Granted Patent
Utility
US 5,082,473 · App. 07/557,132
Extraction and concentration of a gas component
Inventor:
Bowie G. Keefer
Patented Case
View Patent ↗
Granted: Jan 21, 1992
Filed: Jul 23, 1990
Inventor
Bowie G. Keefer
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.