Deep-drawn aluminium screw closure for glass containers under pressure, and deep-drawing device for the manufacture of the top portion of such a closure

摘要

A deep-drawn screw cap made of aluminum for glass bottles under internal pressure, the transition area from the upper end face 1 to the lateral threaded surface 2 has always been deep-drawn until now, should now have at least one undeformed partial area 8. In this way, a section against the lateral mouth edge 7 is omitted and the possibility of a gas outlet is created if the internal pressure of the glass bottle should increase too much. If necessary, several such partial areas 8 should be provided. In the deep-drawing device for a closing head for the manufacture of such rotary closures, the inner recess 12 should have at least one partial extension 14 aligned parallel to the central axis 13 up to approximately the diameter of the upstream recess 11.