WO2007138333A1 - Dishwasher - Google Patents

Abstract

A dishwasher (1) has a compartment (13; 14) which can be divided into wet and dry sections by a movable separator (19; 19'). The position of the separator is detected, and when a wash cycle is commenced, water is supplied only to the wet section, which contains items to be washed. Water is supplied through multiple rotary water jets (17) distributed in the compartment, and in the wash cycle only those in the wet section are activated. In some arrangements an effective seal is provided between the sections so that items can be stored in the dry section.

Description

Dishwasher

This invention relates to a dishwasher.

In a conventional dishwasher, dirty tableware, cooking pans, cutlery and so forth are put into a chamber which is sealed by closing a door. Hot water is then sprayed at the articles to clean them. Some dishwashers also include a drying cycles, but in any event the items are usually loaded onto racks and dry relatively quickly.

A problem with conventional dishwashers is that users prefer to wait until they are full, or nearly full before operating them, to save wastage of water, energy, detergent and so forth. If the dishwasher is used by a person living alone, or in a household where people often eat out, it can take several days before the dishwasher is full.

This can lead to offensive smells, to food being encrusted on dishes, problems with hygiene and so forth. In any event, loads in a dishwasher can vary considerably, depending on whether a person is eating alone, or is giving a dinner party, for example.

In WO-A-OO 16681 there is disclosed a double dishwasher having two separate compartments, one larger than the other, which can be operated independently. A user can choose which compartment to use, the lower or the upper. In use, items to be washed are placed in the lower compartment, and while those dishes are being washed, additional dirty dishes or items can be placed in the upper compartment. Because the upper compartment is of a smaller size, smaller batches of items to be washed can be placed in the upper compartment, thereby adding to the efficiency of the washing machine and minimizing the amount of water and energy needed to wash a small batch of dishes.

A problem with this arrangement is its lack of versatility. The two compartments are of a fixed size, and the size of article that can be washed is restricted by the dimensions of the larger compartment. The two compartments cannot be combined to make one large compartment.

According to the present invention, there is provided a dishwasher comprising a compartment, means for providing access to the compartment, and means for supplying water into the compartment to wash items therein, characterised in that a movable separator is provided for dividing the compartment into two sections, and in that means are provided for selecting which of the sections is to receive the supplied water.

Thus, in a simple arrangement a separator can divide the compartment into two halves. When a small load is to be washed, dishes are placed in one half only and water is supplied to that half only. On the other hand, if a large load is to be washed, the separator can be removed to create one large area to which water is supplied. Removing the separator means that the size of item that can be washed is not limited to the size of article that can be fitted into half of the compartment, and this can be of use in the case of, for example, saucepans with long handles, large oven dishes and so forth.

The arrangement in accordance with the invention can also be used to solve another problem. With conventional dishwashers, once a load has been washed, it is necessary to remove it before a following load is washed. There is no point in washing clean dishes, and excessive washing can affect the surface finish of items. It is also desirable to remove clean items from the dishwasher before dirty items are placed in it, to avoid contamination of the clean items. It is therefore impractical to use a dishwasher as a storage space for clean dishes and so forth. In cramped conditions, such as in a small apartment, storage space can be at a premium.

Using an arrangement in accordance with the invention, initially dirty dishes could be placed in a first section, and a washing cycle instigated in which water is supplied only to that section. After the washing cycles the dishes can be allowed to drain and dry. They can then be left in the first section. A subsequent batch of dirty dishes can then be placed in the second section, and a washing cycle instigated in which water is supplied only to that section. The dishes in the first section can be left in place during this second washing cycle and will not become wet because the separator prevents water supplied to the second section from reaching them.

When a dishwasher in accordance with the invention is not intended to be used for dry storage of items whilst other items are to be washed, there is generally no need for the two sections to be completely sealed from each other. Even if not providing a complete seal against water and steam, the separator will define a space in which water is supplied to wash items. If some of that water escapes to the other section, it need not have a significant effect on the efficiency of washing the items.

