EP4059399A1

EP4059399A1 - Supplying liquid to at least one area of a surface to be cleaned

Info

Publication number: EP4059399A1
Application number: EP21163065.2A
Authority: EP
Inventors: IJpe Bernardus Brada; Fermín Espín Franco
Original assignee: Koninklijke Philips NV
Current assignee: Koninklijke Philips NV
Priority date: 2021-03-17
Filing date: 2021-03-17
Publication date: 2022-09-21
Also published as: EP4307975A1; WO2022194706A1; AU2022240904A1; CN218852563U; KR20240016942A; CN115104951A; US20240032763A1

Abstract

In the context of vacuum cleaning, a suction head (101) is provided, which comprises a housing (30) that is couplable to an air suction source of a vacuum cleaner, and two brushes (20) in a substantially parallel arrangement in the housing (30), wherein each of the brushes (20) is rotatable about a rotation axis (21) and is configured to interact with a surface (10) to be cleaned. The suction head (101) is further equipped with a wetting arrangement (42) that is arranged and configured to enable a direct supply of liquid from at least one liquid supplying position to at least one area of the surface (10) to be cleaned, wherein the at least one liquid supplying position is in an area (24) between the brushes (20) and at a level of the rotation axes (21) of the brushes (20) or closer to surface level.

Description

FIELD OF THE INVENTION

The invention relates to a suction head configured to be applied in a vacuum cleaner and to perform a cleaning action on a surface, the suction head comprising: a housing that includes a coupling area configured to enable coupling of the housing to an air suction source of the vacuum cleaner, and two brushes in a substantially parallel arrangement in the housing, wherein each of the brushes is rotatable about a rotation axis and is configured to interact with the surface to be cleaned.
Further, the invention relates to a cordless vacuum cleaner comprising a suction head as mentioned.

BACKGROUND OF THE INVENTION

Vacuum cleaners are known for removing dirt from a surface to be cleaned. The term "dirt" as used in the present text is to be understood so as to cover any contamination as may be present on a surface and that can be removed under the influence of a vacuum cleaning action, probably combined with another cleaning action such as mopping. Practical examples in this respect include dust and small particles of any kind, and also wet types of contamination such as spilled drinks. A practical example of the surface to be cleaned is a floor, wherein the floor may be of any kind, such as a wooden floor, a carpet floor, a tile floor, etc.
Generally, a vacuum cleaner has a vacuum cleaner head or suction head, which is the part of the vacuum cleaner where the actual process of picking up dirt from a surface to be cleaned is to take place and which is therefore to be put on or at least close to the surface. Further, a vacuum cleaner normally comprises a body portion including a dirt accumulating area, and an arrangement configured to act on the suction head so that a suction force is prevailing in the suction head during operation of the vacuum cleaner. The suction force serves to facilitate transport of dirt that is picked up from the surface during operation of the vacuum cleaner towards the dirt accumulating area, wherein the dirt is made to pass an outlet opening in a housing of the suction head. The suction force may also have a function in the actual process of picking up the dirt from the surface. On the other hand, the suction head may be equipped with at least one movable component for interacting with the surface in order to pick up the dirt, such as at least one rotatable brush that may serve as an agitator of the dirt and that may particularly be configured to help dislodge dirt from the surface and direct it towards the outlet opening.
WO 2011/083373 A1 discloses a cleaning device for removing particles from a surface, comprising spraying means for spraying droplets of a work fluid, a rotatable brush having flexible brush elements, an inlet for receiving dirtied air such as air laden with particles, and a cleansing unit. The cleansing unit is suitable for separating at least a portion of the droplets of work fluid from the air. During operation, the rotatable brush is wetted by the work fluid. The brush is of such a dimension and is rotated at such a rotational speed that the droplets of the work fluid are expelled as a mist of droplets from the flexible brush elements into a coalescing space of the device. The dirtied air received by the inlet is receivable by the coalescing space, to form coalesced particles of the droplets expelled from the brush elements and particles in the dirtied air, the coalesced particles being conveyable from the coalescing space to the cleansing unit.
WO 2012/107876 A1 discloses a cleaning device comprising a head having an open side for facing surfaces to be cleaned, and at least one brush for contacting surfaces to be cleaned, which is rotatably arranged in the head. The at least one brush is provided with a plurality of brush hairs, wherein it is possible that these brush hairs are extremely soft and flexible. In such a case, a cleaning action of a surface is not performed by scrubbing the surface but by putting the brush hairs alternately in and out of contact with the surface during rotation of the brush. In particular, during one revolution of the brush, the brush hairs remove particles and/or liquid droplets from a soiled surface and fling away the particles and/or the droplets when they reach a position in which they are free from contact to the surface and in which they can be fully outstretched. In the head of the cleaning device, in which the brush is arranged, there are means for receiving the particles and/or the droplets, and for possibly transporting the particles and/or the droplets towards a space where they are collected. The cleaning device may be equipped with means for realizing a suction force at the head in order to direct the particles and/or the droplets in a desired direction once they are released from the brush hairs. Further, it is possible that the cleaning device is configured to supply a cleaning liquid to the rotating brush in order to promote the adherence of particles to the brush hairs and/or to realize an additional cleaning effect on a surface to be cleaned.
WO 2017/071727 A1 discloses a vacuum cleaner head comprising a housing having a vacuum extraction zone and first and second rollers configured to locate against a surface to be cleaned, wherein each of the first and second rollers is configured to pick-up dirt from the surface and carry the dirt to the vacuum extraction zone in the housing of the vacuum cleaner head when being rotated and moved over the surface during operation. The vacuum extraction zone is defined between the outlet opening and the first and second rollers. When the vacuum cleaner head is used in a vacuum cleaner and the vacuum cleaner is operated, an airflow is generated through the vacuum extraction zone to the outlet opening. The vacuum cleaner head may further comprise a liquid dispenser to dispense a liquid onto the surface to be cleaned, and the vacuum cleaner head may further comprise a liquid dispenser to dispense a liquid onto at least one of the first and second rollers. Therefore, it is possible to dampen a surface to be cleaned to promote the removal of detritus from the surface.

