Granted Patent
Utility
US 6,220,363 · App. 09/356,231
Wellhead isolation tool and method of using same
Inventor:
L. Murray Dallas
Patented Case
View Patent ↗
Granted: Apr 24, 2001
Filed: Jul 16, 1999
Inventor
L. Murray Dallas
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.