Patent ID: 6840896
Filing Date: 2005-01-11
Classification: B23Q,Y10T

Abstract:
1. An attachment comprising: a rotational power transmission portion to which a rotational power of a main shaft of a machine tool is transmitted; an electric generator configured to generate an electric power in response to the rotational power transmitted to the rotational power transmission portion from the main shaft; an electric motor which is rotated in response to the electric power generated by the electric generator; a tool mounting portion configured to mount a tool which is rotated in response to the rotation of the electric motor; a casing including a first, a second and a third casing part, respectively accommodating the transmission portion, the electric generator and the electric motor; and a coupling system configured to couple the main shaft and the casing in a manner enabling the casing to be indexed about a rotational axis of the main shaft, wherein the transmission portion includes, wherein the coupling system includes, a first annular coupling member having a plurality of teeth defined by the minimum index angle of the casing and fixed to a front end of the main shaft, and a second annular coupling member having a plurality of concave teeth engageable with the convex teeth and connected to the first casing part, wherein the convex teeth of the first annular coupling member and the concave teeth of the second annular coupling member are engaged when the pull stud of the transmission portion is pulled by the collet and the taper shank is fitted into the taper sleeve, wherein the first casing part is connected to the second annular coupling member at one end of the first casing part and to the second casing part at another end of the first casing part, the first casing part accommodating the transmission portion body inside thereof, wherein the second casing part is connected to the first casing part at one end thereof and to the third casing part at another end thereof, the second casing part being formed as an annular casing member configured to accommodate the electric generator, a rotor thereof being coupled to the transmission portion body by an angular ball bearing, permitting free rotation, and a stator thereof being fixed to an inner wall of the second casing member, and wherein the third casing part is connected to the second casing part at one end thereof and to the tool mounting portion at another end thereof, the third casing part being formed as an annular casing part configured to accommodate the electric motor.