GB679157A - Improvements in or relating to power cartridges and their manufacture - Google Patents

Abstract

679,157. Gas-generating cartridges and compositions. IMPERIAL CHEMICAL INDUSTRIES, Ltd. March 8, 1951. [March 8, 1950] No. 5838/50. Classes 9 (i) and 9 (ii). An engine-starter cartridge having ignition means in a metal base and loaded with a smokeless powder charge in such forms that there are unoccupied spaces in the charge-containing portion of the cartridge, is provided with a primary ignition charge consisting of a plurality of multi-perforated shapes of porous smokeless powder. Fig. 1 shows a cartridge having a metal base 1 and a paper wall 3 turned over a celluloid closure disc 5. A percussion cap 4 is placed in the base 1 and in a reinforcing cup 2 are multi-perforated discs 7 of porous smokeless propellant. The perforated discs are 0.2 inches in diameter and 0.1 inches thick, and are traversed by seven parallel perforations 9 symmetrically arranged and 0.015 inches in diameter, Fig. 2. The discs are rendered porous by the inclusion in the propellant composition of 1.5 per cent by weight of potassium nitrate. The potassium nitrate passes a 16 mesh B.S. sieve and is retained by a 60 mesh sieve and after formation of the discs is leached out with warm water. After placing the discs 7 in the cartridge, it is loaded with cylindrical pellets 8 of a slow-burning smokeless propellant. In a modification, the cartridge is fired electrically by means of a fuzehead in a rubber-like sheath placed in the metal base 1. The propellant may be nitroglycerine 29 per cent, guncotton 64.5 per cent, diethyl diphenyl urea 2 per cent, mineral jelly 3.5 per cent, potassium nitrate 4 per cent, all parts being by weight. The slowburning composition 8 may include dibutyl phthalate and the guncotton may be nitrocellulose of 12.2 per cent nitrogen content. The percussion cap composition may be mercury fulminate 19.1 per cent, potassium chlorate 33.3 per cent, antimony sulphide 42.8 per cent, sulphur 2.4 per cent, mealed gunpowder 2.4 ' per cent, all parts being by weight.