Dishwashing System and Impeller Driven Manifold

The present specification generally relates to an inline fluid-driven impeller manifold for driving a gear system, and more specifically, to an impeller driven manifold for one or more oscillating spray tubes in a dishwashing system.

In conventional dishwashing machines, a common approach to distributing water and cleaning agents within the machine's internal volume involves the use of static spray arms or rotating spray bars. These devices typically extend horizontally across the machine and emit water jets upward and/or downward to clean the dishware. While functional, these conventional systems are often inefficient in terms of water usage and mechanical complexity. Specifically, many systems waste water through the use of external propellers or spray arms that require excessive water flow for movement, which does not contribute to the cleaning process. Additionally, these systems may fail to provide uniform water distribution, leading to inconsistent cleaning results. Accordingly, a need exists for a dishwashing system that provides consistent cleaning results without wasting water usage.

The following disclosed system, components, and methods facilitate the efficient distribution of wash fluid within a dishwasher. The herein-described embodiments address the problems associated with the art by providing a system that does not waste water, is cost-efficient, and provides for the targeted, limited oscillatory motion of spray tubes within a dishwasher.

Embodiments disclosed herein include a dishwasher comprising: a housing defining a washtub; a plurality of racks disposed within the washtub; and a manifold in fluid communication with recirculation fluid within the washtub. The manifold further comprises an impeller positioned in fluid communication with an inlet of the manifold; a drive gear system mechanically coupled to the impeller via a drive shaft; a transmission shaft mechanically coupled to the drive gear system; and a spray tube coupled to the transmission shaft. The spray tube is fluidly coupled to the inlet of the manifold and is configured to oscillate to distribute fluid onto items positioned within the washtub.

Other embodiments include a dishwasher comprising: a housing defining a washtub; at least one dishware rack slidably disposed within the washtub from a loading position to a wash position; and at least one manifold coupled to a rear side of the at least one dishware rack. The manifold further comprises an inline impeller in fluid communication with a fluid inlet of the manifold and having an axis of rotation collinear with a fluid path of fluid entering the fluid inlet; a drive gear system mechanically coupled to the impeller via a drive shaft; a transmission shaft mechanically coupled to the drive gear system; and at least one spray tube in fluid communication with the fluid inlet. The at least one spray tube is mechanically coupled at one end to the transmission shaft via a drive oscillator and at the other end to a front side of the at least one dishware rack. The at least one spray tube is configured to oscillate to distribute fluid onto items positioned within the at least one dishware rack.

Other embodiments include a dishwasher comprising: a housing defining a washtub; at least one rack slidably disposed within the washtub; and at least one manifold coupled to a rear side of at least one rack and having a fluid inlet in fluid communication with recirculated fluid within the washtub. The manifold further comprises an impeller positioned in fluid communication with the fluid inlet and rotatable about an impeller axis that is collinear with a fluid path entering the fluid inlet; a drive gear system mechanically coupled to the impeller via a drive shaft that is also collinear with the fluid path entering the fluid inlet; a transmission shaft mechanically coupled to the drive gear system; at least one spray tube in fluid communication with the fluid inlet, the at least one spray tube having a first end and a second end, the first end mechanically coupled to the transmission shaft via a drive oscillator, the second end being coupled to the at least one rack so as to allow the at least one spray tube to rotate about its longitudinal axis; and a range-limiting component configured to limit the range of rotation of the at least one spray tube for targeted cleaning of dishware in the at least one rack.

These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description, in conjunction with the drawings.

As should be appreciated, in conventional dishwashing machines, a common approach to distributing water and cleaning agents within the machine's internal volume involves the use of static spray arms or rotating spray bars. These devices typically extend horizontally across the machine and emit water jets upward and/or downward to clean the dishware. While functional, these conventional systems are often inefficient in terms of water usage and mechanical complexity. Moreover, traditional dishwashers rely on external drives and motors to impart motion to the spray arms, adding to the complexity and potential mechanical failure points of the device. This often results in a bulky arrangement that can interfere with the placement and accommodation of dishware within the machine, as well as a need for more maintenance due to the increased number of moving parts.

