Abstract:
A roof ditch molding having a Class A finish seamlessly including the end caps thereof. An extruded central molding member includes a beam and a head, wherein the end sections have the beam removed and the head is contoured and provided with a notch. The end sections are then placed into a plastic injection molding machine whereat the head is folded at the notch a shot of plastic deposited adjacent the notch for retention of the fold angle and stiffening of the now formed end caps. A pair of nibs provide engagement with spring clips at the ends of the roof ditch.

Description:
TECHNICAL FIELD 
     The present invention relates to roof ditch molding used to cover the roof ditch of motor vehicles, and more particularly to an end formed roof ditch molding in which the Class A finish of the roof ditch molding is continuous, inclusive of the two end caps thereof. 
     BACKGROUND OF THE INVENTION 
     In the automotive arts, it is a well known practice to attach the roof panel to each of the left and right body side panels via a respective roof ditch. In this regard, a sealant or sealer tape is used to seal the overlapping metal edges of the roof and respective body side panels, wherein the roof ditch is thereupon covered by a cosmetic roof ditch molding. See, for example, U.S. Pat. Nos. 7,004,535 and 6,030,701. 
     A roof ditch and associated roof ditch molding of interest is utilized by General Motors Corporation of Detroit, Mich. with respect to its 2006 Chevrolet Impala, of which various aspects are exemplified at  FIGS. 1 through 5 . 
     As shown at  FIG. 1 , a roof ditch  10  runs longitudinally along each of the left and right joinders of the roof panel  12  with the left and right body side panels  14 ,  16 . As best seen at  FIGS. 2 and 3 , the roof ditch  10  is configured as a slot, having at its floor the overlap of a roof edge  12   a  with a respective body panel edge (left body side panel edge  14   a  being shown by way of example in  FIGS. 2 and 3 ). A sealer tape  18  is located at the floor to seal the overlap of the edges. A roof ditch molding  20  is placed into each roof ditch above the sealer tape  18  to provide a cosmetic match between the roof panel and the left and right body side panels. 
     The roof ditch moldings  20  are each composed of a plastic extruded central molding member  20   a  and a pair of separately plastic injection molded end caps  20   b ,  20   c  (see  FIG. 1 , as well as  FIG. 4 , whereat only end cap  20   b  is shown). The central molding member  20   a  has a T-shaped cross-section defined by a head  22  and a beam  24 , having preferably a metal insert  25  for stiffening. The visible portion of the head  22   a  has a Class A finish which cosmetically matches the finish of the roof panel  12  and right and left body side panels  15 ,  16 . At the lower extremity of the beam  24  is a pair of wings  26  which are periodically present along the length of the beam to provide securement by flexed conformance to the roof ditch at locations P 1  and P 2  (see  FIG. 2 ). In order to prevent end peeling of the roof ditch molding from the roof ditch, each end portion of the beam is modified to remove the wings and provide thereat a plunger  28  which interferingly couples to a spring bracket  30  which is, itself, anchored in the roof ditch at the sealer tape  18  (see  FIG. 3 ). 
       FIG. 5  is a block diagram  50  indicating the steps of manufacture of the prior art roof ditch molding  10 . 
     At execution Block  52 , the central molding member  20  is extruded, inclusive of the head  22 , the beam  24  and the wings  26 , wherein the wings may be composed of a more flexible material than the central molding member. 
     At execution Block  54 , the wings are routered away at the end portions of both ends of the beam (see  24   a  in  FIG. 4 ) and at selected periodic locations along the beam so that discrete sections of wings are present between the end portions. 
     At execution Block  56 , a surface prep  32  (see  FIG. 3 ) is applied to the beam  24  at the end portions, the end portions are then placed in an injection molding machine, and the plungers  28  are then formed as a plastic injection mold onto the beam. 
     Finally, at execution Block  58  each end cap  20   d  is separately injection molded onto the respective ends of the central molding member by placement of a section of each end portion of the central molding member into an injection molding machine (the result is shown best at  FIG. 4 ). 
     While the roof ditch molding  20  serves its purpose quite well, there is difficulty encountered with respect to providing a seamless look to the Class A finish  22   a  of the head  22  and the Class A finish  20   d  of the end caps  20   a ,  20   b , particularly in view of the line of interfacial demarcation  34  as between the extruded central molding member and the injection molded end caps. Further, while the injection molding of the plungers creates heat to the Class B side, this heat can cause untoward deformation of the Class A side of the head. 
