GB211022A - Improvements in and relating to electric switches - Google Patents

Abstract

211,022. British Thomson-Houston Co., Ltd., (General Electric Co.). March 15, 1923. Oil switches.-The secondary contacts 38<1>, 45, at which the circuit is finally broken are immersed in an insulating liquid not permanently affected by heat, such as distilled water, or a mixture of water and glycerine, contained in a sump 16 at the bottom of a closed explosion chamber 14, the upper portion of the chamber having corrugations 15 or like means for recondensing the liquid vaporized by the arc. The switch mechanism includes arms 30, 33 pivoted at 31, 34 and geared together so that on raising a rod 21, the arms swing outwards and the primary contacts 13, 32 are separated simultaneously with the raising of a rod 40 carrying the secondary contacts 38<1>. The co-operating secondary contact 45 is sli'dably mounted so that the separation of the secondary contacts occurs after that of the primary contacts. A dash-pot 60 serves to cushion the final movement. Current is led through a hollow lead 24 to the cover 41 of the explosion chamber and thence by conductors to the arms 30, 33. Modified constructions of explosion chamber and switch are described.