GB481299A - Cartridge fuses - Google Patents

Abstract

481,299. Fusible cut-outs. ELECTRIC TRANSMISSION, Ltd., and DANNENBERG, K. Sept. 29, 1936, No. 26447. [Class 38 (i)] A fuse in which a hollow support is mounted in a sheath and carries fuse-wires wound upon it and within it, both surrounded with arcquenching powder, has socket contacts at the ends of the sheath, one of which can be removed to allow replacement of the fuse-wire support as a whole. The support is a ribbed tube 12 having a main fuse 11 within it and an auxiliary. fuse wire or strip 10 wound helically or in zigzag fashion on the ribs 13 on the outside; or on similar ribs on the inside of the support. The two fuses. are connected in parallel to end caps 14 that fit into sockets 6 formed of resilient blades and clamped by washers 8<1> and plates 9 to end caps 2 on the outer sheath 1. The clamping screws 7 are accessible from the exterior. The main fuse is of silver and the auxiliary of tungsten. The support 12 may be coated with gypsum. If a strip is used on the exterior, the edge of the ribs 13 is corrugated so as to space the strip therefrom and if a wire is wound zigzag over the ends of the ribs, these ends are notched and made blunt so that an acute V-bend formed in the wire stands clear of the end of the rib. An indicator to show that the fuse has blown may be constructed as a plunger 21, Fig. 5, attached to the fuse wire 11, the end of which .passes through a cavity 19 containing gunpowder. The charge is sufficient to force the plunger 21 through a sealing foil 24 on the cap 14 and through the disc 9 and may cause it to actuate a signal or relay. According to the Provisional Specification, the two wires may be arranged in separate bores in the support and the endcaps may be blown off or foil seals thereon ruptured to act as an indicator.