Granted Patent
Utility
US 4,805,451 · App. 07/087,541
System for evaluating the condition and performance of a valve and valve operator combination
Inventor:
Robert L. Leon
Patented Case
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Granted: Feb 21, 1989
Filed: Aug 20, 1987
Inventor
Robert L. Leon
Assignee (at issue)
Liberty Technology Center, 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.