"Front-loading laundry washing machine with laundry rejecter"

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TEXT OF THE DESCRIPTION

The present invention concerns a front-loading laundry washing machine. Prior art

Machines of the type indicated include a laundry basket mounted in a washing tub, itself housed in a cabinet. The cabinet has a front-loading opening in correspondence to which a door is mounted, and this opening is substantially aligned with a front opening of the tub, which is in turn substantially aligned with a front opening of the basket. The basket is mounted such that it can rotate around a substantially horizontal or slightly inclined axis, which is in a fixed position with respect to the tub. The tub is flexibly suspended in the cabinet, to allow oscillations caused by the loads acting on the basket during its rotation, such loads being due to the weight of the laundry under treatment. A substantially tubular gasket extends between the front wall of the tub and the front wall of the cabinet, defining a sealed passage. The opening of the cabinet opens at one end of such passage, while the opening of the tub and that of the basket open at the other end. The presence of the above said gasket (commonly called "diaphragm") prevents part of the washing liquid or of the laundry load from coming out from the tub and basket and slipping into the interspace that exists between the tub and the cabinet. The gasket must allow for a certain relative movement between the cabinet and tub, since - as was said - the latter is subjected to oscillation during the rotation of the basket: for this reason the gasket, and therefore the tubular passage defined by it, must have a certain axial length and be elastic, preferably shaped, at least in part, like a bellows.

Usually also an inner or rear portion of the door extends into the tubular passage defined by the gasket, which portion is shaped - in a way that is itself known - to provide a sort of barrier to the exit of laundry, at least from the lower part of the mouth of the basket during the rotation thereof. Between the above-said inner portion of the door, the gasket and the mouth of the basket there must always be an annular interstitial space, so to allow both oscillation of the tub and rotation of the basket.

It may happen that, during rotation of the basket, a portion of a laundry item slips into an area of the above-said interstitial space. Generally this is not considered a problem during the pre-wash, the actual wash and the rinsing phases,

during which the basket rotates at a relatively reduced speed (indicatively 50-60 revolutions/minute or rpm).and the liquid present in the tub serves - so to say - as a lubricant, allowing the laundry item dragged by the basket to free itself or at any rate, to slide on the gasket without being damaged. However, when the rotational velocity of the basket is elevated for the purpose of performing the centrifugation phases of the laundry load (velocity indicatively included between 300 and more than 1800 rpm), in which there is no liquid bath in the tub, the friction of the gasket can hold the above portion of the laundry item in the interstitial space and in this case the rotation of the basket can cause abrasions of the item itself. The rubbing friction can also cause evaporation of the water present in the trapped portion of the laundry item and consequently cause also damage to the gasket.

The problem highlighted above is particularly evident in the case of machines provided with baskets having a wide front opening, which currently are becoming increasingly successful on the market, since they facilitate notably the loading and unloading of the laundry item.

For the purpose of solving the above-said problem, laundry washing machines have been proposed that are provided with an appropriate device called "laundry detacher" or "laundry rejector", essentially consisting of a deflecting member, provided on the gasket and usually made of resilient material, and in some cases having a rigid core fixed to a front flange of the tub. The deflecting member crosses a limited zone of the above-said interstitial space, typically in the upper dead point region of the basket, and it is shaped to protrude toward the inside of the front opening of the basket itself, proximal to its edge.

In this way, as a consequence of the rotation of the basket, the laundry item that was partially trapped in the interstitial space at a certain point reaches the deflecting member, which physically pushes the laundry item toward the inside of the basket, freeing it from the interstitial space. A machine of this type is known, for example from EP-A-I 389 642, on which the preamble of the attached claim 1 is based. Summary of the invention

The Applicant realized that the embodiments of the known rejecting devices, although on average efficacious, can themselves, at times, cause damage of the laundry items under some functioning conditions of the laundry washing machine. Therefore, the object of the present invention is that of providing a front- loading laundry washing machine provided with a rejector device that allows the

reduction of the risk of damaging of the laundry items with respect to the known solutions.

This and other aims, which will be clearer later, are achieved according to the present invention by a front-loading laundry washing machine having the features indicated in the attached claim 1. The preferred characteristics of the machine subject of the invention are indicated in the sub-claims. The claims are an integral part of the technical teaching provided herein in relation to the invention.

