Granted Patent
Utility
US 5,940,929 · App. 08/880,225
Surface maintenance machine with improved dust collection system
Inventor:
David W. Berg
Patented Case
View Patent ↗
Granted: Aug 24, 1999
Filed: Jun 23, 1997
Inventor
David W. Berg
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.