Abstract: A sealed envelope based on a filamentary winding constituted by resin-impregnated glass fibers, for equipment likely to be subjected to large thermal stresses and thus to be the seat of internal excess pressures, the winding adhering to the outside surface of the equipment, wherein the outside surface of the equipment coated with the winding has fiber-free zones forming resin-filled gaps, with the percentage of the surface area not covered with fibers being not less than about 15%.

Abstract: A lightning arrester includes a stack of zinc oxide pellets (1) seated in counterbored recesses of intermediate tubular spacers (2) and two metal end fittings (3). This assembly is wrapped in a filament winding (4) at an angle of 80-90 degrees with the stack axis, thereby providing radial binding without significant axial compression. The filament winding adheres to the side surfaces of all the components of the stack.

Abstract: A double molded over method of manufacturing a lightning arrester in which a central core 1 is made of zinc oxide in a first step, then two metal end fittings 5, 6 are molded onto the end faces and over the side thereof, and finally a coating of elastomer material 7 is molded around the side wall of the central core and over side portions of the end fittings. The core may be formed of a plurality of smaller section bars of zinc oxide regularly disposed about a longitudinal axis with the end fittings molded onto the end faces and about the sides of the end bars whose end faces are partially metallized. In a further variant, a stack of zinc oxide based pellets having the same cross-sectional area as the core in the first example, with the stack having the same overall length as the core if stiffened by thermal compression with fusible metal inserted between pairs of pellets. The stack assembly is then compressed mechanically in conjunction with heat treatment to effect very good mechanical bonding.

Abstract: The present invention relates to a method of manufacturing a lightning arrester (100) having two end fittings (2,20) at either end of a substantially cylindrical central core constituted by a stack of pellets (6, 7, 8) made of a varistor-type material and having holes therethrough whereby the pellets are threaded over a central rod (1) made of stratified material. The stack assembly is put into compression against the two facing faces of the end fittings (2, 20) by means of the rod (1), the space between the rod (1) and the pellets (6, 7, 8) is filled by casting or injecting an insulating material, with the assembly obtained in this way being perfectly rigid, and a coating (30) of an elastomer of the EPDM type is molded over the assembly, with the coating adherring perfectly to all of the surfaces of the core and of the end fittings which it covers.

Abstract: An insulating spacer subjected to bending stresses is formed from a glass fiber reinforced rod having a transverse hollow in the vicinity of at least one end. The rod is covered with a sealing elastomeric sheath. A lightweight cable clamping structure includes two half sleeves clamped around the one end by U-bolts. At least one of the U-bolts also presses a cable clamp toward one of the half sleeves. The one half-sleeve has an internal boss, shaped to fit the transverse hollow so as to fix the half-sleeves on the rod, and a transverse external groove facing the cable clamp to fix a cable against the sleeve.

Abstract: The invention relates to an electric insulator of the line post type which has a rod (2) made of glass fibres agglomerated in resin and covered with a protective elastomer sheath. A socket (15) with an opening (16) is provided to make it fast with post (14). The socket end of the rod is machined to provide a hollow (8) designed to improve the mechanical characteristics of the rod in the fitting (1) of the post (14). A locking piece (17), which is complementary to the hollow (8) in the rod (2), clamps the assembly together by means of two fixing parts (18).

Abstract: An insulator comprising a plurality of fins (1) or one-piece groups of fins made of elastomer and having sleeves (2) disposed end-to-end. The fins surround a central member (3) and are vulcanized. The fins form a water-tight tube whose cohesion is ensured at least by vulcanizing intermediate elastomer portions (5) which are inserted raw between vulcanized fins or one-piece groups of fins and adhere to the facing surfaces of the said sleeves by virtue of their subsequent vulcanization.