Abstract:
A home appliance including an appliance body having an internal framework; a metal panel covering a portion of the internal framework, the panel having a curved portion turned through the curve inwardly toward an interior of the appliance, wherein the panel surface adjacent the curve is substantially smooth and substantially undistorted, the panel being fabricated by engaging a metal sheet with a bender assembly, holding the metal sheet against translational movement, and applying pressure to the metal sheet using a punch having a curved head and being operatively associated with the bender assembly, the pressure being applied by moving the punch against the metal sheet using a damped punch driver operatively associated with the bender assembly.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates broadly to home appliances having skeletal frames covered with body panels fabricated from metal sheets and, more particularly, to a home appliance, especially a range, having a front panel fabricated from a metal sheet that includes in-turned portions, corners, or both that are smooth and undistorted. 
         [0002]    Home appliances, such as ranges, having ovens, steamers, accessory compartments or other openings in the front for user access often include metal panels that extend intermediate the openings to provide a clean, finished look and to cover the essentially skeletal framework that is internal to the range. With such cavities, front panels often include openings themselves to conform to the openings in the framework. 
         [0003]    In order to provide ease of cleaning as well as safety and a finished appearance, such openings include radiused or curved corners rather than a stark 90° angle which can result in surfaces that are difficult to reach during cleaning and are not as visually complimentary to the range. Further, the internal structures themselves are typically formed with rounded corners so that the front panel matches the underlying structure. Such corners often include an in-turned portion of the sheet that extends inwardly for a predetermined distance as a flange to accommodate any spaces that may occur between, for example, an oven cavity and the front of the range. 
         [0004]    When fabricating front panels, corners are difficult to form without some metal distortion, such as buckling or wrinkling. Small holes may be formed in the front panels at the inward curvature to ease stress on the metal during corner fabrication, however, use of such holes has not solved the problem of unsightly front panels due to metal bending that has resulted in metal distortions around the corners. 
         [0005]    There currently, therefore, exists a need for a home appliance with a front panel that includes openings with corners that are smooth and undistorted and a fabrication process and apparatus that will result in such an undistorted and visually appealing front panel. 
       SUMMARY OF THE INVENTION 
       [0006]    It is accordingly an intent of the present invention to provide a home appliance with a front panel including corners that are smooth and undistorted. 
         [0007]    It is accordingly an intent of the present invention to provide a home appliance with a front panel fabricated by holding the panel fast against a damped press assembly that provides a gradual pressing action resulting in corners that are substantially smooth and substantially undistorted. 
         [0008]    To those ends, the present invention is directed to a home appliance including an appliance body having an internal framework; a metal panel covering a portion of the internal framework, the panel having a curved portion turned inwardly toward an interior of the appliance. The panel surface is substantially smooth and substantially undistorted, with the panel being fabricated by engaging a metal sheet with a bender assembly, holding the metal sheet against translational movement and applying pressure to the metal sheet using a punch having a curved head and being operatively associated with the bender assembly, the pressure being applied by moving the punch against the metal sheet using a damped punch driver operatively associated with the bender assembly. 
         [0009]    Preferably the step of engaging includes engaging a metal sheet with a bender assembly having a receiving cup including an upstanding wall member having a working surface and defining a receiving cavity adjacent the working surface. 
         [0010]    Preferentially, the step of holding the metal sheet against translational movement includes holding the metal sheet using a bender assembly having a plate that engages and applies pressure to the metal sheet prior to the arrival of the punch, and holds the metal sheet stationary during punch application. 
         [0011]    It is preferred that the step of applying pressure using a punch operatively associated with a bender assembly includes using a bender assembly having a punch plate supporting the punch in a downwardly directed manner for selective engagement with the metal sheet. 
         [0012]    It is further preferred that the step of moving the punch using a damped punch driver includes moving the punch using a punch driver damped with a plurality of springs operatively associated with the bender assembly. Preferably, the step of moving the punch includes moving the punch using a damped punch driver includes using a punch driver damped with a plurality of springs extending intermediate a spring support plate and a punch plate supporting the curved punch in a downwardly directed manner for selective engagement with the metal sheet. 
         [0013]    It is preferred that the step of moving the punch includes moving the punch using a damped punch driver includes using a punch driver damped with a plurality of springs arranged on the spring support plate in a predetermined pattern for balanced force application. Further, the step of moving the punch may include moving the punch using a damped punch driver includes using a punch driver damped with a plurality of springs arranged on the spring support plate with each of the plurality of springs having a spring stabilizer operatively associated therewith to keep each of the plurality of springs in place intermediate the spring support plate and the punch plate. 
