^λλ A method of producing containers , related container and package including same"

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The present invention relates to containers, such as containers for "surprises", capable of receiving inside them gift articles and/or food products and in their turn destined to be introduced inside a case or hollow body, for example of food material.

These containers have benefited from widespread commercial success, particularly in association with hollow food products such as chocolate eggs. Representatives of containers of this type are, for example, documents DE-A-23 24 344, WO-A-93/00267, EP-A- 0 337 960, EP-A-I 018 302, EP-A-I 110 459, US-A-4 106 657 and US-A-5 792 496.

Substantially similar solutions, or at least solutions that are like those described in the above documents, may be found in GB-A-I 421 516, EP-A-O 951 835, and DE-U-74 36 695. Documents of general interest in regard to the solution described here are also EP-A-O 768 039, US-A-4 863 054, US-B-6 612 440, US-A-2002/139708 and GB-A-2 296 913, all these last-mentioned documents being of generic relevance to the technique for making containers.

A specific sector of application of containers of the .type described above comprises their use to insert "surprises" inside hollow food products, such as chocolate eggs. Products of this type indeed present a shape that is generically similar to that of an egg, in particular a hen's egg. While their dimensions may vary, hens' eggs, if considered with reference to dimensions normalised with respect, for example, to the axial length of the egg, present a well-defined shape.

This shape is respected and reproduced within relatively small tolerances.

A container of the type specified above destined to be used in conjunction with hollow food products that reproduce the form of an egg such as a hen's egg should simultaneously meet four basic requirements: i) the container must be as large as possible (so that "large" surprises will fit in it, in particular one-piece surprises that do not require assembly) and, naturally, must in any case be capable of being inserted into and contained in the hollow product/case in the form of an egg; ii) the container must be producible in a single piece, iii) the container must be easily "machinable" in the sense that it must present an overall form such as to facilitate its handling; in particular, it must be capable of being handled within an industrial process without the need for a specific spatial orientation to be maintained, and iv) the container must adhere as little as possible to the inner wall of the hollow case in egg form: this last requirements is felt to be particularly important in the case in which the container must be placed inside a chocolate egg; in general the container is inserted into the egg in a condition in which the inner wall of the egg may not yet be completely solidified, and, in any case, presents some adhesive capability.

It is entirely evident that the requirements outlined above are, at least in part, completely contradictory one with another.

In particular, the desire to meet the need indicated with i) above would lead to the production of the container that copies from inside the shape of the container in egg form (or even comprises part of the

hollow reception case, as in the case of the solution described in EP-A-I 018 302) .

This choice would however be in contrast with the requirement indicated as iv) and also with the requirement indicated as iii) , which practically requires the container to present symmetrical characteristics, when on the contrary the shape of an egg is essentially an asymmetrical shape, in the sense that an egg such as a hen's egg comprises a first extremity that is approximately hemispherical and an opposing extremity whose ogival (ogive-like) shape is roughly similar to a paraboloid with high degree of convexity.

The object of the present invention is to provide containers able to meet in an excellent manner the above requirements, that are in themselves in contrast with one another.

According to the present invention, this object is achieved thanks to a method having the characteristics set forth in the claims that follow. The invention also concerns the corresponding container, as well as a package that includes this container. The claims form an integral part of the technical disclosure provided herein with regard to the invention. The invention will now be described, by way of non- limiting example, with reference to the attached drawings, wherein:

-- figures 1 to 3 illustrate, in schematic form, the considerations of a geometrical nature that underlie the method described herein,

-- figure 4 is a perspective view of a container according to the invention in open configuration, figure 5 is a perspective view of another embodiment of the container in open configuration,

— figure 6 is a view from above of the container in figure 5,

— figure 7 is a sectional view of the container in figure 4 in closed configuration, and -- figure 8 is a sectional view of the container in figure 4 inserted inside a hollow container such as a chocolate egg.

Figure 1 illustrates in schematic form in an ideal axial section the geometric shape of an egg, such as a hen's egg.

As already indicated in the introductory part of this description, measurements that can be made in this connection show that, independently of the "absolute" dimensions of the egg (that is considering the shape represented in figure 1 as a form normalised to the axial length of the egg, indicated with L) hens' eggs present a shape reproduced by the normal avicultural population within extremely limited margins of tolerance . Any hollow body (such as a chocolate egg) that intends to reproduce the geometry of a natural egg such as a hen's egg will thus present this type of shape. Supposing that the egg is notionally subdivided with an ideal diametric section made at half of the length (that is so as to subdivide the egg into two portions, each having an axial length of L/2 equal to half of the overall axial length L) two parts may in general be distinguished, that is: a bottom part A, of an approximately hemispherical shape, and

-- a top part B of an overall ogive-like (ogival) shape, substantially similar to the shape of a paraboloid with high degree of convexity.

