BRUSH FOR USE IN A CLEANING DEVICE FOR CLEANING SURFACES

Abstract

A brush, rotatably arranged in a cleaning device for cleaning surfaces, is described. The brush includes a core element and brush elements arranged on the core element. The brush elements are arranged in a bristle field extending in a direction of a longitudinal axis of the brush and in a peripheral direction about the longitudinal axis. Further, the brush elements include fiber hairs. Furthermore, a linear mass density of at least tip portions of the brush elements is lower than 15 g per 10 km. In addition, an average of a packing density of the brush elements in the bristle field is lower than 15,000 brush elements per 1 cm.sup.2 so as to ensure that for the purpose of moving the brush during a cleaning action, only a relatively small amount of energy is needed.

Claims

1. A brush configured to be rotatably arranged in a cleaning device which is movable across surfaces for cleaning the surfaces, at the position of a functional head of the cleaning device which is configured to face the surfaces to be cleaned, the brush comprising a core element and brush elements arranged on the core element, wherein tip portions of the brush elements are configured to contact the surfaces to be cleaned, wherein the brush elements are arranged in a bristle field extending in a direction of a longitudinal axis of the brush and in a peripheral direction about the longitudinal axis, wherein the brush elements comprise fiber hairs, wherein a linear mass density of at least the tip portions of the brush elements is lower than 15 g per 10 km, and wherein an average of a packing density of the brush elements in the bristle field is lower than 15,000 brush elements per 1 cm.sup.2.

2. The brush of claim 1, wherein the brush elements are either substantially equally distributed or unequally distributed throughout the bristle field.

3. The brush of claim 2, wherein the brush elements are unequally distributed throughout the bristle field, and wherein the bristle field comprises local interruptions.

4. The brush of claim 1, wherein the average of the packing density of the brush elements in the bristle field is lower than 10,000 brush elements per 1 cm.sup.2, optionally lower than 5,000 brush elements per 1 cm.sup.2.

5. The brush of claim 1, wherein the linear mass density of at least the tip portions of the brush elements is lower than 10 g per 10 km, optionally lower than 5 g per 10 km, further optionally lower than 1 g per 10 km.

6. The brush of claim 1, wherein the average of the packing density of the brush elements in the bristle field is higher than 1,000 brush elements per 1 cm.sup.2, optionally higher than 2,000 brush elements per 1 cm.sup.2, further optionally higher than 5,000 brush elements per 1 cm.sup.2.

7. The brush of claim 1, wherein the linear mass density of at least the tip portions of the brush elements is higher than 0.7 g per 10 km, optionally higher than 0.8 g per 10 km, further optionally higher than 1 g per 10 km.

8. The brush of claim 1, wherein the packing density of the brush elements is higher at the position of an intermediate section of the bristle field than at the position of two side sections of the bristle field and which are located at either side of the intermediate section.

9. The brush of claim 1, wherein the bristle field comprises a pattern of tufts of the brush elements, and wherein a number of brush elements per tuft is at least 300.

10. The brush of claim 1, wherein the brush is shaped like an elongated cylinder having a circular periphery.

11. The brush of claim 1, wherein the brush comprises a cloth which is provided with the brush elements and which is wrapped around the core element.

12. The brush of claim 1, wherein the brush is configured to be driven at a rotation speed involving acceleration including centrifugal acceleration of at least 3,500 m/s.sup.2 at tip portions of the brush elements moving out of contact with a surface to be cleaned during operation of the cleaning device.

13. A cleaning device which is movable across surfaces for cleaning the surfaces, comprising a functional head configured to face the surfaces to be cleaned and at least one brush of claim 1 rotatably arranged in the functional head about a rotation axis extending in the direction of the longitudinal axis of the brush.

14. The cleaning device of claim 13, wherein the cleaning device comprises a mechanism configured to drive the at least one brush at a rotation speed involving acceleration including centrifugal acceleration of at least 3,500 m/s.sup.2 at tip portions of the brush elements moving out of contact with a surface to be cleaned during operation of the cleaning device.

