Patent Publication Number: US-9420930-B2

Title: Manually guided floor cleaning machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of international application number PCT/EP2011/069253, filed on Nov. 2, 2011, which is incorporated herein by reference in its entirety and for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to a manually guided floor cleaning machine, comprising a chassis with a front end and a rear end in relation to a straight ahead forward travel direction, a wheel arrangement, which is arranged on the chassis in the region of the rear end, and a cleaning head, which is pivotably arranged on the chassis in the region of the front end, at least one brush being arranged on the cleaning head and a drive device being arranged for the driven rotation of the at least one brush. 
     A floor treatment machine with a driven floor treatment arrangement with a non-circular treatment face is known from WO 98/43527 A1 or EP 0 926 976 B1, which comprises at least one treatment body that is pivotable about a vertical axis in relation to the floor treatment machine. The floor treatment device has a non-circular treatment face, the width extent of which is oriented transverse to the travel direction. The floor treatment device is pivotable depending on the respective travel direction with its non-circular treatment face about a vertical rotational axis relative to the machine body, in such a way that even when negotiating curves, the width extent of the treatment body in each case remains oriented transversely to the current travel direction. 
     A drivable carriage with at least one pivotable running wheel and/or a pivotable actuating, working or cleaning unit as well as at least one sensor device is known from EP 1 239 762 B1. The sensor device is arranged in such a way that it is pivotable, at least relatively, with the steerable running wheel and/or the pivotable actuating, working or cleaning unit in the same pivoting direction. 
     A floor scrubber operated from behind is known from WO 2004/073477 A1, which comprises a front region with a first wheel pair and a scrubbing head. A rear region is provided having a second wheel pair. The front region and the rear region are pivotably connected to one another by means of a corresponding mechanism, with a vertical pivot axis. A tank for cleaning liquid is provided. Furthermore, a dirty water tank is provided. An operator can bring about a relative rotary movement between the front region and the rear region by means of a steering system. A motor system drives the first wheel pair or the second wheel pair. 
     There is known from U.S. Pat. No. 4,010,507 a floor cleaning machine, which has a seat and a steering device, steering taking place by means of the application of pressure on a handle or on a foot pedal of a yoke arrangement. 
     A floor treatment machine with a variable working width is known from DE 43 37 633 C2, comprising a machine body and an operating device to handle said machine, a floor treatment device, which comprises a treatment body, with a non-circular overall treatment face being provided on the lower side of the machine body. The operating device is position-variable with respect to the machine body in a substantially horizontal plane. 
     A portable polishing device is known from U.S. Pat. No. 4,499,624. 
     An electrically driven hand-held scrubbing machine is known from U.S. Pat. No. 4,005,502. 
     A carpet scrubbing machine is known from U.S. Pat. No. 2,842,788. 
     A floor treatment machine is known from EP 1 344 484 A2. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a manually guided floor cleaning machine is provided, which is compactly constructed and can be easily operated. 
     In accordance with an embodiment of the invention, in the manually guided floor cleaning machine a rotational axis of the at least one brush is parallel to a wheel axis of the wheel arrangement in the straight ahead forward travel direction. 
     It is possible in a configuration of this type, by means of a driven rotation of the at least one brush to bring about or at least to assist a travel movement of the floor cleaning machine. This assistance is also present when negotiating curves and optionally also when travelling backwards. As a result, the expenditure of force to guide the floor cleaning machine is reduced for a user. 
     In accordance with a further embodiment of the invention, the cleaning head, in relation to the straight ahead forward travel direction, is pivotable to the left and/or to the right by more than 90°. Even corner regions that are difficult to access can be cleaned by a correspondingly high pivoting range. Furthermore, the cleaning head can be brought into an (in particular driven) position suitable for travelling backwards in relation to the forward travel direction. The floor cleaning machine then has a high degree of maneuverability. 
     It is particularly advantageous if the cleaning head is pivotable by at least 180° to the left and/or to the right. As a result, a high degree of maneuverability of the floor cleaning machine can be achieved so that corresponding floor areas can be cleaned with a minimized expenditure of force. An optimized cleaning result is achieved even in regions that are difficult to access such as regions close to the wall. A straight ahead-backward travel direction position is realized by a, for example, 180° position in relation to the straight ahead forward travel direction. A driven, backwards travel can also be achieved, for example, thereby. In particular, when the cleaning head can be pivoted to the left and right by at least 180°, in each case, in relation to the straight ahead forward travel direction, a high degree of maneuverability of the floor cleaning machine is produced, a travel movement driven by means of the at least one brush also being achievable in each position of the cleaning head in order to at least assist an operator when pushing or pulling the floor cleaning machine as a whole. 
     In particular, the cleaning head is pivotable by more than 180° (in each case to the left and to the right). This produces an optimized mobility of the floor cleaning machine. 
     In particular, a pivoting axis for the pivotability of the cleaning head is oriented transversely to the wheel axis of the wheel arrangement. This allows a travel direction of the floor cleaning machine to be predetermined by means of a corresponding pivoting position of the cleaning head. In particular, the negotiation of curves can be predetermined by corresponding pivoting positions of the cleaning head. 
     It is favorable if the drive device has at least one an electric motor, which is supplied with electric current by means of a battery device arranged on the chassis. The at least one electric motor drives the rotational movement of the brush (brush roller). As a result, a cleaning process is carried out. This rotational movement can also be used to drive a travel movement of the floor cleaning machine as a whole. By means of the battery device, further components of the floor device, such as a suction motor of a turbine device and a pump device, can also be supplied with electric energy. 
     It is favorable if there is arranged on the cleaning head an application device for cleaning liquid, which is in fluidic connection with a tank arranged on the chassis. This allows cleaning liquid to be discharged at the cleaning head onto a base to be cleaned. 
     Advantageously, the application device has a vessel, which is non-rotatably arranged on the cleaning head and into which at least one pipe opens, which is in fluidic connection with the tank for cleaning liquid. This allows the structural outlay to guide cleaning liquid from the tank for cleaning liquid to the pivotable cleaning head to be reduced. No fluid-tight pipe, which follows the pivotability of the cleaning head, has to be provided between the cleaning head and the corresponding tank. The vessel provides a large “application area” for cleaning liquid from the corresponding tank. The sealing outlay is thereby reduced. As the vessel is non-rotatably connected to the cleaning head, the sealing outlay is also reduced here. 
