Patent Application
20100139698
This disclosure relates to dishwashing machines of the type used in households and commercial settings having upper and lower racks within which are arranged articles to be washed. Ordinarily the lower rack is loaded with larger size plates, pots and pans, and the like, and the upper rack is particularly designed to carry the smaller dishes, cups and glassware. Such dishwashing machines normally have one or more spray arms which rotate on a horizontal plane having orifices or jets which spray the washing and rinsing liquid upwardly and/or downwardly against the dishes in the racks thereabove or therebelow depending on the location of the arm itself. One or more of these orifices or jets may be positioned so that the water streams issuing therefrom cause the spray arm itself to rotate thereby achieving maximum coverage of the dishes by the washing liquid.
One of the problems associated with present spray arms, and associated water jets, is that they are typically either all on or all off. A reduction in water pressure, an increase in pump prime requirements, and an increase in noise usually results from attempting to increase total spray arm flow rate by adding additional jet holes to achieve additional spray arm coverage.
The present disclosure attempts to solve a problem inherent to spray arms, including optional operating modes that utilize selective sprayer arms in various configurations to perform wash cycles in ‘whisper wash’ mode including selective spray arm combinations, and/or various spray arm flow rates.
The disclosure provides for lower wash sound levels including the ability to independently control each spray arm, such that the total noise associated with water jet spray at any given time during a cycle is significantly reduced while providing selective wash cycles.
The disclosure solves the problem of wash noise associated with the action of water jets that spray from multiple rotating spray arms within the dishwasher. The disclosure provides a method for lessening the total noise emanating from the unit, and allows a ‘quiet mode’ button or control that enables a consumer an option for all cycles to run extra quiet, albeit with longer wash time (i.e. ideal for overnight washing).
This application references U.S. patent application Ser. No. ______ entitled “Dishwasher Having Multi-Mode Spray Arm System” filed Dec. 9, 2008, by Errin W. Gnadinger et al., the disclosure of which is incorporated by reference.
The present disclosure provides an automatic dishwasher with an improved spray arm utility having selective and distinct water flow paths that can be activated within the spray arm system from a multi-mode and multi-conduit water feed system.
In one aspect of the disclosure, a spray assembly for an automatic dishwasher is provided comprising a multi-conduit system for receiving pressurized washing liquid for feeding a plurality of spray arms. The plurality of spray arms includes at least a lower spray arm, a middle spray arm, and an upper spray arm. Each of the spray arms includes at least one radially extending hollow projection. Each of the spray arms includes a plurality of orifices formed in the radially extending projection for distributing the liquid throughout the dishwasher. The multi-conduit includes a water feed system and a water diverting mechanism for selectively diverting water into any one of the spray arms, any two of the spray arms, or all three of the spray arms.
In another aspect of the disclosure, a spray assembly for an automatic dishwasher is provided comprising a multi mode conduit system for receiving pressurized washing liquid and a plurality of spray arms. Each of the spray arms includes a plurality of orifices formed therein for distributing the liquid throughout the dishwasher. The multi mode conduit system includes a water feed system and a water diverting mechanism for selectively diverting water flow direction and water flow pressure into fluid communication with the plurality of spray arms. By this arrangement water may be selectively diverted to an upper spray arm only; a middle spray arm only; a lower spray arm only; upper and middle spray arms; upper and lower spray arms; middle and lower spray arms; and upper, middle, and lower spray arms.
In yet another aspect of the disclosure, a wash cycle method for an automatic dishwasher is provided comprising selectively receiving pressurized washing liquid through a multi mode conduit system. The multi mode conduit system includes a water feed system and a water diverting mechanism. The method further provides for distributing the pressurized water to a plurality of spray arms throughout the dishwasher, and further spraying the liquid throughout the dishwasher through a plurality of orifices formed in the spray arms. The method also provides for selectively diverting water flow into the plurality of spray arms, including selectively diverting water flow during the wash cycle to an upper spray arm only, a middle spray arm only, and a lower spray arm only as well as combinations thereof.
A water control system is provided in which spray arm(s) can be selectively individually and/or combinationally controlled to spray upward, downward, both upward and downward, or to alternate between selective flow rates by the dishwasher controller. The system, to be described in more detail hereinafter, has demonstrated significant wash performance benefits in a normal wash mode, single spray arm mode, and/or any combination of two spray arm wash modes, and/or a modified three spray arm mode including variable flow rates.
