Method for producing an enamelled timepiece component

Abstract

The invention relates to a method for producing a timepiece component (10), characterised in that the method comprises the following steps: - providing (E1) a support member (1) comprising a bottom (4) and optionally a peripheral wall (2) and / or at least one stud (9); - forming (E2) an enamel coating (13) on the bottom (4) of the support member (1), the enamel coating (13) resting on the bottom (4) of the support member (1) and being optionally defined on all or part of its sides by a peripheral wall (2) of the support member (1) and / or at least one stud (9); - piercing and / or machining (in particular trimming and / or contouring) (E3) the enamel coating (13) as well as the bottom (4) of the support member (1) in a single operation by means of a laser, in particular a femtosecond laser, in order to form a continuous opening (15) passing through the entire thickness of the enamel coating (13) and all or part of the thickness of the bottom (4) of the support member (1) and / or to form a cut-out of the enamel coating (13) and the bottom (4) of the support member (1).

Description

[0001] Manufacturing process for an enamelled watch component

[0002] The invention relates to a method for manufacturing a watch component, in particular a dial. It also relates to a watch component as such obtained by implementing such a method. Finally, the invention also relates to a timepiece, in particular a watch, for example a wristwatch, comprising such a watch component.

[0003] When one wishes to produce a watch component, such as a dial, it is known to work the surface in order to achieve very high functional and aesthetic requirements. For this, it is known to use enameled surfaces, on which decorative and / or functional elements are added. However, existing processes for manufacturing such enameled components are not satisfactory, because they do not easily achieve the requirement of an enamel with a perfect visual appearance, for example without chips, cracks, or discontinuities, while having functional and decorative elements. The result is therefore often imperfect and / or obtained by a complex process.

[0004] Thus, an object of the invention is to propose a solution for manufacturing an enamelled watch component in a simple and efficient manner.

[0005] For this purpose, the manufacturing method comprises a watch component, characterized in that it comprises the following steps:

[0006] Provide a support comprising a base and optionally a peripheral wall and / or at least one pad;

[0007] Forming an enamel coating on the bottom of the support, this enamel coating resting on the bottom of the support and being optionally delimited on all or part of its sides by a peripheral wall of the support and / or at least one pad and / or at least one partition;

[0008] Drilling and / or machining (in particular routing and / or contouring) the enamel coating as well as the base of the support in a single operation using a laser, in particular a femtosecond laser, to form a continuous opening passing through the entire thickness of the enamel coating and all or part of the thickness of the base of the support and / or to form a cutout of the enamel coating as well as the base of the support.

[0009] The invention also relates to a watch component comprising a support, comprising a bottom and optionally a peripheral wall, and an enamel coating, this enamel coating resting on the bottom of the support and being optionally delimited on all or part of its sides by a peripheral wall of the support, characterized in that it comprises a continuous opening or a cutout passing through the enamel coating and at least partly through the bottom of the support.

[0010] The invention is more precisely defined by the claims.

[0011] These objects, characteristics and advantages of the present invention will be explained in detail in the following description of particular embodiments made without limitation in relation to the attached figures among which:

[0012] Figure 1 schematically represents a sectional view of a watch component during a first step of a first variant of a method of manufacturing the watch component according to a first embodiment of the invention.

[0013] Figure 2 schematically represents a sectional view of the watch component during a second step of the manufacturing process of the watch component according to the first variant of the first embodiment of the invention.

[0014] Figure 3 schematically represents a sectional view of the watch component during a third step of the manufacturing process of the watch component according to the first variant of the first embodiment of the invention.

[0015] Figure 4 schematically represents a sectional view of the watch component during a fourth step of the method for manufacturing the watch component according to the first variant of the first embodiment of the invention. Figures 5 to 8 schematically represent sectional views of a watch component for different steps of a second variant of the method for manufacturing the watch component according to the first embodiment of the invention.

[0016] Figures 9 to 13 schematically represent sectional views of a watch component for different stages of a method of manufacturing the watch component according to a second embodiment of the invention.

[0017] Figures 14 and 15 schematically represent sectional views of a watch component for different stages of a method of manufacturing the watch component according to a first variant of a third embodiment of the invention.

[0018] Figures 16 and 17 schematically represent sectional views of a watch component for different stages of a method of manufacturing the watch component according to a second variant of the third embodiment of the invention.

