Patent Publication Number: US-7219678-B2

Title: Dishwasher

Description:
FIELD OF THE INVENTION 
   The present invention relates to a dishwasher including a covering member for hiding a gap to be opened between a washer tub and a main body of the dishwasher when the washer tub is fully extracted so as to facilitate the process of charging and discharging of the dishware into and from the washer tub. 
   BACKGROUND OF THE INVENTION 
   In the slide opening type(or a drawer type, top loading) dishwasher, a washer tub for accommodating and cleaning the dishware is extracted from and retracted into a main body of the dishwasher in a to-and-fro direction by means of slide rail assemblies. Such a slide opening type dishwasher is preferably built in a kitchen cabinet to establish a system kitchen capable of mounting therein a dishwasher. 
   Referring to  FIG. 17 , there is shown one of prior art slide opening type disclosed in Japanese Patent No. 3129318. As shown, the slide opening type dishwasher includes washer tub  14  having an open top and main body  15  having an open front. Washer tub  14  is coupled with main body  15  in such a manner it can be slidably moved into and out of main body  15  through the open front of main body  15 . Such sliding movement of washer tub  14  is achieved by a slide assembly. The slide assembly has a pair of first slide rails  16 (only one shown) secured on both inner side surfaces of main body  15  and a pair of second slide rails  17 (only one shown) fixed on both outer side surfaces of washer tub  14 . Between first and second slide rails  16  and  17  are provided rotating bodies, e.g., ball bearings. This allows second slide rails  17  fixed at washer tub  14  to slidably move along first slide rails  16 , enabling washer tub  14  to be smoothly extracted from and retracted into main body  15 . 
   The dishwasher described above suffers from certain drawbacks. For example, even when washer tub  14  is fully extracted from main body  15 , a rear section thereof still remains inside main body  15 . In other words, the rear section of washer tub  14  is covered with main body  15 . For this reason, it is rather difficult to charge and discharge the dishware in and from the rear section. 
   When washer tub  14  is fully extracted from main body  15 , a gap will be opened between the rear section of thus extracted washer tub  14  and main body  15 . Particularly, in case electric parts such as a washing pump are provided behind washer tub, some of the electric parts are exposed, spoiling the appearance. Further, if child&#39;s hand or metallic substances are inserted through the gap, it may cause an accident or a failure of the equipment. Accordingly, a scheme for blocking the gap is required. 
   SUMMARY OF THE INVENTION 
   It is, therefore, an object of the present invention to provide a dishwasher enabling a washer tub to be extracted from a main body of the dishwasher sufficiently enough not to be blocked thereby, the dishwasher including a covering member for blocking a gap to be opened between the washer tub and the main body when the washer tub is fully extracted from the main body. 
   In accordance with a preferred embodiment of the present invention, there is provided a dishwasher which includes a main body being generally of a box shape with an open front; a washer tub being extracted from and retracted into the main body through the open front by means of slide rail assemblies, the washer tub having an open top; and a covering member for blocking a gap to be opened between the washer tub and the main body when the washer tub is fully extracted from the main body, wherein, when the washer tub is fully extracted from the main body, a rear end of an inner wall of the washer tub is located in front of a front end of the main body to open the gap and the opened gap is covered by the covering member. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which: 
       FIG. 1  is a schematic side view of a dishwasher in accordance with a preferred embodiment of the present invention with a washer tub thereof extracted from a main body; 
       FIG. 2  provides an exploded perspective view illustrating an inner structure of an inner tub of the washer tub; 
       FIG. 3  illustrates a rear view of a water feed and drain unit disposed behind the washer tub; 
       FIG. 4  depicts a side view of the dishwasher with a side panel thereof removed; 
       FIG. 5  shows a perspective view of a slide rail assembly of the present invention; 
       FIG. 6  presents a cross sectional view of the slide rail assembly shown in  FIG. 5 ; 
       FIG. 7  represents a side view of the slide rail assembly shown in  FIG. 5  mounted at the dishwasher; 
       FIG. 8  describes a partial cutaway cross sectional view of the dishwasher showing the slide rail assembly mounted thereat; 
       FIG. 9  discloses a partial cross sectional view of the dishwasher showing the slide rail assembly installed thereat; 
       FIGS. 10A and 10B  offer respective side views for setting forth an operation of the slide rail assembly; 
       FIG. 11  delineates a schematic side view of the dishwasher setting forth the positional relationship between the washer tub and main body when the former is fully extracted from the latter; 
       FIG. 12  gives a side view of the washer tub in accordance with the present invention; 
       FIGS. 13A and 13B  demonstrate respective partial perspective views of the washer tub showing various extension members provided on the top rear end of the washer tub in accordance with the present invention; 
       FIG. 14  displays a schematic cross sectional view for setting forth an arrangement of a lid of the washer tub; 
       FIG. 15  exhibits a partial side view for setting forth a required length of an extension member of the washer tub; 
       FIG. 16  reveals a perspective view of a retractable mechanism installed at the slide rail assembly; and 
       FIG. 17  explains a side view showing an inner structure of a conventional dishwasher. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , there is provided a schematic side view of a dishwasher in accordance with the present invention. 
