| 摘要 |
<p>A chuck barrel (22) is coupled to a holder (21) which can be mounted on a rotational spindle of a machine tool. A plurality of projections (27) projecting in an axial direction are provided circumferentially at certain intervals on the coupling side of the holder (21), and openings (28) are formed between these projections (27). Protruding teeth (29) are radially formed in a driving ring (23) so as to be fitted in the openings (28) formed in the chuck barrel (22), and male threads (30) are formed in the outer circumferential surfaces of the protruding teeth (29) to permit an axial travel. A tightening ring (24) has female threads (34) formed in the internal surface thereof into which the male threads (30) can be screwed, and it is rotatably held on the outer circumferential surface of the chuck barrel (22). A press-fitting body (25) is secured to the driving ring (23) so as to fit in a tapered hole (22a) in the chuck barrel (22). The driving ring (23) is moved in the axial direction by rotating the tightening ring (24), which in turn moves the press-fitting body (25), whereby the diameter of the press-fitting body (25) is compressedly reduced by the tapered hole (22a) in the chuck barrel (22) so as to clamp the shank of a cutting tool (7).</p> |
