A piece of jewelry consisting of a network of elements connected by shape memory links.
The jewelry design using shape memory alloys and auxetic structures addresses the limitations of traditional jewelry by providing adaptable, comfortable, and aesthetically variable wear through elastic deformation and clasp-less fitting.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- OLIVIER STÉPHANE
- Filing Date
- 2024-11-21
- Publication Date
- 2026-05-22
AI Technical Summary
Existing jewelry lacks adaptability and comfort, failing to conform to the dynamic morphology of the human body and requiring traditional clasps that can be cumbersome.
A jewelry design utilizing shape memory alloys with flexible links and auxetic structures that allow elastic deformation and eliminate the need for clasps, enabling seamless fitting and customizable aesthetics.
The design provides enhanced adaptability, comfort, and aesthetic variability through elastic deformation, ensuring a secure fit without clasps and allowing for dynamic conformability to body movements.
Smart Images
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Abstract
Description
Title of the invention: A jewelry item consisting of a network of elements connected by shape memory links
[0001] The invention relates to a method for manufacturing a piece of jewelry and a piece of jewelry obtained by such a method.
[0002] The object of this invention is the creation of jewelry capable of progressively deforming elastically in order to adapt to the different morphologies of the human body. It can also be used on moving parts of the body, such as joints, or be temporarily enlarged to facilitate its application.
[0003] This type of jewelry possesses intrinsic characteristics that bring it closer to those of clothing and fabric, such as adaptability and comfort. While retaining the qualities and properties of traditional jewelry, it allows for the combination of techniques commonly used in jewelry making with a more contemporary, even futuristic, approach.
[0004] The invention relates to a jewellery article composed of elements (E): (El), (E2), ... linked together by one or more links (L): (Ll-2), (L2-3),... .in shape memory alloy, preformed by heat treatment (P).
[0005] The jewelry article according to the invention may further comprise the following characteristics: • the organization of the elements (E): (E1), (E2), ...and of the links (L): (L1-2), (L2-3),... allows the creation of a network; • the organization of the elements (E): (El), (E2), ... and of the links (L): (L1-2), (L2-3),... allows the creation of a three-dimensional structure; • the organization of the elements (E): (El), (E2), ...and of the links (L): (L1-2), (L2-3),... allows the creation of a three-dimensional surface; • the relative movement of the elements (E): (El), (E2), ... is achieved by the spring-like bending of the links; • the elements (E): (El), (E2), ... are arranged in such a way as to create a tessellation pattern; • the network is arranged in such a way as to create an auxetic structure; • the section (S) of the links (L) has a second moment of area which favors bending in one direction; • the (L) links: (L1-2), (L2-3),...are made of shape memory alloy, chosen from copper-based, nickel-titanium or iron alloys; • The jewelry item does not require the use of a clasp. Putting on and taking off the jewelry is made possible by the elastic flexing of each of the connecting elements (L), generating an overall deformation of the jewelry of sufficient magnitude.
[0006] As illustrated in Figures [Fig. 1], [Fig. 2], [Fig. 3], the proposed jewel consists of multiple elements (El, E2, E3, E4, .... ) that can be connected to each other by links (Ll-2, Ll-2', L2-3, Ll-4, .... ) having a significant elastic bending capacity while maintaining a low longitudinal elongation.
[0007] Shape memory alloys, selected for their super elasticity, exhibit properties allowing flexures of much greater amplitude and number of cycles than conventional steels.
[0008] Shape memory alloys (SMAs) are metallic alloys exhibiting particular properties: single-direction shape memory effect, two-direction shape memory effect, superelasticity and rubbery effect.
[0009] These properties result, at the macroscopic scale, from a microscopic phase change called martensitic transformation.
[0010] Under the effect of stress, an increase in temperature, or both, the atomic structure of the alloy is modified. This results in a change of shape in the case of the shape memory effect, and in a very large reversible elastic deformation in the case of superelasticity.
[0011] Superelastic behavior, also called hyperelastic or pseudoelastic behavior, is observed in metallic materials exhibiting a first-order metallurgical phase transition, known as martensitic, between a high-temperature stable phase, called austenite, and a low-temperature stable phase, called martensite. This phase transition is said to be displacive because it operates, at the grain level, through shearing of the crystal lattice, without irreversible displacement of dislocations. The superelastic state is observed when the material is in the austenitic state, or predominantly austenitic in the case of a polycrystal, but where it is possible, by applying mechanical stress to said material, to form a metastable martensitic phase, also called a stress-induced martensitic phase.
