| 摘要 |
<p>A hammer drill chuck according to the invention has a chuck body centered on an axis and formed with an axially forwardly open hole normally receiving a drill bit, respective jaws displaceable in the body and having front ends radially engageable with a bit in the hole, and an adjustment ring engaged around the body, fitting with the jaws such that rotation of the ring in one direction advances the jaws in the body and rotation in the opposite direction retracts the jaws for respectively clamping and unclamping the drill bit in the front portion, and formed with axially backwardly directed teeth. A locking sleeve axially displaceable on the body is formed with forwardly directed teeth engageable with the teeth of the ring for rotational coupling of the sleeve and the ring, an axially relatively short, radially inwardly open, and axially forwardly open slot, and an axially relatively long, radially inwardly open, and axially forwardly open slot adjacent the short slot and of a predetermined angular width. A radially outwardly projecting stop fixed on the chuck body is of a predetermined angular width substantially less than that of the long slot. This stop is engageable in either of the slots. A spring is engaged between the sleeve and the chuck body for urging the sleeve axially forward on the chuck body and for urging the sleeve angularly in the one direction.</p> |
