Patent Publication Number: US-2005115105-A1

Title: Home appliance assembly and method of manufacturing the same

Description:
This application claims the benefit of Korean Applications No. 10-2003-0085615, No. 10-2003-0085617, and No. 10-2003-0085618, each filed on Nov. 28, 2003, which are hereby incorporated by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to home appliances, and more particularly, to a home appliance assembly and method of manufacturing the same, which employs a coupling plate facilitating the assembly of a home appliance, such as a laundry dryer, having a structurally sound outer case.  
      2. Discussion of the Related Art  
      A home appliance generally comprises a plurality of outer panels forming an outer case for housing the inner workings of the appliance, with each panel essentially constituting one face of the outer case. For logistical and aesthetic reasons, the outer panels are typically provided as components made of sheet metal to be structurally joined at the edges and are typically coated with vitreous enamel to resist corrosion and enhance appearance. In joining these panels to form the outer case of a home appliance, structural strength and integrity and ease of assembly should be considered.  
      As an exemplary home appliance,  FIG. 1  illustrates a contemporary laundry dryer in which an outer case  100  includes a top panel  50  to be assembled to a back cover (not shown in  FIG. 1 ) of the laundry dryer. The outer case  100  further includes a base  10  forming the bottom of the laundry dryer, to which a front panel  20  and a pair of side panels  30  are assembled. It should be appreciated that, for installing an appliance in a home (typically, against a wall), the appliance should be afforded a service space S between the back cover and the wall, which is achieved by extending at least one panel beyond a rear surface of the back cover.  
       FIG. 2  illustrates a coupling structure of a home appliance assembly according to a conventional art, showing the top panel  50  and back cover  40  of the laundry dryer of  FIG. 1 . Here, a mounting rail  40   a  protrudes from an upper rear surface of the back cover  40  to provide a mounting surface for coupling with the top panel  50  along an inner edge of a top panel extension  52 . The top panel  50  is provided with a pair of flanges  50   a  extending downward from a lower edge of the top. panel extension  52 , and a first coupling hole  51  is formed in each flange, to be aligned with a second coupling hole  41  provided at either end of the mounting rail  40   a . Meanwhile, a sheet metal coating process is performed on the top panel  50 , to cover its exterior surface with vitreous enamel, and typically excludes the back cover  40 .  
      To couple the top panel  50  and back cover  40 , the first coupling holes  51  are aligned with the second coupling holes  41  to allow a manual insertion of a threaded coupling means, such as screws or bolts, to be tightened against coated surface of at least the flanges  50   a  of the top panel  50 . Therefore, since the vitreous enamel is weaker than the sheet metal forming the top panel  50 , the necessary tightening of the coupling means tends to crack the vitreous enamel, and, over time, the cracking allows the top panel to corrode. Meanwhile, excessive tightening of the coupling means may distort the mounting rail  40   a  in addition to the cracking.  
      Moreover, alignment of the coupling holes during assembly is time consuming and cumbersome, requiring more than one worker and loose assembly tolerances. Even after such assembly, however, the strength provided by the coupling structure of the conventional art is poor.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present invention is directed to a home appliance assembly that substantially obviates one or more problems due to limitations and disadvantages of the related art.  
      An object of the present invention, which has been devised to solve the foregoing problems, lies in providing a home appliance assembly having an outer case exhibiting high structural strength.  
      Another object of the present invention is to provide a home appliance assembly which facilitates assembly of the outer case.  
      Another object of the present invention is to provide a home appliance assembly which preserves the corrosion resistant properties of a vitreous enamel coating applied to the outer case.  
      Another object of the present invention is to provide a home appliance assembly which preserves the appearance of the outer case.  
      Another object of the present invention is to provide a home appliance assembly which prevents a distortion of the outer case when assembling the top panel and rear cover.  
      Another object of the present invention is to provide a method of manufacturing any one of the above home appliance assemblies.  
      Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
      To achieve these objects and other advantages in accordance with the purpose of the invention as embodied and broadly described herein, there is provided a home appliance assembly comprising at least two panels forming adjacent faces of an outer case; a coupling plate, coupled to each of the at least two adjacent panels, for reinforcing a structural strength of the outer case; and self-alignment means for aligning the coupling plate with respect to at least one of the at least two adjacent panels.  
      The home appliance of the present invention is embodied as a laundry dryer comprising a top panel forming a top face of an outer case; a back cover forming a rear face of the outer case; a coupling plate having a main support for reinforcing a structural strength of the outer case, the coupling plate having a first mounting flange coupled with the top panel and a second mounting flange coupled with the back cover, the first and second mounting flanges integrally formed with opposite edges of the main support; and a self-alignment means. According to a first embodiment, the self-alignment means includes a pair of opposing stops, respectively provided to opposite sides of one of the top panel and back cover, for capturing the coupling plate and thereby horizontally aligning the coupling plate with respect to at least one of the top panel and back cover. According to a second embodiment, the self-alignment means includes at least one alignment finger provided to the coupling plate to oppose at least one finger hole, the finger holes being correspondingly formed in the top panel to receive the at least one alignment finger and thereby horizontally align the coupling plate with respect to at least one of the top panel and back cover.  
      According to another aspect of the present invention, there is provided a method for manufacturing a home appliance assembly including an outer case comprising at least two panels forming adjacent faces of an outer case and a coupling plate for reinforcing a structural strength of the outer case. The method comprises joining the coupling plate with a first panel of the at least two adjacent panels, to form a subassembly having an exterior surface, the subassembly being separately processed from a second panel of the at least two adjacent panels; applying an enamel coating to the exterior surface of the subassembly; and coupling the enamel-coated subassembly to the second panel.  
      It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory 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 embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:  
       FIG. 1  is a perspective view of an outer case of a contemporary laundry dryer;  
       FIG. 2  is a perspective rear view of an assembly structure of the laundry dryer of  FIG. 1 ;  
       FIG. 3  is an exploded perspective rear view of an assembly structure of a home appliance according to a first embodiment of the present invention;  
       FIG. 4  is an exploded perspective rear view of an assembly structure of a home appliance according to a second embodiment of the present invention;  
       FIG. 5  is a reverse perspective view of the coupling plate shown in  FIG. 4 ; and  
       FIG. 6  is a perspective view of the outer case of a home appliance adopting the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.  
      The present invention may be applied to any home appliance having joined panels forming an outer case. In the accompanying drawings, a drum-type laundry dryer is shown for illustrative purposes only.  
      Referring to  FIG. 3 , illustrating an assembly structure of a home appliance having an outer case according to a first embodiment of the present invention, a back cover  400  forms a rear face of the outer case. A top panel  500 , forming a top face of the outer case, has a top panel extension  520  that protrudes a predetermined distance beyond a rear surface of the back cover and creates a service space. Although not shown in the drawings, the back cover  400  may be disposed more rearwardly than a rear surface of the top panel extension  520 . In any event, the rearward-facing surfaces of the top panel extension  520  and the back cover  400  occupy different planes, creating a surface offset for enhancing structural strength.  
      The above assembly structure includes a coupling plate  600  for coupling two adjacent panels forming respective faces of the outer case of the home appliance according to the present invention. In the preferred embodiment, the adjacent components are the top panel  500  and back cover  400 . The coupling plate  600 , which has a cross-section corresponding to the profile of the upper rear side of the outer case, reinforces the strength of the coupling of the top panel  500  and the back cover  400 , while facilitating assembly of the outer case using a threaded coupling means such as a plurality of screws or bolts. The coupling is achieved by manipulating the coupling means via a plurality of coupling holes respectively formed in the top panel  500 , the back cover  400 , and the coupling plate  600 , which are aligned during assembly using a self-alignment means (described later).  
