Anti-tamper closure

1. An anti-tamper closure for containers having a neck and a mouth with an outer thread on the neck and with a projection disposed below the thread, the closure comprising:

an outer capsule comprising an outer cap and an outer skirt, and

an inner pre-threaded element suitable for closing the mouth of the container, comprising an inner cap having an inner thread suitable for engaging the outer thread of the container and an inner annular element,

in which:

the outer cap is connected to the inner cap in a manner such as to allow the closure to be opened and closed normally,

the outer skirt is connected to the outer cap by outer connection means which, after initial opening, render the outer skirt free to rotate and to translate relative to the outer cap,

the inner annular element is connected to the inner cap by inner connection means which, after initial opening, render the inner annular element free to rotate and to translate relative to the inner cap,

the inner annular element is connected to the outer skirt with respect to translation by retaining means projecting inside the closure, and

the outer skirt extends longitudinally towards the container beyond the retaining means.

2. An anti-tamper closure according to claim 1 in which the retaining means comprise at least one abutment surface suitable for engaging in abutment with an opposing surface formed on the inner annular element.

3. An anti-tamper closure according to claim 2 in which the at least one abutment surface is the upper surface of at least one tongue projecting inside the closure and formed in the outer skirt.

4. An anti-tamper closure according to claim 3 in which the outer skirt has a thickness, and the at least one tongue is bent inside the closure by a distance equal to the thickness of the outer skirt.

5. An anti-tamper closure according to claim 1 in which the inner and/or outer connection means are bridges.

6. An anti-tamper closure according to claim 1 in which the inner annular element comprises a plurality of tongues which project inside the closure and which can be deformed outside the closure on fitting the closure onto the container.

7. An anti-tamper closure according to claim 6 in which the tongues have respective inner surfaces which taper so as to diverge downwardly.

8. An anti-tamper closure according to claim 6 , in which the projection has a lower surface and the tongues are such that they can become jammed against the lower surface of the projection of the container as a result of a longitudinal upward movement after fitting on the container, so as to prevent the inner annular element from passing over the projection after the closure has been fitted on the container.

9. An anti-tamper closure according to claim 7 , in which the projection has a lower surface and the tongues are such that they can become jammed against the lower surface of the projection of the container as a result of a longitudinal upward movement after fitting on the container, so as to prevent the inner annular element from passing over the projection after the closure has been fitted on the container.

10. An anti-tamper closure according to claim 1 in which the outer skirt has an upper end, the outer cap has a lower end, the inner pre-threaded element comprises a groove, and the upper end of the outer skirt and the lower end of the outer cap are curved inside the closure inside the groove in a manner such that, after initial opening, one of the upper end and the lower end comes out of the groove, providing evidence that initial opening has taken place.

11. An anti-tamper closure according to claim 2 in which a circumferential groove is formed in the outer skirt, the circumferential groove extending inside the closure and having an upper surface, wherein the at least one abutment surface is the upper surface of the circumferential groove.

12. A method of producing an anti-tamper closure for containers having a neck and a mouth with an outer thread on the neck and with a projection disposed below the thread, the closure comprising:

an outer capsule comprising an outer cap and an outer skirt, and

an inner pre-threaded element suitable for closing the mouth of the container, comprising an inner cap having an inner thread suitable for engaging the outer thread of the container and an inner annular element,

in which:

the outer cap is connected to the inner cap in a manner such as to allow the closure to be opened and closed normally;

the outer skirt is connected to the outer cap by outer connection means which, after initial opening, render the outer skirt free to rotate and to translate relative to the outer cap,

the inner annular element is connected to the inner cap by inner connection means which, after initial opening, render the inner annular element free to rotate and to translate relative to the inner cap,

the inner annular element is connected to the outer skirt with respect to translation by retaining means projecting inside the closure, and

the outer skirt extends longitudinally towards the container beyond the retaining means, the method, comprising the steps of:

producing the outer capsule,

producing the inner pre-threaded element, and

inserting the inner pre-threaded element in the outer capsule,

without comprising any manufacturing step after the insertion step.

13. A method according to claim 12 in which the retaining means comprise at least one abutment surface suitable for engaging in abutment with an opposing surface formed on the inner annular element.

14. A method according to claim 13 in which the at least one abutment surface is the upper surface of at least one tongue projecting inside the closure and formed in the outer skirt.

15. A method according to claim 14 in which the outer skirt has a thickness, and the at least one tongue is bent inside the closure by a distance equal to the thickness of the outer skirt.

16. A method according to claim 12 in which the inner and/or outer connection means are bridges.

17. A method according to claim 12 in which the inner annular element comprises a plurality of tongues which project inside the closure and which can be deformed outside the closure on fitting the closure onto the container.

18. A method according to claim 17 in which the tongues have respective inner surfaces which taper so as to diverge downwardly.

19. A method according to claim 17 , in which the projection has a lower surface and the tongues are such that they can become jammed against the lower surface of the projection of the container as a result of a longitudinal upward movement after fitting on the container, so as to prevent the inner annular element from passing over the projection after the Closure has been fitted on the container.

20. A method according to claim 18 , in which the projection has a lower surface and the tongues are such that they can become jammed against the lower surface of the projection of the container as a result of a longitudinal upward movement after fitting on the container, so as to prevent the inner annular element from passing over the projection after the closure has been fitted on the container.

21. A method according to claim 12 in which the outer skirt has an upper end, the outer cap has a lower end, the inner pre-threaded element comprises a groove, and the upper end of the outer skirt and the lower end of the outer cap are curved inside the closure inside the groove in a manner such that, after initial opening, one of the upper end and the lower end comes out of the groove, providing evidence that initial opening has taken place.

22. A method according to claim 13 in which a circumferential groove is formed in the outer skirt, said circumferential groove having an upper surface, wherein the at least one abutment surface is the upper surface of the circumferential groove.