     Accordingly, what remains needed in the art is some way to make a Class A finish seamlessly extending between the central molding member and the end caps of a roof ditch molding. 
     SUMMARY OF THE INVENTION 
     The present invention is a roof ditch molding having a Class A finish extending between the central molding member and the end caps thereof, effected by the end caps being integrally formed of the head of the central molding member. 
     The end formed roof ditch molding according to the present invention includes a plastic extruded central molding member inclusive of a beam, a head and wings at the lowermost extremity of the beam, wherein end portions of the beam have the wings removed and an end section of each end portion has the beam removed, and wherein at each end section the head is contoured to assume an end cap shape and is provided with a notch. Each end portion is then placed into a plastic injection molding machine whereat the end section thereof is folded at the notch and a shot of plastic deposited adjacent the notch as a brace for retention of the fold angle and stiffening of its now fully formed end cap. Only one end section may have the integral, end formed end cap in situations in which the roof ditch molding requires an end cap at only one end thereof. 
     It is an additional aspect of the present invention that the beam be extruded to include a pair of nibs (one on either side of the beam) disposed between the head and the wings. A metal insert may be provided in the head or beam during the extrusion process. In this regard, the periodic removal of the wings at the end portions of the beam provides for the nibs to interferingly engage the spring brackets of the roof ditch. 
     In operation of the end formed roof ditch molding according to the present invention, because the end caps are integrally formed of the head of the central molding member, the Class A finish is seamlessly continuous from end cap to end cap, and the cosmetic appearance of the end formed roof ditch molding is flawless. 
     Accordingly, it is an object of the present invention to provide an end formed roof ditch molding in which the end caps are integrally formed of the head of the central molding member thereof, whereby the Class A finish is continuous from end cap to end cap so that the cosmetic appearance of the end formed roof ditch molding is flawless. 
     This and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view of a moor vehicle with roof ditches and prior art roof ditch moldings therefor. 
         FIG. 2  is a sectional view taken along line  2 - 2  of  FIG. 1 . 
         FIG. 3  is a sectional view taken along line  3 - 3  of  FIG. 1 . 
         FIG. 4  is a truncated, perspective view of a portion of the prior art roof ditch molding of  FIG. 1 . 
         FIG. 5  is a block diagram of the steps of manufacture of the prior art roof ditch molding of  FIG. 1 . 
         FIG. 6  is a top plan view of a moor vehicle with roof ditches and end formed roof ditch moldings therefor according to the present invention. 
         FIG. 7  is a sectional view taken along line  7 - 7  of  FIG. 6 . 
         FIG. 8  is a sectional view taken along line  8 - 8  of  FIG. 7 . 
         FIG. 9  is a truncated, bottom perspective view of a end formed roof ditch molding according to the present invention, shown at an intermediate state of manufacture. 
         FIG. 10  is a truncated, side perspective view of a final manufactured end formed roof ditch molding of  FIG. 6 . 
         FIG. 11  is a sectional view seen along line  11 - 11  of  FIG. 10 . 
         FIG. 12  is a block diagram of the steps of manufacture of the end formed roof ditch molding of  FIG. 6 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the Drawing,  FIGS. 6 through 11  depict various views of, and  FIG. 12  depicts the manufacturing steps for, an end formed roof ditch molding  100  according to the present invention. 
     Referring firstly to  FIG. 6 , a roof ditch  102  runs longitudinally along each of the left and right joinders of the roof panel  104  with the left and right body side panels  106 ,  108 . The roof ditch  102  is configured generally in a conventional manner as discussed hereinabove with respect to  FIGS. 1 through 3 , being in the general form of a slot having its floor defined by the overlap of a respective roof panel edge  104   a  with a respective body panel edge (left body panel edge  106   a  being shown in  FIGS. 7 and 8  merely be way of example). A sealer tape  110  is conventionally located at the floor of the roof ditch  102  in order to provide a seal of the overlapped roof and side panel edges. 
     As shown best at  FIGS. 7 and 8 , the end formed roof ditch molding  100  according to the present invention is placed into each roof ditch  102  above the sealer tape  110  to provide a flawless cosmetic match between the roof panel and the left and right body side panels. The end formed roof ditch moldings  100  are each composed of a plastic extruded central molding member  112 , wherein it will be described hereinbelow how the end caps  114   a ,  114   b  are integrally formed thereof (see  FIG. 6 , as well as  FIG. 10  whereat only end cap  114   a  is shown). 
