GB1095025A - High tension composite insulators - Google Patents

Abstract

1,095,025. Insulators. BROWN BOVERI & CIE A.G. May 7, 1965 [May 14, 1964; April 1, 1965], No. 19440/65. Heading H2C. Mechanical stresses in a substantially tubular insulating body 4 (Fig. 1) with skirts 5 are borne by a central glass fibre reinforced plastics element 1, and the space between the element and the insulating body is filled with foamed plastic, e.g. polyethylene or polystyrene. The insulating body is of porcelain, glass, or cast resin. The supporting element 1 as shown is shaped like a chain link and is held by a cable thimble 2. It may comprise an epoxy or polyester resin. To obtain additional protection against glow discharge, the foamed plastic may incorporate graphite or silicon carbide to render it semi-conducting. Lids 6, corrugated to allow for expansion, may be sealed before or after foaming of the plastic is complete, or after further gas has been introduced to increase internal pressure. Fig. 4 illustrates an arrangement which reduces further the risk of glow discharge. The conducting clamps 28 which hold the rod-shaped support member 27 at each end are surrounded by non-cellular insulation 32, e.g. wound insulating material or cast resin. Electrode 33 is applied to the inside wall of the body 29 opposite clamp 28 and electrically connected to it through bridge 36. Rod 34 may be coated with a layer 34 of semiconducting resin material, this layer also being in electrical contact with clamp 28 and electrode 33.