Such closures are normally composed of a closure crimped or in some way anchored directly to the opening finish by means of a ring-type relief or a bayonet system. Such type of closures have been known for years and are diffused in the drinks market generally produced in metal or plastic and suitable for containers either made of glass or plastic.

Such solutions are generally without tamper-evident seal and therefore it is added afterwards a paper label over both closure and container or else the closure itself is secured by means of a heat-shrunk sleeve.

Furthermore in other cases, as in the so-called "crown cork/', it is necessary to use a tool to be able to open the container.

Another problem normally encountered in the solutions using plastic materials is that of permeability to gases that in this case is particularly evident when coupled with containers with a large opening and liquid products sensitive to loss of carbonation or to oxidation.

The aim of the invention is to produce a closure of the type described above that would allow its usage on containers for carbonated drinks, while being easy and

relatively economical to produce, and would allow to maintain a seal while under pressure and would allow opening the closure by the simple pulling of a tab without the assistance of tools or special skills.

The objective of the invention is achieved by means of a closure composed of two elements: a first element that includes a disk with means of sealing for the opening of the container while a second element, in the shape of a ring, retains the first element onto the opening by anchoring it to the bead extending along the perimeter of the opening finish of the container itself.

The first element is formed by a metallic disk that includes a seal of suitable material moulded over onto it in such a position as to embrace the external periphery of the opening finish for a predetermined height while a circular flange in contact with the inside of the container seals the opening of the container.

The second element is formed by a ring with a"C" shaped section that embraces the disk and the outer perimeter of the bead extending around the opening of the container.

Such element is pre-assembled to the disk and therefore the two elements are applied to the container together and at the same time.

In accordance with the invention at the time of capping the ring is not deformed by elasticity to go over the external side of the bead of the opening of the container but, as the length of its circumference is adjustable, it is pre-assembled with a diameter slightly

wider than of the external bead of the opening of the container.

When the closure settles onto the opening of the container with a suitable capping machinery the ring is tightened that will then adopt the final dimension useful to retain the disk in a sealing relationship onto the opening of the container. Advantageously the ring is fitted with a pull tab that maintains in the locked position the two overlapped ends of the ring itself, while at the moment of opening the container the tab may be removed or bent to allow the unlocking of the two ends.

The present invention, as it will be better explained later, allows furthermore other and further advantages that will be illustrated in the description of the preferred solution together with the drawings wherein: Fig 1 is represented a prospective view of the complete closure, fixed on the container finish.

Fig 2 is represented a vertical section of the closure according to axis A-A, with the retaining ring in a intermediate position before tightening.

Fig 2a is represented a detail of the vertical section of FIG 2.

Fig 2b is represented another detail of the vertical section of FIG 2.

Fig 2c is represented an orizontal section along the axis D-D of the closure.

Fig 3 is represented a vertical section of the closure according to axis A-A with the retaining ring in the final sealing position.

Fig 3a is represented a detail of the vertical section of FIG 3.

Fig 4 is represented a orizontal section along the axis B-B of the closure with the retaining ring in the intermediate position before tightening.

Fig 4a is represented a detail of FIG 4.

Fig 4b is represented a detail of FIG 4a.

Fig 5 is represented an orizontal section along the axis B-B of the closure with the retaining ring in the final sealing position.

Fig 5a is represented a detail of FIG 5.

Fig 6 is represented a detail of a vertical section of the closure along the axis C-C passing across the pull-tab.

With reference from FIG 1 to FIG 3a, it is overall indicated that 1 a closure applied to a container 2 fitted with a circular lip 3 extending along the external perimeter of its neck 4.

The closure 1 is composed of a disk-like element 5, preferably in metal, including sealing means, and produced by over moulding a crown in plastic materials 6 that covers the outer edge of the disk component itself.

In order to guarantee the anchoring between the two components described above, in the disk-like element 5 are made holes 7 near its external edge that allows to connect the upper side 8 and the lower side 9 of crown 6.

Crown 6 extends downward on the outer bead of the neck of container 2 for a short space by means of a circular flange 10 while two circular relieves 11 and lla lie over the flat surface of the neck opening 4 assuring the sealing under pressure.

The circular flange 10 consists of a plurality of binding segments 10a and lOb. Said binding segments are separate from each other by slots 12. In order to secure the disk-like element 5 inside of the looking ring 15 before capping at least three of the binding segments are moulded bent outwards as shown in the right side of FIG 2 and in FIG 2b where are numbered with lOb.

Externally to the disk-like element 5 is mounted a ring overall indicated with 15 which has a"C"shaped axial section whose upper wing 16 lies unto the upper wall 8 of crown 6 while the lower wing 17 engages under the bead of the lip 3 of the neck of the container 2.

Ring 15 is fitted with an interruption along its circumference and the connection between its two free ends is obtained by means of two appendixes 18 and 19 that overlap for a limited space as indicated in FIG 4 and FIG 4a.

