Granted Patent
Utility
US 5,074,521 · App. 07/505,135
High force-gain valve
Inventors:
Richard C. Alexius, William R. Spencer
Patented Case
View Patent ↗
Granted: Dec 24, 1991
Filed: Apr 5, 1990
Inventors
Richard C. Alexius
William R. Spencer
Assignee (at issue)
LOCKHEED MARTIN 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.