The present invention refers to a screw cap for recipients containing liquid products, in particular but not necessarily liquid food products.

In order to close recipients containing drinks or other liquid food products, screw closing devices are known to be used, made up of two elements: a threaded capsule, which actually closes and possibly seals the recipient, and an inner safety seal, arranged below such a capsule. The function of the inner safety seal is that of preserving the integrity of the liquid product contained inside the recipient until the recipient itself has been opened for the first time by the user.

A first known and common type of this kind of inner safety seal, commonly used on recipients manufactured in plastic or cardboard containing for example milk, fruit juice, infusions or other non-alcoholic drinks, is made up of an aluminium film that is securely connected to the opening of the recipient. In the act of opening the recipient for the first time, the user must manually breake or perforate the film, which normally remains partially fixed to the opening of the recipient itself, thus coming into contact with the liquid product.

Therefore, in order to avoid contact between the inner safety seal, once broken, and the liquid contained in the recipient, breakable walls made of plastic material have been made, fixed to the opening of the recipient and positioned below the closing capsule. Such breakable walls are provided with a holding tab so that the user, after the capsule has been opened for the first time, can completely extract them from the opening of the recipient, breaking their constraints that connect them to the latter. However, even if these walls provided with a tab can be completely extracted from the recipient, they require, in any case, a finger of the user to be inserted into the opening of the recipient itself to remove them, with consequent possibility of contamination of the liquid food product.

The general purpose of the present invention is therefore that of making a screw cap for recipients containing liquid products, in particular but not necessarily for liquid food products, which is able to solve the aforementioned drawbacks of the prior art in an extremely simple, cost effective and particularly functional manner.

In particular, one purpose of the present invention is that of making a screw cap for recipients containing liquid products that is able to form a safety seal for the recipient without such a safety seal coming into contact with the liquid product after its removal.

Another purpose of the invention is that of making a screw cap for recipients containing liquid products in which the removal of the safety seal, after the recipient has been opened for the first time, does not have to be carried out manually by the user.

These purposes according to the present invention are achieved by making a screw cap for recipients containing liquid products, in particular but not necessarily liquid food products, as outlined in claim 1.

Further characteristics of the invention are highlighted in the dependent claims, which are an integral part of the present description.

The characteristics and the advantages of a screw cap for recipients containing liquid products according to the present invention shall become clearer from the following description, given as an example and not for limiting purposes, with reference to the attached schematic drawings in which:

• figure 1 is a perspective view of a screw cap for recipients containing liquid products according to the present invention;
• figure 2 is a top plan view of the cap of figure 1;
• figure 3 is a section view, obtained along the line A-A of figure 2, of the cap of figure 1;
• figure 4 is an enlarged view of the detail indicated with "C" in figure 3;
• figure 5 is a perspective view of a first component of the cap of figure 1;
• figure 6 is a side elevational view of the first component of figure 5;
• figure 7 is a top plan view of the first component of figure 5;
• figure 8 is a section view, obtained along the line B-B of figure 7, of the first component of figure 5;
• figure 9 is a perspective view of a second component of the cap of figure 1;
• figure 10 is a side elevational view of the second component of figure 9;
• figure 11 is a bottom plan view of the second component of figure 9; and
• figure 12 is a section view, obtained along the line C-C of figure 11, of the second component of figure 9.

With reference to the figures, a screw cap for recipients containing liquid products according to the present invention is shown, wholly indicated with reference numeral 10. The cap 10 is configured for being applied to a generic recipient for liquid products (not shown), of the type made for example in recyclable cardboard and provided, on its upper wall, with an outlet hole for the liquid contained therein.

The cap 10 comprises a first cylindrical dispenser element 12 in the form of a sleeve (figures 5-8), provided with an external threading 14 and with an annular base 16 configured so as to be fixedly connected, for example through heat coupling or through glueing, to the wall of the recipient at the relative outlet hole for the liquid contained therein. The sleeve 12 thus forms a mouth through which it is possible to dispense the liquid contained inside the recipient.

The sleeve 12 of the cap 10 is internally obstructed by a breakable circular wall 18, having a perpendicular extension with respect to the rotation axis of the sleeve 12 itself and formed integral with it. The breakable circular wall 18 is connected to the inner side surface of the sleeve 12 by means of a circumferential weakened line 20. The breakable circular wall 18 thus acts as a safety seal for the cap 10, sealingly obstructing its mouth 12 until the recipient is opened for the first time, as shall be better specified hereafter.

The cap 10 also comprises a second cylindrical element 22, or covering capsule (figures 9-12), closed by a bottom plate 24 at its upper end. Along the inner side surface of the covering capsule 22 a first female screw 26 is formed, operatively coupled with the external threading 14 formed on the outer side surface of the sleeve 12.

