Abstract:
Vehicle lamp housing assembly that uses a multiple-piece adhesive track to secure the components together. The assembly and seal can be formed in a single operation. The invention eliminates conventional fastening means such as welding, snaps, screws and nuts, as well as extra operations that would otherwise increase the cost of the finished product. In a preferred embodiment, the same adhesive that is used to seal the lens to the housing is also used for assembly of the components.

Description:
TECHNICAL FIELD 
     The invention relates to lamp housings and particularly to automotive lamp housings. More particularly the invention is concerned with the structure of an automotive lamp housing assembly. 
     BACKGROUND OF THE INVENTION 
     Vehicle headlamps and other lamp housing assemblies include a light source, one or more lenses, a lamp housing or housing, and an applique. Appliques are decorative articles secured to a vehicle usually for aesthetic purposes. One common application of appliques is in the back-up and rear fog lamp assemblies. Such assemblies are generally mounted to the vehicle using screws, by welding or by snapping the various parts together in place. However, state and federal regulations for vehicle optical packages require that the lamp meet certain minimum lighting criteria, which indirectly requires a minimum reflector area. The reflector size can conflict with styling objectives and sheet metal manufacturing limitations. In addition, if located on a vehicle lift gate, there is minimal front to back space for the lamp housing, resulting in very tight space limitations. Providing a housing to lens coupling takes a first amount of space. Providing a lens to applique coupling takes a second amount of space. Hiding the seams internally for a cosmetic exterior surface takes a third amount of space. The cumulative competition for space in such tight quarters makes simple designs difficult. 
     The apparent alternative of more complex designs, leads to multiple components and a plurality of assemble steps. For example, parts may be screwed, or bolted to avoid multiple glue tracks. This leads in turn to increased component and assembly costs. Accordingly, minimization of the number of screws and nuts, or complete elimination of screws and nuts necessary in the construction of such optical packages, would be desirable, and so also would be the elimination of multiple glue tracks. It also would be desirable to design a housing assembly that requires less space, is less costly, and is easy to produce and install. 
     SUMMARY OF THE INVENTION 
     The problems of the prior art have been overcome by the present invention, which provides a vehicle lamp housing that uses a multiple-piece adhesive track to secure the components together. The assembly and seal can be formed in a single operation. The invention eliminates conventional fastening means such as welding, snaps, screws and nuts, as well as extra operations that would otherwise increase the cost of the finished product. In a preferred embodiment, the same adhesive that is used to seal the lens to the housing is also used for assembly of the components. 
     More specifically, the present invention uses a bonding agent to bond an applique, a lens, and a housing together. The applique and lens are designed such that when properly positioned with respect to each other, a groove is formed between them into which the housing is inserted. The bonding agent is applied to the groove to secure the pieces together. The system allows for a face down sequential construction from the backside without causing unsightly bonding agent to seep out the front face of the assembly. Only a single glue track is needed, and only a single gluing pass is necessary during construction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a rear view of the left side of an applique assembly supporting a preferred embodiment of a lamp housing assembly; 
     FIG. 2 is a sectional view, taken along line H—H of FIG. 1 including additional portions of the lift gate structure; 
     FIG. 3 is a sectional view, taken along line M—M of FIG. 1 including additional portions of the lift gate structure; 
     FIG. 4 is a schematic top view showing preferred embodiment of a glue track assembly; 
     FIG. 5 is a schematic top view showing a first alternative embodiment of a glue track assembly; 
     FIG. 6 is a schematic top view showing a second alternative embodiment of a glue track assembly; 
     FIG. 7 is a schematic top view showing a third alternative embodiment of a glue track assembly; 
     FIG. 8 is a schematic top view showing a fourth alternative embodiment of a glue track assembly; and 
     FIG. 9 is a schematic top view showing a fifth alternative embodiment of a glue track assembly. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning now to FIGS. 1,  2  and  3 , there is shown a left side of an applique assembly designed to be used as an insert in a rear lift gate of a vehicle. The appilque assembly supports a preferred embodiment of a lamp housing assembly generally at  10 . The assembly includes portions of the applique  12  having an opening for an outer lens  13 , preferably made of polycarbonate. The applique  12  is preferably made of polycarbonate if it is to be painted, or of acrylonitrile stryene for molded in color appliques. One or more lamp housings  14  (polycarbonate or Apec) are positioned behind the lens  13  as shown in FIGS. 2 and 3. In the embodiment depicted, the assembly houses two lamps, although those skilled in the art will appreciate that one lamp could be used or more than two lamps could be used depending upon the application. In one particular embodiment, lamp  19 A is a rear fog lamp, and lamp  19 B is a back-up lamp (FIG.  2 ). An inner red lens  16  (polycarbonate) is shown for the fog lamp  19 A, positioned so as to define a gap between it and the outer lens  13 . The outer lens  13  extends the entire opening in the applique  12 , thereby providing a lens for both lamp  19 A and  19 B. 
