| 摘要 |
<p>The bi-directional ratchet screw-driver has two sliding pawls (8) which alternate in engaging a pinion (4) and thus control the authorised sense of shaft (3) rotation. The pinion has triangular teeth and is mounted axially on the shaft of the screw-driver blade. The pawls are of rectangular section are thrust onto the pinion by the resp. legs of a forked blade spring (10), and slide on parallel paths which are symmetrically disposed about the shaft axis. The pawls (8) are guided in slide-ways of reciprocal section, and the slideways traverse a cylindrical jacket (2) contg. the pinion (4). the pawls engage the pinion for the whole of their axial length and are each mounted on a rod (8a) which also slides in a jacket (2) hole. A ramped segmental slide (5) in an external jacket groove (2c) is used to effect disengagement of either pawl. the segmental slide (5) is displaced by an outer rotary sleeve (6) to which it is keyed, whence a ramp displaces a pawl-rod (8a) causing the pawl to disengage the pinion.</p> |
