Patent Publication Number: US-2022225852-A1

Title: Floor cleaning machine with hair pickup and method for operating a floor cleaning machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of international application number PCT/EP2019/073890, filed on Sep. 6, 2019, which is incorporated herein by reference in its entirety and for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to a floor cleaning machine, comprising a floor head, and at least one cleaning roller, which is arranged on the floor head and rotates about an axis of rotation in a cleaning operation, wherein the at least one cleaning roller has a textile covering. 
     The invention further relates to a method for operating a floor cleaning machine in which a cleaning roller is arranged on a floor head and the cleaning roller rotates in a cleaning operation. 
     Surface cleaning machines are disclosed in WO 2016/058901 A1, WO 2016/058856 A1, WO 2017/063663 A1, WO 2016/058879 A1, and WO 2016/058956 A1 as well as WO 2016/058907 A1. 
     DE 20 2016 105 296 U1 discloses a floor cleaning apparatus with a cleaning mechanism for a cleaning drum. 
     WO 2018/001754 A1 discloses a wet appliance with a rotatable cleaning roller and a displaceable scraping device. 
     WO 2018/162091 A1 discloses a self-propelled and self-steering floor cleaning appliance. 
     WO 2017/152973 A1 discloses a surface cleaning machine with a suction fan-free coupling of dirty liquid into a dirty fluid tank device. 
     US 2018/0206685 A1 discloses a cleaning mechanism for a cleaning roller. 
     US 2016/0270620 A1 discloses a multifunctional cleaning tool. 
     US 2002/0148056 A1 discloses a floor cleaning machine with a rotating brush. 
     In accordance with an embodiment of the invention, a floor cleaning machine of the kind stated at the outset is provided, with which an optimized cleaning result can be achieved. 
     SUMMARY OF THE INVENTION 
     In accordance with an embodiment of the invention, the floor cleaning machine stated at the outset is provided, wherein arranged on the floor head is at least one pin strip with a plurality of pins for picking up hair and wherein the pins abut against the textile covering or penetrate into the covering. 
     It has been shown that an effective hair pickup is achieved by the use of the at least one pin strip with pins. Hair is wound up, in a sense, on the pins in the manner of a hairbrush. A floor subjected to hair contamination can thus be effectively cleaned. 
     It has been shown that it is favorable if the pins are project into the textile covering with a penetration depth in the range between 0 mm and 4 mm. Here, a penetration depth of 0 mm means that a corresponding pin abuts against the textile covering. If the pins do not contact the textile covering or do not penetrate far enough, then a good hair pickup is not achieved. If the pins penetrate too deep, then this results in an increased current consumption of the floor cleaning machine and an unnecessary increased load on the motor and on the transmission. 
     It is favorable if the pins have a flat face side, which has a diameter in the range between 0.1 mm and 0.5 mm, wherein, in particular, the diameter is about 0.3 mm. This results in an effective cleaning result. Damage to the textile covering as a result of the pins can be avoided because they are not “pointed” enough. 
     For an optimized cleaning result, it is favorable if pins in at least one row are arranged on the pin strip, wherein the at least one row has a longitudinal direction. The pins are arranged at a distance from one another in the row. An optimized hair pickup can thus be achieved. Hair is wound up, in a sense, on the pins in the manner of a hairbrush. 
     It is favorable if the longitudinal direction is at least approximately parallel to an axis of rotation of the at least one cleaning roller. This results in an optimized cleaning result with optimized hair pickup while having a constructively simple structure. 
     An optimized hair pickup is achieved if a plurality of rows are provided, wherein rows are spaced apart in a transverse direction and the transverse direction is oriented transversely to the longitudinal direction. A “wrapping up of hair” on the pins can thus be effectively achieved. 
     It is favorable if the at least one pin strip is positioned on the floor head so as to be releasable by a user. The pin strip can then be removed by a user without great effort in order to clean same (in order to remove hair that is wound up thereon). 
     It is favorable if a scraping device with at least one scraper for scraping dirty liquid from the at least one cleaning roller is provided. Dirty liquid can thereby be removed from the at least one cleaning roller and fed to a tank device for dirty fluid. 
     An effective removal of dirty liquid from the at least one cleaning roller is achieved when the at least one scraper penetrates into the textile covering. Reference is made in this regard to WO 2015/086083 A1, which is expressly referred to. 
     It has proven to be advantageous if the pins project into the textile covering to an equal or lesser extent than the at least one scraper and, in particular, if a difference between a penetration depth of the scraper and a penetration depth of the pins is in the range between 0 mm and 1 mm inclusively. The scraper can be effectively used to remove dirty liquid and the pins can be effectively used to “filter out” hair. 
     It is particularly advantageous if the at least one pin strip is arranged downstream from the at least one scraper in relation to a direction of rotation of the at least one cleaning roller, and, in particular, if the at least one scraper is arranged downstream from a sweeping element in relation to the direction of rotation. The sweeping element then firstly has the function of gathering coarse dirt and providing it to the at least one cleaning roller to be taken up by same. Dirty liquid can subsequently be scrapped off on the scraper and then fed to the tank device for dirty liquid. Hair that is then still found on the at least one cleaning roller after the scraper can be picked up by the at least one pin strip and be “filtered out”. This results in an optimized cleaning result overall. 
     The pins and, in particular, all pins are aligned in a pin direction, with at least one of the following:
         the pins are of straight configuration;   the pin direction is oriented transversely and, in particular, perpendicularly to the axis of rotation of the at least one cleaning roller;   the pin direction is oriented in parallel or obliquely to a z-direction in which a tank device is movably mounted on the floor head in a cleaning operation;   the pin direction is oriented perpendicularly or obliquely to a contact plane of the at least one cleaning roller for the floor to be cleaned;   the pin direction is in an angular range between 0° and 25° to a motion axis of the at least one pin strip;   the pin direction is parallel or at an acute angle to a scraper and/or an opening wall for the at least one cleaning roller.       

     It has been shown that this then results in an optimized cleaning result. 
     It is particularly advantageous if the at least one pin strip is movably and, in particular, displaceably mounted on the floor head. The at least one pin strip can then be brought into such a position that results in an optimized cleaning result. This position is hereby independent of the concrete configuration of the at least one cleaning roller, such that, for example, manufacturing tolerances and wear as well as different roller diameters have no influence on the action of the pins on the textile covering, such that the pins either abut against the textile covering or penetrate into the textile covering with a defined penetration depth. 
