WO2024125790A1

WO2024125790A1 - Laundry washing machine equipped with a filtering group assembly

Info

Publication number: WO2024125790A1
Application number: PCT/EP2022/085988
Authority: WO
Inventors: Paolo Cescot; Carlo Antonio LEONE; Stefano De Paoli; Marco Pessot; Simone Trangoni; Andrea Zattin; Mattia RUSALEN; Maurizio Del Pos; Andrea Contarini; Marco Maiero
Original assignee: Electrolux Appliances Aktiebolag
Priority date: 2022-12-14
Filing date: 2022-12-14
Publication date: 2024-06-20

Abstract

The invention relates a laundry washing machine (1; 301; 401) comprising an outer cabinet (2), a washing tub (3) containing a washing drum (4) suited to receive the laundry to be washed, a liquid supply system (5) suitable to convey liquid to the washing tub (3), a draining system (20) to drain liquid outside the cabinet (2) and a filtering group assembly (30). The filtering group assembly (30) comprise a housing body (32), an inlet (34) for liquid to be filtered and a main outlet (36) for draining filtered liquid outside the housing body (32). A coarse objects filter device (140) is housed inside the housing body (32) and comprises an objects filter element (144) stopping objects while the liquid flows therethrough. A microparticles filter device (40) is housed inside the housing body (32) and arranged downstream the coarse objects filter device (140) so that the liquid, during the functioning of the filtering group assembly (30), firstly flows through the coarse objects filter device (140) and then through the microparticles filter device (40). The microparticles filter device (40) comprises a microparticles filter element (44) having a filtering surface (46) on which microparticles accumulate while the liquid flows therethrough. The filtering group assembly (30) comprises a cleaning device (50) arranged in a gap (25) formed between the coarse objects filter device (140) and the microparticles filter element (44), wherein the cleaning device (50) comprises a wiper (51) for removing microparticles that accumulate on the filtering surface (46) by means of a relative movement between the wiper (51) and the microparticles filter element (44). Microparticles removed from the filtering surface (46) are moved towards a storage volume (61) of a collecting chamber (60) removably associated to the housing body (32).

Description

LAUNDRY WASHING MACHINE EQUIPPED WITH A FILTERING GROUP ASSEMBLY

FIELD OF THE INVENTION

The present invention concerns the field of laundry washing techniques.

Specifically, the invention relates to a laundry washing machine equipped with a filtering group assembly, in particular comprising a microparticles filter device.

BACKGROUND ART

Nowadays the use of laundry washing machines, both “simple” laundry washing machines (i.e. laundry washing machines which can essentially wash, rinse and spin laundry) and laundry washing-drying machines (i.e. laundry washing machines which, in addition to a washing treatment, can also dry laundry by means of a drying airflow), is widespread.

In the present description the term “laundry washing machine” will refer to a simple laundry washing machine or a laundry washing-drying machine.

As known, in a laundry washing machine, laundry to be washed is received in a rotatable washing drum contained in a washing tub.

It is known that during laundry washing cycles, laundry undergoes to mechanical and/or chemical treatments inside the washing drum with the use of a washing liquor, typically water with the possible addition of washing/rinsing products such as detergent, softener, rinse conditioner, etc.

Laundry to be treated in a laundry washing machine typically comprises clothes and linens made of natural or synthetic fabrics. During washing and/or rinsing treatments, laundry loses tiny particles, called microparticles or microfibers. In particular, clothes comprising synthetic materials lose tiny plastic particles fibres, called microplastics, which are non-biodegradable.

Microparticles/microplastics end up in the wastewater drained from the laundry washing machine and eventually end up in the environment contributing to environmental pollution. For example, microplastics washed off from laundry greatly contribute to plastic that is polluting seas and oceans.

Different solutions have been proposed in known laundry washing machines by arranging a microparticles filter to capture microparticles and reduce their drainage in the wastewater.

In a first type of known systems, the microparticles filter is placed outside the machine along the draining hose that is connected to a drainage point.

In different embodiments of known systems, the microparticles filter is placed along a proper hydraulic line inside the machine.

A first known system for microparticles filtration used in laundry washing machine is disclosed in W02020089727A1. Here an assembly comprising a microparticles filter group is positioned along a drainage hose and a filter body houses the filter group. The assembly is made in cylindrical shape and is insertable/removable as a cartridge through an opening made on an outer washing machine wall to allow maintenance and replacement operations of the filter group.

The filter group comprises a cylindrically shaped filter medium for synthetic microfibers and, according to a preferred embodiment, it further comprises a safety pre-filter fluidically positioned upstream of the filter medium. The pre-filter is arranged internally and coaxially to said filter medium.

A second known system for microparticles filtration used in a laundry washing machine is disclosed in W02019081013A1. Here a microparticles filter is arranged along a re-circulation line that takes liquid from the bottom of the washing tub and conveys the same in an upper point of the same washing tub.

The microparticles filter comprises a filtering element, or filter membrane, arranged in a filtering chamber of the filter. According to some embodiments disclosed therein, a cleaning device is movably arranged in the filtering chamber for removing microparticles that accumulate on the filter membrane. Microparticles removed from the filter membrane by the cleaning device are pushed towards a microparticles collecting chamber arranged at a side of the filtering chamber and separated therefrom. Removed microparticles enter the microparticles collecting chamber through an opening closed by a controllable flap. The collecting chamber is then accessible from outside to a user via a door realized on the outer cabinet of the machine so that it can be removed manually.

It is an aim of the present invention to optimize a filtering system in a laundry washing machine.

It is an object of the invention to provide a laundry washing machine that reduces constructional complexity of filtering system equipping the machine.

It is another object of the present invention to provide a solution that makes maintenance operations of the laundry washing machine more comfortable compared to known systems.

A further object of the present invention is to provide a solution that allows maintenance of filtering element/s, such as cleaning or replacing operations of the filtering element/s.

Another object of the present invention is to develop a filtering system in a laundry washing machine that assures easy accessibility to the filtering elements during maintenance.

DISCLOSURE OF INVENTION

Applicant has found that by providing a laundry washing machine equipped with a filtering group assembly comprising a coarse objects filter device having an objects filter element stopping objects while liquid flows therethrough and a microparticles filter device arranged downstream said coarse objects filter device and having a microparticles filter element having a filtering surface on which microparticles accumulate while liquid flows therethrough and by providing a cleaning device arranged in a gap formed between said coarse objects filter device and said microparticles filter element it is possible to reach the mentioned objects. In a first aspect thereof the present invention relates, therefore, to a laundry washing machine comprising:

- an outer cabinet;

- a washing tub containing a washing drum suited to receive the laundry to be washed;

- a liquid supply system suitable to convey liquid to said washing tub;

- a draining system to drain liquid outside said cabinet;

- a filtering group assembly arranged in a flow path between said water supply system and said draining system; said filtering group assembly comprising:

- a housing body;

- an inlet for liquid to be filtered and a main outlet for draining filtered liquid outside said housing body, wherein liquid passing through said filtering group assembly flows from said inlet towards said main outlet;

- a coarse objects filter device housed inside said housing body and comprising an objects filter element stopping objects while said liquid flows therethrough;

- a microparticles filter device housed inside said housing body and arranged downstream said coarse objects filter device so that said liquid, during the functioning of said filtering group assembly, firstly flows through said coarse objects filter device and then through said microparticles filter device, said microparticles filter device comprising a microparticles filter element having a filtering surface on which microparticles accumulate while said liquid flows therethrough; wherein said filtering group assembly comprises a cleaning device arranged in a gap formed between said coarse objects filter device and said microparticles filter element, said cleaning device comprising a wiper for removing microparticles that accumulate on said filtering surface by means of a relative movement between said wiper and said microparticles filter element, said relative movement causing microparticles removed from said filtering surface to be moved towards a storage volume of a collecting chamber removably associated to said housing body.

Advantageously, the coarse objects filter device prevents undesirable objects to reach a pump causing a potential damage thereto and liquid is subjected to a filtration process by the microparticles filter device preventing microparticles leaving the laundry washing machine before the liquid reaches a drainage outside the machine. The operation time of the filtering group assembly, before a maintenance intervention by a user is required, is advantageously prolonged by the wiper action that substantially restores substantially the full efficiency of the filtering surface of the microparticles filter element after removal of the microparticles accumulated thereon.

Further advantageously, the provision of a collecting chamber where microparticles removed from the filtering surface of the microparticles filter element are stored allows the laundry washing machine to operate for several laundry treatment cycles without requiring any user intervention, the interaction of the user with the filtering group assembly has therefore a relatively long periodicity.

In a preferred embodiment, a coarse objects filter device according to the invention extends along a main axis and/or a microparticles filter device according to the invention extends along said main axis.

This allows an efficient use of the space available within the outer cabinet of a laundry washing machine and provides for a filtering surface of appropriate extension.

It has to be noted that throughout the description the expression “main” axis is used to indicate the axis of a device, or a component in general, among any possible axes of the same device around which a prevalent part of the device extends.

According to a preferred embodiment, an objects filter element according to the invention and/or a microparticles filter element according to the invention have a tubular shape, preferably a cylindrical tubular shape.

This allows to limit the extension of the filtering surface along its main axis while ensuring an appropriate surface size.

In a preferred embodiment, an objects filter element according to the invention and a microparticles filter element according to the invention are coaxially arranged one to the other.

This allows to limit the overall size of the filtering group assembly so as to be easily placed within the volume defined by the laundry washing machine outer cabinet. In addition, advantageously, it is possible to use more efficiently the space available inside the housing body of the filtering group assembly.

Preferably, an objects filter element according to the invention has walls delimiting an objects filter volume and a microparticles filter element according to the invention has walls delimiting a microparticles filter volume, wherein the majority of one between said objects filter volume or said microparticles filter volume is contained within the other.

According to a preferred embodiment, a collecting chamber according to the invention is arranged at a side of said gap and in communication therewith.

In this way the movement and accumulation of microparticles removed from the filtering surface of the microparticles filter and collected into the collecting chamber are made efficient.

In a preferred embodiment, a collecting chamber according to the invention is embodied as a cap for closing an opening provided in said housing body.

A cap can be easily handled by a user and removed from the housing body of the filtering group assembly.

According to a preferred embodiment, the main outlet is arranged radially outwardly with respect to the inlet so that liquid flowing through a filtering group assembly according to the invention flows radially outwardly from the inlet towards the main outlet.

According to another preferred embodiment, the inlet is arranged radially outwardly with respect to the main outlet so that liquid flowing through a filtering group assembly according to the invention flows radially inwardly from the inlet towards the main outlet.

In a preferred embodiment, a microparticles filter element according to the invention is removably arranged in the housing body and/or an objects filter element according to the invention is removably arranged in the housing body.

To enhance the filtering group assembly periodical cleaning, especially after a number of wiping actions carried out by the wiper onto the filtering surface of the microparticles filter element, the latter may be extracted so as to allow the user to proceed to a manual cleaning process so as to remove particles that might not be removed by the wiping action of the wiper.

In an embodiment, advantageously, an objects filter element according to the invention may be extracted out from the filtering chamber and from the housing body for a proper cleaning process or substitution, if necessary.

In a preferred embodiment, an opening is provided in the housing body and wherein a microparticles filter element according to the invention and/or an objects filter element according to the invention are extractable from housing body by passing through said opening.

Advantageously, the microparticles filter element and/or the objects filter element are easily extracted out from the housing body through the opening provided in the housing body. Such opening reduces dispersion of liquid and microparticles during the microparticles filter element and/or the objects filter element extraction process.

In further preferred embodiments, a microparticles filter element according to the invention and/or an objects filter element according to the invention may be configured to be not removable from the housing body of the filtering group assembly.

Advantageously, maintenance intervention for the microparticles filter element and/or for the objects filter element is avoided. In case of damage of the microparticles filter element and/or of the objects filter element, the whole filtering group assembly may be substituted.

According to a preferred embodiment, a wiper according to the invention is a movable wiper.

In a preferred embodiment, a wiper according to the invention is a rotatably movable wiper.

In another embodiment, a wiper according to the invention is a translatable wiper, said translatable wiper preferably comprising a piston. According to a preferred embodiment, a wiper according to the invention comprises a worm extending along a main axis, said worm comprising a helixshaped element that winds around said main axis.

In an embodiment of the invention, advantageously, the movable wiper wipes a side of the filtering surface of the microparticles filter element and moves microparticles towards the collecting chamber, acting as a worm conveyor.

A worm allows to wipe a wide area of the microparticles filter element filtering surface when a relative movement between the wiper and the microparticles filter element occurs.

In a preferred embodiment, a helix- shaped element according to the invention is connected to a coarse objects filter device according to the invention, preferably directly fixedly connected to an objects filter element according to the invention. The connection of the said helix- shaped element with the coarse objects filter device makes a user intervention for periodical cleaning or inspection of the filtering group assembly easier.

Preferably, a coarse objects filter device according to the invention is arranged inside a microparticles filter element according to the invention, wherein a helixshaped element according to the invention outwardly extends from a radially outer surface of the objects filter element and towards the microparticles filter element. According to a preferred embodiment, a microparticles filter element according to the invention is arranged inside a coarse objects filter device according to the invention, wherein a helix- shaped element according to the invention inwardly extends from a radially inner surface of the objects filter element and towards the microparticles filter element.

