The present invention relates to a machine for washing and drying floors.

Machines for washing and drying floors are known, which have a frame that can be moved around on the floor to be washed and which supports a washing assembly that usually comprises at least one brush and at least one dispenser of a cleaning liquid, which is constituted by a mixture of water and detergent product.

To the rear of the washing assembly, according to the direction of advancement of the machine, there is a floor wiper that retains the cleaning liquid and the dirt removed from, the floor, so that it can be removed by an aspirator, so as to leave the floor dry and clean.

In particular, mounted on the frame of the machine are a supply tank of the cleaning liquid, which supplies the dispenser, and a tank for collecting the dirty liquid picked up by the aspirator.

With current machines, the necessity of emptying the collection tank and of filling the supply tank of the cleaning liquid entails, during the operations to clean the floor, many machine stops, with a consequent loss of productivity and a high consumption of water.

The aim of the present invention is to provide a solution to the drawbacks of the known art by providing a machine for washing and drying floors which does not require repeated machine stops for filling or emptying its tanks and which enables a considerable saving of water.

Within this aim another object of the present invention is to provide a machine for washing and drying floors which is capable of carrying out an excellent action of cleaning and drying floors, without leaving traces of dirt.

Another object of the present invention is to provide a machine for washing and drying which is in line with the current requirements of environmental friendliness.

Another object of the present invention is to provide a machine for washing and drying which is convenient, reliable and easy to use.

Another object of the present invention is to provide a machine for washing and drying which is competitive from a merely economic viewpoint as well.

This aim and these and other objects which will become better apparent hereinafter are achieved by a machine for washing and drying floors, according to the invention, come defined in claim 1 .

Further characteristics and advantages of the invention will become better apparent from the description of a preferred, but not exclusive, embodiment of the machine for washing and drying floors according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings wherein:

Figure 1 is a schematic diagram of the machine according to the invention;

Figure 2 is a schematic diagram of the machine according to the invention, showing the connections between various different tanks;

Figure 3 is a schematic diagram of the machine, showing paths for cleaning filters.

With reference to the figures, the machine for washing and drying floors, according to the invention, generally indicated with the reference numeral 1 , comprises a frame, not shown for the sake of simplicity, which can be moved around on the floor to be cleaned.

In particular, the frame of the machine supports at least one assembly 2 for washing the floor, which is provided with at least one device 3 for dispensing a cleaning liquid, which is constituted, for example, by one or more nozzles, and is, advantageously, supplied by a supply tank 4.

Conveniently, the cleaning liquid used is constituted by a mixture formed from water and from at least one detergent product, which comprises, for example, surfactants, solvents, chelating agents, dispersants, and hydrotropes capable of facilitating not only the mechanical removal of the dirt from the surfaces to be cleaned but also the efficacious dispersion thereof in the cleaning liquid.

Advantageously, the washing assembly 2 also comprises one or more brushes 5 which are designed to carry out an action of removal of the dirt from the floor by friction.

Fitted on the frame of the machine is, furthermore, at least one aspiration device 6 which retrieves the cleaning liquid, mixed with the dirt removed by the brushes 5, from the floor and sends it, conveniently, to a collection tank 7.

Advantageously, the aspiration device 6 comprises an aspiration intake

6a which is associated with a floor wiper 8 which is arranged at the rear of the washing assembly 2 with respect to the direction of advancement of the machine on the floor.

Conveniently, the aspiration device 6 further comprises an aspiration motor 6b, which is adapted to create the at least partial vacuum inside the collection tank 7, in order to retrieve the cleaning liquid from the floor and send it to the collection tank 7 through the aspiration intake 6a.

The peculiar characteristic of the machine according to the invention consists in that it comprises means of recycling the cleaning liquid used to clean the floor, which comprise at least one decanter tank 9 of the cleaning liquid which has at least one inflow 9a which is connected to the aspiration device 6 and at least one outflow 9b which is connected to the dispensing device 3.

The decanter tank 9 makes it possible to obtain a separation of the particles of dirt from the cleaning liquid picked up by the aspiration device 6, thus making it substantially clear, so as to permit a valid reuse thereof for the cleaning of the floor by way of the dispensing thereof by the dispensing device 3.

