Lightweight and robust watch parts

Abstract

A component, particularly a watch component, comprising at least one porous core comprising or based on a first material having a density of 80% or less, more precisely 60% or less, or more precisely 50% or less of the density of a first fixed material, and a surface coating comprising at least one layer having a density greater than that of the at least one porous core.

Description

Technical Field

[0001] The present invention relates to watch parts, particularly external watch parts, and more generally to any other parts. The present invention also relates to watches, particularly wristwatches, comprising at least one such watch part. The present invention also relates to a method for manufacturing such watch parts.

Background Art

[0002] Watch parts, more particularly external watch parts, must have a number of, possibly conflicting, mechanical properties. The required properties are - Lightness, which makes wearing the watch comfortable, - A very attractive appearance that is free of defects and compatible with the aesthetic requirements of high-end watches, - Robustness to resist the external stresses experienced by the watch so that the watch part maintains the same appearance for a long time, and more generally all of its mechanical properties for a long time. It may be.

[0003] In practice, existing solutions reflect a compromise between these properties. Generally, watch parts are manufactured in bulk from materials that can be lightweight and hard. However, existing solutions have limitations and there is a need to identify new solutions to optimize the properties and / or appearance of watch parts.

Summary of the Invention

Problems to be Solved by the Invention

[0004] For this reason, the aim of the present invention is to provide a solution for obtaining a lightweight and robust watch part, particularly an external watch part, in an improved manner compared to the prior art.

Means for Solving the Problems

[0005] Therefore, the present invention proposes a watch component comprising a shell having a three-dimensional shape defining a cavity, wherein the shell has a degree of porosity of 0.5% or less, more preferably 0.1% or less, more preferably 0.05% or less, and more preferably 0.01% or less, the shell is not closed such that all or part of its cavity opens in a direction toward the interior of the watch, and the watch component includes a reinforcing structure extending to all or part of the cavity, the reinforcing structure forming a lattice or mesh network, and the shell and the reinforcing structure forming an integrated, one-piece cast structure.

[0006] The present invention also proposes a method for manufacturing a watch component, comprising the step of additive manufacturing a shell having a three-dimensional shape defining a cavity, wherein the shell has a degree of porosity of 0.5% or less, more precisely 0.1% or less, more precisely 0.05% or less, and more precisely 0.01% or less, and the shell is not closed, and the simultaneous additive manufacturing of a reinforcing structure extending to all or part of the cavity, wherein the reinforcing structure forms a self-supporting network that enables the manufacture of a grid or mesh network by adding material, in particular without the need for sacrificial support elements.

[0007] The present invention is defined more specifically by the claims.

[0008] The object, features, and advantages of the present invention will be described in detail in the following description of certain embodiments, which are given as non-limiting embodiments with reference to the accompanying drawings. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows a perspective view of the body according to one embodiment of the present invention. [Figure 2] Figure 2 shows a perspective view of a cross-section of the body on a vertical plane according to this embodiment of the present invention. [Figure 3]Figure 3 shows a top view of a horizontal cross-section of the body according to this embodiment of the present invention. [Figure 4] Figure 4 is an enlarged perspective view showing the details of the reinforcing structure of the torso according to this embodiment of the present invention. [Figure 5] Figure 5 shows a cross-sectional view of the corner of the body according to this embodiment of the present invention on a vertical plane. [Figure 6] Figure 6 shows a side view of the torso of a modified embodiment of the present invention. [Figure 7] Figure 7 shows a perspective view of a clock including the body of one embodiment of the present invention. [Figure 8] Figure 8 shows a cross-sectional view of a watch, including the case and bezel, on a vertical plane, according to one embodiment of the present invention. [Figure 9] Figure 9 shows a partial perspective view of the bezel of one embodiment of the present invention. [Modes for carrying out the invention]

[0010] The present invention relates in particular to watch components, especially external watch components, such as a case that can be positioned around or constitutes the perimeter of a watch. Thus, such watch components include a first part oriented toward the interior of the watch, particularly toward the volume containing the watch movement, and a second part oriented toward the exterior, particularly intended to be seen from the outside of the watch. The adjectives “interior” and “exterior,” as defined above, will hereafter be used for watch components considered independently of the watch, in relation to their intended location within the watch.

[0011] Furthermore, the adjective “horizontal” is conventionally used for any direction within the horizontal plane defined by the plane of the watch case back and / or watch glass, or, if the case back and / or watch glass are not perfectly flat, within the plane tangent to these elements. This horizontal plane thus corresponds to the plane of the watch. The adjective “vertical” is used to specify a direction perpendicular to the horizontal plane. The two adjectives “horizontal” and “vertical” are used for watch components considered on the outside of the watch, referring to their predetermined position within the watch. The “height” of a component is considered in relation to the vertical direction.

[0012] To further clarify, the adjectives “lower” and “upper” are used in relation to the vertical direction, with the case back of a watch being located in the lower position of the watch, and the watch glass being located in the upper position of the watch. The two adjectives “lower” and “upper” are also used for watch components considered on the outside of the watch, in relation to their predetermined position within the watch.

[0013] The expression "based on material" should be noted as meaning that the majority consists of the material, and in particular at least 50% by weight of the material. In all cases, where a specific material is mentioned, alternative embodiments based on that specific material, but using different, unspecified materials, are possible. Similarly, the simplified expression "part" is used to specify watch parts, as well as nearly completed watch part blanks, which are a misuse of language. The present invention is described more specifically in the context of external watch parts, but may be used for any other watch part. For this purpose, a part may take the form of a case as described above, but may also take the form of links in a metal bracelet, or plates and bridges in a watch movement.

