摘要 |
<p>A drill rig (10) comprises a drill tower (12), rotation head (14) and drill table (16). Drill tower (12) is in the form of a rectangular box frame (18) and is of fixed length. Rotation head (14) provides torque to a drill string used for drilling a hole and is supported on and linearly traversable along drill tower (12). Drill rig traverse system (20) provides pull back and pull down force to the rotation head (14) enabling the rotation head (14) to traverse along drill tower (12) and controlling contact force between the drill bit and toe of a hole being drilled. Traverse system (20) comprises the combination of a hydraulic ram traverse system (22) which provides both pull back and pull down force; and a winch pull back system (24) which provides pull back only. A winch (60) of winch pull back system (24) is supported on the tower (12). Both hydraulic ram traverse system (22) and winch pull back system (24) can traverse the rotation head for the full length of the tower (12) when simultaneously applying pull back to the rotation head.(14)</p> |