Granted Patent
Utility
US 4,834,183 · App. 07/155,980
Surface controlled subsurface safety valve
Inventors:
Michael B. Vinzant, Craig D. Hines, Rennie L. Dickson, Robert C. Hammett
Patented Case
View Patent ↗
Granted: May 30, 1989
Filed: Feb 16, 1988
Inventors
Michael B. Vinzant
Craig D. Hines
Rennie L. Dickson
Robert C. Hammett
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.