CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of US provisional application 62/219,398 filed September 16, 2015, and hereby incorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to dishwashers and in particular to an appliance for use with dishwashers to improve dish drying.

BACKGROUND OF THE INVENTION

[0003] Dishwashers, such as those found in many homes, provide a washing chamber holding one or more racks sized to support eating utensils and cookware for cleaning. The washing chamber may be sealed by a door opening at the front of the washing chamber to allow loading and unloading of the chamber. The door is closed during a washing cycle to prevent the escape of water sprayed within the volume of the washing chamber during the washing of items placed in the racks. Upon completion of the washing cycle, a drying cycle is initiated during which water is drained from the washing chamber and moist air is discharged through a vent. Cool air, pulled by convection or by a fan into the chamber through a lower vent, flows upward, augmented by natural convection to dry the heated dishes.

[0004] Recent dishwasher designs may employ a one-piece tub, for example, of stainless steel, which defines the washing chamber and, when closed by the door, is sealed from communication with the outside air. The sealed nature of this chamber makes the promotion of air circulation for proper venting particularly difficult. Water droplets on the dishes after completion of the washing and drying cycle may require an additional manual step of drying the dishes before the dishes are put away in cupboards or the like.

SUMMARY OF THE INVENTION

[0005] The present invention provides an aftermarket appliance that can be inserted into a dishwasher along with the dishes and that may automatically activate during the drying cycle to augment the drying process. The appliance provides an enclosed dehumidification element that is exposed to the atmosphere of the dishwasher only during the drying cycle to help remove excess humidity from the drying air. The dehumidification element may be a chemical desiccant or a chilled condensing mass both of which can be regenerated in a base station into which the appliance may be inserted after each use. By providing an appliance that can be inserted in any standard dishwasher rack, the ability to provide improved drying in a wide range of dishwasher models is provided.

[0006] In one embodiment, the invention is a dish drying apparatus providing housing having an internal volume accessible through an opening in the housing and having a movable door operating in a closed state to seal the housing against moisture entering the housing and in an open state exposing the internal volume to outside moisture, the housing sized to be removably placed within a dishwasher supported by a dishwasher rack. A dehumidifier element fits within the internal volume and a door actuator, communicating with the door of the housing, determines the timing of a drying cycle of a dishwasher after the housing is placed in a dishwasher and, based on that determination, moves the door to the open state to expose the dehumidifier element to air within the dishwasher.

[0007] It is thus a feature of at least one embodiment of the invention to provide a product that can be installed in a dishwasher by a consumer to boost dish drying through the timed presentation of a dehumidifier element during the drying cycle.

[0008] The dish drying apparatus may include an electric fan positioned within the housing and may be further actuated by the door actuator to circulate dishwasher air past the dehumidifier element when the door is in the open state.

[0009] It is thus a feature of at least one embodiment of the invention to allow an extremely compact unit to effectively treat the humidity of a much larger dishwasher volume by repeated circulation of dishwasher air through the unit.

[0010] The door actuator may further operate after a predetermined period of time of activation of the fan to turn the fan off, the predetermined period of time selected to be a time after which the dehumidifier element will be saturated.

[0011] It is thus a feature of at least one embodiment of the invention to provide an energy efficient battery-powered dehumidification by controlling a battery-powered fan to operate for a period of time approximately matching the cycle life of the dehumidifier element.

[0012] The dish drying apparatus may include a recharging station and the housing may provide an electric power coupler and contain a rechargeable battery supplying power to the fan and for receiving electrical power from the recharging station when the housing is removed from the dishwasher and placed in the recharging station. [0013] It is thus a feature of at least one embodiment of the invention to provide a reusable dehumidifier element that can take advantage of the extended period between dishwashing cycles in a home environment to recharge in a simple base station.

[0014] The recharging station may further provide a source of electrical power for heating a desiccant used as the dehumidifier element to release moisture from the

dehumidifier element.

[0015] It is thus a feature of at least one embodiment of the invention to make use of a reusable desiccant as the dehumidifier element such as can be automatically "recharged" in the base station along with the battery.

[0016] The desiccant may include an integrated heater and the recharging station may provide electrical power to the integrated heater.

