EP4134323A1

EP4134323A1 - Cap for hermetically closing containers with pressure and/or gasified products

Info

Publication number: EP4134323A1
Application number: EP22382782.5A
Authority: EP
Inventors: José Luis GOMEZ CAO
Original assignee: Individual
Current assignee: FIZZYCAPS, SL
Priority date: 2021-08-11
Filing date: 2022-08-11
Publication date: 2023-02-15
Also published as: ES2933755A1

Abstract

A cap (1) for hermetically closing containers containing pressurized and/or gasified products.

Said containers (29) comprise a mouth (30) having an annular inlet; the cap (1) comprises:
- a head (4) of the cap (1),
- a protrusion (3) having a cylindrical shape, that defines an top base (20) that is attached to the head (4), and a free lower base (21); said protrusion (3) being projected perpendicularly to the horizontal plane of the head (4), and comprising a blind cylindric drain (7), wherein said protrusion (3) is configured to be inserted into the annular inlet of the mouth (30) of the container (29) and to fit, by tightening, with an inner cylindrical surface (31) of said mouth (29) of the container;
- a tightening wall (2), connected to the head (4) and arranged in cantilever with respect to the head (4) that surrounds, at least partially, the container lip (32); said tightening wall (2) having a larger diameter than said protrusion (3); and wherein the tightening wall (2) adapts to the container lip (32);
- the cap (1) is made of an elastically deformable material; and
- the head (4), the protrusion (3) and the tightening wall (2) are formed in one piece.

Description

A cap for hermetically closing containers containing pressurized and/or gasified products, wherein said containers comprise a mouth with an annular inlet; and the cap comprises: a head of the cap; a protrusion having a cylindrical shape that defines an top base that is attached to the head and a free lower base; said protrusion being perpendicularly projected towards the horizontal plane of the head and also comprising a blind cylindrical drain; wherein said protrusion is configured for inserting into the annular inlet of the mouth of the container and to fit, by tightening, with an inner cylindrical surface of said mouth of the container; a tightening wall, connected to the head and arranged in cantilever with respect to the cap head, which surrounds, at least partially, the lip of the container, said tightening wall having a larger diameter than said protrusion; and wherein the tightening wall fits the lip of the container. The is made of an elastically deformable material; and the head, the protrusion and the tightening wall are formed in one piece; is characterized in that the cap head of the cap comprises a concave curved surface at the top base of the protrusion, and in that said concave curved surface, when the gas exerts pressure out of the cap, the curvature is reduced, thus increasing the volume of the protrusion and expanding its top base, increasing the pressure exerted by the top base against the inner wall of the mouth.

OBJECT OF THE INVENTION AND TECHNICAL FIELD

The present invention comprises a cap for hermetically closing the mouths of containers, such as bottles, that contain pressurized and/or gasified products, such as sparkling drinks, rigidly attached to said mouth. Said cap is specially adapted for use in the "tirage" of sparkling beverages such as certain wines, since it can be inserted and removed from the container mouths by either manual or automatic means in a simpler, faster, and more economic manner that the stoppers or caps that can be found in the market at present.
The invention belongs to the field of packing and closing of containers suitable for holding fluids and gas, and more specifically the sector of caps or stoppers for bottles that require or include the "tirage" process.