SUMMARY OF THE INVENTION

In general, it is an object of the invention to provide measures aimed at achieving good cleaning results of a vacuum cleaning action performed on a surface. Further, it is an object of the invention to provide measures aimed at preventing pollution of the suction head.
In view of the foregoing, the invention provides a suction head configured to be applied in a vacuum cleaner and to perform a cleaning action on a surface, the suction head comprising: a housing that includes a coupling area configured to enable coupling of the housing to an air suction source of the vacuum cleaner, two brushes in a substantially parallel arrangement in the housing, wherein each of the brushes is rotatable about a rotation axis and is configured to interact with the surface to be cleaned, and a wetting arrangement that is arranged and configured to enable a direct supply of liquid from at least one liquid supplying position to at least one area of the surface to be cleaned, wherein the at least one liquid supplying position is in an area between the brushes and at a level of the rotation axes of the brushes or closer to surface level.
It follows from the foregoing definition of the suction head according to the invention that the invention involves equipping the suction head with a wetting arrangement that is arranged and configured to enable a direct supply of liquid from at least one liquid supplying position to at least one area of the surface to be cleaned, and that the at least one liquid supplying position is chosen so as to be in an area between the brushes and at a level of the rotation axes of the brushes or closer to surface level. In this way, it is achieved that the surface to be cleaned is wetted in a controlled fashion, wherein the brushes are wetted in an indirect fashion through contact to the surface so that it is not necessary to have a direct supply of liquid to the brushes, although this is not excluded in the context of the invention. As the suction head is normally moved back and forth on the surface to be cleaned by a user, having a supply of liquid at a position that is between the brushes is sufficient and effective to realize a wet condition of both brushes. By having the at least one liquid supplying position at a level of the rotation axes of the brushes or closer to surface level, it is achieved that a bottom side of the suction head can effectively be cleaned by clear liquid. It is practical if the direct supply of liquid to the at least one area of the surface to be cleaned involves a continuous or intermittent flow of liquid, or spray of liquid, directed from the at least one liquid supplying position on the suction head towards the at least one area. The wetting arrangement can be provided more or less as an add-on to an existing design of a suction head, but it is also possible that the wetting arrangement is provided in a more integrated fashion. A practical example of the liquid is water or a mixture of water and a cleaning agent.
In the context of the invention, it is possible that the at least one liquid supplying position is at a bottom surface portion of the suction head that is arranged and configured to face the surface to be cleaned at a distance of at least 2 mm and at most 6 mm to the surface. In that way, a cleaning effect on the bottom surface portion may be obtained, following from the bottom surface portion not being exposed to the dirt 11 that is flung away by the brushes 20 and a possibility that liquid bridges the distance by surface tension. Keeping the bottom surface portion clean is a way of preventing pollution of the suction head and is thereby also helpful in optimizing cleaning results of the surface to be cleaned as there can be no contaminating effect of a clean surface portion of the suction head on the surface.
In a practical embodiment of the suction head according to the invention, the wetting arrangement is arranged and configured to enable a direct supply of liquid from at least two liquid supplying positions distributed over the suction head in the direction in which the rotation axes of the brushes extend. Having the distribution of the liquid supplying positions as mentioned is a factor in achieving that the brushes are sufficiently wetted, without any dry or nearly-dry areas which might render the cleaning action less effective.
According to an advantageous option, the suction head comprises an elongated intermediate component that is located in an area between the brushes and that optionally comprises two portions configured to cover portions of the brushes. It is practical if, at the position of a top side thereof, the elongated intermediate component is suspended from a portion of the housing of the suction head. Covering as much as possible of the brushes, preferably at a very close range, is beneficial when it comes to effectively invoking the suction force in the suction head. The elongated intermediate component may be an integral part of the housing or may be provided as a separate component that could be removably coupled to another component of the housing so as to allow repair or cleaning, for example. On the one hand, the presence of the elongated intermediate component in the suction head disables a known option according to which the one brush wets the other brush during operation, but on the other hand, the elongated intermediate component may have a function in facilitating liquid supply, and also in preventing pollution of internal surfaces of the suction head. In particular, it is possible that the at least one liquid supplying position is at a bottom surface portion of the elongated intermediate component that is arranged and configured to face the surface to be cleaned. When this bottom surface portion of the elongated intermediate component is arranged so as to be close to the surface to be cleaned, i.e. when this bottom surface portion is arranged and configured to face the surface to be cleaned at a distance of at least 2 mm and at most 6 mm to the surface as suggested earlier, the above-described cleaning effect is realized on this bottom surface portion.
