WASHING MACHINE AND METHOD OF INCREASING BALANCE OF THE DRUM OF THE WASHING MACHINE

Abstract

A washing machine having a cabinet, a drum for receiving laundry from its open end where the drum is rotatable around its longitudinal axis within the cabinet, a balancer having a mass channel, and a balancing weight where the mass channel extends in a direction from the lateral surface of the drum to the inside of the drum and receives the balancing weight and the balancing weight is movable within the mass channel along the direction of the extension of the mass channel is disclosed. The invention also relates to a method of increasing the balance of a drum rotating along its longitudinal axis within a washing machine, the method determining the unbalanced load of the laundry received by the drum, and moving a balancing weight in a direction between the lateral surface and the longitudinal axis of the drum.

Claims

1. A washing machine (1) comprising; a cabinet (4); a drum (2) for receiving laundry from its open end, wherein the drum (2) is rotatable around its longitudinal axis (8) within the cabinet (4), a balancer (5) comprising a mass channel (3) and a balancing weight (6), wherein the mass channel (3) at least extends in a direction from the lateral surface of the drum (2) to the inside of the drum (2) and receives the balancing weight (6), and the balancing weight (6) is movable within the mass channel (3) along the direction of the extension of the mass channel (3).

2. The washing machine according to claim 1, wherein the washing machine (1) comprises a sensory circuit for determining the unbalanced load of the laundry received within the drum (2); and a positioner for changing the position of the balancing weight (6) within the mass channel (3) from a first distance perpendicular to the longitudinal axis (8) of the drum (2) to a second distance perpendicular to the longitudinal axis (8) of the drum (2), in response to the determination of the unbalanced load determined by the sensory circuit.

3. The washing machine according to claim 1, wherein the balancing weight (6) comprises a ferrimagnetic material and the positioner (7) comprises a magnet (M1, M2, M3, M4) for changing the position of the balancing weight (6) within the mass channel (3).

4. The washing machine according to claim 3, wherein the positioner (7) comprises means for turning the magnet (M1, M2, M3, M4) for changing the position of the balancing weight (6) within the mass channel (3).

5. The washing machine according to claim 3, wherein the magnet (M1, M2, M3, M4) is an electromagnet.

6. The washing machine according to claim 2, wherein the sensory circuit is arranged to take a first balance measurement when the balancing weight (6) is at the first distance from the longitudinal axis (8) of the drum (2) and take a second balance measurement when the balancing weight (6) is at the second distance from the longitudinal axis (8) of the drum (2).

7. The washing machine according to claim 6, wherein the positioner (7) is adapted to move the balancing weight (6) to a distance from the longitudinal axis (8) of the drum (2), where the taken balance measurement is higher.

8. The washing machine according to claim 1, wherein the washing machine (1) comprises a plurality of the balancers (5).

9. The washing machine according to claim 8, wherein at least two balancers (5) are located at two different distances along the longitudinal axis (8) from the open end of the drum (2).

10. The washing machine according to claim 8, wherein the balancers (5) are located, such that the angular distances between the balancers (5) with respect to the longitudinal axis (8) of the drum (2) are equal.

11. The washing machine according to claim 8, wherein the balancers (5) are located such that the angular distances between the balancers (5) with respect to the longitudinal axis (8) of the drum (2) is 90°.

12. The washing machine according to claim 1, wherein the mass channel (3) extends into the drum (2) in a direction between the lateral surface and the longitudinal axis (8) of the drum (2) perpendicularly.

13. A method of increasing the balance of a drum (2) rotating along its longitudinal axis (8) within a washing machine (1), the method comprising determining the unbalanced load of the laundry received by the drum (2); and moving a balancing weight (5) in a direction between the lateral surface and the longitudinal axis (8) of the drum (2).

