Increased efficiency percussion piston and method for operating same

摘要

PCT No. PCT/FI95/00280 Sec. 371 Date Nov. 24, 1997 Sec. 102(e) Date Nov. 24, 1997 PCT Filed May 23, 1995 PCT Pub. No. WO96/37345 PCT Pub. Date Nov. 28, 1996A percussion piston for use in a drilling apparatus includes a drill bit and at least three tubular parts which increase in diameter in a direction extending from the drill bit toward a rear end of the piston. The piston further includes flanges positioned between the tubular parts and a first corresponding delivery space at the rear end of the piston. At least two additional corresponding delivery spaces are positioned between the first corresponding delivery space and the drill bit. Channels allow the transport of pressurized hydraulic fluid to and from the first and additional corresponding delivery spaces such that an energy pulse produced by impact of the piston on the drill bit is almost completely absorbed by the drilled object.