Patent ID: 7232121

Claim:
A clamping apparatus for detachably fixing a movable member (M) to a reference member (R), comprising: an annular plug portion ( 21 ) having an outer peripheral side and projecting from said reference member (R) toward a leading end direction, and having a tapered outer peripheral surface ( 28 , 54 ) which narrows toward the leading end direction arranged on the outer peripheral side of the plug portion ( 21 ); said movable member (M) provided with a tapered inner peripheral surface ( 12 , 53 ) configured to engage the tapered outer peripheral surface ( 28 , 54 ); a transmission member ( 29 ) supported within a leading end of a cylindrical opening ( 21 a ) in the plug portion ( 21 ) so as to be axially movable within the opening over a predetermined range; a rod ( 31 ) located in the cylindrical opening ( 21 a ) so as to be axially movable therein, the rod being located in a position closer to a base end of the reference member (R) than is the transmission member ( 29 ) whereby during a clamping operation, the rod ( 31 ) may be driven toward the base end direction of the reference member (R) by a driving device (D) provided in the reference member (R), said rod ( 31 ) having an output portion ( 36 ) arranged to move the movable member (M) toward the reference member (R); a transmission gap (G) formed between a pushing portion ( 31 a ) of a leading end of the rod ( 31 ) and a force receiving portion ( 29 b ) of the transmission member ( 29 ); whereby during a an unclamping operation, the rod ( 31 ) may be driven toward the leading end direction by the driving device (D), such that the pushing portion ( 31 a ) of the rod ( 31 ) pushes the movable member (M) via the transmission member ( 29 ).