Patent Application
20140178625
This application claims priority from European Patent Application No. 13165604.3 filed Apr. 26, 2013 and European Patent Application No. 12199276.2 filed Dec. 21, 2012, the entire disclosure of which is hereby incorporated by reference herein by reference.
The present invention relates to a decorative piece. This decorative piece comprises a support into which at least one aesthetic element is set.
There are known, in prior art, decorative pieces which are intended to be set into a wearable object, such as a watch or jewellery, and which consist of setting of an aesthetic element on the parts of said wearable object acting as support.
For this purpose, the support is produced in a metallic alloy and is machined so that housings appear. During this machining, catching means having the shape of hooks are produced. In general, these hooks are produced with the material forming the wearable object, i.e. in a monobloc fashion with the object. When an aesthetic element, such as a precious stone, has to be set, the latter is placed in a housing and the catching means are folded down, cold, by plastic deformation in order to retain said aesthetic element in the housing. This setting method is widely used for setting precious stones on metal supports because the latter has an advantageous plastic deformation capacity. This capacity is even more advantageous with precious metals such as gold because these precious metals are ductile and can be shaped easily. The cold plastic deformation of crystalline metals is possible thanks to the movements of dislocations present in the crystal lattices. The elastic limit, i.e. the stress beyond which a material begins to deform plastically, of a crystalline alloy depends upon the elements which form the latter and also the thermomechanical history of the alloy. For traditional settings, alloys which have relatively low elastic limits are generally chosen in order to facilitate the work of the setter. In addition to a relatively low elastic limit, it is necessary that the alloy has sufficient elongation before rupture in order to be able to fold down the catching means without them breaking. As with the elastic limit, this elongation is the consequence at the same time of the elements present in the alloy and the thermomechanical history of the latter. For example, gold alloys used in the manufacture of timepieces have an elastic limit of the order of 200-400 MPa and a breaking elongation of 20-40%. Stainless steels of type 1.4435 have an elastic limit of 200-300 MPa and a breaking elongation of 25-45%.
Nevertheless, a disadvantage of this method is that it is limited to supports produced in ductile metals or ductile metallic alloys. Now, more and more timepieces are produced in materials which do not have plastic deformation, often hard and/or fragile materials, such as for example ceramics, silicon, composites or even intermetallic alloys.
Consequently, it is no longer possible to use the current method for setting aesthetic elements such as for example precious stones.
This setting operation is therefore replaced by a glueing operation. The disadvantage of glueing is not guaranteeing 100% retention of the stones because, in contrast to setting, this technique does not involve mechanical retention of the stones. In fact the glued zones being in the majority of cases exposed to the exterior environment (humidity, perspiration, UV, air pollution . . . ), the retention of the bonding over the long term is made difficult. Consequently, retention of the stones is not guaranteed, which is not acceptable for quality products.
The invention relates to a decorative piece which remedies the above-mentioned disadvantages of prior art by proposing a decorative piece and its production method which allow setting of the aesthetic element on a piece made of materials which do not have sufficient plastic deformation.
To this end, the invention relates to a decorative piece comprising a support produced in a material which does not include plastic deformation and in which at least one hollow is provided, characterised in that said hollow being filled with a first material being an at least partially amorphous alloy forming a substrate in which at least one housing is provided, said at least one housing being designed so that at least one aesthetic element can be housed therein, said substrate comprising in addition catching means which deform in order to retain said at least one aesthetic element in said at least one housing.
In a first advantageous embodiment, the catching means comprise at least one setting element.
In a second advantageous embodiment, said at least one hollow comprises vertical flanks in order to improve retention of each aesthetic element in the support.
In a third advantageous embodiment, said at least one hollow comprises flanks designed so that the surface of the hollow increases with the depth of the hollow.
In a fourth advantageous embodiment, said at least one hollow comprises flanks designed so that the surface of the hollow decreases with the depth of the hollow.
In another advantageous embodiment, said at least one hollow comprises retaining means which extend from one of the walls of the hollow in order to retain the first material in said hollow.
In another advantageous embodiment, the retaining means have the shape of at least one recess.
In another advantageous embodiment, the retaining means have the shape of at least one through-recess.
In another advantageous embodiment, the retaining means have the shape of at least one protuberance.
