EP2137347B1

EP2137347B1 - Laundry washing machine

Info

Publication number: EP2137347B1
Application number: EP08737502A
Authority: EP
Inventors: Dino Bongini
Original assignee: Indesit Co SpA
Current assignee: Whirlpool EMEA SpA
Priority date: 2007-04-17
Filing date: 2008-04-14
Publication date: 2013-02-27
Anticipated expiration: 2028-04-14
Also published as: US20100050700A1; WO2008125974A2; WO2008125974A3; ITTO20070271A1; EP2137347A2; PL2137347T3

Description

Field of the invention

The present invention concerns a laundry washing machine, in particular a front-loading machine, having

a washing chamber or tub,
a laundry basket mounted in the tub to rotate around an axis substantially horizontal or inclined up to 25° with respect to the horizontal,
motor means to actuate the basket in rotation, and
a system for supplying liquid inside the tub and/or the basket.

Prior art

Laundry washing machines (including the so-called "washer-drier" machines) comprise a cabinet, inside of which a washing chamber or tub is mounted. A basket is provided inside of the tub that, in the "European-type" machines is mounted so to be rotatable around an axis substantially horizontal or inclined usually not more than 25° with respect the horizontal.
The basket has two end walls, between which a perforated peripheral or circumferential wall extends, i.e., a wall practically entirely and uniformly provided with a multitude of holes for the passage of the treatment liquid. In the case of front-loading machines, the rear wall of the basket is closed and imperforated, while the front wall has an opening for the loading and unloading of laundry, facing an opening formed in the front wall of the tub. By contrast, in the case of top-loading machines, both the end walls of the basket are imperforated, the tub has a top opening and a door is provided in the perforated peripheral wall of the basket, to which the user has access when the basket is in a certain angular position inside of the tub.
In machines of the indicated type, the treatment of laundry implies the use of a washing liquid (or a rinsing liquid, depending on the phase of the operating cycle), which is loaded in the tub in an amount such that the lower portion of the basket is slightly submerged in the liquid. Under normal operation, the basket is put in rotation - after possible heating of the liquid - with the liquid contained in the tub able to get into contact with the laundry contained in the basket through the holes provided in the peripheral wall thereof. The treatment is facilitated by the mechanical agitation action of the laundry due to rotation of the basket.
With the aim of improving treatment performance (for example in terms of reductions in water consumption, energy employed and time) machines provided with a treatment liquid recirculation system have been proposed. Such systems essentially comprise a flexible tube departing from the outlet of a suitable pump, the inlet of which is in fluid communication with the lower part of the tub. In other solutions, feeding of liquid to the recirculation tube is obtained by exploiting the drain pump of the machine, downstream of which a deviator valve is mounted, which alternatively addresses the liquid present in the tub toward the recirculation tube or toward the discharge tube of the machine.
Irrespective of the type of pump employed, the recirculation tube ends at an opening formed in the upper zone of the tub. Therefore, the liquid flow exiting from such opening falls onto the basket and can reach the laundry by means of the holes present in the peripheral wall, improving soaking thereof. Solutions of this type usually imply the loading of great volumes of liquid in the tub. The setting up of the recirculation circuit and its components complicates manufacturing of the machine.
In some front-loading laundry washing machines, the recirculation tube ends with a nozzle substantially positioned at the opening of the basket, to directly send a water flow inside the latter. This solution allows for a decided improvement in the efficacy of liquid recirculation, but it further complicates construction of the hydraulic circuit of the machine and of the bellow-like sealing gaskets operating between the front wall of the tub and the front wall of the basket, in which the nozzle must be positioned.
With the prospective of insuring good washing performances, further reducing the volumes of used liquid, washing machines have also been proposed whose basket is provided with a prevalently imperforated peripheral wall, that is being closed for the most part thereof. In some know solutions, typically in the case of front-loading machines, the basket can be rotated around a slightly inclined axis and some liquid discharge holes are formed in the front wall of the basket, around the laundry loading/unloading opening; some discharge holes may be provided in the peripheral wall itself, in a limited annular region proximate to the front wall.
These solutions assure that a certain amount of liquid remains inside of the basket during the rotation thereof, with consequent good soaking of the laundry even when reduced volumes of liquid are used. In fact, in such solutions the liquid can remain in the basket during the treatment phases with a relatively low speed, due to the inclination of the rotational axis of the basket and to the presence of a prevalently imperforated peripheral wall. The liquid is expelled from the basket through the above-said discharge holes: for such purpose, at opportune moments in the treatment cycle, centrifugation phases of the laundry load must be provided (for example, at the end of actual wash phases or at the end of rinse phases). In such phases, due to the high rotational speed of the basket, the liquid present in the laundry tends to be expelled therefrom by effect of centrifugal force; then the liquid tends to run along the peripheral wall of the basket which, as was said, is inclined with respect to the horizontal, to reach the discharge holes, through which the liquid can return to the tub; the liquid is then expelled from the tub through a discharge pump, which is active during the above centrifugation phases.
In these solutions with a basket having a prevalently imperforated peripheral walls, a system for loading or delivering liquid inside the basket must be provided, which is usually configured as a recirculation system of the type described previously, with a flexible tube ending with a nozzle facing into the front opening of the basket. As was previously explained, this solution is a source of drawbacks for the construction of the machine.
EP 1538252 A discloses a plastic tub for a clothes washing machine, comprising a front shell and a rear shell.
DE 4342626 A1 discloses a water supply system for a top-loading washing machine comprising a flexible duct leading from a detergent container to a nozzle in the washing chamber. Washing liquid leaving the nozzle enters the laundry drum through one of at least three ridges designed to move the laundry, each ridge having water receiving apertures and an inner cavity with outlets to deliver the washing liquid within the drum. The nozzle is situated in a wall of the washing chamber so that it is located opposite one of the ridges when the laundry drum is in its loading position. The outlets in the ridges are positioned so that the water flows directly onto the laundry inside the drum.
EP 1505193 A discloses a washing machine including a tub containing a rotatably mounted drum to receive laundry to be washed and a water supply unit operable to supply water for washing to the tub. The water supply unit is configured to supply water directly into the drum and the washing machine includes a controller to control the separate supply of water into the tub and directly into the drum.

