Granted Patent
Utility
US 4,723,606 · App. 07/003,181
Surface controlled subsurface safety valve
Inventors:
Michael B. Vinzant, Phillip S. Sizer, Ronald K. Churchman, Rennie L. Dickson, Roddie R. Smith
Patented Case
View Patent ↗
Granted: Feb 9, 1988
Filed: Jan 13, 1987
Inventors
Michael B. Vinzant
Phillip S. Sizer
Ronald K. Churchman
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.