Abstract: Inflatable devices configured for use particularly in large diameter boreholes and in blasting applications such as vertical cratering, the invention finds utility in blast removal of earth formations wherein the inflatable devices act to suspend explosives and/or stemming materials and the like within a borehole prior to detonation of explosives within said borehole. The inflatable devices are of various shapes and comprise an inner, relatively stretchable inflatable bag enclosed by an outer, relatively non-resilient bag, the inner bag having a valve to allow a fluid such as air to be pumped thereinto with the inner bag expanding to contact inner walls of the outer bag and force the outer bag into contact with walls of the borehole to exert forces against the borehole walls and thus "plug" the borehole at a desired location along the length thereof. Explosive materials and/or stemming materials can thus be suspended at desired locations within the borehole.

Abstract: The invention provides methods and apparatus useful primarily in the presplitting and blast removal of earth formations, the improvements according to the invention involving the use of inflatable devices suspended in boreholes used in shattering earth formations. The inflatable devices of the invention can be of various shapes and are provided with valves to allow a fluid such as air to be pumped into each device on placement of the device at a desired location in a borehole. The inflatable devices are preferably formed of a flexible, polymeric material which allows a desired degree of stretching to cause plugging of a borehole. The "plug" formed by an inflatable device of the invention allows loading of exposives into a borehole in order to produce desired blast results acording to the several methods of the invention.

Abstract: Inflatable devices configured for supporting explosives particularly in vertical boreholes of widely varying diameter. The inflatable devices of the invention can be used in the pre-splitting and blast removal of earth formations by suspending explosives in both pre-splitting and production boreholes. Plugging of such boreholes is accomplished through the use of the present inflatable devices which are formed of flexible polymeric material and which stretch to seal boreholes and to exert forces against borehole walls sufficient to support heavy columns of explosives and/or stemming at desirable borehole locations. The present inflatable devices are restrained into a pre-splitting configuration and inflated to a configuration capable of supporting explosives and/or stemming within a borehole.

Abstract: The invention provides methods and apparatus useful primarily in the presplitting and blast removal of earth formations, the improvements according to the invention involving the use of inflatable devices suspended in boreholes used in shattering earth formations. The inflatable devices of the invention can be of various shapes and are provided with valves to allow a fluid such as air to be pumped into each device on placement of the device at a desired location in a borehole. The inflatable devices are preferably formed of a flexible, polymeric material which allows a desired degree of stretching to cause plugging of a borehole. The "plug" formed by an inflatable device of the invention allows loading of explosives into a borehole in order to produce desired blast results according to the several methods of the invention.

Abstract: The invention provides methods and apparatus useful primarily in the presplitting and blast removal of earth formations, the improvements according to the invention involving the use of inflatable devices suspended in boreholes used in shattering earth formations. The inflatable devices of the invention can be of various shapes and are provided with valves to allow a fluid such as air to be pumped into each device on placement of the device at a desired location in a borehole. The inflatable devices are preferably formed of a flexible, polymeric material which allows a desired degree of stretching to cause plugging of a borehole. The "plug" formed by an inflatable device of the invention allows loading of explosives into a borehole in order to produce desired blast results according to the several methods of the invention.