Patent Publication Number: US-2005133072-A1

Title: Device for supplying washing water in dish washer

Description:
This application claims the benefit of the Korean Application No. P2003-0093826 filed on Dec. 19, 2003, which is hereby incorporated by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to dish washers, and more particularly, to a device for filtering, and supplying washing water to a spray arm.  
      2. Background of the Related Art  
      The dish washer automatically washes, and dries dishes by spraying detergent and washing water to the dishes. In general, the dish washer is provided with racks for placing the dishes thereon, a sump for holding the washing water, spray arms for spraying the washing water to the dishes on the racks, and a motor for supplying the washing water from the sump to the spray arm.  
      In the operation, upon putting the motor into operation, the spray arm sprays the washing water in the sump to the dishes, to wash the dishes. The washing water sprayed to the dishes returns to the sump again, and sprayed to the dishes again.  
      Consequently, the washing water in the sump is gradually contaminated. Continuous use of heavily contaminated washing water, not only drops washing capability, but also is liable to block a passage of the washing water.  
      In order to prevent this, it is required to change the washing water periodically, too frequent change of the washing water may consume too much washing water.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present invention is directed to a device for supplying washing water in a dish washer that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.  
      An object of the present invention lies on effective filtering and supplying washing water in a dish washer to a spray arm.  
      Another object of the present invention lies on preventing wasting of washing water at a dish washer.  
      Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
      To achieve these objects and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, the device for supplying washing water to a dish washer includes a sump for holding washing water, a filtering housing for guiding a portion of the washing water pumped up by a pump from the sump to a spray arm in a washing chamber, and holding rest of the washing water therein, and a filtering panel including a filter portion for filtering the washing water overflowed from the filtering housing by using at least two filters having filtering capabilities different from each other, and apertures for guiding the washing water dropped after washing the dishes in the washing chamber, or passed through the filter portion.  
      In other aspect of the present invention, there is provided a dish washer including a cabinet having a washing chamber therein, at least a spray arm for spraying high pressure washing water to dishes in the washing chamber, and a device for supplying washing water to a dish washer including a sump for holding washing water, a filtering housing for guiding a portion of the washing water pumped up by a pump from the sump to a spray arm in a washing chamber, and holding rest of the washing water therein, and a filtering panel including a filter portion for filtering the washing water overflowed from the filtering housing by using at least two filters having filtering capabilities different from each other, and apertures for guiding the washing water dropped after washing the dishes in the washing chamber, or passed through the filter portion.  
      The filtering housing includes a guide passage for making the pump and the spray arm in communication, and a contaminated water chamber in communication with the pump, for holding the rest portion of the washing water.  
      The filtering panel covers an upper portion of the filtering housing.  
      The filter portion includes at least one first filter on the filtering housing, and a second filter on the filtering housing which is coarser than the first filter.  
      The contaminated water chamber includes an inlet being through which the washing water is introduced into an inside of the contaminated water chamber and a drain for draining the washing water from the contaminated water chamber selectively.  
      The first filter is arranged adjacent to the drain, and the second filter is arranged adjacent to the inlet. The second filter is arranged at a position higher than the first filter.  
      The filer portion includes at least one of a net and a perforated portion. Particularly, the second filter includes a perforated portion or a net formed in the filtering panel.  
      It is to be understood that both the foregoing description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention claimed.  
    
    
     BRIEF DESCRITPION OF THE DRAWINGS  
      The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention.  