In another advantageous embodiment, the first material is a totally amorphous metallic material.
In another advantageous embodiment, the first material comprises at least one element which is of the precious type, included in the list comprising gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium or osmium.
In another advantageous embodiment, the distance between the aesthetic element and one edge of the hollow is at least 0.01 mm.
In another advantageous embodiment, the height of the housing is at least equal to the height of the culet of the aesthetic element.
The invention likewise relates to a method for setting at least one aesthetic element on a support comprising the steps of:
a) providing a support in a fragile material with at least one hollow;
b) providing at least one aesthetic element;
c) filling said hollow with a first, at least partially amorphous metallic material;
d) producing at least one housing and catching means in the first material;
e) setting said at least one aesthetic element by placing it in said at least one housing and by deforming the catching means so as to retain it.
In a first advantageous embodiment, setting step e) consists of a cold plastic deformation of the catching means.
In a second advantageous embodiment, setting step e) consists of a hot plastic deformation of the catching means.
In another third advantageous embodiment, setting step e) consists of an elastic deformation of the catching means.
In a fourth advantageous embodiment, setting step e) consists of thermal expansion of the support and of the first material in order to set said at least one aesthetic element in said at least one hole.
In a fifth advantageous embodiment steps c), d) and e) are simultaneous, the method consists of placing said at least one aesthetic element in the hollow then of filling said hollow with said first material.
In another advantageous embodiment, the setting method of at least one aesthetic element on a support comprises the steps of:
a) providing a support provided with at least one hollow;
b) providing at least one aesthetic element;
c) filling said hollow with a first, at least partially amorphous material;
d) heating said first material locally to at least its glass transition temperature;
e) inserting said at least one aesthetic element into the first material, then cooling.
In another advantageous embodiment, the setting method of at least one aesthetic element on a support comprises the steps of:
a) providing a support provided with at least one hollow;
b) providing at least one aesthetic element;
c) filling said hollow with a first, at least partially amorphous material;
d) heating said at least one aesthetic element locally to at least the glass transition temperature of said first material;
e) inserting said at least one aesthetic element into the first material, then cooling.
In another advantageous embodiment, the aesthetic elements are disposed edge to edge.
In another advantageous embodiment, the first material is a totally amorphous metallic material.
In another advantageous embodiment, the first material comprises at least one element which is of the precious type, included in the list comprising gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium or osmium.
In another advantageous embodiment, step c) of filling the hollow takes place by casting.
In another advantageous embodiment, step c) of filling the hollow takes place by hot forming.
In another advantageous embodiment, step c) of filling the hollow takes place by powder sintering.
In another advantageous embodiment, step c) consists of filling the hollow by driving in. This embodiment consists of heating the support in order to expand it thermally and increasing the dimensions of the hollow then placing the substrate in the hollow and finally contracting the support.
In another advantageous embodiment, the method comprises, in addition, a step consisting of crystallising the first material.
In another advantageous embodiment, the catching means comprise at least one setting element.
In another advantageous embodiment, said at least one aesthetic element comprises at least one throat into which said first material is inserted in order to improve the retention of said at least one aesthetic element.
Another advantage of this solution is that it makes it possible to set any type of material. In fact, the principle employed is a principle of set-in material, i.e. that a substrate in a deformable material is introduced into a plastically non-deformable material so as to allow setting and to give the illusion that it is this plastically non-deformable material which is set.
The aims, advantages and features of the decorative piece and of the method thereof according to the present invention will appear more clearly in the following detailed description of at least one embodiment of the invention, given solely by way of non-limiting example and illustrated by the annexed drawings in which:
In the following description, all the parts of the decorative piece which are well known to the person skilled in the art in this technical field will be explained only in a simplified manner.
As can be seen in
In
Advantageously according to the invention, this support 2 comprises at least one hollow 4, represented in
The first step, which can be seen in
The second step which, can be seen in
The third step consists of filling said hollow with a first material. This first material is then used to serve as substrate 6. The third step makes it possible to obtain the support 2 which can be seen in
Advantageously according to the invention, the first material is an amorphous metallic alloy. It will be understood likewise that the metallic material will be partially amorphous or totally amorphous. The term partially amorphous indicates that, for a block of material, the percentage quantity of material of said block having the amorphous state is sufficient for the block itself to have the features which are specific to metals and amorphous metallic alloys. The amorphous materials have the advantage of being able to be shaped easily. Likewise, it may be possible to use a precious metal or one of these alloys in order to give a precious character to said decorative piece. Thus the precious metal or one of these alloys is included in the list comprising gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium or osmium.