Summary of the invention

One aim of the present invention is to provide a laundry washing machine provided with an improved hydraulic system with respect to the prior art.
Another aim of the present invention is to provide a laundry washing machine wherein some operations that must be performed by the respective user in view of the performance of the washing cycles are particularly simple and convenient. In this regard, the invention proposes providing a machine in which the cleaning operations of a filter associated with a pump of the machine are particularly easy. A
At least one of the above-said aims is achieved, according to the present invention, by a laundry washing machine having the features indicated in the annexed claims. The claims constitute an integral part of the technical teaching provided herein relative to the invention.
According to the invention,*the machine is provided with an inflow conduit, used to deliver a treatment liquid into the tub and/or basket, such conduit being substantially integrated into the tub, or directly defined by the body thereof. The tub is formed by at least two half-shells made of plastic material sealed together, wherein each half-shell defines a respective part of at least one first portion of the inflow conduit, such first portion of the inflow conduit being formed by the union of the two half-shells, which are, for example, welded together.
This solution allows for obtaining a great simplification, from the manufacturing viewpoint, of the hydraulic circuit of the machine, since the recirculation conduit can be formed prevalently in a single piece with the plastic tub, and also allows elimination of the numerous criticalities of the flexible recirculation tubes according to the prior art.
Preferably, at least one second portion of the feeding conduit is also entirely formed in one of the two half-shells of the tub, the first portion and the second portion of the feeding conduit being substantially orthogonal to each other. Also preferably, the body of the tub further integrates or defines a seat for a drain pump and a seat for a deviator valve, which are part of a system for feeding liquid inside the tub and/or basket.
According to one embodiment, the tub of the machine is provided with a seat for the filter of a pump, particularly positioned substantially at a discharge outlet of the tub, and the machine is arranged for allowing access the seat of the filter and/or to remove the filter from the seat by operating from inside the basket.
By means of such embodiment, one of the periodic operations that the user is required to perform for the proper functioning of the machine, i.e., cleaning of the filter, can be performed in a simple and advantageous way from an ergonomic point of view.
In such embodiment, preferably, the peripheral wall of the basket includes a dedicated passage for access to the filter and inside the basket a means for closing such passage is provided, such means being removable or displaceable.
In a possible implementation, said occlusion means is substantially configured as a removable plug, operative in the region of the peripheral wall of the basket wherein the filter-access passage is formed. Preferably, the above-said plug is received in a removable way in a respective engagement seat, defined in a body fixed within the basket, on the peripheral wall thereof.
In a variant, the occlusion means is constrained within the basket in a way so as to be movable between a first and a second position, in the first position the access passage to the filter seat being not accessible and in the second position, instead, the said seat being freely accessible for the removal of the filter. In this case, preferably, the occlusion means is mounted so to be movable between the first and second positions according to a rotation axis that is transverse or substantially perpendicular to the rotational axis of the basket. Advantageously, the occlusion means can be configured as an element for the dragging and/or agitation of the laundry in the basket.

Brief description of the drawings

Additional aims, characteristics and advantages of the inventive solutions will be clear from the detailed description that follows, made with reference to the annexed drawings, provided by way of non-limiting example only, wherein:

figure 1 is a schematic front view of a laundry washing machine according to the invention;
figure 2 is a section according to line II-II of figure 1;
figures 3 and 4 are schematic views, a frontal and a perspective one, respectively, of the oscillating group of the machine in figure 1;
figure 5 is a section according to line V-V of figure 3, in an enlarged scale;
figures 6 and 7 are further schematic and perspective views of the oscillating group of figure 3, viewed from different angle-shots;
figure 8 is a partially exploded schematic view of the oscillating group of figures 3-7, in a different scale;
figure 9 is a lateral view of the oscillating group of figures 3-7;
figure 10 is a section according to line X-X of figure 9;
figure 11 is a front view, in an enlarged scale, of a laundry basket that belongs to the oscillating group of the previous figures;
figure 12 is a schematic section according to line XII-XII of figure 11;
figure 13 is a section of the oscillating group of a machine according to a variant of the invention.

