| 摘要 |
A chuck has a chuck body centered on a chuck axis and having an axially forwardly opening and axially centered recess and an adjustment ring rotatable but not axially displaceable on the chuck body, having a central hole aligned with the recess, and formed with a plurality of guide passages open radially inwardly into the hole. The body and ring normally are carried on a drill spindle with the shank of a drill bit through the recess and hole and the spindle, shank, and chuck axes all coaxial. Respective jaws radially displaceable in the passages have inner ends engageable with the drill-bit shank in the recess. The chuck body has a face directly axially confronting the jaws and formed with an axially projecting spiral ridge. The jaws have axially projecting teeth complementary to and engaging with the ridge. Thus relative rotation of the body and ring about the axis radially displaces the jaws in the ring. |
