"CLOSURE FOR CONTAINERS, PARTICULARLY A PLUG FOR CHAMPAGNE BOTTLES, AND THE LIKE".

The present invention generally relates to a closure for containers, and particularly a plug for bottles to be preferably employed for closing champagne or sparkling wine bottles, and the like.

While the description below is dedicated to food bottles, particularly wine bottles, it is understood that the teachings of the present invention may be as well effectively applied to containers for any type of substances (either alimentary or not) which require sealing closures suitable, on the one hand, for preventing the substance contained therein from leaking out, and on the other hand, gases and/or foreign substances (including the material of which the closure is composed) from entering the container.

In the field of plugs for wine bottles, cork is the most common material used for their fabrication: this material is expensive and increasingly difficult to obtain, as it comes from well specific plants, and therefore it is available in nature in relatively low amounts.

Furthermore, cork plugs have many problems in terms of functionality: these plugs often damage the wine

contained in the bottles, and give the same a taste that is no longer the original one and that is always unpalatable. When a top quality wine is contained in the bottles, the presence of a faulty plug is wasteful and implies considerable costs.

Even when cork plugs show no defects, it is advisable to periodically replace them (every 10-15 years) to avoid damaging the bottle contents.

Cork also entails problems when it is inserted into and removed from a bottle: in fact, automatic corking machines are subjected to be exposed to dust and pieces of cork that become detached, thus polluting the environment and impairing the quality of the process; furthermore, cork is a non-uniform material, whereby its behaviour differs from one supply batch to the next; finally, when the cork is removed from a bottle, such as by means of an ordinary corkscrew, cork bits are likely to fall within the bottle thus polluting the contents therein. Bottle plugs made of plastic material are already available on the market, which perform equal to or better than cork plugs without the above-mentioned problems, but these plugs always raise objections.

The problem is even more felt with plugs for champagne or sparkling wines, because of the particular

performance required. In fact, on the one hand, a closure is required, which is suitable to withstand the pressure that generates within the bottle following refermentation; on the other hand, the tradition requires that these plugs can be removed without the aid of a corkscrew, from which derives the known mushroom shape which allows grasping the plug and applying a lever effect that is indispensable for removing t±ie same. Champagne plugs are known to be made of synthetic material . A first type is the known mushroom- like plugs made of rigid plastic material, in which the portion of the plug that is intended to be inserted within the bottle neck has a lower diameter than the neck and comprises a plurality of sealing rings. This plug, however, does not ensure a suitable performance and its use is thus restrained to low-quality sparkling wines .

A different type of plug is that described in the patent GB 2 190 072. This plug comprises three elements that are assembled in a complicated manner directly on the bottle neck to form a traditional mushroom-like plug. However, besides the complexity of the plug, a further disadvantage is that it requires a bottle especially designed to the purpose, which has a

particular thread on the neck outer surface. Consequently, this plug cannot be used on normal champagne bottles.

On the other hand, United States patent US 5,803,285 describes a capsule to be arranged on a bottle neck, which allows one to easily insert a normal plug within the bottle neck and that couples with this plug in a firm manner due to a series of teeth and ribs of which the inner wall is covered. Thereby, the plug is made integral with the capsule and can be thus removed by manually acting thereon, like a conventional champagne plug. While this structure substantially has a simple construction and functionality, it has a great disadvantage in that, during the step of inserting the cap, the outer surface of the latter is scratched and damaged when it comes in contact with the teeth and ribs of the capsule, and thus is no longer capable of ensuring proper sealing.

The object of the present invention is to solve the above-mentioned problems of the prior art, by providing a closure made of plastic material for containers, particularly for champagne bottles and the like, which has optimum sealing characteristics, and at the same time, is easy to use and can be adapted to the traditional champagne or sparkling wine bottles.

This problem is solved by means of a closure for containers such as that described in the annexed claims . The present invention will be better described by- means of several preferred embodiments, which are provided by way of non-limiting examples, with reference to the annexed drawings, in which:

Fig. 1 is an exploded, perspective, cut-away view of a first embodiment of a closure for containers according to the present invention;

Fig. 2 is a view of a detail of the plug from Fig. 1;

Fig. 3 is a longitudinal, sectional, side view of a second embodiment of a closure for containers according to the present invention;

Fig. 4 illustrates an exploded, perspective view of a detail of the plug from Fig. 3 ; Fig. 5 is a sectional side view of the plug from Fig. 3 assembled to form the closure according to the invention.