[0012] As illustrated in Figure [Fig. 4], the response (RI, R2) of the material to a stress (C) or strain (D) essentially comprises four phases. For increasing stresses (C) or strains (D) (RI), the material, initially in the austenitic state, responds elastically up to a first limiting stress (C1) or strain (D1), beyond which the martensitic phase is induced. The phase transition allows the crystal lattice of the material to deform until all, or almost all in the case of a polycrystal, of the austenite is transformed into martensite, for limiting stress (C2) and strain (D2). Beyond this point (C2, D2), the material's response is governed by the elastic response of the martensite up to a third limiting point (C3, D3), beyond which the material's response results from the plastic deformation of the martensite, leading to irreversible deformations. When the material exhibits a superelastic response, releasing the stress (C) at a level (C4, D4) between the first stress induction limit (C1, D1) of the martensite and the onset of plastic deformation (C3, D3) results in a complete reversal (R2) of the deformation. Beyond this superelastic limit (C4, D4), the reversal (R2) is incomplete, and a permanent deformation remains in the stressed part. The superelastic limit (C4, D4) depends on the nature of the material, its metallurgical state, and the temperature at which the stress is applied.
[0013] These super-elastic alloys exhibit maximum strain rates of 10%, between -100 °C and +100 °C, i.e., 20 to 50 times greater than the maximum strain of a high-yield-strength steel.
[0014] These shape memory alloys can ensure several hundred thousand cycles without breakage for deformation rates of a few percent, unlike most metallic alloys which, for such a large number of cycles, will be limited to a deformation of less than 0.1%.
[0015] Another advantage of these materials is their excellent corrosion resistance and biocompatibility. They also meet the requirements of international jewelry standards.
[0016] The multiple elements (El, E2,...) constituting the jewelry can be chosen from among the materials commonly used in jewelry (metals, precious stones, etc.), but the field of application also includes fancy or creative jewelry with the use of organic or synthetic mineral materials (porcelain, paper, wood, glass, carbon fibers, leather, plastics, elastomers, etc...).
[0017] These different elements (E1,E2,...) can be combined and decorated according to commonly used techniques (crimping, riveting, gluing, engraving, enameling, etc.), without being limited to these assembly or decoration techniques.
[0018] The multiple elements (El, E2,...), as well as the flexible links (Ll, L2, ...) , can be organized into a network [Fig.3] in order to constitute a three-dimensional structure having a strong elastic deformation capacity.
[0019] It should be noted that the multiplication of the links (L), and of the elements (E), makes it possible to reduce the deformation stresses suffered by each of these links (L), thus allowing greater amplitudes of deformation and a greater capacity of resistance to fatigue of the jewel.
[0020] The use of flexible links (L) makes it possible to avoid the need to create joints between each of the elements.
[0021] It is therefore possible to create relative rotations of the elements that are both highly localized and practically invisible. The point of rotation (bending) can even be located at the boundary or even outside the different elements.
[0022] The organization of the elements (E) and the links (L) in an auxetic structure makes it possible to implement the potential of the proposed concept.
[0023] An auxetic structure (see [Fig. 5]) has the property of deforming by expansion (E) when an axial tension (T) is applied, or by contraction in the lateral direction under longitudinal compression. This phenomenon is also called a negative Poisson's ratio.
[0024] There are many geometries, organized into tesserae, for which the relative movement of the elements with respect to each other makes it possible to create auxetic-type transformations. See [Fig. 6] and [Fig. 7]
[0025] During the deformation of the auxetic structures, see [Fig.6], [Fig.7] and [Fig.8], it can be observed that the different elements move relatively without ever colliding. They remain at the boundaries of the geometries concerned.
[0026] It should be noted [Fig.6] and [Fig.7] that the overall relative displacements of the elements of the jewel reveal patterns whose aesthetics vary throughout the deformation.
[0027] The use of non-stretchable flexible wire (L) makes it possible to create very localized joints at the edges of the geometric elements (E). [Fig.8]
[0028] The super elasticity property guarantees an elastic return of the entire structure after deformation.
[0029] The wire cross-section can be chosen to favor (or not) a particular bending direction. See [Fig. 9] for cross-section examples (S).
[0030] A circular cross-section will allow bending about all axes located in the plane perpendicular to the neutral fiber (N) of the wire. See [Fig.9]
[0031] A section having a second moment of area allows certain bending directions to be favored.
[0032] Furthermore, it is possible to pre-form these wires by heat treatment into a shape (P) in order to configure the rest position of these junctions. See [Fig.9]
[0033] It is also possible to use, for each junction, wires comprising a multitude of strands, twisted or not, in order to provide greater flexibility and resistance to fatigue. See [Fig. 10]
[0034] The combination of different parameters (number of strands, wire cross-section, wire preforming, material used, number of bonds, spatial orientation) makes it possible to control the resting shape of the jewelry as well as the kinetics of its overall deformation under stress. It also makes it possible to adjust the overall stiffness of the jewelry and its fatigue resistance.
[0035] Among three-dimensional structures, cylindrical structures can be chosen, which are well suited to the production of bracelets (B). Similarly, among tessellations, auxetic structures based on triangular elements (E) and links (L) can be chosen, see [Fig.11].
