Method for decorating a timepiece component

Abstract

The present invention relates to a method for decorating a timepiece component (30), particularly a skeleton type watch dial. The component (30) comprises at least two different visual appearances, each visual appearance being the unique combination of surface finish and of a colour. The decoration method comprises the following steps: i) providing a component blank (10) having a first unfinished surface (10a), ii) creating on said first unfinished surface (10a) a first termination (12) possessing a first surface finish; iii) applying to the first termination (12) one or more layers of atoms so as to give the first termination a first colour (14); iv) creating a second termination comprising at least one breaking of a corner on the blank in order to form at least a bevel or at least a chamfer (18) having a second unfinished surface (18a), v) creating on said second unfinished surface (18a) a second termination (20) conferring a second surface finish, and vi) using electroplating, PVD or ALD, to deposit a metallic layer, preferably a layer of rhodium or of gold, on the second termination so as to give the second termination a second colour (22).

Description

Decoration process for a watch component technical field

[0001] The present invention relates generally to a method for decorating a component with multiple surface treatments. The method is particularly suitable for decorating a skeleton dial. The invention also relates to a timepiece comprising one or more watch components obtained using the decoration method, in particular a skeleton dial, a movement plate, one or more bridges, and / or an oscillating weight. State of the art

[0002] It is well known to decorate the surface of a watch component, such as a dial, bridge, or movement plate, to give it an interesting visual appearance. Specifically, the component's surface is worked to give it a certain texture, traditionally using processes such as brushing, perlage, satin finishing, or sandblasting. This approach involves a single machining step on the surface to be decorated in order to achieve the desired visual effect. This step can be combined with other steps for applying a thin layer of color using, for example, a PVD or electroplating process.

[0003] As an example, EP3220212 discloses a method for decorating a watch component, including a component preparation step, a corrosion protection step, and a coloring step to form an external colored decorative layer. CH711122, for its part, discloses a method for producing a coating decorative material presenting a white coloured surface obtained by a superposition of layers deposited by electroplating and CVD.

[0004] The decoration possibilities offered by these processes are limited to a restricted choice among a few well-known solutions, which does not allow for original decoration solutions.

[0005] Furthermore, known decoration processes must meet high quality standards so that the decorated component can withstand the stresses a watch, especially a sports watch, is likely to undergo, including shocks and accelerations. For this reason, the number of steps in known processes is reduced to limit production costs.

[0006] CH717065 discloses a manufacturing process for a watch component that allows for a wide range of variations, both technical and aesthetic. The manufacturing process involves machining the watch component to form a predominantly flat face and at least one side bordering the predominantly flat face. A chamfered edge is then machined at the junction between the predominantly flat face and the side, and a coating is applied directly to the raw surface of the chamfered edge.

[0007] One aim of the present invention is to propose a method of decorating a component of a timepiece, which allows the component to be given a wider range of different visual appearances.

[0008] Another objective of the present invention is to propose a method of decorating a component, in particular a watch dial, especially of the skeleton type, increasing the visual quality of the component.

[0009] An additional objective of the present invention is to provide a component, in particular a watch dial, especially of skeleton type, which is resistant to the stresses that a watch, especially a sports watch, may be subjected to. Brief summary of the invention

[0010] These goals are achieved in particular by a decoration process for a component having at least two different visual aspects. Each visual aspect being the unique combination of a surface finish and a color.The decoration process comprises the following steps: i) providing a blank of a component having a first rough surface; ii) making a first finishing on said first rough surface giving a first surface finish; iii) depositing one or more layers of atoms on the first finishing in order to give the first finishing a first color; iv) making at least one bevel on the blank in order to form at least one bevel or at least one chamfer having a second rough surface; v) making a second finishing on said second rough surface giving a second surface finish; and vi) depositing a metallic layer on the second finishing by electroplating, PVD or ALD, preferably a layer of rhodium or gold, in order to give the second finishing a second color.

[0011] According to one embodiment, the decoration process further comprises, between step iii) and step iv), a step consisting of applying a sacrificial protective layer over the first color. This sacrificial protective layer is removed after step vi).

[0012] Depending on one embodiment, the component is selected from a bridge, a plate, an oscillating weight, a dial with one or more windows and a skeleton-type dial. The dial may also include hour markers.

