Single action press for manufacturing shells for can ends

摘要

A single action press for forming a shell used to make a can end includes a first tool and an opposed second tool. The first tool includes a die center insert that performs a forming operation on disc cut from a sheet of end material. The first tool is configured and arranged wherein force is supplied to the die center insert during the downstroke and force is removed from the die center insert at the bottom of the downstroke and at the start of the upstroke, to thereby enable the die center insert to disengage from the shell. One specific embodiment uses a die center piston and compressed air to apply force to the die center insert. Another embodiment uses a cam and cam follower arrangement to remove axial forces at the bottom of the downstroke and either springs or gas pressure to apply force to the die center insert during the downstroke. Actuators are provided in the first tool to reestablished downward forces on the die center insert by the time the top of the upstroke so that the press cycle can be repeated.