     In particular, a position of a mouth of the at least one pipe into the vessel depends on a pivoting position of the cleaning head relative to the chassis. Depending on the pivoting position of the cleaning head, cleaning liquid is injected into the vessel by means of the line at different points of the vessel. 
     It is favorable if the vessel is seated by a pivot bearing for the pivotability of the cleaning head on the chassis. As a result, a simple structure is produced. The pipe runs can be minimized. 
     In particular, the vessel has an annular region, which surrounds the pivot bearing. A receiving space for cleaning liquid is provided by means of this annular region. This receiving space is a type of buffer space for cleaning liquid. 
     Advantageously, arranged on the cleaning head is a suction device, which is in fluidic connection with a tank for dirty water that is arranged on the chassis. Dirty water can thus be sucked up and received at the cleaning head. 
     In one embodiment, the suction device comprises at least one suction beam, which is arranged on the cleaning head. The suction beam forms a wiper for cleaning liquid, wiped-off cleaning liquid being sucked up. 
     It is favorable if a lifting device is provided for the at least one suction beam and is provided on the cleaning head. In the non-operational state, the suction beam can be lifted by means of the lifting device from a base, so said suction beam is no longer in contact with the base. As a result wear to the suction beam or damage to the suction beam is prevented when the floor cleaning machine is not in operation or the corresponding danger is at least reduced. 
     It is favorable if the lifting device comprises a foot pedal, so an operator can easily bring about a lifting or lifting back of the at least one suction beam. 
     It is favorable if a sensor or switch is associated with the lifting device, a sensor signal or a switch signal bringing about a start and/or a stop of a suction motor. As a result, suction can automatically be switched off or on when the suction beam is brought into a non-operative or operative position. 
     In particular, the suction motor is arranged on the chassis here, so a compact structure is produced. 
     A roller device is advantageously arranged on the cleaning head and has at least one first position and one second position, the floor cleaning machine being supported on the roller device in the first position and the at least one brush not being in contact with the base, on which the floor cleaning machine is standing, and the at least one brush acting on the base in the second position. In the first position, which is a non-operative position for the floor cleaning machine, the wear to the brushes can then be reduced as said brushes do not act on the base. In particular, the first position and the second position can be achieved by means of a lifting device for a suction beam. 
     In one embodiment, a steering rod device is provided, which is articulated to the cleaning head, which steering rod device is supported on the chassis and extends upwardly toward the rear end in a direction away from the chassis. By means of the steering rod device, an operator who is standing behind the floor cleaning machine and following it can directly bring about a pivotability of the cleaning head and therefore a direction change during a travel movement of the floor cleaning machine. No intermediate elements for the steering control of the floor cleaning machine are then necessary and said floor cleaning machine can have a compact construction. Furthermore, the steering rod device can be used directly for pushing or pulling the floor cleaning machine. The steering rod device also forms a pushing rod device or pulling rod device. 
     The steering rod device can basically be formed with minimized dimensions, in that a one-part or multi-part steering rod is used. This has a small space requirement and corresponding components of the floor cleaning machine can be arranged around the steering rod device and below it. This in turn produces a compact structure with this structure being optimized. For example, a relatively heavy battery device can be arranged directly above the wheel arrangement. 
     The steering rod device can easily be arranged in a structurally simple manner in such a way that it is positively guided and can only carry out a pivoting movement for a pivoting movement of the cleaning head. A pivoting movement of the steering rod device can then be converted by means of direct coupling to the cleaning head into a pivoting of the latter. The structural outlay is minimized. 
     In particular, the steering rod device is oriented, at least in portions, at an acute angle to a level base when the floor cleaning machine is standing with the wheel arrangement and the cleaning head on the level base. The steering rod device is then guided away steeply upwardly. This allows a compact structure to be achieved. 
     In particular, the acute angle is in the range between 30° and 60° and, in particular, in the range between 40° and 50° and, in particular, at least approximately 45°. This produces an optimized compact structure, the steering rod device advantageously being able to be used as a pushing rod device or pulling rod device. 
     Basically, the steering rod device may be multi-part, for example with a first rod element and a second rod element. It is then basically possible for the first rod element and the second rod element to be oriented at different acute angles to the base (and therefore the chassis). In a preferred solution, the steering rod device is coaxial in the cleaning operation (the first rod element and the second rod element have a zero angle with respect to one another). 
     In particular, a steering wheel arrangement is arranged on the steering rod device at or close to one end, which is remote from an articulation point on the cleaning head. An operator can then ergonomically advantageously bring about a steering movement and, in particular, an optimized gripping surface is then also provided in order to be able to carry out a pushing movement or pulling movement of the entire floor cleaning machine. In the simplest case, the steering wheel arrangement is configured as a cross-bar. 
     It is quite particularly advantageous when the steering wheel arrangement in a projection onto a base, on which the floor cleaning machine is standing, projects beyond the rear end of the chassis. An operator standing or walking behind the floor cleaning machine can then operate the floor cleaning machine by means of the steering wheel arrangement (in particular steer it and push it). In particular, the steering wheel arrangement projects so far that an operator&#39;s feet do not hit the floor cleaning machine in a treatment process of this type. 
     In one embodiment it is provided that the steering rod device is fixably longitudinally variable and/or is pivotable with respect to the chassis, the steering rod device as a whole being pivotable and/or parts of the steering rod device being pivotable relative to one another. The steering rod device can then be adapted in an optimized manner to the special ergonomic requirements of an operator in order to allow work with the floor cleaning machine with little fatigue. Furthermore, the steering rod device can then also be positioned in such a way that the outer dimensions of the manually guided floor cleaning machine are minimized for transportation or storage. It is particularly advantageous if the steering rod device is both fixably longitudinally variable and also fixably pivotable and, in particular, parts of the steering rod device can be pivoted relative to one another. 
