Granted Patent
Utility
US 6,485,259 · App. 09/911,679
Vaneless impeller housing for a vacuum cleaner
Inventor:
Robert C. Berfield
Patented Case
View Patent ↗
Granted: Nov 26, 2002
Filed: Jul 24, 2001
Inventor
Robert C. Berfield
Assignee (at issue)
SHOP VAC CORPORATION
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.