Abstract:
A sunroof panel structure for substantially closing a sunroof aperture in a vehicle. The sunroof panel structure includes a sunroof panel member having a plurality of edges and a weatherstrip mounting flange. The weatherstrip mounting flange and the sunroof panel member are unitarily formed such that the weatherstrip mounting flange is coupled to at least one of the plurality of edges. The weatherstrip mounting flange is configured to receive a weatherstrip seal member without the use of adhesives or other bonding agents or mechanisms. A method for forming a sunroof assembly for an automotive vehicle is also provided.

Description:
TECHNICAL FIELD 
     The present invention relates generally to sunroof assemblies for motor vehicles and more particularly to a vehicle sunroof structure having an integral weatherstrip mounting flange. 
     BACKGROUND OF THE INVENTION 
     Background Art 
     Numerous sunroof assemblies have been developed that employ a weatherstrip holder to retain a resilient weatherstrip to the perimeter of a sunroof panel. The devices shown in FIGS. 1A and 1B are illustrative of the known arrangements in that they include a weatherstrip holder  2  which is bonded to the sunroof panel  4 . The weatherstrip holder  2  typically includes a lip  6  which is spaced apart from the sunroof panel  4  and which terminates at a barb  8 . The lip  6  and the barb  8  are configured to securely engage an attachment groove  10  formed in a weatherstrip  12  to thereby permit the weatherstrip  12  to be fixedly coupled to the sunroof panel  4 . 
     While such arrangements permit the generation of an effective seal around the perimeter of the sunroof panel, several drawbacks have been noted with these arrangements. One of the significant drawbacks concerns the cost of these arrangements. The tooling and labor associated with the fabricating and bonding of the weatherstrip holder to the sunroof panel often represents a significant portion of the overall cost of a sunroof assembly. 
     Another drawback concerns the fact that the use of a separate weatherstrip holder creates an additional joint (i.e., the joint between the weatherstrip holder and the sunroof panel) which, if the bond between the sunroof panel and the weatherstrip holder fails, presents a path through which water and noise could infiltrate the vehicle passenger compartment. While failures of the bond between the weatherstrip holder and the sunroof panel are relatively rare, they are extremely difficult to detect due to the fact that the integrity of such joints is usually established through a destructive test wherein the bonded weatherstrip holder is physically removed from the sunroof panel. 
     Accordingly, there remains a need in the art for a sunroof assembly having a sunroof panel structure with an integrally formed weatherstrip mounting flange which permits the overall cost of the sunroof assembly to be reduced and which improves the integrity of the seal between the sunroof panel structure and a vehicle body. 
     SUMMARY OF THE INVENTION 
     It is one object of the present invention to provide a sunroof panel structure having an integrally formed weatherstrip mounting flange. 
     It is another object of the present invention to provide a method for forming a sunroof panel structure having an integrally formed weatherstrip mounting flange. 
     In one preferred form, the present invention provides a sunroof panel structure for substantially closing a sunroof aperture in a vehicle. The sunroof panel structure includes a sunroof panel member having a plurality of edges or sides and a weatherstrip mounting flange. The weatherstrip mounting flange and the sunroof panel member are unitarily formed such that the weatherstrip mounting flange is coupled to or forms at least one of the plurality of edges. The weatherstrip mounting flange is configured to receive a weatherstrip seal a member without the use of adhesives or other bonding agents or mechanisms. A method for forming a sunroof assembly for an automotive vehicle is also provided. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings, wherein: 
     FIGS. 1A and 1B are cross-sectional views of a sunroof assembly constructed in accordance with the teachings of the prior art; 
     FIG. 2 is a perspective view of a vehicle sunroof assembly constructed in accordance with the teachings of the present invention and illustrated to be operatively associated with a motor vehicle; 
     FIG. 3 is a cross-sectional view taken along the line  3 — 3 ; 
     FIG. 4 is a cross-sectional view of a portion of a mold tool for forming the sunroof panel structure; and 
     FIG. 5 is a cross-sectional view similar to that of FIG. 3 but illustrating an alternate embodiment of the weather strip mounting flange. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIG. 2 of the drawings, a vehicle sunroof assembly constructed in accordance with a preferred embodiment of the present invention is generally indicated by reference numeral  20 . Sunroof assembly  20  is illustrated in operative association with an automotive vehicle  22  having a vehicle body  24  that defines a sunroof aperture  26 . With additional reference to FIG. 3, sunroof assembly  20  includes a sunroof panel structure  30  and a weatherstrip seal member  32  which are coupled to vehicle body  24  and slidable between a first position wherein sunroof assembly  20  substantially closes sunroof aperture  26  and a second position wherein sunroof assembly substantially clears sunroof aperture  26 . 
