Lower rack assembly for dishwasher appliance

A lower rack assembly for a dishwasher appliance includes a lower rack and a lift assembly connected to the lower rack. The lift assembly includes a gear assembly that includes an output spur gear and an input drive gear, and includes a first arm extending between a first end and a second end, the first end of the first arm pivotally coupled to the lower rack, the second end of the first arm coupled to the output spur gear. Movement of the input drive gear causes movement of the lower rack along the transverse direction between a retracted position wherein the lower rack is within the wash chamber and an extended position wherein the lower rack is positioned outside of the wash chamber and along the vertical direction between a lowered position and a raised position wherein the raised position is above the lowered position along the vertical direction.

FIELD OF THE INVENTION

The present subject matter relates generally to dishwasher appliances, and more particularly to lower rack assemblies for use in dishwasher appliances.

BACKGROUND OF THE INVENTION

Dishwasher appliances generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber of the tub for receipt of articles for washing. Spray assemblies within the wash compartment can apply or direct wash fluid towards articles disposed within the rack assemblies in order to clean such articles. Multiple spray assemblies can be provided including e.g., a lower spray arm assembly mounted to the tub at a bottom of the wash compartment, a mid-level spray arm assembly mounted to one of the rack assemblies, and/or an upper spray assembly mounted to the tub at a top of the wash compartment. Other configurations may be used as well.

Typically, the lower rack of a dishwasher is pulled out from the wash chamber for loading and unloading of dishes. A dishwasher door pivots into an open, generally horizontal position and may define a surface having one or more tracks for receiving wheels rotatably mounted on the lower rack. The lower rack is rolled out of the tub onto the open dishwasher door to simplify the loading or unloading process, e.g., by not requiring a user to reach into the wash chamber to add or remove dishes. However, even when the rack is extended outside the wash chamber, consumers must often bend over to reach the dishes located in the lower rack, resulting in discomfort and ergonomic issues. While some dishwashers have incorporated means for lifting the lower rack, these mechanisms often lift the lower rack in a jerky and non-uniform manner. Alternatively, these systems are complex, expensive, and difficult to maintain.

Accordingly, a dishwashing appliance having apparatus for lifting the lower rack when loading or unloading dishes would be useful. More particularly, cost effective rack lifting apparatus that may lift the lower rack in a smooth and uniform manner to provide a simple, ergonomic method of loading and unloading dishes would be advantageous.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with one embodiment, a dishwasher appliance defining a vertical, a lateral, and a transverse direction is provided. The dishwasher appliance includes a wash tub that defines a wash chamber, a fluid circulation assembly for providing a fluid flow within the wash chamber, and a lower rack assembly. The lower rack assembly includes a lower rack configured for receipt of articles for washing, and a lift assembly connected to the lower rack. The lift assembly includes a gear assembly, the gear assembly including an output spur gear and an input drive gear. The lift assembly further includes a first arm extending between a first end and a second end, the first end of the first arm pivotally coupled to the lower rack, the second end of the first arm coupled to the output spur gear. Movement of the input drive gear causes movement of the lower rack along the transverse direction between a retracted position wherein the lower rack is within the wash chamber and an extended position wherein the lower rack is positioned outside of the wash chamber and along the vertical direction between a lowered position and a raised position wherein the raised position is above the lowered position along the vertical direction.

In accordance with another embodiment, a dishwasher appliance defining a vertical, a lateral, and a transverse direction is provided. The dishwasher appliance includes a wash tub that defines a wash chamber, a fluid circulation assembly for providing a fluid flow within the wash chamber, and a lower rack assembly. The lower rack assembly includes a lower rack configured for receipt of articles for washing, and a lift assembly connected to the lower rack. The lift assembly includes a gear assembly, the gear assembly including a gear assembly, the gear assembly including an output spur gear and a manually driven input rack gear. The lift assembly further includes a first arm extending between a first end and a second end, the first end of the first arm pivotally coupled to the lower rack, the second end of the first arm coupled to the output spur gear. Movement of the input rack gear causes movement of the lower rack along the transverse direction between a retracted position wherein the lower rack is within the wash chamber and an extended position wherein the lower rack is positioned outside of the wash chamber and along the vertical direction between a lowered position and a raised position wherein the raised position is above the lowered position along the vertical direction.

