| 摘要 |
PCT No. PCT/FI93/00512 Sec. 371 Date Jun. 5, 1995 Sec. 102(e) Date Jun. 5, 1995 PCT Filed Dec. 1, 1993 PCT Pub. No. WO94/12760 PCT Pub. Date Jun. 9, 1994A drilling apparatus adapted to be fed into a hole to be drilled and extendable in a longitudinal direction includes a casing and a drilling unit. A drilling head of the drilling unit includes a first drilling unit for drilling a center hole and a second drilling unit for reaming the center hole for the casing, the first drilling unit attachably connected to the second drilling unit at the drilling head. A counterpart assembly transmits rotational and impact movement from the first to the second drilling unit. A coupling assembly connects the second drilling unit with a head of the casing such that the second drilling unit freely rotates centrically around a longitudinal axis. A flushing unit for removal of drilling waste comprises at least one first passage extending through the first drilling unit to a drilling point, and communicates with at least one flow channel for transferring flushing medium to a drilling surface and the drilling point. At least one second passage for removal of the drilling waste is formed between the drilling surfaces of the first and second drilling units. A first component of the counterpart assembly is located at the outer surface of the first drilling unit for locking the first and second drilling unit together by a bayonet principle to rotate these units together and to move them together in both longitudinal directions. The at least one second passage is partially formed by the first component of the counterpart assembly. |