[0019] To simplify the description, the same references will be used for the same or similar elements in the different embodiments and their variants.

[0020] Figures 1 to 4 illustrate a first variant of a first embodiment of the invention. These figures illustrate a section, for example a longitudinal section, of a watch component according to different stages of its manufacture.

[0021] As illustrated in Figure 1, the manufacturing method comprises a first step consisting of providing E1 with a support 1, comprising a bottom 4 and a peripheral wall 2 which extends from the bottom 4, in a direction perpendicular to the bottom. The bottom 4 and the peripheral wall 2 delimit a housing 3. This support 1 is advantageously produced by a non-through machining step carried out in the support, to form the housing 3 while retaining a peripheral wall

[0022] 2, to produce enamelling using the champlevé technique, as will be specified later. Any other type of production of this support is possible. For example, it is possible as a variant to apply metal strips or wires to the flat surface of the bottom 4 of the support 1, which corresponds to the cloisonné enamelling technique.

[0023] The support is advantageously made of metal or a metal alloy, in particular an 18-carat gold alloy, or of technical ceramic, such as a technical ceramic based on zirconia or alumina, or sapphire, or glass. It could alternatively be made of any material that withstands the conditions of traditional enameling. The support is advantageously a single-piece and homogeneous structure.

[0024] Figure 2 illustrates a second step of the manufacturing process consisting of forming E2 an enamel coating 13 on the bottom 4 of the support, in the housing

[0025] 3. This enamel coating 13 therefore rests on the bottom 4 of the support 1 and is delimited on all or part of its sides by the peripheral wall 2 of the support 1.

[0026] This enameling step is traditional and can be carried out using any known process. For example, it can be a grand feu enamel. Any other type of enamel, glass-ceramic, or similar material could be used. The enamel used can be transparent or opaque, or even intermediately transparent, i.e., partially transparent. It can be any color. The enamel used for artistic enameling, as is the case in watchmaking, is generally available in powder form, which is dispersed in a liquid so that it can be applied, for example, with a brush. Once the enamel is applied, the enameled support is fired at a high temperature to melt the enamel and bond it to the surface of the support. The temperature and firing time depend on the type of enamel used and the support material.Typically, for “grand feu” enamels according to an exemplary embodiment, deposited on an 18-carat gold support, firing is carried out for 3 minutes at 800°C. After firing, gradual cooling is applied to avoid any risk of cracks. Generally, this enameling step is repeated several times, to form several superimposed layers and achieve the required thickness and quality of the enamel layer. The thickness corresponds substantially to the height of the peripheral wall 2, close to this wall. At the end of these steps, the enamel has a flat and smooth surface, except near the peripheral wall 2 where the enamel coating 13 has a domed portion 12 due to the formation of a meniscus, which forms a convex surface of the enamel coating and a thickness of the enamel coating overall slightly greater than the height of the peripheral wall 2 according to this embodiment.In the figures, the dimension of the domed portion is exaggerated to allow its visualization. In its flat central part, the enamel coating 13 therefore has a thickness greater than that of the peripheral wall 2. It is possible to carry out additional finishes, such as sanding or polishing, to obtain the desired texture and shine, and possibly smooth the domed portion 12, but such finishing steps are not obligatory according to the invention. In this exemplary embodiment, the enameling carried out follows the champlevé technique.

[0027] The manufacturing method then implements a third step consisting of piercing E3 the enamel coating 13 as well as the bottom 4 of the support by means of a laser, in particular a femtosecond laser. This step is carried out in a single operation and makes it possible to form a continuous opening 15 passing through the entire thickness of the enamel coating 13, outside a peripheral wall 2 of the support, or even a stud or a partition, and the entire thickness of the bottom 4 of the support 1 according to this first embodiment variant. According to an embodiment variant not shown, the opening 15 could not completely pass through the bottom 4 of the support 1, and form a blind hole in this bottom 4, in the continuity of the through opening of the enamel coating 13.Figure 3 represents the result obtained by this step E3, on which the resulting watch component 10 therefore comprises a visible enameled surface 14, formed by the enamel coating 13, having an opening 15 which extends over the entire thickness of the enamel coating 13 and also over the entire thickness of the bottom 4 of the support, and therefore finally over the entire thickness of the watch component 10. In this first embodiment, the manufacturing method comprises an additional step E4 consisting of fixing an added element 6 at the level of said opening 15. This added element 6 may be an applique, the function of which is decorative. Alternatively, it may for example be an index, a chaton or a counter.

