EP1321558A1

EP1321558A1 - Bellow for front-loading washing machine

Info

Publication number: EP1321558A1
Application number: EP01830785A
Authority: EP
Inventors: Silvano Fumagalli
Original assignee: Candy SpA
Current assignee: Candy SpA
Priority date: 2001-12-20
Filing date: 2001-12-20
Publication date: 2003-06-25
Also published as: ES2317986T3; DE60230108D1

Abstract

Front-loading clothes washing machine comprising a container having a front wall with a loading aperture (111), a removable door (121) able to close the loading aperture, a washing tub (112) mounted inside the container and having an aperture (117) facing towards the front wall of the container, a loading drum (15) for the clothes to be washed, the drum being mounted in the washing tub (112) in such a way that it can rotate about a horizontal axis and having an aperture (16) aligned with the aperture of the tub (117) and with the loading aperture (111), a connecting duct (120) between the aperture (117) of the washing tub and the loading aperture (111) comprising a bellows-like elastic joint (120a). The machine can take a larger load because of the fact that the space comprised within the connecting duct (120) can be used as an extension of the loading space because it includes at least one basically rigid annular band (120b) that at least partly covers the elastic joint (120a).

Description

The present invention relates to a front-loading clothes washing machine as defined in the preamble of Claim 1.
As is known, a front-loading clothes washing machine, shown schematically in Figure 1, has a supporting and containing structure 10 with a front wall in which an aperture 11 allows the clothes to be loaded and unloaded. A tub 12 is mounted inside the structure on suitable supporting and suspension means 13 and can contain a washing solution 14. A perforated drum 15 rotates inside the tub. The drum and the tub have respective apertures 16, 17 substantially aligned with the aperture 11 of the front wall so that the washing can be inserted into the loading space within the drum 15. An electric motor 18 drives suitable mechanisms 19 which turn the drum with the washing in the washing solution in accordance with preset speeds, times and directions of rotation. A connecting duct 20, typically a bellows-like annular elastic joint, is mounted between the aperture 17 of the tub 12 and the loading aperture 11. The loading aperture is sealed shut by a door 21 hinged to the front wall. The door 21 is shaped in such a way that its inside surface delimits the loading space inside the drum 15. More precisely, it forms a reentrance which, when the door is shut, closes practically the entire aperture of the tub, preventing the clothes from coming out of the loading space during washing and coming into contact with the joint. If this were not the case, friction between the moving clothes and the joint would cause rapid wear of the joint, which is usually made of rubber or other elastomeric material having very good elasticity but poor abrasion resistance.
The chief object of the present invention is to provide a clothes washing machine with a larger loading space.
This object is achieved by making the clothes washing machine defined and characterized in general in Claim 1.
A clearer understanding of the invention will be gained from the following detailed desciption of certain embodiments thereof given by way of example, no limitation being intended, with reference to the attached drawings, in which:
Figure 1 shows diagrammatically in cross section a known type of clothes washing machine,
Figure 2 shows in cross section a detail of a clothes washing machine in a first embodiment of the invention, Figure 2a shows an enlarged detail of Figure 2,
Figures 3a and 3b, Figures 4a and 4b and Figures 5a and 5b show, in plan and in cross section respectively, a projection formed on a band designed to protect the elastic joint, in three embodiments of the invention, and
Figures 6, 6a and 7 show in cross section a detail of a clothes washing machine in further embodiments of the invention.
Figure 2 shows only certain parts of a clothes washing machine according to the invention. Parts not illustrated are of known type, for instance exactly like the corresponding parts of the known machine shown in Figure 1. As the drawing shows, the connecting duct 120 between the aperture 117 of the washing tub 112 and the aperture 111 of the front wall of the container consists not just of a bellows-like elastic joint 120a as in the known machine, but also of an annular band 120b of a basically stiff material that is resistant to abrasion and to the action of water and detergents, e.g. polycarbonate or polypropylene, with surfaces of appropriate roughness, i.e. smooth, which covers the elastic joint 120a, protecting it from the inside of the duct. In this example the band 120b is fixed to a limb 120c of the elastic joint located near the rim 16 of the drum 15 and near the rim of the aperture 117 of the tub 112.
The aperture in the front wall of the container is closed by a door 121 made of for example moulded glass with a steel frame. In this embodiment the door 121 has an inside surface presenting a central concave part 121a that joins a peripheral convex part 121b. The annular band 120b in this example has a width, that is a dimension in the direction of the horizontal axis of the tub, which is constant; however, its width could be greater at the bottom, where contact with clothes during washing is continuous, and less at the top, where there is no or very sporadic contact with the clothes.
