Patent Document

BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to the art of dishwashers and, more particularly, to a system for preventing wash liquid from leaking about a door opening of a dishwasher. 
     2. Discussion of the Prior Art 
     In a typical dishwasher, washing fluid is pumped from a sump into upper and lower wash arms such that kitchenware retained on vertically spaced racks within a tub of the dishwasher will be sprayed with the washing fluid for cleaning purposes. The washing fluid is heated, filtered and recirculated. Prior to recirculating the washing fluid, the fluid is directed through one or more filters to remove soil from the fluid, with the soil being collected in a chamber. Periodically, the system will be purged in order to drain the collection chamber of the soil. 
     Typically, a dishwasher will be provided with a seal mounted around a door opening, wherein the seal is compressed when the dishwasher door is closed in order to prevent liquid from leaking from the tub based on a washing operation. Since the seal is compressed, it usually takes the shape of a portion of the door, such as a door spike, that is pushing into the seal. Unfortunately, repeated compression of the seal can cause the seal to deform. Over time, this deformation can cause the seal to leak. 
     To address this problem, the assignee of the present application has previously modified the flange structure provided about a door opening of a dishwasher tub in an attempt to direct leaking liquid back into the tub. To this end, it has been proposed to form each side flange with a laterally outermost ridge which angles inwardly and terminates at a position spaced from a lowermost portion of the door opening. With this structure, water or other washing liquid which leaks past the seal can be caused to flow along the ridge and be directed back towards the tub. 
     Regardless of this proposed solution to this leakage problem, it has been found that the prior ridge arrangement exhibited only limited success in preventing leakage. For instance, given the structure and configuration of the ridge, the liquid was accorded the opportunity of being re-directed laterally outwardly below the ridge or the liquid could flow over the ridge if relatively high flow rates were experienced. Based on the above, there exists a need in the art for an improved arrangement to prevent liquid from leaking about a door opening of a dishwasher door. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to preventing the leakage of liquid from around a door opening of a dishwasher door, even if a seal provided about the opening is deformed due to being repetitively compressed. In accordance with the present invention, a flange is provided about a door opening of a dishwasher tub laterally outwardly of a seal which is caused to be compressed upon closing of the door. At lower lateral portions of the flange, a bead, including various segments, is formed to re-direct any liquid leaking past the seal back into the tub. 
     The bead in accordance with the preferred embodiment of the invention includes a first, elongated and substantially vertically extending portion, a second downwardly and laterally inwardly extending portion, another vertically extending portion, and a lowermost, inwardly angled portion. The second vertically extending portion is spaced laterally inwardly of the first vertically extending portion and extends adjacent an inwardly directed wall portion of the tub, near the seal, in order to define an elongated guide trough. In addition, in accordance with the most preferred embodiment of the invention, the flange has a reduced dimension along both the second vertically extending portion and the lowermost angled portion, with the lowermost angled portion making a smooth transition into the washing chamber. 
     With this overall arrangement, any liquid leaking past the seal, whether by the splashing of liquid in the tub or through condensation, is initially directed down along the first vertically extending portion. The liquid is then directed laterally inwardly to the point at which the guide trough starts. Thereafter, the liquid is further directed along the second vertically extending portion directly adjacent the interior of the tub. Finally, if the liquid reaches the end of the bead, it reaches the lowermost angled portion which directs the liquid to flow back into the tub. 
     Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an upper right perspective view of a dishwasher constructed in accordance with the present invention, with a door of the dishwasher being open to illustrate internal tub structure; 
     FIG. 2 is an enlarged perspective view of a lower corner portion of the tub of FIG. 1; and 
     FIG. 3 is another perspective view of the lower corner portion of the tub of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With initial reference to FIG. 1, a dishwasher constructed in accordance with the present invention as generally indicated at  2 . As shown, dishwasher  2  includes a tub  5  which is preferably injection molded of plastic so as to include integral bottom, side, rear and top walls  8 - 12  respectively. Within the confines of walls  8 - 12 , tub  5  defines a washing chamber  14  within which soiled kitchenware is adapted to be placed upon shiftable upper and lower racks (not shown), with the kitchenware being cleaned during a washing operation in a manner widely known in the art. Tub  5  has attached thereto a frontal frame  16  which pivotally supports a door  20  used to seal chamber  14  during a washing operation. In connection with the washing operation, door  20  is preferably provided with a detergent tray assembly  23  within which a is consumer can place liquid or particulate washing detergent for dispensing at predetermined portions of the washing operation. Of course, dispensing detergent in this fashion is known in the art such that this arrangement is only being described for the sake of completeness. 
     Disposed within tub  5  and, more specifically, mounted within a central opening formed in bottom wall  8  of tub  5 , is a pump and filter assembly  30 . Extending about a substantial portion of pump and filter assembly  30 , at a position raised above bottom wall  8 , is a heating element  44 . In a manner known in the art, heating element  44  preferably takes the form of a sheath, electric resistance-type heating element. 
