Granted Patent
Utility
US 4,291,575 · App. 06/052,367
Liquid level monitor
Inventor:
Anthony Frissora
Patented Case
View Patent ↗
Granted: Sep 29, 1981
Filed: Jun 27, 1979
Inventor
Anthony Frissora
Assignee (at issue)
Allied Chemical Corporation
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.