CLAIM OF PRIORITY

[0001] This patent application claims the benefit of U.S. Provisional Patent Application No. 63/378,575, filed October 6, 2022, which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

[0002] This disclosure relates generally to warewashing detergent dispensing and more particularly to a method and apparatus for dispensing a solid detergent in a washing machine such as a dishwasher.

BACKGROUND

[0003] A dishwasher, also referred to as a warewasher or warewashing machine, is a machine for automatically cleaning articles, such as dishes, trays, laboratory equipment, dinnerware, and kitchenware. A batch of objects to be cleaned (for example, dishes) can be loaded into a tub of the dishwasher, typically including racks and utensil holders, to be cleaned in a cleaning cycle that include washing and rinsing periods. During the washing period, a cleaning mixture formed by water and dishwasher detergent is sprayed into the loaded tub to blast the dishes. The cleaning mixture is then drained before the rinsing period starts. During the rinsing period, water is sprayed into the washing chamber to remove residue of the cleaning mixture. After the rinsing period complete with the rinsing water being drained, the dishes can optionally be dried using air and/or heat during a drying period. A dishwasher may have various user-selectable settings for each cleaning cycle. The settings may define, for example, time, temperature, and repetition of each of the washing, rinsing, and drying period. The setting may also allow the user to choose which periods to include (e.g., rinsing only, drying only, rinsing and drying, or washing and rinsing without drying).

[0004] A dishwasher may include racks that allow various objects to be arranged in the dishwasher and held in position during the cleaning cycle. Such racks can be built-in components of the dishwasher (e.g., to be slid out for loading dishes and slid in before starting the cleaning cycle) and/or removable racks that may be provided as dishwasher accessories for placement in the dishwasher after loading objects to be washed. Examples of such racks include peg racks each suitable for holding one or more specific types of items such as glasses, cups, plates, trays, and/or silverware as well as open racks suitable for holding items with shapes and/or sizes that are difficult to fit into the peg racks. [0005] A common domestic dishwasher is an undercounter unit intended to be installed under a kitchen counter. Other types of dishwasher include industrial or commercial dishwashers for use in restaurants, hotels, and other commercial establishments with food services. Dishwasher detergents used in these dishwashers can include chemicals capable of cleaning, sanitizing, and/or reducing surface tension of water (and hence water spots on dishes). Such dishwasher detergents are made into various solid and liquid forms. Solid dishwasher detergents include chemicals made in forms of solid blocks such as tablets in various shapes.

SUMMARY

[0006] An apparatus for dispensing a detergent solution from a solid detergent into a dishwasher can be attached to a dishwasher rack around a perimeter of the rack and collect water in the dishwasher and use the collected water to produce the detergent solution by dissolving a portion of the solid detergent. In various embodiments, the apparatus can include a detergent chamber to accommodate the solid detergent and optionally an end-of-detergent indicator to indicate an amount of the solid detergent in the detergent chamber. In various embodiments, release of the detergent solution can be controlled passively using size of a liquid outlet or actively using operational state of the dishwasher and/or a sensed signal indicative of the concentration of the detergent in the dishwasher water.

[0007] In one embodiment, an apparatus is configured to be attached to a dishwasher rack and to dispense a solid detergent. The rack is configured to be removably placed in a dishwasher capable of performing cleaning cycles. The apparatus includes a frame that may include inner edges to be detachably connected to the rack around a perimeter of the rack, a detergent chamber to accommodate the solid detergent, a liquid inlet in fluid communication with the detergent chamber to allow a flow of water into the detergent chamber to at least partially dissolve the solid detergent in the detergent chamber, and a liquid outlet in fluid communication with the detergent chamber to allow a flow of the detergent solution out of the detergent chamber.

[0008] In one embodiment, a system is configured for dispensing a detergent solution from a solid detergent into a dishwasher capable of performing cleaning cycles. The system may include a dishwasher rack and a frame. The dishwasher rack may be configured to be removably placed in the dishwasher. The frame may include inner edges to be connected to the rack around a perimeter of the rack, a detergent chamber to accommodate the solid detergent, a liquid inlet in fluid communication with the detergent chamber to allow a flow of water into the detergent chamber to at least partially dissolve the solid detergent in the detergent chamber, and a liquid outlet in fluid communication with the detergent chamber to allow a flow of the detergent solution out of the detergent chamber. [0009] In one embodiment, a method for operating a detergent dispensing system in a dishwasher is provided. The dishwasher is capable of performing cleaning cycles each including washing and rinsing periods. The method may include holding a solid detergent in a detergent chamber inside a frame configured to be attached to a dishwasher rack. The rack may be removably placed in the dishwasher. The frame may surround a perimeter of the rack when being attached to the rack. The method may further include collecting a portion of water sprayed into the dishwasher during the washing and rinsing periods using a liquid inlet on the frame, using the collected portion of water to form a detergent solution in the detergent chamber by at least partially dissolving the solid detergent, and releasing the formed detergent solution from the detergent chamber using a liquid outlet on the frame.

