Abstract:
A spray assembly for an automatic dishwasher is provided comprising a conduit system for receiving pressurized washing liquid, and an elongated spray arm including an upper surface and a lower surface. The spray arm includes a dividing wall between the upper surface and the lower surface. The spray arm includes a plurality of orifices formed in the upper surface and the lower surface for distributing the liquid throughout the dishwasher. The dividing wall and the upper surface define an upper interior compartment and the dividing wall and the lower surface define a lower interior compartment. The conduit includes a water feed system and a water diverting mechanism for selectively diverting water into the upper compartment, the lower compartment, or both the upper and the lower compartments.

Description:
CROSS REFERENCE 
       [0001]    This application references U.S. patent application Ser. No. 12/330,607 entitled “Staggered Multi-Mode Spray Arm Wash System” filed Dec. 9, 2008, by Errin W. Gnadinger et al., the disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    This disclosure relates to dishwashing machines of the type used in households and commercial settings having upper and lower racks within which are arranged articles to be washed. Ordinarily the lower rack is loaded with larger size plates, pots and pans, and the like, and the upper rack is particularly designed to carry the smaller dishes, cups and glassware. Such dishwashing machines normally have one or more spray arms which rotate on a horizontal plane having orifices or jet holes which spray the washing and rinsing liquid upwardly and or downwardly against the dishes in the racks thereabove or therebelow depending on the location of the arm itself. One or more of these orifices or jet holes may be positioned so that the water streams issuing therefrom cause the spray arm itself to rotate thereby achieving maximum coverage of the dishes by the washing liquid. 
         [0003]    One of the problems associated with present spray arms, and associated water jets, is that they are typically either all on or all off. A reduction in water pressure and an increase in pump prime requirements usually results from attempting to increase total spray arm flow rate by adding additional jet holes to achieve additional spray arm coverage. 
         [0004]    This disclosure attempts to solve a problem inherent to spray arms, including mid-spray or middle spray arms, in which, based on conventional technology, will only spray upward onto the underside of the upper rack, leaving only the lower spray arm as the primary means to wash the lower rack. For example, when using ‘single rack wash’ in upper rack mode, the upper rack receives downward spray from the upper spray arm, and upward spray from the mid spray arm. However, when applying the current process of ‘single rack wash’ to the lower rack, only the lower spray arm is utilized, thus only upward spray is produced from the underside of the lower rack. 
       SUMMARY 
       [0005]    It is an object of this disclosure to provide an automatic dishwasher with an improved spray arm system having selective and distinct water flow paths that can be activated within the spray arms from a multi-mode water feed system. In addition, the present disclosure provides for independent control of at least two (2) different water circuits within a single spray arm. 
         [0006]    In one aspect of the disclosure, a spray assembly for an automatic dishwasher is provided comprising a conduit system for receiving pressurized washing liquid, and an elongated spray arm having at least one radially extending section including upper and lower walls or surfaces. The spray arm includes a dividing wall between the upper and lower surfaces. The spray arm includes a plurality of orifices formed in the upper wall and the lower wall for distributing the liquid throughout the dishwasher. The dividing wall and the upper wall define an upper interior compartment and the dividing wall and the lower wall define a lower interior compartment. The dual conduit includes a water feed system and a water diverting mechanism for diverting water into the upper compartment, the lower compartment, or both the upper and the lower compartments. 
         [0007]    In another aspect of the disclosure, a spray assembly for an automatic dishwasher, having a tub for receiving articles to be washed, is provided comprising a dual conduit system for receiving pressurized washing liquid, and an elongated rotatably mounted spray arm having an inlet hub and at least a first and a second radially extending section extending from the inlet hub. Each section includes a plurality of orifices for distributing the liquid throughout the dishwasher. The dual conduit includes a dual water feed system and a water diverting mechanism for diverting water into the first section, the second section, or both the first and the second sections. 
