A cleaner head

Abstract

A cleaner head for a vacuum cleaner comprises a housing (20, fig 1) which defines a suction chamber (33, fig 1) comprising an inlet. Two rotatable brush bars 50, 51 are arranged inside the housing and

Description

BACKGROUND A cleaner head of a vacuum cleaner usually comprises a housing defining a suction chamber. The housing is configured to be moved over a floor or other surface that needs to be cleaned while air is drawn into the suction chamber together with dust, hair, and other dirt that is thereby removed from the surface. An outlet of the housing is coupled to a motor via a wand or hose which is configured to convey dust, dirt and hair to a dust bin. The motor provides for the suction needed to generate the airflow through the suction chamber. In many modem vacuum cleaners, the cleaner head comprises one or more brush bars or other types of agitator elements that rotate while the housing moves over the surface to be cleaned. The agitator elements serve to detach dirt from the surface and to increase the chance that it is picked up, thereby improving the cleaning performance of the vacuum cleaner. However, hair can become stuck on the brush bar or in the housing, thereby preventing it from being drawn in into the wand or hose for transfer to the dust bin. SUMMARY The present invention provides a cleaner head for a vacuum cleaner, the cleaner head comprising: a housing defining a suction chamber comprising an inlet; and at least two rotatable brush bars with an outer surface, the brush bars being at least partly arranged inside the housing and comprising a proximal end and a distal end, the proximal ends of the two brush bars facing each other, wherein each brush bar is located adjacent to a surface of the housing, wherein the spacing between the outer surface of each brush bar and its adjacent surface is asymmetric such that the outer surface of one brush bar is positioned closer to its adjacent surface than the other. The cleaner head of the present invention is advantageous as the suction pressure created in the cleaner head by the motor is asymmetric due to the outer surface of one of the brush bars being closer to its respective adjacent surface than the other. The asymmetry of the suction pressure from one side of the cleaner head to the other encourages any balls of hair which are carried into the suction chamber to be drawn to one side in preference to the other so that they do not become stuck in the middle of the cleaner head between the two brushes and the housing. The suction pressure is higher of the side of the cleaner head having a smaller gap between the brush bar and its adjacent surface such that any balls of hair tend to be drawn to that side of the cleaner head. Optionally the brush bars may taper from a wider base at the proximal end to a narrower tip at the distal end. This beneficially encourages any hair wrapped around the brush bars to migrate towards the distal end of the brush bar where it can fall off. The housing may optionally be asymmetric about a plane of brush bar symmetry located between the two brush bars. The asymmetry of the housing ensures an asymmetric gap is created between the outer surfaces of the brush bars and their respective adjacent surfaces when the brush bars are symmetrically mounted - with respect to one another - in the housing. A portion of the housing on one side of the plane of brush bar symmetry may be symmetric to a corresponding portion of the housing on the other side of the plane of brush bar symmetry so that there is an aspect of symmetry between the two sides of the housing. This may be desirable for reasons of aesthetic design. In one example, at least a portion of the surface adjacent each brush bar is configured to conform to the shape of the brush bar to ensure well defined suction pathways between the brush bars and the housing. Optionally the cleaner head comprises a first pair of brush bars located on a first side of the suction chamber inlet, and a second pair of brush bars located on a second side of the suction chamber inlet. The provision of two pairs of brush bars is advantageous as it increases the agitation of the surface to be cleaned to facilitate faster cleaning of the floor. The housing may optionally be symmetric about a fore-aft plane of symmetry located between the two pairs of brush bars for reasons of a pleasing aesthetic design. In another aspect, the present invention provides a vacuum cleaner comprising a cleaner head as described above. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a perspective view of an example embodiment of a vacuum cleaner head; Figure 2 shows a plan view of the underside of the cleaner head of Figure 1; and Figure 3 shows a perspective view of a component part of the cleaner head. DETAILED DESCRIPTION Figures 1 and 2 show a perspective view and an underside plan view of a vacuum cleaner head 10 comprising a housing 20 which defines a suction chamber 33. Four brush bars 50, 51, 52, 53 are arranged partially within the housing 20 as described in greater detail below. The housing 20 comprises a cover element 30 and a brush bar support element 35 (Figure 3). The housing 20 comprises an inlet 34 located in the brush bar support element 35. The vacuum cleaner head 10 is removably attachable to a wand (not shown) or directly to a main body of a vacuum cleaner via a wand connector 5. The wand connector 5 is in fluidic communication with the inlet 34 of the suction chamber 33 via a flexible hose 3. Pivotable connectors 2, 4 provide a multi axial connection between the wand connector 5 and the vacuum cleaner head 10. The brush bars 50, 51, 52, 53 each comprise a proximal end 54, 55, 56, 57 and a distal end 58, 59, 60, 61. An outer surface 62, 63, 64, 65 extends between the proximal end 54, 55, 56, 57 and the distal end 58, 59, 60, 61 of each brush bar. The brush bars 50, 51, 52, 53 are generally conical in shape such that each brush bar tapers from a wider base at its proximal end 54, 55, 56, 57 to a narrower tip at its distal end 58, 59, 60, 61. The brush bars 50, 51, 52, 53 are arranged within the housing 20 so that the lowermost portion of the brush bars and the distal ends 58, 59, 60, 61 of the brush bars protrude from the cover 30 to facilitate cleaning of the floor surface and the edges of the floor surface close to walls or furniture without interference from the cover 30 or any other part of the housing 20. As shown in Figure 3, the brush bar support element 35 comprises a pair of support arms 36, 37, each of which rotatably supports a pair of brush bars such that a first pair of brush bars 50, 51 are located one on either side of the support arm 36 with their proximal ends 54, 55 facing each other, and a second pair of brush bars 52, 53 are located one on either side of the other support arm 37 with their proximal ends 56, 57 facing each other. As best shown in Figure 2, the two pairs of brush bars 50, 51 and 52, 53 are located on either side of the inlet 34 about a fore-aft plane of symmetry 66 located between the two pairs of brush bars. The brush bar support element 35 comprises a first surface 40 and a second surface 41 located on either side of the support arm 36. The surfaces 40, 41 are asymmetrical about a plane 67 (see Figure 2) which bisects the support arms 36, 37 and divides the brush bar support element 35 into two sides, with the first surface 40 located on one side of the plane 67, and the second surface 41 located on the other side of the plane. As shown in Figure 2, with reference to the assembled vacuum cleaner head 10, the plane 67 is a plane of brush bar symmetry located between the brush bars 50, 51 and 52, 53 respectively. The first surface 40 comprises a distal portion 44 which is a mirror image of a distal portion 45 of the second surface 41. A proximal portion 46 of the first surface 40 which extends from the support arm 36 to the distal surface portion 44 is partially mirrored in the plane 67 by a proximal portion 47 of the second surface 41 which extends from the support arm 36 to the distal surface portion 45. However, a recessed, generally concave, portion 48 of the first surface 40 is not mirrored by the proximal portion 47 of the second surface 41 such that the brush bar support element 35, and hence the housing 20, is asymmetric about the plane 67. Surfaces 42, 43 located on either side of the support arm 37 and are mirror images of the surfaces 40, 41 in the fore-aft plane of symmetry 66. As best shown in Figure 2, in the assembled vacuum cleaner head 10, the distal portions 44, 45 of the first and second surfaces 40, 41 are configured to conform to the shape of the respective adjacent brush bars 50, 51. Similarly, the distal portions 39, 49 of the surfaces 42, 43 are configured to conform to the shape of the respective adjacent brush bars 52, 53. The asymmetry of the housing 20 in the brush bar plane of symmetry 67 results in a gap 70 between the first surface 40 and the outer surface 62 of the brush bar 50 which is larger than the gap 71 between the second surface 41 and the outer surface 63 of the brush bar 51. Consequently, the brush bar 50 is positioned closer to its adjacent surface 40 than the brush bar 51 to its adjacent surface 41. Similarly, a gap 72 between the surface 42 and the outer surface 64 of the brush bar 52 is larger than the gap 73 between the surface 43 and the outer surface 65 of the brush bar 53. Consequently, the brush bar 52 is positioned closer to its adjacent surface 42 than the brush bar 53 to its adjacent surface 43. Hence, each brush bar 50, 51, 52, 53 is located adjacent to a surface 40, 41, 42, 43 of the housing 20, and the spacing between the outer surface 62, 63, 64, 65 of each brush bar 50, 51, 52, 53 and its adjacent surface 40, 41, 42, 43 is asymmetric about the brush bar plane of symmetry 67. It will be understood that the example vacuum cleaner head 10 described above is one example only, and that modifications may be made. For example, the brush bars need not taper and may instead be generally cylindrical in form. It is not necessary to provide a vacuum cleaner head having two pairs of brush bars, and in another example embodiment the vacuum cleaner head may have only one pair of brush bars.