The disclosed embodiments aim to remedy these issues by integrating one or more manifolds that utilize an inline impeller to convert water flow from the dishwasher's fluid recirculation system directly into rotary motion. This motion is then ultimately translated into the defined and limited oscillation of attached spray tubes, which are aligned to efficiently distribute water and cleaning agents in a desired direction or range of directions onto the dishware. As will be described, the configuration of the manifold and the spray tubes allows for the spray tubes to be positioned closer to the dishes, thereby enhancing the cleaning action through direct targeting of water jets while simultaneously reducing the overall water consumption.

Embodiments disclosed herein relate to inline impeller driven manifolds to convert fluid flow through the impeller to rotary or oscillatory motion to one or more spray tubes within a dishwashing device to provide high velocity liquids directed at desired locations. In particular, embodiments herein relate to impeller driven manifolds for oscillating spray tubes in a dishwashing machine. In the preferred embodiments depicted, the manifold is positioned at a back side of at least one rack within a dishwasher and a dock is provided on the rear wall of the dishwashing device and fluidly connected to a fluid supply. The manifold is configured to be removably coupled to the dock to receive fluid from the dock when the manifold is coupled to the dock. Alternatively, in other embodiments, the manifold of the present description can itself be located on a wall of the dishwashing machine, such as a rear wall. In such embodiments, the manifold is coupled to the fluid supply and there is no need for a dock with which to be removably coupled. Generally speaking, the manifold includes an impeller, a drive gear system coupled to the impeller via a drive shaft, an offset drive wheel on a transmission shaft coupled to the drive gear system, and a plurality of spray tubes coupled to the offset drive wheel and configured to oscillate when water passes through the manifold.

Preferably, the manifold is integrated into or mounted at the backside of one or more of the dishwasher racks, with the spray tubes coupled at or near the front side of each rack and configured to enable rotary or oscillatory motion of the spray tubes. This arrangement saves space and simplifies the internal design of the dishwasher; it is more efficient in water usage; it is more cost-efficient; and it also provides improved aesthetics over devices that utilize external mechanisms such as wall-mounted sprayers, rotary sprayers with external motors, drive systems using flow paths transverse to the axis of rotation of a paddle wheel turbine, and the like. The inline positioning of the impeller within the manifold harnesses the water flow from the recirculation system for mechanical motion without wasting water.

Additionally, the disclosed dishwasher is capable of achieving higher pressures and more efficient cleaning due to the optimized conversion of water flow into mechanical energy. The integration of the impeller and gear train into the manifold and the controlled oscillation of the spray tubes ensure a focused and powerful cleaning action, which translates to shorter cycle times and enhanced cleaning performance. Accordingly, the proposed dishwasher provides a more efficient, reliable, and compact solution for cleaning dishware.

Embodiments of dishwashing devices will now be described in additional detail herein. Turning now to the drawings, wherein like numbers denote like parts throughout the several views,illustrates an example dish washing device in which the various technologies and techniques described herein may be implemented. The term “dishwasher” is used herein as a convenient term for the numerous types of dish washing devices contemplated, including but not limited to, commercial washers, residential washers (built-in, mobile, dish-sink, etc.), industrial washing devices, and the like. For convenience of description herein, “dishwasher” will be the referenced terminology and will be shown as a residential-type built-in dishwasher. As such, dishwasherincludes a front-mounted doorthat provides access to a wash tubhoused within the cabinet or housing. Dooris generally hinged along a bottom edge and is pivotable between the opened position illustrated inand a closed position (not shown). When dooris in the opened position, access is provided to one or more sliding racks. Obviously any number of racks can be utilized within dishwasher, depending on many factors, including the environment in which dishwasheris to be employed, the purpose for which the dishwasheris to be employed, and the size of dishwasherto be used. For example, a small residential dishwashermight have fewer racks than a large commercial version. Similarly, even standard-sized residential built-in dishwashers might have different numbers of racks, depending on style, price point, and user preference. Many residential dishwashers include only two racks. For case of reference, the figures depict a dishwasherhaving three racks: a lower rack, a middle rack, and an upper rack, within which various dishware can be placed for washing. As used herein, the term “dishware” is intended to include all the various types of items that might be cleaned within dishwasher, including but not limited to pots, pans, lids, trays, plates, bowls, glassware, cups, serviceware, utensils, and so forth. Typically, lower rackmay be supported on rollers, while middle rack(if included) and/or upper rackmay be supported on side rails, and each rack is movable between loading (extended) and washing (retracted) positions along a substantially horizontal direction.

