Granted Patent
Utility
US 4,455,040 · App. 06/289,285
High-pressure wellhead seal
Inventor:
Terry L. Shinn
Patented Case
View Patent ↗
Granted: Jun 19, 1984
Filed: Aug 3, 1981
Inventor
Terry L. Shinn
Assignee (at issue)
SMITH INTERNATIONAL, 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.