Abstract:
A cleaning tool for a floor cleaning appliance is provided, including a main body carrying a cleaning cover which is subject to wear, and including a signal transmitter which provides a wireless signal in dependence upon the degree of wear of the cleaning cover. To be able to detect in a cost-effective manner when a maximum admissible degree of wear of the cleaning cover is reached, the signal transmitter is of rigid construction and fixed to a movable carrying part, the carrying part being held on the main body and being movable from a normal position to an evasive position against a restoring force, the carrying part protruding further from the main body in the normal position than in the evasive position, and the carrying part and/or the signal transmitter contacting the floor surface to be cleaned when a maximum admissible degree of wear of the cleaning cover is reached.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of international application number PCT/EP2014/067119 filed on Aug. 8, 2014 and claims the benefit of German application number 10 2013 111 330.3 filed on Oct. 14, 2013, which are incorporated herein by reference in their entirety and for all purposes. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to a cleaning tool for a floor cleaning appliance, comprising a main body carrying a cleaning cover which is subject to wear, and comprising a signal transmitter which provides a wireless signal in dependence upon the degree of wear of the cleaning cover. 
         [0003]    Floor cleaning appliances, for example, sweeping machines, scrubbing machines or floor polishing machines, comprise a cleaning tool with a main body carrying a cleaning cover. The cleaning cover may, for example, be configured in the form of a bristle cover, a polishing disk or a cleaning pad and is subject to increasing wear during use of the cleaning tool. When a maximum admissible degree of wear is reached, the cleaning tool should be replaced as, otherwise, there is a risk of the floor surface to be cleaned being damaged and, in addition, of the achievable cleaning result being inadequate. The wear of the cleaning cover is often visually monitored by the user. However, in many cases, this involves difficulties as the cleaning tool is often installed in a housing of the floor cleaning appliance and, therefore, cannot be readily seen by the user from the outside. 
         [0004]    To detect the degree of wear of a disk brush, it is proposed in WO 97/08984 A1 that the disk brush be mounted on a vertically displaceable linkage, the position of which can be detected by a potentiometer. With increasing wear of the disk brush, it becomes displaced further and further downwards in the direction towards the floor surface to be cleaned. This displacement is detected by the potentiometer and forms a measure of the degree of wear of the disk brush. If the disk brush is replaced, it is necessary to calibrate the position of the new disk brush in order to thereby ensure that the signal of the potentiometer corresponds to the actual degree of wear of the new disk brush. 
         [0005]    In DE 10 2009 018 121 A1 it is proposed that a wear value be stored in a memory element of the cleaning tool, the wear value corresponding to the degree of wear of the cleaning tool at the time the wear value is stored, and that this wear value be repeatedly updated. 
         [0006]    In DE 10 2007 050 351 A1, it is proposed that the degree of wear of the cleaning cover be detected by means of a sensor element which is arranged together with a transponder on a flexible foil printed circuit. The foil printed circuit protrudes together with the sensor element located thereon from the main body of the cleaning tool and, like the cleaning cover, wears away during use of the cleaning tool. When a maximum degree of wear is reached, the sensor element is destroyed, and, as a result, the wireless signal provided by the transponder, which can be detected by an associated reader, changes. 
         [0007]    The provision of a flexible foil printed circuit having arranged thereon a sensor element which is destroyed when a maximum degree of wear of the cleaning cover is reached, makes it possible to detect when the maximum degree of wear of the cleaning cover is reached. However, the arrangement of the sensor element and the transponder on the foil printed circuit involves not inconsiderable costs. 
         [0008]    The object of the present invention is to further develop a cleaning tool of the generic kind in such a way that wear of the cleaning cover can be detected in a cost-effective manner. 
       SUMMARY OF THE INVENTION 
       [0009]    This object is accomplished, in accordance with the invention, with a cleaning tool of the kind mentioned at the outset in that the signal transmitter is of rigid construction and is fixed to a movable carrying part, the carrying part being held on the main body and being movable from a normal position to an evasive position against a restoring force, the carrying part protruding further from the main body in the normal position than in the evasive position, and the carrying part and/or the signal transmitter contacting the floor surface to be cleaned when a maximum admissible degree of wear of the cleaning cover is reached. 