         [0008]    In yet another aspect of the disclosure, a spray assembly for an automatic dishwasher is provided comprising a conduit system for receiving pressurized washing liquid, and an elongated rotatably mounted multi-mode spray arm having at least a first and a second radially extending section. Each section includes a set of orifices for distributing the liquid throughout the dishwasher. The conduit system includes a dual water feed system and a water diverting mechanism for diverting water. The water diverting mechanism is operative to selectively divert water into the first section, the second section, or both the first section and the second section, or alternately into the first and the second sections. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a side elevation cut away view of the interior of a dishwashing machine with the spray arms in an operating mode in accordance with the present disclosure; 
           [0010]      FIG. 2  is a side elevation cut away view of the interior of a dishwashing machine with the spray arms in another operating mode in accordance with the present disclosure; 
           [0011]      FIG. 3  is a side elevation cut away view of the interior of a dishwashing machine with the spray arms in still another operating mode in accordance with the present disclosure; 
           [0012]      FIG. 4  is a partial cross sectional view of a middle or mid spray arm in accordance with a first embodiment of the present disclosure; 
           [0013]      FIG. 5  is a perspective view of the spray arms and conduit system in accordance with the first embodiment of the present disclosure; 
           [0014]      FIG. 6  is a top plan view, partially in section, of a middle spray arm in accordance with a second embodiment of the present disclosure; 
           [0015]      FIG. 7  is a side elevational view of the lower spray arm in accordance with the second embodiment of the present disclosure; and, 
           [0016]      FIG. 8  is a top plan view of the middle spray arm in accordance with a third embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    A water distribution system is provided in which the spray arm(s) can be controlled to spray upward, downward, both upward and downward, or to alternate between upward and downward by the dishwasher controller. 
         [0018]    One feature of this disclosure is the ability for the dishwasher control to select an upward spray mode or a downward spray mode for the middle or mid-spray arm. The result of the aforementioned improved functionality provides enhanced wash performance on the lower rack if the mid-spray arm is used in downward mode. It is to be appreciated, for a ‘normal’ cycle, the mid spray arm can be oscillated continuously between upward and downward mode (not illustrated). For a single rack wash’ mode, the spray arm can be directed exclusively upward ( FIG. 2 ) or exclusively downward ( FIG. 3 ), depending on whether single rack upper or single rack lower is being used. 
         [0019]    The present disclosure provides improved wash performance on the lower rack, in both ‘normal’ wash modes and ‘single rack lower’ wash modes. It is to be appreciated that independent spray arm controls can impact energy consumption and noise levels. For example, a single rack wash mode only will result in lower energy consumption and lower noise levels as compared to normal wash modes. The dishwasher control system can provide the necessary functional programs to provide either upward or downward spray from a single mid-spray arm. 
         [0020]    The embodiments of the proposed mid-spray arms provides for an improvement to the ‘single rack wash’ cycles on the dishwasher. ‘Single rack wash’ is currently a dedicated cycle that activates the mid and upper spray arms exclusively, and is intended exclusively for the upper rack. The present disclosure, shown in  FIGS. 1-8 , provides alternative ‘single rack wash’ systems with options that can be applied to a variety of different cycles, and will allow the consumer to choose, or alternate, between an ‘upper’ mode and/or a ‘lower’ mode in a variety of combinations to be detailed below. 
         [0021]    As shown in  FIGS. 1-3 , there is illustrated a cut away view of the interior of an automatic dishwashing machine  10  including a cabinet  11  defining therein a washing chamber or tub  12 . Access to the washing chamber or tub  12  is obtained by opening a door pivoted at its lower end and located on the front side of the cabinet  11 . Although not illustrated, it is to be appreciated that a dish rack can be supported for slidable movement within the washing chamber  12  so that it may be selectively slid outwardly through the cabinet&#39;s front access opening to facilitate loading and unloading of the items to be washed in the machine  10 . The lower end of the washing chamber  12  is defined by a bottom wall or floor portion  15  that separates it from a lower motor-pump compartment  16 . Housed within the compartment  16  is a motor-pump assembly including an electric motor (not shown) that drives a pump means  19  for recirculating washing liquid to and from the washing chamber  12  and for draining washing liquid from the washing chamber  12  outwardly to the household sewage system. The operational cycle of such a machine generally includes a number of washing and rinsing steps and a final drying step. In a dishwasher machine, such as that shown in  FIG. 1 , heated water from the household supply line is directed into the washing chamber  12  by valve means actuated by a timer control (not shown). The water accumulates to a predetermined level on the floor portion  15  and then the timer control of the machine causes the electric motor to be energized to drive the pump  19  in a recirculation operation. This method of fill is called the “static” method. A dynamic fill can also be used whereby the motor is energized and the pump goes into the recirculation mode during the time-controlled fill period. In the recirculation operation the accumulated washing liquid is drained out of the washing chamber  12  by means of a sump emptying into a conduit  21  leading to the pump  19 . The liquid can then be forced upwardly by the pump  19  through a conduit  22  leading selectively to hollow horizontally elongated spray arms  25 ,  27 ,  29  located within the washing chamber  12 . 
