Granted Patent
Utility
US 4,180,984 · App. 05/866,148
Cryogenic apparatus having means to coordinate displacer motion with fluid control means regardless of the direction of rotation of the drive shaft
Inventor:
Fred F. Chellis
Patented Case
View Patent ↗
Granted: Jan 1, 1980
Filed: Dec 30, 1977
Inventor
Fred F. Chellis
Assignee (at issue)
Helix Technology 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.