Nontilt stacking and nesting container

Claim 1

A generally rectangular stacking and nesting container comprising: a bottom wall bounded by upstanding, upwardly divergent sidewalls; said sidewalls defining an integral upper rim of dimensions such that the bottom wall of an identical container fits within said rim in both a nesting position and a superposed stacking position; at least a first opposite pair of said sidewalls having the same numbers of a plurality of tapered ribs vertically positioned and inwardly extending from top to bottom of said sidewalls, said ribs on one of said sidewalls being unequally spaced one from the other and being of unequal width, the ribs on said first opposite pair of sidewalls forming mirror images of one another, and one of said inwardly extending ribs extending for a substantial distance across the center line between a second pair of opposite sidewalls whereby when two of said containers are stacked and are slid along relative to each other on said inwardly depending ribs the upper container is supported on said ribs and prevented from tilting until the center of gravity of the upper container is outside the rim of the lower container.