Patent ID: 7004693

Claim:
A tool attachable to a spindle of a machine tool, comprising: a cylindrical case defining a reference potential means and not rotated with the spindle; a generator including a stator mounted on an inner wall of the cylindrical case and a rotor facing the stator rotatably fixed to the spindle and rotated by rotation of the spindle to generate AC electric power; an electric circuit mounted on an inner wall of the cylindrical case, said electric circuit including a first conductive member electrically connected to the case defining the reference potential means, a second conductive member electrically connected to the stator of the generator and a third conductive member and configured to rectify the AC electric power generated by the generator to a DC electric power provided between the first and third conductive member; an electro-discharge machining electrode having a shape and configured to transfer its shape to a workpiece; and an electrode holding member configured to exchangeably hold the electrode-discharge machining electrode, and having a hollow shape through which the third conductive member is passed to the electrode, the machine tool being configured to move so as to transfer the shape of the electro-discharge machining electrode to the workpiece.