     It is favorable if a pivot axis of a pivot bearing for the pivotability of the steering rod device is oriented at least approximately parallel to a rotational axis of a brush roller of the cleaning head and/or to a wheel axis of the wheel arrangement in a position of the steering rod device for the straight ahead forward travel direction. This allows a height adaptation to be easily achieved. Furthermore, it can, for example, be achieved thereby that the steering rod device is foldable (with, for example, two parts that can be pivoted relative to one another). This in turn allows the height of a rear end of the steering rod device to be adjusted relative to the chassis and, in particular, also to be adjusted in such a way that the outer dimensions are minimized for transportation and storage. 
     Furthermore, it is favorable if a pivot bearing is positioned on the steering rod device above (in relation to the direction of gravity when the floor cleaning machine is standing on a level base) a tank, past which the steering rod device is guided and/or outside a housing casing, which is arranged on the chassis. This allows a pivotability of the steering rod device to be achieved with minimized outlay. The casing of the floor cleaning machine, through which the steering rod device passes, can be configured with minimized structural outlay, as no pivoting movability of the part of the steering rod device, which passes through the casing or is guided past the tank, has to be provided. Furthermore, the fixing of the pivotability can easily be achieved. An operator can directly access the pivot bearing from outside in order to bring about a release for the pivotability or fixing of the pivotability. 
     In one embodiment, the steering rod device has a sleeve, on which a steering wheel arrangement is arranged, a rod element of the steering rod device being inserted in the sleeve, and a longitudinal position of the sleeve being fixably variable on the rod element. This allows a longitudinally variable steering rod device to be easily realized. The guidance of electric cables and the like within the steering rod device is minimally influenced by the longitudinal variability. The steering wheel arrangement is to a certain extent placed on the rod element by means of the sleeve and held there. At the same time, a telescopic guidance with a longitudinal variability of the steering rod device can easily be configured. 
     It is quite particularly advantageous if the steering rod device forms a pushing rod device for pushing the floor cleaning machine and/or forms a pulling rod device for pulling the floor cleaning machine. This produces optimized working possibilities with a compact structure of the floor cleaning machine. 
     The steering rod device is advantageously articulated by means of a joint device on the cleaning head and, in particular, the joint device comprises a cardan joint. The steering rod device has a pivot axis oriented in a different direction to the pivot axis of the cleaning head. The two pivot axes in particular intersect. A pivoting movement of the steering rod device and a pivoting movement of the cleaning head can be implemented by means of the joint device. 
     In a structurally favorable embodiment, the joint device is arranged on a pivot bearing for the pivotability of the cleaning head on the chassis. This produces a compact structure. It can easily be achieved that a pivot axis of the steering device and the pivot axis of the pivot bearing intersect, so no transverse offset is present. 
     It is quite particularly advantageous if there is non-rotatably arranged on the chassis at least one support element having a recess through which the steering rod device is inserted and in which the steering rod device can be rotated. The support element, on the one hand, ensures a support and therefore retention of the steering rod device relative to the chassis. Furthermore, constraints are imposed by a support element of this type on the steering rod device, so only a rotation about the pivot axis is still possible. 
     In particular, the steering rod device has a one-part or multi-part steering rod, which is articulated on the cleaning head. This produces a simple and compact structure, the space requirement for the steering rod device being minimized. 
     In one embodiment, the chassis has a holding element, on which the cleaning head is pivotably arranged and, in particular, the holding element is formed as a holding plate or comprises a holding plate. The holding element is the basic part of the chassis, on which the corresponding components are directly or indirectly fixed. 
     It is favorable if a first tank and a second tank are arranged on the holding element, the first tank being seated on a first side of the holding element and the second tank being seated on a second side opposite the first side, the second side facing a base, on which the floor cleaning machine is standing. This produces a compact structure of the floor cleaning machine with optimal utilization of space. Floor areas close to the wall can also in turn be cleaned in an optimized manner owing to the compact structure. 
     The steering rod device is supported here on the first side and rises, in particular, above the first side. 
     The tank is advantageously shaped in such a way that a free space is formed, through which the steering rod device is guided. As a result, the steering rod device can to a certain extent be guided through the first tank. This in turn produces an optimized utilization of space and the floor cleaning machine can have a compact structure. 
     The wheel arrangement is advantageously arranged on the second side. The “underside” of the chassis can then also be used. 
     The shape of the second tank is, in particular, adapted to the wheel arrangement. This produces an optimized utilization of space. 
     The second tank is advantageously shaped in such a way that a free space is formed for the pivotability of the cleaning head. This allows said cleaning head to be pivoted within a wide pivoting range, which is, in particular, 360° or more. This in turn produces an optimized operability with an optimized cleaning result even in corner regions that are otherwise difficult to access. Furthermore, the cleaning head can be rotated by 180° in relation to a straight ahead forward travel direction in order to realize a backward travel direction. 
     For example, the first tank is a dirty water tank and the second tank is a tank for cleaning liquid. 
     It is favorable if a holding device for a battery device is arranged on the chassis and, in particular, on the holding element of the chassis, the holding device in particular being arranged above the wheel arrangement. The battery device generally has a large mass. It can then be arranged in an optimized manner, and in particular, forces can be supported in an optimized manner because of the relatively high mass of the battery device. 
     It is favorable if the holding device projects upwardly away from a first side of the holding element, the first side being remote from a second side, which points to a base, on which the floor cleaning machine is standing. The holding device can thus be arranged below the steering rod device. This allows the available space to be utilized in an optimized manner and a compact structure of the floor cleaning machine is produced. 
     In particular, the holding device has a wall, which is oriented transversely to the first side of the holding element. This wall, to a certain extent, separates the holding device with the battery device from a “water region” of the floor cleaning machine. For example, a dirty water tank and a turbine device are arranged in this water region. 
     It is favorable if the holding device comprises a holding region for a charging apparatus for the battery device, the charging apparatus, in particular, being arranged, in relation to a direction between the front end and the rear end of the chassis, closer than the battery device to the rear end. This allows the battery device to be arranged and supported in an optimized manner over the wheel arrangement. 
