METHOD FOR MANUFACTURING DECORATIVE PARTS

Abstract

A method is for manufacturing a part including a support made of an electrically non-conductive material, the support being provided with at least one recess filled with an aesthetic element made of an electrically conductive material, and the aesthetic element forms a decoration on a side of the part that is intended to be visible. The method includes inlaying by pressing a preform intended to form the aesthetic element into the at least one recess of the support, and treating the surface of the aesthetic element. The at least one recess opens in one or more places onto a side of the part that is intended to be non-visible, to respectively form one or more contact points for carrying current across the aesthetic element during the surface treatment.

Claims

1-16. (canceled)

17. A method for manufacturing a part comprising a support made of an electrically non-conductive material, said support being provided with at least one recess filled with an aesthetic element made of an electrically conductive material, said aesthetic element forming a decoration on a side of the part that is configured to be visible, the method comprising: providing the support having said at least one recess and providing a preform configured to form the aesthetic element of the part; inlaying by pressing the preform into said at least one recess in the support; and electrochemically treating the surface of the aesthetic element, wherein said at least one recess opens in one or more places onto a side of the part that is configured to be non-visible, to respectively form one or more contact points for carrying current across the aesthetic element during the surface treatment.

18. The method according to claim 17, wherein the support is made of a material chosen from among ceramic, sapphire and enamel.

19. The method according to claim 17, wherein the aesthetic element is made of an amorphous metal, a crystalline metal or one of their alloys.

20. The method according to claim 17, wherein the aesthetic element is made of an aluminium, titanium or precious metal alloy.

21. The method according to claim 17, wherein said electrochemically treating the surface is performed after mechanical grinding following the inlaying.

22. The method according to claim 17, wherein said electrochemically treating the surface is performed after setting stones in the aesthetic element inlaid in said at least one recess.

23. The method according to claim 17, wherein said electrochemically treating the surface is performed is an anodizing process or a metal deposition process.

24. The method according to claim 17, wherein said electrochemically treating the surface is performed is an anodizing process or a metal deposition process of a precious metal.

25. A part comprising: a support made of an electrically non-conductive material, said support being provided with at least one recess filled with an aesthetic element made of an electrically conductive material, said aesthetic element forming a decoration on a visible side of the part, wherein said at least one recess opens in one or more places onto a face of the part that is configured to be non-visible and the aesthetic element includes a surface coating layer.

26. The part according to claim 25, wherein the coating layer is an anodized layer or a metallic layer notably of a precious metal.

27. The part according to claim 25, wherein the support is made of a material chosen from among ceramic, sapphire and enamel.

28. The part according to claim 25, wherein the aesthetic element is made of an amorphous metal, a crystalline metal or one of their alloys.

29. The part according to claim 25, wherein the aesthetic element is made of an aluminium, titanium or precious metal alloy.

30. The part according to claim 25, wherein the part is an external component for horology or jewellery.

31. The part according to claim 30, wherein the part is a watch bezel forming the support with said at least one recess inlaid with the aesthetic element forming an index or an annular portion of the bezel.

32. The part according to claim 30, wherein the part is a case middle forming the support with said at least one recess inlaid with the aesthetic element forming a portion of the case middle that extends up to a horn of the case.

33. The part according to claim 32, wherein said at least one recess communicates with a hole or insertion of the spring bar arranged in the horn of the case middle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 represents a plan view of a decorative part, and more precisely a watch bezel including indices that are inlaid and electrochemically treated by the manufacturing method of the invention.

[0011] FIG. 2 represents a partial sectional view of this same decorative part.

[0012] FIGS. 3 to 5 schematically represent the steps of inlaying the preform in the support.

[0013] FIG. 6A represents a view of the front side, i.e. the visible side, of the bezel inlaid with several aesthetic elements, and a sectional view focused on one aesthetic element. FIG. 6B represents a view of the back side of this same bezel.

[0014] FIG. 7A represents a three-dimensional view of a watch case whose case middle includes a recess communicating with the hole for insertion of the spring bar. FIG. 7B represents the same watch case including an aesthetic element inlaid in the recess. FIG. 7C represents the same watch case including the aesthetic element inlaid in the recess and set with stones.

DETAILED DESCRIPTION

[0015] The present invention relates to a method for manufacturing a decorative part including a step of inlaying by hot pressing one or more aesthetic elements in a support provided with one or more recesses and including a step of electrochemically treating the surface of said aesthetic elements It also concerns the decorative part produced by the method. The part can, in particular, be an external timepiece component, such as a bezel, a dial, a case, a crown, a push-button, a crystal, a bracelet element, etc. By way of example illustrated in FIGS. 1 and 2, part 1 is a watch bezel including an annular body forming the support 2 provided with recesses 4 arranged in said support 2 for receiving the aesthetic elements 3 forming the indices. By way of another example illustrated in FIGS. 7A to 7C, part 1 is a watch case middle 5 provided with two recesses 4 each inlaid with one aesthetic element 3 set with stones 6.

[0016] According to the invention, the support is made of an electrically non-conductive material, such as a ceramic, an enamel, a sapphire, etc. The aesthetic element is made of an electrically conductive material such as a crystalline or amorphous metal alloy. For example, it may be an alloy of aluminium, of titanium or of precious metals such as gold alloys or platinum alloys. Thus, still by way of example, the part can consist of a zirconia watch bezel with indices made of a crystalline aluminium alloy.

