SPECTACLES

Abstract: In spectacles having two lenses (3), each connected to a temple (2) by means of a temple mounting member (6) and a bridge (7) interconnecting the lenses, the temples (2), the temple mounting members (6) and the bridge (7) are made of wire material. For holding the temple mounting members (6) and the bridge (7) firmly together with the lenses (3) the pieces of wire material which form the temple mounting members (6) and the bridge (7) are curved or bent to provide eyelets (4, 5) which support an extended part of a screw connection, e.g. the head of a yielding plastic screw (8, 9) which is screwed into a threaded bore (11) formed directly in the lenses.

Description: Spectacles. The invention relates to spectacles having two lenses, each of which is connected to a temple by means of a temple mounting member and a bridge inter¬ connecting the lenses, the temples, the temple mount- ing members and the bridge being made of wire mater¬ ial- Spectacles having rim parts made of wire mater¬ ial have per se been known for generations, both rim¬ med and in rimless design. This type of spectacles has, however, had a limited distribution particularly due to its fragility as concerns breaking or splitting of the lenses. In a known design of rimless spectacles the temples are fastened to the lenses either by means of spring clamps placed on the circumference of the lens¬ es as disclosed in US patent No.718,363, or by means of metal screws which are passed through holes in the lenses and are retained in nuts on the front side of the lenses as disclosed in US patents Nos. 906,360, 967,292 and 2,256,846. However, these fastening meth¬ ods all have the inherent disadvantage that even a minor deformation of the wire parts of the rim easily causes splits in the lenses at the spring clamps or around the screws passing through the lenses. For spectacles with lenses of a thermoplastic material it has been proposed in French patent No. 1068345 to fasten a wire rim to a lens by pressing a heated profiled metal pin into the lens material. This fastening method is, however, not applicable for spectacles with lenses made of glass or modern optical plastic materials. Correspondingly, GB patent No.760025 discloses a fastening method by which a pin of yielding plastic material is passed through a pre-drilled bore in the lens and fastened by thermal expansion by heating on the front side of the lenses. Besides the fact that this method in practice does not ensure a sufficiently firm fastening to prevent the lenses from working loose, the heat treatment requirement entails a con¬ siderable risk of damaging the surface treatment of the lenses. During recent years the appearance of new and stronger wire materials such as, e.g. titanium alloys, has given rise to a renewed interest in wire-rimmed spectacles which can be produced with a considerably lower weight than conventional types of spectacles. EP-A-256098 proposes a different form of fastening, whereby the temple mounting members and the bridge serving to connect the lenses are shaped to form a resilient metal strap inserted with spring effect into rectangular slits in the lenses. This method cannot be used for spectacles hav- ing lenses made of glass, since it is impossible to mill out the rectangular slits in such lenses. Even in spectacles having lenses made of plastic material, arrangement of the resilient strap in the underdim- ensioned slits will easily cause the lens to break. If, in order to counteract this risk, the spring tens¬ ion is reduced, the strap will tend to work itself loose and fall out. The object of the invention is to provide an improved design of spectacles with wire temples and bridge, while fully preserving the advantages of this type of spectacles as concerns simplicity of structure and reduced weight, at the same time ensuring that the lenses and rim parts are held firmly together with a considerably reduced risk of breaking or splitting, irrespective of whether the lenses are made of glass or optical plastic materials. This can be achieved according to the invention by forming the temple mounting members and the bridge of at least one piece of wire material curved or bent to provide eyelets underlying an extended part of a screw connection, comprising a member of yielding plastic material adapted for form-fit insertion into a bore of varying cross-sectional profile, drilled dir- ectly in the lens between the front and back of same. Fastening by means of screw connections with members that are adapted for insertion into profiled bores drilled directly in the lens entails a consider¬ ably reduced risk of local tensions around the fasten- ing point, while at the same time the elastic deform- ability of said members contribute to absorb deform¬ ations and ensure a stable fixation. As compared to the above-mentioned embodiment which has a resilient strap, manufacture and mounting are simplified. With the wire materials normally used for temples and bridges the eyelets underlying said extended part of the screw connection can be formed with a diameter of about 2 mms, and by adapting the profiles of said connecting members it is expedient according to the invention that the plastic member is made of a transparent material, e.g. "grilamid". The embodiment according to the invention is applicable for spectacles having lenses made of optic¬ al plastic material as well as of ophthalmical glass. In an embodiment suited for lenses of a plastic mater¬ ial said member and the