[0028] The attachment of the attached element 6 can be done by any means, for example by riveting or gluing or welding.

[0029] According to the embodiment shown in Figure 4, the added element 6 comprises a head 7 positioned at the level of the visible surface 14 of the enamel coating and also comprises a foot 8 extending into said opening 15. According to this embodiment, the foot 8 passes through the entire opening 15 and protrudes beyond the bottom 4 of the support, for its fixing by riveting to the back of the dial. According to a variant not shown, the foot 8 might not extend over the entire length of the opening 15. It therefore extends at least partially into the opening 15. The drilling of the opening 15 is therefore adapted to the foot 8 to be received. For an applique foot, the opening 15 can be produced by drilling and have a cylindrical shape, of constant section between 0.15 mm and 1.2 mm in diameter, for example 0.18 mm in diameter.

[0030] As a note, the head 7 comprises a flat surface which rests on a flat surface of the visible surface 14 of the enamel coating 13. For this, the opening 15 is made in a flat and smooth portion of the enamel, that is to say outside the domed portion 12 near the peripheral wall 2, so that the entire head rests on a flat surface. Alternatively, an opening can be made in the enamel coating, sized so that the head 7 is housed therein totally or partially: for example, it can be ensured that the visible part of the head is on the same plane as the visible surface 14 of the enamel coating 13. The opening can have a variable section, with a dimension adapted to receive the head 7, then another smaller dimension adapted to receive the foot 8. Figure 4 thus represents a finished watch component 10.

[0031] Figures 5 to 8 illustrate a second variant of the first embodiment of the invention.

[0032] This example differs in that the support 1 is limited to the bottom 4. As shown in Figure 5, this bottom 4 is temporarily encircled by a removable strip which forms a temporary peripheral wall 2 around the perimeter of the bottom 4, making it possible to form a housing 3 for the implementation of the enameling. Indeed, during the enameling step, the enamel is in powder form before being placed in the oven, then in viscous form during its passage in the oven. The peripheral wall thus allows the enamel to be held on the bottom 4 during the passage in the oven. After finalization of the enameling, the encircling is removed, as shown in Figures 7 and 8. This embodiment is therefore based on enameling by a molding technique. More generally, any removable partition can be used.

[0033] In a variant not shown, the same result could be achieved by a step consisting of machining, in particular trimming or contouring, the periphery of the support 1 according to the first embodiment variant, preferably using a laser, so as to remove the peripheral wall 2.

[0034] According to another variant not shown, the enameling could be carried out without a side wall, directly on the bottom 4, for example by spraying. In such a variant, an additional sub-step of laser machining, for example laser trimming or laser contouring, could make it possible to make the edge of the component clear, in particular the edge of the enamel coating 13.

[0035] According to another variant not shown, the step consisting of drilling E3 the enamel coating 13 as well as the bottom 4 of the support to form the opening could be replaced by a step consisting of machining E3 the enamel coating 13 as well as the bottom 4 of the support, in cases where it would be desired to make larger openings than those mentioned previously. Drilling is distinguished from other machining operations (including trimming, contouring, etc.), due to the smaller size of the opening made. As a note, "contouring" refers to the fact of carrying out machining which consists of gradually removing material, and "trimming" refers to the fact of making a cut.

[0036] The first embodiment has been described with a single housing 3 delimited by a peripheral wall 2. However, the invention can be implemented on a support comprising several housings, each being delimited by a peripheral wall 2. This therefore applies to a partitioned support, comprising several housings receiving different enamel coatings.

[0037] Figures 9 to 13 illustrate a second embodiment of the invention, particularly suitable for a situation in which a large opening is desired, in particular larger than those described previously in relation to Figures 1 to 4, for example for fixing a kitten.

[0038] Figure 9 represents, like Figure 1, a first step of the manufacturing method consisting of providing E1 with a support 1, comprising a bottom 4 and a peripheral wall 2. Unlike Figure 1, this step keeps a stud 9 positioned at the location where the opening is desired. This stud 9 has a height substantially equal to the peripheral wall according to the embodiment shown, in the direction perpendicular to the bottom 4. In all cases, the dimension of this stud 9 in a plane parallel to the bottom 4 is chosen to be smaller than the section of the added element to be added. The support 1 thus comprises a housing 3 delimited by the bottom 4, the peripheral wall 2 and the stud 9.

