摘要 |
Means for producing reciprocatory movement of a vice carrier (18) across a guideway (17) mounted on a body moulding (11, 16), which partly shrouds a rotatably driven grinding wheel (14), comprise a rack moulding (57) having upper and lower racks (61, 62) which are alternately engaged by a pinion (44) driven from the grinding wheel drive, in use. Rack moulding movement is transmitted to the vice carrier and spring means (67, 68) move the rack moulding to change the pinion engagement from the lower rack to the upper rack and vice versa at the ends of the racks, thereby reversing the rack moulding movement. A guide peg (56) of the body moulding alternately engages in upper and lower slots (65a, 65b) of the rack moulding to maintain the pinion in engagement with its appropriate associated rack while it is between the ends thereof. The arrangement is intended for use as part of a releasable adapter for a powered grinding tool incorporating said grinding wheel. |