Granted Patent
Utility
US 6,735,812 · App. 10/371,940
Dual mode carpet cleaning apparatus utilizing an extraction device and a soil transfer cleaning medium
Inventors:
Frederick A. Hekman, Jeffrey D. Fystrom, Larry Wydra
Patented Case
View Patent ↗
Granted: May 18, 2004
Filed: Feb 21, 2003
Inventors
Frederick A. Hekman
Jeffrey D. Fystrom
Larry Wydra
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.