According to the invention, inside the covering capsule 22 there is a second female screw 28 having a smaller diameter and opposite screwing direction with respect to the diameter and screwing direction of the first female screw 26. The second female screw 28 of the covering capsule 22 is thus capable of engaging with a screw 30 formed integral with the breakable circular wall 18 of the sleeve 12. In turn, also the screw 30, preferably made hollow inside, has a smaller diameter and opposite screwing direction with respect to the diameter and screwing direction of the external threading 14 of the sleeve 12.

In such a way, when the cap 10 is in its closed configuration before the recipient has been opened for the first time, the outer 26 and inner 28 female screws of the covering capsule are engaged with the external threading 14 and the inner screw 30 of the sleeve 12, respectively, as shown in the section view of figure 3. By acting upon the covering capsule 22 there will thus be the unscrewing and the lifting of the latter with respect to the sleeve 12 and, simultaneously, the screwing of the screw 30 inside the respective inner female screw 28. Consequently, with the same movement with which the unscrewing and the lifting of the covering capsule 22 from the sleeve 12 is obtained, there is also the lifting of the breakable circular wall 18 and its detachment from the sleeve 12, through breaking of the circumferential weakened line 20.

Therefore, after the recipient has been opened for the first time, the circular wall 18, separated from the sleeve 12, and the relative screw 30 remain inserted inside the covering capsule 22, without needing any manual intervention by the user to remove the safety seal, consisting of the circular wall 18 itself, and without such a safety seal accidentally being able to fall into the recipient and sink into the liquid contained therein, thus contaminating it. Preferably, in order to obtain the complete lifting and the consequent removal of the breakable circular wall 18 from the sleeve 12 at a different time with respect to that in which the complete unscrewing of the covering capsule 22 from the sleeve 12 itself is obtained, the threading 14 of the sleeve 12 and that of the outer female screw 26 can be made with a different pitch and/or length with respect to those of the threading of the screw 30 and of the inner female screw 28. In particular, based upon the example embodiment illustrated in the figures, the pitch of the threading of both the screw 30 and of the inner female screw 28 of the covering capsule 22 is longer and equal to double the pitch of both the threading 14 of the sleeve 12 and the threading of the outer female screw 26 of the covering capsule 22.

The length of all the threadings present inside the cap 10 can vary according to the specific needs. Based upon the example embodiment illustrated in the figures, the length of the threading of both the screw 30 and of the inner female screw 28 of the covering capsule 22 is considerably smaller than the length of both the threading 14 of the sleeve 12 and the threading of the outer female screw 26 of the covering capsule 22, so as to allow the complete lifting and the consequent removal of the circular wall 18 from the sleeve 12 before obtaining the complete unscrewing of the covering capsule 22 from the sleeve 12 itself.

The covering capsule 22 can be connected, at its lower edge, to an anti-tampering ring 32 through a plurality of breakable bridge elements 34. The first time the cap 10 is opened, it will thus be characterised, apart from by the detachment of the circular wall 18 from the sleeve 12, also by the breaking of the bridge elements 34, caused by the rotation and by the lifting of the covering capsule 22 and by the consequent detachment of such a covering capsule 22 from the underlying anti-tampering ring 32, held by a projecting lip 36 formed below on the outer surface of the sleeve 12.

In detail, on the inner surface of the anti-tampering ring 32 there are one or more wedge-shaped elements 38, preferably arranged evenly along the circumference of such an anti-tampering ring 32, which project radially inwards towards the sleeve 12. The function of the wedge-shaped elements 38 is that of making it possible for the anti-tampering ring 32 to engage with the projecting lip 36 foreseen on the outer surface of the sleeve 12, so as to limit the axial movement of such an annular ring 32 with respect to the covering capsule 22 when it is screwed onto the sleeve 12 itself and the cap 10 is still sealed.

Finally, on the inner surface of the bottom plate 24, that is to say, the surface facing towards the opening of the sleeve 12, an annular sealing lip 40 can be formed projecting downwards (figure 4), intended to be inserted inside the upper edge of the sleeve 12 itself to improve the seal of the cap 10. Of course, the diameter of the annular sealing lip 40 is shorter than the diameter of the sleeve 12 in the respective contact area.

It has thus been seen that the screw cap for recipients containing liquid products according to the present invention achieves the previously highlighted purposes.

The screw cap for recipients containing liquid products of the present invention thus conceived can in any case undergo numerous modification and variants, all covered by the same inventive concept; moreover, all the details can be replaced by technically equivalent elements. In practice the materials used, as well as the shapes and sizes, can be any according to the technical requirements.

The scope of protection of the invention is thus defined by the attached claims.