Technological background Spectacles that can be connected to auxiliary lenses have been and are today still being widely used owing to their practicality and convenience of use. The auxiliary lenses are normally arranged to be connected to the main frame of the spectacles, superposed on the lenses thereof, which means that it is advantageously possible to avoid recourse to separate pairs of spectacles, for example having lenses for sight and sun, respectively, at the same time ensuring optimum conditions of visibility and adaptation to the various light conditions.

Spectacles are known in which the auxiliary lenses are restrained on the main frame using a connection which is exclusively mechanical in nature, for example using means for coupling the lenses to the main frame.

Spectacles having auxiliary lenses are also known in which the auxiliary lenses are connected directly to the main frame by means of magnetic elements. This solution requires the provision of respective frame portions, both main and auxiliary, that are suitable for accommodating a magnetic element or for being magnetised in order to ensure that the frames are connected to one another in a stable manner.

Description of the invention A principal object of the present invention is to provide a device having auxiliary lenses which is designed structurally and functionally not to require the provision, on the main frame of the spectacles, of specific portions and/or appendages intended for magnetic connection to the auxiliary frame, thus making it possible to hold the auxiliary frame on main frames of spectacles of the conventional type.

A further object is to produce a device which enables auxiliary lenses to be connected to a main spectacle frame irrespective of the material from which the main frame is produced.

Yet another object is to ensure that the auxiliary lenses are connected to the main frame in a manner which is stable and which at the same time permits relative rapidity and practicality of use.

Yet another object is to design a device having auxiliary lenses which permits ease and rapidity in the operations of connecting/disconnecting the auxiliary frame from the spectacles, with the advantage of convenience of use for the user.

Those objects and others too, which are pointed out hereinafter, are achieved by the invention by means of a device having auxiliary lenses which can be connected to spectacles, even of the conventional type, and which is produced in accordance with the attached claims.

Brief description of the drawings The characteristics and the advantages of the invention will become clearer from the following detailed description of one of its preferred embodiments which is illustrated by way of non-limiting example with reference to the appended drawings in which:

- Figure 1 is a perspective partial view of an example of an auxiliary lens device according to the invention shown in the position coupled to a pair of spectacles, - Figures 2 and 3 are front and top views, respectively, of the spectacles of Figure 1, - Figures 4 and 5 are cross-sectional views on an enlarged scale of a detail of the device of the preceding Figures in different operative positions, - Figures 6 and 7 are sectioned views, corresponding to those of Figures 4 and 5, of a variant of the device according to the invention.

Preferred embodiment of the invention Referring first of all to Figures 1 to 3,1 indicates generally an example of spectacles produced in accordance with the present invention.

The spectacles 1 comprise a main frame 2 having a pair of lens-carrying rims 2a, 2b suitable for holding respective lenses 3a, 3b.

The frame 2 also comprises a central bridge 4 for connecting the lens-carrying rims 2a, 2b, and a pair of lateral shoulders 5a, 5b for hinged articulation to respective arms 6a, 6b.

It will be appreciated that, although the example described relates to spectacles having a main frame equipped with lens-carrying rims, it is understood that the invention may equally be applied also to frames that do not have lens-carrying rims.

7a, 7b mark elements for bearing on the nose which are formed (or fitted) on the lens-carrying rims 2a, 2b, respectively.

8 indicates generally an auxiliary lens device which is designed structurally and functionally to be removably connected to the main frame 2 of the spectacles.

The device 8 comprises an auxiliary frame 9 which is structurally independent of the main frame and which is suitable for holding respective auxiliary lenses

loua, 10b. In the example described, the auxiliary frame 9 comprises a corresponding central bridge formation 11 which connects the auxiliary lenses and which has opposite ends 1la, lib fixed rigidly to the respective auxiliary lenses 10a, lOb. Alternatively, it is possible to provide that the auxiliary frame comprises a mount having respective auxiliary-lens-carrying rims of conventional structure.

According to the invention, in order to connect the device 8 to the spectacles 1, holding means are provided that include a pair of clamp elements, both indicated 13, which can be clamped onto the main frame 2 as described in more detail hereinafter. It will be appreciated that the holding means may comprise a single clamp element, although the example described represents a preferred choice.

The clamp elements 13 are fixedly joined to the auxiliary frame 9 at the location of the bridge formation 11 in a symmetrical arrangement relative to a median plane of the frame. Only one of the clamp elements 13 will be described in detail because they are structurally identical.

The clamp element 13 comprises a pair of jaws 14,15 articulated to one another about an axis of articulation X. One of the jaws (14) is connected to, or preferably produced integrally with, the bridge 11 of the auxiliary frame, while the other (15) is mounted in an articulated manner on the bridge about the pivot axis X.

