EP0930835B1 - Method for setting stones in the surface of a jewel produced by electroforming and resulting jewel - Google Patents

Abstract

A method for setting stones in the surface of a jewel produced by electroforming, comprising the following steps: producing a base having external shapes and dimensions with a thickness close to the gold film forming the wall of the jewel to be produced and having seats for receiving the stones; depositing on the base, before setting the stones, a protective coating, then a thin gold film; setting the stones in the seats; then depositing a second thicker gold film; and finally extracting or removing the base and the protective coating. The invention is characterized in that when the base is being produced, at least one passage is provided perpendicular to each seat, capable of communicating, once the stone is set, the space between it and the bottom of its seat with outside, so as to enable the depositing of the second gold film to reach the space. The invention is useful for jewels produced by electroforming.

Description

The present invention relates to the production of pieces of jewelry by electroforming and more particularly with the embedding of stones precious, semi-precious or synthetic in the surface of a jewel metallic, especially gold.

The principle of realization by electroforming of pieces of jewelry such as, for example, hoops, earrings, pendants, crosses, bracelets, necklaces, rings, signet rings, brooches, etc. is well known.

It consists in reproducing an object electrolytically from a model precisely designed with the location of the stones which must be trapped on the surface in housing provided for this purpose.

For example, conventionally, to make a Creole, we prepare a solid tin alloy base with outwardly shaped and dimensions to the thickness near the gold layer which will be electro-deposited from the Creole to obtain. The base is then coated by electro-deposition with a very thin layer of copper to separate the gold layer from the tin and then layer of gold that can vary between 120 and 450 micrometers compared to weight of the desired jewel.

The process for depositing gold is as follows. On the layer of copper and before placing the stones, we deposit a fine layer of gold, for example fifteen micrometers. The stones are then placed in the receiving housings. A new layer of gold is deposited, of a thickness for example between 100 and 400 micrometers, followed by a protective layer of copper.

Then, the tin base is extracted thermally, then the copper, by chemical treatment.

A hollow creole is thus obtained with the stones trapped in the surface, whose shapes and reliefs are determined by those of the base that gold married by depositing in a thin layer.

Due to the small thickness of the gold layer forming the wall of the Creole which varies between 120 and 450 micrometers, it is almost impossible perform a traditional seaming because the material is lacking for perform this operation.

Furthermore, one could consider keeping the stones captive by the only layer of gold deposited after placing the stones, but to have a solid embedding this would lead to depositing a layer of gold too thick, the face of the stones facing inwards dwellings not being the subject of an encasement complementary to that of the visible side because the deposit bath does not have access to said housings.

The present invention aims precisely to allow imprisonment solidly the stones and without substantial increase in thickness and therefore the weight of the wall of the jewel.

To this end, the subject of the invention is a method of embedding stones in the surface of a jewel made by electroforming, in which realizes a base presenting externally the shapes and dimensions to the thickness near the layer of gold forming the wall of the jewel to be obtained and fitted housing for receiving stones, deposit on the base, before setting place stones, a protective layer, then a thin layer of gold, we place the stones in said housing, then place a second thicker layer of gold, and finally extracting or removing said base and said protective layer, characterized in that during the production of the base, at at least one passage is provided at the right of each dwelling, likely to communicate, once the stone in place, the space between it and the bottom of its housing with the outside, so as to allow the bath to deposit of said second layer of gold to access said space.

It is thus possible to achieve a real embedding of each stone in his home. Indeed, on either side of the plan defined by the area of physical contact between the stone and its housing, i.e. also well externally, face side of the stone, that on the opposite side, it's ie the bottom of the receiving housing, the stone is tightly trapped between two fronts of the second layer of gold whose thickness, at least 120 micrometers, very significantly greater than that of the first layer, ensures a solid retention, the wall of the jewel, including at the level of stone housings, having the same thickness giving the jewel a good mechanical strength.

The invention also relates to the jewelry obtained in accordance to the above process.

• Figure 1 est une vue de dessus d'une base pour la réalisation d'une pièce creuse selon le procédé de l'invention ;
• Figure 2 est une vue en coupe suivant la ligne Il-Il de la base de la figure 1 ;
• Figure 3 est une vue en coupe suivant la ligne III-III de la base de la figure 1 ;
• Figure 4 représente la base de la figure 2 après dépôt d'une couche protectrice de cuivre ;
• Figure 5 représente la base de la figure 4 après dépôt de la première couche d'or ;
• Figure 6 représente la base de la figure 5 munie d'une pierre ;
• Figure 7 est une vue de dessus de la base de la figure 6 ;
• Figure 8 représente la base de la figure 6 après dépôt de la seconde couche d'or, et
• Figure 9 est une vue agrandie illustrant l'enchâssement de la pierre de la figure 8.

Other characteristics and advantages of the process of the invention will emerge from the description which follows of an embodiment, description given by way of example only and with reference to the appended drawings in which:

• Figure 1 is a top view of a base for producing a hollow part according to the method of the invention;
• Figure 2 is a sectional view along line II-II of the base of Figure 1;
• Figure 3 is a sectional view along line III-III of the base of Figure 1;
• Figure 4 shows the base of Figure 2 after depositing a protective layer of copper;
• Figure 5 shows the base of Figure 4 after depositing the first layer of gold;
• Figure 6 shows the base of Figure 5 with a stone;
• Figure 7 is a top view of the base of Figure 6;
• Figure 8 shows the base of Figure 6 after depositing the second layer of gold, and
• Figure 9 is an enlarged view illustrating the setting of the stone of Figure 8.

