Granted Patent
Utility
US 5,154,233 · App. 07/621,837
Well protection apparatus and method
Inventor:
Godfred L. Gebhardt
Patented Case
View Patent ↗
Granted: Oct 13, 1992
Filed: Dec 4, 1990
Inventor
Godfred L. Gebhardt
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.