In addition, consistent with some embodiments of the disclosure, dishwashermay include one or more tubular spray elements (TSEs), or spray tubes, to direct a wash fluid in a desired direction or range of directions onto dishware disposed in any one or more of lower rack, middle rack, and/or upper rack. As will become more apparent below, spray tubesare rotatable about respective longitudinal axes and are discretely directable by one or more manifoldsto control the direction or range of directions at which the wash fluid is sprayed by each of the spray tubes. In some embodiments, fluid may be dispensed solely through spray tubes, but the disclosure is not so limited. For example, in some embodiments various upper and/or lower rotating spray arms may also be provided to direct additional fluid onto utensils. Still other sprayers, including various combinations of wall-mounted sprayers, rack-mounted sprayers, oscillating sprayers, fixed sprayers, rotating sprayers, focused sprayers, etc., may also be combined with one or more spray tubesin some embodiments.

depicts an embodiment wherein each rack (lower rack, middle rack, and upper rack) includes at least one manifold. It should be understood, however, that it is likely that not every rack will include a manifoldand spray tube. In fact, in some embodiments (e.g.,), only one rack (e.g., upper rack) will include a manifoldand spray tube.shows a sample rack (e.g., upper rack) having two manifolds, wherein each manifoldincludes two spray tubes.shows a sample upper rackhaving two manifolds. As further depicted in, each of the spray tubesis shown mounted and/or otherwise fluidly coupled to a manifold, which may be configured to oscillate the spray tubesduring operation of the dishwasher, as will be described in additional detail herein with reference to. In the embodiments shown, each manifoldis mounted at or near a back side of upper rack, while the spray tubesextending from the manifoldmay be secured at or near a front side of the upper rack. The manifoldis configured to removably couple to a dock, which is in fluid communication with the pumpvia fluid conduit(see). The fluid conduitand the dockare mounted to an inside wall of the wash tub. The removable connection between the manifoldand the dockcan assume any number of male/female or female/male configurations that enable the manifoldand the dockto be fluidly removably engaged. When the manifoldis engaged (docked) in the dock—that is, when the rack on which the manifoldis mounted has been pushed into wash position—an inletof the manifoldis coupled to the dock. As such, fluid is allowed to flow from the fluid conduitthrough the manifoldand out the exit openingsof the spray tubes. In the embodiment shown in, the dockis depicted as a female coupling having a receptacleand a flangethat is tapered to encourage proper seating of inletinto fluid communication with the dock. As mentioned, alternative embodiments are possible where the manifoldis not mounted to a rack at all, but rather could be mounted to a wall within the dishwasher, for example, to a rear wall. In such embodiments, the manifoldmay optionally directly interface with the fluid conduit. In such embodiments, the manifoldand spray tubesdo not move with the racks, but rather stay stationarily mounted to the inside wall of the wash tubwhile the racks move relative to the manifoldand spray tubes.

Control over dishwasherby a user is generally managed through a control panel (not shown in) typically disposed on a top or front of door, and it will be appreciated that in different dishwasher designs, the control panel may include various types of input and/or output devices, including various knobs, buttons, lights, switches, textual and/or graphical displays, touch screens, etc. through which a user may configure one or more settings related to the various wash cycles (including, for example, start, stop, pause, etc. as well as various aspects of a wash cycle, e.g., heat, duration, water control, detergent control, and the like). Referring to, in general the dishwashermay be utilized with and/or controlled by a controllerthat receives inputs from a number of components, including but not limited to the control panel, and drives a number of components in response thereto. Controllermay, for example, include one or more processors and a memory (not shown) within which may be stored program code for execution by the one or more processors. The memory may be embedded in controller, but may also be considered to include volatile and/or non-volatile memories, cache memories, flash memories, programmable read-only memories, read-only memories, etc., as well as memory storage physically located elsewhere from controller, e.g., in a mass storage device or on a remote computer interfaced with controller.

