GB756866A - Improvements in or relating to composite electric insulators - Google Patents

Abstract

756,866. Insulators. KARANTHA, K. V. Aug. 26, 1953, No. 23567/53. Class 36. An insulator comprises a ceramic or glass member which encloses a tension member consisting of fibre glass sheaves or cords. In a suspension insulator (Fig. 1) the tension member 3 may be held between hooks 4 and 5, each of which may terminate in a clevis tongue 6. The upper hook 4 has a threaded stem and the lower hook 5 a flange 10. Metal end caps 7, 8 are provided, the upper having a threaded central hole to engage the stem of hook 4. The flange 10 normally rests on cap 8 except when tension is applied to the insulator. The insulator may be sealed against the ingress of moisture by a flexible metal member 11, the upper and lower edges of which are soldered to the cap 8 and flange 10 respectively. Filler holes 13, 14 may be provided in the caps to enable the space within the insulator to be filled with insulating compound, after which the holes are sealed. In a supporting insulator (Fig. 2) the tension member may comprise a number of separate sheaves 15 symmetrically arranged in the body of the insulator 17, and anchored at the lower end to stem 20 and at the upper end to stem 23. Stem 23 rests on end cap 18, but may be moved upwardly under tension, ingress of moisture being prevented by a flexible member 28. Lower cap 19 rests on screws 25 by which any permanent alteration in the sheaves 15 may be compensated. A flexible joint 26 and non- flexible cap 27 prevent ingress of moisture at the lower end. The ceramic part of the insulator may be made in two or more sections which are secured together by means of rigid or flexible joints.