The present invention generally relates to washing appliances such as laundry washing machines and laundry washing/drying machines. Within this field, the present invention relates to improvements to the arrangement of the draining circuit filter for those washing machines.

Nowadays washing machines generally comprise an external casing provided with a loading/unloading door which allows the access to a washing tub containing a rotatable perforated drum in which the laundry to be washed can be loaded.

Known washing machines comprise a water inlet circuit adapted to feed water and washing/rinsing products (i.e. detergent, softener, etc.) into the tub.

Known washing machines also comprise a water outlet circuit, typically comprising a drain pump and draining pipes, adapted to drain the washing/rinsing liquid (i.e. water and water mixed with washing and/or rinsing products) from the tub after the washing and rinsing phases.

The water outlet circuit usually comprises a filtering device, placed in the water outlet circuit upstream of the drain pump, adapted to retain the fluff and any undesirable body (for example buttons came off from the laundry, coins erroneously introduced into the washing machine, etc.) that may happen to pass through the holes located on the periphery of the drum, or fell to the bottom of the tub by passing between the drum and the tub, which could clog, obstruct or even damage the drain pump.

The most common of these filtering devices consists of a cylindrical box attached to the base of the washing machine and containing a removable filter fluidly connected upstream of the drain pump. This box containing the filter is accessible through a quick-removable plug that allows the filter to be removed and cleaned, the plug being hidden by a door located, depending on the case, on the front or back wall of the external casing of the washing machine.

There are also known washing machines comprising a draining sump, obtained on the lower region of the lateral surface of the tub (i.e. in the bottom of the tub), fluidly communicating with the internal of the latter and fluidly connected upstream of the drain pump.

The filter is placed in the draining sump and is typically a cup-shaped body provided with a filtering surface, i.e. a surface provided with a plurality of apertures which are dimensioned in order to allow the passage of the washing/rinsing liquid, but to prevent the passage of fluff and foreign bodies of prefixed dimensions. In this case the rotatable drum of the washing machine is provided with at least one opening, closable by a removable or openable lid, adapted to allow a user to reach the filter from the internal of the washing machine, for example for inspection or cleaning; typically the filter may be removed from and repositioned into the draining sump, so as to facilitate its inspection, cleaning or replacement.

A prior art washing machine containing a filter used to prevent residual particles of dirt from reaching and obstructing the drain pump and its drainage duct, and which can be removed from the internal of the tub, for inspection, cleaning and replacement, is shown, for example, in GB 1197919, which discloses a washing machine comprising a tank (i.e. a tub) for liquid with an opening in its base, a draining pump connected by a pipe to the opening of the tank, and a basket (i.e. a rotary drum) arranged within the tank; a cup-like filter element having filter openings in its side wall is removably seated in the tank opening, and an opening is provided in the basket, provided with a removable closure, to provide access to the filter element.

Another example of known washing machine provided with a filter which can be removed from the internal of the tub is illustrated in FR 2190966, which discloses a top-loading washing machine comprising a tub containing a rotary drum provided, on its lateral surface, with a first door, adapted for loading/unloading the laundry, and with a second door, arranged opposite to the first door and adapted to allow the recovering of linen which would have slipped between the tank and the drum. A connector is fixed to the bottom of the tub, such connector being provided, at his inferior region, with a duct adapted to receive one of the extremities of a discharging pipe. A housing is provided in the connector, adapted to receive a filter accessible by simultaneously opening the two doors of the drum.

A further known washing machine comprising a filter accessible from the internal of the tub is illustrated in the European patent n. EP 1849904, which discloses a top-loading washing machine comprising a draining filter access apparatus integrated in a lifter diametrically opposite to the drum access door (i.e. to the internal lid allowing the access to the drum). The draining filter access apparatus comprises a body, including an opening aligned with an opening of the same shape and dimensions made in the body of the drum, and a lid, hinged to the body and locking on the body by a simple ratchet mechanism.

EP 2325377, in the name of the present Applicant, discloses a washing machine comprising a washing tub, a draining sump fluidly communicating with the internal of the washing tub and fluidly connected to a draining circuit, a filter, removably associable to a seat provided between the washing tub and the draining sump, adapted to allow the passage of a liquid and to impede the passage of bodies of fixed dimensions. The filter comprises an indicator adapted to be displaced in a first position if the filter is correctly inserted into the seat, and in a second position if the filter is incorrectly inserted into seat.

