| 摘要 |
A drill chuck for a hammer drill apparatus or the like having a plurality of clamp jaws advanceable to and retractable from a chuck drill axis so as to be able to grasp and hold a drill, wherein each of the clamp jaws is advanced into and retracted from a chuck opening in the chuck in a feed channel directed toward, and preferably perpendicular to, the chuck drill axis and further oriented so that the clamp jaws engage and hold the drill in the chuck opening when advanced in the channels, each of the feed channels being conformed so that each of the clamp jaws fits movably, but sufficiently tightly, therein so that drilling dirt does not penetrate between the clamp jaws and the surfaces of the feed channels, and the drill chuck is provided with a plurality of open cleaning passages connecting the interior wall of the chuck opening adjacent a mouth of one of the feed channels to the outside through the chuck. Additionally so that limited axial play and efficient hammer action may be obtained, the clamping surfaces of the chuck jaws are each provided with a row of projections parallel to the drill chuck axis. |
