Patent Publication Number: US-2022211239-A1

Title: Device for cleaning walkable surfaces

Description:
The invention relates to a device for cleaning walkable surfaces, adapted to move forward automatically and to be steered manually by an operator for cleaning walkable surfaces, as for example floors, roads, pavements, etc., particularly where there are present tight spaces for operating such a device or spaces that are difficult to be reached. 
     To date we know different types of machines for cleaning floors by means of motorized rotating brushes, which are also wet by means of a relative delivery system for liquids. 
     Particularly, in the technical field of the present invention, it is known a first type of floor scrubber machine constituted by a lower support frame leant on wheels and one or more motorized brushes with vertical rotation axis or slightly inclined, adapted to rub the floors to be cleaned and to move forward automatically the cleaning machine thanks to the friction with the floor, without the operator must push it or without the use of motorized wheels. 
     Such a frame substantially supports on its upper part the unit motor-battery for actuating such cleaning brushes, the tanks for the clean water, for the possible detergent, and for the dirty water, sucked by an electrical suction system, which is placed on the upper part of said frame too and is associated with an element, which is lengthened horizontally and made of rubber, positioned lowerly in the back part of said support frame, and adapted to collect the dirty water resulted from the brushing action of the floor by the wetted rotating brushes. 
     A fixed guiding body is also secured on the support frame, which is lengthened upward and ending with a handle associated with a console equipped with commands adapted to be grasped by the operator for guiding the cleaning machine and for commanding the electrical and electronic parts thereof. 
     The component elements supported on the upper part of the support frame and to the lower part of the guiding means are covered by a shaped casing. 
     Such a type of cleaning machine for floors, also if it is easily to be guided and commanded, is not adapted to clean floors and tight spaces or in spaces wherein objects are placed on the top and spaced away from same, as for example hanging furniture, tables, chairs, etc., because the machine has considerable dimensions. 
     In this technical field, it is also known a second type of machine for a wet cleaning of floors by means of rotating brushes, constituted by a base body connected, by means of articulated jointing element, to an upper lengthened guiding means. 
     Said base body comprises at its lower part one or more motorized rotating elements, as for example brushes, rollers with bristles, rollers with sponge, etc., with a rotation axis that is horizontal, vertical or inclined, adapted to scrub the floors for cleaning them. 
     An element, made of rubber, is positioned behind said motorized rotating elements, with respect to the direction of advancement of the machine, and is adapted to receive and to keep the dirty brushed from the floor, that is then sucked by means of a suction system and collected in a suitable tank. It may be present also a wetting system of said motorized brushes or similar, for increasing the cleaning efficiency thereof. 
     On the guiding means, in addition to the handle for guiding the machine, there are present the command for setting the operational functions of the same machine. 
     For facilitating the operator, such rotating elements may move forward the machine during the brushing, thanks to the friction with the floor. 
     Various component elements, including the motors, the batteries, the tanks, the operation electrical and electronic systems, the elements of the wetting and suction systems are applied and arranged between the upper part of the base body and the guiding means, in particular with at least tank applied on this latter. 
     This second type of known cleaning machines use a articulated jointing element between the guiding means and the base body, in a manner to be able to bring the upper end portion of the same guiding means nearer to the floor, so that it is possible to clean portions of floors that are covered in a spaced manner by tables, chairs, hanging furniture, etc. 
     As articulated jointing elements there are used joints with one rotation axis, for example that allow a tilting movement of the guiding means, or joints with two rotation axis orthogonally to each other and placed on two different levels, as for example a universal joint, that allow to the guiding means to be bent with its upper end portion toward the floor in different direction, and by twisting the same guiding means, they allow that the base body may rotate toward right or left. 
     In this second type of cleaning machine, the lengthened guiding means may be inclined in a limited manner with respect to the base, up to it goes into contact with it, and this may be result a limitation for cleaning areas of the floor with objects positioned above it and spaced superiorly, and that have a considerable depth. 
