GB2121833A

GB2121833A - Mounting of an oscillation adjusting mass in a washing machine

Info

Publication number: GB2121833A
Application number: GB08312403A
Authority: GB
Inventors: Wilfried Wildung
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-06-15
Filing date: 1983-05-06
Publication date: 1984-01-04
Also published as: IT1163497B; SE8303361L; ES281217U; DE3222479A1; GB2121833B; IT8321561A0; ES281217Y; GB8312403D0; DE3222479C2; SE8303361D0

Abstract

A drum washing machine comprises an oscillatorily mounted washing solution container (2) with an adjusting mass (8) for adjusting of the total mass of the oscillatory unit to a certain resonant rotational speed, the adjusting mass (8) being spatially associated with a carrier plate (9) at the container (2). Since adjusting masses of that kind frequently consist of brittle cast materials, only small free bending lengths should be present in their bodies and the mode of mounting the mass should be as simple and as versatile as possible. For this purpose, the carrier plate (9) has at least one rib (15) which is proud of the outside shell surface of the container (2), is shape-lockingly covered by the adjusting mass (8) and includes fastening holes (18) for fastening devices fastening the mass. <IMAGE>

Description

SPECIFICATION Mounting of an oscillation adjustment mass in a washing machine The present invention relates to a washing machine and has particular reference to the mounting of an oscillation adjustment mass in a drum washing machine.

In a drum washing machine disclosed in DE Utility Model 18 78 414, a washing solution or liquor container is mounted in a carrier plate which is largely adapted to the external outline of the container. Individual portions of this carrier plate are constructed as ribs, which serve for the mounting of two drive motors and supporting and spring elements. The portions of the carrier plate between the ribs serve for mounting of the container. Two additional masses, acting as counterweights for the drive motors, are also fastened to the carrier plate between the ribs.

This arrangement of a carrier plate, in which additional masses can also be fastened, has a number of disadvantages. For example, the additional masses must either be provided with cast-in bolts to enable the additional masses to be fastened in the cheeks of the ribs or else loose bolts should be guided from the interiors of the ribs through fastening bores in the additional masses and threadedly coupled thereto. This manner of fastening, however, requires a complicated casting mould for the additional masses and awkward assembly.

Other kinds of fastening of the additional masses to the carrier plate are not possible if the carrier plate has to be welded to the container, cost considerations being paramount in this connection.

There is accordingly a need for mounting means which can be arranged on the container above the drum axis and serve to mount a counterweight mass, wherein a simple form of casting mould for the mass can be used and the assembly effort kept small. The additional mass should preferably be fastened in such a manner that exposure to loading during spinning operation of the drum washing machine is kept as small as possible, in view of the fact that such a mass may consist of a brittle casting material, for example cast iron or concrete. In this connection it would be desirable for the smallest possible free bending lengths to be present between fastening points and the centre of gravity of the mass.

According to the present invention there is provided a washing machine comprising a washing solution container housing a rotatable laundry drum and supported by support means permitting oscillatory movement of the container, and an adjusting mass for adjusting the natural frequency of the oscillatory mass supported by the support means to a predetermined resonant rotational speed of the drum, the adjusting mass being mounted on the container by means of a mounting member comprising at least one rib which projects outwardly of the container at the periphery thereof and which is provided with at least one opening receiving fastening means fastening the adjusting mass to the member.

In a preferred embodiment, a drum washing machine, which is equipped for spinning operation, has an oscillatorily mounted liquor container and at least one additional mass for adjusting the mass of the oscillatory unit to a certain resonant rotational speed, the additional mass being spatially associated with a carrier plate at the container. The carrier plate comprises at least one rib, which is proud of the outside shell surface of the container, is shape-iockingly covered over by the mass, and contains fastening holes for the mass.

A mode of fastening of that kind offers a large number of possibilities of application and construction to the user, the structuring of the carrier plate as well as that of the adjusting mass being free. In that case, the rib top surface, displaced generally parallelly from the peripheral surface of the container, can serve as a mounting surface for the mass.

A carrier plate with two such ribs is particularly versatile in use and satisfies most requirements in respect of the size of the adjusting mass in relation to smallest possible free bending length.

