Closing cap for containers

Abstract

What is proposed herein is a closing cap (1) for a container (2), comprising a shell (5), provided with a lateral wall (3) extending around an axis (Z) and with a transversal wall (4) positioned at one end of the lateral wall (3), the shell (5) being provided with an inner coupling structure (304) shaped like a thread structure and positioned inside the lateral wall (3) for removably coupling the cap (1) to a neck (201) of the container (2). The cap (1) also comprises an insert (6), inserted in the shell (5), which comprises an inner part (601) configured in a closed condition to engage in a sealed fashion with a supply opening (203) of the neck (201). The shell (5) and the insert (6) are made of PET and are separate components, capable of at least partially rotating one relative to the other during an opening, or a closing, of the neck (201).

Description

[0001] DESCRIPTION

[0002] CLOSING CAP FOR CONTAINERS

[0003] This invention relates to a closing cap for containers.

[0004] In particular, this invention relates to a closing cap for containers, which comprises an outer shell and an insert, wherein the insert is configured to make a fluid-tight seal with a neck of a container.

[0005] There are prior art containers, for example bottles, which define a space for containing a material, for example for containing liquid substances, and have an upper portion, called the neck, suitable for being closed with a respective cap.

[0006] The neck of the container has a body which has a substantially tubular shape, which extends around an axis and which has an upper edge defining a supply opening for the material contained in the container. The neck comprises an outer coupling structure which allows reversible coupling with a respective cap, respectively provided with an inner coupling structure configured to couple to the outer coupling structure of the neck.

[0007] The outer coupling structure may be shaped like a thread structure, to allow the cap to be removably coupled on the neck, by moving the cap axially towards, or away from, the neck.

[0008] Caps usually comprise a cup-shaped body, which is provided with a transversal wall and with a lateral wall extending around an axis, and they are typically made of plastic material.

[0009] Some caps are provided with a protrusion shaped like a sealing lip, which is annular (usually called a plug), which projects from the transversal wall inwards towards the inside of the cap so as to engage, when the cap is in the closed condition, with an inner wall, or with an outer wall, of the supply opening in order to make a fluid-tight seal by applying a contact pressure on that inner wall, or on that outer wall.

[0010] One of the most used materials for making containers, such as bottles, is PET (Polyethylene Terephthalate) whilst in contrast PE (Polyethylene) is usually used for making caps. However, to facilitate recycling of the container and / or of the cap, caps made of the same material, PET, as the container are spreading. In fact, PET is 100% recyclable and does not lose its fundamental properties during the recycling process, meaning that it can be repeatedly processed for making new bottles or other objects.

[0011] However, disadvantageously, a PET cap coupled on a neck of a PET container is difficult to couple to / uncouple from the neck, since the material of the cap does not easily slide on the material of the neck and there is a considerable friction between the outer coupling structure of the neck and the inner coupling structure of the cap which opposes rotation of the cap relative to the neck, when the cap is screwed onto, or unscrewed from, the neck.

[0012] In the same way, there is also a considerable friction between the sealing protrusion of the cap and the inner wall, or the outer wall, of the neck on which the sealing protrusion engages.

[0013] A consumer, who wants to uncouple / couple a cap made of PET from / to a neck of a container, has to apply a removal, or application torque that is very high in order to be able to overcome the friction between the cap and the neck. In fact, the force necessary to uncouple the outer coupling structure of the neck from the inner coupling structure of the cap, for example to unscrew it, must be added to the force necessary to uncouple the sealing protrusion from the cap.

[0014] If the consumer has a weak grip, this may make opening the container extremely difficult at a first use, or at subsequent uses, and the consumer may even be forced to purchase an additional aid in order to be able to open the container.

[0015] Moreover, the fiction between the outer coupling structure of the neck and the inner coupling structure of the cap and the friction between the sealing protrusion of the cap and the inner wall, or outer wall, of the neck may deteriorate the contact surfaces between the cap and the neck, causing them to wear. Therefore, due to this the shape of the cap and / or of the neck may change, and this may reduce the effective sealing capability of the cap on the neck of the container, at the first use or afterwards at the subsequent uses.

[0016] The technical purpose of this invention is therefore to provide a closing cap for containers which is capable of overcoming the disadvantages of the prior art.

[0017] One aim of the invention is to provide a closing cap for containers which requires a regular application and / or removal torque in such a way that it is easy for a consumer to use and does not require additional opening aids.

[0018] Another aim of the invention is to provide a closing cap for containers which is capable of making an effective fluid-tight seal, when the cap is entirely made of PET, reducing the possibility that the contact surfaces between the cap and the neck may deteriorate due to friction.

[0019] Yet another aim of the invention is to provide a closing cap for containers which is made of PET wherein the friction between the outer coupling structure of the neck and the inner coupling structure of the cap and / or the friction between the sealing protrusion of the cap and the inner wall, or outer wall, of the neck are reduced so as not to compromise a good fluid-tight seal between the cap and the neck, thereby preventing the materials contained in the containers from leaking out.

[0020] The technical purpose indicated and the aims specified are substantially achieved by a closing cap comprising the technical features set out in one or more of the accompanying claims. The dependent claims correspond to possible embodiments of the invention.

[0021] The invention can be better understood and implemented with reference to the accompanying drawings, which illustrate several example, non-limiting embodiments of it, in which:

[0022] Figure 1 is a cross-section of a first closing cap joined to a respective container in a closed condition, in which the first cap comprises a first embodiment of a shell and a first variant of an insert, inserted inside the shell, and in which the shell is in a first position relative to the neck; Figure 2 shows the cross-section of the cap of Figure 1 , in which the shell is in a second position relative to the neck, at the end of an initial step of lifting the shell, and in which the insert is still joined to the neck but makes contact with a supporting element of the shell, shaped like a protuberance, which projects from a lateral wall of the shell transversally towards an axis of the cap, and in which an engaging element of the cap makes contact with a stop ring of the neck to promote the breaking of breakable bridges present between a closing element and a retaining ring on the neck;

[0023] Figure 3 shows the cross-section of the cap of Figure 1 , in a final step of lifting the shell, after the initial step, in which the insert is supported by the supporting element and is joined to the shell whilst the neck is at a distance from the insert and from the shell, the closing element already having detached from the retaining ring although the uncoupling between an inner coupling structure of the shell and an outer coupling structure of the neck has not been completed;

[0024] Figure 4 shows the cross-section of a second closing cap, joined to a respective container, in which the second cap comprises a second embodiment of the shell and the first variant of the insert of Figure 1 , in which the supporting element is defined by the inner coupling structure of the cap, and in which the shell is in the second position relative to the neck and the insert is supported by the supporting element, the closing element already having detached from the retaining ring although the uncoupling between the inner coupling structure of the shell and the outer coupling structure of the neck has not been completed;

[0025] Figure 5 shows the first embodiment of the shell of Figure 1 , without the insert;

[0026] Figure 6 shows the first variant of the insert of Figures 1 to 4, without the shell;

[0027] Figure 7 shows a second variant of the insert of Figure 6;

[0028] Figure 8 shows a third variant of the insert of Figure 6;

[0029] Figure 9 shows a fourth variant of the insert of Figure 6; Figure 10 shows a fifth variant of the insert of Figure 6;

[0030] Figure 10a shows an enlarged detail from Figure 10;

[0031] Figure 1 1 shows a cross-section of a third closing cap, joined to a respective container, in the closed condition in which the third cap comprises a third embodiment of the shell of Figure 1 , comprising a pressing element and the second variant of the insert of Figure 7;

[0032] Figure 1 1 A shows an enlarged detail from Figure 1 1 ;

[0033] Figure 12 shows the cap of Figure 1 , at the end of a moulding procedure and before an initial closing step, in which the neck is received in the cap;

[0034] Figure 13 shows the cap of Figure 1 , at the end of the initial closing step, when the shell is in a third position relative to the neck;

[0035] Figure 14 shows the cap of Figure 1 , when the shell is in the second position relative to the neck;

[0036] Figure 15 shows the cap of Figure 1 in the closed condition of Figure 1 , at the end of a final closing step;

[0037] Figure 16 shows a sixth variant of the insert of Figure 6;

[0038] Figure 16a shows an enlarged detail from Figure 16.

