HK40007957B - Method for crimping a stone - Google Patents

Description

Method for crimping gemstones

Technical Field

The present invention relates to a method for assembling a gemstone on a setting rest, said gemstone being cut to have a table, crown, girdle and pavilion. The invention also relates to a method for crimping a gemstone and its setting rest obtained according to said assembly method onto an element of a timing or jewelry part.

Background

Precious, semi-precious or artificial gemstones are known that can be crimped using a jaw (close), nail (grain) or rail (rail). Conventional crimping by assembling a natural gemstone, such as a diamond or emerald, in a setting by means of jaws typically requires dimensional control of 5/100 close to the size of the gemstone. For this reason, this type of crimping is incompatible with the crimping of mass-produced, low-cost crimped gemstones using gemstones with greater precision approaching 1/100, such as synthetic diamonds, zircon, and ruby.

Disclosure of Invention

The object of the present invention is to overcome this drawback by proposing a method for crimping gemstones which allows to overcome the inevitable dimensional variations encountered when using natural gemstones such as diamond or emerald.

To this end, the invention firstly relates to a method for assembling a gemstone on a setting rest, said gemstone being cut to have a table, a crown, a girdle and a pavilion, said method comprising the steps of:

a) providing a substrate comprising at least one groove in which said gemstone is located, said groove being arranged to form a peripheral free space between said substrate and said gemstone at least near the girdle of said gemstone and the area of said crown and pavilion interfacing with the girdle, the bottom of said peripheral free space having an electrically conductive surface;

b) depositing a metal layer at least adjacent the girdle and adjacent the girdle-interfacing regions of the crown and pavilion by electroplating in said peripheral free space so as to confine said girdle in said metal layer to form said setting rest at least substantially around the girdle of the stone;

c) releasing the gemstone and its setting rest from the substrate.

In a particularly advantageous manner, the substrate and its recesses can be produced according to the following steps:

d) providing a substrate having a conductive surface layer and creating at least one via in the substrate;

e) covering the substrate with a photosensitive resin layer and forming a cavity portion in the photosensitive resin layer by photolithography, the cavity portion having a size in a plane of the substrate larger than a size of a waist portion of the gemstone, such that the cavity portion includes a central opening corresponding to the through-hole and a peripheral area including a resin side wall and a bottom portion occupied by the conductive layer of the substrate surrounding the through-hole,

the dimensions of the cavity and the through hole forming the groove are selected such that the pavilion of the gemstone is partially received in the through hole so as to rest on the perimeter of the central opening of the cavity, the remainder of the pavilion above the through hole defining a girdle-interfacing region of the pavilion, and the dimensions of the cavity and the through hole are selected such that the remainder of the gemstone is received in the cavity between said girdle-interfacing region of the pavilion and at least up to the point of the girdle-interfacing region of the crown so as to form said perimeter free space between the gemstone and the walls of the cavity.

The method according to the invention allows the dimensions of the grooves and more particularly the dimensions of the through holes to be selected so as to accommodate the dimensional variations of the stones.

The invention also relates to a method for crimping a gemstone on an element of a timepiece or jewelry part, comprising assembling the gemstone and its setting rest obtained according to the method described above, on a setting subsequently added to said element of the timepiece or jewelry part, or directly on said element of the timepiece or jewelry part.

The invention also relates to an element of a timepiece or jewelry part comprising at least one gemstone assembled on its setting rest, obtained according to the assembly method as described above.

Drawings

Further features and advantages will become apparent from the following description, provided by way of non-limiting example, with reference to the accompanying drawings, in which:

figures 1 to 6 are illustrations of successive steps of a method for assembling a gemstone on a setting rest according to the invention;

figures 7a to 7c are top views of various variants of gems and of setting rests obtained according to the method of the invention; and

figure 8 is a cross-sectional view showing the gemstone and its setting rest mounted on the setting.

Detailed Description

With reference to fig. 1 to 6 and 8, the invention relates to a method for assembling a gemstone 1 on a setting rest 2, said gemstone 1 being cut to have a table top 3, a crown 4, a girdle 5 and a pavilion 6. The gemstone is preferably a natural gemstone, such as a diamond or emerald, and may vary in size from gemstone to gemstone. It is clear that the stone can be any other type of natural or artificial stone, for which the method according to the invention can advantageously also be used.