14. The method of increasing the balance of a drum according to claim 13, wherein determining a position of the unbalanced load of the laundry received within the drum (2) comprises taking a first balance measurement when the balancing weight (6) is at a first distance from the longitudinal axis (8) of the drum (2), taking a second balance measurement when the balancing weight (6) is at a second distance from the longitudinal axis (8) of the drum (2) and comparing the first balance measurement and the second balance measurement.

15. The method of increasing the balance of a drum according to claim 14, wherein the method comprises moving the balancing weight (6) in a direction between the lateral surface and the longitudinal axis (8) of the drum (2) to where the balance measurement is higher.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present disclosure will be more readily appreciated by reference to the following detailed description when being considered in connection with the accompanying drawings in which:

[0047] FIG. 1 is a schematic view of a washing machine with clothes at one point of time;

[0048] FIGS. 2a to 2d are schematic views of the drum of an embodiment of the washing machine according to the invention at four different positions during drum rotation;

[0049] FIG. 3 is a schematic view of the drum of embodiment the washing machine according to FIG. 2 with positioners;

[0050] FIG. 4 is a schematic sectional view of one embodiment of a balancer; and

[0051] FIG. 5 is a schematic sectional view of another embodiment of a balancer.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0052] In the following, the invention will be explained in more detail with reference to the accompanying figures. In the Figures, like elements are denoted by identical reference numerals and repeated description thereof may be omitted in order to avoid redundancies.

[0053] In FIG. 1

[0054] It will be obvious for a person skilled in the art that these embodiments and items only depict examples of a plurality of possibilities. Hence, the embodiments shown here should not be understood to form a limitation of these features and configurations. Any possible combination and configuration of the described features can be chosen according to the scope of the invention.

[0055] FIG. 1 shows an embodiment of a washing machine 1. The washing machine 1 comprises a cabinet 4 with a front opening. Inside of the cabinet 4 a drum 2 is received. The drum 2 is rotatable around its longitudinal axis 8. The drum 2 has an open end, which faces the opening of the cabinet 4. In FIG. 1 laundry is schematically shown inside the drum 2. The laundry is shown at two locations. In particular, one portion of the laundry L1 is at the bottom of the inside of the drum 2 and the other portion L2 is at the top of the inside of the drum 2. Such distribution of the laundry can occurs during rotation of the drum 2, in particular during high-speed spinning.

[0056] FIGS. 2a to 2d show the distribution of the laundry at different rotation states of the drum 2. In particular, FIG. 2b shows the distribution of the portions of laundry L1 and L2 after rotation of the drum 2 by 90° starting from the state of FIG. 2a. FIGS. 2c and 2d show the state at further rotation by 90°.

[0057] In each state shown in FIG. 2, the portions of load L1 and L2 create pressure to the inside of the drum 2 and created centrifugal force are different at different times during drum rotation.

[0058] At a time t, the larger portion of load L1, which may for example have a weight of 4 kg creates a centrifugal force X and the smaller portion of load L2, which can for example have a weight of 3 kg creates a centrifugal force Y. Any difference between the centrifugal forces X and X causes unbalance.

[0059] In FIG. 2 groups 50 of balancers 5 are provided at the drum 2. In particular, at the top and bottom of the drum 2 a group 50 of three balancers is provided, respectively. At the sides of drum 2 a group 50 of two balancers 5 is provided respectively. In FIG. 2 only the balancing weights of the balancers 5 are shown.

[0060] As can be derived from FIG. 2, the balancing weights of the group 50 of balancers 5 at the location, where no portion of the laundry is present, are in an initial state. In the depicted embodiment, in this initial state the balancing weights are positioned such that they extend over the circumference of the drum inwardly and outwardly to the same amount.

[0061] The balancing weights of the group 50 of balancers 5 at the location of the larger portion of load L1 are moved from such an initial state inwardly into the drum 2. Thereby, the distance between the longitudinal axis 8 of the drum 2 and the balancing weight of each of the balancers 5 of the group 50 is smaller than in an initial state. The balancing weights of the group 50 of balancers 5 at the location of the larger portion of load L2 are moved outwardly from the circumference of the drum 2. Thereby, the distance between the longitudinal axis 8 of the drum 2 and the balancing weight of each of the balancers 5 of the group 50 is larger than in an initial state. Thereby, the centrifugal force which is generated at the position of the smaller portion L2 is increased, whereas the centrifugal force which is generated at the position of the larger portion L1 is decreased and the imbalance is decreased and preferably removed.

