Granted Patent
Utility
US 6,729,392 · App. 10/071,650
Tubing hanger with ball valve in the annulus bore
Inventors:
Blake T. DeBerry, Larry E. Reimert
Patented Case
View Patent ↗
Granted: May 4, 2004
Filed: Feb 8, 2002
Inventors
Blake T. DeBerry
Larry E. Reimert
Assignee (at issue)
Dril-Quip, 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.