GB733444A - Improvements in and relating to gas-blast electric circuit breakers - Google Patents

Abstract

733,444. Gas-blast switches. GENERAL ELECTRIC CO. Nov. 10, 1952 [Nov. 9, 1951], No. 28261/52. Class 38 (5). A gas-blast switch has spring-biased movable interrupting contacts 12 co-operating with one end of a tubular fixed conducting member 15, a movable tubular isolating contact 17 coaxial with but spaced from the member 15 and bridging contact members 20 normally interconnecting the other end of the member 15 and the isolating contact 17. When the gas-blast is applied to the switch, the blast initially opens the contacts 12, 15 and the blast is exhausted upwardly (arrows 29) and downwardly (arrows 30) through the member 15 and contact 17. Subsequently the contacts 20 are moved upwardly by the blast gas acting on a piston 21 in which the contacts 20 are carried. The opening of the contacts 20, 17 to form the isolating gap is delayed with respect to the opening of the contacts 12, 15 by the admission of gas through a port 27 to the rear of the piston 21, this gas being exhausted at a controlled rate through a needle valve 28. After, or coincident with, the interruption of the-current which flows through a resistor 16 on the opening of the interrupting contacts 12, 15, the isolating contact 17 is moved downwardly. On the formation of the isolating gap, the blast acting on the gap causes an upward blast component 32 to oppose the downward exhaust from the interrupting contacts 12, 15 to reduce the blast to those contacts, and a downward blast component 31 which exhausts through the contact 17. Specifications 666,834, 712,436, 723,156 and 733,434 are referred to.