Suction head for application in a vacuum cleaner

Abstract

In a suction head 101 of the kind applied in a vacuum cleaner and configured to perform a cleaning action on a surface 10, comprising a housing 30 and two rotatable brushes 20 in a substantially parallel configuration on the housing 30, a face 32 of the housing 30 facing the brushes 20 comprises two adjacent concavely curved regions 34, 35, each of which covers a portion of a respective brush 20a, 20b of the brushes 20. Furthermore, the face 32 comprises an outlet opening 31 in fluid communication with a joining region 33 of the suction head 101, the outlet opening 31 being located at the interface of the concavely curved regions 34, 35 and having dimensions such that it covers only a portion of the length of the brushes 20.

Description

[Technical field]

[0001] The present invention relates to a suction head applied in a vacuum cleaner and configured to perform a cleaning action on a surface, the suction head comprising a housing, the housing including a coupling area configured to enable coupling of the housing with an air suction source of the vacuum cleaner, and two brushes in a substantially parallel configuration on the housing, each of the brushes being rotatable about an axis of rotation and configured to interact with the surface to be cleaned, each of the brushes being designed to be able to pick up liquid from the surface.

[0002] Furthermore, the invention relates to a cordless vacuum cleaner comprising a suction head as described above. [Background technology]

[0003] Vacuum cleaners are known for removing dust from surfaces to be cleaned. As used in this document, the term "dust" should be understood to include any dirt present on a surface and that can be removed under the effect of a vacuum cleaning action, possibly combined with another cleaning action such as wiping. Practical examples in this respect include any kind of dust and small particles, as well as wet types of dirt such as spilled drinks. Practical examples of surfaces to be cleaned include floors, which may be any kind of floor, such as wooden floors, carpet floors, tile floors, etc.

[0004] 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 dust from the surface to be cleaned takes place and therefore should be placed on the surface or at least close to the surface. Furthermore, the vacuum cleaner usually comprises a body part including a dust accumulation area and a component configured to act on the suction head so that a suction force is active at the suction head during the operation of the vacuum cleaner. The suction force acts to facilitate the transport of the dust picked up from the surface towards the dust accumulation area during the operation of the vacuum cleaner, where the dust passes through the outlet opening of the housing of the suction head. The suction force also has a function in the actual process of picking up dust from the surface. Meanwhile, the suction head comprises at least one movable component for interacting with the surface to pick up the dust, such as at least one rotatable brush configured to act as a dust agitator and in particular to help remove the dust from the surface and send it towards the outlet opening.

[0005] WO2011 / 083373A1 discloses a cleaning device for removing particles from surfaces, the cleaning device comprising spray means for spraying droplets of a working fluid, a rotatable brush with flexible brush elements, an inlet for receiving dirty air, such as air carrying particles, and a cleansing unit. The cleansing unit is suitable for separating at least a portion of the droplets of the working fluid from the air. During operation, the rotatable brush is moistened by the working fluid. The brush is dimensioned and rotates at such a rotational speed that the droplets of the working fluid are thrown from the flexible brush elements into a coalescence space of the device as a mist of droplets. The dirty air received by the inlet can be received by the coalescence space, forming coalescence particles of the droplets thrown from the brush elements and the particles in the dirty air, the coalescence particles being transferable from the coalescence space to the cleansing unit.

[0006] WO2012 / 107876A1 discloses a cleaning device comprising a head with an open side facing the surface to be cleaned and at least one brush rotatably arranged on the head and in contact with the surface to be cleaned. The at least one brush comprises a number of bristles, which can be very soft and flexible. In such a case, the cleaning action of the surface is not performed by rubbing the surface, but by alternating between contacting and removing the bristles from the surface during the rotation of the brush. In particular, during one revolution of the brush, the bristles remove particles and / or droplets from the contaminated surface and shake them off when they reach a position where they can completely spread out away from contact with the surface. In the head of the cleaning device, where the brush is arranged, there are means for receiving the particles and / or droplets and possibly for transporting the particles and / or droplets towards a space where the particles and / or droplets are collected. The cleaning device comprises means for realizing a suction force at the head in order to send the particles and / or droplets in a desired direction when they are released from the bristles. Furthermore, the cleaning device can also be configured to supply a cleaning liquid to the rotating brush in order to promote adhesion of the particles to the bristles and / or to realise an additional cleaning effect on the surface to be cleaned.

[0007] WO2017 / 071727A1 discloses a vacuum cleaner head comprising a housing having a vacuum extraction zone and first and second rollers configured to be positioned against a surface to be cleaned, each of the first and second rollers configured to pick up dust from the surface when rotating and moving over the surface during operation and to convey the dust to the vacuum extraction zone in the housing of the vacuum cleaner head. The vacuum extraction zone is defined between an outlet opening and the first and second rollers. When the vacuum cleaner head is used in a vacuum cleaner and the vacuum cleaner is operating, an airflow is generated through the vacuum extraction zone to the outlet opening. The vacuum cleaner head further comprises a liquid dispenser for delivering liquid onto the surface to be cleaned, the vacuum cleaner head further comprises a liquid dispenser for delivering liquid to at least one of the first and second rollers. Thus, the surface to be cleaned can be moistened to facilitate removal of debris from the surface.

