Granted Patent
Utility
US 4,475,265 · App. 06/503,683
Shoe attachment for wet/dry electric vacuum cleaner
Inventor:
Robert C. Berfield
Patented Case
View Patent ↗
Granted: Oct 9, 1984
Filed: Jun 13, 1983
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.