Figure 2 represents the ideal step consisting in taking the ogival portion B of an egg shape, indicated with B, and generating a homothety B ¹ from it.

It should be remembered that the geometrical term "homothety" indicates a particular type of affine transformation through which a duplication of the starting figure can be originated. For example, making reference for the sake of simplicity to the section in figure 2 (which is represented in two dimensions) and supposing that we make reference to two Cartesian axes, x and y, with an origin (also comprising the centre of homothety) located at the centre of the circumference of the base of the ogival part B of the egg shape, the analytical equations of the relative homothety can simply be given:

X=Kx Y=Ky where K is the homothety constant.

In other words, the curve (or, in general, the three-dimensional surface) B ¹ obtained through homothety is a proportional "copy", of size at least slightly smaller (depending on the homothety constant

K), of the ogival part B of the initial egg shape.

By juxtaposing two forms B' obtained through homothety (according to the procedure described above) in opposed orientation, that is with their convexity facing one towards the other, it is possible to generate an overall spindle-shaped form, as represented in figure 3.

This shape is capable of being utilised to produce a container for "surprises" capable of being inserted inside a case, in particular made of food material such as chocolate, that has the initial egg shape.

In general, the axial dimension of the spindle- shaped container thus generated is selected such as to be shorter, typically by an interval between 0 and 5

mm, than the overall axial length of the hollow of the initial ovoid case.

By operating in this manner it is possible to meet at least four requirements, in contrast one with the other, simultaneously.

Firstly, the dimensions of the case thus identified are the maximum dimensions compatible with the requirement given by the fact that the container must be inserted inside the initial case. In particular, the axial length of the container may be selected such as to be smaller than the homologous length of the case in food material only to the extent necessary to ensure a minimum assembly clearance of the container inside the case . Secondly, as. will become clearer below, the case 1 is capable in any case of being produced in a single piece (that is in the form of two complementary shells, or alternatively in the form of a shell closed by a substantially flat wall) . Thirdly, the container 1 thus generated presents a symmetrical shape (indeed it is comprised of two identical caps B', opposed one to the other) . It therefore does not require, during production, handling and insertion inside the case, any particular orientation to be maintained.

Lastly, according to a characteristic considered to be of particular importance, the surface B' generated by homothety according to the criteria described above presents characteristics of "minimal adhesion" with regard to the inner surface of the case. In other words, the risk is minimised that the container will adhere in a stable and undesired manner to the inner wall of the case in which it is positioned.

While not intending to be restricted to any specific theory in this connection, the applicant has

reason to believe that this result (in many ways unexpected and surprising) may be linked to the fact that two surfaces connected by a relation of homothety present, at any point of their surface, a high degree of parallelism. This means that the two, mutually homothetic surfaces present, in correspondence with the surface regions capable of coming face to face when the container is placed inside the case, degrees of convexity that approximately correspond one to the other.

Unlike what might be a expected, this condition, instead of favouring mutual adhesion between the surfaces, tends to minimise the occurrence of said event or, at least, tends to reduce the occurrence with regard to the situation (capable of manifesting in the case of different containers of which mention was made in the introductory part of this description) in which the container presents highly convex regions facing against "flatter" parts of the containing case. With reference to figures from 4 to 8, a container of the type described here, indicated overall with 1, comprises a first and a second half-shell 2, 4 (or 2a, 4a) made of moulded or thermoformed or injection moulded plastic material. The term half-shell, as used in this description, should not be understood as being limited to half- shells with a more or less accentuated degree of concavity, capable of acting as a container, but is also applied to the case in which at least one of the two half-shells in question is of a generally flattened form, such as for example that indicated with 4 in figure 5, essentially having the function of a lid for the other half-shell 2.

Whatever their shape may be, the two half-shells, made to coincide frontally, may be coupled through

reciprocally-engaging formations, constituted for example of a collar 6 borne by one of the two half- shells and capable of engaging with the mouth portion 8 of the other half-shell. To enable a solid connection between the two half- shells, snap-engaging means are usually provided, for example comprising an annular rib 10 capable of snap- engaging with a corresponding groove (not explicitly shown in the drawing) practised on the inner wall of the mouth portion of the other half-shell.