     Sunroof panel structure  30  includes a generally flat sunroof panel member  40  and a weatherstrip mounting flange  42 . Sunroof panel member  40  and weatherstrip mounting flange  42  are unitarily formed so as to eliminate the need for a bonded joint formed therebetween which would be susceptible to leakage if the bonded joint were to fail. Sunroof panel member  40  is configured to conform to the roof profile of vehicle  22  when sunroof assembly  20  is positioned in the first position. Sunroof panel member  40  includes a plurality of edges or sides  44  to which weatherstrip mounting flange  42  is fixedly coupled or formed. 
     In the particular embodiment illustrated, weatherstrip mounting flange  42  includes first and second spaced apart furcations  50  and  52 , respectively, and a gusset  54 . First and second furcations  50  and  52  are arranged generally parallel to a longitudinal axis  56  of sunroof panel member  40 . First furcation  50  extends laterally from edge  44  and has a thickness which is approximately the same as that of sunroof panel member  40 . Second furcation  52  is spaced vertically downwardly from first furcation  50  and extends outwardly from edge  44  parallel to first furcation  50 . Second furcation  52  terminates at its distal end at a barb structure  58  having a tapered nose  60 . The proximal end of barb structure  58  is formed generally perpendicularly to the longitudinal axis  56  of sunroof panel member  40  to thereby create an engagement lip  62 . Gusset  54  couples second furcation  52  to sunroof panel member  40  to thereby strengthen and support weatherstrip mounting flange  42 . 
     Sunroof panel structure  40  is preferably formed in a mold from a clear or tinted plastic material. More preferably, the plastic material from which sunroof panel structure  40  is fabricated is a composite plastic  68  having a film member  70  and a plastic substrate  72 . Film member  70  is preferably formed from a material which provides sunroof panel structure  40  with a relatively high resistance to scratching and/or degradation from ultra-violet radiation. Plastic substrate  72  is preferably formed from a thermoplastic material. 
     In FIG. 4, a mold  90  having a first mold component  92   a  and a second mold component  92   b  is provided for forming sunroof panel structure  40 . Each of the first and second mold components  92   a  and  92   b  includes a mold cavity portion  94  which, when the mold components are clamped or pressed together collectively form a mold cavity  96  that defines the sunroof panel structure  30 . The film member  70  is applied to the surface of the mold cavity portion  94   a  of a first mold component  92   a  as this surface corresponds to the outer surface of sunroof panel structure  40 . Second mold component  92   b  is mated to the first mold component  92   a  and the plastic substrate  72  is injected into the mold cavity  96  while the plastic substrate  72  is in a molten state. The film member  70  and the plastic substrate  72  are bonded to one another during the molding process. Once removed from the mold cavity  96 , the sunroof panel structures  40  are placed in cooling jigs (not shown) so as to prevent them from distorting while they cool. Once sunroof panel structures  40  are sufficiently cooled, weatherstrip seal member  32  and other hardware (not shown) are assembled thereto. 
     Returning to FIG. 3, weatherstrip seal member  32  includes a pair of spaced apart wall members  100  which confront the opposite sides of second furcation  52 . In the particular embodiment illustrated, one of the wall members  100   a  is a coupling flange which is at least partially disposed within a groove  102  formed between the first and second furcations  50  and  52 . The other wall member  100   b  includes a flange member  104  for contacting the engagement lip  62  of the barb structure  58  to inhibit the barb structure  58  from being withdrawn from a barb aperture  106  defined by the pair of wall members  100 . 
     Weatherstrip seal member  32  is preferably formed from a resilient material and includes a seal bead portion  110  having an arcuate outer wall member  112  and a backing wall member  114 . Outer wall member  112  and backing wall member  114  cooperating to define a seal bead aperture  116  which permits seal bead portion  110  to readily compress to form a high quality seal against vehicle body  24 . 
     While the sunroof panel structure  40  has been described thus far as including first and second furcations  50  and  52  which are oriented parallel to the longitudinal axis of the sunroof panel member  40 , those skilled in the art will appreciate that the invention, in its broader aspects, may be constructed somewhat differently. For example, the first and second furcations  50 ′ and  52 ′ may be oriented perpendicular to the longitudinal axis  56 ′ of the sunroof panel member  40 ′ as shown in FIG.  5 . Configuration of weatherstrip mounting flange  42 ′ in this manner is advantageous in that the tooling for fabricating sunroof panel structure  30 ′ is simpler in its configuration and less expensive. Those skilled in the art will understand that all other features of sunroof panel structure  40 ′ are substantially identical to the features of sunroof panel  40  shown in FIG.  3 . 
     Accordingly, while the invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the foregoing description and the appended claims.