BACKGROUND OF THE INVENTION

Currently, in the industry of sparkling beverages such as champagne or cava wine, a fermentation process can be carried out using the method known as "champenoise" or "tirage", where fermentation takes place in the same bottle in which the beverage is bottled.
The method consists of adding the beverage a blend of sugar and yeast, which is known as "liqueur de tirage".
This process consists of three clearly differentiated stages. A first stage of bottle capping, in which the bottles are filled with a beverage such as a previously fermented wine and then the bottles are closed with a temporary cap, thus preparing the bottles for the next step. A second stage of fermentation, where the closed bottles are stored at least for nine months, where they normally reach inner pressures between 6 and 10 kg and even more, depending on the environmental temperature. A third stage of disgorgement, in which the bottles neck is frozen. The cap is then removed by automated means with disgorging machinery, then to place a final cork stopper, attached with a muselet.
Being subjected to these pressures in the fermentation stage, a regular cork stopper, as it is well known by the public, cannot withstand a hermetic sealing on its own, as it would be expelled by the pressure exerted by the gas.
Known in the market for use in this second fermentation are suitable caps that consist at least of two pieces that move axially, one with respect to the other, such as the caps or the stoppers described in documents ES1030658U , ES1044376U , and ES2566202B1 .
These documents describe a stopper or cap for temporary or provisional use, that is, not final, which are suitable to be used in the second fermentation of the beverage that takes place in the bottle. The functioning of these stoppers relies on an internal piece or cap that can be provided with legs or flaps, and which is fitted from inside and outside the mouth of the container, and of an outer retention ring suitable to be tightened from the outer side of the cap over the moth of the container, namely over the neck ring.
These caps, however, have disadvantages or problems that arise specially during the closing and the disgorgement of the containers. For example, the heavy total weight required for an adequately hermetic sealing of a bottle mouth increases the price of the end-product, which complicates high scale commercialization thereof. The significant weight also impacts on other aspects, such as the number of caps that can be stored in each box, besides the heaviness of the boxes.
On the other hand, the outer ring system inherently consists of the ring being attached to the cap, which attachment must be torn in order to lower the ring to a fitting position. This tearing generates plastic debris and becomes a real problem when large numbers of containers are closed.
Another drawback of these stoppers arises during transportation, as well as during the handling stage that takes place between the production and the capping of the product: tearing occurs in the ring-cap union resulting in dimensional changes that affect the correct functioning of the capping machinery.
The diameter of the stopper, with the outer ring, is also larger than the maximum allowed by the system that is normally used in large scale production, a fact that prevents the industrialization of this specific process, so that these stoppers or caps are not viable for large amounts clients.
Also, regarding the large outer diameter, there is a certain process where the cap must be fitted into guiding rails of a certain width, which width is narrower than the total diameter of the cap, a fact that determines and requires that the clients must introduce changes in their own facilities if they are to use the present caps.
In addition to these drawbacks, the caps including legs or flaps run the risk of coming off during the capping process, thereby affecting the correct hermetic sealing of the container.
In addition to these design disadvantages, there is also the problem of the use since this type of caps require a two-stage closure: a first stage when the cap is place on the sealing area of the mouth and a second stage when the ring is lowered to perform the tightening.
This inventor has developed and designed different two-pieces caps for sparkling beverages: the stopper itself and the ring that locks the cap in case of an accidental opening due to the pressure. The relative documents are cited here bellow.
Spanish Utility Model ES1035703 , "Improved stopper", of the year 1996, describes a stopper having a central introductory neck in the mouth of the container and an outer casing provided with retention means outside the neck ring. The stopper also has locking means that ensure the sealing, and it includes an upper cap provided with a sealing ring. This independent upper cap is then joined to the rest of the stopper in the bottling phase.
State of the art is also Utility Model ES1044376U "Improved cap for containers of pressurized products" of the year 1999, which describes a stopper for containers holding pressurized or gasified liquids which comprises two pieces, the first is the body of the stopper itself and the second is ring intending to exert pressure on the lateral surface of the stopper in order to block the corresponding neck of the bottle; the body is cut in the direction of the generators, the ring is attached to a pull ring to effect the opening after release by the axial movement of the ring with respect to the body fitted to the neck ring of the bottle.
Lastly, it is worth mentioning the Utility Model by the same inventor ES1149140U "Assembly of cap and cap locking hood for shipping sparkling wines" of the year 2015, which consists of an assembly of a cap and a cap locking hood for shipping sparkling wines configured for being applied to a bottle with a crown cap having an annular recess in its outer surface, the cap comprising a capping section and an attachment skirt that extends from the perimeter of the capping section and which is provided with at least one radially and inwardly oriented protrusion intended to fit into the annular recess in a locking configuration of the assembly; the skirt being a hollow cylinder sealed by an upper cap, so that, depending on the extent of insertion of the cap into the hood, there may be two extreme configurations: a locking configuration, wherein a part of the hollow cylinder surrounds the outer surface of the attachment skirt, so that it cannot be opened; or an unlocking configuration, wherein the hollow cylinder section is not opposing the outer surface of the fixing skirt and therefore can be deformed; the protrusion or more protrusions of the annular recess can be dislodged and the assembly can be removed from the bottle.
