Abstract:
A load-bearing reinforcement structure for assisting the secure mounting of a load producing element, such as a rear-view mirror assembly, to a vehicular body is advantageously fashioned from a heat and creep resistant plastic, such as glass-reinforced Polyethylene Terephthalate. The reinforcement structure features a mounting element capable of mechanically connecting the reinforcement structure to a surface of a vehicular body, such as an internal surface of a panel of a door assembly, without the need for welding, placement fixtures or use of separate fastening elements.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates generally to reinforcing structures for mounting of load-bearing items. More specifically, the invention concerns mounting reinforcement structures for motor vehicle accessories, such as rear-view mirrors, to be attached to an outer surface of a door of the vehicle. 
     Currently available mounting reinforcement structures for accessories such as rear-view mirrors for vehicles suffer many drawbacks. Such current products are fashioned from steel and require welding processes to be attached to the door subassembly with attendant tool, labor and maintenance costs. Additionally, such current reinforcing structures do not have self-locating features, therefore requiring locating tools in order to be properly assembled between the inner and outer panels of a vehicle door. Also, currently available reinforcing structures require a retainer to hold the part in place until assembled in the full door assembly. 
     Stamped steel mirror reinforcement structures currently lack the necessary rigidity to meet systems performance requirements without incurring the cost of increasing the thickness of either the door sheet metal or that of the mirror housing. Additionally, such steel reinforcements are not corrosion resistant. 
     SUMMARY OF THE INVENTION 
     A load-bearing reinforcement structure for assisting mounting of a load-producing element to a vehicular body includes a support body having a surface adapted to abut a surface of the vehicular body and a mounting element capable of mechanically connecting the support body to the surface of the vehicular body without a need for welding or use of separate fastening elements, wherein the structure is fashioned from a plastic material. 
     In another aspect of the invention, a load-bearing reinforcement structure for a vehicular door includes a plate-like element having a first face adapted to at least partially abut an inner surface of one of the vehicle door&#39;s inner and outer panels. A plurality of hollow tubular members extend from the plate-like element for a distance substantially equal to a distance between the inner and outer panels of the vehicle door, and a locating and attachment assembly is adapted to attachingly engage one of the vehicle door&#39;s inner and outer panels in a preselected orientation with respect thereto. 
     In yet another aspect of the invention, a vehicle includes a door assembly having inner and outer door panels separated by an interior gap and an injection molded plastic reinforcement structure for the door assembly which includes a plate-like element having a first face at least partially engaging an inner surface of the outer door panel. A plurality of hollow tubular members extend from the plate-like element across the gap to a corresponding plurality of openings in the inner door panel, and a locating and attaching assembly is associated with the first face attachingly engages the outer door panel in a preselected orientation with respect thereto. A hollow conduit extends from the first face across the gap to an inside surface of the inner door panel and in communication with substantially mating openings in the outer and inner door panels. Finally, a loading element is coupled to an outer surface of the outer door panel by a plurality of studs, each extending from the loading element through the outer door panels, through one of the plurality of hollow tubular members, and then through a corresponding opening in the inner door panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects and features of the invention will become apparent from a reading of a detailed description, taken in conjunction with the drawing, in which: 
         FIG. 1  is a perspective view of an outwardly-facing side of a reinforcement structure arranged in accordance with the principles of the invention; 
         FIG. 2  is a perspective view of an opposite, vehicle interior-facing side surface of the reinforcement structure of  FIG. 1 ; 
         FIGS. 3A–3C  present perspective views of a door outer panel receiving the reinforcement structure of the invention; and 
         FIG. 4  is a perspective view showing the reinforcement structure of the invention installed between the inner and outer door panels of a door assembly. 
     
    
    
     DETAILED DESCRIPTION 
     One aspect of this invention is the application of a suitable plastic such as Polyethylene Terephthalate (PET) for structural load-bearing components in vehicle mounting systems, such as for mounting a rear-view mirror at the front area of a vehicle door assembly. PET is an environmentally friendly material with multiple benefits enjoyed over steel. First, the weight of the PET is about one fifth of that of steel and yet has an equal energy absorbing capacity. Other benefits of PET over steel are that it is noncorrosive and has a better damping characteristic, which leads to less vibration. 