Brief description of the drawings

The aims, the features and the advantages of the present invention will be clear from the following description, made with reference to the attached drawings, provided as a non-limiting example, in which:

- figure 1 is a schematic front view of a laundry washer according to the present invention;

- figure 2 is a schematic representation in section of the machine of figure 1 with the illustration of only the components that are useful for the purpose of understanding the present invention;

- figure 3 is a schematic section along line III - III of figure 1 ;

- figure 4 is a schematic representation, similar to that of figure 2, of a machine according to a variant of the invention; - figure 5 is a schematic section along line V - V of figure 4;

- figure 6 is a diagram representing some of the steps of an operating cycle of a machine according to the invention;

- figure 7 is a magnified detail of figure 6.

Detailed description of embodiments of the invention Referring to figures 1 to 3, number 1 indicates as a whole a front-loading laundry washing machine according to the invention. The machine 1 comprises a supporting structure or cabinet 2, inside of which a tub 3 is elastically supported in a known manner. Inside the tub 3 a perforated laundry basket 4 is mounted so as to allow it to rotate around an axis A, through an electric motor 5. The tub 3 and the basket 4 have corresponding front openings, indicated with 3A and 4A respectively, and the basket 4 is accessible to the user through an opening indicated with 2A in figure 3 provided in the front wall of the cabinet 2. The openings 2A, 3A and 4A are substantially co-axial or in any case aligned with each other, preferably along the axis A. A door 6 is provided in correspondence to opening 2 A, having a frame 6A

hinged in a know manner to the cabinet 2, and to which a containing body 6B is associated, preferably transparent, for example made of glass. Preferably, as is visible in figure 3, the containing body 6B is shaped to protrude toward the inside of the cabinet 2 in proximity to the loading mouth of the basket 4, that is, to its slightly protruding front part that delimits the opening 4A.

Note that the inner part of the body 6B could possibly extend up to the area of the opening 4A, provided, in every case, that between the edge delimiting such opening and the body 6B a certain interstitial space must always be provided, since - during the functioning of the machine - the group comprising the tub and the basket is capable of oscillating inside the cabinet 2, while the door 6 is in a fixed position.

One can also infer from figure 3 that between the cabinet 2 and the tub 3 a gasket 7 with an overall tubular shape is mounted. The gasket 7, preferably made of a resilient elastomer material and at least in part in the shape of a bellows, has a first end connected in a sealed manner to the front part of the cabinet 2, so as to circumscribe the opening 2A. Instead, the opposite end of the gasket 7 is connected in sealed manner to a flange-like front part 3B of the tub 3, so as to circumscribe the corresponding opening 3A, with the opening 4A of the basket that opens in the generally tubular conduit defined by the gasket 7. As previously clarified, in order to allow the oscillation of the tub-basket assembly and rotation of the basket, the gasket 7 must have a certain axial extension. In addition, a certain free space or annular interstitial space, indicated with G in figure 3, must be provided between the body 6B, the mouth of the basket 4 and the gasket itself. In figures ■ 1 and 2, number 8 indicates as a whole a washing agent dispenser, of a known type, for example having a drawer provided with three single-dose compartments to contain the respective washing agents. The above- said drawer is slidingly housed into a hopper-like container having a lower outlet connected to tub 3, through a tube 9. Number 10 indicates valve means, having an inlet for connection to a domestic water feeding network 1 1. The dispenser 8 and the valve means 10 provide for the selected and controlled transit of a flow of water coming from the network 1 1 through one of the above-said compartments, depending upon the functioning phase of the machine 1 ; water, after passing through the compartment of interest and carrying with it any washing agents that may be present, goes into

the above-said hopper-like container to then reach the tub 3 through the tube 9.

Number 12 indicates a drain conduit, having one end connected to an opening in the lower region of the tub 3 and the other end destined for attachment to the inlet of a sewage conduit 13. A discharge pump 14 is provided along conduit 12.

Number 15 indicates as a whole the manual programming means of the machine 1 , or its user-interface. In the exemplified case, such interface comprises five buttons, and in particular one on/off button, indicated by 15A and four buttons 15B for selection of the treatment cycles that the machine can perform. Number 16 indicates as a whole a control unit of the machine 1 , comprising a micro-controller 16A. The micro-controller 16A comprises in turn, or is operationally connected to, non- volatile memory means 16B, for example, comprising one or more ROM and/or EPROM and/or EEPROM and/or Flash memories. In the memory means 16B the operation or management programs are stored, that control the execution of the treatment cycles, that can be performed by the machine and can be selected through buttons 15B. In such memory means 16B the instructions related to the general operation of the machine 1 are also codified, as well as those for the control of the particular functions provided according to the present invention, described in the following. Clearly, the machine 1 also comprises all of the other components required for its normal operation (level sensors', water heating resistor, filters, safety devices, suspensions, etc.) that are not represented and described herein since they are not of immediate interest for the purpose of the present invention.

