GB897879A - Improvements relating to the getting of coal or other materials naturally occurring in the form of a solid mass - Google Patents

Abstract

897,879. Blasting apparatus. WOOD & CO. Ltd., HUGH. May 19, 1960 [May 28, 1959], No. 18211/59. Class 9(1). Apparatus for injecting liquid into coal, or other natural solid, comprises a tubular shell 2, to be inserted in the borehole, with a rupturable disc 10 and rearwardly inclined discharge ports 11, the shell being connected to a hydraulic accumulator I having a water inlet 16, a piston 13, or flexible diaphragm, and a closure plug 8 for gas supplied to the compression chamber 14. Alternatively a spring may act against the piston instead of gas. In another embodiment an expansible rubber sac replaces the piston and is secured by a gas inlet valve in the place of the plug 8; a compressible solid, or compressible liquid, or a compressible solid without the sac may be used. In another form, Fig. 3 (not shown), the accumulator is incorporated within an annular space in an outer tubular casing and supplied with water from the outer end of the casing, through the annular space and into the accumulator through radial ports therein. A pivotable claw device on the forward end of the discharge shell is extended by discharge water and pierces the wall of the borehole, thereby retaining the apparatus in situ and enabling radial discharge ports to be used. In a further modification, Fig. 4 (not shown), a shear pin and a spring loaded piston valve replace the disc 10.