Patent ID: 7934892

Claim:
A collet clamping nosepiece for a power feed drill comprising: at least one clamping piston located along a centerline of said nosepiece, said at least one clamping piston comprising a plurality of piston rings formed coaxially thereon; a piston housing configured to substantially surround said piston rod, said piston housing comprising a plurality of cylinder portions, each cylinder portion configured to substantially surround the respective said piston ring when said piston housing is assembled; an expansion mandrel comprising a frusto-conical exterior surface; and an expandable collet configured to substantially surround said expansion mandrel and operatively connected to said at least one clamping piston, operation of said at least one clamping piston causing said collet to move along said exterior surface of said expansion mandrel for engagement and disengagement of said collet with a bore configured for insertion of said collet.