Method for manufacturing an exterior component

Abstract

The invention relates to a method for manufacturing an outer part (10), said method comprising the following steps:-producing a substrate (11) comprising a cavity (110); -producing, by moulding, a decorative element (12) made of a transparent polymer material with a reflective particulate filler wherein the decorative element (12) is formed with at least one decorative head (120) connected to the anchoring base (121); -fastening the decorative element (12) in the cavity (110) such that the anchoring base (121) cooperates with the cavity in a form-fitting manner.

Description

Technical Field

[0001] The present invention relates to the decoration of watches, jewelry or fashion items, and more particularly to the manufacture of an external component including one or more decorative elements similar to gemstones.

[0002] In the present context, the term "gemstone" refers indifferently to gemstones and semi-precious stones.

[0003] The method can advantageously be applied to any external component in the fields of watchmaking, jewelry or fashion items (e.g., leather goods, glasses, writing instruments or portable electronic devices). Background Art

[0004] In order to give an object a high added value, it is usually decorated with one or more gemstones inserted into a setting base. This greatly increases the perceived value of the object.

[0005] For both economic and ecological reasons, gemstones can be synthetically produced in the laboratory. In particular, compared to extracting natural gemstones by mining, producing gemstones in the laboratory consumes much less energy, and the price of synthetic stones is between 30% and 40% lower than that of equivalent natural stones.

[0006] Another advantage of synthetically produced stones is that their atomic structure is the same as that of naturally mined stones, and thus, they have the same visual appearance as naturally mined stones.

[0007] In order to further reduce the cost of producing this type of decoration, decorative elements that mimic the appearance of gemstones have been developed using polymer materials. However, although the manufacture of these decorative elements requires only a small fraction of the energy required to produce synthetically manufactured stones, their visual appearance is not suitable as a substitute for these stones.

[0008] Therefore, there is a need for a decorative element that is both inexpensive and energy-consuming to produce, while retaining the decorative elements appreciated in gemstones, such as luster or sparkle, thus giving the decorated object a similar appealing appearance as described above. Summary of the Invention

[0009] To this end, the present invention relates to a method for manufacturing an external component, the method comprising the following steps:

[0010] - Producing a substrate including a cavity,

[0011] - Producing, by molding, a decorative element made of a transparent polymer material having a filler of reflective particles, wherein the decorative element is formed to have at least one decorative head connected to an anchoring foot,

[0012] -Fasten the decorative element in the cavity such that the anchoring base cooperates with the cavity in a form - fitting manner.

[0013] In a particular embodiment, the invention may also include one or more of the following features, which must be considered individually or in any technically possible combination.

[0014] In a particular embodiment, the decorative element is produced by injection molding, wherein the anchoring base is formed by an injection gate.

[0015] In a particular embodiment, in the production step of the decorative element, the decorative element is produced in such a way that the anchoring base forms a support structure connecting a plurality of decorative heads together.

[0016] In a particular embodiment, during the production step of the decorative element, an opaque layer is deposited on the anchoring base by vacuum thin - film deposition, by spraying or selective dip - coating, or by injection molding.

[0017] In a particular embodiment, in the production step of the decorative element, the decorative element is produced in such a way that the decorative element includes decorative heads that are connected to an anchoring base specific to them.

[0018] In a particular embodiment, in the fastening step of the decorative element, the anchoring base is engaged in a part of the cavity having a complementary shape.

[0019] In a particular embodiment, in the fastening step of the decorative element, the anchoring base extends beyond the substrate through an end portion, and the end portion is deformed under the action of heat, i.e., it is deformed after being heated until it is soft enough to be deformed, so as to create a permanent bond between the decorative element and the substrate.

[0020] In a particular embodiment, in the production step of the decorative element, the polymeric material is a thermoplastic selected from polycarbonate, polyamide, or polymethyl methacrylate.

[0021] In a particular embodiment, in the production step of the decorative element, the polymeric material is selected to have a light transmission coefficient greater than 80% or 90% or even 95%.