If one section is to be used for dry storage of items, then preferably the arrangement is such that the two sections are sealed from each other substantially completely, for example hermetically, so that no fluid will pass from one section to another.

However, it may be acceptable for there to be isolation against direct water , whilst some steam may pass from one section into another. The dishes in the "dry" section would soon dry from the effects of such steam.

In any event, in some preferred arrangements the separator has a seal extending around or adjacent all or part of its periphery, to seal against compartment portions when it is in use.

The separator is movable. In a simple embodiment, there could be a defined position for the separator, dividing the compartment into two sections - although these need not be of equal sizes. Effectively there would be two states. Either the separator is in place and the compartment has the two sections of pre-defined size, or the separator is removed to provide the complete compartment. Removal of the separator does not necessarily mean complete removal from the dishwasher, and it may be more convenient to place the separator in an inoperative position within the dishwasher, such as at one end of the compartment. In such systems where the separator is removable,, the dishwasher could incorporate a sensor for detecting whether the - A -

separator is in place or not. If it is not in place, then the wash cycle will preferably select automatically a program in which water is supplied to the whole compartment. If the separator is in place, the sensor will detect it and will supply water only to the section in which items are to be washed. In an arrangement where dry storage of items is not be required, this could always be the same given section, for example the front or rear, or the left or right of the compartment. What the separator varies, is the size of the section in which washing is to take place.

If one section is to be used for dry storage, a system should be provided to offer the user the opportunity of selecting which section is to be wet and which to be dry.

This could, for example, be done by providing a user with an option to select, using a graphic and / or text display to select which section is to be wet and which dry. In an alternative arrangement, the separator can have two orientations, one of which will make the first section wet, and the other of which will make the second section wet. For example, the separator could have "DRY" written on one side and "WET" on the other, and the user would position the separator so that the appropriate section is wet. The sensor arrangement detecting the separator, would ascertain which way round it is and cause an appropriate dishwashing program in what water is supplied only to the wet section.

The arrangement could be such that the sections have separate detergent supply means, or there could be a common detergent source, which is operated to supply one or both sections as appropriate depending on whether the separator is in place or not. In one preferred embodiment, there is a central store of detergent and a control system mixes this into water being supplied to whichever section is to be used for washing. The supply should be capable of lasting for a number of wash cycles. In the same manner, a rinse aid store could be provided, the rinse aid being mixed into rinse water being supplied to the section which is undergoing a wash cycle.

In a preferred arrangement, the separator may occupy one of a number of different positions, so that the compartment can be divided into sections of different sizes. For example, if the compartment has a rear and a front, the separator can be moved from a rearmost position at which the rear section is at a minimum (and even nonexistent) to a front position at which the front section is at a minimum (and even non-existent), hi between, a position of the separator may define sections of substantially the same size, and other positions may define sections of different sizes. Thus the ratio of for example rear section to front section size could vary from 1 :0 to 1 : 1 to 0: 1 , with intermediate positions of 1 :3 and 3:1. More intermediate positions could be provided, and indeed the position of the separator could be infinitely variable.

In an arrangement in which the or each separator may occupy a number of possible positions, sensors are preferably provided to identify the position of the separator, and if appropriate which side is to be wet and which side dry. The sensors could be at discrete positions if the separator has predefined positions, or could be continuous if the separator position is infinitely variable. In one arrangement, the separator man be slide longitudinally to a desired position, and is connected to a continuous belt. A sensor detects the position of the belt, and thus the position of the separator, hi one arrangement, the output of the sensor is used to control a valve which directs water to the appropriate section. The valve may also serve to mix detergent or rinse aid into the water. In an alternative arrangement, the belt drives a pulley connected directly to the valve, the orientation of the pulley determining which outputs are supplied with water.

A sensor could comprise a simple mechanical interlock so that when the separator is in a particular place it operates a valve, for example, to control water flow.

