发明名称 Drill bit extension
摘要 The drill bit extension which utilized a length of conventional pipe or thin wall conduit without modification. A chuck adapter fitting and a drill bit adapter fitting are located at opposite ends of the pipe. Both have a pilot portion adapted to extend into the pipe, and a threaded tapered portion which engages the pipe interior. The chuck adapter fitting has a reduced shank to be received in a conventional drill chuck; and the drill adapter fitting has an opening with means for locking a drill bit into the fitting. Since the fittings are used with an unmodified pipe, the pipe section can be used in drilling the holes and then left in place after the fittings are removed. In this manner, water lines and electrical conduit may be installed simultaneously with drilling the required holes therefore.
申请公布号 US4076444(A) 申请公布日期 1978.02.28
申请号 US19740456021 申请日期 1974.03.29
申请人 SIEBRECHT, GARY L. 发明人 SIEBRECHT, GARY L.
分类号 B23Q1/70;(IPC1-7):B23B31/44 主分类号 B23Q1/70
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