     Furthermore, the base may not rotate on itself on a vertical axis without inclining on a horizontal axis, except with the guiding means positioned vertically, and that in narrow spaces, wherein it is necessary to incline the same guiding means, compels the operator to pull the cleaning machine in the reverse direction with respect to the one in which the motorized rotating elements create propulsion, therefore by tiring the operator and by straining the motors of said rotating elements. This type of cleaning machine is not provided with dampening means that damp collisions with external elements, places on the floor to be treated, thereby creating the risk of damages to the same machine. 
     By placing the tanks for clean water and/or dirty water on the guiding means, in addition to the weight of the liquid contained in the tanks, the water, passing from a tank to the other one, changes the weight distribution on the guiding means, thereby causing a change of the operator&#39;s posture. The object of the present invention is to delete the above said problems and limits, and additional advantages will be described following. 
    
    
     
       This aim and other ones are obtained according to the invention by means of the use of a device for cleaning walkable surfaces realized in a different manner with respect to the known solutions from the prior art, with the characteristics and operating as it will be described, by way of a not-limitative example only and with reference to the accompanying drawings, in which: 
         FIG. 1  shows a front-side perspective view of a first example of the device for cleaning walkable surfaces in a starting rest position thereof, according to the invention; 
         FIG. 2  shows a back-side perspective view of the device of  FIG. 1 ; 
         FIG. 3  shows a back perspective view of the cleaning device of  FIG. 1  in an operational position thereof, without some of component elements thereof for giving prominence additional internal component elements thereof; 
         FIG. 4  shows a view from below of the cleaning device of  FIG. 1 ; 
         FIG. 5  shows a side view of a group of elements that is shown in  FIG. 3 , in a working position thereof; 
         FIG. 6  shows a side view of the group of elements of  FIG. 5 , in a not-working position thereof; 
         FIG. 7  shows a back-side perspective view of the group of elements shown in  FIG. 3 , in an operational position thereof, and one external element; 
         FIG. 8  shows a view from below of  FIG. 7 ; 
         FIG. 9  shows a front view of the cleaning device in an operational position thereof; 
         FIG. 10  shows a back-side perspective view of the cleaning device shown in  FIG. 9 ; 
         FIG. 11  shows a side view of the cleaning device in an additional operational position thereof; 
         FIG. 12  shows a back-side perspective view of the device of  FIG. 11 , together one external element; 
         FIG. 13  shows a perspective view from the top of the cleaning device, in an additional operational position thereof; 
         FIG. 14  shows a front-side view of the cleaning device, in an additional operational position thereof; 
         FIG. 15  shows a back-side view of the cleaning device, in an additional operational position thereof; 
         FIG. 16  shows a perspective view of a group of internal elements of the cleaning device with one element in a rest position thereof; 
         FIG. 17  shows a perspective view of the group of internal elements of  FIG. 16 , with the above said element in a operational position thereof; 
         FIG. 18  shows a side view of the cleaning device in a storage/packaging position thereof; 
         FIG. 19  shows a side perspective view of the group of elements of  FIG. 18 ; 
         FIG. 20  shows a side view of a second example of the cleaning device in a working position thereof, together one external object. 
     
    
    
     The invention relates to a device for cleaning walkable surfaces, adapted to move forward automatically and to be steered manually by an operator for cleaning walkable surfaces, as for example floors, roads, pavements, etc., particularly where there are present tight spaces for operating such a device or spaces that are difficult to be reached. 
     As it is visible particularly in  FIGS. 1-2 , the device  10  is realized as scrubber-dryer machine for cleaning walkable surfaces  11 , as for example floors, pavements, asphalted roads, etc., and is substantially constituted by a cleaning lower base body connected on its upper part to a steering means lengthened upward, by means of a movable jointing element  14 , which is conformed in such a way that such a lower body  12  may move forward at least in one travel direction and that said steering means  13 , from one starting position thereof perpendicular with respect to the base body  12 , be inclinable in all direction without that the base body  12  being inclined, up to be able to touch the walkable surface  11  with its upper free end portion  15 , and may also steer said lower body  12  apart from the inclination wherein it is, as it will be described. 
