FR2793040A1 - Production of spectacles, where material which is analogous to material used for lenses is molded over part of frame receiving lenses before lenses are mounted in frame - Google Patents

Abstract

Before lenses are mounted in a spectacle frame a material is molded over at least part of the frame that receives the lenses. The material is analogous to the material used for the lenses. An Independent claim is included for spectacles produced as above. Preferred Features: The material is applied only to the bridge and/or the hinges. The bridge extends down to grip the nose like a pince-nez.

Description

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 The subject of the present invention is a method of assembling glasses on a spectacle frame, and glasses obtained by implementing said method.

 Traditionally, the lenses of a pair of glasses are mounted encased in a frame which may be metallic or plastic or the like.

 With the aim initially of saving weight and saving, then later of aesthetics, it has been proposed to reduce the dimensions of the frame. Initially the straps in which the glasses are embedded have been removed, so that the latter are only held by their upper edge by means of a crosspiece connecting the hinges of the two branches and incorporating the bridge. Then in a more recent evolution, only the essential elements that are the bridge and the pivots have been kept of the frame, fixed directly to said glasses by various methods.

 The most frequently used method consists in securing the bridge and the pivots to the glasses by means of screws, screwed either in the edge, or in one or the other of the faces thereof. Spectacles constructed according to this method have the drawback of being very fragile, and indeed there is frequently a break in the glass at the tapped bores which are formed there.

 To overcome this drawback, it has been proposed to secure the bridge and / or the pivots by gluing, we thus know from document FR 1,283,283 glasses comprising a metal frame comprising a bridge extended on either side by two extensions each housed between two plastic parts, one of which is fitted with a hinge while the other is glued to the upper edge of a glass.

 The glasses as described in this document which is relatively old, present a questionable aesthetic at present, moreover these glasses, because of their complexity are not economically profitable.

 In addition, however, there have been problems of separation by a shear effect of the adhesive joint.

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 due to the different expansion coefficients of the assembled materials, namely glass and plastic.

 Document FR 2,624,278 also discloses glasses which include a bridge made of plastic material, glued to the edge of the glasses, as well as two studs also made of plastic material, each glued near the outer edge of a glass, on the inner face of the latter, and pierced with a channel intended to receive the end of a branch while allowing the latter to pivot.

 The joining by bonding of the bridge and the studs for fixing the plastic branches on the glasses, when these are plastic organic glasses, makes it possible to partially solve the drawback mentioned previously of the shear effect of the adhesive joint, since the elements to be glued are of a similar nature.

 However, the manufacturing process used does not make it possible to obtain glasses of robust design, it is true that it is intended for the manufacture of extra-flexible and light glasses. Note for this purpose the rudimentary nature of the mode of attachment of the branches, in which the friction of the metal on the plastic generates in the long run wear of said plastic.

 Furthermore, the flexibility of the glasses thus produced, in particular because the bridge is made of plastic, is incompatible with optical accuracy which requires a certain rigidity.

 In addition, since the elements to be bonded are not exactly of the same nature, an adhesive should be chosen which is suitable for bonding the materials from which these elements are made.

 The object of the present invention is to propose a method of assembling the lenses on a spectacle frame making it possible to remedy the various aforementioned drawbacks.

 The method of assembling the lenses on a spectacle frame according to the invention is essentially characterized in that it consists in overmolding at least the parts of the elements intended to come into contact with the lenses, by means of a material.

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 similar to that of which said glasses are made, and then bonding said parts thereon.

 Since the elements to be bonded are of the same nature, there is no shearing effect due to differences in the coefficient of expansion.

 On the other hand, bonding is effective since the adhesive is suitable for bonding a single material.

 According to an additional characteristic of the method according to the invention, only the two ends of the bridge which is made of metal are overmolded.

 According to another additional characteristic of the process according to the invention, only the parts of the hinges intended to come into contact with the glasses are overmolded.

 According to another additional characteristic of the method according to the invention, the glasses as well as the molding material are made of polycarbonate.