[0039] Figure 10 represents the second step which consists of forming E2 an enamel coating 13 on the bottom 4 of the support, in the housing 3. This enamel coating 13 rests on the bottom 4 of the support 1 and is delimited on all or part of its sides by the peripheral wall 2 of the support 1, as well as by the stud 9. As a note, the enamel coating 13 may have curved portions near the walls, as in the first embodiment. The manufacturing method then comprises a third step consisting of making an opening 15. However, this second embodiment differs from the first embodiment in that this step comprises the following two sub-steps:

[0040] The first sub-step consists of drilling E31 an opening blank 17 in the stud 9, as well as in all or part of the thickness of the bottom 4. This sub-step is carried out in the material of the support 1 only, without directly touching the enamel coating 13. It can thus be carried out in a conventional manner, with ease and less risk than during an intervention on the enamel. Thus, this sub-step consisting of drilling E31 an opening blank 17 can be implemented by means of a laser, but also alternatively by any other traditional mechanical means making it possible to drill the material of the support 1. The dimension of the opening blank 17 is smaller than that of the stud 9, so that at the end of this sub-step, represented by FIG. 11, there remains a part of the stud 9 in contact with the enamel, which is therefore not impacted by this sub-step.

[0041] The second sub-step finalizes the opening 15 from the opening blank 17, and acts on the enamel coating 13. According to this second embodiment, this second sub-step consists of machining (here contouring) E32 with a laser the residual material of the stud 9, until it disappears completely, then progressively machining (here contouring) the enamel, to widen the opening, until reaching the final opening 15 having the desired dimension and shape to receive the kitten foot. The result is illustrated by figure 12, which corresponds to figures 3 and 8 of the first embodiment but with an opening 15 of larger section. As mentioned previously, contouring is a machining which consists of progressively removing material. As a note, this second embodiment is produced from a stud 9.The same principle could be applied directly to a partition of the support, for example separating two housings each filled with an enamel coating. Finally, the manufacturing method comprises a fourth step consisting of fixing E4 an added element 6 at the level of said opening 15. This added element 6 can be a chaton. It is secured to the back of the dial by riveting in this embodiment. Alternatively, it could be glued or welded, fixed by any means. Figure 13 represents the finalized watch component 10.

[0042] Figures 14 to 17 illustrate a third embodiment of the invention.

[0043] Figure 14 represents the watch component 10 obtained after making an opening 15, which can be formed by direct machining or by the same method as the second embodiment of the invention.

[0044] Figure 15 represents the watch component 10 after a fourth step of the method, consisting of fixing an added element 6. In this embodiment, the added element 6 is added by the face opposite the enamel coating 13, at the opening 15. According to the first variant of this third embodiment, it is simply fixed under the bottom 4 of the support, at the through opening 15, so that it is visible through this opening, from the visible face 14 of the enamel coating 13. The very clear “cutting profile” of the watch component, that is to say of the enamel coating 13 as well as of the bottom 4 of the support 1, allows a very attractive rendering of the assembly obtained. According to an exemplary embodiment, this added element 6 can be a counter. It can be secured according to the teaching of document EP3712713A1.

[0045] Figures 16 and 17 illustrate a second variant of the third embodiment of the invention.

[0046] Figure 16 corresponds to figure 14, after carrying out an additional sub-step consisting of producing a counterbore 18 from the face of the bottom 4 opposite the enamel coating 13, at the level of the opening 15.

[0047] Figure 17 represents the watch component 10 obtained by this second variant, after fixing an added element 6 at the level of the counterbore 18. This added element can be visible at the level of the enamel or at the level of the bottom 4, depending on the depth of the counterbore, so that two different renderings are possible. This added element can also be a counter.

[0048] All the embodiments described above could be combined with each other, an opening thus being able to be made in different ways, and in all cases by a step consisting of drilling and / or machining (in particular cutting and / or contouring) E3 at least a part of the enamel coating as well as at least a part of the support by means of a laser, in the same operation. This step can make it possible to form an opening within an enameled support, as described in detail, or to make a cut of an enameled support, in particular at its periphery, as described, but more generally to make any cut (for example by trimming). The invention has been described with the making of an opening, or a cut, but it can naturally be implemented to make several openings and / or several cuts.