Movement of the separator could be by sliding as noted above, in which case it may be necessary to pivot the separator to enable this, thus avoiding the obstruction of a plate rack or the like. The separator may be at least partially flexible to assist in pivoting. In one possible arrangement the sensor could be mounted for pivoting about two perpendicular axes, so that it can first be tilted to a horizontal plane, and then pivoted into an upright plane. It could then be pivoted about an upright axis before sliding. The separator could me movable in other was. For example, it could simply be removable or replaceable as mentioned earlier. It could be in the form of a screen that is located in a chosen position and can be erected, for example being unwound from a rolled up condition, or collapsed such as by being allowed to roll up again. This could be under the influence of a spring or the like.

The separator could be held in place by mechanical interengagement of parts or for example by a magnetic latch. Preferably, sealing means are provided on the separator and / or compartment wall portions to ensure that there can be an appropriate seal between the sections.

The sections may be defined in a front / rear direction, or a side to side direction.

The compartment may be a single space, or be part of a larger space defining a plurality of compartments. Thus, for example, a dividing wall could be provided which splits the overall space into two compartments. The use of two separators would then provide four sections. In general separators and dividing walls may be used to define any number of desired sections. Removal of all separators and dividing walls would give access to the entire compartment space for washing bulky items, for example.

It would be possible to have two completely separate compartments, such an upper and lower compartment. This could be separated by a fixed wall, or for example a removable base for the upper compartment (and/or roof for the lower compartment) to provide access to the entire space.

In general, compartments may be in form of drawers which define spaces to receive items to be washed, rather than there being open racks of the type found in a conventional dishwasher. This is to facilitate positioning of the separator. However, if for example a separator can only be in one position or removed completely, then the compartment could have two separate rack portions, between which the separator can be inserted. The drawers should be arranged so that water can flow out, and the base and optionally sidewalls could, for example be perforated. The arrangement must be such that water does not pass into the "dry" sections, if the dishwasher is intended for use as dry storage.

It is necessary for water to be supplied only to the section or sections designated for washing. Preferably, there is provided a plurality of water supply means which between them can spray water into all regions of the compartment, and which can be controlled individually or in groups so that only the or each section designated as wet is provided with water. Thus, a number of water jets could be provided.

Preferably, these are rotating jets - for example being in the form of auto spinners - which distribute the water in multiple directions to provide effective cleaning of dishes in the section in which they are situated.

Mechanical interlocks or simple electronic logic can control which jets are to be active given the requirement for a particular section (or sections) to be wet.

Water jets could be provided on the base and/or top and/or wall of the compartment, as required to provide effective washing.

It will be appreciated that the ability to control which regions of a dishwasher are provided with water is advantageous even is there is no divider system. Such an arrangement could not be used to keep dry items isolated in the dishwasher, but although it would not be as efficient for washing as using the a separator to define an enclosed washing space, it would assist in conserving water. Thus, if dishes are placed in one region only, that area alone may be provided with water. Thus, the user may select the area concerned, or there could be automatic detection of which area contains dishes, for example using optical or other sensors.

Thus viewed from another aspect, the present invention provides a dishwasher comprising a compartment, means for providing access to the compartment, and means for supplying water into the compartment to wash items therein, characterised in that there are provided a plurality of water outlets in the compartment which are arranged to provide water to different sections of the compartment, and in that means are provided for selecting which of the water outlets is operative during washing of items in the compartment, to as to control the section or sections of the compartment to which water is supplied.

It will be appreciated that references to "water" include water containing detergent, softening agents, rinse aids and so forth and are not limited to pure water.

The invention also extends to a method of operating a dishwasher constructed in accordance with the above principles.

Some embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

Figure 1 is an exploded view of a dishwasher in accordance with the invention;

Figure 2 is a schematic front view of the dishwasher;

Figure 3 is a schematic plan view of a drawer of the dishwasher showing one arrangement of components;

Figure 4 is a schematic plan view of the drawer of the dishwasher showing another arrangement of components;

Figure 5 is a schematic plan view of an alternative drawer of a dishwasher in accordance with the invention;

Figure 6 is a diagram showing how a separator can be manipulated for movement;

Figure 7 is a diagram showing one arrangement for controlling the water supply in accordance with the separator position; Figure 8 is a diagram showing another arrangement for controlling the water supply in accordance with the separator position;

Figure 9 is a schematic front view of an alternative dishwasher in accordance with the invention;

Figure 10 is a schematic front view of a second alternative dishwasher in accordance with the invention; and

Figure 11 is a schematic front view of a modification of the dishwasher of Figures 1 and 2.

