Replaceable bushing and contact assembly for blade type air insulated

Abstract

Improved switchblade-type, air dielectric switchgear apparatus is provided which utilizes a minimum of supporting insulators and incorporates readily field-replaceable bushing assemblies so that the switchgear apparatus may be serviced in the field using only conventional tools. In preferred forms, the switchgear apparatus includes internal switch assemblies making use of substantially vertically oriented switchblades mounted for pivotal movement about an elevated, generally horizontal axis located above the corresponding stationary contacts. The replaceable bushing assemblies are advantageously mounted at a level for interconnection with the upper ends of associated switchblades, and the assemblies include a conical outermost connection and adapted to receive a line connecting elbow, together with an elongated, inwardly extending, electrically conductive intermediate portion carrying an innermost terminal. The inner terminal is designed for frictionally engaging the upper end of an associated switchblade, and for this purpose includes a pair of depending, spring-loaded contact plates. If a given bushing assembly requires replacement, it is only necessary to externally disconnect the assembly from the switch housing wall, followed by manual removal of the defective assembly. An identical replacement assembly is then inserted through the tank wall and the assembly terminal is initially positioned relative to the switchblade, this operation being facilitated by visual inspection through a window below the bushing assemblies. The replacement bushing is then attached using external connection hardware, this operation serving to properly and finally position the terminal relative to the switchblade.