   As shown, the dishwasher includes main body  31  having an open front and accommodating therein washer tub  32 , a top of washer tub  32  being opened. Washer tub  32  is coupled with main body  31  in such a manner that it can be movable in a to-and-fro direction by means of a pair of slide rail assemblies  33 (only one shown), so that washer tub  32  can be fully extracted from main body  31  up to a fully extraction position thereby. The dishwasher explained above is preferably built in kitchen cabinet  40  but can be also fixedly installed on a mounting base. 
   Washer tub  32  made by, e.g., a resin molding includes tank  79  and door panel  80  provided at a front portion of tank  79 . As shown in  FIG. 2 , inner tub  34  formed in tank  79  has such a tapered configuration that its open area increases gradually when moving upwards, and has at its bottom surface wash nozzle  35 , heater  75 , filter  76  for removing food remnants. Detachably mounted on inner tub  34  is basket  36  for accommodating therein the dishware. Further, as shown in  FIGS. 3 and 4 , provided behind washer tub  32  are electric pump  37  serving as a drain pump as well as a washing pump for spraying washing fluid via wash nozzle  35  and a water feed and drain unit for feeding and draining water to and from inner tub  34 . The water feed and drain unit has water feed hose  38  and drain hose  39  coupled to the inside of inner tub  34 . Water feed hose  38  and drain hose  39  are supported by hose holder  46 , which is rotatably mounted in main body  31  such that it can rotate in harmony with the forward and backward movement of washer tub  32 . This secures a stable connection between hoses  38 ,  39  and washer tub  32 . 
   As shown in  FIGS. 5 and 6 , each of slide rail assemblies  33  has a triplex rail structure including fixed rail  41 , movable rail  42  and middle rail  43  interposed therebetween via ball bearings  47 . Fixed rail  41  is provided with engagement member  44 . Engagement member  44  has horizontal plane  44   a  extending from one side of fixed rail  41  and vertical plane  44   b  extending perpendicularly from horizontal plane  44   a , thereby being generally of an L shape in cross section. As shown in  FIGS. 7 ,  8  and  9 , fixed rails  41  are respectively mounted at two facing inner side surfaces of main body  31  and movable rails  42  are respectively installed at two opposite outer side surfaces of washer tub  32 . 
   Main body  31  made of, e.g., sheet metal is generally of a front-opened box shape and is provided at its both side surfaces with supports  48  and clamps  49  for holding engagement member  44  therebetween as shown in  FIGS. 7 and 8 . Supports  48  and clamps  49 , in concert with each other, accommodate engagement member  44  therebetween to temporarily support slide rail assembly  33 . As shown in  FIG. 8 , support  48  and clamp  49  are provided by forming protrusions on the inner side surfaces of main body  31  in such a manner that the vertical distance therebetween corresponds to a height of vertical plane  44   b  of engagement member 44 . In such a structure, slide rail assembly  33  is temporarily held on one inner side surface of main body  31  by inserting a top of vertical plane  44   b  of engagement member  44  into clamps  49  and pushing horizontal plane  44   a  thereof onto supports  48 . Subsequently, thus temporarily installed slide rail assembly  33  is mounted on main body  31  by tightening two screws  51  from two through holes  77  formed at main body  31  to two tapped holes  50  of engagement member  44  formed at locations corresponding to through holes  77 . 
