Granted Patent
Utility
US 4,437,643 · App. 06/277,231
Ram-type blowout preventer
Inventors:
William L. Brakhage, Jr., William M. Taylor
Patented Case
View Patent ↗
Granted: Mar 20, 1984
Filed: Jun 25, 1981
Inventors
William L. Brakhage, Jr.
William M. Taylor
Assignee (at issue)
Cameron Iron Works, 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.