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US 5,563,379 AGranted
Composite electrical insulator
AssigneeNGK Insulators, Ltd.
InventorsShigehiko Kunieda, Takeshi Shogo
Life of this patent
Estimating the term…
Abstract
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).
Claims6
A composite electrical insulator comprising:
- a rod comprising an electrically insulating plastic material, said rod having an end portion;
- a sheath covering at least a portion of said rod and having an end portion proximate said end portion of said rod, said sheath comprising a resilient and electrically insulating material;
- and
- a metal fitting having a sleeve portion formed with a bore in which said end portion of said rod and said end portion of said sheath are received, said sleeve portion having a radially inwardly deformed region for tightly clamping at least said end portion of said rod;
- said end portion of said sheath having an outer substantially cylindrical surface opposed and substantially parallel to an inner substantially cylindrical surface of said metal fitting, with at least one circumferential ridge formed on said outer surface of said sheath, wherein said at least one circumferential ridge is the only portion of said outer surface of said sheath that contacts said inner surface of said metal fitting.
2 more elements
Dependencies are inferred from the claim text.