Abstract:
An exterior rearview mirror assembly for a motor vehicle is disclosed having a primary mirror and a spotting mirror. Both the primary mirror and the spotting mirror are secured to the same single mirror support, or backing plate. The spotting mirror is snap fit to the backing plate by having a monolithic structure which is receivable by a recess or hole in the backing plate. The recess acts as a securing device by receiving an abutment surface extending outwardly away from the monolithic structure which snaps over the backing plate and prevents the spotting mirror from moving away from the backing plate.

Description:
This patent application is a continuation-in-part of a U.S. patent application Ser. No. 11/968,989, filed on Jan. 3, 2008, the disclosure of which is hereby expressly incorporated by reference. 
    
    
     BACKGROUND ART 
     1. Field of the Invention 
     The invention relates to exterior rear view mirror assemblies for motor vehicles. More particularly, the invention relates to exterior rear view mirror assemblies that include a plurality of mirrors with differing fields of view. 
     2. Background of the Invention 
     Multiple mirrors in a rear view mirror assembly are common. The multiple mirrors include a primary mirror and what is typically referred to as a secondary or spotting mirror. This secondary reflector is located somewhere adjacent the primary reflective surface and is used to aid the user of the motor vehicle to increase his field of view around the motor vehicle. 
     The spotter mirror is typically curved to increase the field of view rearward of the motor vehicle. Positioning of the auxiliary mirror with regard to the primary mirror is difficult and requires precision to ensure that the field of view for each of the mirrors or reflective surfaces are aligned properly to maximize the ability of the user to increase the field of view rearward of the motor vehicle. 
     SUMMARY OF THE INVENTION 
     An exterior rearview mirror assembly for a motor vehicle is disclosed having a bracket which is fixedly secured to the motor vehicle. A mirror casing is secured to the bracket. The mirror casing defines a primary opening. A primary mirror is disposed within the primary opening and provides a view rearward of the motor vehicle through a primary field of view. A spotting mirror is disposed adjacent the primary mirror. The spotting mirror defines by a radius of curvature differing from said primary mirror such that said spotting mirror provides a second field of view rearward of the motor vehicle. A securing device is formed with the single mirror support to secure the spotting mirror to the single mirror support. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of one embodiment of the invention, partially cutaway; 
         FIGS. 1A through 1C  are cross-sectional views of three separate embodiments taken along lines  1 A- 1 A of  FIG. 1 ; 
         FIG. 2  is a rearview of another embodiment of the invention; 
         FIGS. 2A and 2B  are cross-sectional rearview taken along lines  2 A- 2 A of  FIG. 2 ; 
         FIG. 3  is a rearview of another alternative embodiment of the invention; 
         FIGS. 3A and 3B  are cross-sectional rearview taken along lines  3 A- 3 A of  FIG. 3 ; 
         FIG. 4  is a top view of a motor vehicle with the invention secured thereto and schematically identifying the fields of view created by the mirror assembly; 
         FIGS. 5A and 5B  are cross-sectional side views, partially cut away, of an eighth embodiment of the invention taken along lines  5 - 5  in  FIG. 1 ; and 
         FIGS. 6A and 6B  are exploded perspective views of a backing plate and a spotting mirror incorporating the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1 , an exterior rearview mirror assembly is generally indicated at  10 . The exterior rearview mirror assembly  10  is fixedly secured to a motor vehicle  12  on a side  14  thereof. This is best seen in  FIG. 4 . While only one exterior rearview mirror assembly  10  is shown, it should be appreciated by those skilled in the art that a second exterior rearview mirror assembly  10  may be fixedly secured to a side opposite the side  14  of the motor vehicle  12 . 
     The exterior rearview mirror assembly  10  includes a bracket, graphically represented in  FIGS. 1 and 4  by a bracket cover  16 . The bracket  16  is mounted to the side  14  of the motor vehicle  12 . The mounting thereof is covered by a sail  18 , which is an aesthetic piece that also is able to improve the aerodynamics of the exterior rearview mirror assembly  10 . 
