EP2503050B1

EP2503050B1 - Washing machine comprising a filter element

Info

Publication number: EP2503050B1
Application number: EP11159619.3A
Authority: EP
Inventors: Martino Bondi; Marco Maiero
Original assignee: Electrolux Home Products Corp NV
Current assignee: Electrolux Home Products Corp NV
Priority date: 2011-03-24
Filing date: 2011-03-24
Publication date: 2013-12-18
Anticipated expiration: 2031-03-24
Also published as: EP2503050A1

Abstract

The invention relates to a washing machine (2), in particular a washing machine (2) with a recirculation circuit (28), comprising: a tub (4) with a sump (8), a draining circuit (10), wherein the sump (8) is fluidly connected to the draining circuit (10), and a filter element (12), which is removably positionable in the sump (8), wherein the filter element (12) comprises a valve (14) for selectively obstructing the passage of liquid from the tub (4) to the draining circuit (10).

Description

The invention relates to a washing machine (expression "washing machine" including both "simple" washing machines, i.e. washing machines which can only wash and rinse laundry, and washing-drying machines, i.e. washing machines which can also dry laundry, both of the front-loading or top-loading type) with a draining circuit comprising a valve adapted to selectively open and close the passage of liquid from a tub to the draining circuit.
EP 1 204 792 B1 discloses a washing machine, wherein an inlet of a draining circuit is fluidly connected to a sump. A check valve is arranged between the sump and the inlet of the draining circuit. The check valve shuts off the sump from the draining circuit during a washing cycle by using a valve seat and a ball as closing element. The ball is freely movable within a draining section of the draining circuit.
By using a check valve of the above kind, water within a draining circuit needs not be heated during a heating phase of a washing cycle of the washing machine, whereby the energy consumption of the washing machine is reduced. Assembling of the draining circuit in a way that guarantees proper operation of the valve and long-term functionality of the closing state of the valve may be a problem, as such a check valve however is a component in danger of failure, e.g. because of clogging. As such it needs servicing. Servicing however may be complicated by the valve design and mounting location and in the consequence cost intensive.
US2621505 discloses a combined washing and drying machine provided with a filter in the draining circuit according to the preamble of claim 1 and with means for displacing the filter with respect to the discharge means during the spinning operation.
GB1197919 discloses a washing machine comprising a removably mounted a cup-like filter in the draining circuit.
US2343743 discloses a washing machine provided with a filter in the draining circuit. US5601660 discloses an improved food debris filtering apparatus for a dishwasher. US5848601 I discloses a pump system for a dishwasher provided with a filter. US2681658 discloses a dishwashing machine comprising a washing chamber having a sump with a valve controlled drain outlet.
US4134413 discloses a tandem rack dishwashing machine.
US5937879 discloses dish washing machine provided with a filter.
DE19618879 discloses a washing machine provided with a valve and a filter in the draining circuit.
EP2251477 discloses a washing machine comprising a filter for filtering water drained from a washing tub.
DE3931031 discloses a dishwasher provided with a filter unit inserted in the water drainage circuit.
It is an object of the invention to provide a washing machine having a valve arrangement providing improved reliability of operation and/or improved simplicity in the mounting process and/or improved serviceability.
The invention is defined in claim 1. Particular embodiments are set out in the dependent claims.
According to claim 1, a washing machine comprises a tub with a sump and a draining circuit, wherein the sump is fluidly connected to the draining circuit. Furthermore a filter element is provided, which is removably positionable in the sump, e.g. which can be removed from the sump by a user, e.g. for cleaning or replacement, and can be (re)inserted into the sump thereafter. By inserting the filter element in the sump, preferably upstream the draining circuit, foreign objects and fluff are effectively filtered out of the liquid drained from the tub. In consequence, no or a reduced amount of foreign objects enter the draining circuit of the washing machine. The sump is preferably formed integrally with the tub, such that no additional mounting or assembly step is necessary for mounting the sump at the tub. The washing machine may preferably comprise a chamber for at least a portion of a draining pump, wherein the chamber is preferably integrally formed with the sump and the tub, such that fewer assembling steps and less assembly time for assembling the washing machine are required.
The washing machine according to claim 1 also comprises a valve adapted to selectively open and close a passage of liquid from the tub to the draining circuit. As such, the valve preferably is arranged downstream the tub and upstream the draining circuit. The valve is adapted to seal or close the tub from the draining circuit, preferably in particular during a heating phase of a washing cycle of the washing machine. By blocking the fluid connection to the draining circuit when the valve is in its closed position, water within the draining circuit is not heated and the energy consumption of the washing machine is reduced. For enhancing the serviceability of the washing machine with respect to the valve, e.g. for easy handling of the same, the filter element comprises the valve. By providing a filter element comprising the valve the valve can for example be removed from the sump or be (re)inserted together with the filter element such that easy handling of the valve is provided. In the consequence the serviceability of the washing machine is improved. Preferably the filter element with the valve form a unit that can be mounted in one run during final assembling of the washing machine.
