Patent Publication Number: US-11375872-B2

Title: Dishwasher with tube wash system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 15/079,167, filed Mar. 24, 2016, now U.S. Pat. No. 10,750,924, which is hereby incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Contemporary automatic dishwashers for use in a typical household include a tub and at least one rack or basket for supporting soiled dishes within the tub. At least an upper rack and a lower rack for holding dishes to be cleaned are typically provided within the treating chamber. A silverware basket for holding utensils, silverware, etc. is also usually provided and normally removably mounts to the door or within the lower rack. 
     A spraying system can be provided for recirculating liquid throughout the tub to remove soils from the dishes. The spraying system can include various sprayers, including one or more rotatable sprayers. Various sprayers of the spraying system can be configured to spray toward the racks or silverware basket. One specific type of sprayer that can be included within the spraying system is a rotating spray tube having a plurality of spray holes or nozzles. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The invention relates to a dishwasher for treating dishes according to an automatic cycle of operation. In one aspect of the invention, the dishwasher includes a tub at least partially defining a treating chamber with an access opening, a sump fluidly coupled to the tub, and a liquid recirculation circuit fluidly coupling the sump to the treating chamber. The liquid recirculation circuit includes at least one rotating spray tube located adjacent the at least one wall. The at least one rotating spray tube comprises a hollow tube having first and second opposing ends with the first end fluidly coupled to the liquid recirculation circuit and the second end comprising a drain valve. The hollow tube has a single wall and a longitudinal body axis defining a rotational axis. The at least one rotating spray tube also comprises a plurality of spray nozzles provided in the single wall of the at least one rotating spray tube and arranged about the longitudinal body axis on an exterior of the single wall. Each of the spray nozzles comprises an inlet tube extending into an interior of the at least one rotating spray tube. Each inlet tube also has a single inlet opening and an angled or curved portion extending from each inlet tube further into the interior of the at least one rotating spray tube to define an end facing a liquid flow path through the at least one rotating spray tube and defining each single inlet opening. Each of the angled or curved portions extends into the interior of the at least one rotating spray tube to an extent that the longitudinal body axis passes through each inlet opening and through the end of each angled or curved portion. And, the liquid recirculation circuit also comprises a pump configured to draw liquid from the sump and pump the drawn liquid to the at least one rotating spray tube. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a schematic, cross-sectional view of a dishwasher with a spraying system according to an embodiment of the invention. 
         FIG. 2  is a schematic view of a control system for the dishwasher of  FIG. 1 . 
         FIG. 3  is a schematic front view of a dish rack and spray tube for use in the dishwasher of  FIG. 1 . 
         FIG. 4  is an enlarged perspective view of a rotating spray tube of  FIG. 3 . 
         FIG. 5  is an enlarged schematic side view of a spray nozzle for use with the rotating spray tube of  FIG. 4  according to an embodiment of the invention. 
         FIG. 6  is an enlarged, cross-sectional view of the rotating spray tube of  FIG. 3  according to an embodiment of the invention; 
         FIG. 7  is a schematic front view of a dish rack and spray tube for use in the dishwasher of  FIG. 1  according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
       FIG. 1  illustrates a schematic, cross-sectional view of an exemplary automated dishwasher  10  according to an embodiment of the invention. The dishwasher  10  shares many features of a conventional automated dishwasher, which will not be described in detail herein except as necessary for a complete understanding of the invention. A chassis  12  can define an interior of the dishwasher  10  and can include a frame, with or without panels mounted to the frame. For built-in dishwashers, outer panels are typically not needed. For dishwashers that are not built into existing cabinetry, the chassis  12  can include the panels mounted to the frame to form a cabinet for the dishwasher  10 . An open-faced tub  14  can be provided within the chassis  12  and can at least partially define a treating chamber  16  for washing or otherwise treating dishes. The open face of the tub  14  defines an access opening for the treating chamber  16 . 