     The object stated at the outset is further accomplished in accordance with the invention in that a holder is movable and, in particular, is displaceably mounted on the floor head, with at least one of the following:
         at least one pin strip with a plurality of pins is arranged on the holder, wherein the pins abut against or penetrate into the textile covering of the at least one cleaning roller;   at least one scraper of a scraping device is arranged on the holder, wherein the at least one scraper penetrates into the textile covering.       

     In a sense, the at least one pin strip and/or the scraper can be advanced and preferably automatically advanced to the at least one cleaning roller by way of the holder. The relative position between pins and/or scraper on the textile covering of the at least one cleaning roller is then set in a desired manner, independently of the concrete configuration of the cleaning roller. 
     Manufacturing tolerances can lead to different diameters of cleaning rollers. The diameter can change as a result of wear to the textile covering. Due to the advanceability of the holder, the same position of the pins of the pin strip and/or of the scraper on the at least one cleaning roller and thereby in relation to the textile covering can always be achieved independently of said diameter variations. This results in an optimized cleaning result. Further, an energy-saving operation of the at least one cleaning roller can be achieved, because the pins and/or the scraper do not have to penetrate in any further than is necessary for an optimized cleaning result. 
     In one embodiment, an input-coupling element for dirty fluid into the tank device is arranged on the holder (or the input-coupling element is said holder), in particular with at least one of the following:
         the at least one scraper is arranged on the input-coupling element;   at least one opening for coupling dirty fluid into a tank device (for dirty fluid) is arranged completely or partially on the input-coupling element;   the at least one scraper forms an opening wall;   the at least one pin strip sits on the input-coupling element;   the at least one pin strip is removable from the input-coupling element for a user and/or the input-coupling element is removable from the floor head for a user.       

     In particular, the input-coupling element can be used to hold both the at least one pin strip and the scraper. A movable and, in particular, displaceable arrangement of the input-coupling element results in a simple constructive design. 
     In particular, a motion axis for the at least one pin strip or the holder is provided with at least one of the following:
         the motion axis is oriented transversely and, in particular, perpendicularly to the axis of rotation;   the motion axis is oriented perpendicularly or obliquely to a contact plane of the at least one cleaning roller for a floor to be cleaned;   the motion axis is oriented in parallel or obliquely to a z-axis in which a tank device, which sits on the floor head, is movable;   the motion axis is aligned to the axis of rotation (of the at least one cleaning axis).       

     Thus, an optimized positioning of pins of the at least one pin strip and/or of the at least one scraper relative to the at least one cleaning axis can be achieved. 
     In particular, the at least one pin strip or the holder is movable relative to a tank device, which is arranged on the floor head. The tank device may hereby be fixedly arranged on the floor head, or it itself may be movably arranged on the floor head. 
     It is particularly advantageous if the at least one pin strip or the holder is force-driven in the direction of the at least one cleaning roller and, in particular, is pressed against the at least one cleaning roller. A position of the at least one pin strip and/or of the scraper that is optimized for a cleaning can thus be achieved. 
     For example, a spring device is provided for the at least one pin strip or the holder, which accordingly provides a spring force for force-driven positioning. Alternatively or in addition, it is possible that the at least one pin strip or the holder are gravity-driven, i.e., that gravity ensures an appropriate positioning. 
     It is particularly advantageous if the at least one pin strip and/or the holder have an abutment surface for the at least one cleaning roller (and thereby in particular for a surface of the at least one cleaning roller), wherein, in particular, the pins and/or the at least one scraper protrude from the abutment surface. A contact element for the at least one cleaning roller can thereby be provided, which by striking against the surface of the at least one cleaning roller ensures an optimized positioning of the pins and/or the scraper. 
     In one embodiment, the at least one cleaning roller is of two-part configuration and a center drive is provided. A cleaning close to edges can thereby be achieved. 
     In one embodiment, a tank device, in particular for dirty fluid, is arranged on the floor head and, in particular, dirty liquid that is removed from the at least one cleaning roller is fed to the tank device in a blower-free manner, wherein, in particular, the tank device is mounted for oscillation on the floor head, and one or more sweeping elements are arranged on the tank device. This results in a compact configuration. It is also possible in principle that a tank device for dirty fluid is arranged, e.g., on a holding rod device. 
     It is particularly advantageous if a tank device for cleaning liquid and a supply device for cleaning liquid to the at least one cleaning roller and/or to a floor to be cleaned is provided. A wet wiping of a floor to be cleaned can thereby be performed. Dirt can be loosed by the floor and the cleaning roller being moistened. The dirt can be removed and picked up by way of the mechanical contact of the textile covering of the at least one cleaning roller with the floor. The cleaning liquid is fresh water or a mixture of fresh water and, in particular, surfactant cleaning agent. 
     It is particularly advantageous if a sweeping element is associated with the at least one cleaning roller, and the at least one sweeping element is arranged upstream from a scraper for the at least one cleaning roller in relation to a normal direction of rotation of the at least one cleaning roller in a cleaning operation. Coarse dirt can be gathered and provided to the cleaning roller by way of the sweeping element, dirty fluid including coarse dirt then being removable from the at least one cleaning roller by way of the scraper. 
     In one embodiment, a first cleaning roller and a second cleaning roller are provided, wherein the second cleaning roller is arranged on the floor head at a distance from the first cleaning roller, in particular with at least one of the following:
         a first axis of rotation of the first cleaning roller and a second axis of rotation of the second cleaning roller are oriented in parallel to one another;   in a normal operating mode of the floor cleaning machine, the first cleaning roller and the second cleaning roller rotate in opposite directions;   a tank device for dirty fluid is arranged on the floor head;   the tank device for dirty fluid is positioned between the first cleaning roller and the second cleaning roller;   a blower-free coupling of dirty fluid from the first cleaning roller and the second cleaning roller into the tank device is provided;   a first sweeping element is associated with the first cleaning roller and/or a second sweeping element is associated with the second cleaning roller.       

     This results in an optimized cleaning result. In this respect, reference is made, as an example, to WO 2019/048496 A1 or the not previously published DE 10 2019 109 946. 
     In an alternative embodiment, one single cleaning roller is arranged on the floor head and, in particular, the floor head is supported on a floor to be cleaned only by way of the cleaning roller. This results in a compact structure. In this respect, reference is made, as an example, to WO 2015/086083 A1 or WO 2016/058879 A1. 
     In one embodiment, a holding device is provided for a user, which is arranged and, in particular, is pivotably arranged on the floor head, wherein the floor cleaning machine, in particular, is of hand-held or hand-guided configuration, and wherein same, in particular, is operable by a user in a standing position. A floor cleaning can thus be performed in a simple manner. 
