Patent Publication Number: US-7216944-B2

Title: Dishwasher door assembly

Description:
BACKGROUND OF THE INVENTION 
   This invention relates generally to door assemblies for appliances, and more specifically to dishwasher door assemblies. 
   Known dishwasher door assemblies typically include an escutcheon therein for providing support for control panel components. Typically, the escutcheon is separately molded from a plastic material and is attached to an upper portion of the door assembly above an outer door panel and generally flush with an outer surface of the door panel. Control buttons, knobs, displays etc. extend through the escutcheon for user manipulation to select and execute desired dishwasher features. See, for example, U.S. Pat. No. 5,453,586. 
   In some dishwasher doors, however, the escutcheon can disadvantage the door assembly in several respects. For example, attaching a plastic escutcheon to the top of a door panel can compromise the structural rigidity of the door assembly, i.e., reduce stiffness of the door. The reduced stiffness can frustrate proper door alignment with a latch assembly and undesirably increase a required force to latch the door for dishwasher operation. In addition, plastic surfaces of the escutcheon are vulnerable to stains and are difficult to clean due to textured surfaces of the escutcheon that tend to trap dust, dirt and sediment therein. Still further, the escutcheon tends to complicate the construction of the door assembly, which accordingly increases manufacturing and assembly costs of the dishwasher. 
   At least for the reasons set forth above, consumers and dishwasher users would benefit from a dishwasher door construction that overcomes these disadvantages. 
   BRIEF DESCRIPTION OF THE INVENTION 
   In one aspect, an outer door panel for an appliance door assembly is provided which comprises a frame comprising opposite lateral sides, an outer surface extending from said frame and bowed between said lateral sides, and a recessed control mounting surface extending from said outer surface between said lateral sides. 
   In another aspect, an outer door panel for a dishwasher is provided which comprises a frame comprising a longitudinal axis, an outer surface covering said frame, and a control panel mounting surface within said frame and extending from said frame outer surface, said control panel mounting surface inclined with respect to said longitudinal axis. 
   In yet another aspect, a dishwasher door assembly is provided which comprises an outer door panel comprising opposite lateral sides and a top edge, an outer surface extending between said lateral sides and said top edge, said outer surface surrounding a recessed control surface disposed beneath said top edge of said outer panel, and an inner door panel attached to said outer door panel. 
   In still another aspect, a dishwasher door assembly is provided which comprises an outer door panel comprising a bowed outer surface and a recessed control surface depending from said outer surface, and a unitary inner door panel attached to said outer door panel. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevational view of an exemplary dishwasher system partially broken away. 
       FIG. 2  is a front perspective view of an exemplary outer door panel for the dishwasher shown in  FIG. 1 . 
       FIG. 3  is a front plan view of the outer door panel shown in  FIG. 2 . 
       FIG. 4  is a cross sectional schematic view of the outer door panel shown in  FIG. 3  along line  4 — 4 . 
       FIG. 5  is a cross sectional schematic view of the outer door panel shown in  FIG. 3  along line  5 — 5 . 
       FIG. 6  is a cross sectional schematic view of the outer door panel shown in  FIG. 3  along line  6 — 6 . 
       FIG. 7  is a rear perspective view of the outer door panel shown in  FIGS. 2–6 . 
       FIG. 8  is a front perspective view of a second embodiment of an outer door panel for the dishwasher shown in  FIG. 1 . 
       FIG. 9  is a front perspective view of an outer door panel assembly for the door panel shown in  FIG. 8 . 
       FIG. 10  is a rear perspective view of the outer panel assembly shown in  FIG. 9 ; 
       FIG. 11  is an exploded perspective view of a dishwasher door assembly for the dishwasher shown in  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  is a side elevational view of an exemplary domestic dishwasher system  100  partially broken away, and in which the present invention may be practiced. It is contemplated, however, that the invention may be practiced in other types of dishwashers and dishwasher systems beyond dishwasher system  100  described and illustrated herein. Moreover, the door construction described below may find utility and its benefits accrue to appliances generally Accordingly, the following description is for illustrative purposes only, and the invention is in no way limited to use in a particular type of appliance, such as a particular dishwasher system, for example dishwasher system  100 . 