         [0014]    Preferably, the step of engaging includes engaging a metal sheet with a bender assembly having a receiving cup including an upstanding wall member mounted to a base plate, having a working surface and defining a receiving cavity adjacent the working surface. It is preferred that the step of applying pressure using a punch operatively associated with a bender assembly includes using a bender assembly having a punch plate fixed to the bender assembly in alignment with the base plate to support the punch in a downwardly directed manner toward the receiving cup for selective engagement with the metal sheet at the work surface and receiving cavity. It is further preferred that the step of moving the punch includes moving the punch using a damped punch driver includes using a punch driver damped with a plurality of springs mounted to a spring support plate fixed to the bender assembly in alignment with the base plate, the spring support plate having a hole defined therein in alignment with the punch for passage of the punch therethrough in a downwardly directed manner for selective engagement with the metal sheet at the work surface and receiving cavity. 
         [0015]    It is preferred that the step of applying pressure includes applying pressure to the bender assembly in a machine press. 
         [0016]    The present invention is also directed to a range including a range body having an internal framework and a metal panel covering a portion of the internal framework, the panel having a curved portion turned inwardly toward an interior of the range, wherein the panel surface is substantially smooth and substantially undistorted. The panel is fabricated by engaging a metal sheet with a bender assembly, holding the metal sheet against translational movement and applying pressure to the metal sheet using a punch having a curved head and being operatively associated with the bender assembly, the pressure being applied by moving the punch against the metal sheet using a damped punch driver operatively associated with the bender assembly. 
         [0017]    Preferably, the step of engaging includes engaging a metal sheet with a bender assembly having a receiving cup including an upstanding wall member having a working surface and defining a receiving cavity adjacent the working surface. 
         [0018]    Preferentially, the step of holding the metal sheet against translational movement includes holding the metal sheet using a bender assembly having a plate that engages and applies pressure to the metal sheet prior to the arrival of the punch, and holds the metal sheet stationary during punch application. 
         [0019]    It is preferred that the step of applying pressure using a punch operatively associated with a bender assembly includes using a bender assembly having a punch plate supporting the punch in a downwardly directed manner for selective engagement with the metal sheet. 
         [0020]    It is further preferred that the step of moving the punch using a damped punch driver includes moving the punch using a punch driver damped with a plurality of springs operatively associated with the bender assembly. Preferably, the step of moving the punch includes moving the punch using a damped punch driver includes using a punch driver damped with a plurality of springs extending intermediate a spring support plate and punch plate supporting the curved punch in a downwardly directed manner for selective engagement with the metal sheet. Preferentially, the step of moving the punch includes moving the punch using a damped punch driver includes using a punch driver damped with a plurality of springs arranged on the spring support plate in a predetermined pattern for balanced force application. It is preferred that the step of moving the punch includes moving the punch using a damped punch driver includes using a punch driver damped with a plurality of springs arranged on the spring support plate with each of the plurality of springs having a spring stabilizer operatively associated therewith to keep each of the plurality of springs in place intermediate the spring support plate and the punch plate. 
         [0021]    Preferably, the step of engaging includes engaging a metal sheet with a bender assembly having a receiving cup including an upstanding wall member mounted to a base plate, having a working surface and defining a receiving cavity adjacent the working surface. It is preferred that the step of applying pressure using a punch operatively associated with a bender assembly includes using a bender assembly having a punch plate fixed to the bender assembly in alignment with the base plate to support the punch in a downwardly directed manner toward the receiving cup for selective engagement with the metal sheet at the work surface and receiving cavity. It is further preferred that the step of moving the punch includes moving the punch using a damped punch driver includes using a punch driver damped with a plurality of springs mounted to a spring support plate fixed to the bender assembly in alignment with the base plate, the spring support plate having a hole defined therein in alignment with the punch for passage of the punch therethrough in a downwardly directed manner for selective engagement with the metal sheet at the work surface and receiving cavity. 
