Takata Corporation

Yusuke Iura

Masahiro Shiotani

Hikaru Kameyoshi

Hirokazu Yoshioka

[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 Since the seat belt is then withdrawn, the pinionand the ring gearrotate in a seat-belt withdrawing direction.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.

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Tokyo, Japan

Yusuke Iura