Swiss Aluminium Ltd.

Styner & Bienz Ag

Werner Diemi

Rudolf Luthi

Siegfried Bloeck

Erich Hofling

The pre-fabricated pouring outlet in a lid for cans containing carbonated drinks lies basically at an angle of 0.degree. or 90.degree. to the rolling direction of the sheet from which the lid is made. The surface of the lid features at least one ring-shaped stiffening groove which points towards the can interior, is concentric with the periphery of the lid and is interrupted in the region of the pouring outlet. The diameter of the groove is 65-80% of that of the nominal diameter of the can. The stiffening groove raises the resistance of the lid towards pressure from inside the can by about 10%. This means that, when manufacturing a lid which has to withstand a specific pressure from inside the can, and using the same material, the thickness of the lid can be reduced to save material.

Grooved beverage can lid

A method of making the opening in aerosol can tops in two operations on a transfer press. One operation produces a score line on the upper radius of the pre-drawn cylindrical portion which compresses the material and permits a clean and burr-free separation. In the following station the disc is pulled radially towards the center, formed into a cup and ejected downwards. The fact that the material is being compressed in the scoring operation, that the edge thickness is equal to the original material thickness and that the edge of the opening is clean, smooth and free of burrs, permits the subsequent formation of the curl without the risk of splitting when using harder and less expensive material.

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Bern, Switzerland

Werner Diemi