摘要 |
A mobile rock drill unit (10) is disclosed which automatically adds and removes drill string sections (26) from the drill string (24) of the drill unit. The drill unit includes a conventional drill motor (20) and a centralizer (40). A cylindrical storage rack (34) is both rotatably and pivotally mounted to the mast (14) of the drill unit and has upper and lower rack members (62,64) with aligned fingers (116,118,176,178) to define a number of drill string section storage positions to store drill string sections therebetween. A roller clamp assembly (36) is provided which clamps the coupling (28). The coupling is clamped between rotatably mounted driven and idler rollers (296,322) and the axis of rotation of each of the rollers is canted relative to the drill string axis so that rotation of the driven rollers in a first direction will rotate the coupling and move it downwardly at a rate synchronized with the threads interconnecting the coupling and adjacent drill string section. A control system (38) is provided which automates the task of adding and removing drill string sections from the drill string.
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