      In the drawings;  
       FIG. 1  illustrates a diagram showing a structure of a dish washer of the present invention, schematically;  
       FIG. 2  illustrates a disassembled perspective view of a device for supplying washing water in accordance with a preferred embodiment of the present invention;  
       FIG. 3  illustrates a section of the device for supplying washing water in  FIG. 2 ;  
       FIG. 4  illustrates a section showing a washing water flow in a filtering housing in the device for supplying washing water in  FIG. 2 ;  
       FIG. 5  illustrates a disassembled perspective view showing washing water filtering by overflow from a filtering housing in the device for supplying washing water in  FIG. 2 ;  
       FIG. 6  illustrates a disassembled perspective view of a filtering panel, and a filtering housing of another embodiment of the device for supplying washing water in  FIG. 1 ;  
       FIG. 7  illustrates a disassembled perspective view showing washing water filtering by overflow from a filtering housing in  FIG. 6 ; and  
       FIG. 8  illustrates a disassembled perspective view showing a large amount of washing water is filtered through a second filter in a case contaminants are stuck to a first filter of the filtering panel in  FIG. 6 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In describing the embodiments, parts the same with the related art will be given the same names and reference symbols.  
      Referring to  FIG. 1 , there are a washing chamber  11  inside of a cabinet  10  of the dish washer, and a door  15  at one side of the cabinet  10  for opening/closing the washing chamber  11 . The washing chamber  11  is provided with racks for placing dishes thereon. For reference,  FIG. 1  illustrates an example in which a first rack  21  and a second rack  25  are provided in an upper portion and a lower portion of the washing chamber  11 .  
      Also, there is at least one spray arm in the washing chamber  11  adjacent to the rack. For an example, as shown in  FIG. 1 , a first spray arm  31  and a second spray arm  35  are provided under the first rack  21  and the second rack  25 , respectively.  
      The first, and second spray arms  31 , and  35  are rotatably mounted, and each has a plurality of spray holes or nozzles at one side thereof. The first, and second spray arms  31 , and  35  mounted thus spray high pressure washing water to the dishes on the first, and second racks  21 , and  25 , for washing the dishes.  
      For this, there is a device  100  for supplying washing water to the first spray arm  31 , and the second spray arm  35  inside of the cabinet  10 , for an example, under the washing chamber  11 . There are a first connection pipe  32  and a second connection pipe  33  connected between the first spray arm  31  and the device  100  for supplying washing water, and the second connection pipe  33  and the device  100  for supplying washing water.  
      The washing water supplying device  100  supplies clean washing water from an outside to the first spray arm  31  and the second spray arm  35 , at the same time, or selectively. Moreover, the washing water supplying device  100  cleans the washing water fallen from the washing chamber  11  after washing the dishes, and supplies to the first, and second spray arms  31 , and  35 , respectively.  
      FIGS.  2 ˜ 4  illustrate one embodiment of the washing water supplying device  100  in detail, referring to which the washing water supplying device  100  will be described in more detail.  
      Referring to  FIG. 2 , the washing water supplying device  100  includes a sump  110  for holding the washing water. The sump  110  holds clean washing water received form an outside through a water supplying device (not shown), or the washing water fallen from the washing chamber after washing the dishes.  
      The washing water supplying device  100  also includes a pump for pumping up the washing water from the sump  110 . The pump includes a pumping motor  121  under the sump  110 , and an impeller  125  in the sump  110  to be rotatable by the pumping motor  121 .  
      In the meantime, there are a heater  115  mounted on the sump  110  for heating the washing water, and a filtering housing  130  over the sump  110 . Therefore, the impeller  125  is under the filtering housing  130 , and the washing water pumped up from the sump  110  by the impeller  125  is supplied to the filtering housing  130 .  
      The filtering housing guides a portion of the washing water pumped up from the sump  110  to the first, and second spray arms  31 , and  35 , and holds rest of the washing water therein.  FIG. 3  illustrates a structure of the filtering housing  130  in detail, referring to which the filtering housing  130  will be described in more detail.  
      Referring to  FIG. 3 , the filtering housing  130  has an inlet  131  at one side for the washing water from the impeller  125 , and guide passages connected to the inlet  131 , for an example, a first passage  132 , and a second passage  133 .  
      The first passage  132  has a first connection pipe  32  connected to the first spray arm  31 , and the second passage  133  has a second connection pipe  33  connected to the second spray arm  35 . Accordingly, the guide passages make the pump and the spray arms in communication.  
