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SELECT DISTINCT patent.*, YEAR(date) as year FROM patent LEFT JOIN category ON category.patent = patent.patent AND category.type = patent.type WHERE (category.class = '501') AND (category.subclass = '144') ORDER BY date ASC, patent, type

Total of 6 patents found where: Class is '501'; Subclass is '144';

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T / S Patent Date Description Patentee Category Assigned To
 1922
U 1,409,953 March 21, 1922 Ceramic Insulating Material
Porcelain composition using Sillimanite for high electrical and mechanical strength and low coefficient of expansion, which is particularly suitable for spark plugs		 JEFFERY, Joseph A.
 Porcelain Jeffery-Dewitt Co.
 1927
U 1,633,462 June 21, 1927 Ceramic Insulating Material
Clay mixture to produce a black porcelain body.		 SORTWELL, Harold H.
 Porcelain Star Porcelain Co.
 1939
U Specimen known 2,157,100 May 9, 1939 Glazed Ceramic Insulator and the Like
Glaze - compression glaze		 ROWLAND, Davidge H.
 Glaze Locke Insulator Corp.
 1948
U 2,437,559 March 9, 1948 Insulator and Method of Manufacturing Same
Addition of powdered aluminum to improve quality of porcelain		 ROWLAND, Davidge H.
 Manufacturing The Porcelain Insulator Corp.
 1963
U Specimen known 3,097,101 July 9, 1963 Ceramic Product and Method of Making the Same
Increases the mechanical and electrical strength of porcelain insulators by controlling the grain size of the flint used in the porcelain body and the glaze.		 LESTER, Ronald H.
 Porcelain General Electric Co.
 1982
U 4,332,913 June 1, 1982 Flux Combination of Barium Oxide and Potassium Feldspar for High Strength Alumina Porcelain Electric Insulators
Porcelain composition with low shrinkage during firing		 BOCK, Peter
 Porcelain Rosenthal Technik AG

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