Granted Patent
Utility
US 4,669,547 · App. 06/871,958
High temperature subsurface safety valve
Inventor:
Ronald E. Pringle
Patented Case
View Patent ↗
Granted: Jun 2, 1987
Filed: Jun 9, 1986
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.