     Furthermore, it is favorable if a turbine device for sucking up dirty water, which is in fluidic connection with a dirty water tank and the cleaning head, is arranged on the chassis and, in particular, on a holding element of the chassis. This allows a region below the steering rod device to be utilized in an optimal manner in order to position further components of the floor cleaning machine. 
     For the same reason, it is favorable if a pump device, which is in fluidic connection with a cleaning liquid tank and the cleaning head, is arranged on the chassis and, in particular, on a holding element of the chassis. This allows the pump device to be easily positioned. 
     In particular, the steering rod device has a maximum length between an articulation point on the cleaning head and a rear end, which is at least 1.3 times as large as a length of the chassis between the front end and the rear end. As a result, an operator walking behind the floor cleaning machine (“walk-behind machine”) can bring about a steering movement by means of the steering rod device and optionally also push or pull the floor cleaning machine. 
     The following description of preferred embodiments is used in connection with the drawings to describe the invention in more detail. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of an embodiment of a floor cleaning machine according to the invention; 
         FIG. 2  shows a side view of the floor cleaning machine according to  FIG. 1 ; 
         FIG. 3  shows the same view as  FIG. 2 , parts of the floor cleaning machine having been removed; 
         FIG. 4  shows the same view as  FIG. 2 , further parts having been removed; 
         FIG. 5  shows a sectional view in the plane  5 - 5  according to  FIG. 1 ; 
         FIG. 6  shows a sectional view in the plane  6 - 6  according to  FIG. 1 ; 
         FIG. 7  shows a sectional view along the line  7 - 7  according to  FIG. 6 ; 
         FIG. 8  shows the same view as  FIG. 7 , parts having been removed; 
         FIG. 9  shows a sectional view along the line  9 - 9  according to  FIG. 8 ; 
         FIG. 10  shows a sectional view along the line  10 - 10  according to  FIG. 8 ; and 
         FIG. 11  shows a part view of a variant of a manually guided floor cleaning machine according to the invention with a longitudinally variable and pivotable steering rod device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An embodiment of a floor cleaning machine according to the invention, which is shown in  FIGS. 1 to 10  and designated  10  there, comprises a chassis  12 . The chassis  12  has a holding element  14 , which is, in particular, configured as a holding plate. The holding element  14 , in this case, has a first side  16  and a second side  18  opposite the first side. If the floor cleaning machine  10  is standing on a base  20 , the second side  18  then faces the base  20  and the first side  16  is remote from the base  20 . 
     The chassis  12  has a front end  22  and a rear end  24  remote from the front end  22 . In a straight ahead forward travel direction  26  of the floor cleaning machine ( FIG. 1 ), the front end  22  is directed to the front and the rear end  24  is directed to the rear. The floor cleaning machine  10  is manually guided. In relation to the straight ahead forward travel direction  26 , an operator stands behind the rear end  24  and guides (pushes or pulls) the floor cleaning machine  10 , as described in more detail below. 
     A wheel arrangement  28  is arranged on the chassis  12  in the region of the rear end  24 . The wheel arrangement  28  is a rear wheel arrangement, which is positioned on the holding element  14  and, in particular, the second side  18  of the holding element  14 . The wheel arrangement  28 , in this case, in relation to the straight ahead forward travel direction  26 , has a left rear wheel  30   a  and a right rear wheel  30   b  (cf.  FIG. 7 ). The wheel arrangement  28  has a wheel axis  32  (rotational axis), about which the rear wheels  30   a ,  30   b  can be rotated. The wheel arrangement  28  is unsteered, in other words the rear wheels  30   a ,  30   b  only have the movability of the rotatability about the wheel axis  32 . The floor cleaning machine  10  is placed by means of the wheel arrangement  28  in the region of the rear end  24  on the base  20 . 
     In the region of the front end  22 , a cleaning head  34  is pivotably arranged on the holding element  14 . For this purpose, a pivot bearing  36  is provided. This pivot bearing  36  defines a pivot axis  38  (cf.  FIG. 2 ) for the pivotability of the cleaning head  34  on the chassis  12 . This pivot axis  38  is oriented transversely and, in particular, perpendicularly, to the wheel axis  32 . 
     In one embodiment, the pivot bearing  36  comprises a cylindrical journal  40 , which is arranged in an upper region  42  of the cleaning head  34 . The pivot bearing  36  furthermore comprises an annular element  44  with a cylindrical recess  46 , which is arranged on the holding element  14 . The journal  40  is inserted through the recess  46 . 
     The floor cleaning machine  10  comprises a steering rod device  48 . The steering rod device  48  is articulated at one end  50  (cf. in particular  FIG. 4 ) on the cleaning head  34  by means of a joint device  52 . The joint device  52  comprises a cardan joint  54 . 
     A fixing device  56  (cf.  FIG. 9 ) for the joint device  52  (and therefore the steering rod device  48 ) is formed on the journal  40  of the cleaning head  34 . The fixing device  56  for example, comprises one or more eyelets  58 , on which the joint device  52  can be fixed by means of a bolt or the like. The eyelet  58  in this case projects, in particular, beyond the annular element  44  of the pivot bearing  36 , so the rotatability of the cleaning head  34  by means of the journal  40  on the pivot bearing  36  is not hindered. The joint device  52  is thereby arranged on the pivot bearing  36 . 
     The steering rod device  48  comprises a steering rod  60 . The steering rod  60  may, in this case, basically be one-part or multi-part. The steering rod  60  has a direction of extent  62 . The steering rod device  48  with the steering rod  60  extends upwardly away from the holding element  14  in the direction of the rear end  24 ; the steering rod device  48  is articulated on the cleaning head  34 , which is arranged in the region of the front end  22  on the chassis  12 , in the region of the front end  22 . The steering rod  60  lies at an acute angle  64  (cf.  FIG. 2 ) to the chassis  12  and, in particular, to the holding element  14 . The acute angle  64  is in relation to the straight ahead forward travel direction  26  or to a level base  20  when the floor cleaning machine  10  is placed thereon. In particular, the acute angle  64  is to the first side  16  of the holding element  14 . 
     The acute angle  64  is in a range between 30° and 60° and in particular between 40° and 50°. In one embodiment, the acute angle  64  is 45°. 
