Patent ID: 6305752
Filing Date: 2001-10-23
Classification: E21C

Abstract:
A blasting device for connection to a source of compressed gas, the device being insertable in a previously prepared bore, the device comprising;an elongate housing having one or more apertures on a sidewall,one or more air gun within the elongate housing, each air gun comprising:a high pressure chamber;an exhaust chamber, the exhaust chamber being in intermittent fluid communication with the high pressure chamber; anda repeatably moveable shuttle, the repeatably moveable shuttle alternating between a sealed position and a discharge position, the sealed position allowing fluid pressure to increase in the high pressure chamber and the discharge position permitting fluid to discharge through the exhaust chamber;at least one packer located at one end of the elongate housing,each air gun being associated with an aperture on the side wall of the elongate housing, through which gas is exhausted upon firing of the air gun directed at a high pressure and velocity to create a blasting effect; andthe packer being arranged to form a seal between the housing and a surrounding bore so that liquid introduced into said bore before firing of the air gun is retained within the bore and thereby amplifies the blasting effect of the air gun(s) when fired.