CH711025A2 - A method of mounting a decorative element on a support and said support. - Google Patents

Abstract

The invention relates to a method of mounting at least one decorative element (3) on a support (2) comprising the steps of: a) providing a support (2) provided with at least one cavity; b) providing at least one decorative element (3); c) filling said cavity with a composite filler comprising at least one metal powder and at least one organic binder and having, at the time of filling, a viscosity of between 1000 mPa.s and 1 000 000 mPa.s; d) heating the composite filler material to a temperature above its melting point to make it liquid; e) allowing the filling material to cool to form a substrate (6); f) providing at least one housing in said substrate (6); g) mounting said decorative element (3) in said housing. The present invention also relates to a decorative support (2) provided with at least one cavity filled with said filling material forming a substrate (6) in which at least one housing is arranged, said housing being arranged to receive said decorative element (3) .

Description

Field of the invention

The present invention relates to a method of mounting at least one decorative element on a support. The invention also relates to a decorative support intended to receive at least one decorative element and provided with at least one cavity filled with a filling material forming a substrate in which at least one housing is provided, said housing being arranged for receive said decorative element.

Background of the invention

[0002] Decorative supports are known in the prior art for use on a portable object, such as a watch or jewelry, and having decorative elements, such as stones, and in particular precious stones.

For this, the support is generally made of a metal alloy and is machined to form housings therein. The decorative elements can be mounted in these housings by pushing in or by crimping. In the case of assembly by crimping, hooking means in the form of hooks are produced during this machining. Generally, these hooks are made with the material forming the portable object, that is to say integrally with the object. When a decorative element is to be crimped, the latter is placed in a housing and the hooking means are cold folded by plastic deformation so as to maintain said decorative element in the housing. This method of setting is widely used for setting stones on metal supports because the latter has an advantageous plastic deformation capacity. This ability is even more beneficial with precious metals like gold, because these precious metals are ductile and can be easily shaped.

[0004] However, a drawback of this method is that it is confined to supports made of ductile metals or metal alloys. However, more and more timepieces are made of materials that do not exhibit plastic deformation, often hard and / or fragile, such as ceramics, sapphire, silicon, composites (for example cermets). or even intermetallic alloys.

[0005] As a result, it is no longer possible to use the current method to mount decorative elements such as precious stones.

[0006] This crimping operation can be replaced by a gluing operation. The disadvantage of gluing is that it does not ensure that the stones hold 100% because, unlike setting, this technique does not involve mechanical retention of the stones. In fact, since the bonded areas are in most cases exposed to the external environment (humidity, sweat, UV, air pollution, etc.), the bonding strength over the long term is made difficult. Therefore, the resistance of the stones is not guaranteed, which is not acceptable for quality products. There is also a risk that the glue will release products that are harmful and / or corrosive to the other components of the watch or jewelry. In addition, it is necessary to pre-machine the decorative elements, which can be difficult and expensive, especially if the decorative elements have complicated geometries.

Another solution has been proposed in patent EP 2 315 673, this solution consisting in particular in embedding a decorative element made of an amorphous metal by pressing in a support. This process requires the use of amorphous preforms. However, the number of alloys existing in amorphous form is limited so that it is not always possible to find an alloy with the desired color to match the watch or the jewel. For example, amorphous alloys with a golden color with a yellow or red hue do not exist. In addition, the embedding process requires applying a certain pressing force, so it can hardly be used when the backing is a brittle material.

[0008] Another solution has been proposed in application EP 2 796 297, this solution consisting in particular of crimping a decorative element in a substrate made of an amorphous alloy. However, the various methods describe heating and then cooling the amorphous metal, which must necessarily be rapid to preserve the amorphous state of the metal. This rapid cooling creates a thermal shock which can cause the appearance of internal stresses in the support and thus lead to deformations or even cracks. In addition, the crimping process requires, at the time of crimping, to deform the hooking means, which can be tricky when using an amorphous metal which can be difficult to deform because of its specific elastic properties. . Moreover, as indicated above, the number of alloys existing in amorphous form is limited so that it is not always possible to find an alloy with the desired color to match the watch or the piece of jewelry.