15. The cleaning device of claim 13, wherein the cleaning device is operable in at least a wet operation mode and comprising a wetting system configured to supply a cleaning liquid to an area of the functional head where the at least one brush is located to thereby realize a wet cleaning condition of the at least one brush in the wet operation mode of the cleaning device.

16. The brush of claim 1, wherein the brush is configured with different packing densities of the brush elements in different sections of the bristle field, in the direction of the longitudinal axis of the brush.

17. The brush of claim 8, wherein the packing density of the brush elements at the position of each of the two side sections of the bristle field is at most 50% of the packing density of the brush elements at the position of the intermediate section of the bristle field.

18. The cleaning device of claim 15, wherein the wetting system comprises a pump arrangement configured to supply the cleaning liquid to the area of the functional head where the at least one brush is located, by pumping the cleaning liquid towards the area of the functional head.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention will now be explained in greater detail with reference to the figures, in which equal or similar parts are indicated by the same reference signs, and in which:

[0025] FIG. 1 diagrammatically shows components of a wet cleaning device according to an embodiment of the invention and a portion of a floor having a surface to be cleaned;

[0026] FIG. 2 diagrammatically shows a perspective view of a portion of a brush according to a first embodiment of the invention;

[0027] FIG. 3 diagrammatically shows a perspective view of a portion of a brush according to a second embodiment of the invention;

[0028] FIG. 4 diagrammatically shows a perspective view of a brush according to a third embodiment of the invention;

[0029] FIG. 5 diagrammatically shows a back side of a portion of a cloth provided with brush elements; and

[0030] FIG. 6 illustrates how tufts of the brush elements are arranged on a backing of the cloth shown in FIG. 5.

DETAILED DESCRIPTION OF EMBODIMENTS

[0031] FIG. 1 illustrates the design of a wet cleaning device 1 according to an embodiment of the invention. The particular cleaning device represented in FIG. 1 and described in the following is just one example of many types of cleaning devices which are feasible in the framework of the invention. In this respect, it is noted that the invention does not only relate to wet cleaning devices, but also to other types of cleaning devices such as wet/dry cleaning devices having a dry cleaning function besides a wet cleaning function, and vacuum cleaners having a vacuum cleaning function besides a wet cleaning function and possibly also a dry cleaning function.

[0032] The wet cleaning device 1 is configured to be used for the purpose of subjecting a surface such as a floor surface to a wet cleaning action. At a side that is supposed to face the surface 10 during operation of the cleaning device 1, the cleaning device 1 comprises a cleaner nozzle 20 accommodating two brushes 21. In the following, it is assumed that each of the brushes 21 is provided in the form of a roller that is rotatable about a brush rotation axis 22 that is defined by a central longitudinal axis of the roller, which does not alter the fact that other embodiments of the brushes 21 are possible as well. As indicated in FIG. 1 by means of curved arrows depicted at the position of the brushes 21, the brushes 21 are arranged so as to be rotatable in opposite directions about their respective brush rotation axes 22. In the framework of the invention, the cleaner nozzle 20 may accommodate another number of brushes 21, wherein it is particularly to be noted that having just a single brush 21 is a feasible alternative option. The cleaner nozzle 20 comprises a brush holder frame 23 that serves for suspending the brushes 21. Besides the cleaner nozzle 20, the cleaning device 1 comprises a body portion 30 which is configured to be taken hold of by a user of the cleaning device 1 and that is connectable to the cleaner nozzle 20 through a hinge arrangement 31.

[0033] For the purpose of driving the brushes 21 during operation of the cleaning device 1, the cleaning device 1 is equipped with a suitable electric drive mechanism (not shown). For the purpose of powering the drive mechanism and probably also other components of the cleaning device 1, the cleaning device 1 may be connectable to the mains and/or may be equipped with a suitable battery arrangement. Preferably, the cleaning device 1 is a cordless device comprising a rechargeable battery arrangement, in which case it may further be practical if the cleaning device 1 is part of a set including a charging dock besides the cleaning device 1. Such a set may also include a flushing tray that can be used for the purpose of cleaning the brushes 21. In case the cleaning device 1 is not equipped with a battery, a simple dock that is without charging ability may be provided for receiving and holding the cleaning device 1.

