US Patent 7628833 Multi-cyclone dust separating apparatus

A multi-cyclone dust separating apparatus has a main cyclone comprising one or more cyclones, a sub cyclone comprising one or more cyclones, and being arranged around a part of the main cyclone in parallel relation, and a dust collecting casing provided to enclose the main and the sub cyclones, and collects dust as the dust is separated from the air in the main and the sub cyclones. At least a part of the dust collecting casing enclosing the main cyclone is formed in a half-circular shape.