With reference to the figures, the closure for containers according to the invention will be described herein below, which will be generally designated with numeral 1.

The closure 1 comprises a plug 2 and an insertion sleeve 3 for inserting the plug 2 within the neck of container 4.

The plug 2 has a body 5, which is substantially cylindrical and tapered at the end portion 6 that is intended to be inserted within the neck of the container 4. The tapering can have, for example, a rounded profile, such as in Fig. 1, and has the function of favouring the insertion of the plug 2 within the container 4.

At the end opposite the insertion one, the body 5 of the plug 2 has a fixing portion 7 having a greater diameter than that of the body 5, such that the plug 2 substantially takes a T shape. The upper surface 8 of said fixing portion 7 can have, as in the example in the figures, a slightly convex shape such as to mimic the typical shape of champagne plugs.

The fixing portion 7 has, on the side surface 9, means for locking the plug 2 to the insertion sleeve 3. These locking means, in the example, are embodied by an annular relief 10 that circumferentially projects from the side surface 9 of the fixing portion 7 and comes to cooperate with matching locking means being provided on the insertion sleeve 3, as will be described below. The plug 2 is made of plastic material, preferably

an expanded thermoplastic elastomer. While a wide range of elastomers can be used, said expanded thermoplastic elastomer is preferably selected from block copolymers of the type styrene-butadiene-styrene (SBS) , styrene- isoprene-styrene (SIS) , styrene-ethylene-butylene- styrene (SEBS) , styrene-ethylene-propylene-styrene (SEPS and SEEPS) .

The blowing agent can be of. a chemical (such as azodicarbonamide) or more preferably physical type (such as CO ₂ , nitrogen, air, fluorinated hydrocarbons, etc.) More preferably, the blowing agent will be a fluid in the supercritical state, nitrogen in the supercritical state being particularly preferred.

The method used for preparing the plug will be preferably injection moulding of thermoplastic material, in the presence of a blowing agent, within a suitably shaped mould, as well known to those skilled in the art. According to a particularly preferred embodiment, the plug 2 will have a core made of expanded material and a surface layer made of non-expanded material. Thereby, a greater surface rigidity will be combined with the typical flexibility of the expanded material provided therein. A method to be used for preparing this plug provides that a first portion of the thermoplastic material without blowing agent is injected into the

δ mould and the blowing agent is added to the flow of the remaining thermoplastic material being subsequently- injected, such as described for example in the international laid-open application WO 00/54952. The insertion sleeve 3 comprises a substantially cylindrical body 11 having an upper portion 12 for housing the fixing portion 7 of the plug 2 and a lower portion 13 for inserting the body 5 of the plug 2.

The upper portion 12 has an opening 14 having a diameter substantially corresponding to that of the fixing portion 7 of the plug 2, but slightly lower than the outer diameter of said fixing portion 7 as measured at the annular relief 10.

The upper portion 12 further comprises a seat 15 that is arranged between said opening 14 and the lower portion 13 of the insertion sleeve 3. Said seat 15 is suitable to house the fixing portion 7 of the plug 2. Due to the difference between the diameter of the seat 15 (this diameter substantially corresponds to that of the annular relief 10) and that of the opening 14, the rim of the opening 14 forms an undercut edge 16 acting as the locking means in snap cooperation with the annular relief 10 placed on plug 2.

The lower portion 13 of the insertion sleeve 3 has an insertion hole 17 that opens on the lower surface of

the seat 15 and has a substantially equal or slightly lower diameter than the body 5 of plug 2. The walls of the hole 17 are inwardly tapered, such as to define a smaller aperture substantially matching the inlet aperture of the container 4. Thereby, a prompt is created for inserting the plug 2 in the neck of the container 4.

The lower portion 13 of the insertion sleeve 3 has a fork-like sectional profile, such that an inner circular wall 18 and an outer circular wall 19 are created, which are separated by a gap. The inner 18 and outer 19 circular walls end, at the lower part thereof, by a modelled edge which rests, by means of partial or total shape coupling, on the rounded rim of the container 4. The fork-like section of the lower portion 13 of the insertion sleeve 3 can be also replaced by a solid wall, even though the latter is less preferred because of the higher cost (a greater amount of material is used) and less flexibility during the step of inserting the plug 2.

