| 摘要 |
<p>A bevel gear 15 secured on a spindle 16 is driven in rotation by a motor. On the spindle is disposed a grinding disc held by a retaining nut and the bevel gear is formed with two recesses 21 into which a plunger can be depressed. A barrier plate 27 is disposed about the spindle and is capable of a degree of lost motion with respect thereto, the plate 27 also having two slots 29 through which the plunger can extend. The leading edges 31 of the slots are raised so that depression of the plunger during use of the tool causes the plunger to engage the edges 31 thereby causing the plate to take up said lost motion and cover up the recesses 21 to prevent the plunger from engaging therein. Sudden stopping of the spindle and its dangerous consequences are thus avoided.</p> |