[0039] With reference to Figures 1 to 16, the numeral 1 denotes a cap for closing a container 2, of which container only a neck 201 is shown, in particular a bottle intended to contain a liquid substance such as a beverage.

[0040] It should be noticed that, throughout this description, elements common to the various embodiments of the cap 1 and neck 201 will be labelled with the same reference numbers. Moreover, such common elements will not be repeated, for brevity, in the various embodiments for which only the differences will be highlighted.

[0041] The cap 1 may be made of polymeric material.

[0042] However, according to this invention, the cap 1 is made using the same material used to make the containers 2, such as the bottles, that is to say, using PET (Polyethylene Terephthalate), as described in detail below.

[0043] The cap 1 is shown in Figures 1 , 11 and 15 in a closed condition, in which the cap 1 is coupled to the container 2. The cap 1 comprises a shell 5 provided with a lateral wall 3 which extends around an axis Z, and a transversal wall 4 positioned at one end of the lateral wall 3, so as to close that end. The transversal wall 4 extends transversally, in particular perpendicularly, to the axis Z. The transversal wall 4 may be flat, even though other shapes are theoretically possible. In the example shown, the transversal wall 4 has a substantially circular shape in plan view.

[0044] The shell 5, defined by the lateral wall 3 and by the transversal wall 4, is cup-shaped and is suitable for receiving the neck 201 of the container 2, so that the cap 1 can close the self-same container 2.

[0045] The cap 1 comprises, in addition, an insert 6 which is inserted in the shell 5.

[0046] It should be noticed that the neck 201 comprises a body having a substantially tubular shape, which extends around a respective axis which coincides with the axis Z, when the cap 1 is coupled to the neck 201 .

[0047] The neck 201 also comprises an outer coupling structure 204 configured to allow reversible coupling to the respective cap 1 .

[0048] The lateral wall 3 is connected to the transversal wall 4 by means of an outer connecting zone 401 , which may be shaped, in cross-section, like a bevelled edge or a circular connector.

[0049] The lateral wall 3 may be provided, on an outer surface thereof, with a plurality of knurling lines, not illustrated, extending parallel to the axis Z and suitable for facilitating gripping of the cap 1 by a consumer or by the capping machine which applies the cap 1 on the container 2 to be closed.

[0050] The shell 5 comprises a retaining ring 301 , which is configured to remain anchored to the neck 201 of the container 2 and extends as far as a free edge 303 of the lateral wall 3.

[0051] The shell 5 also comprises a closing element 302 removably engageable with the neck 201 , so as to open or close the container 2. In detail, the closing element 302 is configured to open, or to close, a supply opening 203 of the neck 201 . A separating line (not illustrated) is made in the lateral wall 3 of the shell 5 to define the retaining ring 301 and the closing element 302, which are shown in Figures 3 and 4. In fact, along the separating line there may be breakable bridges (not illustrated) present, which are intended to be broken when the cap 1 is opened for the first time. In fact, when the cap 1 is opened for the first time and is unscrewed from the neck 201 of the container 2, the closing element 302 separates from the retaining ring 301 along the separating line following breaking of the breakable bridges. In this way the retaining ring can remain joined to the neck 201 of the container 2, whilst the closing element 302 can be separated from the container 2 and, subsequently, be screwed back onto the neck 201 .

[0052] The knurling lines may be positioned in the closing element 302, but may also optionally continue, according to one variant, in the retaining ring 301 or as far as the transversal wall 4.

[0053] The shell 5 is provided with an inner coupling structure 304, positioned inside the lateral wall 3, which is configured to removably couple the closing element 302 to the neck 201 of the container 2.

[0054] The inner coupling structure 304 of the shell 5 is positioned inside the closing element 302 and is shaped to engage with the corresponding outer coupling structure 204 present on the outside of the neck 201 of the container 2. The inner coupling structure 304 of the closing element 302 and the outer coupling structure 204 of the neck 201 , as illustrated in the accompanying figures, are made in the form of a thread structure. In this case, the passage from the closed condition to the open condition, and vice versa, is performed by means of a rotating-translating movement, that is to say, rotation of the closing element 302 relative to the neck 201 and its movement away from, or towards, the neck 201 .

[0055] When the cap 1 is “in the closed condition”, which is shown in Figure 1 , this means that the cap 1 is completely screwed onto the neck 201 .

[0056] The closing element 302 may completely disengage from the neck 201 when the inner coupling structure 304 of the shell 5, that is to say, the thread structure of the shell 5, is completely unscrewed from the outer coupling structure 204 of the neck 201 , that is to say, from the thread structure 204 of neck 201 .

[0057] The inner coupling structure 304 and the outer coupling structure 204 may be made using a single helical thread, or using a plurality of helical threads, also called multiple helical threads, each separate from the others. For example, the inner coupling structure 304 and the outer coupling structure 204 may be made using two separate helical threads 304A and 304B, as shown in Figures 1 to 5 and in Figures 11 to 15, or three separate helical threads, not shown.

[0058] The retaining ring 301 is the lower part of the shell 5 when the cap 1 is coupled to the neck 201 , and comprises an engaging element 305 which projects inwards and is configured to engage with a stop ring 202 of the neck 201 of the container 2, during a passage from a closed condition to an open condition of the cap 1 , as shown in Figure 2.

[0059] It should be noticed that the engaging element 305 can project from the free edge 303, as shown in the accompanying Figures, or from an edge zone of the retaining ring 301 placed near the free edge 303.

[0060] At the end of a moulding procedure, the cup-shaped shell 5, shown in Figure 12, is obtained, which has the lateral wall 3 which extends from the transversal wall 4 as far as the free edge 303, beyond which a panel extends which has already been bent to form the engaging element 305 which projects from the free edge 303. Also inserted inside the shell 5 is the insert 6 in such a way that it can be joined to the neck 201 of the container 2.

[0061] When the cap 1 is in the closed condition, the engaging element 305 is positioned in a bent configuration between the retaining ring 301 and the neck 201 of the container 2.

[0062] The engaging element 305 may be made, in the known way, as a single continuous flap, or as a plurality of projecting flaps. In other words, the engaging element 305 may be continuous, as shown in the accompanying Figures, or interrupted (not illustrated). The stop ring 202 projects from an outer surface of the neck 201 and is shaped like an annular protuberance, which extends in a plane placed transversally to the axis Z. An upper wall 202A of the stop ring 202 is directed towards the supply opening 203, whilst a lower wall 202B is directed towards a bottom (not illustrated) of the container 2. The lower wall 202B is substantially planar and is such that, when the cap 1 is in the closed condition and has never been opened before as shown in Figure 1 , the engaging element 305 is placed at least partially below the stop ring 202 to engage with the lower wall 202B, when the cap 1 is opened for the first time, that is to say, the first time that the engaging element 305 makes contact with the lower wall 202B of the stop ring 202.

[0063] Cap 1 “first opening” is, therefore, the first time that the cap 1 is opened and the closing element 302 is at least partially separated from the retaining element 301 .

[0064] The neck 201 comprises an upper edge defining a supply opening 203 for a material contained in the container 2.

[0065] The upper edge comprises an inner wall 206, an outer wall 207 and a top wall 208.

[0066] The inner wall 206 and the outer wall 207 delimit the neck 201 on the inside and on the outside respectively. The coupling structure 204 of the neck 201 projects from the outer wall 207.

[0067] The inner wall 206 and the outer wall 207 have a substantially cylindrical tubular shape and extend around the axis Z.

[0068] The top wall 208 may have a stretch which extends transversally, in particular perpendicularly, to the axis Z and is flat, that is to say, lies in an upper plane which delimits the top of the upper edge of the neck 201 . Other embodiments are theoretically possible and, if the top wall 208 has curved stretches, the upper plane is at a tangent to those curved stretches, delimits the top of them and extends transversally, in particular perpendicularly, to the axis Z. It should be noticed that the expression “upper edge” means the upper part of the edge of the neck 201 , and therefore of the container 2, when the container 2, in use, is resting on a supporting surface. Therefore, the upper edge delimits the top of the neck 201 and helps to make the fluid-tight seal between the cap 1 and the neck 201 .

[0069] Similarly, the expression “delimits the top of”, or “upper”, or “lower” refer to the container 2, when the container 2 is in use resting on the supporting surface.