One of the methods for filling the hollow consists of using hot forming.
Materials of this type are very suitable because they can thus easily fill all the volume of the hollow 4. After cooling, the vertical flanks 7 make it possible to retain the amorphous material by friction. Of course, the flanks 7 can be inclined so as to narrow the surface of the horizontal plane at the bottom of the hollow 4 or else, on the contrary, so as to enlarge it. It goes without saying that the most advantageous case is that where the surface of the bottom of the hollow 4 is largest since it makes it possible to retain naturally the amorphous metallic alloy in the hollow 4. Conversely, when the inclination causes a bigger section at the level of the surface of the support 2, retaining the amorphous material in the hollow 4 is no longer optimal. Another advantage is that this diminishing viscosity involves a reduction in the stress to be applied to fill the hollows 4 with the amorphous metallic alloy. For this reason, the support 2 made of fragile materials does not risk being broken even though a pressing operation is effected.
Of course other types of shaping are possible such as casting or injection moulding, powder sintering or by driving in.
The process of casting or injection moulding consists of heating a metallic preform above its melting point and then of casting or injecting the liquid metal, thus obtained, into the hollow 4 of the support 2.
The process of powder sintering consists of introducing a metallic powder into the hollow 4 of the support 2 and compacting it by applying energy, such as a furnace, a laser beam, an ion beam or any other thermal means. Once the hollow 4 is filled, a cooling step to a temperature lower than the Tg is effected so as to avoid crystallisation of the alloy in order to obtain a hollow 4 filled with amorphous or semi-amorphous metallic alloy.
The process of driving in consists of producing a block of amorphous metallic alloy, the dimensions and the shape of which are slightly greater than those of the hollow 4 and of forcing this block to fit into said hollow 4. Advantageously, it can be provided to produce this assembly step using thermal expansion. In order to do this, the support 2 is heated so that, under the effect of the heat, it expands thermally. The support 2 has its dimensions increased. This increase in the dimensions is likewise applicable to the hollow 4. Consequently, the difference between the dimensions of the hollow 4 and the dimensions of the block is modified so that the dimensions of the hollow 4 become greater than those of the block. It is then easy to insert the block into the hollow 4. When the support 2 is cooled it assumes its initial dimensions again and the block is situated wedged in said hollow 4.
Once the hollow is filled, a fourth preparation step is effected. This step consists of producing the setting housings (holes) 8 in which the aesthetic elements 3 are placed, and of producing the catching means. This step can be produced either in a standard manner, such as machining, milling, piercing, or in a less standard manner, by hot deformation, or by a combination of the two processes. The hot deformation method consists of using a tool which has the negative geometry of the hole and of the setting element and of applying this tool with a definite force and at a temperature greater than the glass transition temperature Tg of the amorphous metal, on the amorphous metallic alloy filling the hollow 4. It is hence possible to avoid the machining steps which can be difficult according to the amorphous metallic alloys which are used.
The catching means 5 have the shape of at least one setting element 9. This setting element 9, in the case for example of a bead setting, consists of prongs or beads provided on the circumference of each setting hole 8. These prongs 9, which can be seen in
It will be understood that other types of setting can be imagined. Therefore, the closed setting, the baguette setting, the rail setting or an invisible setting are conceivable. For example the closed setting consists of a single setting element 9 which extends over the periphery of the aesthetic element 3. The baguette setting is used for setting aesthetic elements 3 cut as a baguette. This setting consists of providing setting elements 9 which extend parallel to each side of the aesthetic element 3 and come to be folded down on the latter. For the invisible setting, it is provided that the setting elements 9 are projecting portions provided in the setting hole 8.
These projecting portions cooperate with at least one throat produced on said aesthetic element 3 so that the setting is produced by inserting the aesthetic element 3 into the hole 8 until the projecting portions are inserted in said at least one throat.