[0008] In the field of suction heads used for wet vacuum cleaning, contamination of the surfaces of these suction heads is a problem. A combination of liquid and debris is a good recipe for dust adhesion to the surfaces of the suction head, including the surface facing the brush, hereafter referred to as the internal surface. This type of contamination is very difficult to remove. Deposits that are not completely dry are a good environment for microorganisms to grow and produce odors. Users of the suction heads will perceive both of these as unhygienic. In some cases, the suction heads need to be subjected to a cleaning operation after use or after several uses. Summary of the Invention [Problem to be solved by the invention]

[0009] Generally, it is an object of the present invention to provide measures aimed at achieving good cleaning results of a vacuum cleaning operation carried out on a surface, and further to provide measures aimed at preventing contamination of the suction head. [Means for solving the problem]

[0010] In view of the above, the present invention provides a suction head adapted for application in a vacuum cleaner and adapted to perform a cleaning operation on a surface, the suction head comprising a housing, the housing including a coupling area adapted to enable coupling of the housing with an air suction source of the vacuum cleaner, and two brushes in a substantially parallel configuration on the housing, each of the brushes being rotatable about an axis of rotation and adapted to interact with the surface to be cleaned, each of the brushes designed to be able to pick up liquid from the surface, the face of the housing facing the brushes comprising two adjacent concavely curved regions, each of the concavely curved regions covering a portion of a respective one of the brushes, the face of the housing facing the brushes comprising an outlet opening in fluid communication with the coupling area, the outlet opening being at the interface of the concavely curved regions and having a dimension such that it covers only a portion of the dimension of the brushes in a longitudinal direction, which is the direction along which the axis of rotation of the brushes extends.

[0011] Given the above definition of the suction head according to the invention, various features become applicable to the suction head. In the following, the background of these features is explained. According to the insight behind the invention, in order to keep the internal surface of the suction head as clean as possible during its use, it is beneficial to keep the air velocity along the surface as high as possible. Three ways are known to increase the air velocity: i) by creating a resistance between the surroundings and the air suction source, resulting in a high pressure, ii) by directing the airflow through a narrow gap, and iii) by applying a high suction force. The latter option is not interesting in the context of a battery-powered vacuum cleaner.

[0012] In view of the above, a first aspect of the approach of the invention is to create a narrow gap, thereby increasing the air velocity and the pressure experienced. The invention therefore involves the encapsulation of the brush in areas of the brush that are not intended to face the surface to be cleaned or to be exposed to the outlet opening in the face of the housing facing the brush. This aspect is based on the feature that the face of the housing facing the brush comprises two adjacent concavely curved areas, each of which covers a portion of a respective one of the brushes.

[0013] A second aspect of the approach of the invention is to have the outlet opening on the face of the housing facing the brush at a strategic location in the suction head, keeping the size of the outlet opening limited. This aspect is based on the feature that the outlet opening is at the interface of the concavely curved area and has a size such that it covers only a part of the length of the brush, i.e. only a part of the dimension of the brush in the longitudinal direction, in the direction in which the rotation axis of the brush extends. This differs from the solutions in the prior art, where the outlet opening often extends along (almost) the entire length of the brush, i.e. along the entire dimension of the brush in the direction of its longitudinal axis.

[0014] Preferably, each of the concavely curved areas of the housing surface facing the brushes follows the working contour of a portion of the respective brush of the brushes at a distance of up to 10 mm. Preferably, said distance is in the range of 0 mm to 2 mm so as to obtain an air velocity along the housing surface with a real cleaning effect on the housing surface. The narrow gap thus obtained also entails a cleaning effect due to the fact that there is practically no room for dust to accumulate.

[0015] Furthermore, it is beneficial to create a narrow gap along as much of the brush as possible. In view of this, it is advantageous if each of the concavely curved regions of the housing surface facing the brushes covers at least a portion of each of the brushes, which is the upper half of the brush. Preferably, at least 65% of the dimension of each of the brushes around the respective rotation axis is covered, at a distance ranging from 0 mm to 2 mm. Furthermore, each of the concavely curved regions of the housing surface facing the brushes may cover each of the brushes along the entire length of the brushes.

[0016] In a practical embodiment of the suction head according to the invention, the working shape of each of the brushes is generally cylindrical with a circular outer periphery, in other words, the working shape of the brushes is generally that of a roller, which roller is an elongated roller, in which case, in order to encapsulate as much of the brushes as possible as desired, it is advantageous if each of the concavely curved areas of the surface of the housing facing the brushes covers a respective one of the brushes at the location of a portion of the curved working contour, and it is advantageous if the surface of the housing facing the brushes also comprises an area covering the ends of the brushes.

