet part of the pipe and that reduces frictional force between the housing and the power transmission member.

Pretensioner, retractor, and seat belt device

[Object] To provide a retractor that is manufacturable at a much lower cost by making a pretensioner operate more effectively, by minimizing the length of a pipe so that a weight reduction is realized effectively, and by easing the restriction for the shape of a guide member. [Solution] A pipein which a plurality of balls as force transmitting members are provided includes an attaching portionas a projection provided at one end portionthereof. A guide memberhaving a guide surfacethat guides the balls has attaching groovesas recesses. The attaching portionis fitted into the attaching grooves, whereby the pipeis attached around the outer circumference thereof to the guide memberattached to a frame. Since the guide memberis provided on the outer circumference of the pipe, the pipecan be shortened.

Seat belt retractor and seat belt apparatus including the same

To allow a seat belt retractor to be easily assembled and to be made compact while effectively operating a pretensioner and an energy absorbing mechanism. A plurality of ballsrotate a ring gearby gas generated in the event of an emergency. Since internal teethare meshed with external teeth, a pinionis rotated by the rotation of the ring gear, and a spool retracts a seat belt. After pressing the ring gear, the ballsseparate from the ring gearand are stored in an arc-shaped passage. Since the seat belt is then withdrawn, the pinionand the ring gearrotate in a seat-belt withdrawing direction. In this case, some of the ballsin contact with the ring gearare returned by the ring gear. Therefore, the ring gearmore smoothly rotates because the influence of the ballsis suppressed.

To effectively operate a pretensioner using a plurality of balls and an energy absorption mechanism, to simplify the structure of an exhaust passage in the pretensioner, and to facilitate the working process of the exhaust passage. A pretensionerincludes a plurality of ballsserving as force transmission members and a pistonin a pipe. A piston bodyof the pistonincludes a shaft portionand a substantially hemispherical head portion. The piston bodyis provided with an exhaust holeextending in the axial direction and exhaust groovescommunicating with the exhaust holethat define an exhaust passage. The exhaust groovesprevent the exhaust holefrom being closed even if the head portionof the pistoncontacts the ball. Since the exhaust holeand the exhaust groovesare simply provided in the piston bodyformed as a single member, the structure of the exhaust passage is simple, and working of the exhaust passage is easy.

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 pretension with improved piston sealing performance. A piston has an expanding section formed at one end thereof contacting a force transmission component. When gas pressure resulting from reactive gas generated by a gas generator causes the piston to exert a pressing force on the force transmission component in the event of an emergency, the expanding section expands toward the inner circumferential surface of a pipe due to the gas pressure. As a result, the outer circumferential surface of the expanding section in the piston comes into contact with the inner circumferential surface of the pipe in a more efficient manner, resulting in enhanced sealing between the piston and the inner circumferential surface of the pipe. This prevents reactive gas from losing gas pressure, thereby allowing the gas pressure to more efficiently act on the piston.

Pretensioner, seat belt retractor having the same, and seat belt apparatus provided therewith

A seat belt retractor includes a spool for winding a seat belt; a locking mechanism having a locking member rotating with the spool in a normal state and being locked not to rotate in a direction of unwinding the seat belt in an emergency state; and an energy absorbing mechanism provided between the spool and the locking member for absorbing impact energy applied on an occupant when the spool rotates in the direction of unwinding the seat belt relative to the locking member in the emergency state. The energy absorbing mechanism includes an energy absorbing member provided in one of the spool and the locking member, and a deforming device provided in the other of the spool and the locking member for deforming the energy absorbing member. The energy absorbing member has a width partially varied.

Seat belt retractor and seat belt device equipped with the same

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.

A seat belt retractor of the invention is basically formed of a first reel, a second reel, a rope extending between the first reel and the second reel, and a spiral spring situated in the second reel as an urging force providing device. The first reel is connected coaxially to a rotational axis of a reel shaft for winding a webbing, and has a drum shape on which the rope fixed at one end to the first reel is wound. The second reel has a rotational shaft disposed parallel to and laterally spaced away from the first reel. The second reel includes a small diameter reel portion, a large diameter reel portion, and a transition portion connecting the small diameter reel portion and the large diameter reel portion. The rope attached to the first reel extends to the small diameter reel portion and the transition portion, and is wound around a groove of the large diameter reel portion. The seat belt retractor is improved in assembling the members, and an approximately constant force for withdrawing the webbing can be achieved even if a withdrawal amount of the webbing is increased.

Growing community of inventors

Tokyo, Japan

Masahiro Shiotani