[0034] The body portion 30 of the cleaning device 1 includes a first reservoir 32 that serves for containing a cleaning liquid, and a liquid supply mechanism 33 that serves for supplying the cleaning liquid to the brushes 21 during operation of the cleaning device 1, and that is positioned between the first reservoir 32 and the cleaner nozzle 20 to that end. The liquid supply mechanism 33 may comprise any suitable type of pump arrangement 34, for example. The body portion 30 of cleaning device 1 further includes a second reservoir 35 that serves for containing used, dirty cleaning liquid, and a conveying area 36 that serves for receiving a mixture of cleaning liquid and dirt from the brushes 21 and for conveying the mixture to the second reservoir 35, and that is at a position between the cleaner nozzle 20 and the second reservoir 35. The body portion 30 may also include a vacuum mechanism 37 configured to create underpressure that is useful to support transportation of dirt through the body portion 30, in a direction away from the brushes 21, for example.

[0035] Although this is not illustrated in FIG. 1, it is practical if the body portion 30 of the cleaning device 1 has a housing for accommodating at least the reservoirs 32, 35, the liquid supply mechanism 33, the vacuum mechanism 37 and possible other components of the cleaning device 1 such as the above-mentioned optional battery arrangement. The body portion 30 of the cleaning device 1 comprises a handle 38 so that the user can easily take hold of the body portion 30 and move the cleaning device 1 across the surface 10 to be cleaned as desired.

[0036] Basic aspects of how the wet cleaning device 1 is operated are as follows. During operation, the brushes 21 are driven so as to rotate and the liquid supply mechanism 33 is activated so as to supply the cleaning liquid to the brushes 21, as indicated in FIG. 1 by a downward arrow on the left, and to thereby cause the brushes 21 to be in a wet cleaning condition. An area of the surface 10 that is within reach of the brushes 21 is wetted by the brushes 21. Any stains as may be present on the area of the surface 10 are detached under the influence of the cleaning liquid and/or are scrubbed off by the brushes 21, and any dirt as may be present on the area of the surface 10 is removed along with the cleaning liquid that is conveyed to the second reservoir 35 and passes through the conveying area 36 in the process, as indicated in FIG. 1 by an upward arrow on the right. In particular, the brushes 21 include a core element and flexible brush elements extending from the core element, which brush elements have tip portions for contacting the surface 10. Dirt and liquid are picked up from the surface 10 by the tip portions of the brush elements and are flung away from the tip portions as the brush rotates and the tip portions move out of contact to the surface 10.

[0037] In the shown example, the cleaning device 1 is equipped with a user interface 41 including an on/off button. Assuming an off mode of the cleaning device 1, operation of the cleaning device 1 is initiated when the user depresses the on/off button. The cleaning device 1 comprises a controlling system 40 including a microcontroller that is programmed to put the brushes 21 in motion and to activate both the liquid supply mechanism 33 and the vacuum mechanism 37 in reaction to the user depressing the on/off button. When the user depresses the on/off button once again, the user causes the controlling system 40 to control the cleaning device 1 to stop operating through shutting down power supply to the various functional components of the cleaning device 1.

