This application claims priority from U.S. provisional application Ser. No. 60/934,359, filed 13 Jun. 2007, the disclosure of which is expressly incorporated herein by reference.
This disclosure relates to automotive vehicles, and more particularly to weatherstrips used in such vehicles. In addition to functional aspects of the weatherstrip, it is recognized that the aesthetics are also extremely important. Over the years, natural rubber, EPDM, and more recently thermoplastics have been used to form the weatherstrip body—generally referred to as an elastomeric material. It is also common to extrude the body from one of these materials because of the ease and reduced costs associated with this form of manufacture.
One desired show surface provides a cosmetic or bright strip, such as a stainless steel or anodized metal that is joined to the elastomer. Heretofore, such assemblies are a multi-part assembly in which a rigid core is coextruded with the rubber, EPDM, or plastic, and a separately formed metal show surface is then manually assembled to the weatherstrip after the weatherstrip is removed from the extrusion line. Typically, the metal show surface has bent or hooked edges, to define a flattened, generally C-shaped cross-section, in which the hooked edges mechanically grip the previously cured weatherstrip. This show surface or cap is mechanically clinched so that the cap is mechanically engaged with the remainder of the weatherstrip. Likewise, in some instances, the cap is also adhesively bonded to the cured weatherstrip with the application of a separate adhesive.
Another issue with the use of a separate, mechanically joined cap is that a metal core and a separate metal show surface must be formed from a similar material or else a barrier must be provided between the materials. Inclusion of a barrier layer further complicates the assembly and adds to the overall cost. Thus, for example, if a stainless steel show surface is desired, it is necessary to then use stainless steel as the inside core material which makes the weatherstrip cost prohibitive. On the other hand, if dissimilar metals are used, i.e., a less expensive core material, it was still necessary to provide a barrier to protect against corrosion issues. Again, the addition of the barrier layer between the dissimilar metals adds undesired costs.
In addition, the use of caps become relatively expensive for at least two reasons. First, the separate manufacture, inventory, handling, etc. of a clinch-on cap adds to the cost. Secondly, subsequent assembly of the cap to the weatherstrip and the associated labor required to assemble the separate components drive the cost of the assembled weatherstrip to an undesired level.
Another way to form a bright strip in a weatherstrip, is to use a more expensive core material (e.g., stainless steel), stripe coat the core, and then extrude the elastomer around the metal core according to a generally known coextrusion process. Thereafter, the elastomer is removed from those regions of the metal which are not stripe coated (since the elastomer is not bonded to the metal) and thus reveals the underlying show surface. As will be appreciated, however, this requires the use of the expensive metal throughout the entire weatherstrip and significantly increases the cost of the final component.
Thus, a continued need exists for ease of manufacture, reducing the cost to manufacture, reducing assembly steps and cost, and providing a functional weatherstrip while still attaining the desired aesthetics of a metal show surface.
An integrated weatherstrip having a show surface that overcomes the above-described deficiencies is provided.
The weatherstrip includes an extrusion body adapted to be secured to an associated vehicle. A core formed from a first material is encompassed in the extrusion body. A metal show surface formed from a second material different from the first material is incorporated into the extrusion body whereby the metal show surface provides an aesthetically pleasing appearance.
In one embodiment, the metal show surface is a stainless steel, and the core is aluminum.
A removable cover layer is provided over the show surface and includes regions of weakness for ease of removal of the cover layer from the show surface after the body has cured.
The weatherstrip may also include an adhesive for bonding the show surface to the extrusion body.
The show surface preferably has hooked edges to preclude removal of the show surface from the weatherstrip.
The core and show surface are segregated from one another along all surfaces by the extrusion body.
The extrusion body may be one of a natural rubber, synthetic rubber, thermoplastic, or another elastomer.
A method of forming the weatherstrip having an aesthetic show surface includes providing a core, providing a metal show surface, introducing the core and show surface into an extrusion die, extruding an elastomer body over the core and metal show surface.
The method may further include tearing away a cover layer of the elastomer body from the show surface after the extruding step.
The method may further include forming hook-shaped edges on the show surface prior to the introducing step.
The extruding step preferably includes introducing elastomer material over the entire surface of the metal show surface.
Preferably, the core and metal show surface are formed to desired configurations different from a planar strip initially introduced into the extrusion line.
An adhesive may also be applied to an interior face of the show surface to enhance bonding between the elastomer body and the show surface.
A primary benefit of this disclosure is the elimination of multiple-piece assembly for the weatherstrip.
Another benefit resides in the decreased amount of expensive metal used in the completed weatherstrip.
Yet another benefit resides in the reduced costs of the weatherstrip.
Still further benefit is the ease of manufacture and the associated reduction in handling and assembly.
Still other features and benefits of the disclosure will become apparent upon reading and understanding the following detailed description.