Irish document IE2000488A "CLOSING STRUCTURE FOR BOTTLES, PARTICULARLY FOR BOTTLES CONTAINING SPUMANTE WINE OR SPARKLING WINES" is a patent application of the year 2000 . The object of the invention is a closing structure for bottles, particularly for bottles containing spumante wines or sparkling wines comprising: a cap head element having basically a dome-shaped form and a larger diameter than the external diameter of a neck of the bottle; an internal element projecting at the bottom from the cap head element, having a basically tubular shape and an external diameter smaller than the internal diameter of the neck of the bottle, and an external side element connected to said cap head element and surrounding said internal element These three elements are joined into a single piece but they perform different functions. This document already describes the idea of a one-piece stopper, although it forms different parts.
European Patent EP3450344 "Cap and method of its production" of the year 2017, in the name of PELLICONI & C. S.P.A. describes a crown cap that can be used for the classic production method of sparkling wines. The object of the invention is a cap for the fermentation in bottles of sparkling wines, comprising a metal capsule and a sealing element, which is situated inside the concavity of the capsule and is cup-shaped for collecting the sediments of the wine during the fermentation step in the bottle; the cap being characterised in that the sealing element is shaped and constrained on the capsule for inserting and moulding a plastic material directly inside the concavity of the capsule; the sealing element being shaped according to a disc-shaped base, adhering to and integral with the bottom of the concavity of the capsule, and according to an annular collar, which rises from the base for engaging in a sealed fashion with the neck of a bottle, wherein the annular collar is defined by a single annular panel which rises from the base, between a first annular end of the panel which is located on the base and a second annular end of the panel which is located in a position distal from the base and the second annular end facing in the shape of a 'U' towards the outer periphery of the base and with the concavity facing towards the base.
It is worth pointing out US Patent US7028588 "QUICK-TWIST POP- OFF CLOSURE", by Stull Technologies , which describes a closure for a container for holding contents therein generally comprises a surface for gripping the closure in order to twist it in either direction to open it. The closure has downwardly projecting teeth on its underside; the container has upwardly projecting teeth, which mate with the downwardly projecting teeth of the closure. An outer ring on the closure circumscribes and holds in place the upper lip of the container in the closed position. Twisting of the closure in either direction causes the closure to be released from the container. This patent, although it claims a particular closure with teeth, it describes a cap that comprises a single piece with a cap head and a protrusion that is inserted under pressure in the mouth of a container.
US Patent US4856668 "BOTTLE CLOSURE FOR CHAMPAGNE BOTTLE AND THE LIKE HAVING THREADED MOUTHS" of the year 1989 , describes a bottle closure, which is useful more particularly for champagne bottles having threaded mouths, and wherein the body of the closure is unitary and is made of plastic and comprises a stopper like sealing shank which penetrates into the neck of the bottle. In this type of bottle closure, the shank runs centrally from the inner surface of the end of the cap, and the internal surface of the wall of the cap comprises a thread with which the external thread of the neck of the bottle can be engaged. The sealing shank projects beyond the area which carries the thread, a bead surrounding the neck of the bottle is provided at the upper end of the neck, and the external thread of the neck is provided between the bead and the upper edge of the neck of the bottle.
US patent US4331248 "SELF LOCKING CONTAINER CLOSURE" dates from the year 1982 . The invention refers to a one-piece container closure for use on a container of the type having a neck, a rim at the end of the neck, the rim circumscribing the mouth edge of the container, and a ring extending around the neck; the closure comprises: an upper part adapted to be pressed against said rim to seal said container; a skirt hanging from said upper part to surround a part of said neck, said skirt having an upper edge attached to said upper part, a lower edge opposite said upper edge, said lower edge being adapted to extend beyond said ring, and a plurality of inwardly directed retainers, said retainers having means for rotationally biasing the retainers away from the ring when said retainers extend beyond the ring in the container said retainers also include a ring engaging surface adapted to engage below said ring to secure the closure on said container; and means, which surround the aforementioned retainers, which are removably attached to said skirt at the lower edge, to restrict the radial movement of the retainers.
It is also worth mentioning patents FR2176801 , US5723085 , CH583646 , FR2162266 , GB920937 , GB970531 , FR2103516 and GB1061220 .
Lastly, single-piece caps are known, such as the one described in the British patent GB867896 "IMPROVEMENTS IN OR RELATING TO BOTTLE STOPPERS" of the year 1959 , which refers to a bottle stopper of resilient thermoplastic material, e.g. polythene, comprises a sleeve having ribs, a skirt made rigid by the thickness of its wall and the lower end of which may be torn or cut off due to an annular portion of lesser thickness near its lower edge. Reinforcing ribs may be provided for bracing the sleeve to the skirt. A tearing tab is provided on the skirt, a vertical gap in the portion of the skirt adjacent the tab being coated with a skin which breaks when the tab is torn. The stopper is designed to resist internal gas pressure from within the bottle, such as that produced by champagne.