[0017] It is thus a feature of at least one embodiment of the invention to provide more efficient desiccant renewal through the use of an integrated heater eliminating any requirement for a heated cavity to receive the desiccant.

[0018] The dish drying apparatus may operate to activate the fan and opens the door when the housing is in place on the recharging station.

[0019] It is thus a feature of at least one embodiment of the invention to make use of the fan when the unit is in the base station for improved recycling of the dehumidifier element.

[0020] The desiccant may be zeolite.

[0021] It is thus a feature of at least one embodiment of the invention to provide a safe and recyclable desiccant material.

[0022] In an alternative embodiment, the recharging station may further provide a source of refrigeration for cooling a condensing mass used as the dehumidifier element.

[0023] It is thus a feature of at least one embodiment of the invention to provide dehumidification through thermal inertia of a chilled mass serving as a condensation surface.

[0024] The recharging station may support the housing to promote drainage of liquid water out of the housing through the door during recharging.

[0025] It is thus a feature of at least one embodiment of the invention to promote the release of condensed liquid from the unit during recharging.

[0026] The housing of the dish drying apparatus may have a volume substantially less than the volume of a standard drinking glass.

[0027] It is thus a feature of at least one embodiment of the invention to provide a unit that can fit easily on most dishwasher racks without special installation.

[0028] The door may be a flap that opens by moving into the housing. [0029] It is thus a feature of at least one embodiment of the invention to provide a door that can open within a tightly loaded dishwasher without being obstructed by adjacent dishes or the like.

[0030] The dish drying apparatus may include a second door positioned opposite the first door to provide for crossflow and the first and second doors maybe actuated by the door actuator.

[0031] It is thus a feature of at least one embodiment of the invention to greatly increase airflow through the unit for a given size fan and power consumption rendering a rechargeable unit practical for improved dehumidification.

[0032] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Fig. 1 is a left-side perspective view of a conventional beneath-the-counter dishwasher with its door open to show insertion of the appliance of the present invention into the dishwasher after removal from a base station;

[0034] Fig. 2 is an exploded cross-sectional view of the appliance and base station in a first embodiment showing the dehumidification element exposed to the air through an elevated end cap so that air may be drawn by a fan downward across a chemical desiccant;

[0035] Fig. 3 is a simplified block diagram of the electrical components of the appliance of Fig. 2;

[0036] Fig. 4 is a flow chart of a program executed by the appliance of Fig. 1 during a drying cycle when the appliance is placed in the dishwasher;

[0037] Fig. 5 is a program executed by the appliance of Fig. 1 when the appliance is returned to the base station for regeneration;

[0038] Fig. 6 is a figure similar to that of Fig. 2 showing an alternative dehumidification element employing a condensing mass; and

[0039] Fig. 7 is a simplified cross-section similar to that of Fig. 2 showing an alternative embodiment of the appliance providing crossflow through separate doors.

[0040] Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of "including" and "comprising" and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] Referring now to Figs. 1 and 2, a dishwasher 10 may include a washing chamber 12 into which dishes and cutlery 14 may be placed for washing on racks 16. The washing chamber 12 may be accessed through an openable door 18 that seals against a front lip of the washing chamber 12. The dishwasher 10 may provide for a washing of the dishes and cutlery 14 through various stages termed "cycles" including a washing cycle in which water is forcibly sprayed on the dishes and cutlery 14 and a drying cycle during which the spraying of water in the washing chamber 12 ceases and water is drained away from the dishes and cutlery 14. The drying cycle may include a heating of the washing chamber 12 and circulation of air through the washing chamber 12.

[0042] A dish drying apparatus 20 of the present invention may be removed from a base station 22 and, as indicated by arrow 24, inserted into the dishwasher 10, for example, on one of the racks 16 in the manner of the dishes and cutlery 14. The base station 22 may, for example, be positioned on a nearby counter and may have line cord 26 providing power to the base station 22 from a wall outlet 28 or the like for use when the dish drying apparatus 20 is being regenerated in between uses in the dishwasher 10.

