Granted Patent
Utility
US 4,342,911 · App. 06/107,782
Focused nuclear interface survey instrument and method of determining density changes in mining and storage wells
Inventor:
Lewis L. French
Patented Case
View Patent ↗
Granted: Aug 3, 1982
Filed: Dec 28, 1979
Inventor
Lewis L. French
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.