[0010] This summary is an overview of some of the teachings of the present application and not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details about the present subject matter are found in the detailed description and appended claims. The scope of the present invention is defined by the appended claims and their legal equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings illustrate generally, by way of example, various embodiments discussed in the present document. The drawings are for illustrative purposes only and may not be to scale.

[0012] FIG. 1 is an illustration showing an embodiment of a detergent dispenser attached to a dishwasher rack in a dishwasher.

[0013] FIG. 2 is a block diagram illustrating an embodiment of a detergent dispenser, such as the detergent dispenser of FIG. 1.

[0014] FIG. 3 is a block diagram illustrating an embodiment of a detergent chamber of a detergent dispenser, such as the detergent dispenser of FIG. 2.

[0015] FIG. 4 is a block diagram illustrating another embodiment of a detergent dispenser, such as the detergent dispenser of FIG. 1.

[0016] FIG. 5 is a block diagram illustrating an embodiment of an end-of- detergent indicator of a detergent dispenser, such as the detergent dispenser of FIG. 4.

[0017] FIG. 6 is a block diagram illustrating another embodiment of a detergent dispenser, such as the detergent dispenser of FIG. 1.

[0018] FIG. 7 is a block diagram illustrating an embodiment of a dispensing control unit of a detergent dispenser, such as the detergent dispenser of FIG. 6.

[0019] FIG. 8 is a block diagram illustrating another embodiment of a dispensing control unit of a detergent dispenser, such as the detergent dispenser of FIG. 6.

[0020] FIG. 9 is an illustration of an embodiment of a detergent dispenser attached to a dishwasher rack, showing an exemplary implementation of the dishwasher rack of FIG. 1 and an exemplary implementation of the detergent dispenser of FIG. 1, 2, 4, or 6.

[0021] FIG. 10 is another perspective-view illustration of the embodiment of FIG. 9 showing the detergent dispenser attached to the dishwasher rack.

[0022] FIG. 11 is a side-view illustration of an embodiment of a detergent dispenser attached to the dishwasher rack of FIGS. 9 and 10, showing an exemplary implementation of the detergent dispenser of FIG. 6.

[0023] FIG. 12 is a cross-sectional view illustration of an embodiment of the detergent dispenser of FIG. 11 DETAILED DESCRIPTION

[0024] The following detailed description of the present subject matter refers to subject matter in the accompanying drawings which show, by way of illustration, specific aspects and embodiments in which the present subject matter may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present subject matter.

References to “an”, “one”, or “various” embodiments in this disclosure are not necessarily to the same embodiment, and such references contemplate more than one embodiment. The scope of the present invention is defined by the appended claims, along with the full scope of legal equivalents to which such claims are entitled.

[0025] The present subject matter relates to methods and devices for dispensing solid detergent in a dishwasher that allow for each load of the solid detergent to last for multiple cleaning cycles. A dispenser can be configured to be a frame that can be detachably attached to a removable dishwasher rack. The solid detergent can be contained in the frame to be dissolved by water running through the frame to form a detergent solution during the washing and/or rinsing cycles of the dishwasher. Release of the detergent solution can be passively controlled using the size of a liquid outlet on the frame or actively controlled based on an operational state of the dishwasher or a sensed detergent concentration in the dishwasher.

[0026] In various embodiments, the present dispenser is easy to use (e.g., substantially automatic detergent dispense, with detergent loaded between multiple cleaning cycles) while providing each cleaning cycle with substantially consistent amount and concentration of detergent solution. The present dispenser can be made spatially and functionally retrofittable to various dishwashers, including undercounter dishwashers for home use, to allow for use of solid detergent blocks as an option in addition to existing option(s) provided by built-in detergent dispensers.

[0027] Among other advantages, the present dispenser eliminates the need for adding dishwasher detergent before every cleaning cycle. It also adds to the consistency of concentration and amount of detergent dispensed by the system. A dishwasher detergent in solid form is a safer alternative to its liquid form because the solid form is more concentrated than its liquid form, is not associated with risk of spilling, and may not need personal protective equipment. Solid detergent also provides sustainability benefits from packaging and water content reduction as well as a smaller storage footprint at customer locations. Because the present dispenser is not fixed to the dishwasher or the rack, it can be easily removed to allow for any service work (e.g., cleaning and/or sanitization) of the dishwasher, the rack, or the dispenser itself.

[0028] As used in the present disclosure, a “dishwasher”, which can also be referred to as a warewasher or a warewashing machine, can include any type of washing machine that can use detergent for cleaning and/or sanitizing purposes. One example includes an undercounter dishwasher for washing dinnerware, flatware, pots and pans, cutlery, flatware, glasses, kitchenware, serving pans, trays, and so on. Commercial dishwashing equipment examples can also use the present subject matter. A dishwasher includes a washing tub formed by interior walls and a door of the dishwasher. In an example of the undercounter kitchen dishwasher, the door rotates up to about 90 degrees about a horizontal axis to switch between a fully closed state and to a fully open state. The door has an interior side and an exterior side that are both substantially vertical when the door is fully closed and substantially horizontal when the door is fully open.