Referring now to the drawings in detail, Figure 1 shows a dishwasher 1 in exploded form. The dishwasher comprises a support 2 with a base 3 and an upwardly extending rear 4. On the base 3 is mounted a first housing 5. On top of this is provided a second housing 6. Housings 5 and 6 are adapted to receive drawers, drawer 7 for housing 6 being shown in exploded form. Above housing 6 is provided a module 8 which contains a control and display unit 8'.

The drawer 7 comprises an upper frame 9, provided with a front panel 10 which is held in place by a lower frame part 11. The upper frame 9 includes a central member 12 which divides the frame into left and right parts provided with means respectively defining a left compartment 13 and a right compartment 14 which are isolated from each other in watertight fashion. The components of the means forming the right hand compartment will be described in detail, the other means corresponding. There is a base tray 15 which catches water that has been sprayed into the compartment, and channels it to a waste outlet and / or re-circulating pump, above which is a tray 16. This is provided with a number of auto rotary water jets 17 which are arranged at intervals across the floor of the tray 16, covering the entire compartment. A wall forming member 18 is provided. In conjunction with front panel 10 and the trays 15 and 16, this member 18 defines an open topped compartment into which dishes can be placed for washing. A removable rack 28 is placed in the compartment to receive the dishes.

A divider, or separator, 19 is provided for splitting the compartment 14 into front and rear sections of varying sizes according to its position, the divider being provided with a magnet so that it can be held in place. A sensor 20 is provided for detecting the position of the divider 19. Depending on which section is to be wet and which dry, in operation water will be supplied only to the jets 17 which are in the wet section. In this embodiment the separator is rigid and is preferably provided with seals extending around, or adjacent, portions of its periphery.

The left hand compartment 13 is of corresponding construction. There is a corresponding bottom drawer 21 for the first housing 5, as shown in Figure 2. Both drawers 7 and 21 are provided with handles 22 and 23 respectively.

Figure 3 shows the top drawer 7 in an open condition. Divider 19 is provided for the right hand compartment 14, and divider 19' for the left hand compartment 13. Four water jets 17 are provided spaced along each compartment. In the configuration shown, the left hand compartment 13 is divided into equal parts, with two jets in each, whilst the right hand compartment 14 is divided into a small front part with one jet, and a larger rear part with three jets 17. The front parts could, for example, contain clean dishes to be kept dry, whilst the rear section parts contain dishes to be washed. Figure 4 shows how the separator 19 in the right hand compartment has been moved, to provide a large front part containing washed dishes, that are to be kept dry, and a small rear part.

In this arrangement there are two drawers, 7 and 21, each of which is divided into left and right parts, and each part being provided with a divider 19 to separate it into front and rear sections. There is a total of eight sections, each of which can be controlled independently so as to be wet or dry. A typical cycle of use of a drawer such as 7 or 21 will be as follows.. Before a meal, the dividers in both the left and right compartments are at their front positions, so that effectively there is one large section in each compartment. These contain dry dishes ready for use. During the meal, some dishes have been taken from the front of each compartment. After the meal, the dividers are moved to divide each compartment into a relatively small front section and a relatively large rear section which contains the dry and unused dishes. The dirty dishes are then placed in the front section.

During the day, further items can be taken from the rear sections, and after use the dividers moved if necessary so that the dirty items can be placed in the front sections.

