Patent Publication Number: US-11390981-B2

Title: Dosing device and system

Description:
The present invention relates to a dosing device or system. The invention especially relates to a dosing device or system for reliably dispensing tablets of active ingredient into an automatic washing machine, such as a dishwasher or a laundry washing machine, multiple times over multiple washing cycles. 
     BACKGROUND RELATING TO THE PRIOR ART 
     Most commercially available domestic dishwashers have a detergent dispenser which the consumer loads with a single dose of detergent before each wash program. However, a developing area of interest in this field has been the provision of a means to store multiple doses of detergent and deliver them automatically during each successive wash program. 
     Devices that have been previously disclosed in this area generally fall into the categories of “machine-independent” or “machine-dependent”. Machine-independent devices are ones which are not physically connected to the dishwasher&#39;s electronics or powered directly by its power source. They can be freely positioned inside the dishwasher, for instance in the rack, so they are not particularly limited by spatial constraints in their design. On the other hand, in order to trigger a dosing step at the appropriate time, they should be designed to respond to sensed parameters of the wash, such as heat, turbidity, etc., which does not always provide a very accurate control mechanism. Conversely, machine-dependent devices are generally connectable to the dishwasher in a predetermined location, and can take their control signals and power from the dishwasher itself. This can lead to more accurate control of when dosing takes place, but brings its own constraints on device design. For instance, a convenient, accessible location to connect such a device is in the door of the dishwasher, but there is limited space in this area, so more attention should be paid to making this type of device as compact and slim as possible. Such machine-dependent devices are the primary focus of the present inventors. 
     It is known that dosing devices can supply active ingredients to the wash in the form of powders or liquids. However, not all active ingredients can be suitably provided in a liquid composition, whereas powders are liable to suffer from dispensing issues due to moisture intake from the humid washing environment, e.g. swelling or becoming sticky, especially when stored in a container inside an automatic washing machine. It is also known that dosing devices can instead supply tablets to the wash, generally hard tablets formed of compressed powder. The device needs to store multiple tablets and dose one or more individual ones per wash program as required. For effective dosing, it is important to ensure that tablets do not become wedged against each other inside the device. This is a particular challenge for tablets having a flat face, whilst spherical ones can be more difficult to manufacture. 
     An example of a machine-dependent dosing device is disclosed in EP 1,355,561. In this prior art dosing device, there is provided a rotating disc which can control the delivery of spherical or cylindrical tablets from a container into the main wash tank of a dishwasher. The tablets are pre-sorted and pre-orientated into columns inside the container, with curved surfaces of the tablets touching and guides physically separating the tablets in different columns to restrict their movement. This arrangement is bulky and awkward to manufacture. Also it does not solve the issue of tablets becoming stuck in the immediate vicinity of the rotating disc. 
     A further prior art dosing device for a dishwasher is disclosed in EP 1,159,913. The main portion of this dosing device is located outside the dishwasher, free from space constraints, and a long delivery tube feeds the dosed tablets down inside the machine to the bottom of the main tank. The main body of the device accommodates a loose filling of tablets and has a rotating disc to meter tablets into the dishwasher. However, the tablets are preferably fed to the disc from the bulk via a feed chute accommodating a single column of tablets, which in turn is fed by a conveyor device. In this prior art dosing device, the conveyor device aligns the tablets such that they are all fed into the rotating disc in the same orientation. In this way, jams inside the dosing device are reduced. Again though, the presence of the feed chute and the conveyor makes the dosing device bulky, such that it takes up a lot of space inside the dishwasher. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of the present invention, there is provided a dosing device or system for dispensing a plurality of tablets, which each comprise at least one active ingredient for an automatic washing process, into an automatic washing machine, wherein the dosing device or system is for dispensing one or more, but not all, of the plurality of tablets at once into the automatic washing machine, wherein the dosing device or system comprises:
         a container for storing the plurality of tablets, wherein the container comprises an exit port;   an outlet for delivering the one or more tablets from the container into the automatic washing machine; and   a metering mechanism located between the exit port of the container and the outlet, and which is moveable between a first position in which the one or more tablets is receivable from the exit port of the container, and a second position in which the one or more tablets is deliverable to the outlet;   wherein the dosing device or system further comprises an agitation means projecting from the metering mechanism to agitate at least one tablet in the vicinity of the exit port.       

     According to a second aspect of the present invention, there is provided a cartridge comprising one or more dosing devices according to the invention in its first aspect, comprising a plurality of tablets inside the or each container, each tablet comprising at least one active ingredient for an automatic washing process. 
     According to a third aspect of the present invention, there is provided a kit comprising an automatic washing machine and at least one cartridge according to the invention in its second aspect. 
