EP3502343B1 - Drum for a washing machine, washing machine and method for producing the drum - Google Patents

Description

The invention relates to a drum for a laundry treatment device, a laundry treatment device and a method for producing the drum. The invention relates in particular to a drum for a laundry treatment device, comprising a cylinder jacket which has a seam in the direction of the width of the cylinder jacket, and at least one side wall, the cylinder jacket at least at one of its ends by means of a fold, which can also be referred to as a flanging, is connected to a side wall, a method for producing this drum and a laundry treatment device which contains this drum.

Laundry treatment devices generally have an aforementioned drum with a flange. This also applies in particular to laundry dryers, referred to herein as dryers, which are mentioned here by way of example. Dryers have a drum for receiving items of laundry. This drum moves while a laundry treatment program is being carried out. In general, the drum runs on wheels or rollers (referred to herein as "rollers"), on which it is rotatably mounted about a substantially horizontally mounted axis. The drum is usually driven by a belt drive. The drum can have an integrated back wall, which thus rotates with the rotation of the drum, or a standing back wall. A drum axis of rotation can be mounted in an integrated rear wall, so that in the case of the integrated rear wall, two rollers that are in contact with the front end of the drum are often sufficient. However, four roles are sometimes used. In the case of a standing rear wall, four rollers are generally used.

The role of the rollers, especially in dryers, is to support the drum. So far, the rollers have been attached below the front base located at the front end of the drum. However, there is a tendency for the drum to be heavily loaded with items of laundry. If the drum loaded with laundry items has a greater weight, it would make sense to mount the drum differently. An advantageous storage would take place via the flange of the drum, the flange being the area at which the drum shell is connected to a side wall. Ever depending on whether the drum has an integrated or standing back wall, there are either one or two flanges. With this solution, the rollers would run on the flange and no longer on the front base. In the case of flanging, however, there is the special feature that the surface of the flanging, referred to herein in particular as a fold, is no longer smooth after the flanging. However, in addition to the roundness of the drum, the roundness and smooth nature of the flange are important for low rolling noise when the drum rotates on the rollers. The drums should run smoothly with regard to low noise development and problem-free running as long as possible.

The publication DE 11 2009 001 081 B4 describes a clothes dryer having a drum rotatably built into the housing and a roller disposed below the drum and configured to support the drum, the roller being attached to a roller axle by a ball bearing. The roller has, inter alia, a special roller frame with several concavo-convex sections and a specially designed outer wheel section. This should be able to support a drum of the clothes dryer particularly well, the role being configured to withstand even a large load. The life of the roller is said to be extended by preventing stress concentration by increasing a contact area between the roller and the drum.

The publication WO 2004/005603 A1 describes a washing machine drum which comprises a cylindrical wall which is provided with a plurality of flood holes and which is connected at its ends by means of a fold to a rear side wall and a front side wall, an embossing being applied along the fold, which extends into all sheet metal layers that form the fold.

The publication WO 2015/058962 A1 describes a method for attaching an unbalance compensation device to a laundry drum, an arrangement for a household appliance and a household appliance. The unbalance compensation device is inserted into a circumferentially formed receptacle of the laundry drum, an extension formed on a housing of the unbalance compensation device being heated and plastically deformed so that the extension engages behind a wall of the laundry drum that delimits the receptacle. The deformation includes that the extension around an axial Front edge of the axially arranged wall is bent. In one embodiment of the method, when the extension is deformed, a projection formed on a side of the wall facing away from the receptacle and pointing away from the receptacle, in particular outward in a radial direction, is engaged behind by the extension. As a projection, in particular a fold of the wall is gripped from behind by the extension.

The publication US 9,758,919 B2 describes an apparatus for treating laundry, comprising a drum for receiving laundry, the drum having an open front axial end and an opened rear axial end, and the drum having a cross-section having at least a first part with a uniform curvature and at least a second part with a non-uniform curvature; a panel provided at a front or a rear end of the drum to seal the front axial end or the rear axial end of the drum; a circular guide coupled between the panel and the corresponding axial end of the drum to support the drum; and a panel seal provided between the drum and the panel, wherein the circular guide has a ring shape and is rotatably provided on the panel, a part of an outer surface of the circular guide being an inner surface of a front side or a rear side of the at least one first Contacted part of the drum, wherein an inner surface of a front or a rear side of the at least a second part of the drum does not contact the circular guide of the drum, wherein the panel seal is placed closer to an axial center of the drum than the circular guide is placed, and wherein an outer edge of the panel seal contacts the inner surface of the front or rear of both the first and second parts of the drum. The drum has a seam in the direction of the width of the cylinder jacket, which is protected from damage by a reinforcement member (R). The reinforcing member R can improve the strength of the seam W and prevent cracks generated in the seam W from growing. The reinforcement member R can be formed on the edge of the drum, for example on the leading edge or trailing edge, and made of a plastic material.

