Granted Patent
Utility
US 5,161,380 · App. 07/743,734
Cryogenic rectification system for enhanced argon production
Inventor:
Harry Cheung
Patented Case
View Patent ↗
Granted: Nov 10, 1992
Filed: Aug 12, 1991
Inventor
Harry Cheung
Assignee (at issue)
Union Carbide Industrial Gases Technology 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.