Granted Patent
Utility
US 4,765,327 · App. 06/944,393
Cartridge humidifier vent valve
Inventor:
Norman Shim
Patented Case
View Patent ↗
Granted: Aug 23, 1988
Filed: Dec 19, 1986
Inventor
Norman Shim
Assignee (at issue)
Respiratory Care, 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.