Granted Patent
Utility
US 4,945,993 · App. 07/354,373
Surface controlled subsurface safety valve
Inventors:
Rennie L. Dickson, Roddie R. Smith
Patented Case
View Patent ↗
Granted: Aug 7, 1990
Filed: May 19, 1989
Inventors
Rennie L. Dickson
Roddie R. Smith
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.