[0029] As used in the present disclosure, a “ dishwasher rack”, which can also be referred to as a warewashing rack, can include any rack that is used in a dishwasher, for example for holding any objects to be washed. Unless noted otherwise, a “rack” in the present disclosure refers to a dishwasher rack. The rack can be a built-in part of the dishwasher or a removable accessory suitable for use in the dishwasher. The rack can be a peg rack or an open rack and can have any size and shape suitable for the dishwasher. Each dishwasher can include one or more built-in racks and/or can host one or more removable racks. [0030] As used in the present disclosure, a “cleaning cycle” can include other periods, such as one or more of a washing period, a rinsing period, and a drying period, depending on settings made by a user of the dishwasher. The door is opened at least once between two consecutive cleaning cycles to allow loading of the dishes and/or other objects to be cleaned and unloading of the cleaned dishes and/or other objects. “Cleaning” can include cleaning only, sanitizing only, or cleaning and sanitizing, depending on, for example, whether the solid detergent blocks are capable of cleaning only, sanitizing only, or cleaning and sanitizing. A “washing period” includes a period or operational mode that is intended for a cleaning mixture formed by water and detergent to be applied to the dishes and/or other objects. A “rinsing period” includes a period or operational mode that is intended for water, or water and a chemical rinsing aid and/or a chemical sanitizer, to be applied to the dishes and/or other objects. Some dishwashers (e.g., commercial dishwashers) may include a rinsing period that is primarily for sanitizing through heat and/or chemical means. A “drying period” includes a period or operational mode that is intended for the cleaned dishes and/or other objects to be dried by air flow and/or heat, without additional water and/or detergent applied. The dishwasher can allow the user to choose whether to include the drying period in the cleaning cycle because the user can open the dishwasher door to allow the washed and rinsed dishes to dry naturally or remove the washed and rinsed dishes to another place for drying.

[0031] Application in a dishwasher is discussed as an example, but not a limitation, for the present subject matter. The present system for dispensing solid detergent can be applied in any washing machine that sprays water that can be collected to dissolve a portion of a solid detergent during a cleaning cycle.

[0032] FIG. 1 is an illustration showing an embodiment of a detergent dispenser 120 attached to a dishwasher rack 110 that is in a dishwasher 100. As shown in FIG. 1 for illustrative but not restrictive purposes, dishwasher 100 includes a washing tub 104 formed by interior walls 106 and a door 102.

Dishwasher 100 can perform cleaning cycles each including at least washing and rinsing periods.

[0033] Rack 110 can be used to hold objects to be washed in dishwasher 100. Rack 110 can be affixed to dishwasher 100 and positioned in tub 104 (i.e., a built-in rack) or removably placed in dishwasher 100 (i.e., a removable rack). Dispenser 120 can be configured for use with rack 110, such as being attached to rack 110. In various embodiments, rack 110 is a removable rack that is configured to be retrofittable into various existing dishwashers, and dispenser 120 is configured to be detachably attached to rack 110, such that the assembly of rack 110 and dispenser 120 is retrofittable into various existing dishwashers. Thus, design of dispenser 120 is subjected to space constraints when being attached to rack 110 and placed in one of the existing dishwashers. [0034] While the embodiments including a dispenser detachably attached to a removable rack is specifically discussed as an example, the present subject matter can be applied to various other combination of racks and dispensers (e.g., a dispenser affixed to a removable rack, a dispenser affixed to a built-in rack, or a dispenser detachably attached to a built-in rack). In various embodiments, rack 110 and dishwasher 100 can each have different spatial characteristics (e.g., different shapes and sizes), and dispenser 120 can include various shapes and sizes designed for compatibility of various versions of rack 110 and various models of dishwasher 100.

[0035] FIG. 2 is a block diagram illustrating an embodiment of a detergent dispenser 220. Dispenser 220 can represent an example of dispenser 120 and can be configured to be attached to rack 110. Dispenser 220 includes a detergent chamber 224 to accommodate a solid detergent, a liquid inlet 222, and a liquid outlet 226. Liquid inlet 222 and liquid outlet 226 are each in fluid communication with detergent chamber 224. Liquid inlet 222 is configured and positioned on dispenser 220 to collect water from dishwasher 100 during the washing and rinsing periods and to allow the collected water to flow into detergent chamber 224 to form the detergent solution by dissolving a portion of the solid detergent. Liquid outlet 226 is configured and positioned on dispenser 220 to allow the formed detergent solution to flow out of dispenser 220 from detergent chamber 224.