BRIEF DESCRIPTION OF THE INVENTION

The present invention belongs to the field of closing caps or stoppers, more specifically to those used in the phase of fermentation of beverages.
The nearest document is British Patent GB867896 .
This patent solves the problem of achieving a better sealing for ready-for-sale bottles of sparkling wine, as it withstands the pressure inside the bottle but can be easily opened for consumption thanks to a collar or outer ring that facilitates the outpouring of the wine.
This type of cap has the drawback that it cannot be employed in the fermentation phases because the pressures that it must withstand are much higher than the those withstood by a closing cap of a bottle prepared for sale. Thus, the closing cap of the nearest document cannot, due to its configuration, bear said high pressures, so that said closing cap will be ejected, releasing the gas and the liquid, and ruining the sparkling wine stored in the bottle.
Moreover, Figure 2 shows what in the text of the patent is identified as "bowl-like recess" without any other indication regarding its technical nature, thus being quite evident that this is a merely aesthetic element, or that, at most, it is included to reduce the material used. This point is also confirmed by the fact that the element does not have any pressure effect on the lip of the container mouth.
The present invention solves the mentioned problems concerning the use of the caps use in bottles that are used in the fermentation phase of sparkling wine, that is, in those bottles in which the inner pressure is much higher than that of sparkling wines bottles that are currently found in stores.
Thus, the cap of the invention comprises a concave curved surface in its top base which, when the gas from the fermenting sparkling presses the cap outwards, it reduces the curve of the concave curved surface, said concave curved surface being pushed so that it maintains a horizontal trend, that is, that the curvature tends to towards horizontality. This allows the volume of the protrusion to grow and expands its top base, thus increasing the pressure of the top base against the wall of the mouth, which ensures that the higher the gas pressure, the more hermetic will be the sealing of the cap on the bottle. An object of the present invention is a cap for hermetically closing containers containing pressurized and/or gasified products, wherein said containers comprise a mouth having an annular inlet, and the cap comprises: a cap head; a protrusion having a cylindrical shape that defines an top base that is attached to the cap head, and a free lower base libre; said protrusion being perpendicularly projected towards the horizontal plane of the cap head; and comprising a blind cylindrical drain, wherein said protrusion is configured to be inserted through the annular inlet of the mouth of the container and to fit, by tightening, with an inner cylindrical surface of said mouth del container; an tightening wall, connected to the cap head and arranged in cantilever with respect to the cap head, which surrounds, at least partially, the lip of the container; said tightening wall having a larger diameter than said protrusion; and wherein the tightening wall fits the lip of the container; the cap is made of an elastically deformable material; and the cap head, the protrusion and the tightening wall are formed in one piece; characterized in that the cap head of the cap comprises a concave curved surface at the top base of the protrusion, and in that said concave curved surface, when the gas presses the cap outwards, the curvatures is reduced, thus increasing the volume of the protrusion and expanding its top base and increasing the pressure of the top base against the lower wall de la mouth.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are intended to help better understand the developed system in relation to a practical example of its preferred embodiment, wherein:

