GB817619A - Improvements in hydraulically actuated electric circuit-breakers - Google Patents

Abstract

817,619. Oil-break switches; hydraulic actuation of switches. GRATZMULLER, J. L. April 4, 1957 [April 4, 1956], No. 10991/57. Class 38 (5). In a circuit-breaker as in Specification 777,750, the insulating feed and exhaust duct, providing the sole connection between the live actuator assembly and the earthed control station, and at least the lower part of the actuator assembly itself are enclosed in an oilfilled insulator whose length is at least twice the separation distance of the fixed contacts. As shown in Fig. 2 and its continuation Fig. 3, the upper fixed contact 5 is connected to a conductor 3 and the lower fixed contact 9 is mounted on a metal bell 8 which is connected to the second conductor 6. The moving contact rod 11 is mounted on moving hydraulic cylinder 12 in which slides a fixed hollow piston 13 and which is urged downwardly by a spring 14. The lower end of the piston 13 is fixed to a flange 16 which also carries the insulating feed and exhaust duct 51. Surrounding the hydraulic jack and the duct 51 between the bell 8 and the earthed control station, indicated at 18, is a hollow insulating cylinder 2 having a length of at least 2L which is filled with the oil surrounding the contacts via holes in the bell 8. Station 18 incorporates a quick evacuating device for the hydraulic cylinder of the type described in Specification 755,096. A perforated tubular metal sheath 35 extends between the bell 8 and the flange 15. A metal sleeve Fig. 4 (not shown), may be interposed between the bell 8 and the top of the insulating cylinder 2. Reference has been directed by the Comptroller to Specifications 755,096 and 777,750.