[0017] It is also practical for the suction head to comprise an airflow directing component comprising a tubular element in fluid communication with an outlet opening in the face of the housing facing the brush and extending towards the coupling region. According to the invention, in particular, the airflow directing component comprises fangs, which are in fluid communication with the outlet opening in the face of the housing and extend on the sides of the tubular element, which are opposite sides in a direction perpendicular to the longitudinal direction of the tubular element at the location of the interface of the concavely curved region of the face of the housing facing the brush. Among other things, the presence of fangs ensures a smooth introduction of air in the tubular element and helps to avoid the adhesion of dirt, which would otherwise be expected.

[0018] The measure aimed at preventing contamination of the wall of the cylindrical element is in the configuration in which the part of the wall of the cylindrical element, located above the outlet opening on the face of the housing facing the brush, is oriented non-perpendicularly to the flow direction, which is from the face to be cleaned through the outlet opening and upwards between the brushes. Avoiding abrupt transitions and gradually bending the airflow to follow the orientation of the cylindrical element is an aspect related to the design on which the avoidance of dust adhesion is based. Moreover, it is advantageous in this respect if the part of the wall of the cylindrical element, when viewed in cross section of the cylindrical element at the interface of the concavely curved region of the face of the housing facing the brush, is generally arc-shaped.

[0019] A further measure aimed at having a narrow gap around the brushes involves applying an elongated intermediate component with two concavely curved portions located in the area between the brushes and arranged to cover parts of the brushes at the suction head. In particular, the elongated intermediate component is suspended from a part of the housing of the suction head at the location of the concavely curved areas of the face of the housing facing the brushes. The elongated intermediate component may be an integral part of the housing or may be provided as a separate component that can be removably coupled to another component of the housing, for example to allow maintenance or cleaning.

[0020] The invention includes further options for realizing a cleaning effect on the surface to be cleaned and possibly also on the internal surface of the suction head. For example, the suction head comprises a dampening arrangement configured to allow the supply of liquid to at least one area of ​​the surface to be cleaned and / or to at least one area in the suction head. Assuming that the suction head comprises at least one wheel rotatably arranged on the suction head and configured to contact the surface to be cleaned, it is possible for the dampening arrangement to be further configured to allow the direct supply of liquid to the at least one wheel. The dampening arrangement can be provided more or less as an add-on to the existing design of the suction head, but it is also possible for the dampening arrangement to be provided in an integral manner. A practical example of a liquid is water or a mixture of water and cleaning agent. It is practical if the dampening arrangement comprises a duct system configured to convey the liquid and release the liquid at one or more suitable positions. In the case where the suction head comprises an elongated, thin intermediate component as described above, the conduit system comprises at least one conduit extending through the elongated, thin intermediate component.

[0021] In order to facilitate the movement of dust picked up by the brush from the surface to be cleaned towards the outlet opening in the face of the housing opposite the brush, it is advantageous for the face of the housing opposite the brush to be provided with a number of grooves which for this purpose are specially designed to have the function of directing dust particles towards the outlet opening as the brush rotates.

[0022] In the context of the present invention, the brushes are of any type suitable for use in picking up dust from the surface to be cleaned, and the brushes may be selected to be identical or different. In particular, each of the brushes is designed, for example, to act as an agitator for agitating the dust particles 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 microfibre elements arranged on the core element. In such brushes, a linear mass density of less than 150 g per 10 km can be applied to the microfibre elements, or at least to their tip parts, whereby the microfibre elements can be very flexible in nature. The above-mentioned linear mass densities can be less than 10 g per 10 km, 5 g per 10 km, 1 g per 10 km. Such microfibre elements can be placed on the core element in a dense arrangement so as to interact very effectively with the surface to be cleaned during the operation of the suction head. Furthermore, it is practical for such microfibre elements to be arranged in tufts on the core element.

[0023] The present invention further relates to a vacuum cleaner, in particular a cordless vacuum cleaner, comprising a suction head as defined and described above, in particular in which the face of the housing facing the brush comprises two adjacent concavely curved areas and the outlet opening is dimensioned to cover only a portion of the length of the brush.

[0024] The above-described and other aspects of the present invention will be apparent from and elucidated by reference to the following detailed description of practical embodiments of the suction head as defined and described above.

