Electrical insulator, manufacturing method of such an insulator and device for carrying out the method

摘要

The e.g. aluminium alloy end-mountings (2A,2B) have sockets receiving the ends of a tubular e.g. glass-fibre former (1). Lathe-mounted, this assembly is rotatable about its longitudinal axis (4) and displaceable axially w.r.t. and extrusion head (14). Using a triangular cross-section die, the latter lays down a conical elastomeric grading ring (9) at the tube/mounting junction, consolidated by an inclined roller and scored axially (16). While the assembly moves axially, an inverted T-section die then extrudes on to the former a helix (20) of the same insulant, which incorporates a projecting helical rain-shed (18). A narrow roller (19) consolidates the material, expelling any air, which at the ends escapes via the scoring (16). The completed assembly is then cured.