         [0022]    Generally, clean water is introduced into the machine for each wash step and again for each rinse step, and detergent is added, by automatic means (not shown), for the wash step. The term “washing liquid” is therefore used herein in a generic sense to refer broadly to any form of liquid utilized for recirculation within the dishwashing machine. The washing liquid can be selectively distributed from the spray arms  25 ,  27 ,  29  by means of orifices spaced therealong. The spray arms  25 ,  27 ,  29  can be reactively driven about inlet hubs  26 ,  28 ,  30 , respectively, by having at least one of the orifices disposed to discharge a jet stream in a direction such that the spray arm reacts to the force of the discharge and rotates in a horizontal plane. A thorough and generally uniform distribution of washing liquid in the washing chamber  12  is thereby obtained. Recirculation of the washing liquid from the washing chamber  12 , through the pump  19  and, thence selectively through the spray arms  25 ,  27 ,  29 , is continued for a predetermined length of time after which the electrical circuit to a drain valve means (not shown) causes the valve to automatically switch an outlet within the pump means  19  so that recirculation ceases and the pump  19  begins to discharge the washing liquid from the washing chamber outwardly through a drain hose leading ultimately to the household sewage system. 
         [0023]    Referring now to  FIGS. 1-5 , a selective spray arm system is provided wherein a water control system is constructed with a dual annulus inlet  40  such that two distinct water flow paths, via conduits  42 ,  44 , can be activated within the spray arm from a dual water feed system. The water feed system can take the embodiment of a multiple conduit system  22 ,  42 ,  44 ,  62 ,  64  in which a water diverter mechanism such as diverter valves  50 ,  52  may be controlled to select which path water will flow to the spray arms, thus activating, for example, either an inner  42  or an outer  44  conduit of the spray arm system. A spray arm may possess, for example, a set of upward jets and a set of downward jets that can be activated at different times during the cycle, or a set of upper jets and a separate set of outward spraying jets. One embodiment can provide for the mid spray arm  27  to be controlled to spray upward and/or downward, resulting in improved wash performance on a lower rack while also activating the existing lower spray arm  25 . The system may also provide sound reduction and energy reduction benefits that result from the control algorithms and flexibility in spray arm control to be described hereinafter. The present disclosure provides independent control of at least two different water circuits within the same spray arm. 
         [0024]    The system can utilize the multiple conduit water supply including diverter valves  50 .  52  for selective diversion of the water supply. As shown in  FIGS. 1-3  the primary conduit  22 ,  42 ,  44  can supply and divert water between the lower spray arm  25 , and the middle  27  and upper  29  spray arms. This arrangement of conduit paths enables the diversion of water flow selectively to the mid spray arm  27  and upper spray arm  29 . 
         [0025]    Referring again to  FIGS. 1-5 , wherein the additional, dual conduit  62 ,  64  is therein shown for the mid-spray arm  27 . Conduit  62 ,  64  enables the diversion of water to one mid-spray arm as shown, but could include other or additional intermediate spray arms. The mid spray arm  27  can have a dual inlet annulas  66 ,  68  and an internal division wall  74  between an upper  76  and lower  78  part such that inlet water flowing to the annulas  66  flows only to the upward orifices  77  of the mid spray arm, and water flowing to the annulas  68  flows only to the lower orifices  79  of the mid spray arm  27 . Furthermore, the system can utilize the diverter valve  52  assembled within the main conduit  22  at the location where the main conduit  22  goes from one path to two paths. The diverter valve  52  may consist of a magnetically controlled flapper or ball mechanism where the magnetic transparency of the stainless steel tub bottom may be utilized to keep the electrical portion of the diverter valve  52  on the dry side of the tub. 