In a dishwasher such as dishwasher, controllermay be interfaced with various components, including an inlet valvethat is coupled to a water source to introduce water into wash tub, which, when combined with detergent, rinse agent, and/or other additives, forms various wash fluids. Controllermay also be communicatively coupled to one or more of a heaterthat heats fluids; a pumpthat recirculates wash fluid within the wash tub by pumping fluid to the various wash arms and/or other spray devices in the dishwasher such as spray tubes; an air supplythat provides a source of pressurized air for use in drying dishware in the dishwasher; a drain valvethat is coupled to a drain to direct fluids out of the dishwasher; and a diverterthat controls the routing of pumped fluid to different tubular spray elements, spray arms and/or other sprayers such as spray tubesduring a wash cycle. In some embodiments, a single pumpmay be used, and a drain valvemay be configured to direct pumped fluid either to a drain or to the diverter, such that pumpis used both to drain fluid from the dishwasher and to recirculate fluid throughout the dishwasher during a wash cycle. In other embodiments, separate pumps may be used for draining the dishwasher and recirculating fluid. As used herein, pumpis deemed to be descriptive of either scenario, whether there is only one pump or multiple pumps. Diverterin some embodiments may be a passive diverter that automatically sequences between different outlets, while in other embodiments divertermay be a powered diverter that is controllable to route fluid to specific outlets on demand. Air supplymay be implemented as an air pump or fan in different embodiments, and may include a heater and/or other air conditioning device to control the temperature and/or humidity of the pressurized air output by the air supply.

In the illustrated embodiment, pumpand air supplycollectively implement a fluid supply for dishwasher, providing both a source of wash fluid and pressurized air for use respectively during wash and drying operations of a wash cycle. A wash fluid may be considered to be a fluid, generally a liquid, incorporating at least water, and in some instances, additional components such as detergent, rinse aid, and other additives. During a rinse operation, for example, the wash fluid may include only water. A wash fluid may also include steam in some instances. Pressurized air is generally used in drying operations, and may or may not be heated and/or dehumidified prior to spraying into a wash tub. It will be appreciated, however, that pressurized air may not be used for drying purposes in some embodiments, so air supplymay be omitted in some instances. Moreover, in some instances, tubular spray elements such as spray tubemay be used solely for spraying wash fluid or spraying pressurized air, with other sprayers or spray arms used for other purposes, so the disclosure is not limited to the use of tubular spray elements for spraying both wash fluid and pressurized air.

Controllermay also be coupled to a dispenserto trigger the dispensing of detergent and/or rinse agent into the wash tub at appropriate points during a wash cycle. Additional sensors and actuators may also be used in some embodiments, including a temperature sensorto determine a wash fluid temperature, a door switchto determine when dooris latched, and a door lockto prevent the door from being opened during a wash cycle. Moreover, controllermay be coupled to a user interfaceincluding various input/output devices such as knobs, dials, sliders, switches, buttons, lights, textual and/or graphics displays, touch screen displays, speakers, image capture devices, microphones, etc. for receiving input from and communicating with a user. In some embodiments, controllermay also be coupled to one or more network interfaces, e.g., for interfacing with external devices via wired and/or wireless networks such as Ethernet, Bluetooth, NFC, cellular, and other suitable networks. Additional components may also be interfaced with controller, as will be appreciated by those of ordinary skill having the benefit of the instant disclosure. For example, one or more manifoldsmay be provided in some embodiments to control one or more spray tubesin dishwasher, as will be discussed in greater detail below.