     As it is visible particularly in  FIGS. 3-4 , said cleaning lower body  12  is constituted by a support frame  16  having a front outline  17 , two side outlines  18 ,  19 , and a back outline  20 , and onto which there is fixed the movable jointing element  14 , in such a way to be positioned in the barycenter of the same lower body  12 . 
     At least a brushing means is housed lowerly to such a support frame  16 , by means of bearings or axle boxes or equivalent means, in such a way to be rotatable along an axis slightly inclined with respect of the vertical of the device  10  leant on to a horizontal plane, thereby be able to brush the walkable surface  11  and removing the dirt present on this latter. 
     In the not-limitative examples described herein there are provided two brushing means  21  and  22 , identical to each other, and each constituted by a raised cylindrical plate  23  provided with a plurality of bristles  24  arranged radially in the lower part of the same cylindrical plate  23  and directed outward with respect to this latter and downward. 
     Said two brushing means  21  and  22  are arranged side by side to each other in a transversal manner with respect the orientation of the lower body  12 , in such a way that an internal portion  24 ′ of the bristles  24  of each means  21 ,  22  is intersected with its own end portions  25 , whereas one external portion of the bristles leans out laterally with its own end portions  25  with respect to the outline of the lower body  12 , furthermore the rotation axis of both brushing means  21  and  22 , with extension upward, is slightly inclined inward the lower body  12 , with the same angle, in such a way that the bristles  24  of the internal portions  24 ′ be more pressed against the walkable surface  11  to be cleaned. 
     Said brushing means  21  and  22  are actuated in rotation by means of respective electrical actuating means  27 ,  28 , constituted as for example by electrical motors, which are arranged on the upper part of said frame  16 , and above to the respective brushing means  21  and  22 , that they have to actuate. Said brushing means  21  and  22  rotates in opposite directions to each other, in particular the internal portion  24 ′ of the bristles  24  move backward with respect to the direction of advancement of the device  10 , in such a way to convey the brushed dirty in a central and back position with respect to themselves, and in such a way that, the friction made by the rotation of the brushing means  21  and  22 , with an inclined rotation axis, between the internal portions  24 ′ of the bristles  24  and the walkable surface  11  made in turn a traction such to allow to the device  10  to move forward automatically in a rectilinear way when the brushing means  21  and  22  are actuated in rotation. At least a system for collecting the dirty conveyed by the internal portion  14 ′ is placed on the back and spaced away from said brushing means  21  and  22 , which system is constituted by at least a restraining means  29  for the dirty, adapted to restrain the conveyed dirty, associated to at least a suction means  30 , adapted to suck the restrained dirty, and at least a collection means  31 , adapted to contain the sucked dirty. 
     In the case it is provided for a manually or automatic inversion of the rotation direction of the brushing means  21  and  22 , at least a second system for collecting the dirty constituted by at least a restraining means  29  for the dirty, at least a suction means  30 , and at least a collection means  31 , is placed on the front part and spaced away with respect to the same brushing means, in such a way that in the case of the inversion of the rotation direction of these latter, it is always at the back with respect to them, such a second example of device  10  is represented in  FIG. 20 . 
     Said restraining means  29  for the dirty is constituted by a lengthened semi-circular support  29 ′ provided with at least a vertical through hole  32  and which supports on its lower edge at least a lengthened element  33 , made of a semi-rigid material, as for example rubber, said support  29 ′ being positioned transversally with respect to the orientation of the device  10 , with its concave part  34  turned toward the two brushing means  21  and  22 , and extending between the two side outlines  18 ,  19 , whereas the lengthened element  33  being extended beyond these latter. 