         [0010]    A rigid signal transmitter which is fixed to a movable carrying part is used in the cleaning tool in accordance with the invention. A standard part such as, for example, a permanent magnet or a transponder, which can be cost-effectively produced in very large numbers, can be used as signal transmitter. The carrying part is held on the main body and can be moved from a normal position against the action of the restoring force to an evasive position. In the normal position, the carrying part protrudes further from the main body than in the evasive position. When a maximum admissible degree of wear of the cleaning cover is reached, the carrying part and/or the signal transmitter contacts the floor surface to be cleaned. This results in the carrying part and/or the signal transmitter being adversely affected by the floor surface upon further use of the cleaning tool. This ultimately causes damage to the carrying part and/or the signal transmitter, which, in turn, leads to a change in the wireless signal provided by the signal transmitter. 
         [0011]    It may, for example, be provided that when a maximum admissible degree of wear of the cleaning cover is exceeded, the signal transmitter is damaged or even destroyed by the floor surface or becomes detached from the carrying part. 
         [0012]    It is expedient for the signal transmitter to provide a predefined wireless signal until a maximum admissible degree of wear of the cleaning cover is reached and for the signal to change abruptly or stop when the maximum admissible degree of wear of the cleaning cover is exceeded. 
         [0013]    The floor surface is cleaned by the cleaning cover contacting the floor surface. The cleaning cover is pressed against the floor surface during the cleaning of the floor surface. For this purpose, the cleaning tool is held, in many cases, movably on the floor cleaning appliance. The force with which the cleaning cover is pressed against the floor surface can often be influenced by the user. Depending on the type of floor surface, the cleaning cover can be pressed with different force against the floor surface. This results in the cleaning cover being compressed to a greater or lesser extent during the cleaning of the floor surface. To prevent the carrying part and/or the signal transmitter from already contacting the floor surface when the cleaning cover is compressed and the floor surface from thereby being damaged before the cleaning cover has reached its maximum admissible degree of wear, the carrying part can be moved against the action of a restoring force from its normal position in the direction of the main body into an evasive position. On the one hand, this has the advantage that the compression of the cleaning cover does not result in the signal transmitter prematurely indicating that the maximum admissible degree of wear of the cleaning cover has been reached, and, on the other hand, the evasive movement of the carrying part ensures that the floor surface to be cleaned is not damaged by the rigid signal transmitter. 
         [0014]    With the cleaning tool in accordance with the invention, it is, therefore, possible to reliably detect that the maximum admissible degree of wear of the cleaning cover has been reached without the user having to visually monitor the cleaning cover. It is ensured that the carrying part and/or the signal transmitter are only adversely affected by the floor surface when the maximum admissible degree of wear of the cleaning cover is reached, without a strong compression of the cleaning cover already resulting in such adverse affecting of the carrying part and/or the signal transmitter. In spite of use of a rigid signal transmitter, there is, therefore, no risk of the floor surface being damaged by the signal transmitter or by the carrying part during normal operation of the cleaning tool. 
         [0015]    In an advantageous configuration of the invention, the cleaning tool is rotatable about an axis of rotation, and in relation to the axis of rotation of the cleaning tool, the carrying part is movable back and forth in the radial or axial direction between the normal position and the evasive position. 
         [0016]    It may, for example, be provided that the cleaning tool is configured as disk brush which is mounted on the floor cleaning appliance for rotation about a substantially vertically aligned axis of rotation, with the carrying part being movable back and forth in the axial direction between the normal position and the evasive position. 
         [0017]    It may also be provided that the cleaning tool is constructed as roller brush which is mounted on the floor cleaning appliance for rotation about a substantially horizontally aligned axis of rotation, with the carrying part being movable back and forth in the radial direction between the normal position and the evasive position. 
         [0018]    In the normal position of the carrying part, the signal transmitter preferably protrudes from the main body and in its protruding region is completely surrounded by the carrying part. The carrying part forms a protective shell which surrounds the signal transmitter at least in its region protruding from the main body. 
         [0019]    It may be provided that in the normal position of the carrying part, the signal transmitter protrudes completely from the main body of the cleaning tool and is completely surrounded by the carrying part. 
         [0020]    In an advantageous configuration of the invention, the carrying part forms a protective sleeve which surrounds the signal transmitter in the circumferential direction. The signal transmitter can be inserted into the protective sleeve and fixed in the protective sleeve. The protective sleeve may, for example, be configured in the form of a circular cylinder. 