[0025] The invention will now be described in more detail with reference to the drawings, in which equivalent or similar parts are designated by the same reference numerals. [Brief description of the drawings]

[0026] [Figure 1]1 illustrates diagrammatically components of a wet vacuum cleaner according to an embodiment of the present invention and a portion of a floor having a surface to be cleaned; [Diagram 2] 1 shows a schematic bottom view of a suction head according to an embodiment of the invention, comprising a housing and two brushes in a substantially parallel configuration on the housing, namely a front brush and a rear brush. [Diagram 3] 4A-4D are diagrams showing schematic cross-sections of a suction head at different longitudinal positions of the suction head; [Figure 4] 4A-4D are diagrams showing schematic cross-sections of a suction head at different longitudinal positions of the suction head; [Diagram 5] FIG. 2 shows a schematic view of a longitudinal section of the suction head taken at the centerline through the front brush, the front brush being omitted and viewed from front to rear; [Figure 6] FIG. 2 shows a schematic view of a longitudinal section of the suction head at a position between two brushes, viewed from front to rear with the rear brush omitted; [Figure 7] FIG. 2 shows a schematic view of a longitudinal section of the suction head taken at the centerline through the rear brush, the rear brush being omitted, viewed from front to rear; [Figure 8] FIG. 3 is a schematic bottom view of the suction head of FIG. 2, with the brush omitted. [Figure 9] FIG. 3 shows a schematic bottom view of the suction head of FIG. 2, with both brushes and the elongated intermediate component omitted. [Figure 10] FIG. 2 is a schematic top perspective view of the components of the suction head, with part of the housing shown transparent; [Figure 11] FIG. 2 is a schematic top perspective view of the components of the suction head, with part of the housing shown transparent; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Fig. 1 shows a design of a wet vacuum cleaner 100 according to an embodiment of the invention. The particular vacuum cleaner illustrated in Fig. 1 and described below is only one example of many types of vacuum cleaners possible within 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 dry vacuum cleaners with only a dry cleaning function and wet / dry vacuum cleaners with a dry cleaning function in addition to a wet cleaning function.

[0028] 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. Figure 1 illustrates the vacuum cleaner 100 in its normal operating orientation relative to the surface 10 to be cleaned. Use of words in this document having an orientational perspective should be understood with reference to this normal operating orientation of the vacuum cleaner 100 relative to the surface 10 to be cleaned, with the surface 10 being assumed to be in a bottom position and the vacuum cleaner 100 resting on top of the surface 10.

[0029] On the side that is expected to face the surface 10 during operation of the vacuum cleaner 100, the vacuum cleaner 100 comprises a suction head 101 housing two brushes 20 arranged 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, rotatable around a rotation axis 21 defined by the central longitudinal axis of the roller, and that each of the brushes 20 comprises a core element 22 and a flexible microfibre element 23 arranged on the core element 22, but this does not modify the fact that other embodiments of the brushes 20 are possible as well. In the case where the brushes 20 comprise a flexible microfibre element 23, the working profile of the brush 20 is the profile of the brush 20 with the flexible microfibre element 23 fully extended. The two brushes 20 may be identical, but this is not necessary in the context of the invention. As indicated by the curved arrows depicted at the position of the brushes 20 in FIG. 1, the brushes 20 are arranged so that they are rotatable in opposite directions around their respective rotation axes 21. The suction head 101 comprises a housing 30 configured to partially cover the brush 20. The housing 30 may be made, for example, of a plastic material.

[0030] Besides the suction head 101, the vacuum cleaner 100 comprises a body portion 102 configured to be grasped by a user of the vacuum cleaner 100. Preferably, the suction head 101 and the body portion 102 are removably connectable to each other. The body portion 102 may be shaped in any suitable manner. The outline of the body portion 102 illustrated in Figure 1 is merely schematic in nature. It is practical for the body portion 102 to comprise a handle so that the user can easily grasp the body portion 102 and move the vacuum cleaner 100 across the surface 10 to be cleaned as desired.

[0031] For the purpose of driving the brush 20 during operation of the vacuum cleaner 100, the vacuum cleaner 100 is provided with a suitable electric drive mechanism (not shown). For the purpose of powering the drive mechanism and possibly also other components of the vacuum cleaner 100, the vacuum cleaner 100 is connectable to a mains power supply and / or is provided with a suitable battery arrangement. Preferably, the vacuum cleaner 100 is a cordless device with a rechargeable battery arrangement, in which case it is more practical if the vacuum cleaner 100 is part of a set which includes a charging dock in addition to the vacuum cleaner 100. Such a set also includes a cleaning tray which may be used for the purpose of washing the brush 20. If the vacuum cleaner 100 does not include a battery, a simple dock without charging capabilities may be provided to receive and hold the vacuum cleaner 100 when it is not in operation.

