Soft aluminium cap for vacuum vessel - has side with internal axial ribs formed in top and bottom zones

摘要

The top zone (5) of the cap has axial inwards-protruding ribs (7) embossed in it, extending over the screw thread beads (2) on the bottle neck, while similar ribs (8) extending as far as the edge are formed in the vertical wall of the bottom zone (6). Two protruding lugs (9) are provided at diametrically opposite points of the bottom zone to form hand grips. - When fitting the cap, the top zone ribs locally distort where they bear against the screw thread beads, forming a thread in the cap, while as the cap side swings inwards the bottom zone ribs from fold points, extending obliquely from below against the peripheral bead (3) on the neck. Thus a locking device is formed to prevent unscrewing, and released by pulling the bottom zone in the radial direction by the lugs before opening for the first time.