Granted Patent
Utility
US 5,012,871 · App. 07/508,895
Fluid flow control system, assembly and method for oil and gas wells
Inventors:
Charles W. Pleasants, David R. Burnett, Donald W. Head
Patented Case
View Patent ↗
Granted: May 7, 1991
Filed: Apr 12, 1990
Inventors
Charles W. Pleasants
David R. Burnett
Donald W. Head
Assignee (at issue)
Otis Engineering Corporation
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.