| 摘要 |
The rotatable chuck for supporting a plastic coated workpiece (W) in a power driven threading machine is disclosed comprising workpiece engaging jaws (30) mounted on the machine spindle (S) for rotation therewith and for pivotal movement relative thereto radially inwardly and outwardly of the spindle axis (A). Each jaw (30) pivotally supports an insert holder provided with a pair of inserts (62, 64) for engaging the outer surface of the workpiece (W). Each of the insert holders pivotally supports a centering link (80) associated with an adjacent jaw (30) so as to be actuated in response to pivotal displacement of the jaws (30) radially inwardly of the spindle axis (A) to control the attitude of the insert holders so that the inserts (62,64) are directed radially inwardly of the spindle axis (A) to assure a uniform gripping action by the two inserts (62,64) of each holder upon engagement with the workpiece (W). The centering links (80) also displace the workpiece (W) to a centered position coaxial with the spindle axis (A) during inward displacement of the jaws (30). <IMAGE> |
