Ngk Insulators, Inc.

Takeshi Shogo

Shigehiko Kunieda

Shuji Fujii

Tsutomu Moriya

The disclosed polymer LP insulator having an FRP rod, an insulation overcoat member made of rubber, which is arranged on an outer surface of the FRP rod, and securing metal members clamped at both end portions of the FRP rod, wherein an end portion of the insulation overcoat member is inserted into an end portion of the securing metal member, includes an elastic member arranged in a space defined by the FRP rod, an inner surface of the securing metal member, and an end surface of the insulation overcoat member, wherein a pressure for clamping and fixing is only applied to a connection portion between the securing member and the FRP rod. The disclosed polymer LP insulator is produced for example by arranging the securing metal member at both ends of the FRP rod; clamping and fixing the securing metal member to the FRP rod by applying a pressure only to a connection portion between the securing metal member and the FRP rod; and forming the insulation overcoat member made of rubber on an outer surface of the FRP rod, and an elastic member in a space defined by the FRP rod, an inner surface of the securing metal member, and an end surface of the insulation overcoat member simultaneously.

Method of producing a polymer LP insulator

A securing method including the steps of inserting a core into a depression portion of a metal member having an open end portion, and connecting the metal member to the core by compressing circumferentially the core and metal member by means of a compression die is disclosed. The improvement includes a step of compressing circumferentially the core and metal member in such a manner that an overall compression portion to be compressed by means of the compression die is divided into a plurality of compression regions arranged from the open end portion of the metal member to the other end portion, and a compression pressure is applied to the compression regions successively from the open end portion to the other end portion

Securing method

A composite electrical insulator (1) includes a plastic rod (2), e.g., an FRP rod, which is covered by a sheath which includes a resilient and electrically insulating material. A metal fitting (4, 5) on each side of the insulator (1) has a radially inwardly deformable sleeve portion formed with a bore in which the end portion of the plastic rod (2) is covered by the sheath (3). The end portion of the sheath (3) has an outer surface opposite to the metal fitting (4, 5), which is provided with at least one circumferential ridge (7a, 7b).

Composite electrical insulator

A metal fitting for a composite electrical insulator (1) including a plastic rod (2), e.g., an FRP rod. The metal fitting (4) includes a radially inwardly deformable sleeve portion having a bore (5) into which an end portion of the rod (1) can be inserted for fixedly securing the metal fitting (4) to the rod (1). The bore (5) in the metal fitting (4) has an inner surface which is formed with fine protrusions (7). These protrusions (7) provide a satisfactory resistivity to the tensile force applied to the insulator (1), to thereby effectively prevent withdrawal of the rod (2) from the metal fitting (4) when it is in use.

Growing community of inventors

Kani, Japan

Takeshi Shogo