Cover for a standard container

A cover for a standard container, said container having a substantially rectangular bottom with rounded corners and side walls that are outwardly flared upwards, the tops of the side walls delimiting a substantially rectangular opening with rounded corners, said cover being constituted by a plate guide made of a thermo-plastic material and provided with upper rib portions which project from its upper surface in a rectangular configuration with gaps therebetween and with lower rib portions which project from its lower surface in a substantially rectangular configuration to fit into the opening;

• the improvement wherein the upper rib portions (8) surround the bottom (3) of an underlying container (2) placed on the cover (1) and wherein said cover (1) has only one set of lower rib portions (6) which fits inside the opening (5) of a container closed by the cover and said set of lower rib portions (6) defining a rectangular configuration and being of a slightly different size to that formed by the set of upper rib portions (8) so that the bottom (3) of the standard container (2) placed on the cover (1) cannot move sideways, and likewise another cover (1') identical to the cover (1) in question and stacked thereon, and wherein said lower rib portions (6) being separated by gaps (7) which are not adjacent to gaps (9) separating the upper ribs (8).