| 摘要 |
<p>A drilling machine includes a boom assembly (34) which has two straight parallel longitudinal beams (50) of extruded steel, each of a section defining straight parallel inwardly and outwardly facing channels, a drilling head (24) in a carriage (52) and rollers (54) guiding said carriage for linear movement of said drilling head parallel to said inwardly facing channels, two straight parallel longitudinal boom extension members (80) and rollers (88, 90) guiding said boom extension members in said outwardly facing channels, and cross members (82, 84) linking said boom extension members to form a frame, plate braces (58, 60, 62, 64) linking said beams (50) in longitudinally spaced planes perpendicular to the axes of the beams, said plate braces being apertured to provide clearance for assembly and normal movement of said carriage (52), said drilling head (24), and drill tubes passing through said drilling head, and further longitudinal members (66) linking said plate braces to form a cradle of the boom assembly (34), said cradle having brackets (44) for pivotally supporting the boom assembly on a base (6, 38). The carriage (52) for the drilling head can be actuated by a hydraulic cylinder (32) having a single double ended piston rod (70), through chains (76) anchored to the cradle and to the carriage (52) and passing over sheaves (74) attached to opposite ends of the piston rod (70).</p> |
