Granted Patent
Utility
US 5,163,471 · App. 07/888,900
Low-pressure pilot valve
Inventor:
Walter W. Powell
Patented Case
View Patent ↗
Granted: Nov 17, 1992
Filed: May 26, 1992
Inventor
Walter W. Powell
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.