     It is also possible that the floor cleaning machine is of self-propelled and self-steering configuration and thereby is configured, in particular, as a cleaning robot and preferably as a wiping robot. 
     The object stated at the outset is achieved in accordance with the invention in the method stated at the outset in that a pin strip with a plurality of pins and/or a scraper is movably mounted and, in particular, displaceably mounted on the floor head and is pressed under the application of force against the at least one cleaning roller. 
     A defined positioning of pins and/or the scraper on the at least one cleaning roller can thereby be achieved independently of the diameter of the at least one cleaning roller. 
     The method in accordance with the invention has the advantages that have already been explained in the context of the apparatus in accordance with the invention. 
     In particular, the method in accordance with the invention can be performed on the floor cleaning machine in accordance with the invention or the floor cleaning machine can be operated with the method in accordance with the invention. 
     In particular, an abutment element is pressed against the cleaning roller (and thereby preferably pressed against a surface of the cleaning roller), and abuts with an abutment surface thereagainst, wherein, in particular, pins of the pin strip and/or the scraper project over the abutment element and abut against or penetrate into a textile covering of the at least one cleaning roller. This results in an optimized cleaning result. 
     The subsequent description of preferred embodiments serves in conjunction with the drawings for further explanation of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a partial depiction of an embodiment of a floor cleaning machine in accordance with the invention, wherein a holding (rod) device is shown in a partial depiction and only one part of a two-part (front) cleaning roller is shown; 
         FIG. 2  shows a side view of the floor cleaning machine in accordance with  FIG. 1 ; 
         FIG. 3  shows an enlarged depiction of the region A according to  FIG. 2  in the moment of the cleaning roller being placed on a floor to be cleaned; 
         FIG. 4  shows the same view as  FIG. 3 , wherein the cleaning roller has been placed for a longer period of time and its diameter has decreased; 
         FIG. 5  shows an embodiment of a tank device or a partial region of a tank device in a perspective depiction; 
         FIG. 6  shows a side view of the tank device or the partial region according to  FIG. 5 ; 
         FIG. 7  shows a cut view along line  7 - 7  according to  FIG. 6 ; 
         FIG. 8  shows a cut view of the floor cleaning machine according to  FIG. 1  in the region of the front cleaning roller in a first position of a pin strip; 
         FIG. 9  shows the same view as  FIG. 8  in a second position of the pin strip; 
         FIG. 10  shows the same view as  FIG. 8  in a third position of the pin strip; 
         FIG. 11  shows a perspective depiction of an embodiment of a pin strip; 
         FIG. 12  shows a further perspective depiction of the pin strip according to  FIG. 11 ; 
         FIG. 13  shows a further perspective depiction of the pin strip according to  FIG. 11 ; 
         FIG. 14  shows a side view of the pin strip according to  FIG. 11 ; 
         FIG. 15  shows a front view of the pin strip according to  FIG. 11 ; 
         FIG. 16  shows a further embodiment of a floor cleaning machine in accordance with the invention (in the configuration as a self-propelled and self-steering floor cleaning machine); and 
         FIG. 17  shows a further embodiment of a hand-held and hand-guided floor cleaning machine. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An embodiment of a floor cleaning machine in accordance with the invention, which is shown in  FIGS. 1 and 2  in a partial depiction and is denoted by  10 , is configured as a hand-held and hand-guided floor cleaning machine, which is operable by a user in a standing position. 
     The floor cleaning machine  10  comprises a floor head  12 . At least one cleaning roller  14  is arranged on the floor head  12 . In the embodiment shown, a first cleaning roller  14   a  and a second cleaning roller  14   b  are rotatably mounted on the floor head  12 . The first cleaning roller  14   a  and the second cleaning roller  14   b  are spaced at a distance and are hereby oriented in parallel to one another. 
     The first cleaning roller  14   a  is rotatable about a first axis of rotation  16   a . The second cleaning roller  14   b  is rotatable about a second axis of rotation  16   b . The first axis of rotation  16   a  and the second axis of rotation  16   b  are in parallel to one another. 
     A first shaft  18  is arranged on the floor head  12  for the first cleaning roller  14   a . A second shaft (not visible in the drawings) is associated with the second cleaning roller  14   b . The first shaft  18  and the second shaft are each connected to a drive motor by way of a transmission device. Said drive motor sits, in particular, on the floor head  12 . 
     Provision is hereby made that at least for a normal operating mode of the floor cleaning machine  10 , the first cleaning roller  14   a  and the second cleaning roller  14   b  are operated in opposite directions and, in particular, at the same rotational speed. 
     Regarding further embodiments for the drive motor and the transmission device, reference is made to the not previously published German patent application Nr. 10 2019 109 946.3 of 15 Apr. 2019 from the same applicant. Express reference is made to this document in its entirety. 
     In one embodiment, the first cleaning roller  14   a  and the second cleaning roller  14   b  are each of two-part configuration. The first shaft  18  comprises a first shaft region  20  and a second shaft region  22 . The respective first part like, for example, the first part  24  of the first cleaning roller  14   a  sits on the first shaft region  20 . The second part of the first cleaning roller  14   a  is not shown in  FIGS. 1 and 2 . There, the second part  26  of the second cleaning roller  14   b  is visible. A center drive is provided for the rotational drive of the first cleaning roller  14   a  and the second cleaning roller  14   b . A torque-effective coupling of the drive motor to the cleaning rollers  14   a  and  14   b  takes place in a middle region between outer ends. In particular, the first cleaning roller  14   a  and the second cleaning roller  14   b  extend up to a side rim  28  of the floor head  12 . A cleaning close to edges is thereby possible. 
     In this respect, reference is made, as an example, to DE 10 2019 109 946. 
     In one embodiment, a cleaning roller  14  comprises a textile covering  30 , which is arranged on a corresponding cylindrical holder  32 . 
     In a cleaning operation of the floor cleaning machine  10 , the floor head  12  is supported on a floor  34  to be cleaned ( FIG. 2 ) by way of the first cleaning roller  14   a  and the second cleaning roller  14   b . The floor head  12  with its cleaning rollers  14   a ,  14   b  has a contact plane  36  for the floor  34 . The floor  34  to be cleaned is, in particular, a hard floor. 