[0036] Dispenser 220 is an example of a “passive” dispensing device in that the amount of the solid detergent dispensed during each cleaning cycle is controlled by sizes of liquid inlet 222 and liquid outlet 226. Liquid inlet 222 can include one or more holes on a top portion of the device, and liquid outlet 226 can include one or more holes on a bottom portion of the device. During the washing and rinsing periods, water enters detergent chamber 224 through liquid inlet 222 to dissolve a portion of the solid detergent. The resulting detergent solution is released through liquid outlet 226. The amount of the solid detergent being dispensed depends on the amount of water that enters detergent chamber 224 and the amount of the detergent solution that is released from detergent chamber 224. Thus, the number, size, and location of the holes can be determined for controlling the amount of the solid detergent dispensed during each cleaning cycle. [0037] FIG. 3 is a block diagram illustrating an embodiment of a detergent chamber 324 of a detergent dispenser, such as detergent dispenser 220. Detergent chamber 324 can represent an example of detergent chamber 224 and can contain a solid detergent 328. Solid detergent 328 can be a detergent, a detergent and a rinse aid, a detergent, a rinse aid, and a salt (“3 in 1”), or any other chemical agent or combination of chemical agents suitable for use in a dishwasher. In various embodiments, solid detergent 328 can be in the form of tablets, pellets, blocks, or any form suitable for being contained detergent chamber 324 and dissolved in an acceptable manner (e.g., erosion rate) in detergent chamber 324. In one embodiment, solid detergent 328 is an ash-based combination of chemical agents for one-pass ware washing with high- performance under a variety of conditions (e.g., various temperatures and/or degrees of water hardness).

[0038] FIG. 4 is a block diagram illustrating an embodiment of a detergent dispenser 420. Dispenser 420 can represent another example of dispenser 120 and can be configured to be attached to rack 110. Dispenser 420 is another example of a passive dispensing device and includes detergent chamber 224, liquid inlet 222, liquid outlet 226, an end-of-detergent indicator 430, and optionally a power supply 432. End-of-detergent indicator 430 can indicate a need for a refill of the solid detergent to the user of the dishwasher. In one embodiment, end-of-detergent indicator 430 includes a transparent window incorporated onto detergent chamber 224. The transparent window allows the user to see the amount of the solid detergent remaining in detergent chamber 224. Power supply 432 is not needed in this embodiment. In another embodiment, end-of-detergent indicator 430 produces an audible or visible alarm signal when the level the solid detergent remaining in detergent chamber 224 is substantially low (e.g., below a specified threshold level). Power supply 432 can include one or more batteries to supply end-of-detergent indicator 430 with electrical power when needed for its operation. Thus, dispenser 420 is basically dispenser 220 with an additional function of indicating the need for detergent refill.

[0039] FIG. 5 is a block diagram illustrating an embodiment of an end-of- detergent indicator 530 of a detergent dispenser, such as detergent dispenser 420. End-of-detergent indicator 530 can represent an example of end-of-detergent indicator 430 and includes a detergent sensor 534. Detergent sensor 534 can sense a detergent level signal indicative of a level of the solid detergent remaining in detergent chamber 224. An example of detergent sensor 534 includes a photoelectric sensor that can detect the level of the solid detergent by transmitting a light through detergent chamber 224, receiving the light, and determining whether the solid detergent is present on the path of the light using the received light. End-of-detergent indicator 530 can indicate a need for refill in response to the detected level falling below a threshold level, for example by producing an alarm (e.g., an audible or visible signal) that can be received by the user before the user starts a new cleaning cycle.

[0040] FIG. 6 is a block diagram illustrating an embodiment of a detergent dispenser 620, such as the detergent dispenser of FIG. 1. Dispenser 620 can represent another example of dispenser 120 and can be configured to be attached to rack 110. Dispenser 620 includes detergent chamber 224, liquid inlet 222, liquid outlet 226, end-of-detergent indicator 430, power supply 432, and a dispensing control unit 640. Dispensing control unit 640 can provide controllable release of the detergent solution from detergent chamber 224 to the dishwasher through liquid outlet 226. Thus, dispenser 620 is basically dispenser 420 with an additional function of actively controlling the release of the solid detergent. Depending on the design of dispensing control unit 640, dispenser 620 can be an example of a “semi-active” dispensing device in that the release of the solid detergent is controlled by the operational state of the dishwasher during each cleaning cycle, as further discussed below with reference to FIG. 7, or an example of an “active” dispensing device in that the release of the solid detergent is controlled by the detergent concentration in the water inside the dishwasher, as further discussed below with reference to FIG. 8.

[0041] FIG. 7 is a block diagram illustrating an embodiment of a dispensing control unit 740 of a detergent dispenser, such as dispenser 620. Dispenser control unit 740 can represent an example of dispenser control unit 640 and can provide the detergent dispenser with a “semi-active” dispensing control that controls the amount of release of the detergent solution per cleaning cycle. In various embodiments, dispenser control unit 740 can detect and/or receive signals indicative of an operational state of the dishwasher, such as dishwasher 100. The operation state can include one or more periods of each cleaning cycle. For example, it may include each of washing, rinsing, and drying periods, or it may include washing and rinsing periods (i.e., when water is sprayed into the washing tub) as one state.

