21 ELECTRICALLY OPERATED SUCTION CLEANERS AND PARTS THEREOF, AND ATTACHMENTS AND ACCESSORIES THEREFOR INCLUDING PAPER FILTERS, FLOOR AND UPHOLSTERY TOOLS, HOSE, EXTENSION PIPES, NOZZLES, AND TOOL HOLDER THEREFOR
DEC. 29, 1939, AS TO "FILTER QUEEN." DEC. 29, 1939, AS TO "FILTER QUEEN."