Detailed description of preferred embodiments Figures 1 and 2 represent an example of a machine for domestic use for the washing and likely drying of laundry according to the invention, indicated with 1 as a whole. In the example, the machine 1 is a front-loading machine.
The machine has a cabinet 2 with a front wall 2a wherein an opening 3 is obtained, having a substantially square shape in the non-limiting example. A control panel 4, only schematically represented and including a display and some command buttons, is mounted on the wall 2a; the control panel 4 is associated with a machine control system, particularly of the microcontroller type, schematically represented by the block CS.
In the following, only the components of the machine 1 useful for understanding the inventive aspects of interest will be described, taking for granted that the machine includes all of the other elements - being known per se - required for its normal functioning, such as valve means and conduits for loading water into the tub, level sensing means, drain conduit, likely anti-flood means, likely drying circuit, suspension/shock absorbing means, and so on.
Inside the cabinet 2 a so-called oscillating group is provided, indicated as a whole with G in figure 2. Below the oscillating group G, within the cabinet, a housing for a drawer is defined, indicated with D.
As is visible in figures 3-10, the oscillating group G comprises a washing tub 5 made of plastic material, having connections 5a for the upper ends of the supporting shock absorbers, which are indicated with 6 only in figure 2 and are only partially visible also in figure 6; the lower ends of the shock absorbers are attached to a lower base of the machine, not represented, being of known conception. In the illustrated case, four shock-absorbers are provided, but this number must be taken as purely exemplary, since the group G could also be supported by only two shock absorbers and/or provides also elastic elements in the form of springs, anchored between the upper region of the tub 5 and the upper region of the cabinet 2.
The oscillating group also comprises a structural component 7, fixed at the front wall 5b of the tub 5 and acting as counterweight; in the illustrated example, the element 7 has a generally annular shape, with a respective axial passage having a section conforming substantially to a front opening 5c of the tub 5. Figures 3-4 and 6-7 illustrate two different possible shapes of the element 7, to which a frontal guard is preferably associated.
In figure 1, 8 designates a porthole of the machine 1 which, in a preferred embodiment of the invention, belongs to the oscillating group G. For such purpose, the porthole 8 is associated with the front wall of the tub 5 or with the component 7 through a hinge indicated schematically with 9. Also in figure 1, 8' indicates a front door of the cabinet 2 of the machine 1 hinged to the cabinet itself through hinges indicated with 9'.
The oscillating group G comprises a laundry basket or drum, indicated with 10 as a whole. The basket 10 is preferably made of stainless steel, although realisation of the basket in plastic material is equally possible; it is equally possible to provide a basket of the so-called hybrid type, that is, including a peripheral or circumferential wall made of steel and front and rear walls made of plastic material. The oscillating group G also comprises an electric motor 11, anchored to the rear wall 5d of the tub and adapted to put the basket 10 in rotation.
As is visible in figures 5 and 8, the basket 10 has a peripheral wall 10a including a prevalently imperforated annular region or strip, i.e., a region defined for the most part thereof by a closed or integral wall, and at least one perforated strip or annular region provided with holes for the passage of the treatment liquid. Furthermore, the basket 10 presents an imperforated rear wall 10b and a front wall 10c in which a main access opening is formed, for the loading and unloading of laundry, indicated with 10c', Preferably, the machine 1 is of the type with high laundry load capacity (indicatively 6-8 kg), such so that basket and the tub have increased dimensions with respect to typical machines with a 5 kg maximum load. To facilitate laundry loading and unloading operations, also the front opening 10c' of the basket has an increased diameter, indicatively comprised between 360 and 410 mm, preferably about 380 mm.
As in the prior art, the front wall 10c of the basket has a central region that generally flares toward the outside, so to protrude within the front wall 5b of the tub 5, which also has a shape that partially flares toward the outside, wherein a respective opening is formed, not indicated.
In the embodiment currently considered as being preferential, the motor 11 is of the type mounted in axis with respect to the basket. For such purpose, as is visible in figures 5 and 8, the motor 11 includes a stator 11a fixed to the rear wall of the tub 5 and a rotor 11b connected to a shaft 11c for actuating the basket 10. Preferably, the motor 11 and the respective control circuit are of the type in which the speed and angular position of the rotor 11b with respect to the stator 11a can be controlled, to allow to angularly position of the rotor, and thus the basket 10, in a desired position. As will be clearer in the following, in an embodiment of the invention, such a motor, together with the control system of the machine, prearranged for this purpose, can be controlled to bring the basket 10 to a substantially predefined angular position within the tub 5.
As is particularly visible in figure 2, the oscillating group G is arranged such that the basket 10 rotates around an axis, indicated with X, which is slightly inclined with respect to the horizontal. In general terms, the angle of X can be included between 0 and 25° with respect to the horizontal, preferably between 5° and 13° and, very preferably, about 10° +/- 2°. Such an inclined arrangement is provided both for the purpose of improving ergonomics of the machine 1, concerning laundry loading and unloading operations with respect to the basket, and for the purpose of collecting and maintaining part of the treatment liquid within the basket during some operation phases of the machine.
At least one body configured to perform the function of a laundry dragging and/or agitating element is provided inside the basket 10. In the exemplified embodiment, three such bodies are provided, substantially hollow, later identified as "draggers" for simplicity. As is visible in figures 2 and 10, in the exemplified embodiment two different types of draggers are provides, and specifically two shorter draggers 17 and a longer dragger 18.
Draggers 17 and 18 are mounted at the peripheral wall 10a of the basket 10 and are preferably made of moulded plastic material; in the illustrated example, draggers 17 are located on the peripheral wall 10a at about 140° with respect to dragger 18. Dragger 18 extends for a prevailing part of the depth of the basket 10, substantially between the walls 10b and 10c, and is provided with holes 18a (figure 3) for the passage of liquid. Draggers 17 are positioned in an anterior region of the peripheral wall 10a of the basket and they are also provides with respective holes - some of which indicated with 17a in figure 5 - for the passage of liquid.
