Granted Patent
Utility
US 5,960,876 · App. 09/012,289
Wellhead equipment that use polymer sealing elements to seal off well pressure
Inventor:
Jim Wiedemann
Patented Case
View Patent ↗
Granted: Oct 5, 1999
Filed: Jan 23, 1998
Inventor
Jim Wiedemann
Assignee (at issue)
Vanoil Equipment 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.