Manufacturing process for 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) having a recessed groove (4) for attachment, said method comprising: closing a mold (8) comprising two parts (8b) forming a molding cavity, one of the parts (8b) comprising a core (10) for forming the opening (2), said core having a peripheral rim (11) extending along a geometry for forming the groove (4); injecting a material to mold the mount (1) with the rim (11) engaged in the groove (4); opening the mold; moving the core (10) along a longitudinal ejection stroke of the mount (1) by inducing a radial retraction of a portion (11a) of the rim (11) in the ejected position, said retraction enabling the mount (1) to be removed from the core (10) by disengaging the rim (11) from the groove (4). Figure 2

Description

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

[0001] The invention relates to a method for 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 spectacles 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] A process for manufacturing such glasses is known from document US-2020 / 0338845, which involves: - closing a mold comprising two parts which are arranged to form between them a molding cavity, one of said parts comprising a core to form the opening, said core having a peripheral border extending over a radial dimension in the cavity following a geometry of throat formation; - inject a material into the cavity to mold the frame with the rim engaged in the groove; - open the mold; - move the core along 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 with a reduced depth, in particular less than 1 mm, since 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 was too deep.

[0005] Thus, this solution does not allow for the satisfaction of certain applications in which a module, in particular an electronic one, must be integrated into at least one mounting groove of an optical lens in a frame of glasses, in order to simplify and make the association of said module with said glasses more reliable.

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

[0007] To attempt to solve this problem, a method for manufacturing glasses is known from document WO-2018 / 005136 in which each peripheral groove includes a first section for fixing an optical lens and a second section, made deeper and slightly offset longitudinally from the first section, in which at least one wire can be fixed.

[0008] However, this solution is not entirely satisfactory, as it proves complex to implement since it requires forming groove sections in a differentiated way.

[0009] The invention aims to improve the prior art by proposing in particular a method for manufacturing a spectacle frame by molding which is simple and quick to implement, by allowing the formation of a groove adapted for the joint mounting of an optical lens 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 for manufacturing a frame comprising an opening delimited by a continuous periphery which is provided with a recessed 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 to form the opening, said core having a peripheral border extending over a radial dimension in the cavity following a geometry of formation of the throat; - 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 along 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 displacement of the core on its ejection stroke being arranged to induce a radial retraction of at least a portion of the rim in the ejected position, said retraction allowing the core mount to be removed by disengaging the rim from the groove.

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

[0013] Other features and advantages of the invention will become apparent from the following description, made with reference to the accompanying figures, in which:

[0014] [Fig. 1] schematically represents, in perspective from the front, a pair of spectacles obtained by a process according to an embodiment of the invention,

[0015] [Fig. la] 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 make a glasses frame according to an embodiment of the invention;

[0017] [Fig.3a] and

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

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

[0020] [Fig.5] schematically represents, in perspective viewed from the front, the rear part of the mold of the preceding figures, after the molding of 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 displacement of the core after molding;

[0023] [Fig.6a] and

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

[0025] In relation to these figures, a method for 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 is described below, as well as glasses comprising a frame 1 manufactured by implementing such a method.

[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 defining an opening 2 intended to be positioned opposite one eye of a wearer respectively, a groove 4 being formed continuously in the inner edge of each rim 5 to allow the attachment of one optical lens 2a respectively.

[0027] Furthermore, each rim 5 includes a tab 7a extending backwards from its outer edge, having come from the material with said rim, said tab being arranged to allow the attachment to it of a means of holding the glasses on the face of a wearer, for example a foldable arm 7b intended to come to rest against the temple and behind the adjacent ear of said wearer.

[0028] In the description, the terms of positioning in space are taken with reference to the position of the glasses in relation to the face of a wearer wearing said glasses. In particular: - the terms "back" and "front" relate to a position respectively facing the face and opposite the face; - the terms "exterior" and "interior" refer to arrangements respectively close to and far from the wearer's nose; - the terms “superior” and “inferior” are taken in reference to the position of the mount as represented in particular on [Fig.1].

[0029] Furthermore: - the terms "internal" and "external" are taken in reference to each opening 2 of the mount 1, and correspond to arrangements respectively close and far from said opening; - the term "longitudinal" refers to a direction extending from front to back, 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 lens 2a has a transparent wall arranged so that vision is seen through it when the glasses are coated by the wearer, for example by being made of 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 the ambient light.

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

[0032] This integration can, in particular, facilitate the tracking of eyeglasses, especially for their sale. Indeed, the integration of RFID chips in items intended for sale allows retail employees to more easily take inventory of said items, particularly at the checkout to remove them from the inventory after a sale to a customer, but also to more easily put said items back on the shelves, for example after customers have tried on said items without making a subsequent purchase.

[0033] In particular, the integration of such an RFID chip into 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 untimely removal of said chip by a customer, and thus to reduce the risks of theft of said glasses.

[0034] A process for manufacturing a frame 1 adapted to produce such glasses is now described.

[0035] The process involves closing a mold 8 comprising two parts 8a, 8b which are arranged to form a molding cavity between them, 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 border 11 extending over a radial dimension in the molding cavity, following a throat formation geometry 4.

[0036] In the embodiment shown, the mold 8 comprises two front parts 8a and rear parts 8b which each comprise an impression - respectively rear 9a and front 9b - intended to delimit together a molding cavity adapted to form a frame 1 with two rims 5 connected at their inner edges by a central nose bridge 6, and provided at their respective outer edges with a tab 7a for the attachment of a foldable arm 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 border 11 as described previously.

