Patent ID: 7325798

Claim:
A clamping apparatus, comprising: An annular central pillar ( 20 ) is projected from a reference block ( 1 ) toward a leading end, an inner sleeve ( 21 ) is fitted onto the central pillar ( 20 ) axially movably within a predetermined range, and the inner sleeve ( 21 ) is advanced toward the leading end by a predetermined advancing stroke by an advancing means ( 25 ), an outer sleeve ( 31 ) to be inserted into a socket hole ( 3 ) of a movable block ( 2 ) makes a wedge engagement with the inner sleeve ( 21 ) from the leading end side, and the outer sleeve ( 31 ) is configured to be diametrically expandable and contractible, an output member ( 36 ) is inserted into a cylindrical hole ( 20 a ) of the annular central pillar ( 20 ) axially movably, and a leading end portion of the output member ( 36 ) is firmly connected to the outer sleeve ( 31 ), a locking means ( 51 ) and a releasing means ( 52 ) are provided in the reference block ( 1 ), the locking means ( 51 ) moves the outer sleeve ( 31 ) toward a base end for locking via the output member ( 36 ), while the releasing means ( 52 ) moves the outer sleeve ( 31 ) toward the leading end for releasing via the output member ( 36 ).