[0014] The concept of the present invention is to propose a watch component in which the structure, or the blank of the structure, mainly comprises a shell and a reinforcing structure that forms a grid network (or mesh network), particularly a network of alternating voids and partitions or reinforcements, particularly partitions or reinforcements that join or intersect and / or contact each other. In particular, the reinforcing structure may include a number of close partitions that define an overall porous structure with small gaps between the partitions, the partitions contacting each other, extending across the volume of the cavity, and in particular assuming the three-dimensional shape of the shell, contacting at least three distinct areas of the internal surface of the shell within a coplanar portion and / or three areas of a distinct plane. In particular, the partitions may contact the upper and lower surfaces of the shell and at least one intermediate surface between the upper and lower surfaces. The shell forms a non-porous surface that constitutes, for example, the external surface of the watch component, defining a cavity that opens inward. The reinforcing structure is housed within the cavity of the shell. Therefore, the reinforcing structure is porous and lightweight, yet possesses sufficient mechanical properties to support the mechanical stresses that the watch components experience during use. The shell provides the necessary resistance while simultaneously achieving a high-quality aesthetic appearance.

[0015] Figures 1 to 5 illustrate a watch component 1 according to one embodiment of the present invention, which is the case. The case has a traditionally overall annular shape, defining a central volume 11 intended to house a watch movement. The structure of the case can be seen more specifically in Figure 2. The case includes a three-dimensional shell 2, which in particular forms the outer periphery of the case. The case includes a slightly curved, substantially vertical outer wall that extends inward at two ends, which are the lower and upper ends, by folds (or edges) in the horizontal plane that form the upper and lower surfaces of the case. These folds extend sufficiently inward to advantageously form an upper assembly surface 18 that receives the watch glass 9 and a lower assembly surface 17 that receives the case back 8, respectively. Thus, the shell has a cross-section that is U-shaped (or C-shaped) overall in its lateral aspect. This shape defines a cavity portion 12 of the case enclosed by the shell 2, which opens inward, i.e., toward the central volume 11. The cavity portion 12 has a substantially annular overall shape. In a modified embodiment, the shell may further include a rim extending from the vertical outer wall of the shell toward the interior of the cavity portion, particularly at the height of the central portion, taking into consideration the height of the wall. In further modifications, there may be multiple rims.

[0016] The shell 2 is preferably a solid, integrally cast, or even a continuous, unbounded material. Alternatively, the shell may comprise an assembly of several separate parts assembled by any mechanical and / or chemical means, such as bonding or welding. For example, the lower assembly surface 17 and / or upper assembly surface 18 may be parts of two separate parts. The shell 2 may have a degree of porosity of 0.5% or less, or 0.1% or less, or 0.05% or less, or 0.01% or less. Thus, the shell 2 forms an external surface 19, particularly a visible surface, which may have a non-porous, attractive appearance, and preferably a continuous appearance.

[0017] The body further includes a reinforcing structure 10 disposed in the cavity portion of the shell 2. The reinforcing structure contacts different walls of the shell 2. Thus, the reinforcing structure forms a support element. The reinforcing structure 10 is designed to withstand mechanical stresses exerted on the shell 2, especially those occurring during the assembly and / or wearing of the watch, and especially impacts.

[0018] The shell 2 and the reinforcing structure 10 actually form an integrated, one-piece casting structure. Thus, there is no physical boundary and no physical discontinuity between the two sub-elements, and the shell and the reinforcing structure are abstractly distinguished by their different shapes and functions. Further, the cavity portion of the shell is an abstract result defined without the reinforcing structure, and in reality, in the completed watch part, considering the presence of the reinforcing structure, there is no cavity portion. The shell and the reinforcing structure cannot be physically separated into two separate parts. The watch part as a whole includes a non-porous shell that at least partially surrounds a porous reinforcing structure that forms the core of the watch part, i.e., occupies the central volume of the watch part, and opens onto at least the inner surface of the watch part and, in a variant, also onto some areas of its outer surface. The "porous reinforcing structure" means a reinforcing structure that includes an alternation of cavities and partitions. Thus, the holes do not have to be fine and may be visible to the naked eye considering the scale of the watch part. Advantageously, the holes remain small enough so as not to form cavity portions within the watch part. Even in the case of holes visible to the naked eye, the reinforcing structure preferably appears to be a porous element that includes partitions occupying the cavity portions and that do not show any cavity portions. The porous reinforcing structure thus takes the form of a lattice network that includes an alternation of cavities and partitions or reinforcements, especially crossovers of partitions or reinforcements.

[0019] In this embodiment, the reinforcement structure 10 advantageously includes juxtaposed elements 13 in which homogeneous and repetitive organisms forming a three-dimensional lattice network are arranged. In the illustrated example, the reinforcement structure 10 includes a first element 13a which here has an elliptical, oval or almond shape. In particular, the first element 13a includes partitions 131a, 132a whose ends are joined or cross, respectively, advantageously at the height of the upper and lower surfaces of the shell. The first element 13a is intended to absorb forces and structurally reinforce the body or the shell of the body when a load is applied, for example when a small watch strap connected to the body is pulled, or when assembling elements on the body, especially when driving a bezel into the body. The reinforcement structure 10 may further include a second element 13b which serves as a spacer, the partitions 131b, 132b, 133b of which cross over and thus advantageously form intersections or stars inside part or all of the first element 13a, in which case each partition 131b, 132b, 133b may extend from the inner surface 130a of the first element 13a and the partitions 131b, 132b, 133b cross inside the central area 130b of the element 13a. The element 13b may in particular absorb impacts or force points and / or very local forces at the height of the shell of the body. Such a reinforcement structure 10 can be seen particularly in FIG. 4.