In a preferred embodiment, a coarse objects filter device according to the invention is rotatable.

In an embodiment of the invention wherein the said helix- shaped element is connected to said coarse objects filter device and a rotation of the latter causes a rotation of the helix-shaped element advantageously produces a movement that compacts the filtered material filtered and make its removal form the filtering group assembly easier.

Preferably, a washing machine according to the invention comprises an actuating device for moving a cleaning device according to the invention.

In an embodiment of the invention, advantageously, the cleaning device may be moved either by a mechanical driving device actuated by a user or by an electrical motor.

According to a preferred embodiment, an actuating device according to the invention comprises a handle or a crank or an automated actuating device.

In a preferred embodiment, a microparticles filter element according to the invention is a movable element, preferably a rotatable element.

Moving of the microparticles filter element allows its filtering surface to be cleaned from microparticles accumulated thereon.

Preferably, in an embodiment of the invention, if the laundry washing machine includes at least the feature that the inlet is arranged radially outwardly with respect to the main outlet, a filtering group assembly according to the invention further comprises a removal coarse materials aid system apt to move objects stopped by an objects filter element according to the invention towards an opening provided in the housing body, wherein the majority of a microparticles filter volume according to the invention is contained within an objects filter volume according to the invention.

The provision of a removal coarse materials aid system allows to simplify the cleaning operations of the filtering group assembly that the user may need to periodically perform. Moving objects stopped by the objects filter element towards an opening allows a user to easily reach those objects and remove them from the filtering group assembly.

According to a preferred embodiment, a removal coarse materials aid system according to the invention comprises a worm extending along a main axis, said worm comprising a helix- shaped element that winds around said main axis.

In a preferred embodiment, a helix- shaped element according to the invention is connected to a coarse objects filter device according to the invention, preferably directly fixedly connected to a objects filter element according to the invention. Preferably, said worm outwardly extends from the radially outer surface of a objects filter element according to the invention.

According to a preferred embodiment, a cleaning device according to the invention and a collecting chamber according to the invention are removably coupled one another, so that when the collecting chamber is removed from the housing body the collecting chamber is disconnected from the cleaning device.

Advantageously, disconnecting the collecting chamber from the cleaning device allows the user to handle a relatively small member of the filtering group assembly thereby avoiding too demanding operations to periodically maintain the filtering group assembly.

In a further preferred embodiment, a cleaning device according to the invention and a collecting chamber according to the invention are removably connected one another so that they can be disconnected one from the other after being unitarily removed from said housing body.

In another embodiment of the invention the collecting chamber may be the means through which the cleaning device can be removed from the housing body of the filtering group assembly. In this way the user does not need to interact directly with the cleaning device for its removal, thereby handling substantially a clean element when the filtering group assembly has to be maintained.

Preferably, a microparticles filter device according to the invention is a filter suitable to filter particles having a minimum dimension comprised between 0,1 pm and 5mm, preferably a minimum dimension comprised between 10pm and 100pm, more preferably a minimum dimension comprised between 10pm and 75pm.

Advantageously, the microparticles filter device is suitable to retain particles present in the waste liquid produced by mechanical and/or chemical treatments of the laundry inside the washing drum, preferably tiny plastic particles released by the laundry, also indicated as microplastics, which are non-biodegradable.

According to a preferred embodiment, a coarse objects filter device according to the invention has a meandering structure or a grid structure retaining objects having a prevalent dimension that is higher than 5mm.

Advantageously the coarse objects filter device is provided for causing objects dispersed in a liquid to be entrapped by a meandering, or labyrinthic, structure through which the liquid passes. Objects that can be stopped by the coarse objects filter device have a dimension prevailing over the others and are, in general, rigid objects such as metal, wood or polymeric elongated objects. Typical objects that are stoppable by the coarse objects filter device are: needles, coins, buttons, staples, i.e. all those objects that cannot freely follow a meandering path of a liquid flow without interacting with the walls defining said path.

In a preferred embodiment, a filtering group assembly according to the invention is arranged in the draining system.

Arranging the filtering group assembly in the laundry washing machine draining system prevents the machine to release microparticles to the ambient thereby avoiding contributing to pollute oceans and seas with foreign objects.

Preferably, the liquid supply system according to the invention includes at least one recirculation system for draining liquid from a bottom region of the washing tub to supply said liquid to a second region of the washing tub.

Advantageously, a recirculation system allows to improve the efficiency of a laundry treating process thereby reducing the overall treating process duration and consequently the generation of microparticles detaching from laundry fabrics.

According to a preferred embodiment, the outer cabinet of the machine further comprises an aperture so that the collecting chamber of the filtering group assembly is accessible therefrom.

Advantageously, the provision, within the volume defined by the outer cabinet of a laundry washing machine, of a filtering group assembly which can be accessed from outside the cabinet avoids a user to install the filtering group assembly on a side of the laundry washing machine and hydraulically connecting the latter to the filter.

In a preferred embodiment, the outer cabinet further comprises an openable door associated to said aperture.

The provision of an openable door to cover the aperture for accessing the filtering group assembly contributes to enhance the aesthetic of the laundry washing machine and to protect the filtering group assembly from any undesired interaction.

Preferably, a filtering group assembly according to the invention further comprises a second outlet which is hydraulically connected to a hydraulic circuit portion of said washing machine located upstream the filtering group assembly.

In a preferred embodiment, the second outlet is provided in a liquid stagnation or sump portion of said housing body.

Advantageously, residue liquid inside the housing body may be expelled through the second outlet and discharged out of the housing body. The housing body thus remains completely emptied and advantageously gets dry.

Furthermore, advantageously, removal of any residue liquid in the housing body avoids proliferation of bacteria and/or yeasts thus improving hygienic conditions and preventing bad smells. In addition, maintenance operations of the filtering group assembly are improved by having a user interacting with dry components of the filtering group assembly thereby avoiding liquid dropping from the assembly during its periodical maintenance.

According to a preferred embodiment, said draining system comprises a conduit adapted to be connected to a tub outlet port, a draining pump hydraulically connected to said conduit, and an outlet pipe, arranged downstream said draining pump, ending outside said outer cabinet, said filtering group assembly being either arranged in said conduit between the tub outlet port and said draining pump or in a portion of said outlet pipe.

In a preferred embodiment, said draining system comprises a draining pump and a further coarse objects filter device arranged upstream said draining pump.

Advantageously, the further objects filter device prevents undesirable objects to reach the draining pump causing a potential damage thereto, in particular when filtering group assembly is arranged downstream the draining pump.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will be highlighted in greater detail in the following detailed description of some of its preferred embodiments, provided with reference to the enclosed drawings. In the drawings, corresponding characteristics and/or components are identified by the same reference numbers. In particular:

- Figure 1 shows a frontal view of a laundry washing machine equipped with a filtering group assembly according to a first embodiment of the invention;

- Figure 2 shows a schematic view of the laundry washing machine of Figure 1 ;

- Figure 3 shows an isometric view of a filtering group assembly according to the first embodiment of the invention;

- Figure 4 shows a first lateral view of the filtering group assembly of Figure 3;

- Figure 5 shows a second lateral view of the filtering group assembly of Figure 3;

- Figure 6 is a longitudinal cross section of the filtering group assembly of figure 5;

- Figure 7 shows the filtering group assembly of Figure 6 in a first operating position;

- Figure 8 shows an exploded view of the filtering group assembly of Figure 6;

- Figure 9 shows an element of the filtering group assembly of Figure 8 isolated from the rest;

- Figure 10 shows the filtering group assembly of Figure 5 in a possible mounting configuration in a laundry washing machine;

- Figure 11 is a longitudinal cross section of the filtering group assembly of figure 10 in a first operating position; - Figure 12 shows a longitudinal sectional view of a further embodiment of the filtering group assembly of the invention in a first operating position;

- Figure 13 shows the filtering group assembly of Figure 3 provided with an actuating device;

- Figure 14 shows a partial exploded view of Figure 13;

- Figure 15 shows the filtering group assembly of Figure 3 provided with another type of actuating device;

- Figure 16 shows a cross section of a further embodiment of the filtering group assembly of Figure 6;

- Figure 17 shows the filtering group assembly of Figure 16 in a first operating position;

- Figure 18 shows an exploded view of the filtering group assembly of Figure 16;

- Figure 19 shows an isometric view of a further embodiment of the filtering group according to an aspect of the invention;

- Figure 20 shows a first lateral view of the filtering group assembly of Figure 19;

- Figure 21 is a cross section along line XXI°-XXI° of the filtering group assembly of figure 20 wherein some components inside the filtering group assembly have been removed;

- Figure 22 shows a cross section of a further embodiment of the filtering group according to an aspect of the invention;

- Figure 23 shows an exploded view of the filtering group assembly of Figure 22;

- Figure 24 shows a cross section of an element of the filtering group assembly of Figure 23 isolated from the rest;

- Figure 25 shows a cross section of a further embodiment of the filtering group according to an aspect of the invention;

- Figure 26 shows the filtering group assembly of Figure 25 in a first operating position;

- Figure 27 shows an exploded view of the filtering group assembly of Figure 25;

- Figure 28 shows a cross section of an element of the filtering group assembly of Figure 27 isolated from the rest;

- Figure 29 shows a cross section of a further embodiment of the filtering group according to an aspect of the invention;

- Figure 30 shows an exploded view of the filtering group assembly of Figure 29;

- Figure 31 shows a cross section of an element of the filtering group assembly of Figure 30 isolated from the rest; - Figure 32 shows a schematic isometric view of some elements of a further embodiment of the filtering group according to an aspect of the invention;

- Figure 33 shows an exploded view of Figure 32;

- Figure 34 shows a longitudinal cross section of Figure 32;

- Figure 35 shows a schematic view of the laundry washing machine of the invention according to a further embodiment of the invention;

- Figure 36 shows a further embodiment of the laundry washing machine of Figure 35.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

As described below, the present invention has proved to be particularly advantageous when applied to laundry washing machines, i.e. appliances able to carry out at least a washing process on laundry and also to laundry washing-drying machines, i.e. appliances able to perform not only a washing process but also a drying process on laundry.

With reference to Figures 1 and 2, a preferred embodiment of a laundry washing machine 1 according to the invention is described.

The laundry washing machine 1 preferably comprises an external casing or outer cabinet 2, a washing tub 3, a container 4, preferably a perforated washing drum 4, where the laundry to be treated can be loaded.

The cabinet 2 preferably comprises a front side wall 2a, visible in Figure 1, laterals side walls, and upper side wall and preferably, although not necessarily, a lower side wall (not visible).

The washing tub 3 and the washing drum 4 both preferably have a substantially cylindrical shape.

The cabinet 2 at its front side wall 2a is preferably provided with a loading/unloading door 8 which allows access to the washing drum 4.

The washing drum 4 is advantageously rotated by an electric motor, as known in the art, which preferably transmits the rotating motion to the shaft of the washing drum 4, advantageously by means of a belt/pulley system. In a different embodiment of the invention, the motor can be directly associated with the shaft of the washing drum 4, without the need of a transmission belt.

The washing drum 4 is advantageously provided with holes or apertures which allow the liquid flowing therethrough. Said holes are typically and preferably homogeneously distributed on the cylindrical side wall of the washing drum 4.

The bottom region 3a of the washing tub 3 preferably comprises a seat 15, or sump, suitable for receiving a heating device 10. The heating device 10, when activated, heats the liquid collected inside the sump 15.

In further embodiments, other type of heating devices may be advantageously placed in the machine 1 to heat liquid.

Preferably, the laundry washing machine 1 comprises a device 19 suited to sense (or detect) the liquid level inside the washing tub 3.

The sensor device 19 preferably comprises a pressure sensor which senses the pressure in a chamber formed in, or connected to, the washing tub 3. Such chamber can be partially filled by the liquid contained in the washing tub 3, thereby modifying the pressure in the unfilled portion of said chamber. From the pressure values sensed by the sensor device 19 it is possible to determine the liquid level of the liquid inside the washing tub 3. In another embodiment, not illustrated, laundry washing machine may preferably comprise (in addition to or as a replacement of the pressure sensor) a level sensor (for example mechanical, electro-mechanical, optical, etc.) adapted to sense (or detect) the liquid level inside the washing tub 3. A liquid (water) supply system 5 is preferably arranged in the upper part of the laundry washing machine 1 and is suited to supply water into the washing tub 3 from an external water supply line E. The water supply system 5 preferably comprises a controlled supply valve 5a which is properly controlled, opened and closed, during a washing cycle or a drying cycle, to properly carry out all the phases thereof. The water supply system of a laundry washing machine is well known in the art, and therefore it will not be described in detail.

Liquid supply system refers, in general, to any system apt to supply water or any liquid into the tub.

The laundry washing machine 1 advantageously comprises a treating agent dispenser 14 to supply one or more treating agents into the washing tub 3 during a washing cycle or a drying cycle. Treating agents may comprise, for example, detergents, rinse additives, fabric softeners or fabric conditioners, waterproofing agents, fabric enhancers, rinse sanitization additives, chlorine-based additives, etc. Preferably, the treating agent dispenser 14 comprises a removable drawer 6 provided with various compartments suited to be filled with the treating agents.

