Granted Patent
Utility
US 4,416,690 · App. 06/268,765
Solid matte-oxygen converting process
Inventors:
Kenneth Richards, David B. George
Patented Case
View Patent ↗
Granted: Nov 22, 1983
Filed: Jun 1, 1981
Inventors
Kenneth Richards
David B. George
Assignee (at issue)
Kennecott Holdings Company
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.