[0070] It should be noticed that the top wall 208 is directed towards the transversal wall 4 of the cap 1 , when the cap 1 is coupled to the neck 201 in the closed condition of the container 2.

[0071] The insert 6 comprises an inner part 601 , which is configured, in a closed condition of the cap 1 , to engage in a sealed fashion with the supply opening 203 of the neck 201 . The insert 6 also comprises an outer part 602, which is annular and extends as far as an outer margin 603 of the insert 6.

[0072] After the closing element 302 has separated from the retaining ring 301 , following breaking of the breakable bridges, the insert 6 remains inserted inside the closing element 302.

[0073] Both the shell 5 and the insert 6 are made of PET.

[0074] For example, the same PET may be used as is used to make bottles with intrinsic viscosity of between 0.7 and 1.15 dl / g, preferably between 0.74 and 0.86 dl / g.

[0075] The density of the PET granule is between 1300 and 1400 kg / mA3, preferably between 1325 and 1385 kg / mA3.

[0076] The shell 5 and the insert 6 are separate components and are capable of at least partially rotating one relative to the other during an opening, or a closing, of the neck 201 of the container 2.

[0077] Thanks to the fact that the cap 1 is entirely made of PET, it is entirely recyclable, together with the container 2 to which it is joined, and therefore facilitates recovery of the plastic materials. In particular, the shell 5 and the insert 6 may be made with the same type of PET and, if present, with the same dye as the relative container 2.

[0078] Thanks to the fact that the cap 1 is made using two separate components, the shell 5 and the insert 6, which can at least partially rotate one relative to the other, removal of the cap 1 from the neck 201 is favoured.

[0079] In fact, when the cap 1 is in the closed condition, the inner coupling structure 304 of the shell 5 engages with the corresponding outer coupling structure 204 of the neck, whilst the inner part 601 of the insert 6 engages with the supply opening 203 of the neck 201 . Therefore, two separate components of the cap 1 , the shell 5 and the insert 6, engage in two respective different zones of the neck 201 and being able to partially rotate one relative to the other they allow an uncoupling between the cap 1 and the neck 201 which can take place at different times in each zone.

[0080] In this way, a first force is necessary, to overcome the friction between the outer coupling structure 204 of the neck 201 and the inner coupling structure 304 of the shell 5, which may be applied at a different moment relative to the moment when a second force must be applied, which is necessary to overcome the friction between the inner part 601 of the insert 6 and the neck 201.

[0081] The consumer, who wants to open the cap 1 , is not forced to simultaneously apply the first force and the second force added together, since they must be applied at different moments in time. In this way, it is easier for the consumer, since he or she is required to apply a removal force which is not excessively high.

[0082] Even if application of the first force partially overlaps with application of the second force, this does not cause problems, since it happens for a very limited period of time.

[0083] The inner part 601 may be inserted, in the closed condition, inside the supply opening 203 to make contact with the inner wall 206 of the neck 201 with interference in such a way as to make the fluid-tight seal, as described in more detail below. In the closed condition, the insert 6 is coupled without interference to the lateral wall 3 and the shell 5 is in a first position relative to the neck 201 , as shown in Figure 1 .

[0084] It should be noticed that the outer part 602 extends on the outside of the neck 201 and is configured to help to make the fluid-tight seal, by applying a pressure on the outer wall 207 of the neck 201 .

[0085] The insert 6 comprises an intermediate part 604, positioned between the inner part 601 the outer part 602, which is planar and is configured, in the closed condition, to make contact with the top edge 208 of the neck 201 , on one side, and the transversal wall 4, on the other side.

[0086] When the shell 5 is in the first position, the insert 6 is clamped between the shell 5 and the neck 201 , and the intermediate part 604 is in contact with the transversal wall 4.

[0087] The insert 6 is configured in such a way that in an initial step of opening the cap 1 , when the shell 5 moves axially away from the neck 201 and moves between the first position and a second position, the insert 6 remains joined to the neck 201 and can, at least partially, rotate relative to the shell 5.

[0088] Thanks to the fact that the insert 6 is coupled without excessive interference relative to the lateral wall 3 when the shell 5 is in the first position, the insert can at least partially rotate relative to the shell 5 in the initial step of opening the cap 1 .

[0089] Thanks to the fact that the insert 6 remains joined to the neck 201 , the insert 6 continues to guarantee the fluid-tight seal between the cap 1 and the neck 201 since the inner part 601 of the insert continues to remain engaged with the supply opening 203. In this way, the fluid-tight seal between the cap 1 and the neck 201 is improved.

[0090] Moreover, in this initial step of opening, the shell 5 moves independently of the insert 6 and therefore it is only necessary to overcome the friction between the outer coupling structure 204 of the neck 201 and the inner coupling structure 304 of the shell 5. In the initial step of opening, the intermediate part 604 is distanced from the transversal wall 4 of the shell 5 since the latter moves away from the neck 201.

[0091] The shell 5 comprises a supporting element configured to support the insert 6 inside the shell 5.

[0092] The insert 6 is configured to make contact with the supporting element when the shell 5 is in the second position, in such a way that, when the shell 5 moves axially further away from the neck 201 in a final step of opening the cap 1 , after the initial step, the insert 6 remains joined to the shell 5. In more detail, in the second position of the shell 5, the bottom of the insert 6 is configured to make contact with the supporting element and this means that when the shell 5 moves further away from the neck 201 , it also drags the insert 6 with it and promotes movement of the insert 6 away from the neck 201.

[0093] Thanks to the supporting element, only in the final step of opening does the insert 6 begin to detach from the neck 201 and therefore loss of the fluid- tight seal is delayed.

[0094] Present between the first position and the second position there is an axial distance H, measured along the axis Z, which is less than or equal to 2.0 mm.

[0095] Even when the axial distance is 0, and therefore the first position and the second position axially coincide since in the closed condition the insert 6 is already resting on the supporting element, it remains the case that the insert may at least partially rotate relative to the neck 201 .

[0096] Thanks to the rotation, the friction between the cap 1 and the neck 201 is therefore reduced.

[0097] In the closed condition there is a transversal distance L present between the outer margin 603 and the lateral wall 3, measured transversally to the axis Z, which is less than or equal to 0.7 mm, for example is equal to 0.3 mm. If the transversal distance L is equal to 0.3, the insert 6 can rotate with relative freedom relative to the shell 5 and that is particularly advantageous when the cap 1 is coupled to the neck 201 , to return the cap 1 to the closed condition from an open condition.

[0098] In fact, at the end of the moulding procedure and when the cap 1 is joined to the neck 201 for the first time, as shown in Figures 12 to 15, the shell 5 is screwed onto the neck 201 and the rotating-translating movement of the shell 5 relative to the neck 201 is performed.

[0099] In an initial step of closing, the insert 6 is joined to the shell 5, and moves together with the shell 5 being supported at the bottom by the supporting element, but it does not graze the lateral wall 3 since it can freely rotate, the shell 5 and the insert 6 being two separate components which are not stably interlocked (or glued) and the transversal distance L being present.

[0100] When the shell 5 is in a third position, shown in Figure 13, the inner part 601 of the insert 6 begins to be received inside the supply opening 203, but there is a friction between the neck 201 and the insert 6 which locks a position of the insert 6 on the neck 201 , preventing the insert 6 from rotating. In the third position, the insert 6 is fixed to the neck 201 .

[0101] Then, when the shell 5 is lowered further by the axial distance H from the third position to the second position, shown in Figure 14, and it moves towards the neck 201 , the insert 6 still remains fixed to the neck 201 and detaches from the shell 5 without grazing the lateral wall 3, until the intermediate part 604 is brought into contact with the transversal wall 4 in the second position.

[0102] It should be noticed that, in the second position, the engaging element 305 is not yet positioned below the stop ring 202.

[0103] In the final step of closing the cap 1 , in which the shell 5 is lowered further by the height H from the second position to the first position, the transversal wall 4 makes contact with at least the intermediate part 604 of the insert 6 and causes the insert 6 to be lowered together with the shell 5, to allow the inner part 601 of the insert 6 to be positioned inside the neck 201 in order to apply the fluid-tight seal.

[0104] As the shell 5 is lowered further from the second position to the first position, shown in Figure 15, the engaging element 305 is positioned below the stop ring 202.

