Patent Publication Number: US-2023135446-A1

Title: Cleaning device for wet cleaning

Description:
CROSS-REFERENCE TO PRIOR APPLICATIONS 
     This application is a U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2021/054997, filed on Mar. 1, 2021, and claims benefit to German Patent Application No. DE 10 2020 108 607.5, filed on Mar. 27, 2020. The International Application was published in German on Sep. 30, 2021 as WO 2021/190862 under PCT Article 21(2). 
    
    
     FIELD 
     The invention relates to a cleaning device and to a method for operating such a cleaning device. 
     BACKGROUND 
     A variety of automatically driving cleaning devices for the wet cleaning of floor surfaces are known from the state of the art. DE 10 2017 126 414 A1 shows a cleaning device for the wet cleaning of floor surfaces, which has a disc-shaped cleaning element comprising a cleaning cloth, which can be raised and lowered. This allows the cleaning element to be brought into contact with the surface to be cleaned. The cleaning element has a relatively large cleaning surface. This has the result that the dimensions of the cleaning device are not compact. 
     When the cleaning device travels over the surface for cleaning the surface, the dirt is collected mainly in the front area of the cleaning element. Uniform use of the cleaning surface is therefore not possible and the cleaning element must be replaced, even though it still has areas with little soiling. 
     In the state of the art, cleaning devices for the wet cleaning of floor surfaces are also known, which have rotating brushes as cleaning elements. With such devices, however, there is only essentially linear contact between the cleaning element and the surface to be cleaned. This makes it more difficult to pick up dirt from the surface to be cleaned. 
     SUMMARY 
     In an embodiment, the present invention provides a cleaning device, comprising: a housing; a drive device configured to automatically move the cleaning device in a movement direction; and a wet-cleaning module accommodated in the housing, comprising a moveable cleaning element for the wet cleaning of surfaces to be cleaned, wherein the cleaning element is belt-shaped. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. Other features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following: 
         FIG.  1    schematically shows a cleaning device in a bottom view; 
         FIG.  2   a    schematically shows the cleaning device in a sectional view; 
         FIG.  2   b    schematically shows an alternative embodiment of a cleaning device in a sectional view; 
         FIG.  3    schematically shows a detailed view of a possible embodiment of a cleaning device; and 
         FIG.  4    schematically shows a variant of the cleaning device in a sectional view. 
     
    
    
     DETAILED DESCRIPTION 
     In an embodiment, the present invention provides a cleaning device which has a compact structure and which at the same time provides good cleaning performance. 
     According to the invention, it has been found to be advantageous for the cleaning element to have a belt-shaped design, which allows good utilization of the cleaning surface of the cleaning element: 
     The cleaning device according to the invention has a housing, a drive device for automatically moving the cleaning device in a movement direction and a wet-cleaning module accommodated in the housing. The movement direction can also be referred to as the main direction of movement. The wet-cleaning module has a movable cleaning element with a cleaning surface for contacting and cleaning the surface to be cleaned. The cleaning device is designed for the wet cleaning of surfaces to be cleaned, in particular floors. According to the invention, the cleaning element has a belt-shaped design, i.e., it is relatively thin and long, in particular comprising a cleaning cloth. The advantage of this cleaning element design is that the belt-shaped cleaning element provides a relatively large cleaning surface compared to cleaning brushes, while at the same time ensuring good utilization of the cleaning surface. Thanks to the belt-shaped design of the cleaning element, a compact structure of the cleaning device is also possible. 
     In a particularly advantageous and therefore preferred further development of the cleaning device, the wet-cleaning module features three positions for the belt-shaped cleaning element:
         The first position is a cleaning position in which the cleaning element contacts the surface to be cleaned with the cleaning surface of the cleaning element.   The second position is a parking position in which the cleaning element is at a distance from the surface to be cleaned.   And the third position is a regeneration position located between the cleaning position and the parking position, in which the cleaning element can be regenerated, i. e., cleaned and reconditioned. Alternatively, the parking position and regeneration position can coincide and have a common position. I. e., both the regeneration position and the parking position are in the second position. During regeneration, whereby the cleaning element is regenerated, i. e., cleaned and reconditioned, the position serves as the regeneration position. If no regeneration is in progress, the position serves as the parking position.       