The washing machine preferably comprises a recirculation circuit, which is fluidly connected to the tub to circulate liquid from a lower portion of the tub to an upper or middle portion of the tub. Without a recirculation circuit and to thoroughly wet laundry within the drum, it is necessary to supply a high amount of water into the tub, such that a great part of the laundry is covered with the water. By providing the recirculation circuit to recirculate the washing water, the amount of water required for wetting the laundry is reduced, as the washing water can repeatedly be sprayed onto or supplied to the laundry in the drum. Consequently, the amount of water to be heated is reduced, and the energy consumption of the washing machine is further reduced. An inlet of the recirculation circuit may be positioned downstream the valve (which is generally arranged between the tub interior and the draining circuit and/or sump). In particular when the valve is in the closed position to shut off the tub from the draining circuit, the inlet of the recirculation circuit is preferably positioned or arranged to be fluidly connected to the draining circuit, preferably close to the valve. Thus the draining circuit is fluidly disconnected from the tub when the valve is closed. Alternatively the inlet of the recirculation circuit is arranged upstream the valve in its closed position or state.
In case undissolved detergent has passed the valve (e.g. during the filling process when detergent is flushed into the tub by liquid) due to a not perfectly watertight sealing of the valve, this detergent collects in the draining circuit substantially below the valve seat. At the next time when the recirculation circuit is operated, the detergent collected in this way below the valve seat can be sucked in through the inlet of the recirculation circuit below (or downstream seen from the tub) the valve, and can be recirculated back into the tub. Thereby the washing effect is enhanced as detergent is more efficiently used instead of being drained from the washing machine. Thus the washing machine provides an economical washing operation with respect to energy and detergent consumption.
The valve preferably has a movable closure element adapted to be releasably engaged with an associated valve seat of the valve to close or open the valve, i.e. its opening within the valve seat. The valve is preferably a valve actuated automatically in dependency of a liquid level and/or a pressure difference acting upon the movable closure element when the valve is situated in the sump, i.e. the valve can be actuated by the liquid. For such actuation the movable closure element is preferably a floatable element. E.g. the closure element floats on the liquid that fills the sump and is eventually pressed towards the valve seat by the rising liquid level, i.e. by buoyant force, and seals thereby a valve opening in the valve seat. Thereby the tub is shut off from the draining circuit. Hence a simple and robust valve is provided which allows for easy servicing.
The valve preferably acts like a ball check valve. Preferably the movable closure element has a ball-like spherical, cylindrical or ellipsoidal shape or a shape substantially representing the same or a combination therefrom such that it may easily engage with the countershaped or mating contour of the valve opening, wherein the contour preferably forms at least a portion of the valve seat. By the mating contour or countershape between the moveable closure element and the valve seat, the valve is preferably self-orienting in its closed position or state. This is advantageous when the closure element is freely floating within a basket filter element of the filter element capturing the same within the sump or draining circuit. Alternatively the closure element is formed by a hinged flap, e.g. like in a swing check valve, which is closed preferably by buoyant force and water pressure.
In an embodiment the basket filter element, which preferably is designed at least partially in form of a cage allowing for liquid, e.g. from the tub, to flow through, is adapted for housing (preferably to spatially capture or confine) the movable closure element of the valve therein, and for filtering foreign objects out of the liquid from the tub. The basket filter element blocks foreign objects (at least a portion thereof) from entering the draining circuit of the washing machine and forms the filtering portion of the filter element, preferably the sole filtering portion of the same. The basket filter element preferably comprises an open end through which the movable closure element can be inserted, wherein, when inserted in the sump, the open end faces in the direction of the inlet end of the sump for receiving liquid from the tub. Preferably the open end is a wall section of the filter where the element comprising the valve seat may be arranged at the filter element. The movable closure element preferably is loosely contained within the basket filter element. The interior of the basket filter element thereby has a size and/or shape allowing for unimpeded opening or closing of the valve by cooperation of the movable closure element with a valve seat arranged at the basket filter element. In an embodiment the (cage-)wall elements and/or interior elements facing the interior of the basket filter element are advantageously adapted to pre-align the closure element with the corresponding valve opening of the valve when the valve is open and the closure element is freely floating within the basket filter element. Such a pre-alignment can be achieved by adapting the interior shape of the basket filter element to correspond with the shape of the movable closure element such that the movable closure element can be guided towards the valve seat. Hence the closing time of the valve can be reduced and reliability of the closing/opening movement is improved.