Applicant has observed that the known solutions of washing machines with filter accommodated in a seat provided between the washing tub and the draining sump, and accessible from inside the drum, are not fully satisfactory, because the location of the filter is not straightly visible from outside the machine (also due to scarce illumination of the drum internal space), and unless the user carefully reads the machine instruction manual (a burden that often the users are not willing to sustain), the user might be induced to look for the more usual filter compartment door on the machine cabinet, and not finding it, the user may at the end forget to periodically clean the filter.

The Applicant has thus faced the problem of overcoming this drawback.

Applicant has found that by providing a lighting device arranged for generating a light which is emitted inside the drum for helping a user to find the location of the filter, the user can easily spot the location of the filter inside the drum, and therefore the risk of forgetting the maintenance of the filter is reduced and also the maintenance of the filter is simplified.

According to an aspect of the present invention, there is provided a washing machine comprising:

• a washing tub;
• a drum rotatably accommodated within the washing tub;
• a draining sump fluidly communicating with the internal of said washing tub and fluidly connected to a draining circuit operable for draining liquid from the washing tub;
• a filter provided between said washing tub and said draining sump and accessible from the inside of the drum through a drum aperture.

The washing machine comprises a lighting device arranged for generating a light which is emitted inside said drum for helping a user to find the location of said filter.

Advantageously, said filter is housed in a filter seat provided between said washing tub and said draining sump, said filter seat being accessible from the inside of the drum through a drum aperture. Said lighting device is advantageously associated with said filter seat.

A closing device is advantageously provided, coupled or couplable to the drum for selectively closing/opening the drum aperture for accessing said filter. Advantageously, the closing device is at least partly in a material transparent to the light for the transmission of the light generated by the lighting device.

Said closing device may comprise an upper region having formed therein a self-explanatory word or symbol in transparent material.

Expediently, the closing device comprises a drum lifter provided along the drum lateral surface for improving the stirring of the laundry during the drum rotation.

Said drum lifter may be pivotable with respect to the lateral surface of the drum or removably coupled to the lateral surface of the drum.

Advantageously, said filter is at least partly in a material transparent to the light for the transmission through it of the light generated by said lighting device.

The lighting device may be arranged to emit light along a direction parallel to an axis of the filter seat, or along a direction transversal to an axis of the filter seat.

Preferably, the lighting device is water-resistant, and comprises a light source advantageously housed inside a water-tight case.

These and other features and advantages of the present invention will clearly result by the following detailed description of exemplary and non-limitative embodiments of the present invention, which, for its better intelligibility, should be read in conjunction with the attached drawings, wherein:

• Fig. 1 is a schematic, lateral and partially sectioned view, of a washing machine according to the present invention;
• Fig. 2A to Fig. 2C show, in isometric views from the outside of a washing machine according to the present invention, some steps of the extraction procedure of the filter for foreign bodies;
• Fig. 3A and Fig. 3B are isometric view partially in cross section of a washing tub and drum assembly of the washing machine of Figs. 2A - 2C, in an embodiment of the present invention;
• Fig. 3C shows an enlarged a detail of Fig. 3A;
• Fig. 4A and Fig. 4B are isometric view partially in cross section of a washing tub and drum assembly of the washing machine of Figs. 2A - 2C, in another embodiment of the present invention;
• Fig. 4C shows an enlarged a detail of Fig. 4A;
• Fig. 5 to Fig. 7 show, in cross-section and in exploded isometric view, a filter according to an embodiment of the present invention.

The washing machine according to the exemplary invention embodiment which will be here considered and is illustrated in the drawings is of the front-loading type; it is however clear that the invention is applicable, substantially without any crucial modification, to a top-loading washing machine.

It is also clear that the invention can be applied, substantially without any modification, both to a "simple" washing machine (i.e. a washing machine which can only wash and rinse the laundry) and to a washing-drying machine (i.e. a washing machine which can also dry the laundry).

With reference to the schematic representation of Fig. 1, the washing machine 100 according to the exemplary invention embodiment here considered comprises an external casing or cabinet 105 having a frontal wall 110 in which an access opening 115 is provided, with an associated laundry loading/unloading door 120, which allows the access to a washing tub 125 contained in the external casing 105; the washing tub 125 contains a rotatable perforated drum 130 in which the laundry to be washed, not illustrated, can be loaded (in the drawings, the holes in the lateral surface of the rotatable perforated drum 130 have not been depicted).

