Structural elements

Claim 1

A set of elements for forming the side walls of a tray-like structure, said elements including a wall member defining a mortice socket opening to one end of said member and a connecting member having a body portion and at least one tenon formation having a free end insertable into the mortice socket to locate the body portion in predetermined alignment with the wall member to form the structure, the tenon formation being provided with a laterally projecting retaining detent for engagement in a mating aperture in a sidewall of the mortice socket to resist withdrawal of the tenon formation therefrom; wherein the improvement comprises: (a) means providing a central region of the tenon formation with a single, generally U-shaped slot defining a resilient tongue carrying said retaining detent at its free, resilient end, said free end of the tongue being directed away from the free end of the formation and being entirely bordered by the remainder of said tenon formation, said tenon formation free end constituting a one-piece, uninterrupted member; (b) said retaining detent having a leading end facing in the direction of the free end of the tenon formation and away from the free end of the tonque and a pair of edge faces diverging away from said leading end to an abutment part of the detent which is substantially broader than said end, (c) said mating aperture being a through aperture in said sidewall so that the detent is accessible from the exterior of the completed structure to enable release of the tenon formation from the mortice socket by pressing the abutment part of the detent and thus said tongue free end inward of the aperture to flex the resilient tongue, and (d) said detent having an acute angle leading tip and an abutment part in the form of a transverse face which merges with the free end of the tongue.