Granted Patent
Utility
US 5,642,872 · App. 08/598,812
Low profile and lightweight high pressure blowout preventer
Inventor:
Charles D. Morrill
Patented Case
View Patent ↗
Granted: Jul 1, 1997
Filed: Feb 9, 1996
Inventor
Charles D. Morrill
Assignee (at issue)
Hydril Company
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.