The frame according to the invention can be of the type with self-supporting lenses wherein the central bridge and the hinges of the temples, or arms, are directly associated with the lenses.

The invention is however applied also in the case where the frame has rims to house and support the lenses.

The frame according to the invention has neither screws to attach the central bridge and the hinges to the lenses nor fulcrum screws for the hinges.

It is thus possible to reduce the number of components and the assembly times, with a consequent reduction in the production costs, and also to considerably reduce the risks of the lenses chipping and breaking during use.

BACKGROUND OF THE INVENTION In the market for eyeglasses there is an ever-increasing demand for extremely light frames which are almost "invisible"when worn.

For example, the state of the art includes frames with so- called self-supporting lenses, which are characterised by the fact that they have no rims to house and support the lenses, and where the central bridge and the temple hinges are directly associated with the lenses.

In other cases there have been proposals for frames with extremely thin plastic rims.

The temples usually consist of wires made of titanium or other similar metal with high resistance and elasticity, which ensure both extreme lightness and a certain intrinsic elasticity.

In this type of frame, the appropriate holes or eyelets are made on the two lenses or on the rims of the glasses, inside which screws are inserted to attach the ends of the central bridge and the screws to attach the ends of the hinges for the arms.

In this type of eyeglasses, the metallic parts of the frame are directly and rigidly associated with the lenses, or the plastic rims; this can cause: he lenses and the rims to crack, chip or even break when here is excessive and repeated stress on the temples, fcr example if they are opened violently or in the event of a knock.

In order to solve this shortcoming, new solutions have been sought to make the attachment cf the metal components of the frame to the less resistant parts less rigid.

For example, there is an embodiment which includes a filiform frame where the front parts of the central bridge and of the hinges are substantially U-shaped and then inserted into corresponding eyelets made on the lenses and restrained there by means of glues cr coupled by having the same shape.

This solution, however, although advantageous from the point of view of the production times and production costs, does not eliminate the problem of the direct contact between the metallic parts of the frame and penses.

Moreover, the fact that the-shaped ends of the components of the frame are coupled shaving the same shape inside the eyelets of the lenses dces not ensure that the glasses are sufficiently stable and solid, and therefore there is a risk that the lens might-all or the glasses come to pieces.

If glues are used, on the one hand this shortcoming is at least partly resolved, but on the cher hand it makes it impossible to interchange the parts, it impedes elasticity

of the temple and increases the risks of chipping in the event of stresses and force exerted on the temple.

In filiform frames of this type, the temple hinges are defined by a spiralled end of the temple which is inserted on a vertical end of a fixed part associated with the lens as described above.

This technique is shown particularly in the European patent EP-B-256.098, which describes a frame wherein every type of screw is eliminated, both for use as a fulcrum element in the hinges of the arms and also for use in attaching the hinges and the bridge tc the lenses.

In this type of hinge, the spiralled end of the temple must be made with extreme accuracy so that, when assembly has been completed, it will be able to close against the vertical end of the fixed part in such a way that there will be a slight friction against the rotation of the temple.

However, because of the wear caused by the sliding of the vertical end of the fixed part of the hinge or the inner part of the spiralled end of the temple, this friction tends to diminish more and more, until it makes it difficult and unstable to ma-nain the arms in a closed position when the glasses are not being used.

The present Applicant has designed and embodied this invention to overcome these shortccmings and to obtain further avantages as shown hereafter.

SUMMARY OF THE INVENTION The invention is set forth and characterised in the main claim, while the dependent claims describe variants of the idea of the main embodiment.

The main purpose of the invention to achieve a filiform frame for eyeglasses, suitable to elim-nate all risks of the lenses or rims cracking and breaking due to a direct contact between the metallic parts of the frame and the lenses

themselves.

Another purpose of the invention is to provide a frame suitable to ensure a perfect clamping of the lenses so as to ensure that the eyeglasses are stable and solid and to eliminate the danger that the lenses might fall or the eyeglasses might accidentally come apart. further purpose of the invention is to allow the lenses tus bue interchanged in a very short time and with a very s-mole operation of assembly/dis-assembly which will not retire specific equipment.

-nother purpose of the invention is to provide an elastic connection between the frame and the lenses which will ensure they are extremely practical and easy to use, even in conditions when the temples are wide open, so that the eyeglasses are extremely adaptable and versatile.

The last but not least purpose is to allow the elements which support the central bridge on the nose to be interchangeable.

