| 摘要 |
PCT No. PCT/SE96/00364 Sec. 371 Date Jan. 12, 1998 Sec. 102(e) Date Jan. 12, 1998 PCT Filed Mar. 22, 1996 PCT Pub. No. WO96/30627 PCT Pub. Date Oct. 3, 1996A drilling device has a frame (1) with a feed device (2) for carrying a drilling device (3) movable to-and-fro for rotating a drill string (4). The drilling device includes a sensor (6) for sensing an end (7) of a drill string element (8) in the drill string (4), and a register for the position of the end (7) along the feed device (2) and for the displacement of the drilling device (3) along the feed device (2). |