Moreover, in some embodiments, at least a portion of controllermay be implemented externally from a dishwasher, e.g., within a mobile device, a cloud computing environment, etc., such that at least a portion of the functionality described herein is implemented within the portion of the controller that is externally implemented. In some embodiments, controllermay operate under the control of an operating system and may execute or otherwise rely upon various computer software applications, components, programs, objects, modules, data structures, etc. In addition, controllermay also incorporate hardware logic to implement some or all of the functionality disclosed herein. Further, in some embodiments, the sequences of operations performed by controllerto implement the embodiments disclosed herein may be implemented using program code including one or more instructions that are resident at various times in various memory and storage devices, and that, when read and executed by one or more hardware-based processors, perform the operations embodying desired functionality. Moreover, in some embodiments, such program code may be distributed as a program product in a variety of forms, and that the disclosure applies equally regardless of the particular type of computer readable media used to actually carry out the distribution, including, for example, non-transitory computer readable storage media. In addition, it will be appreciated that the various operations described herein may be combined, split, reordered, reversed, varied, omitted, parallelized and/or supplemented with other techniques known in the art, and therefore, the invention is not limited to the particular sequences of operations described herein.

Numerous variations and modifications to the dishwasherillustrated inwill be apparent to one of ordinary skill in the art, as will become apparent from the description below. Therefore, the specific implementations discussed herein are not intended to limit the scope of the claims in any way.

Turning now to, a sample manifoldis depicted in additional detail. In these embodiments, the manifoldincludes an impeller, an inletfor receiving fluid from a fluid source (such as fluid conduit), a gear drive system, an offset drive wheelon transmission shaft, and a plurality of drive oscillatorsconfigured to secure the spray tubeswithin the manifold. In the embodiments described herein, the various components of the manifoldmay be further secured within a manifold housing.

As depicted in, pumpmay pump a fluid, such as water, through fluid conduitthat is coupled (removably, in the preferred embodiment) to inletof the manifold. In these embodiments, the fluid entering the inletmay further define a fluid pathway W, as illustrated in. The fluid pathway W leads through the inletand into the impeller, after which the fluid may be dispensed within the wash tub, as will be described in additional detail below.

For example, in the embodiments described herein, the fluid that enters the manifoldvia the inletflows through the impeller. The impeller, as a result of the flow of fluid onto the vanes of the impeller, rotates about a drive shaftthat is collinear with a longitudinal axis of the impeller. The drive shaftof the impellermay be mechanically coupled to the gear drive system, such that rotation of the impellersimilarly causes the various components of the gear drive systemto rotate. The various number, sizes, types, and configurations of the gears that make up the gear drive systemare a matter of design choice, dependent upon, among other things, the desired reduction in rotation speed needed at the output of the gear drive system(described below); and the number of spray tubesbeing driven by the manifold. The impeller, drive shaft, and gear drive systemare configured to translate the rotational motion of the impellerto rotational motion of various gears that make up the gear drive system.

As stated, the number, type, size, and configuration of the gears making up the gear drive systemare subject to design choice based on the parameters needed for the manifoldto ultimately oscillate the one or more spray tubesthat couple to the manifold. The embodiment shown indepict a manifoldthat drives two spray tubes. However, the manifoldcould just as easily drive a single spray tube, or could drive more than two spray tubes. For these alternative embodiments, the number, type, location, and size of the various gears that make up the gear drive systemcould change in each instance. As shown in the embodiments depicted in, one of the gears may be coupled to the offset drive wheelvia a transmission shaft. The offset drive wheelserves as a vehicle for translating rotational motion of the gear drive systemto rotational motion of the spray tubes, in any one of several manners. For example, if desired, the offset drive wheelcould simply be coupled to a spray tubein such a way that the spray tuberotates complementarily with the rotation of the transmission shaft. In this manner, the offset drive wheeland transmission shaftcould cause the spray tubeto rotate a full 360 degrees as the transmission shaftitself rotates 360 degrees. However, as described below, the preferred embodiments described herein and depicted in the figures include a range-limiting assemblythat is configured in such a way that that the transmission shaftprovides oscillatory (back-and-forth rotational) motion over a limited range of rotation of each spray tubeto which the transmission shaftis connected.

