A vacuum cleaner main cleaning chassis has a pair of suction air channels leading from a principal suction area thereof. Suction force is provided in common in the air channels with a single suction motor. One of the suction air channels is adapted to receive an auxiliary cleaning hose which diverts...http://www.google.com.tw/patents/US4811450?utm_source=gb-gplus-share專利 US4811450 - Vacuum cleaner with improved auxiliary cleaning
