Technical field

The present invention relates to a spectacle frame having the features set forth in the preamble of the main claim 1. Technological background

In the technical field concerned, it is known to produce spectacle frames which have lens-carrying rims and in which the lenses are securely coupled to the rims by providing a groove which extends along the internal profile of the rim and into which the external peripheral edge of the lens, which is normally provided with chamfering, is inserted and locked. In these solutions, the lens-carrying rim is produced in such a manner that it is open and clampable on the lens by screw-locking the opposite ends of the rim at which the rim is interrupted. Typically, a pair of respective perforated appendages, also referred to as "tubes", is provided at those ends and each of them is secured to the corresponding end of the rim, for example by soldering, the appendages being provided with optionally threaded holes which are coaxial with one another and which can be engaged by the clamping screw of the rim. In addition to the necessity of providing the above-mentioned structure, and thus that of requiring that the rim be cut and that the tubes be soldered, this known system involves the disadvantage that the screw clamp may possibly become loose, with the risk of the lens escaping from the rim and possibly breaking, in addition to the fact that this loosening may also involve the loss of the screw, thus rendering the frame unusable owing to the consequent removal of the lens. Securing systems are also known in which the frame is provided with lens- carrying rims having a closed contour and in which the interposition of a resilient packing between the rim and the lens is provided for, this constituting a kind of pliable support pad between the rim and the facing edge of the lens suitable for preventing any breakage of the lens during the locking thereof in the rim.

An example of a packing of the above-mentioned type is known from United States patent US 4,340,282. The packing member described there has a cross-section from whose opposite sides rise respective protuberances which extend continuously along the peripheral profile of the packing and which are suitable for engaging corresponding grooves provided in the facing edges of the rim and of the lens in order to ensure that the lens is held in place relative to the rim. However, such a system, because it has continuous opposite protuberances extending along the entire peripheral profile of the packing ring, permits limited resilient expansion of the ring with consequent limitations in performing the action of holding the lens in place. Description of the invention The main object of the invention is to provide a spectacle frame which, on the one hand, enables the lenses to be removably mounted in the lens- carrying rims without involving any screw clamping and, on the other hand, permits greater efficiency of the resilient action of holding the lens in the respective lens-carrying rim, at the same time rendering the lens easily removable from the frame. This and yet more objects which will emerge hereinafter are achieved by the invention by means of a spectacle frame produced in accordance with the appended claims. Brief description of the drawings The features and advantages of the invention will emerge more clearly from the following detailed description of some of its preferred embodiments which are illustrated by way of non-limiting example with reference to the appended drawings, in which:

Figures 1 and 2 are front and top views, respectively, of a spectacle frame produced in accordance with the present invention,

Figure 3 is a sectional view according to the line III-III of Figure 1,

Figures 4 and 5 are side and front views, respectively, of a detail of the frame of Figure 1,

- Figure 6 is an enlarged sectional view according to the line VI-VI of Figure 4,

- Figure 7 is an enlarged view of the detail marked by the arrow A of Figure 4,

- Figures 8 and 9 are front and top views, respectively, of a lens intended for the frame according to the invention, - Figure 10 is an enlarged sectional partial view of the lens of Figure 8,

- Figures 11 and 12 are partial views corresponding to that of Figure 7 in different operative stages of mounting the lens in the frame of the invention,

- Figures 13 and 14 are sectional partial views of the frame according to the invention with lenses of different shapes, Figures 15 and 16 are partial front views of lens-carrying rims having different shapes.

Preferred embodiments of the invention Referring to the mentioned Figures, 1 generally indicates spectacles comprising a frame 2 produced in accordance with the present invention. The frame 2 comprises a front mount having a pair of lens-carrying rims 3 in which respective lenses 4 are held. The rims 3 are connected to each other by an intermediate bridge 5 located in the central region supported on the nose and are in their turn connected, at the opposite lateral ends, to respective support arms for hinges for the articulation of frame side-pieces (not shown). These hinge supports are also known as "lugs" in the relevant technical field.

The lens-carrying rims are produced with a closed contour and extend to surround corresponding peripheral edges of the respective lenses 4, while matching the shape thereof.

Each rim 3 is also provided with a groove 9 which extends internally along the entire longitudinal extent of the rim 3 and which is open in a position facing the thickness of the lens. The groove 9 preferably has a channel- shaped configuration as illustrated clearly in Figure 3. Formed in the thickness of each lens 4, along the entire peripheral edge thereof, is also a respective groove 10, which is open at a position correspondingly facing the groove 9 and which is provided for connection to the corresponding lens-carrying rim 3 by means of a resilient interconnection means, as will emerge clearly in the course of the description. The interconnection means comprises, for each lens 4, an annular member 11 in the form of a resiliently pliable ring, for example produced from plastics material or material having similar characteristics of resilience and flexibility. Advantageously, the resilient member 11 is in the form of a ring having a closed contour, as illustrated in Figure 4.

In accordance with the invention, the annular member comprises a plurality of pairs of appendages, each pair comprising a first and a second appendage, indicated 12a and 12b, respectively. The pairs of appendages 12a, 12b of the above-mentioned plurality are structurally identical to each other and therefore only one pair will be described hereinafter.

The appendages 12a, 12b extend, in each pair, from an external edge 11a of the annular member 11 and advantageously rise from a common point of attachment 13 located on that edge. As illustrated in Figure 7, each pair of appendages 12a, 12b assumes the overall shape of a "V" where the appendages extend from the common vertex, corresponding to the point of attachment 13. These appendages also extend in a substantially rectilinear manner and are reflectively symmetrical to each other with respect to a centre plane of symmetry which passes radially through the point 13 and which also extends perpendicularly to the circular profile of the ring 11. This plane determines an axial direction in the plane of the sheet marked P in Figure 7.

In each pair, the appendages 12a, 12b are also inclined with respect to each other, preferably by an angle B of 120° (at an angle of 60° with respect to the plane P). The pairs of appendages are also spaced angularly from each other along the circumferential profile of the annular member 11, being arranged at regular angular intervals C, the angular interval C preferably being selected to be equal to 10°. In addition, 14 indicates rectilinear portions of the profile of the external edge of the ring 11, each portion extending from the region of attachment (point 13) of each pair. Advantageously, each portion 14 is inclined with respect to the direction tangential to the circular profile of the ring passing through the point of attachment, and the angle of inclination D is selected to be preferably equal to 7°, as clearly illustrated in Figure 7. The particular geometry of the appendages and the plastics material (with resilient characteristics) from which they are produced enables the annular member to hold the lens in the frame, facilitating the insertion thereof into the rim and preventing the removal thereof once mounted. In fact, the appendages are resiliently deformable away from or towards the edge 11a, creating a kind of resilient effect. At the stage of inserting the lens into the rim, the appendages become deformed (moving towards the edge lla), as shown in Figure 11, permitting the insertion thereof. Once the lens has been inserted in the correct position inside the rim, the appendages, by moving back by resilient return in the direction towards the non-deformed position (moving away from the edge lla), ensure that the lens is held inside the rim, opposing the removal thereof, as shown in Figure 12.

The choice of the angle of inclination of the appendages relative to each other, their symmetry, the angular interval and the presence of the inclined portions 14 ensure a suitable relationship between resilience and mechanical strength and also a regular distribution of the stresses created by the lens on the corresponding rim of the frame.

The flexibility of the material from which the annular member is produced enables that member to adapt itself to different shapes of the lens-carrying rim for a given extent. Figures 15 and 16 show different geometries of a lens-carrying rim 3 for which it is possible to use the same annular member 11 as a means of interconnecting the lens in the frame. Referring to Figure 6, the annular member 11 is provided with an internal circumferential edge lib, the cross-section of which has a configuration tapering in the radial direction, for example produced with a rounded profile, in order to ensure centred locking of the ring inside the groove 10. This cross-section is preferably defined by opposite lateral flanks converging in a vertex region having a curved profile. Such a configuration facilitates the insertion of the lens into the corresponding rim with the ring mounted beforehand on the corresponding rim. It has the further advantage of acting as an adapting member, making up for any possible differences in shape between the profile of the rim and the profile of the lens. In this connection it should be noted that the internal circumferential edge of the annular member is capable of engaging the groove 10, being partially received therein, but without substantial contact with the internal surface of the groove.

Referring to Figure 14, the cross-section of the groove 9 has a quadrilateral profile and can thus also be produced on metal spectacles with a ringed profile and on spectacles made of plastics material. Referring to Figure 13, the cross-section of the groove 10 of the lens may have a tapered profile with inclined flanks converging in a rounded base portion. This configuration is that typically provided in non-corrective demonstration or sun lenses. Figure 14, on the other hand, shows a lens having a groove 10 which has a quadrilateral profile and which is typically provided in corrective ophthalmic lenses.

In order to connect the lens to the frame, the annular member 11 is first of all mounted on the corresponding lens-carrying rim 3, with the upper edge (and respective appendages) engaged in the corresponding groove 9 of the rim. The lens is subsequently inserted with thrust into the rim, with initial resilient deformation of the appendages, as described above, in order to permit the insertion of the lens into the rim, and with subsequent resilient return of the appendages in order to ensure that the lens is held in place. The invention thus achieves the proposed objects, obtaining numerous advantages over the known solutions.

A principal advantage resides in the fact that the frame according to the invention permits greater resilient deformation of the resilient ring for interconnection between the rim and the lens, with consequent greater resilient action of relative locking, while nevertheless at the same time ensuring suitable ease and simplicity of execution of the operations of assembling the lens in the rim of the frame. In the same way, operations for any dismounting of the lens, with the removal thereof from the corresponding rim, are facilitated. Compared with known solutions in which the frame has rims which are open and clampable by screw means, the frame according to the invention enables the structure of the rims to be simplified, it being possible for these rims to be produced with a closed contour without providing any soldered tube or any clamping screw. With reference to this last case, the undesired loosening of the screw when the spectacles are in use is advantageously avoided with the invention.

Compared with known solutions which provide for the interposition of packings having a continuous uniform profile between the rim and the lens, the frame according to the invention provides enhanced resilient action for holding the lens in place, permitting greater deformability of the resilient means and greater ease of insertion and locking of the ring between the lens and the corresponding rim. To summarize, there is therefore greater structural simplification, a reduction in the manufacturing times and also a reduction in the time required for the operations of replacing the lenses, and at the same time the aesthetic confines resulting from cutting the front of the frames are also removed.