[0049] The step of drilling and / or machining (in particular cutting and / or contouring) E3 can be carried out by starting with the front face of the component, i.e. the enameled face of the component, then continuing into the support, until passing through all or part of the support. Alternatively, the step of drilling and / or machining (in particular cutting and / or contouring) E3 can be carried out by starting with the rear face of the component, i.e. the support, then continuing towards the enameled face of the component, until passing through all or part of the enamel. The through or blind openings can be kept as such and contribute to the final aesthetics of the component. Alternatively, they can be used to install the foot of an added element, or all or part of an added element. Alternatively, the blind openings can be filled, totally or partially, with another material, for example a lacquer, or a varnish.

[0050] Enamel, such as that applied to a dial, does not tolerate thermal shocks and localized temperature differences well, which can lead to cracking. It might therefore be expected that laser machining would damage enamel and be an unsuitable process for this type of coating.

[0051] The technical problem is accentuated when machining the bi-material stack consisting of an enameled support, since there is both a difference in the reaction of these different materials under the impact of the laser and a difference in the coefficient of expansion of these materials. For example, in the case where the support is made of metal, it is advantageous to choose laser parameters that allow the metal to be machined, while preventing it from expanding. Indeed, since its coefficient of expansion is different from that of the enamel, there would be a risk of generating stresses at the interface between the metal and the enamel, and the latter could peel off and / or crack. For these reasons, it is usually chosen to carry out laser machining of two different materials with laser parameters specific to each of them, in two separate operations.Surprisingly, it was discovered by the invention that a femtosecond laser allows the ablation of both the enamel and the support without inducing defects such as cracks.

[0052] As a non-limiting example, the laser used may be a femtosecond laser in the infrared (IR), generating pulses with a wavelength of 1030 nm. More precisely, it may be a source with a power of 20 W delivering an energy of 40 pJ at a frequency of 500 kHz, with a pulse duration of the order of 300 fs. The fluence at the target is in this example 13.5 J / cm 2(for example for a beam diameter of 19.5 μm). In the invention, the crossing of the enamel and the support is done in a single operation, i.e. with the same equipment (without changing the machining means), and without the need to reposition the component between the treatment of the enamel and that of the support. Advantageously, the same set of laser adjustment parameters can even be developed to treat both the enamel and the support. However, as a variant, it may be the same operation with the same laser, the parameters of which are changed between the enamel and the support, in order to optimize the crossing of the enamel and that of the support (for example in order to limit the machining time). In the examples presented, a scanning technique can be used, which creates a positive draft of the order of 10°.To reduce or even eliminate this clearance, it is possible to use a drilling head or a precession system; the advantage of the latter is also to perform drilling or cutting with zero or even negative clearance.

[0053] Beyond the examples described, the laser may be an ultrashort pulse laser with durations of less than 10 ps, ​​advantageously less than 1 ps, ideally less than 500 femtoseconds. It may typically be a femtosecond or picosecond laser. The wavelength of the laser may be between 300 nm and 1100 nm, advantageously equal to 1030 nm or 515 nm or 343 nm. The energy per pulse at the focal point is advantageously less than 1 mJ, or even less than 0.5 mJ, or even less than 0.3 mJ, or even less than 0.1 mJ, or even less than 0.05 mJ. The beam diameter is less than or equal to 30 pm, advantageously less than or equal to 15 pm. The pulse frequency is advantageously less than or equal to 1 MHz, or even less than or equal to 500 kHz, or even less than or equal to 100 kHz. The parameters depend on the openings to be made and the materials to be engraved.

[0054] The invention has been described with examples including the fixing of an added element at an opening. However, the invention can also simply allow a cutting / trimming of an enameled support of a watch component, and / or to view an element through an enameled support of a watch component by making an opening or a cutting.

[0055] Thus, the invention relates more generally to a method of manufacturing a watch component, characterized in that it comprises the following steps:

[0056] Provide E1 with a support 1 comprising a base 4 and optionally a peripheral wall 2 and one or more pads 9;

[0057] Forming E2 an enamel coating 13 on the bottom 4 of the support 1, this enamel coating 13 resting on the bottom 4 of the support 1 and being optionally delimited on all or part of its sides by a peripheral wall 2 and / or at least one stud 9 of the support 1; Drilling and / or machining (in particular cutting out and / or contouring) E3 the enamel coating 13 as well as the bottom 4 of the support 1 in a single operation by means of a laser, in particular a femtosecond laser, to form a continuous opening 15 passing through the entire thickness of the enamel coating and all or part of the thickness of the bottom 4 of the support 1 or forming a cutout of the enamel coating 13 as well as the bottom 4 of the support 1.

