Cork based closure, with double seal protection diaphragm

Abstract

 The closure (10) comprises a substantially cylindrical cork-based part (12) and a circular diaphragm (14) applied coaxially to that face (16) of the cork-based part (12) intended to lie inside the bottle (11). The diaphragm (14) is of plastic material suitable for contact with foods and has a diameter less than the maximum diameter of the cork-based part (12), but greater than the inner diameter of the neck of the bottle (11). The diaphragm (14) comprises: a coaxial circular first portion (18) of diameter just greater than the inner diameter of the relative neck part of the bottle (11), such that the first portion (18) interferes with the interior of the neck of the bottle (11) to provide a first seal; and, to provide a second seal, a more external annular second portion (20) forming a single piece with the first portion (18) and coaxial thereto. The second portion (20) has a thickness decidedly less than that of the first portion (18) at least with regard to that zone of this latter (18) closest to the second portion (20).

Description

[0001] The present invention relates to both natural and agglomerate cork-based closures traditionally used for sealing bottles containing liquids, and in particular alcoholic beverages.

[0002] As known to the expert of the art, the most valued closures of this type consist of a single piece of cork and are known as natural closures, used in particular for quality wines.

[0003] Less costly closures have also been long known, these being again cork-based but being produced by binding cork granules together using a suitable binder. This has also enabled that cork (representing the major part of cork production) to be used which is not suitable for producing natural closures, while at the same time satisfying the increasing market need for closures which has arisen in recent decades, while cork production during the same period has remained virtually constant.

[0004] It has also been long known, in the case both of natural closures and of agglomerate closures, that their constituent cork can present defects which even substantially modify the organoleptic profile of the beverages contained in the relative bottles. As known to the expert of the art, these defects are mostly already present in the starting cork, but can also be acquired during the preparation of the closures or even during their storage if held in an unsuitable environment. The result is that the beverage contained in a bottle sealed with a closure presenting a defect of this type assumes an abnormal taste, which in practice nullifies the commercial value of the beverage contained in the bottle. The damage is evidently greater the greater the value of the beverage.

[0005] It is also well known to the expert of the art that natural closures can present uniformity defects which can enable the beverage to seep through the closure, and can also enable gaseous exchange with the exterior, giving possible rise to undesirable beverage oxidation phenomena.

[0006] The appearance on the market some decades ago of closures of a plastic material suitable for contact with foods has effectively enabled the aforesaid problems to be overcome.

[0007] Italian Patent 12900357 attempts to overcome the aforesaid drawbacks by providing a natural or agglomerate cork-based closure comprising, on that face thereof which when inside the bottle faces the beverage contained therein, a circular protection diaphragm which should obviate the aforesaid drawbacks. The diaphragm is of a plastic material which is suitable for contact with foods and does not transfer any particular taste or smell to the beverage, in particular polyethylene or polyethyleneterephthalate (PET), silicone or more generally an elastomer suitable for food contact.

[0008] In order to protect the cork base of the closure, the diaphragm must have a diameter at least slightly greater than the inner diameter of the bottle neck once sealed with that closure, such that the diaphragm edge exerts a certain pressure against the inner wall of the bottle neck. If this is not the case, liquid or gas could seep between said edge and the inner wall of the neck, to jeopardize the required protection of the cork-based part of the closure.

[0009] According to the aforestated patent, the diaphragm is conveniently applied to the relative cork-based part by adhesive bonding using a suitable adhesive compatible with food use, or by injection-overmoulding, or by casting onto the cork part.

[0010] According to the patent, that surface of the cork-based part which comes into contact with the diaphragm presents recesses or grooves to receive corresponding projections or ribs with which the diaphragm is provided, in order to improve the fixing of this latter to the cork-based part.

[0011] The aforedescribed closure has not however had the expected success because essentially it is unable to ensure the seal between the cork-based part of the closure and the bottle interior. In this respect it has been found that because of the considerable deformations which the cork-based part undergoes during the sealing operation, there is no guarantee that the entire diaphragm remains adhered to the cork-based part, as the bottling operation gives rise to peripheral detachment zones between the diaphragm and the cork-based part, such detachment compromising the seal between the diaphragm perimeter and the inner surface of the bottle neck. Another drawback is the somewhat unpleasant appearance which the closures assumes after its removal, this being due to the fact that the diaphragm partly prevents the return of the cork-based part substantially to its initial diameter.

[0012] The object of the present invention is to obviate these drawbacks, to hence solve the relative technical problem.

[0013] This object is attained by virtue of the closure according to the accompanying claim 1. Other characteristics of the closure of the invention are defined in the dependent claims.

[0014] It is evident that the closure of the present invention can be produced either in the format normally used for bottles for still wines or in the format (so-called mushroom-shape) used for bottles for sparkling wines.

[0015] The invention will be more apparent from the ensuing description of some embodiments thereof given by way of example. In this description reference will be made to the accompanying drawings, in which:

Figure 1 is a schematic lateral view of a closure according to the present invention;

Figure 2 is a coaxial section therethrough on the line 2-2 of Figure 1;

Figure 3 is a plan view of the closure of Figure 1 taken from above;

Figure 4 is a plan view thereof taken from below;

Figure 5 is a lateral view of just the protection diaphragm;

Figure 6 is a plan view thereof taken from above;

Figure 7 is a plan view thereof taken from below;

Figure 8 is a schematic coaxial vertical section through the neck part of a bottle of sparkling wine type, sealed by a closure of the present invention;

Figure 9 is an enlargement of the detail 9 of Figure 8.

