Patent Publication Number: US-2021170953-A1

Title: Roof rail with divider wall configured to resist clamping force

Description:
TECHNICAL FIELD 
     This disclosure relates to a roof rail for a motor vehicle. In particular, the roof rail includes a divider wall configured to resist a clamping force. 
     BACKGROUND 
     Some motor vehicles include roof rails, which extend along the sides of a roof, and which are used as mounting points for gear, such as luggage or sporting equipment. Roof racks including cross bars may extend between the roof rails. The cross bars are typically clamped to the roof rails. 
     SUMMARY 
     A motor vehicle assembly according to an exemplary aspect of the present disclosure includes, among other things, a roof rail including a closed cross-sectional area and an open cross-sectional area separated by a divider wall. 
     In a further non-limiting embodiment of the foregoing assembly, the divider wall is positioned to correspond to an expected clamping load path of a cross bar. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the divider wall is substantially aligned with the expected clamping load path of the cross bar. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the divider wall is slightly beneath the expected clamping load path of the cross bar. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the roof rail includes a substantially constant exterior shape along substantially an entire length of the roof rail. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the roof rail includes a first side wall having a first end and a second end, a second side wall having a first end and a second end, and a cap wall extending between the second end of the first side wall and the second end of the second side wall. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the assembly includes an elastomeric seal overmolded with the roof rail and projecting outwardly from the roof rail. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the seal is attached to and projects from the first end of the first wall and the first end of the second wall. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the divider wall extends between the first side wall and the second side wall, the divider wall projects from the first side wall at a first location between the first end and the second end of the first side wall, and the divider wall projects from the second side wall at a second location between the first end and the second end of the second side wall. 
     In a further non-limiting embodiment of any of the foregoing assemblies, an exterior dimension of the roof rail is reduced adjacent the first location and the second location. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the first side wall includes a first section projecting toward the second side wall at the first location and the second side wall includes a second section projecting toward the first side wall at the second location. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the assembly includes a mounting bracket partially overmolded with the roof rail. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the mounting bracket includes a first plate and a second plate, the first plate is overmolded with the divider wall, and the second plate includes a base attached to the first plate and two feet projecting from the base. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the feet are attached to fasteners configured to fasten the attachment bracket to a roof panel. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the roof rail is made of a polymer material. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the divider wall includes at least one port permitting water to flow into the closed cross-sectional area during manufacturing. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the roof rail is a first roof rail, and the assembly further includes a second roof rail and a cross-bar clamped to the first and second roof rails. 
     A method according to an exemplary aspect of the present disclosure includes, among other things, using an injection molding process to form a roof rail. The roof rail includes closed cross-sectional area and an open cross-sectional area separated by a divider wall. 
     In a further non-limiting embodiment of the foregoing method, the closed cross-sectional area is formed using a water-assisted injection molding process. 
     In a further non-limiting embodiment of any of the foregoing methods, the method includes overmolding a seal with the roof rail and overmolding an mounting bracket with the roof rail. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an example motor vehicle including roof rails. 
         FIG. 2  is a perspective view of an example roof rail and two cross bars. 
         FIG. 3  is a cross-sectional view of the roof rail taken along line  3 - 3  from  FIG. 2 . 
         FIG. 4A  is a cross-sectional view of the roof rail similar to  FIG. 3 , and illustrates the roof rail relative to an example mounting bracket adjacent a portion of the roof of the vehicle. 
         FIG. 4B  is a cross-sectional view taken along line  4 B- 4 B from  FIG. 4A  and illustrates the mounting bracket in more detail. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure relates to a roof rail for a motor vehicle. In particular, the roof rail includes a divider wall configured to resist a clamping force, such as that which is expected to be applied to the roof rail from a cross bar of a roof rack. An example assembly includes a roof rail with a closed cross-sectional area and an open cross-sectional area separated by a divider wall. The roof rail is manufactured in a manner that reduces material waste, especially relative to extruded metal roof rails, and in a manner that does not compromise the ability of the roof rail to resist clamping loads. These and other benefits will be appreciated from the following description. 
     Referring to the drawings,  FIG. 1  is a front-perspective view of a motor vehicle  10  (“vehicle  10 ”). While an SUV is pictured in  FIG. 1 , this disclosure is also applicable to other types of vehicles. The vehicle  10  includes first and second roof rails  12 ,  14  extending along opposite sides of a roof  16  of the vehicle  10 . 
