AN ACCESSORY UNIT FOR A VACUUM CLEANERThe present invention relates to an accessory unit for a vacuum cleaner, particularly a vacuum cleaner of the so-called "upright" type.
Vacuum cleaners in general fall into two classes, namely the "cylinder" type comprising a generally cylindrical body mounting the motor and having a flexible hose from the suction side of the fan allowing a vacuum head to be moved over the surface to be cleaned without displacing the cylindrical body except occasionally to move from place to place; the other type of vacuum cleaner, namely the "upright" type comprises a body housing the motor and a fixed duct leading to the suction inlet. The body is mounted on small wheels and is movable over the surface to be cleaned by means of a handle pivotally mounted to the body, which handle usually carries a dust-collection bag which is removable for emptying.
One difficulty in use of upright vacuum cleaners lies in the fact that the casing over the body housing the vacuum-generating motor has to be sufficiently robust to carry the relatively heavy components, and for this reason the suction opening, normally in the underface of the casing, is entirely surrounded by a rim which is often thickened by the addition of a resilient "bumper" to prevent damage occuring to the legs of furniture and/or to skirting boards and architraves when the vacuum cleaner is used in close proximity thereto. This arrangement, however, means that the vacuum inlet cannot be brought into direct proximity with the angle between the floor and a wall so that there is always a small strip of floor close to the wall where vacuum cleaning cannot be achieved.This problem does not arise with cylinder type vacuum cleaners because of the possibility of interchanging different vacuum heads and the fact that the absence of heavy components such as the vacuum-generating motor at the vacuum head end of the hose means that the implements can be made in lightweight thin material so that there is no substantial surrounding rim: moreover, cylinder type vacuum cleaner implements are more easily manipulated in order to direct the vacuum opening exactly into a corner such as the corner between the floor being cleaned and a surrounding wall.
The present invention seeks to provide an accessory unit which will allow this disadvantage to be mitigated by dislodging dirt or dust in the very corner between a wall and the floor away from this location so that an upright vacuum cleaner may then carry away such dust.
According to the present invention, therefore, an accessory unit for a carpet sweeper or an upright vacuum cleaner as herein defined, comprising a support member, attachment means for securing the support member at least temporarily to the rim of a cowl or casing of a carpet sweeper or an upright vacuum cleaner, at least one rotary brush mounted on the support member for rotation about a substantially upright axis, the brush having a disc-like member with means forming a resilient rim which, when the brush is mounted in position on the cowl or casing, projects beyond the outline thereof.
In a preferred embodiment of the invention the mounting is resilient to allow displac#ment of the said at least one rotary brush in a direction transverse the axis of the vacuum cleaner.
Preferably, the or each rotary brush is provided with an additional disc-like member coaxial therewith and spaced from the bristle support of the brush, the said disc-like member having a circumferential resilient fender for engagement with the vertical surface of a wall or furniture whereby to cause rotation of the brush about its axis upon contact with the said wall or furniture item.
In a preferred embodiment of the invention the said mounting member has a U-shape spring clip or a plurality of U-shape spring clips for engaging under the lip of the cowling or casing of the vacuum cleaner.
In another embodiment of the invention the said mounting member has a triangular section plastic deformation element moulded in register with an aperture in the mounting member to allow the said deformation element to be pressed through the aperture to locate against a ridge or rib of the vacuum cleaner casing whereby to retain it in position. Most vacuum cleaners are provided with a surrounding fender or bumper of resilient material such as rubber, and the said triangular deformation elements may be adapted to engage over the upper surface of this fender or bumper to retain the mounting in position on the vacuum cleaner.
Other embodiments of the present invention are possible, however, and it is envisaged that the simple arrangement could incorporate a round wire mounting frame bent to shape to form both retaining engagement means and spindle-supporting bearings for the rotary brush or brushes.
In a preferred embodiment of the invention there are two such rotary brushes one at each end of the mounting, and the accessory unit is so arranged that when fitted to the forward edge or lip of the casing of an upright vacuum cleaner the two brushes are located at the front corners of the combined unit comprising the vacuum cleaner and the accessory unit.
Further, the accessory unit may itself have a cowl to protect the major portion of the brush or brushes, each cowl being so shaped that a part of the or each brush may project therethrough for engagement with the wall or furniture to cause rotation of the brush.
One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:Figure 1 is a perspective view of a vacuum cleaner fitted with an accessory unit formed in accordance with the principles of the present invention;Figure 2 is a plan view from above of the forward part of the vacuum cleaner fitted with the accessory unit of the invention;Figures 3a and 3b are respective enlarged perspective views of two further embodiments illustrating in particular the manner in which the accessory unit is fitted to the front flange wall of the vacuum cleaner; andFigure 4 is an enlarged fragmentary perspective view of a detail of the embodiment of Figure 1 seen in the direction of the arrows IV-IV of Figure 1.
Referring now to the drawings, a vacuum cleaner ofupright type comprises a main casing 11 housing the vacuum cleaner motor and ducts leading from an inlet suction opening on the underside of the casing to a discharge chute 12 to which a dust collection bag 13 is fitted. Behind the discharge chute 12 is a rigid guide handle 14 pivotally mounted to the body 11.
The body 11 includes a downwardly extending surrounding flange 15 around the rim of which is a protective rubber strip 16 forming a fender to protect furniture and skirting boards from impacts with the vacuum cleaner. As explained above the inlet opening to the vacuum ducts in the under surface of the body has a perimetral outline which, because of the presence of the flange 15 and the protective fender strip 16 can at best be brought only a certain distance away from the skirting board at the edge of a room, leaving a narrow strip of the floor surface out of the reach of the vacuum cleaner.