Figure 1 shows a perspective view of cap described in the state of the art and found in the market, namely, a cap comprising two sections, an inner cap with tabs and an outer retaining ring.
Figure 2 shows a lower view of a cap herein described, depicting the cap head, a cylindrical-shaped protrusion having a concentric drain, the tightening wall of said closing cap with the notches and the perimetral lip with the grooves.
Figure 3 shows a different perspective of the same cap of Figure 2 depicting the concave curved surface at the inner base of the cap head of the cap.
Figure 4 shows a sectional view of the profile of the cap evidencing the shape of the concave curved surface and the perimetral lip.
Figure 5 shows a top perspective of the cap depicting the smooth outer surface of the cap head of the cap.
Figures 6, 7 and 8 respectively show views of the bottom plane, an elevation, and the top plane of the cap.
Figure 9 shows a section of the cap, object of the present invention, installed on a bottle.

A list of the references used in the figures is provided below:

(1): Cap
(2): Tightening wall
(3): Protrusion
(4): head
(5): Perimetral lip
(6): Concave curved surface
(7): Cylindrical drain
(8): Grooves
(9): Notches
(10): Smooth surface
(20): Top base
(21): Lower base
(22): Chamfered edge
(23): Reliefs
(24): Ridges
(25): Ridges
(29): Container or bottle
(30): Container mouth
(31): Inner cylindrical surface
(32): bottle or container lip
(33): Inner wall
(34): Neck ring
(35): Neck