[0032] The body portion 102 of the vacuum cleaner 100 comprises a liquid reservoir 40 serving to contain a liquid, such as water or a mixture of water and cleaning agent, and a liquid supply mechanism 41 serving to supply liquid to a dampening arrangement 42 of the suction head 101 during operation of the vacuum cleaner 100. The liquid supply mechanism 41 comprises, for example, any suitable type of pump arrangement or is configured to allow a desired displacement of liquid under the influence of gravity. In the illustrated embodiment, the dampening arrangement 42 of the suction head 101 is configured to allow both a direct supply of liquid to the area of ​​the surface 10 to be cleaned and a direct supply of liquid to the two wheels 90 of the suction head 101, as will be explained in more detail below. Furthermore, in the illustrated embodiment, the suction head 101 comprises an elongated intermediate component 25 with two concavely curved portions arranged to cover the areas 24 between the brushes 20, and the moistening arrangement 42 comprises a duct system 43 arranged partially on the elongated intermediate component 25 and arranged to convey liquid and to discharge it on the areas of the surface 10 and on the two wheels 90. In Fig. 1 the liquid reservoir 40, the liquid supply mechanism 41 and the moistening arrangement 42 of the suction head 101 are shown with dotted lines. It is practical if the liquid reservoir 40 is removably coupled to the body part 102 so that the user can separate the liquid reservoir 40 from the body part 102 when it is desired to place the liquid reservoir 40 in a location where it is to be filled with liquid.

[0033] The body portion 102 of the vacuum cleaner 100 further comprises a dust reservoir 50 serving to receive and accumulate the moist dust 11 picked up by the brush 20 from the surface 10 during operation of the vacuum cleaner 100. The dust reservoir 50 may be configured in many conventionally available ways for accumulating moist dust from the incoming dust 11 picked up from the surface 10, such as, for example, a cyclone configuration or a tube-in-cup configuration. The body portion 102 comprises a vacuum mechanism 60 configured to generate a pressure acting to enable the transport of the dust 11 from the area where the brush 20 is located, through the outlet opening 31 in the face 32 of the housing 30 facing the brush 20 and through the suction channel 51 extending from the outlet opening 31 to the dust reservoir 50 in the body portion 102. As can be particularly seen in the top perspective views of the components of the suction head 101 in Figures 10 and 11, the housing 30 includes a mating area 33 configured to enable mating of the housing 30 with the suction channel 51, dust reservoir 50 and vacuum mechanism 60 assembly of the body portion 102 of the vacuum cleaner 100. The outlet opening 31 is in fluid communication with this mating area 33.

[0034] The basic mode of how the wet vacuum cleaner 100 works is as follows: During operation, the brush 20 is driven to rotate and the liquid supply mechanism 41 is actuated to supply liquid to the dampening arrangement 42 of the suction head 101 so that the liquid is projected onto the surface 10 to be cleaned and onto the two wheels 90. In this process, the dirt present on the area of ​​the surface 10 within the reach of the brush 20 is separated under the influence of the liquid and the agitation by the brush 20, and the dust particles and dirt present on the area of ​​the surface 10 are removed together with the liquid and transported through the outlet opening 31 and the suction channel 51 to the dust reservoir 50. The dust 11 is picked up from the surface 10 by the tip portion of the microfiber elements 23 of the brush 20 and is shaken off from the tip portion at the position where the tip portion leaves contact with the surface 10 as the brush 20 rotates.

[0035] 1, the vacuum cleaner 100 comprises a user interface 70 which includes, for example, an on / off button 71. The vacuum cleaner 100 further comprises a control system 80 which includes a microcontroller programmed to respond to inputs received from a user through the user interface 70 to activate the brush 20 and to operate both the liquid delivery mechanism 41 and the vacuum mechanism 60.

[0036] 2 to 11 serve to illustrate aspects of a suction head 101 according to an embodiment of the present invention. In general, the design of the suction head 101 is such that the brush 20 is as enclosed as possible without compromising the required interaction between the brush 20 and the surface 10 to be cleaned, allowing it to be subjected to high pressure and under the effect of high air velocities to effectively transport dust towards and beyond the outlet opening 31.

[0037] 2 and 3 show an advantageous design by having an elongated intermediate component 25 in the suction head 101. Advantageously, as shown, the elongated intermediate component 25 is suspended from a part of the housing 30 at the location of the concavely curved areas 34, 35 of the face 32 of the housing 30 facing the brushes 20. In any case, the elongated intermediate component 25 serves to close the space 24 between the two brushes 20, so that the ingress of air occurs practically only at the bottom side of the brushes 20. As can be seen in fig. 2 and also in fig. 3, the brushes 20 fill the entire opening at the bottom side of the suction head 101. This arrangement of the brushes 20 is supported not only by the presence of the elongated intermediate component 25, but also by the presence of other structural details such as spoilers, edges with cavities and side walls at the location where the face 32 of the housing 30 facing the brushes 20 comprises the area 36 covering the ends of the brushes 20. It is thus achieved that, during operation of the suction head 101 , air passes through the brush 20 mainly at the location of the flexible microfiber elements 23 and enters through the gap between the encapsulation and the brush 20 .