   Dishwasher  100  includes a cabinet  102  having a tub  104  therein and forming a wash chamber  106 . Tub  104  includes a front opening (not shown in  FIG. 1 ) and a door assembly  120  hinged at its bottom  122  for movement between a normally closed vertical position (shown in  FIG. 1 ) wherein wash chamber  106  is sealed shut for washing operation, and a horizontal open position (not shown) for loading and unloading of dishwasher contents. Upper and lower guide rails  124 ,  126  are mounted on tub side walls  128  and accommodate upper and lower roller-equipped racks  130 ,  132 , respectively. Each of upper and lower racks  130 ,  132  is fabricated from known materials into lattice structures including a plurality of elongate members  134 , and each rack  130 ,  132  is adapted for movement between an extended loading position (not shown) in which the rack is substantially positioned outside wash chamber  106 , and a retracted position (shown in  FIG. 1 ) in which the rack is located inside wash chamber  106 . Conventionally, a silverware basket (not shown) is removably attached to lower rack  132  for placement of silverware, utensils, and the like that are too small to be accommodated by upper and lower racks  130 ,  132 . 
   A control panel (not shown in  FIG. 1 ) is mounted at a convenient location on an outer face  138  of door assembly  120  and is coupled to known control circuitry (not shown) and control mechanisms (not shown) for operating a fluid circulation assembly (not shown) that circulates water and dishwasher fluid in dishwasher tub  104 . The fluid circulation assembly is located in a machinery compartment  140  located below a bottom sump portion  142  of tub  104 . The construction and operation of the fluid circulation assembly is believed to be beyond the scope of the present invention but well within the purview of those in the art without detailed explanation, and further discussion of the fluid circulation assembly is therefore omitted. 
   A lower spray-arm-assembly  144  is rotatably mounted within a lower region  146  of wash chamber  106  and above tub sump portion  142  so as to rotate in relatively close proximity to lower rack  132 . A mid-level spray-arm assembly  148  is located in an upper region of wash chamber  106  and is located in close proximity to upper rack  130  and at a sufficient height above lower rack  132  to accommodate a largest item, such as a dish or platter (not shown), that is expected to be placed in lower rack  132  and washed in dishwasher system  100 . In a further embodiment, an upper spray arm assembly (not shown) is located above upper rack  130  at a sufficient height to accommodate a tallest item expected to be placed in upper rack  130 , such as a glass (not shown) of a selected height. 
   Lower and mid-level spray-arm assemblies  144 ,  148  and the upper spray arm assembly are fed by the fluid circulation assembly, and each spray-arm assembly includes an arrangement of discharge ports or orifices for directing washing liquid onto dishes located in upper and lower racks  130 ,  132 , respectively. The arrangement of the discharge ports in at least lower spray-arm assembly  144  provides a rotational force by virtue of washing fluid flowing through the discharge ports. The resultant rotation of lower spray-arm assembly  144  provides coverage of dishes and other dishwasher contents with a washing spray. In various alternative embodiments, mid-level spray arm  148  and/or the upper spray arm are also rotatably mounted and configured to generate a swirling spray pattern above and below upper rack  130  when the fluid circulation assembly is activated and door assembly  120  is properly closed to seal wash chamber  106  for operation. 
     FIG. 2  is a front perspective view of an exemplary outer door panel  160  for use with an appliance door assembly, such as door assembly  120  (shown in  FIG. 1 ) of dishwasher  100  (shown in  FIG. 1 ). In an exemplary embodiment outer door panel  160  includes a frame  162  and an outer surface  164  covering frame  162 . A control panel  166  extends from outer surface  164  and is located in an upper region of outer door panel  160 . In one embodiment, control panel  166  includes an electronic membrane switch assembly mounted to a control mounting surface (described further below) of door panel  160  according to known techniques, such as for example, with pressure sensitive tape. The membrane switch assembly includes a plurality of touch sensitive selection keys (not shown) and one or more displays (not shown) for user-selection of dishwasher features and display of information to the user, respectively. It is believed that the aforementioned membrane switch assembly is familiar to those in the art without further explanation, and in alternative embodiments in lieu of the membrane switch assembly a variety of known control panel schemes, whether mechanical, electrical, or electromechanical may be employed with outer door panel  160  using known mounting methods and techniques. 