In Figures 1 to 3, there is shown by way of example a base traditional 1, for example of tin alloy, for the production of a part of hollow jewelry of generally parallelepiped shape having a pattern of flower with four petals 2 surrounding a circular central zone 3 intended for receive for example a semi-precious stone 4 (figure 6) in the form traditional diamond.

For this purpose, on the upper face of the base 1 is made a well 5 intended to serve as housing for stone 4.

In order to receive the stone belt 4, the housing 5 is provided with recesses 6, in the known manner. Light elevations 7 intended to represent the petals 2 are provided on the surface of the base, the ends of which facing the well 5 have, in accordance with the invention, a nose 8 slightly recessed r (FIG. 2) from the internal wall from the well 5 and projecting above said recesses 6.

The elevations 7 are at a distance from each other and separate two by two by channels 9 which extend radially from the well 5.

The first steps in the electrodeposition process are conventional. They consist in depositing beforehand on base 1 a protective metal layer 10 (FIG. 4), typically copper, on a thickness of 5 micrometers for example, over the entire surface of the based.

Then is deposited a thin layer of gold 11 (Figure 5) of thickness of fifteen micrometers for example.

The two deposited layers being of regular thickness, we find the slight shrinkage r between the wall of the well 5 and the nose 8 of the elevations 7.

Then put the stone 4 in the housing 5 (Figure 6). In this effect, and in accordance with the invention, a slight force is applied to the stone to engage it in the housing, the stone belt having a diameter slightly greater than the spacing between the noses 8, the stone thus being inserted by clipping, the belt being received in the recesses 6.

The stone 4 is thus kept away from the bottom of the well 5. It is note in this connection that in this position, the bottoms of channels 9 emerge into well 5 well below the level of the waist the stone 4.

Then, in accordance with the process of the invention, the deposition is carried out. a second layer of gold 12, of thickness significantly greater than that of the first 10, for example between 120 and 430 micrometers.

Due to the existence of channels 9, the deposit bath accesses easily in the space between the stone and the bottom of the housing 5 to deposit the same layer 12, the front of which comes in 13 in contact with the back side of stone 4, while the front of layer 12 visible in outside of the housing 5 comes in 14 in contact with the table crown of the Pierre.

Stone 4 is thus firmly trapped by the two fronts 13, 14 on either side of the plane of the stone belt.

The final stages are conventional and consist in extracting by heat treatment the base and chemically remove the copper layer 10, a second protective copper layer (not shown in the drawings) can be, before the above treatments, deposited over the gold layer 12.

The final object obtained is a hollow jewel, the part of which bears the stone 4 is shown enlarged in Figure 9.

It is in particular to note that not only the stone is perfectly and securely embedded but also the wall of the well 5 has a significantly reinforced thickness due to the existence of the second layer of gold 12. It is obvious that in the absence of channels 9, this wall would only consist of the first layer of gold 11 of which the thickness would be likely to weaken the jewel.

The table 15 of the stone can be at the level of the ends in look of the petals 2 of the decorative pattern or at a different level.

Finally, the invention is obviously not limited to the embodiment shown and described above, but on the contrary covers all variants in particular with regard to the nature, shape and dimensions of the jewel, the number of stones 4, their shape, the shapes and dimensions of the receiving housings, number, shape, arrangement of channel (s) 9 or the like intended to convey the gold deposit bath under the stones in place in their housing, as well as the shape, dimensions and distribution of parts such as the noses 8 of the elevations 7, decorative or not, intended to allow engagement by clipping of the stones in their housing, before depositing the second layer of gold, or other metal or precious alloy.

Claims (6)

1. The method for setting stones (4) into the surface of a jewel realized by electroforming, in which a basis (1) having externally forms and dimensions of the jewel to obtain less the thickness of the gold layer forming the wall and provided with accommodations (5) for reception of stones (4) is realized, on the basis (1), before installation of stones, a protecting layer (10), then a thin gold layer (11) are deposited, stones (4) are put in place into said accommodations (5), then a second gold layer (12), thicker is deposited, and, finally, said basis (1) and said protecting layer (10) are extracted or removed, characterized in that during the realization of the basis (1), at least one passage (9) is provided in front of each accommodation (5), that is susceptible to make a communication, once the stone (4) in place, between the space comprised between the latter and the bottom of its accommodation (5) and the exterior, in order to allow the deposit bath of said second gold layer (12) to access to said space.
2. The method according to claim 1, further characterized in that, during the realization of the basis (1), heightenings (7) whose a part (8) projects over the groove (6) receiving a stone (4) into a well (5) is provided, said stone being snappingly engaged into said well.
3. Method according to claim 1 or 2, characterized in that said passages making a communication between the space comprised between each stone (4) and the bottom of its accommodation (5) are channels (9) or the like, interposed between said heightenings (7).
4. Jewel realised according to the method of one of claims 1 to 3.
5. Jewel according to claim 4, characterized in that it is hollow and its wall thickness, including the wall of the wells (5) below the stones (4), is constant.
6. Jewel according to claim 5, characterized in that said wall thickness range between 135 and 450 micrometers.

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