A carrier plate with three such ribs, which all serve for the mounting of the adjusting mass, can be of advantage in the case of a mass with large area dimensions.

Embodiments of the present invention will now be more particularly described by wqy of example with reference to the accompanying drawings, in which: Fig. 1 is a schematic vertical sectional view of a drum washing machine embodying the invention, the machine being provided with an adjusting mass mounted on a two-ribbed carrier plate; Fig. 2 is a perspective view of the carrier plate of Fig. 1 without the mass; Figs. 3 to 8 are schematic sectional views of different forms of adjusting mass mounted on such a carrier plate; Fig. 9 is a schematic sectional view of yet another form of adjusting mass and of further mounting means associated with the carrier plate; Fig. 10 is a plan view of the arrangement of Fig. 9;; Figs. 11 to 13 are schematic sectional views of the carrier plate with different forms of fastening elements for the adjusting mass; Figs. 14 to 17 are schematic sectional views of different forms of carrier plate; Figs. 1 8 to 20 are plan views of different rib arrangements for the carrier plate; Fig. 21 is a schematic elevation of a washing machine liquor container with integral carrier plate; and Fig. 22 is a diagram showing the force acting on the mounting of such an adjusting mass during oscillation of a washing machine liquor container.

Referring now to the drawings, there is shown in Fig. 1 a drum washing machine comprising a housing 1 in which is arranged a washing solution or liquor container 2. The container 2 is provided at its underside with an outflow 3 leading to a pump 4, by means of which liquid can be pumped out of the container and removed through a rising duct 5 for discharge into a further outflow (not shown). This outflow system is locally fixed and therefore does not load the container.

Arranged in the container 2 is a rotatable laundry drum, which is drivable for washing and spin operations by a drive motor 6. The motor and associated drive transmission are fastened directly to the container 2 and together with the weight of the container constitute a mass which is supported by resilient damping struts 7 relative to the base of the washing machine.

An adjusting mass 8 is fastened to the container 2 by means of a carrier plate 9 at the upper outside shell surface of the container 2, approximately opposite, with respect to the drum axis, the mass concentration present at the lower part of the container.

The carrier plate 9 is illustrated in perspective view in Fig. 2 and comprises flange portions 10, 1 1 and 12 which are adapted to the outside shell surface 13 of the container 2 and are fastened to this surface by means of spot welds 14.

The carrier plate 9 has two ribs 15, the cheeks 16 of which extend at an angle to the radius R of the drum. The mounting top surfaces 17 of the ribs 15 are spaced from the surface 13 of the container 2 and are disposed in a single plane.

The surfaces 17 have bores 18 for fastening elements fastening the mass 8.

Figs. 3 to 8 show carrier plates 9 of substantially identical construction. Their flange portions 10 to 12 lie snugly against the surface 13 of the container 2 and their ribs 1 5 have substantially trapezium-shaped cross-sections, i.e. notional extensions of their cheeks 1 6 include acute angles, the apices of which point away from the container surface 13.

The adjusting mass 8, of which different forms are shown in Figs. 3 to 8, is advantageously so constructed that it fills out as completely as possible the available space alongside the ribs, in order that the mass takes up as little space as possible upwardly of the ribs. This means that the spaces between the ribs, and possibly also laterally outside the ribs, are filled out to the largest possible extent by the mass 8 insofar as these spaces are not required for other purposes.

Consequently, the mass 8 in each of Figs. 3 to 7 largely fills out the space between the ribs 1 5.

The mass 8 in Fig. 3 rests directly on the mounting surfaces 17 of the ribs 1 5. By means of fastening elements, for example nuts and bolts (indicated by lines and crosses), the mass is fixed at the fastening bores 1 8 of the ribs 15. In that case, the mass 8 is centred merely by the fastening elements and tolerance problems do not arise. The horizontal and vertical forces arising during spinning operation of the drum must, however, be transmitted through the cheeks 16 of the ribs 15 to the container shell.

More advantageously in this respect are the forms shown in Figs. 4 and 5, in which the mass 8 does not rest on the mounting surfaces 17 of the ribs 1 5, but on the flange portion 11 in the case of Fig. 4 and on the flange portions 10 and 12 in the case of Fig. 5, these flange portions being in direct contact with the surface 13 of the container 2.

