Granted Patent
Utility
US 4,928,769 · App. 07/286,603
Casing hanger running tool using string weight
Inventors:
Lionel J. Milberger, Philippe C. Nobileau, Bruce J. Watkins
Patented Case
View Patent ↗
Granted: May 29, 1990
Filed: Dec 16, 1988
Inventors
Lionel J. Milberger
Philippe C. Nobileau
Bruce J. Watkins
Assignee (at issue)
Vetco Gray, LLC
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.