Granted Patent
Utility
US 4,592,111 · App. 06/704,944
Spring retainer for vacuum cleaner nozzle brush
Inventor:
Robert C. Berfield
Patented Case
View Patent ↗
Granted: Jun 3, 1986
Filed: Feb 25, 1985
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.