extended part of the screw connection are formed by the shaft and the head of a screw and said bore is a threaded bore in the lens for receiving the screw. In an embodiment suited for glass lenses, said member is shaped as a pin which in one end is conical for form-fit insertion into a conical portion of said bore at the front side of the lens, the other end of said pin forming a threaded pin to be passed through said eyelet for receiving a nut forming the extended part of the screw connection. The spectacle design according to the invention is likewise applicable both to rimless spectacles where the temple mounting members can be made of short pieces of wire and for designs where the wire material also forms a rim portion connecting the bridge to the temple mounting members. According to the invention an embodiment of the latter type is characterized in that the temple mounting members and the bridge via con¬ necting rim portions extending at least along part of the edge of each lens is made of a single piece of wire material. Both for rimless and rimmed embodiments of spectacles according to the invention the advantage is obtained over conventional wire-rimmed spectacles that soldering joints which may weaken the structure are avoided. In rimless spectacles an added safety for the firm retention of the screws in the lenses can be obtained by connecting each temple to a lens by means of separate mounting members made of wire material, one free end of which is bent to form an anchoring member for arrangement in a notch in the lens edge, whereas the other end forms a hinge joint for the temple. The invention is further explained in the fol¬ lowing with reference to the drawing, in which fig 1 shows an embodiment of spectacles with a wire material rim, which extends along part of the upper edge of the lenses; figs 2-3 are a perspective, and a sectional view, respectively, of the details of the fastening of the lenses in the rim portions; fig 4 shows a rimless embodiment; fig 5 shows a temple mounting member serving as hinge joint for a temple; and fig 6 shows the retention of the lenses in the rim parts in an alternative embodiment having lenses made of ophthalmic glass. In the embodiment of the spectacles 1 accord¬ ing to the invention shown in fig 1 the temples 2 are connected to the lenses 3, which in this embodi¬ ment are made of a plastic material, via hinge joints 2a by means of a rim formed by a single piece of wire material, mainly titanium wire, and providing for each of the lenses mounting eyelets 4 and 5 and a rim part 6 extending along the upper edge of the lens and connecting the eyelets 4 and 5, while a bridge 7 formed by the same piece of wire material connects the eyelets 5 in the two lenses. The portion of the wire rim forming the bridge extends downwards along part of the inner edge of each lens and is bent into a hairpin shape for retention of nose pads 10. As more clearly apparent from figs 2 and 3 the wire rim is connected to the lenses 3 by means of the eyelets 4 and 5 underlying screws 8 and 9 which are screwed into threaded bores 11, provided directly in the lenses 3, which with a view to the desired reduced weight preferably are made of an optical plastic materials such as, e.g. CR39. As it appears from fig 3, the screws 8 and 9 are passed through the lenses 3. The screw end 12 at the front side of the lenses may be deformed, e.g. by being cut off to ensure a further safe fastening of the screw. The screw being passed all the way through the lens and being made of a more yielding material than the latter it will be able to absorb deforming actions which are caused by exposing the wire rim to mechanic- al stress. By using 1.1 mm titanium wire for the rim it will in practice be possible to provide the eyelets 4 and 5 with an interior diameter of 2 mm, and the screws 8 and 9 must then have dimensions adapted hereto, i.e. having a shaft diameter of 2 mm. For aesthetical reasons it is therefore preferred to use screws of a transparent material. As shown in figs 4 and 5 the spectacles accord¬ ing to the invention can also be provided in a rimless design by connecting the temples 14 to each of the lenses 15 by means of a separate mounting member 16 made of a piece of wire bent to form an eyelet 17. At one side of the eyelet 17 the mounting member 16 is bent so as to provide an anchoring member 18 for engagement with a notch 19 in the edge of the lens 15. At the opposite side of the eyelet 17 the mount¬ ing member 16 forms a hinge joint for the temple 14, e.g. by being shaped as a wire winding 20 encom¬ passing a hinge pin 21 formed by the end of the temple 14. The bridge 22, which in this embodiment is not connected to the mounting members 16, is also design¬ ed with bent ends to provide anchoring members 23 for arrangement in notches 24 in the edge of the lenses 15. Whereas the embodiments shown in figs 1-5 are intended for spectacles with lenses made of a plastic material, fig 6 is a sectional view of an alternative embodiment having lenses made of ophthalmic glass and where there is no possibility of forming a threaded bore in the lens itself. The screw connection here comprises a pin 25, which at one end has a conical head 26 adapted for insertion into a corresponding conical portion 27 of a bore in the lens 28, where- as the other end of the pin 25 forms a threaded pin 29, which on the back of the lens is passed through the eyelet 20 formed by a temple mounting member or by the bridge to be retained by a nut 31.