      The top panel  500  has a plurality of first coupling holes  510  formed at predetermined locations in the top panel extension  520 , the back cover  400  has a plurality of second coupling holes  410  similarly formed, and the coupling plate  600  has pluralities of third and fourth coupling holes  610   a  and  610   b , which are through holes corresponding to the first and second coupling holes, respectively. The coupling holes  510  and  410  may be provided as pilot holes or captured nuts for receiving the threads of the coupling means.  
      The coupling plate  600  is formed by bending a metal plate of a predetermined strength into a substantially tri-planer shape having smooth surfaces and rounded edges to promote a hospitable environment for a user. The coupling plate  600  includes a main support  620 , having a width corresponding to that of the top panel extension  520 , and first and second mounting flanges  630  and  640  respectively extending at opposing right angles from opposite edges of the main support, to impart the coupling plate with structural strength. Thus, the coupling plate  600  is shaped so that, when assembled, the first mounting flange  630  abuts the rear surface of the top panel extension  520  of the top panel  500  and the second mounting flange  430  abuts the upper rear surface of the back cover  400 , thereby aligning the third and fourth coupling holes  610   a  and  610   b  with the first and second coupling holes  510  and  410 , respectively. The assembly elements of the outer case are aligned as above so that the coupling means may be inserted and tightened. In doing so, the top panel  500  and back cover  400 , i.e., the two adjacent panels of the outer case of the home appliance assembly of the present invention, are assembled by fixing the coupling plate  600  to each panel.  
      To enhance the appearance of the assembled outer case, the first mounting flange  630  is preferably shorter than a lateral width of the top panel  500 , specifically, the lateral width of the top panel extension  520 , while the length of the main support  620  is roughly equal to the top panel&#39;s lateral width. The material of the coupling plate  600  is preferably a metal having a lower strength than that of the top panel  500 , to prevent a cracking of the vitreous enamel coating the top panel around the first coupling holes  510 , which may occur when applying a tightening force to the coupling means to secure the coupling plate to the top panel. If the coupling plate  600  were weaker than the top panel  500 , the applied tightening force would be transferred to the top panel at the first coupling holes  510 , increasing the tendency for cracking. Since the coupling plate  600  is frequently exposed to moisture, particularly for home appliances such as dishwashers, washing machines, and laundry dryers, the coupling plate is preferably made of stainless steel.  
      Furthermore, though not specifically shown in the drawings, the material of the first and second mounting flanges  630  and  640  may be minimized, to reduce the weight and cost of the coupling plate  600 , by minimally forming one or both flanges to provide each corresponding coupling hole with an individual flange. Thus, each mounting flange  630  and  640  may comprise a plurality of individual flanges, corresponding to the third and fourth coupling holes  610   a  and  610   b  and respectively extending from separate locations along the edges of the main support  620 , to surround each coupling hole with a minimum of material for establishing a mounting surface adjacent the hole.  
      According to the present invention, the coupling plate  600  is aligned with respect to each of the top panel  500  and the back cover  400 , using a self-alignment means for achieving both vertical and horizontal alignment by installing the coupling plate with respect to the outer case during assembly.  
      Vertical alignment of the coupling holes is achieved by abutting the main support  620  against a lower surface of the top panel extension  520 . In the case of disposing the back cover  400  more rearwardly than the rear surface of the top panel extension  520 , the vertical alignment of the coupling holes is achieved by abutting the main support  620  against an upper surface (not shown) created by the surface offset between the reward-facing surfaces of the top panel extension and the back cover.  
      According to a preferred embodiment, horizontal alignment of the coupling holes can be achieved by loading the coupling plate  600  between a pair of opposing stops  650  respectively provided on the top panel  500 . Specifically, the first mounting flange  630  is captured between the opposing stops  650 , which are positioned at opposite ends of the top panel extension  520  to protrude from its rear surface and thereby enable a self-alignment of the coupling plate  600 . As an alternative, the opposing stops  650  may be provided on opposite sides of the upper rear surface of the rear cover  400 , to receive the second mounting flange  640  between the opposingly positioned stops. In either case, the opposing stops  650  may be integrally formed with the top panel  500  or back cover  400  or may be subsequently affixed to its surface. If integrally formed, the top panel  500  or back cover  400  may be recessed to receive the mounting flange  630  or  640  of the coupling plate  600 , so that opposing inner ends of the recess serve as the opposing stops  650 .  
