Patent Publication Number: US-11019981-B2

Title: Dishwasher with rotationally mounted sprayer

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation of U.S. application Ser. No. 16/856,083, filed Apr. 23, 2020, now issued as U.S. Pat. No. 10,820,780, which is a divisional of U.S. application Ser. No. 13/928,787, filed Jun. 27, 2013, now issued as U.S. Pat. No. 10,667,668, both of which are incorporated by reference herein in their entirety. 
    
    
     BACKGROUND 
     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. A spraying system may be provided for recirculating liquid throughout the tub to remove soils from the dishes. The spraying system may include various sprayers including a rotatable sprayer. 
     BRIEF DESCRIPTION 
     The present disclosure relates to a dishwasher for treating dishes according to an automatic cycle of operation. The dishwasher has a tub at least partially defining a treating chamber with four corners and a sidewall, a recirculation system fluidly coupling at least two portions of the tub; and a sprayer fluidly coupled to the recirculation system and located within the treating chamber. The sprayer has a first conduit segment rotationally mounted relative to the tub for rotation about a first axis, a second conduit segment rotationally mounted to the first conduit segment at a location radially spaced from the first axis for rotation about a second axis, a spray head rotationally mounted to the second conduit segment at a location radially spaced from the second axis for rotation about a third axis, a drive link coupling the rotation of the spray head with the rotation of the first and second conduit segments; and a driver coupled to and moving one of the spray head, the first conduit segment, and the second conduit segment, thereby simultaneously rotating the spray head, the first conduit segment, and the second conduit segment. The first conduit segment and second conduit segment are axially aligned and the sprayer has an extended length when the spray head is at one of the four corners and the second conduit segment overlaps the first conduit segment and the sprayer has a retracted length when the spray head is adjacent the sidewall of the treating chamber. The spray head traverses a path having an outer boundary defining a squircle with four rounded corners corresponding to the four corners of the treating chamber 
     Another aspect of the present disclosure is a dishwasher for treating dishes according to an automatic cycle of operation. The dishwasher has a tub at least partially defining a treating chamber with four corners; a recirculation system fluidly coupling at least two portions of the tub; and a sprayer fluidly coupled to the recirculation system and located within the treating chamber. The sprayer has a first arm rotationally mounted to the tub such that the first arm rotates about a first axis, a second arm rotationally mounted to the first arm, at a location radially spaced from the first axis, such that the second arm rotates about a second axis, a spray head rotationally mounted to the second arm at a location radially spaced from the second axis, such that the spray head rotates about a third axis; a drive link coupling the rotation of the spray head with the rotation of the first and second arms; and a driver coupled to and moving one of the spray head, the first arm, and the second arm, thereby simultaneously rotating the spray head, the first arm, and the second arm. As first arm is rotated about the first axis, the second axis of the second arm is translated about the treating chamber along a first path. As the second arm is rotated about the second axis, the spray head moves along a second path with respect to the second arm. As the spray head is rotated about the third axis, the compounded rotation of the first arm and second arm translates the third axis of the spray head along a third path in the treating chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a schematic, cross-sectional view of a dishwasher with a spray system according to one aspect of the present disclosure. 
         FIG. 2  is a schematic view of a control system of the dishwasher of  FIG. 1 . 
         FIG. 3  is a top view of a rotatable sprayer of the spray system of the dishwasher from  FIG. 1 , illustrating the path of travel of the rotatable sprayer. 
         FIG. 4  is a cross-sectional view of the rotatable sprayer from  FIG. 3 . 
         FIG. 5  is an exploded view of the rotatable sprayer from  FIG. 3 . 