[0016] As can be seen from the figures, the closure shown therein, indicated overall by 10, comprises either a natural or an agglomerate cork-based part 12, and a circular diaphragm 14 of a plastic material suitable for food contact, such as polyethylene, polyethyleneterephthalate, or silicone. The cork-based part 12 has an overall cylindrical shape, the diaphragm 14 being applied coaxially to its circular lower face 16, which is intended to lie inside the bottle and to face the beverage contained therein. The diaphragm 14 has a diameter which is less than the diameter of the cork-based part 12, but must be greater than the inner diameter of the relative part of the bottle neck.

[0017] As can further be seen from the figures, the diaphragm 14 comprises a coaxial circular first portion which must have a diameter greater than the inner diameter of the relative neck part of the bottle for which the closure is intended, such as to provide a first seal, and a more outer annular second portion 20, intended to provide a second seal and forming a single piece with the first portion 18 and being coaxial thereto. The second portion 20 has a thickness decidedly less than that of the first portion 18, in particular than that zone of this latter closest to the second portion 20.

[0018] In the specific illustrated case, means are provided for fixing the diaphragm 14 to the cork-based part 12, namely a coaxial annular rib 22 and a central peg 24 which are adapted to be received respectively in a coaxial circular groove 26 and in a coaxial dead hole 28 provided in the lower circular face of the cork-based part 12. The diaphragm 14 can evidently be produced separately and bonded in position, by a suitable adhesive, to the cork-based part 12 in which the circular groove 26 and the dead hole 28 have been previously provided, or can be injection-overmoulded onto the part 12.

[0019] The means for fixing the diaphragm 14 to the cork-based part 12 can evidently be different from those shown. In particular, instead of the annular rib 22, angularly equidistant pegs can be provided, similar to the peg 24 or inclined to the axis of the cork-based part 12.

[0020] It should be noted that the first portion 18 of the diaphragm 14 (which, as stated, provides a first seal) is thicker than its second portion 20, particularly in the vicinity of this latter. The first portion 18 hence has a certain robustness, enabling it to be fixed securely (in particular by said fixing means) to the cork-based part 12, in addition to making it certainly less deformable than the second portion 20 which, having a decidedly smaller thickness, is much more flexible so that it is able to follow the considerable deformations which the surrounding zone of the cork-based part 12 undergoes during the bottling stage, because of which the second portion 20 is bent upwards in practice and is pressed against the inner surface of the bottle neck by the deformed surrounding cork, so that the second portion 20 acts as a gasket providing a second seal. Figure 8 shows a closure of the present invention, used for sealing a bottle of sparkling wine 11, because of which it has the characteristic mushroom shape 10A. The closure of the present invention can obviously also be used for flush-sealing normal bottles, the relative situation not being shown as it is evident (in all cases the lower part of the flush-fitted closure is in the same situation as that of the closure 10A of Figure 8).

[0021] From Figure 8 it will be apparent that the closure of the present invention not only prevents any contact between the liquid 13 contained in the bottle 11 and the first cork-based part 12, but also eliminates the phenomenon of seepage and gaseous exchange with the outside.

[0022] It should also be noted that in its central zone, the diaphragm 14 presents a depression. It has in fact been found that with this expedient, when bottling has taken place (involving a significant deformation of the cork-based part 12), the free surface of the first portion 18 of the diaphragm 14 is able to assume a substantially flat configuration.

Claims

1. A closure (10) for sealing bottles (11) containing liquids, comprising a substantially cylindrical cork-based part (12) and a circular diaphragm (14) applied coaxially to that face (16) of the cork-based part (12) intended to lie inside the bottle (11) and face the beverage (13) contained therein, the diaphragm (14) being of plastic material suitable for contact with foods and having a diameter less than the maximum diameter of the cork-based part (12), but greater than the inner diameter of the relative neck part of the bottle (11), characterised in that the diaphragm (14) comprises: a coaxial circular first portion (18) of diameter just greater than the inner diameter of the relative neck part of the bottle (11) for which the closure (10) is intended, such that the first portion (18) interferes with the interior of the neck of the bottle (11) to provide a first seal; and, to provide a second seal, a more external annular second portion (20) forming a single piece with the first portion (18) and coaxial thereto, the second portion (20) having a thickness decidedly less than that of the first portion (18) at least with regard to that zone of this latter (18) closest to the second portion (20).

2. A closure (10) as claimed in claim 1, wherein the diaphragm (14) is of polyethylene or polyethyleneterephthalate or silicone.

3. A closure (10) as claimed in claim 1, wherein means (22, 26, 24, 28) are provided for fixing the diaphragm (14) to the cork-based part (12).

4. A closure (10) as claimed in claim 3, wherein the means for fixing the diaphragm (14) to the cork-based part (12) comprise a coaxial annular rib (22) and a central peg (24) which are adapted to be received respectively in a coaxial circular groove (26) and in a coaxial dead hole (28) which are provided in the lower circular face of the cork-based part (12).

5. A closure (10) as claimed in claim 1, wherein the diaphragm (14) is produced separately and applied to the cork-based part (12) by a suitable adhesive.

6. A closure (10) as claimed in claim 1, wherein the diaphragm (14) is produced directly by injection-overmoulded it onto the cork-based part (12).

7. A closure (10) as claimed in claim 1, wherein the first portion (18) of the diaphragm (14) presents, in its central zone, a depression which, when the sealing operation has been completed, enables a substantially flat free surface of the first portion (18) of the diaphragm (14) to be achieved.

Drawing