| 摘要 |
<p>An annular front end base portion (11), a main portion (10) and an annular rear end base portion (12) form all together a substantial portion of a collet (9) provided with a tapered outside surface adaptable closely in a tapered hole of a collet chuck and a tool holding hole (13) is formed in the axial portion of the collet (9). In the main portion (10) are formed a first set of axially long radial slits (14) opening at the end surface of said front end base portion (11) and terminating to be closing in the rear end base portion (12) and a second set of axially long radial slits (15) opening at the end surface of the rear end base portion (12) and terminating to be closing in the front base portion (11). Each of the radial slits (14) of the first set and each of the radial slits (15) of the second set are arranged at proper angular intervals and alternatively along the peripheral direction of the collet (9), and respective zigzag paths (16) are formed which are closed over the whole peripheries of the outside and inside surfaces of the collet (9), respectively. The outside and inside surfaces of the collet (9) contact closely the inside surface of said tapered hole and the outside surface of a tool fitted in the tool holding hole (13), respectively along the respective zigzag paths (16). The collet is able to contract radially owing to the radial slits (14,15) of the two sets and the cutting oil supplied to the collet (9) flows out of the collet outwards only through jets (19) provided for feeding oil. <IMAGE></p> |