     Said support  29 ′ is connected to the lower part of the frame  16  by means of at least two pair of levers  35 ,  36 , pivoted at their end portions  37  parallel to each other, and arranged longitudinally with respect to the orientation of the device  10 , thereby creating a pantograph linkage system, which levers are made of elastic metal, preferably of harmonic steel, and are adapted to rotate on their end portions  37  according the vertical movement caused by the restraining means  29  that follows the conformation of the walkable surface  11 , thereby keeping itself always parallel to this latter, or it may be lifted or lowered manually or automatically when the operator considers it necessary, that is when it is foreseen the inversion of the rotation direction of the brushing means  21  and  22 , and said collection system of the dirty is on the front with respect to the direction of advancement of the device  10  in an operational state thereof, furthermore, such levers are structured and adapted to be bent transversally when the restraining means  29  bumps laterally against an external obstacle  80 , for then returning automatically in the original position thereof after having passed such an obstacle. 
     Such a restraining means  29  may be lifted by rotating the levers  35 ,  36  in a manual way or by means of one electrical actuator means  51 , placed on the upper part of the frame  16 , and that operates in the manner that will be described further, said restraining means  29  being kept lifted by means of quick fixing means or magnetic means or electro-magnetic means, or equivalent. 
     Said restraining means  29  may be provided with two support wheels  42 , placed laterally and/or centrally with respect to the lengthened support  29 ′ and are fixed by means of metallic brackets  43 . Said suction means  30  is of the electrical type, and is arranged on the upper part of said frame  16  and above said restraining means  29 , and with its inlet mouth is connected in a communicating way to said vertical through hole  32 , in such a way that when it is actuated it may suck through it the dirty restrained by the same restraining means  29 . 
     The outlet mouth of such a suction means  30  is connected in a communicating manner to said collection means  31 , in such a way that the sucked dirty may be conveyed and collected inside it. Said collection means  31  is constituted by a first tank arranged in a removable manner above the back half portion of said frame  16  and the components placed in this portion of the frame, and has a base that follows the outline and the dimensions of the portion of frame on which is leant and a height that doesn&#39;t interfere with the jointing element  14 . 
     Said brushing means  21 ,  22  are associated with a wetting system adapted to force the washing liquid on to the same means, for making most efficient the cleaning of the walkable surface  11 , for then be mixed to the brushed material to be removed and conveyed by the bristles  24  toward said dirty collection system. 
     Said wetting system is constituted by one containment means  38 , adapted to contain the cleaning liquid, one electrical pumping means  39 , adapted to draw said cleaning liquid, and delivery means  40  for delivering such a liquid on the brushing means  21 ,  22 . 
     Said electrical pumping means  39  is constituted for example by an electrical pump and is placed on the frame  16 , in the central area of this latter, whereas said containment means  38  is constituted nu a second tank arranged in a removable manner above the front half portion of said frame  16  and the components placed in this portion of frame, and has a base that follows the outline and dimensions of the portion of frame on which it is leant and an height that doesn&#39;t interfere with the jointing element  14 . 
     The back wall  38 ′ od said second tank  38  and the front wall  31 ′ of said first tank  31  are almost vertical and coupled to each other thereby forming a unique body  45 , constituted by two above said tanks  31 ,  38 , and having an upper surface  46  almost continuous and inclined frontally downward and side walls  47  inclined inward and upward, and finally having a vertical hole  41 , preferably with a cylindrical cross-section, in correspondence of the jointing element  14 , in such a way that this latter be inserted therein and be free to carry out its function, cylindrical hole  41  obtained by means of two vertical semi-cylindrical grooves identical and specular to each other, and provided on to two said vertical walls  31 ′,  38 ′ coupled to each other, respectively. 
     Such a body  45 , along its lower base outline, is also provided with a plurality of shape recesses  48  identical and equidistant to each other, for the aim that will be described further. 
     Said delivery means  40  are constituted by one or more nozzles positioned in the lower part of the frame  16  and connected in a communicating manner to said pumping means  39  and turned on to the brushes  21 ,  22 , in such a way that these latter may be wetted with the cleaning liquid drawn from the second tank  38 . 