         FIG. 6  is a bottom view of the rotatable sprayer from  FIG. 3 , illustrating the path of travel of the rotatable sprayer. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1 , an automated dishwasher  10  according to one aspect of the present disclosure is illustrated. The dishwasher  10  can treat dishes according to an automatic cycle of operation. Depending on whether the dishwasher  10  is a stand-alone or built-in, the cabinet  12  may be a chassis/frame with or without panels attached, respectively. The dishwasher  10  shares many features of a conventional automatic dishwasher, which will not be described in detail herein except as necessary for a complete understanding of the invention. While the present disclosure is described in terms of a conventional dishwashing unit, it could also be implemented in other types of dishwashing units, such as in-sink dishwashers, multi-tub dishwashers, or drawer-type dishwashers. 
     A controller  14  may be located within the cabinet  12  and may be operably coupled with various components of the dishwasher  10  to implement one or more cycles of operation. A control panel or user interface  16  may be provided on the dishwasher  10  and coupled with the controller  14 . The user interface  16  may 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  14  and receive information. 
     A tub  18  is located within the cabinet  12  and at least partially defines a treating chamber  20  with an access opening in the form of an open face. A cover, illustrated as a door  22 , may be hingedly mounted to the cabinet  12  and may move between an opened position, wherein the user may access the treating chamber  20 , and a closed position, as shown in  FIG. 1 , wherein the door  22  covers or closes the open face of the treating chamber  20 . 
     Dish holders in the form of upper and lower racks  24 ,  26  are located within the treating chamber  20  and receive dishes for being treated. The racks  24 ,  26  are mounted for slidable movement in and out of the treating chamber  20  for ease of loading and unloading. 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; utensils, plates, pots, bowls, pans, glassware, and silverware. While not shown, additional utensil holders, such as a silverware basket on the interior of the door  22 , may also be provided. 
     A spraying system  28  may be provided for spraying liquid into the treating chamber  20  and is illustrated in the form of an upper sprayer  30 , a mid-level rotatable sprayer  32 , a lower rotatable sprayer  34 , and a spray manifold  36 . The upper sprayer  30  may be located above the upper rack  24  and is illustrated as a fixed spray nozzle that sprays liquid downwardly within the treating chamber  20 . The mid-level rotatable sprayer  32  is located between the upper rack  24  and the lower rack  26  and is illustrated as a rotating spray arm. The mid-level spray arm  32  may provide a liquid spray upwardly through the bottom of the upper rack  24 . The mid-level rotatable sprayer  32  may optionally also provide a liquid spray downwardly onto the lower rack  26 , but for purposes of simplification, this will not be illustrated herein. The lower rotatable sprayer  34  is located underneath the lower rack  26  and may provide a liquid spray upwardly through the bottom of the lower rack  26 . 
     The spray manifold  36  may be fixedly mounted to the tub  18  adjacent to the lower rack  26  and may provide a liquid spray laterally through a side of the lower rack  26 . The spray manifold  36  may not be limited to this position; rather, the spray manifold  36  may be located in virtually any part of the treating chamber  20 . While not illustrated herein, the spray manifold  36  may include multiple spray nozzles having apertures configured to spray wash liquid towards the lower rack  26 . The spray nozzles may be fixed or rotatable with respect to the tub  18 . 
     A liquid recirculation system may be provided for recirculating liquid from the treating chamber  20  to the spraying system  28 . The recirculation system may include a sump  38  and a pump assembly  40 . The sump  38  collects the liquid sprayed in the treating chamber  20  and may be formed by a sloped or recessed portion of a bottom wall  42  of the tub  18 . The pump assembly  40  may include both a drain pump  44  and a recirculation pump  46 . 
     The drain pump  44  may draw liquid from the sump  38  and pump the liquid out of the dishwasher  10  to a household drain line  48 . The recirculation pump  46  may draw liquid from the sump  38  and pump the liquid to the spraying system  28  to supply liquid into the treating chamber  20 . While the pump assembly  40  is illustrated as having separate drain and recirculation pumps  44 ,  46  in an alternative example, the pump assembly  40  may include a single pump configured to selectively supply wash liquid to either the spraying system  28  or the drain line  48 , such as by configuring the pump to rotate in opposite directions, or by providing a suitable valve system. While not shown, a liquid supply system may include a water supply conduit coupled with a household water supply for supplying water to the sump  38 . 
