Granted Patent
Utility
US 5,170,845 · App. 07/699,454
Subsurface safety valves and method and apparatus for their operation
Inventors:
Marion H. Gay, Phillip S. Sizer, Imre I. Gazda
Patented Case
View Patent ↗
Granted: Dec 15, 1992
Filed: May 13, 1991
Inventors
Marion H. Gay
Phillip S. Sizer
Imre I. Gazda
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.