Patent GB-1130875-A (GB)
Title: Improvements in cartridges and methods of and apparatus for using same
IPC: F42B5/188
Filed: 1966-01-27
Abstract: 1,130,875. Ammunition cartridges; electrically fired rifle. UNITED SHOE MACHINERY CORP. 27 Jan., 1966 [29 Jan., 1965], No. 3666/66. Headings F3A and F3C. [Also in Division B3] A cartridge which may be used for upsetting rivets, operating a cutting or crimping tool, or to fire bullets from rifles, comprises an explosive charge within a metal coating which is electrically conductive, e.g. aluminium, zinc, nickel, copper, or silver, the coating being formed by deposition of metal around the charge, e.g. by electroplating, electroless plating, or vacuum diffusion. The coating may be confined to the curved surface of a cylindrical charge or the end surfaces may also be coated. The coating on the curved surface may be partially covered with insulating material, e.g. nitrocellulose. The conductive metal layer, e.g. copper, may be applied to the charge by an electroless plating process and a further metal layer, e.g. nickel, deposited by electroplating. The charge may be a double base smokeless powder comprising nitro-cellulose and nitroglycerine and may have a foamed cell structure. A plurality of the cartridges may be confined in a casing of insulating material closed by metal plates (56), (58), so that a conductive path is established between the plates and the cartridges (Fig. 6, not shown). The cartridge may be attached to a projectile, the metal coating being continuous over the charge 330 and projectile 332, the trailing end of the charge may be tapered to increase the diameter. The cartridge may be secured to the base of the projectile by an epoxy resin or as in Fig. 15, the cartridge and projectile may have a dovetailed connection. The rifle has a barrel 302 with a tapered breech end and a sliding bolt 310 through which extends an electrode 346 with a frusto-conical surface 360 adapted to engage the base of the cartridge. Electrode 346 and the gun barrel 302 are in circuit with a battery 307 and a trigger-controlled switch 318. The battery 307 may be a nickel-cadmium cell housed in the butt of the rifle. A safety switch 320 in the circuit is operated by a slidable actuator (322), (Fig. 14, not shown). The rifle is provided with a sight (316). To set hollow rivets in a workpiece the cartridge may either be inserted in a tool (124), (Fig. 11, not shown), having a conductive nosepiece with a shaped end to engage in the rivet and a coaxial electrode (132) insulated from the nose-piece, or placed in the rivet and a tool comprising an insulating sleeve (164), (Fig. 12, not shown), and a coaxial electrode (160) brought to bear against the cartridge. In Fig. 11, a current can be passed through the nose-piece, cartridge coating and coaxial electrode and in Fig. 12, through the rivet, cartridge coating and coaxial electrode. For cutting cables the cartridge is placed in a cylinder (180), (Fig. 13, not shown), behind a piston (190) carrying a knife blade (182). Current is passed through the coating to explode the cartridge and drive the piston by connecting an electrode (202) in circuit with a lead (204) connected to the cylinder (180).