Granted Patent
Utility
US 5,647,093 · App. 08/664,616
Sweeper with dual seal filter
Inventors:
Gregory J. Engel, Robert D. Hennessey, Timothy G. LaRocque, Terence A. Peterson
Patented Case
View Patent ↗
Granted: Jul 15, 1997
Filed: Jun 18, 1996
Inventors
Gregory J. Engel
Robert D. Hennessey
Timothy G. LaRocque
Terence A. Peterson
Assignee (at issue)
TENNANT 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.