[0022] In a particular embodiment, in the production step of the decorative element, the reflective particles consist of flakes of metallic material and / or nacre or glass particles with a reflective coating.

[0023] In a particular embodiment, in the production step of the decorative element, the mass proportion of the reflective particle filler is less than 1%.

[0024] In a particular embodiment, during the production step of the decorative element, a thin reflective layer is deposited on at least one face of the decorative element intended to rest against the cavity in the substrate.

[0025] In a particular embodiment, during the production step of the substrate, a reflective layer is deposited in the cavity.

[0026] In a particular embodiment, the thin reflective layer is deposited by a vacuum deposition method and is made of SiO2 or TiO2.

[0027] In a particular embodiment, when the decorative element is molded, the walls of the mold intended to form the decorative head have a mirror-polished surface finish.

[0028] In a particular embodiment, the method comprises the step of polishing the decorative head so that its faces have a mirror-polished surface finish.

[0029] In a particular embodiment, during the production step of the decorative element, a photoluminescent particulate filler is incorporated into the polymeric material in a mass proportion of less than 1%.

[0030] In a particular embodiment, during the production step of the decorative element, once the decorative element has been obtained by molding, a thin layer of photoluminescent material is deposited on the face of the head intended to rest against the cavity in the substrate.

[0031] The invention also relates to an external component produced by the method as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] With reference to the accompanying drawings, other features and advantages of the invention will become apparent from the following detailed description given by way of example and in no way limiting, in which:

[0033] - Figure 1 shows the production step of the decorative element of the method according to a first exemplary embodiment of the invention;

[0034] - Figure 2 shows the decorative element obtained after performing the steps in Figure 1 ;

[0035] - Figure 3 shows the step of fastening the decorative element to the substrate;

[0036] - Figure 4 shows the production step of the decorative element of the method according to an alternative of the first exemplary embodiment of the invention;

[0037] - Figure 5 illustrates the steps of producing a decorative element according to a second exemplary embodiment of the present invention;

[0038] - Figure 6 and Figure 7 illustrates the steps of fastening a decorative element to a substrate in a specific form of a second exemplary embodiment of the present invention;

[0039] - Figures 8 to 10 illustrates the steps of fastening a decorative element to a substrate in another specific form of a second exemplary embodiment of the present invention.

[0040] It should be noted that, for clarity, the drawings are not necessarily drawn to scale. Detailed Description of the Invention

[0041] The present invention relates to a method for manufacturing an external component 10, such as a dial, flange, crown or bezel of a watch. The method includes steps of producing a substrate 11 and a decorative element 12, followed by a step of fastening the decorative element 12 to the substrate 11 to form the external component 10. These steps are described in detail below.

[0042] During the implementation of the method according to the present invention, the substrate 11 is produced in such a way that it includes a cavity 110 intended to receive the decorative element 12. The substrate 11 can be made of any suitable material, such as metal, ceramic or polymeric material. It should be noted that although the substrate 11 may have a plurality of cavities 110, for clarity, it is described herein and in the drawings with a single cavity 110.

[0043] In particular, the cavity 110 may have a constant cross-section, as Figure 3 shown, or may have a proximal portion 111 leading to the external face 112 of the substrate 11 intended to be visible to the user, and extend with a distal portion 113 having a reduced cross-section, as Figures 6 to 10 shown.

[0044] The cavity 110 can be a blind cavity or a through cavity. In particular, in Figure 3 , Figure 6 and Figure 7 , the cavity 110 is shown as a blind cavity, and in Figures 8 to 10 , the cavity 110 is shown as a through cavity that leads to the internal face 114 of the substrate 11 opposite to the external face 112 via its distal portion 113.

[0045] As Figure 1 and Figure 5As shown in the figure, the decorative element 12 is produced as a single piece by molding, without any specific chronological order with respect to the steps of producing the substrate 11. It is made of a transparent polymer material, such as a thermoplastic selected from polycarbonate, polyamide or poly(methyl methacrylate).