Against this background, the object of the present invention was to provide a drum with at least one fold and a laundry treatment device, in particular a dryer, in which the drum has a better surface quality along its fold or folds. Preferably, when used in a dryer, the drum should also run smoothly when it is unrolled on rollers which are arranged along a fold.

This object is achieved according to this invention by a drum and a laundry treatment device as well as a method for producing the drum with the features of the respective independent claims. Preferred embodiments of the drum according to the invention are listed in the dependent claims, preferred embodiments of the drum according to the invention corresponding to preferred embodiments of the laundry treatment device according to the invention and the method for their production and vice versa, even if this is not expressly stated herein.

The invention thus relates to a drum for a laundry treatment device, comprising a cylinder jacket which has a seam in the direction of the width of the cylinder jacket, and at least one side wall, the cylinder jacket being connected to a side wall at at least one of its ends by means of a fold, and where a plastic part covering the fold at least on a fold top is applied along the fold, the plastic part covering the fold on the fold top and a fold bottom.

In a preferred embodiment, the plastic part is a film made of a thermoplastic or comprises this. The film here preferably has a thickness in the range from 0.3 to 1 mm.

In a further preferred embodiment, the plastic part comprises a plastic molded body. In this case it is again preferred that the plastic molded body has a profile at least on an underside facing the fold. Such a profile serves in particular to ensure that the plastic molded body not only completely covers the fold, but also extends evenly beyond the fold and thus can enlarge a running surface for rollers.

The plastic molding can be in one piece or consist of at least two, preferably three parts. If the plastic molded body has at least two parts, a more complex plastic molded body can more easily be attached along the fold.

In the drum according to the invention, the plastic part preferably contains polyethylene or consists of polyethylene.

In the present invention, the plastic part covers the fold on the fold top and the fold bottom. It is preferred here that the plastic part engages around the fold from the fold top to the fold bottom.

In view of the use of the plastic part as a running surface for rollers, it is preferred in the drum according to the invention that the plastic part is in the part of its upper side that covers the fold, i.e. its surface facing away from the fold is flat.

In addition, it is preferred according to the invention that a width b _K of the plastic part covering the fold is at least 1.5 times the width b _{F of} the fold, particularly preferably at least 2 times the width b _{F of} the fold.

For the purposes of the invention, a fold generally has a width b _F in the range from 4 to 8 mm, in particular in the range from 5 to 7 mm. The plastic part covering the fold can then advantageously have a width b _K in the range from 15 to 25 mm, in particular in the range from 18 to 22 mm.

1. (a) Bereitstellen der Trommel mit einem unbedeckten Falz; und
2. (b) Aufbringen des Kunststoffteils auf zumindest der Falzoberseite durch Verkleben des Kunststoffteils mit der Falz oder durch Aufschrumpfen des Kunststoffteils auf die Falz.

The invention also relates to a method for producing a drum for a laundry treatment device, comprising a cylinder jacket which has a seam in the direction of the width of the cylinder jacket, and at least one side wall, the cylinder jacket being connected to a side wall at at least one of its ends by means of a fold and along the fold a plastic part covering the fold at least on a fold upper side is applied, wherein the plastic part covers the fold on the fold upper side and a fold lower side, comprising the steps

1. (a) providing the drum with an uncovered fold; and
2. (b) Applying the plastic part to at least the top of the fold by gluing the plastic part to the fold or by shrinking the plastic part onto the fold.

The term “shrinking on” is to be understood broadly. Essentially, this means a process step in which a plastic part, usually containing a thermoplastic, is sufficiently heated and thus softened to be attached to the fold. After the thermoplastic has cooled and thus contracted, there is a firm connection between the plastic part and the fold.

The plastic part can be heated in various ways, for example also by ultrasound.

In a preferred embodiment of this method, the plastic part is a film made of a thermoplastic material and is applied to the fold by shrinking. Shrinking on foils is particularly easy.

In a further preferred embodiment of this method, the plastic part is a molded plastic body which has a profile at least on an underside facing the fold and is applied to the fold by gluing or shrinking the plastic part.

If the plastic part is a plastic molded body, it is usually not possible to soften it by heating to the same extent as with a film. For complex plastic moldings, it may therefore be appropriate to produce them in advance in several parts, usually by injection pressure, and then to assemble them at the fold.

Finally, the subject matter of the invention is also a laundry treatment device, comprising a drum for receiving items of laundry to be treated, the drum having a cylinder jacket which has a seam in the direction of the width of the cylinder jacket and at least one side wall, the cylinder jacket at at least one of its ends is connected to a side wall by means of a fold, and a plastic part covering the fold at least on a fold top side is applied along the fold, the plastic part covering the fold on the fold top side and a fold bottom side.