[0043] Referring now to Fig. 2, the dish drying apparatus 20 may provide for a housing 30 having a body portion 31 interfitting with a movable end cap 32 providing a door. In one embodiment, the housing 30 maybe sized to be approximately equal to the size of a drinking glass or between approximately 200 cubic centimeters and 400 cubic centimeters to fit easily on the racks 16 without substantially decreasing washing capacity of the dishwasher 10. The body portion 31 and end cap 32 provide a watertight and humidity resistant interior volume when the end cap 32 is in a closed state positioned against the body portion 31. The housing 30 may be constructed, for example, of a thermoplastic material and may include elastic seals or the like between the end cap 32 and body portion 31 to provide the necessary sealing.

[0044] The end cap 32 may be separated from or sealed against the body portion 31 by operation of an internally contained linear actuator 34, for example, being a wax motor, DC electric motor and gear system, , a servomotor, an electrical solenoid or the like. The linear actuator 34 may provide an extendable shaft 36 aligned generally along a longitudinal axis 38 of the housing 30 to extend upwardly (as shown) when the linear actuator 34 is actuated to elevate the end cap 32 away from the body portion 31 in an open state allowing the flow of moist air 46 into the interior volume of the housing 30.

[0045] Positioned within the volume of the housing 30 generally along the axis 38 beneath the actuator 34 is a propeller-style fan 40 driven by a DC motor 42 that can draw moist air 46 in through the opening between the end cap 32 and the body portion 31. This moist air 46 may pass along the inner surface of a tubular dehumidification element 48 concentrically surrounding the fan 40. The entering moist air 46 proceeds downward to the bottom of the interior of the housing 30 and then may pass upward as drier air 50 flows along the outer surface of the dehumidification element 48. In this way, air may be drawn through the appliance and be dried by the dehumidification element 48 under the influence of the fan 40.

[0046] The dehumidification element 48 may be, for example, a chemical

dehumidification element such as a desiccant. In one embodiment the desiccant may be zeolite being a microporous aluminosilicate capable of absorbing water and being

regenerated by subsequent heating to dry off the absorbed water. Other desiccants such as silica gel and the like are also contemplated. For the purpose of this regeneration, electrical heating elements 52 are applied to the inner and outer surfaces of the dehumidification element 48 to later heat the dehumidification element 48 while providing gaps that expose the dehumidification element 48 to passing air. The electrical heating elements 52 may, for example, be high resistance wire heating elements or conductive polymer materials of the type known in the art. These electrical heating elements 52 are arranged to allow maximum exposure of the dehumidification element 48 to the moist air 46 and exiting drier air 50 and to this end may also or alternatively be embedded within the dehumidification element 48.

[0047] One or more environment sensors 54 may be exposed on an outer surface of the housing 30 and may communicate with circuitry on the inside of the housing 30 as will be discussed below. This environmental sensor may be, for example, a humidity sensor, a water sensor, a temperature sensor, or combination of these. Alternatively, a vibration sensor may be used which may be either outside or inside of the housing 30. In addition an indicator light 55 may be exposed on the outer surface of the housing 30 (or visible through a transparent and sealed window) also communicating with circuitry inside the housing 30 as will be discussed below.

[0048] Centered at the bottom of the housing 30 may be an inwardly extending cavity 57 whose walls protrude into the housing volume while sealing the cavity 57 from the interior of the housing 30. The walls of the cavity 57 within the housing 30 are surrounded by an induction coil 60 wrapped coaxially therearound.

[0049] The cavity 57 may receive a corresponding boss 62 of the base station 22 when the housing 30 is placed on the base station 22. The boss 62 may include a transformer core element 64 extending upwardly into the boss 62 to magnetically couple with the induction coil 60 when the housing 30 is installed on the base station 22. The transformer core element 64 is wound with a solenoid 66 which provides a primary winding of a transformer formed by the solenoid 66, the core element 64, and the induction coil 60. The solenoid 66 may be powered by a power module 68 receiving line power through line cord 26 and adjusting it in current, voltage, and frequency to maximize power transmission into the induction coil 60. The induction coil 60 may communicate with a printed circuit board 56 within the housing 30 of the dish drying apparatus 20. Power processing circuitry on the printed circuit board 56 may rectify and voltage-regulate the received power. The power processing circuitry may also communicate with rechargeable batteries 70 that may be charged by power obtained from the base station 22.