Preferably the valve seat is comprised within or formed by a valve seat element capturing the movable closure element within or at the basket filter element. The valve seat element preferably is a single element, for example a disc like or flat element, for being attached to or at the open end of the basket filter element. The valve seat element advantageously forms the valve seat, e.g. by providing an opening which corresponds with the shape of the closure element meant to engage therewith when closing the valve. The valve seat element of the filter element can be formed by a cap comprising the valve opening, wherein the cap is attachable to the basket filter element. By attaching the valve seat element to the open end of the basket filter element when the movable closure element is already contained therein, the movable closure element is captured or confined easily within the basket filter element and the valve is operable.
Preferably the filter element comprises a hinge advantageously allowing for opening and servicing the filter element by pivoting the valve seat element in an open position allowing for accessing the interior of the basket filter element and e.g. the movable closure element. By use of the hinge there is no necessity to completely detach the valve seat element from the filter element when servicing the filter element. Furthermore, the hinge allows for easy refitting of the filter element comprising the valve by simply pivoting the valve seat element back in a predetermined closed position allowing for fixture. The hinge may be formed by two or more cooperating hinge elements, each of the same preferably formed integrally with the basket filter element or the valve seat element. The hinge is preferable designed to be easily detachable.
Alternatively or additionally the valve seat element is releasably attached to the basket filter element, preferably snap-fitted therewith. By provision of such fixation means which do not require tooling, convenient loosening of the filter element components by a user for servicing the filter element, i.e. its basket filter element, the closure element or the valve seat element can be achieved, e.g. for cleaning or maintenance purposes.
For providing easy installation of the filter element in the sump and for uninstalling therefrom, the filter element, preferably the valve seat element, may advantageously comprise a grip element for easy handling of the filter element. The grip element can span the valve opening and/or filter open end, such that a small shape of the grip element can be realized. Furthermore, the grip element provides enhanced warp-resistance for the valve seat element.
In an advantageous embodiment the filter element may comprise at least one element for magnetically supporting the positioning of the filter element within the sump, i.e. to achieve the operating position of the filter element. Such a magnetic element e.g. is attached subsequent to fabrication of the filter element to an inner or outer surface of the filter element, such that a replacement can be easily achieved. Another example would be to embed such a magnetic element within the filter element, e.g. during molding the filter element. Preferably the magnetic element is at least partially encapsulated and thereby protected by the material of the filter element.
Preferably the at least one magnetic element of the filter element interacts or cooperates with at least one element of the sump for supporting the positioning of the filter element. Such a magnetic element of the sump may be arranged at the sump or alternatively may be provided by the sump, e.g. by its construction material. Preferably such a magnetic element is arranged on an inner surface of the sump, on an outer surface of the sump and can additionally or alternatively be embedded in the sump.
According to a preferred embodiment, a magnetic element of the filter element and/or the sump is a magnet, in particular a permanent magnet or an electromagnet. I.e. such a magnet can be associated to or arranged at the filter element or to the sump. For example the magnetic element of the sump can be an electromagnet which is only operated during inserting the filter element or which increases its magnetic force during inserting the filter element, i.e. the magnetic field force can be adapted to the present requirement. Alternatively the magnetic element of the sump and/or the filter element is a permanent magnet, which provides a low-maintenance possibility for achieving self-alignment and positioning, i.e. securing, of the filter element.
Preferably a magnetic element of the filter and/or the sump comprises ferromagnetic material, e.g. iron, AlNiCo, NdFeB, or ferromagnetic material, like ferrite, adapted to cooperate with the above described corresponding magnet of the magnetic element of the filter element or the sump in that an attractive force is exerted between corresponding magnetic elements of the sump and the filter element.
By providing elements for magnetically supporting the positioning of the filter element in the sump, i.e. interacting magnetic elements, a self-alignment and positioning of the filter element to and at the correct position or operating position can be achieved. That means even when a user places the filter in the sump in an incorrect or misaligned position, the elements for magnetically supporting the positioning move the filter element into the correct position, i.e. into its operating position. In particular the operating position of the filter element may be secured by magnetic attraction force provided by such magnetic elements. Such a washing machine provides a convenient handling and positioning of the filter element within the sump, in particular a user can be certain that the filter element positions itself in its correct position, e.g. such that fluff bypassing the filter or filter drum collisions due to an incorrect position of the filter element as well as valve disfunctionality because of misalignment are avoided. Furthermore, due to the presence of a magnetic force within the filter element supplied by the magnetic elements, metallic foreign objects, e.g. coins, are trapped securely in the filter element.
Preferably the at least one magnetic element of the filter element contacts the at least one magnetic element of the sump in the operating position of the filter element, such that a maximum interaction, i.e. attraction, between the magnetic elements is provided. According to a preferred embodiment the filter element comprises at least two magnetic elements adapted to cooperate with at least two magnetic elements arranged at the sump. Thereby the self-alignment of the filter element within the sump is further improved due to additional attraction force between the additional magnetic elements and the additional attraction points or locations.
