GB379996A - Improvements in and relating to electric gas blast switches - Google Patents

Abstract

379,996. 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.) March 10, 1932, No. 7211. Convention date, March 10, 1931. [Class 38 (v).] In a gas-blast switch in which compressed gas is admitted to the switch from a reservoir by a single valve for the dual purpose of opening the switch contacts and extinguishing the arc, means are provided responsive to the circuit current to close the valve as soon as the arc is extinguished and thereby to avoid waste of gas pressure, and a reserve of gas pressure is maintained for ensuring the completion of the separating movement of the contacts. As shown, the single valve b is opened electromagnetically on energization of a coil supplied from the main circuit. This valve admits pressure from the container a to the switch chamber d and to the cylinder h containing the piston g. The piston operates the switch to the open position and the gas pressure, escaping between the separated contacts f, e, extinguishes the arc. With the circuit broken, the opening coil of the valve is deenergized and the valve closes. The resulting withdrawal of pressure from the supply pipe i to the cylinder h causes a valve m to close thereby segregating an adequate supply of pressure gas in the cylinder to ensure completion of the opening movement. This supply may be increased by including a small reservoir k in the supply connection.