METHOD AND DEVICE FOR CONNECTING LENSES OF EYEGLASSES WITH FRAME ELEMENTS, IN EYEGLASSES HAVING STRUCTURALLY CO-OPERATING LENSES AND FRAMES

Abstract: A method for connecting lenses (2) of glasses (1) directly with frame elements (3, 4, 5) in glasses (1) with lenses (2) and frames (6) structurally co-operating with each other, provided with mutually complementary, removable, connection elements (7, 8), respectively connecting the lenses (2) and the frame elements (3, 4, 5), comprises a phase whereby one of the connecting elements (7, 8) is heated to a temperature appropriately selected with respect to the characteristic softening temperature of the material constituting the lens (2); a phase whereby the heated connecting element (7, 8) is compressed against a first face (2e) of the lens (2) until producing the sinking and incorporation of the connecting element (7, 8) into the material constituting the lens (2); and a cooling phase to produce the solidification of the softened material of the lens (2) and the consequent definitive fastening of the connecting element (7, 8) to the lens (2). The invention further relates to a connecting device (12) for the application of the method.

Description: Description Method and Device for Connecting Lenses of Eyeglasses with Frame Elements, in Eyeglasses Having Structurally Co-operating Lenses and Frames Technical Field The present invention relates to the fabrication of eyeglasses having structurally co-operating frame and lenses and further relates to a method and a device for connecting directly to the lenses the various elements of the frame, such as the temples and/or the bow and, possibly, also the nose supports. The use of eyeglasses with structurally co-operating frame and lenses has become widespread due to their lightness and safety, which make them preferable to conventional eyeglasses. The availability of lenses made of light plastic materials both for sunscreen uses as to correct eyesight defects; the use of materials having reduced specific mass for the fabrication of the frames; the extremely contained dimensional development of the frames, enabled also by their direct fastening to the lenses, allow to obtain eyeglasses with very reduced weight using lenses made of polycarbonate and with very high intrinsic safety especially in the case of facial traumas such as the ones that might occur in road accidents. Background Art At present, several different technologies for the fabrication of the aforesaid eyeglasses are known. Amongst such technologies, a fabrication method is known, substantially according to the preamble to Claim 1 , which entails the mutual connection of the lenses and of the frame elements by means of particular fastening devices comprising mutually complementary, removable connecting elements, whereof one is secured to the lenses associating itself to through holes that are obtained on the lenses in well defined positions. The holes, which are obviously cylindrical, do not prevent the connecting elements housed therein from rotating about an axis transverse to the surface of the lens. Since such freedom of rotation could bring about, with usage, the loss of the correct relative positioning between lens and frame, on the edges of the lens grooves are obtained which, engaging corresponding temple or bow segments, maintain the proper positioning between the lenses and the frame elements. In the construction of the frame with the aforementioned method, drilling the lenses represents the most critical operating phase for the purposes of the rapidity and cost-effectiveness of the fabrication process. The holes are obtained with successive passes of tips having progressively larger diameters, in order to reduce the risk that the lenses, often very expensive by virtue of their dioptric characteristics, may be chipped or otherwise damaged during the drilling operation. Although obtaining the grooves on the edges is not as problematic as the drilling operation, it nonetheless also contributes to raise machining costs. The time required to produce eyeglasses of the aforesaid kind is thus long, with obvious consequences on the costs of the finished eyeglasses. Moreover, those who effect the mounting are not altogether free of the risk of incurring a significant economic loss if the lens should be damaged during the drilling operation, loss which is all the more significant with respect to the mere cost of the lens (which in itself can be high) if one considers that the lens reaches the drilling phase after undergoing all preparatory work operations pertaining to the profiling of its contour and the customisation of the lens according to the specific optical parameters of the users to whom it is destined. Disclosure of Invention The aim of the present invention, as it is characterised by the claims, is to eliminate these drawbacks, by means of a method that allows to secure the connecting elements to the lens with not need to proceed with its drilling. In accordance with the invention, this aim is attained by a method for connecting eyeglass lenses directly with frame elements, in eyeglasses having lenses and frames that co-operate structurally with each other and comprising mutually complementary, removable, connecting elements, respectively connecting the lenses and the frame elements, method