Granted Patent
Utility
US 4,253,522 · App. 06/041,001
Gravel pack tool
Inventor:
John R. Setterberg, Jr.
Patented Case
View Patent ↗
Granted: Mar 3, 1981
Filed: May 21, 1979
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.