Granted Patent
Utility
US 4,338,183 · App. 06/196,428
Method of solvent extraction of coal by a heavy oil
Inventor:
John G. Gatsis
Patented Case
View Patent ↗
Granted: Jul 6, 1982
Filed: Oct 14, 1980
Inventor
John G. Gatsis
Assignee (at issue)
UOP LLC
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.