| 摘要 |
The device comprises a light source which has its light axis parallel with the work direction of the tool, and is directed against the workpiece surface. The source projects an unfocussed "picture" which pref. consists of concentric circles. This allows the operator to see easily whether the the total is positioned at right-angles against the surface by abserving whether the circules are completelt round or are inclined in one direction, thus being able to make the requisite positional adjustment. - The light source consists of a small pocket lamp above the hand drill with an adjustable reflector. The adjustment of this reflector is such that the light diffusion can be varied from approx. 20 to approx. 70 deg. The lamp is fitted parallel to the drill fitted in the tool chuck, with its light aperture forward in the drilling direction. |