In a second embodiment shown in Fig. 3, 4 and 5, the plug 102 is not totally made of an expanded elastomer, but it comprises a skeleton made of a more rigid plastic material (such as ABS) that is made integral with the body 105 of expanded material.

Said skeleton made of a rigid plastic material comprises an insert 120 that results to be mostly- drowned in the expanded material of the body 105, and a cap 121 covering the lower end of the plug 102. The insert 120 comprises a shaft 122 having a lower disc 123 and an upper disc 124 at the ends thereof. The upper disc 124 has a vertically projecting edge along the perimeter thereof, locking means being arranged on the outer surface thereof, which in the example are embodied by an annular relief 110. Even in this case, the locking means 110 are intended to snap-interact with the undercut edge 16 of the insertion sleeve 3.

The upper disc 124 has a set of through holes 125 for the expanded material to penetrate therethrough during the injection step such as to create the body 105 of plug 102.

One or more support discs 126 are arranged on the shaft 122 (two support discs in the example) .

The cap 121 has a cup shape, which follows the tapered shape of the end portion 6 of the plug 2. The profile of the inner surface of the cap 121 is shaped such as to create a seat for the lower disc 123 of the insert 120. The access opening to said seat has a tooth- profiled rim and has a diameter slightly lower than that of the lower disc 123, such that this disc is snap-

inserted within its seat.

The plug 102 is obtained by injecting the thermoplastic material in the presence of a blowing agent, within a mould in which the skeleton consisting of the preassembled insert 120 and cap 121 has been placed. The thermoplastic materials, blowing agents and methods used are the same as described above for the solid plug 2 made of thermoplastic material. The thermoplastic material, by expanding, will be made integral with the insert 120 and cap 121, thereby forming an individual piece.

The skeleton has a double function. The insert 120 serves both to support the plug 102 in the longitudinal direction, and reinforce the sealing between the latter and the container. In fact, as the elastomeric material is subjected to the pressure exerted by the neck of the container (see for example Fig. 5) , it may elongate over time, thereby releasing the sealing pressure against the container walls: this is prevented by the insert 120, due to the provision of the discs 123, 124, 126, which support the expanded material in several points thereby preventing the same from displacing in the longitudinal direction.

The vertical edge of the upper disc 124, which is exposed to the outside and on which the annular relief

110 is arranged, has a sufficient rigidity to facilitate the snap-engagement with the corresponding locking means arranged on the insertion sleeve 3.

The cap 121, on the other hand, acts as a barrier against the passage of gas, both to prevent CO ₂ from exiting the bottle, and to prevent the air from entering, which is detrimental to wine preservation.

The insertion of the closure 1 in the neck of container 4 is carried out as follows. First, the insertion sleeve 3 is arranged into abutment against the rim of the container 4. The plug 2 , 102 is thus centered and, by applying a suitable downwards pressure, the plug is inserted within the container 4 with the aid of the insertion sleeve 3. At the end of the travel, the locking means (annular relief 10) of the plug 2, 102 are snap-engaged with the matching locking means (undercut edge 16) of the sleeve 3 , such that the plug and the sleeve are made integral to each other thus forming the assembly of the closure 1. This operation may be carried out using conventional wine bottle corking equipment, which are provided with a centering and pushing device.

The traditional metal cage may be placed on the closure 1 and tightened about the neck of the container 4 such as to prevent the inadvertent uncorking of the

container due to the pressure generated therein.

The closure 1 may be removed in a traditional manner using bare hands by directly grasping the sleeve 3 and applying the traditional rotary-oscillatory movements for removing the same.

From what has been discussed above, the advantages of the closure 1 according to the invention are immediately apparent.

The closure 1 substantially consists only of two components, i.e. the plug 2, 102 and the insertion sleeve 3. Its application to the container 4, also due to the snap- (rather than screw-) engagement between plug and sleeve, is thus easy and does not require using complicated equipment, which are not always available to bottling factories. Conventional corking machines can be actually used.