       FIG. 2  illustrates the first roof rail  12  and portions of first and second cross bars  18 ,  20 . The first and second cross bars  18 ,  20  clamp to the first roof rail  12  and the second roof rail  14 . The first and second cross bars  18 ,  20  are part of a roof rack, in this example. The first roof rail  12  will now be described in detail. It should be understood that the second roof rail  14  is configured substantially similarly to the first roof rail  12 . In one example, the second roof rail  14  is essentially a mirror image of the first roof rail  12 , reflected about the centerline of the vehicle  10 . 
     The first roof rail  12  includes a substantially constant outer profile along substantially its entire length. Specifically, the first roof rail  12  exhibits a length L between a first end  22  and a second end  24 . With the exception of locations adjacent the ends  22 ,  24 , the first roof rail  12  exhibits a constant outer profile. In this way, the cross bars  18 ,  20  may be clamped at most if not all locations along the length of the first roof rail  12 . In a particular example, the cross bars  18 ,  20  are infinitely adjustable relative to the first and second roof rail  12 ,  14 . 
       FIG. 3  illustrates the first roof rail  12  in cross-section. In  FIG. 3 , the first roof rail  12  includes a closed cross-sectional area  26  and an open cross-sectional area  28  separated by a divider wall  30 . The closed cross-sectional area  26  is vertically above (the “upward” and “downward” directions are labeled in  FIG. 3  for reference) the open cross-sectional area  28 , in this example. 
     The divider wall  30  extends generally in a horizontal direction (i.e., in a direction generally parallel to the “inside” and “outside” directions, which refer to directions relative to a centerline of the vehicle  10 ) between outer walls of the first roof rail  12 . The divider wall  30  is configured to resist a clamping load applied by clamps of the cross bars  18 ,  20 . An example expected clamping load path C is represented in  FIG. 3  by two arrows. The divider wall  30  is positioned to correspond to the expected clamping load path C. In the example of  FIG. 3 , the divider wall  30  is slightly beneath the expected clamping load path C. In other examples, the divider wall  30  is substantially aligned with the expected clamping load path C. In one example, the divider wall  30  is present along the entire length L of the first roof rail  12  and is configured to resist clamping loads at any point along the length L. 
     In this example, the first roof rail  12  includes a first, outer side wall  32  extending vertically between a first, lower end  34  and a second, upper end  36 . Opposite the first side wall  32 , the first roof rail  12  also includes a second, inner side wall  38  extending between a first, lower end  40  and a second, upper end  42 . A cap wall  44  extends between the second end  36  of the first side wall  32  and the second end  42  of the second side wall  38 . The cap wall  44  is spaced-apart from and extends in a direction substantially parallel to the divider wall  30 . Further, the first ends  34 ,  40  are spaced-apart from one another in the horizontal direction. 
     The closed cross-sectional area  26  is bound on all sides. In this example, the closed cross-sectional area  26  is bound by an upper surface of the divider wall  30 , an upper portion of the first side wall  32 , an upper portion of the second side wall  38 , and the cap wall  44 . The open cross-sectional area  28  is bound on three sides by a lower surface of the divider wall  30 , a lower portion of the first side wall  32 , and a lower portion of the second side wall  38 . In this example, the open cross-sectional area  28  is open facing the downward direction, namely toward a portion of the roof  16 . 
     In the example of  FIG. 3 , the divider wall  30  extends between the first side wall  32  and the second side wall  38 . The divider wall  30  projects from the first side wall  32  at a first location  46  vertically between the first end  34  and the second end  36  of the first side wall  32 . Likewise, the divider wall  30  projects from the second side wall  38  at a second location  48  vertically between the first end  40  and the second end  42  of the second side wall  38 . 
     The first and second locations  46 ,  48  correspond to the expected clamping load path C, and in this example a dimension of the first roof rail  12  is reduced adjacent the first location  46  and the second location  48 . Namely, the first side wall  32  includes a first longitudinal groove  50  and the second side wall  38  includes a second longitudinal groove  52 , each of which extend along substantially the entire length L. The first longitudinal groove  50  is a section recessed in the “inside” direction and toward the second side wall  38  relative to adjacent surfaces of the first side wall  32 . The second longitudinal groove  52  is a section recessed in the “outside” direction and toward the first side wall  32  relative to adjacent surfaces of the second side wall  38 . The first and second locations  46 ,  48  are vertically aligned with the first and second longitudinal grooves  50 ,  52 . In this example, the first and second locations  46 ,  48  are slightly vertically offset from one another such that the divider wall  30  exhibits a slight incline relative to a horizontal plane (normal to the direction of gravity). The divider wall  30  could lie in a horizontal plane in other examples. 
