WO2015101890A1

WO2015101890A1 - Washing/drying machine with a system for preventing an air filter from getting clogged

Info

Publication number: WO2015101890A1
Application number: PCT/IB2014/067077
Authority: WO
Inventors: Giovanni Bombardieri; Gianluca Ferro; Lorenzo Verdini
Original assignee: Indesit Company S.P.A.
Priority date: 2013-12-31
Filing date: 2014-12-18
Publication date: 2015-07-09
Also published as: ITTO20131099A1; EP3090096B1; EP3090096A1

Abstract

The invention relates to a washing/drying machine equipped with a system for preventing a drying air filter from getting clogged by filaments released by the laundry during the washing/drying cycle. To this end, the tub of the washing/drying machine has a rough surface, so that it will hold a part of the filaments and reduce the quantity of those trapped in the filter, thereby preventing the latter from getting clogged.

Description

"WASHING/DRYING MACHINE WI TH SYSTEM FOR PREVENTING AN FILTER FROM GE TTING CLOGGED"

DESCRIPTION

The present invention relates to a washing/drying machine, i.e. machines for household, industrial or commercial use intended for washing and drying laundry in general.

These machines, therefore, have some elements in common with washing machines, e.g. the washing tub or chamber that houses a rotary basket or drum; the clothing or laundry to be treated is loaded into the basket through a door, which may be located at the front or at the top, depending on the machine type.

The rotation of the basket keeps the load moving during the washing and/or drying phases, when the tub is supplied with water and air, respectively.

In the course of the working cycle of the washing/drying machine, the load, consisting of clothing, laundry and the like, normally releases filaments that are evacuated through the drain.

This occurs in a simple and direct manner during the wash, in that water is supplied and drained several times for washing the laundry with detergents, rinsing it, etc., so that the filaments released by the fabrics are removed from the laundry and evacuated together with the water being drained .

When laundry is being dried, instead, the filamentous wads generated by the clothes rubbing against the inner wall of the basket (the quantity of which increases as humidity decreases) are dragged by the air flow that circulates in the machine and laps the laundry items contained in the basket in order to dry them, but cannot be evacuated in the same way because no water is supplied into the basket during the drying cycle. As can be easily understood, the drying air must be cyclically filtered to prevent the fan and the associated electric resistor from suffering damage.

To this end, it is known to take air from the washing/drying tub, filter it, reduce the humidity thereof, and introduce it again into the tub.

The air is filtered as it flows through a filter comprising a grid or net made of metal, plastic or the like, arranged on a wall of the washing/drying chamber (in particular, on the back wall, at the outlet section towards the drying circuit) , the mesh of which is sufficiently tight to trap the filaments released by the fabrics; it can be easily understood that the filamentous wads progressively depositing onto the filter will reduce the air passage section thereof and will cause load losses that will slow down the air flow, resulting in a general reduction of the efficiency of the laundry drying cycle.

The present invention aims at overcoming this problem that affects the state of the art.

Therefore, the technical problem at the basis of the invention is to provide a washing/drying machine having such structural and operating characteristics that keep regular and efficient air filtering conditions, so as to ensure the execution of a correct laundry drying cycle. The idea that solves this problem is to reduce or limit the quantity of filaments, released by the laundry being dried by the air circulating in the washing/drying machine, that will deposit onto the filter, thereby preventing excessive accumulation of filaments thereon: in this way, it is possible to prevent the filter from getting clogged quickly, thus keeping it efficient and reducing load losses for a longer time.

This effect is achieved, according to the teaching of the invention, by holding upstream of the filter the filaments circulating together with the drying air flow.

The features of the invention as a whole are specifically set out in the claims appended to this description.

Such features will become more apparent from the following description of a preferred but non-limiting example of embodiment thereof as shown in the annexed drawings, wherein :

- Fig. 1 is a perspective view of a washing/drying machine according to the invention;

- Fig. 2 is a perspective view of the washing/drying tub or chamber of the machine of Fig. 1, with the associated drying circuit;

- Fig. 3 is a perspective view of the washing/drying tub of the machine of Fig. 1 from a different angle than Fig. 2; - Fig. 4 shows the tub of Figures 2 and 3 with a part thereof removed to make the internal parts visible;

- Fig. 5 shows the tub of Figures 2 and 3 with a part thereof removed to make the inner wall visible;

- Fig. 6 shows some possible variants of the surface finish of the wall of the tub of Fig. 5.

