| 摘要 |
<p>A disposable drill bit guide for optically guiding a drill bit in a manner normal to a workpiece, and having, a sheet of relatively thin disposable material said sheet having a reflective surface for providing a reflective image of a drill bit, adhesive means on said sheet for adhesively fastening same on a workpiece with said reflective surface exposed to view, and visible guide lines on said sheet, said guide lines intersecting one another at right angles, whereby a drill bit may be centred on such intersection and its image viewed in said reflective surface, and checked with reference to said guide lines.</p> |