One feature of the present disclosure is the ability for the dishwasher control to selectively vary the spray arm activity and/or flow rate to generate relatively lower noise levels and lower energy consumption during normal wash cycles or during a standalone ‘quiet or whisper wash’ cycle. The result of the aforementioned improved functionality provides enhanced wash performance on a selected spray arm or rack and reduced noise levels for a variety of wash cycles to be described in detail hereinafter.
The present disclosure provides improved wash performance, reduced water flow rates, and reduced noise levels in ‘normal’ wash modes, single spray arm wash mode, or multi spray arm wash modes. The selective wash cycles include a multi speed or variable speed pump, and a valve control system to control water flow, and flow rate, through each spray arm independently.
It is to be appreciated that independent spray arm controls can impact energy consumption and noise levels. For example, a single spray arm wash mode or dual spray arm wash mode will result in lower energy consumption and lower noise levels as compared to simultaneous three spray arm wash modes.
As shown In
The present disclosure provides alternative combinations of spray arm wash modes with options that can be applied to a variety of different wash mode cycles, and will allow the consumer to choose, or alternate, between single upper spray arm (USA) 29 only; single middle spray arm (MSA) 27 only; single lower spray arm (LSA) 25 only; dual upper 29 and lower 25 spray arms; dual middle 27 and lower 25 spray arms; dual upper 29 and middle 27 spray arms; and combined upper 29, middle 27, and lower 25 spray arms. It is to be appreciated that the present disclosure provides for each of the above listed wash mode cycles to operate at either a high, a low, or a variable water flow rate. Thus, each of the combinations listed above can have, for example, at least two different flow rates. In addition, as shown in
Similarly the ‘medium’ setting flow can include, a fourth mode which can direct and control water flow rate to the LSA 31 and the MSA 33; a fifth mode which can direct and control water flow rate to the LSA 31 and the USA 35; a sixth mode which can direct and control water flow rate to the MSA 33 and the USA 35. The ‘high’ setting flow rate can include a seventh mode which can direct and control water flow rate to the LSA 31, MSA 33, and the USA 35 (not illustrated).
Generally, clean water is introduced into the machine for each wash step and again for each rinse step, and detergent is added, by automatic means (not shown), for the wash step. The term “washing liquid” is therefore used herein in a generic sense to refer broadly to any form of liquid utilized for washing or rinsing within the dishwashing machine. Each of the spray arms can include at least one radially extending hollow projection. In one exemplary embodiment, the hollow projections can include upper and lower walls interconnected by side walls. The spray arms further include a plurality of orifices or jets formed in the hollow projection for distributing the liquid throughout the dishwasher. The washing liquid can be selectively distributed from the spray arms 25, 27, 29 by means of orifices or jets (not shown) spaced therealong. The spray arms 25, 27, 29 can be reactively driven by having at least one of the orifices or jets disposed to discharge a jet stream in a direction such that the spray arm reacts to the force of the discharge and rotates in a horizontal plane, as is well known in the art. A thorough and generally uniform distribution of washing liquid in the washing chamber 12 is thereby obtained. Recirculation of the washing liquid from the washing chamber 12, through the pump 19 and, thence selectively through the spray arms 25, 27, 29, is continued for a predetermined length of time after which the electrical circuit to a drain valve means (not shown) causes the valve to automatically switch an outlet within the pump means 19 so that recirculation ceases and the pump 19 begins to discharge the washing liquid from the washing chamber outwardly through a drain hose leading ultimately to the household sewage system.
