EP0752493B1

EP0752493B1 - Laundry washing machine having washing liquid filtering means

Info

Publication number: EP0752493B1
Application number: EP96201862A
Authority: EP
Inventors: Dino Bongini
Original assignee: Merloni Elettrodomestici SpA
Current assignee: Whirlpool EMEA SpA
Priority date: 1995-07-06
Filing date: 1996-07-03
Publication date: 2000-11-02
Anticipated expiration: 2016-07-03
Also published as: ITTO950573A0; EP0752493A1; IT1276479B1; DE69610796D1; ES2152484T3; DE69610796T2; ITTO950573A1

Description

The present invention has as its subject a laundry washing machine, of the type described in the preamble of the annexed claim 1.
A machine of this kind is known from US-A-2,962,886.
It is known that some laundry items, under the mechanical washing action, have the tendency of loosing filaments, or leaving small foreign bodies, occasionally gathered in the laundry or contained in such. Such filaments or foreign bodies are transported and moved by the washing liquid during the functioning of the machine, up to the drainage phase. During such phase, the liquid and residues contained within are sucked towards the drainage pump.
In order to avoid blocking of the drainage pump, due to the gathering of such filaments or the passage of foreign bodies being of significant size, it is known to provide liquid filtering means, arranged before the pump; such filtering means have to be periodically cleaned, generally depending upon the types of fabric washed.
Such an operation results in being rather difficult, due to the arrangement of said filtering means, usually housed in the lower part of the cabinet of the machine and to which access is achieved only after having removed a cover.
A further problem of the known art derives from the fact that, upon termination of a washing cycle, a certain part of the liquid tends to remain in the drainage piping circuit of the machine, before the pump; therefore, when the user removes the access cover from said filter, for its cleaning, such water residues exit the machine and can leek on to the floor of the room in which the machine is installed.
The aim of the present invention is that of overcoming the aforementioned drawbacks and to realise a laundry washing machine equipped with a filtering device of the liquid that is of simple realisation, contained costs and of simple use by way of the user.
Such purpose, and other aims that shall appear in the following, are reached according to the present invention by way of a laundry washing machine incorporating the characteristics of the enclosed claim 1.
Further characteristics and advantages of the present invention, shall result in being clear from the following detailed description and annexed drawings, supplied purely as an explanatory and non limiting example, wherein:

figure 1 is a partially sectioned schematic side view of a laundry washing machine according to the invention, in a first functional condition;
figure 2 is a schematic partial sectioned frontal view of a filtering device of the laundry washing machine of figure 1.

