DESCRIPTION

Technical field

The present invention relates to the field of caps, in particular to the field of caps for bottle and preferably screw-type caps for bottle.

State of the Art

The present invention concerns a cap for bottle, preferably of the screw type, in which a head and a cylindrical element inside the head constitute two parts, which are mutually stably assembled to form a single piece.

As is well known, the screw-type caps for bottle, also called screw caps for bottle, consist, in their simplest version, of a cylindrical-shaped head having a cylindrical cavity on the inner surface of which there are threads that allow the cap to be screwed onto the bottle so as to guarantee liquid-tightness. In this version the caps are made of metallic materials.

In order to improve the hermetic tightness of the screw cap, the upper inner surface of the cylindrical cavity of the head is coated with a layer of partially soft material, typically consisting of expanded plastic material, which interposing between the edge of the neck of the bottle and the lower surface of the cavity of the screw cap, allows to achieve and improve the tightness. Also in this version of the screw cap, this is typically made of metallic material.

However, nowadays, both for aesthetic reasons and for ecological and sustainable reasons, it would be preferable to be able to use screw caps thus made of wood. However, the realization of screw caps in wood imposes the need to employ a cylindrical element in plastic material that, interposing between the liquid and the wood of the head, allows to prevent the wood from getting soaked with liquid. In said embodiment of a screw cap with a wooden head and a cylindrical element inside the head, made of plastic material, the main drawback is the detachment of the wooden head from the cylindrical element that remains tightened on the neck of the bottle.

The use of adhesives to retain the head on the inner cylindrical element only partially solves the problem since in situations of high temperature or intense cold, the adhesive does not guarantee the tightness of the pieces of the cap.

The screw caps available today are made of metallic materials or of plastic materials. Therefore, a further problem is that of making easily biodegradable caps.

Summary of the invention

The problem addressed by the present invention is therefore that of providing a cap for bottle able of allowing the good tightness of the liquid contained in the bottle, of being in a such a way as to guarantee the non-detachment of the head of the inner cylindrical element and, preferably, of being, at least partially, biodegradable, allowing to solve the aforementioned problems, with particular attention to the problem of keeping the various parts of the cap firm.

Such problems are solved by the cap for bottle of the present invention, as outlined by the appended claims, the definitions of which are an integral part of the present description.

In particular, the invention relates to a cap for bottle that, by means of the particular conformation and combination of the pieces that compose it, allows making a cap for bottle in which the head is firmly assembled to the inner cylindrical element, at the same time allowing the at least partial biodegradability of the cap. Further characteristics and advantages of the cap for bottle of the invention will result from the description of the figures of the invention, being embodiments of the invention, provided as an indication thereof.

Brief description of the figures

Further characteristics and advantages of the present invention will become more apparent from the following detailed description of a possible practical embodiment, illustrated by way of non-limiting example in the set of drawings, wherein:

Fig. 1 shows a perspective view partially from above of the partially exploded cap according to an embodiment of the invention;

Fig. 2 shows a perspective view partially from below of the exploded cap, according to an embodiment of the invention;

Fig. 3 shows a bottom view of the cap, according to an embodiment;

Fig. 4 shows a sectional view of the cap of Fig. 3.

Detailed description of the invention

With reference to the attached figures, a cap for a bottle (not shown in the figures) provided with neck 15 is indicated with 1, in accordance with the present invention. The cap 1 comprises a cylindrical head 2 having an axis X-X.

The cylindrical head 2 has a first cylindrical cavity 4 coaxial with the axis X-X of the cylindrical head 2.

The first cylindrical cavity 4 is open at the bottom and closed at the top by a first circular surface 5.

The first cylindrical cavity 4 has an annular channel 6 coaxial with the axis X-X and attached with the first circular surface 5.

The cap 1 further comprises a cylindrical element 3 adapted to be housed inside the first cylindrical cavity 4. The cylindrical element 3 has a second cylindrical cavity 7 coaxial with the axis X-X. The second cylindrical cavity 7 is open at the bottom and closed at the top by a second circular surface 8.

The second circular surface 8 has at least one hole 9.

The second cylindrical cavity 7 has an inner side surface 7a configured to engage removably with an end part of the neck 15 of the bottle.