[0050] Referring also to Fig. 3, the printed circuit board 56 thus provides for electrical communication with the batteries 70, the actuator 34, the fan motor 42, the heater elements 52, the induction coil 60, the indicator light 55, and the external sensor 54. Outputs of power to the fan motor 42, the heating element 52, the actuator 34, and the indicator light 55 may be provided by outputs from a microcontroller 76 either directly or through interface circuitry such as transistors or the like. Inputs from the sensors 54 may be provided to an input of the microcontroller 76, for example, an analog-to-digital converter input. The microcontroller 74 may communicate with memory 78, for example, holding a program 80 and stored program values 81, for example, in nonvolatile memory. Power to the printed circuit board 56 and its components is provided by the batteries 70 which may be recharged through induction coil 60 and power processing circuitry 83 (shown separately for clarity but preferably provided on the printed circuit board 56).

[0051] Referring now to Figs. 2 and 4, the program 80 executed by the microcontroller 74 on the printed circuit board 56 may operate to move to the dish drying apparatus 20 into an "arm" state indicated by process block 82 when the dish drying apparatus 20 is removed from the base station 22 as sensed by the loss of electrical power from the base station 22. At this time, the end cap 32 will have been drawn tightly against the body portion 31 and the indicator light 55 may indicate that the unit is ready for use, for example, by changing from a red to a green signal color. Alternatively the dish drying apparatus 20 may be armed, for example, by pressing the button or the like (not shown) by the user.

[0052] The armed unit may be placed in the dishwasher 10 and as so positioned, monitor the sensor 54 to detect the drying cycle per decision block 84. This detection may make use of one or more of the combination of detecting surface moisture, air humidity, air

temperature, and vibration as well as time duration. Generally, the detection of the drying cycle is intended to occur somewhat after the drying cycle is underway but it may also occur successfully after this time. Several approaches to detection can be used. A low-frequency vibration sensor can detect a conclusion of water spray and pumping associated with washing and a period of time after the last vibration is sensed can be considered a drying cycle. A simple timer from the time that the dish drying apparatus 20 is armed may also be used or combined with vibration sensing. A liquid water sensor or humidity sensor can also be used to detect the beginning of the drying stage by the lack of water and decreased humidity. Likewise temperature will decrease at least by the conclusion of the drying cycle after significant increases that may be used to deduce the drying cycle conclusion.

[0053] After the drying cycle has begun, the program 80 moves to process block 86 and the housing 30 is opened by extending the end cap 32 from the body portion 31 to allow air within the dishwasher cavity to flow into the dish drying apparatus 20. It is primarily important that this operation not be performed during the washing operation such as would allow the entry of water which would overwhelm the contained dehumidification element 48.

[0054] At process block 88, the fan 40 is then activated to increase the airflow past the dehumidification element 48 to remove moisture from moist air 46 and to discharge the drier air 50 back into the dishwasher cavity.

[0055] At process block 90, a timer is interrogated (for example, internal to the microcontroller 76) to determine how long the fan 40 has been activated and after a given period of time, for example, thirty minutes, or based on a humidity sensing of the external sensor 54, the fan 40 is stopped as indicated by process block 92 with the dishes having reduced retained water as a result of the reduction of interior humidity of the dishwasher 10. This time may substantially be the time at which the drying capabilities of the

dehumidification element 48 are fully expended. An internal flag is set in memory 78 indicating that the dehumidification element 48 has been used and needs to be regenerated and the end cap 32 may be closed and the indicator light illuminated (e.g., red) to indicate regeneration is required. [0056] Referring now to Fig. 5, when the dish drying apparatus 20 is returned to the base station 22, as determined by a return of power through the induction coil 60 at process block 94, the flag indicating whether regeneration is necessary is interrogated at process block 100. If regeneration is required, the program 80 proceeds to process block 102 and the end cap 32 is opened by actuation of the linear actuator 34. At process block 104, the fan 40 is activated and at process block 106 the heater elements 52 are also activated to heat the desiccant material of the dehumidification element 48 to remove moisture therefrom. After a predetermined period of time, indicated by decision block 108, the end cap 32 may be closed, the fan 40 stopped, and the heating elements 52 cooled in conclusion of the regeneration cycle. The program 80 then proceeds to the stop state 110 and a green indicator light 55 is illuminated indicating the dish drying apparatus 20 is ready for use again.