The laundry treating appliance is not limited according to the invention as long as it can have a drum according to the invention. However, since the drum according to the invention also has improved running properties on rollers, the laundry treatment device is preferably a dryer. Such a dryer comprises a housing and a drum according to the invention, rotatably mounted about an axis within the housing, for receiving items of laundry, the drum being in contact with at least two roller devices, in particular rollers, during operation of the dryer.

The invention has several advantages. In general, the beading in a drum is protected by the plastic part, and in particular any existing openings can also be covered. In addition, the invention has the advantage that the fold has better stability even when the drum is subjected to high loads and is less prone to possible bending and opening over time.

In addition, such a drum can be used particularly advantageously in a dryer as an embodiment for a laundry treatment appliance according to the invention. A drum according to the invention enables a lower rolling noise in such a dryer, that is to say a lower noise development. In addition, leakage losses are lower because openings that often occur in the edge area during the manufacture of a drum shell can also be covered. In addition, the wear of the rollers used in the dryer can be less if the running surface, i.e. the top of the plastic part is flat.

• Fig. 1 zeigt ein Foto eines Ausschnitts aus einer herkömmlichen Trommel, bei welcher kein Kunststoffteil auf dem Falz angeordnet ist.
• Fig. 2 zeigt schematisch eine Zeichnung der perspektivischen Ansicht der herkömmlichen Trommel von Fig. 1.
• Fig. 3 zeigt schematisch eine Zeichnung der perspektivischen Ansicht einer erfindungsgemäßen Trommel, bei welcher ein Kunststoffteil, hier eine Folie, auf dem Falz angeordnet ist.
• Fig. 4 zeigt eine perspektivische Schnittansicht durch einen mit einer Folie bedeckten Falz.
• Fig. 5 zeigt eine Draufsicht auf einen Schnitt durch einen mit einer Folie bedeckten Falz.
• Fig. 6 zeigt einen Ausschnitt aus einer erfindungsgemäßen Trommel mit einer Folie auf dem Falz.
• Fig. 7 zeigt eine perspektivische Schnittansicht durch einen mit einem Kunststoffformkörper bedeckten Falz.

Further details of the invention emerge from the following description of exemplary embodiments for a drum according to the invention which can be used in a laundry treatment device according to the invention, in particular a dryer. Reference is made to the Figures 1 to 7 .

• Fig. 1 shows a photo of a detail from a conventional drum in which no plastic part is arranged on the fold.
• Fig. 2 FIG. 13 schematically shows a drawing of the perspective view of the conventional drum of FIG Fig. 1 .
• Fig. 3 shows schematically a drawing of the perspective view of a drum according to the invention, in which a plastic part, here a film, is arranged on the fold.
• Fig. 4 shows a perspective sectional view through a fold covered with a film.
• Fig. 5 shows a plan view of a section through a fold covered with a film.
• Fig. 6 shows a section of a drum according to the invention with a film on the fold.
• Fig. 7 shows a perspective sectional view through a fold covered with a plastic molding.

Fig. 1 shows a photo of a detail from a conventional drum 1 in which no plastic part is arranged on the fold 5. The rough structure of the folded surface 6 can be clearly seen. If this folded surface were used as a running surface for rollers, for example in a dryer, it would run unevenly, which would lead to noise and increased wear. 12 here means an opening in the cylinder jacket 2 of the drum 1. A region is shown here over which a film with a width b _K would extend over the fold 5. The opening 12 would be covered by the film.

Fig. 2 FIG. 13 schematically shows a drawing of the perspective view of the conventional drum 1 of FIG Fig. 1 with a side wall 4 and a cylinder jacket 2, which are connected to one another via a fold 5. 12 here means an opening in the cylinder jacket 2 of the drum 1. 11 is the end wall which, as a rule, in dryers with conventional drums, is the running surface used to support the drum during rotation Rolling is.

Fig. 3 shows schematically a drawing of the perspective view of a drum 1 according to the invention with a side wall 4 and a cylinder jacket 2, which are connected to one another via a fold which is not further recognizable here. Here a film 8 is arranged on the fold as a plastic part. In the Fig. 2 The opening shown in the cylinder jacket 2 is covered here by the film 8.

Fig. 4 shows a perspective sectional view through a fold 5 covered with a film 8. The arrangement of the side wall 4 and cylinder jacket 2 in the fold can be clearly seen here. The film 8 here covers the fold 5 on the fold top 6 and the fold bottom 7. In addition, the film 8 encompasses the fold 5 from the fold top 6 to the fold bottom 7.

Fig. 5 shows a plan view of a section through a fold 5 covered with a film 8. The arrangement of the side wall 4 and cylinder jacket 2 in the fold is clearly visible here. The film 8 here covers the fold 5 on the fold top 6 and the fold bottom 7. In addition, the film 8 encompasses the fold 5 from the fold top 6 to the fold bottom 7.

