Takata Corporation

Isamu Mizuno

Masahiro Shiotani

Tetsuya Hamaue

Hiromasa Tanji

Noriyuki Kosugi

Joji Mishina

Yasushi Kanamori

Hiroki Takehara

Hikaru Kameyoshi

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.

Seat belt retractor

A seat belt retractor with a ball type pretensioner including a pipe in which the balls are retained. A front end portion of the pipe is securely retained so that reliable operation of the pretensioner is provided. The pipe does includes a cut-out that does not extend to the front-most end of a pipe. A guide block is fitted in the front-most end of the pipe. The pipe and the guide block are fixed to the plate together by a fastener. The portion where the guide block is fitted to the pipe can provide high rigidity and is thus hardly deformed in every directions. The fastener may be hardened or the material for the fastener may be selected to obtain sufficient strength.

To provide a pre-tensioner which can effectively use ignition pressure of a gas generator and can be constructed in a compact form as a whole and have lighter weight, a pre-tensioner is mounted outside of a side wall of the frame by a base . A hexagonal head portion of a reel penetrates a base . Fixed to the outer periphery of the hexagonal head portion is a pinion . The pinion is provided with external teeth uniformly formed around the periphery thereof. A ring gear is disposed to surround the pinion . The ring gear has internal teeth engageable with the external teeth of the pinion . The ring gear has levers projecting outwardly, which are formed on the outer periphery of the ring gear at predetermined interval. The lever of the ring gear is substantially in contact with the head ball - within the pipe

Pre-tensioner

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

Shiga, Japan

Isamu Mizuno