     The steering rod  60  can be pivoted about a pivot axis  66  (cf.  FIG. 4 ). This pivot axis  66  coincides with the direction of extent  62 , in other words, it is at an acute angle  64  to the chassis  12 . One or more support elements  68 , on which the steering rod device  48  is supported, are seated on the chassis  12 . A support element  70  ( FIG. 7 ), which is non-rotatably fixed to the holding element  14  on its first side  16 , is provided in the region of the front end  22 . This support element comprises an annular element  72  and has a recess  74 , through which the steering rod  60  is inserted. The steering rod  60  is rotatably supported about the pivot axis  66  in the recess  74 . The annular element  72  for example has the shape of a capped annular cylinder. The steering rod device  48  is rotatably supported close to its end  50  on the chassis  12  by means of the support element  70 . 
     One or more further support elements  76  (cf.  FIG. 5 ) to rotatably support the steering rod device  48  may be provided on the chassis  12 , the at least one support element  76  being spaced apart from the support element  70 . 
     The single degree of freedom of movement of the steering rod device  48  is the pivotability about the pivot axis  66 . (The pivotability may basically be limited in this case or allow a rotation through 360°.) The movability is limited to this degree of freedom by the support element(s)  70 ,  76 . By means of the joint device  58 , the pivoting movement of the steering rod device  48  is transferred to the cleaning head  34  to allow a pivotability of the cleaning head  34  about the pivot axis  38 . The cardan joint  54  is formed accordingly. The cardan joint  54  comprises, for example, a universal joint arrangement with, for example, two joints with joint axes lying transversely with respect to one another. In another configuration, the joint device  52  is formed by a gearing device, such as, for example, a crown wheel gearing, bevel wheel gearing or the like. 
     The steering rod device  48  extends from the front end  50  to a rear end  78 . At the front end  50 , the steering rod device  48  is articulated in the direct vicinity of the holding element  14  on the cleaning head  34 . The rear end  78  has a height spacing H (cf.  FIG. 2 ) from the holding element  14 . A sort of triangular structure with an equilateral triangle is thus formed. 
     A steering wheel arrangement  80  is arranged at the rear end  78 . This steering wheel arrangement  80  comprises handle elements  82 , which are spaced apart from one another. An operator can then in each case grasp a handle element  82  with the left hand and the right hand in order to actuate the steering rod device  48 . In particular, the spaced apart handle elements  82  are connected to one another. 
     It may be provided that further operating elements of the floor cleaning machine  10  are arranged on the steering wheel arrangement  80 . 
     The rear end  78  of the steering rod device  48 , and therefore also the steering wheel arrangement  80 , projects beyond the rear end  24  of the chassis  12 . A projection of the steering wheel arrangement  80  or the rear end  78  onto the base  20 , in relation to the straight ahead forward travel direction  26 , lies behind the rear end  24 . An operator, during operation of the floor cleaning machine  10 , walks behind the rear end  24 ; the floor cleaning machine  10  is a walk-behind machine. He can grip the steering wheel arrangement  80  on the handle elements  82  and thus bring about corresponding direction changes. The height of the steering wheel arrangement  80  in relation to the base  20  is such, in this case, that at least in relation to an average size of an operator, he can operate the floor cleaning machine  10  with little fatigue. In particular, in relation to the average size, an operator does not need to bend in order to be able to grasp the steering wheel arrangement  80 , or does not have to stretch up. 
     In one embodiment, it is provided that the steering rod device  48  can be adapted to the special conditions of an operator. In particular, the steering rod  60  is multi-part. Its length between the end  50  and the rear end  78  in the extent direction  62  can be fixably adapted. This is indicated in  FIG. 1  by the reference numeral  84 . For example, the steering rod  60  is multi-part for this purpose, the position of a second part  84  being fixably displaceable relative to a first part  86 . 
     In one embodiment ( FIG. 11 ), the steering rod device  48  comprises a (first) rod element  162 . The steering wheel arrangement  80  is arranged on a sleeve  164 , this sleeve  164  being placed on the first rod element  162 ; the sleeve  164  has a recess  166 , in which the first rod element  162  is inserted. 
     The sleeve  164  is fixably displaceable on the first rod element  162 . The length of the combination of the first rod element  162  and sleeve  164 , and therefore the spacing between the end  50  and the rear end  78  of the steering rod device  48 , can thereby be fixably adjusted. 
     A fixing device designated  168  as a whole is provided. The latter comprises, for example, a clamping lever  170 . The clamping lever  170  is, for example, pivotably arranged on the first rod element  162 . The sleeve  164  has a slot-shaped recess  172 , on which a clamping region  174  of the clamping lever  170  is located. When the clamping region  174  is inactive owing to a corresponding position of the clamping lever  170 , the sleeve  164  can be displaced on the first rod element  162 . In the region of the recess  172 , the sleeve  164  has a contact face  176  for the clamping region  174  of the clamping lever  170 . 
     To adjust the length of the steering rod device  48  between the end  50  and the rear end  78 , the clamping lever  170  is released, so the clamping region  174  is in an inactive position. The sleeve  164  can then be pushed on the first rod element  162  into the desired position. The clamping lever is then correspondingly placed therearound, so the clamping region  174  acts on the contact face  176  and a clamping is achieved. The relative position between the sleeve  164  and the first rod element  162  is thereby fixed. 
     The clamping lever  170  is, in particular, designed in such a way that when it is placed therearound and the clamping region  174  is acting, a self-locking is achieved. 
     Basically it is also possible, (with a corresponding configuration of the joint device  52 ) for the steering rod device  48  to be arranged in a fixably pivotable manner on the chassis  12  with a pivot axis parallel to the wheel axis  32  when the cleaning head  34  is in the straight ahead forward travel direction  26 . In particular, the pivot axis  178  is parallel to a rotational axis  130  of a brush roller  128  of the cleaning head  34  (see below). It may be provided that the steering rod device  48  as a whole is fixably pivotable on the chassis  12 . In one embodiment, the steering rod device is pivotable “per se” ( FIG. 11 ). For this purpose, the steering rod device  48  has the first rod element  162  and furthermore has a second rod element  180 . This second rod element  180  is provided with the end  50  and connected to the joint device  52 . The first rod element  162  and the second rod element  180  are connected by means of a pivot bearing  182 . This pivot bearing  182  has a pivot axis  178 , which is parallel to the rotational axis  130  of the brush roller  128  or parallel to the wheel axis  32  of the wheel arrangement  28  when the steering rod device  48  is in a rotational position such that the cleaning head  34  is positioned for the straight ahead forward travel direction  26 . 
