US Patent 7918909 Cyclone separator with fine particle separation member

A cyclone separator assembly comprises a cyclone separator that removes large particles of dirt from a working airstream as it flows through the cyclone separator, and the separated large particles of dirt are deposited into a dirt cup. The cyclone separator assembly further includes a fine particle separation member comprising a plurality of apertures for separating fine particles of dirt from air in the cyclone separator or the dirt cup. The fine particle separation member can be formed in a wall of the cyclone separator, a sidewall of the dirt cup, or in the outlet of the cyclone separator assembly. The cyclone separator assembly can further include a guide plate for creating a direction change in the path of the working airstream to aid in the separation of fine particles of dirt from air passing through the outlet.