| 摘要 |
PCT No. PCT/SE94/01113 Sec. 371 Date Jun. 19, 1996 Sec. 102(e) Date Jun. 19, 1996 PCT Filed Nov. 22, 1994 PCT Pub. No. WO95/18287 PCT Pub. Date Jul. 6, 1995A rock drill guide tool comprises a sleeve arrangement (8) placed around a tubular drill tube (9) which rotates during a drilling operation and through which drilling liquid is supplied under pressure during drilling intervals. The sleeve arrangement includes a plurality of support units (15, 16) which can be projected out into contact with the wall of a drill hole and which are placed circularly in the sleeve arrangement. The support units (15, 16) are placed in at least two ring sections of the sleeve arrangement and are provided with elements (19, 20) which project out against the wall of a drill hole. These elements engage the rock so as to cut grooves into the wall of a drill hole as the drill is moved down during a drilling operation. The outwardly projecting elements of all shoulder ring sections are placed mutually sequentially in an axial direction along straight lines, so that the outwardly projecting elements that are located behind the foremost elements in each line of elements as seen in the drilling direction will move in grooves cut in the rock by the foremost elements as the drill moves downward. |