Fig. 6 shows a section from a drum according to the invention with a film 8 on the fold. The film 8 here covers an opening in the seam 3. 11 means the front base of the drum.

Fig. 7 shows a perspective sectional view through a fold 5 covered with a plastic molded body 9. The plastic molded body 9 is flat in the part of its upper side that covers the fold 5, encompasses the fold 5 from the fold top 6 to the fold bottom 7 and covers the fold 5 on the fold top 6 The arrangement of the side wall 4 and cylinder jacket 2 in the fold 5 is clearly visible here. It can also be seen that a width b _K of the plastic molded body 9 covering the fold 5 is at least 1.5 times the width b _{F of} the fold 5 is. The plastic molded body 9 thus offers a wider running surface for rollers for use in a dryer. For this purpose, the plastic molded body 9 has a profile on an underside 10 facing the fold 5.

Reference number

1

drum

2

Cylinder jacket

3

Seam (in cylinder jacket)

4th

Side wall

5

Fold; Flanging

6th

Fold top

7th

Rebate underside

8th

foil

9

Plastic moldings

10

Underside (of the plastic molding)

11

Forehead floor

12

Opening in the seam in the cylinder jacket

Claims (14)

1. Drum (1) for a laundry treatment appliance, comprising a cylindrical jacket (2), which has a seam (3) in the direction of the width of the cylindrical jacket (2), and at least one side wall (4), wherein the cylindrical jacket (2) is connected to a side wall (4) at at least one of its ends by means of a fold (5), characterised in that a plastic part (8,9), which covers the fold (5) at least on a fold upper side (6), is attached along the fold (5), wherein the plastic part (8,9) covers the fold (5) on the fold upper side (6) and a fold lower side (7).
2. Drum (1) according to claim 1, characterised in that the plastic part (8,9) is a film (8) made of a thermoplastic, or comprises such a film.
3. Drum (1) according to claim 1 or 2, characterised in that the film (8) has a thickness in the range of 0.3 to 1 mm.
4. Drum (1) according to one of claims 1 to 3, characterised in that the plastic part (8,9) comprises a plastic shaped body (9).
5. Drum (1) according to claim 4, characterised in that the plastic shaped body (9) has a profile, at least on a lower side (10) facing the fold (5).
6. Drum (1) according to claim 4 or 5, characterised in that the plastic shaped body (9) consists of at least two, preferably three parts.
7. Drum (1) according to one of claims 1 to 6, characterised in that the plastic part (8,9) contains polyethylene or consists of polyethylene.
8. Drum (1) according to one of claims 1 to 7, characterised in that the plastic part (7) grasps around the fold (5) from the fold upper side (6) to the fold lower side (7).
9. Drum (1) according to one of claims 1 to 8, characterised in that the plastic part (8,9) is embodied in a flat manner in the part of its upper side covering the fold (5).
10. Drum (1) according to one of claims 1 to 9, characterised in that a width b_K of the plastic part (8,9) covering the fold (5) is at least 1.5 times the width b_F of the fold (5).
11. Method for producing a drum (1) for a laundry treatment appliance, comprising a cylindrical jacket (2), which has a seam (3) in the direction of the width of the cylindrical jacket (2), and at least one side wall (4), wherein the cylindrical jacket (2) is connected to a side wall (4) at at least one of its ends by means of a fold (5), and a plastic part (8,9), which covers the fold (5) at least on a fold upper side (6), is attached along the fold (5), wherein the plastic part (8,9) covers the fold (5) on the fold upper side (6) and a fold lower side (7), comprising the steps

    (a) providing the drum (1) with an uncovered fold; and

    (b) attaching the plastic part (8,9) to at least the fold upper side (6) by adhesively bonding the plastic part (8,9) to the fold (5) or by shrinking the plastic part (8,9) onto the fold (5).
12. Method according to claim 11, characterised in that the plastic part (8,9) is a film (8) made of a thermoplastic and is attached to the fold (5) by shrinking.
13. Method according to claim 11, characterised in that the plastic part (8,9) is a plastic shaped body (9), which has a profile, at least on a lower side (10) facing the fold (5), and is attached to the fold (5) by adhesively bonding or shrinking the plastic part (8,9).
14. Laundry treatment appliance, comprising a drum (1) for receiving laundry items to be treated, wherein the drum (1) comprises a cylindrical jacket (2), which has a seam (3) in the direction of the width of the cylindrical jacket (2), and at least one side wall (4), wherein the cylindrical jacket (3) is connected to a side wall (4) at at least one of its ends by means of a fold (5), characterised in that a plastic part (8,9), which covers the fold (5) at least on a fold upper side (6), is attached along the fold (5), wherein the plastic part (8,9) covers the fold (5) on the fold upper side (6) and a fold lower side (7).

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