[0058] The invention also relates to a watch component obtained by this manufacturing method. In the context of this invention, the watch component may be a watch dial, a bezel disc, a bezel, a case middle, or any other enameled watch component. It may be flat, or even domed (like certain dials), be truncated in shape (like certain bezels or certain bezel discs), or of any other shape.

[0059] The watch component comprises a back cover 4, and optionally a peripheral wall 2, and an enamel coating 13, this enamel coating 13 resting on the back cover 4 and being optionally delimited on all or part of its sides by a peripheral wall 2. The watch component comprises a continuous opening 15 or a cutout passing through the enamel coating 13 and at least partly through the back cover 4. The continuous opening 15 advantageously passes through the entire thickness of the enamel coating 13, outside a peripheral wall 2 of the support, outside a stud and outside a partition.

[0060] The thickness of the enamel coating 13 is advantageously between 0.10 mm and 0.40 mm, for example 0.25 mm. The bottom of the support has for example a thickness of 0.5 mm, the watch component thus having an overall thickness of around 0.75 mm.

[0061] More generally, the thickness of the support (in particular the bottom) is between 0.40 mm and 1.5 mm, particularly when this support represents a dial, or can even go beyond, up to 3 mm, or even up to 5 mm when the support represents a watch bezel, or even up to 10 mm, or even up to 20 mm, when the support represents a watch case. Similarly, several thicknesses of enamel are possible. The thickness of enamel is advantageously greater than or equal to 0.10 mm, or even greater than or equal to 0.2 mm, or even greater than or equal to 0.3 mm and / or less than or equal to 1.0 mm, or even less than or equal to 0.50 mm, or even less than or equal to 0.40 mm.The enamel thickness is advantageously included in this range of values ​​and can thus differ from one component to another or from one place to another in the component (for example due to housings of different depths; or because the enameling is carried out without partitions, so that the enamel thickness is not constant over the entire component).

[0062] According to several embodiments shown, the opening has a constant cross-section. Alternatively, a variable cross-section can be implemented in all embodiments. For example, an opening with a trapezoidal section of an angle less than 15°, preferably less than 10°, can be applied with a constant slope, constituting a draft. Its role is functional; this allows, for example, guidance of the foot of an added element or its attachment by a “swallowtail” system.Alternatively, a variable cross-section may correspond to different functional and / or decorative parts of the component: for example, laser machining may begin from the rear face of the component, to make a counterbore in the support, then an opening of diameter smaller than the counterbore, passing through the rest of the support and the enamel coating; for example again, laser machining may begin from the rear face of the component, to make a counterbore in the support and part of the enamel coating, then an opening of diameter smaller than the counterbore, passing through the rest of the enamel coating.

[0063] For a kitten, the opening 15 may be made by machining rather than drilling, so that the kitten's foot, which may be oblong in shape and 1.2 mm wide and 2 mm long, can be fitted.

[0064] To fix added elements such as a window or a counter to a dial, machining can be carried out to receive this element; typically, the opening can be rectangular or oblong; it can fit into a cylinder measuring more than 0.20 mm in diameter, for example between 0.20 mm and 40 mm in diameter; in practice, there is no upper limit to the size and shape of the opening or cutout made in the watch component.

[0065] The watch component may comprise an added element, fixed to the watch component at the level of said opening. This added element may be, for example, an index, an applique, a chaton, a counter, or a decorative element. Alternatively, any type of added element may be envisaged: it may be lacquered, enameled, decorated with an ornamental stone or mother-of-pearl, covered with a coating deposited for example by the galvanic technique, or PVD (Physical Vapor Deposition), or CVD (Chemical Vapor Deposition), or ALD (Atomic Layer Deposition), or PLD (Pulsed Laser Deposition). For example, it is possible to prepare an added counter (whose shape is that of the counterbore 18 in which it will be positioned) covered with a layer of enamel 6', which is machined (here contoured) to the diameter of the opening 15 in which it will be housed. In other words, at least part of the enamel layer 6' of the added element 6 may be located in the opening 15 and outside the counterbore 18.Such an embodiment is illustrated in Figure 17, where the added element 6 is a counter placed in a counterbore 18, covered with a layer of enamel 6' partially inserted into the opening 15 above the counterbore 18, allowing the surface of this layer of enamel 6' to be set back, in a hollow, relative to the visible surface 14 of the enamel coating 13 of the watch component.