      Referring to  FIG. 3 , there is a flow path control valve  145  among the inlet  131 , the first passage  132 , and the second passage  133 . The flow path control valve  145  is rotated by a control motor  141  under the sump  110 , for making the inlet  131 , the first passage  132 , and the second passage  133  in communication, at the same time or selectively.  
      Therefore, the washing water, pumped up by the pump and introduced through the inlet  131 , is supplied to the first spray arm  31  and the second spray arm  35  at the same time, or to one of them, selectively.  
      In the meantime, the filtering housing  130  also has a contaminated water chamber  136  therein for holding rest of washing water introduced through the inlet  131  after the washing water is introduced into the first passage  132 , and the second passage  133 . For this, a third passage  134  is provided to connect the inlet  131  to the contaminated water chamber  136 .  
      The third passage  134  has a sensor  135  for measuring a level of contamination of the washing water being introduced into the contaminated water chamber  136 . The sensor  135  has a light emitting portion (not shown) and a light receiving portion (not shown), for determining the level of contamination based on a quantity of light received at the light receiving portion.  
      There is a drain  137  at one side of the contaminated water chamber  136  spaced a distance away from the inlet  131 . Therefore, if a drain motor (not shown) works, the washing water held in the contaminated water chamber  136  is drained from the contaminated water chamber  136  to outside of the dishwasher.  
      However, if the drain motor does not work, the contaminated water chamber  136  keeps receiving the washing water through the inlet  131 . Accordingly, if a water level of the washing water becomes higher than the contaminated water chamber  136 , the washing water overflows from the contaminated water chamber  136 , and drops down to the sump  110 .  
      In the meantime, the washing water introduced into the contaminated water chamber  136  contains contaminants formed during washing of the dishes. Therefore, the present invention suggests providing a member for filtering the contaminants contained in the washing water overflowing from the contaminated water chamber  136 . For this, there is a filtering panel  150  on the filtering housing  130  of the contaminated water chamber  136 .  
      Referring to  FIG. 4 , the filtering panel  150 , for an example, of a circular form has a central portion covering an upper portion of the contaminated water chamber  136 . As shown in  FIG. 2 , the filtering panel  150  is provided with at least one first filter  151  at the central portion.  
      For reference, in  FIG. 2 , the first filter  151  is a net of small mesh. However, the first filter  151  is not limited to this, and any structure is adequate as the first filter  151  as far as the structure can filter small contaminants and passes the washing water, such as a perforated plate.  
      In the meantime, as shown in  FIG. 4 , a peripheral portion of the filtering panel  150  covers a portion of an upper surface of the sump  110 . The peripheral portion has at least one aperture  155  making an inside of the sump  110  and an upper portion of the filtering panel  150  in communication.  
      The aperture  155  guides contaminated washing water dropped down after washing the dishes in the washing chamber  11  to the sump  110 . Since the aperture  155  is not for filtering the contaminants the washing water, it is preferable that a size of the aperture  155  is large adequately.  
      Above structure enables filtering of the contaminants from the washing water overflowed from the contaminated water chamber  136  at the first filter  151 . However, contaminants failed to pass the first filter  151  in this process remain in the contaminated chamber  136 , and block the mesh of the first filter  151 .  
      Therefore, for preventing this, as shown in  FIG. 1 , the dish washer of the present invention is further provided with a third spray arm  41 . The third spray arm  41 , over the washing water supplying device  100 , sprays high pressure water toward the first filter  151 , for preventing the contaminants from blocking the mesh of the first filter  151 .  
      In the meantime, the washing water passed through, and cleaned at the first filter  151  passes through the aperture  155  and held in the sump  110 .  
      The operation of the dish washer of the present invention will be described.  
      Upon putting the dish washer into operation, clean washing water is supplied to the sump  110 . When the pumping motor  121  comes into operation, the impeller  125  rotates, to introduce the washing water from the sump  110  to the inlet  131  of the filtering housing  130 .  
