Counterweight for a washing and/or drying machine and washing and/or drying machine comprising such counterweight

Abstract

 The invention relates to a counterweight (1) for a washing and/or drying machine, wherein the counterweight (1) is at least partly composed of a composite material (2) and wherein reinforcing elements (5) are embedded in the composite material (2). The invention relates further to a washing and/or drying machine which comprises such counterweight.
It is an object of the present invention to provide a counterweight with increased rigidity. A further object of the present invention is to provide a simple and reliable counterweight, which can be produced at reduced cost.
At least parts (20) of the reinforcing elements (5) comprise hooks (21).

Description

[0001] The invention is directed to washing and/or drying systems or machines for clothes in general and relates to a counterweight for a washing and/or drying machine, wherein the counterweight is at least partly composed of a composite material and wherein reinforcing elements are embedded in the composite material. The invention is further directed to a washing and/or drying machine which comprises such counterweight.

[0002] In the context of the present invention, the term washing and/or drying machine refers to a machine for washing and/or for drying of laundry in a household or for industrial purposes. The composite material is a material consisting of two or more constituent materials. One of the constituent materials can be a matrix material, i.e. the material into which the reinforcing elements are embedded. Such a matrix material can be concrete, e.g. comprising cement.

[0003] Washing and/or drying machines are generally known to be provided with counterweights serving as means for ballasting the machines in order to reduce dynamic stresses, e.g. vibrations that are imparted during the rotation of a drum containing clothes, especially, during the high-speed rotation phases of the clothes washing or drying process.

[0004] The reinforcing elements may be particles or objects embedded in the composite material to reinforce the material with respect to its rigidity and mechanical strength. The reinforcing elements can be randomly oriented, uniformly distributed and spread over the whole counterweight body or partly in a predetermined space of the counterweight body. Especially, if the counterweight comprises concrete as a matrix material, the character of the reinforced concrete changes with varying concretes and, additionally, depending on the material, geometry, distribution, orientation and density of the reinforcing elements.

[0005] The United States Patent Application Publication US 2007/0220928 A1 discloses a counterweight, connectable to a washing machine tub, comprising a hollow shell of U-shaped cross-section for containing a ballast mass made of concrete to be poured in the shell.

[0006] The United States Patent Application Publication US 2004/0094863 A1 discloses a composite material, a cured composite material and a shaped article made of composite material to be applied, i.a. on counterweights for rotating machine parts and washing machines. The composite material comprises fibers for reinforcement. The fibers are selected from the group consisting of metal fibers including steel fibers, mineral fibers, glass fibers, high temperature fibers, carbon fibers, and organic fibers including plastic fibers. The fibers are chopped fibers, continuous fibers, yarns or ropes, or rovings or staple fibers, or fiber nets or webs.

[0007] It is an object of the present invention to provide a counterweight with increased rigidity and mechanical strength. A further object of the present invention is to provide a simple and reliable counterweight, which can be produced at reduced cost. A further object of the present invention is to provide a washing and/or drying machine which comprises such counterweight.

[0008] These objects are achieved by a counterweight with the features of claim 1 and of claim 8 respectivly.

[0009] Accordingly, at least parts of the reinforcing elements comprise hooks.

[0010] A major advantage of the invention is that the anchoring of the reinforcing elements is greatly improved by their hooks thus leading to increased rigidity of the counterweight material, especially, an increased flexural rigidity. Still, the reinforcement is achieved by a relatively simple feature of the reinforcing elements, which can easily be realized in the manufacturing process of the reinforcing elements.

[0011] The hooks can be arranged with varying orientation, size and form. For example, the hook can abduct from the reinforcing element perpendicular to the elongation of the reinforcing element. Furthermore, the hook may be U-shaped, have circular shape and/or any polygon shape or form. Moreover, the location of the hooks on the reinforcing elements can vary. The hooks can either anchor in the matrix material of the composite material or get caught with each other.

[0012] In the manufacturing process, the hooks can either be added to the reinforcing elements or manufactured preferably as an integrated part of the reinforcing elements.

[0013] Further details, aspects and advantages of the invention are subject of the dependent claims, the drawings and their description.

[0014] In a preferred embodiment of the present invention hooks can be arranged on each of the respective reinforcing element. It is understood that different embodiments or shapes of reinforcing elements might be combined within one counterweight.

[0015] In another preferred embodiment of the present invention, the reinforcing elements comprise fibrous elements. Reinforcing elements with a fibrous geometry lead to a further enhanced strength and elasticity.

[0016] The fibrous elements can be synthetic fibers and natural fibers such as glass fibers, carbon fibers, cellulose fibers, mineral fibers, and mixtures thereof.

[0017] According to another preferred embodiment of the invention, the length of the reinforcing elements ranges between 15 mm and 60 mm. Reinforcing elements of the said dimensions - i.e. relatively small in comparison to the whole counterweight body - are advantageous, especially, for counterweights with complex shape. Using reinforcing elements with the aforementioned dimension, counterweights with comparatively small wall thickness can be realized. If the mentioned reinforcing elements are closely spaced and uniformly distributed, for example in a concrete counterweight, the static and dynamic properties with respect to rigidity are improved substantially.

[0018] According to another advantageous embodiment of the invention, the width of the reinforcing elements ranges between 0.5 mm and 4 mm. Such a width dimension, especially, in combination with the above mentioned length dimension leads to an advantageous geometry for reinforcing the counterweight material.

[0019] The width can correlate or be equal to the diameter of the reinforcing element, e.g. when the reinforcing element shows a cylindrical form in some sections along longitudinal extension of the reinforcing element.

