Granted Patent
Utility
US 4,711,301 · App. 06/773,410
Valve assembly for inflatable packer
Inventor:
William D. Stringfellow
Patented Case
View Patent ↗
Granted: Dec 8, 1987
Filed: Sep 5, 1985
Inventor
William D. Stringfellow
Assignee (at issue)
Weatherford Holding U.S., 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.