In the preferred embodiment here illustrated, the water is supplied into the washing tub 3 from the water supply system 5 by making it flow through the treating agent dispenser 14 and then through a supply pipe 18. The provision of one or more treating agents to the washing tub 3 may be performed by automatically dosing an amount of an agent before delivering it to the washing tub 3. Such dosage is preferably performed by a dosing device having metering means for measuring a desired amount of an agent to be taken from a treating agent storage and delivered to the washing tub 3.

In an alternative embodiment of the invention, a further separate water supply pipe can be provided, which supplies exclusively clean water into the washing tub from the external water supply line.

In further preferred embodiments, not illustrated herein, a water softening device may preferably be arranged/interposed between the external water supply line and the treating agent dispenser so as to be crossed by the fresh water flowing from the external water supply line. The water softening device, as known, is structured for reducing the hardness degree of the fresh water drawn from the external water supply line and conveyed to the treating agent dispenser.

In a different embodiment, the water softening device may be arranged/interposed between the external water supply line and the washing tub, so as to be crossed by the fresh water flowing from the external water supply line and conveying it directly to the washing tub.

A laundry washing machine 1 according to the invention, advantageously comprises a control unit 11 which is in signal and/or electrical communication to the various operational parts of the laundry washing machine 1 such as drum motor, sensors, etc., in order to ensure its operation for carrying out a laundry treating program. The control unit 11 is advantageously connected also to an interface unit I la which is accessible to the user and by means of which the user selects and sets the washing and/or drying parameters from time to time, in particular a desired laundry washing and/or drying program.

A laundry washing machine 1 according to the invention, preferably comprises a draining system 20 to drain liquid outside the cabinet 2 up to a drainage point (not shown). More preferably the draining system 20 withdraws liquid from the bottom region 3 a of the washing tub 3 and drains it outside the cabinet 2.

The draining system 20 preferably comprises a discharging conduit 22 connected to a tub outlet port, for example an outlet port of the sump 15, a draining pump 24 hydraulically connected to the discharging conduit 22 and an outlet pipe 26 ending outside the cabinet 2.

Preferably, the draining pump 24 is a centrifugal pump provided with a rotating component, or impeller, that moves the liquid towards the pump outlet.

According to a first aspect of the invention, a filtering group assembly 30 is arranged in a flow path between the water supply system 5 and the draining system 20.

Preferably, the filtering group assembly 30 is arranged in the draining system 20. More preferably, the filtering group assembly 30 is arranged in the discharging conduit 22 between the tub outlet port and the draining pump 24, i.e. the filtering group assembly 30 is arranged upstream the draining pump 24.

In different preferred embodiments, a filtering group assembly according to the invention may be arranged downstream the draining pump, as better described later.

The filtering group assembly 30 comprises a microparticles filter device 40 for retaining microparticles and a coarse objects filter device 140 for stopping objects having a prevalent dimension that is higher than 5mm.

The coarse objects filter device 140 is preferably adapted to stop objects before they reach, for example, the draining pump 24 in case the filtering group assembly is arranged upstream the draining pump or before they reach, for example, the drainage point outside the cabinet in case the filtering group assembly is arranged downstream the draining pump, as better described later.

The coarse objects filter device 140 preferably has the aim of retaining undesirable objects that may damage a pump, preferably the draining pump 24, for example may damage the impeller in case a centrifugal pump design is used.

Said kind of objects, also indicated hereinafter as coarse materials, have a dimension prevailing over the others and are, in general, rigid objects such as metal, wood or polymeric elongated objects and may comprise, for example, needles, coins, buttons, staples, screws, paper clips, pieces of clothes, etc.

The microparticles filter device 40 is a filter suitable to retain particles having a minimum dimension comprised between 0,1pm and 5mm, preferably a minimum dimension comprised between 10pm and 100pm, more preferably a minimum dimension comprised between 10pm and 75pm.

Particles of this type are typically present in the waste liquid produced by mechanical and/or chemical treatments of the laundry inside the washing drum 4 as tiny particles are released by the laundry. In particular, laundry comprising synthetic materials loses tiny plastic particles fibres, also indicated as microplastics, which are non-biodegradable.

The microparticles filter device 40, therefore, advantageously acts as a microplastics filter device 40.

The coarse objects filter device 140, as said above, is preferably adapted to stop coarse materials. At the same time, the coarse objects filter device 140 allows the passage of microparticles therethrough.

According to a preferred aspect of the invention, therefore, the filtering group assembly 30 prevents coarse materials to reach the draining pump 24 or the drainage point outside the cabinet and liquid is also advantageously subjected to a filtration process preventing microparticles leaving the laundry washing machine 1 before it reaches the drainage point outside the machine 1.

Liquid flowing through the filtering group assembly 30 and that is discharged to the outside through the draining system 20 is therefore advantageously subjected to the action of both the coarse objects filter device 140 and the microparticles filter device 40, as better described later.

An embodiment of a filtering group assembly 30 according to the invention is better described in detail with reference to Figures 3 to 9.

The filtering group assembly 30 preferably shows an elongated shape and preferably extends along a main axis X0. In different embodiments, nevertheless, the filtering group assembly may be differently shaped, for example it may be boxlike shaped, and even not defining any particular main axis of extension.

The filtering group assembly 30 comprises a housing body 32, preferably made of a plastic, i.e. polymeric, material. Thus, the housing body 32 of the filtering group assembly 30 preferably extends between a front side 32a and a rear side 32b thereof. The housing body 32 preferably comprises walls so that to enclose a volume therein. In particular, a rear wall 29 closes the housing body 32 at the rear side 32b thereof.

The microparticles filter device 40 and the coarse objects filter device 140 preferably extend within the same body element, i.e. the housing body 32.

According to a preferred embodiment illustrated in the Figures 1 and 2, the filtering group assembly 30 is preferably arranged in the lower part of the laundry washing machine 1 , more preferably in the lower right side of the laundry washing machine 1.

The filtering group assembly 30 is preferably placed just below the sump 15 and connected thereto by means of a first portion 22a of the discharging conduit 22. The filtering group assembly 30 is preferably placed just above the draining pump 24.

The filtering group assembly 30 preferably comprises an inlet 34 for liquid to be filtered and a main outlet 36 for draining filtered liquid outside the housing body 32. The liquid passing through the filtering group assembly 30 flows from the inlet 34 towards the main outlet 36.

The inlet 34 of the filtering group assembly 30 is preferably connected to the first portion 22a of the discharging conduit 22.

The inlet 34 is preferably arranged at the rear side 32b of the housing body 32 and preferably at the point where the main axis X0, along which the filtering group assembly 30 extends, intersects the rear wall 29 of the housing body 32.

The main outlet 36 of the filtering group assembly 30 is preferably connected to the draining pump 24, preferably through a second portion 22b of the discharging conduit 22.

The main outlet 36 is also preferably arranged at the rear side 32b of the housing body 32.

With reference to the section where liquid passes through the rear side 32b of the housing body 32, the main outlet 36 is preferably arranged radially outwardly with respect to the inlet 34. Liquid passing through the filtering group assembly 30 therefore flows radially outwardly from the inlet 34 towards the main outlet 36. According to a preferred aspect of the invention, the microparticles filter device 40 is arranged downstream the coarse objects filter device 140 so that the liquid during the functioning of the filtering group assembly 30 firstly flows through the coarse objects filter device 140 and then through the microparticles filter device 40. Liquid entering the filtering group assembly 30 by means of the inlet 34 radially exits the coarse objects filter device 140.

The term “downstream” here refers, therefore, to the flowing direction of the liquid that enters the filtering group assembly 30 through the inlet 34 and that reaches the main outlet 36 during the functioning of the filtering group assembly 30.

As said above, the filtering group assembly 30 comprises a microparticles filter device 40 for retaining microparticles.

The microparticles filter device 40 extends along a main axis XI, preferably, but not necessarily, coinciding with the main axis X0 of the filtering group assembly 30. The microparticles filter device 40 is housed in the housing body 32 and comprises a microparticles filter element 44 having a filtering surface 46 at which microparticles accumulate while the liquid flows therethrough.

The microparticles filter element 44 preferably has a tubular shape, more preferably a cylindrical tubular shape. The microparticles filter element 44 preferably extends along said main axis XI. The filtering surface 46 preferably comprises a plurality of meshes 46a, more preferably rectangular meshes 46a (as visible in Figure 8).

Meshes 46a are preferably realized with a woven wire. In a preferred embodiment the wire is made of polyethylene. Said plurality of meshes 46a can be provided by one or more layers of woven wire covering a plurality of openings formed in walls of the microparticles filter element 44. In particular, said walls can be formed by over- injecting a polymeric material on a mesh foil.

Generally, the microparticles filter element 44 has walls delimiting a microparticles filter volume 42, as better visible in Figure 8.

Preferably, the mesh is chosen to have a mesh size configured to retain particles having a minimum dimension comprised between 0,1pm and 5mm, preferably a minimum dimension comprised between 10pm and 100pm, more preferably a minimum dimension comprised between 10pm and 75 pm, as said above.

In a normal operating condition of the microparticles filter device 40, the liquid exiting the coarse objects filter device 140 undergoes to a filtration by passing through the microparticles filter element 44, in particular by passing through meshes 46a. The filtered liquid exiting the microparticles filter element 44 thus reaches an elongated annular chamber 48 that is radially outer the microparticles filter element 44. The elongated annular chamber 48 hydraulically communicates with the main outlet 36 of the filtering group assembly 30 and allows drainage of liquid outside the filtering group assembly 30.

While the liquid flows through the microparticles filter element 44, microparticles progressively accumulate on the filtering surface 46.

As said above, the filtering group assembly 30 also comprises a coarse objects filter device 140 for retaining coarse materials. The coarse objects filter device 140 is located between the inlet 34 for liquid to be filtered and the microparticles filter device 40 so as to intercept all the liquid that enters the filtering group assembly 30.

The coarse objects filter device 140 comprises an objects filter element 144 configured to retain coarse elements when liquid flows therethrough.

The coarse objects filter device 140 preferably extends along a main axis X2, preferably, but not necessarily, coinciding with the main axis X0 of the filtering group assembly 30 and/or coinciding with the main axis XI of the microparticles filter device 40.

The coarse objects filter device 140 is housed in the housing body 32 and comprises an objects filter element 144 stopping coarse materials while said liquid flows therethrough.

The objects filter element 144 preferably has a tubular shape, more preferably a cylindrical tubular shape. The objects filter element 144 preferably extends along said main axis X2.

Generally, the objects filter element 144 has walls delimiting an objects filter volume 43, better visible in Figure 7.

The objects filter element 144 is placed inside the housing body 32 so that the inlet 34 of the filtering group assembly 30 hydraulically communicates with the interior of the objects filter element 144, i.e. with the objects filter volume 43.

The objects filter element 144 preferably has as a grid structure and preferably comprises apertures 146 having proper size to retain objects having a prevalent dimension that is higher than 5mm, for example parallelogram- shaped apertures as shown in the Figures.

In further preferred embodiments, the objects filter element may be configured differently, for example it may have a meandering structure as described with reference to embodiment of Figures 16 and 17.

Preferably, the objects filter element 144 and the microparticles filter element 44 are coaxially arranged one to the other.

According to a first preferred embodiment and as illustrated in Figures 1-9, the objects filter element 144 is arranged inside the microparticles filter element 44. In other words, the objects filter volume 43 delimited by the objects filter element 144 is contained within the microparticles filter volume 42 delimited by the microparticles filter element 44. Preferably, the majority of the objects filter volume 43 is contained within the microparticles filter volume 42.

Advantageously, it is possible to use more efficiently the space available inside the housing body 32. Preferably, therefore, the objects filter element 144 is arranged inside, and coaxially to, the microparticles filter element 44.

A gap 25 is formed between the microparticles filter element 44 and the coarse objects filter device 140. More preferably, the gap 25 is defined between the microparticles filter element 44 and the objects filter element 144. Such gap 25 receives liquid exiting the objects filter element 144 before entering the microparticles filter element 44. Hence, in a configuration wherein both the microparticles filter element 44 and the objects filter element 144 have a tubular shape, said gap 25 is preferably radially outer the objects filter element 144 and radially inner the microparticles filter element 44.

When the draining system 20 operates, with activation of the draining pump 24, the objects filter element 144 of the coarse objects filter device 140 receives liquid coming from the inlet 34 and then liquid undergoes to coarse filtration by passing through the objects filter element 144 with its apertures 146. The filtered liquid thus reaches said gap 25. The coarse objects filter device 140 thus retain in the coarse objects filter volume 43 undesirable objects that may damage the draining pump 24, for example may damage the impeller in case a centrifugal pump design is used.

Liquid exiting the objects filter element 144 then undergoes to the microparticles filtration action by passing through the microparticles filter element 44 and then, once left the microparticles filter element 44, reaches the annular chamber 48. Finally, filtered liquid exits the filtering group assembly 30 through the main outlet 36 and is drained to the outside through the second portion 22b of the discharging conduit 22 and the outlet pipe 26.

Liquid flowing through the filtering group assembly 30 and coming from the inlet 34 thus preferably flows radially outwardly from the inner volume 43 of the filtering group assembly 30, i.e. from the objects filter volume 43, towards the annular chamber 48 and finally up to the main outlet 36.