     The floor cleaning machine  10  comprises a holding device  38 . Said holding device is configured, in particular, as a holding rod device (of which only part is shown in  FIGS. 1 and 2 ). The holding device  38  is pivotably articulated on the floor head  12  by way of a pivot joint  40 . A pivot axis  42  of the pivotability of the holding device  38  in relation to the floor head  12  is oriented, in particular, in parallel to the first axis of rotation  16   a  or the second axis of rotation  16   b.    
     A further pivotability about a pivot axis  44  may also be present, which is locked transversely to the pivot axis  42 . The pivot axis  42  is thereby, in particular, in parallel to the contact plane  36 . 
     The floor cleaning machine  10  is hand-guided. The holding device  38  is configured such that a user can guide the floor cleaning machine  10  over the floor  34  to be cleaned, wherein the floor head  12  is supported on the floor  34  by way of the cleaning rollers  14   a ,  14   b , and the user themselves is standing on the floor  34  at a distance from the floor head  12 ; the hand-guided floor cleaning machine  10  is configured, in particular, such that it is operable by a user in a standing position. In this respect, reference is made to DE 10 2019 109 946. 
     A tank device  46  is releasably arranged on the floor head  12 . The tank device  46  is releasably positioned on a tank device holder  48  of the floor head  12 . The tank device  46  is releasable downwardly from the floor head  12  in a removal direction  50  ( FIG. 1 ). The removal direction  50  is oriented, in particular, perpendicularly to the contact plane  36 . 
     The tank device  46  is positioned on the holder  48  between the first cleaning roller  14   a  and the second cleaning roller  14   b . The tank device  46  serves to accommodate dirty fluid, which is “removed” from the cleaning rollers  14   a ,  14   b  and fed to the tank device  46 . In the embodiment shown, one single tank device  46  is provided for the first cleaning roller  14   a  and the second cleaning roller  14   b.    
     It is also possible in principle that the first cleaning roller  14   a  and the second cleaning roller  14   b  are each associated with their own respective tank, such that the tank device comprises two separate or connected parts. 
     The tank device  46  is arranged, in particular, such that dirty fluid from the cleaning rollers  14  is directly coupleable in a blower-free manner (without suction). This is explained in more detail below. 
     The tank device  46  (cf.  FIGS. 5 to 7 ) comprises a tray  52  with (at least) one receiving space  54  for dirty fluid. The tray  52  has a base  56  on which a peripheral wall  58  is arranged. The receiving space  54  is formed between the base  56  and the wall  58 . 
     In one embodiment, the tray  52  has an at least approximately cuboidal outer form. 
     The tank device  46  comprises a lid  60 . The lid  60  ( FIG. 7 ) may be an element that is separate from the floor head  12 . In particular, the tank device  46  is then removable with the lid  62  from the tank device holder  48 . 
     In an alternative embodiment, the lid of the tank device  46  is formed on the floor head  12 , for example by the tank device holder  48 . In this embodiment, only the tray  52  is removable from the floor head  12  and the corresponding lid remains on the floor head  12 . 
     During a cleaning operation of the floor cleaning machine  10 , an underside  56  of the base  56  of the tank device  46  faces toward the floor  34  to be cleaned. A first side wall  62  of the wall  58  faces toward the first cleaning roller  14   a , and a second side wall  64  opposite the first side wall  62  of the wall  58  faces toward the second cleaning roller  14   b.    
     In one embodiment, the first side wall  62  and the second side wall  64  each have a recess  66 , which serves to partially accommodate the transmission device, by way of which the corresponding shaft (like, for example, the first shaft  18 ) is torque-effectively coupled to the drive motor. The recess  66  is arranged in the middle on the corresponding side wall  62 ,  64 . In one embodiment, fixing elements  68  are arranged on the tray  52 . They are, in particular, of dome-shaped configuration. The fixing elements  68  serve to fix the tank device  46  by way of the tray  52  on the tank device holder  48  (cf.  FIG. 7 ) and, in particular, to hangingly fix and thereby floatingly mount the tray  52  on the floor head  12  (cf.  FIG. 7 ). This is explained in more detail below. 
     The fixing elements  68  also serve, in particular, to center and optionally additionally fix the lid  60  on the tray  52  if such a separate lid  60  is provided. The lid  60  then has corresponding recesses  74  ( FIG. 7 ) through which the fixing elements  68  are passed. 
     Arranged on the floor head  12  is a first sweeping element  70 , which is associated with the first cleaning roller  14   a . Further, arranged on the floor head  12  is a second sweeping element  72 , which is associated with the second cleaning roller  14   b . The sweeping elements  70 ,  72  serve to gather dirt particles (in particular coarse dirt particles) and feed same to the respective associated cleaning roller  14   a  and  14   b . These dirt particles can then be entrained by the cleaning roller  14   a  or  14   b  and be coupled into the tank device  46 . 
     The first sweeping element  70  and the second sweeping element  72  each have a sweeping edge  76 . The sweeping edge  76  is adjacent to the textile covering  30  of the corresponding cleaning roller  14  and can abut against or penetrate into it. Reference is made in this regard to WO 2016/058956 A1, which is expressly referred to. 
     The respective sweeping element  70 ,  72  with its sweeping edge  76  extends, in particular, at least approximately over the entire length of the associated cleaning roller  14 . The sweeping edge  76  is aligned in parallel to the corresponding axis of rotation  16   a ,  16   b.    
     The first sweeping element  70  is arranged on the first side wall  62  at a distance from the base  56  of the tray  52 . Correspondingly, the second sweeping element  72  is arranged on the second side wall  64  at a distance from the base  56 . 
     It is possible that the respective sweeping element  70 ,  72  is made of a rigid material or has a certain inherent elasticity. 
     The sweeping elements  70 ,  72  have, in particular, a contour facing toward the respective cleaning roller  14   a ,  14   b , said contour being adapted to the cleaning roller  14   a ,  14   b.    
     The first sweeping element  70  and the second sweeping element  72  are arranged on the tray  52  and thereby on the respective side wall  62  and  64  (front and rear side wall). 
     It is also possible in principle that the first sweeping element  70  and/or the second sweeping element  72  is arranged on the base  56  with the tray  52  being appropriately configured. 
     The first sweeping element  70  and the second sweeping element  72  are each fixedly connected to the tray  52 , such that they are removable with the tray  52  from the floor head  12  and are also moved in a movability of the tray  52  relative to the floor head. 
     Provision is made that in the operation of the floor cleaning machine  10 , the respective sweeping edge  76  of the first sweeping element  70  and the second sweeping element  72  are at a defined fixed distance D from the floor  34  to be cleaned (cf.  FIGS. 3 and 4 ). This defined distance D is hereby independent of the diameter of the associated cleaning roller  14  and thus independent, for example, of wear to the textile covering  30 . Further, it is independent of manufacturing tolerances. 