[0038] FIG. 2 serves to illustrate aspects of a brush 21 according to a first embodiment of the invention. As explained in the foregoing, the brush 21 includes a core element 24 and brush elements 25 arranged on the core element 24, wherein tip portions 25a of the brush elements 25 are configured to contact the surfaces 10 to be cleaned. For the sake of illustration, three brush elements 25 are diagrammatically depicted in FIG. 2, and an outer imaginary cylinder 50 of circular periphery delimiting an area around the core element 24 where the brush elements 25 are present is shown as well. The core element 24 can be of any suitable design, and may generally be shaped as a hollow cylinder, as shown in FIG. 2, or as a solid cylinder, as shown in FIG. 4, for example. The following features are applicable to the brush elements 25: i) the brush elements 25 are arranged in a bristle field 26 extending in a direction of the longitudinal axis 22 of the brush 21 and in a peripheral direction about the longitudinal axis 22, ii) the brush elements 25 comprise fiber hairs, wherein a linear mass density of at least the tip portions 25a of the brush elements 25 is lower than 15 g per 10 km, and iii) an average of a packing density of the brush elements 25 in the bristle field 26 is lower than 15,000 brush elements 25 per 1 cm.sup.2.

[0039] As mentioned, an average of a packing density of the brush elements 25 in the bristle field 26 is lower than 15,000 brush elements 25 per 1 cm.sup.2. A minimum of the average of the packing density of the brush elements 25 in the bristle field 26 may be applicable as well, such as a minimum of 1,000 per 1 cm.sup.2, a minimum of 2,000 per 1 cm.sup.2, or a minimum of 5,000 per 1 cm.sup.2, for example. This is generally applicable in the framework of the invention, independent of other factors. Further, as mentioned, a linear mass density of at least the tip portions 25a of the brush elements 25 is lower than 15 g per 10 km. A minimum of the linear mass density of at least the tip portions 25a of the brush elements may be applicable as well, such as a minimum of 0.7 g per 10 km, a minimum of 0.8 per 10 km, or a minimum of 1 g per 10 km, for example. This is also generally applicable in the framework of the invention, independent of other factors. An example of an outer diameter of the core element 24 is a diameter in an order of magnitude of 20 mm, and an example of a diameter of the outer imaginary cylinder 50, i.e. a diameter of the brush 21 at an outstretched condition of the brush elements 25, is a diameter in an order of magnitude of 40 mm. In such a case, a length of the brush elements 25 is in an order of magnitude of 10 mm.

[0040] Compared to what is known in the art, the average of the packing density of the brush elements 25 in the bristle field 26 of lower than 15,000 brush elements 25 per 1 cm.sup.2 is low and involves a reduction of consumption of energy for driving the brush 21.

[0041] FIG. 3 serves to illustrate aspects of a brush 21 according to a second embodiment of the invention. In the first place, it is noted that the size of the bristle field 26 in the direction of the longitudinal axis 22 of the brush 21 may be the same as the size of the core element 24 in the direction of the longitudinal axis 22 of the brush 21, but that it is also possible that the size of the bristle field 26 in the direction of the longitudinal axis 22 of the brush 21 is smaller than the size of the core element 24 in the direction of the longitudinal axis 22 of the brush 21. The latter is applicable to the brush 21 according to the second embodiment of the invention, and also to the brush 21 according to the third embodiment of the invention as will be described later with reference to FIG. 4. In the second place, it is noted that the brush elements 25 may be substantially equally distributed throughout the bristle field 26, but that it is also possible that the brush elements 25 are unequally distributed throughout the bristle field 26. The latter is the case in the brush 21 according to the second embodiment of the invention, wherein it is so that the bristle field 26 comprises local interruptions. In the shown example, a spiral-shaped strip portion 26a of the bristle field 26 is empty as compared to a continuous, even bristle field 26. For the sake of clarity, it is noted that in the definition of the invention, the local interruptions 26a are regarded as being included in the bristle field 26. This implies that when a bristle field 26 comprising local interruptions 26a is compared to a continuous bristle field 26, a total area of both bristle fields is the same if a longitudinal distance between edge brush elements 25 at a first longitudinal position in the brush 21 and edge brush elements 25 at another, second longitudinal position in the brush 21 is the same and if an extent to which the bristle field 26 spans the periphery of the brush 21 (which may be expected to be a full extent in many practical embodiments of the brush 21) is the same.

