Process for manufacturing a frame by molding

Abstract

The invention relates to a method for manufacturing a mount (1) comprising an opening (2) delimited by a continuous periphery (3) provided with a recessed groove (4) for fixing, said method providing for: closing a mold (8) comprising two parts (8b) forming between them a molding cavity, one of the parts (8b) of which comprises a core (10) for forming the opening (2), said core having a peripheral edge (11) extending according to a geometry for forming the groove (4); injecting a material for molding the mount (1) with the edge (11) engaged in the groove (4); opening the mold; moving the core (10) on a longitudinal ejection stroke of the mount (1) by inducing a radial withdrawal of a portion (11a) of the edge (11) in the ejected position, said withdrawal making it possible to remove the mount (1) from the core (10) by disengaging the edge (11) from the groove (4). Figure 2

Description

Title of the invention: Method of manufacturing a frame by molding

[0001] The invention relates to a method of manufacturing a frame comprising an opening delimited by a continuous periphery which is provided with a hollow groove for fixing an element in said opening, as well as glasses comprising a frame manufactured by implementing such a method.

[0002] It applies in particular to the manufacture of a frame for glasses by injection and molding of a material, in particular thermoplastic, in a cavity provided for this purpose, in which optical lenses can then be fixed in each of the openings, in particular by fitting their periphery into the hollow groove formed in the respective peripheries of said openings.

[0003] To manufacture such glasses, document US-2020 / 0338845 discloses a method which provides for: - closing a mold comprising two parts which are arranged to form between them a molding cavity, one of said parts comprising a core for forming the opening, said core having a peripheral border extending over a radial dimension in the cavity following a geometry for forming the groove; - inject a material into the cavity to mold the frame with the rim engaged in the groove; - open the mold; - moving the core on an ejection stroke of the molded mount from its molding position to an ejected position located at a longitudinal distance from said molding position.

[0004] This solution is limited to obtaining a groove whose depth is reduced, in particular being less than 1 mm, insofar as the removal of the mount in the ejected position requires disengagement of the edge which induces a risk of deterioration and / or breakage of the groove if it were too deep.

[0005] Thus, this solution does not make it possible to satisfy certain applications in which a module, in particular an electronic module, must be integrated into at least one mounting groove of an optical glass in a spectacle frame, in order to simplify and make reliable the association of said module with said spectacles.

[0006] Indeed, the glass mounting groove must then be enlarged, in particular to a depth greater than 1 mm, in order to be able to accommodate the module in addition to the periphery of said glass, while avoiding a risk of crushing said module and / or of de- fitting of said glass.

[0007] In an attempt to resolve this problem, document WO-2018 / 005136 discloses a method of manufacturing glasses in which each peripheral groove comprises a first section intended for fixing an optical glass and a second section, made deeper and slightly longitudinally offset relative to the first section, in which at least one wire can be fixed.

[0008] However, this solution is not entirely satisfactory, in that it proves to be complex to implement insofar as it requires the differentiated formation of groove sections.

[0009] The invention aims to improve the prior art by proposing in particular a method for manufacturing an eyeglass frame by molding which is simple and quick to implement, by making it possible to form a groove suitable for the joint mounting of an optical glass and a module, and this by limiting the risk of deterioration and / or breakage of said groove during demolding.

[0010] To this end, according to a first aspect, the invention proposes a method of manufacturing a frame comprising an opening delimited by a continuous periphery which is provided with a hollow groove for fixing an element in said opening, said method providing: - to close a mold comprising two parts which are arranged to form between them a molding cavity, one of said parts comprising a core for forming the opening, said core having a peripheral border extending over a radial dimension in the cavity following a geometry for forming the groove; - to inject a material into the cavity to mold the frame with the rim engaged in the groove; - to open the mold; - to move the core on an ejection stroke of the molded mount from its molding position to an ejected position located at a longitudinal distance from said molding position;

[0011] the movement of the core on its ejection stroke being arranged to induce a radial withdrawal of at least a portion of the edge in the ejected position, said withdrawal making it possible to remove the mount from the core by disengaging the edge from the groove.

