Granted Patent
Utility
US 5,651,811 · App. 08/632,111
Filter system
Inventors:
Robert A. Frey, Philip H. Stevenson
Patented Case
View Patent ↗
Granted: Jul 29, 1997
Filed: Apr 15, 1996
Inventors
Robert A. Frey
Philip H. Stevenson
Assignee (at issue)
HMI Industries, 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.