PRACTICAL EMBODIMENT OF THE INVENTION

Figure 2 illustrates a cap 1, a tightening wall 2, a protrusion 3, a perimetral lip 5, a cylindrical drain 7, grooves 8 and notches 9.
Figure 3 shows the cap 1, the tightening wall 2, the protrusion 3, the perimetral lip 5, a concave curved surface 6, the cylindrical drain 7, the grooves 8 and the notches 9.
Figure 4 illustrates the tightening wall 2, the protrusion 3 with its top base 20 and its lower base 21, a head 4, a chamfered edge 22, the perimetral lip 5, the concave curved surface 6 and the cylindrical drain 7.
Figure 5 shows the cap 1, the tightening wall 2, the head 4, the notches 9, a smooth surface 10 and the chamfered edge 22.
Figure 6 illustrates the tightening wall 2, the protrusion 3, the concave curved surface 6, the grooves 8 and the notches 9, reliefs 23, first ridges 24 and second ridges 25.
Figure 7 illustrates the cap 1, the tightening wall 2, the protrusion 3, the head 4, the notches 9, the smooth surface 10 and the chamfered edge 22.
Figure 8 illustrates the head 4, the notches 9 and the smooth surface 10.
Lastly, Figure 9 illustrates the tightening wall 2, the protrusion 3, the head 4, the concave curved surface 6, the grooves 8, the notches 9, the chamfered edge 22, the reliefs 23, a bottle 29 and its mouth 30, an inner cylindrical surface 31, a lip of the bottle 32, an inner wall of the mouth 33, a neck ring 34 and a neck 35.
In a specific embodiment, the cap 1 is useful for hermetically closing containers containing pressurized and/or gasified products; said containers 29 comprise a mouth having an annular inlet, like the inlets of sparkling wine bottles of different types. In other words, in this embodiment, the container 29 will be a sparkling wine bottle.
The cap 1 comprises a head 4 of the cap 1, which is the section that is essentially left at the outside once the bottle is sealed by the cap 1.
The cap also comprises a protrusion 3 having a cylindrical shape so that it may be inserted into the neck 35 of the bottle. Said protrusion 3 has a cylindrical shape and defines a top base 20 that is attached to the head 4 and a free, lower base 21.
The protrusion 3 is projected perpendicularly to the horizontal plane of the head 4, also referred to a normal direction with respect to the cap head 4, that is, adopting a "T" configuration.
Likewise, the protrusion 3, comprises a blind cylindrical drain 7, with the lower base 21 of the protrusion through which the drain is performed and the top base 20, which remains covered. Blind cylindrical drain 7 means that it is not a pass-through, that is, it does not pass through the cap head 4 of the closing cap 1. The central cylindrical protrusion 3 is a hollow projection that allows it to be more easily deformed when it is inserted in the annular inlet of the mouth 30, thus ensuring hermeticity. Optionally, the cylindrical drain can be concentrical to the cylindrical shape of said protrusion 3, being this the preferred embodiment, as all the loads can be balanced in the protrusion 3.
Said protrusion 3 is configured to be inserted through the annular inlet of the mouth 30 and to fit, by tightening, with an inner cylindrical surface 31 of said mouth 30 of the bottle matching the bottle neck 35. In this manner, the cap 1 would be initially fixed, although not secured, to the bottle neck 35.
The cap 1 also comprises a tightening wall 2, connected to the head 4 and arranged in cantilever with respect to the head 4, as illustrated in Figures 2, 3 and 4. In this way, the tightening wall 2 at least partially surrounds the bottle lip 32 (in this embodiment, it fully surrounds the bottle lip 32), said tightening wall 2 having a larger diameter than said protrusion 3, so that said tightening wall 2 may go through while surrounding the bottle lip 32. In addition, the tightening wall 2 fits the bottle lip 32.
In order to surpass the tightening wall 2 and the bottle lip 32 and to adapt to said lip 32, the cap 1 is made of an elastically deformable material, so that once that it is deformed by expanding in order to surpass the bottle lip 32, the cap 1 elastically recovers its initial shape.
As can be seen in the attached figures, the head 4, the protrusion 3 and the tightening wall 2 are comprised in a single, light-weight piece. In this manner the manufacturing procedures of the cap 1 are improved, by simplifying the kinematics of the mould, allowing a larger number of cavities in one same injected surface, offering a high reduction of the production cycle, and reducing the manufacturing costs of the mould itself. Said improvement in the manufacturing procedure implies a reduction in the consumption of energy and water and in the CO2 emissions for manufacturing the same number of caps, as compared with state-of-the-art caps.
The invention is characterised in that head 4 of the cap 1 comprises a concave curved surface 6 (Figure 4) at the top base 20 of the protrusion 3. Said concave curved surface 6, as the gas from the fermentation presses the cap 1 out, when this concave curved surface 6 is pushed by the gas, the curvature of said surface is reduced and the volume of the protrusion 3 is increased.