Liquid flowing through the filtering group assembly 30 and discharged to the outside of the laundry washing machine 1 is thus subjected to the action of both the coarse objects filter device 140 and the microparticles filter device 40. According to an aspect of the invention, the filtering group assembly 30 is equipped with a cleaning device 50 which is configured to remove microparticles that accumulate on the first side of the filtering surface 46 of the microparticles filter element 44 that the liquid encounters when passing through said filtering surface 46. The cleaning device 50 is arranged in the gap 25 between the coarse objects filter device 140 and the microparticles filter element 44.

The cleaning device 50 is configured for moving microparticles removed from the filtering surface 46 towards a storage volume 61 of a collecting chamber 60.

More preferably, the cleaning device 50 is configured for moving microparticles removed from the filtering surface 46 towards the storage volume 61 of the collecting chamber 60 along the main axis XI along which the microparticles filter element 44 extends.

According to another aspect of the invention, the collecting chamber 60 is removably associated to the housing body 32 of the filtering group assembly 30. The collecting chamber 60 is preferably arranged at a side, in particular an end side, of the gap 25 and in communication therewith.

According to a further aspect of the invention, the cleaning device 50 preferably comprises a wiper 51 wiping a side of the filtering surface 46, preferably wiping the first side of the filtering surface 46 that the liquid encounters and where microparticles accumulates during operation of the filtering group assembly 30. Removal of microparticles that accumulate on the filtering surface 46 is obtained by means of a relative movement between the wiper 51 and the microparticles filter element 44.

In the preferred embodiment illustrated in Figures 1-9, the wiping action is obtained by moving the wiper 51, more preferably by rotating the wiper 51, while the microparticles filter element 44 is kept still, as better described later. Hence, the wiper 51 is a movable wiper, in particular a rotatably movable wiper 51.

Preferably, the wiper 51 is embodied as a worm extending along a main axis X3 and having a helix- shaped element 56 that winds around the main axis X3. The helix- shaped element 56 outwardly extends from the radially outer surface of the objects filter element 144 and towards the microparticles filter element 44.

In the preferred embodiment described herein, the main axis X3 preferably coincides with the main axis X2 of the coarse objects filter device 140. While the helix-shaped element 56 rotates, the edge of the helix-shaped element 56 advantageously wipes the filtering surface 46 of the microparticles filter element 44.

In the preferred embodiment illustrated in Figures 1-9, the cleaning device 50 is connected to the coarse objects filter device 140, preferably directly fixedly connected to the objects filter element 144. Preferably the cleaning device 50 is integrally made with the coarse objects filter device 140, more preferably integrally made with objects filter element 144.

In particular, the helix- shaped element 56 is preferably connected to the coarse objects filter device 140, more preferably directly fixedly connected to the objects filter element 144. Preferably, the helix-shaped element 56 is preferably integrally made with the coarse objects filter device 140, more preferably integrally made with the objects filter element 144. Preferably, the helix-shaped element 56 winds around the coarse objects filter device 140 on the radially outer surface thereof, more preferably winds around the objects filter element 144. The helix- shaped element 56 is preferably a circular helix- shaped element 56. According to this embodiment, the helix-shaped element 56 substantially defines a helicoid.

In further preferred embodiments, the wiper may be embodied as a separate device with respect to the coarse objects filter device, as illustrated and described with reference to Figures 32 to 34.

The cleaning effect of the wiper 51 is performed when the wiper 51 is rotated around the main axis X3. During rotation, the helix-shaped element 56 wipes the side of the filtering surface 46 of the microparticles filter element 44 thereby removing microparticles accumulated thereon and, at the same time, it is able to move microparticles towards the storage volume 61 of the collecting chamber 60, eventually acting as a worm conveyor.

Microparticles are therefore collected into the storage volume 61 of the collecting chamber 60 as the wiper 51 rotates. Microparticles removed from the filtering surface 46 are conveyed towards the storage volume 61 of the collecting chamber 60 and towards an opening 37 provided in the housing body 32. The collecting chamber 60 has a storage volume 61 that is preferably sized to store an amount of microparticles that is produced after several laundry washing cycles. In this way the filtering group assembly 30 can operate without the need of emptying the collecting chamber 60 for a relatively long time. Microparticles can be removed from the filtering group assembly 30 by removing the collecting chamber 60 from the housing body 32.

Advantageously, microparticles moved towards the collecting chamber 60 are pressed in the storage area 61 by the action of the helix-shaped element 56. According to the first preferred embodiment illustrated in Figures 1-9, rotation of the wiper 51 is obtained by rotation of the coarse objects filter device 140, in particular of the objects filter element 144, being the wiper 51 connected to the coarse objects filter device 140.

At this purpose, the objects filter element 144 is configured to be rotated around the axis X2. A first end 144a of the objects filter element 144, or rear end 144a, is received in a corresponding supporting seat 45 of the microparticles filter element 44. Preferably, the first end 144a of the objects filter element 144 and the supporting seat 45 of the microparticles filter element 44 are cylindrically shaped. The supporting seat 45 and the rear end 144a of the objects filter element 144 are shaped, for example both cylindrically shaped, and coupled so that the objects filter element 144 may rotate with respect to the supporting seat 45 when the objects filter element 144 and the wiper 51 rotate.

A second end 144b of the objects filter element 144, or front end 144b, is received in a corresponding supporting seat 63 of the collecting chamber 60.

The supporting seat 63 and the second end 144b of the objects filter element 144 are shaped, for example both cylindrically shaped, and coupled so that the objects filter element 144 may rotate with respect to the supporting seat 63 when the objects filter element 144 and the wiper 51 rotate, while the collecting chamber 60 may be disengaged from the objects filter element 144 when the collecting chamber 60 is removed from the housing body 32.

The supporting seat 63 of the collecting chamber 60 preferably opens outwards, i.e. it is a pass-through hole, and the second end 144b of the objects filter element 144 is preferably reachable from outside the filtering group assembly 30.

The second end 144b of the objects filter element 144 is also preferably provided with an actuating seat 145. The actuating seat 145 preferably faces outwards so that it can be reachable from outside the filtering group assembly 30.

Rotation of the objects filter element 144 is preferably obtained through an actuating device 70, for example a flat head screwdriver or a crank or a handle 70 as shown in Figures 13 and 14, that can engage said actuating seat 145. The handle 70 is preferably removably connected to the objects filter element 144 at said actuating seat 145.

Rotation of the actuating device 70, in particular of the handle 70, allows rotation of the objects filter element 144 and of the wiper 51. Hence, when necessary, microparticles are removed from the filtering surface 46 and conveyed towards the storage volume 61 of the collecting chamber 60 through rotation of the handle 70. Said operation is preferably carried out manually by a user when required, for example, after a prefixed number of washing cycles.

In a further preferred embodiment, as illustrated in Figure 15, rotation of the objects filter element 144 may be obtained through an automated actuating device 170, for example a rotatable shaft moved by a motor and engaging the actuating seat 145. The automated actuating device 170 may be preferably controlled by the control unit 11 of the laundry washing machine 1.

The objects filter element 144 and the wiper 51 realized therewith are also configured so that they can be removed from the housing body 32, preferably by extracting the objects filter element 144 along the main axis X2 direction.

As said above, the collecting chamber 60 is configured to be removably associated to the housing body 32. The collecting chamber 60 works as a cap for the opening 37 of the housing body 32 and closes the opening 37 when the collecting chamber 60 is coupled to the housing body 32.

According to a preferred embodiment illustrated in Figures 3-9, the collecting chamber 60 is preferably removably associated to the housing body 32 by a mechanical interference and hence the collecting chamber 60 is preferably removably associated to the housing body 32 by a pushing/pulling action.

In further preferred embodiments, the collecting chamber may be configured to be screwable to the housing body.

Between the collecting chamber 60 and the housing body 32, sealing elements 60a, for example plastic, i.e. polymeric, O-rings, are preferably arranged to guarantee watertightness during the filtering process and also creating mechanical interference.

The objects filter element 144 and the collecting chamber 60 are preferably removably coupled one another so that the collecting chamber 60 can be disconnected from the objects filter element 144 when the collecting chamber 60 is removed from the housing body 32.

When the collecting chamber 60 is removed from the housing body 32, as illustrated in Figure 7, the objects filter element 144 and the wiper 51 realized therewith are reachable so that they can be removed from the housing body 32 and fully extracted out of the housing body 32. The objects filter element 144 and the wiper 51 are thus available for a proper cleaning process, which excludes to rinse them under a flow of liquid that will be wasted without any treatment, and/or substitution of the same in case the objects filter element 144 and/or the wiper 51 are damaged or worn out due to a long period of operation. In particular, the objects filter element 144 and the wiper 51 can be extracted from the housing body 32 through its opening 37.

After the objects filter element 144 and the wiper 51 are fully extracted out of the housing body 32, the microparticles filter element 44 and its filtering surface 46 are advantageously accessible from outside. A user may reach the microparticles filter element 44 and its filtering surface 46 for a further proper cleaning process if necessary.

More preferably, the microparticles filter element 44 is removably arranged in the housing body 32. Advantageously, after removal of the collecting chamber 60 and of the objects filter element 144 the user may also extract the microparticles filter element 44 from the housing body 32 and hence facilitating the cleaning process, still excluding to rinse the microparticles filter element 44 and its filtering surface 46 under a flow of liquid that will be wasted without any treatment, and/or substitution of the same in case the microparticles filter element 44 is worn out or damaged, as illustrated for example in the operating position of Figure 8. In particular, the microparticles filter element 44 can be extracted from the housing body 32 through its opening 37.

Between the microparticles filter element 44 of the microparticles filter device 40 and the housing body 32, sealing elements, for example plastic, i.e. polymeric, O- rings, are preferably arranged in respective grooves 47 to guarantee watertightness during the filtering process.

The microparticles filter element 44 preferably comprises a frontal portion 44a extending towards the frontal part of the housing body 32 of the microparticles filter device 40.

The collecting chamber 60, when connected to the housing body 32, preferably contacts an outer surface of the frontal portion 44a of the microparticles filter element 44.

The frontal portion 44a of the microparticles filter element 44 may be advantageously grasped by the user after removal of the collecting chamber 60 thus facilitating the extraction of the microparticles filter element 44.

As said above, the collecting chamber 60 is configured to be removably associated to the housing body 32 and in the preferred embodiment illustrated in Figures 3-9 the collecting chamber 60 is connected through mechanical interference to the housing body 32. In further preferred embodiments, not illustrated, the collecting chamber may be removably associated to the housing body not directly coupling the collecting chamber to the housing body. For example, the collecting chamber may be removably associated, e.g. screwable, to the frontal part of the microparticles filter element 44 instead of to the housing body 32, the former being connected to the latter. In a preferred embodiment illustrated herein, the cabinet 2 comprises an aperture 7, as shown in Figure 1, so that the collecting chamber 60 and the filter elements 44, 144 of the microparticles filter device 30 are accessible, from outside, to a user. The aperture 7 is preferably realized in the lower right side of the front side wall 2a of the laundry washing machine 1 and aligned with the filtering group assembly 30.

The cabinet 2 then preferably comprise an openable door 13 associated to the aperture 7 to give access thereto.

Operatively, when maintenance needs to be performed the user may operate as follows. First, the user may perform a cleaning process by rotating the objects filter element 144 and the wiper 51, for example using a handle 70 connectable to the actuating seat 145 form the aperture 7. The user may then remove the collecting chamber 60 from the housing body 32 and the collecting chamber 60 can hence be cleaned from microparticles stored in the storage area 61.

Further, if necessary, the user may extract the objects filter element 144 and/or the microparticles filter element 44 for a proper cleaning process or substitution.

Advantageously, the microparticles filter device 30 according to the invention makes maintenance operations of the laundry washing machine 1 more comfortable compared to known systems, such as maintenance of filtering elements 44, 144 or replacing operations of the same.

In Figures 4 to 9 the filtering group assembly 30 and/or its parts are shown in horizontal position. This is a possible real position at which the filtering group assembly 30 may be mounted inside the laundry washing machine 1.

As described above, the filtering group assembly 30 is placed just above the draining pump 24, and when the draining pump 24 is not operating, the liquid is prevented from flowing back inside the housing body 32 from the the draining pump 24. Furthermore, liquid inside the housing body 32 may return towards the first portion 22a of the discharging conduit 22 through the inlet 34 by means of gravity force and at least partially emptying the housing body 32. The housing body 32 thus can even get dry.

Risk that liquid may spill outside the machine 1 and eventually falling on the floor is then reduced or eliminated, in particular when a user removes the collecting chamber 60 and/or the filter elements 44, 144 during maintenance operations.

Furthermore, removal of residue liquid in the housing body avoids proliferation of bacteria and/or yeasts thus improving hygienic conditions and preventing bad smells.

Figures 10 and 11 illustrate a further possible real position at which the filtering group assembly 30 may be mounted inside the laundry washing machine 1.

The filtering group assembly 30 may be preferably mounted inside the laundry washing machine 1 with an inclined position so that the frontal part of the filtering group assembly 30 is at a higher position with respect the rear part thereof, considering the laundry washing machine 1 and the filtering group assembly 30 placed in their standing working position.