It goes without saying that the means of engagement just described is indicated as a simple example, since the same function of guaranteeing a solid connection between the two half-shells, and nevertheless enabling the relative disengagement by the user with ease, may be achieved with means of a different type (for example tooth-like formations or hooks, etc.) .

In its closed configuration, the container 1 presents an elongated conformation with a spindle-like shape.

This general spindle-like shape may normally be noted both in the case in which both half-shells 2a, 4a present a general cup-like shape (as in the case of the embodiment illustrated in figure 4), and in the case in which only one of the shells (in particular that ^' indicated with 2) presents a general cup-like conformation (see the embodiment illustrated in figure 5), whereas the other half-shell (indicated with 4) is essentially in the form of a flat lid or cover. In consequence, the spindle-like shape represented in figure 3, and obtained by frontally combining two shapes obtained by homothety from the ogival half B of the egg shape represented in figure 1, may in general be noted in the plane of connection between the two half-shells, and in the direction identified by the

family of planes parallel to the above-mentioned mouth plane .

In the embodiment to which reference is made in figures 5 to 7, one of the half-shells, that indicated with 2, is destined to contain a "surprise", that is to say an accessory, possibly comprising a food product, such as a sweet, of semi-ovoid form, and the other half-shell 4 essentially acts as a flat cover.

The container 1 thus presents a "hemi-spindle-like" shape, that is the shape of a spindle obtained by virtually coupling two surfaces obtained through homothety from the ogive-like part of an egg shape, and then sectioning into two the form resulting from such coupling, along a plane passing through the long axis of symmetry (that is, in practice, in the plane in which the two half-shells, 2, 4 are coupled together).

In the embodiment shown in figure 5, the half-shell 4 is provided on its external surface with engagement formations 12, for example of the type with bars projecting from the upper surface 4. These formations are capable of engaging a small spoon or spatula or similar tool (whose profile is illustrated in diagram form with dotted lines) useful for the consumption of a food product, for example a cream, contained in the other half-shell 2 in a containing section of the case U to which the container 1 is associated.

In the embodiment shown in figure 4, both half- shells 2a and 4a present a cup-like form. It will be appreciated that whichever solution is adopted, the two half-shells are free of flanges extending outwards from the mouth profile.

In both the embodiments illustrated here, the two half-shells are connected together through at least one hinge element 16 integral with the body of the two half-shells. This is preferentially a hinge element

constituted of a film hinge that extends along a stretch of the perimeter of the two half-shells. This solution is particularly advantageous since it enables the container 1 to be produced in the form of a single piece of moulded or formed material. Naturally, elements consisting of a number of distinct elements, connected by hinged elements of the separable type, are also included within the sphere of the invention.

Preferably, the hinge element presents a rotation axis, indicated with a-a, substantially parallel to the long axis X-X of the mouth profile in correspondence with which the two half-shells are coupled together.

The container 1 described here is destined to be inserted in its closed configuration, including a "surprise" inside it, that is an accessory or further food product generically indicated with A, into a case with a hollow body that typically, as was said in the introductory part of this description, consists of a chocolate egg ϋ whose form typically reproduces (independently of its absolute dimensions) the shape of a hen ' s egg.

In particular, in the case illustrated in figure 8, the container 1 is of semi-ovoid form, of the type shown in figure 2, and occupies approximately half the inner volume of the case U.

Similarly, the container 1 in figure 4 may be inserted into a chocolate egg U.

Naturally, it is intended that the solution described here is not exclusively limited, with regard to the fabrication of the outer case U, to a chocolate shell, but may also include other forms of hollow container, both of food material and of plastic. Thus, for example, the package might comprise two half-cases both of plastic material or one half-shell of food

material and one half-shell of plastic material, as is described in EP-A-O 768 039.

In particular, it will be appreciated that the solution described here lends itself to being used both in combination with cases U that have precisely the shape of a natural egg such as a hen's egg (as has already been stated more than once in the introductory part of this description, this shape is reproduced in nature very closely, independent of the overall dimensions of the egg) and in combination with cases that present an ovoid form of a different type, while still conserving the general subdivision of the egg shape into an approximately hemispherical part (part A in figure 1) and an ogival part (part B in figure 2) . Naturally, in this second case, a necessary stage in the definition of the homothetic shape of the portion B in figure 2 will consist of determining the shape of said tapered part of the containing case.

Of course, without prejudice to the underlying principle of the invention, the details of production and the embodiments may be widely varied with regard to what is described and illustrated here, without thereby departing from the sphere of the present invention, as defined in the claims that follow.