     Above said frame  16 , a respective impact resistant means  49  is housed in correspondence of each recesses  48  of the body  45  and is protruded partially outward the body  45  with its side edge, and is adapted to absorb eventual impacts with external objects with respect the device  10 , such an impact resistant means  49  is constituted for example by a roller pivoted with a vertical rotation axis, free in rotation, and made of semi-rigid elastic material, as for example rubber. 
     At least one electrical sanitation means  52  is fixed to the lower part of the frame  16 , at the back with respect to the direction of advancement of said device  10  and to said restraining means  29 , such a sanitation means  52  being constituted as for example by one or more UV lamps and being adapted to complete the sanitation of the walkable surface  11  just treated. 
     At least a pivoting wheel  79  is positioned in the lower part of the frame  16 , at the back with respect to said electrical sanitation means  52 , and is adapted to support the back part of the lower body  12 , by avoiding that this latter is inclined backward. 
     The device  10  may be equipped with at least a detecting means  53 , constituted for example by a sensor of the gyroscope type or inertial type, positioned on the frame  16  too, and adapted to detect the direction of advancement of the same device  10 , that is if the operator is pushing or pulling the same device  10  for inverting the direction of advancement thereof, therefore the brushing means  21  and  22  may eventually invert the own direction of rotation and that the possible restraining means  29  positioned on the front with respect to the brushing means  21  and  22  with respect to the advancement direction of the device  10  be lifted up from the walkable surface  11 , while the possible restraining means  29  positioned on the back of the brushing means  21  and  22  with respect to the advancement direction of the device  10  be lowered and put into contact with the walkable surface  11 , such an operation of lifting and lowering of the possible restraining means  29  is obtained, as above described, by means the rotation of the levers  35 ,  36 , both in a manual manner and thanks to the actuator means  51 , that may be associated to the sensor means  52  by working automatically or being commanded directly by the operator by means of suitable commands. 
     Said movable jointing element  14 , fixed vertically on the frame  16 , in the barycenter point of the lower body  12 , is adapted to connect the cleaning lower body  12  and the upper steering means  13  in a constraint way in rotation with respect to the vertical axis of the connecting point between the jointing element  14  and the lower body  12  and in a non-constraint way in inclination of the steering means  13  with respect to the lower body  12 . 
     Such a jointing element  14  is constituted by at least a lengthened elastic and internally hollow push element  14  that in a rest position thereof has a rectilinear upward extension, and is constrained with its lower end portion  54  to the frame  16  and with its upper end portion  55  to the steering means  13 , such a lengthened elastic element may be taken after a curvilinear extension by inclining the steering means  13 , that is by moving forcefully its upper end portion  55  downward and externally and in any direction with respect to the vertical axis of the same elastic element in the rest position thereof, being able in this position with curvilinear extension to be rotate along the vertical axis of the same elastic element in the rest position thereof, without that the lower body  12  be interested by such a rotation (See  FIGS. 9-12, 20 ). 
     The elastic element  14  may be curved downward up to the steering means  13  doesn&#39;t touch the walkable surface  11 , so also with inclinations up to at least  90 ° with respect the start position thereof, allowing to the operator to insert the apparatus  10  in to space where there are present external objects  81  at the top, as for example small tables, hanging furniture, etc., without that the steering means  13  finds interferences. 
     By decreasing the downward push force of the upper end portion  55 , the elastic element return toward the rest position, up to reach it with the removal of such a downward push force, therefore by reducing also the weight load on the operator&#39;s arms. 