characterised in that it comprises a phase whereby one of the connecting elements is heated to an appropriately selected temperature with respect to the characteristic softening temperature of the material constituting the lens; a phase whereby the heated connecting element is compressed against a first face of the lens until causing the sinking and incorporation of the connecting element into said material constituting the lens; and lastly a cooling phase to cause the solidification of the softened material of the lens and the consequent definitive fastening of the connecting element to the lens. The aim of the invention is also reached by a fastening device for connecting eyeglass lenses and frame elements in eyeglasses having lenses and frame structurally co-operating with each other, device which comprises a first and a second connecting element shaped complementarily to be able to fastened securely but removably one to the other, characterised in that a said connecting element is so shaped as to be able to be incorporated in the material constituting the lens in a condition of rotation-proof fastening with respect to an axis of rotation transverse to the lens. The method according to the invention allows totally to eliminate the risk of damaging the lenses and to eliminate the machining operations on the edges of the lenses for the positioning grooves: all this allows drastic reductions in mounting time, to the benefit of work processing costs which are extremely reduced. Moreover, inasmuch as the fastening element secured to the lens projects externally therefrom, involving only one of the two faces of the lens, the method allows to obtain eyeglasses that have greater aesthetic value and are easier to clean. The connecting device is so shaped as to be rotation-proof in itself without the use of other elements, and to maintain this condition stable over time once it has been associated to the lens. Moreover the connecting device can be constructed in such a way as totally to hide the connecting element incorporated in the lens from view; and it can advantageously constitute also a support for decorative elements of the frame. The technical features of the invention, according to the aforesaid aims, can clearly be noted from the content of the claims that follow and its advantages shall be made more readily apparent in the detailed description that follows, made with reference to the accompanying drawings, which represent an embodiment provided purely by way of non limiting indication. Description of the Drawings Figure 1 is an overall view of eyeglasses having structurally co-operating lenses and frame, realised according to the invention; Figure 2 is a view of the eyeglasses of Figure 1 sectioned according to the line II-II and shown in highly enlarged scale; Figure 3 shows a first embodiment variation of an element of a connecting device comprised in the invention, seen from the top, from the front and from one side and shown in plan view, in perspective and from the side, in enlarged scale; Figures 4A and 4B are respectively a section view and a partial front view of the eyeglasses of Figure 1, whereto the connecting device of Figure 3 has been applied. Description of the Illustrative Embodiments In accordance with the accompanying drawings, Figure 1 shows eyeglasses 1 of the type comprising lenses 2 and frame element (temples 3, bow 4; nose supports 5) connected with particular direct connection devices, globally indicated as 12, able to allow to obtain eyeglasses 1 wherein the lenses 2 and the frame elements 3,4,5 are structurally co-operating with each other. More specifically, according to a first indicative and non limiting embodiment illustrated in Figures 1 and 2, the connecting devices 12 are embodied by two functionally complementary connecting elements 7,8, mutually removable from each other, and preferably made of metallic material. A first connecting element 7 is provided with a tubular body 7a, internally threaded, having a head 7 and fitted with peripherally protruding projections 7b. The projections 7b can be embodied for instance by one or more tips extending from the body 7a, or from the head 7e, whereto an appropriate polygonal shape has been given, or by an equivalent toothing (knurling) obtained on the body 7a or on the head 7e itself. The first connecting element 7 is destined to be secured to the material constituting the lens 2 in the manner that shall be described farther on, being stably incapable of rotation therein. The second connecting element 8 is instead embodied by a screw, preferably with hexagonal head, provided with a thread complementary to that of the tubular body 7a, whereby the screw 8 is associated directly and securely to the tubular body. One of the two connecting elements 7 is fastened to the lens 2, in practice, with a method which comprises a phase whereby the connecting element 7; 8 is heated to a temperature appropriately selected with respect to the characteristic softening temperature of the material constituting the lens 2, material which in order to meet the safety characteristics required for this type of eyeglasses is normally constituted by a thermoplastic resin; a phase whereby the heated connecting element 7; 8 is compressed against a first face 2e of the lens 2 until causing the sinking