Granted Patent
Utility
US 4,568,528 · App. 06/641,280
Process to produce a krypton-xenon concentrate and a gaseous oxygen product
Inventor:
Harry Cheung
Patented Case
View Patent ↗
Granted: Feb 4, 1986
Filed: Aug 16, 1984
Inventor
Harry Cheung
Assignee (at issue)
Union Carbide Corporation
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.