Surge suppressor construction

Claim 1

A surge suppressor for limiting the magnitude of the surge voltages appearing between two points in an electric power system at widely different potentials, comprising: (a) a tubular housing of insulating material having one end open and an end wall of insulating material at its opposite end, (b) a metal end cap sealingly joined to said one end of the housing, (c) a metal terminal at the other end of said housing extending through said end wall and having a portion located within said housing, (d) a stack of metal-oxide varistor blocks within said housing having two opposed ends, one of which bears against said portion of said terminal, said stack having an external diameter much smaller than the internal diameter of said tubular housing so that a generally cylindrical space is present between said stack and the surrounding wall of said housing, (e) a metal plate bearing against the other end of said stack of blocks, (f) a spring located between said metal end cap and said metal plate and urging said plate into engagement with said other end of said stack, (g) a plurality of rods of insulating material fixed to said end wall independently of said terminal and extending through openings in said metal plate registering with said rods, said rods extending alongside said stack through said cylindrical space and limiting lateral movement of said stack in response to vibrations and mechanical shock, (h) and means at the outer periphery of said metal plate engaging said housing for blocking rotation of said metal plate about the central axis of said tubular housing but allowing axial motion of said plate relative to said housing.