     A closure element, such as a door assembly  18 , can be movably mounted to the dishwasher  10  for movement between opened and closed positions to selectively open and close the treating chamber access opening defined by the open face of the tub  14 . Thus, the door assembly  18  provides accessibility to the treating chamber  16  for the loading and unloading of dishes or other washable items. It should be appreciated that the door assembly  18  can be secured to the lower front edge of the chassis  12  or to the lower front edge of the tub  14  via a hinge assembly (not shown) configured to pivot the door assembly  18 . When the door assembly  18  is closed, user access to the treating chamber  16  can be prevented, whereas user access to the treating chamber  16  can be permitted when the door assembly  18  is open. Alternatively, the closure element can be slidable relative to the chassis  12 , such as in a drawer-type dishwasher, wherein the access opening for the treating chamber  16  is formed by an open-top tub. Other configurations of the closure element relative to the chassis  12  and the tub  14  are also within the scope of the invention. 
     Dish holders, illustrated in the form of upper, middle, and lower dish racks  20 ,  22 ,  24 , can be located within the treating chamber  16  and receive dishes for treatment, such as washing. The upper, middle, and lower racks  20 ,  22 ,  24  are typically mounted for slidable movement in and out of the treating chamber  16  for ease of loading and unloading. Other dish holders can be provided, such as a silverware basket, separate from or integral with any of the upper, middle, and lower racks  20 ,  22 ,  24 . As used in this description, the term “dish(es)” is intended to be generic to any item, single or plural, that may be treated in the dishwasher  10 , including, without limitation, dishes, plates, pots, bowls, pans, glassware, and silverware. While the dishwasher  10  is illustrated herein as having three dish racks  20 ,  22 ,  24 , it will be understood that any suitable number and configuration of dish racks is also within the scope of the invention. 
     A spray system can be provided for spraying liquid in the treating chamber  16  and can be provided, for example, in the form of an upper spray tube  26 , an upper middle spray tube  32 , a lower middle spray tube  28 , and a lower spray tube  30 . The upper spray tube  26 , the upper middle spray tube  32 , and the lower middle spray tube  28  are located, respectively, above the upper rack assembly  20 , above the middle rack assembly  22 , and above the lower rack assembly  24 . The lower spray tube  30  is located beneath the lower rack assembly  24 . By example, the illustrated spray tubes  26 ,  28 ,  30 ,  32  each include a connector  96  located at the rear end of the spray tube  26 ,  28 ,  30 ,  32  and adapted to mate or dock with a header  98  that is provided on a manifold  80 . The manifold  80  can be mounted at the rear of the tub  14 , such as to a supply tube  42 , or in any other suitable location. 
     It will be further understood that the spray tubes  26 ,  28 ,  30 ,  32 , while illustrated as being positioned beneath a central region of the dish racks  20 ,  22 ,  24 , can also be provided adjacent the opposing walls of the tub  14 . Further, at least two of the spray tubes  26 ,  28 ,  30 ,  32  can be adjacent different ones of the at least two opposing walls of the tub  14 , even being provided in such a configuration that the at least two spray tubes  26 ,  28 ,  30 ,  32  are provided adjacent opposing side walls as well as adjacent to the bottom of the same dish rack  20 ,  22 ,  24 , as is shown in  FIG. 7 . It will also be understood that each of the levels of spray tubes  26 ,  28 ,  30 ,  32  can comprise multiple spray tubes  26 ,  28 ,  30 ,  32  provided in parallel with one another and spread out horizontally across the width of the manifold  80 , which can extend generally from one side wall to another side wall of the tub  14 . 
     The spray tubes  26 ,  28 ,  30 ,  32  can be provided at an angle relative to the rack assemblies  20 ,  22 ,  24 . In an exemplary embodiment, a front or second end of the spray tube  26 ,  28 ,  30 ,  32  can be positioned in a higher position than the first or rear end of the spray tube  26 ,  28 ,  30 ,  32  where the connector  96  is located. While the spray tubes  28 ,  30 ,  32  are illustrated herein as being positioned at an angle, it will be understood that the angle of the spray tubes  26 ,  28 ,  30 ,  32  can be any suitable angle relative to the plane of the rack assemblies  20 ,  22 ,  24 , including a zero degree angle, or the spray tubes  26 ,  28 ,  30 ,  32  can be provided in a horizontal position at a 90 degree angle. Further, the spray tubes  26 ,  28 ,  30 ,  32  need not be provided at identical angles, and any combination of angles of the spray tubes  26 ,  28 ,  30 ,  32  is also within the scope of the invention. 
