Ngk Insulators, Inc.

Tsutomu Moriya

Shuji Fujii

Hiroshi Nozaki

Takeshi Shogo

Yasunori Matsuura

Takao Nakamura

Hiroyuki Shinokubo

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 hollow porcelain insulator including an elastic insulating layer having a tensile strength of at least 150 kg/cm.sup.2 and a thickness of at least 2 mm for improving an explosion preventing property.

Explosion preventing porcelain hollow insulator

A suspension insulator having a porcelain insulating member with a head portion and a shed, a metal cap cemented to the top of the head portion, and a metal pin cemented to the lower end of the head portion at a pin hole formed in the head portion. The pin hole has a closed top and a downward opening, and its inside surface includes a cylindrical surface portion around the opening, a curved top surface and a round corner surface forming a smooth boundary between the cylindrical surface portion and the curved top surface. The cemented part of the inside surface of the hole has sands rigidly deposited thereon over a range from its lower end to a level within .+-.3 mm of the junction between the cylindrical surface portion and the round corner surface. The cylindrical surface portion has a radius equal to D and the round corner surface has a radius of curvature equal to Y, such that a ratio of Y/D is in the range of 0.3-0.45.

Suspension insulator

A suspension insulator includes a compressive strain of more than 60.times.10.sup.-6 in the ceramic insulator body at least in the circumferential direction in the vicinity of the shed root of the ceramic head portion of the suspension insulator, whereby a suspension insulator causes no accidents such as separation of cap and pin of suspension insulator, line drop of power transmission lines and the like, even when shot by a rifle.

Growing community of inventors

Chita, Japan

Tsutomu Moriya