In particular, in the preferred embodiments, the range-limiting assemblygenerally includes the offset drive wheel, joint, one or more transmission shaft arms, one or more drive oscillators, and pin. With reference to, the range-limiting assemblyincludes offset drive wheelthat rotates about the transmission shaft, as well as a plurality of transmission shaft arms, such as a first transmission shaft armand a second transmission shaft arm. During operation of the preferred embodiment, the offset drive wheelrotates at approximately 10 rpm, but obviously any desired rotational speed can be achieved with selective design of the gear drive systemand the size and shape of the offset drive wheel. Desirable speeds might range from approximately 5 rpm to approximately 20 rpm. The first transmission shaft armhas a first endand a second endSimilarly, the second transmission shaft armhas a first endand a second endThe first endof the first transmission shaft armis coupled to the offset drive wheelat a jointlocated radially away from the axis of rotation of the offset drive wheel(that is, the transmission shaft). Similarly, the first endis coupled to the offset drive wheelat a jointlocated radially away from the axis of rotation of the offset drive wheel. The jointscan be the same joint, or can be different joints at different locations on the offset drive wheel. In the preferred embodiment shown herein, both endsare connected to the offset drive wheelat the same joint.

Each of the second endsare coupled to a spray tube, respectively, at a drive oscillator. The drive oscillatorincludes a rear retaining portiona front retaining portionand a retainer. The rear retaining portionincludes a pin. The second endsconnect to each respective rear retaining portionat the pin. The front retaining portionis configured to receive the proximal endof the spray tubetherewithin, and to couple to the rear retaining portionvia retainerin a manner that sandwiches the proximal endof the spray tubewithin the rear retaining portionand the front retaining portionOnce inserted into the front retaining portionthe proximal endof the spray tubeis mechanically coupled to the drive oscillatorvia one or more spring tabs. Once assembled, the drive oscillatorcouples the spray tube, via the range limiting assembly, to the offset drive wheelwithin the manifoldin a way that limits the range of oscillation allowed for the spray tubes. In particular, as depicted in, as the gear drive systemrotates the transmission shaft, the transmission shaftrotates the offset drive wheelof the range-limiting assembly. The offset drive wheelcan rotate a full 360 degrees as the transmission shaftrotates 360 degrees. And, because each of the first transmission shaft armand second transmission shaft armis coupled to the offset drive wheelat joint, each of the first endof the first transmission shaft armand the first endof the second transmission shaft armrotates around the offset drive wheela complete 360 degrees. However, because first transmission shaft armand second transmission shaft armare connected to the offset drive wheeland to the drive oscillatorat radial distances away from the centers of rotation of the offset drive wheeland drive oscillator, respectively, and due in part to the offset curvate shape of a portion of the first transmission shaft armand second transmission shaft arm, the drive oscillatoris prevented from making a full 360 rotation despite the offset drive wheelmaking a full 360 degree rotation. Instead, the drive oscillator rotates in a first direction (e.g., clockwise) and then stops and rotates in a second, opposite direction (e.g., counterclockwise) as the first endscontinue to rotate around offset drive wheela full 360 degrees. In this manner, rather than rotating 360 degrees in a single direction, the drive oscillatoroscillates—that is, rotates in one direction to its limit, and then rotates in the opposite direction to its limit. This oscillation pattern repeats with every full rotation of the offset drive wheel. In practice, the range of rotation of the drive oscillator(and, therefore, the spray tubeto which it is connected) is limited to an included cone angle of less than 180 degrees. This is true, of course, because if the drive oscillatorwere allowed to rotate through an included cone angle of more than 180 degrees, the resulting motion would not be a back-and-forth oscillation, but rather would be an undesired full rotation in a single direction, because once 180 degrees is exceeded, the rotation would simply continue in the same direction. In the preferred embodiment, the range of oscillation of the drive oscillator(and, therefore, also of the spray tube) is an included cone angle of between approximately 0 degrees and approximately 150 degrees. It should be appreciated that, in these embodiments, by limiting the oscillation of the spray tubes, it is possible to purposefully focus the flow of fluid exiting the spray tubeson or at a particular region within the wash tub, for example, on or at a particular rack,,(), at a particular location of one or more racks, and/or on particular dishware within the various racks,,().