     FIG. 3 shows a top cross-sectional view, where the lamp housing  14  encloses lamp  19 A, which sits behind lens  13 . 
     FIGS. 4 and 5 show details of a glue track of the present invention. The preferred applique includes a defined opening, an interior surface of which is mated to an exterior surface of a lens. Applique  12  has a forward flange portion  31  and a vertically or upstanding depending wall  32 . A similar flange portion  31 ′ is spaced from section  31 , the spacing accommodating outer lens  13 . Spaced flange portion  31 ′ also includes a vertically or upstanding depending wall  32 ′. The length of seat  33  of flange portion  31  is defined by the upstanding wall  32 , and provides a base for the edge  34  of lens  13  to sit on. A similar arrangement is provided with flange portion  31 ′. Thus, the space between upstanding walls  32  and  32 ′ defines the length of the outer lens  13  that seats between them. 
     Spaced inwardly from each edge  34 ,  34 ′ of the lens  13  are respective upwardly depending walls  35 ,  35 ′. When the edges  34 ,  34 ′ are seated on seats  33 ,  33 ′, respectively, the upwardly depending wall  35  and upwardly depending wall  32  form between them a groove. Similarly, the upwardly depending wall  35 ′ and upwardly depending wall  32 ′ form between them a groove (which may be the same groove as between  32  and  35 ). The groove or grooves are dimensioned to accommodate the respective edges  36 ,  36 ′ (which may be a single edge) of the lamp housing  14  as shown. Preferably the edges  36 ,  36 ′ are straight walls, although the housing can be stepped into cutouts of the lens  13  to allow for improved retention to the applique  30 . 
     A bonding material  37  placed in the groove contacts and secures the housing  14 , the applique  12  and the lens  13  into a three-piece assembly. Suitable bonding materials include epoxies, preferably two-part epoxies such as two-part urethanes, and glues. After curing, the bond is strong enough that the assembly has to be destroyed to be taken apart. As a result, the lamp housing, lens and applique are secured without the use of screws, nuts or snaps, and with little lateral dimension devoted to the joint. 
     In a preferred embodiment, the edge  34 ,  34 ′ is offset from (i.e., not linear with) the front face of the lens  13 . This allows the lens front face  50  to be flush or substantially flush with the front face  52  of the applique. 
     It is not necessary that the defined groove extends all the way around the opening; separate segments could be used so long as there are a sufficient number of sections to provide the overall strength necessary to hold the pieces of the assembly together in use. 
     Unlike FIG. 4 wherein the edges  34 ,  34 ′ of the lens  13  extend almost to the respective upstanding walls  32 ,  32 ′ of the applique, and the housing  14  is bonded in the formed groove above the edges  34 ,  34 ′, FIG. 5 illustrates an embodiment where the edges  34 ,  34 ′ of the lens  54  are much shorter and thus do not extend to the upstanding walls  32 ,  32 ′ of the applique  12 . As a result, the edges  56 ,  58  (which may be the same edge) of the housing  14  extend further down into the groove toward the seat  33  of the flange portion  31  as shown. 
     FIG. 6 is another embodiment where the edges  34 ,  34 ′ of the lens extend all the way to the respective upstanding walls  32 ,  32 ′ to form sharp visual edges  40 ,  40 ′. Thus, the lens  13  and the applique  12  interlock in a stepped fashion to form the groove. 
     FIG. 7 is similar to FIG. 6, except that the flange portions  31 ,  31 ′ of the applique  12  rests on the respective edges  34 ,  34 ′ of the lens rather than vice versa. 
     FIG. 8 is a further embodiment, where the applique  12  and lens  13  do not interlock. Each groove is instead formed by two spaced downwardly depending walls  41 ,  42  of the housing  14 . Upwardly extending walls  43 ,  43 ′ of applique  12 , and upwardly extending walls  44 ,  44 ′ of lens  13 , fit into each groove and are secured with bonding agent  37  as before. 
     FIG. 9 is an embodiment that combines various features from some of the previous embodiments. Downwardly depending walls  41  is slightly shorter than spaced downwardly depending wall  42  to accommodate the thickness of portion  34  of lens  13 . As in the embodiment of FIG. 6, portion  34  of lens  13  interlocks against upstanding wall  32  of the applique  12  (intimate contact between the edge of portion  34  and the wall  32  is not necessary). The housing  14  can have a third downwardly depending wall  45 , preferably centrally located with respect to walls  41  and  42 , to help position the components in proper alignment. 
     Those skilled in the art will appreciate that the glue track of the present invention is not limited to application in the license pocket area of the vehicle. For example, the fascia of the vehicle could act as the portion of the glue track that performs the same as the license pocket in the above description, thereby allowing the conventional mounting to be eliminated or reduced to supporting the lamp in the fascia.