Improvements in and relating to high tension cartridge and like fuses

Abstract

Abstract 479,211. Fusible cut-outs. ELECTRIC TRANSMISSION, Ltd., and DANNENBERG, K. Sept. 29, 1936, Nos. 26446/36 and 12770/37. [Class 38 (i)] In a high tension fuse, the deterioration of the element due to corona discharge is prevented by arranging that the grains of the arc-quenching powder are of such a size and are packed sufficiently closely that ions discharged from the element cancel the field between the element and the grains without impairing the arc-quenching properties of the powder. A hollow refractory sheath 3, provided with ribs 6 to support subsidiary fuse wires 7, preferably of some non-oxidizable material such as tungsten, contains a main fuse wire 1 of silver, embedded in arc-quenching powder such as marble dust, and connected to end caps .4 engaging spring contacts 10 on the end caps 9 cemented with litharge, plaster of Paris, &c., to the outer refractory sheath 8. The marble dust grains may have a maximum diameter of 0À1 mm., the sheaths being packed by shaking in a jig vibrating at least 150 times per minute, the space 13 being filled with powder and closed by end plates 12. In a modification, the wire 1 is passed up and down the inner wall of the sheath 3 over longitudinal ridges having notches at the ends. A single wire cartridge fuse is also described packed with powder and hermetically sealed.

Inventors

No inventors recorded.

Bibliographic Details