US Patent 7568529 Drill tool

A drill tool is provided with: a drive source accommodated in a tool body 2; a bit drive shaft 3 which is rotation-driven by the drive source and provided projectingly from a front end of the drill body 2; and a diamond bit 4 attached to a front end of the bit drive shaft 3. Further, the drill tool is provided with a vibrating apparatus which generates vibrating force which acts in the axial direction of the bit drive shaft 3, a magnitude of which pulsates, and vibrating moment which acts in the rotational direction of the bit drive shaft 3, a magnitude of which pulsates.