It is practical if the wetting arrangement comprises a conduit system configured to transport liquid and to let out liquid at the at least one liquid supplying position. In the case that the suction head comprises the above-mentioned elongated intermediate component, it may be so that the conduit system comprises at least one conduit extending through the elongated intermediate component. Especially when the wetting arrangement is arranged and configured to enable a direct supply of liquid from two or more liquid supplying positions to two or more areas of the surface to be cleaned, it may be advantageous if the above-mentioned conduit system comprises at least one main conduit and at least one branch conduit that is coupled to the at least one main conduit and that extends from the at least one main conduit towards the at least one liquid supplying position. In such a case, the main conduit may serve as a kind of buffer and/or distributor of the liquid. In order to control the flow of liquid from the at least one main conduit to the at least one branch conduit, it may be helpful if a restricted liquid passage is present at an interface of the at least one main conduit and the at least one branch conduit. In an embodiment of the suction head in which the option that the suction head comprises the elongated intermediate component and that at least one conduit of the conduit system extends through the elongated intermediate component is combined with the option that the conduit system comprises at least one main conduit and at least one branch conduit, it may typically be so that the at least one branch conduit is the at least one conduit extending through the elongated intermediate component.
In an advantageous embodiment, the suction head comprises a restriction element in fluid communication with the at least one main conduit and the at least one branch conduit, wherein the restriction element is provided with at least one restriction opening configured to allow liquid to pass in a direction from the at least one main conduit towards the at least one branch conduit. In this embodiment, it may be so that the restriction element or an assembly of components in which the restriction element is included is removably arranged in the suction head. This allows for easy cleaning of the restriction element in order to avoid clogging of the at least one restriction opening of the restriction element.
The wetting arrangement can be used for other purposes besides supplying liquid to at least one area of the surface to be cleaned. For example, assuming that the suction head comprises at least one wheel that is rotatably arranged on the suction head and that is configured to be in contact with the surface to be cleaned, it is possible that the wetting arrangement is further arranged and configured to enable a direct supply of liquid to the at least one wheel. A notable advantage of this option is that cleaning of the at least one wheel can take place automatically, without a need for action from the side of the user and without a need for external cleaning tools nor tools for dismantling the components of the suction head. Thus, a very reliable way of keeping the at least one wheel of the suction head clean is provided, whereby a situation in which the at least one wheel might be of influence on the cleaning result is avoided. In particular, the wetting arrangement may be arranged and configured to enable a direct supply of liquid to the at least one wheel at the position of the tread of the at least one wheel, from outside of the at least one wheel. In that case, the at least one wheel can simply be of conventional design and made up of one or more conventional materials such as plastic and rubber, and the at least one wheel can be mounted in the suction head in any suitable known way. The rotating movement of the wheel can be used to advantage when it comes to spreading the liquid over the entire tread of the wheel. An additional measure aimed at keeping the at least one wheel clean involves arranging the at least one wheel so that the rotating brushes are enabled to interact with the wheel during operation of the suction head. A further effect of this measure may be that portions of the brushes which is near the wheel is wetted to some extent by the wheel. In any case, it may be so that the at least one wheel is located in an area between the brushes.
In the context of the invention, the brushes may be of any type that is suitable to be used for picking up dirt from a surface to be cleaned, wherein the brushes may be chosen to be either identical or different. Each of the brushes may especially be designed to serve as an agitator, for example, agitating dirt particles as may be present on the surface. In a practical embodiment of the suction head according to the invention, at least one of the brushes comprises a core element and flexible microfiber elements arranged on the core element. In such a brush, a linear mass density lower than 150 g per 10 km may be applicable to the microfiber elements, or at least tip portions thereof, so that the microfiber elements really can be highly flexible. The linear mass density as mentioned may even be lower than 10 g per 10 km, 5 g per 10 km or 1 g per 10 km. Such microfiber elements can be placed on the core element in a dense arrangement so as to very effectively interact with a surface to be cleaned during operation of the suction head. Further, it may be practical if such microfiber elements are arranged on the core element in tufts.
It is practical if an operational shape of both brushes is generally the shape of a cylinder having a circular periphery, in other words, if the operational shape of the brushes is generally the shape of a roller, which may be an elongated roller.
The invention further relates to a vacuum cleaner, particularly a cordless vacuum cleaner, comprising a suction head as defined and described in the foregoing, which is equipped with a wetting arrangement that is arranged and configured to enable a direct supply of liquid from at least one liquid supplying position to at least one area of a surface to be cleaned. It is practical if such a vacuum cleaner comprises a reservoir that is configured to receive liquid, to contain liquid, and to let out liquid to the wetting arrangement of the suction head. Advantageously, the reservoir is removably arranged on the vacuum cleaner so that it is easy for a user to take the reservoir to a place where the reservoir can be filled with liquid.
The above-described and other aspects of the invention will be apparent from and elucidated with reference to the following detailed description of a practical embodiment of a suction head comprising a housing and two brushes arranged in the housing, and further comprising a wetting arrangement that is arranged and configured to enable a direct supply of liquid from at least one liquid supplying position to at least one area of a surface to be cleaned.