     A fixing device  184  is associated with the pivot bearing  182 . As a result, a relative pivoting position between the first rod element  162  and the second rod element  180  can be fixed. The fixing device  184  has, for example, a clamping device, which clamps the first rod element  162  with the second rod element  180  on the pivot bearing  182 . This clamping device comprises, for example, an (in particular manually actuable) clamping screw. Other possibilities for fixing, such as, for example, a latching engagement fixing and the like are also possible. 
     The pivot bearing  182  (in relation to the direction of gravity when the floor cleaning machine  10  is placed on a level base  20 ) is located above a first tank  90  (see below), past which the steering rod device  48  is guided. It is furthermore located outside, and in particular above, a housing casing, which is designated  186  as a whole, of the floor cleaning machine  10 . In this case, the only movement possibility allowed of the second rod element  180  relative to the chassis  12  is then a rotation about the pivot axis  66 . 
     The pivot bearing  182  is configured in such a way that the second rod element  180  and the first rod element  162  as well as the steering wheel arrangement  80  and the sleeve  164  have the same rotational axis, namely the pivot axis  66 . With respect to a pivoting of the pivot axis  66 , the second rod element  180  and the first rod element  162  are rigidly connected to one another, even when the fixing device  184  is released. 
     That part of the steering rod device  48  located above the pivot bearing  182 , in comparison to the second rod element  180 , when the fixing device  184  is released and the fixing device  168  is released, has further degrees of freedom of movement: the first rod element  162  is pivotable on the pivot bearing  182 . That part of the steering rod device located between the pivot bearing  182  and the rear end  78  is longitudinally variable by means of the relative positionability of the sleeve  164  on the first rod element  162 . 
     Basically, it is possible for only one fixable pivotability of the first rod element  182  with respect to the second rod element  180  to be provided or only one longitudinal variability of the steering rod device  48  to be provided. In an advantageous embodiment, the steering rod device  48  is variable with respect to its length and a pivotability is provided on the steering rod device  48 . 
     In the embodiment shown in  FIG. 11 , the pivot bearing  182  is arranged in such a way that the fixing device  184  is located outside the housing casing  186 . Furthermore, the fixing device  168  is arranged in such a way that it is located outside the housing casing  186 . An operator can thereby easily and quickly adapt the steering rod device  48  to his requirements. 
     In particular, a height position of the steering wheel arrangement  80  can be adapted by means of the longitudinal variability. In addition or alternatively, the adaptation can optionally be carried out by adjusting a relative pivoting angle between the second rod element  180  and the first rod element  162 . (In this case, the acute angle  64  relates to the second rod element  180 .) 
     It is preferred, in order to achieve simple operability with respect to pushing and pulling the floor cleaning machine  10 , for the first rod element  162  and the second rod element  180  to be co-linearly oriented during operation and for the height adaptation to take place by means of the longitudinal variability. 
     The relative height of the floor cleaning machine  10  can be reduced by means of the pivotability at the gearing rod device  48 , by means of which, in particular, the steering rod device  48  is configured to be foldable. As a result, the floor cleaning machine  10  can be brought into a form, which is preferred for transportation processes and storage, in that the second rod element  180  is folded toward the front end  22 . In particular, the length of the steering rod device  48  is also minimized, in that the sleeve  164  is displaced into a corresponding position. 
     The steering rod device  48  projects beyond the rear end  24  of the chassis  12 . Basically, the steering wheel arrangement  80 , in relation to the straight ahead forward travel direction  26 , forms the rearmost point  88  (cf.  FIG. 2 ) of the floor cleaning machine  10 . The steering rod device  48 , between the end  50  and the end  78 , forms a rigid object, which is mounted about the pivot axis  66 . The steering rod device  48  thus forms a pushing rod device; by exerting pressure on the steering wheel arrangement  80 , an operator can push the floor cleaning machine  10  as a whole. The steering rod device  48  forms a steering device for the floor cleaning machine  10  and a pushing guidance (or pulling guidance in the case of a backward movement) of the floor cleaning machine  10 . 
     A first tank  90  and a second tank  92  are arranged on the chassis  12 . The first tank  90  is a dirty water tank. The second tank  92  is a tank for cleaning liquid. 
     The second tank  92  is arranged on the second side of the holding element  14 . It is adapted with respect to its shape to the wheel arrangement  28 . It has corresponding free regions  94 , the left rear wheel  30   a  and the right rear wheel  30   b  being positioned, in each case, in the free region  94 . 
     Furthermore, the second tank  92  is configured on a side  96 , which faces the cleaning head  34  in such a way that a pivotability of the cleaning head  34  about the pivot axis  38  is made possible within a specific pivoting range, this pivoting range comprising at least 180° to the left and right in relation to the straight ahead forward travel direction  26 . This will be described in more detail below. 
     The second tank  92  is configured in such a way that it can receive an optimized quantity of cleaning liquid and does not thus limit the pivotability of the cleaning head  34 , which can be pivoted below the holding element  14 . 
     A pump device  98  (cf.  FIG. 7 ) is arranged on the chassis  12 . The pump device is fluidically connected by a suction side  100  to the second tank  92 . From the suction side  100  of the pump device  98 , a suction line  102  leads into the tank  92  in order to suck up cleaning liquid. By a pressure side  104 , the pump device  98  is in fluidic connection with an application device  106  for cleaning liquid of the cleaning head  34 , as will be described in more detail below. 
     The first tank  90  for dirty water is arranged on the first side  16  of the holding element  14 . It is configured here in such a way that it is adapted with respect to its shape to the guidance of the steering rod device  48 . It has a free space  108 , through which the steering rod device  48  is inserted. 
