Granted Patent
Utility
US 5,214,922 · App. 07/782,181
Multi-expander cryogenic cooler
Inventor:
John J. Dopazo
Patented Case
View Patent ↗
Granted: Jun 1, 1993
Filed: Oct 24, 1991
Inventor
John J. Dopazo
Assignee (at issue)
Hughes Aircraft 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.