Abstract: Method and apparatus for manufacturing a composite insulator including an FRP core rod which is integrally provided with a sheath and a plurality of sheds formed of an electrically insulating polymeric material. The core rod has a longitudinal end portion provided with a seat for a metal fitting, which is integral with the sheath. To manufacture such a composite insulator, the core rod is placed in a mold cavity of a mold assembly, with a seat forming member detachably fitted to the end portion of the core rod and arranged between a pair of mold halves. An inner space is formed between the seat forming member and a core rod, which is in communication with the mold cavity. An electrically insulating polymeric material is introduced into the mold cavity to form the sheath and sheds, while admitting the polymeric material into the space between the seat forming member and the core rod so as to form a seat for the metal fitting, which is essentially free from burrs.

Abstract: The disclosed method of producing a composite insulator having a core portion, a sheath portion arranged on an outer surface of the core portion, and a plurality of shed portions projected from the sheath portion by using a die and heating the die, includes a step of cooling both end portions of the core portion. In the disclosed method, it is possible to provide a method in which cracks are not generated in the both end portions of the core portion during producing.

Abstract: A compressed powder magnetic corer is disclosed in which the mixing ratio (vol %) of the parts occupied by binder resin, ferromagnetic powder and void formed therebetween is set for a specified value so as to obtain desired magnetic characteristics.

Abstract: A method for manufacturing a fine porous member provides that vacant space within the porous member is sufficiently finely small such that the thermal conductivity of the member is lower than that of stationary air. In the method, a fine particle powder together with an ultrafine particle powder preliminarily subjected to a surface treatment for prevention of cohesiveness and employed at least as a part of the fine particle powder, are molded into the fine porous member, whereby the vacant space between the respective particles are made finely small to a remarkable extent and the porous member is provided as highly adapted to be used as a heat insulator.

Abstract: The ends of a fiber-reinforced resin rod are inserted through sealing grommets into cavities of respective end fittings; the end fittings of the assembly are placed in accurately spaced end moulds; the rod is encased in intermediate half shells; an insulator covering is moulded around the rod by filling the half shells; and the end fittings are then fixed to the rod by embedding or swaging.

Abstract: A wire or other core is enclosed by two concentric extruded layers, at least one of which is of crystallizable polymeric material, by extruding the layers in succession around but spaced from the core. The first and second layers are brought into thermal and mechanical engagement with each other before the first contacts the core, and the relative thermal capacities of the parts and the temperatures of the layers as they are brought into engagement are such that as the second layer cools and increases in strength and the first layer is heated by thermal transfer from the second layer and decreases in strength, a region of least overall yield strength is formed at a position where the temperature of at least one of the parts (being made of a crystallizable polymeric material) is at a temperature between its glass transition temperature and its crystalline melting point.

Abstract: An electrical insulator component comprises a one-piece block of moulded fins (11, 12, 13) disposed around an insulating core (10). The surface of the block of fins includes a moulding line (21, 22, 23) and said moulding line has arcuately displaced segments in that the portion 22 extends circumferentially while the portions 21 and 23 extend longitudinally but in different planes. The net result is that dirt building up along the join line does not form a continuous straight-line low resistance path for leakage currents.

Abstract: A method for fabricating a plastic electrical insulator having a fiberglass-reinforced plastic core rod and a plurality of insulator discs disposed thereon. The insulator discs are formed of a plastic molding compound which is especially suited for outdoor use. In accordance with the invention, the insulator rod is disposed in, and passes through, a mold which, when closed, is filled with the plastic molding compound for forming the insulator discs. The separation plane of the mold is situated near the outermost edge of each disc. Subsequent insulator discs are individually formed so as to partially overlap a previously molded insulator disc.

Abstract: Plastic insulators with protective screens for indoor and outdoor use, especially support and suspension insulators are manufactured by injection molding or transfer molding, using granulated or paste-like molding compounds (rigid or flexible adjustment) on the basis of unsaturated polyester or epoxy resins, heterocyclic polyurethane resins, polypropylene (PP), ethylene-propylene monomer rubber (EPM), ethylene-propylene-diene monomer rubber (EPDM), synthetic rubber, silicone rubber and others. The fabrication can be carried out through one-part or multiple-part injection.

Abstract: A new insulation system, useful for the fabrication of high voltage transformers, capacitors and power supply encapsulation and insulation for high voltage leads, has been developed which substantially eliminates corona and improves reliability of these devices.

Abstract: Method of cementing together the cap, body and stem portions of electrical insulators, comprising introducing measured quantities of water and cement into the cavities of the cap and body, mixing the ingredients within the cavities and immediately assembling the aforesaid portions into a complete article. The method is particularly useful in production line procedures of producing insulators.