     The wet-cleaning module is also equipped with a transport mechanism for moving the cleaning element to its cleaning position, its parking position and its regeneration position. 
     A cleaning device of this type advantageously ensures that the cleaning element does not have to be replaced after use and in the event of a high degree of soiling, but rather can be regenerated, i. e., reconditioned, in the cleaning device itself. It is also ensured that the cleaning element only contacts the surface to be cleaned when cleaning is to be carried out. If the surface to be cleaned is, for example, a parquet floor, it is particularly important that the wet cleaning module only contacts the parquet to be cleaned during the cleaning process. This prevents swelling of the parquet and the formation of water spots. 
     In an advantageous embodiment of the cleaning device described above, the transport mechanism is designed as at least one circulating belt with at least one drive roller and at least one reversing roller. The at least one circulating belt can also be configured as a pair of circulating, parallel belts. 
     The cleaning element is attached and fixed to the outer surface of the circulating belt using fixing means. Fixing can be carried out, for example, by means of a hook and loop fastener or by means of press studs. This enables easy replacement of the cleaning element and facilitates external intensive cleaning, for example by means of washing in a washing machine. The reversing roller of the transport mechanism can be either exclusively used for reversing or have the additional function of driving the belt and thus also be designed as a drive roller. 
     In an advantageous further development of the cleaning device according to the invention, the wet-cleaning module has a regeneration unit for cleaning the cleaning element, comprising at least one cleaning brush and/or a stripping comb and/or a spraying device for wetting and/or rinsing the cleaning element and/or a water tank and/or a pair of squeezing rollers and/or a disinfecting means. A disinfecting means can be a device in which disinfection of the cleaning element takes place. If necessary, a disinfectant, i. e., a disinfecting liquid, can also be used. A UV lamp can also be used as a disinfecting means, for example, to irradiate the cleaning element. It is also possible, for example, to provide two water tanks, a fresh water tank and a waste water tank. 
     In a particularly advantageous and therefore preferred further embodiment of the cleaning device according to the invention, the following applies with regard to the dimensions of the cleaning surface of the cleaning element: The extension in the movement direction of the cleaning device is smaller than the extension perpendicular to the movement direction of the cleaning device. In other words, the depth of the cleaning surface is smaller than the width of the cleaning surface. In particular, the depth is max. 10 cm, especially max. 3-6 cm. Given that most of the dirt is generally collected in the front area—as seen in the direction of movement of the cleaning device—it is thus possible to achieve a cleaning device having a compact structure combined with a wide cleaning area and good cleaning performance. 
     Tests have shown that it is particularly advantageous if the cleaning element is movable perpendicular to the direction of movement of the cleaning device. In particular, when the cleaning element is configured as a circulating belt, it is advantageous if the belt can be moved back and forth perpendicular to the direction of movement. This generates an effective scrubbing movement of the cleaning element and thereby improves the cleaning performance. 
     In one possible embodiment of the cleaning device, the cleaning element is made of a textile material. The textile material may, for example, be a microfiber. Alternatively, the textile material may be a mixture of microfibers and other textiles. It is further advantageous if the cleaning element is comprised of different plies or layers. 
     If the cleaning element is made of a textile material, it has been found advantageous to use plastic elements, e.g., plastic strips, to stiffen the cleaning surface of the cleaning element. Alternatively, stiffening can be achieved by joining additional textile strips to the textile material. This has the advantage that the area of the cleaning surface of the cleaning element remains dimensionally stable. 
     In an advantageous embodiment of the cleaning device, the cleaning element has, in a cleaning position or in its cleaning position, a horizontal cleaning surface for cleaning a horizontal surface, e.g., a floor, and a vertical cleaning surface for cleaning a vertical surface, e.g., a skirting board. 
     In a further development, the cleaning surface of the cleaning element can be convexly curved at least in areas, whereby the curvature extends perpendicular to the direction of movement of the cleaning device. Particularly preferably, the cleaning surface of the cleaning element has a planar cleaning surface which is adjoined by convex curvatures in and against the direction of movement. One advantage of a cleaning surface of this type is, among other things, that the area of the cleaning element contacting the surface to be cleaned is embedded in a stable manner and thus exhibits less wear as a result of frictional stress. Alternatively, or additionally, the cleaning surface can be located between at least two ramps raised relative to the edges of the cleaning surface in such a way that unintentional detachment of the cleaning element due to obstructions or interfering objects on the surface to be cleaned is prevented. 