The accessory unit of the present invention is generally indicated with the reference numeral 17, and in the embodiment illustrated in Figure 1 comprises a body 18 having means, which will be described in greater detail hereinbelow, for attaching it to the flange 15 of the vacuum cleaner body 11 at the forward edge thereof, and downwardly from which project two rotary brushes generally indicated 19 and 20.The rotary brush 20 is illustrated in more detail in Figure 4 and, as will be seen, in this embodiment comprises a disc-like brush body 21 with two flat circular major faces from the upper of which projects a fixed rotary brush spindle 22 and from the lower of which project a plurality of bristles 23 which are closely packed and the radially outer bristles of which are inclined with respect to the axis of the brush 20 by an angle such that the tips of the radially outermost bristles 23 project radially beyond the outermost perimeter of the disc-like rotary brush body 21. Surrounding the perimeter of the disc-like rotary brush body 21 is a resilient guard member 24.
The rotary brush spindle 22 is received within a bearing bush 25 fixed within a cylindrical support carried at the end of a cranked arm 27 of the brush mounting member of the accessory unit 18.
As can be seen in Figure 2, the two rotary brushes 19, 20 are mounted in the accessory unit 18 in such a way that the circumferential resilient guard member 24 which surrounds the perimeter of the disc-like rotary brush body 21 projects laterally just beyond the projection of the line defining the protective fender strip 16 around the downwardly depending flange 15 of the main casing 11.
Thus, as the vacuum cleaner is moved parallel to a wall the resilient guard member 24 contacts the wall and causes the brush 19 or 20 as appropriate to rotate about the rotary brush spindle 22 within the rotary brush spindle bearing bush 25 carried by the cylindrical support 26. This action causes the bristles 23 to move over the surface of the ground displacing the dust or dirt thereon radially inwardly towards the centre line of the vacuum cleaner and into the path of the suction aperture in the underside of the body encased within the main casing 11.In order to encourage this action the brushes 19, 20 are mounted such that their spindles 22 are not accurately perpendicular to the ground, but rather inclined in such a way that the outer and rear arc of the bristle path brings it into contact#with the ground whereas the forward and inner part of the arc of the bristle path brings it out of contact with the ground. As can be seen with reference to Figure 2, the brush is tilted in such a way that the bristles on the right hand side of the inclined line A-A (with reference to the orientation as viewed in Figure 2) is the region where the bristles are in contact with the ground whilst on the left hand side of the line A-A the bristles are progressively less in contact or entirely out of contact with the ground.
Turning now to Figures 3a and 3b, two alternative mounting arrangements for the accessory unit 17 of the invention are illustrated. In Figure 3a the accessory unit 17 incorporates a flat strip mounting member generally indicated 28 having a main strip portion 29 which lies in a substantially vertical plane and extends from side to side of the front flange 15 and from which project the cranked mount arm 27 which carries the cylindrical support 26 for the rotary brush spindle bearing bush 25, and a similar such arm 30 at the other end of the strip 29 which carries a cylindrical support 31 for a rotary brush spindle bearing bush 32 which receives a rotary brush spindle 33 of the rotary brush 19.
Downwardly from the main strip portion 29 project two flat strip arms 34, 35 each of which has a respective hook-ended terminal portion 36, 37 which engages underneath the flange 15 at the front of the casing 11, which flange has an inwardly directed lip portion over which the hook ended terminal portions 36, 37 of the flat strip arms 34, 35 engage.
Each of the flat strip arms 34, 35 has a rectangular opening 38, 39 along one edge of which is located an inclined deformable tab member 40, 41 having an inclined lip portion 42, 43 which, with the mounting member 28 positioned, as illustrated in Figure 3a, with the hook ended terminal portions 36, 37 of the flat strip arms 34, 35 engaged over the lip of the front flange 15 are located just above the upper edge of the protective resilient fender strip 16. The two deformable tabs 40, 41 can then be depressed inwardly to a position where the projecting lip portions 42, 43 rest over the top edge of the protective fender strip 16 and the tabs 40, 41 themselves lie parallel to and flush with the front face of the main strip portion 29 and fill the rectangular openings 38, 39 completely.The mounting member 28 is thus securely held in position and can then be encased by a cowl or cover generally indicated 18.
Referring now to Figure 3b, the components which perform the same or similar function to corresponding components in the embodiment of Figure 3a will be identified with the same reference numerals. Thus, in the embodiment of Figure 3b the accessory unit 17 comprises a main mounting member 28 with a main strip portion 29 downwardly from which project two flat strip arms 34, 35.The cranked mount arms 27 and 30, and the structure supporting the rotary brushes 19, 20 are identical with the corresponding components in the embodiment of Figure 3a, but the downwardly projecting flat strip arms 34, 35 do not have apertures or tabs as in the embodiment of Figure 3a, but rather the hook ended terminal portions 36, 37 of the flat strip arms 34, 35 are provided with deep U-shape resilient springs 44, 45 with oppositely curved spring tips 46, 47 which can be sprung into position by fitting over the inwardly directed lip portion of the downwardly depending flange 15 at the front of the casing 11 in such a way that the tip portions 46, 47 of the U-shape resilient springs 44, 45 press against the inner face of the downwardly depending front flange 15 whilst theU-shape resilient springs 44, 45 themselves are flexed with a bending stress such that the rear face of the main strip portion 29 of the mounting member 28 is pressed against the front face of the downwardly depending flange 15 by the same resilient force.
As with the other embodiments, the axes of the rotary brushes 19, 20 are inclined slightly so that the rotary motion imparted to the brushes by contact of the resilient guard member 24 on the rotary brush body 21 against an item of furniture or a skirting board or wainscot causing rotation of the brush about its axis will act to displace the bristles in contact with the ground to move any dust or dirt engaged thereby inwardly towards the centre line of the vacuum cleaner to be collected thereby.