The machine 1 is further provided with laundry rejecting means, to prevent the risks deriving from the possible trapping of portions of laundry items in the interstitial space G.

According to the invention, the above-said rejecting means comprises a liquid ejector device. As particularly visible in figure 3, such device includes a nozzle 20 at least partially positioned within - or in any case facing to - the sealed passage defined by the gasket 7. For this purpose, preferably, the gasket 7 is provided with an appropriate housing 21 for the sealed fixing of the nozzle 20, which for example can be made of moulded thermoplastic material. In the illustrated embodiment, the nozzle 20 is mounted in a position relatively spaced apart from the opening 4A, and in any case, so as not to protrude inside the basket, thus avoiding its being struck by the laundry items.

The nozzle 20 is oriented to point a jet of liquid 22 towards a substantially predetermined region of the opening 4A, in which the laundry items that tend to exit the basket 4 and pass into the interstitial space G may transit. For this purpose, in this embodiment, the jet 22 points substantially transversally to the sealed passage defined by the gasket 7, to transit at least in part in the interstitial space G and then reach the inside of the opening 4A of the basket 4, in the proximity of its edge. From figure 3 one can infer how, in this embodiment, the nozzle 20 is oriented to point the liquid jet 22 substantially transversally also to the axis of the front opening 4A, towards the inside of the basket 4. Therefore, according to the invention, a fluid jet 22 that pushes the items toward the inside of the basket is provided in place of a deflecting organ that physical gets into contact with the laundry items that can be partially trapped in the interstitial space. Thanks to this characteristic, the risks of damage to the laundry items typical of machines provided with a deflecting member are virtually eliminated.

It must be specified that laundry washing machines provided with an nozzle being operative in the area of the annular gasket connecting the cabinet and the tub are known, such nozzle however not being provided for and suitable to perform the functions of the present invention. In fact, in such known machines the nozzle is provided for the purpose of re-circulating washing and rinsing liquids, and possible to improve the wetting of the laundry load in the basket. In such known machines, the nozzle can generally be found in an area substantially aligned with the upper dead point of the opening of the basket and is shaped to point a liquid jet in a direction substantially parallel to the axis of the opening, hi such known machines, the nozzle is typically activated during the actual washing phases or the rinsing phases of the laundry, the pressure of the liquid jet is relatively modest (in particular, this pressure is determined by the flow rate of the re-circulating pump of the laundry washing machine) and the nozzle is shaped to generate a widespread and/or diffused jet. The jet 22 produced by the nozzle 20 must have a power such to oppose the exiting toward the interstitial space G of portions of the laundry items from the opening 4A. For this reason, in the preferred form of embodiment of the invention the ejecting device is configured to generate a jet 22 with a pressure not lower than approximately 1 bar, preferably included between 1 and 4 bar. In a possible embodiment of the invention, the valve means 10 comprises

an electro-valve with at least two outlets, one of which is in liquid communication with a movable nozzle of the dispenser 8, such a nozzle being controllable to selectively direct the flow admitted to a first outlet of the electro-valve towards one of the washing agent compartments. The second outlet of the above said electro-valve is connected instead to a conduit having a reduced diameter, indicated with 23, destined to feed the nozzle 20. The cross-sections of the conduit 23 and the orifice of the nozzle 22 are suitably calibrated, in a known manner, to provide the desired pressure starting from the network pressure (typically approximately 2.5 bar) to the nozzle 20. It must be noted that the jet 22 generated by the nozzle 20 is preferably thin and concentrate, provided that its primary function is that of pushing laundry items toward the inside of the basket.