     The distance D is predetermined for an optimized cleaning result with respect to the coarse dirt gathering function of the sweeping element  70 ,  72 . If the distance D is too small, the respective sweeping element  70  or  72  can get caught in joints, transitions, or the like on the floor  34  to be cleaned and this results in a more difficult operability. If the distance D is too large, this results in a worsened coarse dirt gathering function. 
     In particular, the distance D is greater than zero and preferably greater than 0.5 mm and preferably greater than 0.7 mm. Further, provision is made, in particular, that the defined distance D is smaller than 1.5 mm and, in particular, smaller than 1.3 mm. 
     In a preferred embodiment, the distance D is about 1 mm. In order to provide this defined distance D in a cleaning operation of the floor cleaning machine  10 , support elements  78  are provided ( FIGS. 3, 4 ) with which the first sweeping element  70  and the second sweeping element  72  are supported on the floor  34  to be cleaned. The support elements  78  are configured as sliding elements, which slide over the floor  34  in the cleaning operation of the floor cleaning machine  10 . 
     The support elements  78  are configured precisely such that the sweeping edge  76  is at the distance D from the floor  34 . 
     In one embodiment, the support elements  78  are formed by spaced apart ribs  80 , which are arranged on the respective sweeping element  70 ,  72 . Said ribs  80  extend beyond the sweeping edge  76  in the direction of the contact plane  36  to achieve the supporting function on the floor  34 . 
     Between adjacent support elements  78  or ribs  80  is a free space over which the corresponding sweeping element  70 ,  72  does not contact the floor  34 . 
     In particular, a row of support elements  78 , in particular in the form of ribs, is provided on a respective sweeping element  70 ,  72 . A corresponding row has a longitudinal direction, which is parallel to the corresponding axis of rotation  16   a ,  16   b  of the associated cleaning roller  14   a  and  14   b , respectively. 
     Alternatively or in addition, it is possible that support elements  78  are arranged on the tank device  46  and thereby on the base  56  of the tray  52 . 
     In the operation of the floor cleaning machine  10 , the tank device  46  is supported on the floor  34  to be cleaned by way of the support elements  78 . To keep the distance D independent of the specific situation of the cleaning roller  14 , the tank device  46  or a partial region of the tank device (the tray  52 ) is floatingly mounted on the floor head  12  and thereby on the tank device holder  48 . The tank device  46  has a movability in a z-direction  82  in relation to the partial region at which the sweeping elements  70 ,  72  are arranged. This z-direction  82  is hereby transverse and, in particular, perpendicular to the contact plane  36  of the cleaning rollers  14  on the floor  34 . 
     Further, the z-direction  82  is oriented transversely and thereby, in particular, perpendicularly to the axes of rotation  16   a ,  16   b.    
     Further, provision is preferably made that the z-direction  82  is oriented transversely and, in particular, perpendicularly to the pivot axis  42 . As a result of the movability of the tray  52  with the sweeping elements  70 ,  72  in the z-direction  82  and as a result of the corresponding floating mounting on the floor head  12 , the sweeping edge  76  is always at the fixed distance D from the floor  34 , independently of the concrete diameter of the cleaning rollers  14 . The movability of the tray  52  in the z-direction  82  results in an automatic setting of said fixed distance D of the sweeping edge  76  from the floor  34  during a cleaning operation. The support elements  78  ensure a “correct” positioning of the sweeping elements  70 ,  72  relative to the floor  34 . 
     In one embodiment, the movability of the tank device  46  or the partial region on which the sweeping elements  70 ,  72  (of the tray  52 ) sit is achieved by a hanging mounting of the tray  52  on the floor head  12 . In particular, the mounting is such that, for one, this fixed distance D can be set and, for another, the tray  52  does not fall off when the floor head  12  is lifted from the floor  34 . 
     For example, corresponding counter fixing elements are associated with the fixing elements  68  on the tank device holder  48 , which counter fixing elements enable the movability in the z-direction  28  and prevent the tray  52  from falling off. In particular, a releasing force and/or special release movement is required to be able to remove the tank device  46  from the floor head  12  in the removal direction  50 . 
     In particular, the movability in the z-direction  82  is then also set such that precisely the compensation with respect to the fixed distance D made possible without the tank device  46  sitting “too loosely” on the floor head  12 . 
     In one embodiment, for example, a respective web sits on adjacent fixing elements  68 , said web then being positioned in a corresponding receptacle of the tank device holder  48  and being movable in the z-direction  82  when the tank device  46  is fixed to the floor head  12 , wherein the movability is limited to a corresponding distance, and a release of the tank device  46  from the tank device holder  48  is blocked without additional measures. 
     Here, it is possible in principle that the tank device  46  as a whole with the lid  60  is movable relative to the floor head  12  in the z-direction or that, for example, the tray  52  is movable in the z-direction relative to a lid  60  or a lid formed by the tank device holder  48 . 
     Provision may additionally be made that the tank device  46  or the partial region of the tank device  46  on which the sweeping elements  70 ,  72  sit is movable in at least one transverse direction  84   a ,  84   b  (cf.  FIG. 5 ) relative to the z-direction  82  and is thereby floatingly mounted on the tank device holder  48 . 
     The floor cleaning machine  10  comprises a tank device  86  for cleaning liquid ( FIG. 1 ). Said tank device  86  for cleaning liquid accommodates a cleaning liquid, which is suppliable directly or indirectly to the floor  34  to be cleaned by way of a supply device  88 . 
     The cleaning liquid is, in particular, fresh water to which a cleaning agent additive and, in particular, surfactant cleaning agent additive may be added. It is also possible in principle that the tank device  86  has separate tanks for fresh water and cleaning agent additive and a corresponding mixing takes place. 
     In one embodiment, cleaning liquid is supplied to the at least cleaning roller  14  by way of the supply device  88 ; the textile covering  30  of the corresponding cleaning roller  14  is then moistened by way of cleaning liquid. 
     Soiling on a floor  34  can be released by the cleaning liquid. In addition, a mechanical action on the dirt takes place by way of the corresponding cleaning roller  14 . A rotational wiping movement of the cleaning roller  14  on the floor  34  takes place. 
     In one embodiment, the tank device  86  is arranged on the holding device  38 . It is also possible in principle that it is arranged on the floor head  12 . 
     In this case, reference is made, as an example, to WO 2017/15345 A1 or DE 10 2019 109 946. 
