Patent Publication Number: US-2005115592-A1

Title: Water guide of dishwasher and dishwasher having the same

Description:
This application claims the benefit of Korean Application No. 10-2003-0072163, filed on Oct. 16, 2003, which is hereby incorporated by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a dishwasher, and more particularly, to a water guide of a dishwasher, by which a flow of water used in the dishwasher is guided.  
      2. Discussion of the Related Art  
      Generally, a dishwasher is an appliance for washing and drying tableware automatically by injecting a detergent and water on the tableware. And, the dishwasher consists of at least one rack provided within a washing chamber to support tableware thereon, a sump storing water therein, at least one injector arranged under the rack to inject the water toward the tableware put on the rack, and a pump supplying the water stored within the sump to the injector.  
      Once the pump is activated, the injector injects the water within the sump onto the tableware to wash. And, the water injected on the tableware is recovered to the sump and is then injected toward the tableware again. After completion of a washing cycle, a drain pump is activated to discharge the water within the sump outside via drain hose. After the drain pump stops being operated, clean water is supplied to the sump for a rinsing cycle.  
      In the above-configured dishwasher, if the drain hose fails to be provided over a water level within the sump, a siphon phenomenon take place due to a pressure difference despite stopping operating the drain pump. The clean water having been supplied to the sump for the rinsing cycle is discharged via drain line consisting of the sump, drain pump, and drain hose. Hence, water consumption increases and the washing or rinsing is unable to be efficiently performed. It is not only difficult but also annoying for a user to install the drain hose over the sump water level each time the dishwasher is newly installed or moved to another place.  
      Moreover, even if the installation position of the drain hose is appropriately adjusted, a pressure within the drain line can be decreased lower than an atmospheric pressure by various factors during the operation of dishwasher. In such a case, the clean water could be unexpectedly discharged by the siphon phenomenon.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present invention is directed to a water guide of a dishwasher and dishwasher having the same that substantially obviate one or more of the problems due to limitations and disadvantages of the related art.  
      An object of the present invention, which has been devised to solve the foregoing problem, lies in providing a water guide of a dishwasher and dishwasher having the same, by which clean water is prevented from being unexpectedly discharged.  
      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 a practice of the invention. The objectives and other advantages of the invention will be realized and attained by the subject matter particularly pointed out in the specification and claims hereof as well as in the appended drawings.  
      To achieve these objects and other advantages in accordance with the present invention, as embodied and broadly described herein, there is provided a water guide of a dishwasher, including a drain passage communicating with a sump receiving a water therein and an external atmosphere, respectively, the drain passage configured to drain a used water and a valve assembly provided to the drain passage, the valve assembly configured to prevent an unused water within the sump from being drained via the drain passage.  
      The drain passage is connected to a drain pump connected to the sump. The drain passage is connected to a drain hose. The drain passage includes a siphon passage for the sump. At least one portion of the drain passage is configured to pass through a position higher than a water level within the sump. And, the drain passage has a reversed ‘U’ type shape.  
      The valve assembly is configured to selectively introduce an external air into the drain passage. For this, the valve assembly is configured to selectively allow the drain passage to communicate with an external atmosphere. Specifically, the valve assembly is configured to isolate the drain passage from an external atmosphere on draining the used water. And, the valve assembly is configured to allow the drain passage to communicate with an external atmosphere after completion of draining the used water.  
      Moreover, the valve assembly is provided within an air passage communicating between the drain passage and an external atmosphere to selectively open/close the air passage. The valve assembly includes a first gate communicating with the external atmosphere, a second gate communicating with the drain passage, and a valve provided between the first and second gates, the valve ascending/descending to close/open the first gate.  
      The valve is configured to be lifted by the water discharged via the drain passage. And, the valve descends by a weight of the valve after draining the water.  
      The second gate is configured to constantly communicate with the drain passage. For this, the second gate is partially greater than the valve.  
      Meanwhile, the valve is configured to allow the second gate to constantly communicate with the drain passage. And, the valve is configured not to close the second gate.  
      For instance, the valve is formed smaller than the second gate to be configured to be caught on the second gate.  
      Moreover, the lowered valve is separated from the second gate to leave a prescribed distance from the second gate not to close the second gate. And, the lowered valve leaving the prescribed distance from the second gate can be lifted from the second gate. Alternatively, the lowered valve is configured to be suspended in the air passage.  