[0105] It should be noticed that the insert 6 makes contact with the neck 201 with interference due to the coupling between the inner part 601 of the insert 6 and the inner wall 206 of the neck 201 , the inner part 601 having an axial sealing point, at a distance from the top wall 208 of the neck 201 , at which the inner part 601 of the insert 6 has a diameter such that it defines an internal diametral interference which allows the fluid-tight seal, as described in more detail below.

[0106] During the final step of closing, the inner part 601 is configured to be positioned at the sealing point, which corresponds to the final position the inner part 601 inside the supply opening 203.

[0107] Thanks to the fact that the interference between the cap 1 and the neck 2 only occurs in the final step of closing, the possibility of abrasion between the cap 1 and the neck 201 is reduced.

[0108] Vice versa, if the insert 6 and the shell 5 were completely fixed or even moulded in one piece, there would be an interference, consequently generating friction between the cap 1 and the neck 201 , for a distance equal to approximately: D x IT x AA / 3600, where D is defined as the sealing diameter of the inner part 601 , n is Pi and AA is an angle of application of the cap 1 on the neck, expressed in sexagesimal degrees.

[0109] Considering for example a cap 1 applied on a neck 201 of the 29 / 25 mm type (where 29 indicates an approximate external diameter and 25 indicates an approximate internal diameter of the neck 201 and they correspond to the neck of standard CEN EN16592, former standard CETIE GME30.26), wherein the inner part 601 of the insert has an axial sealing point with height equal to 2 mm measured relative to the top edge 208, if the insert 6 were fixed to the shell 5 being joined to it with interference, there would be a grazing distance equal to approximately 25.5 x IT x 200 / 360 = 44 mm.

[0110] Otherwise, in accordance with this invention, the cap 1 being made with two separate components wherein the insert 6 is free to rotate relative to the neck 201 , there is a very reduced grazing distance present, which is equal to 2 mm.

[0111] Even when the transversal distance is 0, in the closed condition, and therefore the outer margin 603 of the insert 6 is in contact with the lateral wall 3, the insert 6 can still rotate relative to the shell 5 since it has no interference with the latter.

[0112] It should be noticed that the first position in Figure 15 corresponds to the closed condition of the cap 1 in Figure 1 , in which the cap 1 is found before it is opened for the first time.

[0113] The steps of closing the cap 1 , after the first opening, correspond to the same steps highlighted above, except for the fact that the closing element 302 has already been detached from the retaining ring 301 and therefore it is the closing element 302 which is in the first position, second position, or third position relative to the neck 201 .

[0114] Considering a nominal diameter of contact between the inner wall 206 and the inner part 601 of the insert 6, at least at the sealing point, an internal diameter of the inner wall 206 is less than the nominal diameter whilst an external diameter of the inner part 601 is greater than that nominal diameter. The difference between the internal diameter of the inner wall 206 and the external diameter of the inner part 601 defines the internal diametral interference between the inner part 601 of the insert 6 and the neck 201 , which guarantees the fluid-tight seal.

[0115] The internal diametral interference is greater than or equal to 0.1 mm and less than or equal to 0.8 mm.

[0116] For example, if the container 2 contains carbonated beverages, that is to say, highly carbonated or beverages pressurised with nitrogen, the internal diametral interference may be equal to 0.65 mm. This is a typical value applicable for carbonated water.

[0117] In contrast, for example, if the container 2 contains non-carbonated water, the internal diametral interference may be equal to 0.35 mm.

[0118] The insert 6 may have a thickness of between 0.2 mm and 0.8 mm, with a thickness tolerance equal to 0.3x the thickness itself.

[0119] As shown in Figures 1 , 2, 3 and 5, with reference to a first cap 1 which comprises a first embodiment of the shell 5 and a first variant of the insert 6, the supporting element may comprise an annular protuberance 501 , continuous or interrupted, which projects transversally from the lateral wall

[0120] 3 towards the axis Z and is positioned, axially, between the transversal wall

[0121] 4 and the coupling structure 304.

[0122] In the first position of Figure 1 of the shell 5, it can be seen how the outer margin 603 is at a transversal distance L from the lateral wall 3, and is at the axial distance H from the annular protuberance 501 .

[0123] In the second position of the shell 5, the outer margin 603 makes contact with the annular protuberance 501 , as shown in Figure 2.

[0124] When the shell 5 moves further away from the neck 201 , in the final step of opening, the insert 6 is also lifted, together with the shell 5, since the annular protuberance 501 is in contact with the outer margin 603.

[0125] Figure 4 shows a second cap 1 , which differs from the first cap 1 in that there is a second embodiment of the shell 5 present wherein the annular protuberance 501 is absent.

[0126] In fact, the supporting element comprises the inner coupling structure 304. The inner part 601 of the insert 6 is at least partially at a distance from the transversal wall 4, when the cap 1 is in the closed condition and the shell 5 is in the first position relative to the neck 201. In the second position of the shell 5, the outer margin 603 makes contact with the inner coupling structure 304. In this second embodiment of the shell 5, the outer margin 603 is at the transversal distance L from the lateral wall 3 and is at the axial distance H from the inner coupling structure 304.

[0127] This shape of the supporting element is simple to make.

[0128] As already indicated, the inner coupling structure 304 of the shell 5, and consequently also the outer coupling structure 204 of the neck 201 , may be made using a plurality of helical threads.

[0129] Those helical threads have respective final ends which are near the transversal wall 4 and are angularly equally spaced apart from each other. In this way, in the second position of the shell 5, the outer margin 603 is configured to make contact with the respective final ends of the helical threads. When the shell 5 moves further away from the neck 201 , in the final step of opening, the insert 6 is also lifted, together with the shell 5, since those final ends of the helical threads are in contact with the outer margin 603.

[0130] It should be noticed that in the inner coupling structure 304, shown in Figures 1 to 5 and in Figures 1 1 to 15, the plurality of helical threads is equal to two. In fact, the inner coupling structure 304 comprises two separate helical threads 304A and 304B which have two respective final ends 304A’ and 304B’, which are diametrically opposed to each other.

[0131] As shown in Figure 4, the outer margin 603 makes contact with the two final ends 304A’ and 304B’ in the second position of the shell 5. When the shell 5 moves further away from the neck 201 , in the final step of opening, the insert 6 is also lifted, together with the shell 5, since the final ends 304A’ and 304B’ of the two threads are in contact with the outer margin 603, in diametrically opposed positions of it.

[0132] According to a different embodiment, not shown, there may be a different cap in which the plurality of helical threads is equal to three. In fact, the inner coupling structure 304 may comprise three separate helical threads, whose respective final ends are equally spaced apart from each other by 120°. What was previously said still applies, that is to say, in the second position of the shell 5, the outer margin 603 makes contact with the respective final ends of the three threads in such a way that, when the shell 5 moves further away from the neck 201 in the final step of opening, the insert 6 is also lifted, together with the shell 5 since the outer margin 603 is in contact with the three final ends.

[0133] According to a different embodiment, not shown, there may be a different cap in which, in the second position, the insert 6 makes contact with both the inner coupling structure 304 and with a protrusion of the shell 5.

[0134] For example, in the case in which the inner coupling structure 304 comprises a single helical thread, there is only one respective final end present near the transversal wall 4.

[0135] The supporting element may comprise, in this case, the final end of the single helical thread and a protrusion, continuous or interrupted, which projects transversally from the lateral wall 3 towards the axis Z for a predetermined angular portion, is diametrically opposed to the single final end and is positioned, axially, at the same height as the final end of the single helical thread.

[0136] In this way, in the second position, the inner part 601 may make contact with the final end of the single helical thread on one side and with the protrusion on the other side; in this way, when the shell 5 moves further away from the neck 201 , in the final step of opening, the insert 6 is also lifted, together with the shell 5.

[0137] According to yet another a different embodiment, not shown, there may be yet another different cap in which, in the second position, the insert 6 makes contact exclusively with the inner coupling structure 304 even if the latter comprises a single helical thread, which has only the respective final end near the transversal wall 4.

[0138] The supporting element may comprise, in this case, the final end of the single helical thread and a portion of the single helical thread which is diametrically opposed to the single final end. The portion diametrically opposed to the final end of the single thread is not axially at the same height as the final end, instead it is lower than the final end of the thread.