and incorporation of the connecting element 7; 8 into the material constituting the lens 2, and lastly an air cooling phase to cause the solidification of the softened material of the lens 2 which has flowed around the head 7e during the compression phase, and the consequent definitive fastening of the connecting element 7;8 to the lens 2. After fastening one of the connecting elements to the lens 2, it is possible to proceed with connecting the temples 3 and the bow 4 (which may or may not incorporate the supports 5) by means of the simple fastening of the second interconnecting element 8 by interposing, between the element 8 and the first connecting element 7, suitably shaped extremities 11 of the temples 3 and of the bow 4. In the embodiment described herein, reference has been made to the securing of the tubular body 7a to the lens 2, but it is clear that the two elements of the connecting device 12 are perfectly reversible and nothing prohibits from securing the screw 8 to the lens 2 and then fastening the frame elements 3,4,5 by fastening the tubular body 7a to the screw 8. Reference has also been made to a extremities 11 folded into a U shape and so dimensioned as to encompass the stem of the screw 8, but it is clear that this cannot be considered a limiting feature in that the extremity 1 1 of the frame element 3,4,5 can have a wholly general shape. Returning to the fastening method and referring in particular to Figure 2, it is appropriate to highlight that the compression phase must preferably be interrupted before reaching the complete sinking of the connecting element 7; 8 into the material constituting the lens 2. This allows advantageously to effect a sort of gripping of the end 1 1 of the frame element 3;4;5 involved between the first and the second connecting element 7; 8 mutually coupled; and subsequently to tighten the connecting device 12 fully onto the frame element 3,4,5, avoiding direct contact between the latter and the surface 2e of the lens 2; contact which could damage the lens 2 in case of excessively intense tightening force. Moreover, the phase whereby the connecting element 7; 8 is compressed is preferably carried out in such a way as to involve the outer face 2e of the lenses 2. Since most lenses present similar curvatures of the outer faces 2e, this allows to establish nearly constant positional references which enable to minimise the operative times required correctly to position and orient the connecting element 7 with respect to the lens 2, before the later is sunk into the lens 2 itself. Without modifying the aforesaid concept for securing one of the connecting elements 7;8 to the lens 2, the connecting device 12 can be constructed in numerous other embodiments. A first embodiment variation of the device 12 shown in Figures 3, 4 A and 4B provides for the adoption of an arm 7c integral with the body 7a of the connecting element 7; 8 which is secured to the lens 2. The arm 7c is elongated in such a way as to be able to fold back against a first peripheral edge 9a of the lens 2, thereby being itself able to serve, aiding or replacing the projections 7b, as an obstacle to the rotation of the connecting element 7 about an axis of rotation 10 transverse to the lens 2. If the arm 7c of the connecting element 7 is of suitable length, it is possible to fold it a second time against a second peripheral edge 9b of the lens 2 and, approaching it to a face 2i of the lens opposite to the face 2e involved by the first connecting element 7; 8, it is possible to hide from view the area of the lens 2 involved with the connection. The use of the arm 7c allows for other advantages, amongst them that of enabling the fastening of the frame element 3,4,5 in a position lateral to the lens 2, for instance using a support 7d for coupling the frame element: whether it is constituted by the temple 3; by the bow 4 or by the nasal support 5. In this case, the arm 7c can also provide an effective support for sustaining decorative elements 13 of the frame, to the advantage of a greater aesthetic value of the eyeglasses 1 themselves. The invention thus conceived can be subject to numerous modifications and variations, without thereby departing from the scope of the inventive concept. Moreover, all details can be replaced by technically equivalent elements. A possible embodiment of such variations can pertain to the connecting system operating between the first and the second connecting element 7 and 8. Unlike the threaded connection, the tubular body 7a of the first connecting element 7 can have a smooth inner surface. Similar smooth surface can be possessed by the corresponding complementary part of the second connecting element 8. In this case, by means of a preliminary insertion into the tubular body 7a of a pellet of material with deformable plastic material, such as an easily deformed metal like lead or even an equally deformable plastic material, and successive penetration of the two elements along the axis 10, it is possible mutually to connect the two connecting elements 7,8, securely fastening them by axial forcing and consequent transverse interference. Naturally, whenever it is necessary to detach said parts the separation of the connecting elements 7,8 will always be possible by applying an adequate force in the opposite direction.

Claims: Claims 1. Method for connecting lenses (2) of eyeglasses (1) directly with frame elements (3,4,5) in eyeglasses (1) with lenses (2) and frames (6) structurally cooperating with each other and comprising mutually complementary, removable, connecting elements (7,8), respectively connecting the lenses (2) and the frame elements (3,4,5), method characterised in that it comprises a phase whereby one of the connecting elements (7;8) is heated to a temperature appropriately selected with respect to the characteristic softening temperature of the material constituting the lens (2); a phase whereby the heated connecting element (7; 8) is compressed against a first face (2e) of the lens (2) until producing the sinking and incorporation of the connecting element (7;8) into the material constituting the lens (2); and a cooling phase to produce the solidification of the softened material of the lens (2) and the consequent definitive fastening of the connecting element (7; 8) to the lens (2). 2. Method, according to claim 1, characterised in that said compression phase is interrupted before reaching the complete sinking of the connecting element (7;8) into the material constituting the lens (2). 3. Method, according to claim 1 , characterised in that it entails the use of a said connecting element (7;8) so shaped as to be incapable of rotating in the material constituting the lens (2), after said definitive fastening. 4. Method, according to claim 2, characterised in that it entails the use of a said connecting element (7; 8) having a body (7a) provided with at least a protruding projection (7b) able to be associated to the material constituting the lens (2). 5. Method, according to claim 4, characterised in that said one or each protruding projection (7b) is realised by a corresponding tip of said connecting element (7;8). 6. Method, according to claim 4, characterised in that said one or each projection (7b) is realised by a toothing obtained on the connecting element (7;8). 7. Method, according to claim 1, characterised in that it comprises at least a first phase whereby an arm (7c) of the connecting element (7; 8) is folded back against a first peripheral edge (9a) of the lens (2) to realise a rotation-proof coupling of the connecting element (7;8) around an axis of rotation (10) transverse to the lens (2). 8. Method, according to claim 7, characterised in that it comprises a second phase whereby the arm (7c) of the connecting element (7;8) is folded back against a second peripheral edge (9b) of the lens (2), followed by a subsequent approach of the arm (7c) on a face (2i) of the lens (2) opposite to the face (2e) involved by the first connecting element (7;8). 9. Method, according to any of the previous claims, characterised in that it comprises a fastening of an extremity (11) of a frame element (3;4;5) by means of gripping said frame element between the first and the second mutually coupled connecting elements (7;8). 10. Method, according to one of the previous claims from 7 to 9, characterised in that said arm (7c) is provided with a support (7d) to fasten the frame element (3;4;5) thereto. 11. Method, according to any of the previous claims, characterised in that said phase whereby the connecting element (7;8) is compressed is carried out on the outer face (2e) of the lens (2). 12. Fastening device for connecting lenses (2) of eyeglasses ( 1 ) and frame elements (3,4,5) in eyeglasses (1) having lenses (2) and frame (6) structurally co-operating with each other, device (12) which comprises a first and a second connecting element (7; 8) complementarily shaped to be able to be fastened securely, but removably to each other, characterised in that a said connecting element (7;8) is so shaped as to be able to be incorporated into the material constituting the lens (2) in a fastened condition incapable of rotation with respect to an axis of rotation (10) transverse to the lens (2). 13. Device, according to claim 12, characterised in that said connecting element (7;8) is provided with at least a protruding projection (7b) able to be associated to the material constituting the lens (2). 14. Device, according to claim 13, characterised in that said one or each protruding projection (7b) is embodied by a tip extending from the connecting element (7;8). 15. Device, according to claim 13 , characterised in that said one or each proj ection (7b) is embodied by a toothing obtained on the connecting element (7;8). 16. Device, according to claim 12, characterised in that it comprises at least an arm (7c) integral to the connecting element (7;8), which is able to be folded back against a first peripheral edge (9a) of the lens (2) to realise a coupling of the connecting element (7;8) incapable of rotating about an axis of rotation (10) transverse to the lens (2). 17. Device, according to claim 16, characterised in that said arm (7c) of the connecting element (7;8) is able to be folded back against a second peripheral edge (9b) of the lens (2) and to be approached to a face (2i) of the lens (2) opposite to the face (2e) involved by the first connecting element (7;8). 18. Device, according to claim 16 or 17, characterised in that said arm (7c) is provided with a support (7d) for fastening the frame element (3;4;5). 19. Device, according to claim 12, characterised in that said first connecting element (7) is provided with a tubular body (7a) and said second connecting element (7,8) is so shaped as to be axially inserted into the tubular body (7a), a plastically deformable material inteφosed between said first and second connecting element (7,8) allowing to fasten said first and second connecting element (7,8) by axial forcing and consequent transverse interference.

Inventors: GIOACCHINI GIOVANNI, GIOACCHINI, GIOVANNI
Applicants: GIOACCHINI GIOVANNI, OTTICO FOTO G I O S N C DI GIO, CENTRO OTTICO FOTO G.I.O. S.N.C. DI GIOACCHINI GIOVANNI & C., GIOACCHINI, GIOVANNI
Application year: 1999
Main classification: G02C1
IPC codes: G02C1