     According to a fourth aspect of the present invention, there is provided a cartridge for use in a dosing system according to the invention in its first aspect, comprising:
         a container, for storing a plurality of tablets which each comprise at least one active ingredient for an automatic washing process, wherein the container comprises an exit port; and   an agitation means;   wherein the cartridge is configured to connect with an automatic washing machine that has a metering mechanism as defined in the invention in its first aspect, in a manner such that the agitation means: engages with or against, and projects from, the metering mechanism; and is operable to agitate at least one tablet in the vicinity of the exit port.       

     According to a fifth aspect of the present invention, there is provided an automatic washing machine comprising a metering mechanism as defined in the invention in its first aspect and an agitation means projecting from the metering mechanism;
         wherein the automatic washing machine is configured to connect with a cartridge that comprises a container as defined in the invention in its first aspect to form a dosing system according to the invention in its first aspect.       

    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1 a    shows a cross-sectional view of a first embodiment of a dosing device according to the invention in a first, closed, position; and 
         FIG. 1 b    shows a cross-sectional view of this dosing device in a second, open, position. 
         FIG. 2 a    shows a perspective view of a second embodiment of a dosing device according to the invention; and 
         FIG. 2 b    shows a schematic cross-sectional view of this dosing device in a first, closed, position; and 
         FIG. 2 c    shows a schematic cross-sectional view of this dosing device in a second, open, position. 
         FIG. 3 a    shows a schematic cross-sectional view of a third embodiment of a dosing device according to the invention in a first, closed, position; and 
         FIG. 3 b    shows a schematic cross-sectional view of this dosing device in a second, open, position. 
         FIG. 4 a    shows a cross-sectional view of a fourth embodiment of a dosing device according to the invention in a first, closed, position; and 
         FIG. 4 b    shows a cross-sectional view of this dosing device in a second, open, position. 
         FIG. 5  shows a cross-sectional view of a fifth embodiment of a dosing device according to the invention. 
         FIG. 6  shows a schematic view of a dosing system according to an embodiment of the invention. 
         FIG. 7  shows a schematic view of a cartridge according to an embodiment of the invention. 
         FIG. 8  shows a schematic view of a dishwasher according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments described herein in relation to one aspect of the invention apply equally to other aspects of the invention unless specified to the contrary or the context otherwise requires. 
     In the present invention, the agitation means projects from the metering mechanism. In an embodiment, the agitation means is integrally formed with the metering mechanism. Alternatively, the agitation means may be a separately formed component from the metering mechanism. It may engage with or against the metering mechanism. In any case, when the metering mechanism causes the agitation means to move, any tablets in the vicinity of the exit port are agitated, which reduces the chance of them becoming wedged against each other or against the sides of the exit port and thereby blocking the exit port. 
     Both the metering mechanism and an integral/non-integral agitation means may be located in a cartridge for connection to an automatic washing machine, or both may be located in an automatic washing machine for connection to a cartridge. Alternatively, when the agitation means is non-integral with the metering mechanism, the agitation means may be located in a cartridge whilst the metering mechanism is located in an automatic washing machine, such that when the cartridge is connected to the automatic washing machine (e.g. via an interface), together they form a system in which the agitation means projects from the metering mechanism. 
     The agitation means may extend around the exit port. By extending around the exit port, the agitation means can therefore inhibit the formation of a bridge of tablets which might form either side of, and over, the exit port. The agitation means may be operable in use to move through the exit port. In this way, the agitation means can effectively agitate any tablet which might otherwise block the inside of the exit port. 
     The agitation means may be rotatable inside the container, and/or moveable linearly inside the container. It may comprise a helically shaped portion which extends into the container. It may comprise a crenelated portion which extends into the container. In this case, the crenelated portion may comprise at least one crenelation which is triangular, or some other geometrical shape e.g. a rectangle or semi-circle. 
     The agitation means may comprise a flexible portion, such that the agitation means is not so rigid that it causes damage and/or a breakup of the tablets when the tablets are agitated. 
     Preferably, a maximum width of the agitation means is no more than four times, more preferably no more than three times, a maximum diameter of the exit port. In this way, the size of the agitation means can be restricted so as to not occupy a large amount of space inside the container. 
     Depending on the design of the dosing device or system, the metering mechanism may be linearly moveable or rotatable between the first position and the second position. The metering mechanism may be both linearly moveable and rotatable between the first position and the second position, for instance in the case of a metering mechanism which moves between the first and second positions by way of a screw thread. 
     Movement of the metering mechanism between its first and second positions may be driven by a motor. 
     The metering mechanism preferably defines at least one cavity in which one or more tablets, preferably only one tablet per cavity, is operable to be held during movement of the metering mechanism from the first position to the second position. 