When the draining pump 24 is not operating the liquid is not drained outside the cabinet 2 and residue liquid may remain inside the housing body 32.

By mounting the filtering group assembly 30 with said inclined position and when the draining pump 24 is not operating, the liquid, or residue liquid, collected inside the housing body 32 returns towards the first portion 22a of the discharging conduit 22 through the inlet 34 by means of gravity force. The housing body 32 thus remains substantially emptied and can even get dry. The inclined position of the filtering group assembly 30 increases the liquid that is discharged through the inlet 34 compared to a horizontal arrangement of the filtering group assembly 30.

Again, risk that liquid may spill outside the machine 1 and eventually falling on the floor is then reduced or eliminated.

Figure 12 shows a further preferred embodiment of the invention which differs from the preferred embodiment previously described in that the objects filter element 144 and the collecting chamber 60 of the microparticles filter device 30 are removably connected one another so that while the collecting chamber 60 is removed from the housing body 32 the objects filter element 144 preferably remains connected to the collecting chamber 60 and afterwards the collecting chamber 60 may be removed from the objects filter element 144.

In the drawings, corresponding characteristics and/or components of the first embodiment previously described with reference to Figures 6-11 are identified by the same reference numbers.

According to this preferred embodiment, the front end 144b of the objects filter element 144 is preferably configured to be received in the corresponding supporting seat 63 of the collecting chamber 60 with a predetermined value of mechanical interference. Said value of mechanical interference is dimensioned to allow rotation of the objects filter element 144 with respect to the supporting seat 63, as described above with reference to the cleaning process when the objects filter element 144 and the wiper 51 are rotated to wipe the filtering surface 46 of the microparticles filter element 44. At the same time said value of mechanical interference is dimensioned so that when the collecting chamber 60 is removed from the housing body 32, the collecting chamber 60 remains engaged with the front end 144b of the objects filter element 144, as illustrated in the operating position of the Figure.

In the operating position illustrated in Figure 12, which may refer to a maintenance phase of the laundry washing machine 1, the collecting chamber 60 and the objects filter element 144 are together fully extracted out of the housing body 32. The collecting chamber 60 may then be removed from the objects filter element 144 with a stronger reciprocal separation force applied by the user to the elements 60, 144.

In an alternative embodiment, the front end 144b of the objects filter element 144 can be provided with a hook- like element engaging a portion of the supporting seat 63 and/or the collecting chamber 60 so as to ensure that the objects filter element 144 and the collecting chamber 60 remain connected each other if a push or pull action is exerted on the collecting chamber 60, and so as to allow a relative rotation between the collecting chamber and the objects filter element 144. The disconnection between the objects filter element 144 and the supporting seat 63 and/or the collecting chamber 60 can be performed by acting on the hook-like element by removing its engagement with a portion of the supporting seat 63 and/or the collecting chamber 60. It is also possible to provide a hook-like element in the supporting seat 63 and/or the collecting chamber 60 to engage a portion of the front end 144b of the objects filter element 144

Figures 16 to 18 show an alternative preferred embodiment of the coarse objects filter device 240 of the filtering group assembly 30 of the invention.

In the drawings, corresponding characteristics and/or components of the embodiment described with reference to Figures 3 to 15 are identified by the same reference numbers.

The coarse objects filter device 240 comprises an objects filter element 244 configured to retain coarse elements when liquid flows therethrough.

In the preferred embodiment illustrated in Figures 16-18, the objects filter element 244 preferably has a cylindrical tubular shape, so as to define a channel 245, and preferably extends along a main axis X2.

The objects filter element 244 is placed inside the housing body 32 so that the inlet 34 of the filtering group assembly 30 hydraulically communicates with the channel 245.

The channel 245 of the objects filter element 244 is preferably provided with a meandering structure, for example in the form of tabs 246 that are arranged along the channel 245, so as to create a labyrinthic path. Liquid coming from inlet 34 flows through the channel 245 while objects (coarse materials) are stopped by the tabs 246.

Liquid flowing through the channel 245 exits the objects filter element 244 passing through one or more apertures 247 at the front end 244b of the objects filter element 244 and reaches the gap 25. From there, liquid then undergoes to the microparticles filtration, as described above for the first preferred embodiment. Figures 19 to 21 show a a filtering group assembly 430 according to a further preferred embodiment of the invention.

In the drawings corresponding characteristics and/or components of the filtering group assembly described in Figures 3 to 18 are identified by the same reference numbers.

The filtering group assembly 430 differs from the preferred embodiments previously described in that the filtering group assembly 430 further comprises a second outlet 402.

Preferably, the second outlet 402 is provided in a liquid stagnation or sump portion 33 of the housing body 32. The liquid stagnation or sump portion 33 preferably coincides with a lower zone of the housing body 32, as better visible in Figure 21. Preferably, the second outlet 402 of the filtering group assembly 430 is hydraulically connected to a pipe arranged upstream the filtering group assembly 430, i.e. a pipe supplying liquid to be filtered to the filtering group assembly 430, for example as illustrated and described later with reference to Figure 36 wherein the second outlet 402 of the filtering group assembly 430 is hydraulically connected to the first portion 26a of the outlet pipe 26 through a draining pipe 404. According to an aspect of the invention, the second outlet 402 is provided for draining liquid, that is collected in the sump portion 33, out of the housing body 32.

When the filtering group assembly 430 works, the liquid to be filtered is conveyed to the inlet 34 of the filtering group assembly 430 and the filtered liquid is expelled through the main outlet 36, as already widely explained above. In particular, the liquid to be filtered and flowing through the inlet 34 into the filtering group assembly 430 is subjected to the filtration process by the microparticles filter element 44 and then expelled through the main outlet 36. According to this embodiment, when the filtering group assembly 430 works, the liquid subjected to the filtration process by the microparticles filter element 44 is also expelled through the second outlet 402.

When the filtering group assembly 430 does not work, the liquid to be filtered is not conveyed to the inlet 34 of the filtering group assembly 430 anymore, for example after a washing cycle has terminated.

The filtered liquid that was subjected to the filtration process by the microparticles filter element 44 inside the housing body 32 falls in the sump portion 33 of the housing body 32 by means of gravity force so as to define a residue liquid.

The residue liquid in the sump portion 33 is advantageously expelled through the second outlet 402 and discharged out of the body 32 of the filtering group assembly 430 by means of the gravity force. The housing body 32 thus remains completely emptied and can get dry.

Removal of any residue liquid in the housing body 32 avoids proliferation of bacteria and/or yeasts thus improving hygienic conditions and preventing bad smells.

Furthermore, removal of any residue liquid in the housing body 32 avoids that liquid may spill outside, and eventually falling on the floor, when the collecting chamber 60 is removed from the housing body 32 and/or when the objects filter element 144 is extracted from the housing body 32 and/or when the microparticles filter element 44 is extracted from the housing body 32.

In the preferred embodiments of the filtering group assembly described above, the objects filter element is arranged inside the microparticles filter element or, as said above, the objects filter volume delimited by the objects filter element is contained within the microparticles filter volume delimited by the microparticles filter element. Preferably, the majority of the objects filter volume is contained within the microparticles filter volume. Furthermore, liquid flowing through the filtering group assembly flows radially outwardly from the inlet towards the main outlet.

In further preferred embodiments, nevertheless, the microparticles filter element may be arranged inside the objects filter element and the liquid flowing through the filtering group assembly may flow radially inwardly from the inlet towards the main outlet.

Figures 22 to 24 show a filtering group assembly 530 of this type. In the drawings, corresponding characteristics and/or components of the embodiments previously described are identified by the same reference numbers.

According to this preferred embodiment, the microparticles filter element 544 of the microparticles filter device 540 is arranged inside the objects filter element 644 of the coarse objects filter device 640. In other words, the microparticles filter volume 542 delimited by the microparticles filter element 544 is contained within the objects filter volume 543 delimited by the objects filter element 644. Preferably, the majority of the microparticles filter volume 542 is contained within the objects filter volume 543. Furthermore, preferably, with reference to the section where liquid passes through the rear side 32b of the housing body 32 of the filtering group assembly 540, the inlet 534 is preferably arranged radially outwardly with respect to the main outlet 536. Reciprocal positions of inlet 534 and outlet 536 of this embodiment are therefore inverted compared to previous embodiments. Therefore, as better described later, liquid flowing through the filtering group assembly 530 flows radially inwardly from the inlet 534 towards the main outlet 536.

According to this embodiment, the microparticles filter device 540 is still advantageously arranged downstream the coarse objects filter device 640 so that the liquid during the functioning of the filtering group assembly 530 firstly flows through the coarse objects filter device 640 and then through the microparticles filter device 540.

The microparticles filter device 540 extends along a main axis XI, preferably, but not necessarily, coinciding with the main axis X0 of the filtering group assembly 530. The microparticles filter device 540 is housed in the housing body 32 and comprises the microparticles filter element 544 having a filtering surface 546 at which microparticles accumulate while the liquid flows therethrough. In this preferred embodiment, microparticles then externally accumulate at said filtering surface 546.

The microparticles filter element 544 preferably has a tubular shape, more preferably a cylindrical tubular shape. The microparticles filter element 544 preferably extends along said main axis XI. The filtering surface 546 preferably comprises a plurality of meshes 546a, more preferably rectangular meshes 546a, for example of the type described above.

The microparticles filter element 544 has walls delimiting a microparticles filter volume 542.

The microparticles filter volume 542 hydraulically communicates with the main outlet 536 of the filtering group assembly 530.

The coarse objects filter device 640 is located between the inlet 534 for liquid to be filtered and the microparticles filter device 540.

The coarse objects filter device 640 is housed in the housing body 32 and comprises an objects filter element 644 stopping coarse materials while said liquid flows therethrough.

The coarse objects filter device 640 preferably extends along a main axis X2, preferably, but not necessarily, coinciding with the main axis X0 of the filtering group assembly 530 and/or coinciding with the main axis XI of the microparticles filter device 540.

The objects filter element 644 preferably has a tubular shape, more preferably a cylindrical tubular shape. The objects filter element 644 preferably extends along said main axis X2.

The objects filter element 644 has walls delimiting an objects filter volume 543.

The objects filter element 644 preferably has as a grid structure and preferably comprises apertures 646 having proper size to retain objects having a prevalent dimension that is higher than 5mm, for example parallelogram- shaped apertures as shown in the Figures.

An elongated annular chamber 548 is preferably defined between the housing body 32 and the objects filter element 644. The elongated annular chamber 548 hydraulically communicates with the inlet 534 of the filtering group assembly 530. As said above, the microparticles filter element 544 of the microparticles filter device 540 is arranged inside the objects filter element 644 of the coarse objects filter device 640.

Preferably, the objects filter element 644 and the microparticles filter element 544 are coaxially arranged one to the other. More preferably the objects filter element 644 and the microparticles filter element 544 are coaxially arranged one to the other so that their respective axes X2, XI coincide.

A gap 525 is formed between the microparticles filter element 544 and the coarse objects filter device 640. More preferably, the gap 525 is defined between the microparticles filter element 544 and the objects filter element 644. Such gap 525 receives liquid exiting the objects filter element 644 before entering the microparticles filter element 544. Hence, in a configuration wherein both the microparticles filter element 544 and the objects filter element 644 have a tubular shape, said gap 525 is preferably radially inner the objects filter element 644 and radially outer the microparticles filter element 544.

When the draining system of the laundry washing machine receiving the filtering group assembly 530 operates, for example with activation of a draining pump, the objects filter element 644 of the coarse objects filter device 640 receives liquid coming from the inlet 534 and then liquid undergoes to coarse filtration by passing through the objects filter element 644 with its apertures 646.

The filtered liquid thus reaches said gap 525. Undesirable objects that may damage the draining pump, for example may damage the impeller in case a centrifugal pump design is used, are thus retained in the elongated annular chamber 548.

Liquid exiting the objects filter element 644 then undergoes to the microparticles filtration action by passing through the microparticles filter element 544 and then, once left the microparticles filter element 544, reaches the microparticles filter volume 542. Finally, filtered liquid exits the filtering group assembly 530 through the main outlet 536. Liquid flowing through the filtering group assembly 530 and coming from the inlet 534 thus preferably flows radially inwardly from the annular chamber 548 towards the microparticles filter volume 542 and finally up to the main outlet 536.

Liquid flowing through the filtering group assembly 530 and discharged to the outside of the laundry washing machine is thus advantageously subjected to the action of both the coarse objects filter device 640 and the microparticles filter device 540.

The filtering group assembly 530 is then preferably equipped with a cleaning device 550 which is configured to remove microparticles that accumulate on the first side of the filtering surface 546 of the microparticles filter element 544 that the liquid encounters when passing through said filtering surface 546. The cleaning device 550 is arranged in the gap 525 between the coarse objects filter device 640 and the microparticles filter element 544.

The cleaning device 550 is configured for moving microparticles removed from the filtering surface 546 towards the storage volume 61 of the collecting chamber 60.

According to this embodiment, the cleaning device 550 preferably comprises a wiper 551 wiping a side of the filtering surface 546, preferably wiping the first side of the filtering surface 546 that the liquid encounters and where microparticles accumulates during operation of the filtering group assembly 530.

