Granted Patent
Utility
US 4,730,851 · App. 06/882,873
Downhole expandable casting hanger
Inventor:
Gerald D. Watts
Patented Case
View Patent ↗
Granted: Mar 15, 1988
Filed: Jul 7, 1986
Inventor
Gerald D. Watts
Assignee (at issue)
Cooper Industries Holdings
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.