Granted Patent
Utility
US 6,014,933 · App. 08/942,631
Downhole charge carrier
Inventors:
Donald V. Umphries, Harold D. Owen, Bobby R. Ford, David S. Wesson
Patented Case
View Patent ↗
Granted: Jan 18, 2000
Filed: Oct 2, 1997
Inventors
Donald V. Umphries
Harold D. Owen
Bobby R. Ford
David S. Wesson
Assignees (at issue)
Weatherford US Holding, L.P. a Louisiana Limited Partnership
Owen Oil Tools LP
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.