[0020] For this reason, in an advantageous configuration, the reinforcement structure 10 may include a continuity of the first element 13a with the second element 13b associated with it. Such a configuration is preferred, for example, at the height of the side of the body or at the height of other surfaces which are exposed to impacts and / or tend to come into contact with blunt external elements of the body. The reinforcement structure 10 may of course include a continuity of the first element 13a associated with each second element 13b. Alternatively, the reinforcement element may include a continuity of the first element 13a without the second element 13b. Such a configuration is preferred, for example, between the corners of two adjacent bodies. The reinforcement structure thus advantageously includes a regular, non-random, three-dimensional structure forming a repetitive network.

[0021] For this reason, the reinforcement structure 10 is formed by elements 13 in the form of basic parts that define intervals. Thus, apart from its mechanical function described above, the reinforcement structure 10 advantageously defines intervals that impart lightness to the watch parts. In an advantageous embodiment, the intervals are further shaped to assist in the discharge of powder during the additive manufacturing steps described in detail below. Element 13a further includes a portion having a cross-section in the shape of an ellipse, an egg, or an almond to assist in said discharge. In the case of an elliptical shape, the ellipse may have a minor axis of 1 mm and a major axis of 4 mm. The partitions 131a and 132a advantageously project inward from the shell to the cavity part over a length ha on the order of 2 mm. The partitions 131b, 132b, 133b project in the same direction over a length hb shorter than ha and between 0.5 mm and 1 mm, thereby further assisting in the discharge of powder. More generally, hb < ha, particularly 1.2×hb < ha, and further 2hb < ha.

[0022] The cavity part 12 that opens towards the central volume 11 thus makes it possible to participate in the discharge of powder from the intervals of the reinforcement structure 10.

[0023] The structure has been described above for the annular part of the body. The structure is advantageously used for the entire volume of the body, including a corner 14 for fixing a small watch strap. FIGS. 3 and 4 thus illustrate the structure of the body 1, particularly at the height of the corner 14. Each corner 14 is thus advantageously formed by a shell 2 housed in the cavity of the corner and the reinforcement structure 10. Such a reinforcement structure consists of a repetition of elements 15 in the shape of a gyroïde in this embodiment. The shape is selected particularly for its high resistance and the simplicity and speed of manufacturing. These elements also form a network of conduits that particularly enable the discharge of powder from the additive manufacturing step. The reinforcement structure 10 also forms an interval with a dimension between 0.3 mm and 3 mm at each corner 14.

[0024] More generally, the reinforcing structure may therefore include a lattice network formed over most, even virtually, or even entirely, the volume (cavity) defined by the shell. The reinforcing structure forms a skeleton of alternating voids and partitions, constituting a regular or irregular, TPMS, cellular, helical, Schwarz, or spherene porous network. The lattice network may include intersecting partitions, particularly randomly or with clearly defined periodicity. The lattice network may include repetitions of one or more juxtaposed basic elements, particularly in contact with each other, to form a continuous porous structure. The lattice network advantageously forms an open porous structure, where pores or gaps are interconnected. For this reason, the reinforcing structure includes numerous adjacent partitions, with small gaps between them, defining an overall porous structure, which are in contact with each other and extend across the volume of the cavity, particularly in contact with at least the substantially vertical surface of the shell and the upper and lower surfaces of the shell, respectively. Each partition may have a thickness l (as can be seen in Figure 4), for example, between 0.1 mm and 0.5 mm. The thickness l of the partition may depend on its length ha measured from the outside inward, and advantageously, l <ha / 5である。

[0025] The shell 2 and the reinforcing structure 10 are made of the same first material, which includes at least a metal or metal alloy, in particular a precious metal alloy, a metal superalloy, or stainless steel or titanium alloy, and in particular one or more elements of Fe, Mg, Al, Ti, Au, Pd, Pt, Ni, Si, and / or Co. The first material may include at least one amorphous or partially amorphous alloy, in particular at least one amorphous or partially amorphous metal alloy. The first material may also include at least one ceramic, in particular an alumina-based ceramic.

[0026] In modified embodiments, the watch component may include multiple different metals, i.e., the aforementioned first material may consist of multiple different materials. For example, the watch component may include different materials structured in layers, stacked, for example, vertically and / or horizontally, and even diagonally, and some of the layers may be made of different materials.

[0027] The present invention is, of course, not limited to the specific shapes of the shell and reinforcing structure described above. The structural concept of these two parts may be implemented only partially of the volume of the watch component, i.e., not the entire volume, contrary to the above description. Furthermore, the shell and its cavity portion may have different shapes. For example, the cavity portion (in other words, the reinforcing structure) does not have to extend over the entire inner surface of the watch component, for example, in the case of the case body described herein, it does not have to extend over the entire inner circumference 111 toward the central volume 11. The cavity portion may, advantageously, extend over at least 80% of the inner surface or inner circumference 111, and even more precisely, over at least 90% thereof. Furthermore, the cavity portion may extend over all or part of the watch component. The cavity portion may, advantageously, extend over at least 75% of the height h of the inner surface or inner circumference 111 of the watch component, and even more precisely, over at least 85% of the height h of the inner circumference 111 of the watch component.

[0028] In this embodiment, the body also includes support elements 16 positioned within the hollow portion 12 and projecting into the central volume 11. These support elements 16, in particular, serve as support structures for receiving, and / or positioning, and / or securing, the movement or casing ring.

