Abstract:
A water flow control device for an appliance includes a sump to collect water from a washtub, a supply passage to supply water from the sump to the washtub, a drain passage, coupled to the sump to discharge water; and a disposer to dispose contaminates in water from the sump. The disposer is in fluid communication with the drain passage but not the supply passage.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the Korean Patent Application No. 10-2008-0081801, filed on Aug. 21, 2008, which is hereby incorporated by reference as if fully set forth herein. 
     BACKGROUND 
     1. Field of the Invention 
     One or more embodiments disclosed herein relate to dishwashers or other washing appliances. 
     2. Background 
     Most dishwashers include a nozzle, a driving unit, and a rack for holding dishes. The driving unit may be formed from a sump for collecting water and a wash pump for pumping the water from the sump through the nozzle and onto the dishes. The dishwasher may also include a supply passage for supplying water to a washtub, a drain passage for draining contaminated water from the dishwasher, and a drain pump for discharging water stored in the sump through the passage. 
     Dishwashers of the aforementioned type have several disadvantages. For example, the supply passage is coupled to a disposer. As a result, garbage from the disposer is supplied to the washtub with water during a washing cycle. To compensate, an increased quantity of water is flushed through the supply passage so that the garbage will not enter or be retained within the washtub of the dishwasher to contaminate the clean dishes. This wastes resources and increases costs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing one embodiment of a dishwasher. 
         FIG. 2  is a cross-sectional diagram of the dishwasher shown in  FIG. 1 . 
         FIG. 3  is a cross-sectional diagram of a sump of the dishwasher of  FIG. 2 . 
         FIG. 4  is a diagram showing an embodiment having a disposer driven by a motor for driving a wash pump. 
         FIG. 5  is a diagram showing an embodiment having a disposer driven by a motor for driving a drain pump. 
         FIG. 6  is a diagram showing an embodiment where a bottom of a coarse filter in a sump is blocked and no disposer is included. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  show one embodiment of dishwasher that includes a case  1  having an open front side and a door  2  which opens and closes relative to the front side. The case also includes a washtub  20  for accommodating water therein, and a sump  30  is also provided at a bottom of the washtub. The sump collects water sprayed into the washtub, and a filter assembly  50  is provided in advance of a water flow path relative to the sump to filter particles from the water introduced into the sump. 
     The interior of the washtub includes upper and lower racks  21  and  22  that are vertically separated to accommodate dishes and other tableware, and upper and lower nozzles  23  and  24  are provided to spray water toward the upper and lower racks. Upper and lower passages  27  and  28  are provided to supply the water collected in sump  30  to upper and lower nozzles  23  and  24  respectively. 
     In addition to the foregoing features, a water supply passage  41  is provided to enable water to be supplied into the washtub. The supply of water is provided from a water supply source located outside the case. A drain passage  42  drains contaminated water for discharge outside the dishwasher. A drain pump  70  is provided to the drain passage to drain the water collected in sump  30  from the dishwasher. The drain passage  42  may include a damping member such as a rubber pipe and/or a flexible pipe to absorb vibration. 
       FIG. 3  shows a supply passage  31  provided to supply water collected in the sump  30  to the washtub  20  from a location under the washtub  20 . A wash pump  35  is provided to the supply passage  31  for supplying water to upper and lower nozzles  23  and  24 . The supply passage  31  includes an inlet pipe  36  that connects the sump  30  and wash pump  35  together and an outlet pipe  37  that connects the wash pump  35  and the upper and lower passages  27  and  28 . The supply passage  31  may include a damping member such as a rubber pipe and/or a flexible pipe to absorb vibration. 
     As also shown in  FIG. 3 , water pumped by wash pump  35  is selectively sprayed via the upper and lower passages  27  and  28 . A diverging portion between the upper and lower passages includes a passage switching valve  29  for enabling water supplied by the wash pump to be selectively supplied to the upper and lower passages  27  and  28 . 
     The sump also includes a filter assembly  50  for filtering particles from the water introduced into the sump. The filter assembly may include a middle filter  51  provided over sump  30 . The middle filter may have a hollow dish shape, and a coarse filter  53  may be provided under the middle filter to have a cylindrical shape. The sizes of perforated holes in the middle filter may be smaller than that the perforated holes in coarse filter  53 , and a bottom of the coarse filter may have an open configuration. 
     Using this filter assembly, particles that are relatively large in size among particles in the water introduced into sump  30  will not be sucked into wash pump  35 , but rather will be collected in the drain passage  42  which is coupled to the bottom of the coarse filter  53 . 
     In addition to filter assembly  50 , a filtering arrangement  60  may be included for removing particles from the water. This filtering arrangement may include a pipe  61  that diverges from one side of outlet pipe  37 , a garbage chamber  62  for collecting particles in the water introduced from the diverging pipe, and a filter  63  adjusted to (e.g., over or on top of) the garbage chamber to filter particles from water introduced into the garbage chamber. 
     A discharge passage  64  is coupled to a bottom of the garbage chamber to drain the particles collected in the garbage chamber. The discharge passage may be coupled to drain passage  42 . A valve  65  may be included in or in advance of the flow of the discharge passage, so that the particles collected in the garbage chamber can be discharged into the drain passage via the discharge passage  64  only if the valve  65  is turned on. Drain pump  70  is coupled to drain passage  42  for draining water collected in the sump  30 . 