In figures 4 and 5, a second embodiment of the invention is represented. In such figures the same reference numbers as those in figures 1-3 are used to indicate elements technically equivalent to those previously described. In this embodiment, the nozzle 20 is positioned such that the main direction of the jet 22 is substantially parallel to the axis A, or substantially perpendicular to the diameter of the opening 4A of the basket 4. Also in this case, the gasket 7 is provided with a suitable housing 21 for the sealed fixing of the nozzle 20. Also in this embodiment, the nozzle 20 is preferably mounted so as not to protrude inside the basket, thus avoiding its being stuck by the laundry items, and the jet 22 is pointed toward a substantially predetermined region of the opening 4A, in which the laundry items that tend to exit from the basket could transit. With this arrangement, the nozzle is closer to the mouth of the basket and the power of the jet can be lower with respect to that of the embodiment of figures 1-3. The general function of the rejecting means provided according to the variant of figures 3 and 4 is in any case similar to that of the first embodiment described above.

In the preferred embodiment of the invention, the ejecting device is activated, for the above-indicated purposes, during one or more operational phases of a treatment cycle other than the pre-wash phases (if foreseen), the actual wash phases and the rinse phases; the pre-wash (when foreseen), wash and rinse phases are typically performed - also by the machine according to the invention - with a rotational speed of the basket 4 included indicatively between 30 and 60 rpm and in the presence of a liquid bath in the tub. More particularly, the jet 22 is activated during the phases in which the

basket 4 is brought to an angular speed greater than or equal to the minimum speed (also known as "satellization" speed) allowing the laundry load to remain attached to the circumferential wall of the basket. The speed used in the above said phases can vary in function of the radius of the basket 4 and is indicatively comprised between 80 and 95 rpm, for a basket with a diameter of approximately 470 mm.

Preferably, the operating phases during which the jet 22 is activated are phases immediately preceding a respective centrifugation phase of the laundry load. More specifically, the control system 16 is prearranged to activate the delivery of the jet 22 during a phases of distribution of the laundry load present within the basket 4, i.e., a phase of rotation of the basket causing the uniform positioning of the load in view of the successive centrifugation, the latter involving a rotational speed indicatively comprised between 300 and over 1800 rpm. Note that during the distribution phases of treatment programs according to the prior art, no liquid loading is traditionally provided, these phases being those in which, instead, one wants to remove water from the tub.

In figure 6 an example of a laundry distribution phase with corresponding successive centrifugation is represented in diagram form, while in figure 7 an enlarged detail of such a diagram, with the indication of the activation periods of the jet 22, is represented. The distribution phase follows a rinse and is followed by a centrifugation.

In figure 6, D indicates a first step of the phase of distribution of the laundry load, which involves an initial acceleration ramping of the speed of the basket 4, from zero or near zero to a distribution or satellization speed, here equal to approximately 90 rpm. During the speed ramping, the laundry items are continuously "remixed" within the basket 4 until they settle, when the minimum satellization speed is reached, substantially adhering to the circumferential wall of the basket. At the end of the above said ramping, the speed reached is maintained for a certain time so as to verify, using known manner that are beyond the purposes of the present invention, if the laundry load is correctly arranged or balanced for the purpose of the execution of successive high-speed centrifugation. In the affirmative, the motor 5 of the machine 1 is operated to bring the basket 4, without interrupting the rotation, from the distribution speed to the centrifugation speed. On the other hand, in the case in which the control system 16 detects an imbalance of the laundry load, the rotational speed of the basket is reduced from

that of distribution to a relatively low rotational speed. Next, a balancing step B follows, involving a new acceleration to the distribution speed and a new maintaining of such speed for the purpose of verifying the state of balancing of the load. In the case in which the load is now balanced, the centrifugation begins, while in the opposite case, a new balancing step B is performed, and so on until an acceptable balancing condition is obtained. To this purpose, figure 6 illustrates a case of distribution phase including an initial step D, seven balancing steps B with negative outcomes and an eighth balancing step Bn with a positive outcome, at the end of which the centrifugation indicated by S is launched. In the detail of figure 7, ON and OFF respectively indicate the periods of activity and inactivity of the nozzle 20, limited to the case of step D and the first step B of figure 6. As can be inferred, the nozzle 22 is activated:

- at least during the acceleration ramp (from approximately 30 rpm to the distribution speed of approximately 90 rpm in the example represented) of the initial step D and, when load redistribution could be needed,

- at least during the ramping of reaching the distribution speed (from approximately 25 rpm to approximately 90 rpm, in the example represented) of the balancing step B (and, in general, during the acceleration ramp of each step B that could be required to balance the load). During the above-said ramps the laundry items are not yet perfectly satellized orbit, and substantially remain "up in the air" during the rotation of the basket: in such moments, the action of pushing toward the inside of the basket 4 applied by the jet 22 emitted by the nozzle is therefore more efficacious. Instead, upon reaching satellization speed, the load is substantially stabilised, i.e., adhering to the circumferential wall of the basket, with no risk of displacement of the laundry items outside of the opening 4A.