         [0022]    Preferentially, the step of applying pressure includes applying pressure to the bender assembly in a machine press. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a front view of a home appliance according to the preferred embodiment of the present invention; 
           [0024]      FIG. 2  is a perspective view of the home appliance illustrated in  FIG. 1 ; 
           [0025]      FIG. 3  is a perspective view of a portion of a front panel of the home appliance illustrated in  FIG. 2 ; 
           [0026]      FIG. 4  is an underside view of the panel illustrated in  FIG. 3 ; 
           [0027]      FIG. 5  is a front view of a bender assembly according to the preferred embodiment of the present invention; 
           [0028]      FIG. 6  is a rear view of the bender assembly illustrated in  FIG. 5 ; 
           [0029]      FIG. 7  is a perspective view of the receiver plate of the bender assembly illustrated in  FIG. 5 ; 
           [0030]      FIG. 8  is an underside view of the spring plate of the bender assembly illustrated in  FIG. 5 ; 
           [0031]      FIG. 9  is a top view of the punch plate separated from the spring plate of the bender assembly illustrated in  FIG. 5 ; 
           [0032]      FIG. 10  is a perspective view of a metal plate being fabricated into a panel using the bender assembly of  FIG. 5 ; 
           [0033]      FIG. 11  is a perspective view of pressure being applied to the bender assembly of  FIG. 5  by a machine press; 
           [0034]      FIG. 12  is a perspective view of the bender assembly pressing a curved portion into the panel illustrated in  FIG. 11 ; 
           [0035]      FIG. 13  is a perspective view of the machine press relieving pressure on the bender assembly as illustrated in  FIG. 12 ; and 
           [0036]      FIG. 14  is a perspective view of the finished panel emerging from being fabricated by the bender assembly device illustrated in  FIG. 5 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0037]    Turning now to the drawings and, more particularly, to  FIGS. 1 and 2 , a range is illustrated generally at  10  and includes a floor-standing, box-like body  12  that defines a number of operational openings including an oven  18  as seen in  FIG. 1  and a steamer unit which may be combined with a convection oven as seen at  24  in  FIG. 2 . A control panel  22  is located above the oven  18  and steamer  24 . A first door  20  covers the oven  18  and a second door  26  covers the steamer  24 . 
         [0038]    A front panel  14  overlies the internal portions of the range  10  and is generally covered by the doors  20 ,  26  in the closed position. Curved panel portions are defined over the face of the front panel  14 , and, for example, are defined at the corners of the oven  18  as illustrated at  16  in  FIG. 1 , and at the corners of the steamer/oven combination  24 , as illustrated at  28  in  FIG. 2 . According to the present invention such corners are smooth and free of metal distortion resulting from fabrication of the front panel  14 . 
         [0039]    As seen in  FIGS. 3 and 4 , a portion of a front panel  14  is illustrated on either side showing a portion having a corner formed therein. It should be noted that lines on the illustrations, especially  FIG. 3 , are meant to indicate curvature and are not to be construed as metal distortion. There, a corner  16  includes a curved corner surface  30  and an in-turned flange  32  extending substantially perpendicularly away from the curved corner surface  30  with the curved corner surface  30  and the flange  32  defining a smoothly curved junction. The flange  32  is seen in  FIG. 4  as extending away from the underside  38  of the panel  14  at the underside curved corner surface  40 . 
         [0040]    An opening  34  is formed at the innermost portion of the corner  30  and extends from the flat curved portion  30  onto the flange  32  for relief of internal pressure during bending and to enhance the ability of the panel  14  to emerge from bending with a smooth, substantially undistorted finish. Additionally, spaces  36  are defined in the panel  14  as keyhole-shaped openings at either end of the flange  32  to further enhance the ability of the panel  14  to resist wrinkling and distortion during bending. 
         [0041]    With reference to  FIG. 5 , a bender assembly  42  is illustrated at an operational position in a machine press, or press brake including a upper ram P 1  and a lower die support P 2 . In operation, the press brake will drive the ram P 1  toward the die support P 2 , with the resulting pressure acting on any material therebetween. 
         [0042]    The bender assembly  42  includes three generally planar plates that can be made from solid aluminum billet, including a punch plate  44  for contact with the ram P 1  and a die plate  48  for support by the die support P 2 . A spring plate  46  is intermediate the punch plate  44  and the die plate  48 . 
         [0043]    The punch plate  44  includes a generally cylindrical punch  50  extending downwardly and away from the punch plate  44  at approximately the center of the punch plate  44 . The spring plate  46  includes nine springs  60  generally evenly spaced throughout the spring support plate  46  which are maintained in position by spring stabilizers  62  that extend through the coil springs  60  and are rods firmly mounted to the spring plate  46  within the coil of each spring  60 . The spring supports  62  are accommodated by the punch plate  44  using openings that allow the spring supports  62  to pass therethrough, so as the punch plate  44  descends toward the spring plate  46 , the springs  60  are compressed and the spring supports  62  project upwardly from the punch plate  44 , as seen in  FIG. 12 . 
         [0044]    As seen in  FIG. 5 , the die plate  48  includes a die  64  having a receiving well  68  with the die  64  being configured to support the metal sheet and to cooperate with the punch  50  to perform the shaping of the metal sheet during bending operations. 