In accordance with another embodiment, a dishwasher appliance defining a vertical, a lateral, and a transverse direction is provided. The dishwasher appliance includes a wash tub that defines a wash chamber, a fluid circulation assembly for providing a fluid flow within the wash chamber, and a lower rack assembly. The lower rack assembly includes a lower rack configured for receipt of articles for washing, and a lift assembly connected to the lower rack. The lift assembly includes a gear assembly, the gear assembly including an output spur gear and an input spur gear. The lift assembly further comprises a motor operable to rotate the input spur gear. The lift assembly further comprises a first arm extending between a first end and a second end, the first end of the first arm pivotally coupled to the lower rack, the second end of the first arm coupled to the output spur gear. Rotation of the input spur gear causes movement of the lower rack along the transverse direction between a retracted position wherein the lower rack is within the wash chamber and an extended position wherein the lower rack is positioned outside of the wash chamber and along the vertical direction between a lowered position and a raised position wherein the raised position is above the lowered position along the vertical direction.

DETAILED DESCRIPTION

FIGS. 1 and 2depict a dishwasher appliance100according to an exemplary embodiment of the present subject matter. Dishwasher appliance100defines a vertical direction V, a lateral direction L (FIG. 1) and a transverse direction T (FIG. 2). The vertical, lateral, and transverse directions V, L, and T are mutually perpendicular and form an orthogonal direction system.

Dishwasher appliance100includes a chassis or cabinet102having a tub104. Tub104defines a wash chamber106and includes a front opening (not shown) and a door120hinged at its bottom122for movement between a normally closed vertical position (shown inFIGS. 1 and 2), wherein wash chamber106is sealed shut for washing operation, and a horizontal open position for loading and unloading of articles from dishwasher appliance100. A latch114is used to lock and unlock door120for access to chamber106.

Slide assemblies124are mounted on opposing tub sidewalls128to support and provide for movement of an upper rack130. Lower guides126are positioned in opposing manner of the sides of chamber106and provide a ridge or shelf for roller assemblies136so as to support and provide for movement of a lower rack132. Each of the upper and lower racks130and132is fabricated into lattice structures including a plurality of elongated members134and135that extend in lateral (L), transverse (T), and/or vertical (V) directions. Each rack130,132is adapted for movement between an extended loading position (not shown) in which the rack is substantially positioned outside the wash chamber106, and a retracted position (shown inFIGS. 1 and 2) in which the rack is located inside the wash chamber106. This is facilitated by slide assemblies124and roller assemblies136that carry the upper and lower racks130and132, respectively. A silverware basket150may be removably attached to the lower rack132for placement of silverware, small utensils, and the like, that are too small to be accommodated by the upper and lower rack assemblies130,132.

Dishwasher appliance100also includes a lower spray assembly144that is rotatably mounted within a lower region146of the wash chamber106and above a tub sump portion142so as to rotate in relatively close proximity to lower rack132. A spray arm or mid-level spray assembly148is located in an upper region of the wash chamber106and may be located in close proximity to upper rack130. Additionally, an upper spray assembly (not shown) may be located above the upper rack130and mounted to an upper wall of tub104.

Lower and mid-level spray assemblies144,148and the upper spray assembly are fed by a fluid circulation assembly for circulating water and wash fluid in the tub104. Portions of the fluid circulation assembly may be located in a machinery compartment140located below tub sump portion142of tub104, as generally recognized in the art. Each spray assembly includes an arrangement of discharge ports or orifices for directing washing liquid onto dishes or other articles located in upper and lower rack assemblies130,132, respectively. The arrangement of the discharge ports in at least the lower spray assembly144provides a rotational force by virtue of washing fluid flowing through the discharge ports. The resultant rotation of lower spray assembly144provides coverage of dishes and other articles with a washing spray.

