Patent Publication Number: US-2010107347-A1

Title: Floor-cleaning machine

Description:
The invention concerns a floor-cleaning machine, and in particular, a professional-type floor-cleaning machine which is mainly designed for cleaning relatively extensive floors, for example inside commercial and/or small industrial premises. 
     Professional floor-cleaning machines are usually divided into two different categories. Machines mounted on self-propelled vehicles, which are designed to be driven by an operative, are usually called “man on board” machines, while machines mounted on trolleys which are manually propelled by an operator walking behind the machine are referred to as “walk-behind” machines. 
     This invention concerns both types of floor-cleaning machines. 
     As is known, floor-cleaning machines in general comprise operating groups which perform specific floor-cleaning operations, among which, one or more motorised rotating organs which scrub the surfaces, a dispenser group which dispenses a detergent liquid, and a suction group to which a floor-wiping group is associated. The floor-wiping group normally comprises one or more flexible rubber blades, which slide on the floor to collect the detergent liquid and the dislodged dirt, facilitating removal thereof by the suction group. 
     The operating groups are usually covered by suitable plastic or sheet-metal covers, and are mounted on board a sturdy, solid support frame, usually of large dimensions, which is provided with wheels so that it can be moved, manually or by a motor, on the floor to be washed. 
     The rotating organs in the state of the art generally comprise a support disc which is connected to the shaft of a drive motor and is provided with a plurality of frontal bristles which project from the lower surface so as to be in direct contact with the floor to be washed. 
     Known rotating organs have the task of dislodging the dirt from the floor, which dirt, together with the water used for the washing operation, is then removed by the suction group. 
     As they move along the floor, the rotating organs however also have a certain abrasive effect, which makes these floor-cleaning machines unsuitable for cleaning delicate surfaces. 
     Further, after prolonged use, the bristles wear out rapidly and tend to lose their shape, flattening against the support disc and acquiring a bent shape which reduces their effectiveness. 
     For this and other reasons, the dirt removal delivered by traditional rotating organs is not always satisfactory, and in addition requires the use of a large quantity of detergent liquid or water. 
     The large quantity of detergent liquid or water in turn means that the floor is often rather wet after cleaning operations, whence the need for a very large suction group, thus giving rise to greater energy consumption in use. 
     The poor cleaning effectiveness of known rotating organs also means that they must be pressed hard against the floor to be washed. 
     This pressure gives rise to greater friction of the rotating organs on the floor and thus to greater resistance in opposition to the drive motor, which therefore consumes a large amount of energy. 
     The aim of this invention is to obviate the above-mentioned drawbacks at least in part, by providing a floor-cleaning machine which cleans more effectively than those presently available. 
     A further aim of the invention is to achieve the above aim with a simple, rational and relatively inexpensive solution. 
     These aims are achieved by the characteristics of the invention which are described in the independent claim herein below. The dependent claims delineate preferred and/or particularly advantageous aspects of the invention. In greater detail, the invention provides a floor-cleaning machine comprising a support frame which is mobile on the floor, upon which support frame are installed at least a rotating cleaning organ which remains in contact with the floor, and a motor for drawing in rotation the cleaning organ, the rotating cleaning organ comprising a microfibre cleaning element which is destined to be directly in contact with the floor. 
     Typically a microfibre is a synthetic fibre measuring less than a denier. The denier is a measure of the fineness of a yarn and expresses the linear density of the fibre. In more detail, the denier is defined as the mass in grams of 9000 metres of fibre: a fibre which measures 1 denier is a fibre which is so thin that 9000 metres of the fibre weighs 1 gram. 
     Thanks to the infinitesimal dimension of the yarn, the microfibre cleaning element performs a physical and mechanical action on dirt particles, removing them from the floor effectively and trapping them among the fibres. The cleaning element can be made of polymer microfibres, preferably polyester or polyamide, or of a combination of polyester microfibres and polyamide microfibres. 
     Polyester microfibres exhibit a hooked microstructure which, thanks to the presence of water, performs a non-abrasive, mechanical dirt-dislodging action, while polyamide microfibres have a high power of absorption, being capable of absorbing the water, and with it the dislodged dirt. 
     In this way, the cleaning element is not only capable of dislodging the dirt from the floor, but it also removes the dirt, together with the water used for washing. 
     When a cleaning element is full of dirt, it can be replaced by a new, clean one; the used cleaning element could potentially be washed for further multiple re-use. 
     Thanks to the microfibre cleaning element it is also possible to clean floors effectively using only water, without the addition of chemical detergent substances. 
     Since microfibres need only be damp to perform their cleaning action, the quantity of water required is further reduced by 90% compared with the amount required with traditional brushes. 
     The result is that floors are substantially almost dry after cleaning operations, to such an extent that in some circumstances it is no longer necessary to use the suction group, thus saving energy. 
