Abstract: A frangible coupling utilizable in a sign assembly is provided, formed of a web having a through-extending opening and a plurality of through-extending slits extending outwardly from the opening and defining first and second web portions which will separate under impact loading. The terminations of the slits are short of the end of the web and provide out-of-plane tearing stress concentration. The coupling may be readily manufactured in a variety of manners, such as being cast or even being capable of being stamped. A method of stamping the coupling from a metal plate (e.g. steel plate) is also provided.

Abstract: A guard rail system including a number of W-beam rail elements with a rail end mounted to one of the elements. A number of vertical posts are provided for supporting the rail elements in substantially horizontal position, the four posts closest to the rail end being mounted to break away upon an axial impact. The rail elements are attached to each other in overlapping relationship so that they will move axially with respect to each other upon an axial impact, but will maintain full tensile strength, and thus their re-directional characteristics, upon other than axial impacts, by a plurality of first bolts received by openings in the rail elements. Each opening is bordered on one end thereof by a tang formed in the rail element. Second, frangible bolts attach the rail elements to the posts. The guard rail system prevents spearing, as well as absorbing the energy of the impact.

Abstract: Coupling webs are provided for an upright assembly that functions so that there is a high stress concentration for horizontal impact loading while providing zero or low stress concentration for wind or tensile loadings. At least one web is provided with at least one vertical groove in it, and at least one through-extending transverse opening adjacent one end of the groove and providing the end termination of the groove. A portion of the web on one side of the opening is connected to a generally vertical upright member, while the portion of the web on the opposite side of the through-extending opening is connected to a generally vertical base member. A sign preferably is provided on the upright member, and the web may be disposed in a plane generally parallel to the sign.

Abstract: An upright standard assembly for failing when subjected to horizontal impact forces while solidly supporting an upright standard under normal conditions. The assembly includes a generally vertical standard, a base member, a connection member to releasably attach the standard to the base member, at least one fracture initiating slot formed in the coupling body, and a washer having one or more teeth formed therein for receipt by the fracture-initiating slot(s) of the coupling body. The washer is made of harder material than the coupling body, and has a smooth bore extending therethrough so that no positive holding action is provided between it and the connection member extending therethrough. The coupling body also does not have any threads formed on the portion thereof between the longitudinal termination of the slot(s) and the connection member receiving end thereof.

Abstract: An improved breakaway coupling is provided which is particularly suitable for use in assemblies which are subject to impact such as roadway lamp standards, highway signs and the like. A number of longitudinal grooves provide fracture-initiating regions which provide relatively high compressive and tensile strength in a fracturable coupling.