Abstract:
A junction box assembly includes first and second structures, such as upper and lower cases. T-shaped aligning protrusions extend beyond an edge of a sidewall of the second structure and mate with a receiving member contained in the first structure. When the first structure is being aligned with the second structure, chamfers on the T-shaped aligning protrusion may be provided to help start the alignment process before the first and second structures are joined together. This allows for faster and easier assembly of the junction box and helps to reduce the mating forces between the first and second structures.

Description:
BACKGROUND 
       [0001]    This invention relates to a junction box assembly, such as an electrical junction box assembly that mounts on a vehicle or the like. 
         [0002]    In various junction box assembly processes, a first casing is mated with a second casing and then locked together. Properly positioning and aligning the first casing to the second casing in order to assemble the junction box can be both difficult and time consuming, especially in the context of an assembly line or the like in which many repetitions of an assembly process are performed. 
       SUMMARY 
       [0003]    As junction box casings increase in size, it becomes even more difficult to position the upper casing with respect to the lower casing for assembly. A conventional junction box has a first casing with a first sidewall edge and a second casing with a second sidewall edge. The second casing is provided with T-shaped ribs to restrict the sidewalls of the first casing and the second casing from separating from each other by deforming. These T-shaped ribs only extend up to the second sidewall edge of the sidewalls of the second casing in the conventional art. 
         [0004]    As shown in  FIG. 1 , by providing T-shaped aligning protrusions  200  on a second casing  20  that extend beyond the second sidewall edge  24  of the sidewalls  26 , and mating the T-shaped aligning protrusion with a receiving member (not shown in  FIG. 1 ) in the first casing  10 , faster and more accurate assembly of the junction box can be achieved. Moreover, when the first casing is being aligned with the second casing, chamfers on the T-shaped aligning protrusion may be provided to help start the alignment process before the sidewalls of the first and second casing come together. These chamfers help to reduce the mating forces between the first and second casings. 
         [0005]    Embodiments of this invention increase ease of alignment of the first and second casing by providing T-shaped aligning protrusions at the first and/or second casing of the junction box. 
         [0006]    These and other objects, advantages and salient features of the invention are described in or apparent from the following description of embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Exemplary embodiments will be described with reference to the accompanying drawings, in which like numerals represent like parts, and wherein: 
           [0008]      FIG. 1  is an exploded perspective view of a junction box with T-shaped aligning protrusions; 
           [0009]      FIG. 2  is a top view that illustrates a T-shaped aligning protrusion of  FIG. 2  prior to engagement; 
           [0010]      FIG. 3  is a front view that illustrates the T-shaped aligning protrusion prior to engagement; 
           [0011]      FIG. 4  is a side view that illustrates the T-shaped aligning protrusion prior to engagement; 
           [0012]      FIG. 5  is a top view that illustrates a receiving member prior to engagement; 
           [0013]      FIG. 6  is a front view that illustrates the receiving member prior to engagement; 
           [0014]      FIG. 7  is a side view that illustrates the receiving member prior to engagement; and 
           [0015]      FIG. 8  is an oblique view that illustrates a fully engaged state of the T-shaped aligning protrusion and the receiving member of  FIGS. 3-8 . 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0016]    A conventional junction box assembly has a first casing and a second casing. The second casing is provided with T-shaped ribs to prevent sidewalls of the first casing and the second casing from separating from each other by deforming. More specifically, a sidewall of the first casing slides past a sidewall of the second casing, when the first and second casings are engaged with each other, such that an inward-facing surface of the sidewall faces an outward-facing surface of the sidewall. The T-shaped ribs engage with corresponding receiving members formed on the inside surface of the sidewall, and thereby prevent the sidewall from deforming outward and thus becoming separated from the sidewall. Such separation would be undesirable because of the open gap that would be formed between the two sidewalls. Generally, the T-shaped ribs only extend up to the second sidewall edge of the sidewalls of the second casing in the conventional art. 
         [0017]      FIG. 1  illustrates a junction box assembly according to an exemplary embodiment. T-shaped aligning protrusions  200  are provided on a second casing  20 . The T-shaped aligning protrusions  200  extend beyond the second sidewall edge  24  of the second casing  20 , and mate with a receiving member (not shown in  FIG. 2 ) of the first casing  10 . The T-shaped aligning protrusions  200  extend beyond the second sidewall edge  24  by a certain amount. The amount may be in a range of from about 0.25 inches to about 5.0 inches, such as, e.g., about 0.5 inches, about 0.75 inches, about 1.0 inches, about 2.0 inches, or about 3.0 inches. The T-shaped aligning protrusions  200  may extend beyond the second sidewall edge of the second casing  20  for a distance about equal to the height of the sidewall  26  of the second casing  20 , as shown in  FIG. 1 , or a distance longer or shorter than the height of the sidewall  26 . Although not depicted, various fuses, relays, transistors, connectors, bus bars, circuit boards, and/or the like may be accommodated within the junction box assembly. 