     In a further development of the cleaning device, it is equipped with a sensor, in particular an optical sensor, for detecting the surface to be cleaned or the cleaned surface and to determine cleaning performance. The sensor can be arranged in particular above the cleaning element in its cleaning position and can be activated when the cleaning element is located outside of its cleaning position (A), for example in its parking position. Advantageously, this enables the cleaning result to be determined immediately after cleaning without the need to move the position of the cleaning device. Rather, the cleaning element only has to be moved from its cleaning position to the parking position. The result of the assessment or the result of the ascertained cleaning performance can, for example, be displayed on the user&#39;s smartphone via an app. 
     It is preferable if the cleaning element of the cleaning device is provided with a means of communication, which in particular is provided with an electrically readable identifier, to communicate with the cleaning device. The means of communication may be, for example, QR codes, punched tape patterns, or radio transponders such as RFID chips. This type of configuration has the advantage that it enables the user of the cleaning device to be provided with information regarding the use of a correct cleaning element suitable for the surface to be cleaned and also regarding the timely replacement of the cleaning element to maintain cleaning performance. This information can also be communicated via app, for example. 
     The cleaning performance of the cleaning device can be further improved by accommodating an additional dry-cleaning module in the housing of the cleaning device for dry cleaning of the surfaces to be cleaned. Preferably, the wet-cleaning module and dry-cleaning module are arranged one behind the other in the direction of movement of the cleaning device, wherein the dry-cleaning module is located in front of the wet-cleaning module in the direction of movement during forward travel. The dry-cleaning module can thus be used for pre-cleaning, and it is ensured that the surface to be cleaned, which has been moistened by the wet-cleaning module, can dry and is not smeared by cleaning elements of the dry-cleaning module. 
     The invention also relates to a method of operating a cleaning device of the type described above, wherein the cleaning element in its cleaning position performs a back-and-forth movement in the manner of a scrubbing movement. Thanks to the fact that the cleaning element not only wipes but also scrubs, firmly adhering dirt can be reliably removed, thus substantially improving the cleaning performance. 
     The invention described and the described advantageous further embodiments of the invention, in combination with one another—insofar as this is technically feasible—also constitute advantageous further embodiments of the invention. 
     In  FIG.  1   , a cleaning device  100  is shown in a bottom view. The cleaning device  100  has a housing  1 , in which a drive device  2 , a wet-cleaning module  3  and a dry-cleaning module  4  are accommodated. The drive device  2  includes two motor-driven wheels. The dry-cleaning module  4  has a segmented structure and includes two rotatable brushes and a rotatable roller. In a direction of movement V, which is the main movement direction of the cleaning device  100 , the dry-cleaning module  4  is located in front of the wet-cleaning module  3 . In this way, when moving over a surface  1000  to be cleaned, cleaning can first be carried out by means of the dry-cleaning module  4  and then by means of the wet-cleaning module  3 . 
     The wet-cleaning module  3  has a cleaning element  30  comprising a cleaning surface  37 . 1 ., which can be brought into contact with the surface  1000  to be cleaned. The cleaning surface  37 . 1 . has an extension s 1  in the movement direction V and an extension s 2  perpendicular to the movement direction V, that is, a depth sl and a width s 2 . The depth s 1  is substantially smaller than the width s 2 , which essentially extends across the width of the cleaning device  100 . As indicated by a double arrow, the cleaning element  30  can be moved back and forth perpendicular to movement direction V, i. e., it can perform a movement from right to left and back again in the drawing plane. In this way, the cleaning element  30  generates a scrubbing movement, resulting in a particularly good cleaning performance of the wet-cleaning module  3 . This scrubbing movement is also indicated by a double arrow in  FIG.  2     a.    
     The sectional view of  FIG.  2   a    shows the structure of the wet-cleaning module  3 . The wet-cleaning module  3  has a belt-shaped cleaning element  30 , which is attached to a circulating belt  32  by fixing means  35 . The circulating belt  32  is part of a transport mechanism  31  used to move the cleaning element  30 . In addition to the circulating belt  32 , the transport mechanism  31  comprises at least one drive roller  33  and a reversing roller  34  around which the circulating belt  32  is routed. The circulating belt  32  is thus configured as an endless belt that is driven by the drive roller  33 —as indicated by a double arrow. The wet-cleaning module  3  features three different positions for the belt-shaped cleaning element  30 :
         a cleaning position A, in which the cleaning element  30  contacts the surface  1000  to be cleaned and performs cleaning,   a parking position B 2 , in which the belt-shaped cleaning element  30  is at a distance from the surface  1000  to be cleaned,   and a third position, namely a regeneration position B 1 , which is located between cleaning position A and parking position B 2 .       