   As shown in  FIG. 9 , tank  79  of washer tub  32  is provided with a pair of coupling portions  45 , extending outward from both outer side surfaces thereof for the connection with movable rails  42 . As shown in  FIG. 12 , each of coupling portions  45  has fitting protrusion  52  extending backward from a rear end thereof and inserting protrusion  54  extending downward from a front portion thereof. When washer tub  32  is slidably pushed into main body  31  after setting tank  79  on movable rails  42  by putting coupling portions  45  thereon, fitting protrusion  52  is fitted into inverted L-shaped cutoff  53  protruded at a rear section of movable rail  42  and protrusion  54  is inserted into opening  55  provided at a front section thereof(see  FIG. 5 ), enabling washer tub  32  to be firmly installed in position on slide rail assemblies  33 . In order to establish a secure coupling of washer tub  32  and slide rail assemblies  33 , at least one screw  92  is tightened from at least one through hole  67  formed at a front portion of coupling portion  45  to at least one tapped hole  91  formed at movable rail  42 , as shown in  FIG. 8 . 
   Slide rail assemblies  33  have the triplex rail architecture as described above. Therefore, when washer tub  32  is extracted from main body  31 , movable rails  42  mounted on washer tub  32  smoothly travel on middle rails  43  first, and then middle rails  43  begins to move on fixed rails  41 . 
   A sliding process of slide rail assembly  33  will now be described in detail with reference to  FIGS. 10A and 10B .  FIG. 10A  represents a side view of slide rail assembly  33  when washer tub  32  is accommodated in main body  31  and  FIG. 10B  depicts same when washer tub  32  is fully extracted from main body  31 . When extracting operation of washer tub  32  starts as shown in  FIG. 10A , movable rails  42  fixed at washer tub  32  begin to move on middle rails  43  as indicated by a phantom line. Movable rails  42  move by a predetermined distance in such a manner that retainers  90  for maintaining ball bearings  47  inserted between movable rails  42  and middle rails  43  in position (see  FIG. 6 ) are always interposed between movable rails  42  and middle rails  43 . Then, middle rails  43  follow the movement of movable rails  42 . Additional retainers  90  are provided between middle rails  43  and fixed rails  41  as well, for maintaining ball bearings  47  inserted therebetween in position. By virtue of such arrangement, when washer tub  32  is completely extracted as shown in  FIG. 10B , about a half of a length of middle rail  43  corresponding to a length of retainer  90  remains on fixed rails  41  and the rest thereof extends therefrom. Similarly, about a half of a length of movable rail  42  stays on middle rail  43  and another remaining half thereof extends therefrom. As a result, it is possible to increase the amount of extraction of washer tub  32  from main body  31 . 
   Further, since middle rail  43  is disposed between fixed rail  41  and movable rail  42  to increase the sliding distance of slide rail assembly  33 , slide rail assembly  33  can support washer tub  32  stably even when washer tub  32  heavily weighs on movable rails  42  extending from fixed rails  41 . 
   Washer tub  32  needs to be maximally extracted from main body  31 , when the dishwasher is built in kitchen cabinet  40  below countertop  61  thereof, as shown in  FIG. 1 . In such an arrangement, normally front end “I” of countertop  61  is positioned in front of fore end “II” of kitchen cabinet  40  and the dishwasher is built in immediately below countertop  61 , as shown in  FIG. 1 . In such a case, it is preferable to enable washer tub  32  to be extracted from main body  31  up to a position where rear top end “A” of inner tub  34  is located in front of front end “I” of countertop  61 . Then, the entire open top of inner tub  34  is fully exposed without blockage, facilitating the process of charging and discharging the dishware into and from inner tub  34  and removing the remnants after the cleaning process. 
   Inner tub  34  has such a tapered configuration that its open area increases gradually when moving upwards. It is preferable that washer tub  32  is configured such that it can be extracted up to its fully extracted position where rear bottom end “B” of inner tub  34  is positioned in front of front end “I” of countertop  61 . Alternatively, washer tub  32  may be configured such that when fully extracted rear top end “A” of inner tub  34  is located in the back of front end “I” of countertop  61 . In such a case, a small portion of open top of inner tub  34  will be covered with countertop  61 . However, the process of charging and discharging the dishware into and from inner tub  34  would not be hindered thereby because the amount of covering is small and there exists a vertical gap between the lower surface of countertop  61  and rear top end “A” of inner tub  34 . 