In accordance with one embodiment of the invention, the band 120b has an interruption at the top where the clothes do not touch the elastic joint.
In the embodiment shown in Figure 2a, the band 120 curves away at the bottom to form a part 120e sloping towards the aperture of the washing tub 112 in order to encourage the clothes to slide down towards the loading drum 15.
This slope may vary circumferentially, e.g. reducing to zero, i.e. constant diameter at the top.
As can be seen, the annular band 120b and the inside surface of the door 121 delimit, when the door is shut, a space that represents an extension of the loading space formed by the drum 15. With a rotating drum of given volume, therefore, the load of clothing to be washed can be greater than with a machine of known type. During washing, the band 120b efficiently protects the elastic joint 120a, preventing the clothes from contacting the joint itself and, owing to its smooth and resistant surface, gives the clothes a low-friction bearing surface during washing.
The protection of the elastic joint 120a is supplemented, in the embodiment of the invention shown in Figure 2, by the convexity of the peripheral part 121b of the inside surface of the door 121. This convexity also contributes to hermetic sealing of the door, which can be easily ensured by giving the elastic joint an annular lip 120d which is in firm contact with the door when the door is closed.
The annular band 120b has an essentially cylindrical uniform inside surface. However, in other embodiments of the invention it may have at least one radial projection at the bottom. For instance, good results have been obtained with two projections separated by 40-60° from each other symmetrically on either side of the vertical plane passing through the axis. There are two reasons for the projection or projections 340, firstly to encourage the clothes to move back into the drum and secondly to induce a secondary local rotation of the clothes about an axis along the direction of the projection. To fulfil these purposes as well as possible, the projections may be shaped and positioned in a variety of different ways. For example, they may basically be in the shape of a suitably attached isosceles triangle whose height and base decrease towards the interior, that is towards the aperture of the tub, and may extend in the axial direction, as shown in cross section and in plan in Figures 3a and 3b, respectively, or may extend at a sloping angle relative to the axial direction, as shown in Figures 4a and 4b, or may be shaped like straight or curved fins with asymmetrical leading and trailing edges. One embodiment with curved fins that are asymmetrical with reference both to the radial direction and to the axial direction is shown in cross section and in plan in Figures 5a and 5b, respectively. Naturally, any combination of projections with different profiles is possible. If using asymmetrical and/or curved fin-type projections, these are arranged on the band in such a way that their interference with the clothes during rotation of the loading drum is such as to encourage them to slide inwards into the drum and give them a local secondary rotation.
In accordance with one embodiment of the invention, a central projection is arranged centrally in the lower portion of the annular band and two lateral projections, smaller than the central projection, are arranged on each side of the central projection at an angle of about 60°.
In the embodiment shown in Figure 6 there are two annular bands, one marked 320b, similar to the band 120b of Figure 2 and fixed in the same way, but narrower than the latter, and another, marked 320e, fixed to the front wall of the container 10, specifically to the rim of the loading aperture. This latter annular band may be made of the same smooth, anti-wear material as the band 320b and may be fixed by a restrained joint, as shown in the drawing, but may also be made of stainless steel and fixed to the wall by welding or other means of fixing.
In this embodiment the elastic joint, here marked 320a, is fixed on the one hand to the rim of the aperture of the washing tub, as in the example of Figure 2, and on the other to the free edge of the band 320e.
Both bands may have continuous cylindrical surfaces or may have projections similar to those described above in relation to Figures 3a, 3b, 4a, 4b, 5a and 5b. In the example shown in Figure 6, each of the two bands includes at least one projection, lower on band 320b, marked 320f, and higher on band 320e, marked 320g, the profiles of which connect up with each other and with the profile of the concave part 321a of the inside surface of the door 321.
An elastomeric annular insert 330 is applied to the band 320e to ensure sealed closure of the door.
The embodiment indicated in Figure 6a is particularly advantageous because it provides a continuous elastic seal between the inside surface of the door 321 and the tub 112, the seal extending without interruption underneath the band 320e.
In this context it is also possible to make the annular band in the form of a low-friction coating applied directly to the seal. Naturally, in this case the seal would have to be stiff enough to resist the mechanical stresses to which it would be subject.
The advantages of the invention compared with the prior art are numerous and substantial. In particular:

