GB815532A - Improvements in or relating to explosive connecting cords - Google Patents

Abstract

815,532. Detonating fuze cord. ANDREW, D. J., FELCH, R. W., and NODDIN, G. A. May 20, 1957 [July 11, 1956], No. 15952/57. Class 9(1) A detonating fuze cord for connection to blasting charges comprises an explosive core 1 surrounded by a metal sheath 2 which may be covered by a non-metallic countering 3, the core having 0.1 to 10 grains of explosive per ft. length. The sheath 2 may be of lead or aluminium or other ductile metals such as tin, silver, copper, magnesium or alloys thereof. The countering 3 may be a woven fabric or a coating of flexible plastic material such as polyethylene, polyvinyl chloride or rubber. Wire or other metal reinforcement may be incorporated. The explosive may be PETN, RDX, lead azide or nitromannite. In an example 30 ft. of lead tubing with inner and outer diameters 0.095 inches and 0.406 inches respectively was filled with 1200 grains of PETN and drawn to an outer diameter of 0.092 inches to produce a core of 0.020 inches diameter and 1.9 grains of PETN per ft. A bituminous coating, helically wound yarns and a wax finish was applied to the drawn tube. In a second example, a 1/32 inches squaresectioned groove was lined with aluminium foil, the groove then being filled with nitro-mannite, which was then covered by the foil. Lead azide granules cemented with nitrocellulose may form the core, the sheath being aluminium.