GB378377A - Improvements in and relating to air-blast electric switches - Google Patents

Abstract

378,377. High tension switches. INTERNATIONAL GENERAL ELECTRIC CO., Inc., 120, Broadway, New York, U.S.A.-(Assignees of Allgemeine Elektricitats-Ges.; 2, Friedrich Karl-Ufer, Berlin.) April 1, 1931, No. 9901. Convention date, April 3, 1930. [Class 38 (v).] An air blast switch having a number of breaks in series is provided with pneumaticallyoperated isolating contacts. In the arrangement shown, gas pressure within the container 1 is supplied through the valve 2 to the chamber 4 to press inwards two pistons 9, 10 against the action of a spring 17 and so to withdraw the plug contact-members 13, 14 from their nozzle contacts 19, 20 and release a blast of air to blow out the arc. The same gas pressure operates other contact-members 15, 16 in series with 13 and 14 and mounted in a plane parallel therewith but at an angular position displaced with relation thereto. When the gas pressure ceases the circuit is re-established by the action of the springs 17, 18. Further contacts 25, 26 in the series circuit serve to isolate the switch when the circuit has been opened at the main contacts. The movable contact 26 is operated by pressure supplied to one side or the other of the piston 24. Two different pressures are employed for the two sides of the piston and both are supplied through one and the same supply pipe through a spring- loaded reversing valve provided on the cylinder 23 which allows the gas to pass beneath the piston at the higher pressure and to the upper side at the lower pressure.