Summary of the invention

[0009] The aim of the invention is in particular to overcome the various drawbacks of the methods of mounting a known decorative element.

[0010] More specifically, an objective of the invention is to provide a method of mounting a decorative element on a support, allowing the use of a fragile support.

[0011] The invention also aims to provide a method for mounting a decorative element on a support, making it possible to adapt to the composition and to the color of the support.

[0012] The invention also aims to provide a method for mounting a decorative element on a support, allowing simple and economical implementation.

To this end, the present invention relates to a method of mounting at least one decorative element on a support comprising the steps of: a) providing a support provided with at least one cavity; b) have at least one decorative element; c) filling said cavity with a composite filling material comprising at least one metallic powder and at least one organic binder and having, at the time of filling, a viscosity of between 1000 mPa.s and 1,000,000 mPa.s; d) heating the composite filler material to a temperature above its melting point to make it liquid; e) allowing the filling material to cool to form a substrate; f) making at least one housing in said substrate; g) mounting said decorative element in said housing.

[0014] Such a method makes it possible to use a composite filling material having a pasty appearance, simple to apply locally without constraint on the support, and not requiring rapid cooling. In addition, the composite filler material offers great flexibility in the choice of metal powder, binder and any additives, which improves the affinities of the composite filler material with the support.

[0015] The present invention also relates to a decorative support intended to receive at least one decorative element and provided with at least one cavity filled with a filling material forming a substrate in which at least one housing is arranged, said housing being arranged to receive said decorative element, said filling material being obtained from a composite filling material comprising at least one metallic powder and at least one organic binder and having, at the time of filling, a viscosity of between 1000 mPa.s and 1,000,000 mPa.s.

[0016] The use of a composite material makes it possible to adapt the color of the substrate to that of the support.

Brief description of the drawings

The aims, advantages and characteristics of the present invention will emerge more clearly in the following detailed description of at least one embodiment of the invention given solely by way of non-limiting example and illustrated by the accompanying drawings in which : Fig. 1 schematically shows a decorative support using the present invention; and fig. 2 to 7 schematically illustrate the steps of an assembly method according to the invention.

Detailed description of the invention

[0018] With reference to FIG. 1, there is shown a decorative piece 1 comprising a decorative support 2 according to the invention in which is mounted a decorative element 3. The decorative piece 1 is for example a watch bezel inlaid with indices which constitute decorative elements. The decorative piece 1 could also be a watch crystal or a dial or any interior or exterior part of a watch or a timepiece. The decorative piece 1 can also be a pen or a cufflink or an item of jewelry such as a ring or an earring.

The support 2 can be any type of material, and more particularly any hard and fragile material, which does not have sufficient plastic deformation for the implementation of a conventional crimping process. The material of the support 2 has a higher melting temperature than that of the composite filling material. Advantageously, the support 2 is made of a material chosen from the group comprising ceramics, cermets, sapphire, ruby, diamond, silicon, quartz or glass. The surface of the support 2 on which the decorative element 3 is mounted can be flat or curved (concave or convex).

The support 2 has a cavity 4 filled with a filling material forming a substrate 6, said substrate 6 being used to receive the decorative element 3 and allow the mounting of said decorative element 3 on the support 2. In particular, the substrate 6 may include hooking means 5 which deform to hold the decorative element 3.

For this purpose, and in accordance with the invention, the method of mounting the decorative element 3 on the support 2 comprises the first step a) consisting in providing a support 2, preferably in a material which does not deform plastically such as ceramic, as shown in fig. 2, and to produce at least one cavity 4 in the support 2, as shown in FIG. 3. The cavity 4 can be produced for example by laser machining or any other technique appropriate to the material of the support 2. Preferably, the cavity 4 has flanks perpendicular to the visible surface of the support 2. In order to improve the final grip of the support. substrate 6 in the support 2, it is possible to machine in the cavity 4 negative undercuts or hooking holes or any other particular structuring of the bottom of the cavity.

In addition, the method of mounting the decorative element 3 on the support 2 can advantageously comprise, before step c), an additional step h) of metallization of the surface of the cavity 4. The walls of the cavity 4 can be covered with a metallization layer making it possible to improve the adhesion of the composite filling material on the support 2. Such a metallization layer can be based on gold, nickel or chromium and has a melting point. greater than that of the composite filler material.