BRIEF DESCRIPTION OF THE DRAWINGS

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:

Fig. 1 diagrammatically shows components of a wet vacuum cleaner according to an embodiment of the invention and a portion of a floor having a surface to be cleaned,
Fig. 2 diagrammatically shows a view of a longitudinal section of a suction head according to an embodiment of the invention, taken at a position between two brushes which are included in the suction head,
Fig. 3 shows an enlarged detail of Fig. 2,
Fig. 4 diagrammatically shows a perspective top view of a portion of the suction head,
Figs. 5 and 6 diagrammatically show views of a cross-section of the suction head, taken at different longitudinal positions on the suction head,
Fig. 7 shows an enlarged detail of Fig. 6, and
Fig. 8 illustrates an optional set-up of a conduit system of a wetting arrangement that is included in the suction head.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Fig. 1 illustrates the design of a wet vacuum cleaner 100 according to an embodiment of the invention. The particular vacuum cleaner represented in Fig. 1 and described in the following is just one example of many types of vacuum cleaners which are feasible in the framework of the invention. In this respect, it is noted that the invention does not only relate to wet vacuum cleaners, but also to other types of vacuum cleaners such as wet/dry vacuum cleaners having a dry cleaning function besides a wet cleaning function.
The wet vacuum cleaner 100 is configured to be used for the purpose of subjecting a surface 10 such as a floor surface to a wet cleaning action. Fig. 1 shows the vacuum cleaner 100 in a normal, operational orientation relative to the surface 10 to be cleaned. The use in the present text of a term having an orientation aspect is to be understood in relation to this normal, operational orientation of the vacuum cleaner 100 relative to the surface 10 to be cleaned, wherein it is assumed that the surface 10 is at a bottom position and the vacuum cleaner 100 is placed on the surface 10.
At a side that is supposed to face the surface 10 during operation of the vacuum cleaner 100, the vacuum cleaner 100 comprises a suction head 101 accommodating two brushes 20 which are configured to interact with the surface 10 during operation of the vacuum cleaner 100. In the following, it is assumed that each of the brushes 20 is provided in the form of a roller that is rotatable about a rotation axis 21 that is defined by a central longitudinal axis of the roller, and that each of the brushes 20 comprises a core element 22 and flexible microfiber elements 23 arranged on the core element 22, which does not alter the fact that other embodiments of the brushes 20 are possible as well. The brushes 20 may be identical, but this is not necessary in the context of the invention. As indicated in Fig. 1 by means of curved arrows depicted at the position of the brushes 20, the brushes 20 are arranged so as to be rotatable in opposite directions with respect to each other about their respective rotation axes 21. The suction head 101 comprises a housing 30 that is configured to partially cover the brushes 20. The housing 30 can be made of a plastic material, for example.
Besides the suction head 101, the vacuum cleaner 100 comprises a body portion 102 that is configured to be taken hold of by a user of the vacuum cleaner 100. Preferably, the suction head 101 and the body portion 102 are removably couplable to each other. The body portion 102 can be shaped in any appropriate way. The outline of the body portion 102 as shown in Fig. 1 is of a diagrammatical nature only. It is practical if the body portion 102 comprises a handle so that a user can easily take hold of the body portion 102 and move the vacuum cleaner 100 across the surface 10 to be cleaned as desired.
For the purpose of driving the brushes 20 during operation of the vacuum cleaner 100, the vacuum cleaner 100 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 vacuum cleaner 100, the vacuum cleaner 100 may be connectable to the mains and/or may be equipped with a suitable battery arrangement. Preferably, the vacuum cleaner 100 is a cordless device comprising a rechargeable battery arrangement, in which case it may further be practical if the vacuum cleaner 100 is part of a set including a charging dock besides the vacuum cleaner 100. Such a set may also include a flushing tray that can be used for the purpose of cleaning the brushes 20. In case the vacuum cleaner 100 is not equipped with a battery, a simple dock that is without charging ability may be provided for receiving and holding the vacuum cleaner 100 while the vacuum cleaner 100 is not being operated.