     The spray assemblies  26 ,  28 ,  30 ,  32  are illustrated as spray tubes by example but are not limited to only tubes. For example, the spray assemblies  26 ,  28 ,  30 ,  32  could comprise a combination of rotating spray arms and rotating or stationary spray tubes. Furthermore, the spray system can include additional and/or alternative spray assemblies. For example, a distribution header or spray manifold can be located at the rear of the tub  14  at any vertical position. An exemplary spray manifold is set forth in detail in U.S. Pat. No. 7,594,513, issued Sep. 29, 2009, and titled “Multiple Wash Zone Dishwasher,” which is incorporated herein by reference in its entirety. 
     A recirculation system can be provided for recirculating liquid from the treating chamber  16  to the spray system. The recirculation system can include a sump  34  and a pump assembly  36 . The sump  34  collects the liquid sprayed in the treating chamber  16  and can be formed by a sloped or recess portion of a bottom wall of the tub  14 . The pump assembly  36  can include both a drain pump  38  and a recirculation pump  40 . The drain pump  38  can draw liquid from the sump  34  and pump the liquid out of the dishwasher  10  to a household drain line (not shown). The recirculation pump  40  can draw liquid from the sump  34 , and the liquid can be simultaneously or selectively pumped through a supply conduit or tube  42 , into the manifold  80 , and then distributed to each of the spray tubes  26 ,  28 ,  30 ,  32  for selective spraying. The supply tube  42  and manifold  80  extend along a wall of the tub  14  and fluidly connect the pump assembly  36  to the at least one spray tube  26 ,  28 ,  30 ,  32 . 
     While not shown, a liquid supply system can include a water supply conduit coupled with a household water supply for supplying water to the treating chamber  16 . A heating system including a heater  44  can be located, for example, within the sump  34  for heating the liquid contained in the sump  34 . 
     A control system including a controller  46  can also be included in the dishwasher  10 , which can be operably coupled with various components of the dishwasher  10  to implement a cycle of operation. The controller  46  can be located within the door assembly  18  as illustrated, or it can alternatively be located somewhere within the chassis  12 . The controller  46  can also be operably coupled with a control panel or user interface  48  for receiving user-selected inputs and communicating information to the user. The user interface  48  can include operational controls such as dials, lights, switches, and displays enabling a user to input commands, such as a cycle of operation, to the controller  46  and receive information. 
     As illustrated schematically in  FIG. 2 , the controller  46  can be coupled with the heater  44  for heating the wash liquid during a cycle of operation, the drain pump  38  for draining liquid from the treating chamber  16 , and the recirculation pump  40  for recirculating the wash liquid during the cycle of operation. The controller  46  can be provided with a memory  50  and a central processing unit (CPU)  52 . The memory  50  can be used for storing control software that can be executed by the CPU  52  in completing a cycle of operation using the dishwasher  10  and any additional software. For example, the memory  50  can store one or more pre-programmed cycles of operation that can be selected by a user and completed by the dishwasher  10 . The controller  46  can also receive input from one or more sensors  54 . Non-limiting examples of sensors that can be communicably coupled with the controller  46  include a temperature sensor and turbidity sensor to determine the soil load associated with a selected grouping of dishes, such as the dishes associated with a particular area of the treating chamber  16 . 
     The dishwasher  10  can include all of the above exemplary systems, a selection of the above exemplary systems, and/or other systems not listed above as desired. Further, some of the systems can be combined with other systems and/or can share components with other systems. Examples of other systems that the dishwasher can further include are a dispensing system that supplies one or more treating agents or chemistries to the treating chamber  16  and an air supply system that may provide air, which can be heated or not heated, to the treating chamber  16 , such as for drying and/or cooling the dishes. An exemplary air supply system is set forth in U.S. patent application Ser. No. 12/959,673, filed Dec. 3, 2010 and published as U.S. Patent Application Publication No. 2012/0138106 on Jun. 7, 2012, both of which are incorporated herein by reference in their entireties. 