When it is divided to commence a washing cycle, the supply of water is controlled so that only the water jets in the front sections are operated, the clean dishes in the rear sections being untouched. Of course, it would be possible to use all of the dishes before starting the wash cycle, in which case the dividers would be fully at the rear and the whole of each compartment would be used for washing. Furthermore, all or a section of one compartment could be put through a washing cycle, whilst the other compartment remains dry.

Figure 5 shows an alternative drawer 24, with one large section and a single divider 25 which can be moved from left to right instead of from front to rear.

The divider 19 may consist of a relatively rigid upper cross bar, for example of a plastics material, and a more flexible portion which provides the main barrier between sections of the drawer, for example of a rubber material. In some preferred arrangements, the divider is pivotally mounted to e.g. a belt, so that it can be pivoted clear of a dish rack or the like in the drawer and slid to a new position. Having a flexible main portion facilitates such pivoting of the divider. However, pivoting would also be possible with a rigid divider, by going through the steps shown in Figures 6 (a) to (d). In Figure 6 (a) there is shown diagrammatically a divider 19 which is to be moved longitudinally with respect to central member 12. The divider if firstly tilted about axis X, to the position shown in Figure 6 (b). It is then pivoted about axis Y, to the position shown in Figure 6 (c). Finally it is rotated about axis z to the position shown in Figure 6 (d) so that it can be slid with respect to central member 12. When the divider is in the appropriate position, the reverse process will move the divider to its operative position, separating the wet and dry compartments. As noted above, if the main part of the divider 19 is flexible, then it will be possible to pivot the divider directly from the position of Figure 6 (a) to the position of Figure 6 (d).

Figure 7 shows a divider 19 connected to an endless belt, cord or the like 26 which passes round pulleys 27 and 28. The sensor 20 cooperates with the belt 26 to determine its position and thus the position of the divider 19. The sensor signals are fed to a control unit 29 which controls an electric motor 30 to adjust the position of a valve 31. The valve 31 receives feed 33 of water, feed 34 of detergent and feed 25 of rinse aid, and directs the appropriate liquid to selected outlets 32 connected to the jets 17. Alternatively, the detergent and rinse aid could be mixed into the water, when required, at a previous location.

Figure 8 shows an alternative arrangement in which the divider 19 is connected to a belt 26' passing over pulleys 36 and 37. The belt is diverted by pulleys 38 and 39 to rotate a pulley 40 which is connected to an alternative valve 41. The angular position of the valve directly controls which outlets are supplied, this taking the place of the motor 30.

In any event, if there are sections in a drawer which may be either wet or dry, it is not sufficient for the system to know where the divider is. It must also know which side is to be wet, and which dry. This can be achieved by user intervention to specify which is dry and which wet, using control panel 8'. In alternative arrangements, one side is always dry and one wet, and only the size changes. The size of the wet section can be used to determine not only which water jets are to be used, but also the quantity of detergent to be mixed in and, if used, the quantity of rinse aid. Control of the system, which can include one or more pumps, valves, reservoirs, sensors and the like, can be effected by suitably programmed data processing means which can also handle other aspects such as temperature, the type of dishwashing cycle and so forth.

In preferred arrangements in accordance with the invention, construction can be simpler and sealing maintained, if the drawers do not open at the front so that a rack can be slid out. Preferably the drawers slide out themselves, and a rack will be inserted from above.

When the dishwasher is to be used for dry storage, sections of the compartment need to be sealed hermetically, or to such extent as will prevent items to be kept dry, becoming wet. If the dishwasher is not to be used for dry storage, such a level of sealing between the divider and portions of the compartment is not necessary.

In preferred embodiments a distributor supplies water to water jets, so as to target the right area. In preferred embodiments where a section can be either wet or dry, it will not be applicable to have detergent and, if used, rinse aid associated with a compartment as such, as in conventional dishwashers. Instead, introduction of detergent is handled elsewhere.

