Granted Patent
Utility
US 4,909,922 · App. 07/359,269
Heater-built-in oxygen sensor
Inventors:
Nobuhide Kato, Yasuhiko Hamada
Patented Case
View Patent ↗
Granted: Mar 20, 1990
Filed: May 31, 1989
Inventors
Nobuhide Kato
Yasuhiko Hamada
Assignee (at issue)
NGK INSULATORS, LTD.
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.