     In use of the dosing device or system, tablets which are located in the container are preferably fed by gravity towards the metering mechanism. In this way, the need for a separate mechanism to feed tablets inside the container towards the metering mechanism is removed. In an embodiment, the metering mechanism is linearly moveable in a vertical direction in use. In another embodiment, the metering mechanism comprises a rotatable wheel which is preferably vertically oriented in use such that it rotates about a horizontal axis. 
     The metering mechanism may have a sloping surface at an end adjacent the exit port, along which a tablet can slide. 
     The dosing device or system may further comprise a biasing means for biasing the metering mechanism from the second position to the first position. This biasing means helps keep the dosing device or system in a closed position when the device is not carrying out a dispensing step. In this way, the biasing means also helps prevent any moisture which may be present in the air at the outlet (such as moisture deriving from the interior space of the automatic washing machine, or atmospheric moisture during storage) from leaking back into the container, and degrading the tablets located therein. 
     In an embodiment, the dosing device or system further comprises a housing which surrounds the metering mechanism, wherein the housing comprises an inlet opening for receiving at least one tablet from the exit port of the container, and an output opening for delivering the tablet to the outlet. The metering mechanism may be moveable in the housing between the first position in which the tablet of active ingredient is receivable in the inlet opening, and the second position in which the tablet is deliverable to the outlet. The presence of the housing provides protection to the metering mechanism, and also serves to better guide the metering mechanism between the first and second positions. Preferably, the inlet opening extends in a direction which is transverse the direction of the output opening. Additionally or alternatively, the metering mechanism may be threadably engageable with the housing. 
     The metering mechanism may comprise a tube for delivering a tablet from the exit port of the container to the inlet opening of the housing. The agitation means may be defined by a crenelated portion at the upper surface of the tube which is located in or around the exit port. The tube may be rotatable, causing the crenelations to oscillate to agitate tablets in the vicinity of the exit port. 
     The housing may be cylindrical. The metering mechanism may be rotatable inside the housing about a spindle extending through the housing. The metering mechanism may comprise a cavity as discussed above, which is offset from the rotation axis of the spindle. 
     The dosing device or system may further comprise a push member which is operable to push at least one tablet from the metering mechanism to the outlet when the metering mechanism is in the second position. In this case, the push member may be operable to pass through an opening in the metering mechanism. 
     The cartridge, dosing device or system may be made of any suitable materials. Preferably, at least the container is made of a plastics material and/or is thermally insulated, to prevent heat damage to the tablets inside. Preferably, the container converges towards the metering mechanism. For example, it may be funnel shaped. 
     Preferably, the dosing device or system is configured to dispense only one tablet at a time. 
     In an embodiment, the cartridge, dosing device or system has no internal electrical power source, e.g. no battery. In an embodiment, the cartridge, dosing device or system is electrically connected to the automatic washing machine. 
     The cartridge, dosing device or system need not comprise any temperature, turbidity, conductivity and/or water sensor. It may comprise no sensors at all. It may be controlled based on signals from such sensors found elsewhere in the automatic washing machine. This simplifies its construction and reduces its cost. 
     The tablets comprise one or more active ingredients for an automatic washing process. As will be appreciated by the skilled person, the nature of the active ingredient(s) used in the tablets will vary depending on the desired application. When used inside a dishwasher, the tablets may, for example, comprise an active ingredient performing a dishwasher detergent, rinse aid, machine cleaner or dishwasher deodorizing function. In the context of laundry washing machines, the tablets may, for example, comprise an active ingredient performing a laundry detergent or fabric softener function. Suitable active ingredients will be known to the skilled person; examples include bleach, bleach activator, bleach catalyst, enzyme, surfactant, builder, pH-adjusting agent, corrosion inhibitor, and fragrance. 
     Advantageously, each tablet contains a unit dose of the active ingredient, i.e. the entire amount of the active ingredient desired to be used in the washing process, such that only one tablet of that active ingredient needs to be dispensed per washing process (though multiple dosing devices or systems may still be used to dispense multiple tablets of different active ingredients per washing process). In other embodiments, it may be an advantage for the unit dose of the active ingredient to be provided by more than one tablet. For example, in some cases a single tablet containing the entire unit dose may be rather large or heavy, and dosing may be more effective or reliable using multiple smaller or lighter tablets. Preferably, the desired dose of the active ingredient is provided by no more than 10 tablets, preferably no more than 9, 8, 7, 6, 5, or 4 tablets. Preferably, the unit dose is provided by 1, 2, 3 or 4 tablets, in an embodiment 3 or 4 tablets. 
     Another useful option is to provide tablets each of which contains an amount of active ingredient that corresponds to no more than one unit dose of the active ingredient for at least one washing process of the automatic washing machine. Some automatic washing machines are configured to allow selection between various different modes of operation, such as an intensive wash program and a light wash program, which require different amounts of the active ingredient. Thus, a number of tablets may be dosed during one mode of operation and a different number of tablets are dosed during a different mode of operation. For example, one tablet may be dosed during a wash program for a certain soiling level and two tablets during a wash program designed for a higher level of soiling. 