[0042] Dispenser control unit 740 can be coupled between detergent chamber 224 and liquid outlet 226 to provide dispense 620 with controllable release of the detergent solution by controlling liquid flow from detergent chamber 224 to liquid outlet 226. Dispenser control unit 740 can include a valve 742, a valve controller 744, and a cleaning cycle detector 746. Valve 742 is coupled between detergent chamber 224 and liquid outlet 226 and driven by a release signal. In one embodiment, valve 742 includes a unidirectional valve (as known as check valve) that allows for liquid flow in the direction from detergent chamber 224 to liquid outlet 226 only. Valve controller 744 can generate the release signal using an operational state signal indicative of the operational state of the dishwasher. The release signal causes valve 742 to release a volume of the detergent solution for each cleaning cycle of the dishwasher (e.g., by opening valve 742 for a specified period of time). In various embodiments, valve controller 744 can cause valve 742 to open for a programmed amount of time during each washing period or during each washing period and each rinsing period.

[0043] Cleaning cycle detector 746 can use any available means to detect the operational state signal. In various embodiments, cleaning cycle detector 746 can include a sensor to sense a signal indicative of the operation state of the dishwasher. Examples of the sensor can include one or any combination of an optical sensor, a flow sensor, and a temperature sensor. The optical sensor can sense light indicating that the door of the dishwasher (e.g., door 102 of dishwasher 100) is open. An open door indicates that the dishwasher is inactive between two cleaning cycles. The flow sensor can sense liquid flow in the dishwasher (e.g., through liquid inlet 222). The sensed liquid flow indicates that the dishwasher is during a washing or rinsing period. The temperature sensor can sense a temperature inside the dishwasher. The sensed temperature can indicate each of the washing, rinsing, and drying period, depending on the temperature settings of the dishwasher, as well as when the dishwasher is inactive between two cleaning cycles. In some embodiments in which one or more signals indicating the operational state of the dishwasher is available (e.g., when the dishwasher can be remotely controlled using wirelessed transmitted signals), cleaning cycle detector 746 can include a receive to receive the signal(s) and detect the operation state form the received signal(s).

[0044] FIG. 8 is a block diagram illustrating an embodiment of a dispensing control unit 840 of a detergent dispenser, such as dispenser 620. Dispenser control unit 840 can represent another example of dispenser control unit 640 and can provide the detergent dispenser with an “active” dispensing control that controls the amount of release of the detergent solution by sensing and maintaining the concentration of the detergent in the liquid inside the washing tub of the dishwasher, such as tub 104 in dishwasher 100. In various embodiments, dispenser control unit 840 can collect liquid from the washing tub and sense the electrical conductivity of the collected liquid. The electrical conductivity of the liquid is known to be indicative of the concentration of the detergent in the liquid. Dispenser control unit 840 can release the detergent solution from detergent chamber 224 when the electric conductive (and hence the concentration of the detergent) is below a specified (e.g., empirically determined) threshold.

[0045] Dispenser control unit 840 can be coupled between detergent chamber 224 and liquid outlet 226 to provide dispense 620 with controllable release of the detergent solution by controlling liquid flow from detergent chamber 224 to liquid outlet 226. Dispenser control unit 840 can include a valve 842, a valve controller 844, and a conductivity sensor 846. Valve 842 is coupled between detergent chamber 224 and liquid outlet 226 and driven by a release signal. In one embodiment, valve 842 includes a unidirectional valve (as known as check valve) that allows for liquid flow in the direction from detergent chamber 224 to liquid outlet 226 only. Valve controller 844 can generate the release signal using a concentration signal indicative of the concentration of the detergent in the liquid collected from the washing tub of the dishwasher. For example, valve controller 844 can generate the release signal when the concentration signal indicates that the concentration of the detergent is below a specified (e.g., empirically determined) threshold during a cleaning cycle and stop generating the release signal when the concentration signal indicates that the concentration of the detergent reaches or exceeds the specified threshold or when the dishwasher is inactive between two cleaning cycles. Valve 842 releases the detergent solution from detergent chamber 224 only when the release signal is present.

[0046] Conductivity sensor 846 can sense the electrical conductivity of a liquid and produce the concentration signal indicative of the concentration of the detergent in that liquid. In various embodiments, conductivity sensor 846 is positioned to sense the electrical conductivity of the liquid in the dishwasher outside of the detergent dispenser. For example, conductivity sensor 846 can be positioned outside of the detergent dispenser to receive the liquid outside of the detergent dispenser or positioned within the detergent dispenser to receive the liquid that enters liquid inlet 222 before the liquid reaches detergent chamber 224. Conductivity sensor 846 can sense the electrical conductivity of the received liquid and produce the concentration signal. In various embodiments, in place of or in addition to sensing the electrical conductivity of the liquid in the dishwasher outside of the detergent dispenser, conductivity sensor 846 can be used to sense the electrical conductivity of the liquid in detergent chamber 224 and produce the concentration signal as an indication for the amount of the solid detergent remaining on detergent chamber 224. In such embodiments, end-of- detergent indicator 430 can produce the audible or visible alarm signal in response to the concentration signal falling below a specified threshold (indicating that the concentration of the detergent in detergent chamber 224 is below a threshold concentration).

