Granted Patent
Utility
US 4,968,329 · App. 07/252,984
Pressure swing adsorption for concentration of a gas component
Inventor:
Bowie G. Keefer
Patented Case
View Patent ↗
Granted: Nov 6, 1990
Filed: Oct 1, 1988
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.