         [0021]    It is expedient for the carrying part to be positionable on the floor surface to be cleaned when a maximum admissible degree of wear of the cleaning cover is reached. Further use of the cleaning tool then results in the carrying part sliding along the floor surface and being mechanically influenced by the floor surface. For example, the carrying part can be abraded by the floor surface. After a short time, the increasing mechanical influence on the carrying part may result in the signal that is provided by the signal transmitter fixed to the carrying part undergoing a change. This signal change can be detected by a signal receiver and it can thereby be indicated to the user that the cleaning cover has exceeded its maximum admissible degree of wear. 
         [0022]    It is advantageous for the carrying part to be destroyable by use of the cleaning tool when the maximum admissible degree of wear of the cleaning cover is reached. The carrying part can be destroyed by contact with the floor surface. For example, it may be provided that the carrying part breaks into at least two parts. The fixing of the signal transmitter on the carrying part is thereby adversely affected, which, in turn, results in a change in the signal provided by the signal transmitter after the cleaning cover has reached its maximum admissible degree of wear. 
         [0023]    In an advantageous embodiment of the invention, the signal transmitter is removable from the main body when the maximum admissible degree of wear of the cleaning cover is reached. For example, it may be provided that the signal transmitter is ejected from the main body moving relative to the floor surface when the maximum admissible degree of wear of the cleaning cover is reached. This results in the signal transmitter no longer being able to provide a signal detectable by the user. The absence of the signal, therefore, indicates to the user that the cleaning cover has reached its maximum admissible degree of wear. 
         [0024]    It is advantageous for the signal transmitter to be configured as transponder. The signal transmitter, therefore, forms a radio communication element, which receives and responds to incoming signals. A wireless transmission channel can be created between the cleaning tool and an external reader of the floor cleaning appliance by means of the transponder. The transponder has a data memory in the form of a read/write memory and may additionally include a control logic device. The transponder preferably has an antenna coil. By means of being inductively coupled to an associated reader, the transponder can be supplied with power and its data memory can be read. It may, however, also be provided that the transponder is equipped with a power source of its own. The person skilled in the art is familiar with such combinations of a transponder and a reader under the term RFID technology (Radio Frequency Identification technology). 
         [0025]    The rigid signal transmitter is preferably configured as ferrite core/glass transponder. 
         [0026]    As mentioned above, the carrying part can be moved against the action of a restoring force from a normal position to an evasive position. The restoring force is preferably provided by a spring element. 
         [0027]    In a preferred configuration of the invention, the carrying part is held in a linearly displaceable manner on the main body. For example, it may be provided that the main body is rotatable about an axis of rotation, and, in relation to the axis of rotation of the main body, the carrying part is held so as to be displaceable in the radial direction. 
         [0028]    The carrying part is expediently held in a displaceable manner in a guide part which is fixable to the main body. 
         [0029]    The carrying part expediently forms a sleeve which with a front end region protrudes from the main body and with a rear end region is arranged inside the main body. The signal transmitter is expediently arranged in the front end region of the sleeve, and a spring element which is supported on the main body extends into the rear end region of the sleeve. The carrying part constructed as sleeve can be held in a normal position by means of the spring element, and the carrying part can be moved into the evasive position against the spring force of the spring element. In the normal position, the carrying part protrudes further from the main body than in the evasive position. 
         [0030]    It may be provided that the main body is of cylindrical configuration and, in relation to the cylinder axis, comprises a radial bore or a bore aligned parallel or at an incline to the radial direction, into which the guide part is insertable. 
         [0031]    It is particularly advantageous for the guide part to be latchable to the main body. The guide part may, for example, comprise latching elements which assume a latching position when the guide part is inserted into the main body, so that the guide part is no longer readily removable from the main body. 
         [0032]    It is particularly advantageous for the main body to be constructed as hollow cylinder and to comprise a preferably radially aligned bore into which the guide part is insertable, with at least one latching element of the guide part being positionable on an inner side of the hollow-cylindrical main body after insertion of the guide part into the bore. 
