Granted Patent
Utility
US 4,808,302 · App. 07/040,077
Water purifier valve
Inventor:
Richard W. Beall, Jr.
Patented Case
View Patent ↗
Granted: Feb 28, 1989
Filed: Apr 20, 1987
Inventor
Richard W. Beall, Jr.
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.