         [0026]    It is to be appreciated that the total water jet coverage produced by mid spray arm  27  can be essentially doubled to include, for example, a full set of downward orifices  79  in addition to the traditional upward orifices  77 . The disclosure provides the ability to double a spray arm&#39;s area coverage without inducing a pressure drop in the water system or an increase in the prime (water usage), by providing a water distribution system capable of alternating flow paths (spray arm inlet annuli) throughout the cycle. The system can be optimized to achieve various performance enhancements such as improved wash in a target area of a rack, enhanced and targeted tubular heater jets for higher energy efficiency, as well as other sound reduction and energy efficiency enhancements. One feature of the present disclosure is the ability to selectively enable one of several possible spray modes of a spray arm through the use of: a multi-inlet annulus  66 ,  68  at the spray arm hub; a multi-water feed system (multi-conduit)  22 ,  42 ,  44 ,  62 ,  64 ; and, a water diverting mechanism  50 ,  52  to divert water into the desired flow path. 
         [0027]    As shown in  FIGS. 6-8 , the present disclosure provides alternative middle spray arm embodiments  127  ( FIG. 6) and 227  ( FIG. 8 ) with the ability to spray, for example, an inner annular region  182 A of dishes via orifices  177  and  181  distributed along a first section  182  of spray arm  127 , or an outer annular region  184 A, via orifices  180  and  179  distributed along a second section  184  of spray arm  127 . Section  182  comprises a hollow portion of spray arm  127  that is in fluid communication with its respective conduit (not shown) and inlet hub  128 , and section  184  comprises a hollow portion segregated from section  182  and in fluid communication with its respective conduit (not shown) and hub  128 . More specifically, orifices  177  and  181  are distributed along one or both of the upper and lower surfaces of section  182  such that when spray arm  127  completes a full rotation, the orifices sweep annular region  182 A. Orifices  179  and  180  are distributed along section  184  of spray arm  127  such that as spray arm  127  completes a full rotation, orifices  179  and  180  sweep the annular region  184 A. Orifices  179  and  180  are disposed at a greater radial distance from hub  128  relative to orifices  177  and  181 . Consequently the annular region  184 A circumscribes annular region  182 A. Spray arm  127  has the ability to spray dishes upward using orifices  177 ,  179  and/or downward using orifices  180 ,  181 . 
         [0028]    A targeted area to the side such as a heating element  135  can be sprayed via outwardly directed orifices  131  in the alternate bottom spray arm embodiment  125  for enhanced heat transfer. Alternative spray arm embodiment  227  (i.e. middle spray arm) has the ability to provide a relatively high velocity spray using orifices  283  from manifold  284  or relatively slow velocity spray using orifices  281  from manifold  282 . It is to be appreciated that the orifices  281 ,  283  can be of different diameters to facilitate the respective spray velocities. Any number and combination of the multiple modes described above can be implemented with this disclosure. 
