Granted Patent
Utility
US 4,848,214 · App. 07/192,704
Supply and return air plenum unit for duct air-conditioning systems
Inventors:
Teruyuki Nagao, Shigeo Tanaka
Patented Case
View Patent ↗
Granted: Jul 18, 1989
Filed: May 10, 1988
Inventors
Teruyuki Nagao
Shigeo Tanaka
Assignee (at issue)
Diesel Kiki Co., 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.