Surge arrester with improved insulative bracket.

摘要

The insulative support bracket (21) of a surge arrester sincludes a concentric annular concavity (50 or 57) formed at one or both ends of a bolt hole (53). A washer (25), when pressed concentrically to the concavity (50 or 57), contacts the insulative bracket only, at least initially, at surfaces adjacent the outer edge of the washer (25). An annular convexity (49), surrounding the concavity (50 or 57), wil mate with the central portion of an external tooth lockwasher (26) to prevent the full penetration of the teeth of the lockwasher into the insulative bracket (21). The ability of the insulative bracket to withstand the mechanical forces transmitted to it by the washers (25,26) is thereby enhanced. The concavity (50) may be formed either in a surface of the insulative bracket (21) or in a surface of the washer (25).