Granted Patent
Utility
US 4,199,938 · App. 05/863,579
Method of operating a three-way catalyst for internal combustion engines
Inventors:
Takamichi Nakase, Tadashi Hattori, Junichiro Naito, Kenji Kondo
Patented Case
View Patent ↗
Granted: Apr 29, 1980
Filed: Dec 22, 1977
Inventors
Takamichi Nakase
Tadashi Hattori
Junichiro Naito
Kenji Kondo
Assignee (at issue)
NIPPON SOKEN, INC.
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.