is similar to, but shows the internal wallof manifoldthat separates the fluid flow path W from the gear drive system. As fluid enters the manifoldand traverses the fluid pathway W through the impeller, the fluid is directed towards each drive oscillator. The fluid then flows into the proximal endof each of the spray tubescoupled to the manifold. Each spray tubeincludes nozzles or other exit openingsspaced at various locations along the length of the spray tube. The exit openingshave a much smaller diameter than that of the spray tubeitself. Thus, as the fluid flows out of the spray tubevia the exit openings, the fluid exits the spray tubeat a high velocity. This high velocity of the exiting fluid can result in increased cleaning action of the fluid as it impacts the dishware to which it is directed.

Turning now to, the manifoldis depicted coupled to two spray tubes. However, as stated above, it should be appreciated that the manifoldmay alternatively be configured to receive any other number of spray tubes, including one spray tube, three spray tubes, or more, without departing from the scope of the present disclosure. Furthermore, it should be understood that the dishwashermay include a plurality of manifolds. As stated above, the manifoldscan be located on various walls within the wash tub(for example, a rear wall), or can be located on one or more racks, including but not limited to lower rack, middle rack, and/or upper rack, depending on the design goals and the particular dishwasherenvironment. The preferred embodiments have the one or more manifoldscoupled to or formed on the rear of the racks on which a manifoldis desired. In these preferred embodiments, the distal endsof each spray tubeis coupled at or near a front of the rack in a with a bearing-like attachmentthat allows the spray tubeto oscillate throughout its range of motion while still supporting the distal end

Referring now to, an exemplary schematic of a front view of a dishwashing environment of the dishwasheris depicted. The wash tubincludes lower rack, middle rack, and upper rack. Dishware is depicted in the form of plates in lower rackand middle rackand in the form of smaller items, such as utensilsin upper rackto be cleaned during a washing cycle. In the embodiment depicted, two manifoldsare shown coupled to the upper rack, and each manifoldis shown coupled to two spray tubes. By securing the manifoldsto the upper rack, the spray tubesextend in a front-to-back direction at a bottom surface of the upper rackand are secured to a front portion of the upper rack. As a result, it is possible to focus the fluid that is expelled from the exit openingsof the spray tubesonly on dishware that is positioned within the upper rack. As has been described herein with references to, and further depicted in, oscillation of the spray tubesmay be limited to an included cone angle range of less than 180 degrees, and in the preferred embodiments, between approximately 0 degrees and approximately 150 degrees. The zone of spray provided by each spray tubeis depicted by the shaded zones of the upper rack spray tubes, and can be seen to be focused on the dishware. Accordingly, when the manifoldsand spray tubesare disposed on the upper rack, the spray tubesare limited in their rotation to approximately 150 degree cone angle, thus directing their focus directly onto dishware. In this manner, a focused wash on the upper rackcan occur that can result in more efficient cleaning. And because all the fluid from the recirculation pumpthat flows into the manifoldsflows inline through the impellerand ultimately out of the spray tubes, the drive mechanism for the spray tubesis very efficient and does not waste fluid.

Further aspects of the embodiments described herein are provided by the subject matter of the following clauses:

Clause 1. A dishwasher comprising: a housing defining a washtub; a plurality of racks disposed within the washtub; a manifold in fluid communication with recirculation fluid within the washtub, the manifold further comprising: an impeller positioned in fluid communication with an inlet of the manifold; a drive gear system mechanically coupled to the impeller via a drive shaft; a transmission shaft mechanically coupled to the drive gear system; and a spray tube coupled to the transmission shaft and fluidly coupled to the inlet of the manifold, the spray tube being configured to oscillate to distribute fluid onto items positioned within the washtub.

Clause 2. The dishwasher of clause 1, wherein the manifold is coupled to at least one of the plurality of racks.

Clause 3. The dishwasher of clauses 1 or 2, wherein the impeller is axially aligned with the inlet of the manifold, such that fluid that enters the manifold traverses the impeller in a direction collinear with the axis of rotation of the impeller.