Claims: P A T E N T C L A I M S 1. Spectacles having two lenses (3, 15, 28), each connected to a temple (2, 14) by means of a temple mounting member, and a bridge (7, 22) intercon¬ necting the lenses, the temples (2, 14), the temple mounting members (6, 16) and the bridge (7, 22) being made of wire material, c h a r a c t e r i z e d in that the temple mounting members (6, 16) and the bridge are formed by at least one piece of wire mater¬ ial curved or bent to provide eyelets (4, 5; 17, 30) for supporting an extended part of a screw connection, comprising a member (8, 9; 17, 25) of yielding plastic material adapted for form-fit insertion into a bore (11, 27) of varying cross-sectional profile, drilled directly in the lens (3, 15, 28) between the front and back of same. 2. Spectacles as claimed in claim 1, c h a r ¬ a c t e r i z e d in that said member is made of a transparent material. 3. Spectacles as claimed in claim 1 or 2 having lenses made of a plastic material, c h a r a c t e r ¬ i z e d in that said member and the extended part of the screw connection are formed by the shaft and the head of a screw (8, 9, 17) and that said bore is a threaded bore (11) formed in the lens (3, 15) for receiving said screw (8, 9, 17). 4. Spectacles as claimed in claim 1 or 2, hav¬ ing lenses made of ophthalmic glass, c h a r a c t ¬ e r i z e d in that said member is shaped as a pin (25) one end (26) of which is conical for form-fit insertion into a conical portion (27) of said bore at the front side of the lens, the other end of said pin forming a threaded pin (29) to be passed through said eyelet (30) for receiving a nut (31) forming the extended part of the screw connection. 5. Spectacles as claimed in one of the preced¬ ing claims, c h a r a c t e r i z e d in that the temple mounting members (6) and the bridge (7) via connecting rim portions extending at least along part of the edge of each lens (3) are made of a single piece of wire. 6. Spectacles as claimed in one of the preced- ing claims, c h a r a c t e r i z e d in that each of the temples (14) is connected to a lens (15) by a separate temple mounting member (16) made of wire material, one free end of which is bent to form an anchoring member (18) arranged in a notch (19) in the lens edge, whereas the other end forms a hinge joint (20, 21) for the temple (14). 7. Spectacles as claimed in claim 6, c h a r ¬ a c t e r i z e d in that the hinge joint is designed as a wire winding (20) which encompasses a bent end of the temple (14) serving as a hinge pin (21) . 8. Spectacles as claimed in claim 3, c h a r ¬ a c t e r i z e d in that the the free end (12) of the screw (8, 9) is deformed_ at the side of the lens opposite the screw head. 9. Spectacles as claimed in claim 4, c h a r ¬ a c t e r i z e d in that the free end of the thread¬ ed pin (29) which is passed through the nut (31) is deformed. 10. Spectacles according to claims 8 or 9, c h a r a c t e r i z e d in that said deformation is provided by cutting off said free end.

Inventors: HOUMAND JAN, HOUMAND, JAN
Applicants: HOUMAND JAN, HOUMAND, JAN
Application year: 1991
Main classification: G02C1
IPC codes: G02C1