Granted Patent
Utility
US 4,217,201 · App. 05/954,015
Integrated coal cleaning, liquefaction, and gasification process
Inventor:
Michael C. Chervenak
Patented Case
View Patent ↗
Granted: Aug 12, 1980
Filed: Oct 23, 1978
Inventor
Michael C. Chervenak
Assignee (at issue)
Hydrocarbon Research, 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.