Preferably the at least two magnetic elements of the filter element and additionally or alternatively the at least two magnetic elements arranged at the sump have opposite polarity. For example the at least two magnetic elements of the filter element have opposite polarities, i.e. the side of the magnetic elements facing the sump comprise opposite polarities. The magnetic elements of the sump also comprise the corresponding opposite polarities to each other, but opposite to the polarity to the magnetic elements of the filter element. Thus an attraction force is exerted between the at least two magnetic elements of the filter element and of the sump which is at its maximum when the filter element is in its operating position. Thereby it is prevented that the filter element is positioned back to front as in such a position the like polarities or poles of the magnetic elements of the filter element and the sump would cause them to repel. I.e. a user would recognize the incorrect position of the filter element, because the filter element would not be attracted to the sump. In a further preferred embodiment the filter element may comprise an element for magnetically cooperating with a sensing element of the washing machine, for example for triggering a sensor signal indicating an operating position of the filter element within the sump. Such an element can match or be identical with the at least one magnetic element of the filter element for magnetically supporting the positioning of the filter element. Alternatively the one or more element for magnetically cooperating with a sensing element can be a further magnetic element, for example chosen from magnetic elements, ferromagnetic elements, permanent magnets or electromagnets.
According to a preferred embodiment the at least one magnetic element of the filter element for magnetically cooperating with a sensing element of the washing machine is designated to trigger a sensor signal within a sensing circuit of the washing machine dependent on the position of the filter element relative to the sump. Such a sensing circuit preferably provides the additional function of verifying the filter element being in its operating position. In particular a sensing element is adapted to sense whether the magnetic element of the filter is in its correct position.
Preferably the sensing element is connected to a logic unit of the washing machine for receiving the sensor signal. The logic unit enables an operation of the washing machine only if the filter element is correctly positioned in the sump as indicated by the sensor signal (preferably enables a washing operation). E.g. a washing operation is prevented when the filter is not in its operating position, whereby a leakage of liquid during a washing operation is prevented.
According to a preferred embodiment the sensing circuit comprises a sensing element in form of a reed sensor or a hall sensor to detect the operating position of the filter element. Reed sensors and hall sensors are robust and not sensitive to environmental influences like water and heat. Thus a robust sensing element for conditions in a washing machine is provided. The sensing element preferably is arranged at the sump, wherein the magnetic element of the sump described above can be part of the sensing circuit.
Preferably the sensing circuit is connected to a visual interface, e.g. of the washing machine console, and additionally or alternatively to a speaker. The sensing element is connected, e.g. wireless or by wire, to the logic unit of the washing machine or is directly connected to an interface control having e.g. an audio source and/or indicator, such that an incorrect position of the filter element can be communicated/indicated to a user. E.g. in case the filter element is not within the sump the user is informed thereof and can take the appropriate steps, i.e. insert the filter element into the sump.
According to a preferred embodiment the filter element, the sump may comprise a locking element, for example a snap fitting element, for removably fixing or locking the filter element in place within the sump. I.e. after the above described self-alignment and positioning of the filter element within the sump, the filter element is snapped or locked securely in the sump. This is particularly advantageous as the user does not have to check or verify himself whether the filter element is in the correct position to lock the filter element with the snap fitting element, but this position is provided by the self-alignment of the filter element. Self-alignment may be enhanced by the above mentioned magnetic elements (if present) of the filter element and the sump. In another embodiment the attractive force between such magnetic element(s) is strong enough that a self-locking is provided by the magnetic attraction, such that no additional locking element is required. Alternatively or additionally to the magnetic detector for detecting the filter element being in its operational position and/or correctly positioned in the operational position, a mechanically activated position detector may be advantageously provided. The position detector may be arranged at or in proximity to the locking element. As with the magnetic sensor or detector, the position detector provides a signal to a controller, preferably to the controller of the washing machine to indicate presence of the filter element. Signal processing and/or indication to the user via an optical and/or acoustical signal in response to the detector signal is provided (and can e.g. be designed as the one described above for the magnetic sensor).
The above described washing machine can be a front-loading type or a top-loading type washing machine. Further, the washing machine can also be a washing machine having a dryer function. Preferably the washing machine comprises a drum with an openable lid, preferably comprises in a lifter of the drum, through which the filter element is removable from the sump.
Reference is made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying figures, which show:

Fig. 1: a schematic cross-sectional side view of a washing machine comprising a filter element,
Fig. 2: a schematic cross-sectional front view of a washing machine with a recirculation circuit, wherein the tub is partially filled with water,
Fig. 3: a schematic cross-sectional view of the washing machine of Fig. 2 during a recirculation phase,
Fig. 4: a perspective view of an exemplary tub structure of a washing machine with a filter element,
Fig. 5: an exploded view of the filter element of Fig. 4,

Fig. 6: a cross-sectional side view of a detail of the structure of Fig. 4,
Fig. 7: a cross-sectional front view of a detail of the structure of Fig. 4,
Fig. 8: a detail of a perspective front view of a sump and a filter of a washing machine, and
Fig. 9: a schematic view of the filter element arranged within the sump and a sensor circuit structure of the washing machine.

Like elements of different embodiments are designated with the same reference numerals. Like elements having the same reference numeral indicate the same or essentially the same function and/or structure of such elements.
Fig. 1 schematically depicts a washing machine 2 comprising a tub 4 and a rotatable drum 6 rotatably arranged therein. At the bottom of the tub 4 a sump 8 is arranged, the sump 8 being fluidly connected to a draining circuit 10 of the washing machine 2. Within the sump 8 a filter element 12 comprising a valve 14 adapted to selectively open and close the passage of liquid between the tub 4 and the draining circuit 10 is removably positioned. A liquid inlet for fresh water from tap as well as a draining outlet are depicted by arrows. The fresh water runs preferably through a detergent drawer 16 into the tub 4. For its draining, the washing liquid is pumped to the outside by a draining pump 18 within the draining circuit 10.
At least one lifter 20 is preferably arranged within the tub 4 of the washing machine 2 for turning laundry. Another lifter 22 within the tub 4 is advantageously additionally adapted for easy removal and insertion of the filter element 12 comprising the valve 14, i.e. openable or removable. In a further embodiment the lifer 20 is not present, and there is only the lifter 22. The filter element 12 comprising the valve 14 is accessible, through a door 24 of the washing machine, by opening or lifting a lid 26, preferably comprised in the lifter 22, which covers a corresponding opening 15 in the drum 6. Underneath the opening 15 (in the drum orientation shown in Fig. 1) or underneath the drum, the filter element 12 is arranged in the sump 8 such that a user can remove or insert the filter element 12 comprising the valve 14 through the opening 15 after lifting the lid 26. In a embodiment, not illustrated, the opening of the drum and the lid for accessing the sump may be positioned in another position, i.e. not in correspondence of a lifter of the drum. The washing machine 2 depicted in Fig. 1 is a washing machine 2 without a recirculation circuit. The above arrangement correspondingly applies also if the washing machine is a top-loader with horizontal drum rotation axis (compare Fig. 4).
In Figs. 2 and 3 a washing machine 2 with a recirculation circuit 28 is depicted, wherein Figs. 2 and 3 further exemplify different closing states of the valve 14 of the filter element 12.
The recirculation circuit 28 is provided to recirculate liquid from a lower portion of the tub 4 to an upper portion of the tub 4. The recirculation circuit 28 comprises a recirculation pipe 30 fluidly connected to the sump 8. At a section of the recirculation pipe 30 at least a portion of (e.g. the vane and/or the motor) a recirculation pump 32 is arranged. Liquid from the sump 8 can be fed through the recirculation pipe 30 into the drum 6 by operating the recirculation pump 32. The amount of liquid for effectively wetting the laundry as well as the energy for heating the liquid can consequently be reduced. In a further embodiment, there is only a pump acting both ad recirculation pump and draining pump; in this case, downstream this pump there is preferably a three way valve, not illustrated, connected to the pump, to the draining circuit and to the recirculation circuit, actuating which, when the pump operates, the washing fluid is selectively drained or recirculated.
Figs. 2 and 3 show the filter element 12 comprising the valve 14 inserted in the sump 8 of the washing machine 2. The sump 8 is fluidly connected to the draining circuit 10, wherein the draining circuit 10 preferably comprises a draining suction pipe 34 in fluid connection with the sump 8, a draining filter 36, a draining pump 18 and a draining riser pipe 38. The sump 8 is preferably integrally formed with the tub 4. It is to be noted that the pumps 32 and 18 in Fig. 2 and 3 are advantageously not completely liquid-tight, such that the liquid level in the recirculation pipe 30 and the draining riser pipe 38 corresponds to the liquid level in the tub 4 or draining suction pipe 34 when the pumps 18, 32 are not operated and the valve 14 is open.