         [0033]    In an advantageous configuration of the invention, the carrying part comprises a carrying body which accommodates the signal transmitter, and a base body which is connectable to the main body of the cleaning tool and is connected to the carrying body by way of an elastically deformable spring body. The base body can, for example, be inserted into a receptacle of the main body of the cleaning tool, and the carrying body accommodating the signal transmitter can be moved back and forth relative to the base body between a normal position and an evasive position by the provision of the elastically deformable spring body. During the movement from the normal position to the evasive position, the carrying body can be acted upon with a restoring force by the elastically deformable spring body. 
         [0034]    It is advantageous for the carrying body, the spring body and the base body to jointly form a one-piece plastic molded part. 
         [0035]    The spring body is expediently configured as elastically deformable spring arm. The carrying body is connected to the base body by way of the spring arm. 
         [0036]    The main body of the cleaning tool is expediently of cylindrical configuration and at an end face has a recess into which the carrying part is preferably insertable in the axial direction. 
         [0037]    It is particularly advantageous for the recess of the main body to be connectable with positive locking to the base body of the carrying part. This facilitates assembly of the carrying part on the main body. 
         [0038]    As mentioned above, the cleaning tool may be configured as cleaning brush rotatable about an axis of rotation. In this case, it is advantageous for there to be arranged in the direction of rotation of the cleaning brush, in front of the signal transmitter, cleaning bristles, which cover the signal transmitter at least partially during use of the cleaning tool until a maximum admissible degree of wear of the cleaning bristles is reached. The cleaning bristles project outwardly from a main body of the cleaning brush. In particular, the cleaning bristles can project, in relation to the axis of rotation of the cleaning brush, in the radial direction from the main body of the cleaning brush. The cleaning bristles are bent backwards opposite to the direction of rotation of the cleaning tool by contact with the floor surface to be cleaned. Cleaning bristles arranged in the direction of rotation of the cleaning brush in front of the signal transmitter cover the signal transmitter at least partially until the cleaning bristles have reached their maximum admissible degree of wear. After the maximum admissible degree of wear has been reached, the cleaning bristles can no longer cover the signal transmitter, and so it contacts the floor surface and is thereby adversely affected by the floor surface. This can result in a change and, in particular, in an interruption of the signal provided by the signal transmitter, and this signal change can be recognized by the user. 
         [0039]    It is particularly advantageous for the cleaning tool to be configured as roller brush rotatable about an axis of rotation and to have a cylindrical main body which carries a cleaning cover in the form of a bristle cover with a large number of outwardly projecting cleaning bristles between which the signal transmitter fixed to the carrying part is arranged. 
         [0040]    The following description of two preferred embodiments of the invention will serve in conjunction with the drawings for further explanation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0041]      FIG. 1  is a perspective representation of a first embodiment of a cleaning tool in accordance with the invention; 
           [0042]      FIG. 2  is a longitudinal sectional view of the cleaning tool shown in  FIG. 1 ; 
           [0043]      FIG. 3  is an enlarged representation of detail A from  FIG. 2 ; 
           [0044]      FIG. 4  is a perspective representation of a guide part of the cleaning tool from  FIG. 1 ; 
           [0045]      FIG. 5  is a schematic representation of the cleaning tool from  FIG. 1  during the cleaning of a floor surface, wherein the cleaning tool is pressed with a relatively low force against the floor surface; 
           [0046]      FIG. 6  is a schematic representation of the cleaning tool from  FIG. 1  during the cleaning of a floor surface, wherein the cleaning tool is pressed with a relatively high force against the floor surface; 
           [0047]      FIG. 7  is a schematic representation of the cleaning tool from  FIG. 1  during the cleaning of a floor surface, wherein a cleaning cover of the cleaning tool has reached its maximum degree of wear; 
           [0048]      FIG. 8  is a perspective representation of a second embodiment of a cleaning tool in accordance with the invention; 
           [0049]      FIG. 9  is a perspective representation of the cleaning tool from  FIG. 8  in the manner of an exploded drawing; 
           [0050]      FIG. 10  is a view of an end face of the cleaning tool from  FIG. 8 ; 
           [0051]      FIG. 11  is an enlarged representation of detail B from  FIG. 10 ; 
           [0052]      FIG. 12  is a schematic representation of the cleaning tool from  FIG. 8  during the cleaning of a floor surface, wherein the cleaning tool is pressed with a relatively low force against the floor surface; 
           [0053]      FIG. 13  is a schematic representation of the cleaning tool from  FIG. 8  during the cleaning of a floor surface, wherein the cleaning tool is pressed with a relatively high force against the floor surface; and 
           [0054]      FIG. 14  is a schematic representation of the cleaning tool from  FIG. 8  during the cleaning of a floor surface, wherein a cleaning cover of the cleaning tool has reached a maximum degree of wear. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0055]    A first advantageous embodiment of a cleaning tool in accordance with the invention, which is denoted in its entirety by reference numeral  10 , is shown schematically in  FIGS. 1 to 7 . The cleaning tool  10  is configured as roller brush  12  and has a hollow-cylindrical main body  14  which can be mounted on a floor cleaning appliance, known per se, for rotation about an axis of rotation  16 . 