A first step a) of the method according to the invention for assembling a gemstone 1 on a setting rest 2 comprises providing a substrate 8 having at least one groove 10, said gemstone 1 being positioned in said groove 10, said groove 10 being arranged to form a peripheral free space 12 between the substrate 8 and said gemstone 1 at least around the waist 5 of the gemstone 1, the bottom 14 of said peripheral free space 12 having an electrically conductive surface 16. By "around the girdle" is meant that the peripheral free space 12 is located at least in the vicinity of the girdle 5 and the zones 4a and 6a of the crown 4 and pavilion 6, respectively, bordering the girdle 5.

More specifically, the substrate 8 and its grooves 10 can advantageously be produced according to the following steps d) and e):

step d) comprises providing a substrate 8 with a conductive surface layer 16 and creating at least one via 18 in said substrate 8. A through hole 18 is formed for each gemstone 1 to be assembled. Advantageously, the substrate 8 is for example based on silicon, glass, ceramic or quartz. For example, a silicon wafer for microelectronics can be used. For example, the conductive layer 16 may be obtained by PVD (physical vapor deposition) of chromium, titanium, gold, and combinations thereof. Any other suitable conductive layer may be used. For example, the through-hole 18 may be formed on the substrate 8 by laser ablation. Advantageously, the distribution of the through holes 18 on the surface of the substrate is specifically optimized, according to the dimensions of the grooves, the shape of the inlay rests, etc., so as to have the maximum number of through holes on the surface of the substrate 8.

Step e) comprises covering the substrate 8 with a layer of photosensitive resin 20 as shown in fig. 1, and then forming a cavity 22 in said photosensitive resin 20 by photolithography, said cavity 22 and through hole 18 forming the groove 10, in which groove 10 the gemstone 1 will be positioned as will be described hereinafter. The cavity 22 is hollowed out until the conductive layer 16 is present.

The dimensions of the through hole 18 in the plane of the base 8 are smaller than the dimensions (commonly referred to as "diameter") of the waist 5 of the gemstone 1, and the dimensions of the cavity 22 in the plane of the base 8 are larger than the diameter of the waist 5 of the gemstone 1. The cavity 22 is therefore larger in size in the plane of the base 8 than the through-hole 18, the cavity 22 thus comprising a central opening 24 corresponding to the through-hole 18, and a peripheral area having a resin side wall 26 and a bottom, i.e. the bottom 14 occupied by the conductive layer 16 of the base 8 around the through-hole 18. Thus, the groove 10 has a T-shaped cross-section in a plane perpendicular to the substrate 8, as shown in fig. 2.

In a particularly advantageous manner, step e) comprises using a negative-type (negative) photosensitive resin 20, for example SU8 resin, wherein the photosensitive resin layer 20 is UV-irradiated through a mask corresponding to the contour of the desired inlay holder, and removing the non-irradiated portions of the photosensitive resin layer 20, so as to obtain a cavity portion 22 having a contour corresponding to the contour of said desired inlay holder. Such photolithography is known per se to those skilled in the art and does not need to be described in more detail.

Once the substrate 8 and its grooves 10 have been created, step a) of the assembly method according to the invention proceeds to mounting the gemstone 1 in each formed groove 10.

The dimensions of the cavity 22 and the through hole 18 forming the groove 10 are chosen such that the pavilion 6 of the gemstone 1 is partially housed in the through hole 18 so as to rest on the periphery of the central opening 24 of the cavity 22, wherein the rest of the pavilion 6 above the through hole 18 defines the zone 6a of the pavilion 6 bordering the girdle 5, and the dimensions of the cavity 22 and the through hole 18 forming the groove 10 are chosen such that the rest of the gemstone 1 between said zone 6a of the pavilion 6 bordering the girdle 5 and at least up to the position of the zone 4a of the crown 4 bordering the girdle 5 is housed in the cavity 22 so as to form said peripheral free space 12 between the gemstone 1 and the walls of the cavity 22, i.e. the side walls 26 and the bottom 14.

