Granted Patent
Utility
US 4,397,330 · App. 06/294,366
Mixing valve for back to back installation
Inventor:
Dennis J. Hayman
Patented Case
View Patent ↗
Granted: Aug 9, 1983
Filed: Aug 19, 1981
Inventor
Dennis J. Hayman
Assignee (at issue)
United States Brass 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.