Granted Patent
Utility
US 6,823,937 · App. 09/502,350
Wellhead
Inventors:
Robert Lance Cook, David Paul Brisco, R. Bruce Stewart, Lev Ring, Richard Carl Haut, Robert Donald Mack
Patented Case
View Patent ↗
Granted: Nov 30, 2004
Filed: Feb 10, 2000
Inventors
Robert Lance Cook
David Paul Brisco
R. Bruce Stewart
Lev Ring
Richard Carl Haut
Robert Donald Mack
Assignee (at issue)
SHELL OIL COMPANY
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.