     Furthermore, reference is made to WO 2016//058901 A1. For example, in a cleaning operation of the floor cleaning machine  10  in which the cleaning rollers  14  are rotated, a supply of cleaning agent from the tank device  86  by way of the supply device  88  to the cleaning rollers  14  is automatically effected by a valve being opened accordingly or a pump being switched on accordingly. 
     A respective scraping device  90  associated with the cleaning rollers  14  is arranged on the floor head  12  (cf.  FIG. 8 ). The scraping device  90  comprises a scraper  92 , which penetrates into the textile covering  30  of the associated cleaning roller  14   a ,  14   b . By means of the corresponding scraper  92 , dirty fluid can be removed from the associated cleaning roller  14  and conveyed into the tank device  46 . Reference is made in this respect to WO 2019/086083 A1. 
     For this purpose, (at least) one feed channel  94  is provided, which opens into the receiving space  54 . 
     In one embodiment, the scraper  92  is arranged on an input-coupling element  96 . An opening  97  for the feed channel  94  is arranged on the input-coupling element  96 . The scraper  92  forms an opening wall for the opening  97 . In particular, the tank device  46  or the partial region on which the sweeping elements  70 ,  72  sit is movable in the z-direction  82  relative to the input-coupling element  96 . 
     To enable this movability of the tank device  46  and to obtain a sealed supply channel  94 , a sealing device  98  is provided, which seals the supply channel  94  from the input-coupling element  96  in order to obtain a fluid-tight supply channel  94  when the tank device  46  is at different positions in the z-direction relative to the input-coupling element  96 . The scraper  92  is positioned at a distance from the respective sweeping element  70 ,  72 . 
     In one embodiment, provision is made that the corresponding cleaning roller  14  rotates in such a direction of rotation  100  that the scraper  92  is arranged downstream from the corresponding sweeping element  70  or  72 . Coarse dirt that is picked up by the corresponding sweeping element  70 ,  72  can thereby be transported by the corresponding cleaning roller  14  to the scraper  92 . Dirty fluid is removed on the scraper  92  and conveyed into the receiving space  54  via the at least one feed channel  94 . 
     It is possible, for example, that the input-coupling element  96  and/or the supply channel  94  are arranged on a lid  60  of the tank device  46 . Reference is made in this respect to WO 2019/029821 A1. 
     It is then advantageous, in particular, if the tray  52  is movable relative to said lid  60  in order to enable the movability in the z-direction  82  to in turn be able to set the fixed distance D of the sweeping edges  76  from the floor  34 . 
     With regard to the floatingly mounted tank device  46 , the floor cleaning machine  10  functions as follows: 
     In a cleaning operation of the floor cleaning machine  10 , it is placed on the floor  34  to be cleaned by way of the cleaning rollers  14   a ,  14   b  and is displaced over said floor  34 . 
     The cleaning rollers  14   a ,  14   b  are applied with cleaning liquid from the tank device  86 . The cleaning rollers  14   a ,  14   b  rotate in the direction of rotation  100  and, in particular, rotate in opposite directions. 
     The textile covering  30  is moistened. The cleaning rollers  14   a ,  14   b  act with a corresponding covering region on the floor  34  to be cleaned. A mechanical action takes place, and dirt is moistened in order to improve the detachment thereof. 
     Coarse dirt is gathered by way of the sweeping elements  70 ,  72  and can be entrained by the corresponding cleaning roller  14   a ,  14   b  in the direction of rotation  100 . 
     Dirty fluid including coarse dirt can be removed from the cleaning roller  14  on the respective scraper and is then conveyed into the tank device  46  and thereby into the corresponding receiving space  54 . 
     The sweeping elements  70 ,  72  are arranged on the tray  52  and thereby on the tank device  46  or on a partial region of the tank device  46 . The tray  52  with the sweeping elements  70 ,  72  is swimmingly mounted on the floor head  12  in the z-direction  82 . In the cleaning operation, the tray  52  is supported on the floor  34  to be cleaned by way of the support elements  78 . The fixed defined distance D between the sweeping edge  76  and the floor  34  is thereby automatically set. 
     This automatic setting takes place in the case of the different covering thicknesses B of the corresponding cleaning roller  14   a ,  14   b  (cf.  FIGS. 3 and 4 ). The covering thickness B can change, for example, in the case of corresponding wear to the cleaning roller  14 , or may be different due to manufacturing tolerances. 
     For example, the textile covering  30  is also compressed to a greater extent at a placement region on the floor  34  to be cleaned than outside of said region (cf.  FIGS. 3 and 4 ). When the tank device  46  is full, the width B may be smaller than when it is empty. 
     The floating mounting of the tank device  46  or of the tray  52  enables a movability of the tray  52  in relation to the axis of rotation  16   a  or  16   b  of the corresponding cleaning roller  14  in the z-direction  82 . Compare the  FIGS. 3 and 4  in which the tray  52  adopts different positions relative to the axis of rotation  16   a.    
     This always results, as explained, in the fixed distance D of the sweeping edge  76  from the floor  34 , independently of the situation on the cleaning roller  14 . This in turn results in an optimized coarse dirt gathering function for the respective sweeping element  70 ,  72 . Thus, on the one hand, it can be prevented that it catches on the floor  34  and, on the other hand, it is prevented that larger particles can “slip through” under the respective sweeping element  70 ,  72 . 
     The corresponding function is independent of manufacturing tolerances and is ensured over the lifetime of the cleaning roller  14  with wear to the textile covering  30  (with a reduction of the diameter of the cleaning rollers  14 ). 
     In one embodiment, provision is made that the tank device  46  or the tray  52  is mounted on the floor head  12  such that it is pressed against the floor  34  in a gravity-driven manner so that the support elements  78  rest on the floor  34 . The dead weight of the tray  52  effects the automatic positioning of the sweeping edge  76  at the fixed distance D from the floor  32 . Alternatively or in addition, it is possible that a spring device  102  presses the tray  52  in a direction  104  toward the contact plane  36  (cf.  FIG. 3 ). The spring device  102  is thereby supported, in particular, on the tank device holder  48  and on the tray  52  in order to correspondingly press the support elements  78  against the floor  34 . 
     A pin strip  106  with a plurality of pins  108  is arranged on the floor head  12 . The pins  108  of the pin strip  106  are pins that abut against the textile covering  30  or project into the textile covering  30  of the associated cleaning roller  14   a ,  14   b.    
     The pin strip  106  serves to pick up hair in the manner of a hairbrush. 
