| 摘要 |
<p>A gear has along its inside periphery an annular inward protrusion 30C on which are formed engaging projections 31. An annular member 35 is disposed alongside a side wall of the inward protrusion 30C in a manner turnable relative to the side wall. The annular member 35 is formed with abutment projections 36 each of which has inclined surfaces extending in circumferential directions and adapted to be engaged by engaging pawls Rp. The annular member 35 is urged by return springs 38 in such a manner that the portion of each abutment projection 36, at least other than the inclined surfaces, overlaps each engaging projection 31 as viewed in axial direction. Each inclined surface of the abutment projection 36 is made up of a bottom-side inclined surface 36pb having an inclination angle allowing abutment by the engaging pawls Rp, and a top-side inclined surface 36ps having an inclination angle not allowing abutment by the engaging pawls Rp but causing sliding movement of the engaging pawls Rp. Therefore, it is prevented for the engaging pawls Rp to be imposed with excessive local load when the engaging pawls engage the engaging projections of the gear.</p> |