     Referring now to  FIG. 3 , a front view of an exemplary dish rack  22  and spray tube  28  is illustrated. The dish rack  22  can be constructed of a wire frame effectively forming opposing side walls  60 , front and rear walls (not shown), and a bottom wall  66  that together define an open-top holding compartment  68 . The bottom wall  66  can be completely flat, as illustrated by example, to form a flat bottom dish rack or it can have a varied configuration comprising a plurality of inclined and, possibly, flat walls that effectively forms an overall horizontal bottom of an inclined bottom. Additionally, a plurality of supports  70 , such as panels, tines, or other structures, can extend upwardly from the bottom wall  66  and/or the side walls  60 , or the front and rear walls (not shown) to support various dish items. 
     The dish rack  22  can be equipped with the spray tube  28  adapted to provide treating liquid to dish items placed on the dish rack  22 . The spray tube  28  can be stationary or can selectively rotate about its longitudinal axis. By rotating the spray tube  28 , the treating liquid can be sprayed in multiple spray angles and trajectories. In the case that the spray tube  28  is rotatable, rotation of the spray tube  28  can be driven by a single drive mechanism that is coupled directly to the spray tube  28 . It will also be understood that rotations of a plurality of spray tubes  26 ,  28 ,  30 ,  32  can be driven concurrently by a single unified drive mechanism that can control the rotation of multiple spray tubes  26 ,  28 ,  30 ,  32  by the use of, for example, a series of gears that connects the spray tubes  26 ,  28 ,  30 ,  32  and drives them all to rotate in parallel. The mechanism or actuator for driving the rotation of the spray tubes  26 ,  28 ,  30 ,  32 , either in series or individually, can be any suitable driving mechanism, non-limiting examples of which include an electric or hydraulic motor selectively operable to directly drive rotation of one or more spray tubes  26 ,  28 ,  30 ,  32  or a gear assembly, which could be provided in the form of a worm gear assembly, spur gears, etc. Nozzles on the spray tube  28  may be oriented such that the spray itself may cause the spray tube  28  to rotate. 
     The dish rack  22  is provided with an attachment mechanism  62  that extends downwardly from the bottom wall  66  of the dish rack  22  to attach to and support the spray tube  28 . The attachment mechanism  62  can be any suitable shape that provides support for the front end of the spray tube  28  and allows for selective rotation of the spray tube  28 . Non-limiting examples of such an attachment mechanism include a hook, a hanger, a bracket, etc. 
     The spray tube  28  can be fixedly mounted to the dish rack  22  by the attachment mechanism  62  for movement therewith when the dish rack  22  is slid relative to the tub  14 , or the spray tube  28  can be fixedly mounted to the tub  14  so as to retain its position relative to the tub  14  upon movement of the dish rack  20 . In the former case, the spray tube  28  can dock with the supply tube  42  ( FIG. 1 ) or other structure of the liquid supply and/or recirculation systems, such as the manifold  80 , when the dish rack  22  is slid to its most rearward position in the tub  14  to establish fluid communication with the liquid supply and/or recirculation systems. By example, the connector  96  ( FIG. 1 ) located at the rear end of the spray tube  28  can be adapted to selectively mate or dock with the header  98  ( FIG. 1 ) provided on the manifold  80 . The manifold  80  can be adapted to selectively mate or dock with the supply tube  42 . 
     The spray tube  28  can be provided with a plurality of spray nozzles  64  that can be positioned to spray treating liquid onto the dish items contained within the holding compartment  68  of the dish rack  22 . The spray nozzles  64  can be provided along the length of the spray tube  28  in any suitable configuration, which will be described in more detail below. The spray nozzles  64  can be provided on or slightly lifted away from the surface of the spray tube  28 , or they can be indented or recessed into the surface of the spray tube  28 . The volume and velocity of the treating liquid emitted from the spray nozzles  64  can be based on the type of dish item contained within the dish rack  22 , can be generic for all types of dish items, and/or can be variable from one treating cycle of operation to another and/or within a single treating cycle of operation. Additionally, the spray nozzles  64  can spray liquid alternately (e.g., between rows—one row at a time wherein the rows are sequenced on and off, within rows—sets of nozzles  64  within a row sequenced on and off), continuously, and/or intermittently. 
