| 摘要 |
849,133. Ignition fuze cords. ENSIGN - BICKFORD CO. July 28, 1958 [July 26, 1957], No. 24195/58. Class 9(1). Ignition fuze cord comprises a plurality of strands 2 coated with a combustible material and surrounded by a loose fitting flexible tubular casing 1 so that flame may pass freely through the casing when the strands are ignited. The strands may be made of cotton, jute, synthetic material or twisted paper. Fibre glass may also be used, but a soft fibre is preferred. The casing is preferably formed by extrusion from polyethylene. Polyvinyl chloride or polyvinylidene chloride or rubber may also be used. The combustible may be a black powder comprising potassium or sodium nitrate, charcoal and sulphur. Potassium perchlorate mixed with carbon, potassium nitrate mixed with carbon or potassium, nitrate mixed with lead oxide and silicon may also be used. The mixture together with a binder, such as nitrocellulose, starch, animal glue, wax or a synthetic resin, may be applied to the strands by dipping, spraying or by an extrusion process. After treatment, the fibres are gathered together, either in parallel or by twisting, before enclosure in the casing 1. A second envelope 3 of fibre glass, cotton, linen, rayon, nylon or wire may be braided over the casing 1. Over the envelope 3 a jacket 4 of an organic plastic material or rubber is formed. Wax, glue or polyethylene are alternatives for the jacket 4. The ignition cord may be used to connect two lengths of detonating fuze cord 5, Fig. 3. A length TL of the ignition cord secured in a blasting cap 6 at each end is bound by tapes 7 to the free ends of the cord 5 to cause a delay in the firing of a charge connected to one of the cords 5, the delay depending on the extent of the ignition cord. A connecting sleeve may be used to secure the ends of the cord 5 to the cord TL. One end of the cord, Fig. 7, may extend into a fitting 10 having an axial recess 11 filled with a delay composition, e.g. red lead and silicon. The terminal fitting is coloured or marked to indicate the burning time of the delay and the fitting is inserted into a blasting cap 6. Fig. 9 shows an arrangement in which the ignition cord is used to connect explosives charges 13, 14, e.g. for operating positions, to an ignition source 15, which may be a percussively or electrically operated primer. A hollow T-shaped connector 16 having an internal stop 17 receives the free ends of cords TL.
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