The oscillating group G further comprises a gasket indicated with 19, for example in figure 5, preferably made of elastomer material and associated with the front wall 5b of the tub 5. The gasket 19 is destined to cooperate with the porthole 8, having a substantially circular shape, to guarantee the necessary fluid sealing with respect to the tub 5, and therefore avoid that the treatment liquid leaks out from the tub itself during the operation of the machine 1: In this regard, note that the door 8' essentially performs the function of closing the front opening 3 of the cabinet 2, as well as safety functions. In fact, it will be appreciated that during operation of the machine 1 the porthole 8, being part of the oscillating group G, will itself be subjected to vibrations and movements. In such regard, door 8' is provided to avoid the risk of contact by the user with the oscillating group G, and namely with the porthole 8 and the component 7 during operation of the machine 1. For such a purpose, both the porthole 8 and the door 8' are preferably provided with lock devices which guarantee blocking thereof during the operation of the machine, according to a technique known per se in the field. It will also be appreciated that, with this solution, it is no longer necessary to provide a tubular bellow-like gasket extending between the cabinet of the machine and the opening of the basket, which gasket is instead typical of the prior art.
As mentioned previously, the peripheral wall 10a of the basket 10 includes a prevalently imperforated strip or annular region and at least one first perforated strip or annular region. As can be seen in figure 12, two end portion can be identified in the peripheral wall 10a of the basket, indicated with A and B, having essentially opposing truncated cone-like shapes, between which a substantially cylindrical portion indicated with C is found. In the perforated region of the basket, or in portion B, an annular array of main discharge holes is provided, which are arranged in groups 50, as will be clear later. The annular region of the peripheral wall 10a formed by portions A and C is instead prevalently hole-free, in the sense that it is, for the most part thereof, a closed wall: more in particular, in such region only some passages, dedicated to respective specific functions are provided, such as the passages indicated with 20 and 21 in figures 8 and 12, and an annular array of secondary discharge holes indicated with 22. The passages 20 and 21 have respective diameters by far greater than the average diameter of the holes traditionally provides in the circumferential walls of baskets according to the prior art: indicatively, the passage 20 can have a diameter comprised between 20 and 30 mm, while the passage 21 a diameter comprised between 50 and 80 mm. As is visible in figure 10, one of the draggers 17 is mounted inside of the basket 10 on the peripheral wall 10a, substantially in correspondence to the passage 20.
Summarizing, in the peripheral wall 10a of the basket two annular arrays of discharge holes are present, each being substantially proximate to a respective end wall of the basket, between which an intermediate annular band that is almost completely imperforated extends.
The body of the tub 5 integrates or defines a substantial part of the inflow conduit used to admit treatment liquid inside the basket 10; in the embodiment described herein, such system is essentially of the recirculation type.
The above-said conduit, which preferably extends outside of the containment volume of the tub 5, is indicated as a whole with 30 in figures 6 and 7. This conduit 30 has two portions 31 and 32 arranged orthogonally to each other, and in particular a first portion 31, which extends according to the axial dimension of the peripheral wall 5e of the tub 5, and a second portion which substantially extends according to a circumferential dimension of the tub 5, i.e., substantially along a circumferential arch along the peripheral wall 5e. As can be noted in figures 6 and 7, the conduit portion 31 is formed in a lower region of the tub 5; the second conduit portion 32 ascends from portion 31 along the peripheral wall 5e to end with a delivery outlet opening into the tub, indicated with 33 in figure 10; in the non-limiting example illustrated, the outlet 33 is found in a lower position with respect to the horizontal centreline of the tub.
In a preferred embodiment, the tub 5 is formed by at least two moulded half-shells of plastic material, indicated with 5' and 5", sealingly made integral to each other, by means of welding or by fixing bolts or the like. As is seen in figures 6, 7 and 8, the first conduit portion 31 is entirely formed in the half-shell 5'. Each half-shell 5', 5" then defines a respective part of the second conduit portion 32.
As can be noted, in particular in figure 8, half-shell 5' includes a substantially flange-like circumferential part, indicated with 35, and half-shell 5" includes a grooved part 36, i.e., a part provided with a cavity or groove facing toward the flange-like part 35 of half shell 5'. When the two half-shells 5', 5" are joined, for example, through welding, the flange-like part 35 and the grooved part 36 define the second portion 32 of the external feeding conduit 30. Note that also half-shell 5" has, in any case, a respective flange-like part 37 which, together with the grooved part 36, is destined to cooperate, with the flange-like part 35 of the half-shell 5', with the aim of allowing a secure sealed union of the two half-shells 5', 5"; the flange-like part 37 can also be conveniently provided with a seating for a gasket, destined to cooperate in forming a seal with the flange-like part 35 of the half-shell 5'. As can be noted, for example in figure 10, the external conduit 30 - that is, its portion 32 - ends with the delivery outlet 33 in a point on the peripheral wall 5e of the tub 5 which is lower with respect to the horizontal centreline of the tub itself. Indicatively, the outlet 33 can be located at about 40° - 60° with respect to the lower dead point of the tub and basket; preferably, the outlet 33 is, in any case, found at a height greater than the maximum level which can be reached by the liquid inside the tub 5.
According to a further preferential characteristic, the body of the tub 5 integrates or defines also a seat indicated with 40, for an electric drain pump indicated with 41. In particular, the seat 40 is configured to receive the impeller 41a of the pump (figure 5) and define the inflow inlet and the delivery outlet - not visible - of this pump. The front part of the seat 40 has an annular seating for a sealing gasket, destined to cooperate with the body of the pump 40; at the seat 40 at least one flange is also conveniently provided, for anchoring the body of the pump 41.
Again according to a preferred embodiment, the body of the tub 5 also integrates or defines a seat 42 for a deviator device 43, later referred to as deviator valve. The seat 42 is configured to receive a deviator member of the valve 43 and defines one inlet and two outlets, not visible. The inlet of the seat 42 is in fluid communication with the delivery outlet of housing 40 of the pump 41; one outlet of the seat 42 is in fluid communication with the inflow conduit 30; the other outlet of the seat 40 is destined instead to be connected with a drain tube of the machine 1, not represented. Also the front part of the seat 42 can conveniently have a seating for a sealing gasket, destined to cooperate with the body of the actuator of the valve 43, and fixing projections of the cited valve actuator 43 are conveniently formed at the seat 42. Furthermore, advantageously, the body of the tub 5 directly defines also the hydraulic connection passages between the seats 40 and 42, in addition to the connection point for the above-said drain tube. As can be noted, for example in figures 6 and 7, the seats 40 and 42 are formed in the rear part of the peripheral wall 5e of the tub, in the lower zone thereof, both in the half-shell 5' which integrates also the conduit portion 31.
As will be seen below, the drain pump 41 and the deviator valve 43, with their respective seats 40, 42, are part of a recirculation system that, together with the inflow conduit 30, is used for the aim of performing phases of loading the liquid inside the basket 10. Such a recirculation system could include, instead of a drain pump and a deviator valve, an appropriate recirculation pump: in this case, a seat for such a recirculation pump is defined in the body of the tub 5, such a seat having an inflow inlet in communication with the inside of the tub 5 and a delivery outlet in communication with the inflow conduit 30.
