Granted Patent
Utility
US 5,652,201 · App. 08/500,560
Lubricating oil compositions and concentrates and the use thereof
Inventors:
Andrew G. Papay, Rolfe J. Hartley
Patented Case
View Patent ↗
Granted: Jul 29, 1997
Filed: Jul 11, 1995
Inventors
Andrew G. Papay
Rolfe J. Hartley
Assignee (at issue)
Ethyl Petroleum Additives, 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.