Granted Patent
Utility
US 4,252,187 · App. 06/036,660
Bearing-equipped well tool
Inventor:
Michael L. Wilson
Patented Case
View Patent ↗
Granted: Feb 24, 1981
Filed: May 7, 1979
Inventor
Michael L. Wilson
Assignee (at issue)
Armco 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.