| 摘要 |
PURPOSE:To prevent a crack caused from torsion in an internal end and the like of a cut groove, by performing final tightening of a collet without causing the rotation of the collet and preventing generation of torsional distortion in a chuck part. CONSTITUTION:A working member 19 is circumferentially provided to a cylindrical supporter 1, and an annular groove 5 is formed in the internal periphery of a base end part 3 of said cylindrical supporter 1, then an internal thread ring 8 is mounted in said groove, further an external thread 14, provided to a collet 12, is screwed to said internal thread ring 8. When mounting is finished, a control bar (a), inserted from a sliding long hole 6 of the base end part 3, is moved tilting, and the internal thread ring 8 is turned, here final tightening of the collet 12 is performed without causing the rotation of the collet. Accordingly, torsional distortion is never caused circumferentially of a chuck part. |