[0047] Dispensing control units 740 and 840 are discussed by way of example, but not by way of limitation, to show how the release of the detergent solution can be controlled in dispenser 620. Other examples can include a combination of features of these dispensing control units. For example, another example of dispensing control unit 640 may include both cleaning cycle detector 746 and conductivity sensor 846 such that the release signal can be a function of both the operational state signal and the concentration signal. This allows dispensing control unit 640 to, for example, release the detergent solution from detergent chamber 224 when the concentration signal indicates that the concentration of the detergent in the liquid is below the threshold during the washing period only.

[0048] FIG. 9 is an illustration of an embodiment of a detergent dispenser 920 attached to a dishwasher rack 910. FIG. 10 is another perspective-view illustration of the embodiment of dispenser 920 attached to rack 910. Rack 910 represents an example of an implementation of rack 110. Dispenser 920 represents an example of an implementation of dispenser 120, 220, 420, and 620. [0049] Rack 910 can be a rectangular rack (illustrated in FIG. 9 as a squared open rack) that has 4 sidewalls 912 and a bottom panel 914 coupled to sidewalls 912. Bottom panel 914 has holes allowing the passage of liquid in the washing tub of the dishwasher during the washing and rinsing periods. In the illustrated embodiment, bottom panel 914 is a mesh bottom panel. In various embodiments, rack 910 can be an open rack or a peg rack and can have any shape and size suitable for being placed in a dishwasher.

[0050] Dispenser 920 is configured to be attached to rack 910 such that dispenser 920 can move with rack 910, thereby reducing unwanted movements of frame 920 during the cleaning cycles. Dispenser 920 can include a frame 950 that is configured to be attached to rack 910 for its dispensing operation. Frame 950 includes inner edges 956 that are to be connected to rack 910 around a perimeter of rack 910. In the illustrated embodiment, frame 950 has an upper portion 952 and a lower portion 954, and upper portion 952 has inner edges 956 for attaching frame 950 to a bottom portion of rack 910 by surrounding the perimeter of rack 910 at its bottom portion (i.e., attached to bottom portions of sidewalls 912 adjacent bottom panel 914). In various embodiments, frame 950 can be detachably attached to the bottom portion of rack 910. Inner edges 956 can be detachably connected to rack 910 around a perimeter of rack 910. In one embodiment, frame 950 is a snap-on frame that can be attached to the bottom portion of rack 910 with a snap. In various embodiments, frame 950 has a geometrical design that is compatible with the geometrical design of rack 910 and retrofittable into various dishwashers when being using with rack 910.

[0051] In the illustrated embodiment, frame 950 is a hollow frame formed by a frame wall having an interior surface defining at least a portion of a detergent chamber 924 for containing the solid detergent (e.g., in the form of tablets or pellets). A liquid inlet 922 is shown as a hole on the frame wall at a side of upper portion 952 of frame 950. A liquid outlet 926 is shown as a hole on the frame wall at the bottom of lower portion 954 of frame 950. For compatibility with rack 910 as illustrated, frame 950 has a rectangular shape (illustrated in FIG. 9 as a squared shape) having four inner edges 956 connected to the bottom portion of 4 sidewalls 912 of rack 910 when dispenser 920 is attached to rack 910. Each side of frame 950 is about 20-30 mm wide and 20-30 mm tall, with length and/or width depending on the length and/or width of rack 910. Frame 950 does not have a bottom panel connected to the sides, thereby minimizing it effect on movement of the liquid through rack 910 during the washing and rinsing periods.

[0052] In various embodiments, frame 950 includes detergent chamber 924 and, when needed, houses electronic and power supply. For example, when dispenser 220 is implemented as dispenser 920, detergent chamber 224 implemented as detergent chamber 924 can occupy the entire interior space of frame 950. When dispenser 420 is implemented as dispenser 920, detergent chamber 224 implemented as detergent chamber 924 can occupy the remaining interior space of frame 950 after end-of-detergent indicator 430 and power supply 432 are accommodated. When dispenser 620 is implemented as dispenser 920, detergent chamber 224 implemented as detergent chamber 924 can occupy the remaining interior space of frame 950 after end-of-detergent indicator 430, power supply 432, and dispensing control unit 640 are accommodated. In various embodiments, detergent chamber 924 are refillable, and frame 950 includes a door (not shown) for adding the solid detergent into detergent chamber 924. The door can be secured closed after each refill of the solid detergent. In various embodiments, liquid inlet 922 and liquid outlet 926 can each include one or more holes in any shape.