[0139] In this way, in the second position, the inner part 601 makes contact on one side with the final end of the thread and when the shell 5 moves further away from the neck 201 , in the final step of opening, the insert 6 is also lifted, together with the shell 5 and on the other side also makes contact with the portion of the thread diametrically opposed to the final end of the thread. This shape of the supporting element is even simpler to make.

[0140] The outer part 602 of the insert 6 is inclined relative to the intermediate portion 604 and is at a distance from the transversal wall 4, when the insert 6 is in the first position relative to the shell 5.

[0141] Considering in more detail the shape of the insert 6, shown in Figures 6 to 10 and 16, it can be noticed how the insert 6 is shaped like a disk which extends around an axis Y. When the insert 6 is inserted in the shell 5, the axis Y coincides with the axis Z.

[0142] Figure 6 shows the first variant of the insert 6, in which the inner part 601 , in the closed condition, is at least partially at a distance from the transversal wall 4, and comprises a central portion 605 at a distance from the transversal wall 4 and a lateral portion 606 which is configured to make a seal with the supply opening 203.

[0143] The lateral portion 606 has a tubular and annular shape to make contact with the inner wall 206 of the supply opening 203.

[0144] The internal diametral interference described above should be considered, when the insert 6 is inserted in the shell 5 in the closed condition, between the lateral portion 606 and the inner wall 206.

[0145] The central portion 605 may be planar, as shown in Figure 6.

[0146] Figure 7 shows a second variant of the insert 6, which differs from the first variant of Figure 6, in that the lateral portion 606 is “U”-shaped. An outer branch of the “U”” is configured to make contact with the inner wall 206 whilst an inner branch of the “U”” is adjacent and joined to the central portion 605, which is planar and is aligned with the intermediate part 604. In this second variant of the insert 6, in the closed condition of the cap 1 , in which the shell 5 is in the first position relative to the neck 201 , both the central portion 605 and the intermediate part 604 are configured to make contact with the transversal wall 4 of the shell 5.

[0147] The internal diametral interference described above should be considered, in this second variant of the insert 6, between the outer branch of the “U” of the lateral portion 606 and the inner wall 206.

[0148] Figure 8 shows a third variant of the insert 6, which differs from the first variant of Figure 6 in that the central portion 605 is concave.

[0149] Figure 9 shows a fourth variant of the insert 6, which differs from the first variant of Figure 6 in that the central portion 605 is convex.

[0150] The internal diametral interference described above, now considering the third variant and the fourth variant of the insert 6, should be considered, for the third variant and for the fourth variant, when the insert 6 is inserted in the shell 5 in the closed condition, as for the first variant of the insert 6, that is to say, between the lateral portion 606 and the inner wall 206.

[0151] Figure 10 and the enlarged view of Figure 10a, show a fifth variant of the insert 6, which differs from the first variant of Figure 6 in that the inner part 601 comprises a planar central portion 605, aligned with the intermediate part 604 and an appendage 607 which is annular, is positioned between the intermediate part 604 and the central portion 605, is configured to extend inside the supply opening 203 and is shaped to make contact with the inner wall 206.

[0152] The appendage 607 has a first zone R1 which is configured to make contact with the inner wall 206, and a second zone P2, positioned near the intermediate part 604, which is smaller than the first zone R1 .

[0153] It should be noticed that the first zone P1 may be of maximum size.

[0154] The appendage 607 may for example be provided with an olive bead moulding-shaped free end, at which the first zone P1 can be measured. Alternatively, the appendage 607 may be shaped with an increasing crosssection. Measuring the first zone P1 and the second zone P2 perpendicularly to the axis Y, the second zone P2 is greater than or equal to the first zone P1 multiplied by 0.4, and is less than or equal to the first zone P1 multiplied by 1.2.

[0155] In contrast, measuring a height along an axis parallel to the axis Y relative to the intermediate part 604, it can be seen how the first zone P1 is at a first height from the intermediate part 604 and how the second zone P2 is at a second height from the intermediate part 604, the second height being less than the first height.

[0156] The internal diametral interference described above, now considering the fifth variant of the insert 6, should be considered between the appendage 607 and the inner wall 206, at the first zone P1 .

[0157] Again, the internal diametral interference may be greater than or equal to 0.1 mm and less than or equal to 0.8 mm.

[0158] Figure 16 shows a sixth variant of the insert 6, which differs from the first variant of Figure 6 in that the inner part 601 comprises the planar central portion 605, aligned with the intermediate part 604, and the appendage 607 which is annular, which is positioned between the intermediate part 604 and the central portion 605, is configured to extend inside the supply opening 203 and is shaped to make contact with the inner wall 206.

[0159] The sixth variant of the insert 6 is similar to the fifth variant shown in Figure 10, as regards the appendage 607 provided with the olive bead mouldingshaped free end at which the first zone R1 can be measured, but it differs from it in that the outer part 602 of the insert 6 is also planar and is aligned relative to the intermediate part 604.

[0160] The appendage 607 has the first zone P1 , which is configured to make contact with the inner wall 206, and the second zone P2, positioned near the intermediate part 604, which is smaller than the first zone R1 .

[0161] What was previously said with reference to the fifth variant of the insert of Figure 10 still applies, that is to say, measuring the first zone R1 and the second zone P2 perpendicularly to the axis Y, the second zone P2 may be greater than or equal to the first zone P1 multiplied by 0.4, and may be less than or equal to the first zone P1 multiplied by 1 .2.

[0162] In contrast, measuring a height along an axis parallel to the axis Y relative to the intermediate part 604, it can be seen how the first zone P1 is at a first height from the intermediate part 604 and how the second zone P2 is at a second height from the intermediate part 604, the second height being less than the first height.

[0163] For the sixth variant of the insert 6 too, the internal diametral interference described above, similarly to what was said for the fifth variant of the insert 6, should be considered between the appendage 607 and the inner wall 206, at the first zone P1 and may be greater than or equal to 0.1 mm and less than or equal to 0.8 mm.

[0164] In this sixth variant of the insert 6, the first zone P1 may have, for example, a size equal to 0.785 mm and the second zone P2 may have, for example, a size equal to 0.375 mm, measuring the first zone and the second zone perpendicularly to the axis Y.

[0165] The axial thickness of the insert 6, at the outer part 602, at the intermediate part 604 and at the central portion 605 may be constant and may be, for example, equal to 0.35 mm.

[0166] With reference to the fifth variant and to the sixth variant of the insert 6, which have the appendage 607 for which the first zone P1 and the second zone P2 can be defined, the Applicant ran experimental tests aimed at assessing different shaped caps 1 , having the same shaped shell 5 and different shapes of insert 6.

[0167] In this way it was possible to determine an effective compromise between a shape of the appendage 607, determined by a value of the second zone P2 and by the internal diametral interference measured at the first zone R1 , and the resulting fluid-tight seal and application toque, the shape of the shell 5 being equal. The fluid-tight seal and the application torque were respectively measured using a Secure Seal Tester (acronym SST) in “pound-force per square inch” (acronym psi Ibf / inc2) and Application Torque (acronym AT) measured in inch pound-force (acronym in Ibf Ibf x inc).

[0168] To check the fluid-tight seal of a container filled with a material and closed with a respective cap, in the closed condition, the use is known of an instrument called a Secure Seal Tester which uses pressurised air to check if the sealing element of the bottle is intact and whether or not it guarantees the fluid-tight seal.

[0169] The test on a sample to be measured is carried out at a predetermined pressure with the sample immersed in water. If the sample produces air bubbles when it is immersed in water, that means that the fluid-tight seal is not made.

[0170] The term “Application Torque”, in the technical sector of caps for bottles, refers to a rotational force applied to tighten the closure expressed in “pound-force”, that is to say, inch pound-force (in Ibf).

[0171] For that purpose, different types of inserts 6 were considered, each defined by a different shaped appendage 607 defined by a respective pair of values which are the value of the second zone P2 in mm and the value of the internal diametral interference at R1 in mm, and for each of those inserts the SST value in psi and the AT value in Ibf were measured.