[0066] The invention meets the desired objective and more generally presents the following advantages:

[0067] - The added elements are placed in an area without a wall, so that they are positioned in an area where the enamel is flat and smooth on the surface of the dial, without a meniscus due to the proximity of a wall;

[0068] - The surface of the enamel coating is smooth without having to be polished in the areas where the opening is envisaged (thanks to the absence of partitions); therefore, it is not necessary to add a polishing step before the formation of an opening;

[0069] - It is possible to choose added elements forming enameled decorations, with different appearances depending on the position on the dial plate. There may be enameled areas with a taut / smooth appearance, which coexist with areas with a domed appearance (near a wall), which is not the case if the enamel coating is polished after its deposition (it would then be smooth over its entire surface, eliminating any domed areas);

[0070] - This allows the enameling to be completed with the heat treatment step (the last of which allows the glaze), which in addition to the natural creation of a domed portion (which would be eliminated if the process were completed by polishing) gives shine to the enamel (which would be diminished if the process were completed by polishing);

[0071] - Carrying out the opening in a single operation avoids errors that would be obtained if two separate operations were implemented, respectively for the enamel and the support, due to inaccuracies during indexing;

[0072] - Furthermore, the invention occurs when the watch component is almost finished, which allows the added elements such as the appliques and indexes to be personalized in the last stage of the manufacturing process. The manufacturing processes of the different models of watch components, such as dials, therefore have the same stages up to the personalization which comes at the end of the chain, which is very advantageous;

[0073] - The opening or cutting operation using a laser surprisingly forms a clean wall, i.e. without any chipping in the enamel, or the start of cracks, and over the entire thickness of the watch component. Surprisingly, the use of a laser allows, in a single step, to drill / machine / contour / trim the enamel as well as its support, although the materials from which they are made show very different compositions and mechanical properties.

Claims

CLAIMS:

1. Method for manufacturing a watch component (10), characterized in that it comprises the following steps: Provide (E1) a support (1) comprising a base (4) and optionally a peripheral wall (2) and / or at least one pad (9); Form (E2) an enamel coating (13) on the base (4) of the support (1), this enamel coating (13) resting on the base (4) of the support (1) and being optionally delimited on all or part of its sides by a peripheral wall (2) of the support (1) and / or at least one pad (9); Drilling and / or machining (in particular cutting out and / or contouring) (E3) the enamel coating (13) as well as the bottom (4) of the support (1) in a single operation using a laser, in particular a femtosecond laser, to form a continuous opening (15) passing through the entire thickness of the enamel coating (13) and all or part of the thickness of the bottom (4) of the support (1) and / or to form a cutout of the enamel coating (13) as well as the bottom (4) of the support (1).

2. Method for manufacturing a watch component according to the preceding claim, characterized in that the step of drilling and / or machining (E3) comprises the use of the same laser continuously, optionally without modifying the parameters of the laser, to form the opening (15) or the cutout both in the enamel coating (13) and in the bottom (4) of the support (1).

3. Method for manufacturing a watch component according to one of the preceding claims, characterized in that the step of drilling and / or machining (E3) comprises making an opening (15) on a flat part of the enamel coating (13) outside a peripheral wall (2) of the support (1).

4. Method for manufacturing a watch component according to one of the preceding claims, characterized in that the support (1) is made of metal or metal alloy, in particular gold alloy, or technical ceramic, such as a technical ceramic based on zirconia or alumina, or sapphire, or glass.

5. Method for manufacturing a watch component according to one of the preceding claims, characterized in that said laser of the step consisting of drilling and / or machining (E3) is an ultrashort pulse laser with durations of less than 10 ps, ​​or even less than 1 ps, with a wavelength between 300 nm and 1100 nm, with energy per pulse of less than 1 mJ, or even less than 0.5 mJ, or even less than 0.3 mJ, or even less than 0.1 mJ, or even less than 0.05 mJ.

