Patent Publication Number: US-2010107507-A1

Title: Cover item provided with a seal and production method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of and claims priority to International Application PCT/IT2007/000352 file May 16, 2007, which was published in English and which is hereby incorporated by reference in its entirety for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention refers to a manufactured item, for example a vehicle door, equipped with a seal. The following description is made with reference to this field of application, with the goal of simplifying its illustration. The invention also refers to a method for the production of one such manufactured item. 
     2. Background 
     It is known that car doors are composed of a metal panel and a manufactured cover item, usually a paneling, on which plastic components are housed/obtained, such as for example arms, grips, handles, switch housings etc. 
     The manufactured cover items are applied or glued to the metal frame with the interposition of a polymer seal, obtained according to the prior art with the following methods: 
     (i) the seal is separately made and is applied or mounted inside a groove or slot made in the plastic manufactured item, by pressing the seal so as to obtain the sealing by means of anchoring means. The seal in this case can be made with a thermoplastic elastomer, more frequently a thermosetting elastomer, of the type used for making seals of O-ring or polyurethane foam type; 
     (ii) the seal, still made separately, is glued by means of glues or solvents or simply attached with adhesives on the plastic manufactured item. Also in this case, the seal is usually a thermosetting piece; 
     (iii) the seal, in this case a polymeric foam, is applied to the previously molded plastic manufactured item by means of a robotized plant which drips a liquid mixture in a prearranged groove by means of a mixing and metering head. The polymerization occurs at a specific time, directly on the piece, leading to the formation of the seal. The mixing head can be fixed or moved by a robot. 
     The above-described methods have drawbacks. They require high process times for the production of the finished composite manufactured item (i.e., for example, a car door) which comprises the panel and the internal manufactured cover item equipped with seal. Consequently, the cost associated with the production is unavoidably high. The laying of the seal is difficult, so that the resulting composite manufactured items must often be discarded. Finally, one must often employ high-cost robotized systems. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a production method of a manufactured cover item, equipped with seal, which eliminates the abovementioned problems. Such object is reached with a production method of a manufactured cover item equipped with seal comprising the steps of 
     forming a manufactured cover item by means of injection of plastic material into a main mold, 
     forming anchoring means for a seal associated with said manufactured cover item, 
     characterized in that it comprises the step of 
     forming the seal by means of overmolding over the anchoring means. 
     Preferably, said anchoring means are slots prearranged for receiving the material, slots obtained with the traditional methods of two-component molding. 
     Preferably, the molding of the seal occurs immediately after the simultaneous molding of the manufactured item and said anchoring means (for example by employing known mold part movement techniques to mold one piece on another already contained in the mold). 
     Also forming the object of the present invention is a manufactured item equipped with a seal characterized in that it is made according to the aforesaid method. 
     The invention attains the following advantages:
         high production speed of the finished manufactured item and possibility of large production quantities, thus eliminating the dead times and the waiting times for pieces in storage;   the seal is obtained with classical molding methods;   highly qualified personnel are not required for the seal insertion;   there is no use of robotized system for the application of the seal;   a very high adhesion level is obtained, without using glues, adhesives or solvents and without the use of mechanical clasps;   the aesthetic aspect of the obtained seal is high-level, seal joint and slippage lines are not visible;   the system is very precise and repeatable, it does not depend on the operator;   since the seal is thermoplastic, the discards can be recovered and the material possibly recycled.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The characteristics and advantages of the invention will be clear from the description, made here below, of an embodiment given as indicative and non-limiting with reference to the attached drawings. 
       In  FIG. 1  a manufactured cover item is shown equipped with seal according to the invention. 
       In  FIG. 2  an enlarged view is shown along the surface of section A-A of  FIG. 1 . 
       In  FIG. 3  a section is shown of a manufactured item according to the invention with regard to one variant. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Initially, a manufactured cover item  10  is formed (for example a vehicle door) by means of mechanical injection of a material in a prearranged mold, said main mold. 
     Such material is usually of thermoplastic type and/or has characteristics which allow it to easily take the shape of the mold in which it is inserted, without requiring any other manual or automated intervention. 
     According to the invention, anchoring means are made on the manufactured cover item  10  so as to be able to anchor a seal  16 , which then permits the coupling with the metal panel not shown in the figure. Such anchoring means can be made in different modes. According to one embodiment of the invention, there can be slots  18  made on the manufactured cover item  10  which are adapted to receive the seal  16  of elastomeric material; this is the case shown in  FIG. 2 . 
     Alternatively, pins with notches  12  can be used to permit the seal  16  to be locked on the manufactured cover item  10 . According to one advantageous characteristic of the invention, the step of anchoring the seal  16  to the manufactured cover item  10  by means of slots  18  or pins with notches  12  occurs during the forming of the manufactured cover item in the main mold. The seal nevertheless does not necessarily need slots or pins to be locked on the piece, since the adhesion can be ensured by the chemical-physical compatibility of the two materials—that of the seal and that of the manufactured item  10 . In this case, the anchoring means consist of adequate flat or corrugated zones, prearranged to accept the plastic material which upon solidification will make up the seal. Here, the slot can serve as a guide for a subsequent mounting, to ensure a perfect coupling to the metal panel such that the seal is set therein, or for protection of the seal during the coupling. 
     The slots  18  can be made according to known molding techniques, such as molding with moving blades; alternatively, a translation or rotation mold can be used. 
     The method according to the invention permits a high production speed of the finished manufactured item (completed door), ensuring large-scale productions and attaining the above-mentioned advantages. 
     At the end of the mold step, the manufactured item composed of the manufactured cover item  10  and the associated seal  16  is extracted.