      A portion of the washing water introduced through the inlet  131  is guided to the first passage  132  and the second passage  133  by the flow path control valve  145 , at the same time or selectively. According to this, the first spray arm  31  and the second spray arm  35  spray the washing water, at the same time, or individually, to wash the dishes on the first and/or second racks  21 , and  25 .  
      The contaminated washing water having washed the dishes at the washing chamber  11  drops on the filtering panel  150 , passes the aperture  155 , and held in the sump  110 . According to this, the sump  110  also holds the contaminants formed during washing of the dishes, together with the washing water.  
      On the other hand, rest of the washing water introduced through the inlet  131  of the filtering housing  130  after pumped up from the sump  110  is introduced into the contaminated water chamber  136  through the third passage  134 .  
      In this instance, the sensor  135  measures the level of contamination of the washing water being introduced into the flow water chamber  136 , and transfers to the control portion (not shown). If the washing water is contaminated heavily, the control portion operates the drain motor, for draining the washing water from the contaminated water chamber  136  to an outside of the dish washer. Opposite to this, if the contamination is not heavy, the control portion does not operate the drain motor, to hold the washing water introduced into the third passage  134  in the contaminated water chamber  136 .  
      If there is much water introduced into the contaminated water chamber  136 , the washing water overflows from the contaminated water chamber  136 . In this instance, as shown in  FIG. 5 , the first filter  151  of the filtering panel  150  filters the contaminants from the washing water. Therefore, cleaned water is introduced into the sump  110  through the aperture  155 , and contaminants failed to pass the first filter  151  remains in the contaminated water chamber  136 .  
      Thus, the dish washer of the present invention filters only the washing water that is pumped up by the pump, and introduced into the contaminated water chamber  136  through the third passage  134 . According to this, it seems that only a portion of the washing water is filtered. However, an effect that almost all the washing water is filtered can be obtained.  
      According to this, the dish washer of the present invention can filter the washing water effectively, and supply to the first, and second spray arms. Moreover, the washing water can be filtered and used continuously, to enable to use an amount of the washing water less than the related art in washing the dishes.  
      However, despite of above advantages, the dish washer of the present invention described with reference to FIGS.  1 ˜ 4  has the following a few problems, still.  
      First, for improving a filtering performance, a net with small mesh is used as the first filter  151 . In this case, even if the filtering performance of the dish washer is improved, the filtering performance of the first filter  151  drops as an operation time period of the dish washer passes by because the mesh of the first filter  151  is susceptible to be blocked by the contaminants in the washing water.  
      Second, a water pressure of the contaminated water chamber  136  increases once the contaminants block the mesh of the first filter  151 . According to this, as a pressure acting on the filter  151  also increases, the first filter  151  is liable to deform.  
      Third, the increase of the pressure of the contaminated water chamber  136  also drains the washing water from the contaminated water chamber  136 , and to introduce washing water newly from an outside, resulting in waste of the washing water.  
      Fourth, the increased water pressure of the contaminated water chamber  136  may cause back flow of the washing water from the contaminated water chamber  136  to the third passage  134  and the inlet  131 . In this case, the sensor  135  is liable to fail correct measurement of the level of the contamination, such that the control portion operates the drain motor, then a large amount of washing water is wasted.  
      Accordingly, the present invention suggests providing a device for supplying washing water in a dish washer of an improved structure that can solve above problems. The device for supplying washing water of the improved structure enables an effective prevention of increase of the pressure acting on the first filter  151  when the washing water overflows from the contaminated water chamber  136 , thereby improving a performance of washing water filtering.  
      The device for supplying washing water of such an improved is illustrated in FIGS.  6 ˜ 8 , referring to which the device will be described in more detail. For reference, in describing the embodiment, parts identical to ones described with reference to FIGS.  2 ˜ 5  will be given the same names and reference symbols, and repetitive description of which will also omitted.  