6. Method for manufacturing a watch component according to one of the preceding claims, characterized in that the step of drilling and / or machining (E3) produces an opening of constant cross-section over its entire length through the thickness of the watch component, in particular a cylindrical opening, and / or an opening of variable cross-section through the thickness of the watch component, in particular an opening with a trapezoidal cross-section, in particular with an angle of less than 15°, preferably less than 10°.

7. A method of manufacturing a watch component according to one of the preceding claims, the step of which consists in providing (E1) a support forming a stud (9) or a partition which extends from the bottom (4) over a thickness greater than or equal to the thickness of the enamel coating (13) to be deposited, and the step of which consists in drilling and / or machining (E3) is characterized in that it comprises a sub-step consisting in drilling (E31) the stud (9) or the partition forming a rough opening (17) of said opening (15) within said stud (9) or said partition, then a sub-step consisting in going around (E32) the enamel coating and / or the enamel coating and the bottom (4) of the support in the rough opening (17) until all the material of the stud (9) or the partition is removed and the opening (15) is formed at least within the enamel coating (13).

8. Method for manufacturing a watch component according to one of the preceding claims, characterized in that it comprises an additional step consisting of fixing (E4) an added element (6) at the level of said opening (15), in particular by riveting or gluing or welding, the added element (6) comprising a head (7) positioned at the level of the visible surface (14) of the coating in enamel (13) and comprising a foot (8) extending at least partially into said opening (15), and / or the added element (6) being secured under the lower surface of the bottom (4) of the support at the level of the opening (15) or in a counterbore (18) formed in the bottom (4) of the support (1) and optionally in the opening (15) within the enamel coating (13).

9. Watch component (10) comprising a support (1), comprising a bottom (4) and optionally a peripheral wall (2), and an enamel coating (13), this enamel coating (13) resting on the bottom (4) of the support (1) and being optionally delimited on all or part of its sides by a peripheral wall (2) of the support (1), characterized in that it comprises a continuous opening (15) or a cutout passing through the enamel coating (13) and at least partly through the bottom (4) of the support (1).

10. Watch component according to the preceding claim, characterized in that the opening is a cylindrical opening with a diameter of between 0.15 mm and 1.2 mm, or less than or equal to 0.50 mm, or less than or equal to 0.20 mm, or an opening inscribed in a cylinder with a diameter of between 0.20 mm and 40 mm, or less than or equal to 10 mm, or less than or equal to 5 mm, and / or in that the opening has a constant or variable cross-section over its entire length, and / or in that the watch component has a thickness of between 0.40 mm and 1.5 mm, or less than or equal to 1.5 mm, or less than or equal to 3 mm, or less than or equal to 5 mm, or less than or equal to 10 mm, or less than or equal to 20 mm, and / or in that the enamel thickness is greater than or equal to 0.10 mm, or greater than or equal to 0.20 mm. mm, or even greater than or equal to 0.30 mm and / or in that the enamel thickness is less than or equal to 1.0 mm, or less than or equal to 0.50 mm, or less than or equal to 0.40 mm.

11. Watch component according to claim 9 or 10, characterized in that the support (1) is made of metal or metal alloy, in particular gold alloy, or technical ceramic, such as a technical ceramic based on zirconia or alumina, or sapphire, or glass.

12. Watch component according to one of claims 9 to 11, characterized in that it comprises an added element (6), such as an index, an applique, a setting, a counter, or a decorative element, fixed to the watch component at the level of said opening.

13. Watch component according to the preceding claim, characterized in that the added element (6) comprises a head (7) resting on the visible surface (14) of the enamel coating (13) and a foot (8) extending into the opening (15), possibly secured at the level of the bottom (4) of the support (1), or in that the added element (6) is fixed under the bottom (4) of the support (1) at the level of said opening (15) or in a counterbore (18) so as to be visible by the opposite visible surface of the watch component (10).

14. Watch component according to one of claims 9 to 13, characterized in that it comprises a visible surface (14) of the unpolished enamel coating (13) comprising a first domed portion (12) near a peripheral wall (2) and a second flat portion further from the peripheral wall (2), the opening (15) being positioned in said second flat portion.

15. Watch component according to one of claims 9 to 14, characterized in that it is a watch dial and in that the support (1) is a dial plate, or a bezel, or a bezel disc, or a case middle.

16. Timepiece, characterized in that it comprises at least one timepiece component according to one of claims 9 to 15.

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