METHOD FOR MANUFACTURING A PERCENTAGE TOOL FOR MAKING AN INDIVIDUAL PART FOR JEWELRY, JEWELRY OR CLOCKS

Description

Technical field of the invention

[0001] The invention falls within the field of tooling for the production of finishing components, and relates in particular to a method for producing a striking tool for the manufacture of a finishing component for jewelry, watchmaking or watchmaking. Technological background

[0002] In the fields of jewelry, fine jewelry or watchmaking, for aesthetic reasons, it may be desirable to create a complex decoration on a component whose appearance may vary, for example depending on its orientation relative to a user.

[0003] In watchmaking, in particular, it is well known to structure a component, such as the dial, so that its appearance changes depending on the angle of incidence of light rays. Specifically, guilloché dials allow for highly varied and complex relief designs with a very high level of reflectivity, and therefore a highly sought-after aesthetic. However, hand-crafted guilloché work is difficult to repeat, relatively time-consuming, and expensive to produce.

[0004] Furthermore, to enhance the aesthetic appeal of watches, it is also known to set visible parts on the dial or case back in motion. For example, watches may feature complications that display animations, such as moon phases, tourbillons, automata, roller displays for time indication, etc. However, all these solutions have the drawback of requiring an energy input to be set in motion. The prior art document EP 3 266 738 B1 discloses examples of manufacturing processes for a striking tool obtained by covering a base layer surmounted by a base pattern with a metallic layer.

[0005] The present invention therefore proposes to meet the need to provide a decoration on a cladding component which has significant aesthetic appeal while being simple, quick and inexpensive to manufacture. Summary of the invention

[0006] To this end, the present invention relates to a method for making a striking tool for manufacturing a component for jewelry, watchmaking, or watchmaking components, comprising the following steps: machining of a substrate surface to obtain a reference surface having a three-dimensional shape corresponding to a predefined design, at least a portion of which has a mirror-polished surface finish; generation of a part on the reference surface of the substrate, the interface surface of which rests at every point against said reference surface so as to closely follow its shape so that the interface surface of the part has a three-dimensional shape corresponding to the inverse of the predefined design, and such that every point of the interface surface has a surface finish identical to that of the reference surface with which it is opposite; separation of the part and the substrate; and installation of said part in a tool holder so as to constitute a stamping tool for stamping a design onto a blank of a trim component by stamping the interface surface.

[0007] In particular embodiments, the invention may further comprise one or more of the following features, taken individually or in all technically possible combinations.

[0008] In certain implementation methods, the part generation step is carried out by material deposition.

[0009] In certain implementation methods, the part generation step is carried out by galvanic nickel growth.

[0010] In certain implementation methods, the part generation step is carried out by hot pressing an amorphous metal. More specifically, for example, the amorphous metal can be an alloy with good hot-forming properties, such as the metals commonly designated as Vit106a or LM1b.

[0011] In particular modes of implementation, the machining step is carried out so that the portion of the reference surface having a mirror polished surface condition is constituted at least by a plurality of striations forming segments and having a mirror polished surface condition.

[0012] In certain implementation methods, the machining step comprises the successive operations of: application of a layer of photosensitive resin on a surface of the substrate, exposure for a predetermined time of at least a part of said surface of the substrate to a light source in order to define one or more parts to be machined of said surface, dissolution of the layer of photosensitive resin on the part(s) to be machined of said surface, electrochemical machining of the part(s) to be machined of said surface, said operation being completed by electrochemical polishing of the part(s) to be machined of said surface, removal of the residual layer of photosensitive resin.

[0013] In certain implementation methods, the machining step is carried out by mechanical machining.

[0014] In certain implementation methods, the machining step is carried out by guilloché cutting.

[0015] In certain implementation methods, the part is driven into the tool holder.

[0016] In specific implementation methods, the substrate is made of steel, copper, copper alloy, aluminum, or platinum, silver, or gold alloys. Brief description of the figures

[0017] Other features and advantages of the invention will become apparent from the following detailed description, given by way of non-limiting example, with reference to the accompanying drawings in which: THE figures 1 to 4 schematically represent, in section view, the successive steps of an example of the implementation of a method for manufacturing a striking tool for the production of a component for jewelry, watchmaking, or fine jewelry components according to the invention; The figure 5 schematically illustrates the component made with a striking tool obtained by implementing the process illustrated by the figures 1 to 4 ; THE figures 6 to 8schematically represent successive operations in a machining step of a substrate surface, according to an example of process implementation illustrated by the figures 1 to 4 .

[0018] Note that the figures are not drawn to scale for reasons of clarity. Detailed description of the invention

[0019] There figure 1 schematically represents the first step in a process for manufacturing a striking tool 10 intended for use in the production of a finishing component 20 in the jewelry, watchmaking, or fine jewelry industry. Such a component is schematically shown on the figure 5 in view of section.