[0020] In a further advantageous embodiment of the invention, the reinforcing elements are at least partly composed of metal. This increases the compression strength of the counterweight, e.g. if it is composed of concrete. In a practical realization of metal reinforcing elements, the metal can be some type of steel being composed of iron, e.g. comprising an alloying material such as carbon. In a possible design of a reinforcing element made of metal, the length of the reinforcing element ranges between 10 and 100, particular preferably between 20 and 60 mm, and the width ranges between 0.1 and 10 mm, preferably between 0.5 and 3 mm.

[0021] In an advantageous embodiment of the present invention, the reinforcing elements are at least partly composed of plastic material. By the use of plastic reinforcing elements, the compression strength, e.g. of a concrete counterweight, can be decreased. When using both metal and plastic reinforcing elements, the compressions strength can be regulated, for example by choosing an appropriate ratio of the amount of metal to the amount of plastic reinforcing elements. Additionally, the weight of the counterweight can be regulated by choosing the amount of plastic reinforcing elements.

[0022] In the context of the present invention, the term plastic refers to a polymeric material such as polypropylene. In a functional design of a reinforcing element made of plastic material, the length of the reinforcing element ranges between 15 and 60 mm and the width ranges between 1 and 4 mm.

[0023] A washing and/or drying machine advantageously comprises an oscillating assembly and the counterweight of the present invention whereby the counterweight is attached to the oscillating assembly.

[0024] The foregoing and further objects, features and advantages of the present invention will become apparent from the following description of embodiments by way of a non-limiting example with reference to the accompanying drawings, in which:

Figure 1

is a sectional view of an embodiment of the claimed counterweight,

Figure 2

is a possible arrangement of the counterweight on a washing and/or drying tub.

[0025] Figure 1 is a sectional view of a counterweight 1 composed of a composite material 2 comprising as a matrix material 3 concrete 4. Embedded in the composite material 2 are reinforcing elements 5 which are randomly orientated, uniformly distributed and spread over the entire body of the counterweight 1. The reinforcing elements 5 are fibrous elements 6 with a length 7 ranging between 15 and 60 mm and a width 8 ranging between 0.5 and 4 mm.

[0026] Parts 20 of the reinforcing elements 5 comprise hooks 21 arranged at the ends 22 of the reinforcing elements 5 and at portions 23 along the reinforcing elements 5. The hooks 21 anchor in the matrix material 3 and are in several areas 24 caught with each other. Furthermore, some of the hooks 21 abduct perpendicular from the reinforcing elements 5. Some of the hooks 21 show circular form 25 or U-form 26. The reinforcing elements 5 are composed of metal 27 and plastic material 28.

[0027] Figure 2 shows a possible arrangement of a counterweight 1 attached to a tub 30 of a washing machine. The tub 30 is part of an oscillating assembly of the washing machine. In the following description, elements identical or corresponding to the ones described above are indicated with the same numerals. The tub 30 is composed of a front portion 31 and a back portion 32. The front portion 31 is composed of a peripheral cylindrical band 33 joined with a front annular wall 34. The back portion 32 is made of a peripheral cylindrical band 35 joined with a circular bottom wall (not shown) at the end 36 of the tub 30. The front portion 31 is adapted to be joined with the back portion 32 by means of fixing. The tub 30 houses a drum 40 for laundry that is driven into rotation wherein the drum 40 rotates around the axis 41.

[0028] The counterweight 1 is fixed on the front portion 31 of the tub 30 at its lower part 42 adapting part-wise to the cylindrical band 33 and the annular wall 34. During the rotation of the drum 40 the counterweight 1 serves as a counterbalance 43 for centrifugal forces and to avoid undesired movements of the oscillating assembly in the washing machine.

REFERENCE LIST

[0029] 

1

counterweight

2

composite material

3

matrix material

4

concrete

5

reinforcing elements

6

fibrous elements

7

length

8

width

20

parts

21

hooks

22

ends

23

portions

24

areas

25

circular form

26

U-form

27

metal

28

plastic material

30

tub

31

front portion

32

back portion

33

cylindrical band

34

annular wall

35

cylindrical band

36

end

40

drum

41

axis

42

lower part

43

counterbalance

Claims

1. Counterweight (1) for a washing and/or drying machine,

- wherein the counterweight (1) is at least partly composed of a composite material (2) and

- wherein reinforcing elements (5) are embedded in the composite material (2),

characterized in that

- at least parts (20) of the reinforcing elements (5) comprise hooks (21).

2. Counterweight of claim 1,
characterized in that

- at least some reinforcing elements (5) comprised hooks (21) which are arranged at the ends of the reinforcing elements (5).

3. Counterweight of claim 1 or 2,
characterized in that

- the reinforcing elements (5) comprise fibrous elements (6).

4. Counterweight of claim 1, 2 or 3,
characterized in that

- the length (7) of the reinforcing elements (5) ranges between 15 mm and 60 mm.

5. Counterweight of at least one of the preceding claims,
characterized in that

- the width (8) of the reinforcing elements (5) ranges between 0.5 mm and 4 mm.

6. Counterweight of at least one of the preceding claims,
characterized in that

- the reinforcing elements (5) are at least partly composed of metal (27).

7. Counterweight of at least one of the preceding claims,
characterized in that

- the reinforcing elements (5) are at least partly composed of plastic material (28).

8. Washing and/or drying machine comprising an oscillating assembly and a counterweight (1) which is attached to the oscillating assembly,

- wherein the counterweight (1) is at least partly composed of a composite material (2) and

- wherein reinforcing elements (5) are embedded in the composite material (2),

characterized in that

- at least parts (20) of the reinforcing elements (5) comprise hooks (21).

Drawing