In the lower region of the body of the tub 5, a seat 44 for a filter 45 is also advantageously defined, this seat being in particular obtained at the drain outlet of the tub, which is in communication with the seat of the drain pump (see for example figure 5, wherein 40a indicates the inflow inlet of the seat 40 of the pump 41). Preferably, the seat 44 includes or defines at least part of a system for locking the filter in place, such as a coupling system - for example a bayonet-like system - or a threaded system, another part of such a system being integrated in the filter 45.
From the figures it can be noted how the body of the tub 5 further defines, in the lower zone thereof, a collecting well indicated with 46, within which a resistance 47 for heating the treatment liquid is positioned. In the illustrated example at least one part of the well 46 extends longitudinally in the axial direction of the peripheral wall 5e of the tub 5, and this part of the well consists of a front portion 46a defined in the body of the half-shell 5" and a rear portion 46b defined in the body of the half-shell 5' (see figure 8). Also in this case, the sealed union between the two half-shells 5', 5" forms the well 46. The anterior part of the well 46 is conveniently configured for the purpose of the sealed fixing of the resistor 47, which is substantially cantilevered-mounted, through a front anchoring plate thereof. The well 46 communicates with the seat 44, which, as was said, communicates in turn with the inflow inlet of the seat 40 of the pump 41.
In an advantageous embodiment, the machine 1 is arranged to allow access to the seat 44 and/or removal of the filter 45 from the seat 44 by acting directly from inside the basket 10.
For such purpose, the peripheral wall 10a of the basket 10 includes a specific access passage to the filter, indicated with 21 in figures 8 and 12. As can be noted, such an access passage 21 is formed in the prevalently imperforated annular region of the peripheral wall 10a, where the passage 20 for the inflow of the treatment liquid into the basket 10 is also provided.
As is visible in figures 4 and 5, a hollow body 48 is mounted inside the basket 10 at the access passage 21, defining a seat for a removable plug or lid, indicated with 49. The body 48 and the lid 49 are conveniently formed by thermoplastic material, the first being stably anchored to the peripheral wall 10a by known means. The separable coupling between the plug 49 and the body 48 can be of any kind suitable for the purpose, for example, a threaded coupling or a bayonet coupling. A sealing gasket can operate between the cap 49 and the body 48.
When the user wishes to access the seat 44, he must only remove the plug 49 from the body 48: in this way, the passage 21 is in view and the user can easily remove the filter 45 from the seat 44, operating from inside the basket 10, through the front opening 10c' thereof.
Note that the body 48 and/or the plug 49 are preferably configured for isolating the passage 21 also to prevent the substantial exiting of liquid from the basket 10 through the same passage 21, for purposes that will be clear later. Regarding this, for example, a gasket can be mounted on the edge of the opening 21, destined to cooperate with the plug 49 to form a seal (or visa versa the plug 49 can have a gasket which cooperates with the edge of the passage 21 to form a seal).
The rotational axis X of the basket 10 is inclined so that its peripheral wall 10a is, at least in part, angled downward starting from the front wall 10c. In this way a liquid collecting zone is defined in the lower part of the basket, between the peripheral wall 10a and the rear wall 10b of the basket. The rear wall 10b lacks holes and, as was said, also the prevailing part of the peripheral wall 10a is almost completely free of holes, with the exception of the array of holes 22 and of the inflow and access passages 20, 21 (in addition to at least one possible additional dedicated passage, described below).
As was explained (see figure 12), the part of the peripheral wall 10a that is prevalently imperforated includes a rear truncated cone-like portion A and a substantially cylindrical portion C. The remaining front truncated cone-like portion B of the peripheral wall 10a, proximate to the front wall 10c of the basket, is instead provided with discharge holes.
According to one embodiment, the discharge holes of portion B are substantially arranged in groups, wherein at least part of the holes of each group are formed in an upper wall of a respective protrusion located in the peripheral wall of the basket, the groups of holes being arranged according to the circumference of the peripheral wall, preferably uniformly spaced. The groups of holes are indicated with 50 in figures 5 and 12.
In the embodiment currently considered as the preferential one, the machine I includes positioning means, which are arranged for bringing and maintaining the basket 10 in a substantially predetermined respective angular position within the tub 5. An example of such a predetermined position is represented in figure 10.
As can be noted, in such a position, the inflow passage 20 formed in the peripheral wall 10a of the basket 10 is substantially aligned with the outlet 33 of the inflow conduit 30; in this way, the passage 20 can receive a flow of liquid from the outlet 33, which is then sent inside the basket 10 through the dragger 17. For this purpose, the body of the dragger 17 is at least partially hollow and it defines internally a passage conduit for the liquid, in communication with the series of openings 17a of the dragger; the mouth of the internal conduit of the dragger, i.e., its end adjacent to the passage 20, is configured to facilitate entry of the liquid flow coming from the outlet 33 and/or increasing its speed, for example by means of a Venturi conformation.
In the embodiment currently considered preferential, the positioning means comprise the motor 11, which - as was said - is of the type in which the speed and the angular position of the rotor 11b with respect to the stator 11a can be controlled, for the purpose of being able to bring and stop the former in a desired position with respect to the latter. It will be appreciated that in this way, due to the connection of the basket 10 with the rotor 11b of the motor 11, it is possible to bring the basket to the above-said predetermined angular position. The positioning means further comprise the control system CS of the machine, which is configured to perform one or more steps of loading liquid in the basket 10, during one or more phases of an operating cycle of the machine 1.
For the purpose of performing these loading steps, the control system CS control the motor 11 to obtain a slow rotation of the basket 10, until it is brought to the predetermined angular position, in which the delivery outlet 33 of the conduit 30 and the inflow opening 20 are substantially aligned. Note that the control system CS can possibly be configured so as to automatically control the positioning of the basket 10, as represented in figure 10, at the end of a treatment cycle: therefore, the basket will already be in the predetermined position at the start of a next treatment cycle.
Next, the control system CS enables the flow of liquid in the conduit 30.
It should be specified that the machine is provided with means, not represented, for loading into the tub water from a water network. Such means are of known type and may include, for example, a supply solenoid valve, managed by the control system CS and having an inlet connected to the water network and an outlet connected with the inside of the tub 5, as well as a device for controlling the level of the liquid loaded into the tub, such as a system including a pressure switch or a flow meter. In the typical operation of these means, the control system CS controls opening of the supply solenoid valve, such that the water flow reaches the inside of the tub 10; in reaching a predetermined water level within the tub, detected through a pressure switch device or the like, system CS controls closing of the supply valve. When foreseen by the phase of the cycle, the control system CS then provides for powering of the resistor 47, for the purpose of heating the loaded liquid; upon reaching the programmed temperature, detected through a suitable sensor, the control system CS starts the previously-described recirculation system.
