Patent Application
20050055785
The present invention relates to a carpet sweeping appliance of the type particularly used to clean floors and carpets and commonly referred to as a “carpet sweeper” although finding applicability in the sweeping of dirt from a variety of other surfaces.
Conventional carpet sweepers comprise a housing which supports a pair of rollers or pairing of wheels and a bristle-carrying rotary brush. The housing is formed with an elongate slot adjacent the brush, leading to an internal dirt-receiving enclosure. The brush is arranged so that the bristles pass over the surface on which the sweeper is resting so that as the brush rotates particles of dirt are swept into the enclosure. In a very common form the brush has the form of a bristle carrying drum which is mechanically linked to the wheels or rollers so that as the carpet sweeper is pushed across the ground the wheels rotate and in turn rotate the brush. In the case of a brush which rotates in the same manner [sense] as a ground supporting roller or wheel, it is also necessary that the brush rotate at a speed faster than the speed at which the carpet sweeper is being pushed across the ground, so as to impart movement to the particles of dirt. This is typically achieved by forming the wheels of a smaller diameter than the bristle-carrying drum, or by using a speed-increasing gear mechanism to link the wheels and the brush. Other arrangements may be used to drive the brush in a reverse direction using a gear mechanism.
In yet another form, the brush may be motor driven, generally by a simple electric motor, in which case the motor is connected to the brush by a speed reducing gear train.
The present invention provides a sweeping appliance having an outer housing defining an internal dirt receiving enclosure. A slot-like opening is formed in the underside of the housing. An elongate rotary brush having a plurality of resilient bristles is located towards the front of the carpet sweeper, within the slot-like opening. The housing is supported on front and rear pairs of wheels. A lower region of the housing is bent down to provide a ramp up which particles of dust are swept. A deflector is provided on the forward facing side of the brush and extends rearwardly into the space defined by the bristles. The deflector halts the progress of the bristles until the brush rotates sufficiently to force the bristles forward of the deflector, the resilience of the bristles causing them to spring forward in a flicking action. The outer end of the bristles strike the ground at speed where they impact particles of dirt and force them up the ramp and into the internal enclosure.
The structure of the sweeping appliance enables it to impart very rapid movement to the bristles, and thereby rapid movement to the particles of dirt being swept up into the sweeping appliance and in an extremely simple yet effective manner.
Alternatively of front and rear wheels, any roller means such as rollers of greater axial extent than simple wheels may be used. In any event, the wheels or rollers engage the surface to be cleaned. The rotary brush may be coaxial with and directly connected to the first pair of wheels, thereby avoiding the need for any more complex drive arrangements.
The deflector may be a blade-like edge or member unitarily formed with or joined to the housing. The deflector is preferably disposed to engage the bristles so that they move through an angular distance of about 90° as they spring past the deflector. However, considerable variation of the precise angle is still possible whilst yielding effective results.
The rotary brush may comprise a central member from which the bristles radially extend.
An embodiment of the invention is now described, by way of example only, with reference to the following drawings in which:
FIGS. 3(a), (b), (c), (d), (e) and (f) are schematic views of the brush of the sweeping appliance showing progressive movement of a single bristle to illustrate the sweeping action.
Turning to the drawings,
Alternatively, the wheels 12 may be rollers of greater axial extent than simple wheels or any other roller means. The wheels 12 are themselves rotatably supported on the housing 4. Note that the wheels 12 are not shown in
As can be seen in
Further details of the brush are now described. As illustrated in
On the forward facing side of the brush 10 (the left side as shown in
FIGS. 3(a) to (e) illustrate the movement of an opposed pair of bristles, with all the other bristles not shown for reasons of clarity. As the brush 10 rotates on rotation of the rollers 12, the outer end of the bristle B abuts the deflector 28, the deflector acting to halt the forward progress of the bristle B whilst the brush 10 rotates through a defined angle, the bristle B adopting the curved shape shown in
The movement of the bristle B required to effectively move the dirt particle D is not dissimilar to the effective striking of a golf ball by a golf club, requiring that the dirt particle be hit at speed and imparted appropriate lift. The deflector 28 is able to do this in a very simple yet effective manner. The precise movement of any particular bristle is affected by the length and diameter of the bristles, its elasticity and by hysteresis effects. In practice, the deflector 28 stores a number of bent bristles behind it such that immediately in front of the deflector 28 there is a void which is free of bristles and through which bristles flicking past the deflector 28 rapidly move on their travels between the positions of FIGS. 3(a) to (e).
Although the front wheels 12 of the illustrated embodiment directly drive the brush 10, the sweeping device may alternatively be configured such that the brush 10 is indirectly driven through a mechanical linkage such as a gear mechanism. Alternatively, a simple motor may be provided to drive the brush 10.
