Patent GB-455962-A (GB)
Title: Improvements in or relating to suction cleaners
IPC: A47L9/14
Filed: 1935-03-26
Abstract: 455,962. Silencing vacuum cleaners. HOOVER, Ltd., Greenford, Middlesex.-(Hoover Co. ; North Canton, Ohio, U.S.A.) March 26, 1935, No. 27491/36. Divided out of 455,715 and 455,855 under which a Specification was laid open to inspection under Sect. 91 of the Acts, Nov. 25, 1935. [Class 8 (i)] [See also Group XXVII] A suction cleaner of the kind having a motor-driven fan exhausting into a dust bag has a tubular sound muffler connected at one end to the exhaust from the cleaner fan and opening at the other end into the upper part of the dust bag so that heavy particles of dust will tend to fall to a part of the dust bag remote from the region at which the air issues into it from the muffler. A suction cleaner comprises, Fig. 1, a nozzle A, supporting wheels B and a fan chamber C containing a fan driven by an electric motor mounted with its axis transverse to the direction of movement; the fan and motor casing pivot with respect to the nozzle about the axis of the fan. A handle D is rigidly connected to the fan casing so that the casing and handle pivot together as a unit with respect to the nozzle, in the manner set forth in Specification 412,894. The muffler comprises, Fig. 3, an outer tubular sheet-metal member F<1> and a perforated inner tubular sheet-metal member F<2> having between them sound-deadening material F<3> such as felt. The tubes are secured to a flanged sleeve G fixed by screws H to the fan exhaust outlet C<2>. The lower end of the dust bag E surrounds the tube F<1> and is secured to the sleeve G ; the upper end of the dust bag E is closed by a clip E<1> suspended by a spring E<2> from the handle D. The muffler pivots with the handle as set forth in Specification 455,715. The upper end of the muffler is provided with a non-return valve J of fabric or the like; when the cleaner is switched off, the valve collapses and prevents dust from returning into the muffler. In a modification, Fig. 6, the muffler is permanently connected to the fan exhaust outlet C<2> and its upper end has projecting rivets F<4> engaging bayonet grooves K<2> in the metallic mouth K<1> of the dust bag which has a portion extending below the mouth and provided with clips K<3> for securing it to the exhaust outlet C<2>. In a further modification, the portion of the dust bag extending below the mouth completely surrounds the muffler, the lower end of the bag being secured to a flanged ring co-operating with the flange on the exhaust outlet of the fan casing, said flange being provided with openings to allow the passage of air passing through the inner wall of the dust bag. In a further modification, Fig. 8, the muffler comprises an outer tubular member L with a lining L<1> of rubber faced with felt. An opening in its underside permits the escape of dust particles which are too heavy to be carried through and clear of the muffler, so as to prevent the accumulation of such particles in the muffler; baffles L<2> extend transversely across the opening, and outside the opening a hood L<3> is provided so that the muffling properties are not interfered with.