Cargo containers

A cargo container for carrying cargo alone as an individual container or to be rigidly connected to one or more other identical containers for handling together as a rigid container unit, the container including:

• a top wall, a bottom wall and a series of side walls;
• corner castings located at each corner region formed between the walls;
• a plurality of male coupling parts, each male coupling part having a mounting structure rigidly mounting that respective part adjacent one of the container side walls and providing an elongate mounting bore of substantial length opening therefrom, each male coupling part also having an elongate connecting element of substantial length slidingly mounted in a respective mounting bore for limited linear movement along a longitudinal mounting bore axis between a projected position projecting from the bore and extending beyond the one container side wall and a retracted position, the male coupling parts being located entirely within an outline of the container defined by the corner castings when the connecting elements are in the retracted position;
• a plurality of female coupling parts, each female coupling part having a mounting structure rigidly mounting that respective part adjacent an opposite container side wall and providing an elongate receiving bore of substantial length opening therefrom, the female coupling parts also being located entirely within the outline of the container by the corner castings, the coupling parts being arranged so that, when the container and an identical container are placed with their opposing side walls in complete face-to-face relation and immediately adjacent one another, the connecting elements of the male coupling parts of the container co-axially align with respective receiving bores of the female coupling parts of the identical container, whereby the connecting elements are slidingly received in the receiving bores when linearly moved in the projected position, the connecting elements slidingly fitting in their respective mounting bores and receiving bores along generally the substantial lengths thereof and in the absence of any other means to hold the container side walls in the face-to-face relation and prevent shifting of the containers out of the relation;
• and
• locking elements for positively securing the connecting elements of the male coupling parts of the container to the female coupling parts of the identical container when received in the receiving bores thereby to releasably couple the coupling parts together and hold the containers rigidly together as a rigid container unit.