A mounting bracket for attaching a mirror to the exterior of a vehicle, the bracket having a pair of metal plates disposed in face-to-face abutting relationship and encased within a synthetic plastic resin frangible along the plane of abutment of the plates. Each plate includes threaded members so that the bracket may be secured to the vehicle and to mirror supporting members.

BACKGROUND OF THE INVENTION 
This invention relates to a break-away bracket and more particularly to 
such a bracket for use in mounting a rear view mirror on the outside of a 
vehicle. 
Rear view mirrors of the type mounted on the exterior of a vehicle are 
conventionally attached to a rigid bracket which in turn is bolted to the 
vehicle door or fender. In the case of a truck cab for pulling a wide 
bodied vehicle and other wide bodied vehicles the mirror is connected to 
elongated arms which are secured to the bracket, the bracket being bolted 
directly to the door of the vehicle. If the mirror or the arms strike an 
external object, such as another vehicle, a tree, building etc., the 
moment acts to force the bracket away from the vehicle pulling the 
attaching bolts so that costly damage results to the vehicle body portion 
to which the bracket is attached. 
The known relevant prior art mirror attaching brackets are those 
illustrated in U.S. Pat. Nos. 3,599,926 (Takahashi); 3,887,156 
(Hugonnier); 4,066,235 (Hashiguchi) and 4,368,868 (Urban). Takahashi and 
Hashiguchi relate to the mounting of interior mirrors while Hugonnier and 
Urban are directed to the mounting of mirrors on the exterior of the 
vehicle. The Takahashi and Hashiguchi patents respectively show a 
break-away plastic plate interposed between an attaching base of a rear 
view mirror and the body of the vehicle, the plate having a groove 
surrounding the area where an attaching screw connects the plates to the 
base and breaks at the groove when a force is applied to the mirror; and a 
rear view mirror having a pair of plastic mirror mounting members which 
are connected together at a frangible portion formed by tiny holes about a 
central portion of one of the members, the other member together with the 
central portion breaking away from the first portion on impact. The 
Hugonnier and Urban patents respectively disclose the end of the mirror 
arm connected within the bore of a socket of a base secured to the 
vehicle, the connection between the arm and the base being through a 
plastic ring that separates to release the arm when the mirror is 
impacted; and a mirror carrying arm capable of breaking away from the 
hollow threaded neck of a plastic bracket when the mirror is impacted. In 
each of these prior art disclosures a relatively complex and expensive 
mirror mounting arrangement is proposed to overcome the difficulties of 
conventional mirror mounting brackets. 
SUMMARY OF THE INVENTION 
Consequently, it is a primary object of the present invention to provide a 
simple and inexpensive break-away mirror mounting bracket which can be 
readily attached to the exterior of a vehicle and simply shears upon 
impact of the mirror or the mirror supporting arms against an extraneous 
object. 
It is another object of the present invention to provide a break-away 
mounting bracket for supporting a mirror on the exterior of a vehicle 
body, the bracket comprising a pair of separable plates encased in a 
frangible synthetic plastic, the casing breaking upon impact to separate 
the plates. 
It is a further object of the present invention to provide a pair of 
abutting metal plates, one plate being secured to a vehicle and the other 
plate being supporting to mirror attaching means, the plates being encased 
within a brittle plastic molded about the plates so that if the mirror or 
the mirror attaching means is impacted by a force, the plastic will 
fracture and the plates will separate. 
Accordingly, the present invention provides a mounting bracket for 
attaching a mirror, mirror supporting means or the like to the exterior of 
a vehicle, the bracket being such that it will shear upon impact of the 
mirror or supporting means by an extraneous object without resulting in 
damage to the structure of the vehicle. The mirror comprises a pair of 
plates, preferably metal, disposed in face-to-face abutting relationship 
and encased within a frangible synthetic plastic housing. Each plate 
includes means for securing it to a respective one of either the vehicle 
body or the mirror supporting means. When an extraneous force or object 
strikes the mirror or its supporting means, the plastic will shear along 
the frangible edges lying in the plane of the abutting plate faces, 
thereby resulting in separation of the mirror mounting plate from the 
vehicle mounted plate. Consequently, damage to the vehicle is precluded.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, FIG. 1 illustrates a truck 10 having a door 
12 on which a mirror 14 is mounted by means of a pair of mirror mounting 
brackets, the brackets being depicted as shearing, but each is indicated 
generally at 16 in FIG. 2. Since the mirror 14 of a truck is generally 
huge a pair of such brackets is secured in spaced apart relationship on 
the door 12 and to mirror supporting means such as arms 18 pivotably 
mounted to a lug 20 at respective upper and lower ends of the mirror. 
As best illustrated in FIG. 3, the mirror mounting bracket 16 comprises a 
pair of metal plates 22 and 24 respectively, the plates being mounted in 
face-to-face abutting relationship. Each plate 22, 24 may have a plurality 
of threaded studs 26, 28 respectively secured to the non-abutting faces as 
by welding or the like. The studs 26 may be secured to conventional 
brackets 30 by means of nuts 32, while the studs 28 may be secured to the 
vehicle body such as the door 12 also by means of nuts (not illustrated) 
secured either directly to the door 12 or to other brackets. In the 
alternate form illustrated in FIGS. 4 and 5 the studs 28 may be replaced 
by screw members 128 having enlarged heads 129, the threaded shank portion 
of the screw members extending through an aperture in the plate 24 which 
allows the threaded portion but not the head 129 to extend therethrough, 
but the plate 22 has an aperture permitting the head 129 to pass freely 
therethrough. 
The plates are disposed in abutting relationship with the studs 26, 28 
extending in opposite directions, and the plates are encapsulated within a 
plastic casing or housing 34 which is molded about the plates while 
permitting the studs 26, 28 to extend therefrom. The casing 34 is 
preferably formed from any brittle synthetic resin such as the plastic 
polymers including polypropylene, polyethylene, polyoctal etc. The 
thickness of the casing is such that it securely holds the plates 22 and 
24 together under normal circumstances and is of a strength to withstand 
minor shocks and jolts, but if a sufficient force is applied to the mirror 
14 or the supporting arms 18, the casing will fracture along the plane of 
the abutting faces of the plates 22 and 24, illustrated at 36. The plane 
36 is a frangible plane along which the plastic material will readily 
break due to an impact force applied tending to separate the plates 22 and 
24 in the shearing direction. 
In the modification illustrated in FIGS. 4 and 5 the casing 34 includes an 
aperture 38 through which the screw 128 together with the head 129 may 
pass so that the head 129 extends through the enlarged aperture in the 
plate 22 to abut the surface of the plate 24 lying in the plane 36. Since 
the head 129 of the screw 128 does not physically engage the plate 22 a 
shearing force between the plates 22 and 24 will not be absorbed by the 
screw 128 but will be applied directly to the casing 34 as in the 
embodiments of FIGS. 2 and 3, to fracture the casing along the plane 36. 
Numerous alterations of the structure herein disclosed will suggest 
themselves to those skilled in the art. However, it is to be understood 
that the present disclosure relates to the preferred embodiment of the 
invention which is for purposes of illustration only and not to be 
construed as a limitation of the invention. All such modifications which 
do not depart from the spirit of the invention are intended to be included 
within the scope of the appended claims.