The body portion 102 of the vacuum cleaner 100 includes a liquid reservoir 40 that serves for containing a liquid such as water or a mixture of water and a cleaning agent, and a liquid supply mechanism 41 that serves for supplying the liquid to a wetting arrangement 42 of the suction head 101 during operation of the vacuum cleaner 100. The liquid supply mechanism 41 may comprise any suitable type of pump arrangement, for example, or may be configured to enable displacement of the liquid as desired under the influence of gravity. In the shown example, the wetting arrangement 42 of the suction head 101 is configured to enable both a direct supply of liquid to areas of the surface 10 to be cleaned and a direct supply of liquid to two wheels 90 of the suction head 101 (see Figs. 2, 3, 5 and 6), as will be explained later in more detail. Further, in the shown example, the suction head 101 comprises an elongated intermediate component 25 that is located in an area 24 between the brushes 20 and that comprises two concavely curved portions configured to cover portions of the brushes 20, and the wetting arrangement 42 comprises a conduit system 43 that is partially arranged in the elongated intermediate component 25 and that is configured to transport the liquid and to let out the liquid to the areas of the surface 10 and to the two wheels 90. In Fig. 1, the liquid reservoir 40, the liquid supply mechanism 41 and the wetting arrangement 42 of the suction head 101 are indicated by means of dotted lines. It is practical if the liquid reservoir 40 is removably coupled to the body portion 102 so that a user is enabled to separate the liquid reservoir 40 from the body portion 102 when it is desired to take the liquid reservoir 40 to a place where the liquid reservoir 40 is to be filled with liquid.
The body portion 102 of the vacuum cleaner 100 further includes a dirt reservoir 50 that serves for receiving and accumulating wet dirt 11 that is picked up from the surface 10 by the brushes 20 during operation of the vacuum cleaner 100. The dirt reservoir 50 can be configured in numerous ways as conventionally available for accumulating wet dirt from the incoming dirt 11 that is picked up from the surface 10 such as for instance a cyclonic arrangement or a tube-in-cup arrangement. The body portion 102 includes a vacuum mechanism 60 configured to create underpressure that is functional to enable transport of the dirt 11 from the area where the brushes 20 are located to the dirt reservoir 50 in the body portion 102, through an outlet opening 31 in a surface 32 of the housing 30 facing the brushes 20 and a suction channel 51 extending from the outlet opening 31 to the dirt reservoir 50. As can be seen in the view of the portion of the suction head 101 in Fig. 4, the housing 30 includes a coupling area 33 that is configured to enable coupling of the housing 30 to the assembly of the suction channel 51, the dirt reservoir 50 and the vacuum mechanism 60 in the body portion 102 of the vacuum cleaner 100. The outlet opening 31 is in fluid communication with this coupling area 33.
Basic aspects of the way in which the wet vacuum cleaner 100 is operated are as follows. During operation, the brushes 20 are driven so as to rotate and the liquid supply mechanism 41 is activated so as to supply liquid to the wetting arrangement 42 of the suction head 101 so that liquid may be let out to the surface 10 to be cleaned and to the two wheels 90. Any stains as may be present on an area of the surface 10 that is within reach of the brushes 20 are detached under the influence of the liquid and agitation by the brushes 20, and dirt particles and dust as may be present on the area of the surface 10 are removed along with the liquid and conveyed to the dirt reservoir 50, passing through the outlet opening 31 and the suction channel 51 in the process. The dirt 11 is picked up from the surface 10 by tip portions of the microfiber elements 23 of the brushes 20 and is flung away from the tip portions as the brushes 20 rotate, at a position where the tip portions move out of contact to the surface 10.
As illustrated in Fig. 1, the vacuum cleaner 100 may be equipped with a user interface 70, which user interface 70 may include an on/off button 71, for example. The vacuum cleaner 100 may further comprise a controlling system 80 including a microcontroller that is programmed to put the brushes 20 in motion and to activate both the liquid supply mechanism 41 and the vacuum mechanism 60 in reaction to input received from the user through the user interface 70 to that end.
