A household appliance of the type in which a cleaning, polishing, or massaging effect is obtained by a rotating head or tool is improved by splitting the cleaning, polishing, or massaging head or tool into concentric or parallel multiple heads or tools arranged for coaxial or side-by-side differential...http://www.google.com/patents/US6032313?utm_source=gb-gplus-sharePatent US6032313 - Household appliance having plural coaxially rotatable or parallel linearly movable heads or tools