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

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

[0040] The process then involves 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 rim 11 of each core 10 engaged in the corresponding groove 4, formed by said molding with a hollow geometry which is complementary to the protruding geometry of said rim.

[0041] Finally, after hardening of the molding material injected into the cavity, the process 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 disposed in support against the impression 9b of the rear part 8b of the mold 8 (figures 5, 5a, 5b), to 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 retraction of at least a portion lia of the edge 11 in the ejected position, said retraction allowing, in particular by being over a sufficient distance, the mount 1 to be removed from the core 10 by disengaging the edge 11 from the groove 4.

[0043] The radial removal of the edge 11 according to this process allows the frame 1 to be removed without significant mechanical stress on the groove 4, even of significant depth, which limits the risk of damage and / or breakage of said groove during demolding.

[0044] In particular, it is possible to make a frame 1 with a groove 4 of sufficient depth to accommodate a module 4a in addition to the periphery of the lens 2a, while avoiding a risk of crushing said module and / or dislodging said lens.

[0045] Advantageously, the height of the edges 11 of each core 10 is greater than 1 mm, in order to be able to place on it an electronic module 4a comprising an RFID chip, an antenna and an electrical 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 molded mount 1 with such dimensions of grooves 4, the radial withdrawal of each border 11 is greater than 50%, in particular greater than 80%, and for example of the order of 100% of the height of said border.

[0047] The edges 11 can be arranged to form grooves 4 with a substantially hemispherical bottom geometry so that the components of the electronic module (chip, antenna, connecting wire) fit snugly against the walls of said groove. In relation to [Fig. 1a], the groove 4 has a shape arranged to provide a deep space suitable for receiving the antenna 4a of an RFID chip located in a shallow space.

[0048] According to one embodiment, the process provides for nuclei 10 each formed of at least one lobe 16a, 16b, 16c carrying a portion of border lia, said lobe being moved on the ejection race in a longitudinally convergent direction to induce the radial withdrawal of said portion of border.

[0049] In the embodiment shown, each nucleus 10 has several lobes 16a, 16b, 16c, and in particular three lobes 16a, 16b, 16c, which are each displaced along the ejection path in a longitudinally convergent 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 inner edge 18 and an outer edge 19 bearing the border portion 1la, the inner edge 18 being straight and the outer edge 19 having two sections connected by a bend.

[0052] In relation to figures 5a and 5b, each core 10 comprises a lower lobe 16a whose outer edge 19 has a substantially elliptical geometry, with a very slight 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 approximately 90°; and - for the inner lobe 16c, an angle less than 90°, depending on the inclination of the inner lateral portion of the corresponding ring 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 a portion of the rim 11b which is displaced radially inwards by the longitudinal retraction of said nut.

[0056] To achieve this, the method notably provides 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 make a radial displacement inwards 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 border 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 intercalated between two adjacent lobes 16a, 16b, 16c, so as to form the border 11 of the corresponding kernel 10 by an alternating succession of border portions 11a carried by a lobe 16a, 16b, 16c and border 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 rest between two adjacent lobes 16a, 16b, 16c to block their longitudinal sliding.

[0060] Similarly, when the central nut 14 is retracted rearward, it releases the radial movement of the inserts 20 inward, thereby interrupting the pressure 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 along its ejection stroke.

[0061] As shown in the figures, the inserts 20 each have straight lateral edges 25, which are 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 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 mount 1.

Claims

Demands

1. A method for manufacturing a frame (1) comprising an opening (2) delimited by a continuous periphery (3) which is provided with a groove (4) in a hollow for fixing an element in said opening, said method comprising: - 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 rim (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 rim (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 displacement of the core (10) on its ejection stroke is arranged to induce a radial retraction of at least a portion (1la) of the rim (11) in the ejected position, said retraction allowing the mount (1) to be removed from the core (10) by disengaging the rim (11) from the groove (4).

2. A method of manufacturing a mount (1) according to claim 1, characterized in that it provides for a core (10) formed of at least one lobe (16a, 16b, 16c) carrying a portion of the rim (lia), said lobe being moved on the ejection stroke in a longitudinally convergent direction to induce the radial retraction of said portion of the rim.

3. Method of manufacturing a frame (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 any one of claims 2 or 3, characterized in that the core (10) has several lobes (16a, 16b, 16c) which are each displaced along the ejection stroke in a longitudinally convergent direction.

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

6. Method of manufacturing a frame (1) according to claim 5, characterized in that the inner edge (18) is straight, the outer edge (19) having two sections connected by a bend.

7. Method of manufacturing a mount (1) according to any one of claims 1 to 6, characterized in that it provides for 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. Method of manufacturing a mount (1) according to claim 7, characterized in that it provides for a core (10) comprising at least one insert (20) disposed around the nut (14), said insert carrying a portion of rim (11b) which is displaced radially inwards by the longitudinal retraction of said nut.

9. Method of manufacturing a frame (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 frame (1) according to any 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 for a border (11) formed by an alternating succession of border portions (1a) 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 shrinkage of the rim (10) is greater than 50%, and in particular greater than 80%, of the height of the rim (11).

13. Method of manufacturing a frame (1) according to any one of claims 1 to 12, characterized in that the height of the rim (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 lens (2a) is fixed in the groove (4), said eyeglasses further incorporating a module (4a) which is fixed in a section of 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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