Granted Patent
Utility
US 4,316,603 · App. 06/187,293
Stockline armor construction for blast furnaces
Inventor:
Howard W. Steffen
Patented Case
View Patent ↗
Granted: Feb 23, 1982
Filed: Sep 15, 1980
Inventor
Howard W. Steffen
Assignee (at issue)
United States Steel Corporation
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.