Patent ID: 8220804

Claim:
An apparatus for releasably holding a tubular toolholder shank, comprising: a) a base member having a forwardly facing surface and a bore intersecting the forwardly facing surface and, wherein the bore extends rearwardly therefrom along a longitudinal axis for receiving the toolholder shank; b) a lock rod with a forward and rearward end, wherein the lock rod is rotationally restrained about the longitudinal axis and is movable within the base member in a rearward and forward reciprocating motion for pulling the toolholder shank rearwardly within the bore into a locked position and for releasing the toolholder shank from the bore to an unlocked position; c) a torque nut rotatively mounted to the base member and operable upon the rearward end of the lock rod to provide the rearward and forward reciprocating motion of the lock rod, wherein the torque nut has a segment with an outer surface and has one of an aperture extending within the outer surface or a groove extending at least partially around the outer surface and, wherein at least a portion of the groove is angled relative to the longitudinal axis; d) a compression sleeve engaged by the torque nut through at least one compression member and further resiliently engaging the lock rod, wherein the compression sleeve has the other of an aperture extending within the sleeve or a groove extending at least partially around the sleeve; e) wherein the aperture is aligned with the associated groove and the at least one compression member is positioned within the groove and within the aperture, such that when the torque nut is rotated in one direction, the at least one compression member and compression sleeve are displaced axially rearward within the base and, when the torque nut is rotated in the opposite direction, the at least one compression member and compression sleeve are displaced axially forward within the base.