摘要 |
A lightning arrester consists of two metal armatures (3), a series of electrical components extending along its lengthwise axis between them, and an outer casing (6) surrounding them so that an electrical contact is maintained between them. The casing is made from a thermoplastic material, e.g. reinforced with glass or silica fibres, which is moulded over the electrical components and armatures and has a corrugated outer surface with projections (8, 9) and recesses (7), the recesses being in the form of lateral apertures for a free release of gases into the outside air. Each of the metal armatures has an annular groove with base facets to engage with the casing, and the outer corrugations of the casing are in the form of both lengthwise (8) and radial (9) ribs. An outer housing of an elastomer polymer surrounds the casing and fills the hollows in its outer surface. |