     The greater cleaning effectiveness of the microfibre element further enables the pressure with which the microfibre must be pressed against floors to be reduced, thereby reducing friction and thus delivering further energy savings which are equal to approximately 60% of the consumption of present machines. 
     In particular, the pressure of the cleaning organ on the floor can be very low, between 3 kg and 15 kg, compared with between 15 kg and 90 kg for traditional machines, which means that the cleaning organ can be made to rotate at a comparatively higher number of revolutions, up to 800 rpm. 
     In a preferred aspect of the invention, the floor-cleaning machine can be fitted with a heating device, typically a small heater, for heating the water or more in general the cleaning liquid before the cleaning liquid is dispensed on the floor or onto the cleaning element. 
     This improves the standard of floor-cleaning obtained, since the hot liquid not only enables the microfibre cleaning element to dislodge and remove dirt more easily, but if the temperature is high enough it can also perform a certain antibacterial action. 
     The heater device is preferably provided with adjustment means, such as for example a thermostat, to allow the user to vary the temperature of the water according to requirements, for example from a minimum of 20° C. to maximum temperatures which are high enough to transform the water into steam. 
    
    
     
       Further characteristics and advantages of the invention will emerge from the following detailed description provided by way of a non-limiting example, with the aid of the appended figures of the drawings. 
         FIG. 1  is a side view of a floor-cleaning machine of the invention, in which the rotating cleaning organ is sectioned along an axial plane. 
         FIG. 2  is a view of the floor-cleaning machine of  FIG. 1  in which the cleaning organ is not sectioned and in which some components have been eliminated for greater clarity. 
         FIG. 3  is a plan view of the floor-cleaning machine of  FIG. 2 . 
         FIG. 4  is a side view of the floor-cleaning machine of  FIG. 2 , shown in a rest position. 
     
    
    
     The floor-cleaning machine  1  comprises a rather compact, lightweight support frame  2  which exhibits a horizontal base  20  and is provided with three support wheels, two of which are coaxial, fixed-axle, forward wheels  21 , and one of which is a pivoting rear wheel  22 . 
     Two oppositely-positioned salient side elements  23 , which are identical in shape and preferably made of plastic, are fixed to the mobile support frame  2  and laterally delimit the loading space of the mobile support frame  2 . 
     A rigid frame  3 , which is preferably made from sheet steel, is hinged to the side elements  23 . 
     As shown in  FIG. 3 , the frame  3  has rounded corners and exhibits two transverse bars, a forward transverse bar  30  and a rear transverse bar  31 , which are connected by two oppositely-positioned, identical, shaped longitudinal bars  32 . 
     The rigid frame  3  is inserted externally on the side elements  23  of the mobile support frame  2 , to which mobile support frame  2  it is hinged by means of two hinge joints  24  which singularly join a respective side element  23  to the adjacent longitudinal bar  32 . 
     The hinge joints  24  are perfectly coaxial, such as to define a single axis of rotation A of the rigid frame  3  with respect to the mobile support frame  2 . 
     As shown in  FIG. 1 , the axis of rotation A is oriented such as to be horizontal when the mobile support frame  2  is resting on the floor, and is arranged in an intermediate position along the longitudinal bars  32 , such that the rigid frame  3  is hinged to the mobile support frame  2  like a reciprocating lever. 
     In this way, a lowering of the rear transverse bar  31  corresponds to a raising of the forward transverse bar  30 , and vice versa. 
     In more detail, the longitudinal bars  32  of the frame  3  extend downwardly, so that the forward transverse bar  30  projects beyond the base  20  and is arranged substantially at the same height as the base  20 , while the rear transverse bar  31  is arranged at a higher level. 
     Thus the rear transverse bar  31 , which serves as a grip for the user pushing the floor-cleaning machine  1 , is arranged at a level where it can conveniently be gripped. 
     A support plate  33  is attached to the rigid frame  3  (see  FIG. 2 ) at the forward transverse bar  30  position, an operating group denoted in its entirety by reference numeral  5  being installed upon the support plate  33 ; the operating group comprising a rotating cleaning organ  50  to which a gear reducer  51  is associated. 
     In particular, the cleaning organ  50  comprises a rigid support disc  52 , preferably made of metallic material, to the lower surface of which a cleaning element  53  made of microfibre is attached. 
     The microfibre cleaning element  53  is conformed as a flat, thin, substantially circular element, which is arranged coaxially to, and almost completely covers, the lower surface of the support disc  52 . 
     The cleaning element  53  can be a cloth, a mat, or a thin pad which is more or less soft. 
     The cleaning element  53  is preferably made of a composition of polyester microfibres and polyamide microfibres. 