[0062] In FIG. 3 the drum 2 of an embodiment of the washing machine of the present invention is shown with positioners 7. In this embodiment, four groups 50 of balancers 5 are provided on the circumference of the drum 2. As in FIG. 2, also in FIG. 3 only the balancing weights of the balancers 5 are shown. Each group 50 of balancers 5 has two balancers 5. The groups 50 of balancers 5 are provided at an angular distance with respect to the longitudinal axis 8 of the drum 2 of 90°. The balancing weights of the balancers 5 are magnetic. Preferably the balancing weights consist of ferrimagnetic material.

[0063] In the embodiment shown in FIG. 3, four positioners 7 are provided. The positioners 7 are magnets M1, M2, M3, M4. The magnets M1, M2, M3, M4 can be permanent magnets or electromagnets. The positioners 7 can be mounted to the cabinet 4 (see FIG. 1) of the washing machine 1. The positioners 7 can be stationary with respect to the drum 2. In particular, the positioners do not rotate around the longitudinal axis 8 of the drum 2. In the depicted embodiment, the positioners 7 can, however, be turned about an axis so that different sides of the positioner 7 can be facing the outside of the drum and thus the balancers 5 at different times. This is schematically shown in FIG. 3 by the curved arrows. The movement of the positioners 7, in particular the turning of flipping over of the positioners 7, can be controlled by a control unit (not shown) which can be the control unit of the washing machine 1 or a separate control unit. In particular, the control unit is a microcontroller unit, MCU.

[0064] At the beginning of a wash cycle or spinning cycle, the control unit does not know, that the portion of the load L2 at the bottom of the inside of the drum 2 is larger than the portion of the load L4 at the top of the inside of the drum 2. The control unit may therefore assume any point of the drum 2 or the respective weight acting on that point to cause unbalance. The control unit can then activate the positioner 7 at that assumed point or close to that assumed point. In particular, the respective magnet M1, M2, M3, M4 is turned to either attract or repel the balancing weight of the balancer 5. The balance of the drum is measured until the sensory circuit detects the highest balance measurement, i.e. lowest unbalance measurement. Instead of assuming a point, where the load which causes the unbalance is located, the control unit may also sequentially change the position of each balancer or group of balancers 5 to determine the appropriate adjustment of the balancing weights for compensating imbalance.

[0065] For example, the method can carried out in such a way, that only the balancing weight of the balancers 5 where the portion of load L1 has accumulated, is moved in and out by means of turning magnet M1 and the other magnets M2, M3, M4 remain in an initial position. The control unit in this embodiment can measure the unbalance of the drum at the position of the balancing weight of the balancer 5 close to magnet M1 being moved out and at a position of the balancing weight of the balancer 5 close to magnet M1 being moved into the drum. The setting of the magnet M1 which provides the highest balance measurement, can then be used for subsequent spinning. The same measurement can be carried out for the other portions of load L2, L3 and L4 and the respective setting of the magnets M2, M3 and M4 can be determined.

[0066] Another embodiment of the method according to the invention will now be described with reference to FIG. 3. At an initial state all magnets M1, M2, M3, M4 are arranged such that the same side is facing the circumference of the drum 2. For example all magnets are turned such that their repelling side is facing the drum 2 and thus the balancers 5. The control unit measures the unbalance of the drum 2 at that state. The rotational speed of the drum 2 may for example be 60 rpm (rotation per minute). This means that the drum 2 rotates one round per 1 second. Since four magnets M1, M2, M3, M4 are provided, the portions of load L1, L2, L3, L4 inside the drum pass a magnet every 0.25 seconds.