The frame according to the invention comprises, in its main parts, a pair of arms, a pair of connection hinges defined by a fixed part and a movable part solid with a relative arm or consisting of the arm itself, and a central bridge.

According to the invention, each fixed part of the relative hinge and the central bridge are equipped with association ends suitable to be inserted and clamped into corresponding through holes made either directly on the lenses near the perimeter, in the case of a self-supporting frame, or on the relative rims which position the lenses.

According to a first characteristic of the invention, between the association ends and the inner surface of the holes inserts made of at least partly elastic material are inserted; the function of the inserts is to receive the

association ends, absorbing any improper knocks and stresses to which the components of the frame are subjected in order to prevent possible cracks and breakages of the lenses or rims.

According to another characteristic of the invention each association end of the frame is gripped in the corresponding through hole by clamping elements suitable to be coupled with the association ends both at the front and at the back of the lens.

According to another characteristic of the invention each connection hinge is obtained by coupling the spiralled ends respectively of the fixed part and the part which is solid with or integral to the arm.

The spiralled ends are coupled to each other substantially by screwing together the spirals on one side inside the spirals on the other side, so as to obtain a reciproca clamping due to a simple interpositicning of the spirals and the rotation of one spiralled end with respect to the other.

This coupling is then made stable by means of a cylindrical pin suitable to be inserted inside the cylindrical seating defined by the superimposed spirals of the two coupled parts of the hinge and equipped at the ends with axial retaining means.

BRIEF DESCRIPTION OF THE DRAWINGS These and other characteristics of the invention will become apparent from the following description ofa preferred form of embodiment, given as a non-restrictive example, with reference to the attached Figures, wherein: Fig. 1 is an exploded view of a pair of glasses using a preferential embodiment of the frame according to the invention; Fig. 2 is an exploded view of a detail of the connection hinge of the frame shown in Fig. 1;

Fig. 3 is an exploded view from the side of the central bridge of the frame shown in Fig. 1; Fig. 4 is a front view of an enlarged detail of Fig. 1; Fig. 5 shows in section an enlarged detail of the hinge shown in Fig. 2 in its assemble condition; Fia. 6 shows in section an enlarged detail of the association area between the lenses and the frame according to the invention; Fig. 7 shows the section from A to A c Fig. Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT with reference to Fig. 1, a frame 10 according to the invention is made entirely of metallic wire, for example titanium, and comprises in its essent-al parts two arms 11, two connection elements 12 and a central bridge 13.

The following description concerns a frame of the self- supporting type, that is to say, wit : cut rims to house and support the lenses, but it is understood that the invention can also be applied to frames equipped with thin rims, pre'erably of plastic, on which the ends of the arms of the fixed elements of the hinges are anchcred.

Each connection element 12 defines, with one end of the respective arm 11, the elastic hince which connects the frame 10 to the lenses 14.

The connection element 12 comprises a first end 112, that is to say, the one which is associated with the lens 14, substantially bent back in a U-shape, and a second end 212, that is to say, the one which is associated with the arm 11, spiral-shaped with spirals of a defined pitch and diameter.

The first end 112 is connected with the second end 212 by means of a first segment 412 facing the outside of the lenses 14, so as to allow the user ço put on the glasses even when the lenses 14 are very srr. all, and by a second segment 312 which is substantially rectilinear so as to

constitute a substantially continuous line with the relative arm 11.

The end 111 of the arm 11 which couples with the connection element 12 is spiral-shaped with at least one spiral, mating in diameter with the spirals of the end 212, which ends in a substantially straight extension 17 facing downwards.

The arm 11 and the relative connection element 12 are coupled by placing, at an appropriate corner position, the spirals of the end 111 of the arm 11 between the spirals of the second end 212 of the connection element 12.

Subsequently, the arm 11 is rotated around the vertical axis 15 through an angle of about 360° or above, substantially screwing the end 111 onto the spirals of the end 212, until the extension 17 of the end 111 abuts against the segment 312 of the end 212, stopping the arm 11 in the stable open position shown in Fig. 1.

The joining of the two ends 111 and 212 is in itself stable and is made indissoluble by inserting a cylindrical pin 16 inside the cylindrical seating defined by the superimposed spirals.

In the embodiment shown here, the cylindrical pin 16 is made of plastic material and is hot upset at the ends (Fig.

5) so as to prevent the axial release of the two parts which have been reciprocally screwed together.