     The cleaning organ  53  is attached to the support plate  52  by means of a perimetral frame  54  which surrounds both the cleaning organ  53  and the support plate  52 , the transverse section of which is hook-shaped so as to press the edge of the cleaning organ  53  against the edge of the support plate  52  (see  FIG. 1 ). 
     Obviously the perimetral frame  54  could be replaced by a plurality of hooks having the same transverse section as the frame  54  and being arranged at a distance from each other along the perimeter of the cleaning organ  53  and of the support plate  52 ; or by any other means for attaching. 
     The cleaning organ  50  is positioned beneath the support plate  33 , with a substantially vertical axis of rotation, such as to rest the microfibre cleaning element  53  frontally on the floor. 
     The support disc  52  and the microfibre cleaning element  53  both exhibit a central hole, to allow the cleaning organ  50  to be keyed to the shaft of the gear reducer  51 . 
     The geared motor  51  is controlled by a control lever  55  which is mounted on the rear transverse bar  31  of the rigid frame  3 , and which is connected to the gear reducer  51  via flexible cables (not illustrated). 
     Further, a suction group, denoted in its entirely by  6 , is mounted on the support plate  33 , which suction group schematically comprises a pump with the relative drive motor. 
     The suction group  6  is also controlled by manual organs (not shown) which are preferably mounted on the rear transverse bar  31  of the rigid frame  3 , so that they can be conveniently activated by the user. 
     As shown in  FIG. 1 , the suction group  6  is connected via a first flexible pipe  60  to a closed collecting reservoir  61 , preferably made of plastic, which is arranged on board the mobile support frame  2 , and is in turn connected, via a second flexible pipe  62 , to a floor-cleaning group  7 . 
     The collecting reservoir  61  rests upon a lower reservoir  63 , which is mounted on the base  20  of the mobile support frame  2 , which reservoir  63  contains a washing liquid, typically water or possibly water mixed with a detergent substance. 
     The reservoir  63  is connected to one or more washing liquid dispenser nozzles (not shown), which are attached to the rigid frame  3  at the cleaning organ  50  in order to dispense the liquid directly onto the floor or onto the cleaning element  53  made of microfibre. 
     The dispensing nozzles are connected to the reservoir  63  via at least one conduit  64  along which a manual adjustment valve (not visible) is generally arranged. 
     In a preferred aspect of the invention, a heater  65  is installed along the conduit  64 , between the reservoir  63  and the dispenser nozzles, which heater  65  heats the cleaning water before the water is dispensed. 
     The heater  65  can be an electric heater, which heats the cleaning water just as it transits along the conduit  64 . 
     A thermostat is associated to the heater  65 , the thermostat being manually adjustable by the user to vary the water temperature, for example from a minimum of 20° C. to a temperature such as to transform the water into steam. The thermostat can be adjusted via a control knob (not illustrated) which is preferably installed on the rear transverse bar  31 , for convenient activation by the user. 
     The floor-cleaning group  7  is of known type and comprises two thin flexible blades  70 , preferably made of rubber, which are oriented vertically so as to be arranged with edges thereof against the floor. 
     As shown in  FIG. 3 , the flexible blades  70  are joined together at the ends and are kept separate by a rigid framework  71 , which defines a space that is downwardly open. 
     A connector  73  is associated to the rigid framework, which connector terminates within the space and is connected to the second flexible pipe  62  coming from the reservoir  61 . 
     As shown in  FIG. 1 , the rigid framework  71  is connected to the mobile support frame  2  by means of two superposed connecting rods  76 , which define a four-bar hinge enabling the floor-wiping group  7  to perform vertical movements which are driven manually via a handle bar  78 . 
     In detail, the four-bar hinge enables the floor-wiping group  7  to be moved between the work position of  FIG. 1 , in which the flexible blades  70  are in contact with the floor, and the rest position of  FIG. 4 , in which the flexible blades  70  are raised and are not in contact with the floor. 
     The floor-cleaning group  7  can be blocked in the rest configuration thanks to a magnet  26  which is mounted on the mobile support frame  2  in such a way that it contactingly receives the upper connecting rod  76  of the four-bar hinge. 
     In operation, the floor-cleaning machine  1  is pushed and guided on the floor by the user, who proceeds on foot behind it while gripping the rear transverse rod  31  of the tilting support frame  3 . 
     The tilting support frame  3  is in the configuration shown in  FIG. 1 , in which the operating group  5  is in a lowered work position in which the microfibre cleaning element  53  is frontally in contact with the floor. 
     For effective cleaning, the cleaning element  53  needs to exert a pressure of preferably between 3 kg and 15 kg on the floor. 
     For this reason, the machine  1  is generally provided with one or more weights which under the effect of gravity push the cleaning element  53  down onto the floor with adequate force. 
