Upright vacuum cleaner with cyclonic air path

An upright vacuum cleaner with a cyclonic airflow path includes a floor-engaging base unit, a body unit pivotally mounted to the base unit and a motor/fan assembly mounted on one of the base unit or body units. A dirt collecting enclosure is also mounted on the body unit and includes a first large chamber and a second smaller chamber. A filter unit is disposed in the first large chamber. Dirt laden air is introduced into the first large chamber in a tangential manner so as to impart a cyclonic action to the airflow. The filter in the first large chamber is effective for removing larger particles of debris from the airflow. The remaining airflow is communicated to the second chamber where smaller particles of debris are removed. Airflow from the second smaller chamber is then communicated through a cyclonic chamber disposed above and transverse to the dirt collecting enclosure, to a third chamber where a second filter is disposed. The smallest particles of debris are removed from the airflow by the second filter disposed in this third chamber. The upright vacuum cleaner can include an arrangement for sensing pressure differences across one or more of the filters thereby providing an indication that the filter is dirty or clogged. The upright vacuum cleaner can also include an elevator mechanism for raising and lowering the dirt collecting enclosure thereby facilitating the task of emptying and then reinstalling the dirt collecting enclosure.