More in particular, after the basket 10 has been brought to the above-said predetermined position, the control system CS controls valve 43 so that the respective deviator member closes the outlet of the seat 42 communicating with the drain conduit of the machine 1. In this way, the outlet of seat 42 corresponding to the inlet of conduit 30 remains open. After the switching of valve 43, the control system CS controls activation of the drain pump 41. In this way, the liquid present in the bottom region of the tub 5 is sucked into the seat 40, following a passage through the filter 45, and sent under pressure to the seat 42, which in turn, conveys the liquid flow into the conduit 30. At the end of the conduit 30, i.e., at the delivery opening 33, the pressurised flow traverses a short path in air and passes into the inflow opening 20 and then into the dragger 17: thus the liquid flows into the conduit inside the dragger 17, to then flow inside of the basket 10.
After a predetermined time, defined during designing to obtain the loading of the desired amount of liquid in the basket 10 in the above said way, the control system CS stops operations of the pump 41 and sets the basket in rotation for the purpose of performing the treatment phase, whether a washing phase or a rinsing phase, at a relatively slow speed, for example, 40 - 50 rpm. Possibly, control of the amount of liquid loaded into the basket can be performed through the detection of the reduction below a certain threshold in the liquid level in the well 46, for example through a pressure switch sensor, instead of by activating the recirculation system for a predetermined time. Note that the maximal filling quantity of the basket is in any case determined by the overflow level of the holes 51 present in the front region of the peripheral wall 10a.
Due to presence of a prevalently imperforated peripheral wall of the basket, the reduced diameter of holes 22 and inclination of the axis X of the basket, an amount of liquid can be maintained for a certain period inside the basket. During rotation, the presence of holes 22 allows a progressive exiting of the liquid from the basket 10, but such an exiting occurs relatively slowly due to the reduced diameter of holes 22: therefore, during rotation a certain volume of water can be maintained within the basket for some minutes (indicatively 2-4 minutes), so guaranteeing an effective soaking of the laundry.
In the course, then, after a certain rotation time, the liquid which is not retained by the laundry will have escaped from the basket 10 and returned within the tub 5. Then the control system CS controls the motor 11 to bring the basket 10 again to the above-said predefined position, and causes a new activation of the pump 41, with a consequent new loading of liquid into the basket, in ways analogous to those described previously. The new activation of pump 41 can be time-controlled (for example, after a certain interval, set during designing, counted starting from the end of the previous liquid loading), or when exceeding of a given level of liquid in the tub is detected, for example, through a pressure switch. After loading liquid into the basket, system CS then controls a new rotation of the basket 10 at the relatively low speed.
The described sequence is repeated, with successive further loading of liquid into the basket, during advancement of the considered phase of the cycle, whether it is a washing or a rinsing phase.
Therefore, as can be seen, within a phase of the treatment cycle of the machine the recirculation process of the liquid with respect to the basket occurs in a discontinuous or intermittent way, in the sense that the pump 41 is activated and deactivated with a certain duty cycle, due to the fact that the liquid level inside the basket is subject to a decreasing from the time in which the recirculation phase is interrupted to the moment in which the successive recirculation phase is performed. Such mode of operation allows for obtaining, in addition to an effective laundry soaking, an optimal exploitation of the washing agent possibly present in the treatment liquid.
In the conclusive period of the treatment phase under consideration, the control system CS controls at least one step of laundry centrifugation, at a speed indicatively comprised between 700 - 800 rpm. During such a centrifugation step, the liquid still contained in the laundry is progressively expelled from the same by way of centrifugal force. Because of the inclination of the basket 10, such liquid expelled from the laundry (and the liquid possibly still present in the basket 10 because it was not yet discharged through the holes 22) tends to flow or rise back along the peripheral wall 10a, up to reach the perforated region B, wherein the discharge holes 51 are provided. Then the liquid can leave the basket through these holes 51 and return to the tub 5.
Note that the cited centrifugation step is started with the drain pump 41 being active and with the valve 43 being positioned by the control system CS in a way opposite to the previous one (i.e., such that the fluid pushed by the pump is not sent into the recirculation conduit 30, but toward the drain tube of the machine). In this way, the liquid present in the tub 5 is initially evacuated through the drain pump 41, and during the centrifugation phase, the liquid that progressively escapes from holes 51 of the basket 10, passes into the tub 5 and is then evacuated from it also through the pump 41.
It must be specified that the machine 1 according to the invention is also arranged for performing treatment cycles that do not provide centrifugation steps and/or is provided with control means (for example, a button) for the exclusion of the centrifugation steps possibly foreseen in the frame of a treatment cycle. Regarding this, it is recalled that treatment of some types of textile items, particularly delicate items (silk, for example) must be performed preferably without centrifugation phases of the laundry load. For this purpose, it is therefore common practice to provide the laundry washer with suitable delicate cycles, or to provide an appropriate key for exclusion of centrifugation, to satisfy the user's needs.
In the described machine 1 the presence of the array of holes 22 located on the peripheral wall 10a of the basket close the end opposite to that in which the holes 51 are found, allows for discharging the liquid at the end of a treatment phase in the case wherein the cycle selected by the user does not foresee performance of step of centrifugation. In fact, it will be appreciated that at the end of the phase of the cycle under consideration, at least one of the holes 22 finds itself at a minimum height (substantially at the lower dead point of the basket), so as to guarantee the emptying of the basket 10 even without centrifuging. On the other hand, as was previously said, the much-reduced diameter of holes 22 does not significantly preclude the capacity of the basket to perform the "role of tub", during the phase under consideration in which various steps of loading/recirculation of the liquid in the basket itself are provided.
In any case, at the end of the treatment phase of the cycle, the liquid has been discharged from the tub 1. For this purpose, as was said, the control system CS controls the valve 43 such that the relative deviator member closes the outlet of the seat 42 that is in communication with the conduit 30, thus opening the outlet which is in communication with the drain tube of the machine. Then, the pump 41 is activated, so as to evacuate the liquid from the tub 5.
The positioning means allowing the control of the rotation of the basket through the motor, in order to bring it to the predefined angular position, can possibly include sensor means of the angular position of the basket within the tub.