      In another aspect of the present invention, there is provided a dishwasher including a housing, a tub provided within the housing to receive tableware therein, a sump provided to the tub to receive water therein, an injector provided within the tub to inject the water within the sump to the tableware, a drain passage communicating with the sump and an external atmosphere, respectively, the drain passage configured to drain a used water, and a valve assembly provided to the drain passage, the valve assembly configured to prevent an unused water within the sump from being drained via the drain passage.  
      In the above-configured dishwasher, the water guide is provided with the foregoing-described features.  
      In the present invention having the above-described configurations, the water guide enables to prevent the water from being drained by the siphon phenomenon using the valve assembly.  
      It is to be understood that both the foregoing explanation and the following detailed description of the present invention are exemplary and illustrative and are intended to provide further explanation of the invention as claimed. 
    
    
     BRIEF DESCRIPTION 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 embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:  
       FIG. 1  is a cross-sectional diagram of a dishwasher according to the present invention;  
       FIG. 2  is a cross-sectional diagram of a water guide of a dishwasher according to the present invention;  
       FIG. 3A  and  FIG. 3B  are cross-sectional diagrams of explaining an operation of a water guide according to the present invention;  
       FIG. 4A  is a perspective diagram of a valve within a water guide according to the present invention;  
       FIG. 4B  is a cross-sectional diagram of an modification of a valve within a water guide according to the present invention;  
       FIG. 5A  is a cross-sectional diagram of a modification of a gate included within a water guide according to the present invention;  
       FIG. 5B  is a cross-sectional diagram according to a cutting line I-I in  FIG. 5A ;  
       FIG. 6A  and  FIG. 6B  are perspective and cross-sectional diagrams of a modification of a valve within a water guide, respectively;  
       FIG. 7A  and  FIG. 7B  are cross-sectional diagrams of modifications of a valve and gate within a water guide, respectively;  
       FIG. 8  is a cross-sectional diagram of a modification of a valve within a water guide; and  
       FIG. 9A  and  FIG. 9B  are cross-sectional and perspective diagrams of a modification of a valve within a water guide, respectively. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Throughout the drawings, like elements are indicated using the same or similar reference designations where possible.  
       FIG. 1  is a cross-sectional diagram of a dishwasher including a water guide according to the present invention.  
      Referring to  FIG. 1 , in a dishwasher according to the present invention, a tub  10  forms a washing chamber that is opened or closed by a door  11  provided in front of the tub  10 . And, at least one rack  30  is provided within the washing chamber to receive tableware therein. The rack  30  can be pulled out of the washing chamber when the door  11  is open. For instance, although one rack  30  is shown in  FIG. 1 , at least two racks can be provided to the washing chamber.  
      A sump  20  holding water therein is provided to a bottom part of the tub  10 . The sump  20  preferentially holds clean water supplied from outside. A water guide  100  is connected to the sump  20  to guide a flow of the clean water to the sump  20 . And, the sump  20  receives the polluted water falling downward after the tableware within the washing chamber has been washed. Moreover, a filter (not shown in the drawing) is connected to the sump  20  to filter the water polluted by the washing to reuse.  
      A pump (not shown in the drawing) is connected to the sump  20  to pump the water held within the sump  20  to an injector  40 . The pump includes a motor (not shown in the drawing) connected to one side of the sump  20  and an impeller (not shown in the drawing) provided within the sump  20  to be connected to the motor. Hence, once the motor is activated, the impeller revolves to pump the water held within the sump  20  to the injector  40 . The injector  40  is supplied with the water pumped by the pump and is generally provided beneath the rack  30 . The injector  40  provided with at least one nozzle  41  so that the pumped water can be injected within the washing chamber via the nozzle  41 . The injector  40  is rotatably installed and the nozzle  41  is oriented to tilt. Hence, the injector  40  is rotated by a reactive force exerted from the water that is jetted out of the nozzle  41  on the slant. Hence, the injected water is evenly sprinkled inside the washing chamber to cleanse the tableware put in the rack  30 . The used or polluted water is retrieved to the sump  20  and is repeatedly injected into the washing chamber by the injector  40 .  
      After completion of a plurality of washings or rinsings, the polluted water is drained from the sump  20  to be discharged outside the dishwasher. For this, a drain pump  60  is connected to the sump  20  and the water guide  100  is connected to the drain pump  60 . And, a drain hose  70  is connected to the water guide  100  that guides a flow of the polluted water discharged outside from the sump  20 . After completion of draining the polluted water, clean water is supplied to the sump  20  again via the water guide  100 .  