       FIG. 4  illustrates an enlarged perspective view of an exemplary embodiment of the spray tube  28  for use in the dishwasher  10  according to the disclosure herein. It will be understood that the spray tube  28  having such a structure and design can be used at any suitable position within the dishwasher  10  and can be provided in any suitable quantity necessary within the dishwasher  10  for providing sufficient treating liquid to the dishes being treated. The spray tube  28  has a longitudinal body  100  that is provided as a hollow, cylindrical tube. The spray tube  28  has a longitudinal body axis  102  that defines a rotational axis for the spray tube  28 . 
     The spray tube  28  can also be provided with a channel  106  provided on its surface. In an exemplary embodiment, the channel  106  spirals around the axis  102  of the spray tube  28  along the longitudinal length of the spray tube  28 . The spiral channel  106  can include any suitable number of revolutions about the axis  102  of the spray tube  28 . In an exemplary embodiment, the spiral channel  106  will complete at least one full revolution about the spray tube  28 . The channel  106  can be a recessed channel  106  in the surface of the spray tube  28 . It is also contemplated that the spray tube  28  can include an additional piece that wraps around the spray tube  28 , non-limiting examples of which include a decorative piece, which can be formed of metal, and which covers the surface of the spray tube  28  where no nozzles  64  are present. The nozzles  64  for supplying treating liquid to dishes can also be arranged in a spiral pattern about the longitudinal axis  102  of the spray tube  28  with or without a channel. In an exemplary embodiment, the nozzles  64  are located within the spiral channel  106 . 
     While the pattern of the nozzles  64  is illustrated as being a spiral pattern, it will also be understood that any suitable non-linear pattern of arrangement of the nozzles  64  is within the scope of the disclosure. By using a non-linear arrangement of the nozzles  64 , over-accumulation of treating liquid in the sump  34  at one time can be avoided. When the flow of treating liquid leaving the nozzles  64  all runs down at least one wall of the tub  14  to the sump  34 , the capacity of the pump assembly  36  to draw the liquid from the sump  34  can be exceeded. By varying the direction of the flow of treating liquid leaving the nozzles  64 , the over-accumulation of treating liquid can be prevented. It will be further understood that the nozzles  64  could also be arranged in a linear pattern if the nozzles  64  were not all oriented to release the spray in a uniform or linear direction. By example, all of the nozzles  64  on a spray tube  28  could be provided in a single line along the length of the longitudinal axis  102  so long as the nozzles  64  provided in the line were oriented or angled in such a way that the nozzles  64  did not all release the spray in the same direction. By further example, the nozzles  64  could alternate orientations with the spray being directed in an opposite direction between the two possible orientations. Alternatively, the nozzles  64  could vary slightly down in their orientation down the length of the longitudinal axis  102  such that the nozzles  64  gradually change the direction in which the spray is released from one end of the spray tube  28  to the other end. 
     The spray tube  28  can also be provided with an end cap  104  provided at the front end of the spray tube  28 . The end cap  104  at least selectively prevents treating liquid from exiting the spray tube  28  at the front end nearest the door assembly  18 . In one embodiment, the end cap  104  can be a solid plug that does not permit any treating liquid from exiting the front end of the spray tube  28 . In another embodiment, the end cap  104  can be provided as a drain valve that can selectively allow or prevent the escape of treating liquid from the front end of the spray tube  28 . Any suitable type of drain valve can be used within the end cap  104 , non-limiting examples of which include a flapper valve, check valve, or other type of pressurized valve. 
       FIG. 5  illustrates an enlarged cross-sectional view of a design for a nozzle  64  according to an embodiment of the invention. The nozzle  64  comprises a head portion  110  and an inlet tube  112 . The head portion  110  can have a cylindrical shape, a hexagonal shape, or any other suitable geometry. The inlet tube  112  extends from the exterior side of the spray tube  28 , passing through an opening  120  in the spray tube  28 , and into the interior  118  of the spray tube  28 . The inlet tube  112  can have an angled or curved portion  114  that defines an inlet opening  116  into which treating liquid can flow. The angle of the curved portion  114  can be any suitable angle for directing a flow of water in the spray tube  28  into the inlet tube  112 . The treating liquid flows from the back end to the front end of the spray tube  28  along the flow path indicated by the arrow  108 . The inlet opening  116  of the inlet tube  112  faces the liquid flow path  108 . Further, the inlet tube  112  and the angled portion  114  extend into the interior  118  of the spray tube  28  to an extent that the body axis  102  of the spray tube  28  passes through the inlet opening  116 . 