In an further possible variant, the positioning means may comprise an electromechanical device controllable by the control system of the machine with the purpose of stopping the basket in the substantially predetermined angular position.
In one embodiment of the invention, the machine is provided with a dispensing device of washing agents having a container for at least one washing agent associated with the basket.
In the described embodiment, such dispenser comprises the dragger 18, which embodies a body for housing the above said washing agent container and which is mounted inclinable inside the basket. Also the dragger 18 is preferably hinged to the basket 10 in its rear zone, to be displaced between a position substantially parallel to the circumferential wall 10a of the basket and a position inclined or angled with respect to such circumferential wall. In the inclined position the front of the dragger and of the container face directly the opening 10c' of the basket 10, such that the container itself can be brought to the respective extracted position, indeed through the frontal opening of the basket.
Naturally, without prejudice to the principles underlying the invention, the details of construction and the embodiments may vary widely with reference to what has been described and illustrated by way of example only, without departing from the scope of the present invention as defined by the claims that follow.
Figure 13 shows a possible variant of the oscillating group of a machine according to the invention.
In this variant, a dragging body 17' is provided, having a general configuration and dimensions similar to dragger 18. In addition, preferably, in this embodiment the access passage 21 to the seat 44 of the filter 45 and the inflow passage 20 of liquid into the basket 10 are substantially aligned with each other along the axial direction of the peripheral wall 10a of the basket, and therefore in the axial direction of the dragger 17'.
The dragger 17' is mounted inside the basket 10 in correspondence with, in addition to the emission passage 20, also the access passage 21, and is hinged inside the basket so to be angularly movable according to an axis indicated with Y', which is transverse or substantially perpendicular to the rotation axis of the basket 10. In this way, the dragger 17' is selectively movable between two positions; in its first position the dragger 17' is adjacent to the peripheral wall of the basket, making the passage 21 inaccessible. In its second position, visible in figure 13, instead, the dragger 17' is inclined upward with respect to the peripheral wall 10a of the basket 10, so as to make the passage 21 accessible, and thus extraction of the filter 45 from the corresponding seating 44 ( figure 13 illustrates the filter raised from its seat).
The body of the dragger 17' has a rear zone in which a hinge element is obtained, indicated with 17b. This hinge element 17b cooperates with a second hinge element 17c belonging to a respective support, indicated with 17", which is anchored inside the basket 10 and is preferably formed in plastic material. A front portion 17d of the support 17" extends adjacent to the front wall 10c of the basket 10, and in this portion 17d a seat 17e is formed, destined to cooperate with a hooking tooth 17f formed in a front wall of the dragger 17'. The arrangement is such that, through the engagement of the tooth 17f in the seat 17e, the dragger 17' is maintained in a fixed position with respect to the support 17", i.e., in the above-said first position, in which the dragger itself is substantially adjacent to the peripheral wall of the basket. The centrifugal force due to rotation of the basket 10 during operation of the machine contributes to guaranteeing the maintenance of the position adjacent to that wall 10a.
Whenever the user wishes to access the seat 44 of the filter 45, he need only to exert a slight pressure on the front wall of the dragger 17', provided for the purpose with a pull-tab, indicated with 17g. In this way it is possible to disengage the hooking means 17e-17f which maintain the dragger 17' in the reclined position. Then the user can lift the dragger 17', moving it regularly around the axis Y', as is visible in figure 13. When the dragger 17' is in such a position, the access opening 21 is in view and therefore the user can easily remove the filter 45 from the seat 44, operating from inside the basket 10, through the front opening 10c' of the latter. Naturally, the support 17' has a respective passage in correspondence with the passage 21 for such purpose. Also between the dragger 17i and the relative support 17", a bi-stable mechanism can be provided, having functionalities similar to the mechanism 83 of the dragger 18, as well as end-of-stroke means for the angular movement allowed to the dragger 17'.
In the preferred embodiment of the present variant, means for closing the access opening 21 are also provided. These occlusion means may consist, for example, of a plug which can be removed by the user and which is mounted in a removable way at the access opening 21. In a preferred embodiment, these means are integrated directly in the body of the dragger 17', in the part thereof facing toward the peripheral wall 10a of the basket. For this purpose, the internal part of the dragger 17' may, for example, provide a respective massive part, destined to be located over the access opening 21, capping it, when the dragger is in the reclined position. Advantageously, in this embodiment, a gasket is conveniently mounted on the edge of the access opening 21, destined to cooperate with the above-said massive part in forming a seal.
The body of the dragger 17' is provided with a respective internal conduit, not represented, whose mouth is adjacent to the inflow opening 20 provided on the peripheral wall 10a of the basket 10. Furthermore, in the exemplified case, at the passage 20, the support 17" includes a tubular body 20a, which extends longitudinally along a radial direction of the basket 10, destined to send the flow of liquid inside the dragger 17'. Also in the variant of figure 20, the liquid loading/recirculation phases are performed with the basket in a predefined position similar to that of figure 10.
In another possible variant embodiment, the inflow opening 20 can be formed in the rear wall 10b of the basket and the conduit 30 can be located such that the delivery opening 33 opens in the rear wall of the tub 5. liquid. Also in this solution the positioning means provide for bringing and/or maintaining the basket in a substantially predefined angular position, in which the delivery opening present in the rear wall of the tub and the inflow passage provided in the rear wall of the basket are substantially aligned, with an overall operation being similar to the previously described one.
According to a further possible variant, the cap 49 for access to the filter 45 can be replaced by a movable hatch attached to the body 48, for example, hinged to it, and provided with a user-operable locking/releasing mechanism.
In another variant, the treatment liquid is delivered inside the basket of the machine by exploiting the presence of an annular array of holes provided in its peripheral wall 10a, for example, the array provided in its portion B. Therefore, in such a variant - keeping the other previously described aspects constant - it is not strictly necessary to bring and/or maintain the basket 10 in the above-said predetermined position, since the loading of liquid into the basket can occur even with the basket in rotation. For the purposes of the inflow of liquid into the basket, the control system of the machine controls a rotation at very slow speed, indicatively comprised between 10-15 revolution, as well as the activation of the pump 41 in the manner already described above. Preferably, in this case, liquid conveying elements are obtained or fixed on the outside of the peripheral wall of the basket, aimed to facilitate the inlet of the liquid itself through the holes of the annular array.