[0012] According to a second aspect, the invention provides eyeglasses comprising a frame manufactured by implementing such a method, in which an optical glass is fixed in the groove, said eyeglasses further integrating a module which is fixed in a section of said groove.

[0013] Other features and advantages of the invention will appear in the following description, given with reference to the attached figures, in which:

[0014] [Fig.l] schematically represents, in perspective front view, an eyeglass frame obtained by a method according to an embodiment of the invention,

[0015] [Fig. 1a] representing in partial section the periphery of an opening centered on the fixing groove;

[0016] [Fig.2] schematically represents, in perspective front view, the rear part of a mold adapted to produce a spectacle frame according to an embodiment of the invention;

[0017] [Fig.3a] and

[0018] [Fig.3b] schematically represent, in exploded view respectively from the side and from above, the two parts of a mold according to the invention;

[0019] [Fig.4] schematically represents, in perspective view from the rear, the front part of the mold of the preceding figures;

[0020] [Fig.5] schematically represents, in perspective view from the front, the rear part of the mold of the preceding figures, after molding the frame,

[0021] [Fig.5a] and

[0022] [Fig.5b] being partial views centered on a rim of said mount, respectively in perspective and in front view, showing the movement of the core after molding;

[0023] [Fig.6a] and

[0024] [Fig.6b] schematically represent, in perspective respectively lateral and top view, the rear part of the mold of the preceding figures in the position ejected from the mount.

[0025] In relation to these figures, a method of manufacturing a frame 1 comprising an opening 2 delimited by a continuous periphery 3 which is provided with a hollow groove 4 for fixing an element in said opening, as well as glasses comprising a frame 1 manufactured by implementing such a method, is described below.

[0026] In the embodiment shown, the frame 1 comprises two continuous rims 5 connected at their respective inner edges by a central nose bridge 6, each delimiting an opening 2 intended to be arranged opposite a respective eye of a wearer, a groove 4 being formed continuously in the inner edge of each rim 5 to allow the attachment of a respective optical glass 2a.

[0027] Furthermore, each rim 5 comprises a tab 7a which extends rearwardly from its outer edge, being integral with said rim, said tab being arranged to allow the fixing thereon of a means for holding the glasses on the face of a wearer, for example a foldable branch 7b intended to come to bear against the temple and behind the adjacent ear of said wearer.

[0028] In the description, the terms of positioning in space are taken as reference the position of the glasses relative to the face of a wearer wearing said glasses. In particular: - the terms “back” and “front” relate to an arrangement respectively facing the face and opposite the face; - the terms “exterior” and “interior” relate to arrangements respectively close to and far from the wearer’s nose; - the terms “upper” and “lower” are taken in reference to the position of the mount as represented in particular in [Fig.l].

[0029] Furthermore: - the terms “internal” and “external” are taken with reference to each opening 2 of the frame 1, and correspond to arrangements respectively close to and far from said opening; - the term “longitudinal” refers to a direction extending between the front and the rear, and in particular perpendicular to a frontal plane along which the mount 1 extends substantially, the term “radial” referring to a direction perpendicular to this longitudinal direction.

[0030] Each optical glass 2a has a transparent wall arranged so that vision takes place through it when the glasses are put on by the wearer, for example by being based on glass or a transparent thermoplastic polymer material. In particular, the optical properties of the transparent wall can be arranged to adapt to the wearer's vision and / or to the ambient brightness.

[0031] The glasses further integrate a module 4a, in particular an electronic module, for example a radio-identification chip (RFID) connected to an antenna, which is fixed in a section of a groove 4 for fixing a glass 2a.

