Granted Patent
Utility
US 5,249,425 · App. 07/906,401
Venting control system for cryostats
Inventor:
Ralph C. Longsworth
Patented Case
View Patent ↗
Granted: Oct 5, 1993
Filed: Jul 1, 1992
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.