| 摘要 |
The present invention is a device and method for aligning a hand drill so that holes can be drilled at a desired angle in a workpiece. A light source and a template are attached to the drill so that an image is projected onto the workpiece surface. For drilling holes perpendicular to the surface, the direction of the projected light beam is parallel to the axis of the drill bit. The preferred image is comprised of two concentric circles and two perpendicular straight lines of equal length whose midpoints correspond with the center of the circles. The two lines preferably have discontinuities of equal length at their midpoints so as to be comprised of segments of equal length. When the drill is not properly aligned relative to the workpiece, the projected circles appear oval in shape and at least some of the lines or line segments differ in length. The eye can readily discern these image distortions so that the drill can be readily adjusted to the desired angle.
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