Abstract: A sandwich type insulation for electrical machinery comprising a laminate of a polymeric material such as polyimide which contains particles of an inorganic corona resistant material, said polymeric material being bonded to mica paper consisting of mica, wherein said mica paper may be impregnated with polymeric resin containing particles of inorganic corona resistant material. The resultant insulation may be used as a tape or wrapper.

Abstract: This invention relates to a process for producing an insulation system (1) for an electrically conductive component (10). Use is made of an insulating material (5) which is protected against damage by the partial discharge of electric fields. To produce the insulating material (5), a substrate material (2) having an insulating coating (3) on one or both of its surfaces is impregnated with a chemical compound (4). This is hardened by radiation polymerisation and/or the application of heat to secure the insulating material (5) and bond the insulation system (1) permanently to the component (10).

Abstract: The present invention relates to a method of thermally and mechanically protecting cables and bundles of cables by use of a sheath braided directly around the element to be protected using a braiding yarn constituted by a plurality of elementary strands formed by interlacing synthetic fibers obtained after cracking and spinning an aramid fiber and a carbonizable oxidized organic fiber. The carbonizable oxidized organic fiber constitutes the major portion of the synthetic fibers making up the elementary strand for the braiding yarn. The invention also provides a thermal and mechanical protective sheath for cables and bundles of cables obtained by the method. In order to improve certain mechanical or thermal characteristics of the sheath, it may be associated with a material made of a fiber additional to said two synthetic fibers, in order to form the elementary strand, or indeed the sheath braided in this way may itself be covered in additional braiding based on aramid fibers.

Abstract: An improved electrical insulation tape is formed from a sheet of fiberglass cloth having a layer of thermoplastic resin bonded thereto. The thermoplastic resin layer is applied to the fiberglass sheet by melting the resin while contacting the fiberglass, and then the composite is cooled to bond the two components together. The composite sheet is then slit into tapes with substantially no unraveling of the fiberglass component at the slit edges of the tapes. The resultant tapes are easily wrapped on, and adhered to, conductors, such as magnet wire, or the like, by remelting and resolidifying the thermoplastic layer. The tape possesses excellent dielectric properties and heat dissipation properties. Alternatively, the fiberglass sheet may be impregnated with the melted thermoplastic component whereby a composite, rather than a relatively definitive two layer laminate, is formed.

Abstract: An improved insulated thermocouple having no asbestos insulation material. The improved thermocouple and a method for making it are described whereby individual conductors are wrapped with high temperature fiberglass insulation and are then coated with a fiberglass binder that may be a modified silicone liquid. The individual conductors are then assembled in a parallel configuration and an outer jacket of high temperature fiberglass is applied by a braiding process. The entire assembly having the exposed outer jacket is coated with a fiberglass binder that may be a polyurethane liquid, and then cured.

Abstract: The purpose of the invention is to manufacture varnish-bonded thread-covered circular-section and profile-section wires and braided conductors in a manner which is particularly cheap and which involves particularly little risk of contaminating the environment.Suitable thread-covered wires and braided conductors are obtained by impregnation, in one operation, with partially crystalline or amorphous thermoplastic polycondensates.

Abstract: An electrically insulating, overcoated bulky sleeve is disclosed comprising a tubular sleeve prepared from bulky (i.e. low density, high surface area) continuous filament yarns and an overcoating. When an electrical conductor is positioned therewithin, the large surface area of the bulky yarns of the interior of the sleeve provides an intimate fit for an expanded range of conductor diameters. For applications where a void-free impregnation of the sleeve interior between the overcoating and the conductor is desired, the large interior surface area of these sleeves can promote retention of the impregnation composition. The overcoated sleeve can be expandable, deforming to allow pull-back and return or fold-over, and/or conforming to accept transitions in conductor diameter. The overcoated bulky sleeve can be employed in a method for electrically insulating a conductor, which method may further include an interstitial impregnation step.

Abstract: Electric windings comprising an electric conductor and a plurality of cured insulating layers wrapping around the conductor, said cured insulating layers being obtained by bonding two or more insulating materials with a binder solution containing a mixture of a condensation polymerization type silicone resin containing hydroxyl groups in the molecule and an addition polymerization type silicone resin to form a composite insulating material, wrapping the composite insulating material around the conductor, impregnating the wrapped composite insulating material with an impregnating varnish of an epoxy-isocyanate resin and curing the impregnated composite insulating material, have excellent water resistance in addition to excellent thermal resistance, and mechanical properties.

Abstract: In the production of electric cable in an extruder head having undulated tension relief elements embedded in the jacket, the jacketing material and tension relief elements are introduced at a velocity greater than the cable core, with such velocity being subsequently decreased to provide a compressive force which forms the undulations.

Abstract: An insulated cable core is sheathed in polyolefin. The polyolefin for instance sheath of polyolefin for instance contains parallel non impregnated glass fibers which are undulated to improve mechanical bonding with the sheath.