"Collapsible frame for eyeglasses and related manufacturing process"

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Field of the invention The present invention generally refers to eyeglass frames including a front with nosebridge and a pair of temples joined to the front.

More in particular, the invention regards a frame thus made having a collapsible structure in such a manner to be able to acquire a generally flat state so as to be inserted into a case with low thickness.

Even more in particular the invention regards frames, for example for sunglasses, with front and temples made of moulded plastic material, provided with foldable elements in order to allow the frame to acquire the abovementioned collapsed state. Prior art

In the known frames of the type defined above, the foldable elements are usually made of actual articulated hinges, with the consequent production and mounting costs, or more simply the foldable elements are made of flexible hinges made up of thinned zones of the same plastic material of which the frame is made.

Examples of frames of this type are described and illustrated in documents EP-1555566 and WO-0075715.

In the first case, in cases where the front and temples have a configuration with a more or less marked curvature, it is not possible to provide the frame - in the folded or collapsed state - with a thickness sufficiently low to allow its accommodation in a thin case. In the second case, the collapsible structure of the frame is subject to premature breakage due to the yielding of the plastic material making up the integral flexible hinges. Summary of the invention

The object of the present invention is that of providing a collapsible frame of the type defined above, such frame being manufactured in an extremely economical manner, and simultaneously being provided with a strong and resistant structure lasting even after several collapsing cycles.

Another object of the invention is that of providing an eyeglasses frame of the type indicated above, adapted to be collapsed to acquire a configuration having a very low thickness even in cases where the front has, under use, a marked enveloping curvature and also in cases in which the temples themselves are curved.

According to the first aspect of the invention, these objects are attained due to the fact that the foldable elements of the front and temples of the frame are defined by deformable portions or core elements incorporated in the plastic material of the front and temples respectively, said deformable portions being exposed at interruptions of the plastic material and being covered by inserts made of flexible material.

Such portions of the core elements may be elastically deformable, in such a manner to return the frame from the collapsed state to the use state of the eyeglass - due to its elasticity - so to speak in an automatic manner, or they may be plastically deformable, and in this case the return of the frame from the collapsed state to the use state shall require a positive action by the user. In both cases, the core elements defining the abovementioned deformable portions shall conveniently be made up of metal plates or wires, for example respectively made of spring steel or annealed metal.

In a preferred embodiment of the invention, the abovementioned deformable portions of the core elements

are provided for at the nosebridge and the intermediate zones of the temples, as well as at the articulated zones between each temple and front.

According to another aspect the invention also provided for is a process for manufacturing the abovementioned collapsible frame.

Brief description of the drawings

Now, the invention shall be described in detail with reference to the attached drawings, strictly provided for exemplifying and non-limiting purposes, wherein: figure 1 is a top plant view showing an embodiment of a collapsible frame for eyeglasses according to the invention, represented in the open state of use,

- figure 2 is a side view of figure 1,

- figure 3 is a perspective view showing the frame in the collapsed state for insertion into a case,

- figure 4 is a view analogous to figure 1 showing the frame in an intermediate step of the process of manufacture thereof, and

- figure 5 is a side view of figure 4. Detailed description of the invention

Initially referring to figures 1 and 2, a collapsible frame for eyeglasses according to the invention is indicated in its entirety with 1, including a front 2 formed by a pair of rims 3 for the insertion of respective lenses 4, and interconnected by a nosebridge, and a pair of temples 6 connected in an articulated manner to the opposite sides of the front

2.

In the case of the illustrated example, the articulated connection between each temple 6 and the front 2 is provided for through respective conventional hinges 7, which however are not strictly necessary and

can be possibly omitted.

As clearly observable in figure 1 the front 2 has an enveloping shape, due to the curved construction of both the rims 3, and the nosebridge 5, and the temples 6 analogously in turn have a marked curvature. This construction would theoretically prevent the frame 1 from acquiring - in the state wherein the temples 6 are folded against the front 2 - a considerably flattened collapsed configuration, such as the one represented in figure 3, with the aim of allowing the insertion of the frame 1 into a case A, for example a cardboard box, having an extremely low thickness.

