GB276649A - Improvements in and relating to electric switches - Google Patents

Abstract

276,649. British Thomson-Houston Co., Ltd., (Assignees of Rankin, W. K.). Aug. 30, 1926, [Convention date]. Oil switches for high voltages and heavy currents comprise an oil tank 1 from the bottom of which the explosion chamber 10 is supported carrying segmental socket contacts 15 and upper segmental contacts outside, the explosion chamber, and a bridging contact-rod 16 which is raised rapidly to the off position by oil pressure transmitted through the passage 9. The oil pressure is produced by a piston 38 which is first raised against the action of a powerful spring 45 and locked in the raised position by levers 48. 49 geared together and having roller ends engaging a cam surface on an extension 41 of the piston rod. The links are maintained in the set position by an overset toggle 52 which can be tripped by the electromagnet 53 or by hand. When tripped the spring depresses the piston and forces the contact-rod 16 upwards out of the contact 15, the rod being followed by a stream of cold oil which extinguishes the arc. The contact-rod is raised against the action of a spring 28 and in the upper position is engaged and retained by a spring-latch 33. In this position. the piston 38 can be again raised and held in the upper position and then the latch 33 withdrawn to permit the spring 28 to press the rod into the contactmaking position again.