DESCRIPTION

Technical field

The present invention relates to the field of caps, in particular to the field of bottle caps and in particular of the mushroom type bottle caps.

Background art

The present invention relates to a bottle cap of the mushroom type, wherein a head and a stem constitute two parts, which are mutually fixed together to form a single piece. In particular, as it is known, the so-called mushroom caps are constituted by a cylindrical or frustoconical body being said stem, which is inserted into the neck of the bottle, and by an upper portion having a greater diameter than that of the stem, being said head, which rests on the upper edge of said neck to realize the closure of the bottle.

Nowadays, the stem and the head are made of different materials, for example the head is made of plastic material or wood and the stem is made of cork.

Therefore, the coupling of the head with the stem plays an important role because such coupling must ensure that the cap is removed from the neck of the bottle without the head detaching and leaving the stem inside the neck of the bottle.

In particular, this coupling between the head and the stem must remain firm even in climatic conditions of high heat or intense cold, where the adhesive used to hold the stem together with the head of the caps can respectively melt, soften or, conversely, crystallize, thus causing the easy detachment of the head from the stem of the cap. Such temperature situations may also occur during transport, for example during air transport of the bottles. Therefore, an objective problem is to provide a bottle cap of the mushroom type with an increased coupling between head and stem or with an improved mechanical seal between the head and the stem.

Summary of the invention

The problem addressed by the present invention is therefore to provide a bottle cap capable of being used even in climatic conditions of high heat or intense cold, with high sealing between head and stem, avoiding the detachment of the head from the stem of the cap and thus allowing the aforementioned problems to be solved.

Such problems are solved by the bottle cap of the mushroom type of the present invention as outlined in the appended claims.

In particular, the invention relates to a bottle cap which, by means of the particular conformation and combination of the pieces that make it up, allows the creation of a bottle cap with increased sealing of the head on the stem, even in cold or intense heat conditions.

Brief description of the figures

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

FIG. 1 shows an exploded perspective view of the cap, according to one embodiment of the invention.

FIG. 2 shows a section of an exploded view of the cap, according to one embodiment of the invention.

FIG. 3 shows a section of the cap, according to one embodiment of the invention.

FIGS. 4 and 5 show perspective views of the cap, according to one embodiment of the invention. Detailed description of the invention

With reference to the attached figures, the numeral 1 generally indicates a cap of the mushroom type in accordance with the present invention.

The cap 1 extends along an axial direction X-X between an upper portion la configured to be grasped by a user and a lower portion lb configured to couple internally with the neck 21 of a bottle 20.

The cap 1 comprises a head 2, a stem 3 associated with the head 2 and a layer of adhesive 9 arranged between the head 2 and the stem 3.

The head 2 has a cylindrical cavity 4 extending along the axial direction X-X. The cylindrical cavity 4 has a lower opening 13 and it is closed at the top by an upper head surface 10. The head 2 is internally provided with an annular head channel 5 coaxial with the cylindrical cavity 4.

The stem 3 comprises an upper cylindrical portion 6 of diameter smaller than or equal to the diameter of the cylindrical cavity 4 of the head 2.

The upper cylindrical portion 6 has an upper stem surface 11. The stem 3 comprises an annular stem channel 7 arranged below the upper cylindrical portion 6, and a lower cylindrical portion 8 arranged below the annular stem channel 7.

The lower cylindrical portion 8 has a diameter greater than or equal to the diameter of the cylindrical cavity 4 of the head 2.

The layer of adhesive 9 is arranged at least between the upper head surface 10 of the cylindrical cavity 4 and the upper stem surface 11 of the upper cylindrical portion 6 of the stem 3 and inside the annular head channel 5 and/or the annular stem channel 7.

It has in fact been surprisingly found that the combination of the elements constituting the cap of the invention, i.e. the head 2 and the stem 3, the annular head channel 5 and/or the annular stem channel 7, allows to effectively solve the problem of detachment of the head from the stem of the cap in situations of high heat or intense cold.

Indeed, the fact of making the annular head 5 and stem 7 channels and filling one or both of them with adhesive greatly improves the mechanical tightness of the stem 3 on the head 2.

In one embodiment, the cylindrical cavity 4 and/or the lower cylindrical portion 8 of the stem 3 have a diameter ranging from 15 mm to 30 mm.

In one embodiment, the upper cylindrical portion 6 has a diameter smaller than the diameter of the cylindrical cavity 4 of a range between 0.1 and 0.3 mm. Therefore, in this embodiment, the upper cylindrical portion 6 has a diameter of, for example, 14.7 mm or 14.9 mm when the cylindrical cavity 4 has a diameter of 15 mm, thus respectively having a diameter between 98.0% and 99.3% of the diameter of the cylindrical cavity 4. Or, for example, the upper cylindrical portion 6 has a diameter of, for example, 29.7 mm or 29.9 mm when the cylindrical cavity 4 has a diameter of 30 mm, thus respectively having a diameter between 99.0% and 99.7% of the diameter of the cylindrical cavity 4.

In such a case, the upper cylindrical portion 6 of the stem 3 has a diameter between 98.0% and 99.9% of the diameter of the cylindrical cavity 4.

The annular stem channel 7 may have a radial depth ranging from 0.3 to 1.0 mm.

According to a preferred embodiment, the assembly of the head 2 with the stem 3 realizes, by the juxtaposition of the annular head channel 5 and the annular stem channel 7, an annular adhesive channel 12 having a circular section and being apt to be filled by the adhesive.

In this configuration, in which the annular adhesive channel 12 is filled with adhesive, a better mechanical seal is in fact achieved between the stem 3 and the head 2. Therefore, according to one embodiment, the annular adhesive channel 12 is filled with adhesive.

According to one embodiment, the adhesive is a hot melt adhesive, more preferably EVA (ethylene vinyl acetate) or polyurethane based.

According to one embodiment, the lower cylindrical portion 8 has a diameter ranging from 100.1% to 110%, preferably between 101% and 105%, of the diameter of the cylindrical cavity 4.

In fact, this configuration on the one hand provides that the adhesive does not escape from the head 2 and soil the stem 3, and on the other hand is able to increase the pressure of the stem 3 on the head 2 so that the adhesive interposed between them completely fills the annular head channel 5 and/or the annular stem channel 7 or the annular adhesive channel 12.

According to one embodiment, the head 2 is made of wood or plastic material. According to one embodiment, the stem 3 is made of cork or plastic material. According to a preferred embodiment, the head 2 is made of wood and the stem 3 of cork.

A further object of the present invention is a method for the realisation of the cap 1 disclosed above. The method comprises the following steps: a) providing the head 2, the stem 3, as disclosed above, and the adhesive, b) pouring a quantity of adhesive onto the upper head surface 10, c) inserting the stem 3 inside the head 2 and exerting a pressure, at least along the axial direction X-X, between the stem 3 and the head 2 such that the adhesive forms at least one layer on the upper head surface 10 and on the upper stem surface 11 and goes inside the annular head channel 5 and/or the annular stem channel 7.

According to a preferred embodiment of the method, the annular adhesive channel 12 has a circular section and in step c) the pressure exerted between the stem 3 and the head 2 is such as to push the adhesive to fill the annular adhesive channel 12.