The washing tub 125 is connected to the external casing 105 preferably via a flexible bellows 135, connected between the frontal, opened, surface of the washing tub 125 facing the access opening 115, and the border of the latter.

The washing machine 100 comprises a water inlet circuit 140 adapted to feed water and washing/rinsing products (i.e. detergents, softeners, etc.) into the washing tub 125; the water inlet circuit 140 advantageously comprises a removable drawer 145, adapted to be filled with washing and/or rinsing products, for example detergents, softener, bleaching substances, etc.

The water inlet circuit 140 comprises also an inlet duct 150, connectable to water delivery mains present outside the washing machine 100, and adapted to deliver fresh water to the drawer 145; the water inlet circuit 140 comprises also an outlet duct 155, fluidly connecting the drawer 145 and the tub 125 and adapted to deliver water and washing/rinsing products into the washing tub 125. Advantageously the water inlet circuit 140 also comprises one or more valves, not shown, adapted to regulate the flow of water.

When fresh water is admitted into the drawer 145 via the inlet duct 150, such fresh water washes away the washing/rinsing products contained in the drawer 145, and delivers these products into the washing tub 125 via the outlet duct 155.

In other embodiments, not shown, the water inlet circuit 140 comprises one or more reservoirs for one or more washing/rinsing products from which a certain amount of these washing/rinsing products, depending on the washing program, is automatically delivered to the washing tub 125.

The washing machine 100 comprises a draining sump 160, obtained preferably on a lateral surface 165 of the tub 125, fluidly communicating with the internal of the tub 125, and fluidly connected to a draining circuit 170 adapted to drain the washing/rinsing liquid (i.e. water and water mixed with washing and/or rinsing products) from the washing tub 125.

Advantageously, as better explained in the following, in the exemplary invention embodiment here considered the draining sump 160 is accessible from inside the drum 130.

Advantageously, the draining sump 160 is placed in the lower region of the washing tub 125, so that the liquid contained in the latter can be conveyed by gravity towards the draining sump 160, and therefore to the draining circuit 170.

In other words, the draining sump 160 is a sort of container associated downstream to the washing tub 125 and adapted to collect the washing/rinsing liquid exiting the latter.

Preferably, the draining sump 160 is obtained in a single-piece construction with the lower region of the tub 125, advantageously by moulding of a plastic material.

The draining circuit 170 comprises a draining pump 175 provided with an impeller, not illustrated, housed in an impeller chamber 180 which is preferably, but not necessarily, obtained in a single-piece construction with the draining sump 160 and with the washing tub 125, preferably in correspondence to an extension of the draining sump 160.

In other advantageous embodiments of the invention, not shown, the draining circuit 170 can be also provided with a recirculation circuit, adapted to drain the washing/rinsing liquid from the bottom of the tub 125, and to re-admit such liquid into an upper region of the tub, for improving the wetting of the laundry. The recirculation circuit of a washing machine is well known in the art, and therefore will not be described in detail.

The washing machine 100 comprises a filter 185, provided between the washing tub 125 and the draining sump 160, advantageously accommodated, preferably removably, in a suitable seat 190 provided between the washing tub 125 and the draining sump 160, and adapted to allow the passage of washing liquid and to prevent the passage of foreign bodies of fixed dimensions from the washing tub 125 to the draining circuit 170 (and therefore to the draining pump 175). These foreign bodies can be, for example, buttons came off from the laundry, coins or other little objects contained in the pockets of trousers or other clothes and erroneously introduced into the washing machine 100, lint, fluff, etc.

In the exemplary embodiments here considered, the seat 190 for the filter 185 is advantageously obtained inside the draining sump 160, and partially coincides with the latter; in other advantageous embodiments, not shown, the seat 190 may be provided partially internally and partially externally to the draining sump 160, or totally externally to the draining sump 160, provided that it is arranged in such a way that when the filter 185 is correctly inserted in the seat 190, all the washing/rinsing liquid has to pass through the filter 185 in order to flow into the draining sump 160.

Advantageously, the seat 190 is accessible from inside the drum 130.