     The tablets may be of any suitable form, such as solid, gel tab, or water soluble package/container (preferably of low deformability). Preferably, at least the exterior of the tablets are solid. For example, a capsule of a dissolvable (preferably hard) shell material could enclose a powder, liquid or gel composition. Advantageously, however, the tablets are formed of a compressed powder. Each tablet may, for example, be single phase or multi-layered, and may be otherwise structured to ensure that each active ingredient is released from the tablet at the most optimal time. The tablets may be wrapped in a film of water-soluble material, but preferably they are unwrapped. They may be coated with a suitable coating, e.g. to reduce friability. 
     The tablets may be of any suitable shape, such as cylindrical, disc-shaped, spherical, spheroidal, or cuboid. In an embodiment, each tablet has at least one flat face. Preferably the tablets are cylindrical or disc-shaped, since spherical tablets are more difficult to manufacture whilst shapes such as cuboid are less easily dispensed. In the case of a cylindrical tablet, preferably the length of the tablet is up to 5% more or less than the diameter of the tablet. When the tablet has edges, preferably at least some of these edges are chamfered and/or filleted to reduce the liability to chip during manufacture and whilst the tablet is in the dosing device. Preferably the chamfer has an angle of 15 to 20 degrees. 
     In an embodiment, each tablet has a weight of: at least 0.1 g, at least 0.5 g, at least 0.7 g, at least 1 g, at least 1.2 g, at least 1.5 g, at least 2 g, at least 3 g, at least 4 g, or at least 5 g; and/or up to 15 g, up to 14 g, up to 13 g, up to 12 g, up to 11 g, up to 10 g, up to 9 g, up to 8 g, up to 7 g, or up to 6 g. In an embodiment, each tablet has a maximum length and/or diameter of: at least 5 mm, at least 6 mm, at least 7 mm, at least 8 mm, at least 9 mm, or at least 10 mm; and/or up to 20 mm, up to 19 mm, up to 18 mm, up to 17 mm, up to 16 mm, or up to 15 mm. 
     Preferably, the tablets are loosely filled into the container. Preferably, they are randomly oriented therein. The maximum dimension of each tablet may be, for example, less than ⅔ of, or less than half of, the width of the exit port. Thus, there is plenty of room for the tablets to be agitated in the vicinity of the exit port. 
     The cartridge of the second aspect of the invention comprises one or more of the inventive dosing devices, and a plurality of tablets inside the or each container. The third aspect of the invention provides a kit of at least one of these cartridges and an automatic washing machine. 
     Advantageously, the invention allows the dispensing of different tablets into the automatic washing machine separately. Different tablets may need to be stored separately due to incompatibility, or may be more effective if dispensed at different times during a single wash process, or may be adapted to different types of wash programs. For example, it may be advantageous to dose a bleach-containing tablet separately from an enzyme-containing tablet. It may also be desirable to dose a tablet containing a high level of an active ingredient during an intensive wash program for heavily soiled items, but a tablet containing a lower level of an active ingredient during a lower intensity wash program for more lightly soiled items. 
     In an embodiment, the cartridge comprises at least two of the inventive dosing devices. Alternatively or in addition, two or more cartridges may be provided in a kit. Preferably, the tablets inside the container of a first dosing device are different from the tablets inside the container of a second dosing device. The tablets may differ in the type of active ingredient(s) included, or in the amount of active ingredient(s), or in another respect. The operation of the first dosing device is preferably independent from the operation of the second dosing device. 
     Each container may be refillable with tablets, or may be single-use such that when a container runs out of tablets, it is disposed of. 
     An automatic washing machine may be provided with a dosing device of the invention or a system comprising two or more dosing devices of the invention. Preferably, the dosing devices can be operated independently. 
     The automatic washing machine may be, for example, a dishwasher or a laundry washing machine. Preferably, it is a dishwasher, preferably a domestic dishwasher. In an embodiment, it is a dishwasher having a single tank. Preferably, the dishwasher does not operate on a conveyor system, i.e. the dishes remain stationary during the wash rather than being moved through one or more tanks. Preferably, the dishwasher has a main wash space which is closed by a door. In an embodiment, the cartridge, dosing device or system is located at least partially inside the main wash space during use, for example it may be partially embedded in a wall and partially projecting into the main wash space during use, or it may be attached to a wall of the main wash space. In an embodiment, the outlet of the dosing device or system delivers the tablets directly into the main wash space. 
     In an embodiment, the inventive cartridge, dosing device or system connects to the automatic washing machine in a predetermined location of the automatic washing machine. The connection may be via an interface. In the case of a dishwasher, preferably the inventive cartridge, dosing device or system connects to the dishwasher via an interface in a door of the dishwasher. The interface may comprise electrical and/or optical connections to transfer power and/or control signals between the automatic washing machine and the cartridge, dosing device or system. 
