Granted Patent
Utility
US 6,684,452 · App. 09/982,124
Dual cleaning mode carpet extractor
Inventors:
Dexter Lehman, Nick Graupe, Agnes Friese
Patented Case
View Patent ↗
Granted: Feb 3, 2004
Filed: Oct 17, 2001
Inventors
Dexter Lehman
Nick Graupe
Agnes Friese
Assignee (at issue)
Nilfisk-Advance, 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.