Abstract: A vacuum cleaner including a dirty air inlet (12, 14) communicating with a clean air outlet by way of an airflow path has a cyclone (18) arranged in the airflow path. In use, air flowing along the airflow path from the dirty air inlet (12, 14) to the clean air outlet passes through the cyclone (18). At least one bleed valve (20) is arranged in the wall of the airflow path upstream of the cyclone (18). Preferably, three bleed valves (20) are located in the wall of the airflow path and, more preferably, the bleed valves (20) are substantially identical to one another. Control may be provided for controlling the amount of air bled through the bleed valve (76) when a single bleed valve is provided.

Abstract: A back-pack vacuum cleaner comprises a back-pack harness, an upper casing attached to the harness and a lower casing rotatably mounted on the upper casing. A cyclonic cleaning assembly is mounted within the upper casing such that at least part of the assembly extends into the lower casing. The motor is positioned within the upper casing above the cyclonic cleaning assembly.