Patent Abstract:
A sideview mirror for a vehicle. A pivot assembly is provided between the mirror head and the mounting bracket. The pivot assembly allows the mirror head to pivotally rotate with respect to the mounting bracket. A load support structure provides a design to provide improved resistance to cantilever forces imposed on the mirror.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage of International Application No. PCT/AU00/00815, filed Jul. 6, 2000. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a wing mirror for a motor vehicle, and in particular to a structure for supporting cantilever loads applied to the wing mirror. 
     BACKGROUND OF THE INVENTION 
     Modern wing mirrors for motor vehicles are designed so that they pivotally attach to a vehicle mounting bracket. This pivotal attachment is normally via a vertical spigot on the mounting bracket. The mounting bracket has a base surface surrounding the spigot which supports the mirror head and various detents used to hold the mirror head in the required position. The mirror head is provided with necessary bearing surfaces to enable it to rotate with respect to the spigot. A coil spring is normally used to hold the mirror head against the base surface and any detents that may be located between the mirror head and base surface. The coil spring acts between the mirror head and a retainer that is normally fitted to the end of the spigot. 
     Such arrangements enable the mirror head to be moved to a park position or enable it to break away upon impact forces being applied. 
     In addition to manual movement of mirror heads, it has become common to provide electric drive means to automatically move the mirror from a deployed or operating position to a park position where the mirror is moved alongside the vehicle. Again, these mechanisms normally rely on a spigot secured to a mounting bracket about which the mirror head rotates. 
     A design requirement for wing mirrors is to be able to withstand cantilever loads which are applied at the outermost point of the mirror head. Vehicle manufacturers normally specify the static load which a mirror head must be able to withstand. 
     This cantilever load results in the mirror head tending to rotate about a horizontal axis. The centre of rotation will normally be the outer edge of the base surface of the mounting bracket which in turn will result in some compression of any coil spring. In turn, the mirror housing will come into contact with the spigot and apply a side loading. This side loading causes a bending strain within the spigot. 
     Alternatively, if the mirror has an electric drive means, the side loading force may be applied to the drive mechanism. 
     In most mirror designs, materials are selected to produce cost effective volume manufacture. The most suitable materials are normally polymeric or diecast metals. However, such materials generally have inadequate strength particularly in respect of bending or tensile loads. Accordingly, it has not been though possible to produce suitable and economic designs using these materials which can support significant cantilever loads. 
     Accordingly, it is an aim of this invention to produce a design which better resists the cantilever forces and to produce a design which is able to withstand higher forces using conventional materials. 
     SUMMARY OF THE INVENTION 
     In its broadest form, the invention is a wing mirror comprising: 
     A mirror head, 
     A vehicle mounting bracket, 
     A pivot assembly between said mirror head and said mounting bracket enabling the mirror head to pivotally rotate with respect to said mounting bracket, and; 
     Load support structure comprising a first surface on said mirror head and a second surface fixed with respect to said mounting bracket located over said first surface so that rotation of said mirror head about a horizontal axis is resisted by engagement of said first and second surfaces. 
     Preferably, the first surface is the upper surface of a flange on the mirror head and the second surface is the lower surface of a ledge fixed to the mounting bracket. The ledge on the mounting bracket is preferably supported some distance above the base surface of the mounting bracket. Other variations will be possible such as the first surface on the mirror head comprising one of the surfaces of a recess within the mirror head. 
     Preferably there is some clearance between the first and second surfaces to enable the mirror head to rotate freely. However, the clearance should be such that rotation of the mirror head about a horizontal axis does not allow significant side loading to be applied to the pivot means. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order to fully understand the invention, a preferred embodiment will be described, but it should be realized that the invention is not to be confined or restricted to the precise details of this embodiment. The embodiment is illustrated in the following figures in which: 
     FIGS. 1 and 2 show a schematic representation of a conventional mirror head and bracket design with a cantilever force applied, and the resultant movement of the mirror head; 
     FIG. 3 shows an exploded perspective view of a mounting bracket and mirror head fitting that are pivotally connected and incorporate the invention; and 
     FIG. 4 shows a part perspective view of the mounting bracket and mirror head assembled. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiments(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     FIG. 1 illustrates a conventional mirror head and mounting bracket assembly. The mounting bracket  10  has a spigot  11  on a base surface  12 . The mirror head  13  pivots with respect to the vertical axis of the spigot  11 . A spring  14  is located around the spigot  11  and forces the mirror head  13  on to the base surface  12 . A retainer  15  is used to hold the spring  14  in place on the spigot  11 . 
