Granted Patent
Utility
US 4,444,266 · App. 06/463,462
Deep set piston actuated well safety valve
Inventor:
Ronald E. Pringle
Patented Case
View Patent ↗
Granted: Apr 24, 1984
Filed: Feb 3, 1983
Inventor
Ronald E. Pringle
Assignee (at issue)
Camco Inc.
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.