Granted Patent
Utility
US 4,460,150 · App. 06/335,219
Annular blowout preventer
Inventors:
Robert J. Turlak, Bolie C. Williams, III, Gary R. Schaeper
Patented Case
View Patent ↗
Granted: Jul 17, 1984
Filed: Dec 28, 1981
Inventors
Robert J. Turlak
Bolie C. Williams, III
Gary R. Schaeper
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.