[0020] The first step of the process according to the invention is a machining step of a substrate surface 30, in order to obtain a surface called a "reference surface" 31, so as to obtain a three-dimensional shape, for example, a generally concave shape corresponding to a predefined design. In this text, the term "machining" refers to any action of removing material from a blank. Furthermore, the term "shape" is understood as defining the general shape of the design, and may include one or more raised and / or recessed features.

[0021] During this machining step, at least a portion of the machined surface of the substrate is polished so that the reference surface 31 has, over all or part of its surface, a mirror-polished finish. The objective of this step is to obtain a decoration identical to that which is intended to be formed by stamping on the trim component 20, as shown in the Figures 1 and 5 .

[0022] The substrate 30 is advantageously made of steel, copper or copper alloy, aluminum or precious metal alloys, such as platinum, silver or gold alloy.

[0023] The process according to the invention subsequently comprises a step of generating a part 11 on the reference surface 31 of the substrate 30. This step is carried out such that an interface surface 12 of the part 11 with the substrate 30 rests at every point against the reference surface 31 in order to intimately conform to its shape, as illustrated in the figure 2 . Thus, advantageously, at the end of this step, every point of the interface surface 12, in other words every part of the interface surface 12, has a surface state identical to that of the reference surface 31 with which it is opposite.

[0024] Next, a separation step is performed between part 11 and substrate 30. The resulting interface surface 12 of part 11 has a three-dimensional shape, for example, generally convex, corresponding to the inverse of the predefined decoration applied to substrate 30. The interface surface 12 of part 11 therefore has at least one portion with a mirror-polished surface finish.

[0025] Part 11 is then installed in a tool holder 13 so as to constitute a stamping tool 10 for stamping a decoration onto a blank 40 of a trim component 20, as schematically represented on the figure 3In other words, part 11 and tool holder 13 form an upper matrix intended to produce a decoration on the blank 40. Part 11 is preferably pressed into a cavity in tool holder 13, but it can also be fixed to tool holder 13 by any other suitable means, such as with a layer of glue or mechanical holding means.

[0026] Thanks to the characteristics of the process according to the present invention, it is possible to manufacture a stamping tool 10 adapted to produce a trim component 20, on the one hand, having a particularly attractive appearance insofar as the stamping tool 10 can reproduce on said trim component 20 a very rich and complex decoration, the surface condition of which can be very varied, and on the other hand, in an easily repeatable and inexpensive way, with constant production quality and with industrial production rates.

[0027] In particular, the striking tool 10 obtained through the process according to the invention makes it possible to replicate, on an industrial scale, on cladding components, decorations of a very high level of quality and complexity, typical of manual decoration work, for example, guilloché work. More generally, the striking tool 10 makes it possible to reproduce, identically, easily, and quickly on a cladding component, a complex decoration created on the substrate 30.

[0028] The machining step of a surface of the substrate 30 in order to obtain the reference surface 31 can thus be advantageously carried out by guilloché, as described above, by mechanical machining, by electro-erosion or by any other material removal technique, the present invention having the advantage of allowing the use of expensive and time-consuming machining techniques insofar as only the substrate 30 is machined and not each component of the cladding to be produced.

[0029] For example, as depicted on the figures 6 to 8 The machining step can be implemented by electrochemical machining. In this example, the machining step then comprises the successive operations of: deposition of a layer of photosensitive resin 32 onto a surface of the substrate 30 as shown in the figure 6, such a resin being known as such by those skilled in the art; the application can be carried out by spraying, centrifugal coating, etc. exposure for a predetermined time of at least a portion of said substrate surface 30 to a light source, for example through an optical mask or by direct selective exposure, also known to those skilled in the art by the acronym "DLW" for "Direct Laser Writing", in order to define one or more parts to be machined of said surface; dissolution of the photosensitive resin layer 32 on the part(s) to be machined of said surface in a suitable solution, this step being known as such by those skilled in the art; this step is shown on the figure 7 , electrochemical machining of the part(s) to be machined of said surface, said operation being completed by electrochemical polishing of the part(s) to be machined of said surface, as visible on the figure 8This step is carried out by immersing part 30 in an electrolytic bath and applying a voltage and current; removal of the residual photosensitive resin layer 32 by exposure to a plasma or a solvent in order to obtain the substrate 30 as shown in the diagram. figure 1 .

[0030] Preferably, in order to increase the attractiveness of the aesthetic appearance of the trim component 20, the machining step is carried out so that the portion or portions of the reference surface 31 having a mirror-polished surface condition are made up of at least a plurality of striations forming segments extending in straight or curved directions, parallel to each other or not.

[0031] Thanks to these characteristics, the trim component 20 made from the striking tool 10 can reflect incident light in different ways depending on the orientation of the trim component 20, which is likely to cause a change in the appearance of the decoration it contains depending on the orientation of the user's viewing angle.

[0032] Preferably, the step of generating a part 11 is carried out by material deposition, and more particularly by galvanic nickel growth. This material deposition method has the advantage of allowing very high fidelity in reproducing the shape of the reference surface 31 by the shape of the interface surface 12 of the part 11 formed by the material deposition, in addition to allowing easy separation of said part 11 from the substrate 30. Another advantage of this material deposition method lies in the fact that the nickel thus deposited is suitable for use as the material of a striking tool 10.