The filter element 12 preferably comprises a basket filter element 40 serving the purpose of filtering foreign objects out of the liquid from the tub 4 when passing through it. At the open end of the basket filter element 40 which represents an inlet end of the basket filter element 40, a valve seat 42 of the valve 14 is arranged. A movable and floatable closure element 44 of the valve 14 is preferably loosely and floatably contained and captured within the basket filter element 40, i.e. in the interior of the basket filter element 40. For capturing the movable closure element 44 within the basket filter element 40, a valve seat element 46 comprising the valve seat 42 is preferably associate or associable to the open end (40a in Fig. 5) of the basket filter element 40. The movable closure element 44 and the valve seat 42 cooperate in selectively obstructing (or closing) the passage of liquid from the tub 4 to the draining circuit 10, wherein the basket filter element 40 is advantageously arranged downstream the valve 14.
In a further embodiment, not illustrated, the filter element 12 comprises a valve 14 adapted to selectively open and close the passage of liquid between the tub and the draining circuit which comprises a valve seat 42, a movable closure element 44, and an actuating device, for example an electric motor, operatively connected or connectable to a logic unit 72 of the washing machine 2 so that the logic unit 72 can selectively command the opening and the closure of the valve 14.
Fig. 2 exemplary depicts the washing machine 2 during a washing cycle, wherein the valve 14 is in a closed condition or state such that the passage of liquid from the tub 4 to the draining circuit 10 is closed. The tub 4 of the washing machine 2 is partially filled with liquid for washing, wherein neither the recirculation pump 32 nor the draining pump 18 are activated. Due to the high liquid level and the hydrostatic buoyant force acting upon the closure element 44, the floatable closure element 44 is urged against the valve seat 42, thereby closing the valve 14. As can be readily seen, the valve 14 of the filter element 12 provides a robust and simple mechanism for automatically closing the passage between the tub 4 and the draining circuit 10 during those phases of the washing cycle, in which neither pump 32 nor 18 is operated and in which the water level has an appropriate or minimum height to urge the floatable closure element 44, e.g. a spherical or ball like element, against the valve seat 42, i.e. acting like a check valve or ball check valve. For example during a heating phase a closure of the valve 14 prevents liquid exchange between the draining circuit 10 and the tub 4 interior.
As an example Fig. 3 depicts the washing machine of Fig. 2 with the valve 14 in an open condition or state, wherein the passage of liquid from the tub 4 through the valve 14 to the draining circuit 10 is unimpeded. The open condition of the valve 14 is achieved e.g. during a washing cycle of the washing machine 2 when the liquid level is low or a pump 32, 18 is activated or when the liquid level is low.
In Fig. 3 e.g. the recirculation pump 32 of the washing machine 2 is operated. By the suction force generated therefrom, the floatable closure element 44 experiences a force drawing the same away from the valve seat 42. In the consequence, the valve 14 opens. Likewise opening of the valve 14 can be achieved by operation of the draining pump 18 or both pumps 32, 18. By operating a pump 32, 18 a pressure difference is acting upon the floatable closure element 44, in particular resulting from a suction force (of the pump), the buoyant force and a force resulting from gravity.
Fig. 4 depicts a structure of a washing machine 2 with a tub 4 and a filter element 12, wherein the sump 8 is integrally formed with the tub 4. The tub 4 is of a top-loading type including an opening at an upper end thereof for insertion of laundry. Within the sump 8 the filter element 12 comprising the valve 14 is removably positioned. The filter element 12 and the sump 8 are designed for accurate fit of the filter element 12 within the sump 8.
Fig. 5 is an exploded view of the filter element 12 of Fig. 4. The filter element 12 comprises the basket filter element 40, the movable closure element 44 of the valve 14 and the valve seat element 46 comprising the valve seat 42 of the valve 14. The basket filter 40 advantageously comprises a hollow, cage-like, filter body with an open end 40a for inserting the floatable closure element 44 therethrough. After insertion of the closure element 44 the valve seat element 46, which preferably has the form of a disc-like cap with the valve opening 48 of the valve seat 42 therein, is attached to the basket filter element 40, i.e. at its open end 40a, thereby capturing the closure element 44 within the basket filter element 40 and completing the valve structure of the filter element 12. The valve seat element 46 also preferably comprises a grip element 50 provided for easy handling of the filter element 12 by a user. By arranging the grip element 50 spanning the opening 48 a flat and warp-resistant overall design of the valve seat element 46 is achieved.
