Granted Patent
Utility
US 4,461,448 · App. 06/277,341
Well blowout preventer, and packing element
Inventors:
Wai J. Huey, Fernando Murman, Eugene Matsuda
Patented Case
View Patent ↗
Granted: Jul 24, 1984
Filed: Jun 25, 1981
Inventors
Wai J. Huey
Fernando Murman
Eugene Matsuda
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.