Descending into further detail, the machine according to the invention is, advantageously, provided with means 10 of conveying the cleaning liquid from the aspiration device 6 to the dispensing device 3, along which, conveniently, filtration means are interposed which, in cooperation with the decanter tank 9, make it possible to recycle the cleaning liquid picked up from the floor by way of the aspiration device 6, by separating the removed dirt from it, so that it can be sent back to the dispensing device 3 in order to be reused.

Preferably, as in the example shown, the inflow 9a of the decanter tank 9 is connected to the collection tank 7, while its outflow 9b is connected to the supply tank 4.

As illustrated, in particular, in Figure 2, the conveyor means 10 comprise, advantageously, at least one connecting line 1 1 that extends from the collection tank 7 to the decanter tank 9 and at least one connecting duct 12 that connects the outflow 9b of the decanter tank 9 to an inflow port 4a of the supply tank 4.

Conveniently, the aspiration device 6 comprises a pump 13 which is arranged along the connecting line 1 1.

Advantageously, the means of filtering the cleaning liquid comprise at least one mechanical filter 14, which is interposed between the collection tank 7 and the decanter tank 9, along the connecting line 1 1.

Conveniently, the filtration means comprise, furthermore, at least one strainer filter 15, which is arranged, advantageously, upstream of the mechanical filter 14, in the direction of flow of the cleaning liquid from the aspiration device 6 to the dispensing device 3 and which permits the collection of the coarser particles of dirt.

Preferably, the strainer filter 15 is arranged inside the collection tank 7 between an inflow connector 7a of the collection tank 7, which is connected to the aspiration device 6 and, more specifically, to the aspiration intake 6a, and an outflow connector 7b of the same collection tank 7, which is, instead, connected to the connecting line 1 1.

Advantageously, the filtration means comprise at least one coalescence filter 16, which is, conveniently, arranged inside the decanter tank 9, along a path taken by the cleaning liquid from the inflow 9a of the decanter tank 9 to the outflow 9b of the decanter tank 9.

In particular, the coalescence filter 16 is intended to be passed through by the cleaning liquid upward from below and is adapted to carry out an action of separation of the greasy and oily component of the dirt.

Conveniently, as illustrated, the inflow 9a of the decanter tank 9 is, for example, arranged in an upper region of the decanter tank 9 and is connected to a channel 9c, which is defined inside the decanter tank 9 and makes it possible to convey at least a part of the cleaning liquid arriving in the decanter tank 9 toward the bottom of the decanter tank, substantially proximate to which the entry point 16a of the coalescence filter 16 is arranged.

It should be noted that the outflow 9b of the decanter tank 9 is arranged, conveniently, above the outflow 16b of the coalescence filter 16 and, in any case, in the upper part of the decanter tank 9, so that the supply tank 4 can receive the cleaning liquid from the decanter tank 9 by skimming, through the connecting duct 12.

Advantageously, the mechanical filter 4 can be provided with means of washing against the current, which can be, conveniently, managed, by way of sensors, automatically.

For example, as illustrated, in particular, in Figure 3, such means of washing against the current comprise a circuit 17 for backwashing the mechanical filter 14, which is connected to the decanter tank 9 conveniently by way of the interposition of the pump 13.

Such backwashing circuit 17 has, for example, a backwashing duct 18 which is connected to an offtake port 18a defined in the decanter tank 9, conveniently downstream of the outflow 16b of the coalescence filter 16, and to at least one backwashing port 14a, which is provided in the mechanical filter 14 for the entry of the cleaning liquid used for the backwashing of the mechanical filter 14.

Alternatively, it is also possible that the backwashing duct 18 can optionally draw at its inflow point from an offtake port defined in the supply tank 4, instead of in the decanter tank 9, so as to have a cleaning liquid that is cleaner, so as to improve the efficacy of the operation of backwashing the mechanical filter 14.

The backwashing circuit 1 7 is completed by a discharge duct 19, which extends from an outflow port 14b of the mechanical filter 14 and which leads into the collection tank 7, for example downstream of the strainer filter 15.

Advantageously the pump 13 is of the centrifuge type, with variable supply, so as to make it possible to adapt its operation to the step of recycling the cleaning liquid or to the step of backwashing the mechanical filter 14.