[0029] Figure 6 illustrates a modification of the embodiment in which the case includes a convex relief 113 (projection) that extends over at least a portion of its outer surface 19, i.e., projecting outward from the outer surface of the shell 2. These reliefs are advantageously visible on the final watch, as shown in Figure 7. The convex relief 113 advantageously corresponds at least partially to the shape or contour of the element 13, particularly to some or all of the elements 15 of the partitions 131a, 132a, 131b, 132b, 133b and / or corners 14. More generally, these convex reliefs 113 correspond at least partially to the shape of the reinforcing structure 10. In other words, these convex reliefs form at least partially an extension of the lattice network of the reinforcing structure 10. Thus, these reliefs evoke the complexity of the lattice network without compromising the seal of the central volume 11, especially when the case back and watch glass are assembled on the case using a seal.

[0030] More generally, the convex relief 113 can be formed independently of the reinforcing structure 10, and therefore does not necessarily correspond to the reinforcing structure.

[0031] Therefore, the clock component may include a first grid network that can be considered "internal" and a second grid network that can be considered "external," and these two grid networks are separated by a shell. The network may be homogeneous or non-homogeneous, and may have a porous gradient in particular.

[0032] In other modified embodiments, part or all of the outer surface 19 of the shell 2 may be covered with at least one coating layer. By combining this other modification with the preceding modification, the convex relief 113 can be used to define a network of cavities 110 that form a container for receiving such coating at the height of the outer surface 19 of the watch component. The convex relief preferably forms a projection on the order of 0.1 mm to 2 mm measured from the outer surface 19 of the shell 2.

[0033] In an advantageous embodiment, at least one coating layer has a surface Vickers hardness of 500 HV or higher, or 600 HV or higher, or 900 HV or higher.

[0034] At least one coating layer may consist of a second material which may be different from the first material. In particular, the first material may have a lower density than the second material.

[0035] For example, in the first modified embodiment, the second material may include tungsten carbide (WC) particles and cobalt-chromium (CoCr) particles that act as a binder.

[0036] Such layers may have a thickness of, for example, between 100 μm and 500 μm. Surface coatings provided with such layers thus impart the required robustness and hardness to watch components, which may be made of a very lightweight and / or ductile primary material.

[0037] In a second modified embodiment, the coating may have the function of forming a decorative layer. For this purpose, the second material may be a metal or a metal alloy based on at least one element of the type Au, Ag, Pt, or Pd. The second material may form a layer, for example, having a thickness between 500 nm and 20 μm.

[0038] The advantage of such an external layer is that it allows for the formation of a higher-hardness, higher-density surface layer that can meet the stringent requirements of high-end watches. This decorative layer contributes to the overall robustness of the coating, complementing any other possible hard layers, while forming an exposed, visible, attractive, and highly hard external surface of the watch components.

[0039] In a third modified embodiment, the second material may include an amorphous or partially amorphous metal. For example, the second material may be a metallic glass or an amorphous or partially amorphous metal alloy, comprising a metal base formed from at least one metal from the elements Ni, Cu, Pd, Pt, Fe, Co, Ti, Nb, and Zr. Such a coating layer may have a thickness between 20 μm and 500 μm, and even between 70 μm and 350 μm.

[0040] Such a coating layer, which includes a second, at least partially amorphous metal, has a high surface Vickers hardness, which may be 500 HV or more, while also conferring properties advantageous to watch components, including high corrosion resistance and anti-allergic properties.

[0041] In a fourth modified embodiment, the second material may include at least one elastic material to form a coating in which at least one layer is elastic. For this reason, the elastic material may be a polymer, particularly a thermoplastic elastomer (TPE) or fluoroelastomer (FKM, FFKM, or FEPM), or a polymer such as natural rubber (NR) or synthetic rubber (SBR, HNBR, EPDM), or vinyl methylsiloxane (VMQ) or fluorosilicone (FVMQ). Alternatively, the second material may be a thermosetting elastomer.

[0042] A coating layer containing such an elastic secondary material has the particular advantage of providing extremely high impact resistance.

[0043] In the fifth modified embodiment, the second material may be a composite material. The second material may be, for example, a polymer-ceramic composite material, particularly a composite material known by the trade name HyCeram®.

[0044] All of these modified embodiments can, of course, be combined if technically compatible. In particular, a first part of the outer surface 19 of the watch component may be covered with a first coating, and a second part of the outer surface 19 may be covered with a different second coating. Furthermore, the same coating may include multiple distinct layers, for example, layers of different materials. For example, the coating may be formed from a hard first layer and a hard, decorative second layer. Similarly, an elastic layer may be formed on the surface of the component and covered with a hard layer and / or a hard, decorative layer. In this case, the second material consists of multiple different materials.

[0045] At least one coating layer may, advantageously, have a degree of porosity of 0.5% or less, or 0.1% or less, or 0.05% or less, or 0.01% or less. The coating layer may have a density of 90% or more, and even 99% or more, of the density of the solid second material.

[0046] Finally, the coating may have a thickness between 500 nm and 500 μm, for example, forming a thin layer with a thickness between 500 nm and 20 μm, or a thick layer greater than 100 μm, even between 100 μm and 500 μm, or even between 100 μm and 300 μm.

[0047] According to yet another modified embodiment of the watch component, which is not shown, a third material can be distributed within the reinforcing structure 10. For example, this may be an elastic third material provided to absorb shock and thus optimally protect the component. Such a watch component may or may not be covered. The third material may therefore fill some or all of the gaps in the grid network forming the reinforcing structure 10. The third material will henceforth be referred to as the filler material.

[0048] The second and third materials described above may, advantageously, be different from the first material in order to provide the various functions described above. However, this is not essential. In particular, the second material may be identical to the first material or form part of the same group. For example, a titanium body may be manufactured and then coated with a titanium layer by thermal spraying.

