Patent ID: 8287214

Claim:
A machine tool comprising: a tool head having a boring cutter and a grinding tool; rotating means for rotating said tool head; a hollow main shaft connecting said rotating means to said tool head and transmitting rotational power from said rotating means to said tool head; a support, wherein said main shaft extends axially through said support and is rotatably supported in said support; moving means for moving said support in an axial direction of said main shaft, a shaft housed in the main shaft and axially movably splined to the main shaft; and wherein said tool head comprises expanding means for radially expanding said boring cutter and said grinding tool under predetermined expanding forces and at a predetermined position in response to axial movement of said shaft, said expanding means including a driving source fixedly mounted on said support, wherein said main shaft remains unchanged in diameter while being rotated by said rotating means during both a boring process, in which said tool head is rotated and moved towards a workpiece while said boring cutter bores said workpiece, and a grinding process, in which said tool head is rotated and reciprocally moved while said grinding tool grinds said workpiece, wherein the machine tool performs boring process and grinding process by radially expanding said boring cutter and said grinding tool, and wherein said support comprises a first support and a second support, and said moving means comprises a first moving means as a linear motor for moving the first support in the axial direction of the main shaft and a second moving means for moving the second support in the axial direction of the main shaft.