   In a particular embodiment, outer door panel frame  162  is generally rectangular and includes a top edge  168 , a bottom edge  170  extending opposite to and substantially parallel with top edge  168 , and opposite lateral sides  172 ,  174  extending substantially parallel to one another between top and bottom edges  168 ,  170 . Outer door panel outer surface  164  extends from frame edges  168 ,  170 ,  172 ,  174 , and in, one embodiment, is bowed or outwardly curved between lateral sides  172 ,  174 . 
   Control panel  166  is disposed within frame  162 , i.e., between edges  168 ,  170 , and sides  172 ,  174  so that control panel  166  is mounted to outer door panel  160 . Door panel outer surface  164  extends above and below, and on either side of, control panel  166 . As such, and unlike known dishwasher door constructions, outer door panel  160  completely surrounds control panel  166  so that outer door panel  160  is structurally rigid and stiff in comparison to conventional escutcheons mounted to a top of a door panel. In an exemplary embodiment, door panel  160  is of single piece or unitary construction, and in a further embodiment is fabricated from metal, such as stainless steel according to a deep drawing process or stamping process known in the art. In alternative embodiments, other known materials are utilized to fabricate outer door panel  160  according to the aforementioned methods or other suitable methods familiar to those in the art. 
   Unitary construction of outer door panel  160 , and the associated structural rigidity, facilitates proper door alignment with dishwasher  100  (shown in  FIG. 1 ) and accordingly reduces a required force to close a latch assembly to seal wash chamber  106  (shown in  FIG. 1 ). 
   In addition, and further unlike conventional dishwasher door assemblies, outer door panel  160  does not include a escutcheon that tends to complicate assembly of the door. Rather, control panel  166  is mounted directly to outer door panel outer surface  164  via a control mounting surface (described below) extending from outer surface  164 . As such, manufacturing costs and assembly costs are saved by eliminating the escutcheon. In addition, textured surfaces of the escutcheon that tend to be difficult to clean are eliminated and replaced with stain resistant painted surfaces adjacent frame top edge  168 . 
     FIG. 3  is a front plan view of outer door panel  160  illustrating panel outer surface  164  extending over frame  160 , and a control mounting surface  180  extending from outer surface between frame Lateral sides  172 ,  174  in an upper region  182  of frame  162  adjacent frame top edge  168 . In an exemplary embodiment, control mount surface  180  is substantially flat or planar and therefore facilitates installation of a control panel, such as panel  166  (shown in  FIG. 2 ). To facilitate wire leads and control panel connections, control mount surface  180  includes an aperture  184  extending therethrough for passing of wires (not shown) of a control panel, such as the membrane switch assembly referred to above in relation to  FIG. 1 . In further embodiments, control mount surface  180  may include other apertures as desired to facilitate installation of other control panel schemes and associated displays, etc. 
   In an illustrative embodiment, and as depicted in  FIG. 3 , control mount surface  180  is saucer-shaped between frame lateral sides  172 ,  174  More specifically, control mount surface  180  includes a straight side  186  extending beneath and generally parallel to frame top edge  168 , an outwardly curved side  188  (concave as illustrated in  FIG. 3 ) extending opposite control mount surface straight side  186  and further extending substantially a full length between frame lateral sides  172 ,  174 , and two angled sides  190  connecting respective ends of control mount surface straight side  186  to respective ends of control mount surface curved side  188 . Control mount surface  180  is sized and dimensioned to receive a corresponding control panel, such as the membrane switch control panel  166  (shown in  FIG. 2 ). In alternative embodiments, however, it is contemplated that other shapes of control mount surface  180  may be employed in outer door panel  160 . 
   In one embodiment, control mount surface  180  is integrally formed with a remainder of outer door panel  160  according to a known fabrication process, such as deep drawn metal processes and stamping operations, thereby forming a unitary construction of outer door panel  160  Fabricating control mount surface  180  integrally with door panel  160  further rigidifies the structure of door panel  160  in comparison to known dishwasher door assemblies. 