     The mechanical properties of PET are excellent when body components are subject to high temperature, stress and cyclic conditions for long periods of time. PET is a stiffened, super tough thermoplastic polyester and has the highest combined stiffness/toughness of any thermoplastic. In addition, it offers outstanding appearance, high and low temperature performance, good electrical properties and dimensional stability. All these characteristics meet the requirements of the invention for a material having a high melting point—on the order of 350–375° F.—capable of withstanding typical temperatures encountered in paint application and baking chambers in the automotive industry. Additionally, the material is capable of withstanding at least 100 inch-pounds of torque from mirror mounting nuts. The material also exhibits high creep resistance to prevent loosening over the lifetime of the vehicle in multi-temperature environments. 
     For the purposes of this invention, the preferred PET material is glass reinforced, more particularly, 35–40% mica/glass reinforced. Examples of PET&#39;s suitable for this invention are Rynite® 935 and Rynite® 940 commercially available from E. I. DuPont de Nemours and Company. 
     With reference to  FIGS. 1 and 2 , mirror mounting reinforcement structure  100  is fashioned from Rynite® 935 in an injection molding process and features a flat carrier plate surface  102  which substantially matches the surface of the inner facing surface of a door outer panel to provide anti-rattle effect to the door outer panel. Wiring bundle or harness passage  104  is a substantially rectangular conduit extending from inwardly facing surface  202  of the structure for a distance substantially equal to the gap between the inner and outer door assembly panels. 
     Three mounting stud-receiving tubes  106   a, b, c  likewise span the distance between the door inner and outer panels. Tubes  106   a,    106   b  and  106   c  act as structural columns when a clamp load, such as the rear-view mirror assembly, is applied to the door system. 
     A locating feature, slot  108 , is cut out of the plate-like structure  100  and engages a member spanning the inner and outer door panels such that the structure  100  will be positioned properly without the use of external positioning tools. Slot  108  is used in conjunction with a locating and installing assembly  110  which includes a flexible tab  112  bearing a locating protrusion  114  on its surface. Raised tangs  116  and  118  are used along with the flexible tab  112  in a manner to be described below for properly mechanically attaching element  100  to an inner surface of the outer door panel and for properly locating it in conjunction with element  108 . 
     Mounting studs from a device such as the rear-view mirror assembly are received in tubular openings  105   a, b, c,  respectively defined by tubes  106   a, b  and  c.    
     Stiffening struts  204 ,  206  and  208  provide rigidity to structure  100  by coupling the mounting tubes and the wire harness closeout  104  as shown in  FIG. 2 . 
       FIGS. 3A , B and C set forth the method of installation of support structure  100  to an interior surface of door outer panel  302 . As seen from  FIG. 3A , door outer panel  302  includes a locator/installing assembly receiving cavity  310  which will receive the locating and installing assembly  110  of structural element  100 . Door outer panel  302  also includes a tab  312  for abutting receipt of flexible tab  112 . Aperture  314  in door outer panel  302  is positioned for mating receipt of locating protrusion pin  114  carried by flexible member  112 . Slots  316  and  318  in door outer panel  302  are positioned for receipt of respective tangs  116  and  118  of the locating and installing assembly  110  of the reinforcement structure  100 . Finally, openings  305   a, b, c  in outer panel  302  are aligned respectively with openings  105   a, b, c  in reinforcement structure  100 . 
     In  FIG. 3B , after locating and installing assembly  110  has been placed in opening  310  of door panel  302 , the structure  100  is then pushed in a direction marked F in  FIG. 3B  downwardly such that flexible tab  112  rides up over tab  312  in door panel  302  until its protrusion  114  snaps into place in cavity  314  of panel  302  thereby mechanically attaching structure  100  to panel  302  in the proper orientation, all without the necessity of a welding process or positioning tools. 
     With reference to  FIG. 4 , reinforcement structure  100  is depicted installed between door outer panel  402  and door inner panel  404 . Mirror housing  406  has three mounting studs  408   a, b, c  which extend through the mounting columns of structure  100  from the mirror housing  406  through the columns and then through mating apertures in the cabin-facing surface of door inner panel  404 . Additionally, a wiring harness or bundle  410  is seen coming from mirror assembly  406  through the wiring bundle closeout  104  of  FIGS. 1  or  2  to a mating aperture in the cabin-facing surface of door inner panel  404 . Each stud  408   a, b, c  threaded at its end for receipt of mounting nuts. In this manner, the wiring harness is isolated from the interior space intermediate door inner and outer panels  402  and  404  and is less subject to vibration and attendant noise. 
     The invention has been described with reference to an exemplary detailed description. The scope and spirit of the invention are to be determined from appropriately interpreted appended claims.