Granted Patent
Utility
US 6,698,513 · App. 10/136,992
Apparatus for use in cementing an inner pipe within an outer pipe within a wellbore
Inventor:
John N. Yokley
Patented Case
View Patent ↗
Granted: Mar 2, 2004
Filed: May 2, 2002
Inventor
John N. Yokley
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.