     Preferably, the automatic washing machine has a controller which controls the operation, and dispensing of tablets from, the container(s). 
     Also disclosed herein is a method of dispensing tablets into an automatic washing machine, using a dosing device or system according to the invention, comprising agitating at least one tablet in the vicinity of the exit port using the agitation means, and metering the tablet into the automatic washing machine. In an embodiment, at least one tablet is dispensed directly into a main wash space of the automatic washing machine. Preferably, at least one tablet is dispensed during a main wash cycle of a dishwasher. Alternatively or in addition, at least one tablet may be dispensed during a rinse cycle of the dishwasher. 
     The agitation means preferably agitates the tablets concurrently with, and/or just prior to, metering by the metering mechanism. The agitation means does not need to agitate the tablets at other times, which helps to conserve power. 
     Preferred embodiments of the invention will now be described further with reference to the accompanying Figures. 
     With reference to  FIGS. 1 a  and 1 b   , there is shown a dosing device  10 ; 10   a  for use in an automatic washing machine. At its top end, the dosing device  10  comprises a container  12  containing a plurality of tablets (not shown). The bottom of the container  12  is funnel shaped and converges towards an exit port  14  of the container  12 . 
     A metering mechanism  20 , cylindrical in shape, is connected to the container  12  for receiving a tablet from the exit port  14 . The metering mechanism is surrounded by a housing  22  in which the metering mechanism  20  is moveable in a linear direction between a first, closed, position as shown in  FIG. 1 a    and a second, open position as shown in  FIG. 1   b.    
     The housing  22  is cylindrical in shape, and is vertically orientated such that it defines a top surface  24  comprising an inlet opening  25  through which a tablet is fed from the exit port  14  of the container  12 . Extending through a side wall  26  of the housing  22  is an output opening  28  through which a tablet is dispensed when the metering mechanism  20  is in its second position. The bottom of the housing  22  comprises a projection  30  which engages with a corresponding slot  32  located towards the bottom of the metering mechanism  20 . 
     The top portion of the metering mechanism  20  is configured to support a tablet originating from the container  12 . In this regard, the top portion of the metering mechanism  20  comprises a sloping surface  34  which, when the metering mechanism is in the first position, extends from the inlet opening  25  towards a portion of the side wall  26  which is located above the output opening  28  of the housing  22 . When the metering mechanism is lowered into its second position, the sloping surface extends towards the output opening  28  of the housing  22 . In this way, a tablet located on the sloping surface  34  is operable to slide from the surface and out through the output opening  28 . 
     The output opening  28  from the housing  22  is connected to an outlet  29  (not shown in  FIGS. 1 a  and 1 b   ) of the dosing device  10 , which delivers a tablet fed through the metering mechanism  20  into the dishwasher in which the dosing device is located in use. 
     Projecting from the top portion of the metering mechanism  20 , and through the exit port of the container  12 , is an agitation means  40 . The agitation means is linearly moveable with the metering mechanism, and is preferably integrally formed therewith such that the agitation means  40  and the metering mechanism  20  form the same component. 
     The function of the agitation means  40  from the dosing device  10  is to agitate tablets in the vicinity of the exit port  14  as the metering mechanism  20  is moved, such to help dislodge any tablets in the container  12  which would otherwise block the exit port  14 . 
     The agitation means  40  can take any shape which helps with the agitation of tablets located near the exit port  14 . For instance, although shown in  FIGS. 1 a  and 1 b    as being block-shaped, the agitation means  40  could comprise a helically shaped portion which extends into the container  12 . 
     To prevent damage to any tablets located inside the container  12  as the agitation means  40  moves in use, the agitation means  40  preferably has a degree of flexibility. 
     With reference to  FIGS. 2 a -2 c   , there is shown an alternative dosing device  10 ; 10   b  for administering tablets into an automatic washing machine. 
     In common with the dosing device shown in  FIGS. 1 a  and 1 b   , the second dosing device  10 ; 10   b  comprises a container  12  for tablets  1 , a metering mechanism  20 , a cylindrical housing  22 , an outlet  29 , and an agitation means  40 . The second dosing device  10 ; 10   b  is operable to move between a first position as shown in  FIG. 2 b    and a second position as shown in  FIG. 2   c.    
     The metering mechanism  20  from the second dosing device  10   b  is rotatable inside the housing  22  about a spindle  50  which extends completely through the housing  22 . The output opening  28  of the housing  22  is located on a bottom surface  52  of the housing  22 . 