     By applying a twisting moment to the upper end portion  55  of the lengthened elastic element  14 , this latter twist along the own axis, both that it is in the position with rectilinear extension thereof and that it is in a position with a curvilinear extension thereof, by creating a twisting moment in the connecting point between its lower end portion  54  and the frame  16 , by allowing to the lower body  12  to rotate on its perpendicular axis extent upward of the angle desired by the operator, without that it be inclined, so by using a limited space for change direction, and so it is advantageous for the cleaning in tight spaces. Furthermore, by rotating the lower body  12  on itself, this latter from a spaced position from the operator, it returns close to the same operator automatically, always in the starting direction of advancement (See  FIGS. 13-15 ). 
     Such a lengthened elastic element  14  is constituted by a sprung element, as for example:
         one spring, made of metal or polymer (shown in the attached drawings);   at least two springs inserted or co-moulded concentrically one inside the other, made of metal and/or polymer;   one metal bellow, as for example made of steel, with a core made of elastic and semi-rigid material, as for example rubber;   a pipe made of elastic and semi-rigid material, as for example rubber, provided with an internal reinforcement made of reinforcing fibers woven to each other, as for example wire made of metal, nylon, Kevlar, carbon, technopolymer;   a set of coned-disc springs joined to each other with their edges, arranged in an alternate way in succession, therefore the large base of the first coned-disc spring is joined to the large base of a subsequent second coned-disc spring, and the tight base of this latter is joined to the tight base of a subsequent third coned-disc spring, and so the remaining coned-disc springs that compose the entire lengthened elastic element  14 .       

     Such an elastic element  14  may also be constitute by any other type of lengthened elastic and internally hollow body. 
     The steering means  13 , lengthened upward, is constituted by a central lengthened body  56 , shaped with a structure almost box-shaped provided with an external seat along one vertical front or back wall thereof, adapted to house in a removable manner one means for supplying power energy  57 , as for example a rechargeable battery, adapted to power all the electrical and electronic components of the device  10 , such a central lengthened body  56  being connected with its lower end portion  58  to the upper end portion  55  f the jointing element  14  and being provided at its upper end portion  59  with a shaped handle  60  and one control and settings panel  61  for the device  10 . 
     The power supply, in addition to the means for supplying power energy  57 , may be provided by the electrical domestic grid by means of electrical cables and on electrical plug (not shown) arranged on the lengthened body  56 . 
     Such a handle  60  is of the closed ring type and is extended upward with two first lengthened segments  62  identical and specular to each other and inclined slightly outward, and continue with two second lengthened segments  63  identical e specular to each other and extended frontally, and close itself with a horizontal lengthened segment  64  which connect the upper end portion of two second segments  63 . 
     This conformation of the handle  60  allows to the operator to grab it with one or two hands in the point that is suitable for him depending on the inclination of the steering means  13 , that is this latter is basically in a vertical position thereof and the operator grabs the first two lengthened segments  62 , when the steering means will be in a inclined position thereof, hence the handle  60  will be close to the walkable surface  11 , the operator, for not bowing and tiring too much, will grab the third horizontal segment  64 , which will be in a raised position with respect to the other segments. 
     The control and settings panel  61  is adapted to activate the device  10  and to select a operational program loaded in advance for the electrical and electronic component elements and means above described, and is constituted by at least a display, where the data of the device  10  are visible, and a plurality of setting means, as for example push-buttons and/or knobs and/or touch screen commands, which are built-in in the above display, furthermore, such a panel  61  is associated with at least a first electronic control and command means (not shown), constituted as for example by an electronic circuit board equipped with a microprocessor, housed inside the lengthened body  56  and powered by the battery  57 . 
     Said first control and command means us adapted to set the activation and the power-down of the device  10  and to set the operational program loaded in advance of the electrical and electronic means comprised in the device, as for example the intensity of the operation, the direction of the rotation of the brushing means  21  and  22 , etc. 
     Said first control and command means may be also associated to at least a second electronic control and command means (not shown), constituted as for example by an electronic circuit board equipped with at least a microprocessor too, and positioned on the frame  16 , which second control and command means is adapted to receive instructions from the first control and command means and to adjust the activation and the shot-down of the electric and electronic means comprised in the device, to carry out the operational program and to adjust the intensity of operation. 