As was said, in the machines of known type, the distribution phase with possible load-balancing steps, is traditionally performed in the absence of a liquid bath in the tub. The activation of the jet 22 provided according to the invention increases the soaking of the laundry pieces, but in a completely negligible way, provided that the laundry items are already soaked with liquid from the previous rinse. Furthermore, the activation phases of the jet 22 are of limited duration (1 to 5 seconds each) and in any case, the volume of liquid sprayed is small (as said, the specific purpose of the jet 22 is not that of distributing liquid onto the laundry but of concentrating a thin jet, of a reduced flowrate, in a predefined zone with a

pressure sufficient to displace the laundry items). The liquid soaking the laundry is then expelled from the laundry through the successive centrifugation phase or phases, during which the drain pump 14 is operated by the control system 16 in a continuous or pulsed way. The operation of the ejecting device provided according to the invention is managed by the control system 16, which is prearranged to command the rotation of the basket 4 at the various operational speeds, to control the valve means 10 (or other alternative means provided to feed the nozzle 20), to verify the balance condition of the load, all of this using ways that are clear to one skilled in the art. It must also be specified that, in the case of the invention, the nozzle 20, or the predetermined region wherein the jet 22 is pointed to, are at an angular position spaced apart from the upper and lower dead point regions of the basket (meant as dead point +/- 15°). Preferably the angular position is intermediate to said dead point regions and, very preferably, is included between +/- 30° with respect to the horizontal centreline of the front opening of the tub and/or of the basket, and therefore, closer to such a centreline than to the above-said dead point. In the embodiment currently considered as the preferential one, the nozzle 20 - or the point from which the jet 22 originates - is found at an angle "C" of approximately +10° with respect to the horizontal centreline of the opening 4A towards the upper dead point, with reference to the rotational direction of the basket, indicated by the arrow F in figures 1 and 2.

In general terms, the positioning zone of the nozzle 20 will depend upon the direction of rotation of the basket 4. In particular, for machines in which, during centrifugation, the basket 4 rotates in a counter-clockwise direction, the positioning will be that represented in the figures (that is, on the left side of the machine); vice versa, for machines in which the basket 4 rotates clockwise during centrifugation, the positioning will be symmetrical to that represented in the figures (that is, on the right side of the machine).

From the above description, the characteristics of the invention are clear. A substantial advantage is represented by the fact that the laundry rejector means provided according to the invention allows for avoiding the physical contact of mechanical parts with laundry items, thus avoiding the risk of damage and abrasion to said items.

Clearly, while maintaining the principle of the invention, the details of construction and the embodiments could vary widely with respect to what has

been described and illustrated as an example, without departing from the scope of the present invention as defined in the attached claims.

In a possible variant, the nozzle 20 can be fed at the required pressure through a conduit connected to the outlet of a pump. The inlet of such pump can be in communication - through an electro-valve - with the water network 11 , or with the lower region of the tub 3 (in which a small quantity of rinsing water will be maintained for the purpose, or clean water from the network will be loaded).

According to a further variant, sensor means arranged to detect the presence of laundry portions protruding out of the front opening 4A of the basket 4 can be interfaced to the control system of the machine. Such sensor means, comprising an emitter and a receiver of electromagnetic radiation, can be, for example, of the type described in US 6, 784, 997.

Finally it is clear that, if desired, the control system 16 of the machine 1 can be prearranged to activate the jet 22 also during the normal phases of pre- wash, wash or rinse, for example, for the purpose of improving the soaking of the laundry, favouring the re-circulation of the liquid and/or of the corresponding washing agents.

The valve means 10 can include, in place of a double outlet electro-valve, an ON/OFF single outlet electro-valve. In this case, downstream of such ON/OFF electro-valve, a deviator or bypass electro-valve is provided, to alternatively direct the water flow to the dispenser 8 or to the conduit 23. Clearly, also the operation of such electro- valves will be managed by the control system 16, to alternatively remove the washing agents from the dispenser 8 or feed the nozzle 20.

In other variants the nozzle 20 is formed at least in part in a single piece with the gasket 7 and/or the gasket is moulded over the body of the nozzle.