[0053] FIG. 11 is a side-view illustration of an embodiment of a detergent dispenser 1120 attached to rack 910. FIG. 12 is a cross-sectional view illustration of dispenser 1120. Dispenser 1120 represents an example of dispenser 920 that is an implementation of dispenser 620 (i.e., configured to include the components of dispenser 620). Dispenser 1120 includes inner edges 1156 to be connected to rack 910 around a perimeter of rack 910, thereby attaching dispenser 1120 to rack 910.

[0054] Dispenser 1120 includes a frame 1250 (e.g., to be implemented as frame 950) that can be attached to rack 910. Frame 1250 includes four hollow sides and an interior space distributed in the four sides. The interior space accommodates the component of dispenser 1120 including: • Detergent chambers 1224 A and 1224B: an example of detergent chamber 224;

• Dispensing control units 1240A and 1240B: an example of dispensing control unit 640;

• End-of-detergent indicator 1230: an example of end-of-detergent indicator 430; and

• Power supply 1232: an example of power supply 432, which supplies power to end-of-detergent indicator 1230 and dispensing control units 1240 A and 1240B.

It is noted that dispenser 1120 includes liquid inlet(s), liquid outlet(s), electrical connections between various components, and fluid conduits between various components, that are not seen in the cross-sectional view as illustrated in FIG.

12. It is also noted that the illustrated embodiments includes two sets of detergent chambers and dispensing control units as a specific example of component arrangement. In various embodiments, components the detergent dispenser can be arranged in various manners, including to various design constrains and considerations.

[0055] Some non-limiting examples (Examples 1-22) of the present subject matter are provided as follows:

[0056] In Example 1, an apparatus configured to be attached to a dishwasher rack and to dispense a solid detergent is provided. The rack is configured to be removably placed in a dishwasher capable of performing cleaning cycles. The apparatus includes a frame that may include inner edges to be detachably connected to the rack around a perimeter of the rack, a detergent chamber to accommodate the solid detergent, a liquid inlet in fluid communication with the detergent chamber to allow a flow of water into the detergent chamber to at least partially dissolve the solid detergent in the detergent chamber, and a liquid outlet in fluid communication with the detergent chamber to allow a flow of the detergent solution out of the detergent chamber.

[0057] In Example 2, the subject matter of Example 1 may optionally be configured such that the frame is configured to be detachably attached to the rack with a snap.

[0058] In Example 3, the subject matter of any one or any combination of Examples 1 and 2 may optionally be configured such that the frame includes a hollow frame formed by a frame wall having an interior surface defining the detergent chamber, and the liquid inlet and the liquid outlet each include one or more holes on the frame wall.

[0059] In Example 4, the subject matter of any one or any combination of Examples 1 to 3 may optionally be configured such that the frame further includes an end-of-detergent indicator including a transparent window incorporated onto the detergent chamber to allow for observation of an amount of the solid detergent in the detergent chamber.

[0060] In Example 5, the subject matter of any one or any combination of Examples 1 to 3 may optionally be configured such that the frame further includes an end-of-detergent indicator including a detergent sensor configured to sense a detergent level signal indicative of a level of the solid detergent remaining in the detergent chamber. The end-of-detergent indicator is configured to indicate an end of detergent in response to the sensed detergent level signal indicating that the level is below a threshold level.

[0061] In Example 6, the subject matter of Example 5 may optionally be configured such that the detergent sensor includes a conductivity sensor configured to sense a concentration signal indicative of a concentration of the detergent in the detergent chamber, and the end-of-detergent indicator is configured to indicate the end of detergent in response to the sensed concentration signal falling below a threshold concentration.

[0062] In Example 7, the subject matter of any one or any combination of Examples 1 to 6 may optionally be configured such that the frame further includes a dispensing control unit configured to actively control a volume of the flow of the detergent solution out of the detergent chamber.

[0063] In Example 8, the subject matter of Example 7 may optionally be configured such that the dispensing control unit includes a cleaning cycle detector configured to detect an operational state signal indicative of an operational state of the dishwasher, a valve coupled between the detergent chamber and the liquid outlet, the valve configured to be driven by a release signal, and a valve controller configured to generate the release signal using the sensed operational state signal. The release signal causes the valve to release a specified volume of the detergent solution for each cleaning cycle of the cleaning cycles. [0064] In Example 9, the subject matter of Example 7 may optionally be configured such that the dispensing control unit includes a conductivity sensor configured to sense a concentration signal indicative of a concentration of the detergent in the dishwasher, a valve coupled between the detergent chamber and the liquid outlet, the valve configured to be driven by a release signal, and a valve controller configured to generate the release signal when the sensed concentration signal indicates that the concentration is below a threshold concentration.

