Granted Patent
Utility
US 4,699,707 · App. 06/779,939
Process for producing lubrication oil of high viscosity index from shale oils
Inventors:
Eric L. Moorehead, Sidney Y. Shen
Patented Case
View Patent ↗
Granted: Oct 13, 1987
Filed: Sep 25, 1985
Inventors
Eric L. Moorehead
Sidney Y. Shen
Assignee (at issue)
Union Oil Company of California
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.