| 摘要 |
The present invention provides a hole cutter (70) for cutting a hole (H) in a surface (S). The cutter comprises a cutting head (22) having a cavity (24) formed therein and a cutting surface (36) at one end for cutting the hole. A passage (15) for a drill (12) extends from the cavity to the cutting surface. The drill is adapted for being rotatably driven for relative axial movement in the cavity between a first position in which the drill extends through the passage and a cutting end of the drill projects beyond the cutting surface, and a second position in which the drill has been at least partially retracted into the head. In use, when the drill is rotatably driven whilst in the first position it can be advanced into the surface to drill a pilot hole therein until the cutting head contacts the surface, wherein the drill can then be moved relatively axially in the head to the second position, and thereafter further rotation of the drill causes the cutting head to rotate to enable cutting of the plug hole.
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