Granted Patent
Utility
US 4,252,299 · App. 06/001,819
Method and apparatus for discharging material from a shaft furnace
Inventor:
Alphonse T. Lobue
Patented Case
View Patent ↗
Granted: Feb 24, 1981
Filed: Jan 8, 1979
Inventor
Alphonse T. Lobue
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.