       FIG. 6  illustrates a disassembled perspective view of a filtering panel, and a filtering housing of an improved structure. As can be noted from  FIG. 6 , in the embodiment, the filtering panel  150  has a filter portion  153  for filtering the washing water. Different from the embodiment described with reference to FIGS.  2 ˜ 5 , the filter portion  153  includes at least two filters, for an example, a first filter  151  and a second filter  152 , having filtering capabilities different from each other. Of course, the filter portion  153  may include more number of filters having filtering capabilities different from one another.  
      Referring to  FIG. 6 , the first filter  151 , and the second filter  152  are placed on the filtering housing  130 , more specifically, on the contaminated water chamber  136 . In this instance, though the first filter  151  has one large sized body, as shown  FIG. 6 , it is preferable that the first filter  151  has a plurality of small bodies for better endurance to a high water pressure.  
      The filter portion  153  may be a net or a perforated portion. For reference, in  FIG. 6 , an embodiment in which the first filter  151  is the net, and the second filter  152  is the perforated portion is illustrated. However, configuration of the filter portion  153  is not limited to this, but it does not matter even if the first filter  151  is the perforated portion and the second filter  152  is the net. Of course, both of them may be the same material.  
      In the meantime, the second filter  152  is coarser than the first filter  151 . That is, the aperture of the second filter  152  is greater than the aperture of the first filter  151 .  
      This structure enables the washing water to escape through the second filter  152  even if the apertures or mesh are blocked by the contaminants. According to this, the operation time of the dish washer increases, to prevent drop of the filtering capability of the filter portion  153 .  
      Referring to  FIG. 6 , it is preferable that the first filter  151  is arranged adjacent to the drain  137 , and the second filter  152  is arranged adjacent to the inlet  131 , because of the following reasons.  
      As described before, the washing water introduced into the filtering housing  130  through the inlet  131  is held in the contaminated water chamber  136  through the third passage  134 , the drain  137  is provided at one side of the contaminated water chamber  136  far from the inlet  131 .  
      Therefore, it may be called that the inlet  131  side is an upstream of the washing water, and the drain  137  side is a downstream of the washing water. During operation of the dish washer, the contaminants in the washing water accumulates at the downstream side rather than at the upstream side.  
      Therefore, referring to  FIG. 7 , at the initial stage of operation of the dish washer, the first filter  151  having better filtering performance at the downstream side much contaminant accumulates thereon filters the washing water, normally. Of course, the second filter  152  also filters comparatively large sized contaminants.  
      Then, as time goes by, if the first filter  151  is blocked as substantial portion of the contaminants are filtered from the washing water, as shown in  FIG. 8 , a large amount of washing water is discharged to an outside of the contaminated water chamber  136  through the second filter  152  at the upstream.  
      According to this, operating of the drain motor caused by sudden increase of the water pressure in the contaminated water chamber  136  coming from blocking of the first filter  151  can be prevented. After, the first filter  151  loses the filtering function, the second filter  152  keeps filtering comparatively large contaminants from the washing water. According to this, an effect that the filtering performance of the filter portion is improved can be obtained.  
      In the meantime, in the filter portion  153 , it is preferable that the second filter  152  is arranged at a position higher than the first filter  151 . For reference,  FIG. 6  illustrates an example in which the second filter  152  is arranged at a position higher than the first filter  151  by “H”. This structure enables to prevent drop of filtering performance more because a major portion of the washing water passes through, and filtered at the first filter  151  as far as the first filter  151  performs normally.  
      Above washing water supply device of an improved structure, not only prevents the increase of the water pressure in the contaminated water chamber, but also improves the filtering performance of the filter portion. Therefore, the dishes can be cleaned by using a small amount of water. Moreover, deformation of the filter caused by the high pressure can be prevented, and back flow of the washing water from the contaminated water chamber  136  can be prevented effectively, to prevent waste of the washing water coming from malfunction of the sensor  135 .  
      It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.