As observable further ahead this state, on the contrary, is obtainable due to the characteristics of the frame according to the invention, hereinafter described in detail.

Both the front 2, and the temples 6 are made of relatively rigid thermoplastic material (typically ABS or an acetal resin or nylon) , and they are typically made through injection moulding in respective moulds previously inserted into which are core elements which are incorporated in the plastic material thus moulded.

These core elements are normally made of metal and they may be made up of a plate or a steel spring wire, hence elastically deformable, or they may be made up of an annealed metal or the like, plastically deformable in such case.

The core elements of the two temples β may be extended longitudinally over the entire length or only over the part of the length of the temples, and the core element of the front 2 may also extend over its entire extension, or only over a part thereof, along the upper sides of the rims 3, connecting them at the nosebridge 5. The step of moulding rigid plastic material to make

the front 2 and the temples 6 with the relative core elements incorporated therein is performed, according to a distinctive aspect of the invention, in such a manner to provide for material interruptions both at the nosebridge 5, and the intermediate zone of the temples β, as well as possibly between each side of the front 2 and the relative hinge 7 for joining to the respective temple 6. In such manner the frame shall have, at the end of the moulding step, the temporary configuration represented in figures 4 and 5: thus, the respective portions of the abovementioned core elements, respectively indicated with 11, 12 and 13, are exposed in the plastic material interruption zones corresponding to the nosebridge 5, indicated with 8, in the interruption zones of the temples 6, indicated with 9, as well as the interruption zones between the front 2 and the temples 6, indicated with 10.

The portions 11, 12 and 13 are per se deformable in an elastic manner, in cases where the relative core elements are made of elastically deformable material as mentioned, or in a plastic manner in cases where such core elements are, on the contrary, made of plastically deformable material as mentioned.

The last step of the process of manufacturing the frame according to the invention provides for forming, at the interruptions 8, 9 and 10, inserts made of flexible material and preferably elastic adapted to cover and envelop the respective deformable portion 11, 12 and 13. Such inserts can conveniently be made through overmoulding soft plastic material, such as for example thermoplastic rubber or the like.

Inserts thus overmoulded are indicated with 14, 15 and 16, respectively in figures 1 and 2.

At the end of the manufacturing process, the deformable portions 11, 12 and 13 with the respective

equally deformable inserts 14, 15 and 16 allow, after folding the temples 6 against the front 2 through the hinges 7, to collapse the entire frame arranging it in the flattened state represented in figure 3, wherein both the front 2 and the temples 6 have a thin, almost flat configuration. In such state, the frame 1 can be comfortably accommodated in the case A, whose thickness may thus for example not exceed 19-20 mm.

The return of the front 2 and the temples 6 from the substantially flat collapsed state to the curved state, after extracting the frame 1 from the case A, may occur in an automatic manner in cases where the portions 11, 12 and 13 of the core elements are elastically deformable, given that in such case they will spontaneously return to the respective undeformed positions. In cases where such portions 11, 12 and 13 have, on the contrary, been deformed plastically, their return to the initial state shall require to be actively deformed by the user. Obviously, the construction details of the frame may widely vary with respect to the description and illustration provided above, without for this reason departing from the scope of the present invention.

Thus, for example, the presence of the two hinges 7 for the articulation between the front 2 and the temples 6 is not strictly indispensable. Should they be present, the front 2 and the temples 6, as mentioned previously, shall be made separately in the respective moulds, and in such case the deformable portions 11-13 on one side, and 12 on the other, shall correspond to three distinct core elements, incorporated in the aforedescribed manner one into the front 2, and the other two into the temples 6. At the end of the manufacturing process, the front 2 and the temples 6 shall thus be assembled together through the hinges 7.

On the contrary, in case the two hinges 7 are not provided for, the frame 2 and the temples 6 may be formed in a single mould, and in this case the deformable portions 11, 12 and 13 shall form part of a single core element incorporated through the front 2 and the temples 6, which shall thus be mutually joined. The articulation between the temples 6 and the front 2 shall in such case be ensured by the deformable portions 13 with the relative inserts 16.