Granted Patent
Utility
US 4,909,072 · App. 07/222,864
Measurement and control of exhaust gas recirculation with an oxygen pumping device
Inventors:
Eleftherios M. Logothetis, Richard E. Soltis
Patented Case
View Patent ↗
Granted: Mar 20, 1990
Filed: Jul 22, 1988
Inventors
Eleftherios M. Logothetis
Richard E. Soltis
Assignee (at issue)
Ford Motor Company
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.