| 摘要 |
<p>A device for drilling, reaming in and/or lining holes in earth, rock or such like. A casing (12) which is designed to be lowered together with a drilling unit (21) or reamer which is mounted on a rotating drill pipe centrally positioned in the casing and equipped with two or more cutters (24C). The drilling unit (21) is equipped with an activating organ (27) which operates with drilling fluid through the drill pipe (14) and is integrated with the cutters (24C) to guide them between their active and passive positions. In addition, the drill pipe is equipped with a gripping unit (18) which given downward motion of the drill pipe makes firm contact (at 20) with the casing (12) so that this is forced downwards.</p> |
