Abstract: A high voltage insulator made up of a number of coaxially nested interlocking metal shell-like elements tapered from one end to the other, there being a layer of insulating material arranged between adjacent elements; the elements are each formed with corrugations that are uniformly spaced in the axial direction and have a radial extent greater that the thickness of the insulation, the externally convex portions of the corrugations increase in size from the smaller end to the larger and the externally concave portions correspondingly decrease in size; the thickness of the metal and the thickness of the insulation layer are substantially uniform where the elements overlap and the overlapping surfaces of each element are equi-distant at all places from the surface from any overlapped or overlapping element. The corrugations are annular or helical, in the latter case the elements being screwed together to constitute the insulator.

Abstract: A method of surface treating elastomer surfaces comprises applying thereto a 4-substituted-1,2,4-triazoline-3,5-dione preferably in solution. The treatment improves adhesion using normal elastomer adhesives, improves resistance to peeling with flexible paints and reduces the surface tack of the elastomer. The method is advantageous over prior art chlorination and halogen donor techniques particularly in that the triazoline diones are relatively non-corrosive and non-toxic.