The movable closure element 44 preferably has a shape which allows for pre-aligning or self-orienting with respect to the countershaped opening 48, wherein the interior shape of the basket filter element 40 cooperates with the movable closure element 44 in doing the same, i.e. by corresponding shape. The shape of the movable closure element 44 is preferably of partially round form, more preferably of cylindrical form, the front sides being designed as semi-shells. Generally rotationally-symmetric, spherical, ellipsoidal or shapes substantially representing such forms preferably apply for the closure element 44. The filter element 12 preferably comprises a hinge 52 advantageously allowing for opening and servicing the filter element 12 without having to completely detach the valve seat element 46 therefrom. The hinge 52 preferably comprises a first 52a and a second 52b hinge elements, each of the same formed integrally with the basket filter element 40 or the valve seat element 46, respectively. Preferably the hinge elements are arranged in such a way that they can be easily detached from each other.
Furthermore the filter element 12 preferably comprises snap-fit elements 54 for interlocking of the valve seat element 46 and the basket filter element 40. The snap-fit elements 54 provide for easy assembly and disassembly and hence easy servicing of the elements 40, 46. The snap-fit elements 54 keep the valve seat element 46 in the position for cooperation with the closure element 44 when interlocked. Likewise the filter element 12 preferably comprises a locking element, for example a snap-fit element 56, for engaging with a corresponding element 58 arranged at the sump 8 of the washing machine 2. The snap-fit element 56 can easily be locked or unlocked by a user in the course of servicing the filter element 12, i.e. when inserting or removing same. The hinge elements 52a, 52b as well as the snap- fit elements 54 and 56 can be advantageously molded in a single process together with the basket filter element 40 and/or the valve seat element 46.
Fig. 6 depicts a sectional view of the filter element 12 inserted in the sump 8 of the washing machine 2. The filter element 12 is shown in a closed state of the valve 14, wherein the closure element 44 is urged against the valve seat 42. The snap- fit elements 54, 56 are locked, wherein snap-fit element 56 is engaged with the machine structure 58 of the washing machine 2. The hinge 52 is shown in a closed position.
In Fig. 7, depicting another sectional view of the filter element 12 within the sump 8, an inlet 30a of a recirculation pipe 30 as well as an inlet 34a of draining suction pipe 34, each in fluid connection with the sump 8, are displayed. By sucking in liquid from the sump 8 in any such inlet 30a, 34a a suction force acting upon the movable closure element 44 can be applied, hence the valve 14 be opened.
Fig. 8 depicts a filter element 12 from below and a corresponding receptacle 60 of the sump 8 for the filter element 12. The filter element 12 preferably, but not necessarily, comprises an element 62 for magnetically supporting the positioning of the filter element 12. Element 62 is preferably a magnet integrated or embedded in an bottom part of the basket filter element 40. The magnet 62 preferably cooperates with another magnetic element 64 of the sump 8 for precise alignment and positioning of the filter element 12 in the sump 8. The magnetic element 64 e.g. is a ferromagnetic element.
By magnetic attraction force occurring between the magnetic elements 62 and 64, the filter element 12 can be drawn into its correct position when being inserted into the sump 8. Furthermore, also a misaligned insertion can be magnetically corrected. In the course of a magnetically supported alignment and positioning the interlocking means 56 can automatically engage its counterpart 58, hence the user has little effort in installing the filter element 12 in the sump 8. Furthermore the magnetic elements 62, 64 keep the filter element 12 securely in place, i.e. positioned in its operating position.
Fig. 9 schematically depicts a sectional view of the filter element 12 arranged within the sump 8 and a sensor circuit 66 of the washing machine 2. Herein the magnetic element 62 magnetically cooperates with a sensing element 68 of the washing machine 2. The sensing element 68 is preferably arranged at the sump 8 from the outside such that the sensing element 68 is not subjected to soiling. Advantageously a sensor line 70 connects the sensing element 68 to a logic unit 72 of the washing machine 2 for providing the sensor signal to the logic unit 72. The sensing element 68, e.g. a reed sensor or switch, is providing a sensor signal when the magnetic element 62 is neighboring the sensing element 68 or contacting the same. In other words, the sensing element 68 is actuated when the filter element 12 is in its operating position. The logic unit 72 is preferably connected to a user interface 74, for example to a display, for signaling the filter element 12 comprising the valve 14 being in its operating position. Advantageously, the logic unit 72 is preferably adapted to prevent an operation of the washing machine 2 when the filter 12 is not inserted in its position within the sump 8. In other words the washing machine 2 is preferably provided with a sensing and feedback system for detecting the filter 12 being in its operation position. The sensing element 68 can comprise or make use of the magnetic element 64 for positioning the filter element 12.