     While the dishwasher is operating, drain pump  70  is not working. As a result, relatively large particles gather within drain passage  42 . Thus, a disposer  80  is provided to discharge the large particles that gathered within drain passage  42  from the dishwasher. The disposer performs this function by grinding or pulverizing the particles into smaller particles, as the disposer is driven by a motor  81 . 
     According to one embodiment, the disposer  80  is installed at a location lower than that of supply passage  31 . This location is preferable in some instances because if the disposer is located higher than the supply passage, the particles ground by the disposer may be introduced into the supply passage. 
       FIG. 4  shows another embodiment of a dishwasher, where the disposer is in a location different from the disposer in  FIG. 3 . In this second embodiment, the disposer is driven by the same motor used to drive the wash pump  35 . No separate motor is therefore required to drive the disposer. In order to enable the disposer to be driven by the wash pump motor, a rotational shaft of the motor is configured to be coupled with a rotational shaft rotated by the disposer, via, for example, a bevel gear. 
     As a result of this arrangement, if the wash pump is driven to supply the water collected in sump  30  to the washtub, the disposer is rotated to grind particles that have gathered in the drain passage  42 . 
     The filter assembly in  FIG. 4  may also be different from the filter assembly in  FIG. 3 . For example, filter assembly  50  may further include a fine filter  52  provided outside coarse filter  53  in order to filter fine particles. Therefore, it is able to filter fine particles introduced toward supply passage  31  in part as well. 
     Operation of the dishwasher will now be provided. In an initial step, a user puts tableware on upper and/or lower racks  21  and  22  and then activates the dishwasher. Once activated, water and detergent are supplied into washtub  20 . As wash pump  35  is driven, upper and lower nozzles  23  and  24  spray the water on the tableware. The water is sprayed as it passes through upper and lower passages  27  and  28  by the centrifugal force of the wash pump  35 . 
     The water used in washing the tableware flows down to the bottom of the washtub and introduced into the sump  30 . Some of the particles contained in the water introduced into the sump are filtered by filter assembly  50  and the rest of the particles gather in the drain passage  42 . The water filtered by the filter assembly is re-sprayed by wash pump  35 . And, the water sprayed by the wash pump is introduced into garbage chamber  62  via diverging pipe  61  in part and then is filtered by the filter  63 . 
     Meanwhile, while the wash pump is operating, relatively large particles gathered in the drain passage  42  are grinded by the disposer  80 . 
     After completion of the washing cycle of the dishwasher, valve  65  is opened to allow particles gathered in garbage chamber  62  to pass into discharge passage  64  and then into drain passage  42 . At the same time, drain pump  70  is activated to discharge both the water and garbage from the dishwasher. 
       FIG. 5  is a diagram for depicting an embodiment of the dishwasher where the disposer  80  is driven by the motor for driving the drain pump  70 . When the disposer is driven by the drain pump motor, particles gathered in drain passage  42  are ground while the drain pump is operating. As a result, when water is discharged from the dishwasher, particles in the water are grinded. 
       FIG. 6  shows a dishwasher according to another embodiment. This embodiment is different in that a bottom of coarse filter  53  in filter assembly  50  is not open. This embodiment is also different in that it does not include a disposer in drain passage  42 . 
     In operation, large particles among the particles in the water introduced into sump  30  from washtub  20  are filtered by coarse filter  53  of the filter assembly. As a result, it is unnecessary to provide a disposer in drain passage  42 . In this case, a user dissembles the coarse filter from the filter assembly and then manually disposes of the particles filtered by the coarse filter. 
     Accordingly, one or more of the embodiments disclosed herein do not provide a disposer that grinds or pulverizes particles to a supply passage for supplying water, thereby reducing a quantity of water supplied to a washtub. 
     In accordance with one embodiment, a dishwasher is provided that washes tableware using a small quantity of water. This is accomplished by separating a passage for supplying water from a passage that is used to accumulate and/or discharge contaminants and garbage derived from washing the tableware during a washing cycle. 
     In accordance with another embodiment, a dishwasher includes a washtub, a sump collecting water sprayed into the washtub, a supply passage for supplying the water collected in the sump to the washtub, a wash pump provided to the supply passage to pumping the water to the washtub, a drain passage for guiding the water collected in the sump to be discharged from the dishwasher, and a disposer provided to the drain passage to grind garbage. Preferably, the disposer is located lower than the supply passage. 
     The dishwasher may further include a garbage chamber for collecting the garbage contained in the introduced water pumped by the wash pump in part. In addition, an exit of the garbage chamber may be configured to communicate with the drain passage. 
     The dishwasher may further include a coarse filter for filtering off the garbage introduced into the supply passage. In this case, the coarse filter is configured to have an open bottom. And, a fine filter for filtering off fine garbage is provided to an outside of the coarse filter. 
     According to one embodiment, the disposer is driven by a motor for driving the wash pump. According to another embodiment, the dishwasher includes a drain pump provided to the drain passage to drain the water collected in the sump from the washtub. In this embodiment, the disposer may be driven by a motor for driving the drain pump. The motor may include a dual-shaft motor. Also, the supply passage may include a damping member or the drain passage may include a damping member. 
     According to one or more of the aforementioned embodiments, water containing contaminates and garbage is prevented from being supplied into a washtub, by separating a passage for supplying water and a passage for accumulating the garbage and contaminates from each other. As a result, washing tableware is performed using less water than other types of dishwashers. 
     Any reference in this specification to “one embodiment,” “an exemplary,” “example embodiment,” “certain embodiment,” “alternative embodiment,” and the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment as broadly described herein. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to affect such feature, structure, or characteristic in connection with other ones of the embodiments. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, numerous variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.