With reference to the above-listed drawings, reference numeral 1 designates as a whole a washing/drying machine in accordance with the present invention, which comprises an external structure 2 substantially shaped like a parallelepiped cabinet, with a front panel 3 equipped with user controls (e.g. push-buttons, knobs, etc.) and various indicators, lamps, displays, or other means such as detergent drawers, useful for the control and operation of the machine 1.

It is worth pointing out that reference will be made in this description, for simplicity and clarity, only to those elements of the washing/drying machine 1 which are useful for understanding the invention; for more information, reference can be made to the prior art, e.g. washing/drying machines created by the present Applicant or described in patent applications filed by the latter on this matter, such as European patent applications EP 2116647, EP 2281081, EP1907616, EP 1775368, EP 1647621 and more, which are integrally recalled herein, and the contents of which should be considered as incorporated in the present description because applicable thereto.

At the front of the structure 2 there is the load opening 4 of the washing/drying machine, which is closed by a door 5. The structure 2 of the washing/drying machine internally houses a washing/drying chamber or tub 10, in which a basket 11 for loading laundry to be treated is supported in a per se known manner. The chamber or tub 10 is intended for washing/drying laundry, in that a machine like the one considered herein performs a dual function as a water tub during the washing cycle and as a drying chamber during the drying cycle.

The basket 11 has the typical drum-like configuration, with a perforated wall allowing water to flow through, as visible in Figures 1 and 4, and is equipped with inner paddles or lifters 12 for stirring the load while rotating when the machine 1 is in operation.

The chamber 10 comprises a substantially cylindrical skirt or side wall 15 (possibly slightly convex) closed at the rear by a back wall 16, while at the front it has a collar 17 on which a gasket 18 is applied, sealing the opening 4 of the cabinet 12 of the washing/drying machine 1.

Outside the washing/drying chamber 10 a drying air circuit 20 is arranged, which comprises an intake channel 21 (also acting as a condenser) and a delivery channel 22, between which a fan 23 is arranged for air circulation.

In particular, the delivery channel 22 extends from the collar 17 of the chamber 10 to the fan 23, whereas the intake channel 21 extends from the fan 23 to an intake port formed in the back wall 16 of the chamber 10, where a filter 26 is arranged.

The latter is slightly eccentric relative to the axis of rotation of the basket 11, where the support and/or rotation means of the basket 11, such as shaft, bearings, pulleys, etc. (not shown in the drawings because per se known) are applied to the back wall 16 of the chamber 10. The filter 26 may be designed in any suitable manner, e.g. with a metal or plastic grid or net having a mesh suitable for trapping the filaments released by the laundry being treated in the washing/drying machine 1; the mesh may have a polygonal (e.g. square, rectangular, hexagonal) or circular shape, etc., the mesh size being smaller than 1 mm².

In accordance with the invention, the inner walls of the washing/drying chamber 10 (in particular at least a portion of the side wall 15) have a rough, coarse or wrinkled surface finish.

Such a finish can be obtained through any suitable machining, whether mechanical or of a different nature (e.g. chemical, electric or electrochemical processes and the like) , with or without removal of material, whether carried out manually or by using suitable machine tools. Some examples of suitable machining processes are knurling (with or without chip removal), lapping, grinding, milling, pressing, abrasion, electroerosion, and the like; their use will depend on the material used for the side wall 15 of the tub 10, its thickness, the surface to be treated, and other factors related to industrial production (e.g. costs, times , etc . ) .

Advantageously, the surface finish is obtained together with the rest of the tub wall, being produced thereon during a single pressing operation.

Figure 6 shows some possible examples of surface finish of the wall 15, respectively obtained by pressing, knurling and grinding; also the asperities 40 have different profiles (corrugated, sawtooth, conical) .

It must be pointed out that this finish may reproduce a regular or irregular pattern.

The wall 15 of the tub 10 is usually made of plastic material or, alternatively, stainless steel, the thickness of which may vary from 1.8 to 2.5-3 mm; the surface roughness of the side wall 15 preferably has asperities 40 having a height of less than 50 %, preferably 10% to 40%, of the thickness of the wall 15 of the washing/drying tub 11.

With the thickness values specified above, therefore, there will be asperities shorter than 1 mm, preferably in the range of 0.2 to 0.8 mm; in this regard, it must be pointed out that also the back wall 16 (in particular the portion thereof around the filter 26) and/or the collar 17 of the washing/drying chamber 10 may have a rough surface finish, in accordance with the above explanation.

