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AssigneeCentral Electricity Generating Board
InventorsCyril Harold Arthur Ely, Peter John Lambeth, John Sidney Thomas Looms
Estimating the term…
An insulator having a central portion or stem and one or more sheds is provided with a barrier over at least one of the sheds whereby a substantial improvement in withstanding flashover is obtained yet significant damage to the surface of the insulator is avoided. The barrier comprises a sheet of dielectric material positioned over the upper surface of a shed but spaced away therefrom, the sheet extending radially outwardly to overhang the periphery of the shed. The barrier is furthermore spaced radially away from the central portion or stem of the insulator over at least a substantial part of the inner periphery of the barrier. The barrier may be made of rigid material, for example, constructed from a plurality of sectors but is preferably made from a flexible material so that it can be fitted around an existing conventional insulator. The underside of the barrier is preferably provided with a number of projections for spacing it away from the upper surface of the shed.
A method of improving an insulator having a central portion or stem and one or more sheds comprising the step of putting a barrier of dielectric material over the upper surface of a shed but spaced away therefrom, the barrier extending radially outwardly to overhang the periphery of the shed by at least 5 mm around the whole of the shed, the barrier furthermore being spaced radially from the central portion or stem of the insulator over at least a substantial part of the inner periphery of the barrier.
An insulator having a central portion or stem and one or more sheds extending outwardly therefrom in combination with a discharge barrier comprising a sheet of dielectric material and positioned around the central portion or stem of the insulator above at least one shed, said sheet being spaced away from the upper surface of the shed, said sheet furthermore being arranged to overhang the shed by extending radially outwardly therefrom for a distance of at least 5 mm, said sheet furthermore being dimensioned to leave a gap between the insulator central portion or stem and the sheet over at least a substantial part of the inner periphery of the sheet.
A shed for an electrical insulator, comprising a flexible polymeric shed and a barrier of dielectric material, said barrier being spaced away from the upper surface of said flexible polymeric shed and having an inner periphery of greater diameter than the inner periphery of said flexible polymeric shed.
An annular barrier for fitting on a shed and about a stem of an electrical insulator, comprising an annular barrier sheet of flexible, dielectric, anti-tracking material, said annular barrier sheet having a substantially radial division, means for joining said barrier sheet to close said substantially radial division and a plurality of projections on one side of said annular barrier sheet to space said annular barrier sheet from the upper surface of the shed.
Dependencies are inferred from the claim text.