Dishwasher appliance100is further equipped with a controller116to regulate operation of dishwasher appliance100. Controller116may include a memory and microprocessor, such as a general or special purpose microprocessor operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller116may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

Controller116may be positioned in a variety of locations throughout dishwasher appliance100. In the illustrated embodiment, controller116may be located within a control panel area110of door120as shown. In such an embodiment, input/output (“I/O”) signals may be routed between the control system and various operational components of dishwasher appliance100along wiring harnesses that may be routed through bottom122of door120. Typically, the controller116includes a user interface panel112through which a user may select various operational features and modes and monitor progress of the dishwasher appliance100. In one embodiment, user interface panel112may represent a general purpose I/O (“GPIO”) device or functional block. In one embodiment, the user interface panel112may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. User interface panel112may include a display component, such as a digital or analog display device designed to provide operational feedback to a user. User interface panel112may be in communication with controller116via one or more signal lines or shared communication busses.

It should be appreciated that the present subject matter is not limited to any particular style, model, or configuration of dishwasher appliance. Thus, the exemplary embodiment depicted inFIGS. 1 and 2is provided for illustrative purposes only. For example, different locations may be provided for a user interface112, different configurations may be provided for upper and lower racks130,132and/or lower and mid-level spray assemblies144,148, and other differences may be applied as well.

FIGS. 3 through 10illustrate embodiments and components of a lower rack assembly200in accordance with embodiments of the present disclosure. Lower rack assemblies200in accordance with the present disclosure advantageously facilitate lifting of the lower rack132as desired to, for example, load or unload articles. Further, lower rack assemblies200in accordance with the present disclosure may advantageously be cost effective and may facilitate lifting and lowering in a smooth, uniform and ergonomic manner.

Lower rack assembly200may include, for example, lower rack132. The lower rack132may define an interior volume206. In particular, a bottom wall210, a back wall216, a front wall217and side walls218,219of rack assembly200may assist with defining interior volume206of rack assembly200. Thus, interior volume206of rack assembly200may be defined between bottom wall210, back wall216, front wall217and side walls218,219of rack assembly200. Articles for washing, such as cups, bowls, bottles, etc., may be placed or positioned within interior volume206of rack assembly200such that the articles for washing are supported by rack assembly200during operation of dishwasher appliance100.

Rack assembly200can also include a plurality of tines220, which as shown are fixed tines but alternatively may be rotatable tines, for assisting with supporting articles within interior volume206of rack assembly200. Tines220are mounted to bottom wall210of rack assembly200and extend into interior volume206of rack assembly200, e.g., upwardly along the vertical direction V. In particular, as shown inFIG. 6, bottom wall210may include a series of lateral members212fixed to a series of transverse members214. Each lateral member of lateral members212extends along the lateral direction L. Lateral members212are also spaced apart from one another along the transverse direction T. Similarly, each transverse member of transverse members214extend along the transverse direction T. Transverse members214are also spaced apart from one another along the lateral direction L. Thus, lateral members212and transverse members214form a lattice structure for containing articles within rack assembly200. Fixed tines220may be mounted or fixed (e.g., welded) to lateral members212and/or transverse members214of bottom wall210of rack assembly200and extend into interior volume206of rack assembly200, e.g., upwardly along the vertical direction V, from bottom wall210.

In exemplary embodiments, rack assembly200further includes one or more roller assemblies136, each of which may include one or more wheels137and a carriage138which is generally connected to the wheels137. One or more roller assemblies136may be positioned each sidewall218,219. The roller assemblies136may facilitate movement of the rack assembly200along the transverse direction T. For example, as illustrated, rack assembly200is movable along the transverse direction T between a retracted position (seeFIGS. 3, 4, 7 and 8) wherein the lower rack132is within the wash chamber106and an extended position (seeFIGS. 5, 6, 9 and 10) wherein the lower rack132is positioned outside of the wash chamber106. Wheels137may contact and roll along the inner surface of door120to move the rack assembly200along the transverse direction T as required.