[0172] The results indicated below were obtained with inserts 6 of the sixth variant, but they were also repeated with inserts 6 of the fifth variant, obtaining the same results. In fact, the inserts 6 of the fifth and of the sixth variant used in the tests both had the same shaped appendage 607.

[0173] If the container 2 contains carbonated beverages, that is to say, highly carbonated or beverages pressurised with nitrogen, a fluid-tight seal with SST greater than or equal to 30 psi (approximately 2 bar) must be guaranteed.

[0174] Moreover, it is preferable for the application torque AT to be less than or equal to 30 in Ibf or even more preferably less than or equal to 25 in Ibf, in order to be manageable in container capping lines and for users. In fact, if the application torque AT has values greater than or equal to 30 in Ibf it was found that the caps 1 obtained are not easy to apply to the containers, in the capping lines, and that they are difficult for a user to manage.

[0175] From the results obtained it can be seen how the value of the application torque AT was always less than 30 in Ibf.

[0176] However, the best result is that shown in bold above, in which the insert 6 has the appendage 607 which, having the second zone P2 at 0.45, and the internal diametral interference equal to 0.35 mm, obtains a high fluid-tight seal with SST equal to 46 (psi) even though requiring a relatively low application torque, that is to say, equal to 22 (Ibf).

[0177] In other words, the insert 6 which has these specific values relative to the second zone P2 and to the internal diametral interference, allows a closing cap 1 to be obtained which guarantees a very high fluid-tight seal and can also meet the standards required for containers which contain carbonated beverages. At the same time, the closing cap 1 made in this way requires a relatively low application torque, which facilitates both application of the closing cap 1 on a container, in capping lines, and manageability for a user. It should be noticed that with the internal diametral interference values in the range indicated above, which may be greater than or equal to 0.1 mm and less than or equal to 0.8 mm, an effective fluid-tight seal and easy application of the cap are confirmed. Figure 1 1 shows a third closing cap 1 , joined to a respective container 2, in the closed condition, in which the third cap 1 comprises a third embodiment of the shell of Figure 1 and the second variant of the insert 6, of Figure 7. The cap 1 is in the closed condition in which the shell 5 is in the first position and both the central portion 605 and the intermediate part 604 are in contact with the transversal wall 4.

[0178] The third embodiment of the shell 5 differs from the first and from the second embodiments in that the shell 5 comprises a pressing element 502 configured to press, in the closed condition, an outer face of the outer part 602, in such a way that an inner face of the latter (positioned on the opposite side to the outer face) in turn presses against an outer wall 207 of the neck 201.

[0179] It should be noticed that the pressing element 502 is configured as a projection, which may project from the transversal wall 4 and extend along an axis parallel to the axis Z, as shown in Figure 11 , or which may project from the lateral wall 3 and extend along an axis perpendicular to the axis Z. Alternatively, in a way not shown, the pressing element 502 may project from a border zone between the transversal wall 4 and the lateral wall 3 and be inclined towards the axis Z. This border zone is a zone placed inside the shell 5 which corresponds to the outer connecting zone 401 between transversal wall 4 and the lateral wall 3.

[0180] In this way the top edge 208, which in the closed condition is in contact with the intermediate part 604 of the insert 6, is enveloped on both the inside and the outside by the insert 6, since the inner part 601 engages with the inner wall 206 and the outer part 602 engages with the outer wall 207 which is pressed by the pressing element 502 against the outer wall 207. That increases the fluid-tight seal of the insert 6 against the neck 201 .

[0181] If the shell 5 comprises the supporting element, shaped like the annular protuberance 501 , or comprises the protrusion, continuous or interrupted, which projects from the lateral wall 3 towards the axis Z for a predetermined angular portion, the pressing element 502 is positioned, axially, between the transversal wall 4 and the protuberance 501 , or between the transversal wall 4 and the protrusion.

[0182] Even in the absence of the pressing element 502, the outer part 602 extends on the outside of the neck 201 and is configured to help to make the fluid- tight seal, by applying a pressure on the outer wall 207 of the neck 201 .

[0183] Considering a nominal diameter of contact between the outer wall 207 and the outer part 602, an external diameter of the neck 201 , that is to say, of outer wall 207, is greater than the nominal diameter whilst an internal diameter of the outer part 602 is less than that nominal diameter. The difference between the external diameter of the outer wall 207 and the internal diameter of the outer part 602 defines an external diametral interference.

[0184] In detail, the internal diameter of the outer part 602 is measured at the outer margin 603.

[0185] The external diametral interference may be greater than or equal to -0.2 mm and less than or equal to 0.6 mm.

[0186] For example, for carbonated beverages the external diametral interference may be equal to 0.3 mm.

[0187] Alternatively, for non-carbonated water the external diametral interference may be equal to 0.15 mm.

[0188] If the external diametral interference is between -0.2mm and 0 mm, there is a clearance between the outer margin 603 and the outer wall 207 and this facilitates the coupling and the uncoupling of the cap 1 to and from the neck 201.

[0189] If the external diametral interference is between 0 and 0.6 mm, the pressing element 502 strengthens a contact between the outer part 602 and outer wall 207 and this is particularly advantageous for beverages which are highly carbonated or pressurised with nitrogen when the internal pressure is high.

[0190] Both if the external diametral interference is positive, and if the external diametral interference is negative, the pressing element 502, if present, may prove advantageous for pressing the outer part 602 against the outer wall 207.

[0191] In use, the shell 5 and the insert 6 are made as separate components using PET and then assembled, in such a way as to make the cap 1 .

[0192] The shell 5 may be obtained by injection moulding, or compression moulding, or injection compression moulding.

[0193] The insert 6 may be obtained by injection moulding, compression moulding or by thermoforming from a flat sheet of plastic material made of PET.

[0194] The predetermined separating line may be made during the moulding, or after the moulding with a further cutting operation.

[0195] Therefore, to obtain the cap 1 , the following production steps may be carried out:

[0196] - moulding of the shell 5 and of the insert 6;

[0197] - execution of the cutting operation to obtain the separating line (if the separating line is obtained by cutting and not by moulding);

[0198] - if necessary bending of the engaging element 305 inwards (if the engaging element is made as an appendage which extends beyond the free edge 303 and then must be bent);

[0199] - assembly of the shell 5 and of the insert 6.

[0200] If the bending on the engaging element 305 is necessary, it can be carried out before or after execution of the cutting operation for making the separating line.

[0201] The insert 6 is positioned inside the shell 5 and is fitted towards the transversal wall 4, in such a way that the outer margin 603 of the insert moves past the undercut represented by the annular protuberance 501 , if present, and / or in such way that the inner part 601 moves past the undercut represented by the th read / th reads of the inner coupling structure 304.

[0202] When the insert 6 is inserted inside the shell 5, and the cap 1 obtained in this way is not coupled to the neck 1 , the insert 6 is supported by the supporting element.

[0203] This invention is advantageously applicable to a cap 1 , which is suitable for being used, for example, on necks 201 in the following list, each neck 201 being associated with a respective code which identifies the name of the neck 201 , the diameter of the outer surface of the neck 201 , and the diameter of the supply opening of the neck 201 , in accordance with the nomenclature of CETIE (www.cetie.org) or ISBT

[0204] For each code, if the neck 201 is also a European standard, the reference number is also provided.

[0205] The specifications described below apply for the cap 1 according to this invention and for the neck 201 already known.

[0206] GME30.39 25 / 22 mm

[0207] GME30.28 26 / 22 mm DIN EN 16594:2016

[0208] GME30.38 26 / 22 mm

[0209] GME30.37 26 / 22 mm

[0210] GME30.40 26 / 22 mm

[0211] GME30.24 27 / 22 mm EN 16067:2012

[0212] PCO1881 28 / 22 mm

[0213] PCO1810 28 / 22 mm

[0214] GME30.26 29 / 25 mm EN 16592:2015

[0215] GME30.21 30 / 25 mm EN 16064:2012

[0216] GME30.31 32 / 26 mm

[0217] GME30.36 32 / 27 mm

[0218] GME30.30 33 / 28 mm

[0219] GME30.25 38 / 33 mm

[0220] GME30.29 38 / 32 mm

[0221] As regards the type of beverage which can be contained in the container 2, it should be noticed that this invention is particularly applicable to a cap 1 which is suitable for use for beverages in the following list: carbonated beverage up to 1 1 g / l of CO2; carbonated beverage up to 9 g / l of CO2; carbonated beverage up to 7 g / l of CO2; non-carbonated beverage, for example still water; pressurised beverage, for example due to the presence of N2 (nitrogen) in a head space of the container with overpressure of up to 1 .5 bar, preferably up to 1 bar; beverage sensitive to oxidative degradation, or beverage sensitive to microbial degradation; cold filled beverages (<35°C); hot filled beverages <65°C.