     Said first control and command means is also associated to the sensor means  53 , for being able to carry out the above the described operations, particularly, said first control and command means receives the data from the sensor means  53  and sends command to the second control and command means. 
     Said first control and command means is also associated to at least an additional detecting means (not shown) positioned in the upper end portion  59  of the steering means and adapted to detect the presence of the operator in close proximity to the device  10 , in such a way that if the device  10  is in the operational state and the operator is not detected, said first control and command means sends the command to the second electronic control and command means to deactivate all the electrical and electronic means, which are operative in that moment, for then re-activate them when the operator is detected. 
     Such an additional detecting means is constitute by at least a proximity sensor, that may be of the ultrasound type or of the optical type and position in the area of the control and setting panel  61 , thereby be able to detect the presence of the operator within a determined distance, and/or may be of the capacitive type and position on the handle  60 , thereby be able to detect if the operator is grabbing or not said handle  60  with at least one hand. 
     Said box-shaped structure of the lengthened body  56  is provided inside with a lengthened fixing means  66  (See  FIGS. 16-17 ), constituted by a vertical rod  71  to which an horizontal rod  68  is fixed on its the upper part and housed in a sliding manner within a vertical hollow guide member  67 , and moved by the operator by means of the horizontal rod  68 , which is extended with at least one its side end portion beyond the side vertical walls of the body  56 , by means of two vertical through slots  70  provided on to this latter and specular to each other. 
     In the starting position of the device  10 , such a fixing means  66  from a rest raised position thereof, in which it is maintained by means of fixing means of the magnetic type or by means of a pawl wherein it is engaged the horizontal rod  68 , may slide downward by the operator in an operational lowered position thereof passing through the opened end portion  58  and stopping at the internal base of the jointing means  14 , where an end-of-stroke element  72  is positioned, constituted preferably by a vertical hollow cylinder into which the lower end portion  73  of the same fixing means  66  engage itself, in this manner the device  10  is locked in the starting position thereof, for be able to be stored, therefor by avoiding the possibility that the jointing means  14  may be curved. 
     A plurality of wheels  74  may be fixed under the frame  16  in a raised manner, preferably in front with respect to the brushing means  21  and  22 , in such a way that when the fixing means  66  is in the operational position thereof, the operator may incline the device  10  by leant such wheels  74  on the walkable surface  11 , therefore it is possible to easily transport it without that the brushes  21  and  22  and the restraining means  29  create friction, since they are in a raised position thereof. 
     Said lengthened body  56  may be connected with its lower end portion  58  to the jointing element  14  by means of a joining means  75 , which is lockable in position and adapted to maintain the steering means  13  in an operational position thereof or to release it from such a position for allowing it to be inclined without to intervene on the jointing element  14  (See  FIGS. 18, 19 ), therefore for being able to reduce the overall dimensions and packaging or storing it easily. 
     Such a joining means  75  is constituted by a lower part  76  connected by means of a horizontal pivot to an upper part  77 , in such a way that two parts are tilting to each other, and may be locked in position, when such two parts  76  and  77  are adjacent one above the other, by means of a locking means  78 , constituted as for example by a bolt. 
     The lower part  76  is fixed to the upper end portion of the jointing element  14 , whereas the upper part  77  is fixed to the lower end portion  58  of the lengthened body  56  of the steering means  13 . Said parts  76  and  77  are each provided with a respective vertical concentric through hole  79 ,  80  (See  FIG. 19 ), adapted to allow the passage of the vertical rod  71  of the fixing means  66 . 
     In addition to the aims and advantageous above listed, such a device has the advantageous characteristic that by using a jointing means  14 , that is of the elastic type, the vibrations created by the device  10  during its operational state, or possible impacts with external objects, are absorbed by the same jointing means  14  that twist automatically for return then in the position thereof in which it was before the impact, without so weigh on the operator, therefore who may work with small loss of energy and with few traumas.