DE20308581U1 - domestic washing machine - Google Patents

Description

GREENECKER

^! &fsCjiWANHOUSES

LAW FIRM

GKS & S MAXIMILIANSTRASSE 58 D-80538 MUNICH GERMANY

LAWYERS

LAWYERS

MUNICH

DR. HELMUT EICHMANN

GERHARD BARTH

DR. ULRICH BLUMENRÖDER, LL. M.

CHRISTA NIKLAS-FALTER

DR. MAXIMILIAN KINKELDEY, LL. M.

DR. KARSTEN BRANDT

ANJA FRANKE, LL.M.

UTE STEPHANI

DR. BERND ALLEKOTTE, LLM.

DR. ELVIRA PFRANG ₁ LLM.

KARIN LOCHNER

BABETT ERTLE

CHRISTINE NEUHIERL

SABINE PRÜCKNER

PATENT ATTORNEYS EUROPEAN PATENT ATTORNEYS

MUNICH

DR. HERMANN KINKELDEY

PETER H. JAKOB

WOLFHARD MEISTER

HANS HILGERS

DR. HENNING MEYER-PLATH

ANNE EHNOLD

THOMAS SCHUSTER

DR. KLARA GOLDBACH

MARTIN AUFENANGER

GOTTFRIED KLITSCH

DR. HEIKE VOGELSANG-WENKE

REINHARD KNAUER

DIETMAR KUHL

DR. FRANZ-JOSEF ZIMMER

BETTINA K. REICHELT

DR. ANTON K. PFAU

DR. UDO WEIGELT

RAINER BERTRAM

JENS KOCH, M.S. (U of PA) M.S.

BERND ROTHAEMEL

DR. DANIELA KINKELDEY

THOMAS W. LAUBENTHAL

DR. ANDREAS KAYSER

DR. JENS HAMMER

DR. THOMAS EICKELKAMP

JOCHEN KILCHERT

DR. THOMAS FRIEDE

YOUR REF.

OUR REF.

PATENT ATTORNEYS EUROPEAN PATENT ATTORNEYS

BERLIN

PROF. DR. MANFRED BÖNING

DR. PATRICK ERK, M.S. (MIT)

COLOGNE

DR. MARTIN DROPMANN CHEMNITZ MANFRED SCHNEIDER

OF COUNSEL PATENT ATTORNEYS

AUGUST GRÜNECKER DR. GUNTER BEZOLD DR. WALTER LANGHOFF

DR. WILFRIED STOCKMAIR (-1996)

DATE

G4962-80/Peu 02.06.03

Electrolux Home Products Corporation N.V.

Belgicastraat17
Brussels
Belgium

Household washing machine

GRÜNECKER KINKELDE ¹ Y
STOCKMAIR &
MAXIMILIAN STREET 58
D-80538 MUNICH
GERMANY

*FA)i

••FAX

http://www.grunecker.de

e-mail: postmaster@grunecker.de

8| DEUTSCHE BANK MUNICH No. 17 51734 BLZ 700 700 SWIFT: DEUT DE MM

Household washing machine

The present invention relates to a household washing machine, preferably a top-loading washing machine, which is capable of providing advantageous performances and which at the same time is compact and has a simple construction.

It is desirable to keep the dimensions of household appliances as small as possible without limiting their performance and ensuring a simple design. In household washing machines, it is known to use an element to close the bottom of the drum housing from below, in order to prevent the detergent introduced into the drum with the flow of water from reaching the drain pump housing prematurely and therefore not being used optimally. This closing element is usually in the form of a ball that can float, so that the liquid in the drain pump housing, which rises upwards according to the principle of communicating tubes, pushes the ball upwards until the ball reaches a suitable point located between the bottom of the drum housing and the pipe that extends from the drum housing to the drain pump, thus closing this point.

The advantages of the design and functionality of such machines are known and will therefore not be explained further.

However, such machines have disadvantages that may become unacceptable.

One of these disadvantages is the buoyancy of the ball. To ensure that the liquid reaches the housing of the drain pump without first entering the drum housing, the water column that is in the drain pipe after the draining process is completed is traditionally used. However, the amount of water flowing back from the drain pipe is not always sufficient to push the ball upwards until the drum housing is closed. To increase the capacity of the drain pipe, an additional reservoir or an additional vessel is used.

which is installed at the highest point, immediately before the downward bend of the drain pipe.

This solution achieves an increase in capacity, but it has disadvantages that should not be underestimated; in particular, it requires more space both inside and outside the machine for the additional vessel.

In case of lack of space, an alternative solution has been proposed, which involves using a drain pipe with an increased diameter so that the pipe can accommodate the required amount of liquid.

However, the use of a larger drain pipe is not satisfactory in the case of top-loading machines, i.e. machines that are loaded from above, also because this solution entails additional functional disadvantages that are particularly detrimental in the case of machines with backflow of the liquid.

