Granted Patent
Utility
US 5,019,346 · App. 07/247,279
Drain treatment product and method of use
Inventors:
Francis L. Richter, James Wilson, Daniel E. Pedersen
Patented Case
View Patent ↗
Granted: May 28, 1991
Filed: Sep 21, 1988
Inventors
Francis L. Richter
James Wilson
Daniel E. Pedersen
Assignee (at issue)
ECOLAB INC.
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.