[0057] Referring now to Fig. 6, in an alternative embodiment, the dehumidification element 48 may be a condensing mass 111, for example, a high specific heat material incorporating heat-exchanging surfaces 112 to help exchange heat between the condensing mass 111 and moist air 46. The condensing mass 111 may, for example, be a solid metal material such as aluminum or steel or a phase change material held in a conductive envelope.

[0058] The condensing mass 111 serves to cool the moist air 46 and condense moisture therefrom by this cooling. The condensing mass 111 of dehumidification element 48 may thermally communicate through the bottom of the housing 30 with a thermal conductor connector 114 on the base station 22 releasably connecting the condensing mass 111 to one side of a Peltier device 1 16. The opposite side of the Peltier device 116 communicates with a base station heatsink 118 that may communicate with ambient air through openings 120 in the base station 22.

[0059] During the regeneration cycle of Fig. 5, the microcontroller 76 may communicate with the base station 22 through electrical connectors 122 to provide a two- stage regeneration process during process block 106. During the first stage, the Peltier device 116 is operated to heat the condensing mass 111 to help evaporate moisture accumulated in the housing 30 during the drying process. After a predetermined period of time, the Peltier device is electrically biased in reverse to cool the condensing mass 111 for use in the dishwasher 10 to dry the air. Once the condensing mass 111 is fully cooled, the green indicator light 55 may be illuminated.

[0060] It will be understood that during the regeneration cycle, the batteries 70 may be recharged and that relatively little power is required from the batteries 70 which operate only the fan 40, whereas the heating or cooling of the dehumidification element 48 can be performed using line power.

[0061] Referring now to Fig. 7, in an alternative embodiment, the housing 30 may have door flaps 124a and 124b positioned at opposite ends of the housing 30 standing in lieu of the end cap 32. These door flaps 124 may pivot at pivots 126 inside the housing 30 between closed positions (as shown) to open positions by movement inward as indicated by arrow 128. The latter open positions allow cross flow of moist air 46 through the interior of the housing 30 past a condensing mass 111, for example, in the form of a finned metal component. This airflow may be under the influence of a fan 40 operating as described above. Both door flaps 124 may be simultaneously activated by a linkage to actuator 34 during the drying cycle. Activation of the door flaps 124 and the fan 40 will be analogous to the operation of the end cap 32 and fan 40 as described above.

[0062] When the dish drying apparatus 20 is placed in the dishwasher 10, the housing 30 may be oriented so that the door flaps 124a and 124b are in a horizontal opposition. The inward movement of the door flaps 124 prevents this opening from being obstructed by dishes or the like on the rack on which the dish drying apparatus 20 is placed within the dishwasher.

[0063] When the dish drying apparatus 20 is installed on the base station 22, one of the door flaps 124b may be positioned downwardly so that water condensed by the condensing mass 111 in the housing 30 may flow out of the flap 124b downward into a receiving basin 130 or the like built into the base station 22. In this embodiment both power and data may be communicated through connectors 122. In other respects, the operation of the dish drying apparatus 20 of Fig. 7 will be as described above with respect to the embodiments of Fig 6.

[0064] It will be appreciated that other methods of opening and closing the housing 30 may be provided including, for example, sliding doors, irises, and the like.

[0065] Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as "upper", "lower", "above", and "below" refer to directions in the drawings to which reference is made. Terms such as "front", "back", "rear", "bottom" and "side", describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms "first", "second" and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. [0066] When introducing elements or features of the present disclosure and the exemplary embodiments, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of such elements or features. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0067] References to an electric fan can be understood to include propeller type fans, squirrel cage type centrifugal air pumps, and the like unless otherwise noted.

[0068] It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties. Various features of the invention are set forth in the following claims. It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The

embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention.