| 摘要 |
<p>A system for aligning the bit of a hand-held tool (6) with the surface of a workpiece (15) wherein a laser beam (21) essentially parallel to the axis of the bit (9) is projected forwardly toward the workpiece and onto a mirror (31) maintained at a preselected angle 'to the workpiece surface. The incident beam is reflected backwardly onto means (13) detecting both the incident beam and the reflected beam and indicating when the beams are coincident.</p> |