Clause 4. The dishwasher of any of clauses 1-3, further comprising a range-limiting assembly mechanically coupled to the transmission shaft.

Clause 5. The dishwasher of clause 4, wherein the range-limiting assembly is configured to limit rotational movement of the spray tube.

Clause 6. The dishwasher of clauses 4 or 5, wherein the spray tube is configured to oscillate within an included cone angle of between approximately 0 degrees and approximately 150 degrees.

Clause 7. The dishwasher of clauses 1 or 2, wherein the spray tube is coupled to a front portion of at least one of the plurality of racks via an attachment bracket.

Clause 8. The dishwasher of any of clauses 1-7, wherein the manifold includes more than one spray tube.

Clause 9. The dishwasher of any of clauses 1-8, wherein each of the plurality of racks includes at least one manifold.

Clause 10. A dishwasher comprising: a housing defining a washtub; at least one dishware rack slidably disposed within the washtub from a loading position to a wash position; at least one manifold coupled to a rear side of the at least one dishware rack, the manifold further comprising: an inline impeller in fluid communication with a fluid inlet of the manifold and having an axis of rotation collinear with a fluid path of fluid entering the fluid inlet; a drive gear system mechanically coupled to the impeller via a drive shaft; a transmission shaft mechanically coupled to the drive gear system; and at least one spray tube in fluid communication with the fluid inlet and mechanically coupled at one end to the transmission shaft via a drive oscillator and at the other end to a front side of the at least one dishware rack, the at least one spray tube being configured to oscillate to distribute fluid onto items positioned within the at least one dishware rack.

Clause 11. The dishwasher of clause 10, further comprising a range-limiting assembly mechanically coupled to the transmission shaft.

Clause 12. The dishwasher of clause 11, wherein the range-limiting assembly further comprises an offset drive wheel coupled to the transmission shaft and having a coupling joint disposed radially thereon a first distance from an axis of rotation of the disc.

Clause 13. The dishwasher of clause 12, wherein the drive oscillator further comprises a hollow cylindrical body having a pin located thereon at a distance radially disposed away from a central axis of the drive oscillator.

Clause 14. The dishwasher of any of clauses 11-13, wherein the range-limiting assembly further comprises a transmission shaft arm having a first end and a second end.

Clause 15. The dishwasher of clause 14, wherein the first end of the transmission shaft arm is coupled to the offset drive wheel at the coupling joint and the second end of the transmission shaft arm is coupled to the pin.

Clause 16. The dishwasher of any of clauses 11-15, wherein the at least one spray tube is configured to oscillate about its cylindrical axis between an included cone angle of approximately 0 and approximately 150 degrees.

Clause 17. A dishwasher comprising: a housing defining a washtub; at least one rack slidably disposed within the washtub; at least one manifold coupled to a rear side of at least one rack and having a fluid inlet in fluid communication with recirculated fluid within the washtub, the manifold further comprising: an impeller positioned in fluid communication with the fluid inlet and rotatable about an impeller axis that is collinear with a fluid path entering the fluid inlet; a drive gear system mechanically coupled to the impeller via a drive shaft that is also collinear with the fluid path entering the fluid inlet; a transmission shaft mechanically coupled to the drive gear system; at least one spray tube in fluid communication with the fluid inlet, the at least one spray tube having a first end and a second end, the first end mechanically coupled to the transmission shaft via a drive oscillator, the second end being coupled to the at least one rack so as to allow the at least one spray tube to rotate about its longitudinal axis; and a range-limiting assembly configured to limit the range of rotation of the at least one spray tube for targeted cleaning of dishware in the at least one rack.

Clause 18. The dishwasher of clause 17, wherein the range-limiting assembly further includes an offset drive wheel coupled to the transmission shaft, a transmission shaft arm having a first end and a second end, and a pin coupled to the drive oscillator.

Clause 19. The dishwasher of clause 18, wherein the first end is coupled to the offset drive wheel at a location radially disposed away from a center of the disc, and the second end is coupled to the drive oscillator at a location radially disposed away from a center of the drive oscillator.