Granted Patent
Utility
US 6,544,487 · App. 09/199,311
Chemical feeder
Inventors:
Richard H. Ferguson, Stanley R. Pickens, Paul T. Rice
Patented Case
View Patent ↗
Granted: Apr 8, 2003
Filed: Nov 25, 1998
Inventors
Richard H. Ferguson
Stanley R. Pickens
Paul T. Rice
Assignee (at issue)
PPG Industries Ohio, 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.