         [0029]    Referring again to  FIGS. 2-3 , wherein single rack wash modes are illustrated. A ball valve, breakthrough ball valve, or magnetic ball valve  50  can be utilized to block water flow to the lower spray arm  25 , wherein the water is then directed to the mid spray arm  27  and upper spray arm  29 . In one illustrative example, valve  50  can selectively divert the water supply to LSA  25 . The valve  50  can be assembled within the conduit  22  and allow selective flow or shut-off of water. The conduit valve  50  can consist of a magnetically controlled flapper or magnetic ball valve mechanism (not illustrated) where the magnetic transparency of the stainless steel tub bottom may be utilized to keep the electrical portion of the conduit valves on the dry side of the tub to either shut off water flow or allow water flow. A ball can be contained within the conduit  22  and can be magnetically held in place remote from a sealing orifice when a valve actuator is de-energized, for example. A magnet can be located on one end of the valve actuator to hold the ball against the conduit wall and to allow water to flow therethrough. The magnet can include enough attraction in order to hold the ball through the stainless steel tub wall and the conduit wall. Because the magnetic ball valve can work through the stainless steel tub, a hole is not necessary through the tub wall or the conduit wall. This alleviates the potential for leaks. A motor, i.e. a wax push motor (not illustrated), can be positioned at a distal end relative to the magnet. When energized, the motor can push the distal end of the actuator thereby pivoting the magnet away from the tub wall. The ball is then free to move within the conduit and can then travel with the flow of water into a sealing orifice thereby stopping the flow of water. 
         [0030]    In particular, the water can be diverted into conduit  44 , and into conduit  62  of the mid spray arm  27 , wherein the water is directed to an upper compartment or first projection  76  such that the water is channeled and sprayed upward during a wash cycle. As shown in  FIG. 3 , the water flow can be diverted to the lower spray arm  25  and a mid spray arm  27 , and blocked from the upper spray arm  29 . In this embodiment, the water flow can be further channeled to the mid spray arm  27  via conduit  42 ,  64  wherein the water flows to a lower compartment or second projection  78  wherein the water flows downward during a wash cycle. The upper compartment  76  is defined by dividing wall  74  and an upper wall  75  of the spray arm. Similarly, the lower compartment  78  is defined by a lower wall  73  and the dividing wall  74  of the spray arm. In one selected arrangement, the water is directed to the upper compartment  76  and during a wash cycle is projected through the orifices  77  of the upper wall  75 . In another arrangement, the water is directed to the lower compartment  78  and during the wash cycle the water is projected downward through the orifices  79  of the lower wall  73 . It is to be appreciated that if the wash cycle includes a single upper rack mode or a single lower rack mode, the water will be directed to the upper compartment  76  and the lower compartment  78 , respectively, of the mid spray arm  27 . If the wash cycle includes a normal wash, both racks, the water can be directed to both the upper compartment  76  and the lower compartment  78  wherein the water is projected outward through the orifices  77 ,  79  of both the upper wall  75  and the lower wall  73 . The water being directed to both the upper and lower compartments  76 ,  78  can either be simultaneous and/or alternating from upper to lower and back again. The mid spray arm  27 , conduit and conduit valve system can be controlled such that the water sprays upward and/or downward as desired. 
         [0031]    As shown in  FIGS. 1-3 , examples of conduit systems are therein shown. The diverter valves  50 ,  52  are positioned such that water can be diverted to or from the lower spray arm  25 , the mid spray arm  27 , and/or the upper spray arm  29 . As displayed, the mid spray arm  27  includes a dual mid conduit  62 ,  64  that can provide water flow to either an upper compartment or a first compartment  76 , a lower compartment or second compartment  78 , or to both the upper and lower compartments  76 ,  78 . As shown in  FIG. 8 , the orifices  281 ,  283  of the respective first section  282  and second section  284  can be different thereby affecting flow rates from the first section and second section. Although not shown, it is to be appreciated that the water can be delivered to spray arms  127 ,  227  utilizing the conduit and valve arrangement as per the description for spray arm  27 . Similarly, water can be diverted to spray arm  125  utilizing the conduit and valve arrangement as per the description for spray arm  25 . It is further to be appreciated that water can flow from a variety of combinations of the middle spray arm embodiments  27 ,  127 ,  227 , for example, first section, second section, first and second sections concurrently, first and second sections alternating, first section upward, first section downward, second section upward, second section downward, first and second concurrently upward, first and second concurrently downward, alternating first and second upward, first and second downward, and differing flow rates from the first section relative to the second section 
         [0032]    It should be apparent to those skilled in the art that the embodiments described heretofore are considered to be the presently preferred forms of this disclosure. In accordance with the Patent Statutes, changes may be made in the disclosed mechanism and in the manner in which it is used without actually departing from the true spirit and scope of this disclosure.