[0036] This cylindrical structure and this triangular-based auxetic structure are chosen to illustrate the point and do not in any way constitute a limitation of the scope of the patent.
[0037] As shown in [Fig.12], [Fig.13], [Fig.14], the elements (El), (E2), (E...).. can each be made up of several sub-elements (Ela, Elb,....), (E2a, E2b,..) in order to allow the assembly of the different links (Ll-2 ...) to the elements (El, E2,
[0038] On [Fig.12], [Fig.13], [Fig.14] two elements (El) and (E2) are presented. Element (El) secures the joint (Ll-2) by sandwiching it between sub-elements (Ela) and (Elb), and on the other side, element (E2) secures the joint (Ll-2) by sandwiching it between sub-elements (E2a) and (E2b). The other joints (Ll-3), (Ll-4), (L2-5), (L2-6) are attached to other elements (E3), (E4), (E5), (E6), ... not shown.
[0039] The bracelet (B) has a starting position in which all the clasps are in their resting shape. See [Fig. 15]. This shape (P) had been previously produced by heat treatment.
[0040] The bracelet (B) can be progressively deformed under stress. The overall expansion of the bracelet is achieved by the multitude of elastic flexures of each of the links (L) constituting the bracelet (B). See [Fig. 16]
[0041] It should be noted that the overall reversible deformation of the bracelet depends on the applied stresses. Each of the links (L) progressively propagates its stress and therefore its displacement to the following elements.
[0042] Brief description of the drawings.
[0043] Figure 1 shows two elements E1, E2 connected by an L1-2 link
[0044] Figure 2 shows two elements E1, E2 connected by several links L1-2, L1-2', ...
[0045] Figure 3 presents a multitude of elements E1, E2, E3, E4, ... connected to each other by network via L1-2, L2-3, L1-4, L2-4, ... links
[0046] Figure 4 shows a Stress / Strain curve characteristic of shape memory alloys.
[0047] Fig. 5 illustrates the auxetic structure deformation (negative Poisson's ratio).
[0048] Fig. 6 illustrates a first set of simple auxetic structures and their progressive deformation.
[0049] Fig. 7 illustrates a second set of more complex auxetic structures and their progressive deformation.
[0050] Fig. 8 illustrates the arrangement of the links in the corners at the edge of the auxetic structure, as well as its progressive deformation.
[0051] Figure 9 illustrates a link (L) of section (S) having been preformed according to a preform (P)
[0052] Fig. 10 illustrates the case of multi-strand bonding.
[0053] Fig. 11 illustrates a perspective example of a network intended for the creation of a bracelet using an auxetic structure composed of triangular elements.
[0054] Figure 12 illustrates in perspective the assembly of 2 elements
[0055] Figure 13 illustrates, from a top view, the assembly of 2 elements
[0056] Figure 14 illustrates, from below, the assembly of 2 elements
[0057] Figure 15 illustrates the same bracelet in the rest position before elastic deformation (the decorative faces Ea have been removed so as to make visible all the connections (L) between the different elements (E)
[0058] Fig. 16 illustrates the same bracelet in an expanded position when subjected to a deformation stress.
Claims
Demands
1. Jewellery article composed of elements (E): (E1), (E2), ... linked together by one or more links (L): (L1-2), (L2-3),...in shape memory alloy, preformed by heat treatment (P).
2. Jewellery article according to claim 1, characterized in that the organization of the elements (E): (E1), (E2), ...and of the links (L): (L1-2), (L2-3),... forms a network.
3. Jewellery article according to claim 2, characterized in that the arrangement of the elements (E): (E1), (E2), ... and the links (L): (L1-2), (L2-3),... forms a three-dimensional structure.
4. Jewellery article according to claim 2, characterized in that the arrangement of the elements (E): (El), (E2), ...and of the links (L): (L1-2), (L2-3),... forms a three-dimensional surface.
5. Jewellery article according to any one of claims 1, 2, 3, 4, characterized in that the relative movement of the elements (E): (E1), (E2), ... is achieved by the spring-effect bending of the links.
6. Jewellery article according to any one of claims 1, 2, 3, 4 and 5, characterized in that the elements (E): (E1), (E2), ... form a tessellation pattern.
7. Jewellery article according to any one of claims 2, 3, 4, 5 and 6, characterized in that the network consisting of the elements (E) and the links (L) transforms in an auxetic manner.
8. Jewellery article according to claim 5, characterized in that the section (S) of the links (L) has a second moment of area favoring bending in one direction.
9. Jewellery article according to claims 1 to 8, characterized in that the links (L): (L1-2), (L2-3),...are made of shape memory alloy, selected from copper-based, nickel-titanium or iron-based alloys.
10. A jewellery article according to any one of claims 1 to 9, characterized in that the putting on and taking off of the jewellery are by the elastic bending of each of the connecting elements (L), generating an overall deformation of the jewellery of sufficient amplitude.