         [0056]    The main body  14  carries on its outer side a cleaning cover which is configured in the form of a bristle cover  18  and comprises a large number of cleaning bristles  20  which protrude outwardly from the main body  14 . 
         [0057]    In the course of time, the cleaning bristles  20  wear away during use of the roller brush  12  and become shorter. 
         [0058]    When a maximum admissible degree of wear has been reached, this can be wirelessly indicated to the user by a rigid signal transmitter  22 . The signal transmitter  22  is configured in the form of a rigidly constructed transponder, in particular, in the form of a ferrite core/glass transponder. 
         [0059]    The signal transmitter  22  is fixed in a carrying part configured in the form of a sliding sleeve  24 , which in a guide part in the form of a guide sleeve  26  is slidable in the radial direction in relation to the axis of rotation  16  of the roller brush  12 . The guide sleeve  26  comprises two latching wings  28 ,  30  and can be inserted into a radial bore  32  of the hollow-cylindrical main body  14 . The latching wings  28 ,  30  are thereby supported on the inner side  34  of the main body  14 , and a radially outwardly facing support flange  36  of the guide sleeve  26  is supported on the outer side  38  of the main body  14 . By means of the two latching wings  28 ,  30  and the support flange  36 , the guide sleeve  26  can, therefore, be fixed to the radial bore  32  of the main body  14 . 
         [0060]    As will be clear, in particular, from  FIG. 3 , the guide sleeve  26  accommodates the sliding sleeve  24 , and the sliding sleeve  24  is supported with a radial extension  40  in the axial direction on a step  42  of the guide sleeve  26 . A spring element in the form of a pressure spring  44  extends into the sliding sleeve  24 . The pressure spring  44  is supported, on the one hand, on the main body  14  and, on the other hand, on the signal transmitter  22  positioned in the sliding sleeve  24 . By means of the pressure spring  44 , the sliding sleeve  24  and the signal transmitter  22  are pressed radially out of the main body  14  until the radial extension  40  of the sliding sleeve  24  abuts on the step  42  of the guide sleeve  24 . In this position, the sliding sleeve  24  assumes a normal position from which it can be moved against the elastic restoring force of the pressure spring  44  into an evasive position. In the normal position, as shown, for example, in  FIG. 5 , the sliding sleeve  24  protrudes further from the main body  14  than in the evasive position, which is shown in  FIG. 6 . 
         [0061]    The radial bore  32  is arranged in the region between the cleaning bristles  20  of the roller brush  12 , and so the sliding sleeve  24  and the signal transmitter  22  also assume a position between the cleaning bristles  20 . This will be clear, in particular, from  FIG. 1 . In the direction of rotation of the main body  14  in front of and behind the sliding sleeve  24  and the signal transmitter  22 , cleaning bristles  46 ,  48  immediately adjacent to the sliding sleeve  24  and the signal transmitter  22  are arranged on the outer side of the main body  14 . 
         [0062]    The signal transmitter  22  provides a wireless signal, which can be detected by a reader  50 , known per se. The reader  50 , like the roller brush  12 , is arranged on the floor cleaning appliance and is usually connected to a display device of the floor cleaning appliance. 
         [0063]    A floor surface  52  can be cleaned in the usual way by means of the roller brush  12 . This is shown schematically in  FIGS. 5, 6 and 7 . During the cleaning of the floor surface  52 , the cleaning bristles  20  of the cleaning brush  12  wear away increasingly and thereby become shorter. 
         [0064]    Depending on what force the roller brush  12  is to exert on the floor surface  52  to be cleaned, the roller brush  12  can be brought up to the floor surface  52  to a greater or lesser extent. In a first position, which is shown in  FIG. 5 , the roller brush  12  exerts a relatively low force on the floor surface  52  to be cleaned, whereas in a second position shown in  FIG. 6 , the roller brush  12  is closer to the floor surface  52  and, consequently, exerts a greater force on the floor surface  52 . 