[0038] 3, it can be seen that in the illustrated embodiment of the suction head 101, approximately 75% of the upper side of the brush 20 is enclosed at a very small distance, such as a distance of approximately 1 mm. As already explained, this is beneficial since it allows a narrow gap in which the air velocity can be relatively high, thereby supporting the functionality of the suction head 101 for dust transport, which is ultimately directed towards the coupling area 33. Preferably, the face of the elongated intermediate component 25 facing the brush 20 is smooth, not uneven, the same applies to the face 32 of the housing 30 facing the brush 20 at the position of the housing part 37, which is located at approximately the same level as the elongated intermediate component 25 (which is at or below the level of the rotation axis 21 of the brush 20). In another housing part 38, in particular in the higher housing part 38, the face 32 of the housing 30 facing the brush 20 comprises two adjacent concavely curved areas 34, 35, one of which 34 covers a part of the front brush 20a and the other of which 35 covers a part of the rear brush 20b. The terms "front" and "rear" are to be understood in relation to the normal position of a user handling the vacuum cleaner 100 including the suction head 101, the normal position of the user being the rear brush 20b side. During operation, the user moves the suction head 101 back and forth with the front brush 20a in front and the rear brush 20b in the rear.

[0039] Preferably, the surface 32 of the housing 30 facing the brush 20, as best seen in Figures 8 to 11, is provided with a number of grooves 39 at the locations of two adjacent concavely curved regions 34, 35. The grooves 39 are shaped to promote the movement of the dust surface 32 adhering to the brush 20 towards the outlet opening 31 when the brush 20 rotates. This advantageous effect depends on the following aspects, either independently or interacting with each other:

[0040] The liquid can be transported by the microfiber elements of the brush 20. Droplets of liquid project from the rotating brush 20 onto the face 32 of the housing 30 facing the brush 20 and are then guided by the geometric shape of the grooves. The air currents created in the space between the brush 20 and the housing 30 by the rotation of the brush 20 contribute to realizing the movement of the liquid in the grooves 39.

[0041] The coarse particles are carried away under the influence of the forces induced by the rotation of the brush 20 and are guided by the geometry of the grooves.

[0042] Small particles are carried by the microfiber elements, and may also be carried by interactions with other particles, air currents created in the space between the brush 20 and the housing 30 by the rotation of the brush 20, and interactions with liquids.

[0043] The housing parts 37, 38 which serve to closely cover the brush 20 except for the part of the brush 20 which is to be exposed to the surface 10 to be cleaned, functionally constitute a single enclosure, but for practical reasons, in particular manufacturability reasons, may be provided as separate parts which are joined together during the manufacturing process of the suction head 101.

[0044] Figure 4 illustrates a cross-sectional view of the suction head 101 at its central position in the longitudinal direction l, along which the rotation axis 21 of the brush 20 extends. At the outlet opening 31, the brush 20 is exposed to the cylindrical element 27 of the airflow directing component 28, which runs up to the connecting area 33 and is intended to be connected to the aforementioned suction channel 51 at the connecting area 33 and also to the fangs 29 of the airflow directing component 28, as will be described later. As indicated by the arrow in Figure 4, a part of the wall of the cylindrical element 27 located above the outlet opening 31 is oriented in a non-perpendicular direction to the upward flow of liquid, dust and air received from the area 24 between the brushes 20. In this way, it is achieved that the flow is smoothly bent backwards towards the connecting area 33 and that adhesion of dust to the wall of the cylindrical element 27 is avoided.

[0045] As explained above, most of the brush 20 is enclosed so as to have a high air velocity, thereby facilitating the transport of dust through the suction head 101. Another advantageous effect of a high air velocity is that the internal surface of the suction head 101 can be kept clean. In the suction head 101 according to the invention, the outlet opening 31 has dimensions such that it covers only a part of the dimension in the longitudinal direction l of the brush 20, i.e. only a part of the length of the brush 20. In this respect, it is noted that in many known suction heads, the outlet opening 31 has an elongated appearance in the longitudinal direction l for the purpose of receiving dust along the entire length of the brush 20. The disadvantage of such a conventional shape of the outlet opening 31 is that the air velocity is lower and that the internal surface is more likely to be oriented perpendicular to the air flow, which increases the risk of contamination of the internal surface. By narrowing the outlet opening 31 and the cylindrical element 27, not only is the air velocity increased, but also the concentration of liquid in the cylindrical element is increased, which helps to wash the dust out of the cylindrical element 27. On the other hand, it is practical if the size of the outlet opening 31 and the size of the cross section of the tubular element 27 to which it provides access are large enough to provide an acceptable resistance. Furthermore, as explained, the walls of the tubular element 27 are preferably not perpendicular (or close to perpendicular) to the direction of the flow of liquid, dust and air at any point, so that adhesion of dust in one or more areas of the walls can be prevented.