     In general, pump and filter assembly  30  is adapted to direct washing fluid to a lower wash arm  47  and an upper wash arm (not shown). Dishwasher  2  has associated therewith a drain hose  85  including at least one corrugated or otherwise curved portion  89  that extends about an arcuate hanger  92  provided on an outside surface of side wall  10 . Drain hose  85  is also preferably secured to tub  5  through various clips, such as that indicated at  94 . In any event, in this manner, an upper loop is maintained in drain hose  85  to assure proper drainage in a manner known in the art. Actually, a detailed description of the exact structure and operation of pump and filter assembly  30  of dishwasher  2  does not form part of the present invention, but is rather set forth in pending U.S. application Ser. No. 10/186,739 entitled “Dishwasher Pump and Filtration System” filed Jul. 2, 2002, incorporated herein by reference. 
     Instead, the present invention is directed to the inclusion of liquid containment structure, generally indicated at  95 , provided along each of side walls  9  and  10  for preventing the leakage of wash liquid from around dishwasher door  20 . More specifically, frontal frame  16  actually extends along an outwardly projecting front flange  100  formed integral with both side walls  9 ,  10  and top wall  12 . A front surface  101  (see FIGS. 2 and 3) leads to an in-turned wall portion  102  of side wall  9  which, in turn, leads to a flat wall strip  103 . Wall strip  103  carries an elongated gasket or seal  105 , between in-turned wall portion  102  and an extension  108  of side wall  9 , against which door  20  seats in order to seal off washing chamber  14  during operation of dishwasher  2 . That is, seal  105  is caused to be compressed upon closing of door  20  to prevent washing liquid, whether water or a combination of water and detergent, from flowing outside of dishwasher  2 . 
     FIGS. 2 and 3 best show the arrangement of front flange  100  and containment structure  95 . Here it should be noted that seal  105  is only shown in part for the sake of clarity. As depicted, front flange  100  is formed with an outermost, forwardly projecting ridge or bead generally indicated at  110  which functions to re-direct any wash liquid leaking past seal  105  back into tub  5 . More specifically, bead  110  includes various segments, i.e., a first, elongated and substantially vertically extending portion  125  leading to a downwardly and laterally inwardly extending portion  130 , followed by another vertically extending portion  135 , and terminating in a lowermost, inwardly angled portion  140 . With this arrangement, containment structure  95  is raised to a plane offset from a plane of front surface  101 , with bead portion  130  essentially defining a generally triangular-shaped plateau. 
     At this point, it should be recognized that front flange  100 , through to and including bead portions  125  and  130 , has heretofore been utilized by the assignee of the present invention for the purpose of diverting any leakage past seal  105  back into tub  5 . However, in accordance with the present invention, front flange  100  has been modified from this prior arrangement and bead portions  135  and  140  have been effectively added. More particularly, front flange  100  in accordance with the invention has been provided with a cut-out  150  so as to define a reduced dimensional portion of front flange  100  along which bead portions  135  and  140  extend. The presence of cut-out  150  advantageously enables a compact hinge arrangement (not shown) for door  20  to be employed. As shown, second vertically extending portion  135  is spaced laterally inwardly of the first vertically extending portion  125  and is spaced from in-turned wall portion  102  by an elongated guide trough  160 . As indicated above, second vertically extending portion  125  leads to inwardly angled portion  140  which, in turn, tapers to a corner juncture  170  between guide trough  160  of front flange  100  and in-turned wall portion  102  of tub  5 . 
     During operation of dishwasher  2 , any liquid leaking past seal  105 , whether from the spraying of washing liquid or, particularly, condensation, is initially directed down along first vertically extending portion  125 . The liquid is then directed laterally inwardly, due to the presence of bead portion  130 , to the point at which guide trough  160  starts. Thereafter, the liquid is further directed within guide trough  160  along second vertically extending portion  135 . Finally, if the liquid reaches the end of containment structure  95 , it comes upon lowermost angled portion  140  which smoothly transitions the liquid to flow back into tub  5 . Therefore, with this arrangement, even if seal  105  becomes deformed by repeatedly being compressed upon the closing of door  20 , any resulting liquid flow along front flange  100  will be contained within tub  5  instead of leaking to the surrounding environment. 
     Although described with reference to a preferred embodiment of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, although seal  105  is typically mounted to tub  5 , seal  105  could actually be carried by door  20 , while seating against tub  5 . In addition, bead  110  is preferably formed integral with tub  5 , but could be constituted by one or more separate elements mounted to tub  5  to perform the liquid containment function. Surprisingly, it has been found that containment structure  95 , in combination with the generally serpentine flow path from washing chamber  14  outwardly to front flange  100 , prevents leakage from washing chamber  14  of dishwasher  2  even when seal  105  is removed or severely damaged. In any case, the invention is only intended to be limited by the scope of the following claims.

Technology Category: 1