[0049] Therefore, it should be noted that the watches shown in Figures 1 to 5 include the main structure of the present invention, namely the shell and the reinforcing structure. These are not necessarily complete, considering that variations may include coatings and filling of the reinforcing structure. For simplicity, such watch component blanks are referred to as watch components in any case, since the blanks already contain the main structure.

[0050] The present invention is particularly suitable for any component, especially any watch component, and especially any external component. The watch component can take on a variety of shapes. Part or all of the watch component 1 may, advantageously, extend around a volume intended to receive a small watch movement or other watch component, or to mount a watch, and may have, for example, an annular shape. The watch component may be, for example, a case, a bezel, a bezel disc, or a flange. The present invention has been described in detail in the case of manufacturing a case, but for this reason it may also be applied to other watch components, for example, the bezel shown in Figure 9.

[0051] In particular, to provide a lightweight and robust miniature watch casing with an attractive appearance that is compatible with the aesthetic requirements of the finest timepieces, it is advantageous that various watch components according to the present invention can be assembled. For example, such a casing may include the body according to the present invention and a bezel and / or flange as shown in Figures 6 and 7.

[0052] The present invention also relates to a clock, including the aforementioned clock components.

[0053] The hollow portions 12 and / or central volumes 11 of the watch components are advantageously protected from the external environment once the components are assembled to form a watch. In the case of the case, the central volume 11 is sealed once the watch glass and case back, and all means for operating the watch (such as the crown and / or buttons or adjustment mechanism) are assembled onto the case. In the case of the flange, the flange can be assembled within the case, and the flange is sealed once the bezel and case back are assembled onto the case. In the case of the bezel disc or bezel, the hollow portion 12 can face the joint and / or seal once the disc or watch glass is assembled onto the case, as shown in the seal 22 in Figure 8. The reinforcing structure 10 is preferably permanent, i.e., its integrity is preserved even if the watch is disassembled. Under certain conditions of use, the reinforcing structure 10 may be deformed or damaged when the watch is disassembled.

[0054] The present invention also relates to a method for manufacturing a watch component for a watch, the method comprising the step of additive manufacturing a shell 2 having a three-dimensional shape defining a cavity 12, wherein the shell 2 has a degree of porosity of 0.5% or less, more preferably 0.1% or less, more preferably 0.05% or less, and more preferably 0.01% or less, and the shell 2 is not closed such that all or part of the cavity 12 opens in an orientation intended for positioning toward the inside of the watch, the additive manufacturing step simultaneously produces a reinforcing structure 10 extending all or part of the cavity 12, the reinforcing structure 10 forming a grid network.

[0055] The step is preferably carried out using a powder layer dissolution technique, which has the advantage of manufacturing the structure with great precision. The cavity portion 12 advantageously simplifies the additive manufacturing step by allowing for the discharge of powder. For this purpose, the cavity portion opens onto the inner surface of the watch component. Furthermore, the opening surface of the cavity portion is preferably large and extends over most of the entire inner surface of the watch component and / or over most of the height. For this purpose, the cavity portion 12 may extend over at least 80% of the inner surface of the shell, and / or over at least 90% of the inner surface of the shell, and / or over at least 75% of the height of the inner surface of the shell, and / or open over all or almost all of its inner surface.

[0056] The grid network is preferably self-supporting and has a shape that enables additive manufacturing without the need for any sacrificial support elements. In modified cases, sacrificial support elements may be used.

[0057] For defining and sizing the reinforcing structure 10, progressive design methods such as digital simulation and topology optimization (with or without the support of artificial intelligence models and / or machine learning models) can be advantageously utilized. These methods allow for the distribution of materials only where needed to provide the expected function, particularly resistance to mechanical stress, enabling a substantial reduction in the total mass of the part without compromising mechanical resistance. In advantageous modified embodiments, the reinforcing structure may therefore be designed to have the complementary functions of powder discharge during manufacturing and being self-supporting, as described above. To satisfy these requirements, the reinforcing structure may have the above-described structure based on juxtaposed elements, or in modifications, may have other architectures.

[0058] Furthermore, the additive manufacturing method for obtaining parts is particularly advantageous because it allows for minimizing the amount of material used.

[0059] The manufacturing method is optional. - A step of reworking a watch component in order to obtain a desired surface condition, particularly at the height of the external surface 19, which may include, for example, a step of mechanical reworking that enables the acquisition of a polished surface or a surface having a predetermined roughness, particularly enabling the acquisition of a polished surface or a surface having a predetermined roughness, or a step of using a laser, particularly a femtosecond laser, - A friction finishing step, which includes a mechanical chemical step that complements or is otherwise related to a preceding step, such as a rotational or friction finishing step. - A step of depositing at least one layer of a surface coating, the various techniques used or foreseen are described below, in which case the method may perform any complementary step of reworking the coated watch part, such step may consist of a step of reworking only the coating, or a step of reworking both the shell and the coating of the part, in the latter case, the watch part produced by additive manufacturing includes one or more excess thicknesses in various areas that are reworked in the reworking step in order to achieve the final dimensions of the part, - A step of structuring and / or coloring at least one layer of the surface coating, the various techniques used or anticipated are described below, step, - A step of filling the gap formed by the reinforcing structure 10 with a filling material, particularly an elastic material, in which case the method may include an optional step of reworking the filling material that has overflowed from the reinforcing structure, - At least one operation to clean both the external and internal surfaces of the body to remove any manufacturing residue. The method may include one or more other steps, which may be cumulative depending on the modified embodiment and / or performed in a different order.

[0060] The watch component advantageously includes at least one surface intended to allow the component to be held in place during the manufacturing and / or finishing steps. In the particular structure of the case described above, the upper assembly surface 18 of the watch glass or a surface pre-forming the upper assembly surface 18 of the watch glass may provide this function.