Lower rack assembly200further includes one or more lift assemblies230. Each lift assembly230may be connected to the lower rack132and may facilitate raising and lowering of the lower rack132. For example, in exemplary embodiments, lower rack assembly200may include two lift assemblies230; one lift assembly230may be disposed proximate and connected to the sidewall218, and another lift assembly230may be disposed proximate and connected to the opposing sidewall219.

Lift assembly230may include a gear assembly240. As illustrated, gear assembly240may be disposed above the lower rack132along the vertical direction V, and may for example be adjacent to the upper rack130. Components of the gear assembly240, such as gears thereof, may be disposed exterior to the tub104. Further, components of the gear assembly, such as shafts connected to gears, may extend through sidewalls128of the tub104into the wash chamber106. In alternative embodiments, however, the entire gear assembly240may be disposed within the wash chamber106. Movement of the gear assembly240may generally drive movement of the lower rack132. In particular, the gear assembly240may include an input drive gear242and an output spur gear244. Movement of the input drive gear242may generally drive movement (such as rotation) of the output spur gear244, which may in turn drive movement of the lower rack132.

Movement of the input drive gear242may cause movement of the lower rack132along the transverse direction T between a retracted position and an extended position. In the retracted position, the lower rack132is within the wash chamber106, as discussed above. In the extended position, the lower rack132is positioned outside of the wash chamber106, as discussed above. Movement of the input drive gear242may further cause movement of the lower rack132along the vertical direction V between a lowered position (seeFIGS. 3-5 and 7-9) and a raised position (seeFIGS. 6 and 10). In raised position, the lower rack is above the lowered position along the vertical direction V, as shown. In exemplary embodiments, movement of the input drive gear242in a first direction causes movement of the lower rack132first along the transverse direction T from the retracted position (FIGS. 4 and 8) to the extended position (FIGS. 5 and 9) and second along the vertical direction V from the lowered position (FIGS. 5 and 9) to the raised position (FIGS. 6and10). Movement of the input drive gear242in a second opposite direction may cause opposite movement of the lower rack132, first from the raised position to the lowered position and second from the extended position to the retracted position.

In some embodiments, as illustrated inFIGS. 3 through 6, the input drive gear242may be linearly movable (such as in a first direction and second opposite direction), such as along the transverse direction T. For example, the input drive gear242may in exemplary embodiments be a rack gear, as illustrated. Such linear movement, such as of the input rack gear242, may cause movement, such as rotation, of the output spur gear244. Further, in some embodiments, as illustrated, gear assembly240may further include a pinion gear246rotatably meshed between the input drive gear242and the output spur gear244. Additionally, in some embodiments as illustrated, additional intermediate gears may be provided and may be rotatably meshed with the input drive gear242and/or output spur gear244. Alternatively, the input drive gear242may be directly rotatably meshed with the output spur gear244.

In alternative embodiments, as illustrated inFIGS. 7 through 10, the input drive gear242may be rotatably movable, (such as in a first direction and second opposite direction), such as about the lateral direction L. For example, the input drive gear242may in exemplary embodiments be a spur gear, as illustrated. Such rotational movement, such as of the input spur gear242, may cause movement, such as rotation, of the output spur gear244. In some embodiments, as illustrated, the input drive gear242may be directly rotatably meshed with the output spur gear244. Alternatively, in some embodiments, various intermediate gears may be provided and may be rotatably meshed with the input drive gear242and/or output spur gear244.

Further, in some embodiments the gear assembly240may be manually operated and driven, while in other embodiments the gear assembly240may be driven by, for example a motor248. The motor248may for example be manually actuated by a user as desired, or automatically actuated by controller116at suitable times, such as upon opening of door120.

For example,FIGS. 3 through 6illustrate one embodiment of a manually actuated gear assembly240. As shown, a handle249may be connected to the input drive gear242. A user can grasp the handle249and pull, push or otherwise move the handle249to move the input drive gear242.

FIGS. 7 through 10illustrate one embodiment of a motor-driven gear assembly240. Motor248is operable to move the input drive gear242. For example, as shown, the motor248may be connected to the input drive gear242via a motor shaft. Actuation of the motor248may cause rotation of the input drive gear242.