[0017] Support 2 includes at least one recess 4 made by laser etching, machining etc. On the surface 2a of support 2 that is intended to be visible, recess 4 has a shape 4a corresponding to the contour of the desired decoration (FIG. 2). According to the invention, at least one of the recesses opens onto a non-visible side 2b of support 2. Advantageously, the whole space of recess 4 is filled with aesthetic element 3 which projects from or is flush with surface 2a of support 2. In a variant, it is also possible for the aesthetic element to only partially fill the space of the recess.

[0018] According to the invention, the aesthetic elements are inlaid by a hot pressing process in the recesses of the support. The pressing temperature is variable according to the inlaid material. For example, for a crystalline metal alloy, inlaying is performed at a temperature comprised between the solidus temperature and the liquidus temperature of the alloy forming the aesthetic element. For an amorphous metal alloy, inlaying is performed at a temperature comprised between the glass transition temperature Tg and the crystallisation temperature Tx of the alloy. Likewise, the pressure is adapted according to the material. For example, the load may be comprised between 300 and 1000 kg. The inlay process is performed in a similar manner to that described in EP Patent No. 2315673. More precisely, the inlay steps of the manufacturing method of the invention are schematically illustrated with reference to FIGS. 3 to 5. Firstly, support 2 provided with recess(es) 4 and the preform(s) intended to form the aesthetic element(s) 3 are provided (FIG.3). In the case of a watch bezel to be decorated with indices, the aesthetic element to be inlaid takes the form of an annular preform with a ring diameter and width of substantially equivalent dimensions to those of the indices. Preform 3 is placed on surface 2a of support 2 in recess 4. The assembly is placed in a press and the inlay process is performed under a pressure P within the aforementioned temperature ranges in which the material is softened (FIG. 4). The step of inlaying the alloy in the recesses is then followed by a cooling step and possibly a mechanical grinding step performed on upper surface 2a and aesthetic element 3, such as polishing, to remove any surplus from aesthetic element 3 (FIG. 5) and to create exposed surfaces of the support and of the aesthetic element that are connected to each other without discontinuity.

[0019] By way of example, in the case of an aluminium 7075 alloy inlay in a zirconia support, the preform was heated at 550 C. for 90 seconds and pressed under a load on the order of 750 kg.

[0020] After the inlay step and any mechanical grinding step, the aesthetic element is subjected to a finishing treatment. This finishing treatment consists of a selective electrochemical treatment of the inlaid metallic material intended to change the appearance and/or hardness of said material. It may be an anodizing process with or without dyeing, deposition of a precious metal, such as silver, gold, rhodium, platinum, etc. It is thus possible to envisage inlaying a less expensive aluminium alloy and then hardening it with an anodizing process or inlaying a less expensive conductive material and then electroplating a precious metal. As the present invention is intended for electrically non-conductive supports, the difficulty lies in carrying the current to the aesthetic elements during the electrochemical treatment via contact points which absolutely must be non-visible on the decorative part. To this end, one or more of the recesses are configured to open onto a side of the decorative part that is intended to be non-visible. These recesses opening onto the non-visible side form as many contact points for carrying current across the inlaid aesthetic elements. Returning to the example of the ceramic watch bezel having metallic indices formed by an inlay process, the recess 4 for each of the indices opens onto the back side 2b of bezel 1, as illustrated in FIG. 2. Contact points 4b carry the current across each of the indices during the electrochemical treatment. These contact points 4b on back side 2b of support 2 can have a smaller cross-section than that of part 4a of the recess opening onto visible side 2a of support 2. These contact points make it possible to perform the same electrochemical treatment for each index or to combine different treatments by only carrying the current across one or more of the indices for each electrochemical treatment.

[0021] If aesthetic element 3 is of larger size, as in the examples of FIGS. 6A and 7B, several contact points may be required per aesthetic element in order to ensure a uniform electrochemical treatment of the aesthetic element. In FIG. 6A, for example, three aesthetic elements 3 are arranged on an annular portion of visible side 2a of bezel 1. In this configuration, aesthetic elements 3 are inlaid on substrate 2 including the indices made of a non-conductive material. On its back side 2b visible in FIG. 6B, bezel 1 is provided with several orifices 4b communicating with recesses 4 to form the contact points for carrying current across these three elements. As represented in the sectional view of FIG. 6A, two contact points 4b are provided per aesthetic element 3. FIGS. 7B and 7C represent another configuration of an aesthetic element inlaid in a recess arranged in a support. The inlaid aesthetic element 3 extends as far as a horn 5a of watch case middle 5 and includes a plurality of housings 3a for setting stones 6 in a subsequent operation, which is particularly advantageous for decorating watch cases made of non-ductile material such as ceramic. In a similar manner to the other examples, the recess receiving the aesthetic element opens in at least one place onto a non-visible side of the watch case. It is thus possible for recess 4 to communicate with hole 7 for insertion of the spring bar, as illustrated in FIG. 7A. Of course, recess 4 can communicate in several places via other through orifices to make contact points carrying current to aesthetic element 3. By means of contact point(s) provided on a non-visible side of the watch case, the present invention thus makes it possible to perform an electrochemical treatment on the aesthetic element once the stones have been set.

[0022] The present invention was more specifically illustrated for a decorative part used in horology, but it is evident that the method of the invention applies to the making of decorative parts in many other fields, such as jewellery, telephony, the automobile industry, etc.

Key to Drawings

[0023] (1) Decorative part

[0024] (2) Support [0025] a. Visible side [0026] b. Non-visible side

[0027] (3) Aesthetic element or preform [0028] a. Housing

[0029] (4) Recess [0030] a. Portion opening onto the visible side of the support [0031] b. Portion opening onto the non-visible side of the support

[0032] (5) Watch case [0033] a. Horn

[0034] (6) Stone

[0035] (7) Hole for insertion of the spring bar