[0061] With respect to the step of depositing at least one layer of the surface coating, the first approach may consist of adding a hard layer, particularly to provide a protective function. In this case, the deposition may be carried out by thermal spraying, advantageously at a high temperature, which may be above 800°C. Such modified embodiments use, for example, high-temperature thermal spraying at 900°C, of ​​ceramic and / or metal particles, such as tungsten carbide (WC) and cobalt-chromium (CoCr) particles (where cobalt-chromium acts as a binder between the WC particles in the coating), where the WC particles can have an average diameter of 40 μm, or even smaller. Alternatively, other binders such as iron-chromium (Fe-Cr) can be considered. Alternatively, the layer may be without a binder. The thermal spraying may be of the plasma type (known as vacuum plasma spraying (VPS)), which has numerous advantages, such as enabling the spraying of many different materials, such as ceramics, oxides, and metals, which allows for the control of the chemical properties of the material.

[0062] Alternatively, other spraying or deposition techniques are also possible, particularly anodizing, and especially plasma electrolytic oxidation. Cold spraying processes are also possible. In the latter case, the cold spraying process is carried out at a temperature lower than the melting point of the powder and / or below the phase transition temperature (e.g., below 900°C) to form the high-hardness layer. The cold spraying process allows for coating of temperature-sensitive components and / or allows for the deposition of powder while maintaining its structure. The spraying technique is adapted in particular to the material used. In all cases, the selected coating technique offers the advantage of allowing for the deposition of thick coatings (coatings with a thickness of 100 μm to 500 μm).

[0063] Therefore, spraying makes it possible to obtain a thick layer of coating formed, for example, with tungsten carbide (WC) and cobalt-chromium (CoCr) or iron-chromium (FeCr). Alternatively, other materials can be used, such as carbides, nitrides, and / or oxides of metallic elements such as Ti, Al, Cr, and Zr. Therefore, spraying makes it possible to obtain a thick layer formed, for example, TiN, TiC, or TiCN, Cr2O3, Al2O3, or ZrO2. Advantageously, oxide, carbide, or nitride particles are sprayed in combination with a binder in the form of simultaneous spraying of powders of different materials, thereby making it possible to obtain a specific surface coating layer. Alternatively, it is also possible to spray particles without a binder, such as metallic particles, such as titanium or titanium alloy particles. Alternatively, to obtain a black, polishable surface with a Vickers hardness of about 500 HV, it is also possible to use black cermets, such as Al2O3-Ti or Al2O3-Cr types. More generally, the coating may be in the form of a ceramic-metal composite material. By adjusting the relative content of ceramics and metals, the properties of the coating material, such as toughness and / or hardness, can be altered. An advantage of this approach is that the spraying technique is compatible with a wide range of materials.

[0064] The sprayed particles are, more advantageously, in the case of thermal spraying, in a semi-paste state so that they are dispersed by impact and form a uniform and high-density layer. In contrast to the solid particles ("cold particles") that produce an irregular structure in the aforementioned "cold spray" process, which is particularly suitable for high-temperature sensitive materials, the term "semi-paste state" means a semi-solid or semi-liquid state. The resulting coating layer may therefore be neither too coarse nor too condensed and may have low porosity.

[0065] Alternatively, the coating layer may primarily serve the decorative function of the watch component. In this case, the coating layer may be deposited, for example, by physical vapor deposition (PVD), chemical vapor deposition (CVD), or atomic layer growth (ALD). The coating layer may be a layer of, for example, a metal or metal alloy of the Au, Ag, Pt, or Pd type. The layer may have a thickness of, for example, between 500 nm and 20 μm.

[0066] Alternatively, it may be chosen to deposit at least a partially amorphous metal layer. In this case, the deposition may be carried out by overmolding. The at least partially amorphous material may be metallic glass. In particular, the at least partially amorphous material may be an at least partially amorphous metal alloy having a metal base consisting of at least one metal from the elements Ni, Cu, Pd, Pt, Fe, Co, Ti, Nb, and Zr. In particular, the at least partially amorphous metal alloy may be based on zirconium, titanium, nickel, palladium, or platinum. In modified embodiments, deposition includes a substep of forming or overmolding a metal alloy in a liquid or superplastic form, particularly at high temperatures, to obtain a metal alloy in an amorphous or predominantly amorphous form, which is then quenched. In other modified embodiments, the technique of superplastic forming is used, which consists of heating the metal alloy in an amorphous form above its glass transition temperature and below its crystallization temperature, then deforming it under low stress in a mold or imprint, and then cooling it before crystallization. Suitable alloys include zirconium-based alloys such as Zr55Cu30Al10Ni5, or palladium-based alloys such as Pd40Cu30Ni10P20, as well as any alloy that can be obtained in a partially amorphous form and has a wide temperature range over which the method can be carried out (in particular, in the example of alloy Zr55Cu30Al10Ni5 with Tg=409°C and Tx=494°C, a significant difference between the glass transition temperature Tg and the crystallization temperature Tx, i.e., Tx-Tg=85°C). In practice, the watch component and the metal alloy in at least a partially amorphous form are placed in a mold, the alloy which has become viscous at the deformation temperature is then deformed, the mold and the component containing the overmolded at least partially amorphous alloy are then quenched, and the watch component is then removed from the mold. In further modifications, injection molding techniques, particularly injection molding techniques, are used for amorphous metal alloys. In this case, the watch component is placed in an injection mold that forms a cavity, the alloy is melted at a temperature above its melting point, the liquid alloy is injected into the cavity between the mold wall and the component, for example via an injection piston, the component and its alloy are then quenched to allow the alloy to become amorphous or partially amorphous, and then the component is removed from the mold.Suitable metal alloys for such modified embodiments of the method are preferably selected from alloys based on zirconium, copper, nickel, iron, palladium, titanium, cobalt, or hafnium, such as alloys having the composition Zr58Cu16Ni13Al10Nb3, Zr41Ti14Cu13Ni10Be22, or Pd43Cu27Ni10P20. Alternatively, other methods suitable for overmolding amorphous or partially amorphous metal alloys onto parts may be used.