Though preferable, this is nevertheless not strictly necessary, and the surface finish of the back wall 16 and of the collar 17 may be different from that of the cylindrical side wall 15: this will depend on several factors, such as the shape and size of the washing/drying chamber 10, the configuration of the air circulation circuit (i.e. the intake 21 and delivery 22 channels, the fan 23, etc.), the characteristics of the filter 26, etc. Irrespective of this, the operation of the washing/drying machine 1 described so far is as follows.

In order to dry the laundry, the fan 23 is activated and produces an air flow that is taken from the chamber 10 through the channel 21 and is then reintroduced into the same chamber 10 by means of the delivery channel 22; along its path outside the chamber, the air is dehumidified in the condenser 21 and possibly heated by heating means (e.g. an electric resistor arranged in the delivery channel 22), which are not shown in the drawings because they are known in the art .

In the chamber 10, the air flow generated by the fan 23, in addition to removing humidity from the load of laundry and various clothing, also removes many fibers and filaments: however, unlike the prior art, these are held by the surface asperities 40 of the cylindrical side wall 15 of the chamber 10, and, if present, also by those of the back wall 16 and of the collar 17.

As a result, when the air flow directed towards the external circuit 20 reaches the filter 26, it will carry a reduced quantity of filaments, since they will have been held upstream by the walls of the washing/drying chamber 10.

Thus, the filter 26 will only have to perform a fine removal of any residual filaments in the air flow, so that there will be no risk of clogging due to bigger wads or downy formations, as it happens in known washing/drying machines .

Therefore, this reduces the load losses caused by the filter, promotes air circulation, and, consequently, increases the efficiency of the whole drying cycle.

The filaments held by the walls 15 (16 and 17) of the washing/drying chamber 10 are then easily removed by supplying water into the chamber itself: this can preferably be done at the beginning of a next washing cycle of the machine 1.

It can be easily understood from these explanations how this machine can solve the technical problem addressed by the invention.

In fact, the capability of holding filaments through means other than the usual filters arranged in the drying air circuit prevents, or anyway reduces, the risk of clogging normally incurred by filters.

This result is attained thanks to the roughness characteristics given to the washing/drying chamber 10, without needing any specific additional devices that would make the machine 1 more complex.

In addition to the embodiment taken into account herein, further variants of the invention are of course also possible .

It has already been mentioned that also the back wall 16 and/or the collar 17 of the chamber 10 may have a rough finish, in addition to the cylindrical side wall 15; it must however be remarked that the principle of holding the filaments by exploiting the surface finish of parts of the washing/drying machine can be extended to other parts thereof .

For example, said principle may be applied to the outer wall of the basket 11, in which case the outside of the basket will be given a rough finish as previously explained: in this manner, the filaments will also be held by the basket, not just by the washing chamber, leading to even better results.

Other variants can then be obtained by using air circuits 20 which are more complex than the one of the case shown in the drawings .

All of these variants will still fall within the scope of the following claims.

Claims

1. Washing/drying machine comprising a washing/drying chamber (10), a basket (11), housed in said chamber (10), for loading laundry to be treated, a circuit (20, 21, 22, 23) for circulating air taken from the chamber (10) and reintroduced therein, means (26) for filtering the air along the circuit (20-23), characterized in that it comprises surface means (11, 15, 16, 17, 30) for holding the filaments removed from the laundry and borne by the air, arranged along the air path comprising the chamber (10) and the circuit (20-23) .

2. Machine according to claim 1, wherein the means for holding the filaments comprise at least one rough surface portion (15, 16, 17, 30) .

3. Machine according to claim 2, wherein the rough surface portion is obtained on at least one wall (15, 16, 17) of the washing/drying chamber (10) .

4. Machine according to claim 3, wherein the side wall (15) of the chamber has a roughness with asperities (30) smaller than 50%, preferably between 10% and 40%, of the thickness of the side wall.

5. Machine according to any one of claims 1, 2, 3 and 4, wherein the outer wall of the basket (11) for loading laundry comprises a rough surface portion.

6. Machine according to any one of the preceding claims, wherein the means for holding the filaments comprise a rough surface portion (11, 15, 16, 17) with asperities smaller than 1 mm.

7. Machine according to any one of the preceding claims, comprising an operating step wherein the filaments held by said surface means (11, 15, 16, 17, 30) are removed with water and drained.