Container for bulk material

Claim 1

A container for the handling and storage of large quantities of bulk material comprising a unitary molded plastic liquid-tight tub having a bottom and four upwardly extending sides; a lip along the upper edges of the sidewalls; three parallel, laterally spaced, downwardly extending, hollow ridges forming supporting members for the container being integrally molded in said bottom; said ridges extending substantially the full length of the bottom of said tub, and establishing, between adjacent pairs of ridges, spaces for the entry of the tines of a forklift or pallet jack; removable cover means adapted to rest on the upper edges of said four upwardly extending sides and to enclose said tub; said cover means also being composed of molded plastic; said cover means having means for engaging the sides of the tub and preventing lateral movement of the cover with respect to the tub comprising four downwardly extending sides forming a skirt adapted to fit tightly over the lip along the upper edges of the tub sidewalls; said cover means also having means providing three elongated, parallel substantially coplanar surfaces on the upper side thereof; said cover surfaces being adapted to support parallel, laterally spaced, downwardly extending hollow ridges of another container resting thereon; at least one of said three elongated, parallel cover surfaces being surrounded by ridge means integrally molded into said cover; said ridge means extending upwardly from said cover surfaces; said ridge means conforming to the shape of a ridge of the container and being adapted thereby to surround said container ridge and to secure said container resting on said cover surfaces against lateral motion.