CH704681A2 - Enamelled part, useful for dial of timepiece, jewelry and gemstones that are useful for cuff links, earrings and pendants, comprises ceramic substrate coated with first enamel layer to improve appearance of part, and second enamel layer - Google Patents

Abstract

The invention relates to an enameled part for a dial comprising a ceramic substrate coated with a first enamel layer (12) in order to improve the appearance of said part. According to the invention, the piece comprises at least one other enamel layer (16) partially covering the first enamel layer (12) to form a decoration with a similar improved appearance. The invention also relates to a manufacturing method for such a part. The invention relates to the field of timepieces, jewelery and jewelery.

Description

Field of the invention

The invention relates to an enamelled piece for a timepiece or jewelry and more specifically, such a piece with decorations.

Background of the invention

It is known from EP 1 640 822 to produce enamelled dials with high-end appearance from a ceramic substrate coated with an enamel layer to make them less artisanally. However, it becomes necessary to also form the indexes or graduations according to the same high-end appearance. Currently, as an example, it is not possible to make sets with the same rendering main remaillage of the dial or even offer metal decorations rendering as high-end.

Summary of the invention

The object of the present invention is to overcome all or part of the disadvantages mentioned above by providing enamelled parts, such as for a dial, whose metallized decorations or not are made substantially equivalent to main remeshing of the piece.

For this purpose, the invention relates to an enamelled piece for a dial having a ceramic substrate coated with a first enamel layer to improve the appearance of said piece characterized in that it comprises at least one other enamel layer partially covering the first enamel layer to form a decor with a similar improved appearance.

It is therefore understood that, preferably according to the invention, it is possible to obtain enameled parts for a dial, that is to say the dial itself or a part attached to the dial or a part similar to a dial, whose decorations, metallized or not, offer a consistent overall performance compared to main remaillage of the piece, that is to say, upscale.

According to other advantageous features of the invention: the enamelled piece has several other layers of enamel partially covering the first layer of enamel; said at least one other layer is of different color and / or substantially identical to the first enamel layer; said at least one other layer is completely covered with a metal layer so that said decoration has a reflection that is homogeneous regardless of the light incidence; said at least one other layer is partially covered with a metal layer so that said decoration has a reflection which is homogeneous irrespective of the light incidence and comprises a pattern of the color of said at least one other layer; said decoration forms at least one alphanumeric symbol and / or a drawing.

In addition, the invention relates to a method of decorating an enamelled piece for a dial comprising the following step: a) forming a ceramic-based substrate whose visible portion is coated with a first enamel layer;

[0008] characterized in that it comprises the following steps: b) selectively forming another enamel layer over the first enamel layer to form a pattern on said visible surface.

According to other advantageous features of the invention: several steps b) are performed so that several layers of enamel are formed over the first enamel layer; step b) comprises phases c): selectively printing, on said first enamel layer, said decoration using a solution precursor of said another enamel layer and d): heating the room to transform the precursor enamel solution; the transformation temperature of the said other enamel layer is at least 100 ° C lower than that of the first enamel layer so as not to damage it during each step b); phase c) is performed by pad printing or screen printing; said another layer is of different color and / or substantially identical to the first enamel layer; the method comprises the final step e): completely covering said another layer of enamel with a metal layer so that said decoration has a reflection that is homogeneous regardless of the light incidence; the method comprises the final step e '): partially covering said another layer of enamel with a metal layer so that said decoration has a reflection which is homogeneous regardless of the light incidence and comprises a pattern of the color of said another enamel layer.

Brief description of the drawings

Other features and advantages will become apparent from the description which is given below, for information only and not limiting, with reference to the accompanying drawings, in which: fig. 1 is a representation of a first variant of application according to the invention; fig. 2 is a representation of a second variant of application according to the invention; fig. 3 is a representation of a third variant of application according to the invention; fig. 4 is a representation of a fourth variant of application according to the invention; figs. 5-7 are representations of main steps of a decoration method according to a first embodiment of the invention; fig. 8 is a representation of a final optional step of the decoration method according to a second embodiment of the invention.

Detailed Description of the Preferred Embodiments

The invention has been developed for an enameled part of a timepiece such as a dial or a crown. Of course, the present invention can not be limited to the field of watchmaking. Other applications are also conceivable, such as, for example, jewelery or jewelery for cufflinks, earrings or pendants.