[0032] This integration can in particular facilitate the tracking of glasses, in particular for their sale. Indeed, the integration of RFID chips in articles intended for sale allows employees of a point of sale to carry out an inventory of said articles more easily, in particular when they pass through the checkout to remove them from said inventory after their sale to a customer, but also to store said articles more easily on the shelf, for example after a trial of said articles by customers without subsequent purchase.

[0033] In particular, the integration of such an RFID chip in the frame 1 of the glasses makes it easier to conceal said chip, which does not affect the aesthetics of the glasses, but also makes it possible to limit the risks of inadvertent removal of said chip by a customer, and thus to reduce the risks of theft of said glasses.

[0034] A method is now described for manufacturing a frame 1 suitable for producing such glasses.

[0035] The method provides for closing a mold 8 comprising two parts 8a, 8b which are arranged to form between them a molding cavity, one of said parts 8b comprising a core 10 to form the opening 2 for receiving an element - here an optical glass 2a -, said core having a peripheral edge 11 extending over a radial dimension in the molding cavity, following a geometry for forming the groove 4.

[0036] In the embodiment shown, the mold 8 comprises two front 8a and rear 8b parts which each comprise an imprint - respectively rear 9a and front 9b - intended to delimit together a molding cavity adapted to form a frame 1 with two hoops 5 connected at their inner edges by a central nose bridge 6, and provided at their respective outer edges with a tab 7a for fixing a foldable branch 7b for holding on the head of a wearer.

[0037] In particular, the rear part 8b comprises two cores 10 arranged to each form an opening 2 in the mount 1, each core 10 having a peripheral edge 11 as described previously.

[0038] To do this, the imprint 9a of the front part 8a comprises two patterns 12 each intended to form a ring 5, each pattern 12 surrounding a central platform 13 whose geometry is similar to that of the corresponding core 10.

[0039] Furthermore, each core 10 comprises a central nut 14 which extends longitudinally in a forward projection to be arranged in a blind orifice 15 of complementary geometry formed in the center of each platform 13, in order to guarantee good centering of the cores 10 on their respective support platforms 13 before molding the mount 1.

[0040] The method then provides for injecting a material, in particular a thermoplastic resin, into the cavity of the mold 8, so as to mold the desired mount 1 there, with the edge 11 of each core 10 engaged in the corresponding groove 4, formed by said molding with a hollow geometry which is complementary to the projecting geometry of said edge.

[0041] Finally, after hardening of the molding material injected into the cavity, the method provides for opening the mold 8, then moving each core 10 on an ejection stroke of the molded mount 1 from its molding position, in which it is arranged to bear against the imprint 9b of the rear part 8b of the mold 8 (figures 5, 5a, 5b), towards an ejected position at a distance from this molding position (figures 2, 3a, 3b, 6a, 6b).

[0042] To facilitate the demolding of the mount 1, the movement of a core 10 on its ejection stroke is arranged to induce a radial withdrawal of at least a portion 11a of the edge 11 in the ejected position, said withdrawal making it possible, in particular by being over a sufficient distance, to remove the mount 1 from the core 10 by disengaging the edge 11 from the groove 4.

[0043] The radial withdrawal of the edge 11 according to this method makes it possible to remove the mount 1 without significant mechanical stress on the groove 4, even of significant depth, which limits the risk of deterioration and / or breakage of said groove during demolding.

[0044] In particular, it is thus possible to produce a frame 1 with a groove 4 of sufficient depth to be able to house a module 4a in addition to the periphery of the lens 2a, while avoiding a risk of crushing said module and / or of said lens coming loose.

[0045] Advantageously, the height of the edges 11 of each core 10 is greater than 1 mm, in order to be able to place there an electronic module 4a comprising an RFID chip, an antenna and an electric wire for connecting these elements, in addition to the peripheral edge of an optical glass 2a.

[0046] Furthermore, to facilitate the essentially longitudinal withdrawal of the frame 1 molded with such dimensions of grooves 4, the radial withdrawal of each edge 11 is greater than 50%, in particular greater than 80%, and for example of the order of 100% of the height of said edge.