       FIG. 4  illustrates an assembly structure of a home appliance according to a second embodiment of the present invention, in which horizontal alignment is achieved by alternative means. Here, a coupling plate  600 ′ includes at least one alignment finger  652  for achieving horizontal alignment by inserting the finger(s) into at least one finger hole  651  formed in a top panel extension  520 ′. Preferably, there is a finger hole  651  formed at each end of the top panel extension  520 ′ for respectively receiving a pair of correspondingly provided alignment fingers  652  protruding inwardly from the first mounting flange  630 . The finger holes may be alternatively or additionally formed in the back cover  400  for receiving alignment fingers provided to the second mounting flange  640 , or the finger holes may be formed in at least one of the mounting flanges of the coupling plate for receiving alignment fingers correspondingly provided on the top panel extension and/or back cover. In any event, when the alignment fingers  652  are inserted into the finger holes  651 , the coupling plate  600 ′ is provisionally fixed to the rear surface of the outer case of the home appliance, to align the third coupling holes  610   a  with the first coupling holes  510  and align the fourth coupling holes  610   b  with the second coupling holes  410  and thereby allow insertion and tightening of the coupling means.  
      As shown in  FIG. 5 , the alignment finger  652  preferably has an L-shaped cross-section formed by a hook  652   b  extending downward from the distal end of an arm  652   a  integrally formed with the coupling plate  600 ′ by a lancing process. The inner surface of the hook  652   b  is separated from the inner surface of the coupling plate  600 ′ by a predetermined distance corresponding to a panel thickness of the top panel extension  520 ′, allowing the alignment finger  652  to engage firmly with the finger hole  651  when the alignment finger is inserted into and caught by the finger hole so that the coupling plate is seated by being dropped into place.  
      In manufacturing the above-described outer case of a home appliance assembly according to the presenting invention, the top panel  500  (a first panel) and back cover  400  (a second panel) are adjacent panels to be coupled while a hole alignment is performed using the coupling plate  600 , which is self-aligned according to the first or second embodiments. In doing so, the coupling plate  600  (or  600 ′) is first joined to one of the two adjacent panels to produce a subassembly to be subsequently coupled to the other adjacent panel by installing coupling means such as screws or bolts. Thus, the subassembly includes the coupling plate  600  (or  600 ′) and the top panel  500  as shown in  FIG. 6 , or a subassembly (not shown) of the coupling plate and back cover  400 , and the subassembly is coated with vitreous enamel before installing the coupling means to the other adjacent panel, thereby minimizing the chances for generating cracks in the vitreous enamel when tightening the coupling means. As an alternative to a universal use of the above-described coupling means, the coupling plate  600  (or  600 ′) may be joined to the adjacent panel (e.g., the top panel  500 ) using a plurality of spot welds, rivets, or Tox round joints corresponding to the first and third coupling holes  510  and  610   a  or the second and fourth coupling holes  410  and  610   b .    
      The above-described assembly structure of a home appliance adopting the present invention enhances the structural strength of an outer case of the home appliance, since the coupling plate disposed at the rear of the outer case has a profile corresponding to the surface offset created by rearward-facing surfaces of the top panel extension and the back cover. Damage to the vitreous enamel during coupling can be prevented by forming the coupling plate of a metal having a lower strength than that of the top panel and can be minimized by performing the vitreous enamel coating process to a subassembly produced by first joining the coupling plate to one of the top panel and back cover, i.e., before installing and tightening screws or bolts, which also reduces assembly time by eliminating a separate coating step for the coupling plate. The coupling holes are self-aligned horizontally by inserting a pair of alignment fingers into corresponding finger holes to produce a provisional assembly of the coupling plate and a panel (face) of the outer case or by providing a panel with a pair of opposing stops for receiving a mounting flange of the coupling plate.  
      It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.