The closure, before been applied to the container is pre-assembled with appendixes 18 and 19 partially overlapping. On the external surface of appendix 19 are positioned axial saw-tooth indicated and 20 and 20a, while on the internal surface of appendix 18 are positioned axial saw-teeth 21 and 21a. In the intermediate pre-assembly position at least one tooth 20 engages onto one tooth 21.

Advantageously, as indicated in FIG 4b the inclined back of saw tooth 20 is oriented towards appendix 18 helping the overcoming of tooth 21 whose back is instead oriented towards the appendix 19. The face of tooth 20 forms preferably a"X"angle comprised within 5° and 20° with the radius passing on the edge of the tooth, while the back will have an angle"Y"comprised within 60° and 75°. The inclination of the two opposite faces overlapping of the saw-teeth 20 and 21 facilitate the engagement of the two appendixes of the ring and their correct positioning.

The FIG 6 shows as the positioning is also assured by means of a tab 22 extending axially in correspondence with appendix 19 and connected by means a shoulder 23 to the upper wing 16 of ring 15.

Shoulder 23 is fitted with a weakening line 21 that allows the separation of tab 22 from ring 15 at the moment of opening the container 2. The tear-off tab 22, during the phase preceding the capping operation, maintains in position the overlapping appendixes of the ring thus avoiding that the ring opens up and therefore that the disk-shaped top comes apart from the rest of the closure.

During the capping operation the closure is positioned on top of the neck of container 2 and ring 15 positions itself around neck finish 3 without any interference between the neck finish and the lower wing 17 of the closure. By means of a suitable capping head a vertical pressure is applied onto the closure and by means of mobile radial elements on the capping head the external diameter of ring 15 is reduced by increasing the overlapping of the two appendixes 18 and 19. Preferably, as shown in the FIG 5 and FIG 5a of the example of realisation of the invention the saw-teeth are at least two for each appendix.

It is thus achieved the overcoming of the saw-teeth 21 and 21a in relation to saw-teeth 20 and 20a, securing the positioning of wing 17 under the circular bead 3 of opening finish 4 of container 2.

In this way it is improved the seal of the container by means of appendixes 11 and lla of crown 6 that position themselves on the top surface of opening finish 4 of container 2. The tear tab 22 will undergo a deformation by elasticity during such overcoming and, when the two appendixes 18 and 19 will have reached the final position, it will ensure the irreversibility of their sliding movement and it will avoid therefore the accidental opening of the container.

At the same time the binding segments 10a snap under the bead 14 of opening finish 4 of container 2.

The binding segments 10b moulded bent outwardly thanks to their flexibility bend towards the bead 14 and engage under the same bead 14 like the other binding

segments 10a. Between the lower part of the bottle bead 14 and the upper part of the bead 13 of the binding segments 10a and 10b a suitable gap is provided for allowing the venting process during opening.

The consumer, in order to open the container, will have to flip upwards the tear off tab 22 freeing in the process the two appendixes 18 and 19 of ring 15 and by applying a full force in a radial direction the saw-teeth will be disengaged, the ring will be open and it will be possible to remove it and therefore freeing the disk-like element of the top seal. The sealing means 11 and lla relax or loose the pressure applied over the mouth of the container 2 for hermetic purpose. Thus the venting process take place in a secure way, considering that the binding segments 10a grip under the neck finish bead 14 of the container 2. The binding segments 10b thanks to their resilient memory bend outwardly and consumer can use one of them to pull-off the disk-like element 5 from the container.

The closure, according to the present invention, is assembled to form a single element which can be handled individually simply by inserting along axis x-x the first element onto the second element of ring-like form partially closed, so that the two elements do not become separated during handling and transport.

The closure, assembled in such a way, is ready to be positioned onto the opening finish of container by means of a device that exerts a vertical pressure and at the same time tightens its external lateral surface.

The advantage that is obtained from using a closure according to the invention consists in the fact that the ring that secures the top to the container is not deformed by elasticity during the capping operation but it is tightened around the opening finish by means of a radial movement without any stress being applied to the closure.

In this way any deformation or enlargement that may compromise the seal is avoided, the materials employed to manufacture the ring need not be particularly resilient and tough at the same time, and therefore difficult compromising solutions are avoided where maintaining the seal over a long period of time, particularly for carbonated products or sensitive to oxidising or to contact with other gases, is not easy. Another advantage that is obtained with a closure according to the invention is to have an axial push that acts on wing 17 of the ring that may be sized as required due to the fact that it does not have to overcome elastically the opening finish 3 during capping, and such feature makes this closure particularly suitable for capping large mouth containers. The axial pressure is marginal on the saw- teeth that hold the two appendixes of the ring together and therefore it is sufficient a minimum contrast to hold them together. Such a contrast is assured by a tab that when flipped upward at the moment of opening is used as grip to release the ring and to separate it from the container.

The closure according to the invention allows therefore the closing of containers for carbonated drinks overcoming the setbacks presented by devices of known techniques. The present invention is realised in a

device that guaranteed the seal of pressured containers and at the same time is of easy and simple fabrication and of easy use. Obviously an expert of this technology in order to satisfy specific and contingent requirements may introduce numerous specifications and variations to the closure as described above, without departing the scope thereof as defined by the following claims.