Abstract: A filtering device filters out impurities contained in an air stream, and includes an inner filter plate, an outer frame that houses said filter plate thereinside, a structure for retaining said filter plate and conveying the shaking motion, a support socle applied on to said structure, a rotary electric motor, whose rotor is provided with one or more unbalanced masses, and which is fixedly mounted on said socle. The electric motor is operated in an intermittent manner, preferably with a direct-current, substantially square-wave supply voltage according to an ON-OFF cycling pattern, so as to generate a very broad spectrum of shaking frequencies that proves more effective in enabling impurities to be removed from the filter plate.

Abstract: A floor washing-drying machine includes a brush (2) adapted to scrub a floor (4) with a cleaning liquid in view of removing soil and dirt therefrom, and a wiping device (3) adapted to scrape the floor (4) in order to remove the dirty cleaning liquid therefrom. The wiping device (3) includes a front flap (5) and a rear flap (6) adapted to elastically and slidably engage the floor (4) so as to define a suction chamber (7) therebetween, with the suction chamber being fluidly connected with a suction device (8). A further elastic flap (10) is mounted to the wiping device behind the rear flap, and the width of the further flap is smaller than the width of the front and rear flaps (5, 6).