     Arranged on the holding element  14  is a holding device  110 , which holds a battery device ( 112 ) (cf., for example,  FIG. 3 ). The holding device  110  is arranged here above the wheel arrangement  28 . The battery device  112 , which, in particular, comprises one or more rechargeable batteries, generally has a considerable mass proportion of the total mass of the floor cleaning machine  10 . By means of an arrangement on the holding element  14  directly above the wheel arrangement  28 , optimized force ratios can be achieved. 
     The holding device  110  comprises a wall  114  (cf., for example,  FIG. 1 ), which projects transversely and, in particular perpendicularly, beyond the holding element  14  on its first side  16 . The wall  114  and the holding device  110  as a whole are configured in such a way that they are positioned spaced apart from the steering rod device  48  below the latter. The wall  114  is a delimitation from a space, in which the first tank  90  (and elements connected thereto) are arranged. 
     A charging apparatus  116  for the battery device  112  is furthermore rigidly arranged on the holding device  110 . The charging apparatus  116  can, in particular, be connected to mains current and, by means of corresponding conversion, ensures the charging of the battery in the battery device  112 . 
     The charging apparatus  116 , in relation to the straight ahead forward travel direction  26 , is arranged behind the battery device  112 , in other words, it is arranged closer than the battery device  112  to an operator who grips the steering wheel arrangement  80 . 
     Arranged between the first tank  90  and the wall  114  below the steering rod device  48  is a turbine device  118  with a suction motor. The turbine is in fluidic connection on a pressure side with the first tank  90 ; dirty water that has been sucked up is conveyed into the first tank  90 . By a suction side, the turbine device  118  is in fluidic connection with a suction device  120  ( FIG. 1 ) of the cleaning head  34 . 
     Arranged between the first tank  92  and the holding device  110  are casing elements, which form a closed housing to protect inner components (such as the turbine device  118 , fluid lines, electric lines etc.). 
     The battery device  112  provides electrical energy for the turbine device  118  with a suction motor, the pump device  98  and a drive device  122  of the cleaning head  34 . 
     The cleaning head  34  comprises a housing  124 . The housing  124  has a first housing region  126 , which is open at the bottom toward the base  20 . A brush  128  (brush roller) is arranged in the first housing region  126 . The brush  128  can be rotated about a rotational axis  130 . When the cleaning head  34  is in the forward travel direction, in which the floor cleaning machine  10  travels in the straight ahead forward travel direction  26 , the rotational axis  130  lies parallel to the wheel axis  32 . The rotational axis  130  lies transversely, and in particular perpendicularly, to the pivot axis  38  of the cleaning head  34 . The brush  128  is formed by a brush roller with corresponding bristles, which emerge from the region of the first housing region  126 , which is open at the bottom, and can act on the base  20  to be cleaned. 
     A closed second housing region  132  is arranged on the first housing region  126 . This second housing region receives the drive device  122  to rotate the brushes  128 . The drive device  122  in this case comprises an electric motor  134 , which is supplied with electric current by the battery device  112 . Lines corresponding thereto from the battery device  112  to the cleaning head  34  are provided. 
     The electric motor  134  is dimensioned in such a way that owing to the rotation of the brush roller  128 , an assistance of the travel drive is also achieved. For example, the electric motor  134  has a power of at least 150 W with a torque of at least 1.0 Nm at 1600 rpm. 
     Cleaning liquid can be fed to the base  20  in the region of the brush  128  by the application device  106 . The application device  106  in this case comprises a vessel  136  ( FIG. 8 ), which is non-rotatably seated on the cleaning head  34 . The vessel  136  is arranged here above the second housing region  132 . The vessel  136  has an annular receiving space  138 , which surrounds the journal  40  of the pivot bearing  36 . One or more lines for cleaning liquid lead from the receiving space  138  to the brush (brush roller)  128 . The receiving space  138  is correspondingly sealed, so that a fluid path  140  ( FIG. 10 ) is formed in a defined manner and is guided past the electric motor  134 . 
     A pipe  142  with a mouth  144  is connected to the pressure side  104  of the pump device  98 . The pipe  142  is, in particular, rigidly configured and, for example, in the form of a connecting piece. The mouth  144  is oriented in such a way that cleaning liquid can lead into the receiving space  138 . The position of the line  142  and the mouth  144  with respect to the receiving space  138  depends here on the pivoting position of the cleaning head  34 . The pipe  142  and the mouth  144  are arranged and configured in such a way here that in each pivoting position, cleaning liquid, which is provided by means of the pump device  98 , flows into the receiving space  138 , the angular position of the mouth  144  (as a rotation angle with respect to the pivot axis  30 ) varying at different pivoting positions. The sealing outlay for injecting cleaning liquid into the application device  106  of the pivotable cleaning head  34  is thereby minimized. 
     The suction device  120  comprises a suction beam  146 , which is arranged on the cleaning head  34  and can be pivoted with the latter. The suction beam  146  extends in a direction parallel to the first housing region  126 . In one position of the cleaning head  34 , in which the straight ahead forward travel direction  26  is realized, the suction beam  146  is at least approximately parallel to the wheel axis  32 . The suction beam  146  is arranged here behind the brush  128 , in other words, it is closer than the brush  128  to the rear end  24 . In the straight ahead forward travel direction  26 , the suction beam  146  is positioned between the brush  128  and the side  96  of the second tank  92 . 
     The free region between the cleaning head  34  and the second tank  92  is configured in such a way here that the cleaning head, proceeding from the straight ahead forward travel direction  26  (cf.  FIG. 7 a   ), is in each case pivotable to the left (indicated by the reference numeral  148 ) and to the right (indicated by the reference numeral  150 ) by more than 90° and preferably at least 180° and, in particular, 180° and more. 
     A connection  152  for a hose is arranged on the suction beam  146 . A corresponding hose leads from the connection  152  to the turbine device  118  in order to be able to inject sucked up dirty water into the first tank  90 . The hose (not shown in the drawing) is configured and guided here in such a way that it does not hinder the pivotability of the cleaning head  34 . 
