Granted Patent
Utility
US 4,715,785 · App. 06/840,315
Oil detection apparatus for submersible pumps
Inventor:
Richard R. Gurega
Patented Case
View Patent ↗
Granted: Dec 29, 1987
Filed: Mar 14, 1986
Inventor
Richard R. Gurega
Assignee (at issue)
Richal Corporation
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.