[0033] Alternatively, the step of generating a part 11 can be carried out by hot pressing an amorphous metal onto the reference surface 31 of the substrate 11. This method has the advantage of being fast and also allows very high fidelity in reproducing the shape of the reference surface 31 by the shape of the interface surface 12 of the part 11. The amorphous metal is suitable to constitute the material of the striking tool.

[0034] According to an example of a method not covered by the wording of the claims, a method for manufacturing a jewelry, watchmaking, or fine jewelry component 20 is disclosed, implemented with the previously described striking tool 10. Such a jewelry component 20, visible on the figure 5For example, it is made from a blank 40 in copper or copper alloy, aluminum, steel, platinum, gold or silver alloy, or amorphous metal alloy. These materials are particularly well suited to being deformed by stamping and to reproducing with high fidelity the shape of the interface surface 12 of the stamping tool 10.

[0035] The manufacturing process for the housing component 20 includes a preliminary step of mirror polishing a housing surface 41 of the blank 40 of the housing component 20. The housing surface 41 is, in this text, a surface of the housing component 20 intended to be visible to a user.

[0036] The mirror polishing step is followed by a stamping step of the dressing surface 41 of said blank 40 by striking with the interface surface 12 of the striking tool 10 in order to form on said dressing surface 41 a three-dimensional decoration corresponding to the complementary shape, i.e. the inverse shape, of that of the decoration presented by the striking tool 10. This stamping step is carried out by a strike whose force is for example between 50 kN and 700 kN, and more particularly between 250 kN and 300 kN.

[0037] The blank 40 of the trim component 20 is held in position by a lower die (not shown in the figures), in a manner known to those skilled in the art, in order to be able to absorb the forces applied by the stamping tool 10 and to be able to deform properly at the level of its trim surface 41, during the stamping step.

[0038] Advantageously, the stamping step allows for the reproduction of the shape of the interface surface 12 of the striking tool 10, as well as its various surface finishes, at the micrometer or submicrometer scale. Following the stamping step, the surface finish of the dressing surface 41 therefore corresponds to that of the interface surface 12.

[0039] The invention can, in particular, advantageously be applied to the field of watchmaking and relate to a method of making a striking tool 10 for the manufacture of a dial, and a method of manufacturing a dial with such a striking tool 10.

[0040] More generally, it should be noted that the implementation and realization methods considered above have been described as non-limiting examples, and that other variants are therefore conceivable.

Claims

1. A method for producing a stamping tool (10) for manufacturing an external part (20) for use in jewellery, fine jewellery or horology, characterised in that it comprises the following steps: - machining a surface of a substrate (30) to produce a reference panel (31) with a three-dimensional shape corresponding to a predefined decoration, at least a portion of the reference panel (31) having a mirror-polished surface state, - hobbing a workpiece (11) on the substrate's (30) reference panel (31), which has an interface surface (12) with the substrate (30) that rests in all points against the reference panel (31) in order to closely match its shape so that the interface surface (12) has a three-dimensional shape corresponding to the reverse of the predefined decoration, and such that any point on the interface surface (12) has a surface state identical to that of the reference panel (31) of which it is the opposite. - separating the workpiece (11) from the substrate (30), and installing said workpiece (11) in a tool holder (13) such that it constitutes a stamping tool (10) for stamping a decoration onto an ebauche (40) of a component (20) of an external part by stamping the interface surface (12).

2. The method according to claim 1, in which the workpiece (11) hobbing step is carried out by material deposition.

3. The method according to claim 2, in which the workpiece (11) hobbing step is carried out by galvanic nickel growth.

4. The method according to claim 1, in which the workpiece (11) hobbing step is carried out by hot pressing an amorphous metal.

5. The method according to any of claims 1 to 4, in which the machining step comprises the successive operations of: - depositing a layer of photosensitive resin (32) on a surface of the substrate (30), - exposing at least part of said substrate surface (30) to a light source for a predetermined period of time in order to define one or more parts to be machined from said surface, - dissolving the photosensitive resin layer (32) on the part or parts to be machined from said surface, - electrochemical machining of the part or parts to be machined from said surface, said operation being finished by electrochemical polishing of the part or parts to be machined from said surface, - removing the residual layer of photosensitive resin (32).

6. The method according to any of claims 1 to 5, in which the machining step is carried out by mechanical machining.

7. The method according to any of claims 1 to 6, in which the machining step is carried out by engine turning.

8. The method according to any of claims 1 to 7, in which the workpiece (11) is driven in the tool holder (13).

9. The method according to any of claims 1 to 8, in which the substrate (30) is made of steel, copper or its alloys, of aluminium, or of platinum, silver or gold alloys.

10. The method according to any of claims 1 to 9, in which the machining step is carried out such that the reference panel portion (31) that has a mirror-polished surface state is made up of at least a plurality of striations forming segments that have a mirror-polished surface state.