GB184666A - Improvements in and relating to electric switches - Google Patents

Abstract

184,666. British Thomson - Houston Co., Ltd., (General Electric Co.). July 13, 1921. Oil switches.-To minimize the danger due to - rupturing high-power circuits by oil-switches, in addition to air cushions above the oil surface, baffles of cooling-material, such as gravel, are provided to split up the products formed. In one construction, Fig. 1, the baffle has a top portion 18 with top and bottom plates 22, perforated and carrying between them gravel 23. A depending part 19 of the baffle rests on the base of the tank 10, but is lifted, when the switch is opened, by the expansion of gas, which passes through the gravel and out of the vents 17. In a modifica.- tion, a stationary baffle may be employed, stretching below the oil surface and having an air space between it and the walls of the tank. Wire netting may also be placed between the gravel and its perforated plates to strengthen the baffle. The explosion-chamber switch, Fig. 4, is put in an outer oil-tank, and consists of an explosion-chamber 34, depending from the fixed electrode 33, and an outer shell 42, with gravel 44 between them. Valves 35 are opened by the escaping gases which then pass through the gravel 44 and out into the main tank. Pot 34 is filled with oil and the oillevel of the rest of the tank is shown. The electrode 52 is hollowed out to allow the oil to escape, thus furnishing an arc-quenching oil-blast. Fig. 5 shows a double oil-blast switch, the electrodes being 63, 64. Here, oil follows the electrode 64 up through the hole in baffle 77 and oil also is forced out of chamber 67 as the arc rises through the insulator 68. Gases pass through the gravel 74 and holes in baffles 75, 76 to the vents 62. Fig. 6 shows an electrode 83 which moves up through a funnel-shaped hole 87 in an insulator 84. Oil follows it through orifices 88, 89, the screen 85 keeping these jets free of gas. The gases are passed through the gravel 94 and out of a tube 95 also filled with gravel. A stuffing-box 98 prevents gases escaping around the electrode 83.