GB579281A - Improvements in or relating to explosive primers - Google Patents

Abstract

579,281. Explosive primers. MORRIS, G., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. June 16, 1943, No. 9634. [Class 9 (i)] An explosive primer of the kind comprising a tube closed at one end only and containing within the closed end a charge of compressed crystalline explosive powder, the primer being adapted to receive into the open end of the tube a detonable explosive element, e.g. a detonating fuze, is so constructed that the portion of the charge at the closed end of the tube is less highly compacted than the remainder of the charge. The primer is initiated from the closed end of the tube by a detonating impulse whereby an enhanced detonating impulse is transmitted to the detonating fuze &c. The explosive powder may be tetryl, pentaerythritol tetranitrate or cyclotrimethylene-trinitramine or other explosive which is sensitive to a detonating impulse but is relatively insensitive to flame or mechanical shock. The tube 1 may have an inverted cup-shaped member 2 located at the closed end of the tube by a force fit, so as to provide a transverse partition having an aperture through which the explosive powder may pass until the space 3 between the partition and the closed end of the tube is filled, and also a part 4 above the partition. The tube is shaken or tapped subsequently to the introduction of the power and a loading pressure of 5-15 tons per square inch applied to the powder to compact the powder in the space 4. Instead of a separate member 2, the tube may be cannelured to provide a restricted throat through which the powder can pass but which prevents the transmission of the full loading pressure' from the part 4 to the powder at the closed end of the tube.