Patent GB-190706224-A (GB)
Title: Improvements in and connected with Protective Fuses for use on Electrical Circuits.
Inventor: HANDCOCK HENRY WILLIAM
Filed: 1907-03-14
Granted: 1908-03-12
Abstract: 6224. Handcock, H. W., Dykes, A. H., and Smith, R. T. March 14. Cut - outs couplings. - Electric cut - outs for battery rooms and other situations in which au ordinary fuse would become corroded are made of incorrodible material, such as lead, lead alloy, &c., and are mounted on an insulating core or bridge,' the ends of which are suitably formed so as to mechanically unite with lugs cast or moulded on their ends. In several forms, the fuse is cast in one piece with the lugs ; and in another form, a lug is formed to support an insulating incombustible shield which encircles the fuse. As shown in Fig. 1, the insulating-bridge A has grooves, preferably spiral, cut on its surface, and the ends are drilled, roughened, or grooved. Fusible non- corrodible metal is cast round this in such a manner as to form lugs B, C, which may be of any shape and adapted for connexion to the circuit terminals by 'burning' or clamping in any manner ; for this purpose, they may have holes formed therein. The fusible portions F are cast in one piece with the lugs B, C. The mould may be grooved instead of the bridge-piece A. The complete fuse may be painted for additional protection. The bridge-piece itself may be a tube, hollow sphere, &c. of insulating material, and the fusible strips may be cast on its inside or outside surface, or drawn through it and held in place while the lugs are cast on ; or, the lead lugs may be forced on to its ends by pressure, and the fuse strips either burned on or squeezed into contact with the lugs. According to the Provisional Specification, the lugs in this case may be screwed to the insulating-core. The fuse strips may be of any number, or even a solid tube which may be perforated during casting or otherwise to reduce the section. The lead 'sleeve' in the latter type may be screwed on to the lugs by right and left handed threads. Fig. 9 shows the insulating- bridge V with lugs W cast thereon, and a fusible tube X having conical right and left handed screw threads at each end ; the lugs W are similarly screwed. The terminal lugs Y are internally screwed right and left hand, so that the act of screwing the fuse V, W, X into circuit clamps the whole together, the terminals Y being, if desired, burnt on to the circuit leads. In another modification, flanged and screwed lugs are cast on to the bridge-piece, the fuse wires passing through holes in the flange and being clamped thereto by clamping-rings screwed over the lugs. According to the Provisional Specification; the lugs &c. in this modification may be of brass &c. with lead cast thereon, and the fuse wire may be of copper cased with lead. In Figs. 6 and 7, which show a side view partly in section and a cross-section of a further modification, the bridge piece K has lugs L, M cast thereon having circumferential serrations N, N<1>. The fuse wires O are separately burned into the notches thus formed, and may be replaced after fusion by burning others into the unused notches whatever be the position of the fuse. The serrations N<1> are suitably shaped to support an insulating incombustible tube Q, which confines the explosion that occurs on fusing. Where any of the devices above described are burned into the circuit terminals, temporary clamps are provided to bridge the gap while a new fuse is being inserted.