Granted Patent
Utility
US 5,142,909 · App. 07/085,377
Material level indicator
Inventor:
James S. Baughman
Patented Case
View Patent ↗
Granted: Sep 1, 1992
Filed: Aug 14, 1987
Inventor
James S. Baughman
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.