   Alternatively, washer tub  32  can be preferably designed to be fully extracted up to a location where upper top end “C” of basket  36  is positioned in front of front end “I” of countertop  61 . In this case, since top of entire basket  36  is exposed without blockage, the process of charging and discharging the dishware into and from basket  36  can be carried out easily. 
   In case washer tub  32  is installed in a place other than under a countertop-like object, it is preferable that washer tub  32  can be extracted in such a manner that, when fully extracted, at least one of rear top end “A” of inner tub  34 , rear bottom end “B” thereof and upper top end “C” of basket  36  as shown in  FIG. 11  is located in front of front upper end “III” of main body  31 . Under the circumferences, it is possible to readily charge and discharge the dishware into and from washer tub  32  or remove remnants when necessary. 
   However, with large extraction of washer tub  32  described above, electric parts such as electric pump  37  disposed behind washer tub  32  may be exposed through the gap opened between a rear end of washer tub  32  and a front upper end III of main body  31 . Particularly, in case electric pump  37  is accommodated in a space prepared by recessed portion  74  provided at the back of tank  79  as shown in  FIG. 4 , a large portion of electric pump  37  is exposed when washer tub  32  is completely extracted up to its fully extracted position, spoiling the appearance. Further, if child&#39;s hand or metallic substances are inserted through the gap to touch electric parts such as electric pump  37 , it may cause an accident or a failure of the equipment. In order to solve these problems, the present invention includes a covering member for blocking the gap. 
   As shown in  FIGS. 4 and 12 , bottom cover  56  for hiding such parts as water pipes and connections therebetween is attached under coupling portion  45  of each side of washer tub  32  and extends downward therefrom up to a level below the bottom of washer tub  32 . Each of the pair of bottom covers  56  has extended portion  56   a  extending from a rear end thereof as depicted by hatching in  FIG. 4 . Therefore, a space below the level of slide rail assemblies  33  can be concealed by bottom cover  56  and extended portion  56   a.    
   The present invention further includes a pair of side covers  58  and top extension member  57  in order to block parts provided in space behind washer tub  32 . Side covers  58  are attached on both sides of washer tub  32  above coupling portions  45  and extend backward therefrom. Side covers  58  and washer tub  32  can be made by resin molding as a single body. Top extension member  57  of a plate shape extends backward from the top rear end of tank  79 , as shown in  FIGS. 12 to 13B . Top extension member  57  is formed in such a manner that, when washer tub  32  is fully extracted from main body  31 , its free end “F” is located under lid  60 , as shown in  FIG. 15 . 
   Lid  60  is movably installed in main body  31  by means of link devices  62  and spring  63 . More specifically, each link device  62  has a pair of pivoting ends, first pivoting end coupled to lid  60  via pivot  94  and second pivoting end coupled to main body  31  via pivot  93 , imparting a translational motion to lid  60  with respect to pivots  93 . Spring  63  is provided between main body  31  and lid  60  in order to bias lid  60  in a forward upward direction. This allows washer tub  32  to move to a position as indicated by a broken line in  FIG. 14  when washer tub  32  is extracted from main body  31 . While washer tub  32  is retracted into main body  31 , lid  60  is pushed in a backward direction by pressing protrusion  59  formed at the upper front portion of tank  79  and moves against the biasing force of spring  63  to thereby move in a backward downward direction by means of the link device  62 . When washer tub  32  is fully retracted into main body  31 , i.e., up to a tub accommodation position at which washing operation is carried out, central portion  95  of lid  60  is fitted into the open top of inner tub  34  of washer tub  32 , closing tank  79 . At this time, inner tub  34  is sealed with packing  78  provided at bottom periphery of lid  60 . 
