Granted Patent
Utility
US 4,986,358 · App. 07/509,531
Flapper mount for well safety valve
Inventors:
Edgar D. Lueders, Brian A. Roth
Patented Case
View Patent ↗
Granted: Jan 22, 1991
Filed: Apr 16, 1990
Inventors
Edgar D. Lueders
Brian A. Roth
Assignee (at issue)
Camco International, 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.