Referring again toFIGS. 3 through 10, movement of the lower rack132may be caused by movement of the gears of the gear assembly240and movement of a first arm250coupled to the gear assembly240. First arm250may extend between a first end252and a second end254. The first end252may, for example, be pivotally coupled to the lower rack132, such as to a sidewall218,219thereof. For example, the first end252may be coupled to the lower rack132via a suitable mechanical fastener, or via a bracket such as bracket260(seeFIGS. 7 through 10) which is connected to the sidewall218,219. Bracket260may define a slot262, which may be vertically extending and in which the first end252may be rotatably and slidably disposed.

The second end254may, for example, be coupled to the output spur gear244. In exemplary embodiments, rotation of the output spur gear244causes rotation of the first arm250. For example, the second end254may be fixedly coupled to the output spur gear244, such that rotation of the output spur gear244causes rotation of the second end254. Rotation of the second end254may cause rotation of the first end252(and remainder of the first arm250) relative to the second end254and output spur gear244. The rotation of the first arm250may, in turn, cause movement of the lower rack132. As illustrated, for example, rotation of the first arm250may cause movement of the lower rack132from the retracted position to the extended position (and vice versa) and from the lowered position to the raised position (and vice versa).

Additional arms may be provided to facilitate movement of the lower rack132. For example, a second arm270may be provided. Second arm270may extend between a first end272and a second end274. The first end272may, for example, be pivotally coupled to the lower rack132, such as to a sidewall218,219thereof. For example, the first end272may be coupled to the lower rack132via a suitable mechanical fastener, or via a bracket such as bracket260(seeFIGS. 7 through 10) which is connected to the sidewall218,219. Bracket260in these embodiments defines a plurality of slots, each of which may be vertically extending and in one of which the first end272may be rotatably and slidably disposed.

In some embodiments, as illustrated, inFIGS. 3 through 6, the second end274may be pivotally coupled to a sidewall128of the tub104. In these embodiments, the second arm270is a passive arm which simply provides stability to the lift assembly230. In other embodiments, as illustrated inFIGS. 7 through 10, the second arm270may be an active arm which additionally causes (when moved by gear assembly240) movement of the lower rack132. For example, the gear assembly240in some embodiments may include a plurality of output spur gears244. The output spur gears244may be movably driven, such as rotatably driven, by the input drive gear242. The second end254of the first arm250may be coupled to one of the plurality of output spur gears244, and the second end274of the second arm270may be coupled to another of the plurality of output spur gears244. The second end274may, for example, be coupled to the output spur gear244. In exemplary embodiments, rotation of the output spur gear244causes rotation of the second arm270. For example, the second end274may be fixedly coupled to the output spur gear244, such that rotation of the output spur gear244causes rotation of the second end274. Rotation of the second end274may cause rotation of the first end272(and remainder of the second arm270) relative to the second end274and output spur gear244. The rotation of the second arm270may, in turn, cause movement of the lower rack132. As illustrated, for example, rotation of the second arm270may cause movement of the lower rack132from the retracted position to the extended position (and vice versa) and from the lowered position to the raised position (and vice versa).

In some embodiments, as illustrated inFIGS. 3 through 6, an auxiliary support arm280may additionally be provided. Auxiliary support arm280may extend between a first end282and a second end284. The first end282may, for example, be pivotally coupled to the lower rack132, such as to a sidewall218,219thereof. For example, the first end282may be coupled to the lower rack132via a suitable mechanical fastener, or via a bracket such as bracket286which is connected to the sidewall218,219. The second end284may be a free end which is pivotally coupled to a wheel137(which is separate from roller assemblies136). The wheel137may, when the lower rack132is moved to the extended position, contact an inner surface of the door120. Further, when the lower rack132moves from the lowered position to the raised position, the auxiliary support arm280and second end284thereof may pivot about the first end282such that the wheel137remains in contact with the inner surface of the door120. The auxiliary support arm280is additionally pivotable in the opposite direction when the lower rack132moves from the raised position to the lowered position. Accordingly, the auxiliary support arm280may provide additional support to the lower rack132when in the raised position.