CORRESPONDING APPARATUS

TECHNICAL FIELD

The present disclosure relates to a washing machine. In particular the present disclosure relates to a washing machine having a washing bowl rotating around a vertical axis or in some embodiments a horizontal axis.

BACKGROUND

Washing machines typically include some type of mechanism for adding detergent. Traditionally washing machines are using detergent drawers to dissolve and dispense detergents into washing bowl.

However, such a mechanism is known to have drawbacks. In particular such a mechanism does not ensure efficient and effective detergent dilution as this typically leaves behind traces of remaining detergent particles on laundry as residues.

Further, washing machines can generally be divided into two types depending on the rotational axis around which the washing bowl revolves. Thus, there are washing machines with washing bowls revolving around a horizontal axis and there are washing machines with washing bowls revolving around vertical axis. A washing machine with a horizontal washing bowl axis is typically loaded from the front. A washing machine having a vertical washing bowl axis is typically loaded from the top. A top loaded washing machine with a vertical washing bowl axis is described in the US patent No. 7, 810, 362.

There is a constant desire to improve the performance of a washing machine. Hence, there is a need for an improved washing machine. SUMMARY

It is an object of the present invention to provide an improved washing machine. It is a particular object of the present invention to provide an improved mechanism for dispensing detergent in the washing machine.

This object and/or others are obtained by the washing machine as set out in the appended claims.

In accordance with one embodiment a method of dissolving detergent in a washing machine having a rotating bowl is provided. In accordance with the method water and detergent is provided to a pump for recirculating water in the washing machine; and during a period of time the pump is controlled by a controller to intermittently start and stop to pump water and detergent into a hose interconnecting the bottom of the bowl and the top of the bowl, wherein the pumping is controlled to stop before any water reaches the top of the hose. Hereby it is obtained that the water and detergent is mixed properly before the mix of water and detergent enters the bowl. When the period of time when mixing takes place a washing cycle can be started.

In accordance with one embodiment the pump is pumping water and detergent via a hose provided with a chamber. Hereby the volume of water that can be used to mix with the detergent can be increased.

In accordance with one embodiment 4 the time from when the pump is started to when the pump is stopped during said period of time is determined by a timer. As an alternative the time from when the pump is started to when the pump is stopped during said period of time is determined by a number of revolutions in the pump. In yet another alternative, the time from when the pump is started to when the pump is stopped during said period of time is determined by an input signal from a water level sensor provided on the hose. In accordance with some embodiments the bowl rotates around a vertical axis.

Because of the improved mixing of water and detergent it can in some embodiments be possible to provide un-heated water to mix with the detergent. This can save energy.

The invention also extends to a water recirculation system adapted to employ the methods as set out above and also to a washing machine comprising such a water recirculation system. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described in more detail by way of non-limiting examples and with reference to the accompanying drawings, in which:

- Fig. 1 is a top view from the side of a washing machine,

- Fig. 2 is a top view from the side of a washing machine,

- Fig. 3 is a top view from the side of a washing machine with the top section thereof removed,

- Fig. 4 is a top view from the side of a washing machine with the top section and the side cover removed.

- Fig. 5 is a sectional view of a washing machine,

- Fig. 6 is a view from the side of a water recirculation system for a washing machine,

- Fig. 7 .is a flow chart illustrating some steps performed when dissolving detergent in water in a washing machine, and - Fig. 8 is a view of a controller used for controlling a pump of a water circulation system of a washing machine. DETAILED DESCRIPTION

In the following a detergent dilution system and a washing machine comprising a detergent dilution system will be described. In the figures, like reference numerals designate identical or corresponding elements throughout the several figures. It will be appreciated that these figures are for illustration only and are not in any way restricting the scope of the invention. Also it is possible to combine features from different described embodiments to meet specific implementation needs. For example the embodiments below specify that the bowl rotates around a vertical axis. However, it is also envisaged that the bowl can rotate around a horizontal axis. Also, the embodiments described below all show a top loaded washing machine, but the washing machine can also be a front loaded washing machine.

In Fig. 1 a washing machine 1 is depicted as a top view from the side. The washing machine 1 is a top loaded washing machine with a washing bowl 2 having a vertical axis. The washing bowl 2 typically comprises an inner bowl 2a and an outer bowl 2b. The washing machine 1 is shown without a hinged door that normally is provided. The washing machine 1 also has a drawer 3 for adding detergent to the washing machine.

Fig. 2 is also a top view from the side of the washing machine 1. Fig. 2 is similar to Fig. 1. In Fig. 2 the drawer 3 is opened. Fig. 3 is a top view from the side of the washing machine 1 with the top section thereof removed. In Fig. 3 a tray 4 for receiving detergent loaded into the drawer 3 is shown.

Fig. 4 is a top view from the side of the washing machine 1 with the top section thereof removed. Fig. 4 is similar to Fig. 3 but in Fig. 4 the side cover is removed. In Fig. 4 a water circulation system 5 of the washing machine 1 is shown. In Fig. 4 the inner bowl 2a adapted to spin inside the outer bowl 2b is shown. The inner bowl 2a can then also be termed spin drum. Fig. 5 is a sectional view of the washing machine 1 depicted in Fig.4. As is set out above, the washing machine 1 comprises of a tray 4 on top of the outer bowl 2b to receive detergent dispensed from the detergent drawer 3 (see Fig. 1 and Fig. 2) or through a port connected to outer bowl from detergent dispenser system. The washing machine 1 comprises a water circulation system. The water circulation system can comprise a pump 6. The pump 6 can be mounted at the bottom of outer bowl 2b. The pump 6 can be connected to a hose 7 fixed to the outlet of the pump 6. In one embodiment water circulation system further comprises a chamber 8 connected to or integrated into the hose. The water circulation system further comprises a water outlet 9. In one embodiment the outlet 9 is connected to a dispensing nozzle which opens on top the inner bowl 2a.