Figs. 2-8 serve to illustrate aspects of a suction head 101 according to an embodiment of the invention, especially aspects of the wetting arrangement 42 of the suction head 101. It can be seen in Figs. 2 and 4 that the conduit system 43 of the wetting arrangement 42 comprises two main conduits 44, 45 which are located in different halves of the suction head 101 as seen in a longitudinal direction / being the direction which the rotation axes 21 of the brushes 20 extend, and which are couplable to the liquid supply mechanism 41. Further, the conduit system 43 comprises four branch conduits 46, 47, 48, 49, namely, as seen from left to right in Fig. 2, i) a branch conduit 46 that is coupled to a first one 44 of the main conduits 44, 45, that is configured to let out liquid to one of the wheels 90, and that extends from the first one 44 of the main conduits 44, 45 to the wheel 90, ii) a branch conduit 47 that is also coupled to the first one 44 of the main conduits 44, 45, at a longitudinal position more or less between the wheel 90 and the outlet opening 31, that is configured to let out liquid to a first area of the surface 10 to be cleaned, and that extends from the first one 44 of the main conduits 44, 45 to the surface 10, iii) a branch conduit 48 that is coupled to a second one 45 of the main conduits 44, 45, at a longitudinal position more or less between another wheel 90 and the outlet opening 31, that is configured to let out liquid to a second area of the surface 10 to be cleaned, and that extends from the second one 45 of the main conduits 44, 45 to the surface 10, and iv) a branch conduit 49 that is also coupled to the second one 45 of the main conduits 44, 45, that is configured to let out liquid to the other wheel 90, and that extends from the second one 45 of the main conduits 44, 45 to the wheel 90.
The branch conduits 47, 48 which are configured to let out liquid to the surface 10 to be cleaned are arranged to partially extend through the elongated intermediate component 25, and the liquid supplying positions where the liquid is let out to the surface 10 are at a bottom side of the elongated intermediate component 25, i.e. at a bottom surface portion 26 of the elongated intermediate component 25 that is arranged and configured to face the surface 10 to be cleaned. In this respect, it is noted that in general, in the context of the invention, the liquid supplying positions where the liquid is let out to the surface 10 are at a level of the rotation axes 21 of the brushes 20 or closer to surface level, i.e. at the level of the rotation axes 21 of the brushes 20 or at a lower level.
Letting out liquid to the surface 10 at liquid supplying positions which are distributed along the brushes 20 in the longitudinal direction 1 is a factor in achieving that the brushes 20 are sufficiently wetted, without any dry or nearly-dry areas which might render the cleaning action less effective. Letting out liquid to the wheels 90 during operation of the suction head 101 results in keeping the wheels 90 wet and clean, so that any negative influences on the results of the action of cleaning the surface 10 following from the fact that the surface 10 is contacted by the wheels 90 are avoided. It can be seen in Figs. 2 and 3 that the position at which the liquid is let out to a wheel 90 is a position right above the wheel, such that the liquid can be received by the wheel 90 at the position of the tread 91 thereof.
Fig. 5 shows another advantageous aspect of the design of the suction head 101 according to the embodiment of the invention, which resides in the fact that each of the two wheels 90 is arranged so as to be in contact with the brushes 20, especially with the microfiber elements 23 of the brushes 20. In the first place, this contributes to keeping the wheels 90 clean. In the second place, this contributes to realizing that the brushes 20 are wetted along their length, i.e. their dimension in the longitudinal direction 1.
Fig. 6 illustrates the advantageous option of the at least one liquid supplying position for letting out liquid to the surface 10 to be cleaned being at a bottom surface portion of the suction head 101 that is arranged and configured to face the surface 10 at a distance of at least 2 mm and at most 6 mm to the surface 10. By having only a small space between the surface 10 and the bottom surface portion of the suction head 101, it is achieved that the bottom surface portion of the suction head 101 is effectively kept clean. It is practical if the bottom surface portion of the suction head 101 that is arranged and configured to face the surface 10 at the relatively small distance to the surface 10 as mentioned comprises the bottom surface portion 26 of the elongated intermediate component 25.
On the basis of the foregoing, an overview of the advantageous aspects of the small space between the surface 10 to be cleaned and the bottom surface portion of the suction head 101 is provided:

The liquid beneath the bottom surface portion bridges with the surface 10 and cleans the bottom surface portion by means of the surface tension, capturing small dirt particles that could adhere to the bottom surface portion.
The flow of clean liquid from the different positions at which the liquid is let out has a direct cleaning effect on the bottom surface portion, especially on the bottom side of the elongated intermediate component 25.
The movement of the suction head 101 results in the area underneath the bottom surface portion being in constant interaction with the brushes 20.

It is further noted that it is advantageous if the surface 32 of the housing 30 facing the brushes 20 is arranged so as to cover the brushes 20 at only a minimal distance, as in that case, the suction force is effectively invoked in the suction head 101, as a result of which air speed along the surface 32 can be relatively high, which also contributes to keeping the surface 32 clean, besides the fact that there is practically no room where dirt might build up.
In order to promote equal distribution of the liquid over the respective branch conduits 46, 47, 48, 49, it is practical if a restricted liquid passage 27 is present at an interface of the main conduits 44, 45 and the respective branch conduits 46, 47, 48, 49, as can best be seen in Fig. 7. The fact is that the restricted liquid passages 27 function to prevent drainage of the main conduits 44, 45 at the position of the branch conduit 47, 48 that comes first as seen in a downstream direction, which would hamper the supply of fluid to the other branch conduit 46, 49. Hence, on the basis of the presence of the restricted liquid passages 27, controlled retrieval of liquid from the main conduits 44, 45 at the positions where the branch conduits 46, 47, 48, 49 are coupled to the main conduits 44, 45 is realized.
Fig. 8 illustrates an option according to which a main conduit 44 is more or less dimensioned so as to serve as a buffer of the liquid 15, and according to which a restriction element 28 is applied at the position where the respective branch conduits 46, 47 are coupled to the main conduit 44. In the shown example, the restriction element 28 comprises a strip that is provided with two restriction openings. The restriction openings are dimensioned so as to realize restricted liquid passages 27 which are configured to create a flow of droplets of the liquid 15 rather than a continuous flow. Preferably, the restriction element 28 or an assembly of components in which the restriction element 28 is included is removably arranged in the suction head 101 so that the restriction element 28 or the entire assembly may be removed by a user from time to time for cleaning purposes. Cleaning the restriction element 28 and possibly also adjoining components on a regular basis may especially be helpful in avoiding that the restriction openings get clogged and that the supply of liquid 15 to the wheels 90 and the surface 10 to be cleaned is thereby hindered.
Although both the option of directly supplying liquid 15 to at least one area of the surface 10 to be cleaned and the option of directly supplying liquid 15 to the at least one wheel 90 are illustrated and explained in the context of a single embodiment of the suction head 101 according to the invention, it is to be understood that the options can be applied independently. Further, it is noted that additionally or alternatively to the option of directly supplying liquid 15 to the at least one wheel 90, an option of directly supplying liquid 15 to a position in the suction head 101, such as a position on one or both of the brushes 20, is feasible in the context of the invention. Generally speaking, the wetting arrangement 42 may be realized in any suitable way. For instance, it is possible to design the wetting arrangement 42 with a functionality to temporarily stop the supply of liquid to the at least one wheel 90 if so desired. This may be useful in view of a situation in which a type of surface 10 to be cleaned requires more than an average amount of liquid, this may allow a user to manually initiate a cleaning action of the at least one wheel 90 from time to time, etc.
When the suction head 101 comprises an elongated intermediate element 25 covering a portion of the brushes 20 from the bottom side of the suction head 101, as is the case in the shown embodiment of the suction head 101, it may be beneficial to use the elongated intermediate element 25 to accommodate at least a portion of one or more conduits of a conduit system 43 of the wetting arrangement 42, but this is not essential in the context of the invention.
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.
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.
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.
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".
Notable aspects of the invention are summarized as follows. In the context of vacuum cleaning, a suction head 101 is provided, which is of the type comprising: a housing 30 that is couplable to an air suction source 60 of a vacuum cleaner 100, and two brushes 20 in a substantially parallel arrangement in the housing 30, wherein each of the brushes 20 is rotatable about a rotation axis 21 and is configured to interact with a surface 10 to be cleaned. The suction head 101 is further equipped with a wetting arrangement 42 that is arranged and configured to enable a direct supply of liquid 15 from at least one liquid supplying position to at least one area of the surface 10 to be cleaned, wherein the at least one liquid supplying position is in an area 24 between the brushes 20 and at a level of the rotation axes 21 of the brushes 20 or closer to surface level.