[0042] FIG. 4 shows a brush 21 according to a third embodiment of the invention which may comply with at least one of the above-mentioned numerical criteria in respect of the linear mass density of at least the tip portions 25a of the brush elements 25 and the average of the packing density of the brush elements 25 in the bristle field 26, although this is not necessary. FIG. 4 relates to an additional or alternative energy saving measure, and particularly illustrates the fact that in the direction of the longitudinal axis 22 of the brush 21, three different sections 27, 28, 29 of the bristle field 26 can be discerned. In respect of these sections 27, 28, 29 of the bristle field 26, it is noted that a packing density of the brush elements 25 is higher at the position of an intermediate section 27 of the bristle field 26 than at the position of two side sections 28, 29 of the bristle field 26 and which are located at either side of the intermediate section 27. In this way, good dirt and/or liquid removal performance of the brush 21 is obtained while it takes less energy to move the brush 21 over the surface 10 than if the packing density of the brush elements 25 in the bristle field 26 would not be reduced at the position of the two side sections 28, 29 of the bristle field 26. In particular, interaction between the brush 21 and the surface 10 at the position of the intermediate section 27 of the bristle field 26 contributes more to dirt and/or liquid removal performance of the brush 21 than interaction between the brush 21 and the surface 10 at the position of the side sections 28, 29 of the bristle field 26, and interaction between the brush 21 and the surface 10 at the position of the side sections 28, 29 of the bristle field 26 requires less energy than interaction between the brush 21 and the surface 10 at the position of the intermediate section 27 of the bristle field 26.

[0043] With reference to FIGS. 5 and 6, it is noted that it may be practical if the brush 21 comprises a cloth which is provided with the brush elements 25 and which is wrapped around the core element 24. FIG. 5 shows a back side of a portion of an example of a cloth 60 as mentioned. The cloth 60 comprises a backing 61 including a carrier grid of strands 62, wherein tufts 63 of the brush elements are provided on the backing 61 by means of yarns 64 which are interwoven with the strands 62 of the backing 61. FIG. 6 illustrates that by way of example, each yarn 64 is interwoven with three strands 62 in a W-shaped fashion, wherein one outside leg of the W-shaped yarn 64 constitutes a first tuft 63 of brush elements 25, and wherein the other outside leg of the W-shaped yarn 64 constitutes a second tuft 63 of brush elements 25. Each tuft 63 includes a plurality of brush elements 25, wherein the number of brush elements 25 per tuft 63 may be in an order of hundreds of brush elements 25, or even 1,000 brush elements 25 or more.

[0044] It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims. It is intended that the invention be construed as including all such amendments and modifications insofar they come within the scope of the claims or the equivalents thereof. While the invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The invention is not limited to the disclosed embodiments. The drawings are schematic, wherein details which are not required for understanding the invention may have been omitted, and not necessarily to scale.

[0045] Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the claims, the word comprising does not exclude other steps or elements, and the indefinite article a or an does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope of the invention.

[0046] Elements and aspects discussed for or in relation with a particular embodiment may be suitably combined with elements and aspects of other embodiments, unless explicitly stated otherwise. Thus, the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0047] The terms comprise and include as used in this text will be understood by a person skilled in the art as covering the term consist of. Hence, the term comprise or include may in respect of an embodiment mean consist of, but may in another embodiment mean contain/have/be equipped with at least the defined species and optionally one or more other species.

[0048] Notable aspects of the invention are summarized as follows. A brush 21 is configured for use in a cleaning device 1 which is movable across surfaces 10 to be cleaned and comprises a core element 24 and brush elements 25 arranged on the core element 24. The brush elements 25 are arranged in a bristle field 26 extending in a direction of a longitudinal axis 22 of the brush 21 and in a peripheral direction about the longitudinal axis 22, and comprise fiber hairs, wherein a linear mass density of at least tip portions 25a of the brush elements 25 is lower than 15 g per 10 km. An average of a packing density of the brush elements 25 in the bristle field 26 is lower than 15,000 brush elements 25 per 1 cm.sup.2 so as to ensure that for the purpose of moving the brush 21 during a cleaning action, only a relatively small amount of energy is needed.