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SELECT DISTINCT patent.*, YEAR(date) as year FROM patent WHERE (assigned_to = 'Jeffery-Dewitt Co.') ORDER BY date ASC, patent, type

Total of 6 patents found where: Assigned To is 'Jeffery-Dewitt Co.';

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T / S Patent Date Description Patentee Category Assigned To
 1920
U Specimen known 1,329,770 February 3, 1920 Insulator
Suspension type for J-D		 JOHNSTON, Robert M.
 Suspension Jeffery-Dewitt Co.
 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.
 1923
U 1,451,815 April 17, 1923 Rapid Decorating Firing Furnace or Kiln
Kiln for firing porcelain spark plug insulators		 DAVENPORT, Ransom W.
 Manufacturing Jeffery-Dewitt Co.
U 1,468,947 September 25, 1923 Furnace for Decorating Ceramic Ware
Kiln for firing porcelain spark plug insulators		 JEFFERY, Joseph A.
 Manufacturing Jeffery-Dewitt Co.
 1924
U 1,512,299 October 21, 1924 Temporary Binder for Ceramic Bodies
Use of wheat flour to act as an organic binder to aid in holding the shape of a ceramic material before it is fired		 NAGLE, Josehp A.
 Manufacturing Jeffery-Dewitt Co.
 1929
U Specimen known 1,716,963 June 11, 1929 Insulator
Suspension coupling device (see 1,329,770)		 JOHNSTON, Robert M.
 Suspension Jeffery-Dewitt Co.

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