| 摘要 |
Drilling means for directional drilling in a bore hole comprising a drill pipe (10) and a drilling head, including a slippable clutch device (12) linking the drill pipe (10) and said drilling head (16, 18, 20) such that torque due to rotation of said drill pipe can be controllably applied to said drilling head through at least partial engagement of said clutch, and control means (16) operable to sense an actual orientation angle of said drilling head and compare said actual orientation angle with a required orientation angle adjustably set in said control means and to control said slippable clutch such that when the actual orientation angle and the required orientation angle are the same, the slip torque of the slipping clutch equals the motor reaction torque, so maintaining the orientation angle of the drilling tool at said required orientation angle. |