[0222] As regards the transversal wall 4 of the cap 1 , it should be noticed that this invention is particularly applicable to a cap 1 in which the transversal wall 4: may be flat, or concave, or may have an outer annular zone, flat or concave, at a first distance from the free edge and a central zone, flat or concave, at a second distance from the free edge, the second distance being greater than the first distance, to define a raised space; it may optionally have internal logos, or external logos; it may have a smooth or rough outer surface, as defined in accordance with standard ISO1302, for example between NO and N10, preferably between N4 and N9; it may have a thickness of between 0.4 mm and 2 mm; it may have an inner surface provided with reinforcing ribs, where the reinforcing ribs can be made using radial spokes, or concentric rings, or a combination thereof.

[0223] As regards the lateral wall 3, as already indicated, it can be provided with knurling lines 312.

[0224] With reference to those knurling lines, it should be noticed that this invention is particularly applicable to a cap 1 in which the knurling lines: may be angularly equally spaced apart from each other around the axis Z, numbering between 30 and 144, preferably between 60 and 120; may be grouped and each group may be separated from the adjacent group by a space without a knurling line, for example there may be 24 groups present, in which each group has 3 knurling lines which are angularly equally spaced apart from each around the axis Z; there may be service knurling lines present, with reduced length, used to guide the cap during a cutting operation; may be present on the lateral wall and optionally on the transversal wall and / or on the retaining ring.

[0225] As regards the lateral wall 3, it should be noticed that this invention is particularly applicable to a cap 1 in which the lateral wall 3 may have: a constant thickness, for example between 0.35 and 1 .2 mm; or may have an uneven thickness, which is for example greater towards the free edge 303 of the lateral wall 3; or it may have a smooth or rough inner surface, as defined in accordance with standard ISO1302, for example between NO and N10, preferably between N4 and N9, however preferably the sealing surfaces of the cap and neck are smooth, polished.

[0226] As regards the coupling structure 304, which is configured to removably couple the closing element 302 to the neck 201 of the container 2, it should be noticed that this invention is particularly applicable to a cap 1 in which the coupling structure 304 may have: a thread structure with single helical thread with angular extent between 500° and 930°, preferably between 650° and 760°, in which the thread optionally has a plurality of interruptions numbering between 4 and 30; a thread structure with a plurality of helical threads, that is to say, with multiple helical threads, for example with two helical threads 304A, 304B, or with three helical threads, wherein each thread has an angular extent between 90° and 380°, preferably between 120° and 250°, wherein each thread optionally has a plurality of interruptions numbering between 2 and 15, for example the coupling structure may comprise two helical threads 304A, 304B, or three helical threads.

[0227] The interruptions of each thread, in the thread structures described above, are preferential escape routes for the gas which may be present inside the container 2. It should be noticed that this invention is particularly applicable to a cap 1 in which the interruptions may be made exclusively on the thread, or may be dug in the lateral wall 3 of the cap 1 , to guarantee greater depth for the interruption and therefore to increase a passage for the gas which may be present in the container 2.

[0228] As regards the production method, it should be noticed that the shell 5 may be made as a concave body obtained by means of injection moulding, or compression moulding, or injection compression moulding.

[0229] The closing element 302 may completely detach from the retaining ring 301 , at the moment when the cap 1 is opened for the first time, when the breakable bridges are broken, or the closing element 302 and the retaining ring 301 may remain joined to each other, in an open condition of the cap 1 , by means of a connecting band made by making in the cap 1 a further separating line (not illustrated) along which breakable elements are present which are intended to also be broken when the cap 1 is opened for the first time. The latter caps 1 in which a connecting band is present between the closing element 302 and retaining ring 301 are commonly known as “tethered” caps.

[0230] The breakable bridges and / or the breakable elements may be made using special moulds during moulding of the cap 1 , or by means of a cutting operation, after the concave body has been made.

[0231] A tab (not illustrated) may be defined between the separating line and the further separating line when the breakable bridges are broken.

[0232] In the latter case, the cutting operations may be carried out by means of respective blades, for example circular or linear, which interact with the lateral wall from the outside of the latter, or from the inside.

[0233] The blades may have an interrupted cutting edge, if the decision is made to leave the breakable bridges defined along the separating line and / or to leave respective breakable elements defined along the further separating line.

[0234] It is also possible that the blades do not cut through the entire thickness of the lateral wall, but instead only partially cut through the thickness of the lateral wall, so as to leave, along the separating line and / or along the further separating line, a thin membrane intended to be broken when the cap is opened for the first time.

[0235] Alternatively, each blade may have a continuous cutting edge if a respective strip of the lateral wall intended to be cut comprises a plurality of enlarged parts, circumferentially distributed in the strip and configured to be partially cut by a 360° cut by the continuous cutting edge, in such a way as to define the breakable bridges along the separating line and / or the breakable elements along the further separating line.

[0236] As regards the retaining ring 301 , it should be noticed that this invention is particularly applicable to a cap 1 in which, after the cap has been opened for the first time, the retaining ring 301 : may completely separate from the closing element 302 and remain joined to the neck 201 of the container 2; may partially separate from the closing element 302 to keep the cap 1 joined to the container 2; may be provided with one or more vertical incisions to remain connected to the closing element 302, but completely separated from the neck 201 of the container 2.

[0237] As already indicated, the retaining ring 301 comprises the engaging element 305, which is configured to engage with the stop ring 202 of the neck 201 of the container 2 in such a way as to allow separation of the closing element 302 from the retaining ring 301 , promoting breaking of the breakable bridges, when the cap 1 is opened for the first time.

[0238] It should be noticed that this invention is particularly applicable to a cap 1 in which the engaging element 305 may be shaped like a flap, which projects inwards towards the inside of the cap 1 starting from its initial end and may be placed on the free edge 303, or near the free edge 303.

[0239] Along the initial end of the engaging element 305 there may be a plurality of drainage openings present, which have a small angular extent, are equally spaced apart from each other and serve to drain any washing liquid after moulding of the cap 1 . The number of drainage openings may be between 3 and 30, preferably between 5 and 16.

[0240] It should be noticed that this invention is particularly applicable to a cap 1 in which the engaging element 305 may be moulded inwards, that is to say, it may be formed already directly bent inwards towards the inside of the cap, or in which it may be moulded outwards from the cap, that is to say, it may be made as an appendage which extends beyond the free edge 303 and is then bent.

[0241] It should be noticed that this invention is particularly applicable to a cap 1 in which, alternatively and according to an embodiment not shown in these figures, the engaging element may not be shaped like a flap, instead being a protuberance which projects inwards towards the inside of the cap 1 ; which may be continuous; which may be interrupted and having a plurality of portions angularly equally spaced apart from each other, numbering between 3 and 15; which may have a flexibility recess adjacent to it, on the transversal wall 4 side, in which the lateral wall 3 has a reduced cross-section; which may have a further protuberance continuing on from it which projects less than the protuberance and is positioned, when the cap 1 is coupled to the neck 201 , at the stop ring 202 of the neck 201 .

[0242] It should be noticed that this invention is particularly applicable to a container 2 which may be obtained by injection and stretch-blow moulding, or by injection and blow moulding, or by extrusion and blow moulding or by compression and blow moulding.

[0243] If the container 2 is a bottle, not illustrated, which comprises the neck 201 and a containment body provided with a resting bottom, wherein the containment body is connected to the neck 201 by a shoulder, it should be noticed that this invention is particularly applicable to a container 2 wherein, alternatively and according to an embodiment not shown in these figures, the shoulder may be conical; concave (“flask-style"); convex; round; and wherein the containment body, according to an embodiment not shown in these figures may be: with round cross-section; with rectangular cross-section with rounded, or smoothed edges; with square cross-section with rounded, or smoothed edges; completely smooth on the outside; decorated on the outside; ribbed on the outside.