In a particular embodiment which can be seen in
In another example, it is defined that the distance between the aesthetic element 3 and the edge of the hollow 4 is composed of a zone termed machined, i.e. a zone in which the setting beads are produced, this zone being able to be hollow, and of a zone termed non-machined which is an aesthetic visual zone. In this case, this non-machined zone will be at least 0.01 mm and at most 0.20 mm, preferably it will be 0.10 mm.
Equally, it will be understood that the height of the hole 8 is at least equal to the height of the culet of the aesthetic element 3. This makes it possible, when the aesthetic element 3 is set, to see the first material forming the substrate 6 as little as possible. In this case, the setting beads 9, four in number, are produced so as to have the shape of a right-angled triangle, the hypotenuse of which is convex. Preferably, the convex shape of the hypotenuse is similar to the curve of that of the aesthetic element 3 when the latter is seen from above.
Once the fourth preparation step is finished, the support 2, which can be seen in
The standard setting step consists of a deformation. This technique consists of placing the aesthetic element 3 in the hole 8 and deforming the substrate and/or the setting elements 9 in order to place them on said aesthetic element 3, as can be seen in
The deformation can likewise be elastic or obtained by thermal expansion. In the case of elastic deformation, the setting is obtained by clipping the aesthetic element in the catching means 5. It is obvious that, in this case, a slight plastic deformation of the catching means 5 could take place. In the case of deformation by thermal expansion, the setting is obtained by heating the support 2 to a sufficiently high temperature to allow inlaying of the aesthetic element 3 in its hole 8 without force. Cooling will then make it possible to contract the material allowing thus the aesthetic element 3 to be retained by the catching means 5.
It should be noted that amorphous metals, in contrast to crystalline metals, do not have dislocations and therefore cannot be deformed plastically by the movement of the latter. They therefore generally have a fragile behaviour, i.e. they break suddenly once the elastic limit is exceeded.
It has however been confirmed that certain amorphous alloys can accommodate a permanent macroscopic deformation by generation of bands of slippage on a microscopic scale. The exact nature of the latter is not at present clearly identified. Apart from depending upon the type of amorphous alloy, the capacity to accommodate a permanent deformation in the amorphous metals depends greatly upon the dimensions of the piece. Thus the more the dimensions of the stressed zone are small, the more the permanent deformation will be able to be large. For example, it is possible to fold, permanently, a strip of thickness 100 μm made of amorphous alloy Pt57.5Cu14.7Ni5.3P22.5 up to an angle greater than 90° without breaking, whilst a strip of the same dimension made of amorphous alloy Fe56Co7Ni7Zr8Ta8B20 will not accommodate any permanent deformation.
With respect to the preceding and in order to be able to use various amorphous alloys independently of their permanent deformation capacity, various embodiments have been conceived.
A first embodiment is used in the case where the amorphous alloys accommodate permanent deformation and have elastic limits which are not too high, typically less than 1,500 MPa: the setting method is identical to that used for crystalline metals, i.e. cold plastic deformation of the beads 9 produced in the amorphous alloy.
A second embodiment is used in the case where the amorphous alloys have elastic limits which are too high for cold plastic deformation, typically greater than 1,500 MPa: the setting method consists of heating the beads 9 to a temperature greater than the glass transition temperature Tg of the amorphous metallic alloy in order to reduce greatly the viscosity and therefore the force necessary for deformation thereof. Once the beads 9 are at the right temperature, they are deformed so that the setting can take place. A cooling operation is then effected in order to solidify them and to make it possible to make the setting definitive. This solution has the advantage of allowing an intimate contact between the amorphous metallic alloy and the aesthetic element 3, which improves retention of the latter. In fact, in the case of cold plastic deformation, as much for crystalline metals as amorphous ones, elastic resilience operates during release of the force applied on the bead 9. This resilience inevitably involves a slight separation between the bead 9 and the aesthetic element 3 which can cause retention problems. Now, the hot deformation used does not involve elastic resilience and there is therefore no release. This hot deformation can be produced after a cold deformation step or the converse.