     The exterior rearview mirror assembly  10  also includes a mirror casing  20 . The mirror casing  20  is secured to the bracket  16 . The mirror casing  20  defines a primary opening  22 . The primary opening  22  faces rearward of the motor vehicle  12 . For purposes of this disclosure, the direction rearward is the direction opposite the direction in which the motor vehicle  12  is going when it is driving in a forward direction. Therefore, the mirror casing  20  includes a forward surface  24  which extends forward of the exterior rearview mirror assembly  10  (best seen in  FIG. 4 ). The mirror casing  20  is generally closed but for the primary opening  22 . In many embodiments, the mirror casing  20  includes exterior lighting units for illuminating the mirror casing  20  depending on the particular situation. Examples of lighting units include turn signals and ground illumination lighting units. Such units may be incorporated into the mirror casing without deviating from the invention. The mirror casing  20  also includes a neck  26  which extends out from the mirror casing  20  and is received by the brackets  16 . It should be appreciated by those skilled in the art that the function of the neck  26  may be assumed by the brackets  16  resulting in a mirror casing  20  without a neck  26 . 
     Referring to all the Figures, the exterior rearview mirror assembly  10  includes a primary mirror  28  which is disposed within the primary opening  22 . The primary mirror  28  provides a view rearward of the motor vehicle  12 . An operator  30  using the primary mirror  28  will see a primary field of view  32  as shown in  FIG. 4 . 
     The exterior rearview mirror assembly  10  also includes a spotting or secondary mirror  34 . The spotting mirror  34  is disposed adjacent the primary mirror  28 . The spotting mirror  34  defines a single radius of curvature which is different from the primary mirror  28  such that the spotting mirror  34  provides a secondary field of view  36  rearward of the motor vehicle. The spotting mirror  34  is defined by the single radius of curvature and that radius is a defined, finite number. The primary mirror  28  is substantially planar or flat defining a primary plane and, therefore, has a radius of curvature that is infinite. As such, the radius of curvature for the spotting mirror  34  is different than the radius of curvature for the primary mirror  28 . In the embodiment shown, the spotting mirror  34  has a radius of curvature that is less than the radius of curvature of the primary mirror  28 . The exterior rearview mirror assembly  10  is configured such that the primary field of view  32  and the secondary field of view  36  overlap to create an overlap field of view  38 . The overlap field of view  38  is desired to ensure that the operator  30  does not miss anything between the perspective fields of view  32 ,  36  of the primary  28  and spotting  34  mirrors. 
     The exterior rearview mirror assembly  10  includes a single mirror support  40  which supports both the primary mirror  28  and the spotting mirror  34  with respect to each other within the primary opening  22 . More specifically, the single mirror support  40  is used to position the primary mirror  28  and the spotting mirror  34  such that the primary field of view and the secondary field of view  36  create an overlap field of view  38 . By using a single mirror support  40 , the relationship between the secondary field of view  36  and the primary field of view  32  is constant and is not dependent upon the quality of the assembling procedures. 
     Referring to  FIG. 1A , the single mirror support  40  defines a primary portion  42  and a spotting portion  44 . The primary portion  42  includes an area substantially equal to the area defined by the primary mirror  28 . The primary mirror  28  is fixedly secured to the primary portion  42  of the single mirror support  40 . Likewise, the spotting portion  44  of the single mirror support  40  has the spotting mirror  34  fixedly secured thereto. The primary portion  42  and the spotting portion  44  of the single mirror support  40  have radii of curvature which mirror the radii of curvature for the spotting mirror  34  and the primary mirror  28  respectively. More specifically, the primary portion  42  defines a primary plane  46  that is substantially flat and the spotting portion  44  defines a spotting mirror radius of curvature that is substantially equal to the single radius of curvature  35 . The primary plane  46  and the single radius of curvature  35  are best seen in  FIG. 4 . 
     Referring to  FIGS. 1A through 1C , alternative embodiments of the invention are shown. In particular, the alternative embodiments, wherein referenced numerals are offset by 100, the spotting mirror  34  is positioned with respect to the primary mirror  28  differently through each of the three embodiments. In the preferred embodiment,  FIG. 1A , the spotting mirror  34  is disposed in a position such that an edge  47  of the spotting mirror  34  is coplanar with the primary mirror  28 . In  FIG. 1B , the spotting mirror  134  is forward of or recessed to the primary mirror  28 . And in  FIG. 1C , the spotting mirror  234  is rearward or proud of the primary mirror  128 . In the first and second alternative embodiments shown in  FIGS. 1B and 1C , respectively, a divider  148 ,  248  extends between the spotting mirror  134 ,  234 , and the primary mirror  128 ,  228 . The divider  148 ,  248  is an extension of the single mirror support  140 ,  240 . The divider  148 ,  248  provides a visible separation to the two different reflective elements. 
