GB945052A - Improvements in and relating to switchgear - Google Patents

Abstract

945,052. Fluid actuation of switches; regulating switches; controllers. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. June 21, 1960 [June 24, 1959], No. 21697/59. Heading H2B. Switchgear for controlling, e.g. electric motors comprises a plurality of switch units arranged in parallel planes and having the moving contact carriers secured to support bars extending parallel to the switch axis for rotation about that axis, each carrier consisting of a plurality of section which can be assembled to and dissembled from the support bars without disturbing the remaining switch units. A plurality of switch units are assembled between end and intermediate support plates 11 connected by tie rods 12-15. On each rod is insulatingly clamped a contact carrier 27 to which fixed contacts 24, 25 are screwed. Between the support plates 11 mounting rods 40, 41, interconnected by end plates, pivot on stub axles about a central axis O. On each rod 40, 41 contact carriers 46, 47 and 48, 49 are clamped, on which contact supports 63 are mounted. Each support carries a movable contact 20-23 and is arranged to pivot about a knife-edge under spring pressure to provide a wiping action. With a supply connected to the fixed contacts and a load, e.g. an electric motor, to the terminals of the movable contacts, rotation of the switch will reverse the load connections. A central " OFF " position is provided. Operation of all the switch units in unison is obtained through two opposed fluid-pressure jacks 83, 84 mounted centrally along the switch assembly. The jacks are connected by respective lost-motion links 85, 86 to a pin on an operating lever 72 rigidly connected by a cross-head to the mounting bars 40, 41. Location of the switch units in the three positions is assisted by a toothed plate 74 coacting with rollers 77, 78 on spring-urged arms 79, 80. In an alternative embodiment, Fig. 6 (not shown), the fixed contacts 24, 25 are each divided into two separate contacts, each mounted on its own tie-rod 12-15, and no central " OFF " position is provided. The two types of switch unit may be combined in one assembly to provide greater flexibility of switching. Specification 945,053 is referred to.