     As shown herein, the recirculation pump  46  has an outlet conduit  50  in fluid communication with the spraying system  28  for discharging wash liquid from the recirculation pump  46  to the sprayers  30 - 36 . As illustrated, liquid may be supplied to the spray manifold  36 , mid-level rotatable sprayer  32 , and upper sprayer  30  through a supply tube  52  that extends generally rearward from the recirculation pump  46  and upwardly along a rear wall of the tub  18 . While the supply tube  52  ultimately supplies liquid to the spray manifold  36 , mid-level rotatable sprayer  32 , and upper sprayer  30 , it may fluidly communicate with one or more manifold tubes that directly transport liquid to the spray manifold  36 , mid-level rotatable sprayer  32 , and upper sprayer  30 . Further, diverters (not shown) may be provided within the spraying system  28  such that liquid may be selectively supplied to each of the sprayers  30 - 36 . The sprayers  30 - 36  spray water and/or treating chemistry onto the dish racks  24 ,  26  (and hence any dishes positioned thereon) to effect a recirculation of the liquid from the treating chamber  20  to the liquid spraying system  28  to define a recirculation flow path. 
     A heating system having a heater  54  may be located within or near the sump  38  for heating liquid contained in the sump  38 . A filtering system (not shown) may be fluidly coupled with the recirculation flow path for filtering the recirculated liquid. 
     As illustrated in  FIG. 2 , the controller  14  may be provided with a memory  56  and a central processing unit (CPU)  58 . The memory  56  may be used for storing control software that may be executed by the CPU  58  in completing a cycle of operation using the dishwasher  10  and any additional software. For example, the memory  56  may store one or more pre-programmed cycles of operation that may be selected by a user and completed by the dishwasher  10 . A cycle of operation for the dishwasher  10  may include one or more of the following steps: a wash step, a rinse step, and a drying step. The wash step may further include a pre-wash step and a main wash step. The rinse step may also include multiple steps such as one or more additional rinsing steps performed in addition to a first rinsing. The amounts of water and/or rinse aid used during each of the multiple rinse steps may be varied. The drying step may have a non-heated drying step (so called “air only”), a heated drying step or a combination thereof. These multiple steps may also be performed by the dishwasher  10  in any desired combination. 
     The controller  14  may be operably coupled with one or more components of the dishwasher  10  for communicating with and controlling the operation of the components to complete a cycle of operation. For example, the controller  14  may be coupled with the recirculation pump  46  for circulation of liquid in the tub  18  and the drain pump  44  for drainage of liquid in the tub  18 . The controller  14  may also be operably coupled to the heater  54 . Further, the controller  14  may also be coupled with one or more optional sensors  60 . Non-limiting examples of optional sensors  60  that may be communicably coupled with the controller  14  include a moisture sensor, a door sensor, a temperature sensor, a detergent and rinse aid presence/type sensor(s). The controller  14  may also be coupled to a dispenser  62 , which may dispense a detergent during the wash step of the cycle of operation or a rinse aid during the rinse step of the cycle of operation. 
       FIG. 3  is a top view of the rotatable sprayer  34  and tub  18 . The sprayer  34  includes a spray head  64  and a conduit  66  that fluidly couples the spray head  64  to the recirculation system. The conduit  66  can include a first conduit segment  68  rotationally mounted relative to the tub  18  for rotation about a first axis X and a second conduit  70  segment rotationally mounted to the first conduit segment  68  at a location radially spaced from the first axis X for rotation about a second axis Y. The spray head  64  can be rotationally mounted to the second conduit segment  70  at a location radially spaced from the second axis Y for rotation about a third axis Z. The first and second conduit segments  68 ,  70  are shown herein as first and second arms, respectively, that each rotate about distinct axes X, Y. 