[0067] In other variations, the coating includes at least one elastic layer that can be deposited by overmolding. Such techniques are particularly suitable for depositing polymers, especially elastomers such as thermoplastic elastomers (TPE) or fluoroelastomers (FKM, FFKM, or FEPM), or natural rubber (NR) or synthetic rubber (SBR, HNBR, EPDM), or vinyl methylsiloxane (VMQ) or fluorosilicon (FVMQ). More generally, the material may be a thermoplastic or thermosetting polymer.

[0068] Furthermore, as described above, the method may also include a step of structuring and / or coloring at least one layer of the surface coating, and this optional step is therefore applicable when a coating is present. The coating can therefore be structured and / or colored by a laser, particularly by a femtosecond laser, especially in the case of a coating that includes a hard layer provided with or based on a ceramic metal composite, particularly tungsten carbide and cobalt-chromium, or based on tungsten carbide and iron-chromium. Structuring includes, for example, the production of relief by satin finish, soft sandblasting, or sandblasting. Such structuring may be carried out downstream of an intermediate step of grinding or polishing or microbead blasting of the hard layer of the coating.

[0069] Finally, at least one coating layer may have a surface condition such as textured, polished, sandblasted, or satin finish.

[0070] With respect to the optional step of filling the gaps formed by the reinforcing structure 10 with a filler material, the filler material may be an elastic material selected in particular from the list of elastic materials mentioned above. The step may include a step in which the filler material penetrates the lattice network. For this purpose, a step of injection molding of the filler material, for example, an elastomer, may be used, and the watch components are placed in the mold beforehand. The pressure and temperature used are between 50 bar and 200 bar and between 100°C and 250°C, respectively, adapted for maximum penetration and enabling cross-linking in the case of an elastomer, for example. Alternatively, any material that is compatible with a step of liquid or paste phase penetration, such as the penetration of at least partially amorphous metal alloys, can be used. For this purpose, the reinforcing structure forms an open porous structure, i.e., the gaps defined by the reinforcing structure are interconnected to allow circulation of the filler material within the volume. For this purpose, the reinforcing structure includes, for example, conduits. The injection (or more generally, penetration) of the filler material is advantageously carried out via the internal surface of the reinforcing structure. The penetration is therefore carried out at the height of the opening surface. The reinforcing structure has, advantageously, heterogeneous porosity that changes particularly from the inside out. The porosity increases in particular from the inside surface to the outside surface of the reinforcing structure. This can be achieved through a pore diameter gradient that increases from the inside out. Such embodiments are supported by a good flow of filler material from the inside out, which advantageously ensures that the filler material reaches the outside of the reinforcing structure, particularly the shell. In a modified embodiment, the outer surface of the shell does not cover the entire reinforcing structure, so that its porous outer surface is visible on the outer surface of the watch component. Once the step of filling with filler material is carried out, the filler material therefore reaches the outer surface of the reinforcing structure until it fills the pores to the height of the outer surface and becomes visible from the outside of the watch component at the height of the surface due to the absence of the shell. The process then produces an aesthetic effect which has a variation at the height of the outer surface of the watch component between the visible surface of the watch component consisting of the outer surface of the shell and the visible surface consisting of the filler material and / or reinforcing structure.To amplify this effect, and more specifically to distinguish the two materials—the reinforcing structure and the filler—at the height of the outer surface of the watch component, the materials can be selected to have very different appearances, such as different colors. The ends of the outer surface of the shell and the ends of the filler may, of course, be different. In such implementations, the material may be an elastomer, particularly an elastomer with a Shore A hardness greater than 40, for example, to enable good wear resistance.

[0071] Of course, it is also possible to combine the modified embodiments described above.

[0072] Finally, the present invention makes it possible to combine two primary objectives of watch components, particularly external watch components, which have not been achieved before. The present invention makes it possible to obtain watch components that are lightweight and mechanically robust, while also being aesthetically pleasing.

Claims

1. A watch component comprising a shell (2) having a three-dimensional shape defining a cavity (12), wherein the shell (2) has a degree of porosity of 0.5% or less, more preferably 0.1% or less, more preferably 0.05% or less, and more preferably 0.01% or less, the shell (2) is not closed such that all or part of the cavity (12) opens in a direction intended to be positioned toward the interior of the watch, and the watch component comprises a reinforcing structure (10) extending all or part of the cavity (12), the reinforcing structure (10) forming a lattice or mesh network, and the shell (2) and the reinforcing structure (10) forming an integrated, one-piece cast structure. Watch parts.

2. The cavity portion (12) extends over at least 80% of the inner surface of the shell (2), and further over at least 90% of the inner surface of the shell (2), and / or extends over at least 80% of the inner perimeter (111) of the shell (2), and further over at least 90% of the inner perimeter (111) of the shell (2), and / or extends over at least 75% of the height h of the inner surface of the shell, and further over at least 85% of the height h of the inner surface of the shell (2), The watch component according to claim 1.

3. The reinforcing structure (10) is a skeletal morphology formed by a regular or irregular pore network, particularly of the lattice, TPMS, honeycomb, cellular, or columnar type, and / or the reinforcing structure (10) optionally includes juxtaposed elements, particularly elements in contact with each other, to form a continuous structure including elements having an elliptical, egg, or almond shape, filled with spacers, particularly star-shaped spacers. The watch component according to claim 1 or 2.

