Granted Patent
Utility
US 5,337,572 · App. 08/057,708
Cryogenic refrigerator with single stage compressor
Inventor:
Ralph C. Longsworth
Patented Case
View Patent ↗
Granted: Aug 16, 1994
Filed: May 4, 1993
Inventor
Ralph C. Longsworth
Assignee (at issue)
APD Cryogenics, Inc.
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.