A third embodiment is used when the amorphous alloys are difficult to set by cold or hot plastic deformation. This embodiment consists of making use of the high elastic deformation of amorphous alloys, typically 2%, in contrast to crystalline alloys which deform plastically from 0.5%. The method consists of pressing the aesthetic element 3 into the setting hole of the substrate 6. Under pressure, the amorphous metallic alloy of the substrate 6 deforms elastically making it possible for the aesthetic element 3 to be inserted. When the catching means 5, in the shape of a setting recess, and the girdle or end or the edge 3a of the aesthetic elements 3 are situated one opposite the other, an elastic resilience operates. The elastic resilience of the catching means 5 on the aesthetic element 3 makes it possible to retain the latter definitively, as can be seen in
A fourth embodiment is likewise envisaged. In this embodiment, the support 2 is heated thermally such that all of the support expands, i.e. the support 2 and the substrate 6 made of amorphous alloy. Consequently, the setting hole 8 likewise expands. Consequently, the aesthetic element 3 can be placed in the setting hole 8. The aesthetic element 3 is then retained in the hole 8 by the catching means 5 after cooling of the support 2, as can be seen in
A fifth embodiment can be envisaged in which the fourth step d) and the fifth step e) are simultaneous. This embodiment consists of heating the aesthetic element to a temperature greater than the glass transition temperature Tg of the first material then pressing it into the latter, i.e. the amorphous metallic alloy. The heat released by said aesthetic element heats the substrate 6 locally up to a temperature greater than the Tg which makes it possible for the amorphous metallic alloy to have its viscosity lowered greatly which thus facilitates the insertion. Then, once the aesthetic element is inserted, the substrate 6 is cooled in order to keep the amorphous state of the alloy and is trimmed of any surplus material. This step therefore allows better catching of the aesthetic element 3 in the substrate 6 thanks to the capacity of the amorphous metallic alloy to mould well to the contours.
A sixth embodiment in which the third c), fourth d) and fifth step e) are simultaneous is envisaged. This variant consists of providing that the aesthetic element 3 is placed directly in the hollow 4 before the step of filling said hollow 4 by the first material. The filling of the hollow 4 therefore takes place by casting, by hot forming or by sintering, the details of which have been explained previously. This technique makes it possible to have a more rapid setting process whilst guaranteeing good retention of the aesthetic elements 3.
A seventh embodiment, characteristic of an invisible setting, and able to be seen in
In a variant of the fifth to seventh embodiments, the aesthetic element 3 comprises at least one throat 31. This throat 31 makes it possible, during setting of the aesthetic element, for the amorphous metallic alloy to be inserted in said throat 31. In fact, as the amorphous metallic alloy moulds perfectly to the contours of a piece when it is heated to a temperature greater than the Tg or when it is liquid, the throat 31 therefore acts as a means allowing the aesthetic element to be anchored in the substrate 6 made of amorphous metal, as can be seen in
One advantage of the invention is that it makes it possible to set any type of material. In fact, the principle used is a principle of a set-in piece, i.e. that a substrate in a material which can accept a deformation is set in a material which is not plastically deformable so as to allow setting and to give the illusion that it is this plastically non-deformable material which is inset.
In a first variant which can be seen in
In the case where the first material is an amorphous metallic alloy, the low viscosity of the amorphous material makes it possible to fill the hollow 4 easily. Analogously, this low viscosity of the amorphous material likewise makes it possible to fill the recesses 51 better or to envelope the protuberances 52 better.
These recesses 51 or protuberances 52 can be situated on the vertical flanks 7 of the hollow 4 or at the level of the base 7a of the hollow 4. Likewise the recesses 51 can be through-recesses or not.
It will be understood that various modifications and/or improvements and/or combinations evident to the person skilled in the art can be applied to the various embodiments of the invention explained above without departing from the scope of the invention which is defined by the annexed claims.
Thus, it is conceivable that once the amorphous metal is shaped in the hollow 4 a crystallisation step takes place just before or just after the step of producing the setting holes 8. This step consists of heating the amorphous metal above its glass transition temperature Tg which lasts for a sufficiently long time for the crystallisation to be able to take place. Once crystallised, the alloy can be cooled. The crystallisation parameters (time and temperature) must be chosen so as to ensure the growth of crystalline, ductile and non-fragile phase(s). This makes it possible to take advantage of the properties for shaping the amorphous metal and to take advantage of the readiness of crystalline metals to deform plastically, in particular when cold.
| Number | Date | Country | Kind |
|---|---|---|---|
| 12199276.2 | Dec 2012 | EP | regional |
| 13165604.3 | Apr 2013 | EP | regional |