Simultaneously, as the gas reduces the curvature of the concave curved surface 6, it expands its top base 20, which increases the pressure of the top base 20 against the wall of the mouth 33, thus sealing even more the cap 1 over the bottle. In other words, the pressure exerted by the gas, instead of pushing the cap 1 outwards of the bottle, in fact it tightens the sealing as the concave curved surface 6 expands the top base 20 by pressing the top base 20 against the mouth wall 33. This is important because it eliminates the need to include the tabs or ribs mentioned in other patents, among them, in the nearest document.
Optionally, the radius of the concave curved surface 6, when in a stationary condition, is between 32 y 47 millimetres.
For a vast majority of sparkling wines, optionally, the radius of the concave curved surface 6, when in a stationary condition, is between 37 y 41 millimetres.
Another optional configuration would provide, between the cap head 4 and the tightening wall, a chamfered edge 22 that surrounds, at least partially, the bottle mouth 30. This chamfered edge allows the right fit with the concave curved surface 6. This chamfered edge 22 allows a simpler and more natural fit between the cap 1 and the bottle lip 32, preventing unwanted deformations of the cap 1 that might affect the correct sealing of the bottle 29.
In one of the embodiments, the outer diameter of the cap 1 is configured with the same or a smaller outer diameter of the neck ring 34 of the bottle. This is aimed at preventing that the cap 1 does not take contact or abuts anything when handling the bottles 29 during the fermentation process and therefore avoiding that the cap 1 accidentally opens and the content of the bottle 29 is wasted.
For a better attachment of the cap 1 to the bottle 29, it has optionally been provided that the tightening wall 2 comprises a perimetral lip 5, facing towards the protrusion 3 whose perimeter is deformed for surpassing the bottle lip 32, so that the bottle 29 be perfectly sealed. In this way, the perimetral lip 5 is coupled or inserted when fitting the tightening wall 2 to the bottle mouth 30, by adding a retention element to the cap 1 that increases the friction force between the closing cap 1 and the bottle mouth 30.
It is possible to configure the cap 1 so that the perimetral lip 5 comprises a plurality of grooves 8, arranged in a circular pattern, radially directed with respect to the cylindric shape of Ia tightening wall 2, which define elastically deformable corresponding reliefs 23 that facilitate the deformation of the perimetral lip 5, in order to seal the bottle 29. These grooves 8 facilitate the deformation of the perimetral lip 5 by fitting to the neck ring 34 of the bottle.
Optionally, the tightening wall 2 comprises a plurality of notches 9 arranged in a circular pattern, outwardly and radially oriented with respect to the cylindrical shape of the tightening wall 2. Said notches 9 allow a greater grip of the cap by providing a larger surface contact.
In addition, the mentioned notches 9 define ridges 24, 25, at least a first ridge 24 being positioned in coincidence with a relief 23, which confer a greater thickness to the outer area of the tightening wall 2 and at least one second ridge 25 in coincidence with a groove 8, securing a minimum perimetral thickness (Figure 6).
The special configuration of the cap 1 would allow the manufacturing of the cap 1 by means of a process of injecting material into a mould, since all the component parts of said cap are manufactured in one single piece, with a deformable material, elastic enough to be fitted to a mouth 30 of a container; the injection process fulfils these manufacturing features.
Optionally, high density polyethylene has been found as a suitable material that could comply with the requirements for manufacturing the cap 1. This material offers good thermal, chemical and impact resistance. It is solid, colourless, translucent, almost opaque, it is easy to process, that is, it may be processed with shaping methods used for thermoplastics such as injection and extrusion; and it is flexible, even at low temperatures.
In addition, in a possible embodiment, the head 4 of the cap could comprise an outer smooth surface 10. Said smooth surface 10 is visible when the cap 1 is sealing the container mouth 30. The process for which this cap 1 is used, the tirage, requires a printing of the cap head 4, and the smooth surface 10 feature greatly improves the design of state-of-the-art caps, which have a very small printing surface.
In this particular embodiment, the cap 1 of the present invention will be used in a sparkling wine manufacturing process according to the "champenoise" method, consisting of a second fermentation inside the bottle 29.
This process consists of three clearly differentiated stages:

1. Bottle 29 capping procedure: the bottles 29 are filled with previously fermented wine; the caps 1 are applied; the bottles 29 are sealed and prepared for the next phase.
- The cap 1 is placed on top of the bottle 29. A treading machine hits the cap 1 against the bottle 29 and the tightening wall 2 becomes elastically deformed and surpasses the bottle lip 32; once the bottle lip has been completely overcome by the tightening wall 2, the latter recovers its initial position, the perimetral lip 5 securing the cap 1 over the bottle 29.
- At the same time, the protrusion 3 penetrates the mouth 30 and is lodged into the bottle neck 35.
- The force required by the treading machine is about 70 kgs, whereas at present the required force is approximately 350 kg., which sometimes causes the tearing of the bottle 29. Besides, by reducing the force applied the noise is also reduced, which improves the decibels level by 30 decibels.
2. Fermentation: the capped bottles 29 are stored for at least nine months, where the bottles reach pressures of approximately 8 kgs. and up to 10 kgs. in extreme cases.
3. Disgorgement. The bottles neck 35 is frozen to subsequently automatically remove the caps 1 by means of disgorgement machinery. Then the bottles are sealed with the final cork cap.

The present invention describes a new cap for hermetically closing containers holding pressurized and/or gasified products. The examples mentioned in this document are not limitative of the present invention, which may have different applications and/or adaptations, all of which within the scope of the appended claims

Claims

A cap for hermetically closing containers containing pressurized and/or gasified products, wherein said containers (29) comprise a mouth (30) having an annular inlet; the cap (1) comprising:
- a head (4) of the cap (1);

- a protrusion (3) having a cylindrical shape, that defines an top base (20) that is attached to the head (4) and a free lower base (21), said protrusion (3) being projected perpendicularly to the horizontal plane of the head (4), and comprising a blind cylindric drain (7), wherein said protrusion (3) is configured to be inserted into the annular inlet of the mouth (30) of the container (29) and to fit, by tightening, with an inner cylindrical surface (31) of said mouth (29) of the container;

- a tightening wall (2), connected to the head (4) and arranged in cantilever with respect to the head (4) that surrounds, at least partially, the container lip (32); said tightening wall (2) having a larger diameter than said protrusion (3); and wherein the tightening wall (2) adapts to the container lip (32);

- the cap (1) is made of an elastically deformable material; and

- the head (4), the protrusion (3) and the tightening wall (2) are formed in one piece;
characterized in that the head (4) of the cap (1) comprises a concave curved surface (6) at the top base (20) of the protrusion (3), and in that said concave curved surface (6), when the gas presses the cap outwards (1), its curvature is reduced and thus volume of the protrusion (3) is increased, expanding its top base (20) and increasing the pressure of the top base (20) against the lower wall (33) of the mouth (30).
The cap according to claim 1, characterized in that the concave curved surface (6) radius, when in a rest condition, is between 32 y 47 millimetres.
The cap according to claim 2, characterized in that the concave curved surface (6) radius, when in a rest condition, is between 37 y 41 millimetres.
The cap according to claims 1, or 2, or 3, characterized in that the head (4) of the cap (1) comprises an outer smooth surface (10).
The cap according to claim 1, characterized in that between the head (4) and the tightening wall there is comprised a chamfered edge (22) that surrounds at least partially the mouth (30) of container (29).
The cap according to claim 1, characterized in that the outer diameter of the cap (1) is equal or smaller than the outer diameter of the neck ring (34) of the container (30).
The cap according to claim 6, characterized in that Ia tightening wall (1) comprises a perimetral lip (5), facing towards the protrusion (3) whose perimeter is deformed to surpass the lip (32) of the container.
The cap according to claim 7, wherein the perimetral lip (5) comprises a plurality of grooves (8), arranged in a circular pattern, radially directed towards the cylindric shape of the tightening wall (2), which grooves define respectively elastically deformable reliefs (23).
The cap according to claim 8, characterized in that Ia tightening wall (2) comprises a plurality of notches (9) arranged in a circular pattern, radially oriented with respect to the cylindrical shape of Ia tightening wall (2) and outwards, said notches defining (9) ridges (24, 25), there being at least one first ridge (24) positioned in coincidence with a relief (23) and at least a second ridge (5) that coincides with a groove (8).
The cap according to any of the previous claims, wherein said cap (1) is made by a process of injecting material into a mould.
The cap according to any of the previous claims, wherein said cap (1) is made of high density polyethylene.