Granted Patent
Utility
US 4,254,829 · App. 06/078,112
Well locking device
Inventor:
Fred E. Watkins
Patented Case
View Patent ↗
Granted: Mar 10, 1981
Filed: Sep 24, 1979
Inventor
Fred E. Watkins
Assignee (at issue)
Camco 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.