System for joining edge to edge folded sides of metal containers - includes steps of blanking out of container such that projections are formed on each of lateral edges,these projections being long and short respectively

摘要

In the first operation the container is blanked out so that on each of the lateral edges (7a,7b) of the container are formed a series of projections respectively long (8a,8b) and short (9a,9b). The long sections of one edge being offset to coincide with the short projections on the mating edge. The container is then formed with the sides (4,5) touching at the edges (7a,7b) thus forming an angle and the projections long (8a,8b) and short (9a,9b) are bent to have a direction in line with the line bisecting the angle between the two sides. In the following joining phase, each angle is held between an internal die and an external die and the long projections (8a,8b) are folded over the short projections (9a,9b). The external die for this operation is made up of two parts, one `V' shaped and the other acting as a pinching blade. Use/Advantage - A process and tool for the formation of metal containers where the joining of the edges of the folded sides does not require extra joining pieces thus cutting the cost of its manufacture.