[0046] Proper functioning of the suction head 101 in terms of efficient dust transport and prevention of dust adhesion to the internal surfaces can be obtained by compliance with the following requirements, which should in no way be understood as essential to the invention: i) the height of the part of the front brush 20a exposed to the cylindrical element 27 through the outlet opening 31 is between 0.3 and 0.5 times the diameter of the brush; ii) the length of the part of the front brush 20a exposed to the cylindrical element 27 through the outlet opening 31 is between 0.8 and 1.3 times the brush diameter; iii) in the horizontal direction perpendicular to the longitudinal direction l, the dimension Q of the part of the two brushes 20 exposed to the cylindrical element 27 through the outlet opening 31 is between 0.6 and 1.1 times the distance P between the axes 21 of the two brushes 20. iv) As can be seen in Fig. 6, the cross section of the cylindrical element 27 along the vertical direction between the brushes 20, i.e. at the interface of the concavely curved areas 34, 35 of the face 32 of the housing 30 facing the brushes 20, has a circular arc shape and a substantially straight base. This circular arc shape can be, for example, circular or triangular with a rounded top. v) The angle α between the horizontal direction and the root of the circular arc shape is at least 60°, with a preferred value of approximately 67.5° to effectively prevent the adhesion of dust to the internal surface. The circular arc shape of the cross section of the cylindrical element 27 smoothly connects to the downstream part of the cylindrical element 27. Figs. 5 and 7 show the cross section of the cylindrical element 27 at other positions, showing the same circular arc shape. It is noted that for the sake of clarity, in both of these figures, the cross section of the bearing / drive structure of the brush 20 is shown.

[0047] Figures 8 and 9 provide a schematic view of the outlet opening 31 seen from the bottom, i.e. from the side on which the brush 20 is located. Figures 10 and 11 provide a view of the intersection of the housing 30 with the airflow directing component 28, and it is noted that the fangs 29 of the airflow directing component 28 extend all the way up to the level of the axis of rotation 21 of the brush 20. The fangs 29 extend on the sides of the tubular element 27, which are opposite sides in a direction perpendicular to the longitudinal direction of the tubular element 27, and descend until they reach the level of the axis of rotation 21 of the brush 20 at the interface of the concavely curved regions 34, 35 of the face 32 of the housing 30 at which the outlet opening 31 is located.

[0048] The details of the dampening arrangement 42 of the suction head 101 can be best seen in figure 6. The conduit system 43 of the dampening arrangement 42 comprises two main conduits 44, 45 located in different halves of the suction head 101 when viewed in the longitudinal direction 1. The main conduits 44, 45 are connectable to the liquid supply mechanism 41. Furthermore, the conduit system 43 comprises two branch conduits 46, 47, 48, 49 for each main conduit 44, 45, i.e. one branch conduit 46, 49 arranged to discharge liquid towards the wheel 90 and another branch conduit 47, 48 arranged to discharge liquid towards the area of ​​the surface 10 to be cleaned. The branched conduits 47, 48 configured to discharge liquid onto the surface 10 to be cleaned are arranged to extend partially through the elongated intermediate component 25, and the liquid supply location from which liquid is discharged onto the surface 10 is the bottom side of the elongated intermediate component 25, i.e. the bottom portion 26 of the elongated intermediate component 25 configured to face the surface 10 to be cleaned.

[0049] The moistening arrangement 42 shown here is only one of many possible embodiments having any desired moistening function, including at least one of the direct moistening of at least one of the brushes 20 and the indirect moistening of at least one of the brushes 20, in the context of the present invention. When the suction head 101 comprises an elongated intermediate element 25 that covers a part of the brushes 20 from the bottom side of the suction head 101, as is the case in the illustrated embodiment of the suction head 101, it is advantageous to use the elongated intermediate element 25 to accommodate at least a part of one or more of the conduits of the conduit system 43 of the moistening arrangement 42, but this does not change the fact that the present invention also includes other options.

[0050] Advantageously, the bottom portion 26 of the elongated intermediate component 25 is at a relatively low level, which is at least 2 mm and at most 6 mm above the level of the surface 10 to be cleaned when the suction head 101 is in its operating position above the surface 10. Advantageous aspects of having such a narrow space between the surface 10 to be cleaned and the bottom portion 26 of the elongated intermediate component 25 include the following:

[0051] The liquid beneath bottom portion 26 bridges with surface 10 and cleans bottom portion 26 by surface tension, trapping small dirt particles that may otherwise adhere to bottom portion 26 .

[0052] The flow of clean liquid from the different locations where it is released has a direct cleaning effect on the bottom portion 26 .

[0053] The movement of the suction head 101 causes the area under the bottom portion 26 to always interact with the brush 20 .

[0054] It will be apparent to those skilled in the art that the scope of the present invention is not limited to the embodiments discussed above, and that several improvements and modifications thereof are possible without departing from the scope of the present invention as defined in the appended claims. It is intended that the present invention be construed as including all such improvements and modifications insofar as they are within the scope of the claims or their equivalents. Although the present invention has been illustrated and described in detail in the drawings and description, such illustration and description should be considered merely illustrative or exemplary and not restrictive. The present invention is not limited to the disclosed embodiments. The drawings are schematic, omitting details that are not necessary for understanding the present invention, and are not necessarily drawn to scale.

[0055] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the description, and the appended claims. In the claims, the word "comprising" does not exclude other steps or elements, and the word "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.