Removal of microparticles that accumulate on the filtering surface 546 is obtained by means of a relative movement between the wiper 551 and the microparticles filter element 544.

In the preferred embodiment illustrated in Figures 22-24, the wiping action is obtained by moving the microparticles filter element 544 and its filtering surface 546, more preferably by rotating the microparticles filter element 544, while the wiper 551 is kept still, as better described later.

Preferably, the wiper 551 is embodied as a worm extending along a main axis X3 and having a helix- shaped element 556 that winds around the main axis X3. The helix- shaped element 556 inwardly extends from the radially inner surface of the objects filter element 644 and towards the microparticles filter element 544 that is contained, preferably for the majority of its volume, within the objects filter volume 543 delimited by the objects filter element 644. In the preferred embodiment described herein, the main axis X3 preferably coincides with the main axis X2 of the coarse objects filter device 640. While the microparticles filter element 544 rotates, the edge of the helix-shaped element 556 advantageously wipes the filtering surface 546 the microparticles filter element 544.

In the preferred embodiment illustrated in Figures 22-24, the cleaning device 550 is connected to the coarse objects filter device 640, preferably directly fixedly connected to the objects filter element 644. Preferably the cleaning device 550 is integrally made with the coarse objects filter device 640, more preferably integrally made with objects filter element 644.

In particular, the helix- shaped element 556 is preferably connected to the coarse objects filter device 640, more preferably directly fixedly connected to the objects filter element 644. Preferably, the helix-shaped element 556 is preferably integrally made with the coarse objects filter device 640, more preferably integrally made with the objects filter element 644. Preferably, the helix-shaped element 556 winds internally the coarse objects filter device 640 on the radially inner surface thereof, more preferably winds internally the objects filter element 644.

The cleaning effect of the wiper 551 is performed when the microparticles filter element 544 is rotated around the main axis XI. During rotation, the helix-shaped element 556 wipes the side of the filtering surface 546 of the microparticles filter element 544 thereby removing microparticles accumulated thereon and, at the same time, microparticles move towards the storage volume 61 of the collecting chamber 60.

Microparticles are therefore collected into the storage volume 61 of the collecting chamber 60 as the the microparticles filter element 544 rotates. Microparticles removed from the filtering surface 546 are conveyed towards the storage volume 61 of the collecting chamber 60 and towards the opening 37 provided in the housing body 32. Microparticles can be then removed from the filtering group assembly 530 by removing the collecting chamber 60 from the housing body 32. According to the preferred embodiment illustrated in Figures 22-24, the microparticles filter element 544 is configured to be rotated around its axis XI. A first end 544a of the microparticles filter element 544, or rear end 544a, is received in a corresponding supporting seat 545 of the objects filter device 640. Preferably, the first end 544a of the microparticles filter element 544 and the supporting seat 545 of the objects filter device 640 are cylindrically shaped.

The supporting seat 545 and the rear end 544a of the microparticles filter element 544 are shaped, for example both cylindrically shaped, and coupled so that the microparticles filter element 544 may rotate with respect to the supporting seat 545 when the microparticles filter element 544 rotates.

A second end 544b of the microparticles filter element 544, or front end 544b, is received in a corresponding supporting seat 63 of the collecting chamber 60.

The supporting seat 63 and the second end 544b of the microparticles filter element 544 are shaped, for example both cylindrically shaped, and coupled so that the microparticles filter element 544 may rotate with respect to the supporting seat 63 when the the microparticles filter element 544 rotates, while the collecting chamber 60 may be disengaged from the microparticles filter element 544 when the collecting chamber 60 is removed from the housing body 32.

The supporting seat 63 of the collecting chamber 60 preferably opens outwards, i.e. it is a pass-through hole, and the second end 544b of the microparticles filter element 544 is preferably reachable from outside the filtering group assembly 530. The second end 544b of the microparticles filter element 544 is also preferably provided with an actuating seat 645. The actuating seat 645 preferably faces outwards so that it can be reachable from outside the filtering group assembly 530. Rotation of the microparticles filter element 544 may be preferably obtained through an actuating device, for example a flat head screwdriver or a crank or a handle as previously described, that can engage said actuating seat 645.

Rotation of the actuating device allows rotation of the microparticles filter element 544. Hence, when necessary, microparticles are removed from the filtering surface 546 and conveyed towards the storage volume 61 of the collecting chamber 60 through rotation of the actuating device.

The objects filter element 644 and the wiper 551 realized therewith are also configured so that they can be removed from the housing body 32, preferably by extracting the objects filter element 644 along the main axis X2 direction.

The microparticles filter element 544 is also configured so that it can be removed from the housing body 32, preferably by extracting the microparticles filter element 544 along the main axis XI direction.

The microparticles filter element 544 and the collecting chamber 60 are preferably removably coupled one another so that the collecting chamber 60 can be disconnected from the microparticles filter element 544 when the collecting chamber 60 is removed from the housing body 32.

When the collecting chamber 60 is removed from the housing body 32, the microparticles filter element 544 is reachable so that it can be removed from the housing body 32 and fully extracted out of the housing body 32. The microparticles filter element 544 is thus available for a proper cleaning process, which excludes to rinse them under a flow of liquid that will be wasted without any treatment, and/or substitution of the same in case the the microparticles filter element 544 is damaged or worn out due to a long period of operation. In particular, the microparticles filter element 544 can be extracted from the housing body 32 through its opening 37.

After the microparticles filter element 544 is fully extracted out of the housing body 32, the objects filter element 644 is advantageously accessible from outside. A user may reach the objects filter element 644 and its filtering surface 646 for a further proper cleaning process if necessary.

More preferably, the objects filter element 644 is removably arranged in the housing body 32. Advantageously, after removal of the collecting chamber 60 and of the microparticles filter element 544 the user may also extract the objects filter element 644 from the housing body 32 and hence facilitating the cleaning process, which excludes to rinse them under a flow of liquid that will be wasted without any treatment, and/or substitution of the same in case the objects filter element 644 is damaged or worn out due to a long period of operation. In particular, the objects filter element 644 can be extracted from the the housing body 32 through its opening 37.

Between the objects filter element 644 of the objects filter device 640 and the housing body 32, sealing elements (not shown), for example plastic, i.e. polymeric, O-rings, are preferably arranged in respective grooves 647 to guarantee watertightness during the filtering process.

The objects filter device 640 preferably comprises a frontal portion 644a extending towards the frontal part of the housing body 32 of the objects filter device 640. The collecting chamber 60, when connected to the housing body 32, preferably contacts an outer surface the frontal portion 644a of the microparticles filter element 544.

The frontal portion 644a of the objects filter device 640 may be advantageously grasped by the user after removal of the collecting chamber 60 and has thus the aim of facilitating the extraction of the objects filter device 640 from the housing body.

Figures 25 to 28 show a filtering group assembly 730 according to a further preferred embodiment of the invention. In the drawings, corresponding characteristics and/or components of the embodiments previously described are identified by the same reference numbers.

This embodiment differs from the preferred embodiment previously described in Figures 22 to 24 mainly in that the objects filter device 840, the microparticles filter device 740 and the cleaning device 750 are configured so that the wiping action is obtained by moving the wiper 751, more preferably by rotating the wiper 751, while the microparticles filter element 744 is kept still, as better described later.

The microparticles filter device 740 extends along a main axis XI, preferably, but not necessarily, coinciding with the main axis X0 of the filtering group assembly 730. The microparticles filter device 740 is housed in the housing body 32 and comprises the microparticles filter element 744 having a filtering surface 746 at which microparticles accumulate while the liquid flows therethrough.

The microparticles filter element 744 preferably has a tubular shape, more preferably a cylindrical tubular shape. The microparticles filter element 744 preferably extends along said main axis XI. The filtering surface 746 preferably comprises a plurality of meshes 746a, more preferably rectangular meshes 746a, for example of the type described above.

The microparticles filter element 744 has walls delimiting a microparticles filter volume 742.

The microparticles filter volume 742 hydraulically communicates with the main outlet 536 of the filtering group assembly 730.

The coarse objects filter device 840 is housed in the housing body 32 and comprises an objects filter element 844 stopping coarse materials while said liquid flows therethrough.

The coarse objects filter device 840 preferably extends along a main axis X2, preferably, but not necessarily, coinciding with the main axis X0 of the filtering group assembly 730 and/or coinciding with the main axis XI of the microparticles filter device 740.

The objects filter element 844 preferably has a tubular shape, more preferably a cylindrical tubular shape. The objects filter element 844 preferably extends along said main axis X2.

The objects filter element 844 has walls delimiting an objects filter volume 743.

The objects filter element 844 preferably has as a grid structure and preferably comprises apertures 846 having proper size to retain objects having a prevalent dimension that is higher than 5mm, for example parallelogram- shaped apertures as shown in the Figures.

An elongated annular chamber 548 is preferably defined between the housing body 32 and the objects filter element 844. The elongated annular chamber 548 hydraulically communicates with the inlet 534 of the filtering group assembly 730. The microparticles filter element 744 of the microparticles filter device 740 is arranged inside the objects filter element 844 of the coarse objects filter device 840.

Preferably, the objects filter element 844 and the microparticles filter element 744 are coaxially arranged one to the other. More preferably the objects filter element 844 and the microparticles filter element 744 are coaxially arranged one to the other so that their respective axes X2, XI coincide.

A gap 525 is formed between the microparticles filter element 744 and the coarse objects filter device 840. More preferably, the gap 525 is defined between the microparticles filter element 744 and the objects filter element 844.

The filtering group assembly 730 is then preferably equipped with a cleaning device 750 which is configured to remove microparticles that accumulate on the first side of the filtering surface 746 of the microparticles filter element 744 that the liquid encounters when passing through said filtering surface 746. The cleaning device 750 is arranged in the gap 525 between the coarse objects filter device 840 and the microparticles filter element 744.

The cleaning device 750 is configured for moving microparticles removed from the filtering surface 746 towards the storage volume 61 of the collecting chamber 60.

According to this embodiment, the cleaning device 750 preferably comprises a wiper 751 wiping a side of the filtering surface 746, preferably wiping the first side of the filtering surface 746 that the liquid encounters and where microparticles accumulates during operation of the filtering group assembly 730.

Removal of microparticles that accumulate on the filtering surface 746 is obtained by means of a relative movement between the wiper 751 and the microparticles filter element 744.

In the preferred embodiment illustrated in Figures 25-28, the wiping action is obtained by moving the wiper 751, more preferably by rotating the wiper 751, while the microparticles filter element 744 is kept still. Hence, the wiper 751 is a movable wiper, in particular a rotatably movable wiper 751.

Preferably, the wiper 751 is embodied as a worm extending along a main axis X3 and having a helix- shaped element 756 that winds around the main axis X3. The helix- shaped element 756 inwardly extends from the radially inner surface of the objects filter element 844 and towards the microparticles filter element 744 that is contained, preferably for the majority of its volume, within the objects filter volume 743 delimited by the objects filter element 844. In the preferred embodiment described herein, this main axis X3 preferably coincides with the main axis X2 of the coarse objects filter device 840.

While the helix-shaped element 756 rotates, the edge of the helix-shaped element 756 advantageously wipes the filtering surface 746 of the microparticles filter element 744.

Preferably, the cleaning device 750 is connected to the coarse objects filter device 840, preferably directly fixedly connected to the objects filter element 844. Preferably the cleaning device 750 is integrally made with the coarse objects filter device 840, more preferably integrally made with objects filter element 844.

In particular, the helix- shaped element 756 is preferably connected to the coarse objects filter device 840, more preferably directly fixedly connected to the objects filter element 844. Preferably, the helix-shaped element 756 is preferably integrally made with the coarse objects filter device 840, more preferably integrally made with the objects filter element 844. Preferably, the helix-shaped element 756 winds internally the coarse objects filter device 840 on the radially inner surface thereof, more preferably winds internally the objects filter element 844.

Preferably, rotation of the wiper 751 is obtained by rotation of the coarse objects filter device 840, in particular of the objects filter element 844, being the wiper 751 connected to the coarse objects filter device 840.

At this purpose, the objects filter element 844 is configured to be rotated around the axis X2. A first end 844a of the objects filter element 844, or rear end 844a, is arranged outside a first end 745 the microparticles filter element 744. Preferably, the first end 844a of the objects filter element 844 and the first end 745 of the microparticles filter element 744 are cylindrically shaped.

A second end 844b of the objects filter element 844, or front end 844b, is received in a corresponding supporting seat 63 of the collecting chamber 60.

The supporting seat 63 and the second end 844b of the objects filter element 844 are shaped, for example both cylindrically shaped, and coupled so that the objects filter element 844 may rotate with respect to the supporting seat 63 when the objects filter element 844 and the wiper 751 rotate while the collecting chamber 60 may be disengaged from the objects filter element 844 when the collecting chamber 60 is removed from the housing body 32.

The supporting seat 63 of the collecting chamber 60 preferably opens outwards, i.e. it is a pass-through hole, and the second end 844b of the objects filter element 844 is preferably reachable from outside the filtering group assembly 730.

The second end 844b of the objects filter element 844 is also preferably provided with an actuating seat 845. The actuating seat 845 preferably faces outwards so that it can be reachable from outside the filtering group assembly 730.