   In case washer tub  32  is taken out from main body  31  and inner tub  34  of washer tub  32  is heavily loaded with dishes, its rear section and front section tend to be lifted and lowered respectively. For this reason, when washer tub  32  is retracted into main body  31 , top extension member  57  extending from the rear upper portion of tank  79  may collide with front upper end “D” or front bottom end “E” of lid  60 , as shown in  FIG. 15 , to impede a smooth operation of retracting washer tub  32 . Therefore, in accordance with the present invention, top extension member  57  is designed in such a manner that, when washer tub  32  is fully extracted, i.e., up to the fully extracted position, its free end “F” is positioned at a location under central portion  95  of lid  60  and behind front bottom end “E” of lid  60 . Therefore, while washer tub  32  is retracted into main body  31 , top extension member  57  can move along a bottom surface of lid  60 , guiding washer tub  32  to the tub accommodation position without being hindered by front upper end “D” and/or front bottom end “E” of lid  60 . If it is only required to smoothly guide washer tub  32  into main body  31 , at least one, e.g., two guide projections  57   a  extending partially from the rear upper end of washer tub  32  can be provided in lieu of top extension member  57 , as shown in  FIG. 13B . 
   If washer tub  32  is not completely retracted into main body  31  up to the tub accommodation position, inner tub  34  may be insufficiently sealed with lid  60  to result in water leakage or a latching operation, e.g., by way of using a handle locking washer tub  32  at the tub accommodation position, may not be properly operated. For this reason, the present invention further includes retraction mechanism  64  mounted on each of slide rail assemblies  33 , for forcing washer tub  32  up to the tub accommodation position in main body  31  as shown in  FIGS. 5 ,  6 ,  10 A,  10 B and  16 . 
   As shown in  FIG. 16 , retraction mechanism  64  is provided on one side of fixed rail  41  of slide rail assembly  33 . Retraction mechanism  64  has coupling member  65  with a pair of coupling projections  65   a ,  65   b  spaced apart from each other, and one side surface of movable rail  42  is provided with engaging member  66  to be coupled with coupling member  65  through its protrusions  66   a . When washer tub  32  is retracted into main body  31 , protrusions  66   a  of engaging member  66  are inserted between coupling projections  65   a  and  65   b . Engaging member  66  is movably coupled with one end of spring shaft  68 , and the other end of spring shaft  68  is provided with spring support  73 . Spring support  73  is accommodated in spring case  72  generally having a cylinder shape. Coil spring  70  is provided around spring shaft  68  within spring case  72 . 
   When washer tub  32  begins to be extracted from main body  31 , movable rail  42  and engaging members  66  fixed thereto travel together to move coupling member  65 , which in turn pulls spring shaft  68  in a direction as indicated by an arrow in  FIG. 16 , compressing coil spring  70 . Coupling member  65  is slidably guided along a groove defined by side walls  69  of retraction mechanism  64  and one of side walls  69  is provided with recess  71  for accommodating therein coupling projection  65   a . Therefore, when coupling projection  65   a  coupled with engaging member  66  to be moved by movable rail  42  reaches recess  71 , it is inserted into recess  71 , releasing the engagement between coupling projection  65   a  and protrusions  66   a  of engaging member  66 . Since the coupling projection  65   a  is kept in recess  71 , coil spring remains to be compressed by spring support  73 . 
   When washer tub  32  is retracted into main body  31 , movable rails  42  are moved backward. When engaging member  66  reaches coupling member  65  located in recess  71 , protrusion  66   a  of engaging member  66  is engaged with to press coupling projection  65   b  staying on side wall  69 , which in turn releases coupling projection  65   a  of coupling member  65  from recess  71 . Then, the restoring force of compressed coil spring  70  is exerted on engaging member  66  via spring shaft  68  and coupling member  65 . This allows movable rail  42  to retract washer tub  32  up to the tub accommodation position without recourse to further external force for the retraction thereof. 
   In the retraction mechanism  64 , spring case  72  has a cylinder shape and spring support  73  supports one end of coil spring  70  and simultaneously acts as a piston as well. For this reason, when compressed coil spring  70  returns, it is possible to obtain air damper effect of compressing air in spring case  72 . Accordingly, as washer tub  32  approaches the tub accommodation position, moving speed decreases, thereby smoothly accommodate washer tub  32  therein. 
   While the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.