Granted Patent
Utility
US 3,992,291 · App. 05/624,611
Method of filtering oil from liquids
Inventor:
Gene Hirs
Patented Case
View Patent ↗
Granted: Nov 16, 1976
Filed: Oct 22, 1975
Inventor
Gene Hirs
Assignee (at issue)
Hydromation Filter 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.