In accordance with one embodiment, the inner side surface 7a of the second cylindrical cavity 7 comprises threads 10 configured to engage removably with threads 16 formed on the end part of the neck 15 of the bottle.

The cap 1 further comprises a layer of plastic material 11 adapted to fill the annular channel 6 and to form a circular layer 12 that covers at the bottom, preferably entirely, the second circular surface 8.

It has in fact surprisingly been found that the combination between the head 2, an inner cylindrical element 3 and a layer of plastic material which, by filling an annular channel 6 of the head 2 and by covering the lower surface of the cylindrical element 3, allows to avoid the detachment of the head 2 of the inner cylindrical element 3, thus allowing to make robust caps for bottle having, for example, head in wood and inner cylindrical element in plastic, well assembled with each other.

Thanks to the undercut made by the annular channel 6, a mechanical coupling is formed on the head 2 of the cap 1 which does not permit to the cylindrical element 3 to escape from the first cylindrical cavity 4. In other words, it is the presence of the “T-shaped” hollow on the head 2 that guarantees the mechanical tightness between the head 2 and the cylindrical element 3. The annular channel 6 may have a diameter comprised between 101% and 120% with respect to the diameter of the first cylindrical cavity 4, preferably between 105% and 115%.

The annular channel 6 may have a cross-section of rectangular or semi-circular shape, preferably having a rectangular cross-section.

The annular channel 6 is attached to the first circular surface 5, i.e. the edge of the annular channel 6 is attached to, i.e. merged with the first circular surface 5. The term attached means that part of the annular channel 6 consists, on the one hand, of the first circular surface 5. According to a preferred embodiment, the annular channel 6 has a rectangular-shaped cross-section and consists, on the one hand, of the first circular surface 5.

According to a preferred embodiment, the first circular surface 5 of the head 2 is partially covered by a circular protrusion 13. Said circular protrusion 13 has the function of keeping the cylindrical element 3 partially detached from the first circular surface 5 so as to realize, according to one embodiment, a space for the passage of the molten plastic material so that it reaches the annular channel 6.

According to one embodiment, an upper part of the second circular surface 8 of the cylindrical element 3 has at least one groove 14 extending between the hole 9 and the outer perimeter of the cylindrical element 3. Said groove 14, according to one embodiment, allows the passage of the molten plastic material, entered from the hole 9, so that it reaches the annular channel 6.

According to one embodiment, the groove 14 has a rectangular-shaped cross-section. According to one embodiment, the groove 14 is tapered with taper increasing from the hole 9 to the outer perimeter of the cylindrical element 3. In other words, the gap of the groove 14 increases from the hole 9 to the outer perimeter of the cylindrical element 3.

Preferably, the number of grooves 14 is the same as the number of holes 9.

The cylindrical element 3 has at least one hole 9 that allows the passage of the molten injected plastic material so that it fills the annular channel 6 that guarantees the tightness between the two parts, cylindrical element 3 and head 2. Preferably, the cylindrical element comprises from 5 to 20 holes, more preferably from 5 to 10 holes, even more preferably it comprises 6 holes.

According to a preferred embodiment, in the cap 1, the head 2 is made of wood or similar material, such as cork, another biodegradable material of natural origin.

According to a preferred embodiment, the cylindrical element 3 is made of plastic material, preferably of rigid plastic material. Traditional plastic or composite plastic material is typically used.

According to a more preferred embodiment, the head 2 is made of wood or similar material and the cylindrical element 3 is made of plastic material.

As a further advantage, the circular layer 12 that covers the entire lower part of the circular surface 8 of the cylindrical element 3 also performs the function of seal.

Another object is the process for making the cap 1 as described above.

The process comprises the following steps: a) inserting the cylindrical element 3 inside the first cylindrical cavity 4 of the head 2, b) injecting molten plastic material so as to form, after cooling, a layer of plastic material 11 adapted to fill the annular channel 6 and to form a circular layer 12 that covers at the bottom the second circular surface 8 of the cylindrical element 3. Preferably, the cap for bottle 1 described above can be used to close bottles of wine, of super alcohols, of perfumes and of cosmetic products, such as creams, lotions, oils, etc.