Step b) of the process consists of providing a decorative element 3. These decorative elements can be precious stones, such as diamonds or rubies, or non-precious stones such as zircons, or any other decorative element appropriate.

[0024] The next step c) of the process consists in filling the cavity 4 with a composite filling material. According to the invention, the composite filling material comprises at least one metallic powder, at least one organic binder and possible additives, and has, at the time of filling, a viscosity of between 1000 mPa.s and 1000,000 mPa .s.

Such a composite filler material is for example in the form of solder paste, sold for example by the company Hilderbrand & Cie SA. The presentation of the composite filling material in the form of a paste allows local and very easy application of the composite filling material in the cavity 4. In particular, the pasty form of the composite filling material makes it possible to fill the cavity 4 without any stress. mechanical support 2. Therefore, if the support 2 is made of a fragile material, there is no risk of it breaking. The viscosity of the composite filling material, at the time of filling, that is to say at the time of its application into the cavity 4, is preferably between 5,000 mPa.s and 500,000 mPa.s. The composite filler material can be thixotropic and have a higher viscosity at rest.

Preferably, the metallic powder comprises at least one metallic element chosen from the group comprising, in the form of an element or an alloy, gold, silver, copper, platinum, palladium, l aluminum, titanium, zinc, tin, gallium, indium, nickel, silicon, germanium, and mixtures thereof.

Examples of metal powder composition are shown in the table below:

[0028] Precious alloys, based on platinum, palladium and gold are particularly preferred because they offer good corrosion resistance and good color stability (no oxidation or tarnish when worn).

The diameter of the metal particles used for the metal powder is typically less than 500 μm, and preferably less than 100 μm. The particle size distribution can be unimodal or multimodal. A multimodal (eg bimodal) distribution can be chosen to increase the volume percentage of the metallic phase in the total volume of the composite. Advantageously, the composite filler material comprises at least 50% by volume, and preferably at least 60% by volume, of metal powder relative to the total volume of the composite filler material.

[0030] The organic binder is generally in the form of a mixture of organic binders chosen according to the desired properties of the composite filler material in the pasty state. Preferably, the organic binder is chosen from the group comprising cellulose, glycerin, glycols, resins, petroleum distillates, and mixtures thereof. The binder will be removed during the step of heating the composite filler material.

[0031] Advantageously, the composite filler material can include additives, such as at least one stripping agent or flux additive, to deoxidize the surfaces and improve the wettability between said liquid composite filler material and the support. Flux additives are formed from a mixture of mineral salts and / or acids such as boric acid, borax, boron, alkali borates (potassium pentaborate, potassium tetraborate, ...), (bi-) alkali fluorides ( aluminum fluoride, potassium bifluoride, ...), chlorides (zinc chloride, lithium chloride, ammonium chloride, ...) acids (hydrochloric acid, phosphoric acid, etc.). Additives will be removed during the heating step of the composite filler material.

[0032] The next step d) of the process consists in heating the composite filling material to a temperature above its melting point to melt it and make it liquid. The heating of the composite filling material is achieved by an energy input such as an oven, a laser beam, an ion beam or any other thermal means. The temperature depends on the nature of the composite filling material, and can be between 200 ° C and 1000 ° C for example. The liquid composite filling material has the advantage of filling the entire volume of cavity 4 well, regardless of its shape, in particular by virtue of its good wettability and / or by capillary effect.

[0033] The next step e) of the process consists in allowing the filling material to cool. The cooling temperature cycle is standard. Typically, during cooling, the temperature is lowered from 10 ° C / min to 100 ° C / min in industrial brazing furnaces. No rapid cooling is applied. The cooled and solidified filling material constitutes a substrate 6 in crystalline form.

[0034] Steps c) to e) can be carried out successively at least twice. Indeed, after the first filling of the cavity 4, a withdrawal of the filling material can be created in the cavity 4, after cooling. It is therefore necessary to apply at least a second layer of composite filling material in the cavity 4, to heat, then to cool, in accordance with steps c) to e) described above. Steps c) to e) are repeated until the filling material reaches the desired height in cavity 4.