Claims

Suction head (101) configured to be applied in a vacuum cleaner (100) and to perform a cleaning action on a surface (10), the suction head (101) comprising:
a housing (30) that includes a coupling area (33) configured to enable coupling of the housing (30) to an air suction source (60) of the vacuum cleaner (100),

two brushes (20) in a substantially parallel arrangement in the housing (30), wherein each of the brushes (20) is rotatable about a rotation axis (21) and is configured to interact with the surface (10) to be cleaned, and

a wetting arrangement (42) that is arranged and configured to enable a direct supply of liquid (15) from at least one liquid supplying position to at least one area of the surface (10) to be cleaned, wherein the at least one liquid supplying position is in an area (24) between the brushes (20) and at a level of the rotation axes (21) of the brushes (20) or closer to surface level.
Suction head (101) according to claim 1, wherein the at least one liquid supplying position is at a bottom surface portion of the suction head (101) that is arranged and configured to face the surface (10) to be cleaned at a distance of at least 2 mm and at most 6 mm to the surface (10).
Suction head (101) according to claim 1 or 2, wherein the wetting arrangement (42) is arranged and configured to enable a direct supply of liquid (15) from at least two liquid supplying positions distributed over the suction head (101) in the direction (l) in which the rotation axes (21) of the brushes (20) extend.
Suction head (101) according to any of claims 1-3, comprising an elongated intermediate component (25) that is located in an area (24) between the brushes (20) and that optionally comprises two portions configured to cover portions of the brushes (20).
Suction head (101) according to claim 4, wherein the elongated intermediate component (25), at the position of a top side thereof, is suspended from a portion of the housing (30).
Suction head (101) according to claim 4 or 5, wherein the at least one liquid supplying position is at a bottom surface portion (26) of the elongated intermediate component (25) that is arranged and configured to face the surface (10) to be cleaned.
Suction head (101) according to any of claims 1-6, wherein the wetting arrangement (42) comprises a conduit system (43) configured to transport liquid (15) and to let out liquid (15) at the at least one liquid supplying position.
Suction head (101) according to claim 7 insofar as dependent on claim 6, wherein the conduit system (43) comprises at least one conduit (47, 48) extending through the elongated intermediate component (25).
Suction head (101) according to claim 7 or 8, wherein the conduit system (43) comprises at least one main conduit (44, 45) and at least one branch conduit (47, 48) that is coupled to the at least one main conduit (44, 45) and that extends from the at least one main conduit (44, 45) towards the at least one liquid supplying position.
Suction head (101) according to claim 9, comprising a restriction element (28) in fluid communication with the at least one main conduit (44, 45) and the at least one branch conduit (47, 48), wherein the restriction element (28) is provided with a restriction opening configured to allow liquid (15) to pass in a direction from the at least one main conduit (44, 45) towards the at least one branch conduit (47, 48), and wherein the restriction element (28) or an assembly of components in which the restriction element (28) is included is removably arranged in the suction head (101).
Suction head (101) according to any of claims 1-10, comprising at least one wheel (90) that is rotatably arranged on the suction head (101) and that is configured to be in contact with the surface (10) to be cleaned, wherein the wetting arrangement (42) is further arranged and configured to enable a direct supply of liquid (15) to the at least one wheel (90).
Suction head (101) according to claim 11, wherein the wetting arrangement (42) is arranged and configured to enable a direct supply of liquid (15) to the at least one wheel (90) at the position of the tread (91) of the at least one wheel (90), from outside of the at least one wheel (90).
Suction head (101) according to claim 11 or 12, wherein the at least one wheel (90) is arranged so that the rotating brushes (20) are enabled to interact with the wheel (90) during operation of the suction head (101).
Suction head (101) according to any of claims 11-13, wherein the at least one wheel (90) is located in an area (24) between the brushes (20).
Cordless vacuum cleaner (100), comprising a suction head (101) according to any of claims 1-14.