[0046] The decorative element 12 advantageously aims to have reflective particulate fillers. These reflective particles help to increase the refractive index of the decorative element 12 and increase its reflectivity, so as to make its appearance closer to that of a gemstone. The reflective particles can consist of metallic materials and / or flakes of nacre, and their mass ratio is generally less than 1%. In addition, the polymer material is selected to have a light transmission coefficient greater than 80% or 90% or even 95%, so that the visual appearance of the decorative element 12 tends to be as similar as possible to the visual appearance of a gemstone.

[0047] The decorative element 12 is formed to have at least one decorative head 120 connected to an anchoring base 121, as shown in the drawings. Preferably, the decorative element 12 is produced by injection molding, and the anchoring base 121 is formed by all or part of an injection sprue, as Figure 1 and Figure 5 shown in. Thus, the anchoring base 121 is cylindrical in shape and can have a cross-section that is circular, oval or polygonal, etc.

[0048] In Figures 1 to 3 the first exemplary embodiment shown in, the decorative element 12 is produced such that the anchoring base 121 forms a support structure that connects a plurality of decorative heads 120 together. In particular, as can be seen in Figure 2 , in this case, the anchoring base 121 can have an annular shape, and the decorative heads 120 are evenly distributed around the axis of rotation on this base.

[0049] In this exemplary embodiment, the method can include the following steps: depositing an opaque layer on the anchoring base 121 in order to visually isolate the transparent decorative heads. Preferably, the opaque layer is configured such that it has the same visual appearance as the outer face 112.

[0050] The opaque layer can be deposited on the anchoring base by vacuum thin-film deposition, by spraying or selective dip coating, or can be deposited by injection molding during the step of producing the decorative element 12. In particular, as Figure 4 shown in, the opaque layer can be double injection molded with the decorative head 120 and the anchoring base 121. The opaque layer can be made of the same polymer material but with an opaque filler, such as an opaque filler of a given color.

[0051] In Figures 5 to 10In the second exemplary embodiment shown, the decorative element 12 is produced such that it comprises a single decorative head 120 which is connected to an anchoring base 121 specific thereto.

[0052] Preferably, in the step of producing the decorative element 12, a thin reflective layer is deposited on at least one face of the decorative element 12 intended to rest against the cavity 110 in the substrate 11. Alternatively, in the step of producing the substrate 11, a reflective layer is deposited in the cavity 110. For example, the thin reflective layer can be deposited by a vacuum deposition method and is made of, for example, SiO2 or TiO2.

[0053] Advantageously, the wall of the mold intended to form the decorative head 120 has a mirror-polished surface finish such that the face of the decorative head 120 also has a mirror-polished surface finish. Alternatively, the method can include a step of polishing the decorative head 120 such that its face has a mirror-polished surface finish. This feature increases the transparency of the decorative head 120.

[0054] Another feature of the present invention that enables an increase in the attractiveness of the visual appearance of the decorative element 12 consists in incorporating a photoluminescent particulate filler in a proportion of less than 1% by mass into the polymer material during the step of producing the decorative element 12. Alternatively or additionally, a thin layer of a photoluminescent material can be deposited on the face of the head intended to rest against the cavity 110 in the substrate 11.

[0055] Once the substrate 11 and the decorative element 12 have been produced, the decorative element 12 is fastened in the cavity 110 in the substrate 11. In particular, during this step, the anchoring base 121 cooperates with a part of the cavity 110 having a complementary shape.

[0056] More specifically, during the fastening step, the anchoring base 121 is engaged in the cavity 110 until the decorative element 12 stops moving, for example via its decorative head 120. The decorative element 12 can be fastened in the cavity 110 by bonding the base inside the cavity 110, for example when the cavity is a blind cavity, as Figure 7 shown.

[0057] Alternatively, if the cavity 110 is a through cavity, the anchoring base 121 can extend beyond the substrate 11 via an end portion 122, as Figure 9 shown. This end portion 122 is deformed under the action of heat, for example by extrusion, i.e. after being heated to soften the material, in order to produce a radial lip of the material forming an axial stop, as Figure 10 shown. This axial stop holds the decorative element 12 in place in the cavity 110. It goes without saying that when the end portion 122 of the decorative element 12 is deformed, the decorative element 12 is subjected to a force opposite to the force required to extrude the material of the end portion 122.

