US Patent 7526937 Can bottom forming assembly

A can bottom forming assembly for use in forming the bottom of metal cans, such as steel and aluminum two piece cans. The bottom forming assembly is lightweight, compact and comprises outer and cylinder housing assemblies which house a clamp ring retainer assembly, a transfer piston assembly and an annular spring member. The clamp ring retainer assembly includes biasing members to float a clamp ring thereby centering the clamp ring and domer die plug with respect to the ram of a bodymaker. Increased piston size, spring position and size are provided to permit increased clamp ring pressure.