Claims

Laundry washing machine having a washing chamber or tub (5), a laundry basket (10) mounted in the tub (5) so as to rotate around an axis (X) substantially horizontal or inclined up to approximately 25° with respect to the horizontal, motor means (11) to actuate the basket (10) in rotation and a system for feeding liquid in the tub (5) comprising an inflow conduit (30), wherein the basket (10) has a first and a second end wall (10b, 10c), between which a peripheral wall (10) extends and wherein the tub (5) has a body formed by at least two half-shells (5', 5") of plastic material sealingly joined together, characterised in that each half-shell (5', 5") defines a respective part (35, 36) of at least one first portion (32) of the inflow conduit (30), the first portion of the conduit (32) being formed as a result of the joining of the two half-shells (5', 5").
Machine according to claim 1, wherein one half-shell (5') comprises a flange-like circumferential part (35) and the other half-shell (5") comprises a grooved part (36) and the two half-shells (5', 5") are joined such that the flange-like part (35) and the grooved part (36) cooperate to form said first portion (32) of the inflow conduit (30).
Machine according to claim 1, wherein the inflow conduit (30) comprises a second portion (31) which is entirely formed in one of the two half-shells (5', 5") and is substantially orthogonal to the first portion (32).
Machine according to claim 3, wherein the second portion (31) extends according to an axial dimension of a peripheral wall (5e) of the tub (5) and the first portion (32) substantially extends according to a circumferential dimension of the tub (5).
Machine according to claim 1, wherein the tub (5) integrates a seat (40) for a pump (41).
Machine according to claim 5, wherein said pump is a drain pump (41) and the tub (5) further integrates a seat (42) for a deviator device (43) having one inlet and two outlets, the inlet being in fluid communication with the seat (40) of the pump (41), one outlet being in fluid communication with the inflow conduit (30) and the other outlet being in communication with a drain tube, where in particular the tub (5) integrates the passages for hydraulic connection of the seat of the pump with the seat of the valve.
Machine according to claim 5, wherein the pump is a recirculation pump, belonging to said system for feeding liquid, having an inlet in communication with the inside of the tub (5) and an outlet in communication with the inflow conduit (30).
Machine according to claim 5, wherein the tub (5) integrates a seat (44) for a filter (45) of the pump (40).
Machine according to claim 8, wherein the machine (1) is arranged to allow access to said seat (44) for the filter (45) and/or removal of said filter (45) from the seat (44) thereof operating from inside the basket (10).
Machine according to claim 9, wherein the peripheral wall (10a) of the basket (10) comprises an access passage (21) to the filter (45) or the seat thereof (44).
Machine according to claim 10, wherein means (17'; 49) for selectively hiding and/or occluding the access passage (21) are provided, said means being removable from the basket (10) or constrained to the basket in a movable way.
Machine according to claim 8, wherein the seat (44) for the filter (45) includes or defines one part of a system for locking the filter in place, another part of said system for locking being integrated in the filter (45).
Machine according to claim 1, wherein the tub (5) further defmes, in the lower zone thereof, a collecting well (46), within which a heating resistance (47) is positioned.
Machine according to claim 13, wherein at least one part of the well (46) extends longitudinally in the axial direction of the peripheral wall (5e) of the tub (5), said one part of the well (46) consists of a front portion (46a), defined in the body of one (5") of said the half-shells (5', 5"), and a rear portion (46b) defined in the body of the other one (5') of said half-shells (5', 5").