Method for fabricating timepiece components including a decorative coating of aventurine

Abstract

A method for fabricating a timepiece component partly formed of aventurine, including providing at least one piece of aventurine formed of a mass of coloured glass containing copper crystals scattered throughout the mass; grinding at least one piece of aventurine to obtain a granular powder; depositing at least part of the granular powder on a surface of a support intended to receive a decorative coating; then introducing the support with the granular powder deposited on the surface into a furnace and melting this granular powder so as to obtain, after removing the assembly thus obtained from the furnace and allowing the assembly to cool, an enamel layer made of aventurine which covers the support surface. The timepiece component is, for example, a dial, a moon phase disc or a bezel.

Description

FIELD OF THE INVENTION[0001]The present invention concerns a method for fabricating timepiece components including a decorative coating of aventurine, in particular a method for fabricating watch dials partially formed of aventurine.BACKGROUND OF THE INVENTION[0002]It has been known for a long time to make watches incorporating, for decoration, parts made of precious or semi-precious stones. In particular, it is known to make dials from precious stones, for example lapis-lazuli, which give watches the character of jewelry.[0003]To make dials from precious or semi-precious stones, firstly, stones are provided which are cut into thin slices, which are then polished and cut. Current cutting techniques make it possible to cut various profiles and to make apertures in the thin slices obtained. It will be noted that, to make the stone dial less brittle and to ensure its positioning in the watch, those skilled in the art generally bond fine slices of stone onto metal supports, preferably m...

AI Technical Summary

Benefits of technology

[0022]In another preferred variant, a final step of polishing the decorative coating is performed, this polishing can have a preliminary phase consisting of stone cutting to better level out the upper surface of the decorative coating. Polishing is made easier to carry out and the result is generally better when a flux layer is deposited on the aventurine enamel. Indeed, the cooled flux layer can be polished to give a perfectly smooth upper surface, whereas the aventurine enamel is problematic for polishing due to the presence of copper crystals in the aventurine enamel which may be at or close to its surface.

[0023]In a particular implementation of the method of the invention, enamelling is performed on a back surface of the support, i.e. on the opposite side to that of the surface intended to receive the decorative coating, this enamelling forming a counter-enamel to better preserve the initial shape of the support when one or more enamel layers are formed to make the decorative coating and to prevent cracks appearing in this decorative coating as it is made.

Problems solved by technology

Indeed, these aventurine dials are difficult to prepare and to assemble.

Cutting aventurine pieces into thin slices and cutting the desired profiles into these slices generates quite a lot of waste.

Further, aventurine quite often has small air bubbles which appear after polishing and which make the thin slices obtained unusable.

Moreover, these thin slices are fragile and therefore brittle.

They are awkward to handle and assembling these thin slices with their respective supports to make the dials is a complex operation.

It will also be noted that even transferring motifs and / or hour symbols onto slices of aventurine is likely to crack them.

This method requires various handling operations, so there is a significant risk of breaking the slice.

However, the process of assembling a thin aventurine slice thus perforated to its support carries a significant risk of breaking it.

It is understood, therefore, that it is necessary to have manufacturing tolerances so that small gaps appear between the embossed motifs and / or hour symbols and the perforated aventurine slice, which is detrimental to the aesthetics of the dial and therefore to its quality.

Next, it was noted that, even once bonded to their respective supports, these thin aventurine slices remain fragile and can crack or break in case of shocks to which watches must generally be resistant.

This creates small crevasses visible to the naked eye, which thus impairs the aesthetic appearance of these dials.

Moreover, these small fragments can easily get into the watch movements of watches provided with aventurine dials thus damaged by shocks and impair or block their functioning.

Finally, another drawback lies in the fact that possible embodiments are limited by the fact that flat aventurine slices are generally used for making dials, so that the dials are flat.

It is, of course, possible to machine pieces of aventurine to make aventurine glass that is convex, at least on top, but the manufacturing cost will be very high.

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