     The metering mechanism  20  defines a cavity  54  in which a tablet  1  from the container  12  is operable to be held during rotation of the metering mechanism  20  inside the housing  22  from the first position to the second position. The cavity  54  is located towards the side wall  26  of the housing  22 , and is offset from the rotation axis of the spindle  50 . The bottom of the cavity  54  is defined by a first plate  56  which is located inside the housing  22  and which radially projects from a lower portion of the spindle  50 . The first plate  56  is connected to the spindle  50  such that it separates the cavity  54  from the outlet  29  when the metering mechanism  20  is in the first position, but not in the second position. 
     The top of the cavity  54  is defined by a second plate  58  which similarly extends from the spindle  50 , and which is located inside the housing  22  above the first plate  56 . In use, the second plate  58  separates the cavity  54  from the exit port  14  of the container  12  when the metering mechanism  20  is in the second position, but not in the first position. 
     A tube  60  is connected to the spindle  50  for delivering a tablet  1  from the exit port  14  of the container  12  down into the cavity  54  when the metering mechanism  20  is located in the first position. In this first position, the first plate  56  prevents the tablet  1  from passing from the cavity  54  through to the output opening  28  of the housing  22  and the outlet  29  of the dosing device  10   b.    
     Upon subsequent rotation of the spindle  50  to the second position, the top of the cavity  54  is covered by the second plate  58  to prevent a further tablet  1  entering the cavity  54 , and the first plate  56  no longer blocks the output opening  28  of the housing  22 , such that the tablet  1  can pass through to the outlet  29  of the dosing device  10   b.    
     The agitation means  40  from the second dosing device  10   b  is defined by a crenelated portion  62  added to the top surface of the tube  60 . In this regard, the top surface of the tube  60 , which is located around the exit port  14  of the container  12 , comprises a plurality of crenelations  64  each defining a geometric shape, such as a triangle, a rectangle, or a semi-circle. Since the tube  60  is connected to the spindle  50 , as the spindle  50  rotates during use of the dosing device  10   b , the crenelations  64  on the top surface of the tube  60  rotate around the exit port  14  from the container  12  to agitate tablets in the vicinity of the exit port  14 . 
     With reference to  FIGS. 3 a  and 3 b   , there is shown another dosing device  10 ; 10   c  for administering tablets  1  into an automatic washing machine. 
     In common with the dosing device shown in  FIGS. 1 a  and 1 b   , and  FIGS. 2 a -2 c   , the third dosing device  10 ; 10   c  comprises a container  12  for tablets  1 , a metering mechanism  20 , a housing  22 , an outlet  29 , and an agitation means  40 . The third dosing device  10 ; 10   c  is operable to move between a first position as shown in  FIG. 3 a    and a second position as shown in  FIG. 3   b.    
     The metering mechanism  20  from the third dosing device  10   c  comprises a wheel  66  which is rotatable inside the housing  22 . The wheel  66  comprises a recess  68  in which a tablet  1  from the container  12  is operable to be held during rotation of the wheel  66  inside the housing  22  from the first position to the second position. In the third dosing device  10   c , the cylindrical housing  22  is horizontally orientated such that it defines a space in which the wheel  66  is operable to rotate inside the housing  22  about a substantially horizontal axis. 
     The inlet opening  25  from the third dosing device  10   c  is located in an uppermost portion of the horizontal side wall  26  of the housing  22 . The output opening  28  is located in a lowermost portion of the horizontal side wall  26 , and in a position which is diametrically opposed from the inlet opening  25  inside the housing  22 . 
     In the first position of the metering mechanism  20 , the recess  68  from the wheel  66  faces upwards and is in communication with the inlet opening  25  of the housing  22  (as shown in  FIG. 3 a   ). Upon rotation of the wheel  66  to the second position of the metering mechanism  20 , in this second position the recess  68  from the wheel  66  faces downwards and is in communication with the output opening  28  of the housing  22  and the outlet  29  of the dosing device  10   c  (as shown in  FIG. 3 b   ). 
     The radius of the wheel  66  is not uniform around its circumference, such that the radius (R 1 ) of the wheel is at a minimum at the angular position of the recess  68 , and is at a maximum (R 2 ) at the angular position which is diametrically opposed the recess  68 . As a result of this varying radius, the wheel  66  defines an eccentric shape such that as it rotates inside the housing  22 , the separation (S 1 ) between the wheel  66  and the inlet opening  25  is maximised when the wheel is in the first position (i.e. when the recess is in communication with the inlet opening  25 ), and the separation (S 2 ) between the wheel  66  and the output opening  28  is maximised when the wheel is in the second position (i.e. when the recess  68  is in communication with the output opening  28 ). 
     By providing a small amount of additional clearance between the recess  68  at the points where it is in communication with either of the inlet opening  25  and the output opening  28 , this additional clearance helps guide a tablet  1  into the recess  68 , such that the likelihood of a tablet  1  becoming stuck, or getting jammed, inside the metering mechanism  20  during its operation is reduced. 