     In the area of regeneration position B 1 , a regeneration unit  36  is arranged, which is used to clean the cleaning element  30 . The cleaning element  30  is regenerated as it is passed through the regeneration unit  36  by the transport mechanism  31 . The regeneration unit  36  can comprise a number of different components, which are marked with reference numerals in  FIG.  2   b   : a cleaning brush  36 . 1 , a spraying device  36 . 2 , a squeezing roller  36 . 3 , which acts as a pair of rollers together with the drive roller  33 . The components of the regeneration unit  36  are shown by way of example. In addition to the components described, stripping combs, tanks, or disinfecting means can also be provided for example. 
     In  FIG.  2   b   , the wet-cleaning module  3  of the cleaning device  100  is shown in a specific application scenario. The cleaning element  30  contacts a surface  1000  to be cleaned, thus performing cleaning of the surface. For this, the cleaning element  30  has a horizontal cleaning surface  37 . 1 ., which contacts a horizontal surface  1000  to be cleaned. The cleaning element  30  also has a vertical cleaning surface  37 . 2  which contacts a vertical surface  1000  to be cleaned. The vertical surface  1000  to be cleaned may be a skirting board, for example, and the horizontal surface  1000  to be cleaned may be a floor, for example. 
     A sensor  6 , for example an optical sensor, is arranged above the cleaning element  30  in its cleaning position A. With the aid of this sensor  6 , the cleaning performance can be evaluated. In order to clear the line of sight between sensor  6  and the surface  1000  to be cleaned, the cleaning element  30  must be moved from its cleaning position A to its parking position B 2  or at least to its regeneration position B 1 . The sensor  6  can then detect the condition of the surface to be cleaned. The cleaning element  30  can then be moved back to its cleaning position A and cleaning of the surface  1000  can be carried out. After cleaning has been completed, the cleaning element  30  can be moved back to the regeneration position B 1  or to the parking position B 2  and another inspection can be carried out by the sensor  6 . By comparing the readings before and after cleaning, cleaning performance can be evaluated. Alternatively, it is possible to store reference values in a memory of a control unit of the cleaning element  30  which enable a comparison of ACTUAL values with stored SET values. 
     A communication means  39  is arranged on the belt-shaped cleaning element  30 , which, upon appropriate configuration, can also be read by the sensor  6 . Alternatively, however, other detection means could also be provided to read out the communication means  39 . The communication means  39  can, for example, be implemented as a data matrix code or as an RFID chip or RFID tag. Information regarding the cleaning device type, a maximum planned and/or already completed number of cleaning cycles, time of first use, etc. can be assigned to the communication means  39 . 
       FIG.  3    shows a detailed view of an embodiment of the wet-cleaning module  3 . The cleaning element  30  is made of a belt-shaped textile material, which is provided with plastic elements  38  to stiffen its cleaning surface. In order to prevent the cleaning element  30  being damaged, being pushed off or slipping off in the event of contact with an obstacle  1001  during cleaning, ramps  5  are provided on both sides of the cleaning element  30 . These form a safeguard for the cleaning element  30  in the event of it running over an obstacle  1001  during cleaning. 
     The sectional view of  FIG.  4    shows an alternative design of a wet-cleaning module  3 . The wet-cleaning module  3  has a belt-shaped cleaning element  30 , which can be moved by a transport mechanism  31 . The wet-cleaning module  3  features two different positions for the belt-shaped cleaning element  30 :
         a cleaning position A, in which the cleaning element  30  contacts the surface  1000  to be cleaned and performs cleaning, and   a parking position B 2 , in which the belt-shaped cleaning element  30  is at a distance from the surface  1000  to be cleaned, whereby position B then functions as regeneration position B 1  when regeneration of the cleaning element  30  is carried out there.       

     While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments. 
     The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C. 
     LIST OF REFERENCE NUMERALS 
       1  housing 
       2  drive unit 
       3  wet-cleaning module 
       4  dry-cleaning module 
       5  ramp 
       6  sensor 
       30  cleaning element 
       31  transport mechanism 
       32  circulating belt 
       33  drive roller 
       34  reversing roller 
       35  position fixing means 
       36  regeneration unit 
       36 . 1  cleaning brush 
       36 . 2  spraying device 
       36 . 3  squeezing roller 
       37  cleaning surface 
       37 . 1  horizontal cleaning surface 
       37 . 2  vertical cleaning surface 
       38  plastic stiffening element 
       39  communication means 
       100  cleaning device 
       1000  surface to be cleaned 
       1001  obstacle or object 
     s 1  extension in movement direction 
     s 2  extension perpendicular to movement direction 
     A cleaning position 
     B 1  regeneration position 
     B 2  parking position 
     B combined regeneration and parking position 
     V movement direction