         [0045]    With reference to  FIG. 6 , the plates  44 ,  46  and  48  are mounted between two vertically extending stanchions  56 ,  58 . With continued reference to  FIG. 5  and  FIG. 6 , it can be seen that nine coil springs are mounted intermediate the punch plate  44  and the spring plate  46 . As seen in  FIG. 6  and  FIG. 9 , the nine springs include three springs equally spaced along the rear portion of the spring plate  44  and two springs at each front corner of the spring plate  44  forming an outer spring group  76 . Four springs are evenly spaced around the punch and placed inwardly of the other five springs, forming an inner spring group  74 . Such even spacing of the springs  60  provides an even damping force resisting the downwardly pressing ram to ease internal stresses on any metal being bent in the present bender assembly  42 . The spring plate  46  also engages the panel  14  before the punch  50  contacts the panel  14 , and uses the force of the ram P 1  via the springs  60  to hold the panel  14  in position for bending. The spacing of the springs within the inner spring group  74  and the outer spring group  76  results in even, firm holding pressure in the region of the bend. The more rigidly the panel  14  is held, the less likely metal distortions will result from bending. 
         [0046]    Turning now to  FIG. 7 , the die  64  includes a generally curved wall defining a working surface  66  and a receiving cup  68 , open on one side and located adjacent the working surface  66 , with the receiving cup  68  having approximately the radius of the punch  50 . A working trough  70  is defined by the die  64  adjacent the working surface  66  and the receiving cup  68 . The die  64  is mounted to the die support plate  48  using fasteners  72 . The working surface  66  supports the sheet metal blank used to form the panel  14 , a portion of which is driven into the receiving cup  68  by the punch  60 . 
         [0047]    Turning to  FIG. 8 , the underside of the spring plate  46  is shown as defining an opening  54  through which the punch  50  must pass to reach a workpiece, such as the panel  14 , at the die  64 . The punch  50  has a curved or sloped head  52  which helps to define the curvature and the rate of bending at the corner when forming the panel  14  from the metal blank. Gradual bending contributes to the resultant smooth and undistorted panel  14 . Such curvature can be seen in  FIG. 9  which illustrates the spring plate  46  raised from the punch plate  44  which is shown inverted. The location of the punch opening  54  in the spring plate  46  is also shown in  FIG. 9 . 
         [0048]    In operation, and with reference to  FIG. 10 , a sheet blank forming a panel  14  is placed intermediate the die  64  and the lower surface of the spring plate  46 , the ram P 1  being raised to accommodate such positioning of the work piece. The bender assembly  42  is mounted to the machine press or press brake with the die plate  48  is supported on the die support P 2 . 
         [0049]    With reference to  FIG. 11 , the ram P 1  is driven downwardly to press the work piece supported on the die  64 . The spring plate  46  engages the panel  14  and holds the panel  14  rigidly in position for bending. The springs  60  act to absorb or dampen any irregularity or jerkiness of ram motion by providing a cushion against the force of the ram, as well as distributing the ram force evenly across the panel  14  adjacent the proposed bend. Further, the springs  60  assist the spring plate  46  in holding the panel  14  against any possible translational movement. 
         [0050]    As seen in  FIG. 12 , the pressing process has bottomed out, with the punch plate  44  and spring plate  46  at their closest positions with the springs  60  fully compressed, and the spring supports  62  projecting a maximum distance beyond the punch plate  44 . The punch  50  has passed through the opening  54  in the spring plate  46 , and has driven the metal of the panel  46  gradually downwardly into the receiving well  68  of the die  64 . The rigidly held panel  14  is not pulled into the receiving well  68  and accordingly further avoids metal distortion during the bend. 
         [0051]    As seen in  FIG. 13 , the ram P 1  has reversed motion and is releasing the pressure on the punch plate  44 , thereby allowing the springs  60  to assist the movement of the ram P 1  in driving the punch plate  44  away from the die  64 . 
         [0052]    As seen in  FIG. 14 , the spring plate  46  and the punch plate  44  have been lifted from any further action on the die  64  allowing the panel  14  to emerge from the die  64  having a smooth undistorted corner  28 . 
         [0053]    By the above, the present invention provides a home appliance with a front panel that is substantially smooth and substantially distortion free. By operation of the spring plate  46  to hold the panel  14  rigidly in place, to distribute the ram force evenly over the panel  14  and to damp the ram force, in combination with gradual curving provided by the smoothly curved punch  50 , a smooth and undistorted curved panel  14  is achieved. 
         [0054]    It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. While the present invention is described in all currently foreseeable embodiments, there may be other, unforeseeable embodiments and adaptations of the present invention, as well as variations, modifications and equivalent arrangements, that do not depart from the substance or scope of the present invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.