High voltage vacuum type circuit interrupter

Abstract

A high voltage vacuum-type circuit interrupter is disclosed that includes a single or one-piece ceramic insulating housing providing both the external solid insulation between a line terminal and a switch terminal and the external solid insulation between the line terminal and electrical ground. The ceramic housing is mounted on a metallic base by the wedging action of a spring disposed under tension on an exterior inclined surface at the lower longitudinal end of the insulating housing and on an interior inclined surface of the base. A solenoid operated toggle mechanism disposed in the base actuates an elongated operating rod that effectuates the opening and closing of a pair of switch contacts positioned in an evacuated ceramic casing that includes a relatively shallow recess formed about its internal periphery intermediate its longitudinal ends. A tubular metallic vapor shield is held in the ceramic casing by a plurality of metallic ring segments positioned in the recess. Radially outwardly protuberant portions formed in the shield both above and below the ring segments secure the shield to the ring segments. The switch and the line terminals are formed as flattened longitudinal ends of elongated conductive tubular members. A flexible pressure equalization diaphragm is formed in situ in the base and is secured therein and is movable to equalize pressure. A visually discernible position indicator, located within the base, provides a visual indication of the 'OPEN' position or 'CLOSED' position of the switch contacts. The contacting portion of each switch contact is disposed within an elongated, tubular contact stem and is brazed substantially flush with the end of the stem; subsequently, a portion of the stem at that end is removed to reduce the possibility of the welding together of the contacting portions of the switch contacts.