Abstract:
Disclosed is a unitary cowl top ventilation component for a motor vehicle. The component includes structural and elastomeric portions molded into a single unitary body. Also disclosed are methods for malting the component.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority of U.S. Provisional Patent Application Ser. No. 60/813,742 filed Jun. 14, 2006, entitled “Motor Vehicle Component and Method.” 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates generally to nonmetallic components of motor vehicles and to methods for their manufacture. More specifically, the invention relates to injection molded components of motor vehicles, comprising rigid, structural polymeric members having integral seals, formed from an elastomeric polymer, bonded thereto. Most specifically, the invention relates to a cowl top ventilator component for a motor vehicle and to methods for its manufacture.  
       BACKGROUND OF THE INVENTION  
       [0003]     The cowl top ventilator is a component of a motor vehicle which operates to bridge the space between the windshield, hood and other body components of the motor vehicle while allowing for entry of outside air into the heating, ventilation and air conditioning system of the vehicle. The cowl must further operate to exclude exhaust and other vapors from the engine compartment so that such materials will not enter the passenger cabin of the motor vehicle. The cowl component must further operate to exclude water from the passenger cabin and the engine compartment of the vehicle. In the prior art, such cowl top ventilator assemblies were typically multicomponent structures fabricated from a rigid structural material such as metal or a high-strength polymer, and further incorporating a plurality of separate sealing gaskets. The multipart nature of these assemblies complicates the inventory, handling and installation of the cowl top ventilators, and can also lead to problems with the quality of the water or gas-tight seal provided thereby. As a consequence, such assemblies are costly and difficult to use.  
         [0004]     As will be explained in detail hereinbelow, the present invention provides for a unitary cowl top ventilator component which is fabricated from a high strength structural polymer and includes a series of integral seals, comprised of a polymeric material, molded thereonto. The components of the present invention are preferably manufactured by a multiple shot injection molding process which provides for a tight, fusion bond between the structural material and the sealing material. As a consequence, high quality, integral, permanently bonded seals are provided.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0005]     Disclosed is a unitary cowl top ventilator component for a motor vehicle. The component comprises a rigid polymeric body having a channel configured to receive a windshield of a motor vehicle and/or a hood-engaging portion. A first body of an elastomeric material is bonded to the channel portion and operates to engage the edge of a windshield disposed in the channel. A second body of elastomeric material is bonded in the channel and engages the face of the windshield. An optional third member may engage a hood of a motor vehicle, and an optional fourth member may engage a plenum of the vehicle. Also disclosed are injection molding methods for manufacturing the component.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is a cross-sectional view of portions of a cowl ventilator component;  
         [0007]      FIG. 2  is a schematic depiction for a molding process which may be used to manufacture the cowl of  FIG. 1 ;  
         [0008]      FIG. 3  depicts a further step in the molding process; and  
         [0009]      FIG. 4  and  FIG. 5  depict portions of the cowl component. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0010]     In a typical component of the present invention, a first seal or set of seals establishes contact with the windshield of the motor vehicle, and in this regard may include one seal which engages the edge of the glass and another which engages a face of the glass proximate its perimeter. The component may further include another seal which engages the hood portion of the motor vehicle and operates to seal the engine compartment, and yet a third seal which engages the plenum wall of the motor vehicle.  
         [0011]     Referring now to  FIG. 1 , there is shown a cross-sectional view of two pieces  10 ,  12  of a cowl top ventilator component of the present invention. The first piece  10  represents the windshield-engaging portion, and the second piece  12  represents the hood-engaging portion of the component. Now with reference to the first section of the component  10 , it will be seen that the component is comprised of a structural member  14 , typically fabricated from a high strength polymer such as nylon, ABS, polypropylene, ASA, PC, other thermoplastic polyolefins (TPO) or the like. This polymer may, as is known in the art, be reinforced with a material such as glass fiber, carbon fiber, mineral material, metallic material or the like, so as to increase its strength. As shown in  FIG. 1 , the structural member  14  includes a channel portion  16  which is configured to engage the windshield of a motor vehicle. Integral with, and bonded to, the channel portion  16  is a first body of elastomeric polymer  18  which forms a sealing member which engages an edge of a windshield (not shown). A second body of a thermoplastic elastomeric material  20  forms a front, flange-like seal which contacts the face of the windshield, proximate at least one edge thereof. As shown herein, the two sealing portions  18 ,  20  are contiguous, although it is to be understood that they may be separate bodies. The thermoplastic elastomeric material may comprise natural rubbers, synthetic rubbers, copolymers, as well as any other natural or synthetic material providing the requisite combination of strength and resiliency.  
