Granted Patent
Utility
US 6,759,968 · App. 10/032,114
Method and apparatus for determining position in a pipe
Inventor:
Joseph A. Zierolf
Patented Case
View Patent ↗
Granted: Jul 6, 2004
Filed: Dec 21, 2001
Inventor
Joseph A. Zierolf
Assignee (at issue)
Marathon 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.