       FIG. 4  is a cross-sectional view of the lower rotatable sprayer  34  from  FIG. 3 . The conduit  66  defines a fluid path  72  extending through the first and second arms  68 ,  70  from the recirculation system to the spray head  64 , wherein the first arm  68  is fluidly coupled to the recirculation system and the second arm  70  is fluidly coupled to the spray head  64 . The arms  68 ,  70  may be at least partially hollow to define the fluid path  72 , with the first arm  68  defining an interior chamber  74  that fluidly communicates with an interior chamber  76  defined by the second arm  70 . The outlet conduit  50  is fluidly coupled to the first interior chamber  74  of the first arm  68  by a coupler  75 , which can releasably mount the first arm  68  to the outlet conduit  50 , such as via a bayonet-type mount. Seal rings  77  can be provided between the coupler  75  and the underside of the first arm  68 , between the top side of the first arm  68 , the underside of the second arm  70 , and between the top side of the second arm  70  and the underside of the spray head  64  to ensure a fluid-tight connection between the moving parts of the rotatable sprayer  34 . 
       FIG. 5  is an exploded view of the rotatable sprayer  34  from  FIG. 3 . The spray head  64  can include a spray body  78  and a spray cover  80  received on top of the spray body  78 . The spray body  78  can be supported by the second arm  70 , and the spray cover  80  can be supported by the spray body  78 , with the second arm  70 , spray body  78 , and spray cover  80  held together by a fastener assembly, such as shaft  82  which extends through the second arm  70 , spray body  78 , and spray cover  80  and nut  84  which attaches to the shaft  82  at the top of the spray cover  80 . The fastener assembly further includes a washer  86  located between a top side of the second arm  70  and the underside of the spray cover  80 . A slip ring  88  can be located between the top side of the spray cover  80  and the underside of the nut  84 . 
     The spray body  78  can be X-shaped, with four radially extending arms  90 , each of which is provided with one or more outlet nozzles  92  for spraying liquid. The outlet nozzles  92  can be oriented in the same or in a plurality of different directions such that the spray from the outlet nozzles  92  is projected at the same or in a plurality of different angles. At least one of the outlet nozzles  92  can be drive nozzles  94 , such that the rotation of the spray head  64  is driven by the spray from the drive nozzles  94 . As shown herein, the outermost nozzle on each arm  90  can be configured as a drive nozzle  94 . 
     The spray cover  80  can be disc-shaped, with a substantially circular outer periphery  96  that extends downwardly over the arms  90  of the spray body  78 , giving the spray head  64  an overall substantially circular outer periphery when viewed from above. The spray cover  80  includes one or more outlet passages  98  which are aligned with the one or more outlet nozzles  92  in the spray body  78  for spraying liquid. The spray cover  80  can further be provided with one or more openings  100 , which allows liquid and soil to pass through the spray cover  80  and past the spray body  78 , rather than accumulating on top of the spray head  64 . 
     Alternatively, the spray cover  80  of the spray head  64  can be eliminated, such that only the spray body  78  with the X-shaped profile remains as the spray head  64 . In still another configuration, the spray cover  80  can be eliminated and the spray body  78  itself can be disc-shaped. Configurations other than circular and X-shaped are also possible. 
     A driver is coupled to and moves one of the spray head  64 , the first arm  68 , and the second arm  70 , thereby simultaneously rotating the spray head  64 , the first arm  68 , and the second arm  70 . As shown herein the driver can include the drive nozzles  94  provided on the spray head  64  and the recirculation pump  46  ( FIG. 1 ) to which the drive nozzles  94  are fluidly coupled, such that the rotation of the sprayer  34  is driven by the spray from the drive nozzles  94 . Other examples of drivers include a motor. 
     A drive link couples the rotation of the spray head  64  with the rotation of the first and second arm  68 ,  70 . The drive link shown herein includes a first gear set  102  coupling the rotation of the second arm  70  with the rotation of the spray head  64  and a second gear set  104  coupling the rotation of the first arm  68  with the rotation of the second arm  70 . The drive link may be another suitable linkage system including one or more gears, cranks, belts, or a combination thereof. 