Claims

Laundry washing machine (2) comprising:
a tub (4) having a sump (8),

a rotatable drum (6) rotatably arranged in the tub (4),

a draining circuit (10), wherein the sump (8) is fluidly connected to the draining circuit (10), and

a filter element (12), which is adapted to be removably positioned in the sump (8),

characterized in that
the filter element (12) comprises a valve (14) adapted to selectively open and close the passage of liquid from the tub (4) to the draining circuit (10).
Laundry washing machine (2) according to claim 1, wherein the valve (14) has a movable closure element (44) adapted to be releasably engaged with a valve seat (42) of the valve (14) to close or open the valve (14).
Laundry washing machine (2) according to claim 2, wherein the valve (14) is closed and opened in dependency of a liquid level and/or a pressure difference acting upon the movable closure element (44).
Laundry washing machine (2) according to claim 2 or 3, wherein the movable closure element (44) is a floatable element.
Laundry washing machine (2) according to claim 4, wherein the movable closure element (44) has a spherical, cylindrical or ellipsoidal shape or a combination thereof.
Laundry washing machine (2) according to any of the previous claims, wherein the valve (14) is a check valve.
Laundry washing machine (2) according to claim 6, wherein the valve (14) is a check valve acting like a ball check valve or a swing check valve.
Laundry washing machine (2) according to any of the previous claims 2-7, wherein the filter element (12) comprises a basket filter element (40).
Laundry washing machine (2) according to claim 8, wherein the movable closure element (44) of the valve (14) is contained within the basket filter element (40).
Laundry washing machine (2) according to claim 9, wherein said valve seat (42) of said valve (14) is comprised within a valve seat element (46) capturing said movable closure element (44) within or at said basket filter element (40).
Laundry washing machine (2) according to claim 10, wherein said valve seat element (46) of said valve (14) is releasably attached to said basket filter element (40).
Laundry washing machine (2) according to claim 10 or 11, wherein said valve seat element (46) is hinged to said basket filter element (40).
Laundry washing machine (2) according to any of the previous claims wherein said filter element (12) comprises a grip element (50).
Laundry washing machine (2) according to any of the previous claims, wherein said filter element (12) and/or said sump (8) comprise at least one locking element (56, 58) for removably fixing said filter element (12) in said sump (8).
Laundry washing machine (2) according to any of the previous claims, said drum (6) comprising an openable lid (26) through which the filter element (12) is removable from the sump (8), wherein the openable lid (26) is adapted to expose an opening in said drum (6) when being opened or removed, the opening being adapted for letting the filter element (12) to pass through the opening.