The possible next step i), between steps e) and f), consists of eliminating the filling material present around the cavity 4. This excess filling material around the cavity 4 can be removed by any suitable process, such as polishing, machining, etc.

We then obtain a support 2 as shown in FIG. 4, comprising a cavity 4 filled with a non-amorphous and only metallic substrate 6, the organic binder and the additives having been burned or having evaporated during the heating step d).

[0037] The next step f) of the process consists in making at least one housing 8 in the substrate 6, as shown in FIG. 5. This step can be performed by conventional methods such as machining, milling, drilling, etc.

[0038] The next step g) of the process consists in mounting the decorative element 3 in the housing 8.

[0039] According to a first variant, step g) of the assembly of the decorative element 3 is carried out by driving. To do this, the decorative element 3 is made so as to have dimensions slightly larger than those of the cavity 4 and to forcefully enter said cavity 4.

[0040] According to a second variant, step g) of mounting the decorative element 3 is carried out by crimping. In this case, step g) comprises the production of hooking means 5 in the substrate 6 and the crimping of the decorative element 3 by deformation of said hooking means 5 so as to maintain said decorative element 3 in its housing. 8. More specifically, the hooking means 5 are in the form of at least one crimping element 9. This crimping element 9, in the case for example of a crimping grains, consists of studs or grains arranged on the perimeter of each housing 8. These studs 9, visible in FIGS. 6 and 7, are produced by machining, before or after the drilling of the housings 8. In fact, during the machining of the housings 8, the material of the substrate 6 is removed so as to form these crimping elements 9. Preferably , in the case of a grain crimping, it is ideal to have four crimping grains 9 near housing 8.

[0041] It is obvious that other types of crimping can be envisaged, such as closed crimping, rod crimping, rail crimping or invisible crimping are possible. For example, the closed crimp consists of a single crimp element 9 extending around the periphery of the decorative element 3. The baguette crimp is used to crimp the decorative elements 3 cut into a baguette. This crimping consists in providing crimping elements 9 extending parallel to each side of the decorative element 3 coming to fall back on the latter. For invisible crimping, provision is made for the crimping elements 9 to be protruding portions arranged in the housing 8. These protruding portions cooperate with at least one groove made on said decorative element 3 so that the crimping is done by inserting the. decorative element 3 in the housing 8 until the projecting portions fit into said groove.

The crimping step consists in placing the decorative element 3 in the housing 8 and in deforming the hooking means 5 to press them onto said decorative element 3. As a result, the latter is held in the housing 8 The deformation of the hooking means 5 is effected by means of a tool called a beader 100 used to deform each crimping element 9, as shown in FIG. 8. This gives the decorative element 3 crimped as shown in FIG. 9. The filling material constituting the substrate 6 is sufficiently ductile to allow deformation of the attachment means.

[0043] It is obvious that any other suitable method for mounting the decorative element in the substrate can be used. An advantage of the invention is that it allows the decorative element to be mounted in any type of material, and in particular in a hard and / or fragile material. Indeed, the principle used is a principle of attached part, that is to say that a substrate made of a material capable of accepting a deformation is attached in a plastically non-deformable material so as to allow mounting of a decorative element, such as than a crimping, and to give the illusion that it is this plastically non-deformable material which is crimped. The support material, which is not plastically deformable, does not undergo any mechanical stress, and therefore does not risk breaking.

So that the illusion of mounting in the support 2 is intact, it is expected that the width of the cavity 4 is ideally equal to that of the decorative element 3. Consequently, the distance between the element decoration 3 and the edge of the cavity 4 should be reduced to a minimum, and ideally zero, so that the filling material is not visible and give the impression that the decorative element 3 remains embedded in the support 2 in ceramic for example and not in the filling material. In practice, the distance between the decorative element 3 and the edge of the cavity 4 will depend on the dimensions and shapes of the decorative elements 3. By way of example, for a decorative element 3 with a diameter of 1 mm, the distance between the decorative element 3 and the edge of the cavity 4 will be 0.45 mm.