Advantageously, in order to facilitate the filling of the tank on the machine with water, there is a single water loading manifold 20, which conveniently can be connected to the water mains and is connected to the collection tank 7, to the decanter tank 9 and to the supply tank 4, by way of respective connection branches 20a.

Conveniently, in order to instead allow a rapid emptying of the tanks of the machine, there is a single discharge manifold 21 , to which are connected, with respective emptying connectors 22a, 22b, 22c, the collection tank 7, the decanter tank 9 and the supply tank 4.

Advantageously, inside the decanter tank 9 there is at least one flocculating agent, which is, conveniently, introduced into the decanter tank 9 through an access port 23 thereof, which is defined, for example, in an upward region and can be closed by way of a lid 23a.

For example, the flocculating agent can be constituted by adapted polymers and/or salts of polyvalent metals capable of facilitating the coalescence of the particles of material removed from the floor and present in the cleaning liquid picked up by the aspiration device 6.

It should be noted that the cleansing action and the flocculating action can be carried out by two separate products to be mixed at the time of use, or it can be obtained with a single product, perfectly balanced with specific characteristics in each component thereof, which is capable of ensuring a cleansing action with an alkaline pH, for example comprised between 9 and

1 1 , and a flocculating action that is carried out in the period of time available between the arrival of the cleaning liquid recovered from the floor inside the decanter tank 9 and its sending to the supply tank 4.

It should be noted that the use is also possible of deodorant agents, which are capable of controlling the odors deriving from the decomposition of the gathered dirt.

Advantageously, the flow of the cleaning liquid between the different tanks of the machine is controlled by way of a plurality of valves, which, conveniently, can be actuated pneumatically, by way of compressed air produced by a compressor installed on board the machine.

More specifically, as can be seen in Figure 2, along the connecting line

1 1 there are, for example, an inflow valve 24, which is adapted to control the inflow of the mechanical filter 14, and an outflow valve 25, which is adapted to control the outflow of the mechanical filter 14.

Interposed between the supply tank 4 and the dispensing device 3 there is, conveniently, a delivery valve 26.

As can be seen in Figure 3, along the circuit 17 for backwashing the mechanical filter 14 there are one or more backwashing valves 27a, 27b, which are interposed along the backwashing duct 18 and are adapted to control a respective port 14a for backwashing the mechanical filter 14, and at least one drainage valve 28 which is adapted to control the outflow from the mechanical filter 14 through its discharge duct 19.

Conveniently, a filling valve 29 controls the water loading manifold 20, by permitting its connection to the water mains, while respective emptying valves 30a, 30b, 30c are adapted to intercept the emptying connectors 22a, 22b, 22c respectively of the collection tank 7, of the decanter tank 9 and of the supply tank 4.

Advantageously, arranged in the' individual tanks 4, 9 and 7 are level sensor means, which are constituted for example by floats that make it possible to carry out the adjustment of the maximum and minimum filling levels of said tanks and the intervention of the pump 13.

Preferably, the floats are functionally connected to automatic means of control of the machine, which are constituted for example by an electronic controller and are adapted to actuate the automatic activation/deactivation of the means of recycling the cleaning liquid as a function of the signals coming from the floats, by way of the actuation of the valves and of the pump 13.

Conveniently, at a user interface of the machine, there can be an indicator light, also not shown, which is functionally connected to the floats, in order to alert the user to the need to manually restore, by way of loading water, the correct level of cleaning liquid in the collection, decanter and supply tanks 7, 9 and 4, following losses owing to evaporation and absorption by the floor.

Operation of the machine according to the invention is the following. Initially, the user fills the supply tank 4, the collection tank 7 and the decanter tank 9 by connecting the loading manifold 20 to the water mains. The level of water reached inside the tanks 4, 7 and 9 is monitored by the floats positioned inside said tanks.

At this point, the user adds the specific product, with detergent and flocculation characteristics, according to a preset dosage, for example by pouring it into the decanter tank 9 through its access port 23.

Once the machine has been prepared in this manner, the user can proceed to start the work phase.

In particular, after bringing the machine to the work area, the user proceeds to actuate the washing assembly 2, so as to activate the brushes 5 and the device 3 for dispensing the cleaning liquid, and proceeds to actuate the aspiration device 6, by way of activating the aspiration motor 6b. By way of the delivery valve 26, the user controls the flow of cleaning liquid fed by the dispensing device 3.