     Arranged on the cleaning head is a roller device  154 , which has at least one support roller. The roller device  154  is, in this case, in particular positioned between the brush  128  and the suction beam  146 . During a cleaning operation of the floor cleaning machine  10 , the latter is supported by the roller device  154  on the base  20 , specifically in such a way that a cleaning process can be carried out by the brush  128 . The cleaning head  34  with the roller device  154  thus forms a front wheel arrangement of the floor cleaning machine  10 . 
     A lifting device, designated  156  as a whole, is arranged on the cleaning head  34 . The roller device  154  can be folded with the suction beam  146  by this lifting device  156 . In a first position, which is a non-operative position, it can be achieved that the floor cleaning machine is supported on the roller device  154  in the region of the cleaning head  34  and the brush  128  is thus not in contact with the base  20 . Furthermore, the suction beam  146  is then spaced apart from the base  20 . In this non-operative position, the floor cleaning machine  10  can be moved, the brush  128  and the suction beam  146  being treated with care as they do not touch the base. 
     In a second position, which has already been described above, the roller device  154  is fixably folded in such a way that the suction beam  146  and the brush  128  act on the base  20  to be cleaned. 
     For transfer between the first position and the second position or vice versa, a foot pedal  158  is provided, in particular. 
     A sensor or switch  160 , which detects whether the first position or second position is present, is associated with the cleaning head  34 . During the transition from the second position to the first position, a change in the loading on the switch  160  takes place. This can be used in order, in particular, to automatically switch on the suction motor or to switch it off. If an operator mechanically transfers the roller device  154  and the suction beam  146  from the first position (non-operative position) to the second position by means of the foot pedal  158 , the suction motor is switched on. If an operator carries out a transfer from the second position into the first position, the suction motor is switched off by means of the switch  160 . 
     The floor cleaning machine  10  according to the invention functions as follows: 
     An operator can steer and push or pull the floor cleaning machine  10  by means of the steering rod device  48  arranged at the acute angle  34 . Thus there results a compact structure, components of the floor cleaning machine  10 , such as, for example, the turbine device  118  and the first tank  90  being positioned on and below the steering rod device  48 . Elements of the floor cleaning machine  10  with a large mass and, in particular, the battery device  112 , can thus be positioned directly above the wheel arrangement  28  and supported accordingly. 
     The brush  128  of the cleaning head  34  is driven, specifically about a rotational axis  130 , which, in the straight ahead forward travel direction  26 , is parallel to the wheel axis  32 . With a corresponding rotational direction of the brush  128 , this drive ensures a forward movement of the floor cleaning machine  10  as a whole. As a result, the pushing movement of the operator is assisted and the exertion of force is reduced for the operator. Work with little fatigue results. 
     The cleaning head  34 , in relation to the straight ahead forward travel direction  26 , is pivotable to the left and right by at least 180° and, in particular, by more than 180°. As a result, the cleaning head  34  with the brush  128  can also be guided into corner regions that are difficult to access. Furthermore, a change can be made from a straight ahead forward travel direction  26  to an opposite, driven, backward travel direction (without changing the rotational direction of the electric motor  134 ). 
     The steering rod device  48  is, in particular, arranged in a central region in relation to the projection of the holding element  14 . It and the steering wheel arrangement  80  do not project beyond a left and right side of the floor cleaning machine  10 . This allows the floor cleaning machine  10  to travel into a corner region without the steering limiting the freedom of movement of the floor cleaning machine  10  as a whole (for example by bumping into a wall). 
     The energy-consuming elements of the floor cleaning machine  10  are supplied with electrical current by means of the battery device  112 . This produces a compact, self-sufficiently usable floor cleaning machine, which can be used with little fatigue by an operator and is thus maneuverable, so regions close to the wall and corner regions can also be effectively cleaned. Both an application of cleaning liquid to a base  20  to be cleaned and a sucking up of dirty water take place. 
     Owing to the positioning of the holding device  110  for the battery device  112 , batteries with a high energy density (with a correspondingly high space requirement) can also be used. 
     The steering rod device  48 , between the end  50  and the end  78 , has a length that is greater than the length of the chassis  12  between the front end  22  and the rear end  24 . In particular, said length of the steering rod device  48  is at least 1.3 times, preferably at least 1.35 times and preferably at least 1.4 times greater than the length of the chassis  12  between the front end  22  and the rear end  24 . 
     LIST OF REFERENCE NUMERALS 
     
         
           10  floor cleaning machine 
           12  chassis 
           14  holding element 
           16  first side 
           18  second side 
           20  base 
           22  front end 
           24  rear end 
           26  straight ahead forward travel direction 
           28  wheel arrangement 
           30   a  left rear wheel 
           30   b  right rear wheel 
           32  wheel axis 
           34  cleaning head 
           36  pivot bearing 
           38  pivot axis 
           40  journal 
           42  upper region 
           44  annular element 
           46  recess 
           48  steering rod device 
           50  end 
           52  joint device 
           54  cardan joint 
           56  fixing device 
           58  eyelet 
           60  steering rod 
           62  direction of extent 
           64  acute angle 
           66  pivot axis 
           68  support element 
           70  support element 
           72  annular element 
           74  recess 
           76  support element 
           78  rear end 
           80  steering wheel arrangement 
           82  handle element 
           84  second part 
           84  first part 
           88  rearmost point 
           90  first tank 
           92  second tank 
           94  free region 
           96  side 
           98  pump device 
           100  suction side 
           102  suction line 
           104  pressure side 
           106  application device 
           108  free space 
           110  holding device 
           112  battery device 
           114  wall 
           116  charging apparatus 
           118  turbine device 
           120  suction device 
           122  drive device 
           124  housing 
           126  first housing region 
           128  brush 
           130  rotational axis 
           132  second housing region 
           134  electric motor 
           136  vessel 
           138  receiving space 
           140  fluid path 
           142  pipe 
           144  mouth 
           146  suction beam 
           148  “to the left” 
           150  “to the right” 
           152  connection 
           154  roller device 
           156  lifting device 
           158  foot pedal 
           160  switch 
           162  first rod element 
           164  sleeve 
           166  recess 
           168  fixing device 
           170  clamping lever 
           172  recess 
           174  clamping region 
           176  contact face 
           178  pivot axis 
           180  second rod element 
           182  pivot bearing 
           184  fixing device 
           186  housing casing