In a particularly preferred manner, the dimensions of the cavity 22 and the through hole 18 are chosen such that the pavilion 6 of the gemstone 1 is almost completely housed in the through hole 18, so that the zone 6a of the pavilion 6 bordering on the girdle 5 extends immediately below only the girdle 5 and the zone 4a of the crown 4 bordering on the girdle 5 extends immediately above only the girdle 5, so as to form said peripheral free space 12 between the gemstone 1 and the walls of the cavity 22 (i.e. the side walls 26 and the bottom 14) substantially only around the girdle 5, i.e. in the vicinity of the girdle 5 and only on both sides of said girdle 5, as shown in fig. 3. Furthermore, the height of the groove 10 and more particularly of the cavity 22 is such that the table 3 of the gemstone 1 exceeds said groove 10 and more particularly said cavity 22, as shown in fig. 3. The thickness of the resin layer 20 is selected for this purpose.

Since the only precise dimensions of the gemstone that can be provided are the "diameter" of the waist 5 and its height, it is possible that the gemstone 1 is not correctly mounted and that it is not ensured that sufficient flatness is provided for the table 3 of the gemstone 1.

In this case, the assembly method according to the invention may comprise, between steps a) and b), a step f) of correcting the orientation of the gemstone. Advantageously, referring to fig. 4, this step f) may comprise bringing the table 3 of the gemstone 1 into contact with a repositioning device 28, the repositioning device 28 being arranged to reposition the gemstone 1 in its groove 10. Such a repositioning device 28 comprises, for example, a rigid plate 30 covered with a deformable sheet or foam 32, allowing the height of the stone 1 to be compensated. The re-positioning device 28 is arranged so that the plate or foam 32 is brought into contact with the table 3 of gems positioned in their respective grooves 10 on the substrate 8 so as to modify the orientation of the gems and provide flatness of the table 3 of gems 1.

Before removing the repositioning apparatus 28, it may be necessary to provide a step g) of inlaying the pavilion 6 of the gemstone 1 in the through-hole 18, between steps f) and b). This step g) allows maintaining the correct positioning of the gemstones 1 in their grooves 10 even after the repositioning device 28 has been removed.

Step g) for example comprises introducing a holding adhesive 34 around the pavilion 6 of the gemstone 1 through the open entrance of the through-hole 18, thereby allowing the gemstone 1 to be set in the groove 10. To prevent the holding adhesive 34 from entering the cavity 22 in the presence of a gap between the gemstone 1 and the central opening 24, a holding adhesive of sufficient tack that does not fill the narrowest gap may be used. It is also possible to block any gap existing between the gemstone 1 and the central opening 24 on the cavity portion 22 side before depositing the retaining adhesive 34. For this reason, the resin can be injected into the gap at the cavity portion 22 side, and the resin can be easily removed (for example, by dissolution). Provision may also be made to deposit an indium layer of about 50 μm on the silicon substrate 8 before mounting the gemstone 1. The indium layer has the advantage of deforming during step f) of correcting the orientation of the gemstone by levelling the table top 3, and is thus able to provide a seal in the vicinity of the central opening 24 of the cavity 22.

Step g) is followed by a step h) of removing the repositioning device 28, so as to be able to continue to implement the assembly method of the invention.

Once gemstone 1 has been positioned in its groove 10 on substrate 8 by forming between said substrate 8 and said gemstone 1, according to step a) above, a peripheral free space 12 at least in the vicinity of waists 5 and of zones 4a and 6a of crowns 4 and pavilions 6, respectively, contiguous to waists 5, the assembly method according to the invention proceeds to carry out step b). This step b) comprises depositing a metal layer 36 in the vicinity of girdle 5 and in the vicinity of zones 4a, 6a of crown 4 and pavilion 6, respectively contiguous with girdle 5, by electroplating in said peripheral free space 12 from the base 14 of said peripheral free space 12 occupied by conductive layer 16, so as to confine said girdle 5 in said metal layer 36, so as to form said inlay rest 2 at least substantially around girdle 5 of gemstone 1, as shown in fig. 6. With its waist 5 confined in the metal layer 36 forming the inlay rest 2, the gemstone 1 is now rigidly connected to its inlay rest 2.

