Granted Patent
Utility
US 4,579,314 · App. 06/696,086
Annular blowout preventer
Inventors:
Gary R. Schaeper, William M. Taylor, Bolie C. Williams, III
Patented Case
View Patent ↗
Granted: Apr 1, 1986
Filed: Jan 29, 1985
Inventors
Gary R. Schaeper
William M. Taylor
Bolie C. Williams, III
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.