Granted Patent
Utility
US 4,400,976 · App. 06/165,253
Ultrasonic transceiver circuit for level sensing
Inventor:
Frederick K. Blades
Patented Case
View Patent ↗
Granted: Aug 30, 1983
Filed: Jul 2, 1980
Inventor
Frederick K. Blades
Assignee (at issue)
PureCycle 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.