Patent ID: 8419325

Claim:
A tool unclamping device capable of unclamping a tool clamped to a spindle of a machine tool, comprising: a casing; an output shaft set on said casing and capable of outputting power necessary for unclamping said tool; a power source capable of supplying power for driving said output shaft to unclamp said tool; a power transmission mechanism transmitting the power from said power source to said output shaft; and an auxiliary power source capable of supplying auxiliary power to said power transmission mechanism to assist the power source to unclamp said tool, wherein said power transmission mechanism includes a rotary shaft provided with: a first eccentric cam, provided eccentrically with respect to a rotational axis of the rotary shaft, pressing said output shaft, and a second eccentric cam, provided eccentrically with respect to the rotational axis, transmitting the auxiliary power from said auxiliary power source to said first eccentric cam.