4. The reinforcing structure (10) includes a number of partitions defining an overall porous structure with spacing between them, the partitions being in contact with each other, extending into the volume of the cavity portion (12), and in contact with at least three distinct areas of the internal surface of the shell (2) within the same planar portion, in particular the upper and lower surfaces of the shell (2) and at least one intermediate surface between the upper and lower surfaces, and / or, depending on the three-dimensional shape of the shell, in contact with at least three areas in a distinct plane. A watch component according to any one of claims 1 to 3.

5. The reinforcing structure (10) includes, in particular, at the height of the upper and lower surfaces of the shell (2), a first element (13a) having an elliptical, egg-shaped, or almond-shaped cross-section formed by partitions (131a, 132a) that connect or intersect, and optionally a repeat of a second element (13b) that serves as a spacer in an intersecting or star-shaped structure within part or all of the first element (13a). A watch component according to any one of claims 1 to 4.

6. The shell (2) and the reinforcing structure (10) are made of a first material which includes at least one metal or metal alloy, particularly noble metal alloys or metal superalloys or stainless steel or titanium alloys, particularly containing one of the elements Fe, Mg, Al, Ti, Au, Pd, Pt, Ni, Si, and / or Co, and / or the shell (2) and the reinforcing structure (10) include at least one amorphous or partially amorphous alloy, particularly at least one amorphous or partially amorphous metal alloy, and / or the shell (2) and the reinforcing structure (10) include at least one ceramic, particularly a ceramic based on alumina or zirconia. A watch component according to any one of claims 1 to 5.

7. The outer surface (19) of the shell (2) includes at least one layer of coating, A watch component according to any one of claims 1 to 6.

8. The shell (2) and the reinforcing structure (10) are made of a first material, and at least one layer of the surface coating includes a second material different from the first material, in particular the first material having a lower density than the second material. The watch component according to claim 7.

9. The at least one coating layer has a surface Vickers hardness of 500 HV or more, more specifically 600 HV or more, and / or the at least one coating layer is made of a second material and has a degree of porosity of 0.5% or less, more specifically 0.1% or less, more specifically 0.05% or less, and / or has a density of 90% or more, and / or 99% or more of the density of the solid second material, and / or the at least one coating layer is covered with a thin decorative layer having a thickness particularly between 500 nm and 20 μm, and / or the at least one coating layer has a textured, polished, sandblasted, or satin-finished surface condition, and / or the at least one coating layer has a thickness between 20 μm and 500 μm, and / or between 70 μm and 350 μm. The watch component according to claim 7 or 8.

10. The at least one coating layer comprises a ceramic base secondary material, or is an oxide, or is a metal or metal alloy, or is a mixture of ceramic and metal alloys, or is based on tungsten carbide and cobalt-chromium, or is based on tungsten carbide and iron-chromium, and / or the at least one coating layer comprises an amorphous or partially amorphous metallic material, particularly an amorphous metal base formed from at least one metal from the elements Ni, Cu, Pd, Pt, Fe, Co, Ti, Nb, Zr The present invention includes an elastic material comprising a group alloy or metallic glass, and / or the at least one coating layer being an elastomer such as a polymer, particularly a thermoplastic elastomer (TPE), a thermosetting elastomer, or a fluoroelastomer (FKM, FFKM, or FEPM), or natural rubber (NR) or synthetic rubber (SBR, HNBR, EPDM), or vinyl methyl silicon (VMQ) or fluorosilicon (FVMQ), and / or the at least one coating layer comprising a polymer ceramic composite material. A watch component according to any one of claims 7 to 9.

11. A filling material, particularly an elastic material, is provided in part or all of the gaps in the reinforcing structure (10). A watch component according to any one of claims 1 to 10.

12. On the outer surface (19) of the shell (2), a protruding shape corresponding to the shape of the reinforcing structure (10) is provided, particularly including protrusions on the order of 0.1 mm to 2 mm, wherein the protrusions optionally define cavities that form surfaces to receive at least one coating layer. A watch component according to any one of claims 1 to 11.

13. The support element (16) is located in the hollow portion (12) of the shell (2), A watch component according to any one of claims 1 to 12.

14. A shape defining a central space intended to include the movement of the watch or the watch glass or dial is, in particular, an annular case, bezel, or flange, wherein the hollow portion opens into the central space. A watch component according to any one of claims 1 to 13.

15. The hollow portion (12) of the shell (2) has a groove shape, particularly an annular groove shape. The watch component according to claim 14.

16. The case body includes a corner portion (14) for securing at least one small watch strap portion, and the hollow portion (12) and the reinforcing structure (10) extend into the corner portion (14). A watch component according to any one of claims 1 to 15.

17. A method for manufacturing a watch component, comprising the step of additive manufacturing a shell (2) having a three-dimensional shape defining a cavity (12), wherein the shell (2) has a degree of porosity of 0.5% or less, more preferably 0.1% or less, more preferably 0.05% or less, and more preferably 0.01% or less, and the shell (2) is simultaneously additive manufacturing a reinforcing structure (10) that is not closed and extends to all or part of the cavity (12), such that all or part of the cavity (12) is open in a orientation toward the interior of the watch, wherein the reinforcing structure (10) forms a self-supporting network that enables the manufacture of a grid or mesh network by adding material, in particular without the need for sacrificial support elements.

18. The steps include depositing at least one coating layer on all or part of the outer surface (19) of the shell (2), and further including reworking the at least one coating layer and / or the shell (2), particularly the protruding shape on the outer surface (19) of the shell (2), A method for manufacturing a watch component as described in claim 17.

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