Granted Patent
Utility
US 6,681,852 · App. 09/774,287
Tubing hanger shuttle valve
Inventors:
David Baskett, Bhailal Parmar
Patented Case
View Patent ↗
Granted: Jan 27, 2004
Filed: Jan 29, 2001
Inventors
David Baskett
Bhailal Parmar
Assignee (at issue)
Kvaerner Oilfield Products A.S.
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.