The use of particular bottles, such as having a threaded neck as in the prior art described above, is not required since the sleeve 3 is simply rested on the rim of the opening of the container to be closed.

The provision, on the insertion sleeve 3, of the locking means 16 arranged on a greater circumference than that of body 5, 105 of the plug 2, 102 avoids that an interference may occur, during the insertion step, between said locking means 16 and the surface of the

plug body. Thereby, this surface, which is intended for sealing the container, will not be scratched or damaged, which would alter its sealing performance.

Both the shape of the closure 1 and the modes for removing the same are similar to the traditional ones, which makes this closure attractive also that public who is fonder of the characteristic rituality of oenology.

In the embodiment in which the plug 102 comprises an insert 120 and a cap 121, this plug ensure a higher performance also for a long time.

As will be apparent to those skilled in the art from the above descriptions of some preferred embodiments of the invention, what has been illustrated and described herein should be obviously construed as a non-limiting example of the scope of protection of the present invention such as defined in the annexed claims.

For example, along with the normal ink printing techniques, laser-based methods can be used for providing writings, drawings or inscriptions on the surface of the closure 1 according to the invention. The type of laser and the energy required for this marking method will depend on the plastic material to be marked. For the material used in the closures of the present invention, a NdYAG laser, having 30 to 200 Watt power and 1064 nm wavelength (secondary waves 532-355-266 nm)

will be generally preferred. The plastic material of which the plug is made must be added with a colour- changing master capable of changing colour when struck by the laser beam. A preferred master is SARMATENE ^® from Clariant. The colour-changing master is added in amounts ranging between 1% and 4%, preferably about 2%. The selection of a laser-marking method involving the use of a colour-changing master, instead the laser methods where the marking is produced by surface carbonization, is fundamental, because in the case of a closure for containers in which leaktightness of the container is essential, marking by surface carbonization leads irremediably to unacceptable irregularities on the surface. These surface irregularities would then prevent compliance with the inside surface of the container neck as required for ensuring an airtight closure.

The equipment for carrying out the marking method is of a known type and commercially available and will not therefore be described herein below in greater detail.

A further object of the present invention is a closure for a container, particularly a sparkling wine bottle, comprising: a plug 2, 102 intended to interfere with the inner walls of said container 4, said plug 2, 102

comprising a body 5, 105 and a fixing portion 7, 107, locking means 10, 110 being arranged thereon; and an insertion sleeve 3 suitable to be placed on the opening of said container 4 and comprising a seat 15 for housing said fixing portion 7, 107 of the plug 2, 102, said insertion sleeve 3 being provided with locking means 16 matching the locking means 10, 110 of the plug 2, 102, wherein said insertion sleeve 3 comprises a substantially cylindrical body 11 having an upper portion 12 for housing the fixing portion 7, 107 of the plug 2, 102 and a lower portion 13 for inserting the body 5, 105 of the plug 2, 102, said closure 1 being characterized in that said lower portion 13 for inserting the body 5, 105 of the plug 2, 102 has a fork- like profile comprising an inner circular wall 18 and an outer circular wall 19 separated by a gap, said inner circular wall 18 and outer circular wall 19 ending in the lower part thereof with a modelled edge that is intended to be abutted against the rim of the container 4 by means of partial or total shape-coupling.

This characteristic, independently from that outlined in claim 1, has a substantial advantage over what has been described in the prior art documents, particularly US 5,803,285. In fact, the structure of the plug as described in this document provides an inner

circular wall projecting relative to the outer circular wall as much as to be inserted within the bottle neck. The outer circular wall also fits the bottle neck on the outside, such as to create an astride configuration that requires a considerable force to be mounted on the bottle. Furthermore, the inner and outer circular walls are connected by a plurality of reinforcement ribs that stiffen the assembly. In these conditions, suitable jaws are absolutely required to fit the closure on the bottle, with a consequent change in the filling line of the bottling plant .

Vice versa, the closure as described above resolves this problem by means of an inner circular wall and an outer circular wall that are not inserted inside and outside the bottle neck, respectively, but rest on the rim due to the fact that their end is suitably modelled by means of total or even only partial shape-coupling. Furthermore, the closure outlined herein is not provided with reinforcement ribs between the inner and outer circular walls, which provides a much more flexible structure .