Granted Patent
Utility
US 4,268,283 · App. 06/108,763
Fluid control means for geothermal wells
Inventor:
Allen Roberts
Patented Case
View Patent ↗
Granted: May 19, 1981
Filed: Dec 31, 1979
Inventor
Allen Roberts
Assignee (at issue)
W-K-M Wellhead Systems, 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.