      As mentioned in the foregoing description, the water guide  100  leads the polluted water drained from the sump  20  outside the dishwasher as well as guides the clean water supplied from outside to the sump  20 . The water guide  100  is attached to an outer surface of the tub  10  and includes a water supply passage assembly and a drain passage assembly. The water guide  100  is applicable to all kinds of dishwashers and is explained in detail with reference to  FIG. 2 .  
      First of all, the water guide  100  includes a case attached to the tub  10  to provide an inner space inside. An air inlet  110  is provided to the water guide  100 , e.g., an upper part of the water guide, to make the inner space and external atmosphere communicate with each other. And, a water supply passage  120  guiding the clean water and a drain passage  130  guiding the polluted water are provided to the inner space of the case.  
      The water supply passage  120  is connected to a water supply valve  50  shown in  FIG. 1  and the sump  20  shown in  FIG. 1 , respectively. An inlet  121  and outlet  122  of the water supply passage  120 , as shown in  FIG. 2 , are provided beneath the water guide  100 . The inlet  121  is connected to the water supply valve  50 , as shown in  FIG. 1 , and the outlet  122  is connected to the sump  20 . Hence, once the water supply valve  50  is turned on, the clean water is supplied to the sump  20  via the water supply passage  120 .  
      And, the drain passage  130  is connected to the drain pump  60  and the drain hose  70 , respectively. The drain passage  130  is arranged next to the water supply passage  120  and includes an inlet  131  and outlet  132  provided beneath the water guide  100 . The inlet  131 , as shown in  FIG. 1 , is connected to the drain pump  60  communicating with the sump  20  and the outlet  132  is connected to the drain hose  70  communicating with outside the dishwasher. Hence, once the drain pump  60  is activated, the water within the sump  20  is drained outside via the drain pump  60 , drain passage  130 , and drain hose  70 , in turn. Moreover, a portion of the drain passage  130 , as shown in  FIG. 1 , is formed to pass through a position higher than a water level within the sump  20  (cf.  FIG. 1 ). The drain passage  130 , as shown in the drawing, has a reversed ‘U’ shape and substantially plays a role as a siphon passage for the sump  20 . Since the drain passage  130  extends higher than the water level of the sump  20 , it is able to prevent a drain phenomenon caused by a height difference between the water level of the sump  20  and a height of the drain hose  70 . Namely, even if the drain pump  60  stops operating, the newly supplied water fails to keep being discharged from the sump  20  by the siphon phenomenon. Yet, the pressure within the drain passage  130  could be reduced lower than the atmospheric pressure working on the water within the sump  20  by various factors. The pressure difference from the atmospheric pressure within the drain passage  130  raises the water within the drain passage  130 . In case of being raised by the pressure difference to be higher than a height between the water level of the sump  20  and a peak of the drain passage  130 , the water is discharged outside by the siphon phenomenon via the drain passage  130  and the drain hose  70 . Thus, for the above-explained reasons, the water, which is newly supplied after completion of the drain, can be discharged outside the dishwasher from the sump  20 .  
      Hence, the water guide  100  according to the present invention includes a valve assembly  200  configured to prevent the unused water from being unnecessarily drained by the siphon phenomenon. As mentioned in the foregoing description, the siphon phenomenon occurs from the pressure difference between the drain passage  130  and the external atmosphere. In order to overcome the pressure difference, the valve assembly  200  is configured to optionally introduce external air into the drain passage  130 . For the introduction of the external air, the valve assembly  200  makes the drain passage  130  to communicate with the external atmosphere selectively. Namely, in order to prevent the siphon phenomenon, the valve assembly  200  is configured to make the drain passage  130  communicate with the external atmosphere only when the used water is completely drained. Moreover, the siphon phenomenon should be overcome before the water arrives at the peak of the drain passage  130 . Hence, the valve assembly  200  is preferably provided over the peak of the drain passage  130 , i.e., an upper part of the drain passage  130 . In other words, the valve assembly  200  is provided to or in the vicinity of a bent portion of the reversed ‘U’ type drain passage  130 .  
      The valve assembly  200  is additionally explained in detail with reference to  FIGS. 3A  to  4 B as follows.  