The advantage of this mode of fastening is that the horizontal inertia forces of the mass 8 during the spinning operation of the drum are directly transmitted to the shell of the container 2, so that the ribs 15 do not have to absorb these forces.

The connections of the carrier plate 9 to the container are therefore not loaded. The vertical inertia force of the mass 8 load the bolt connections in tension or the bearing surfaces of the mass in compression so that at least the downwardly directed vertical forces are also transmitted directly to the shell of the container 2.

Another possible mode of fastening is shown in Figs. 6 and7, this mode of fastening utilising positional securing, produced by centering effect, of the mass 8 through interengaging inclined contact surfaces of the mass and the carrier plate.

Fig. 8 shows a mode of fastening which is a combination of those shown in Figs. 3 and 5.

Independently of the particular mode of fastening, the carrier plate has a low bending stiffness in the direction of the circumference of the container and substantial rigidity parallel to the drum axis. For that reason, the carrier plate can be readily adapted to different radii of the container sheel and the forces arising in operation are distributed over a large area without stress concentration at the container. The carrier plate can also serve as a fastening element for parts of the oscillatory unit, for example a carrier star 19 as shown in Figs. 9 and 1 0. This star stabilizes the container at its rearward end and supports the drum. For this purpose, a strap 20 projecting beyond the rim of the drum shell is provided at the carrier plate 9.

Different numbers of screw or bolt mounting points can be provided in the mounting surfaces of the rib 15 in correspondence with the shape of the mass 8 and its position and in correspondence with the magnitude of the operational loading.

These mounting points all lie in the same plane so that a simple fitting of the fastening elements by means of a mechanical screwdriver is possible and an exact tightening torque can therefore be adhered to.

The mass 8 can be secured in different ways. In the example illustrated in Fig. 1 1, nuts are welded on or pressed in below the mounting surfaces 17 of the ribs 1 5. In the example of Fig. 12, strips of a cast material, preferably cast iron, are pushed into the ribs 15 and have threaded holes under the fastening bores 18, these strips supplementing the mass 8. An optimum utilisation of space is achieved with this arrangement. In the example of Fig. 13, strips of resilient material are inserted into the interiors of the ribs 1 5 and wedge in place bolts 22 which have been introduced into the fastening bores 18 before mounting of the carrier plate 9 on the shell surface 13 of the container 2. In place of the strips 21, however, bolt heads can be welded or pressed in.

In the illustrated embodiments, the cheeks 16 of the ribs 1 5 are without exception arranged obliquely, which results in a slight increase in the rigidity of the ribs and also an advantage in the mounting of the carrier plates. In particular, the carrier plates, through their symmetrical construction, can be stacked in space-saving manner and can be introduced automatically into the assembly process in a simple manner. When other requirements are present, however, the cheeks of the ribs 15 can extend perpendicularly to the mounting surfaces 17.

Fig.14 shows an embodiment with a carrier plate 23 having a single rib 15 which is completely covered by an adjusting mass 24. In this case, in a mode of fastening which is particularly advantageous the mass 24 rests on lateral flange portions of the carrier plate 23. For better distribution of the biassing forces produced by the fastening bolt, a metal support plate 25, stiff in bending, is placed below the nut or the bolt head so that the biassing forces acting on the additional mass 24 are transmitted directly and without bending moments to the flange portions of the carrier plate.

Similar presumptions are present in the examples of Figs. 4, 5 and 8, in which such a metal support plate can also be employed.

In the example illustrated in Fig. 15, there is provided a carrier plate 26 which has three ribs 15 serving for a more secure support of an adjusting mass of larger area. These ribs can, however, also serve in part for fastening of other components and in addition stiffen the shell of the container.

In the example illustrated in Fig. 16, the ribs 27 of the carrier plate 28 each have only one full cheek 29 and thereby contribute to saving in material. The mass 8 can be constructed as in the examples of Figs. 3 to 6 and 8.

In the case of Fig.17, to facilitate the adaptability of a carrier plate 30 to the bending radius of the container shell, the portion between ribs 31 of the plate is arranged above than the container shell.