In addition, the use of a composite filling material makes it possible to have a very large number of different compositions, making it possible to produce a substrate whose color is adjusted for example to the color of the decorative element or by compared to other components of the room in which the decorative support is used.

[0046] Furthermore, the use of a composite filler material makes it possible to have a very large number of different compositions making it possible to improve the affinities of the composite filler material with the support. In particular, the use of a composite filling material offers great flexibility in the choice of the composition in order to match the chemistry of the composite filling material to that of the support. For example, the basic element constituting the metal powder of the composite filling material is the same as the basic element constituting the support 2 in order to ensure a chemical affinity between the composite filling material and the support. It is also possible to choose the composition of the composite filling material so that the latter has a coefficient of thermal expansion similar to that of the support. The addition of a stripping agent improves the wettability of the composite filler material.

Claims (15)

1. A method of mounting at least one decorative element (3) on a support (2) comprising the steps of: a) have a support (2) provided with at least one cavity (4); b) have at least one decorative element (3); c) filling said cavity with a composite filling material comprising at least one metallic powder and at least one organic binder and having, at the time of filling, a viscosity of between 1000 mPa.s and 1,000,000 mPa.s; d) heating the composite filler material to a temperature above its melting point to make it liquid; e) allowing the filling material to cool to form a substrate (6); f) making at least one housing (8) in said substrate (6); g) mounting said decorative element (3) in said housing (8). 2. Method according to claim 1, characterized in that the composite filling material comprises at least 50% by volume, and preferably at least 60% by volume, of metal powder relative to the total volume of the composite filling material. 3. Method according to one of the preceding claims, characterized in that the composite filling material further comprises at least one stripping agent. 4. Method according to one of the preceding claims, characterized in that the metallic powder of the composite filling material comprises at least one metallic element chosen from the group comprising, in the form of an element or an alloy, gold, silver, copper, platinum, palladium, aluminum, titanium, zinc, tin, gallium, indium, nickel, silicon, germanium, and mixtures thereof. 5. Method according to one of the preceding claims, characterized in that the organic binder of the composite filling material is chosen from the group comprising cellulose, glycerin, glycols, resins, petroleum distillates, and mixtures thereof. 6. Method according to one of the preceding claims, characterized in that step g) is carried out by driving. 7. Method according to one of the preceding claims, characterized in that step g) is carried out by crimping, and in that step g) comprises the production of hooking means (5) in the substrate (6). ) and the crimping of the decorative element (3) by deformation of said hooking means (5) so as to maintain said decorative element (3) in its housing (8). 8. Method according to one of the preceding claims, characterized in that it further comprises, before step c), a step h) of metallization of the surface of the cavity (4) of the support (2). 9. Method according to one of the preceding claims, characterized in that it further comprises, between steps e) and f), a step i) consisting in removing the filling material present around the cavity. 10. Method according to one of the preceding claims, characterized in that steps c) to e) are carried out successively at least twice. 11. Decorative support (2) intended to receive at least one decorative element (3) and provided with at least one cavity (4) filled with a filling material forming a substrate (6) in which at least one housing (8) ) is arranged, said housing (8) being arranged to receive said decorative element (3), characterized in that said filling material is obtained from a composite filling material comprising at least one metal powder and at least one binder organic and having, at the time of filling, a viscosity of between 1,000 mPa.s and 1,000,000 mPa.s. 12. Decorative support (2) according to claim 11, characterized in that the metallic powder of the composite filling material comprises at least one metallic element chosen from the group comprising, in the form of an element or an alloy, gold. , silver, copper, platinum, palladium, aluminum, titanium, zinc, tin, gallium, indium, nickel, silicon, germanium, and mixtures thereof. 13. Decorative support (2) according to one of claims 11 and 12, characterized in that it is made of a material chosen from the group comprising ceramics, cermets, silicon, sapphire, ruby, diamond. and quartz. 14. Decorative support (2) according to one of claims 11 to 13, characterized in that the base element constituting the metal powder of the composite filling material is the same as the base element constituting the support (2) . 15. Decorative support (2) according to one of claims 11 to 14, characterized in that the substrate (6) further comprises hooking means (5) deforming to hold said decorative element (3).