A cup chuck.

摘要

The present invention discloses a cup chuck in which a workpiece (4) is able to be removed and replaced "true" as many times as is necessary. The frusto-conical cavity (3) of a conventional cup chuck is replaced with a substantially cylindrical cavity (13) having an internal thread (17) and a thread cutting arrangement (11,18,20) which is capable of cutting a mating external thread on a substantially cylindrical boss (16) on the workpiece (4). Thus the workpiece (4) is releasably threadably engaged with the cavity (13).