Fig. 6 is a view depicting the water circulation system 5 and the top section of the outer bowl 2b. As is seen in Fig. 6, the chamber 8 can be located on the hose 7 interconnecting the pump 6 at the bottom of the outer bowl 2b and the outlet 9 at the top of the inner bowl. The chamber 8 can have any suitable shape. In one embodiment the chamber has a generally flat shape. In one embodiment the chamber 8 has a flat side facing a side cover of the washing machine at the side where the chamber is located. Such a shape is advantageous because the volume of the chamber is allowed to be larger but at the same time the chamber can be fitted inside the washing machine without having to redesign the machine. In one embodiment the chamber 8 is located at the top of the hose 7, such as above the middle of the hose 7 or at a height above the middle of the washing machine 1.

Fig. 7 is a flow chart illustrating some steps performed when adding and dissolving detergent in the washing machine 1 . First, in a step 701, detergent is dispensed into the drawer 3. Next, in a step 703, detergent dispensed into the drawer 3 drawer enters through a hole of the drawer 3 to reach the tray 4 that can be located on the cover outer bowl 2b or through a port connected to outer bowl from detergent dispenser system. The detergent can then be dispensed into the inner of the washing machine 1 in as step 705. For example the detergent can be dispensed in the gap between the inner bowl 2a (spin drum) and the outer bowl 2b. Then, in a step 709, the inner bowl 2a can be rotated to create a drift of the dispensed detergent into water so that the detergent can be pushed towards the inlet of the pump 6 mounted at bottom of outer bowl 2b. The water can in some embodiments be un- heated, such as having a temperature below 25 degrees Celsius. In some embodiments the water is provided from the cold water tap. The steps 701 - 709 serves to get the detergent to the water recirculation system 5 of the washing machine 1. Other methods for providing the detergent to the recirculation system 5 of the washing machine can also be used. Next, in a step 71 1 , the pump is controlled to turn on and off intermittently to discharge a certain quantity of water from outer bowl 2b into the hose 7 that can include the hose chamber 8, connected to outlet of the pump 6.

When the pump 6 stops, the discharged water from the pump 6 flows back from the hose 7 into the outer bowl 2b. This creates a shake of water which help to dissolve detergent into water by blending it into water. Hence, by running the pump 6 intermittently during a period of time (detergent dissolving period), the detergent can be made to better dissolve in the water in the washing machine. The water with detergent will be pumped out into the hose 7 by running of the pump 6, but the pump will be controlled to not let the water enter the inner bowl 2a (spin drum) during the detergent dissolving period. Instead the pump will stop before the water with detergent reaches the top of the hose 7. Stopping of the pump 6 will result in that the water returns to the pump 6 by gravitational force and returns to the bottom of the outer bowl 2b. The pump 6 can be controlled to start and stop a suitable number of times during the detergent dissolving period to allow the detergent to fully dissolve into the water. When the detergent dissolving period ends in a step 71 3, the pump 6 is controlled to dispense the water with dispensed detergent into the inner bowl 2a. The water recirculation system is the operated in a conventional manner to allow water recirculation in the washing machine 1.

The pump 6 can be controlled in any suitable manner during the detergent dissolving period in step 71 1. The pump 6 can typically be controlled by a controller 22 (see Fig. 8) that is conventionally used in a washing machine. For example the pump 6 can be controlled to run a predetermined time that ensures that the water does not reach the inner bowl 2a. In another embodiment the pump 6 is controlled to run a predetermined number of revolutions that ensures that the water does not reach the inner bowl 2a. In yet another embodiment a sensor is provided at the top of the hose 7 adapted to output a sensor signal to the controller 22 when the water level in the hose 7 reaches the sensor. In response to such a sensor signal, the controller stops the pump 6 to allow the water to return to the bottom of the outer bowl 2b. In Fig. 8 an exemplary controller 22 is depicted. All of the steps described above for controlling the pump 6 can be performed by the controller 22. The controller 22 can typically be the controller used when controlling the program(s) of the washing machine 1. The controller 22 can be implemented using suitable hardware and or software. The hardware can comprise one or many processors 401 that can be arranged to execute software stored in a readable storage media 402. The processor(s) can be implemented by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared or distributed. Moreover, a processor or may include, without limitation, digital signal processor (DSP) hardware, ASIC hardware, read only memory (ROM), random access memory (RAM), and/or other storage media. The processor 22 is adapted to send and receive signals from other entities in the washing machine 1 using an interface 403.

The washing machine and the method for controlling a washing machine as described herein provides an improved detergent dilution system that dissolves detergents away from clothes without generating suds and detergent residue on clothes. In addition to improve di lution of detergent energy can be saved as hot water usage is reduced by using chemical energy effectively through detergent dilution to form a concentrated detergent solution. Thus, since the detergent is efficiently dissolved in a small quantity of water before the wash cycle starts, it is possible to use less amount of hot water in the wash cycle. This helps to increase energy saving due to reduction in usage of hot water. Also, detergents can be dissolved in cold water only to further result in energy savings and increase versatility of the concept to operate in customer usage conditions.