     As shown in FIG. 2, a cantilever force F applied to the mirror head  13  will cause rotation of it about a horizontal axis. The pivot point for this rotation will be at the end of the mounting bracket at Point R. 
     If sufficient force is applied, the rotation of the mirror head  13  will cause compression of the spring  14 , and may enable a portion of the mirror head  13  to come into contact with the spigot  11  or to indirectly apply load to the spigot  11  via the retainer  15 . This can occur at any point along the spigot  11  such as the base or at its upper end. This then results in a side loading being applied to the spigot  11 . Sufficient cantilever force can result in damage to the spigot or its complete failure. 
     In order to overcome this problem, the invention uses a load support structure  17  as illustrated in FIGS. 3 and 4. FIGS. 3 and 4 illustrate an internal structural member  23  which forms part of the mirror head  13  assembly. The mirror head cover and mirror plate have not been illustrated in FIG. 3 or  4  for the take of clarity. The internal member  23  is the component secured pivotally to the mounting bracket  10 . The mirror head cove and mirror plate are in turn carried by the internal member  23 . 
     In addition, the spigot has not been shown in FIGS. 3 and 4 for clarity. The spigot is secured within circular recess  24 . 
     The load support structure  17 , shown assembled in FIG. 4, comprises a first surface  18  on the internal member  23 . This first surface  18  is the upper surface of a flange  16  which projects away from a portion of the internal member  23 . 
     The mounting bracket  10  is provided with a second surface  19  that is located over the first surface  18 . The second surface  19  is the lower surface of a ledge  22  that extends from a projection  20  where the projection  20  and second surface  19  are integrally moulded with the mounting bracket  10 . The second surface  19  and base surface  12  comprise a channel through which the flange  16  in the mirror head locates so that the second surface  19  is located over the first surface  18 . 
     Horizontal rotation of the mirror head and internal members  23  with respect to the mounting bracket  10  is limited by engagement of the first surface  18  with the second surface  19 . Accordingly, any cantilever load applied to the outer end of the mirror head is transferred to the projection  20 . The projection  20  can be reinforced by gussets  21  so that it can withstand much higher forces than could otherwise be resist if these loads were applied to the spigot. 
     A second load support structure  27  is provided to support uplifting force which may be applied to the mirror head. The second load support means  27  comprises a third surface  28  and a fourth surface  29  that abut to resist upward movement of the mirror head. 
     The third surface  28  is located on a ledge  30  that is supported by a projection  31 . The ledge  30  and projections  31  extend below the internal member  23 . 
     The base surface  12  of the mounting bracket  10  has a recess  33  that extends part way around the spigot recess  24 . The projection  31  and ledge  30  located within the recess  33 . A flange  34  extends part way into the recess  33  and does not extend to the ends of the recess  33 . This provides the necessary aperture at either end of the recess  33  to locate the ledge  30  into the recess  33  and for it to located under the flange  34 . The lower surface of the flange  34  comprises that fourth surface  29  which abuts against the third surface  29  on the ledge  30 . 
     When the mirror head is in its deployed position, the ledge  30  is located directly below that flange  33 . Any upward movement of the mirror head is thereby limited by engagement of the third and fourth surfaces  28  and  29 . 
     Accordingly, this invention enables much higher cantilever loads to be supported by wing mirrors. 
     As seen in FIGS. 3 and 4, the width of the projection  20  and the recess  33  are such that the first and second surfaces  18  and  19  and third and fourth surfaces  28  and  29  will be engaged when the mirror head is in its normal deployed or in-use position. If the mirror head is rotated to a fully forward or fully rearward position, then the first surface  18  will be clear of the second surface and projection  19  and  20  and the ledge  30  will clear the flange  33 . This will enable the mirror head to be fitted to the spigot  11 . 
     Clearly, the invention is a simple and convenient way of providing a design which will withstand much higher cantilever loads. 
     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

Technology Classification (CPC): 8