     While the spray tube  28  is illustrated herein as having nozzles  64  placed within openings  120  to direct the flow of treating liquid out of the spray tube  28 , in an additional embodiment of the invention, it is contemplated that the spray tube  28  could be provided only with openings  120  not having nozzles  64  placed within the openings  120 . The openings  120  can be drilled or formed so as to that allow the flow of treating liquid out of the interior  118  of the spray tube  28 . Without the nozzles  64  present to guide and direct the spray of the treating liquid, it is contemplated that the directionality of spray through the openings  120  can be determined by the angle at which the opening  120  is provided within the cylindrical body  100  of the spray tube  28 . For example, some openings  120  can pass straight through the spray tube  28 , perpendicular to the body axis  102 , while other openings  120  can be provided at angles in order to direct the spray of treating liquid in a different direction. Any suitable combination of angles of the openings  120  can be employed. The openings  120 , like the nozzles, can be provided in any suitable non-linear pattern, including the spiral pattern described above, or even in a linear pattern with varying angles of openings  120  such that the spray does not all leave the spray tube  28  in a uniform direction. 
       FIG. 6  illustrates an enlarged cross-sectional view of a spray tube  28  according to an embodiment of the invention. In this embodiment, the spray tube  28  has a through opening  120  which wash liquid can pass through to exit the spray tube  28 . The through opening has a centerline, which can form an angle relative to a tangent line on the surface of the spray tube  28 . Ideally, this angle is zero degrees relative to the tangent line, which would result in the centerline being tangential to the surface. However, practically, a tangential centerline for the through opening is not physically possible. In most cases, the centerline will form a small angle, generally less than 10 degrees, relative to the tangent line. 
     The purpose of such a through opening  120  that has a centerline tangent to the surface or forming a small angle relative to a tangent line is for the liquid being emitted to impart a rotational force to the spray tube  28 . These “tangent” through openings can be thought of a rotational through openings. Not all of the through openings need be “tangent” through openings to impart rotation to the tube. 
     In this case of “tangent” through openings, the center line of the through opening  120  does not pass through the longitudinal axis of rotation  102  of the spray tube  28 . While the through opening  120  is illustrated herein as not being provided with a nozzle  64 , it will be understood that a nozzle  64  could be inserted within the through opening  120  provided at the angle illustrated in  FIG. 6 . An orientation of the through opening  120  or nozzle  64  such as this could allow for the force of the spray of the wash liquid exiting the spray tube  28  to at least partially drive the rotation of the spray tube  28 . 
     In a traditional dishwasher, spray assemblies can be a significant contributor to space constraints. Using a rotating spray tube rather than a spray arm reduces the height of the spray assemblies and allows for more usable space in the dish racks. However, rotating spray tubes that spray treating liquid in a single line from multiple nozzles cause a large volume of liquid to flow down the walls of the tub in a single wave, resulting in an over-accumulation of water in the sump that may exceed the capacity of the pump for removing the liquid from the sump. Further, the treating liquid flowing down the wall or walls of the tub in a single wave can also increase turbulence in the water gathered in the sump, resulting in the pump taking in air. Aspects of the present disclosure provide similar or improved performance to contemporary appliances without requiring additional mechanics or increased space within the dishwasher. 
     To the extent not already described, the different features and structures of the various embodiments can be used in combination with each other as desired. That one feature may not be illustrated in all of the embodiments is not meant to be construed that it cannot be, but is done for brevity of description. Thus, the various features of the different embodiments can be mixed and matched as desired to form new embodiments, whether or not the new embodiments are expressly described. All combinations or permutations of features described herein are covered by this disclosure. 
     While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the forgoing disclosure and drawings without departing from the spirit of the invention which is defined in the appended claims.