The access to the filter 185, for example for its inspection, cleaning and/or replacement (provided that filter 185 is removable), is performed from the internal of the drum 130 via a suitable aperture (visible for example in Figs. 2A - 2C, wherein it is indicated as 205) provided on the lateral surface 197 of the drum 130 so that, in a particular angular position of the latter, such aperture 205 faces the seat 190; during the washing machine operation, this aperture 205 is closed by a closing device 199, for example a lid or a porthole, adapted for selectively closing the aperture 205. In an exemplary embodiment of the invention, the closing device 199 advantageously comprises a drum lifter (i.e. one of the laundry lifters that are often provided along the drum lateral surface 197 for improving the stirring of the laundry during the drum rotation) which is pivotable with respect to the lateral surface 197 of the drum 130, so that it can be swiveled open for allowing the access to the underlying aperture; when not swiveled open, this lifter operates as a traditional laundry lifter, and is therefore useful for improving the stirring of the laundry during the rotation of the drum 130. In other embodiments of the invention, the closing device (e.g. a lifter) may be removably coupled to the drum lateral surface 197, instead of being hinged thereto.

The filter 185 may be for example box-shaped (or cup-shaped) and it may be preferably substantially cylindrical (but it may be also prismatic, or cubic, or parallelepiped, or may have any other box-shaped conformation). Later on, an exemplary filter structure will be described.

The filter 185 advantageously comprises a filtering surface 195, advantageously perforated, adapted to allow the passage of a liquid and for retaining fluff, lint and foreign bodies of fixed dimensions; the filtering surface 195 allows the passage of the washing liquid from the washing tub 125 to the draining circuit 170, but prevents the passage of foreign bodies of prefixed dimensions, for example buttons, coins, etc.

Fig. 2A to Fig. 2C show some steps of a procedure of extraction of the filter 185 from its seat 190. After opening the loading/unloading door 120, the user rotates the drum 130 to reach the proper angular position in which the aperture 205 faces the seat 190, for example bringing the closing device (e.g. lifter) 199 at the bottom; then the user swivels the lifter 199 open to free the access to the aperture 205 in the lateral surface 197 of the drum 130, and thus to the filter seat 190 (in Fig. 2A, the filter 185 - still within its seat 190 - is not visible being hidden by the cabinet). The user then grasps the filter (later on, an exemplary embodiment of filter 185 will be described, and the means for facilitating the grasping by the user will be shown) and pulls it out of the seat 190, as shown in Fig. 2B. The user can then extract the filter from the machine.

It is underlined that the present description of an advantageous embodiment refers to a removable filter 185, but it is clear that the present invention can be applied as well to a non-removable filter (i.e. a filter fixed in a non-removable way to the seat 190), which may be cleaned by a user via the aperture 205, but not removed.

According to the present invention, in order to facilitate the user in spotting the location where the filter 185 is (as already explained in the foregoing, the accessibility of the filter 185 from inside the drum 130, even if it is a solution already known in the art, is something still uncommon for most of the users, who are accustomed to having the filter accessible by opening a small door at the bottom of the front panel of the machine cabinet, and moreover, the drum internal space is scarcely illuminated), a lighting device is provided, arranged for generating a light which is emitted inside the drum 130 for helping a user to find the location of the filter 185. It is underlined that, if the filter is removable, "location of the filter" means, when the filter is associated to its seat in the washing machine, the position in which the filter is placed, while, when the filter has been removed from the machine (for example for its cleaning), the position in which the removed filter have to be repositioned.

Preferably, the lighting device is associated with the draining sump 160; more preferably, the lighting device is associated with the filter seat 190. Advantageously the closing device provided for closing the aperture 205 in the lateral surface 197 of the drum 130, i.e. the lifter 199 in the current advantageous embodiment, is formed at least partly transparent to light; for example, an upper region of the closing device 199 may have formed therein a self-explanatory word, like the word "FILTER" (possibly in the language of the country where the appliance is sold), or a self-explanatory symbol, e.g. "F", in transparent material. The lighting device advantageously comprises a light source 320 operable to generate light, which for example may comprise a lamp or a LED; the light generated by the lighting device is transmitted through the closing device 199, and is easily visible by the user when looking into the drum 130, who can thus spot the location of the filter 185.

Hereinafter, two exemplary and non-limitative embodiments of the present invention are presented.