Rotation of the objects filter element 844 may be preferably obtained through an actuating device, for example a flat head screwdriver or a crank or a handle as previously described, that can engage said actuating seat 845.

Rotation of the actuating device allows rotation of the objects filter element 844 and of the wiper 751. Hence, when necessary, microparticles are removed from the filtering surface 746 and conveyed towards the storage volume 61 of the collecting chamber 60 through rotation of the actuating device. The frontal portion 744a of the microparticles filter element 744 is preferably provided with a pin 744b. The pin 744b may be advantageously grasped by the user after removal of the collecting chamber 60 and of the coarse objects filter device 840 thus facilitating the extraction of the microparticles filter element 744 from the housing body 32.

Figures 29 to 31 show a filtering group assembly 930 according to a further preferred embodiment of the invention. In the drawings, corresponding characteristics and/or components of the embodiments previously described are identified by the same reference numbers.

This embodiment differs from the preferred embodiment previously described in Figures 25 to 28 in that the filtering group assembly 930 further comprises a removal coarse materials aid system 980.

As explained above, when the draining system of the laundry washing machine operates the objects filter element 644 of the coarse objects filter device 640 receives liquid coming from the inlet 534 and undesirable objects, or coarse materials, that may damage the draining pump are retained in the elongated annular chamber 548.

In order to facilitate the extraction of the coarse materials from the elongated annular chamber 548, the filtering group assembly 930 is thus preferably provided with said removal coarse materials aid system 980 that has the function of moving coarse materials in the elongated annular chamber 548 towards the opening 37 of the housing body 32.

The removal coarse materials aid system 980 is preferably embodied as a worm extending along a main axis X4 and having a helix-shaped element 986 that winds around the main axis X4. The helix-shaped element 986 preferably outwardly extends from the radially outer surface of the objects filter element 844 and towards the radially inner surface of the housing body 32. The helix- shaped element 986 extends inside the elongated annular chamber 548.

While the helix-shaped element 986 rotates, coarse materials in the elongated annular chamber 548 are moved towards the opening 37 of the housing body 32, and towards the collecting chamber 60.

When the collecting chamber 60 is removed from the housing body 32, coarse materials moved by the removal coarse materials aid system 980 is reachable from outside by a user, thus facilitating the cleaning process.

Preferably the removal coarse materials aid system 980 is integrally made with the coarse objects filter device 840, more preferably integrally made with objects filter element 844.

Preferably, the helix-shaped element 986 is preferably connected to the coarse objects filter device 840, more preferably directly fixedly connected to the objects filter element 844. Preferably, the helix-shaped element 986 is integrally made with the coarse objects filter device 840, more preferably integrally made with the objects filter element 844.

Preferably, rotation of the helix-shaped element 986 is obtained by rotation of the coarse objects filter device 840, in particular of the objects filter element 844, being the helix-shaped element 956 connected to the coarse objects filter device 840.

According to the preferred embodiment illustrated in Figures 25-28 rotation of the coarse objects filter device 840 therefore both moves microparticles towards the collecting chamber 60 and coarse materials towards the opening 37 of the housing body 32.

In the preferred embodiments of the filtering group assembly described above the devices, or components in general, are preferably configured to extend along respective axes. In particular the filtering group assembly extends along a main axis X0, the microparticles filter device extends along a main axis XI, the coarse objects filter device extends along a main axis X2 and the wiper is embodied as a worm extending along a main axis X3. Furthermore, in the preferred embodiments described above said axes are preferably coinciding. This feature allows a simple construction and/or functioning of the devices/components of the filtering group assembly of the invention. For example, as described above, the microparticles filter device and the coarse objects filter device are cylindrically shaped with respective coinciding axes XI and X2. The gap formed therebetween is thus symmetric and advantageously receive a rotatable wiper embodied as a worm having a helix-shaped element. In different preferred embodiments, nevertheless, the devices/components may extend along respective axes in general that do not coincide. For example, the microparticles filter device may extend along a main axis XI and the coarse objects filter device may extend along a main axis X2 which is inclined of some degrees with respect the main axis XI of the microparticles filter device.

The gap formed therebetween is thus non symmetric and the wiper may be preferably embodied as a worm having a flexible helix-shaped element. The helixshaped element may thus deform during its rotation inside the gap so that it is maintained in contact with the filtering surface of the microparticles filter element to obtain the desired wiping action, despite the asymmetric shape of the gap.

The flexibility of a part of the wiper therefore compensates the asymmetry caused by the fact that the axes do not coincide.

In the preferred embodiments of the filtering group assembly described above, furthermore, the cleaning device, and in particular the wiper, which is arranged in the gap formed between the coarse objects filter device and the microparticles filter element is embodied as an element, for example a helix- shaped element, which is connected to the coarse objects filter device and more preferably directly fixedly connected to the objects filter element.

In further preferred embodiments, nevertheless, the wiper may be embodied as a separate device with respect to the coarse objects filter device.

Figures 32 to 34 schematically show a preferred solution of the wiper of this type. In the drawings, corresponding characteristics and/or components of the embodiments previously described are identified by the same reference numbers. In the drawings, furthermore, only some components of the filtering group assembly are depicted and constructional details of the same components, exhaustively described above, are omitted.

In the preferred embodiment illustrated in Figure 32-34, the filtering group assembly 1030 according to the invention preferably comprises a microparticles filter device 1040 for retaining microparticles and a coarse objects filter device 1140 for stopping coarse materials. The microparticles filter device 1040 and the coarse objects filter device 1140 preferably extend within the same body element, i.e. the housing body (not shown). The microparticles filter device 1040 preferably extends along a main axis XI and the coarse objects filter device 1140 preferably extends along a main axis X2.

The microparticles filter device 1040 preferably comprises a microparticles filter element 1044 having a filtering surface 1046 at which microparticles accumulate while the liquid flows therethrough. The microparticles filter element 1044 preferably has a tubular shape, more preferably a cylindrical tubular shape. The microparticles filter element 1044 preferably extends along said main axis XI. The filtering surface 1046 preferably comprises a plurality of meshes, not shown and of the type previously described, for example, with reference to Figure 8.

The coarse objects filter device 1140 preferably comprises an objects filter element 1144 stopping coarse materials while said liquid flows therethrough. The objects filter element 1144 preferably has a tubular shape, more preferably a cylindrical tubular shape. The objects filter element 1144 preferably extends along said main axis X2.

According to an aspect of this preferred embodiment, the objects filter element 1144 is arranged inside the microparticles filter element 1044. The objects filter element 1144 and the microparticles filter element 1044 are reciprocally arranged one relative to the other so that their respective axes X2, XI are parallel and coplanar, but they do not coincide.

A gap 1025 is formed between the microparticles filter element 1044 and the coarse objects filter device 1140. More preferably, the gap 1025 is defined between the microparticles filter element 1044 and the objects filter element 1144.

According to another aspect of the invention, the filtering group assembly 1030 is equipped with a cleaning device 1050 which is configured to remove microparticles that accumulate on the first side of the filtering surface 1046 of the microparticles filter element 1044 that the liquid encounters when passing through said filtering surface 1046. The cleaning device 1050 is arranged in the gap 1025 between the coarse objects filter device 1140 and the microparticles filter element 1044.

The cleaning device 1050 is configured for moving microparticles removed from the filtering surface 1046 towards a storage volume of a collecting chamber (not shown) facing one end region of the microparticles filter element 1044 and preferably being intersected by the main axis XI of the microparticles filter element 1044.

More preferably, the cleaning device 1050 is configured for moving microparticles removed from the filtering surface 1046 towards the storage volume of the collecting chamber. Microparticles are preferably moved along a direction parallel to the axes XI, X2.

The cleaning device 1050 preferably comprises a wiper 1051 wiping a side of the filtering surface 1046, preferably wiping the first side of the filtering surface 1046 that the liquid encounters and where microparticles accumulates during operation of the filtering group assembly 1030.

Removal of microparticles that accumulate on the filtering surface 1046 is obtained by means of a relative movement between the wiper 1051 and the microparticles filter element 1044.

In the preferred embodiment illustrated in Figures, the wiping action is obtained by moving the wiper 1051, more preferably by translating the wiper 1051 along a direction parallel to the axes XI, X2 while the microparticles filter element 1044 is kept still. Hence, the wiper 1051 is a movable wiper, in particular a translatable wiper 1051.

Preferably, the wiper 1051 is embodied as a piston with a reciprocating rectilinear motion along said direction parallel to the axes XI, X2.

The piston 1051 preferably comprises a head portion 1054 and a main shaft 1056. External edges of the head portion 1054 wipes the filtering surface 1046 of the microparticles filter element 1040. Microparticles removed from the filtering surface 1046 are moved towards the collecting chamber by the translation movement of the piston 1051.

The reciprocating rectilinear motion of the piston 1051 is preferably obtained through an actuating device, not shown.

In the preferred embodiment of the filtering group assembly 1040 just described the microparticles filter device 1040 extends along a main axis XI and the coarse objects filter device 1140 extends along a main axis X2 wherein the axes X2, XI are parallel and coplanar, but they do not coincide.

In different preferred embodiments, nevertheless, the microparticles filter device 1040 may extend along a main axis XI and the coarse objects filter device 1140 may extend along a main axis X2 which is inclined of some degrees with respect the main axis XI of the microparticles filter device 1040. The gap 1025 formed therebetween is thus non symmetric and the wiper 1051 may be preferably embodied as having a flexible head portion 1054. The head portion 1054 may thus deform during its translation inside the gap so that it is maintained in contact with the filtering surface 1046 of the microparticles filter element 1040 to obtain the desired wiping action, despite the asymmetric shape of the gap 1025.

The flexibility of the head portion 1054 therefore compensates the asymmetry causes by the fact that the axes are inclined one to the other.

Figure 35 shows a schematic view of a further preferred embodiment of a laundry washing machine 301 according to the invention. In the drawing, corresponding characteristics and/or components of the embodiment described in Figure 2 are identified by the same reference numbers.

This preferred embodiment of the invention differs from the preferred embodiment previously described with reference to Figure 2 firstly in that the filtering group assembly 30 is arranged downstream the draining pump 24, preferably along the outlet pipe 26.

In the Figure, the filtering group assembly is simply indicated with the reference number 30. Nevertheless, the filtering group assembly used herein can be a filtering group assembly according to anyone of the embodiments of the invention. The inlet 34 of the filtering group assembly 30 is connected to a first portion 26a of the outlet pipe 26 and the main outlet 36 of the filtering group assembly 30 is connected to a second portion 26b of the outlet pipe 26 which preferably protrudes out of the cabinet 2. In one embodiment of the invention, the filtering group assembly 30 is arranged in a top portion of the cabinet 2.

The draining system 20 of the laundry washing machine 301 then preferably comprises a further coarse objects filter device 328, in a form that is known per se, arranged upstream the draining pump 24.

The further coarse objects filter device 328 is more preferably arranged in the discharging conduit 22 between the tub outlet port and the draining pump 24.

The further coarse objects filter device 328 is adapted to stop objects before they reach a pump, for example the draining pump 24. The further coarse objects filter device 328, similarly to what described above with reference to the coarse objects filter device 140 of the filtering group assembly 30, has the aim of retain undesirable objects (coarse materials) that may damage the draining pump 24, for example may damage the impeller in case a centrifugal pump design is used. Preferably, therefore, the further coarse objects filter device 328 is suitable to filter objects having a prevalent dimension that is higher than 5mm.

In a preferred embodiment, as known in the art, the further coarse objects filter device preferably comprises a casing having a housing wherein a objects filter element is received. The housing preferably forms a channel through which liquid to be filtered flows. Said objects filter element is preferably provided with a meandering structure, for example in the form of tabs that are arranged along the channel when the objects filter element is placed within the housing so as to create a labyrinthic path through which the liquid flows while objects are stopped by the tabs, analogously for example to the objects filter element 240 described above. For cleaning purposes, the further coarse objects filter device 328 can preferably be removed from the housing and from the cabinet through an openable gate placed advantageously on the front side wall 2a of the cabinet 2.

The further coarse objects filter device 328 and respective gate are preferably arranged in the lower part of the laundry washing machine 301, more preferably in the lower right side of the laundry washing machine 301.

The draining pump 24 and the further coarse objects filter device 328 are preferably embodied as a group assembly, for example by directly connecting the draining pump 24 to the casing defining the housing of the further coarse objects filter device 328.

The first portion 22a of the discharging conduit 22 preferably connects the bottom region 3a of the washing tub 3 to the further coarse objects filter device 328.

In a further embodiment, not illustrated, the casing of the further coarse objects filter device may be provided directly in the washing tub, preferably obtained in a single piece construction with the latter. In this case, the further coarse objects filter device is fluidly connected to the outlet of the washing tub, in such a way that liquid drained from the washing tub enters the further coarse objects filter device.

As known in the art, the laundry washing machine 301 then further preferably comprises a first recirculation system 330 which is adapted to drain liquid from a bottom region 3a, placed at a bottom part of the washing tub 3, and to re-admit such a liquid back again into said bottom region 3 a of the washing tub 3 and preferably a second recirculation system 340 which is adapted to drain liquid from said bottom region 3 a of the washing tub 3 and to re-admit such a liquid into a second region 3b of the washing tub 3, placed at a higher level relative to the bottom region 3 a.