     The first gear set  102  can include a pinion gear  106  coupled at the head of the shaft  82  connecting the second arm  70 , spray body  78 , and spray cover  80  together such that the movement of the spray head  64  rotates the pinion gear  106 , and a spur gear  108  is fixed to one end of the first arm  68 . The spur gear  108  is received on a collar  110  at one of the first arm  68 , such that the spur gear  108  is fixed in place, with the pinion gear  106  progressing around the spur gear  108  as the spray head  64  rotates. As such, the spur gear  108  defines an orbital path for the spray head  64  with respect to the second arm  70 . 
     The second gear set  104  can be a gear train which includes a drive gear  112  coupled with the second arm  70 , a driven gear  114  carried on the first arm  68 , and one or more intermediate gears  116 ,  118  coupling the drive gear  112  and the driven gear  114 . The drive gear  112  can be a pinion gear coupled at one end of a shaft  120  holding the first and second arms  68 ,  70  together, such that the movement of the second arm  70  rotates the drive gear  112 . The driven gear  114  can be received on the coupler  75  which mounts the first arm  68  to the outlet conduit  50  ( FIG. 3 ). 
     Referring back to  FIG. 3 , the tub  18  includes four side walls  124  which extend upwardly from the bottom wall  42 . One of the side walls  124  can be defined by the closed door  22  ( FIG. 1 ) of the dishwasher  10 . The side walls  124  meet at and define four corners  126  of the tub  18 . While the tub  18  is shown herein as generally being square in shape with straight side walls  124  and corners  126  that are right angles, this is for illustrative purposes only, and the tub  18  can have other configurations. For example, the tub could be rectangular in shape, the side walls  124  could contain some irregularities, and or the corners  126  could be non-right angles or rounded. 
     The drive link can be configured such that the first arm  68  rotates at a lower revolutions per minute (RPM′) than the second arm  70  and the spray head  64  rotates at a higher RPM than the first arm  68  and the second arm  70 . In one example, the gear ratio of the first gear set  102  is 4:1 and the gear ratio of the second gear set  104  can be 6:1, which gives the spray head  64  a total mechanical advantage of  241 . Thus, the spray head  64  will rotate 24 times faster than the first arm  68 . With this mechanical advantage, if the first arm  68  rotates at 2.5 RPM, the spray head  64  will rotate at 60 RPM. Such a significant difference in the rotation speeds of the first arm  68  and the spray head  64  can allow the spray head to dwell in sections of the treating chamber  20  for longer periods of time and provide a localized, intense washing zone that moves slowly around the treating chamber  20 . 
     The dimensions of the rotatable sprayer  34  can also affect the cleaning performance. The spray head  64  can be configure to have a diameter of a little less than half of the width of the treating chamber  20  in order to maximize spray coverage. In one example, the spray head  64  can have a diameter of approximately 236 mm. The first arm  68  can be longer than the second arm  70  so that the first arm  68  has a longer period of rotation than the second arm  70 . In one example, the ratio of the length of the first arm  68  to the length of the second arm  70  is 6:1. 
     The third axis Z that passes through the center of the spray head  64  and the path A traversed by the center of the spray at the third axis Z comprises four corners corresponding to the four corners  126  of the treating chamber  20 . The actual spray path of the spray head  64  is wider, since the outlet nozzles  92  extend radially outwardly with respect to the third axis Z. As such, the spray head  64  traverses a path B having an outer boundary defining a squircle with four rounded corners corresponding to the four corners  126  of the treating chamber  20 . While the term squircle is commonly defined as a mathematical shape with properties between those of a square and a circle, and is a special case of a superellipse, as used herein, the term squircle is a shape that has qualities of both a square and a circle, and expressly includes a rounded square or squared circle. The path C of a typical center-mounted sprayer or wash arm is shown in  FIG. 3  for comparison. As can be seen in  FIG. 5 , the rotatable sprayer  34  increases the amount of spray coverage in the corners  126  of the treating chamber  20  in comparison to a typical center-mounted sprayer or wash arm. 
