US Patent 7377953 Cyclone dust collecting apparatus having contaminants counterflow prevention member

A cyclone dust collecting apparatus comprises a deformable contaminants counterflow prevention member mounted to within 10 to 12 mm of the inner surface of the cyclone dust collecting apparatus. The deformable contaminants counterflow prevention member is soft enough to be elastically transformed to allow large contaminants to be drawn past it and drop into a dust collecting apparatus yet resilient enough so that it returns to its original shape after a large contaminant is passed.