[0013] Depending on the form of embodiment, the watch component is made of copper alloy such as nickel silver, steel such as 316L steel, durnico, etc..., ceramic or precious metal such as gold, platinum or palladium.

[0014] Depending on the form of production, the first finish is obtained by sandblasting, microblasting, satin finishing (straight line, circular or spiral), bluing, hammering (manual or mechanical), guilloché, perlage, Côtes de Genève finish, hand engraving or polishing.

[0015] Depending on one form of realization, the second finish is obtained by straight satin finishing, planing, hand beveling, hand engraving or sandblasting.

[0016] According to one embodiment, step iii) consists of performing a PVD, ALD or electroplating treatment on the first termination.

[0017] Another aspect of the invention relates to a watch component, in particular a bridge, a plate, an oscillating weight, a dial with one or more apertures or a skeleton type dial obtained by the decoration process according to the invention.

[0018] In one embodiment, the component is a skeleton watch dial. This dial comprises dial sections and openwork sections defined by the contours of the dial sections. The dial sections preferably include flat surfaces extending in the plane of the dial, and bevels arranged around the openwork sections. These dial sections feature the first termination and the first color to create a first visual appearance. The dial's bevels feature the second termination and the second color to create a second visual appearance different from the first.

[0019] The invention also relates to a timepiece comprising the component obtained by the process according to the invention, in particular a skeleton dial of the aforementioned type. Brief description of the figures

[0020] Examples of implementation of the invention are given in the description illustrated by the accompanying figures, in which: Figures 1a to 1h schematically illustrate the different stages of the decoration process according to a preferred embodiment of the invention, and - Figure 2 illustrates a view of a skeleton-type watch dial obtained by the decoration process according to one embodiment of the invention. Examples of embodiments of the invention

[0021] According to a preferred form illustrated by steps 1a to 1g, the process includes a first step consisting of carrying out on a rough surface 10a of a blank 10 of a watch component, a first decoration operation in order to obtain a first termination 12 according to figure 1b.

[0022] For a skeleton dial illustrated in Figure 2, the process includes a step prior to the decoration operation, which consists of creating openwork sections 32 on a dial blank that is in the form of a solid disc with a rough surface. This operation is preferably carried out by a wire electrical discharge machining (EDM) process.

[0023] The blank 10 of the component, in particular the blank of the dial, is preferably made of copper alloys, especially nickel silver, capable of withstanding mechanical stresses, in particular the accelerations to which a sports watch may be subjected.

[0024] The first termination 12 is made on the rough surfaces of the dial portions surrounding the various openwork parts. These rough surfaces are preferably flat and typically extend to the surface of the skeleton dial.

[0025] The first finish 12 can be achieved through various decorative techniques, including sandblasting to create a certain roughness, and satin finishing, which involves covering the rough surface 10a of the blank 10 with a series of extremely fine, parallel lines—for example, straight, circular, or spiral lines—to catch the light from multiple angles. Other techniques can be used to work and structure the rough surface 10a of the blank 10 to give it a unique visual appearance, such as microblasting, guilloché work, perlage, Côtes de Genève finishing, manual or mechanical hammering, hand engraving, polishing, or bluing.

[0026] Blanks made of other materials can also be used, particularly steel, for example a low-carbon steel. type 316L to avoid corrosion, in precious metals, for example gold, platinum, palladium or even ceramic or titanium.

[0027] Once the first termination 12 is completed, a PVD (Physical Vapor Deposition) treatment is performed on the first termination 12 to deposit a thin film 14 of the desired color (Figure 1c), particularly black, under vacuum. An ALD (Atomic Layer Deposition) treatment or an electroplating treatment can also be performed instead of the PVD treatment to obtain the film 14. A sacrificial protective layer 16 (Figure 1d) is then applied to the entire dial. This protective layer can, for example, be an epoxy varnish to protect the film 14 from particles produced by the subsequent stages of the decoration process described below.

[0028] According to Figures 1e and 2, the skeleton dial is then machined to break the angles, for example, of the contours of the openwork sections 32 of the dial, to obtain bevels or chamfers 18 which notably reveal the base material (for example, nickel silver) that constituted the blank. These bevels or chamfers define the perimeter of the openwork sections 32 of the dial. A second finish 20 is then made on a rough surface 18a of the bevels or chamfers 18 (Figure 1f). Like the first finish 12, the second finish 20 can be obtained by various decorative techniques, including sandblasting, straight satin finishing, planing (for example, with a diamond point), hand beveling, or hand engraving.