       FIG. 6  is a bottom view of the rotatable sprayer  34  and tub  18 , illustrating the path of travel of the rotatable sprayer  34  within the treating chamber  20 . During operation, the rotatable sprayer  34  can be driven by spraying liquid from the drive nozzles  94  on the spray head  64 . Liquid can be pumped to the nozzles by the recirculation pump  46  ( FIG. 1 ), through the first and second arms  68 ,  70 , to the spray head  64 , and out of the drive nozzles  94 . Liquid will also be sprayed out of the outlet nozzles  92 . 
     As the first arm  68  is rotated about the first axis X, the second axis Y of the second arm  70  is translated about the treating chamber  20  in a path D having a generally circular route. As the second arm  70  is rotated about the second axis Y, the spray head  64  moves in an orbital path E with respect to the second arm  70  having a smaller circular route. However, the spray head  64  is not limited to the path E, because as the spray head  64  is rotated about the third axis Z, the compounded rotation of the first and second arms  68 ,  70  translates the third axis Z of the spray head  64  along path A. Path A has a generally rectangular route in the treating chamber  20 , the rectangular route having four corners corresponding to the four corners  126  of the treating chamber  20  to provide a direct spraying in the four corners  126  of the treating chamber  20 . More specifically, the spray head  64  can move along a generally square route, especially in the case when the tub  18  has a substantially square shape. The shape of the path A can be tailored to the shape of the tub  18 , so that the spray from the spray head  64  can cover substantially the entire treating chamber  20 . 
     Several exemplary positions of the spray head  64  are shown in  FIG. 6 , including the four positions I-IV in which the spray head  64  is located at the corners  126  of the treating chamber  20 . In these positions, the first and second arms  68 ,  70  are axially aligned such that the rotatable sprayer  34  is at its maximum length. A fifth exemplary position V is also shown in  FIG. 6 , in which the spray head  64  is located at the center of one of the side walls  124  defining the treating chamber  20 . In this position, the first and second arms  68 ,  70  are axially aligned, but the end of the second arm  70  coupled with the spray head  64  overlaps the first arm  68 , such that the rotatable sprayer  34  is at its minimum length. In this way, the sprayer  34  and the drive link are configured to extend the spray head  64  into the corners  126  and retract the spray head  64  as it passes closer to the side walls  124  in a repeating, cyclical pattern. 
     There are several advantages of the present disclosure arising from the various features of the apparatuses described herein. For example, the aspect of the present disclosure described above allows for more complete spray coverage of the treating chamber using less water. For superior cleaning performance, it is best to flood the treating chamber with wash liquid. However, as less water is used in dishwashers in order to make them more energy efficient, this flooding action is harder to achieve. The rotatable sprayer  34  of the present disclosure solves this problem by flooding smaller sections of the treating chamber at a time, rather than trying to cover the entire treating chamber at one time. The rotatable sprayer  34  of the present disclosure effectively dwells the spray head  64  at different locations by slowing the rotation of the first arm  68 , such that the first arm  68  rotates much slower than the spray head  64 . 
     Another advantage is that the aspect of the present disclosure described above allows for better corner cleaning. Typical dishwashers employ sprayers that rotate in a circular path, and since the treating chambers are typically rectangular or square, the corners of the treating chamber may not experience as much spray action at the center. The rotatable sprayer  34  of the present disclosure solves this problem by mounting the spray head  64  on two rotating arms  68 ,  70  such that the compounded rotation of the first and second arms  68 ,  70  translates the spray head  64  into the corners of the treating chamber, but also pulls the spray head  64  back to clear the side walls of the treating chamber. 
     While the present disclosure 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.