     FIG. 4  is a longitudinal cross sectional schematic view of outer door panel  160  about a longitudinal axis  200 , and illustrates control mount surface  180  extending inwardly from bowed outer surface  164  at an angle with outer door panel longitudinal axis  200 . In one embodiment, control panel is inclined with respect to panel outer surface  164  and extends at approximately a 60° angle, and in a particular embodiment at a 58° angle with respect to longitudinal axis  200 . It is contemplated, however, that greater or fewer angles of control mount surface  180  with respect to longitudinal axis  200  (including control mount surface  180  extending parallel to longitudinal axis  200 ) may be employed while achieving at least some of the benefits of the instant invention. 
   Inclined control mount surface  180  allows for a recessed, protected control panel, such as control panel  166  (shown in  FIG. 1 ), to be mounted to control mount surface  180 . As such, control mount surface  180  is mostly shielded by an overhanging panel outer surface  164  (see  FIG. 1 ), thereby reducing exposure of the control panel to countertop drips and spills onto panel upper region  182 . Thus, difficult to clean areas associated with the control panel are less likely to become soiled. 
     FIGS. 5 and 6  are cross sectional schematic views transverse to panel longitudinal axis  200  (shown in  FIG. 4 ). Referring to  FIG. 5 , control panel mount surface  180  (shown in  FIGS. 1–3 ) extends inwardly (downwardly in  FIG. 5 ) from panel outer surface  164  at control mount surface curved side  188  to control mount surface straight side  186  extending generally parallel to frame top edge  168 . Control mount surface angled sides  190  extend (upwardly in  FIG. 5 ) from control mount surface straight side  186  to respective ends of control mount surface curved side  188 , thereby completing the saucer-shaped control mount surface  180 . 
   Referring now to  FIG. 6 , a latch portion  210  of outer door panel  160  is illustrated that extends above control panel mount surface  180  (see  FIG. 3 ) and is generally flush with door panel outer surface  164  extending between frame edges  172 ,  174  and located above control panel mount surface  180  adjacent frame top edge  168 . 
     FIG. 7  is a rear perspective view of outer door panel  160  illustrating frame edges  168 ,  170 ,  172 , and  174  forming a generally box-like configuration, and panel outer surface  164  extending between the edges and generally bowed outwardly between frame lateral sides  172 ,  174 . A door latch  220  extends rearwardly, i.e., away from panel outer surface  164 , and substantially parallel to frame top edge  168  for engagement with a latch assembly (not shown) of an inner door panel (described below). 
   Lateral attachment flanges  224 ,  226  extend inwardly, i.e., toward a center of outer door panel  160 , from frame lateral sides  172 ,  174 , respectively and include a plurality of openings therethrough for receiving known fasteners (not shown) such as screws, for attaching outer door panel  160  to an inner door panel (described below). Attachment flanges  228 ,  230  also extend from frame top edge  168  and include a plurality of openings therethrough, also for receiving known fasteners (not shown) such as screws, for attaching outer door panel  160  to an inner door panel (described below). In one embodiment, attachment flanges  224 ,  226 ,  228 , and  230  are integrally fabricated into door panel  160  so that outer door panel is a unitary piece. 
     FIG. 8  is a front perspective view of a second embodiment of an outer door panel  250  for use with an appliance door assembly, such as door assembly  120  (shown in  FIG. 1 ) of dishwasher  100  (shown in  FIG. 1 ). Like outer door panel  160  (shown in  FIGS. 2–7 ), panel  250  includes a frame  252  and an outer surface  254  covering frame  252 . Frame  252  includes a top edge  256 , a bottom edge  258  extending opposite top edge  256 , and lateral sides  260 ,  262  extending between top edge  256  and bottom edge  258  to form a substantially box-like configuration. Outer surface  254  extends between lateral sides  260 ,  262  and is outwardly bowed therebetween. 