[0047] The edges 11 can be arranged to form grooves 4 with a bottom of substantially hemispherical geometry so that the elements making up the electronic module (chip, antenna, connection wire) fit the walls of said groove. In relation to [Fig. 1a], the groove 4 has a shape arranged to have a deep space adapted to receive the antenna 4a of an RFID chip received in a superficial space.

[0048] According to one embodiment, the method provides cores 10 each formed from at least one lobe 16a, 16b, 16c carrying a border portion 11a, said lobe being moved on the ejection stroke in a longitudinally converging direction to induce the radial withdrawal of said border portion.

[0049] In the embodiment shown, each core 10 has several lobes 16a, 16b, 16c, and in particular three lobes 16a, 16b, 16c, which are each moved on the ejection stroke in a longitudinally converging direction.

[0050] As shown more particularly in Figures 2, 3a, 3b, each lobe 16a, 16b, 16c is carried by an arm 17 which is actuated in translation along an inclined track, formed in the rear part 8b of the mold 8.

[0051] Each of the three lobes 16a, 16b, 16c has an internal edge 18 and an external edge 19 carrying the border portion 11a, the internal edge 18 being rectilinear and the external edge 19 having two sections connected by an elbow.

[0052] In relation to figures 5a and 5b, each core 10 comprises a lower lobe 16a whose external edge 19 has a substantially elliptical geometry, with a very slightly marked connecting bend, as well as two upper lobes 16b, 16c arranged to each form an upper corner of the corresponding opening 2.

[0053] In particular, each upper lobe 16b, 16c has an upper section which extends substantially horizontally, as well as a lateral section which forms with the corresponding upper section: - for the outer lobe 16b, an angle of the order of 90°; and - for the inner lobe 16c, an angle less than 90°, depending on the inclination of the inner lateral portion of the corresponding hoop 5.

[0054] As shown in Figures 5a and 5b, the central nut 14 of each core 10 is retracted longitudinally prior to the movement of said core on the ejection stroke of the mount 1.

[0055] Each core 10 comprises at least one insert 20 which is arranged around the nut 14, carrying an edge portion 11b which is displaced radially inwards by the longitudinal retraction of said nut.

[0056] To do this, the method provides in particular that the insert 20 is radially constrained on the nut 14, in order to allow, during the longitudinal retraction of said nut, a release of the movement of said insert, which can then perform a radial displacement towards the interior as said longitudinal retraction progresses.

[0057] In the figures, each core 10 comprises three inserts 20 distributed angularly around the central nut 14, together forming a substantially triangular geometry, each insert 20 comprising an external edge 21 on which the edge portion 11b is formed, as well as an internal edge 22 provided with a longitudinal groove 23, in which a complementary rail 24 formed on the central nut 14 is mounted in longitudinal sliding.

[0058] Advantageously, the inserts 20 are arranged between the nut 14 and the lobes 16a, 16b, 16c, in particular being interposed between two adjacent lobes 16a, 16b, 16c, so as to form the edge 11 of the corresponding core 10 by an alternating succession of edge portions 11a carried by a lobe 16a, 16b, 16c and edge portions 11b carried by an insert 20.

[0059] Thus, when the central nut 14 is deployed, it radially forces the inserts 20 outwards, so that said inserts come to bear between two adjacent lobes 16a, 16b, 16c to block their longitudinal sliding.

[0060] Similarly, when the central nut 14 is retracted rearwardly, it releases the radial movement of the inserts 20 inwardly, which makes it possible to interrupt the support exerted by said inserts on the adjacent lobes 16a, 16b, 16c. Thus, the lobes 16a, 16b, 16c can move longitudinally, so as to move the mount 1 on its ejection stroke.

[0061] As shown in the figures, the inserts 20 each have rectilinear lateral edges 25, and in particular complementary to the respective internal edges 18 of the adjacent lobes 16a, 16b, 16c, in order to form, at the front of the core 10, a continuous surface intended to come to bear against the corresponding platform 13, and thus to avoid the infiltration of injected material between said core and said platform during the molding of the frame 1.

