| 摘要 |
The depth minder comprises a drill bit having a shank and an integrally attached flange, with male threads thereon, which has a larger diameter than the shank so that it prevents drilling to a deeper depth than the length of the drill bit beyond the flange. A primary spacer is also used which has female threads to accept the male threads of the flange partially into the top of the spacer, a bottom surface, and a central hole which is large enough to accommodate the largest sized drill bit of a series of bits, thereby further selectively reducing the drilling depth. One or more adaptor spacers of plastic or of metal are additionally used to provide additional options regarding the depth of penetration desired for the drill bit. Such an adaptor spacer is adhesively attached to the bottom surface of the primary spacer or to the lower surface of the flange, thereby providing a range of drilling depths. If made of metal, the bottom surface of the adaptor spacer is preferably covered with felt in order to prevent marring of the work surface.
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