Thus, in FIG. 1, we can see an example of a timepiece 1 whose dial 3 has most of the pitfalls that can be encountered. The dial 3 thus comprises a main surface P constituting the widest visible face.

As shown in FIG. 1, over the surface P, the dial 3 may include, reported (s), an hour turn 2 and / or a secondary display 4 formed (s) by at least one index and / or at least one alphanumeric symbol .

The dial 3 may also include a secondary display 5 whose visible surface is mounted in a plane above the surface P to form a raised area. Conversely, the dial 3 may also include a secondary display 6 whose visible surface is mounted in a plane below the surface P to form a recessed area.

The dial 3 may also include a window 7, that is to say an opening of the dial 3 to show a portion of the movement 8 mounted under the dial 3, as a moon phase 11 in the example of fig. 1.

The invention relates advantageously to a decorated enamelled piece having a single plane P, that is to say comprising a single plane surface or not, or several planes. According to the invention, the enameled part comprises a ceramic substrate which is coated with a first layer of enamel to improve the appearance of said dial. Of course, when we speak of an enamel layer in the present text, it is necessary to understand a stack of coatings of the same enamel with a thickness of between 0.1 mm and 0.4 mm making it possible to give the color more or less sustained desired.

Advantageously according to a first embodiment of the invention, the enameled part comprises at least one other layer of enamel partially covering the first layer of enamel to form a decoration with an improved appearance similar to that of the first enamel layer. The term at least one other enamel layer is understood as one or more layers. Each layer may cover the first layer of enamel and / or another layer of enamel as will be explained below.

Thus, advantageously according to the invention, each at least one other layer may be of different color or substantially identical to the first enamel layer. Indeed, it is sometimes desirable to include "secret" signatures, that is to say hardly identifiable at first glance. This is made possible by the application of a second enamel layer of the shape of the signature 9, as illustrated in FIG. 1, a color substantially identical to that of the first enamel. The signature 9 will then be visible only by the shadow that it will project in grazing light incidence.

Each at least one other layer may also comprise a different color layer. Thus, a first possibility may consist in forming the entire decoration with a layer of a single second enamel cutting with the color of the first enamel. By way of example, a rendering quality close to the first enamel layer is obtained while contrasting the decoration with respect to the first enamel layer as shown in FIG. 1for the hour turn 2.

Alternatively to this first possibility, parts of the decor may include a thicker layer of the second enamel to give the impression of a gradient of color. Indeed, the parts of the decor having less thickness of the second enamel, let, through transparency, pass part of the color of the first enamel giving the impression of an intermediate color.

By way of example, the part 21 of FIG. 3forms an enamel layer celestial card 25 over a first layer of white enamel 24. In order to present a variation of light blue to dark blue, an area 22 has a smaller thickness of the second enamel 25 than the rest of the decor passing from zone 22 of the light blue towards the rest of the decor in dark blue from the same type of enamel layer 25.

A second possibility may consist in forming several layers of different colors to provide a more refined presentation called "degraded". The decoration 2 illustrates in FIG. 4 this second possibility by at least one layer of an enamel intermediate color, which layer is then itself partially covered with said layer of second enamel cutting edge with the color of the first enamel. For example, it is thus possible, for a first white enamel 4, to successively form an intermediate layer of enamel 6 gray for all the decor 2 and a final layer of enamel 8 black in the widest parts of the decor 2.

According to a second embodiment of the invention, said at least one other layer is, advantageously, totally or partially covered with a metal layer so that said decoration has a reflection that is homogeneous whatever the luminous incidence.

Indeed, if a metal layer is formed directly on an enamelled piece, it does not reflect the light and therefore returns its color only by a single incidence which has the disadvantage of an enamelled piece high-end rendering with dark metal parts except under a particular luminous incidence.

Advantageously according to the second embodiment of the invention, after a thickness setting made according to the first embodiment, a metal layer is formed over it. Indeed, the setting thickness makes the decor substantially curved and, once coated with a layer of metal, returns a portion of its color regardless of the light incidence. We thus obtain a metal rendering as high-end as the first layer of enamel.

Thus, according to a first alternative of the second embodiment, the metal layer covers the entire second enamel layer to present a completely metallic decoration as a clock tower 2 of FIG. 1 or the constellations 23 of FIG. 3. Of course, it is thus possible to form either fully coated surfaces such as the moon 13 of FIG. 2, only contours coated like the stars 15 of FIG. 2of which the center is empty by making visible the first layer of enamel 12.