Referring to
The multi water feed system can include a multi conduit valve system 50, 52 which may be controlled to select a single path, a dual path, or a multi-feed path where water will flow selectively to the upper 29, middle 27, and/or lower 25 spray arms. The mid spray arm 27 (
The system can utilize a conduit water supply 42, 44, including diverter or flapper valve 52 for selective diversion of the water supply to conduits 42, 44. As shown in
The system also utilizes conduit water supply 40, including valve 50, for selective diversion of the water supply to LSA 25. The conduit valve 50, assembled within the conduit 40, allows selective flow or shut-off of water. The conduit valves 50, 52 may consist of a magnetically controlled flapper or magnetic ball valve mechanism 60 (i.e. rare earth magnet) where the magnetic transparency of the stainless steel tub bottom 15 may be utilized to keep the electrical portion of the conduit valves on the dry side of the tub to either shut off water flow or allow water flow (refer to
The conduit that feeds any spray arm can have the above described ball valve mechanism. In one position, the ball is seated against the rim of an orifice where it blocks the flow to one or more spray arms. In another position, the ball can be held in place by the magnet out of the way of the flow. When the ball is out of the way of the orifice and held against the wall of the conduit, the spray arms are supplied with water. When the ball blocks the flow of water, selected spray arms can be blocked from the supply of water. This enables selective arms to be supplied with water resulting in reduction in noise, water, and energy when less than all of the spray arms are activated
It is to be appreciated that the water flow rate supplied to each spray arm can be altered to include, for example, a high flow rate, a low flow rate, or other variable flow rate. As such, the disclosure provides the ability to not only select which spray arm(s) is activated, but at which flow rate to run the spray arm, thereby providing a means for the dishwasher controller to alternate flow paths (spray arm inlet conduit) and flow rates throughout the cycle. The controller can be optimized to achieve various performance enhancements such as improved wash in a target area of a rack(s), sound reduction, lower water consumption, and energy efficiency enhancements. One feature of the present disclosure is the ability for the dishwasher controller to select one of several possible spray modes of a spray arm through the use of multi-water feed system (multi-conduit) 40, 42, 44; and, water valve mechanisms 50, 52 to restrict water into the desired flow path(s). As shown in
Referring again to
It is to be appreciated that if the wash cycle includes a single upper rack mode or a single lower rack mode, the water can be directed to the USA 29 and MSA 27, or LSA 25, respectively. If the wash cycle includes a normal wash of both racks, the water can be directed to all three spray arms. The water being directed to the three spray arms can either be simultaneous and/or alternating from one spray arm (or pair of spray arms) to any other spray arm (or pair of spray arms) in any variety of sequences. The spray arms conduit and conduit valve systems can be controlled such that the water sprays from each arm for a selected duration and flow rate, as desired.
As described above, the valves 50, 52 are positioned such that water can be diverted to or from the lower spray arm 25, the mid spray arm 27, and or the upper spray arm 29. Thus, a dishwasher wash system with a ‘whisper wash’ type mode can be used on a three (or more) spray arm system by which the electronic controller activates only one spray arm at any given time by use of a multi-conduit water feed with multi-conduit valve system in conjunction with a variable flow rate pump mode (i.e. multiple speed pump motor). The controller can activate each spray arm with a unique pump speed, or any combination of spray arms with an appropriate and unique pump speed to achieve desired water jet flow rate and pressure, and desired sound level. As described above, the pump speed can have a first low setting when one spray arm is activated, a second medium setting when two spray arms are activated, and a third high setting when three spray arms are activated. Sequential spray arm utilization and variable flow rates can be utilized to achieve wash results comparable to traditional means.
By employing a variable speed motor (i.e. induction) with the system, the flow to any of the spray arms can be maintained at a constant rate while the flow to the other spray arms are blocked allowing for noise reduction. The dishwashing system can also include a turbidity sensor for sensing the cleanliness of the wash water. The sensor can activate or deactivate spray arms as necessary based on the amount of soil in the water. For example, heavy soil can be detected by the turbidity sensor, i.e. via light diffusion, being occluded and would result in all spray arms being activated. Similarly, light soil can be detected by the turbidity sensor not being occluded and would result in one or two spray arms being activated. It is to be appreciated that any type of turbidity sensor can be utilized for detecting the cleanliness, or lack thereof, of the dishwater. This selective activation, based on soil, would also allow for quieter operation and reduction in energy consumption while still allowing a user to wash an entire load.
As discussed, the present disclosure includes the concept of sequential activation of the spray arms by staggering the spray arm activation by use of a multi-conduit and valve device. The system can change the pump speed to a predetermined value to match as appropriate for each possible combination of spray arm activation. The system can provide a ‘quiet or whisper mode’ as a selectable option to a consumer to be applied to any normal wash cycle.
It is to be appreciated that the system can provide an algorithm/control to control independent valve spray arms in order to achieve lower noise. The algorithm/control can change pump speed (using a variable speed or multi-speed pump) dependent on which combination of spray arms is activated.
It should be apparent to those skilled in the art that the embodiments described heretofore are considered to be the presently preferred forms of this disclosure. In accordance with the Patent Statutes, changes may be made in the disclosed mechanism and in the manner in which it is used without actually departing from the true spirit and scope of this disclosure.