[0244] If the containment body has outer ribs, not shown in these figures, these ribs may be: straight, or undulating; continuous, or interrupted; and may have a crosssection that is square, or circular, or has a different dedicated shape.

[0245] It should be noticed that this invention is particularly applicable to a container 2 in which, alternatively and according to an embodiment not shown in these figures, the resting bottom may be: flat, and may have a plurality of shapes which derive from the number and the position of the outer ribs which, positioned like radial spokes starting from a central zone of the resting bottom, at least partially extend upwards on the outside of the containment body of the container 2; concave, like a champagne bottom; having a plurality of resting projections, called petals, their number being greater than or equal to 3 and less than or equal to 7; preferably their number being greater than or equal to 4 and less than or equal to 6, wherein each resting projection maybe divided in half in a resting part, configured to rest on the supporting surface, by means of a rib with small dimensions in order to increase the mechanical strength of the rib itself.

Claims

CLAIMS1 . Closing cap (1 ) for a container (2), comprising- a shell (5), provided with a lateral wall (3) extending around an axis (Z) and with a transversal wall (4) positioned at one end of the lateral wall (3), the shell (5) being provided with an inner coupling structure (304) shaped like a thread structure and positioned inside the lateral wall (3) for removably coupling the cap (1 ) to a neck (201 ) of the container (2);- an insert (6), inserted in the shell (5), comprising an inner part (601 ), which is configured in a closed condition to engage in a sealed fashion with a supply opening (203) of the neck (201 ), and an outer part (602), which is annular, which extends as far as an outer margin (603) of the insert (6);- wherein the shell (5) and the insert (6) are made of PET and are separate components, capable of at least partially rotating one relative to the other during an opening, or a closing, of the neck (201 ).

2. Closing cap (1 ) according to claim 1 , wherein in the closed condition the insert (6) is coupled without interference to the lateral wall (3) and the shell (5) is in a first position relative to the neck (201 ), the insert (6) being configured in such a way that in an initial step of opening the cap (1 ), when the shell (5) moves axially away from the neck (201 ) and moves between the first position and a second position, the insert (6) remains joined to the neck (201 ) and can, at least partially, rotate relative to the shell (5).

3. Closing cap (1 ) according to claim 2, wherein the shell (5) comprises a supporting element (501 ; 304) configured to support the insert (6) inside the shell (5), wherein the insert (6) makes contact with the supporting element in the second position, in such a way that when the shell (5) moves axially further away from the neck (201 ) in a final step of opening the cap (1 ), after the initial step, the insert (6) remains joined to the shell (5) making contact with the supporting element (501 ; 304).

4. Closing cap (1 ) according to claim 2, or 3, wherein there is an axial distance (H), measured along the axis (Z), present between the first position and the second position, said axial distance being less than or equal to 2.0mm.

5. Closing cap (1 ) according to one of claims 2 to 4, wherein in the closed condition there is a transversal distance present between the outer margin (603) and the lateral wall (3), measured transversally to the axis (Z), which is less than or equal to 0.7mm.

6. Closing cap (1 ) according to one of claims 3 to 5, wherein the supporting element is an annular protuberance (501 ), continuous or interrupted, which projects from the lateral wall (3) towards the axis (Z) and is positioned between the transversal wall (4) and the coupling structure (304), the outer margin (603) being configured to make contact with the supporting element in the second position.

7. Closing cap (1 ) according to one of claims 3 to 5, wherein in the closed condition the inner part (601 ) is, at least partially, at a distance from the transversal wall (4); and wherein the supporting element comprises the inner coupling structure (304), the outer margin (603) being configured to make contact with the inner coupling structure (304) in the second position.

8. Closing cap (1 ) according to claim 7, wherein the inner coupling structure (304) comprises a plurality of helical threads (304A; 304B), having respective final ends (304A’; 304B’) which are near the transversal wall (4) and angularly equally spaced apart from each other; wherein in the second position the outer margin (603) is configured to make contact with the respective final ends (304A’; 304B’).

9. Closing cap (1 ) according to claim 7, wherein the coupling structure (304) comprises a single helical thread, having a respective final end near the transversal wall (4), and the supporting element comprises a protrusion, continuous or interrupted, which projects from the lateral wall (3) towards the axis (Z) for a predetermined angular portion, is diametrically opposed to the single final end and is positioned, axially, at the same height as the final end of the single helical thread; in the second position the outer margin (603) being configured to make contact with the final end of the single helical thread and the protrusion.

10. Cap (1 ) according to claim 7, wherein the coupling structure (304) comprises a single helical thread, having a respective final end near the transversal wall (4), a portion of the single helical thread being diametrically opposed to the single final end, in the second position the outer margin (603) being configured to make contact with the final end of the single helical thread and the portion of the single helical thread diametrically opposed to it.1 1. Closing cap (1 ) according to one of the preceding claims, wherein the insert (6) comprises an intermediate part (604) which is planar and configured, in the closed condition, to make contact with a top edge (208) of the neck (201 ), on one side, and the transversal wall (4), on the other side, and wherein the outer part (602) of the insert (6) is inclined relative to the intermediate part (604) and is at a distance from the transversal wall (4).

12. Closing cap (1 ) according to one of the preceding claims, wherein the inner part (601 ) comprises a central portion (605) which, in the closed condition, is at a distance from the transversal wall (4) and a lateral portion (606) which is configured to make a seal with the supply opening (203); wherein the lateral portion (606) has a tubular and annular shape for making contact with an inner wall (206) of the supply opening (203) and wherein the central portion (605) is concave, or convex, or planar; or wherein the lateral portion (606) is “U”-shaped, an outer branch of the “U” making contact with the inner wall (206), an inner branch of the “U” being adjacent to the central portion (605), which is planar.

13. Closing cap (1 ) according to claim 11 , wherein the inner part (601 ) comprises a planar central portion (605), aligned with the intermediate part (604) and an appendage (607), which is annular, is positioned between the intermediate part (604) and the central portion (605), and extends inside the supply opening (203); wherein the appendage (607) is shaped (for example it is provided with an olive bead moulding-shaped free end) and has a first zone (P1 ), which is configured to make contact with an inner wall (206) of the supply opening (203), and a second zone (P2), positioned near theintermediate part (604), which is smaller than the first zone (P1 ); the first zone (P1 ) and the second zone (P2) being measured perpendicularly to the axis (Z), (for example the first zone being measured at the olive bead moulding-shaped free end); wherein the second zone (P2) is greater than or equal to the first zone (P1 ) multiplied by 0.4, and is less than or equal to the first zone (P1 ) multiplied by 1.2; or wherein the first zone (P1 ) is equal to 0.785 mm and the second zone (P2) is equal to 0.375 mm.

14. Closing cap (1 ) according to claim 12, or 13, wherein a difference between an internal diameter of the inner wall (206) and an external diameter of the inner part (601 ) defines an internal diametral interference between the inner part (601 ) of the insert (6) and the neck (201 ) which is greater than or equal to 0.1 mm and less than or equal to 0.8 mm.

15. Closing cap (1 ) according to claim 14, when it is dependent on claim 13, wherein the second zone (P2) is equal to 0.45 and wherein the internal diametral interference is equal to 0.35, to guarantee a high fluid-tight seal (for example with SST equal to 46 (psi)) even though requiring a relatively low application torque (for example equal to 22 (Ibf)).

16. Closing cap (1 ) according to one of the preceding claims, wherein a difference between an external diameter of an outer wall (207) of the neck (201 ) and an internal diameter of the outer part (602), measured at the outer margin (603), defines an external diametral interference between the outer part (602) of the insert (6) and the neck (201 ) which is greater than or equal to -0.2 mm and less than or equal to 0.6 mm.

17. Closing cap (1 ) according to one of the preceding claims, wherein the shell comprises a pressing element (502) configured to press, in the closed condition, an outer face of the outer part (602) in such a way that an inner face of the latter in turn presses against an outer wall (207) of the neck (201 ), wherein the pressing element (502) is configured as a projection, which projects from the transversal wall (4) and extends along an axis parallel to the axis (Z), or projects from the lateral wall (3) perpendicularly towards the axis (Z) or projects from a border zone between the transversalwall (4) and the lateral wall (3) and is inclined towards the axis (Z).

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