         [0012]     The second portion of the cowl top ventilator component  12  also includes a portion of the structural member  14  as discussed above. The structural member  14  is configured to include a hood-engaging portion  22 , and in accord with the present invention, a body of elastomeric material  24  is fusion bonded to the structural member  14 . As shown, this body of elastomeric material  24  forms a flange seal operable to engage a portion of the hood of a motor vehicle. As is further shown in  FIG. 1 , yet another body of elastomeric material is bonded to the structural member  14 . This body of elastomeric material  26  defines a plenum seal which engages the plenum of the motor vehicle and aids in sealing the passenger compartment from the engine compartment. Depending on the particular configuration of motor vehicle, the physical dimensions and shape of the cowl top ventilator component may vary. For example, the number or placement of the elastomeric seals may vary as may the basic shape of the structural member. All of such modifications and variations are within the scope of the present invention.  
         [0013]     Various processes may be used to fabricate the components of the present invention. Injection molding is one particular method which may be employed, and multiple shot injection molding is a specific type of injection molding which may be used with advantage in the present invention. In such processes, different types of molding material may be simultaneously or sequentially injected into a mold to fabricate unitary articles having different types of material fusion bonded to one another. Within the context of this disclosure, fusion bonding shall refer to bonds formed by contacting bodies of material together when at least one of those materials is in a molten state.  
         [0014]      FIG. 2  is a schematic depiction of a first step in a molding process wherein articles of the present type may be fabricated. Such molding processes are generically referred to as retracting blade processes, since a retractable masking blade or other such member is employed to control the flow of molding material in a mold cavity. As is shown in  FIG. 2 , a structural member of the component is formed in a first step by injection molding a high strength polymeric material into a mold cavity.  FIG. 2  shows only a portion of the structural component, in this instance the window channel portion  10 , although it is to be understood that the entire member is molded in this first step. As will be seen, the molding apparatus includes a first slide member  30  which engages and defines a portion of the channel surface of the structural member segment  10 . As will be explained in detail below, this slide  30  will be moved in subsequent steps. The slide  30  includes a gate  32 , termed a cashew gate, which in subsequent steps will operate to deliver a second molding material to the system. This gate  32  is in communication with a source of elastomeric polymeric material  34 , but in the  FIG. 2  configuration it is in a forward position and not operable to deliver polymeric material thereto.  
         [0015]     Referring now to  FIG. 3 , there is shown a subsequent step in the operation which is carried out after the injection of the material comprising the structural member  10 . In this stage of the process, the slide  30  is withdrawn thereby defining a further mold cavity corresponding to the aforedescribed seals  18  and  20 . By withdrawing slide  30 , the injection gate  32  is placed in communication with the source of elastomeric polymer  34 , and this material is then injected into the newly opened cavity so as to form the elastomeric bodies  18  and  20 . The result of this process is that elastomeric polymer is fusion bonded to the high strength structural polymer thereby providing a composite component having structural integrity and integral sealing members.  
         [0016]     The hood seal and plenum seal are similarly molded as will be seen from  FIGS. 4 and 5 . Typically, the hood and plenum seals are molded concomitant with the window contacting seal, although the various seal members may be formed sequentially.  
         [0017]     The foregoing represents one system for fabricating the component of the present invention. Other molding systems, including transfer molding systems as well as yet other systems operative to mold multimaterial articles, may be adapted for the practice of the present invention.  
         [0018]     In view of the foregoing, it will be appreciated by one of skill in the art that yet other embodiments and modifications of the system may be implemented. Therefore, it is to be understood that the foregoing drawings, discussion and description are illustrative of particular embodiments of the invention, but are not meant to be limitations upon the practice thereof. It is the following claims, including all equivalents, which define the scope of the invention.