Abstract: The present invention is directed to a system for fragmenting rock obstacles and obstructions in mines. The system uses a projectile having a flat or concave nose and a detonating device that has a safety pin to prevent a striker from prematurely igniting the primer during handling of the projectile. The primer is designed to initiate a detonator which detonates an explosive charge upon impact of the projectile with the target rock. The system can include transmitters and receivers and counters to provide remote operation of projectile launch, prearming, arming and/or detonation.

Abstract: A cartridge shell 10 comprises a main body 12 defining a volume 14 for holding energetic material. The main body 12 has a first end 16 for location adjacent a toe 48 of a hole 46 and a second end 18 directed to the collar 50 of hole 46. The second end 18 is tapered to reduce in transverse area away from the first end to form a point or wedge-like member 20.

Abstract: The present invention is directed to a cartridge that includes a number of advantageous features. For example, the cartridge can include a bulk energetic material, an igniter located in a central portion of the cartridge body, and a low void space in the cartridge.

Abstract: The present invention is directed to a system for fragmenting rock obstacles and obstructions in mines. The system uses a projectile having a flat or concave nose and a detonating device that has a safety pin to prevent a striker from prematurely igniting the primer during handling of the projectile. The primer is designed to initiate a detonator which detonates an explosive charge upon impact of the projectile with the target rock. The system can include transmitters and receivers and counters to provide remote operation of projectile launch, prearming, arming and/or detonation.

Abstract: 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.

Abstract: The present invention is directed to a small charge blasting system that provides a relief volume for a pressurized working fluid in the bore of a barrel that is inserted into a hole in the material to be broken, an end cap on the barrel to inhibit the entry of water and detritus into the bore, a stepped downhole end of the barrel to pressurize both the sidewall and bottom of the hole, and/or a thin barrel wall that flexes outwardly in response to pressure exerted on the wall by the pressurized working fluid to provide improved sealing of the fluid in the bottom of the hole.

Abstract: The present invention is directed to a method for selecting pressure wave suppression devices from among a menu of pressure wave suppression devices to satisfy the pressure wave requirements of a given job or application. The present invention is further directed to pressure wave suppression devices that can be used in the hole, at or near the opening of the hole, or at a distance from the hole to perform pressure wave and/or flyrock protection. The invention is particularly useful in suppressing airblast and other excavation equipment noise in urban areas.

Abstract: The present invention is directed to a method for selecting flyrock control devices from among a menu of flyrock control devices to satisfy the flyrock requirements of a given job or application. The present invention is further directed to flyrock devices that can be used in the hole, at or near the opening of the hole, or at a distance from the hole to perform flyrock and/or pressure wave protection. The invention is particularly useful in suppressing flyrock in urban areas.

Abstract: Rock and other hard materials, such as concrete, are fragmented by a controlled small-charge blasting process. A cartridge containing an explosive charge is inserted at the bottom of a hole drilled in the rock. The explosive charge is configured to provide the desired pressure in the hole bottom, including, if desired, a strong shock spike at the hole bottom to enhance microfracturing. The cartridge is held in place or stemmed by a massive stemming bar of high-strength material such as steel 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 cartridge incorporates additional internal volume designed to control the application of pressure in the bottom hole volume by the detonating explosive.

Abstract: The present invention is directed to a method for breaking rock and other hard materials using small-charged blasting techniques followed by a mechanical impact breaker. In small-charge blasting techniques, a gas is released into the bottom of a sealed hole located at a free surface of the hard material. The gas pressure rises rapidly in the hole until the gas pressure causes the hard material to fracture. In one embodiment, the a deeper hole is drilled and/or a small amount of blasting agent is used to cause the formation of a network of subsurface fractures while either not removing any of the rock or removing the rock with very low energy flyrock. In another embodiment, only the central portion of the face is broken and/or removed by blasting. The impact breaker is then used to complete fracturing and removal of the material.

Abstract: Rock and other hard materials, such as concrete, are fragmented by a controlled small-charge blasting process. A cartridge containing an explosive charge is inserted at the bottom of a hole drilled in the rock. The explosive charge is configured to provide the desired pressure in the hole bottom, including, if desired, a strong shock spike at the hole bottom to enhance microfracturing. The cartridge is held in place or stemmed by a massive stemming bar of high-strength material such as steel 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 cartridge-incorporates additional internal volume designed to control the application of pressure in the bottom hole volume by the detonating explosive.