It would therefore be desirable, and it is an object of the present invention, to provide a washing machine provided with a floating ball or a similar floating element suitable for closing the connecting pipe between the drum housing and the underlying drain pump housing from below, without having the aforementioned disadvantages which arise, for example, in the case of a larger drain pipe or an additional vessel.

In addition, such a washing machine should be easy to manufacture and construct using existing technologies, and should be equally easy to use; in particular, such a washing machine should be able to be manufactured with few changes to the current production process; in addition, the changes introduced must not jeopardise the reliability of the washing machine.

These objects are achieved with a washing machine having the features of claim 1. In the following, the invention is described with reference to the embodiment shown in the figures.

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Fig. 1 shows the hydraulic diagram of a washing machine according to the present invention before starting the operation;

Fig. 2 shows the scheme of the same washing machine during the inflow of the washing liquid;

Fig. 3 shows the diagram of the same washing machine during the washing process;

Fig. 4 shows a detail of an improved embodiment of the machine shown in the previous figures.

The washing machine according to the invention comprises a perforated drum (not shown in the figures) which is rotatable within a closed drum housing 2. A supply device 3 for supplying water to the housing comprises a small container for the distribution of detergent and other products. In addition, the machine comprises a pipe 3A (see Fig. 4) connecting this container and the drum housing 2.

The device 3 is connected to the water supply system by a line 33.

In the lower area, the drum housing has an opening 4 to which a drain collector 5 is tightly connected. The area of the drain collector opposite the drum housing ends in a housing 6 in which a drain pump is located. This housing is connected to the drain pipe 7 in a conventional manner.

In correspondence with the upper part of this drain collector 5, a second housing 8 is mounted, which is suitable for containing the above-mentioned closing element or the above-mentioned closing ball 9.

The drain pipe 7 has an upward part which ends with a bend 10 from which a downward part 11 extends; as is known, the height "h" of this bend, with respect to the plane of installation of the washing machine, must not exceed

not fall below the legally prescribed value in order to avoid the washing machine being constantly emptied.

According to the present invention, an additional pipe 13 is provided which is located between the inflow pipe 33 and the discharge pump housing 6.

This additional tube may also have a large diameter; however, this solution would partially reduce the advantages of the present invention.

The additional tube 13 advantageously has a low cross-section; in particular, the size of the cross-section can be adjusted experimentally, as will be explained below; with reference to Fig. 4, in addition, the tube 13 has an interruption 14 known as an air bridge, the destination of which is also known.

The initial section of the additional pipe 13 ends in the pipe 33, in a section located in the direction of flow upstream of an air bridge 23; the air bridge 23 is provided by law upstream of the distributor 3.

On a lateral part of the additional pipe 13, which is located below the air bridge 14 in the direction of flow, an opening 15 is provided which is connected to the outer region by a sleeve 16; the sleeve 16 is oriented upwards.

The various parts described above are positioned and dimensioned to ensure the following functionality:

1) At the beginning of the washing cycle (see Fig. 1), there is no water in the washing machine, except in the lower part, because of the residual liquid that has remained in the upward part of the drain pipe 7 and has flowed back into the pump and into the drain collector 5; residual water is also present in the additional pipe 13.

2) After the washing process has started, the water starts to flow into the distributor 3, towards the drum housing through the pipe 3A; at the same time, the

Water from the pipe 33 into the additional pipe 13 (see Fig. 2); however, the pressure on the distributor 3 is relatively low compared to the pressure with which the water flows into the additional pipe 13. This results from the point along the pipe 33 where the water flows into the device 3 being downstream of the air bridge 23, as previously described (see Fig. 4).

Therefore, the water flows into the additional pipe 13 at a speed and pressure that are significantly higher than the inflow speed and the inflow pressure into the device 3.

After the water has passed through the air bridge 14, the water continues to flow in a continuous downward current inside the tube 13; by a phenomenon known per se, which is due to the small cross-section of the tube, at the level of the opening 15, air particles are alternately sucked in through the sleeve 16, so that a kind of gurgling is created in the additional tube;

3) as the process continues, small columns of water and air are formed in the additional pipe 13, which are separated from each other but stable in themselves; however, and this is the phenomenon that the invention seeks to exploit, the pressure that builds up in the housing 6 of the drain pump depends not only on the sum of the heights of the individual water columns, but also, and above all, on the dynamic pressure of the water coming from the water supply system.

This result is due to the fact that with a sufficiently small cross-section of the additional pipe 13, preferably smaller than 75 mm ² , the water columns remain separated by air bubbles and the recoil force of the dynamic pressure prevails and fills the drain collector before the water starts to collect on the bottom of the drum housing.

