Granted Patent
Utility
US 4,541,639 · App. 06/419,080
Ram-type blowout preventer with improved ram front packer
Inventor:
Bolie C. Williams, III
Patented Case
View Patent ↗
Granted: Sep 17, 1985
Filed: Sep 16, 1982
Inventor
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.