According to a second alternative of the second embodiment, the metal layer partially covers the second enamel layer in order to present a decoration comprising a metal part and an enamelled part other than the first layer of enamel such as the moon 17 of fig. 2dont the face is formed by perforations of the metal layer by making visible the second layer of enamel 14. Of course, it is also possible to form contours coated as the stars 19 of FIG. 2 whose center is perforated to reveal the second layer of enamel 16.

It is therefore understood that, preferably according to the invention, it is possible to obtain enamelled parts for a dial, that is to say the dial itself or a portion attached to the dial or a part similar to a dial, whose decorations, metallized or not, offer a consistent overall performance compared to main remaillage of the piece, that is to say, upscale.

The manufacture of the enameled part according to the invention will be better understood in relation to FIGS. 5 to 8. The method according to the invention relates to the decoration of an enamelled piece for a dial, that is to say, suitable for a dial. According to a first step a) of a first embodiment, the method consists in forming a ceramic substrate 31 whose visible part 32 is coated with a first enamel layer 33. As can be seen in FIGS. 5 and 6, the visible surface 32 is not necessarily flat and may also include upper (s) and / or lower (s) (not shown) as explained above.

According to the invention, the process is continued with one or more step (s) b) of selectively forming another layer of enamel 35, 37, 39, 41, 43, 45 over the first layer enamel 33 to form a decoration on said visible surface 32 as shown in FIG. 7. Thus, the number of steps b) depends as explained above, if one wishes to achieve a decoration with a single layer of enamel with 45, or not 43, different thicknesses such as the invisible signature 9 of the fig. 1 or the bottom 25 of the celestial chart of FIG. 3, if it is desired to make several decorations with a single layer of enamel 39 with or without different thicknesses such as the hour turn 2 of FIG. 2, if it is desired to create a decoration with several different enamel layers 35, 41 with or without different thicknesses as the decoration 2 of FIG. 4 or if it is desired to make several decorations with several layers of enamel 37, 39, 41, 43, 45 different or not and with different thicknesses or not as the part 11 used to display moon phases.

Preferably, according to the invention, each step b) comprises a first phase c) of selectively printing, on said first enamel layer 33, the decoration 35, 37, 39, 43, 45 or on another layer of enamel. enamel 35, the decor 41 using a precursor solution of the future enamel layer, then a second phase d) of heating the workpiece to transform the precursor solution into enamel. According to the invention, the precursor solution is formed of particles, comprising enamel powder and pigments for the future coloration, which are suspended in a solvent such as oil.

In addition, the transformation temperature of the phase c) of each additional enamel layer 37, 39, 41, 43, 45 is, preferably, at least 100 ° C lower than that of the first layer. enamel 33 so as not to damage the first layer of enamel 33 existing during each step b). To achieve this, one can, for example, use so-called "small fire" enamels for decorations 35, 37, 39, 41, 43, 45 and a glaze called "big fire" for the first layer 33. As for example, the enamel "small fire" can for example react and vitrify around 600 ° C and enamel "big fire" around 1000 ° C. This difference in temperature much higher than 100 ° C is chosen so that, during warming of the enamel "small fire", the structure of enamel "big fire" is not or little influenced.

It is therefore understood that, according to the number of additional layers of enamels 37, 39, 41, 43, 45 to be added to the first layer 33, it is preferable to choose the characteristic temperatures of each of the enamels or to achieve the consecutivity each step b) from the highest transformation temperature to the lowest. Thus, it will prevent the enamel layers from being weakened and / or damaged. For example, it is preferred to use an enamel 41 which vitrifies at a lower temperature than the enamel 35, itself vitrifying at a lower temperature than the first enamel 33.

In order to allow sufficient printing accuracy, the phase c) is preferably carried out by pad printing or serigraphy to deposit clearly by contrasting the maximum layers 35, 37, 39, 41, 43, 45 of color different or not to the first layer of enamel 33.

According to the second embodiment, after the steps a) and at least a step b) of the first embodiment, the method comprises a final step e) of completely covering said another layer of enamel 39 of a metal layer 38 for forming, for example, the moon 13, the stars 15 or the constellations 23 or e ') consisting of covering only partially said another layer of enamel 37 with a metal layer 36 to form the moon 17 with the face 14 openwork or 19 stars with openwork centers.

Preferably, according to the invention, step e) or e ') comprises a first phase f) of covering the decoration or only a part with a solution of the colloidal type formed by a solvent and of the metal powder in suspension, then a second phase g) of heating the part to evaporate the solvent and form a homogeneous metal layer. According to the invention, the metal powder may be based on a precious metal such as gold or platinum.