     The pins  108  are, in particular, made of a plastic material. 
     The pin strip  106  is arranged on the floor head  12  such that it is removable as a whole by a user. The user can then clean the pin strip  106  with hair caught therein. 
     The pin strip  106  comprises a support  110  on which the pins  108  are arranged. The pins  108  thereby project beyond the support  110 . 
     The pins  108  extend in a pin direction  114 . They have a flat face side  116 . In particular, a pin  108  on the face side  116  has a diameter in the range between 0.1 mm and 0.5 mm. In one embodiment, this diameter on the face side  116  is about 0.3 mm. 
     In one embodiment, the pin strip  106  is formed on an input-coupling element  118 . The input-coupling element  118  is positioned on the floor head  12 . The input-coupling element  118  is removable as a whole from the floor head  12 , or the pin strip  106  is removable from the input-coupling element  118 . 
     The input-coupling element  118  comprises a holder  120 . The support  110  of the pin strip  106  with the pins  108  sits fixedly or releasably on the holder  120  (see above). 
     Further, the scraper  92  sits on the holder  120  of the input-coupling element  118  at a distance from the pins  108 . 
     Further, in one embodiment, the opening  97  is at least partially formed on the input-coupling element  118 . 
     Arranged on the support  110 , which, in particular, sits fixedly on the holder  120 , are a first row  122   a  and a second row  122   b  of pins  108 . 
     The first row  122   a  and the second row  122   b  extend in a longitudinal direction  124  ( FIG. 11 ). In particular, the face sides  116  of the pins  108  in a row  122   a  or  122   b  are in a line parallel to the longitudinal direction  124 . 
     When the pin strip  106  is positioned on the floor head  12 , the longitudinal direction  124  is in parallel to the corresponding first axis of rotation  16   a  for the first cleaning roller  14   a  or to the second axis of rotation  16   b  for the second cleaning roller  14   b.    
     Further, the longitudinal direction  124  is at least approximately parallel to the contact plane  36 . 
     The second row  122   b  is spaced at a distance from the first row  122   a  in a transverse direction  126 . 
     In the embodiment shown, the pins  108  in the first row  122   a  and in the second row  122   b  are each in a line. 
     It is possible in principle that pins are also offset in the transverse direction  126  within a row. 
     The rows  122   a ,  122   b  have, in particular, a length that corresponds substantially to a length of the associated cleaning roller  14   a ,  14   b  or is somewhat shorter. A pickup of hair is thereby ensured substantially over the entire length of the corresponding cleaning roller  14 . 
     Coupling elements  128  and, in particular, latching elements, by way of which the pin strip  106  is connectable and, in particular, latchable to a corresponding counter element on the floor head  12 , sit on the holder  120  and, in particular, on the support  110 . The coupling elements  128  and their counter elements are configured such that a user can release and replace the pin strip  106  or the input coupling element  128  in a simple manner, in particular for cleaning purposes. 
     In the operation of the floor cleaning machine  10 , the pins  108  of the pin strip  106  abut against or penetrate into the textile covering  30 , cf. in particular  FIG. 10 . 
     In the operation of the floor cleaning machine  10 , the scraper  92  penetrates into the textile covering  30  of the corresponding cleaning roller  14  with a depth T 1  ( FIG. 10 ). A corresponding penetration depth of pins  108  is T 2 . 
     The penetration depth T 2  is in the range between 0 mm and 4 mm inclusively, wherein a penetration depth of 0 mm means that the pins  108  abut with the face side  112  against the textile covering  30 . 
     In particular, provision is made that the pins  108  project to an equal or lesser extent into the textile covering  30  than the scraper  92  (as an opening wall for scraping off dirty fluid and coupling into the tank device  46 ). 
     In particular, a difference T 1 -T 2  is in the range between 0 mm and 1 mm inclusively. 
     Pins  108  and, in particular, all pins  108  are aligned in the pin direction  114  on the pin strip  106 . This pin direction  140  is oriented transversely and, in particular, perpendicularly to the corresponding axis of rotation  16   a  or  16   b  of the associated cleaning roller  14 . 
     The pin direction  140  is further oriented in parallel or obliquely to the z-direction  82 . A corresponding angle  130  of the pin direction  114  to the z-direction  82  (and thus also to a normal of the contact plane  36 ) is, e.g., in the range between 0° and 10°. 
     Further, the pin direction  140  is in parallel or at an acute angle  132  to the scraper  92  (cf.  FIG. 10 ). This angle  132  is, in particular, in the range between 0° and 25°. 
     It results in an optimized result for the pickup of hair if the pin direction  114  and the scraper  92  are not aligned in parallel to one another, but rather at an acute angle and, in particular, at an acute angle of about 20°. 
     The pins  108  on the pin strip  106  are arranged similarly to elements on a hairbrush in order to achieve an optimized pickup of hair. The pin strip  106  is arranged downstream from the scraper  92  in relation to the direction of rotation  100 . Hair that was not coupled into the opening  97  can be picked up by the pin strip  106 . 
     The pin strip  106  is resiliently mounted on the floor head  12 . Alternatively or in addition, the scraper  92  with the opening  97  is mounted on the floor head  12  subjected to a force and, in particular, is mounted in a spring-loaded manner. 
     In the embodiment shown, the input-coupling element  118  is mounted on the floor head  12  subjected to a force and, in particular, is mounted in a spring-loaded manner. The pin strip  106  and the scraper  92  are thereby jointly mounted on the floor head  12  subjected to a force and, in particular, are mounted in a spring-loaded manner. 
     The input-coupling element  118  is mounted on the floor head  12  so as to be movable and, in particular, displaceable in a motion axis  134 . The input-coupling element  118  sits on a displacement guide  136 . The motion axis  134  is thereby oriented transversely and, in particular, perpendicularly to the respective axis of rotation  16   a  or  16   b.    
     The motion axis  134  is, in particular, at an acute angle to the z-direction  82 . Further, the motion axis  134  is at an acute angle to the normal of the contact plane  36 . The motion axis  134  is, in particular, aligned to a central axis of the associated cleaning roller  14 . 
     In one embodiment, the motion axis  134  is oriented in parallel to the scraper  92 . A spring device  138  for applying a force is associated with the input-coupling element  118  (cf.  FIG. 8 ). The spring device  138  exerts a spring force, which seeks to press the input-coupling element  118  with the pin strip  106  and the scraper  92  against the textile covering  30  of the associated cleaning roller  14 . 
