Abstract: A high voltage DC bushing including a fluid duct with non-constant width (?r) along the axial direction of the bushing.

Abstract: An electrical insulator comprises an elongate shank and one or more sheds disposed along the length of the shank. The surface of the insulator comprises longitudinally extending flutes, the depth of which are varied along the length of the insulator such that the circumferential distance of all transverse sections along the length of the insulator is substantially constant or controlled. Instead of flutes, the surface may be formed with an array of protuberances and/or concavities. The insulator thus provides a defined perimeter and surface area along its length, such that areas of the surface are not preferentially heated by surface currents to form dry bands and thereby cause arcing. Such topography also renders the insulator less susceptible to the degrading effects of surface pollution.

Abstract: An assembly is provided having a core and a housing. The housing has an internal passageway extending from a first housing end to a second housing end for receiving the core. A coating of an uncured moisture activated material is disposed between the housing and the core. The coating cures upon reacting with moisture penetrating the housing to reseal the housing at a point of moisture penetration. The material cross-links in the presence of the moisture, thereby bonding with the moisture to prevent the moisture from contacting the core. The cured material is a rubber-like substance that adheres to the housing and to the core, thereby resealing the housing at the point of moisture penetration.

Abstract: A weathershed for use in a composite insulator includes a molded polymer body. The body configuration is such that the leakage distance across the weathershed is increased, while at the same time the amount of material needed is reduced. This provides a lightweight and easily manufactured weathershed. The weathershed includes a radially curved outer edge which reduces the electric field gradient and also reduces the tendency to trap contaminants.

Abstract: Polymer Insulator which is characterized by a rode having on its outer surface an umbrella-like housing or insulator layer and having end portions which are formed so as to freely expand with at least one splitting groove; a fixture having a mounting hole in which the end portion of the rod is inserted and which has an inner surface tapering inwards against which the outer surface of said rod abuts in its expanded state; and a wedge fixed in said mounting hole, the wedge being inserted into a splitting groove formed in the end portion of the rod when the end portion of said rod is mounted into said mounting hole of said fixture, the top end of the wedge having an engaging portion which is held in the splitting groove thereby to cause the whole wedge to engage in the splitting grove.

Abstract: A reinforced electrical insulator has a load sustaining mechanical core with a pair of attachment members located at its longitudinal ends. One of the attachment members extends longitudinally into the mechanical core to provide reinforcement to the mechanical core. The mechanical core member is constructed of a rigid, dielectric material with a first end section, a second end section, and a center section. A plurality of weathersheds extending outwardly from the center section of core member in a substantially radial direction relative to the longitudinal axis. The first and second end sections having maximum widths which are larger than the maximum width of the center section. The attachment members have inner portions embedded within the end sections of the core and outer portions extending outwardly from the end sections of the core.

Abstract: An electrical insulator in the form of a pintype insulator has a load sustaining mechanical core and a dielectric sheath overlying the mechanical core to protect the mechanical core from the weather. The mechanical core is constructed of a load sustaining dielectric material which is different from the dielectric material of the sheath. The mechanical core has a profiled outer surface with a top groove, two side grooves, an annular rib and an axially extending threaded bore. The dielectric sheath is applied over the mechanical core as thin as practical to minimize the amount of sheath material being used. However, the dielectrical sheath is molded on the mechanical core to form a pair of weathersheds which can either extend radially outwardly therefrom or substantially downwardly therefrom in the form of vertical sheds.

Abstract: A composite insulator with a silicone rubber sheath coating the insulator rod between metal fittings. Adjacent the line fitting, at least, a series of weathersheds are mounted on the rod and fastened to the sheath with their hubs in abutting relationship and with one hub abutting the line fitting. Another series of sheds are spaced from each other and from the series of weathersheds having their hubs in abutting relationship.

Abstract: Rigid electrical insulator including a soda-lime glass dielectric with an average thickness of 10 to 15 mm, exhibiting a substantially parabolic stress curve, wherein the maximum value of the surface compression stresses at any point in the part falls within the range of 30 to 80 MPa, while the maximum value of the internal tensile stresses at any point in the part falls within the range of 15 to 40 MPa.

Abstract: An underground electrical conduit hexagonal in cross-section and having internal partition walls subdividing the conduit into a plurality of longitudinal ducts. The internal partition walls are symmetrically disposed about a central longitudinal axis of the conduit and serve as bracing structure to strengthen and support the outer walls of the conduit.

Abstract: A method is disclosed for upgrading insulators of a current distribution system when the voltage of the system is to be increased. New, additional insulators are coupled with the existing ones, and the coupling is accomplished without detachment of the current conductor from the existing insulator. The mounting stud for the existing insulator is unsecured from a support member, such as a crossarm, is detached from the existing insulator, and is thereafter attached to a new, additional insulator. The two insulators are then coupled together to provide increased electrical insulation, and the mounting stud is resecured to the supporting member. Time and materials are saved by not having to detach and reattach the conductor, and by reusing the existing insulator, the conductor attachment means, and the mounting stud.