Granted Patent
Utility
US 4,601,341 · App. 06/713,080
Flexible piston well safety valve
Inventors:
Ronald E. Pringle, William D. Eatwell
Patented Case
View Patent ↗
Granted: Jul 22, 1986
Filed: Mar 18, 1985
Inventors
Ronald E. Pringle
William D. Eatwell
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.