초록 ▼

A cartridge containing an explosive charge is inserted at the bottom of a short hole drilled in the rock. The cartridge is held in place or stemmed by a massive stemming bar of high-strength material such as steel. The cartridge incorporates additional internal volume designed to control the applica

A cartridge containing an explosive charge is inserted at the bottom of a short hole drilled in the rock. The cartridge is held in place or stemmed by a massive stemming bar of high-strength material such as steel. The cartridge incorporates additional internal volume designed to control the application of pressure in the bottom hole volume by the detonating explosive. The primary method by which the high-pressure gases are contained in the hole bottom until relieved by the opening up of controlled fractures, is by the massive inertial stemming bar which blocks the flow of gas up the drill hole except for a small leak path between the stemming bar and the drill hole walls. The stemming bar is preferably connected to a boom mounted on a carrier. A preferred embodiment incorporates an indexing mechanism to allow both a drill and a small-charge blasting apparatus to be used on the same boom for drilling and subsequent charge insertion and firing operations.

대표청구항 ▼

1. A device for fracturing a hard material, the device being placed in a hole in the hard material, the device comprising:an energetic substance; and an elongate member for stemming the hole in the material and for impending the escape of high pressure gases, released by the energetic substance, fro

1. A device for fracturing a hard material, the device being placed in a hole in the hard material, the device comprising:an energetic substance; and an elongate member for stemming the hole in the material and for impending the escape of high pressure gases, released by the energetic substance, from the hole; wherein the elongated member is positioned in the hole and the energetic substance is positioned in a bottom portion of the hole and adjacent to the downhole end of the elongated member and wherein the energetic substance is contained in a cartridge and the cartridge includes a cartridge base and an outer cartridge housing attached to the cartridge base, the outer cartridge housing including a nose portion, the cartridge base and nose portion being located at opposite ends of the cartridge, the energetic substance being in contact with the nose portion and decoupled from the elongated member, wherein, when the cartridge is placed in contact with a surface of the hole, the energetic substance is coupled with the surface of the hole.