Improvements in or relating to electric igniters for use in electric initiating devices for explosive, incendiary and like compositions

摘要

627,431. Electric fuzes. ASHCROFT, D. G., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. April 14, 1947, No. 9873. [Class 9 (i)] An electric igniter in which the pole-pieces consist of the bared ends 3 of insulated leading wires extending beyond a spacing element comprising a strip 4 of compressible material, has a part of each wire bent to form a loop contacting the two faces and four side edges of the strip, the end portions of the loop being on the same face of the strip and each end portion being bent over on itself. The ends 3 of pairs of leading wires 2 are flattened and part of the insulating material 1 is removed, the wires being made parallel by passage through guide channels. A strip 4 which may be notched or perforated at intervals is fed transversely to the wires and the pairs of wires are then attached simultaneously by a row of folding and pressing tools. When the strip is perforated the doubled portions of flattened wire are passed through the perforations. A resistance wire 8 is attached to the pole-pieces by soldering or by bending the flattened ends 10 of the wires over the resistance wire. A continuous resistance wire may be used, a match-head composition 9 applied, the resistance wire and strip 4 then being cut to form the individual igniters. Before attachment to the strip 4, the pairs of leading wires may be partly twisted together and threaded through a plug 7 of resilient waterproof material for insertion in a charged detonator tube, the tube being crimped to the plug.