Granted Patent
Utility
US 4,580,313 · App. 06/531,456
Walk behind floor maintenance machine
Inventor:
Michael L. Blehert
Patented Case
View Patent ↗
Granted: Apr 8, 1986
Filed: Sep 12, 1983
Inventor
Michael L. Blehert
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.