         [0018]    As used in this disclosure, “T-shaped” is not limited to the shape shown in the depicted exemplary embodiments, and encompasses any shape in which a first portion having a relatively large width is attached to a second portion having a relatively smaller width, such as a mushroom shape, a keyhole shape, etc., in addition to more traditional “T” shapes. The small-width portion of the T-shaped member attaches to a first junction box structure (such as a casing), such as at the sidewall or another suitable surface facing substantially perpendicular to a direction of engaging the first junction box structure with a second junction box structure. When the first and second junction box structures are engaged, a receiving member holds the large-width portion of the T-shaped member so that the large-width portion cannot disengage from the receiving member in a direction perpendicular to the direction of engaging the first junction box structure with a second junction box structure. 
         [0019]      FIGS. 2 ,  3 , and  4 , illustrate an embodiment of a T-shaped aligning protrusion  200 . The T-shaped aligning protrusion  200  includes an upper surface  220 , a lower surface  222 , chamfers  224 , sidewalls  226 , extensions  228 , and inward-facing corners  229 . The chamfers  224  allow the T-shaped aligning protrusion to easily be guided into a receiving member (described below). The upper end of the T-shaped aligning protrusion  200 , including the upper surface  220 , may be inserted into the receiving member to help the alignment process between the first casing and the second casing. Additionally, the extensions  228  interlock with the receiving member to keep the T-shaped aligning protrusion engaged with the receiving member. As shown in  FIG. 3 , in this embodiment, inward-facing corners  229  of the T-shaped aligning protrusion  200  are tapered in plan view, rather than being right-angled corners. 
         [0020]      FIGS. 5 ,  6 , and  7  illustrate an exemplary receiving member  100 . The receiving member  100  has an end surface  109 , a base portion  111 , and a pair of engaging brackets  113  that extend from the base portion  111 . The engaging brackets  113  are spaced from each other at a distance corresponding approximately to the width of the lower surface  222  of the T-shaped aligning protrusion  200  so as to provide space for the entry of the T-shaped aligning protrusion between the engaging brackets. The engaging brackets  113  are configured to allow the T-shaped aligning protrusion  200  to slide into the space between the engaging brackets  113 . As shown in  FIG. 5 , inward-facing surfaces  115  of the receiving member  100  extend substantially parallel to sidewall  16 . 
         [0021]    As shown in  FIG. 8 , as the T-shaped aligning protrusion  200  proceeds to its final engagement position with respect to the receiving member  100 , the T-shaped aligning protrusion  200  slidably engages with the engaging brackets  113  of the receiving member  100 . Additionally, the lower surface  222  of the T-shaped aligning protrusion  200  moves towards the upper surface  109  of the receiving member. During this action, the chamfers  224  make it easy to guide the end of the T-shaped aligning protrusion  200  into the open end of the receiving member  100 . Additionally, the inward-facing corners  229  of the T-shaped aligning protrusion  200  engage the inward facing surfaces  115  of the receiving member  100  in a substantially line contact manner, rather than a plane contact manner. This helps reduce the actual force necessary to push the T-shaped aligning protrusion  200  into the receiving member  100 . The sidewall  16  of the first casing  10  may slide past the sidewall  26  of the second casing  20 , such that an inward-facing surface of the sidewall  16  faces an outward-facing surface of the sidewall  26 . The T-shaped aligning protrusions  200  engage with corresponding receiving members formed on the inside surface of the sidewall  16 , as described above, and thereby prevent the sidewall  16  from deforming outward and thus becoming separated from the sidewall  26 . 
         [0022]    While the invention has been described in conjunction with a specific embodiment, this embodiment should be viewed as illustrative and not limiting. Various changes, substitutes, improvements or the like are possible within the spirit and scope of the invention. 
         [0023]    For example, the number of T-shaped aligning protrusions  200  in the second casing is not limited to the three depicted in  FIG. 1 , but may be any number, including one. 
         [0024]    As another example, the location of the T-shaped aligning protrusion is not limited. Specifically, the T-shaped aligning protrusion may be located in the first casing  100  and the receiving member may be located in the second casing  200  or the first and second casings could contain both T-shaped aligning protrusions and receiving members. As another example, the T-shaped aligning protrusion could be located on an interior wall or surface of the first or second casing.