 The present invention also relates to glasses obtained by implementing the method according to the invention, and which are essentially characterized in that they comprise two glasses connected by a bridge, at least the ends of which are intended to come into contact with said glasses. glasses, as well as at least the parts of the hinges intended to come into contact with said glasses, are overmolded with a material identical to that of which said glasses are made, the joining of said parts overmolded to said glasses being carried out by an adhesive joint suitable for bonding said material.

 The advantages and characteristics of the device according to the invention will emerge more clearly from the description which follows and which relates to the appended drawing, which represents a non-limiting embodiment thereof.

 In the accompanying drawing, the single figure represents a partial schematic perspective view of a pair of glasses produced according to the method according to the invention.

 In this figure, it can be seen that a pair of glasses produced according to the process which is the subject of the present invention comprises two glasses 1 connected by a bridge 2, as well as two branches 3 each mounted on a hinge 4 secured to a glass 1.

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 The bridge 2 is in the form of a metal bar 20 bent to approximate the bridge of the nose, the ends 21 of which are each extended downwards by an extension 22 provided with a fin 23 so as to constitute a clamp -nose.

 It will be noted that the presence of a nose clip is not compulsory, it nevertheless makes it possible to stabilize the pair of glasses.

 The ends 21 of the metal bar 20 are each overmolded with a stud 24 made of a material identical to that of which the glasses 1 are made.

 The connection of the bridge 2 to the glasses 1 is obtained by bonding the studs 24 to the edge 10 of the glasses 1 by means of a seal 5 of an adhesive suitable for bonding the material from which the glasses 1 and the studs 24 are made.

 It will be noted that preferably the studs 24 are overmolded on parts of the metal bar 20 whose shapes ensure the stability of the studs 24, with a view to providing perfect rigidity in the connection of the two glasses 1.

 It will also be noted that it is perfectly possible to completely overmold the metal bar 20 and thus give the bridge 2 an original shape.

 The hinges 4 are secured to the glasses 1 in the same way, that is to say that they are enveloped by overmolding of a material identical to that of which the glasses 1 and the pads 24 are made, which allows them to be secured on the edge 10 of the glasses 1 on the outside of these by means of a seal 6 of the same glue.

 It will be noted that the hinges 4 may not be completely wrapped by overmolding, in this case, only their part intended to come into contact with a glass 1 is overmolded, this part being clearly understood in a shape capable of retaining the overmolding material.

 It will also be noted that it is possible to secure the bridge 2 and the hinges 4 other than on the edge 10 of the glasses 1, on the inner face of these and at the edge for example, with the disadvantage of narrowing the field. of vision.

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 in addition to the aforementioned advantages of solidity and reliability of the collages, the method of assembling the lenses on a spectacle frame according to the invention makes it possible to vary the color of the frame by using molding materials of different colors.

Claims (6)

1. A method of assembling the glasses on a spectacle frame, characterized in that it consists in overmolding at least the parts of the elements (2,4) intended to come into contact with the glasses (1), by means of a material similar to that of which said glasses (1) are made, then bonding said parts to the latter.  2. Method according to claim 1 characterized in that only the two ends (21) of the bridge (2) which are made of metal are molded.  3. Method according to claim 1 or claim 2, characterized in that only the molded parts of the hinges (4) intended to come into contact with the glasses (1).  4. Method according to any one of the preceding claims, characterized in that the glasses (1) and the overmolding material are made of polycarbonate.  5. Spectacles obtained by implementing the method according to any one of the preceding claims, characterized in that they comprise two glasses (1) connected by a bridge (2) of which at least the ends (21) intended to come in contact with said glasses (1), as well as at least the parts of the hinges (4) intended to come into contact with said glasses (1), are overmolded with a material identical to that of which said glasses (1) are made, the joining of said overmolded parts to said glasses (1) being produced by a seal (5,6) of an adhesive suitable for sticking said material.  6. Spectacles according to claim 5, characterized in that the ends of the bridge (2) are each extended downwards by an extension (22) provided with a fin (23) so as to constitute a nose clip.