As noted in the Background, it is often desired by the OEM and customer to have a bright strip or show surface along selected regions of the vehicle. A common location for inclusion of these aesthetic accents is in association with the weatherstrip. While prior arrangements have been multi-part, and mechanically assembled arrangements that suffer from the deficiencies noted previously, the present disclosure includes an extrusion body 40 formed around a rigid core such as an aluminum core 42 with a show surface 44 integrated into the coextrusion process and assembly. A portion of the extrusion body provides a physical barrier between the core and the show surface, which are dissimilar metal such as stainless steel, anodized steel, etc. for the show surface and a less costly metal such as aluminum for the core. Because these metals are dissimilar, a corrosion barrier is required. However, the high cost of assembly is reduced with the present weatherstrip, as will become more apparent from a description associated with the weatherstrip cross-sections of
Turning first to
A second seal lip 80 is also provided as another portion of the extrusion body and extends outwardly, for example, from the second leg 54 for sealingly engagement with the outer door panel 62 and also to provide a smooth transitional appearance between the outer belt and the door. In addition, a show region 82 of the extrusion body is provided along an upper extremity of the outer belt and preferably includes a hiding lip 84 that extends toward the window. Generally speaking, the description of the structure of outer belt to this point is generally conventional, i.e., the outer belt is preferably a co-extruded structure in which the aluminum core 42 is roll-formed just ahead of, or upstream of, the extruding die into the inverted, generally U-shaped configuration. As the core proceeds through the die cavity, the elastomeric body 40 is extruded therearound to encase the core at least in part, and also advantageously form the gripping fingers 64, first seal lip 66, second seal lip 80, and show region 82. It will also be appreciated that various portions of this body may be formed of different materials due to the intended function or aesthetic purpose that is desired of the particular portion. For example, gripping fingers 64 may be formed of an elastomer such as EPDM having a hardness of approximately 70 durometer, while show region 70 may be formed of the same material. On the other hand, the central body portion encapsulating the core 54 may be formed from an EPDM having a higher, 90 durometer rating. The particular types of elastomer, or hardness of these materials, however, should not be construed to limit the present invention. Rather, the description of these different materials are intended to illustrate that various materials may be used to form the extrusion body of the weatherstrip.
The integrated show surface 44 is shown here as a stainless steel or other desired metal 90 (e.g., anodized steel or bright black steel) having hooked edges 92 that are preferably roll-formed just ahead of, or upstream, of the extrusion die. In this manner, the rigid core 42 and the show surface 44 are both introduced into the extrusion die, and in the preferred arrangement, both are roll-formed adjacent an upstream end of the extrusion die and the elastomer (rubber, EPDM, or thermoplastic, etc.) co-extruded around the core and show surface. It will also be appreciated by one skilled in the art viewing
The edges integrated show surface are also preferably hook-shaped. This provides a lock-shape for the show surface even though it is preferred that the extruded elastomeric material will bond to at least a rear face 90b of the metal show surface. It is envisioned that the elastomeric body will preferably be formed of a compound that has good adhesive qualities for bonding to at least the rear face of the metal show surface, although it will also be appreciated that use of a separate adhesive coating on the metal show surface except for the outer face 90a where the removable layer 94 contacts the metal show surface could be used as an alternative.
The removable layer 94 also serves to prevent inadvertent scratching of the metal show surface during processing through the die. Although the weatherstrip could also be sent to the end customer with the removable layer in place, this likely would not be the normal practice. Instead, the removable layer would be separated post extrusion to allow inspection of the completed weatherstrip. It will be appreciated, though, that the removable layer would likely be maintained in place during any weatherstrip processing such as notching, stretch bending, trimming, or piercing. Once the removable layer is torn off and discarded, a protective film is often reapplied for shipment of the completed weatherstrip to the customer and the protective film removed after installation on the vehicle door or upon delivery of the vehicle to the dealership.
In summary, this arrangement integrates the cosmetic strip to the outer belt, glass run, or upper reveal weatherstrip. The integrated show surface eliminates multiple piece assembly. It decreases the amount of the show surface, typically stainless steel and reduces the high costs associated therewith. It provides for integrative formation by roll-forming two metal components, of different metal material, to permit them to pass through an extrusion die, where different materials are then coextruded to integrate, encapsulate, and serve as barrier layers therebetween while also providing the desired functions required for the remainder of the weatherstrip. It also provides for a removable layer that protects the show surface during extrusion and further processing.
The invention has been described with reference to the preferred embodiment. Modifications and alterations will occur to others upon reading and understanding this specification. It is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims or the equivalents thereof
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US08/66887 | 6/13/2008 | WO | 00 | 11/16/2009 |
Number | Date | Country | |
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60934359 | Jun 2007 | US |