the load volume, for equal volume of the loading drum, is greater because the space delimited by the connecting duct can be used, together with the drum, to contain the load,
loading ergonomics are noticeably better because the door, which is usually hinged to the front wall, does not when open have projecting parts to get in the way of inserting or removing the clothes,
the forces exerted by the clothes on the door during washing are reduced, and therefore the size and weight of the door can also be reduced,
washing efficiency is better, owing to the additional mechanical action of the clothes being drawn over the annular band.

Furthermore, the features of the invention are easily applicable to many clothes washing machines of known type with few and simple modifications. The invention can therefore be carried out without requiring expensive modification to the production lines.
Although only a few embodiments of the invention have been illustrated and described, it is clear that numerous variants and modifications are possible within the scope of the same inventive concept.

Claims

Front-loading clothes washing machine comprising:

a container having a front wall with a loading aperture (111),

a removable door (121) able to close the loading aperture,

a washing tub (112) mounted inside the container and having an aperture (117) facing towards the front wall of the container,

a loading drum (15) for the clothes to be washed, the drum being mounted in the washing tub (112) in such a way that it can rotate about an essentially horizontal axis and having an aperture (16) more or less aligned with the aperture of the tub (117) and with the loading aperture (111),

a connecting duct (120) between the aperture (117) of the washing tub and the loading aperture (111) comprising a bellows-like elastic joint (120a),

characterized in that the connecting duct (120) includes at least one basically rigid annular band (120b) that at least partly covers the elastic joint (120a) and delimits, with the inside surface of the door (121) when the latter is closed, a space that forms an extension of the loading space of the drum (15).
Clothes washing machine according to Claim 1, in which the inside surface of the door (121) is essentially flat.
Clothes washing machine according to Claim 1, in which the inside surface of the door (121) includes at least one concave part (121a).
Clothes washing machine according to any one of Claims 1 to 3, in which the connecting duct (120) includes a single basically rigid annular band (120b) fixed to the rim of the aperture (117) of the washing tub (112).
Clothes washing machine according to any one of Claims 1 to 3, in which the connecting duct (120) includes two basically rigid annular bands (320b, 320e), one fixed to the rim of the aperture of the washing tub and the other to the rim of the loading aperture.
Clothes washing machine according to Claim 5, in which the elastic joint (320a) is fixed on the one hand to the rim of the aperture of the washing tub and on the other to the free edge of the annular band (320e) fixed to the rim of the loading aperture.
Clothes washing maching according to any one of the preceding claims, in which one or more annular bands (120b, 320b, 320e) are fixed to the said elastic joint (120a, 320a).
Clothes washing machine according to any one of the preceding claims, in which at least one annular band is shaped in such a way as to include, at least at the bottom, a part (120e) that slopes towards the aperture of the washing tub.
Clothes washing machine according to any one of the preceding claims, in which at least one annular band includes at least one projection.
Clothes washing machine according to Claim 9, in which the projection extends basically in the direction of the axis of rotation of the loading drum with a height profile that decreases towards the tub aperture.
Clothes washing machine according to Claim 10, as dependent on Claim 3, in which the profile of the projection connects up with the concave part of the inside surface of the door.
Clothes washing machine according to Claim 11, as dependent on Claim 5, in which the two annular bands include respective projections (320f, 320g) whose axial profiles connect up with each other.
Clothes washing machine according to any one of Claims 9 to 12, in which two or more projections are formed at a distance from each other on the annular band or bands at the bottom of the connecting duct.
Clothes washing machine according to Claim 13, in which two projections are formed at a distance from each other on the annular band or bands at the bottom of the connecting duct.
Clothes washing machine according to Claim 9, in which the projection extends in a direction that slopes relative to the direction of the axis of rotation of the loading drum with a height profile that decreases towards the tub aperture.
Clothes washing machine according to any one of Claims 10 to 15, in which at least one projection is shaped as a fin with asymmetrical leading and trailing edges.
Clothes washing machine according to any one of the preceding claims, in which the said annular band is made from a low-friction coating applied directly to the seal.