Abstract: Apparatus for interlocking the ends of first and second channel-shaped wall sections, comprising a substantially perpendicular first tongue integral with and extending inwardly from the end of the first wall section, with a slot at the juncture therebetween. A substantially perpendicular second tongue is integral with and extends inwardly from the second wall section. The second tongue is dimensioned for insertion through the aforesaid slot, and it has a detent arranged to cooperate in mechanical engagement with the first tongue, as long as the second tongue is operatively positioned beneath and in parallel relationship to the first wall section. A third tongue on the first wall section holds the second tongue in its operative position.

Abstract: An expanded composite picture frame having inner and outer channel-shaped frame components held in mutually spaced relationship by an intermediate filler piece. The inner frame component supports the picture and is mechanically interlocked to the inner edge of the filler piece. The outer frame component firmly grips and decoratively overlaps the outer edge of the filler piece.

Abstract: A mounting means for fixing a hinge relative to a container wall. A hinge receiving element is provided with an inner plate having an outer lip joined thereto by an intermediate web. The container wall is received between and thus reinforced by the aforesaid inner plate and outer lip, with the intermediate web being supported on a wall edge. Preferably, the inner plate has upstanding ears, the intermediate web is notched at one end, and the container wall has inwardly protruding flange segments at opposite ends of the aforesaid wall edge. The notch permits both pivotal and lateral movement of the hinge receiving element in order to position the upstanding ears on the inner plate beneath and in contact with the undersides of the flange segments on the wall member. The inner plate is adapted to receive a hinge leaf in engagement therewith, and the hinge leaf, when thus engaged, prevents reverse lateral movement of the hinge receiving element.