Each jaw 14,15 comprises a respective first portion 14a, 15a having a surface 14c, 15c for clamping against the main frame 2 and a respective separate second portion 14b, 15b provided with means for magnetic connection to the other jaw.

The magnetic connection means comprise at least one magnetic element 16 in one of the jaws (in the portion 14b of the jaw 14 in the example described)

and a respective magnetisable surface 17 on the other of the jaws (in the portion 15b of the jaw 15 in the example described), the jaws being pivotable away from and towards an operative position (Figure 4) in which the magnetic element 16 and the magnetisable surface 17 are connected magnetically in such a manner as consequently to generate a clamping load on the clamp element 13.

It is alternatively provided that each of the jaws 14,15, which are articulated to one another, is provided with a respective magnetic element 16, said elements being capable of being placed on top of one another (with mutual bearing contact of respective surfaces) in the above-mentioned operative position, for a consequent action of mutual magnetic attraction.

The magnetic connection between the jaws is such as to generate the clamping load of the clamp on the main frame, in particular on a portion of the bridge 4 thereof which is therefore clamped between the jaws of the clamps 13.

The clamping surfaces 14c, 15c of the jaws may advantageously be in a form such that they match the corresponding surfaces of the main frame with a substantial form fit. They may also have profiles that are advantageously polygonal in order to constitute means for preventing the main frame from rotating relative to the auxiliary frame when the clamp 13 is clamped onto the main frame.

It will be appreciated that the structure of the clamp elements 13 is in any case designed to permit stable clamping of the jaws on portions of the central bridge of the main frame that have different configurations according to the various types of conventional spectacles.

18 indicates an appendage which projects from the jaw 15 and which is in a form and position such as to interfere with the bridge of the main frame 2

during the closing pivoting of the jaws 14,15 (Figure 5), in order to promote the closure of the clamp, during the coupling stage. In the coupling stage, the movement of the main frame promotes the closure of the clamp by acting on the appendage 18 until the magnetic element and the appendage (or the jaw surface facing the magnetic element) are sufficiently close to one another to generate a force which leads to the locking of the system (clamp closed) with maximum action with the contacting surfaces.

The portions 14a, 15a and 14b, 15b of the jaws of the clamp 13 which is shown in Figures 4 and 5 are arranged on the same side relative to the axis of articulation X. In that case, the portions 14b, 15b for magnetic connection are turned towards the inner side of the spectacles,"inner"meaning the side facing the user's face when the spectacles are in use.

In a variant of the device 8, which variant is illustrated in Figures 6 and 7 where details similar to those of the preceding example are marked with the same reference numerals, it is provided that the first (14a, 15a) and the second (14b, 15b) portion of each jaw are arranged on opposite sides relative to the axis of articulation X. In that case, the portions 14b, 15b for magnetic connection are turned towards the outer side of the spectacles (opposite the above-mentioned inner side).

In use, in order to connect the auxiliary lens device 8 to the spectacles 1, the auxiliary frame 9 is superposed on the main frame 2 with the latter in a position facing the clamps 13. The structure of the clamps enables them, starting, for example, from an initial closed position, to open in the initial insertion stage under the action exerted by the main frame (if they are already open, the main frame does not exert any action during the initial insertion stage). In the subsequent insertion stage, the main frame interferes with the appendage 18 promoting the closure of the clamp, at the same time moving

towards one another the surfaces that are capable of mutual magnetic attraction. In the final stage, the approach of the surfaces towards one another until they come into contact with one another generates the clamping load with which the clamps 13 clamp the main frame 2 and keep the auxiliary frame 9 locked on the main frame. It will be appreciated that the clamping action between the jaws is generated exclusively by the effect of magnetic attraction existing between the jaws when they are in their closed operative position.

Conversely, in order to disconnect the auxiliary lens device from the spectacles, it is necessary only to open the jaws 14,15, against the magnetic holding effect between them, in order to disengage the main frame 2 from the respective clamp elements 13.

The invention thus achieves the intended objects, obtaining numerous advantages over the known solutions.

A first advantage resides in the fact that the auxiliary lens device according to the invention does not require a special arrangement of the main frame of the spectacles, either with magnetic (or magnetisable) elements or with mechanical coupling elements, in order to enable it to be connected to auxiliary lenses.

A further advantage is that the auxiliary lens device according to the invention permits mutual connection to spectacles, even conventional spectacles, irrespective of the material from which the main frame of the spectacles is produced.

Yet another advantage resides in the rapidity and practicality of use of the device, which at the same time ensures that the auxiliary lenses are connected stably to the spectacles.

In particular, the magnetic coupling according to the invention ensures almost instantaneous unlocking of the main frame from the auxiliary frame, making this disengagement particularly convenient to use.