In this manner, during the movement of the machine on the floor to be cleaned, the cleaning liquid delivered by the dispensing device 3 onto the floor is picked up by the aspiration device 6 and is gathered in the collection tank 7 where it undergoes a first filtration by the strainer filter 15, which separates the coarser particles of dirt from the collected cleaning liquid.

The activation of the means of recycling the cleaning liquid occurs automatically under the control of the electronic controller, in response to the signals coming from the adapted floats positioned in the tanks 4, 7 and 9.

In particular, the electronic controller activates the pump 13 so as to convey the cleaning liquid collected inside the collection tank 7 by the aspiration device 6 and filtered through the strainer filter 1 5 toward the decanter tank 9, making it pass through the mechanical filter 14, which carries out a finer filtration than the strainer filter 15.

The cleaning liquid thus sent to the decanter tank 9 is channeled toward the bottom of the decanter tank 9 so that it can pass through, by rising back upward, the coalescence filter 16 which performs a separation of the greasy and oily component of the dirt.

From the upper part of the decanter tank 9 the cleaning liquid, which is now clean and substantially clear, arrives at the supply tank 4 by skimming, through the connecting duct 12, so that it can be fed anew by the dispensing device 3 onto the floor.

If necessary, the activation of the circuit 17 for backwashing the mechanical filter 14 can also occur automatically under the command of the electronic controller, which activates the pump 13 and controls the opening of the backwashing valves 27a, 27b and of the drainage valve 28.

If the indicator light lights up to signal the need to restore the level of the water, the user interrupts work, moves to the loading station and connects the loading manifold, and hence the tanks 4, 7 and 9, to the water mains. In this case also, the floats make it possible to monitor the fill level reached in the various tanks 4, 7 and 9. Once the correct level of cleaning liquid has been restored, the user can resume work.

Once cleaning of the floor has been completed, the user stops the washing assembly 2 and the aspiration device 6 and proceeds to restore the levels of the water in the tanks 4, 7 and 9 and to remove and wash the strainer filter 15 and to reposition it in its seat inside the collection tank 7.

At the end of every weekly work cycle, the user empties the three tanks 4, 7 and 9 by opening the emptying valves 30a, 30b, 30c and washes them with a water jet.

Furthermore, the user removes the strainer filter 15 so as to be able to wash it and, then, repositions it in the collection tank 7.

From the foregoing description it can be seen that the invention is capable of fully achieving the set aim in that it makes it possible to carry out an optimal recycling of the cleaning liquid.

Another advantage of the machine according to the invention consists of the increase in productivity, in that it makes it possible to eliminate the machine stops that are necessary in order to empty and fill the supply tank and the collection tank and which would require times that range from 15% to 20% of the time spent on-site for machine models of this type.

Another advantage of the present invention consists of the significant reduction (over 60%) in the quantity of waste to be disposed of.

Furthermore, the machine according to the invention enables a drastic reduction of the consumption of water thanks to the valid reuse of the starting quantity of cleaning liquid and to the fact that it requires the tanks to be cleaned at the end of the weekly work cycle and not after each daily use.

Another important advantage of the machine according to the invention consists in that it washes the floor using a cleaning liquid which is clear even after several operating cycles, thanks to the peculiar methods of treatment of the recovered cleaning liquid. This aspect, in addition to ensuring a high level of hygiene of the cleaning operation, makes it possible to avoid leaving dark patinas on light-colored floor surfaces.

Last but not least, an advantage of the invention is its exceptional flexibility, which renders the method of recycling the cleaning liquid usable in applications in different sectors including large-scale retail.

All the characteristics of the invention, indicated above as advantageous, convenient or similar, may also be missing or be substituted by equivalent characteristics.

The individual characteristics set out in reference to general teachings or to specific embodiments may all be present in other embodiments or may substitute characteristics in such embodiments.

The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

In practice the materials employed, provided they are compatible with the specific use, and the dimensions and shapes, may be any according to requirements and to the state of the art.

Moreover, all the details may be substituted by other, technically equivalent elements.

Where the technical features mentioned in any claim are followed by reference numerals and/or signs, those reference numerals and/or signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference numerals and/or signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference numerals and/or signs.