The metal layer 36 deposited in step b) is preferably made of a material selected from the group comprising nickel, gold, silver, platinum, rhodium, palladium, copper and alloys thereof.

The Electroforming conditions, in particular bath composition, system geometry, voltage and current density, are chosen for each metal or alloy to be electrodeposited according to techniques well known in the art of Electroforming (see for example Di barri g.a., "Electroforming" Electroplating Engineering Handbook, 4 th edition, published by l.j.durney, Van nonstand Reinhold Company inc., new york, 1984).

The size of the inlay holder 2 is defined by the dimensions of the through hole 18 and cavity 22 in the plane of the base 8 and the height of the metal layer 36 deposited according to the plating parameters.

Preferably, these parameters are chosen such that the metal layer 36 is deposited only substantially in the vicinity of the girdle 5 and the zones 4a, 6a of the crown 4 and pavilion 6 extending only on both sides of the girdle 5, so that the inlay rest 2 is located substantially only around the girdle 5, as shown in fig. 8. The inlay rest 2 is slightly beyond the zones 4a and 6a of the crown 4 and pavilion 6, respectively, where the girdle 5 meets, but most of the crown 4 and pavilion 6 remain free.

The following step c) consists in releasing the gemstone 1 assembled on its setting rest 2 from the base 8. For this reason, the silicon substrate 8 and the holding adhesive 34 are removed by dissolution. For example, 20% potassium hydroxide, KOH, may be used, heated to 85 ℃ to dissolve the silicon, and a commercial solvent may be used to dissolve the binder.

The assembly method according to the invention achieves adaptation to the dimensional variations of the gemstone 1 by providing through holes 18 of various diameters in the base 8 that are appropriate for the size of the gemstone 1.

Figures 7a to 7c show some variants of a gemstone 1 assembled on its inlay rest 2, which may be obtained by using various photolithographic exposure masks corresponding to the profile of the desired inlay rest.

The gemstone 1 assembled on its setting rest 2 thus released can be used in the crimping method according to the invention.

Said method for crimping said jewel on an element of a timing or jewellery part comprises assembling the jewel 1 obtained according to the assembly method described above and its setting rest 2 on an setting 38, as shown in fig. 8. The setting 38 is then added to the element of the timing or jewelry part.

In another variant, the gemstone 1 and its setting rest 2 obtained according to the assembly method described above are mounted directly on said element of the timing or jewelry part.

The assembly of the setting lug 2 carrying the gemstone 1 on the setting 38 or directly on the element of the timing or jewelry part may be performed by clamping, pressing, crimping, gluing, etc.

Said element of the timing or jewellery part can be, for example, a dial, a bezel, a rotating bezel, an intermediate piece, a corner of a watch case, a crown, a hand, an indicator (index), a link or other chain element, a pendant element, a ring, a collar, etc., or any timing/jewellery element that can be crimped.

Claims (13)

1. An assembly method for assembling a gemstone (1) on a setting rest (2), said gemstone (1) being cut to have a table top (3), a crown (4), a girdle (5) and a pavilion (6), said assembly method comprising the steps of:

a) providing a substrate (8) comprising at least one groove (10) in which said gemstone (1) is positioned, said groove (10) being arranged to form a peripheral free space (12) between said substrate (8) and said gemstone (1) at least in the vicinity of said girdle (5) and regions (4a, 6a) of said crown (4) and pavilion (6) bordering said girdle (5), said peripheral free space (12) comprising a pavilion (14) having an electrically conductive surface layer (16);

b) -depositing a metal layer (36) at least in the vicinity of said waists (5) and of the zones (4a, 6a) of said crown (4) and pavilion (6) contiguous to said waists (5) by electroplating in said peripheral free spaces (12), so as to confine said waists (5) in said metal layer (36) to form said inlay rests (2);

c) releasing the gemstone (1) and its setting rest (2) from the substrate (8),

wherein the substrate (8) and its grooves (10) are generated according to the following steps:

d) providing a substrate (8) having a conductive surface layer (16) and creating at least one through-hole (18) in the substrate (8);

e) -covering the substrate (8) with a photosensitive resin layer (20), and-forming a cavity (22) by photolithography in the photosensitive resin layer (20), the size of the cavity in the plane of the substrate (8) being larger than the size of the waist (5) of the gemstone (1), such that the cavity (22) comprises a central opening (24) corresponding to the through hole (18) and a peripheral area comprising a resin side wall (26) and a bottom (14) occupied by a conductive surface layer (16) of the substrate surrounding the through hole (18).