Figure 9 shows a dishwasher 42 in accordance with the invention, with two narrow drawers 42 and 43 in an upper and lower layout. Figure 10 shows a dishwasher 45 in accordance with the invention, with a single wide drawer 46. Figure 11 shows a dishwasher 47 substantially in accordance with Figures 1 and 2, with upper and lower drawers 48 and 49 identical to drawers 7 and 21. However, a lower module 50 is also provided, this being provided with stores 51 and 52 for detergent and rinse aid as desired. The stores are big enough to cover a number of dishwashing cycles, typically twenty or more. A control system will determine the amount of detergent supplied for a given was cycle, depending on the size of the compartment(s) in which washing is to take place, as well as optionally user input to determine the type of wash cycle, from a detergent free wash to a wash for heavily soiled items.

The lower module may also include a fan to draw hot air and steam out of the compartments, although this could also be positioned elsewhere.

In embodiments of components typically used to protect from heat can be replaced by e.g. silicone so as to improve sealing. Silicone skins can be applied to the, outside of each compartment.

As a consequence of constructing the dishwasher in a modular form, with one or more separate drawers, it is easier to build a range of products of different sizes.

The components of the dishwasher can be made from suitable materials such as injected plastics, pressed inox or, particularly for the front panel, glass.

Thus, at least in the preferred embodiments there is provided a dishwasher having a compartment which can be divided into two sections by a movable separator. The position of the separator is detected, and when a wash cycle is commenced, water is supplied only to the wet section, which contains items to be washed. Water is supplied through multiple rotary water jets distributed across the compartment, and in the wash cycle only those in the wet section are activated. In some preferred embodiments, one of the sections can be kept substantially dry so that previously washed items can be stored whilst other items are washed.

Claims

1. A dishwasher comprising a compartment, means for providing access to the compartment, and means for supplying water into the compartment to wash items therein, characterised in that a movable separator is provided for dividing the compartment into two sections, and in that means are provided for selecting which of the sections is to receive the supplied water.

2. A dishwasher as claimed in claim 1 , wherein the separator is moveable and may occupy one of a number of different positions, so that the compartment can be divided into sections of different sizes.

3. A dishwasher as claimed in claim 2, wherein means are provided for detecting the position of the separator.

4. A dishwasher as claimed in claim 1 , 2 or 3, wherein a number of water outlets are provided, distributed across the compartment, and means are provided for selecting which of the outlets is to be operative so that water is supplied only to, the section which has been selected to receive water.

5. A dishwasher as claimed in claim 4, wherein the water outlets are individual auto rotating water jets.

6. A dishwasher as claimed in claim 2 or 3, wherein a control device controls the amount of detergent supplied to the section which is to be supplied with water, in dependence of the size of that section.

7. A dishwasher as claimed in any preceding claim, wherein a central supply for detergent is provided and the detergent is fed to whichever section is to be supplied with water.

8. A dishwasher as claimed in claim 7, wherein means are provided for mixing the detergent into water, and a distributor controls the section to which the water and detergent are supplied.

9. A dishwasher as claimed in any preceding claim, comprising a drawer divided into a plurality of said compartments, each provided with a separator.

10. A dishwasher as claimed in any of claims 1 to 8, comprising a plurality of drawers each defining a said compartment.

11. A dishwasher as claimed in claim 10, wherein at least one drawer is divided into a plurality of said compartments, each provided with a separator.

12. A dishwasher as claimed in any preceding claim, wherein the separator provides a substantial barrier to the passage of water between the two sections.

13. A dishwasher as claimed in claim 12, wherein the separator provides a seal between the two sections so that one section can be used for dry storage of items whilst the other is used for washing items.

14. A method of operating a dishwasher in accordance with claim 13, wherein items which are not to be washed are positioned in a first section on one side of the separator, items to be washed are positioned in a second section on the other side of the separator, and a wash cycle is carried in respect of the second section but not in respect of the first section.

15. A dishwasher comprising a compartment, means for providing access to the compartment, and means for supplying water into the compartment to wash items therein, characterised in that there are provided a plurality of water outlets in the compartment which are arranged to provide water to different sections of the compartment, and in that means are provided for selecting which of the water outlets is operative during washing of items in the compartment, so as to control the section or sections of the compartment to which water is supplied.