      The drain passage  120  needs to directly communicate with the external atmosphere for effective introduction of the external air. Hence, the drain passage  120  is connected to an air passage  140  communicating with the external atmosphere. The valve assembly  200  is substantially installed within the air passage  140  and selectively open/close the air passage  140  to control the introduction of the external air.  
      Specifically, the valve assembly  200  includes first and second gates  210  and  220  provided within the air passage  140  and a valve  230  provided between the first and second gates  210  and  220 .  
      The first gate  210 , as shown in the drawing, communicates with the external atmosphere, whereas the second gate  220  communicates with the drain passage  130 . Hence, the external air is introduced into the drain passage  130  via the first and second gates  210  and  220  within the air passage  140 . And, the first and second gates  210  and  220  are substantially configured with first and second ribs  210  and  220  extending from an inner surface of the air passage, respectively. The first and second ribs  210  and  220  play a role in supporting the valve  230  and putting limitation on the movement of the valve  230 .  
      The valve  230  ascends/descends between the first and second gates  210  and  220  to close or open the first gate  210 . The first gate  210  always has a size smaller than the valve  230  to be closed by the valve  230 . In the present invention, the movement of the valve  230  is basically performed by the drained water. Specifically, once the drain pump  60  in  FIG. 1  is activated, the used water within the sump  20  is introduced into the drain passage  130  via the inlet  131 . The introduced water, which was pumped by the drain pump  60 , is raised fast by the high pressure and then falls to be drained outside the dishwasher via the outlet  132  and the drain hose  70 . During the draining, a portion of the water, as shown in  FIG. 3A , is introduced into the air path  140  via the second gate  220 . The valve  230  is then raised by the water to block the first gate  210 . Namely, when the used water is drained, the valve assembly  200 , and more specifically, the valve  230  is raised by the water to close the first gate  210  so that the drain passage  130  can be isolated from the external atmosphere. Consequently, the used water avoids leaking via the air path  140  but is drained outside via the drain passage  410  and the drain hose  70 .  
      Once the drain pump  60  stops operating, an amount of the water reaming within the drain passage is abruptly reduced. The valve  230 , as shown in  FIG. 3B , descends due to its own weight so that the first gate  210  can be open. Namely, after completion of the drain of the used water, the valve  230  descends due to its weight to open the first gate  210  so that the drain passage  130  can communicate with the external atmosphere. Hence, the external air is quickly introduced into the drain passage  130  via the first and second gates  210  and  220 . In doing so, the drain passage  130  remains in an atmospheric state to settle the pressure difference between the sump  20  and the drain passage  130 , whereby the siphon phenomenon is removed. Consequently, once the drain pump  60  stops operating, the drain is automatically and completely stopped by the valve assembly  200 .  
      Preferably, the valve  230  has buoyancy to be well raised by the water. Hence, the valve  230  may include a floating body formed of a material having the buoyancy. Alternatively, the valve  230  can include a hollow body to have the buoyancy. The hollow valve  230 , as shown in  FIG. 4B , can be easily provided using a pair of pieces  230   a  and  230   b  assembled to each other. Moreover, the valve  230 , as shown in  FIG. 4A , can further include an extension  231  extending in a length direction of the valve  230 . The extension  231  is inserted in the first or second gate  210  or  220  according to its provided location. Since the extension  231  is guided by the first or second gate  210  or  220 , the valve  230  enables to move stably. Hence, the extension  231  prevents a malfunction of the valve  230  and enhances reliability. Preferably, a pair of extensions  231  are provided to top and bottom of the valve  230  to be stably guided by the first and second gates  210  and  220 , respectively.  
      Meanwhile, if the second gate  220  is closed by the lowered valve  230  or other reasons, it is unable to supply the external air to the drain passage  130  to settle the pressure difference even if the first gate  210  is open. Hence, the second gate  220  needs to be constantly open to communicate with the drain passage  130 .  FIGS. 5A  to  9 B show various modifications for opening the second gate  220  constantly.  