Claims

Claims

1. A method of manufacturing a frame (1) comprising an opening (2) delimited by a continuous periphery (3) which is provided with a recessed groove (4) for fixing an element in said opening, said method providing: - closing a mold (8) comprising two parts (8a, 8b) which are arranged to form between them a molding cavity, one of said parts (8b) comprising a core (10) for forming the opening (2), said core having a peripheral edge (11) extending over a radial dimension in the cavity according to a geometry for forming the groove (4); - injecting a material into the cavity to mold the frame (1) with the edge (11) engaged in the groove (4); - opening the mold (8); - to move the core (10) on an ejection stroke of the molded mount (1) from its molding position to an ejected position located at a longitudinal distance from said molding position;said method being characterized in that the movement of the core (10) on its ejection stroke is arranged to induce a radial withdrawal of at least a portion (11a) of the edge (11) in the ejected position, said withdrawal making it possible to remove the mount (1) from the core (10) by disengaging the edge (11) from the groove (4).;

2. Method of manufacturing a mount (1) according to claim 1, characterized in that it provides a core (10) formed of at least one lobe (16a, 16b, 16c) carrying a border portion (11a), said lobe being moved on the ejection stroke in a longitudinally converging direction to induce the radial withdrawal of said border portion.

3. Method of manufacturing a mount (1) according to claim 2, characterized in that the lobe (16a, 16b, 16c) is carried by an arm (17) which is actuated in translation along an inclined track.

4. Method of manufacturing a mount (1) according to one of claims 2 or 3, characterized in that the core (10) has several lobes (16a, 16b, 16c) which are each moved on the ejection stroke in a longitudinally converging direction.

5. Method of manufacturing a frame (1) according to claim 4, characterized in that it provides a core (10) formed of three lobes (16a, 16b, 16c) each having an internal edge (18) and an external edge (19) carrying the border portion (11a).

6. Method of manufacturing a frame (1) according to claim 5, characterized in that the internal edge (18) is rectilinear, the external edge (19) having two sections connected by an elbow.

7. A method of manufacturing a mount (1) according to any one of claims 1 to 6, characterized in that it provides a core (10) comprising a central nut (14) which is retracted longitudinally prior to the movement of the core (10) on the ejection stroke.

8. A method of manufacturing a mount (1) according to claim 7, characterized in that it provides a core (10) comprising at least one insert (20) arranged around the nut (14), said insert carrying a border portion (11b) which is displaced radially inwards by the longitudinal retraction of said nut.

9. Method of manufacturing a mount (1) according to claim 8, characterized in that it provides that the insert (20) is radially constrained on the nut (14).

10. Method of manufacturing a mount (1) according to one of claims 8 or 9 when it depends on claim 4, characterized in that inserts (20) are arranged between the nut (14) and the lobes (16a, 16b, 16c).

11. Method of manufacturing a frame (1) according to claim 10, characterized in that it provides a border (11) formed by an alternating succession of border portions (11a) carried by a lobe (16a, 16b, 16c) and border portions (11b) carried by an insert (20).

12. Method of manufacturing a frame (1) according to any one of claims 1 to 11, characterized in that the radial withdrawal of the edge (10) is greater than 50%, and in particular greater than 80%, of the height of the edge (11).

13. Method of manufacturing a frame (1) according to any one of claims 1 to 12, characterized in that the height of the edge (11) is greater than 1 mm.

14. Eyeglasses comprising a frame (1) manufactured by implementing a method according to any one of claims 1 to 13, wherein an optical glass (2a) is fixed in the groove (4), said eyeglasses further incorporating a module (4a) which is fixed in a section of the said throat.

15. Glasses according to claim 14, characterized in that the module (4a) comprises an RFID chip connected to an antenna.

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