[0067] At the beginning, the control unit for example assumes that the portion of load L3 shown on the right side of the drum 2 in FIG. 3 cause unbalance. At that stage, the magnets M2 and M4 may remain in a position, where the attracting side faces the drum 2. Magnet M1 is rotated so that its repelling side faces the drum 2 to decrease centrifugal force of unbalanced load and magnet M3 remains in the position, where the attracting side faces the drum 2 to decrease centrifugal force of unbalance. Every 0.25 seconds the unbalance load changes its position and the magnets M1, M2, M3, M4 rotate accordingly. During this process the control unit measures the unbalance.

[0068] The control unit repeats the steps mentioned above, but every time the control unit assumes a different portion of load L1, L2, L3, L4 to cause the unbalance, adjusts the orientation of the magnets M1, M2, M3, M4 accordingly and the control unit measures unbalance.

[0069] After the above steps, the control unit determines which portion of load L1, L2, L3, L4 causes unbalance. The spinning process is then continued with the magnets M1, M2, M3, M4 being adjusted to compensate the unbalance depending on that determination.

[0070] In FIGS. 4 and 5 embodiments of balancers 5 according to the invention are shown. In the embodiment of FIG. 4, the balancer 5 has a mass channel 3 which is open at its ends. The balancing weight 6 has an oblong shape and may be a rod. The length of the balancing weight 6 is longer than the length of the mass channel 3. In this embodiment the balancing weight 6 has an enlarged diameter at its longitudinal ends to prevent the balancing weight 6 from escaping the mass channel 3. In the embodiment of FIG. 5, the mass channel 3 is closed at both ends and the balancing weight 6 is received in the mass channel 3. The balancing weight 6 has a shorter length than the mass channel 3, so that the balancing weight 6 can move within the mass channel 3.

[0071] The position of the balancer 5 can be such that the mass channel 3 extends through the lateral surface of the drum 2 (see FIG. 4) or that the mass channel 3 is attached to the inside of the lateral surface of the drum 2 (see FIG. 5).

[0072] The principle of the invention is to create balanced opposite side of unbalanced load to absorb unbalance and to reduce centrifugal force of unbalance load.

[0073] During the spinning phase of a washing machine, the drum turns with high speed so that clothes can create pressure on the inner surface of the drum due to centrifugal force. This pressure force of clothes cause unbalance. With the present invention, a force can be created at the opposite side of drum to the point where the centrifugal force due to the clothes acts. This force can absorb the force generated by the clothes and can thus reduce unbalance.

[0074] During spinning cycle clothes expand inside the drum randomly and aimlessly. Some clothes accumulate at any point of the drum more than at other point and this unbalanced distribution creates pressure on this point and at the opposite side of this point clothes may also come together. If the portions of laundry or amount of clothes that accumulate at opposite sides of any point are the same, these loads absorb each other. However, if not the same amounts of load accumulates on opposite points, there is more pressure on the point which clothes amount to more than at the opposite side.

[0075] According to one embodiment of the invention, at least one balancer, which can also be referred to as a moving pin, is provided at the drum of the washing machine. This balancer can be moved from the inside to the outside of the drum and vice versa. This movement can be controlled by a micro controller. If there is less load on one side of the drum than on the opposite side of any point, the pin(s) move outside of the drum at this point which has less load located and the pin(s) move inside of the drum on the opposite side of the point which has less load located.

LIST OF REFERENCE NUMERALS

[0076] 1 washing machine [0077] 2 drum [0078] 3 mass channel [0079] 4 cabinet [0080] 5 balancer [0081] 50 group of balancers [0082] 6 balancing weight [0083] 7 positioner [0084] 8 longitudinal axis [0085] M1 magnet [0086] M2 magnet [0087] M3 magnet [0088] M4 magnet [0089] L1 portion of load of laundry [0090] L2 portion of load of laundry [0091] L3 portion of load of laundry [0092] L4 portion of load of laundry