     The central molding member  112  has a T-shaped cross-section defined by a head  116  and a beam  118 . Preferably a metal insert  120  for stiffening is provided during the extrusion process. A pair of nibs  122   a ,  122   b , one nib disposed on each side of the beam  118 , are also provided during the extrusion process. At the lower extremity of the beam  118  is a pair of wings  124  also provided during the extrusion process, which may be formed of a material more flexible that that of the beam and the head. The wings  124  are periodically present along the length of the beam  118  to provide securement to the roof ditch by flexed conformance at locations P 1 ′ and P 2 ′ (see comparison between unflexed state of the wings at  FIG. 11  to the flexed state of the wings in the roof ditch at  FIG. 7 ). 
     The visible portion of the head has a Class A finish  116   a , and end caps  114   a ,  114   b  also have a Class A finish  114   c , wherein the Class A finish is flawlessly continuous with respect to the head and end caps. This feature is made possible because the end caps are integral with the head. The Class A finish of both the head and the end caps cosmetically matches the Class A finish  105  of both the roof and right and left body side panels. 
     In order to prevent end peeling of the end formed roof ditch molding  100  from the roof ditch  102 , each end section (see  126  at  FIG. 10 ) of the beam  118  is modified to remove the wings  124 , whereby the nibs  122   a ,  122   b  are then thereat the lowest extremity of the beam. The nibs  122   a ,  122   b  interferingly couple to a spring bracket  128  secured in the roof ditch at the sealer tape  110  (see  FIG. 8 ), obviating the above mentioned plunger and all its associated manufacturing steps 
       FIG. 12  is a block diagram  200  indicating the steps of manufacture of the end formed roof ditch molding  100 , wherein a mid-stage of the manufacture is shown at  FIG. 9 , and a finished stage of the manufacture is shown at  FIGS. 10 and 11 . 
     At execution Block  202 , the central molding member  112  is plastic extruded, inclusive of the head  116 , beam  118 , nibs  122   a ,  122   b , wings  124  and insert  120  (if present), wherein the wings may be composed of a more flexible material than the central molding member, and wherein as the extrusion proceeds, the wings are sliced off at the end portions of the beam, as for example by a blade positioned appropriately near the extrusion location of the plastic extrusion machine, whereby the removal of the wings results in the nibs becoming locally thereat at the lowest extremity of the beam. 
     At execution Block  204 , at the end section  130  of the head  116  (see  FIG. 9 ), the beam  118  is removed, an end cap contour C is provided, and a fold notch  132  provided, these three operations all being preferably provided by a grinding operation. The end result of execution Block  204  is shown at  FIG. 9   
     Finally, at execution Block  206  a selected part of the end portion  126  of the central molding member is placed into a plastic injection molding machine, wherein the end section  130  is bent at the fold notch  132  to the predetermined angle with respect to the head, and a shot of plastic is injected at the fold notch to provide a brace  134  which affixes the orientation of the completed respective end cap  114   a ,  114   b , (see  FIG. 6 , and in particular see the end cap  114   a  shown at  FIG. 10 ). 
     As can be understood from  FIG. 10 , since the head and the end caps are an integrally formed single piece, there is no interfacial demarcation therebetween, and that since the head and the end caps have continuously the same Class A finish, the cosmetic appearance of the end formed roof ditch molding  100  is flawless, being far superior to the prior art roof ditch molding which has an interfacial demarcation and differing manufactures of the head and the end caps. 
     It is to be understood that the inclusion of the pair of nibs with the central molding member provides an “I-beam” cross-section thereof (i.e., of the head, the beam and the pair of nibs) which improves the bending strength of the roof ditch molding according to the present invention as compared to the prior art roof ditch molding having an absence of nibs. This improved bending strength improves the final appearance and is based upon a right balance of the nib dimensions and the wing geometry with respect to the rest of the part, as shown at  FIG. 11 . Further, since there is no injection molding step to add a plunger, as is required in the prior art, there is an improved surface appearance to the Class A side of the head whereat the Class A finish is located. 
     It is to be further understood that while it is most preferred to include both the nibs and at least one integral, end formed end cap in the most preferred embodiment of the present invention, other embodiments of the present invention can be derived therefrom, namely: 1) the extrusion process of the head and beam can include the nibs whether or not the end caps are formed integrally with the head, and 2) the end caps can be made integrally with the head whether or not the nibs are part of the extrusion of the head and beam. 
     To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.