[0058] More generally, it should be noted that the embodiments and examples considered above are described by way of non-limiting examples, and thus other alternatives are possible.

[0059] For example, in the drawings, the decorative head 120 is shown as having facets, cut planes, a crown, and a pavilion in a manner similar to a cut gemstone, but they may have different appearances.

Claims

1. A method for producing an exterior component (10), characterized in that The method comprises the following steps: - producing a substrate (11) comprising a cavity (110), - producing by moulding a decorative element (12) made of a transparent polymer material with a reflective particle filler, wherein said decorative element (12) is formed with at least one decorative head (120) connected to an anchoring base (121), - Fastening the decorative element (12) in the cavity (110) such that the anchoring base (121) cooperates with the cavity in a form-fitting manner.

2. The method according to claim 1, wherein: The decorative element (12) is produced by injection molding, wherein the anchoring base (121) is formed by an injection gate.

3. The method according to any one of claims 1 or 2, wherein: In the production step of the decorative element (12), the decorative element is produced in such a way that the anchoring base (121) forms a supporting structure connecting a plurality of decorative heads (120) together.

4. The method according to claim 3, wherein: During the production step of the decorative element (12), an opaque layer is deposited on the anchoring base (121) by vacuum thin-film deposition, by spraying or selective dipping, or by injection molding.

5. The method according to any one of claims 1 or 2, wherein: In a production step of the decorative element (12), the decorative element is produced in such a way that the decorative element (12) comprises a decorative head (120) connected to an anchoring base (121) specific thereto.

6. The method according to claim 5, wherein: During the step of fastening the decorative element (12), the anchoring base (121) engages in a portion of the cavity (110) having a complementary shape.

7. The method according to claim 5, wherein: During the step of fastening the decorative element (12), the anchoring base (121) extends beyond the substrate (11) by means of an end portion (122) which is deformed under the action of heat in order to produce a permanent bond between the decorative element (12) and the substrate (11).

8. The method according to any one of claims 1 or 2, wherein: In the production step of the decorative element (12), the polymer material is a thermoplastic selected from polycarbonate, polyamide or polymethyl methacrylate.

9. The method according to any one of claims 1 or 2, wherein: During the production step of the decorative element (12), the polymer material is selected to have a light transmission coefficient greater than 80%.

10. The method according to any one of claims 1 or 2, wherein: In the production step of the decorative element (12), the reflective particles consist of flakes of metallic material and / or mother-of-pearl.

11. The method according to any one of claims 1 or 2, wherein: In the production step of the decorative element (12), the mass proportion of the reflective particle filler is less than 1%.

12. The method according to any one of claims 1 or 2, wherein: In a step of producing the decorative element (12), a thin reflecting layer is deposited on at least one face of the decorative element (12) intended to lie facing the cavity (110) in the substrate (11).

13. The method according to any one of claims 1 or 2, wherein: In the step of producing the substrate (11), a reflective layer is deposited in the cavity (110).

14. The method according to claim 12, wherein: The thin reflective layer is deposited by a vacuum deposition method and is made of SiO 2 or TiO 2 .

15. The method according to any one of claims 1 or 2, wherein: When the decorative element (12) is moulded, the walls of the mould intended to form the decorative head (120) have a mirror-polished surface finish.

16. The method according to any one of claims 1 or 2, comprising the following steps: The decorative head (120) is polished so that its surface has a mirror-polished surface finish.

17. The method according to any one of claims 1 or 2, wherein: During the production step of the decorative element (12), photoluminescent particulate filler is incorporated into the polymer material in a proportion of less than 1% by mass.

18. The method according to any one of claims 1 or 2, wherein: In a production step of the decorative element (12), once the decorative element (12) is obtained by molding, a thin layer of photoluminescent material is deposited on the face of the head intended to rest facing the cavity (110) in the substrate (11).

19. External component (10) produced using the method according to any one of claims 1 to 18.

Images