     In one embodiment, the input-coupling element  118  comprises an abutment element  140  with an abutment surface  142  as a contact surface for the textile covering  30 . The abutment surface  142  may abut against the textile covering  30  or penetrate into it. 
     In particular, the pins  108  and the scraper  92  extend over the abutment surface  142 . The abutment element  140  forms a stop for the input-coupling element  118  against the corresponding cleaning roller  14 . It is configured such that the pins  108  and the scraper  92  each penetrate into the textile covering  30  with the desired penetration depth T 2  and T 1 , respectively. 
     It is thus guaranteed that the corresponding (preset) penetration depth T 1  and penetration depth T 2  is achieved, independently of the diameter  30  of the corresponding cleaning roller  14 . 
     The abutment element  140  is pressed against the surface of the cleaning roller  14  by the spring device  138 , independently of the diameter of the cleaning roller  14 . 
     Even if, for example, the diameter of the cleaning roller  14  is reduced due to wear to the textile covering  30 , the depth T 1  and T 2  that is predetermined for an optimized cleaning result is maintained. 
     Corresponding manufacturing tolerances can also be compensated for by the displaceable mounting and spring mounting of the input-coupling element  118 . 
     By means of the input-coupling element  118 , a constant distance from the textile covering  30  is achieved, independently of the condition or the configuration of the corresponding cleaning roller  14 . This results in an optimized scraping result both for dirty fluids and for hair. 
     The penetration depths T 1  and T 2  are independent of tolerances, roller diameters, and wear. An optimized dirt pickup (including hair pickup) can thus be ensured. For one, an insufficient penetration is prevented (which can have a negative effect on the dirt pickup) and, for another, an excessive penetration is prevented (which can can lead to increased current consumption by the floor cleaning machine  10  as well as an increased load on the motor and on the transmission). 
     The spring device  138  can be formed by one or more coil springs. The application of force can also be formed, e.g., by one or more rubber buffers. It is also possible that, for example, a pressure cylinder is provided for the application of force. 
     In principle, it is also possible that the abutment of the abutment element  140  against the textile covering  30  of the associated cleaning roller  14  is gravity-driven alone. 
     In the described embodiment, an input-coupling element  118  is provided, on which both the pin strip  106  and the scraper  92  are arranged. 
     It is possible in principle that separate movable and, in particular, displaceable elements are provided for the pin strip  106  and for the scraper  92 . 
     It is further possible that either only the pin strip  106  is movably and, in particular, displaceably mounted, or only the scraper  92  is displaceably mounted. 
     Shown in  FIGS. 8 to 10  are respective different positions of the input-coupling element  118  on its displacement guide  136  relative to the first cleaning roller  14   a.    
     The positions shown in  FIGS. 8 and 9  are transition positions for explaining the basic functionality. 
     Shown in  FIG. 10  is a final position in which the abutment surface  142  abuts against the textile covering  30  on the outside, such that the pins  108  and the scraper  92  each penetrate into the textile covering  30  with the respectively predetermined penetration depth T 1  and T 2 . 
     As mentioned above, provision may also be made, for example, that the pins  108  only touch the textile covering  30  and do not penetrate into it (with a penetration depth T 2  of 0 mm). 
     The position shown in  FIG. 9  is, in particular, also a position for the input-coupling element  118  when, for example, the cleaning roller  14  is to be exchanged. 
     It is possible that a floatingly mounted tank, as is described on the basis of the floor cleaning machine  10 , is also used in the case of a floor cleaning machine  144  ( FIG. 16 ), which is of self-propelled and, in particular, self-steering configuration. On such a floor cleaning machine, which has a floor head  146 , in particular, a tank device for cleaning liquid is then also arranged on the floor head. 
     With respect to the floating mounting of the tank device for dirty liquid, on which one or more sweeping elements are arranged, the functioning is the same as described above. The floor cleaning machine  144  may also be equipped with one or more pin strips  106  for hair pickup. 
     Further, it is possible that a corresponding pin strip  106  and/or a scraper  92  for a corresponding cleaning roller  14  is movably and, in particular, displaceably mounted and, in particular, is mounted under the application of force. A further embodiment of a floor cleaning machine  148  ( FIG. 16 ) comprises a floor head  150 . The floor head  150  is supported on a floor to be cleaned by way of one single cleaning roller  152  in a cleaning operation. A removable tank device  154  for dirty fluid sits on the floor head  150 . 
     The floor head  150  is provided with a pin strip corresponding to the pin strip  106 , which, in particular, sits on the tank device  154 . 
     In particular, provision is made that the pin strip  106  and/or a corresponding scraper for the cleaning roller  152  is movably and, in particular, displaceably mounted and, in particular, mounted in a spring-loaded manner, as described above. 
     REFERENCE NUMERAL LIST 
     
         
           10  floor cleaning machine 
           12  floor head 
           14   a  first cleaning roller 
           14   b  second cleaning roller 
           16   a  first axis of rotation 
           16   b  second axis of rotation 
           18  first shaft 
           20  first shaft region 
           22  second shaft region 
           24  first part 
           26  second part 
           28  side rim 
           30  textile covering 
           32  holder 
           34  floor 
           36  contact plane 
           38  holding device 
           40  pivot j oint 
           42  pivot axis 
           44  pivot axis 
           46  tank device 
           48  tank device holder 
           50  removal direction 
           52  tray 
           54  receiving space 
           56  base 
           58  wall 
           60  lid 
           62  side wall 
           64  side wall 
           66  recess 
           68  fixing element 
           70  first sweeping element 
           72  second sweeping element 
           74  recess 
           76  sweeping edge 
           78  support elements 
           80  ribs 
           82  z-direction 
           84   a ,  84   b  transverse direction 
           86  tank device for cleaning liquid 
           88  supply device 
           90  scraping device 
           92  scraper 
           94  feed channel 
           96  input-coupling element 
           97  opening 
           98  sealing device 
           100  direction of rotation 
           102  spring device 
           104  direction 
           106  pin strip 
           108  pin 
           110  support 
           112  face side 
           114  pin direction 
           116  face side 
           118  input-coupling element 
           120  holder 
           122   a  first row 
           122   b  second row 
           124  longitudinal direction 
           126  transverse direction 
           128  coupling element 
           130  shaft 
           132  shaft 
           134  motion axis 
           136  displacement guide 
           138  spring device 
           140  abutment element 
           142  abutment surface 
           144  floor cleaning machine 
           146  floor head 
           148  floor cleaning machine 
           150  floor head 
           152  cleaning roller 
           154  tank device 
         D distance from the floor  34   
         T 1 , T 2  penetration depth