2. The assembly method of claim 1,

the dimensions of the cavity (22) and the through hole (18) forming the groove (10) are selected such that a pavilion (6) of the gemstone (1) is partially accommodated in the through hole (18) so that the gemstone (1) rests on a periphery of a central opening (24) of the cavity (22), the remaining part of the pavilion (6) above the through hole (18) defining a region (6a) of the pavilion (6) bordering the girdle (5), and the dimensions of the cavity (22) and the through hole (18) forming the groove (10) are selected such that the remaining part of the gemstone (1) between the crown region (6a) of the pavilion (6) bordering the girdle (5) and at least up to the position of the region (4a) of the pavilion (4) bordering the girdle (5) is accommodated in the cavity (22), so as to form said peripheral free space (12) between said gemstone (1) and the resin side wall (26) and the bottom (14) of said cavity (22).

3. Method of assembling according to claim 2, characterized in that the dimensions of said cavity (22) and said through hole (18) are chosen such that the pavilion (6) of said gemstone (1) is almost completely accommodated in said through hole (18), such that the zone (6a) of the pavilion (6) bordering the girdle (5) extends immediately below only the girdle (5) and the zone (4a) of the crown (4) bordering the girdle (5) extends immediately above only the girdle (5), so as to form said peripheral free space (12) between said gemstone (1) and the resin side wall (26) and the pavilion (14) of said cavity (22) substantially in the vicinity of said girdle (5) and said areas (4a, 6a) of said crown (4) and pavilion (6) bordering said girdle (5).

4. Method of assembling according to claim 1, characterized in that the height of said groove (10) is such that the table top (3) of said gemstone (1) exceeds said groove (10).

5. The assembly method according to claim 4, characterized in that it comprises, between steps a) and b), a step f) of correcting the orientation of the gemstone (1).

6. The assembly method according to claim 5, wherein step f) comprises bringing the table (3) of the gemstone (1) into contact with a repositioning device (28) for repositioning the gemstone (1) in its groove (10).

7. The assembly method according to claim 6, characterized in that it comprises, between steps f) and b), a step g) of inlaying a pavilion (6) of said gemstone (1) in said through hole (18).

8. Assembly method according to claim 7, wherein step g) is followed by a step h) of removing the repositioning device (28).

9. The assembly method according to claim 1, characterized in that the metal layer (36) deposited during step b) is made of a material selected from the group comprising nickel, gold, silver, platinum, rhodium, palladium, copper, and alloys thereof.

10. Assembly method according to claim 1 or 2, characterized in that step e) comprises using a negative-type photosensitive resin layer (20), wherein said negative-type photosensitive resin layer (20) is UV-irradiated through a mask corresponding to the contour of the desired inlay holder (2) and removing the non-irradiated parts of said negative-type photosensitive resin layer (20) in order to obtain said cavity (22) having a contour corresponding to the contour of said inlay holder (2).

11. The assembly method according to claim 1, characterized in that the substrate (8) is based on a material selected from the group comprising silicon, ceramic, glass and quartz.

12. Method for crimping a gemstone (1) onto an element of a timing or jewelry part, comprising assembling the gemstone (1) on an inlay rest (2) and assembling the gemstone (1) thus obtained and its inlay rest (2) on an inlay seat (38) added to or directly on an element of said timing or jewelry part, using the assembly method according to any one of claims 1 to 11.

13. Element of a timepiece or jewelry part, comprising at least one gemstone (1) assembled on a setting rest (2) thereof, obtained according to the assembly method of any one of claims 1 to 11.