     The third dosing device  10   c  comprises a tube  70  for delivering a tablet  1  from the exit port  14  of the container  12  down towards the inlet opening  25  of the housing  22 . 
     The agitation means  40  from the third dosing device  10   c  is defined by a crenelated portion  62  added to the top surface of the tube  70 . The top surface of the tube  70 , which is located around the exit port  14  of the container  12 , comprises a plurality of crenelations  64  each defining a geometric shape, such as a triangle, a rectangle, or a semi-circle. 
     The bottom of the tube  70  comprises a series of teeth  72  which engage with corresponding teeth  74  extending around the circumference of the wheel  66 . 
     Since the bottom of the tube  70  comprises teeth  72  which engage with the corresponding teeth  74  on the wheel  66 , as the wheel  66  rotates during use of the dosing device  10   c , the crenelations  64  on the top surface of the tube  70  linearly oscillate up and down, and also rotate around the exit port  14  from the container  12  to agitate tablets in the vicinity of the exit port  14 . 
     With reference to  FIGS. 4 a  and 4 b   , there is shown a fourth dosing device  10 ; 10   d  for administering tablets  1  into an automatic washing machine. 
     In common with the dosing device shown in  FIGS. 1 a  and 1 b   , the fourth dosing device  10 ; 10   d  comprises a container  12  for tablets  1  (not shown in  FIGS. 4 a  and 4 b   ), a metering mechanism  20 , a housing  22  defining an inlet opening  25  at its top and an output opening  28  at its bottom, an outlet  29 , and an agitation means  40  (also not shown in  FIGS. 4 a  and 4 b   ). In use, the metering mechanism is operable to move between a first position as shown in  FIG. 4 a    in which a tablet is receivable in the inlet opening  25 , and a second position as shown in  FIG. 4 b    in which the tablet is deliverable to the outlet  29 . 
     The metering mechanism  20  from the fourth dosing device  10 ; 10   d  is substantially cylindrical and is operable to hold a vertical stack of tablets  1 . The bottommost tablet  1  from the stack is operable to sit on a shelf  75  located at the bottom of metering mechanism  20 . 
     The container  12  from the fourth dosing device  10 ; 10   d  is operable to connect with the top portion of the housing  22 , preferably by way of a screw thread located around the exit port  14  of the container  12  which engages with a corresponding screw thread  76  located on the top portion of the side wall  26  of the housing  22 . 
     The agitation means  40  in the fourth dosing device  10 ; 10   d  is detachably connected to a slot  78  which extends around the top portion of the metering mechanism  20 . In the first position of the dosing device  10 ; 10   d , and when the container  12  and the agitation means  40  are connected to the dosing device  10 ; 10   d , the agitation means  40  projects from the metering mechanism  20  and extends through the exit port  14  into the container  12 . 
     To operate the fourth dosing device, the metering mechanism  20  is initially rotated inside the housing  22  such that the agitation means  40  connected to the metering mechanism  20  agitates tablets in the vicinity of the exit port  14 . After the tablets have been agitated, the metering mechanism  20  is then lowered from the first position shown in  FIG. 4 a    to the second position shown in  FIG. 4 b   . In the second position, the dosing device  10 ; 10   d  uses a push member  80  to push a tablet  1  located on the shelf  75  in a lateral direction to the outlet  29 . In  FIG. 4 b   , the push member  80  is shown as being actuatable through a slot  82  located in a side portion of the metering mechanism  20 . 
     After a tablet  1  from the stack has been pushed out from the metering mechanism  20  via the push member  80 , a higher tablet in the stack is able to drop down onto the shelf  75 , such that it can be pushed to the outlet  29  via a subsequent actuation of the push member  80 . 
     With reference to  FIG. 5 , there is shown a fifth dosing device  10 ; 10   e  for administering tablets  1  into an automatic washing machine. 
     In common with the dosing device shown in  FIGS. 4 a  and 4 b   , the fifth dosing device  10 ; 10   e  comprises a container  12  for tablets  1  (not shown in  FIG. 5 ), a metering mechanism  20 , a housing  22  defining an inlet opening  25  at its top and an output opening  28  at its bottom, an outlet  29 , an agitation means  40 , and a screw thread  76  located on the top portion of the housing  22  for connecting the housing  22  to the container  12 . The fifth dosing device  10 ; 10   e  is operable to move between a first position in which a tablet is receivable from the exit port of the container, and a second position in which the tablet is deliverable to the outlet  29 . 
     The metering mechanism  20  from the fifth dosing device  10 ; 10   e  is substantially cylindrical and is operable to hold a vertical stack of tablets  1 . The bottommost tablet  1  from the stack is operable to sit on a shelf  75  located at the bottom of metering mechanism  20 . 