In the embodiment depicted in Fig. 3A to Fig. 3C, the lighting device 305 is located below the filter 185 (when the latter is housed in its seat 190), preferably at the bottom of the filter seat 190, preferably in such a way that the light generated by the light source 320 of the lighting device 305 propagates along the direction of the axis of the filter seat 190 (upwards in the current embodiment). For example, the lighting device 305 may be accommodated inside a receptacle 310 provided in proximity of the bottom of the filter seat 190, preferably projecting down from the bottom of the filter seat 190; the receptacle 310 is preferably in one piece construction with the draining sump 160. The receptacle 310 may for example take the form of a sleeve open at the bottom end for the insertion of the lighting device 305, and opening into the filter seat 190, at the bottom of the latter. The lighting device 305 is connected, preferably by wires (not shown), or wireless, to a control electronics of the machine (also not shown), which controls inter alia the activation of the lighting device 305. The lighting device 305 is advantageously water-resistant, with the light source 320 advantageously housed inside a water-tight case 325.

When the filter 185 is inside the filter seat 190 and the lighting device 305 is activated to emit light, the emitted light (schematized in Fig. 3C by the arrows in broken line) passes through the filter 185 and through the closing device 199 (which, as mentioned, is at least partly transparent to light) and goes into the drum 130, where the user can see it, thereby easily spotting the location where the filter 185 is. Preferably, in order to enhance the transmission of light, the filter 185 structure is at least partly made of transparent material (later in the present description, a filter structure according to an exemplary embodiment of the present invention will be presented).

In the embodiment depicted in Fig. 4A to Fig. 4C, the lighting device 305 is located laterally to the filter 185 (when the latter is housed in its seat 190), preferably on one side wall of the filter seat 190, in such a way that the light is emitted by the light source 320of the lighting device approximately orthogonally (or, more generally, not parallel) to the direction of the axis of the filter seat 190. For example, the lighting device 305 may be accommodated inside a receptacle 410 placed in proximity of the side wall of the filter seat 190, preferably projecting from the side wall of the filter seat 190 transversally (more preferably orthogonally)to the axis of the filter seat 190.

The receptacle 410 is preferably in one piece construction with the draining sump 160. The receptacle 410 may for example take the form of a sleeve with open end for the insertion of the lighting device 305, and opening into the filter seat 190. Preferably, the receptacle 410 opens into the filter seat 190 in a region proximate to the bottom wall thereof. The lighting device 305 is connected preferably by wires (not shown), or wireless, to a control electronics of the machine (also not shown), which controls inter alia the activation of the lighting device 305. The lighting device 305 is advantageously water-resistant, with the light source 320 preferably housed inside a water-tight case 325.

When the filter 185 is inside the filter seat 190 and the lighting device 305 is activated to emit light, the emitted light (schematized in Fig. 4C by the arrows in broken line) passes through the perforated filtering surface 195 of the filter 185 and propagates up to the closing device 199, which, being as mentioned is at least partly transparent to light, allows the light to pass through and to go into the drum 130, where the user can see it, thereby easily spotting the location where the filter 185 is. Preferably, in order to enhance the transmission of light, the filter 185 structure may be at least partly in transparent material.

In this embodiment of the invention, the provision of the lighting device 305 has, in addition to the function of easing the spotting of the filter location by the user, the further function of warning the user when the filter 185 is clogged: when this happens, the light emitted by the lighting device 305 can not pass through the perforated filtering surface 195 of the filter 185, due to the presence of fluff or other bodies inside the filter. As a consequence, the light generated by the light source 320 cannot reach the closing device (e.g. lifter) 199 and pass therethrough to reach the inside of the drum 130. The user can in this way be warned of the necessity of cleaning the filter 185.

In Fig. 5 to Fig. 7, the structure of the filter 185 according to an exemplary embodiment of the present invention is shown. The exemplary filter structure corresponds to that described in the EP 2325377.

In this exemplary embodiment the filter 185 is substantially cylindrical, and the filtering surface 195 is comprised in the lateral cylindrical surface of the filter 185.

Advantageously, the filtering surface 195 is provided with a plurality of openings 510 adapted to allow the passage of liquids, but preventing the passage of fluff, lint and foreign objects (e.g. coins, buttons, etc.) whose dimensions are higher than a prefixed value depending on the dimensions of the openings 510.

The filter 185 is advantageously adapted to be removably inserted into the seat 190, and advantageously comprises a coupling device adapted to releaseably fix it to the seat 190. For example, the coupling device comprises an outwards-projecting peripheral flange 515, projecting from an upper border 520 of the filter 185 and adapted (as visible for example in Fig. 3C and Fig. 4C) to abut against a border of washing tub 125 surrounding the filter seat 190, while the remaining of the filter 185 is received inside the seat 190, for avoiding that the filter 185 fall into the draining sump 160.

In the shown exemplary embodiment, the coupling device advantageously also comprises snap-fitting means adapted to allow a snap-fit connection of the filter 185 to the seat 190. For example, the snap-fitting means comprise two or more arms 705a, 705b, associated with the filter 185, and elastically deformable so that they may be elastically pressed in a radial direction with respect to the lateral cylindrical surface of the filter 185. In the shown embodiment, the arms 705a, 705b are connected to the lateral cylindrical surface of the filter 185 in proximity of the bottom surface 505 thereof.

The arms 705a, 705b comprise a first region 710, connected to the lateral cylindrical surface of the filter 185 in proximity of the bottom surface 505 thereof, and sloped in such a way that its distance from the lateral cylindrical surface of the filter 185 increases while approaching the upper border 520 of the filter 185. The arms 705a, 705b comprise a second region 715, contiguous to the first region 710 and sloped in an opposite direction with respect to the first region 710 of the same arm, comprising the free end 720 of each arm; the arms 705a, 705b, in proximity of their free ends 720, are therefore sloped in such a way that their distance from the lateral cylindrical surface of the filter 185 decreases while approaching the upper border 520 of the filter 185.

As visible in Fig. 3C and Fig. 4C, an annular riddle 315 advantageously protrudes from the border of the washing tub 125 surrounding the seat 190, towards the internal thereof. During the insertion of the filter 185 into the seat 190, the first region 710 of the arms 705a, 705b slides against the annular riddle 315, and, due to the slope of such first region 710, the arms 705a, 705b are elastically pushed towards the lateral cylindrical surface of the filter 185. After the free end 720 of the arms 705a, 705b trespasses the annular riddle 315, the arms 705a, 705b elastically move towards the external of the filter 185, positioning with their free ends 720 below the annular riddle 315; the filter 185 is therefore locked to the seat 190. For removing the filter 185 from the seat 190, the user has to pull the filter 185 in the opposite direction with respect to the draining sump 160; the free ends 720 of the arms 705a, 705b slide against the annular riddle 315 and, due to their particular slope, they cause the arms 705a, 705b to elastically flex towards the lateral cylindrical surface of the filter 185, releasing the arms 705a, 705b from the annular riddle 315, and allowing the free removal of the filter 185.

Advantageously, the filter 185 comprises a grasping element, which will be better described in the following, adapted for allowing a user to easily remove the filter 185 form the seat 190.

As will be better explained in the following, the filter 185 advantageously comprises an indicator adapted to be displaced in a first position if the filter 185 is correctly inserted into the seat 190, and in a second position if the filter 185 is incorrectly inserted into the seat 190. This allows the user to check whether or not the filter 185 has been correctly inserted into the seat 190, simply by looking at the position of the indicator: if the indicator is in the first position, the user is aware that the filter 185 has been correctly inserted into the seat 190, whereas if the indicator is in the second position, the user is aware that the filter 185 has been incorrectly inserted into the seat 190.

Preferably, but not necessarily, when the indicator is in the above mentioned first position, the indicator is visible from the external of the filter 185, while when in the second position the indicator is not visible from the external of the filter 185. In other embodiments, the indicator may be visible from the external of the filter 185 in both the first and second positions.

Advantageously, as will be better explained in the following, the indicator is arranged in such a way that if the filter 185 is correctly inserted into the draining sump 160, the indicator engages the internal surface of the draining sump 160 and is moved into the first position.

In the shown exemplary embodiment, the indicator comprises a movable element, like a pin 525, associated with the filter 185, in such a way that, if the filter 185 is correctly inserted into the seat 190, the pin 525 is displaced into a first position, while if the filter 185 is incorrectly inserted into the draining seat 190, the pin 525 is displaced into a second position.

The filter 185 comprises a guide 530 adapted to allow the sliding of the pin 525 therein. The bottom surface 505 of the filter 185 is opportunely substantially frusto-conical, with an aperture 535 preferably provided in correspondence of the minor base of the frustum of cone.

