Insulators having improved steep wave front characteristics
AssigneeNGK Insulators, Ltd.
InventorsShoji Seike, Takao Totoki, Toshiyuki Mima
Life of this patent
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Abstract
A high voltage porcelain insulator having a glaze applied to at least a head portion of the insulator which head portion is covered by a metal fitting and a cement. The glaze essentially consists of, in terms of weight, from 64.0 to 68.0% of SiO.sub.2, from 17.5 to 19.0% of Al.sub.2 O.sub.3, from 5.0 to 6.5% of MgO, not more than 3.0% of CaO, from 2.0 to 2.8% of K.sub.2 O and Na.sub.2 O in a total amount, and from 3.0 to 9.0%, when calculated as MnO, a compound which is converted to MnO and or MnO.sub.2 after being fired at a temperature range suitable for firing porcelain.
Claims8
A high voltage porcelain insulator having a glaze applied to at least a head portion of the porcelain insulator which head portion is covered with a metal fitting and cement, said glaze comprising, in terms of weight, from 64.0 to 68.0% of SiO.sub.2, from 17.5 to 19.0% of Al.sub.2 O.sub.3, from 5.0 to 6.5% of MgO, not more than 3.0% of CaO, from 2.0 to 2.8% of K.sub.2 O+Na.sub.2 O in a total amount, and from 3.0 to 9.0%, when calculated as MnO, of a compound which is converted to MnO or MnO.sub.2 after being fired at a temperature range suitable for firing porcelain.
A high voltage porcelain insulator having a glaze applied only to a head portion of the porcelain insulator which head portion is covered with a metal fitting and cement, said glaze comprising, in terms of weight, from 64.0 to 68.0% of SiO.sub.2, from 17.5 to 19.0% of Al.sub.2 O.sub.3, from 5.0 to 6.5% of MgO, not more than 3.0% of CaO, from 2.0 to 2.8% of K.sub.2 O+Na.sub.2 O in a total amount, and from 3.0 to 9.0%, when calculated as MnO, of a compound which is converted to MnO or MnO.sub.2 after being fired at a temperature range suitable for firing porcelain.
Dependencies are inferred from the claim text.