     Referring to  FIGS. 2 ,  2 A and  2 B, third and fourth alternative embodiments are generally shown. In these embodiments, the divider  148 ,  248  is not present. In these embodiments, the spotting mirror  34  and the primary mirror  28  appear to be more of a unified structure without the division therebetween. 
     Referring to  FIGS. 3 ,  3 A and  3 B, fifth and sixth embodiments of the invention are shown.  FIG. 3  represents a side view of both embodiments shown in  FIGS. 3A and 3B . In  FIG. 3A , the spotting mirror  534  defines a periphery  550 . The periphery  550  includes a rim flange  552  that extends thereabout the periphery  550 . The rim flange  552  extends underneath a portion of the primary mirror  528 . 
     The single mirror support  540  defines a flange channel  554  which receives a portion of the rim flange  552  therein. The rim flange  552  being seated within the flange channel  554  and partially covered by the primary mirror  528  accurately positions the spotting mirror  534  with respect to the primary mirror  528 . 
     The rim flange  552  includes a rim extension  556 . The rim extension  556  extends out from the rim flange  552  perpendicularly thereto. A top face  558  of the rim extension  556  is the surface that is disposed adjacent a back side  560  of the primary mirror  528 . 
     In  FIG. 3A , the spotting mirror  534  defines an outer reflective surface  562  that defines a single radius of curvature. This outer reflective surface is a coated surface that includes a chrome or chrome-like material. 
     Referring to  FIG. 3B , the spotting mirror  634  includes an outer flat surface  664  and an inner reflective surface  667 . The inner reflective surface  667  is coated with a reflective material. In this seventh embodiment, the spotting mirror  634  is fabricated from a translucent polymer resin to allow the light impinging thereupon to pass through the spotting mirror  634  with as little refraction as possible. The inner reflective surface  667  is curved such that the reflection on the inner reflective surface will create the necessary secondary field of view which will overlap the primary field of view created by the primary mirror  628 . 
     Referring to  FIGS. 5A ,  5 B,  6 A and  6 B, a portion of an eighth embodiment of the invention is shown, wherein like primed numerals in  FIGS. 5B and 6B  represent a sub-embodiment of the eighth embodiment shown in  FIGS. 5A and 6A . In these embodiments, a securing device  770  extends out of a backing surface  774  of the spotting mirror. The backing surface  771  is opposite a reflective surface  773 . The securing device  770  secures the spotting mirror  734  thereto. In the embodiment shown in  FIGS. 5 and 6 , the securing device  770  is a monolithic structure. There are monolithic structures  770  shown in  FIG. 6 . It should be appreciate by those skilled in the art that any number of monolithic structures, including a single monolithic structure  770  may satisfactorily secure the spotting mirror  734  to the single mirror support  740 . 
     A recess  772  may extend through the single mirror support  740  or it may only partially extend through. In the embodiment shown, the securing device  770  extends completely through the recess  772  and the single mirror support  740 . 
     Each recess  772  is associated with each of the securing devices  770  of the spotting mirror  734 . Therefore, for the embodiment shown in  FIGS. 5 and 6 , there are six monolithic structures  770  extending out from the spotting mirror back side  774 . Each of the monolithic structures  770  extend out from the spotting mirror back side  774  in close proximity to the periphery  750  of the spotting mirror  734 . 
     Each of the monolithic structures  770  includes an abutment surface  776  or barb. The abutment surfaces  776  positively engage the single mirror support  740  to prevent the spotting mirror  734  from moving relative to the single mirror support surface  740 . The abutment surfaces  776  each have a predefined width that allows the monolithic structures  770  to fit through each of the recesses  772  but are large enough positively engage the single mirror support  740 . The abutment surfaces  776  snap into place once they reach a relief, either cut into the single mirror support  740  or by extending all the way through the single mirror support  740  such that the abutment surface  776  uses a back side  778  of the single mirror support  740  as a relief. 
     If the thicknesses of the various parts are sufficient, the recesses  772 ′ may extend into the spotting mirror  734 ′ and the monolithic structures  770 ′ can extend outwardly from the single mirror support  740 ′. This would, however, require the recesses  772 ′ to be cut into a middle section of the spotting mirror  734 ′ along the edge  750 ′ thereof. 
     The invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. 
     Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.