Granted Patent
Utility
US 4,668,402 · App. 06/677,831
System for treating fluids
Inventor:
William W. Norton
Patented Case
View Patent ↗
Granted: May 26, 1987
Filed: Dec 3, 1984
Inventor
William W. Norton
Assignee (at issue)
CULLIGAN INTERNATIONAL COMPANY
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.