[0056] Elements and features discussed with or in connection with a particular embodiment may be suitably combined with elements and features of other embodiments, unless expressly 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.

[0057] As used in this document, the words "comprise" and "include" will be understood by those skilled in the art to cover the word "consisting of." Thus, the words "comprise" or "include" may mean "consisting of" in some embodiments, but may mean "containing / having / having at least the specified species and optionally one or more other species" in other embodiments.

[0058] The salient aspects of the invention are summarized as follows: In a suction head 101 of the kind applied in a vacuum cleaner 100 and configured to perform a cleaning action on a surface 10, comprising a housing 30 and two rotatable brushes 20 in a substantially parallel configuration on the housing 30, the face 32 of the housing 30 facing the brushes 20 comprises two adjacent concavely curved regions 34, 35, each of which covers a portion of a respective brush 20a, 20b of the brushes 20. Furthermore, the face 32 of the housing 30 facing the brushes 20 comprises an outlet opening 31 in fluid communication with a coupling region 33 of the suction head 101, the outlet opening 31 being located at the interface of the concavely curved regions 34, 35 and having dimensions such that it covers only a portion of the length of the brushes 20.

Claims

1. 1. A suction head for application in a vacuum cleaner to perform a cleaning action on a surface, the suction head comprising: a housing, the housing including a coupling area allowing coupling of the housing to an air suction source of the vacuum cleaner; two brushes in a substantially parallel configuration in the housing, each of the brushes being rotatable about an axis of rotation and interacting with the surface to be cleaned, each of the brushes being capable of picking up liquid from the surface; Equipped with the surface of the housing facing the brush comprises two adjacent concavely curved regions; each of the concavely curved regions covering a portion of each of the two brushes; the face of the housing facing the brush includes an outlet opening in fluid communication with the coupling region; the outlet opening is located at the interface of the two adjacent concavely curved regions and has a dimension that covers only a portion of the dimension of the brush in a longitudinal direction along which the axis of rotation of the brush extends; the working shape of each of the brushes is generally cylindrical with a circular outer periphery, each of the concavely curved regions of the surface of the housing facing the brushes covers the respective brush of the two brushes at a position of a portion of the curved working contour of the respective brush of the two brushes, and the surface of the housing facing the brushes also includes a region covering an end of the brush; Suction head.

2. 2. A suction head as claimed in claim 1, wherein each of said concavely curved areas of said surface of said housing facing said brushes follows the motion contour of said portion of said respective one of said two brushes by a distance of up to 10 mm.

3. 3. A suction head as claimed in claim 2, wherein each of said concavely curved regions of said surface of said housing facing said brushes follows said operating contour of said portion of said respective one of said brushes by a distance in the range of 0 mm to 2 mm.

4. A suction head as claimed in any one of claims 1 to 3, wherein each of the concavely curved regions of the surface of the housing facing the brushes covers at least a portion of the respective one of the two brushes that is the upper half of the brush.

5. A suction head as claimed in any one of claims 1 to 4, wherein at least 65% of the dimension of each of the brushes around its respective axis of rotation is covered by a distance in the range 0mm to 2mm.

6. A suction head as claimed in any one of claims 1 to 5, wherein each of the concavely curved regions of the surface of the housing facing the brushes covers the respective one of the two brushes along the overall dimension of the brushes in the longitudinal direction.

7. A suction head according to claim 1 , comprising an airflow directing component including a cylindrical element in fluid communication with the outlet opening in the face of the housing facing the brush and extending towards the coupling area.

8. 8. The suction head of claim 7, wherein the airflow directing component comprises fangs that are in fluid communication with the outlet opening in the face of the housing and extend to opposing sides of the tubular element in a direction perpendicular to the longitudinal direction of the tubular element at the interface of the concavely curved region of the face of the housing facing the brush.

9. 9. A suction head as claimed in claim 7 or 8, wherein a part of the wall of the tubular element located above the outlet opening on the face of the housing facing the brushes is oriented non-perpendicular to a flow direction which is a direction from the face to be cleaned, through the outlet opening and upward between the brushes.

10. 10. The suction head of claim 9, wherein the portion of the wall of the tubular element is generally arc-shaped when viewed in cross section of the tubular element at the interface of the concavely curved region of the surface of the housing facing the brush.

11. A suction head according to any one of claims 1 to 10, comprising an elongated intermediate component with two concavely curved portions located in the area between the brushes and covering parts of the brushes.

12. 12. A suction head as claimed in claim 11, wherein the elongated intermediate component is suspended from a portion of the housing of the suction head at the concavely curved region of the face of the housing facing the brush.

13. A suction head according to any one of the preceding claims, comprising a wetting arrangement enabling the supply of liquid to at least one area of ​​the surface to be cleaned and / or to at least one area of ​​the suction head.

14. A cordless vacuum cleaner comprising a suction head according to any one of claims 1 to 13.

Images