Patent ID: 6910693

Claim:
A chuck for holding a workpiece comprising; a chuck body having a chuck axis, a bore having a bore axis angled relative to said chuck axis, and a puller cavity communicating with said bore; a jaw rod assembly having a jaw rod disposed in said bore for movement along said bore axis between a retracted position and an extended position; a puller disposed for movement in said puller cavity and operatively coupled to said jaw rod assembly to displace said jaw rod along said bore axis, said jaw rod being coupled to said puller for rotation relative to said puller; and a cam assembly having a cain follower formed in or coupled to one of said chuck body and jaw rod and a cam groove, the other of said chuck body and jaw rod defining said cam groove, said earn groove having a linear segment and a helical segment, said cam follower operatively engaging said cain groove as said jaw rod moves along said bore axis to cause said jaw rod to first move axially and then helically within said bore when said jaw rod is moved from said retracted position toward said extended position, wherein said cam groove is a chordal planar surface.