As the plan view of Fig. 18 shows, the ribs of the carrier plate do not necessarily need to be of equal length if, for any reason, the adjusting mass does not rest on the entire length of each rib. The space not taken up by the rib 32 can, however, still be taken up by a part of the adjusting mass.

An enhanced rigidity of the container shell in the region of the carrier plate can be achieved with a frame-like arrangement of the ribs 32 as shown in Figs. 19 and 20. The carrier plate can also be constructed asymmetrically in departure from the examples illustrated here, so that one rib is perhaps higher than the other.

The carrier plate can, according to the example in Fig. 21, be an integral component of the shell of the container 2, with the ribs being formed during the pressing of the sheet metal shell.

According to Fig. 21, more than two or three ribs can be provided at the shell surface when further adjusting masses or other components of the oscillatory unit are to be fastened thereto.

In the case of the modes of fastening shown in Figs. 5 to 8 and 14, the screw or bolt biassing force can be kept smaller than for the remaining examples. Fig. 22 represents the force relationships in the case of a support surface of the adjusting mass at the shell extending along the tangent T to the circumference of the container 2. Fv signifies the biassing force of the screw or bolt and F the horizontal inertia force of the adjusting mass relative to the shell surface.

The angle of the tangent to the horizontal through the contact point is represented by a. The biassing force can then be calculated from the equation: 1 Fv=F tan (a+S) wherein g is the angle of friction.

Claims

1. A washing machine comprising a washing solution container housing a rotatable laundry drum and supported by support means permitting oscillatory movement of the container, and an adjusting mass for adjusting the natural frequency of the oscillatory mass supported by the support means to a predetermined reasonant rotational speed of the drum, the adjusting mass being mounted on the container by means of a mounting member comprising at least one rib which projects outwardly of the container at the periphery thereof and which is provided with at least one opening receiving fastening means fastening the adjusting mass to the member.

2. A washing machine as claimed in claim 1, wherein the adjusting mass is shaped to engage at least partially around said at least one rib.

3. A washing machine as claimed in either claim 1 or claim 2, wherein the mounting member comprises two such ribs.

4. A washing machine as claimed in either claim 1 or claim 2, wherein the mounting member comprises three such ribs.

5. A washing machine as claimed in either claim 3 or claim 4, wherein the ribs extend parallel to each other and to the axis of the drum.

6. A washing machine as claimed in claim 3, wherein the ribs extend at an angle to each other.

7. A washing machine as claimed in any one of claims 3 to 6, wherein the lateral surfaces of each rib extend perpendicularly to a top mounting surface thereof.

8. A washing machine as claimed in any one claims 3 to 6, wherein the lateral surfaces of each rib extend at such an angle relative to each other that the base of the rib is wider than the opposite top surface of the rib.

9. A washing machine as claimed in either claim 7 or claim 8, wherein the adjusting mass rests on the top surfaces of the ribs.

10. A washing machine as claimed in either claim 7 or claim 8, wherein the mounting member is in the form of a plate having portions which extend laterally from the ribs and bear against the peripheral surface of the container, and the adjusting mass rests on at least one of said portions of the plate.

11. A washing machine as claimed in claim 8, wherein the adjusting mass is provided with correspondingly relatively angled support surfaces bearing against the lateral surfaces of the ribs.

12. A washing machine as claimed in any one of the preceding claims, wherein the mounting member further comprises a fastening strip for a carrier star of the container.

13. A washing machine as claimed in any one of the preceding claims, wherein the interior of the or each rib is filled with a strip of cast material.

14. A washing machine as claimed in any one of claims 1 to 9 and 11, wherein the mounting member is an integral part of the container.

15. A washing machine as claimed in any one of the preceding claims, wherein the mounting member comprises a plurality of such ribs and at least one of the ribs is arranged to extend in the peripheral direction of the container and substantially arcuately about the axis of the drum.

16. A washing machine substantially as hereinbefore described with reference to Figs. 1 and 2 of the accompanying drawings.

17. A washing machine substantially as hereinbefore described with reference to any one of Figs. 3 to 8 and 11 to 21 of the accompanying drawings.

18. A washing machine substantially as hereinbefore described with reference to Figs. 9 and 10 of the accompanying drawings.