GB2022328A - Electric insulators - Google Patents

Abstract

The present invention provides a synthetic resin insulator consisting essentially of a reinforced synthetic resin material providing the mechanical strength and having metal fittings and synthetic resin shells Sch 1 of different chemical composition and structure, wherein shells produced from an elastomeric material and provided with bores are pushed over a rod 'S' consisting of a mechanically reinforced synthetic resin, the diameters of the bores being equal to or slightly greater than that of the rod, and the shells are firmly and tightly joined to one another, or are integrally produced, to give a shell arrangement which is under axial tension and the ends of the shell arrangement are firmly joined to the rod and/or a fitting. Plastically or elastically deformable compression sleeve Z is also shown. An axially tensioned elastomeric cylinder ZS (Figure 3, not shown) may be provided with semiconducting or insulating shells, or a helical shell may be glued, vulcanised or welded thereto. Dielectric shells may have closed or open pores, and beads or grooves may be on the upper and lower shell surfaces. End fittings are force locked by hydrostatic deformation. Differently shaped shells (Sch 2) (Figure 2, not shown) may be provided at the ends. Further applied tensioning in use increases compression on the insulating viscous packing in gap F and increases longitudinal electrical strength of the inner boundary. Materials are exemplified. <IMAGE>