Granted Patent
Utility
US 4,399,080 · App. 06/301,828
Humidifier apparatus
Inventor:
Robert P. Swank
Patented Case
View Patent ↗
Granted: Aug 16, 1983
Filed: Sep 14, 1981
Inventor
Robert P. Swank
Assignee (at issue)
Champion Spark Plug 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.