Disconnect contact assembly for metal-clad switchgear and the like

Claim 1

A disconnect contact assembly for metal clad switchgear and the like, comprising: a. a metal plate at ground potential having an opening therein, b. a first conductive stud extending forwardly through said opening in radially-spaced relationship to the periphery of said opening and terminating in a free end, c. a tubular insulator surrounding and fixed to said first stud and also extending through said opening, said tubular insulator having a forward tubular portion that surrounds and is radially spaced from said free end of said first stud, d. a second conductive stud generally aligned with said first stud and having an end portion surrounded in radially-spaced relationship by said forward portion of said tubular insulator, e. a bridging contact subassembly bridging the ends of said studs and conductively interconnecting said ends, said bridging contact subassembly being located in a position surrounded by said forward portion of said tubular insulator and radially spaced from said forward portion of said tubular insulator, f. an annular current transformer secondary assembly surrounding said portion of said tubular insulator, g. a first metallic coating normally at ground potential surrounding said portion of said tubular insulator and said secondary assembly, and coating the outer periphery of said portion of said tubular insulator, h. a second metallic coating normally at the potential of said first stud coating the inner periphery of said forward portion of said tubular insulator and surrounding said bridging contact subassembly in radially-spaced relationship thereto, i. a first semiconductor coating having non-linear resistivity properties on the external surface of said tubular insulator at the forward end of said first metallic coating, and j. a second semiconductor coating having non-linear resistivity properties on the internal surface of said tubular insulator at the forward end of said second metallic coating.