[0065] In Example 10, a system for dispensing a detergent solution from a solid detergent into a dishwasher capable of performing cleaning cycles is provided. The system may include a dishwasher rack and a frame. The dishwasher rack may be configured to be removably placed in the dishwasher. The frame may include inner edges to be connected to the rack around a perimeter of the rack, a detergent chamber to accommodate the solid detergent, a liquid inlet in fluid communication with the detergent chamber to allow a flow of water into the detergent chamber to at least partially dissolve the solid detergent in the detergent chamber, and a liquid outlet in fluid communication with the detergent chamber to allow a flow of the detergent solution out of the detergent chamber.

[0066] In Example 11, the subject matter of Example 10 may optionally be configured to further include the solid detergent, which includes a detergent agent and a rinse aid agent and is in a form of tablets or pellets.

[0067] In Example 12, the subject matter of any one or any combination of Examples 10 and 11 may optionally be configured such that the rack is a rectangular rack having four sidewalls and a bottom panel coupled to the four sidewalls, and the frame includes four inner edges each connected to a portion of a sidewall of the four sidewalls of the rack when the frame is attached to the rack.

[0068] In Example 13, the subject matter of Example 12 may optionally be configured such that the inner edges are configured to be detachably connected to the rack around the perimeter of the rack, such that the frame is configured to be detachably attached to the rack.

[0069] In Example 14, the subject matter of any one or any combination of Examples 10 to 13 may optionally be configured such that the frame further includes a dispensing control unit configured to controllably release the detergent solution from the detergent chamber to the liquid outlet. The dispensing control unit includes a cleaning cycle detector configured to detect an operational state signal indicative of an operational state of the dishwasher, a valve coupled between the detergent chamber and the liquid outlet, the valve configured to be driven by a release signal, and a valve controller configured to generate the release signal using the sensed operational state signal, the release signal causing the valve to release a specified volume of the detergent solution for each cleaning cycle of the cleaning cycles.

[0070] In Example 15, the subject matter of any one or any combination of Examples 10 to 13 may optionally be configured such that the frame further includes a dispensing control unit configured to controllably release the detergent solution from the detergent chamber to the liquid outlet. The dispensing control unit includes a conductivity sensor configured to sense a concentration signal indicative of a concentration of the detergent in the dishwasher, a valve coupled between the detergent chamber and the liquid outlet and to be driven by a release signal, and a valve controller configured to generate the release signal when the sensed concentration signal indicates that the concentration is below a threshold concentration.

[0071] In Example 16, the subject matter of any one or any combination of Examples 10 to 15 may optionally be configured such that the frame further includes an end-of-detergent indicator including a detergent sensor configured to sense a detergent level signal indicative of a level of the solid detergent remaining in the detergent chamber. The end-of-detergent indicator configured to indicate an end of detergent in response to the sensed detergent level indicating that the level is below a threshold level.

[0072] In Example 17, a method for operating a detergent dispensing system in a dishwasher is provided. The dishwasher is capable of performing cleaning cycles each including washing and rinsing periods. The method may include holding a solid detergent in a detergent chamber inside a frame configured to be attached to a dishwasher rack. The rack may be removably placed in the dishwasher. The frame may surround a perimeter of the rack when being attached to the rack. The method may further include collecting a portion of water sprayed into the dishwasher during the washing and rinsing periods using a liquid inlet on the frame, using the collected portion of water to form a detergent solution in the detergent chamber by at least partially dissolving the solid detergent, and releasing the formed detergent solution from the detergent chamber using a liquid outlet on the frame.

[0073] In Example 18, the subject matter of holding the solid detergent as found in Example 17 may optionally include holding tablets or pellets of a combination of detergent and rinse aid agents.

[0074] In Example 19, the subject matter of releasing the formed detergent solution from the detergent chamber as found in any one or any combination of Examples 17 and 18 may optionally include releasing the formed detergent solution from the detergent chamber through one or more holes on the frame. The one or more holes are sized to control a volume of the formed detergent solution to be released.

[0075] In Example 20, the subject matter of releasing the formed detergent solution from the detergent chamber as found in any one or any combination of Examples 17 and 18 may optionally include releasing a specified volume of the detergent solution from detergent chamber for each cleaning cycle of the cleaning cycles.

[0076] In Example 21, the subject matter of releasing the formed detergent solution from the detergent chamber as found in any one or any combination of Examples 17 and 18 may optionally include: sensing a conductivity signal indicative of a concentration of the detergent in a liquid in the dishwasher using a sensor incorporated into the frame, and controlling the release of the detergent solution from the detergent chamber using the conductivity signal.

[0077] In Example 22, the subject matter of any one or any combination of Examples 17 to 21 may optionally further include monitoring a level of the solid detergent remaining in the detergent chamber and producing an end-of-detergent alarm using an outcome of the monitoring.

[0078] This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. The scope of the present invention should be determined with reference to the appended claims, along with the full scope of legal equivalents to which such claims are entitled.