Claims

1. A cleaner head for a vacuum cleaner, the cleaner head comprising:a housing defining a suction chamber comprising an inlet; andat least two rotatable brush bars with an outer surface, the brush bars being at least partly arranged inside the housing and comprising a proximal end and a distal end, the proximal ends of the two brush bars facing each other,wherein each brush bar is located adjacent to a surface of the housing, wherein the spacing between the outer surface of each brush bar and its adjacent surface is asymmetric such that the outer surface of one brush bar is positioned closer to its adjacent surface than the other.

2. A cleaner head according to claim 1, wherein the brush bars taper from a wider base at the proximal end to a narrower tip at the distal end.

3. A cleaner head according to claim 1 or 2, wherein the housing is asymmetric about a plane of brush bar symmetry located between the two brush bars.

4. A cleaner head according to claim 3, wherein a portion of the housing on one side of the plane of brush bar symmetry is symmetric to a corresponding portion of the housing on the other side of the plane of brush bar symmetry.

5. A cleaner head according to any preceding claim, wherein at least a portion of the surface adjacent each brush bar is configured to conform to the shape of the brush bar.

6. A cleaner head according to any preceding claim, comprising a first pair of brush bars located on a first side of the suction chamber inlet, and a second pair of brush bars located on a second side of the suction chamber inlet.

7. A cleaner head according to claim 6, wherein the housing is symmetric about a fore-aft plane of symmetry located between the two pairs of brush bars.

8. A vacuum cleaner comprising a cleaner head as claimed in any preceding claim.

Images