| 摘要 |
<p>A seat belt retractor for winding up a seat belt by the rotation of a spool, characterized by including a gear (20) having external teeth being not symmetrical about any plane passing through the axis wherein said gear (20) is interfitted with the shaft (19) of said spool, and in that fitting portions (20a-20d) between the shaft (19) of said pool and said gear (20) are configured not to be symmetrical about any plane passing through the axis or not to be symmetrical about a plane at the center between one side facing the spool and the other side of said gear (20). Therefore, even by taking an action of fitting the pinion (20) the spool gear (19) wrong side out, the pinion (20) and the spool gear (19) can never be interfitted with each other, thereby preventing the mistake assembly. <IMAGE></p> |
