Granted Patent
Utility
US 4,411,697 · App. 06/388,428
Metal refining processes
Inventors:
Gene D. Spenceley, Brian C. Welbourn
Patented Case
View Patent ↗
Granted: Oct 25, 1983
Filed: Jun 14, 1982
Inventors
Gene D. Spenceley
Brian C. Welbourn
Assignee (at issue)
British 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.