With reference to figures 1 and 2, the number 1 indicates the washing machine as a whole according to the invention; such machine 1 comprises in the known manner, a washing tub 2 within which a washing basket 3 is arranged, having a horizontal axis, which is operated with a rotary motion around such axis.
Near to the bottom of the tub 2, an opening of a drainage duct 4 is defined, which enters the intake zone of a pump 5, of the type known, which is operated when the washing cycle provides for a partial or complete emptying of the tub.
An auxiliary duct is indicated with 6, the first extremity 6a of which communicates with the inside of the tub 2 and arranged above the level 7 reached by the water during washing due to the effect of the rotation of the basket 3. The second extremity of the auxiliary duct 6 is connected to the drainage duct 4, before the pump 5: advantageously, a union sump 8 is provided on the drainage duct 4, which further lowers the level of the drainage duct 4, and the second extremity of the auxiliary duct 6 joins in fact near to the bottom of such union sump 8.
Appropriately, the first extremity 6a of the auxiliary duct 6 is water tightly connected to the lower zone of a water tight bellows seal 10; such seal 10 connects the tub 2 to the loading opening 11 of the machine, to which a loading door 12 is arranged in a known way.
According to the invention, in such seal 10 a seat is also obtained, indicated with 13, for a filter, indicated with 14; advantageously such filter 14 is housed in the seat 13 in a removable manner.
The machine also provides for a programming device, or timer, which supervises the operations of the various washing cycles that can be selected by the user of the machine; such device has not been represented in the figures for reasons of simplicity, inasmuch its realisation and functioning is known.
The functioning of the laundry washing machine according to the invention is the following.
The user, after having loaded the laundry to be washed in the basket 3, through the door 12, selects the desired washing cycle and starts the machine.
At an appropriate moment of such cycle, the programming device of the machine controls the introduction of the water to the tub 2, at the beginning of the washing phase in the strict sense; in practice, during such phase, the washing water coming from the mains is made to pass through an appropriate dispensing device, in itself known and not represented in the figures, so as to transport the detergents to the washing tub 2; the water in the tub is heated by way of appropriate resistences, upon a command of the programmer of the machine, to a suitable temperature to fit the needs, for instance 60°.
During the washing phase, the basket 3 is made to rotate at a determined speed, under the control of the programming device; the mechanical rotational action of the basket (which produces the movement of the laundry), together with the chemical action (determined by the presence of the detergents) and thermal action (water temperature) allows for obtaining the washing of the laundry.
As said, during the washing phase it occurs that the clothes release fibres and/or foreign bodies, which therefore mix with the washing liquid.
According to the invention, the rotation of the basket 3, combined with the presence of laundry within, projects part of the washing liquid contained in the tub 2 against the internal wall of the tub and towards the loading door 12 which, as seen from figure 1, extends in the direction of the tub 2 and towards the interior of the basket (which has the usual frontal opening).
The liquid that is projected against the loading door 12, descends along its surface, gathers in the lower zone of the seal 10 where the seat 13 of the filter 14 is defined; as mentioned, below the seat 13 the opening 6a of the auxiliary duct 6 is found: therefore, the liquid projected against the door 12, or however towards the seat 13, results in being filtered by way of the filter 14, before penetrating the duct 6.
Due to the difference in the levels which is created between the liquid contained in the auxiliary duct 6 and the liquid in the tub 2, a flow is generated from the auxiliary duct 6 towards the union sump 8 and from this to the tub 2, through the duct 4.
In practice, therefore, part of the washing liquid employed within the laundry washing machine is made to re-circulate by way of the basket 3, the seat 13, the duct 6, the sump 8 and the duct 4.
It is noted that such re-circulation of the liquid also has the effect of causing, during the washing phase, a gradual return to the tub 2 of the detergents eventually accumulated in the drainage duct 4 and in the union sump 8.
The above described functional situation is illustrated in figure 1, where the arrows inside the ducts 4 and 6 indicate the flow of the re-circulated liquid.
Advantageously the quantity of washing liquid projected towards the loading door 12 can be increased by using a basket provided with spoons or sacks 19 on its interior surface obtained on the projecting ridges 20 for the movement of the laundry , as can be seen in figure 2, that collect the liquid from the bottom of the tub and project it from above on the laundry below. Such ridges 20 can therefore be shaped so as to also favour the passage of liquid towards the door 12 and the seat 13.
If considered that, within a washing cycle, the various moving phases of the laundry basket last for numerous minutes, it is clear that, with good approximation, the greater part of the washing liquid employed in such phases passes such seat 13 on numerous occasions (approximately ten times), and is thus placed under the filtering action.
In such way, therefore, according to the invention, the action of recirculating the liquid favours the gathering of fibres and small foreign bodies in the seat 13, in correspondence with the filter 14. This avoids the use of a filter containing a drainage pump as is the case with the known art.
As is clear, the position of the filter 14, according to the invention, results in being much more satisfactory if compared to the known art; the same is said for its access, for which no removal of any covering element is required.
The ergonomic positioning and the simplified access to the filter 14 therefore stimulates its cleaning by the user, who can also keep the situation under control.
Another substantial advantage of the invention consists in that the stylistic line of the machine may not be disturbed by the presence, in the frontal part of the cabinet, of a small access door to the filter as is typical in the known art.
With the solution according to the invention, the risk of leaks from the drainage circuit of the machine is completely avoided, when cleaning the filter (typical problem of the known art, as indicated at the beginning of the present description).
From the given description the characteristics of the present invention result in being clear, as do its advantages.
The laundry washing machine thus realised is susceptible to numerous modifications and variants, all falling within the scope of the inventive concept. In practice, the materials used, and their dimensions, can be of any type according to needs and the state of the art; moreover, all the particulars can be substituted with technically equivalent elements.
From among the possible variants it is mentioned that of realising the internal glass part of the door 12 (i.e. the part facing the opening of the tub 2 and the basket 3) in such a way as to favour to the maximum possible the passage of the liquid towards the seat 13. The same can be said for the profile of the opening of the tub 2, of the basket 3 and of the seal 10, that could be in fact realised for simplifying a substantial passage of liquid from the inside of the basket 3 towards the seat 13.

Claims

Laundry washing machine, comprising a washing tub (2) which houses a basket (3), the tub (2) and the basket (3) having respective openings facing an opening (11) being present in the cabinet of the machine (1), wherein

a door (12) is provided for said opening (11) of the cabinet (11),

a seal (10) is provided between the opening (11) of the cabinet and the opening of the tub (2),

a conduit (6,4,8) is provided, for re-circulating washing liquid agitated within the tub (2) by the basket (3) in motion, the outlet of said conduit (6,4,8) being arranged at a lower lever with respect to the inlet thereof,

a filtering element (14) is provided, being arranged in a relevant seat (13), for filtering the re-circulated liquid,

characterized in that said seat (13) is provided in said seal (10) in correspondence of the inlet of said conduit (6), at a level being higher than the level (7) reached by the liquid in the tub (2) during the washing, said seat (13) being able to collect liquid agitated within the tub (2) by the basket (3) in motion, in such a way that the liquid collected in said seat (13) is filtered by said filtering element (14) and then re-circulated through said conduit (6) in the washing tub (2).
Laundry washing machine, according to claim 1, characterized in that said conduit comprises a duct (6) extending from said seat (13) and connected to a drainage duct (4) of the liquid from the machine, which is arranged below said tub (2).
Laundry washing machine, according to at least one of the previous claims, characterized in that said filtering element (14) is housed in said seat (13) in a removable manner.
Laundry washing machine, according to at least one of the previous claims, characterized in that said filtering element (14) is housed in a position being visible by the user upon opening said door (12).
Laundry washing machine, according to at least one of the previous claims, characterized in that said basket (3) has provided on its internal surface movement ridges (20) of the laundry and that said ridges (20) are shaped in a way to favour the passage of liquid from the inside of said basket (3) or tub (2) towards said seat (13).
Laundry washing machine, according to at least one of the previous claims, characterized in that the internal part of said door (12) is shaped in a way to favour the passage of liquid from the inside of said basket (3) or tub (2) towards said seat (13).
Laundry washing machine, according to at least one of the previous claims, characterized in that the profile of the frontal opening of said tub (2) and/or the profile of the frontal opening of said basket (3) and/or the profile of said seal (10) is shaped so as to favour a substantial passage of liquid from the inside of said basket (3) or tub (2) towards said seat (13).