[0029] Once the second termination 20 has been completed, a trimming operation is generally carried out on the dial to give the dial its final shape.

[0030] Referring to Figure 1g, the trimming operation is followed by an electroplating process performed on this second termination 20 to deposit a metallic film 22 of the desired color. This metallic film is, for example, a rhodium, gold, NAC, or black NAC film, black NAC being a deep anthracite-colored black coating.

[0031] The dial is then stripped of its protective epoxy varnish by applying a solvent to the entire surface. A decal application is then performed on the dial to create, among other things, the dial markers.

[0032] The decoration process can also be applied to watch components made of aluminum or aluminum alloy, and to watch components made of titanium or titanium alloy. For this type of material, an anodizing process can be used to give the first and second ends a primary and secondary color, respectively.

[0033] Although the above description primarily describes a decoration technique applied to a skeleton dial, the technique can be applied to any other watch component with a main surface, preferably flat, and one or more bevels or chamfers. This technique can therefore be applied, in particular, to a bridge, the mainplate of a watch movement, the oscillating weight of an automatic movement, or a dial with beveled or chamfered hour markers and / or apertures.

[0034] Furthermore, the coloring of the first and second endings 12, 20 can be carried out using the same method, albeit with a variation in implementation. For example, the first and second endings 12 f 20 can both undergo PVD / ALD treatment or galvanic treatment. However, care must be taken to ensure that the parameters of these treatments differ between the first and second terminations 12, 20.

[0035] Dial 30 in Figure 2 thus has two different visual aspects, each visual aspect being the unique combination of a surface condition and a color.

Claims

Demands 1. A method for decorating a component (30) for a watch part, the component having at least two different visual aspects, each visual aspect being the unique combination of a surface condition and a color, the decoration method comprising the following steps: i) providing a rough (10) of the component having a first rough surface (10a), ii) performing on said first rough surface (10a) a first finishing (12) conferring a first surface condition; iii) depositing on the first finishing (12) one or more layers of atoms in order to confer on said first finishing a first color (14);(iv) perform at least one bevel cut on the blank in order to form at least one bevel or at least one chamfer (18) comprising a second rough surface (18a), (v) perform on said second rough surface (18a) a second termination (20) conferring a second surface finish, and (vi) deposit on the second termination a metallic layer by electroplating, PVD or ALD, preferably a layer of rhodium or gold, in order to give said second termination a second color (22).

2. A decoration method according to claim 1, further comprising, between step iii) and step iv), a step consisting of applying a sacrificial protective layer (16) on the first color (14), said sacrificial protective layer (16) being removed after step vi).

3. Decoration method according to claim 1 or 2, wherein the component is selected from a bridge, a plate, an oscillating weight, a dial with one or more apertures and a skeleton type dial.

4. A decoration method according to any one of the preceding claims, wherein the component is made of steel, gold, platinum, palladium, ceramic or copper alloy, in particular nickel silver.

5. A decoration method according to any one of the preceding claims, wherein said first finish (12) is obtained by sandblasting, microblasting, satin finishing of the straight, circular or spiral type, bluing, hammering of the manual or mechanical type, guilloché work, perlage, Côte de Genève finishing, hand engraving or polishing.

6. A decoration method according to any one of the preceding claims, wherein said second finish (20) is obtained by straight satin finishing, planing, hand beveling, hand engraving, or sandblasting.

7. Decoration method according to any one of the preceding claims, wherein step iii) consists of carrying out a PVD, ALD or galvanic treatment on the first termination (12).

8. Watch component, in particular a bridge, a plate, an oscillating weight, a dial with one or more apertures or a skeleton dial obtained by the decoration process according to any one of the preceding claims.

9. A watch component according to the preceding claim, in the form of a skeleton-type watch dial (30), comprising dial portions and openwork portions defined by the contour of the dial portions, the dial portions comprising a surface and bevels or chamfers adjacent to the surface of said dial portions and arranged around the openwork portions, said surface comprising said first termination and said first color to assume a first appearance Visually, the bevels or chamfers include the second termination and the second color in order to give a second visual appearance different from the first visual appearance.

10. Timepiece comprising the timepiece component according to claim 8 or 9.

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