The liquid taken from the washing tub 3 is preferably re-admitted to the bottom region 3a of the washing tub 3 for mixing and/or dissolving laundry treating products, in particular detergent in powder or liquid form. Mixing and/or dissolving of a laundry treating product is preferably carried out during a washing cycle when one of the products is supplied into the washing tub 3 from the treating agent dispenser 14.

Preferably, the second region 3b of the washing tub 3 substantially corresponds to an upper region 3b of the washing tub 3. The liquid is preferably re-admitted to the upper region 3b of the washing tub 3 to improve wetting of the laundry inside the washing drum 4. This action is preferably carried out at the beginning of a washing cycle when the laundry needs to be completely soaked. Furthermore, this action is preferably carried out during rinsing phases at the beginning of the washing cycle or during rinsing phases in successive steps of the washing cycle. Furthermore, this action can be also carried out during a main wash phase so as to efficiently reach laundry that rest in an upper region of the drum.

The first recirculation system 330 preferably comprises a first recirculation pump 332 connected downstream the further coarse objects filter device 328 and a first recirculation line 334 for conveying liquid to the bottom region 3a of the washing tub 3.

The second recirculation system 340 preferably comprises a second recirculation pump 342 connected downstream the further coarse objects filter device 328 and a second recirculation line 344 for conveying liquid to the second region 3b of the washing tub 3.

According to this preferred embodiment, the further coarse objects filter device 328 is advantageously arranged upstream the pumps 24, 332, 342 and prevents coarse objects damage them when are operated, as explained above.

Furthermore, the filtering group assembly 30 arranged downstream the draining pump 24 prevents residual coarse materials, i.e. coarse material that has not been stopped by the further coarse objects filter device 328, to reach the drainage point outside the cabinet and liquid is subjected to a filtration process preventing microparticles leaving the laundry washing machine 301 before it reaches the drainage point outside the machine 301. By providing for an efficient filtration performed by the further coarse objects filter device 328, the coarse objects filter device 140 of the filtering group assembly 30 can be designed to filter out thinner objects than those stopped by the further coarse objects filter device 328.

Furthermore, the filtering group assembly 30 allows removal of microparticles stored in the storage area 61 of the collecting chamber 60 and maintenance/cleaning of the filter elements 44, 144 when necessary.

Figure 36 shows a laundry washing machine 401 equipped with a filtering group assembly 430 according to a further preferred embodiment of the invention, an example thereof being depicted in Figures 19 to 21.

The laundry washing machine 401 according to this preferred embodiment of the invention has the same configuration of the laundry washing machine 301 described with reference to Figure 35, wherein there is provided a further coarse objects filter device 328, a first recirculation system 330 and a second recirculation system 340. This preferred embodiment of the invention differs from the preferred embodiment previously described with reference to Figure 35 in that the filtering group assembly 430 is a filtering group assembly 430 according to the embodiment described with reference to Figures 19 to 21, i.e. a filtering group assembly 430 comprising a second outlet 402.

Here, the second outlet 402 of the filtering group assembly 430 is hydraulically connected to the first portion 26a of the outlet pipe 26 through a draining pipe 404. In further preferred embodiments, not illustrated, the second outlet of the filtering group assembly may be hydraulically connected, for example, upstream the draining pump 24 at the second portion 22b of the discharging conduit 22 or upstream the further coarse objects filter device 328, for example at the sump 15 or at the first portion 22a of the discharging conduit 22.

In the preferred embodiments above described and illustrated, the wiper is preferably embodied as a helix- shaped element wherein an edge of the helixshaped element wipes the filtering surface of the microparticles filter element or as a piston with a head portion having edges wiping the filtering surface of the microparticles filter element.

In further preferred embodiments, not illustrated, the wiper may be differently embodied. For example, the wiper may comprise a brush apt to remove microparticles from the filtering surface of the microparticles filter element when a relative movement is carried out between the wiper and the microparticles filter element.

Furthermore, in the preferred embodiments above described and illustrated, the microparticles filter element and the objects filter element are removably arranged in the housing body of the filtering group assembly. In further preferred embodiments, not illustrated, the microparticles filter element and/or the objects filter element may be configured to be not removable from the housing body of the filtering group assembly. In such a case, maintenance intervention for the microparticles filter element and/or for the objects filter element is avoided. In case of damage of the microparticles filter element and/or of the objects filter element, the whole filtering group assembly may be substituted.

It has thus been shown that the present invention allows all the set objects to be achieved. In particular, the invention makes possible to provide a laundry washing machine that reduces constructional complexity of the filtering system and makes maintenance operations more comfortable compared to known laundry washing machines.

While the present invention has been described with reference to particular embodiments shown in the figures, it should be noted that the present invention is not limited to the specific embodiments illustrated and described herein; on the contrary, further variants of the embodiments described herein fall within the scope of the present invention, which is defined in the appended claims.

Claims

1. A laundry washing machine (1; 301; 401) comprising:

- an outer cabinet (2);

- a washing tub (3) containing a washing drum (4) suited to receive the laundry to be washed;

- a liquid supply system (5) suitable to convey liquid to said washing tub (3);

- a draining system (20) to drain liquid outside said cabinet (2);

- a filtering group assembly (30) arranged in a flow path between said water supply system and said draining system (20); said filtering group assembly (30) comprising:

- a housing body (32);

- an inlet (34) for liquid to be filtered and a main outlet (36) for draining filtered liquid outside said housing body (32), wherein liquid passing through said filtering group assembly (30) flows from said inlet (34) towards said main outlet (36);

- a coarse objects filter device (140) housed inside said housing body (32) and comprising an objects filter element (144) stopping objects while said liquid flows therethrough;

- a microparticles filter device (40) housed inside said housing body (32) and arranged downstream said coarse objects filter device (140) so that said liquid, during the functioning of said filtering group assembly (30), firstly flows through said coarse objects filter device (140) and then through said microparticles filter device (40), said microparticles filter device (40) comprising a microparticles filter element (44) having a filtering surface (46) on which microparticles accumulate while said liquid flows therethrough; characterized in that said filtering group assembly (30) comprises a cleaning device (50) arranged in a gap (25) formed between said coarse objects filter device (140) and said microparticles filter element (44), said cleaning device (50) comprising a wiper (51) for removing microparticles that accumulate on said filtering surface (46) by means of a relative movement between said wiper (51) and said microparticles filter element (44), said relative movement causing microparticles removed from said filtering surface (46) to be moved towards a storage volume (61) of a collecting chamber (60) removably associated to said housing body (32).

2. Washing machine (1; 301; 401) according to claim 1, characterized in that said coarse objects filter device (140) extends along a main axis (X2) and/or said microparticles filter device (40) extends along said main axis (XI).

3. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said objects filter element (144) and/or said microparticles filter element (44) have a tubular shape, preferably a cylindrical tubular shape.

4. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said objects filter element (144) and said microparticles filter element (44) are coaxially arranged one to the other.

5. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said objects filter element (144) has walls delimiting an objects filter volume (43) and said microparticles filter element (44) has walls delimiting a microparticles filter volume (42), wherein the majority of one between said objects filter volume (43) or said microparticles filter volume (42) is contained within the other.

6. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said collecting chamber (60) is arranged at a side of said gap (25) and in communication therewith.

7. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said collecting chamber (60) is embodied as a cap for closing an opening (37) provided in said housing body (32).

8. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said main outlet (36) is arranged radially outwardly with respect to said inlet (34) so that liquid flowing through said filtering group assembly (30) flows radially outwardly from said inlet (34) towards said main outlet (36).

9. Washing machine (1; 301; 401) according to any claims 1 to 7, characterized in that said inlet (534) is arranged radially outwardly with respect to said main outlet (536) so that liquid flowing through said filtering group assembly (530) flows radially inwardly from said inlet (534) towards said main outlet (536).

10. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said microparticles filter element (44) is removably arranged in said housing body (32) and/or said objects filter element (144) is removably arranged in said housing body (32).

11. Washing machine (1; 301; 401) according to claim 10, characterized in that an opening (37) is provided in said housing body (32) and wherein said microparticles filter element (44) and/or said objects filter element (144) are extractable from housing body (32) by passing through said opening (37).

12. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said wiper (51) is a movable wiper (51).

13. Washing machine (1; 301; 401) according to claim 12, characterized in that said wiper (51) is a rotatably movable wiper (51).

14. Washing machine (1; 301; 401) according to claim 12, characterized in that said wiper (1051) is a translatable wiper, said translatable wiper preferably comprising a piston.

15. Washing machine (1; 301; 401) according to any of the claims 1 to 13, characterized in that said wiper (51) comprises a worm extending along a main axis (X3), said worm comprising a helix-shaped element (56) that winds around said main axis (X3).

16. Washing machine (1; 301; 401) according to claim 15, characterized in that said helix- shaped element (56) is connected to said coarse objects filter device (140), preferably directly fixedly connected to said objects filter element (144).

17. Washing machine (1; 301; 401) according to claim 16, characterized in that said coarse objects filter device (140) is arranged inside said microparticles filter element (44), wherein said helix- shaped element (56) outwardly extends from a radially outer surface of said objects filter element (144) and towards said microparticles filter element (44).

18. Washing machine (1; 301; 401) according to claim 16, characterized in that said microparticles filter element (540) is arranged inside said coarse objects filter device (640), wherein said helix- shaped element (556) inwardly extends from a radially inner surface of said objects filter element (644) and towards said microparticles filter element (540).

19. Washing machine (1; 301; 401) according to any of the claims 16 to 18, characterized in that said coarse objects filter device (140) is rotatable.

20. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said washing machine (1; 301; 401) comprises an actuating device (70; 170) for moving said cleaning device (50).

21. Washing machine (1; 301; 401) according to claim 20, characterized in that said actuating device (70; 170) comprises a handle (70) or a crank or an automated actuating device (170).

22. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said microparticles filter element (544) is a movable element, preferably a rotatable element (544).

23. Washing machine (1; 301; 401) according to any of the preceding claims when depending on claim 9 and 5, characterized in that said filtering group assembly (930) further comprises a removal coarse materials aid system (980) apt to move objects stopped by said objects filter element (844) towards an opening (37) provided in said housing body (32), wherein the majority of said microparticles filter volume (742) is contained within said objects filter volume (743).

24. Washing machine (1; 301; 401) according to claim 23, characterized in that said removal coarse materials aid system (980) comprises a worm extending along a main axis (X4), said worm comprising a helix-shaped element (986) that winds around said main axis (X4).

25. Washing machine (1; 301; 401) according to claim 24, characterized in that said helix-shaped element (986) is connected to said coarse objects filter device (840), preferably directly fixedly connected to said objects filter element (844).

26. Washing machine (1; 301; 401) according to claim 24 or 25, characterized in that said worm outwardly extends from the radially outer surface of said objects filter element (844).

27. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said cleaning device (50) and said collecting chamber (60) are removably coupled one another, so that when said collecting chamber (60) is removed from said housing body (32) said collecting chamber (60) is disconnected from said cleaning device (50).

28. Washing machine (1; 301; 401) according to any of the claims 1 to 26, characterized in that said cleaning device (50) and said collecting chamber (60) are removably connected one another so that they can be disconnected one from the other after being unitarily removed from said housing body (32).

29. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said microparticles filter device (40) is a filter suitable to filter particles having a minimum dimension comprised between 0,1pm and 5mm, preferably a minimum dimension comprised between 10 pm and 100 pm, more preferably a minimum dimension comprised between 10pm and 75pm.

30. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said coarse objects filter device (140; 240) has a meandering structure or a grid structure retaining objects having a prevalent dimension that is higher than 5mm.

31. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said filtering group assembly (30) is arranged in said draining system (20).

32. Washing machine (301; 401) according to any of the preceding claims, characterized in that said liquid supply system (5) includes at least one recirculation system (330; 340) for draining liquid from a bottom region of the washing tub (3) to supply said liquid to a second region of the washing tub (3).

33. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said outer cabinet (2) of said machine further comprises an aperture (7) so that the collecting chamber (60) of said filtering group assembly (30) is accessible therefrom.

34. Washing machine (1; 301; 401) according to claim 33, characterized in that said outer cabinet (2) further comprises an openable door (13) associated to said aperture (7).

35. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said filtering group assembly (430) further comprises a second outlet (402) which is hydraulically connected to a hydraulic circuit portion (26a) of said washing machine (1; 301; 401) located upstream the filtering group assembly (430).

36. Washing machine (1; 301; 401) according to claim 35, characterized in that said second outlet (402) is provided in a liquid stagnation or sump portion (33) of said housing body (32).

37. Washing machine (1; 301; 401) according to any of the preceding claims, characterized in that said draining system (20) comprises a conduit (22) adapted to be connected to a tub outlet port, a draining pump (24) hydraulically connected to said conduit (22), and an outlet pipe (26), arranged downstream said draining pump (24), ending outside said outer cabinet (2), said filtering group assembly (30) being either arranged in said conduit (22) between the tub outlet port and said draining pump (24) or in a portion of said outlet pipe (26).

38. Washing machine (301; 401) according to any of the preceding claims, characterized in that said draining system (20) comprises a draining pump (24) and a further coarse objects filter device (328) arranged upstream said draining pump.