     The first roof rail  12  is integrally formed as a single, one-piece component in one example. In another example, the first roof rail  12  is overmolded with other structures, in which case the first roof rail  12  is still a single, integrated component. Overmolding is the process of adding material, such as the material forming the first roof rail  12 , over already-existing pieces or parts using a molding process. For instance, the first roof rail  12  in this example is overmolded with an elastomeric seal  54  ( FIG. 2 ). The elastomeric seal  54  encircles the entire first roof rail  12  in this example. The elastomeric seal  54  increases the aesthetic appearance of the first roof rail  12  by providing a smooth transition between the first roof rail  12  and the roof  16 . The elastomeric seal  54  is attached to and projects outward from the first ends  34 ,  40 . Namely, the elastomeric seal projects in the “outside” direction from the first end  34  and in the “inside” direction from the first end  40 . The elastomeric seal  54  could be formed with the first rail  12  using a two shot molding process. In an example first step of such a process, at least a majority of the first roof rail  12  is molded of a first polymer or composite material. In a second step, the elastomeric seal material is molded over material injected during the first step. 
     Another example structure which may be overmolded with the first roof rail  12  is a mounting bracket. An example mounting bracket  56  is somewhat schematically illustrated in  FIGS. 4A and 4B . While only one mounting bracket is shown, additional mounting brackets may be used to attach the first roof rail  12  to the roof  16 . 
     The mounting bracket  56  is partially overmolded with the first roof rail  12 . Specifically, a portion of the mounting bracket  56  is overmolded with the divider wall  30  and another portion of the mounting bracket  56  projects from the divider wall  30  downward into the open cross-sectional area  28 . The mounting bracket  56  and the first roof rail  12  are configured to fit within a channel  58  between inner and outer panels  60 ,  62  of the roof  16 , in this example. The open cross-sectional area  28  facilitates attachment of fasteners between the mounting bracket  56  and the inner and outer panels  60 ,  62 . 
     The mounting bracket  56  in this example includes a first plate  64  and a second plate  66 , both of which may be metallic. The first plate  64  is an upper plate, in this example, and is overmolded with the divider wall  30 . The second plate  66  includes a base  68  attached to the first plate  64  by welding, for example, and two feet  70 ,  72  projecting from the base  68 . Welds are represented by the circled “X” marks in  FIG. 4B . The feet  70 ,  72  are attached to fasteners  74 ,  76 , which in this example are weld nuts welded to the feet  70 ,  72  and configured to receive a fastener, such as a bolt, which also engages the inner and outer panels  60 ,  62 . The fasteners  74 ,  76  may directly contact the respective feet  70 ,  72 . The feet  70 ,  72  are spaced-apart from the base  68  in the downward direction by respective inclined walls, in this example. The feet  70 ,  72  lie in a plane substantially parallel to the base  68  in this example. 
     The first roof rail  12  is made of a polymer material or a composite material. The first roof rail  12  may be made by injection molding in one example. Specifically, the closed cross-sectional area  26  may be made using a water-assisted injection molding process. In such a process, water is used to push polymer material, for example, to the outer perimeter of a mold cavity to form a hollow cross-section. To this end, the ends of the first roof rail  12  or the divider wall  30  may include at least one port permitting water to flow into and out of the closed cross-sectional area  26  during manufacturing. While the divider wall  30  may include a port, the closed cross-sectional area  26  is still fully closed at the vast majority of cross-sections taken along the length L. 
     Directional terms such as “upward,” “above,” “downward,” “under,” “below,” “side,” “inside,” “outside,” “horizontal,” etc., are used herein with reference to the normal operational attitude of a motor vehicle. It should be understood that terms such as “slightly,” “generally,” “substantially,” and “about” are not intended to be boundaryless terms, and should be interpreted consistent with the way one skilled in the art would interpret those terms. 
     Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. In addition, the various figures accompanying this disclosure are not necessarily to scale, and some features may be exaggerated or minimized to show certain details of a particular component or arrangement. 
     One of ordinary skill in this art would understand that the above-described embodiments are exemplary and non-limiting. That is, modifications of this disclosure would come within the scope of the claims. Accordingly, the following claims should be studied to determine their true scope and content.