Variable depth self-locking container

Claim 1

A variable depth container, formed from a unitary blank of foldable paperboard, with a self-locking closure arrangement, said container comprising: (a) opposed pairs of major and minor side walls foldably interconnected to form a tubular body open at the ends; (b) integral closure means for at least one end of said tubular body including opposed pairs of major and minor closure flaps foldably joined to corresponding edges of respective major and minor side walls of said body along aligned first fold lines; (c) said major walls having aligned second fold lines disposed parallel to and spaced inwardly from said first fold lines to define therewith a plurality of aligned strips which are adapted to become portions of related closure flaps to permit the depth of said container to be reduced by alternatively folding said flaps on said second fold lines instead of on said first fold lines; (d) said closure flaps being arranged for interlocking engagement when folded normal to said body side walls, with said first major flap being an inner flap, said second major flap being an outer flap, and said minor flaps being intermediate flaps between said inner and outer flaps; (e) certain of said flaps having contour features for receiving portions of other flaps to accommodate interlocking engagement therebetween when said flaps are folded on said first fold lines and having additional contour features for receiving other portions of said other flaps to accommodate interlocking engagement therebetween when the dimensions of said flaps are increased by being folded on said second fold lines to reduce the depth of said container; (f) said first major closure flap having an opening for receiving a projection of said second major closure flap when the depth of the container is reduced; (g) said minor closure flaps having recesses for receiving portions of at least one of said major closure flaps when the depth of the container is reduced.