     In the fifth dosing device  10 ; 10   e , the metering mechanism  20  comprises an outer surface which defines a screw thread  84  which is operable to engage with a corresponding screw thread  86  located on the inner surface of the side wall  26  from the housing  22 . 
     The agitation means  40  in the fifth dosing device  10 ; 10   e  is detachably connected to a slot  78  which extends around the top portion of the metering mechanism  20 . In the first position of the dosing device  10 ; 10   e , and when the container  12  and the agitation means  40  are connected to the dosing device  10 ; 10   e , the agitation means  40  projects from the metering mechanism  20  and extends through the exit port  14  into the container  12 . 
     To move the metering mechanism  20  between the first and second positions, the metering mechanism  20  is rotated inside of the housing  22 , such that the engaging screw threads  84 ; 86  lower the metering mechanism  20  inside the housing  22 . 
     When the metering mechanism  20  is lowered to the second position, a tablet  1  resting on the shelf  75  is able to pass out from the metering mechanism  20  to the outlet  29 . In this regard, the shelf  75  may be downwardly sloped towards the outlet  29  such that the tablet  1  proceeds to the outlet  29  via gravity. Alternatively, a push member  80  may be provided as in the fourth dosing device  10 ; 10   d  to push the tablet  1  off the shelf  75 . 
     Each of the dosing devices  10 ; 10   b ; 10   c ; 10   d ; 10   e  described above are operable to dispense at least one tablet into a dishwasher during a wash cycle of the automatic washing machine. 
     Preferably, for each movement of the metering mechanism  20  of each dosing device  10  from the first position to the second position, the dosing device  10  is configured to dispense a single tablet from the container  12  to the outlet  29  of the dosing device. 
     Movement of the metering mechanism  20  between its first and second positions is controlled using a motor (not shown in the Figures) which is connected to the metering mechanism  20 . Operation of the motor is governed by commands sent from a controller located in the automatic washing machine. For a given wash cycle, the controller is configured to instruct the motor to move the metering mechanism  20  between its first and second positions, such that one or more tablets are dispensed by the dosing device  10  into the machine at different times during the wash cycle. 
     It will be appreciated that by having a plurality of dosing devices  10  arranged in parallel, a dosing system  100  can be provided as shown in  FIG. 6 . With such a dosing system  100 , the dosing devices  10  can be filled with tablets  1  of different active ingredients. In this way, and by having each dosing device  10  individually controlled by the controller, the dosing system can dispense different tablets at different times. 
     It will also be appreciated that any number of dosing devices  10  and/or dosing systems  100  can be supplied as a cartridge  200 , as shown in  FIG. 7 . The cartridge  200  may either be refillable such that each container  12  therein may be refilled with tablets  1 , or the cartridge  200  may be single-use such that when a container  12  runs out of tablets  1 , the cartridge  200  is disposed of. 
     The dosing device  10 , dosing system  100 , and cartridge  200  described herein are preferably intended to be connected to, and communicate with a controller located in, a dishwasher  300  as shown in  FIG. 8 . Possible connection points for the dosing device  10 ; dosing system  100 ; or cartridge  200  inside the dishwasher  300  include the door  301 , the main housing  302 , or the interior wash space  303  of the dishwasher  300 , though the door  301  is most preferred for easy accessibility. 
     Although the dosing device, dosing system, and cartridge of the invention have been described above as being useable with a dishwasher, it is appreciated that they may also be used to administer tablets into other automatic washing machines, such as a laundry washing machine. In this case, the dosing device  10  (or dosing system  100 /cartridge  200 ) would connect to, and communicate with a controller, and a motor, located in the laundry washing machine. When the dosing device  10  is connected with a laundry washing machine, a tablet may advantageously be operable to pass from the outlet  29  of the dosing device  10  into a water tank of the laundry washing machine, such that the tablet can be dissolved into a solution of the active ingredient, which may be then fed, by a pump, into the drum of the machine. 
     In this way, during operation of the dosing device  10  in a given wash cycle in the laundry washing machine, the controller would be configured to instruct the motor to move the metering mechanism  20  of the dosing device  10  between its first and second positions, such that one or more tablets can be dispensed into the laundry washing machine at different times during the wash cycle. 
     It will also be appreciated that rather than have all of the components from the dosing device  10  located in a cartridge  200  or all in an automatic washing machine, the components from the dosing device  10  may be distributed between the cartridge and the automatic washing machine. For example, in one configuration the cartridge  200  may be arranged to house the container  12  together with its tablets  1 , and the automatic washing machine arranged to support the metering mechanism  20 , the housing  22 , and the outlet  29 . The agitation means  40  may be located in either the cartridge  200  or in the automatic washing machine. When the cartridge  200  is inserted into the automatic washing machine, the components from the dosing device  10  would then connect up to form the dosing device  10  as described and shown herein.