   Unlike outer door panel  160 , however, door panel  250  includes a control panel cutout portion  264  or opening in lieu of control panel mount surface  180  (shown in  FIGS. 3 and 4 ). As such, panel  250  is simpler to manufacture with known methods and techniques, such as deep drawn metal processes and stamping operations. As illustrated in  FIG. 8 , panel outer surface  258  completely surrounds cutout portion  264  to maintain rigidity of outer door panel  250 . A rigid, unitary door panel  250  is therefore provided that facilitates installation of a control panel (not shown in  FIG. 8 ). 
     FIG. 9  is a front perspective view of outer door panel  250  including a control mount surface  270  received in cutout portion  264  (shown in  FIG. 8 ). In an illustrative embodiment, control mount surface is a separately fabricated piece fabricated from, for example, injection molded plastic that is inserted into and engaged with panel cutout portion with known methods and techniques. As such, control mount surface may be considered to be an escutcheon fitted within panel cutout portion  254  without compromising rigidity of the door assembly that tends to frustrate proper door alignment and complicate operation of a door latch assembly (not shown). 
   Like outer door panel  160 , control mount surface  270  is recessed or inclined with respect to panel outer surface  254  so as to protect a control panel scheme mounted on control mount surface  270 . Thus, staining of a plastic escutcheon surface is less likely than with conventional dishwasher doors, and maintenance and cleaning of the control panel is less difficult due to a more sheltered control panel in comparison to known dishwasher control panels. Control mount surface  270  is further configured with openings  272 ,  274  for control system displays and lead wires, and is sized and dimensioned to accommodate a desired control panel scheme, such as a membrane switch assembly. 
     FIG. 10  is a rear perspective view of outer panel  250  illustrating attachment flanges  280 ,  282  extending from frame lateral sides  260 ,  262 , respectively. Flanges  260 ,  262  include a plurality of openings therethrough for receiving known fasteners (not shown) such as screws, for attaching outer door panel  160  to an inner door panel (described below). Additional attachment flanges  284 ,  286  are provided in upper corners of frame  252  for attaching outer door panel  250  to an inner door. Control mount surface is received in panel cutout potion  264  (shown in  FIG. 8 ) and attached thereto by known methods. 
   Thus, panel  250  provides a rigid outer door panel  250  of reduced manufacturing cost while using low cost materials, such as plastic, for control mount surface  270  while avoiding the disadvantages of known plastic escutcheons in dishwasher door assemblies. 
     FIG. 11  is an exploded perspective view of a dishwasher door assembly  300  for an appliance, such as dishwasher  100  (shown in  FIG. 1 ). Door assembly  300  includes an outer door panel  302  and an inner door panel  304 . Outer door panel  302  may be either of outer door panel  160  (shown in  FIGS. 2–7 ) or outer door panel  250  (shown in  FIGS. 8–10 ) to provide a rigid door construction that is relatively easy to operate, clean and maintain. 
   Inner door panel  304 , in an exemplary embodiment, includes an opening  306  therethrough for a vent assembly (not shown) and an opening  308  therethrough for receiving a detergent dispenser (not shown). Inner door panel  304  is further contoured in a bottom region  310  for accommodating lower rack  132  (shown in  FIG. 1 ) of dishwasher  100  (shown in  FIG. 1 ). It is understood, however, that inner door  300  is intended for illustrative purposes only, and that the outer door panels of the present invention could be used with a wide variety of inner door panels. 
   In an illustrative embodiment, inner door panel  304  is also of unitary, one piece construction and is fabricated from, for example, plastic materials according to known techniques. Inner door panel  304  is attached to outer door panel  302  via attachment flanges  312  on an outer perimeter of inner door panel  304  fastened to attachment flanges  314  in outer door panel  302 . An appliance control module (not shown) and a latch assembly are further accommodated into door assembly  300  as those in the art will appreciate. Also, sealing features and door assembly mounting features, further appreciated by those in the art, complete assembly for installation onto an appliance, such as dishwasher  100  (shown in  FIG. 1 ). 
   Unitary construction of inner door panel  304  and outer door panel  302  provides a structurally rigid door that will enhance customer satisfaction with a lower cost, improved quality door assembly  300  that is easier to use, clean and maintain than conventional dishwasher door assemblies. 
   While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.