| 摘要 |
A drilling apparatus especially useful in drilling holes in wooden joists and studs, through which plumbing and electrical cables are to be routed, includes a bracket for engaging a joist or stud and a movable carriage supporting an electric motor and drill bit. A lever mechanism moves the carriage, and hence the motor and drill bit forcibly toward the bracket, forcing the drill bit through the joist. Countertorque from the drill bit is resisted by the coaction of the bracket and the drill bit in the hole being drilled. This avoids possible loss of balance by the operator.
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