It should further be noted that what is commonly referred to as a water column located in the pipe 13 is a column consisting of a plurality of small water columns inserted in a plurality of corresponding small pure air columns; i.e., even when speaking of a water column located in the additional pipe 13, it must be noted that it is not a pure

A column of water is, as one would understand it in the physical sense of the word, a column consisting only of water.

What actually counts, with regard to the static pressure created in the housing 6, is the sum of the individual heights of the water columns consisting of pure water that are located in the additional pipe.

4) As the washing process continues, the drain collector 5 is filled with water which flows in both from the additional pipe 13 and, although to a lesser extent, through the lower open opening 4. The inflowing water pushes the ball 9 upwards until it reaches a point immediately in front of the closure;

5) however, the pressure of the water in the additional pipe 13 is higher than the pressure of the water in the drum housing; therefore, the drain collector 5 is filled more by the water from the additional pipe than by the water in the drum housing 6. Due to this difference, the level of water in the drain collector 5 rises by the amount necessary to drive the ball upwards until the ball reaches the opening 4 and thus closes it.

6) From this point on, the filling process of the drum housing proceeds in the normal way; however, this requires that the components described above are dimensioned in such a way that the pressure in the discharge collector 5, which drives the ball upwards until the opening 4 is closed, remains higher than the pressure of the water in the drum housing.

7) The process continues until the water level in the drum housing reaches a predetermined value, which is determined, for example, by a pressure regulator. After this, the flow of water into the drum housing is stopped and the filling process is completed (see Fig. 3).

However, a residual amount of water remains in the additional pipe 13; if the level of this water column were below the bend 10 of the drain pipe, • ·

·

·

no problems would arise; however, since this water column is difficult to control, it may happen that the water level reaches the level of this bend, which will obviously lead to an overflow of the water in the additional pipe; in particular, the water would first overflow through the additional pipe, then through the drain pump housing and finally through the drain pipe.

To avoid this problem, it is preferable to use an overflow pipe 15 extending between a point 17 of the additional pipe 13 and an access opening 18; it is understood that the point 17 can be placed in any area connected to the additional pipe 13 (e.g. also in the area of the housing of the drain pump), while the opening 18 must have a level "v" lower than the level "h" of the bend 10. In this way, it is achieved that the water overflows, according to the principle of communicating pipes, from the additional pipe 13 into the drum housing without the water flowing through the drain pipe.

Of course, this also applies to the filling process, since it can happen that the water in the additional pipe 13 overflows through the drain pipe 7 due to the height of the water level in the additional pipe 13.

Claims (10)

1. Washing machine, in particular a household washing machine, with: - a rotating perforated drum to collect and wash laundry, - a housing ( 2 ) containing said drum, - an inlet device ( 3 ) which is connected to the water supply system by a line ( 33 ) and is suitable for introducing a predetermined amount of water and a quantity of detergent into the housing through an upper line (3 A) and - a drain collector ( 5 ) with a closing element ( 9 ) to close an opening ( 4 ) in the bottom of the drum housing, characterized in that: - an additional pipe ( 13 ) is provided which is connected both to the inflow device ( 3 ) and to the outflow collector ( 5 ). 2. Washing machine according to claim 1, characterized in that it comprises a drain pump located in a tank ( 8 ) connected to the lower part of the drain collector ( 5 ). 3. Washing machine according to one of claims 1 or 2, characterized in that the drain collector ( 5 ) has a container ( 6 ) which accommodates the closing element. 4. Washing machine according to one of the present claims, characterized in that it comprises an air bridge which is located in the line ( 33 ) upstream of the inlet device ( 3 ). 5. Washing machine according to claim 4, characterized in that the air bridge ( 23 ) is located between the device ( 3 ) and the deviation of the additional pipe ( 13 ). 6. Washing machine according to one of claims 1 to 5, characterized in that it comprises a drain pipe ( 7 ) connected to an end portion of the drain pump and suitable for discharging the water pumped by the pump, and provided with an upwardly oriented part and a bend ( 10 ) to which a downwardly oriented part ( 11 ) of the pipe is connected. 7. Washing machine according to one of the present claims, characterized in that the additional pipe ( 13 ) comprises an air bridge ( 14 ) located downstream of the inlet device ( 3 ). 8. Washing machine according to one of the present claims, characterized in that the additional pipe ( 13 ) has a small cross-section, preferably not larger than 75 mm ² . 9. Washing machine according to one of the preceding claims, characterized in that on a lateral part of this additional tube ( 13 ) an opening ( 15 ) is provided, which is connected to the external region by an upwardly oriented sleeve ( 16 ). 10. Washing machine according to one of the preceding claims, characterized in that an overflow pipe ( 15 ) is provided which connects the interior of the additional pipe ( 13 ) to a suitable opening ( 18 ), the opening being provided for the inflow into the drum housing and being arranged at a level "v" which is lower than the level of this bend ( 10 ).