      Referring to  FIG. 5A  and  FIG. 5B , the second gate  229  itself is configured to constantly communicate with the drain passage  130 . Namely, the second gate  220  is partially formed greater than the valve  230 . If the second gate  220  is greater than the valve  230  overall, the second gate  220 , and more precisely, the second rib  221  is unable to limit the movement of the valve  230 . Specifically, the second gate  220 , as shown in  FIG. 5B , can further include an auxiliary gate  222  extending from the second gate  220  in a radial direction. Even if the valve  230  is lowered to be placed on the second gate  220  as indicated by the doted line in  FIG. 5B , the second gate  220  enables to communicate with the drain passage  130  via the auxiliary gate  222 . Hence, the external air can be introduced into the drain passage  130  via the first and auxiliary gates  210  and  222  even if the valve  230  is lowered.  
      Alternatively, in the present invention, the valve  230  is configured to allow the second gate  220  to constantly communicate with the drain passage  130 . Namely, the valve  239  is configured not to close the second gate  220 .  
      Referring to  FIG. 6A  and  FIG. 6B , the valve  230  is formed smaller than the second gate  220  and is configured to be latched on the second gate  220  in case of descending. Specifically, a rib  232  is provided to a lateral side of the valve  230 . The rib  232  is latched on the second rib  221  to put limitation on the descent of the valve  230  smaller than the second gate  220 . Namely, the valve  230  is approximately smaller than the second gate  220  but is partially greater than the second gate  220  for the limited descent of the valve  230 . Preferably, a pair of ribs  232 , as shown in the drawing, are provided to the lateral side of the valve  230  so that the valve  230  can be stably supported by the second rib  221 . In such a modification, even if the lowered valve  230  is put on the second rib  221 , a clearance between the valve  230  and the second gate  220  still allows the second gate  220  to communicate with the drain passage  130 . Hence, the external air can be introduced into the drain passage  130  via the open first gate  210  and the clearance.  
      Moreover, the valve  230  can be configured to leave a predetermined distance from the second gate in ascending not to close the second gate  220 .  
      Referring to  FIG. 7A  and  FIG. 7B , the lowered valve  230  is lifted from the second gate  220  to leave a prescribed distance from the second gate  220 . Specifically, at least one protrusion  233 , as shown in  FIG. 7A , is provided to a lower end of the valve  230  or at least one protrusion  223 , as shown in  FIG. 7B , is provided to a periphery of the second gate  220 , and more particularly, to the second rib  221 . The protrusion  233  or  223  supports the lowered valve  230  to be lifted from the second gate  220 . In such a modification, the lowered valve  230  is substantially separated from the second gate  220  so that a clearance is provided between the second gate  220  and the valve  230 . The second gate  220  is constantly open by the clearance to communicate with the drain passage  130 . Hence, once the first gate  210  is open, the external air can be introduced into the drain passage  130  via the first and second gates  210  and  220 .  
      Moreover, the lowered valve  230  is configured to be suspended in the air passage  140  to be separated from the second gate  220 . First of all, the lowered valve  230 , as shown in  FIG. 8 , is configured to be suspended on a wall of the air passage  140 . Specifically, the valve  230 , as shown in  FIG. 8 , is connected to an inner surface of the air passage  140  by a wire  234 . A length of the wire  234  is adjusted so that the valve  230  suspended by the wire  234  can avoid being contacted with the second rib  221 . Alternatively, the lowered valve  230 , as shown in  FIG. 9A  and  FIG. 9B , can be configured to be suspended below the first gate  210 . Specifically, the valve  230  includes an extension  235  extending from the valve  230  in a radial direction. The extension  235  is caught on the first gate  210  when the valve  230  is being lowered, whereby the valve  230  enables to be suspended below the first gate  210 .  
      Meanwhile, when the valve  230  is lowered to open the first gate  210 , the extension  235  may come into being caught on the first gate  210  to close the first gate  210 . Hence, the extension  235  preferably includes at least one perforated hole  235   a  communicating with the first gate  210  to allow the external air to pass through. In the above-explained modifications, the lowered valve  230  is substantially separated from the second gate  220  by the wire  234  or the extension  235  so that the clearance can be provided between the second gate  220  and the valve  230 . The second gate  220  is open to constantly communicate with the drain passage  130  via the clearance. Hence, once the first gate  210  is open, the external air can be introduced into the drain passage  130  via the first and second gates  210  and  220 .  
      As mentioned in the foregoing description, the valve assembly according to the present invention enables to effectively prevent the clean water from being unexpectedly drained by the siphon phenomenon. Therefore, the reliability of the dishwasher can be considerably enhanced.  
      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 such modifications and variations, provided they come within the scope of the appended claims and their equivalents.