Of course, the present invention is not limited to the example shown but is susceptible to various variations and modifications that will occur to those skilled in the art. In particular, it is understood that the shapes and dimensions of the decorations can be completely different without this complicating the manufacturing process.

In addition, as explained above, the application of the invention can not be limited to the field of watchmaking but applies to the decoration of any enamelled piece suitable for a dial as, without limitation , a decorative disc encased in a cufflink, in an earring or in a pendant.

Finally, it is obvious that a last layer may optionally be deposited by a usual pad printing. For example, if a step e) was performed instead of a step e '), this last usual pad printing step could be used, for example, to draw a face on the moon 13.

Claims (17)

An enameled part (3, 11, 21) for a dial having a ceramic substrate (31) coated with a first enamel layer (4, 12, 24, 33) to improve the appearance of said characterized in that it comprises at least one other layer of enamel (6, 8, 9, 14, 16, 25, 35, 37, 39, 41, 43, 45) partially covering the first layer of enamel (4, 12, 24, 33) to form a decor with a similar improved appearance. 2. Part according to the preceding claim, characterized in that it comprises several other layers of enamel (6, 8, 9, 14, 16, 25, 35, 37, 39, 41, 43, 45) partially covering the first layer of enamel (4 \ 12, 24, 33). 3. Part according to claim 1 or 2, characterized in that said at least one other layer (6, 8, 14, 16, 25, 35, 37, 41, 43, 45) is of different color to the first enamel layer (4, 12, 24, 33). 4. Part according to claim 1 or 2, characterized in that said at least one other layer is substantially identical in color (9, 39) to the first enamel layer. 5. Part according to one of the preceding claims, characterized in that said at least one other layer (39) is completely covered with a metal layer (13, 15, 23, 38) so that said decoration has a reflection which is homogeneous regardless of the luminous incidence. 6. Part according to one of claims 1 to 4, characterized in that said at least one other layer (37) is partially covered with a metal layer (17, 19, 36) so that said decoration has a reflection which is homogeneous regardless of the luminous incidence and comprises a pattern of the color of said at least one other layer. 7. Part according to one of the preceding claims, characterized in that said decoration forms at least one alphanumeric symbol. 8. Part according to one of claims 1 to 6, characterized in that said decoration forms at least one drawing. 9. A method of decorating an enamelled piece (3, 11, 21) for a dial comprising the following steps: a) forming a ceramic-based substrate whose visible portion (32) is coated with a first enamel layer (4, 12, 24, 33); characterized in that it comprises the following step: b) selectively forming another enamel layer (6, 8, 9, 14, 16, 25, 35, 37, 39, 41, 43, 45) over the first enamel layer (4); , 12, 24, 33) to form a decoration on said visible surface. 10. Method according to the preceding claim, characterized in that several steps b) are performed so that several layers of enamel (6, 8, 9, 14, 16, 25, 35, 37, 39, 41, 43, 45) are formed over the first enamel layer (4, 12, 24, 33). 11. The method of claim 9 or 10, characterized in that step b) comprises the following phases: c) selectively printing on said first enamel layer said decoration using a precursor solution of said other enamel layer; d) heat the room to turn the precursor solution into enamel. 12. Method according to the preceding claim, characterized in that the transformation temperature of said another enamel layer is at least 100 ° C lower than that of the first enamel layer so as not to deteriorate the latter during each step b). 13. The method of claim 11 or 12, characterized in that the phase c) is performed by pad printing or screen printing. 14. Method according to one of claims 9 to 13, characterized in that said another layer (6 8, 14, 16, 25, 35, 37, 41, 43, 45) is of different color to the first enamel layer. 15. Method according to one of claims 9 to 13, characterized in that said another layer (9, 39) is substantially identical in color to the first enamel layer. 16. Method according to one of claims 9 to 15, characterized in that it comprises the following final step: e) completely covering said other layer of enamel with a metal layer (13, 15, 23, 38) so that said decoration has a reflection that is homogeneous regardless of the light incidence. 17. Method according to one of claims 9 to 15, characterized in that it comprises the following final step: e ') partially covering said another layer of enamel with a metal layer (17, 19, 36) so that said decoration has a reflection which is homogeneous irrespective of the luminous incidence and comprises a pattern of the color of said another layer of enamel.