Inflatable devices for suspending explosives and stemming materials in boreholes

摘要

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.