Granted Patent
Utility
US 5,019,250 · App. 07/404,866
Automatic chemical dispenser
Inventor:
Walter C. Lorenzen
Patented Case
View Patent ↗
Granted: May 28, 1991
Filed: Sep 8, 1989
Inventor
Walter C. Lorenzen
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.