| 摘要 |
<p>A compact, easily disassembled, minimum headroom drilling unit is disclosed. The drill, especially useful for newly developed vertical retreat mining methods, drills at compound angles from the vertical and horizontal directions.</p><p>The drill includes a frame (12), wheels (14) for moving the drill, a column (16) pivotally attached to the frame, an hydraulic cylinder (40) for raising and lowering the column, a mast (18) supported by the column, the mast being movable through a predetermined arc (A) by a second hydraulic cylinder (48), and a drill motor (20) that can be moved up and down on the mast by a doubie-acting cylinder (22) fixed at each of its ends to the mast. The drill also includes jacks (36, 38 and 42) for maintaining the drill in the position.</p> |