     The weights comprise the operating group  5  and the suction group  6 , the force of the weight of which tends to make the tilting frame  3  rotate in a clockwise direction C, that is, in the direction which corresponds to a lowering of the forward transverse bar  30 , thus pressing the microfibre cleaning element  53  onto the floor with a corresponding force. 
     If the weight of the operating group  5  and of the suction group  6  is insufficient to reach the desired pressure values, suitable weights can be added which are applied to the support plate  33  of the tilting frame  3  as ballast. 
     If on the other hand the weight of the operating group  5  and of the suction group  6  is excessive, the machine  1  can be provided with contrasting means which limit the force unloaded onto the floor via the cleaning element  53 . 
     In the example shown in  FIG. 2 , the contrasting means comprise a wheel  56  which rests on the floor, and which is connected to one of the longitudinal bars  32  of the tilting frame  3  via a vertically oriented telescopic arm  57  which is positioned downstream of the axis of rotation A. 
     Shortening of the telescopic arm  57  is contrasted by a spring  58  which is installed in two reciprocally sliding tracts of the telescopic arm  57 , in such a way that the telescopic arm  57  can proportionally support a part of the weight of the operating group  5  and of the suction group  6 , thus limiting the remaining part which is unloaded on the microfibre cleaning element  53 . During washing operations, the rotating cleaning organ  50  is made to rotate by the geared motor  51 , while contemporaneously, dispensing of the liquid from the reservoir  63  is commanded. 
     The liquid is dispensed directly onto the floor or onto the cleaning element  53 , in such a way that the scrubbing action of the cleaning element  53  and the detergent action of the liquid enable the dirt to be removed from the floor. In detail, the polyester microfibres present in the cleaning elements  53 , thanks to the water and their hooked microstructure, give rise to a non-abrasive mechanical dirt-removing action. The polyamide microfibres, thanks to their elevated absorbent power, absorb and retain the water, and together with the water, the removed dirt. 
     During the cleaning phase, the heater  65  can be kept active so as to heat the cleaning water to be dispensed later onto the floor. 
     In fact the use of hot water facilitates the dislodging and removal of dirt by the cleaning element  53 . 
     Further, by adjusting the thermostat which is associated to the heater  65 , the user can vary the temperature of the water cleaning according to requirements. 
     In particular, the user can choose to heat the water in the heater  65  to the point of transforming the water into steam, which is then used to improve the cleaning action or to perform an antibacterial action. 
     During the cleaning phase, the suction group  6  can also be activated, thus creating a depression in the reservoir  61  and, via the flexible conduit  62 , in the gap defined between the flexible blades  70  of the floor-wiping group  7  which is in a lowered work position. 
     The liquid mixed with dirt which is not absorbed by the cleaning element  53  is then brushed and collected by the flexible blades  70  sliding on the floor, and is then sucked into the reservoir  61 . 
     When washing operations are terminated, the user pushes the rear transverse bar  31  of the tilting frame  3  downwards, thus raising the forward bar  30 . 
     In this way, the operating group  5  and the suction group  6  are raised from the floor until they reach a rest position shown in  FIG. 4 , in which the cleaning element  53  is not touching the floor and in which the tilting frame  3  is locked using known means. 
     In comparative tests which the Applicant has carried out, a floor-cleaning machine  1  provided with a microfibre cleaning element  53  requires a much smaller amount of water than a similar traditional floor-cleaning machine requires to obtain the same results. 
     In more detail, while a traditional floor-cleaning machine needs to dispense approximately 1.5 litres of water per minute, the floor-cleaning machine  1  with the microfibre cleaning element  53  needs only 0.15-0.2 litres of water per minute. 
     It is in fact sufficient for the microfibre cleaning element  53  to be damp for it to perform an effective cleaning action. 
     The result is that after floor-cleaning operations, floors are substantially almost dry, to the extent that in some circumstances it is not even necessary to use the suction group  6 , thus saving energy. 
     Further, the damp cleaning element  53  has the effect of heating the dirt particles by friction, thus performing a bactericidal action. 
     The small quantity of water used provides the further advantage that the water can be heated in a low energy consumption heater  65 . 
     Further, the pressure with which the microfibre cleaning element  53  is pressed on the floor is much less than the pressure with which the rotating brushes of traditional floor-cleaning machines are pressed on the floor, which pressure can reach 90 kg. 
     The reduced pressure makes it possible for the cleaning organ  50  to be made to rotate at a comparatively higher number of revolutions, up to 800 rpm, while since it also reduces friction, the geared motor  51  absorbs up to approximately 60% less energy than that absorbed by the motors of traditional floor-cleaning machines. 
     Obviously, a person skilled in the art might bring numerous technical and applicational modifications to the invention without forsaking the ambit of the invention as claimed herein below.