GB512592A - Improvements in or relating to circuit-breakers for high voltage - Google Patents

Abstract

512,592. High-tension switches; switchgear structures. NIJLAND, H. A. H. July 18, 1938, No. 21308. [Class 38 (v)] A circuit-breaker has its contact make-andbreak element, comprising fixed contacts and co-operating movable contact, accommodated in a fixed metal tank which is provided with fixed lead-in conductors passing through insulators in the wall thereof and is adapted to be filled with an insulating fluid, such as mineral oil, or to contain a gas, and the make-and-break element is connected to the lead-in conductors in such manner that it can be entirely withdrawn from and inserted into the tank while those conductors are alive, and is surrounded by an insulating casing which completely isolates the space in which the switching operation is carried out from the compartment which those conductors enter. The make-and-break element comprises the fixed contact 10 and movable-rod contact 26 mounted in the insulating tube 7, which is closed at the bottom by a plate 8 carrying the contact 10 and a socket 11 for engaging the pluglike end of the bus-bar lead-in conductor 3. Rod 26 slides in a contact 14 which is secured to the cover 6 by insulators 15, 16 and connected by conductor 18 to a socket 19, which engages the cable lead-in conductor 4 and is carried by the closure-plate of an insulator 21 also secured to the cover 6. Conductor 18 is surrounded by an insulating tube 22 passing through a metal funnel 9 mounted on the tube 7, and the parts 7, 9, 21, 22, are filled with mineral oil 23 which also fills the metal tank 1 as shown at 5, but the two oil-bodies 5, 23 are separated. The two bodies of fluid need not be of the same composition or of a liquid character, but if the body 5 is a liquid, its incompressibility may reinforce the tube 7, for which purpose the partition 24, with small vents.25, may be provided below the liquid-level.