Granted Patent
Utility
US 4,954,463 · App. 07/283,230
Magnesium aluminate spinel refractory
Inventor:
Richard J. Knauss
Patented Case
View Patent ↗
Granted: Sep 4, 1990
Filed: Dec 12, 1988
Inventor
Richard J. Knauss
Assignee (at issue)
Dresser Industries, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.