The filter 185 advantageously comprises a hollow body 540, preferably tubular, projecting from the border of the aperture 535 provided at the bottom surface 505 of the filter 185, partially positioned internally to the lateral cylindrical surface of the filter 185 and extending with its upper end 545 above the upper border 520 of the filter 185, so that when the filter is positioned into the seat 190 the upper end 545 of the hollow body 540 protrudes above the bottom of the washing tub 125, so as to be stricken by the flux of water moved by the rotatable drum 130 during its rotation.

Moreover, the upper end 545, extending above the upper border 520 of the filter 185, may be grasped by a user in order to remove the filter 185 from the seat 190; in this case, therefore, the grasping element comprises the upper end 545 of the hollow body 540.

The washing liquid enters the filter 185 from the upper border 520 thereof, and goes to the draining sump 160 passing through the filtering surface 195 (i.e. the holes 510); fluff, lint and foreign bodies contained in the washing liquid and whose dimensions are bigger than the holes 510 remains trapped between the filtering surface 195, the bottom surface 505 of the filter 185 and the external surface of the hollow body 540.

The guide 530, preferably substantially cylindrical, for the movable element, is advantageously provided inside the hollow body 540, preferably, but not necessarily, concentrically thereto, in such a way that there is a first gap 550 between the internal surface of the hollow body 540 and the external surface of the guide 530.

Preferably, but not necessarily, the upper end 555 of the guide 530 is opened, and it is placed in correspondence of the free end 545 of the hollow body 540.

Advantageously, the hollow body 540 comprises one or more apertures 560, provided on its upper end 545, fludily communicating with the first gap 550 and adapted for allowing the entrance of washing liquid from the washing tub 125 into the above mentioned first gap 550. Advantageously, the apertures 560 are adapted to allow the passage of liquids, but for preventing the passage of objects (e.g. coins, buttons, etc.) whose dimensions are higher than a prefixed value depending on the dimensions of the apertures 560; in particular the dimensions of the apertures 560 are such that if a body can not pass through the filtering surface 195, it can neither pass through the apertures 560 (in the embodiments illustrated in the enclosed figures, therefore, the dimensions of the apertures 560 are equal or smaller than the dimensions of the holes 510).

Advantageously, the apertures 560 are positioned in such a way that when the filter 185 is in the seat 190, they are stricken by the flux of water moved by the rotatable drum 130 during its rotation.

A foot 565 protrudes from the second end 570 of the pin 525, preferably at least partially countershaped to the external surface of the bottom surface 505 of the filter 185, and therefore, in this embodiment, substantially frusto-conical.

The pin 525 may therefore slide from the first position, in which a stopping element 575 (for example an annular riddle) provided on the lateral surface of the pin 525, contacts a second flange 577 protruding from a lower end 579 of the guide 530, towards the internal of the latter, and the second position, in which the foot 565 contacts a plurality of spacing elements 580 protruding from the external surface of the bottom surface 505 of the filter 185.

When the pin 525 is in the second position, a second gap 583 is obtained between the external surface of the bottom surface 505 of the filter 185 and the foot 565; this second gap 583 fluidly communicates with the first gap 550.

Advantageously, the length of the pin 525 is such that when it is in the first position, the first end 585 of the pin 525 protrudes from the upper end 555 of the guide 530, so as to be visible and/or touchable from outside the filter 185; on the contrary, when the pin 525 is in the second position, the first end 585 of the pin 525 is totally contained in the guide 530, and therefore can not be seen nor touched by a user. This feature allows a user to easily check if the filter 185 has been correctly inserted into the seat 190 or not.

The pin 525 may be arranged in such a way that it is visible both in the first position and in the second position, but in such a way that in these two positions it protrudes from the guide 530 in two different ways.

When the filter 185 is correctly inserted into the seat 190, the foot 565 contacts (i.e. engages) the internal surface of the seat 190 (in this case the bottom of the draining sump 160), and the pin 525 is positioned in the first position; in this position a by-pass conduit, comprising the apertures 560, the first gap 550 and the second gap, fluidly connects the washing tub 125 and the internal of the draining sump 160, by-passing the filtering surface 195 of the filter 185.

As mentioned in the foregoing, in order to improve the transmission of the light generated by the lighting means 305, the filter 185 is advantageously made at least partly in transparent material. For example, the pin 525 may be made in a material transparent to light, so as to behave as a light guide.

Some embodiments of the present invention have been here described; it should be clear to those skilled in the art that several changes to the described embodiments, as well as alternative ways of practicing the invention are possible.