According to the invention, the cylindrical pin 16 is inserted with a certain degree of interference with respect to the cylindrical seating defined by the superimposed spirals of the coupled ends 111 and 212, so as to ensure a particular friction when the arm 11 is rotated.

This friction makes it possible to maintain the arm 11 stably in the open or closed position thus making the glasses easier to use.

In the event that the arms 11 are rotated outwards beyond the limit position defined by the abutment of the extension 17 against the segment 312, the spirals of the end 111 of the arm 11 slide between the spirals of the second spiralled end 212 of the connection element 12, allowing the arm 11 to open elastically for a certain angle without any risk of breaking.

Moreover, this elastic opening allows the glasses to adapt to the characteristics of the user, improving the support on the temples.

The central bridge 13 is made from a piece of wire whose ends 113, that is to say, those which are associated with the lenses 14, are bent back substantially in a U-shape so as to assume a conformation which is substantially the same as the first end 112 of the connection element 12.

The part of the bridge 13 between the ends 113 has a bow- shaped upper segment 213 which cor-urates with the bone of the nose and two U-shaped extensions 313 facing downwards.

On each extension 313 a respective nose pad 18 (Fig. 3) is removably inserted to rest on the ncstrils; it is made of elastically deformable material, for example rubber.

The nose pad 18, according to the invention, is equipped with a lateral extension 118 defining a space 19 suitable to be easily and rapidly inserted cn the corresponding extension 313, allowing the nose pad to be removed every time it needs to be for reasons of maintenance or replacement.

According to one characteristic of this invention, the frame 10 is associated with the lenses 14 by inserting the U-shaped ends 112 and 113 respectively of the connection elements 12 and the bridge 13 into corresponding eyelets 20 made at a peripheral position, near the perimeter, of the lenses 14.

To be more exact, the frame 10 is assembled with the lenses 14 using an insert 21, a forward clamping element 22, a rear clamping ring 23 and a cap 24, for each eyelet 20.

The elements 21,22 and 24 are made of non-metallic material, for example knock-resistant plastic or rubber, so as to prevent any type of contact between the lens 14 and the metallic parts.

The insert 21, mating in shape wi h the eyelet 20 of the lens 14, substantially equal in des to the thickness of the lens 14 and hollow inside, is introduced into the eyelet 20 until one perimeter edge 25 abuts on the rear surface of the lens 14.

At this point, the end 112 of each connection element 12 and the ends 113 of the bridge 13 are inserted into the hole 26 of the corresponding insert 21 until the respective central side, 112a and 113a, of the U defining the ends 112 and 113 protrudes in front of the lens 14.

This allows the front clamping ele ent 22 to be interposed between the central side 112a and and the lens 14.

The front clamping element 22 isolat and substantially elliptic in shape and is equipped, on the front surface, with a groove 27 suitable to house the central side 112a and 113a of the U of the ends 112 and 113.

Once the front clamping element 22 has been positioned, the end 112 or 113 is made to retract until the rear surface of the clamping element 22 abuts on the lens 14.

At this point, the coupling of the frame 10 and the lenses 14, which is already stable because of the compression exerted by the two parallel segments of the U against the inner part of the insert 21, is further consolidated by inserting the clamping ring 23 on the terminal part 28 of the end 112 or 113.

The rear clamping ring 23, shown in detail in Fig. 4, is

of the elastic type; it is inserted under pressure in the terminal part 28 and securely clamped in position by the high level of friction which its radial fins 123 exert on the metallic wire of the frame 10.

The clamping ring 23 completely surrounds the terminal part 28, eliminating every possible risk of contact between the metallic wire of the frame 10 and the lens 14; it rests on the perimeter edge 25 of the insert 21 and therefore does not have any parts in contact with the lens 14.

According to the thickness of the lens 14, the terminal part 28 is cut to a length suitable to allow the cap 24 to be inserted; the cap 24 has an aesthetic function, acts as a guarantee against accidental scratches and also prevents the terminal part 28 from catching on anything.

The cap 24 is inserted in contact with the terminal part 28 so as to prevent it from accidentally coming off.

According to a variant, the insert 21 is made of elastically deformable material, for example rubber; this allows to absorb the knocks and stresses on the parts of the frame 10 which might crack, chip or break the lenses 14.

According to another variant of the invention, moreover, the inserts 21, the front clamping elements 22 and the caps 24 are made of transparent material so as to allow them to be visually integrated, at least partly, into the body of the lens 14.

It is obvious that modifications and additions may be made to this invention, yet will remain within the field and spirit thereof.