GB397203A - Improvements in or relating to blasting cartridges - Google Patents

Abstract

397,203. Blasting-cartridges. SCOTT, A. C., Davington House, Faversham, Kent. Feb. 24, 1932, No. 5568. [Class 9 (i).] A blasting-cartridge is made to comprise in combination a pressure-resistant but rupturable container 11, in which is placed a quantity of non-explosive salt decomposable by heat so as to yield non-inflammable products of decomposition, together with a heating element 18 consisting of a self-combustible mixture inadequate by its own combustion to burst the container, and means to ignite the same so that the salt may be decomposed and the container ruptured. The container shown is of the kind known for holding compressed carbon dioxide and comprises a strong body provided with a shear disc 13 secured by a screw plug 14 formed with a central bore 15 and lateral outlets 16, a centralhole 17 serving for the insertion of a drift for the subsequent removal of the sheared part of the disc 13. The salt used is ammonium nitrate, to which ammonium or sodium chloride, ammonium oxalate, sodium bicarbonate. zinc sulphate, magnesium sulphate, or sodium sulphate may be added. 1 to 2 per cent of asbestos may be mixed with the ammonium nitrate to prevent binding and recrystallization. The heating element may be black powder or a mixture of potassium chlorate or perchlorate with a fuel for example cellulose acetate, and the ignition may be performed electrically.