         [0065]    While cleaning the floor surface  52 , the cleaning bristles  20  are bent backwards opposite to the direction of rotation of the roller brush  12 . The cleaning bristles  46  or  48  immediately adjacent to the sliding sleeve  24  thereby cover the sliding sleeve  24  at least partially, and so the sliding sleeve  24  is unable to directly contact the floor surface  52  as long as the cleaning bristles  24  have not yet reached their maximum admissible degree of wear. 
         [0066]    If a relatively high force is exerted by the roller brush  12  on the floor surface  52 , as shown in  FIG. 6 , the cleaning bristles  20  press the sliding sleeve  24  together with the signal transmitter  22  in relation to the axis of rotation  16  radially inwards into an evasive position in which the sliding sleeve  24  and the signal transmitter  22  protrude to a lesser extent from the main body  14  than in the normal position shown in  FIG. 5 . The sliding sleeve  24  is also covered by the cleaning bristles  20  in the evasive position, as long as the cleaning bristles  20  have not yet reached their maximum admissible degree of wear. 
         [0067]    The consequence of the cleaning bristles  20  reaching the maximum admissible degree of wear is that the sliding sleeve  24  is no longer covered by the cleaning bristles  20 . This is shown schematically in  FIG. 7  and results in the sliding sleeve  24  directly contacting the floor surface  52  and being mechanically adversely affected by the floor surface  52 . The consequence of further use of the roller brush  12  is that an end wall  54  of the sliding sleeve  24  is abraded by the floor surface  52  during further use of the roller brush  12 . The signal transmitter  22  is pressed by the pressure spring  44  against the inner side of the end wall  54 . Once the end wall  54  has been abraded, the signal transmitter  22  is pushed by the pressure spring  44  out of the sliding sleeve  24 , with this movement being supported by the centrifugal force caused by the rotating roller brush  12 . This has the consequence that after the maximum admissible degree of wear of the cleaning bristles  20  has been reached, the signal transmitter  22  is ejected from the roller brush  12 . This, in turn, has the consequence that a signal can no longer be received by the reader  50 . The absence of the signal can be indicated to the user on the display device of the floor cleaning appliance, and so the user receives the information that the cleaning bristles  20  have reached their maximum admissible degree of wear. 
         [0068]    By means of the sliding sleeve  24  and the signal transmitter  22  fixed therein, it is, therefore, possible to indicate in a simple way to the user that the maximum admissible degree of wear of the cleaning bristles  20  has been reached, and the signal transmitter  22  together with the sliding sleeve  24  can be moved back and forth between a normal position and an evasive position before the maximum admissible degree of wear of the cleaning bristles  20  is reached. The normal position is assumed by the sliding sleeve  24  and the signal transmitter  22  insofar as the roller brush  12  exerts only a relatively low force on the floor surface  52  to be cleaned. If, however, the roller brush  12  is brought up closer to the floor surface  52  by the user, so that it exerts a greater force on the floor surface  52 , the sliding sleeve  24  and the signal transmitter  22  then move into their evasive position. The sliding sleeve  24  is thereby prevented from contacting and damaging the floor surface  52 . When the cleaning bristles  20  have reached their maximum admissible degree of wear, the sliding sleeve  24  is then abraded by the floor surface  52  and the signal transmitter  22  is ejected from the roller brush  12 . The force with which the roller brush  12  is pressed against the floor surface  52  to be cleaned, therefore, has no influence on the indicating of the maximum admissible degree of wear of the cleaning bristles  20  by the signal transmitter  22 . 
         [0069]    A second advantageous embodiment of a cleaning tool in accordance with the invention, which is denoted in its entirety by reference numeral  60 , is shown in  FIGS. 8 to 14 . The cleaning tool  60  is configured in the form of a roller brush  62  comprising a hollow-cylindrical main body  64  which can be mounted on a floor cleaning appliance for rotation about an axis of rotation  66 . The main body  64  carries a bristle cover  68  with a large number of cleaning bristles  70  on its outer side. 
