Granted Patent
Utility
US 4,288,082 · App. 06/145,328
Well sealing system
Inventor:
John R. Setterberg, Jr.
Patented Case
View Patent ↗
Granted: Sep 8, 1981
Filed: Apr 30, 1980
Inventor
John R. Setterberg, Jr.
Assignee (at issue)
Otis Engineering 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.