Patent attributes
An upright vacuum cleaner includes an upright housing section and a nozzle base section. A cyclonic airflow dirt and dust separating chamber is defined in the upright housing section. A suction source pulls air and entrained dirt, dust, and other contaminants through a main suction opening formed in the underside of the nozzle base section and into the cyclonic airflow chamber. The cyclonic airflow chamber causes the suction airstream to travel in a cyclonic path such that the entrained contaminants are separated therefrom and deposited into a dirt container that defines the chamber. A main filter element filters residual contaminants from the suction airstream between the chamber and the suction source. An exhaust filter housing includes an airstream suction duct in fluid communication with an outlet of the airflow chamber and an inlet of the suction source. An outlet of the suction source is in fluid communication with an exhaust plenum of the exhaust filter housing. An exhaust filter is positioned radially outward of the exhaust plenum such that exhaust air is forcedly radially outward through the exhaust filter from the exhaust plenum to ensure that the air discharged into the atmosphere is contaminant free, including those contaminants introduced into the airstream by the suction source itself.