         [0070]    In a manner corresponding to the roller brush  12  explained hereinabove with reference to  FIGS. 1 to 7 , the roller brush  62  also comprises a rigid signal transmitter  72  which, in the illustrated exemplary embodiment, is configured as ferrite core/glass transponder. The signal transmitter  72  wirelessly supplies a reader  74 , known per se and, therefore, shown only schematically in  FIG. 8 , which can be positioned on an end face of the roller brush  62 , with a signal which is dependent upon the degree of wear of the cleaning bristles  70 . 
         [0071]    For movable mounting of the signal transmitter  72  on the main body  64 , the roller brush  62  comprises a carrying part  76  with a hollow-cylindrical carrying body  78 , which accommodates the rigid signal transmitter  72  and is connected by way of an elastically deformable spring body  80  to a base body  82 . The carrying body  78  forms in combination with the spring body  80  and the base body  82  a one-piece plastic molded part. 
         [0072]    The main body  64  of the roller brush  62  has a through-opening  84  which opens into an end face  86 . Adjoining the through-opening  84  in the circumferential direction is a recess  88  which is delimited on the outer side  90  of the main body  64  by an outer wall  92  and on the inner side  94  of the main body  64  by an inner wall  96 . 
         [0073]    An end region of the recess  88  facing away from the through-opening  84  accommodates the base body  82  of the carrying part  76  with positive locking. The carrying body  78  which surrounds the signal transmitter  72  in the circumferential direction assumes a position outside of the through-opening  84 , the carrying body  78  being connected to the base body  82  by way of the spring body  80 . The spring body  80  forms an L-shaped spring arm  100  with a first spring leg  102  which adjoins the base body  82  and in relation to the axis of rotation  66  of the main body  64  is aligned in the circumferential direction. Adjoining the first spring leg  102  in the region of the through-opening  84  is a radially outwardly directed second spring leg  104 , which carries the cylindrical carrying body  78  at its free end. 
         [0074]    In a manner corresponding to the roller brush  12  explained hereinabove, the roller brush  62  can also be brought up to a floor surface  106  to a greater or lesser extent in order to clean the floor surface  106 . When the roller brush  62  assumes a first position, as shown in  FIG. 12 , it exerts a relatively low force on the floor surface  106  to be cleaned. When the roller brush  62  is brought up closer to the floor surface  106 , as shown in  FIG. 13 , it exerts a greater force on the floor surface  106 . 
         [0075]    During the cleaning of the floor surface  106 , the cleaning bristles  70  are bent backwards opposite to the direction of rotation of the roller brush  62 . Cleaning bristles  108  immediately adjacent to the carrying part  76  and the signal transmitter  72  cover the carrying part  76  and, therefore, also the signal transmitter  72  until the cleaning bristles  108  have reached their maximum admissible degree of wear. Depending on the force with which the roller brush  62  is pressed against the floor surface  106 , the cleaning bristles  108  immediately adjacent to the carrying part  76  move the carrying part from its normal position shown in  FIG. 12  into an evasive position, as shown in  FIG. 13 . In the evasive position, the carrying part  76  and the signal transmitter  72  protrude to a lesser extent from the main body  64  than in the normal position. 
         [0076]    When the cleaning bristles  108  immediately adjacent to the carrying part  76  have reached their maximum admissible degree of wear, they are then shortened to such an extent that they can no longer cover the carrying part  76 . This has the consequence that the carrying body  78  contacts the floor surface  106  and is mechanically adversely affected by the floor surface  106 . The carrying body  78  is thereby abraded in its circumferential region contacting the floor surface  106  by the floor surface  106 . As a consequence of this, the signal transmitter  72  arranged in the carrying body  78  becomes detached from the carrying body  78  after a short time and is ejected from the roller brush  62 . Therefore, after the maximum degree of wear of the cleaning bristles  70  has been reached, a signal is no longer supplied to the reader  74  associated with the roller brush  62 . The absence of the signal can be indicated to the user on a display device connected to the reader  76 , and so the user receives the information that the cleaning bristles  70  have reached their maximum admissible degree of wear. 
         [0077]    With the roller brush  62 , too, the movable mounting of the rigid signal transmitter  72  ensures that the reaching of the maximum admissible degree of wear of the cleaning bristles  70  independently of the force exerted by the roller brush  72  on the floor surface  106  is only indicated when the cleaning bristles  70  have reached their maximum admissible degree of wear.