Breakaway mirror mounting

Claim 1

A breakaway mounting for a mirror attached to one end of a supporting arm, said mounting comprising: a base member; continuous grooves formed in a matching relationship on opposite surfaces of said base member, said grooves defining a thinned region therebetween and having varying depths whereby the bottoms of the respective grooves lie in substantially parallel planes which are inclined with respect to the planes of said base member surfaces; a plurality of spaced apertures in said thinned region extending between said grooves; means for interconnecting a portion of the base member enclosed by said grooves to the end of said supporting arm opposite that to which the mirror is attached, said opposite end comprising an enlarged arm portion having a contour substantially corresponding to that of the base member; and means for joining the remaining portion of the base member to an external support whereby when said mounting is exposed to a force in excess of a predetermined value, said base member fractures at its thinned region permitting the mirror, the supporting arm and the portion of the base member enclosed by the grooves to break away from the remaining portion of the base member, said means for joining the remaining portion of the base member to the external support comprising: a plurality of coaxial apertures through said enlarged arm portion, the remaining portion of the base member and the external support; and bolting means located within said apertures, said apertures in the enlarged arm portion having dimensions greater than those of the bolting means therein.