Assembly of elements such as links of wristband

Abstract

The invention relates to an assembly of elements such as links of a wristband. The invention relates to a component (21), in particular a wristband, comprising at least two groups (1) of elements (3, 5, 7), in particular chain links, assembled together. According to the invention, the fastening between the elements (3, 5, 7) in the groups and between the groups is effected by gluing (glue 15) rather than by screwing. The invention also relates to a method for producing a component (21).

Description

Technical Field

[0001] This invention relates to components, and more specifically to parts comprising multiple sets of components assembled together. These components can form links of a wristband, decorative item, or jewelry item. Background Technology

[0002] In the watchmaking and jewelry industry, a wide variety of materials are used to create wristbands with diverse appearances. In particular, wristbands made from hard materials are known. Hard materials are defined as those with a Vickers hardness greater than 1000 HV. These hard materials are, for example, ceramics such as silicon nitride, zirconium oxide, or alumina. Ceramic materials may also be used. Hard materials are used because of their mechanical properties, especially their excellent scratch resistance. Wristband links made from these materials are typically obtained after an injection molding step (to give the links the desired shape) and then hardened through a sintering step.

[0003] Assembling wristband links requires internally threaded holes in the links for tightening screws or externally threaded components. Machining these threads in hard materials is difficult.

[0004] Furthermore, manufacturing internal threads requires complex molds, which limit the possibilities for injection on these links. Therefore, the injection point must be located on a surface excluding the internal thread, i.e., on the visible surface of the link. At this injection point, defects such as segregation or flow lines may exist, especially when injecting colored ceramics. The presence of these defects on the visible surface necessitates machining to eliminate them. Therefore, it is impossible to directly inject the link into its final form. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned disadvantages by proposing an installation that does not require tightening between chain links, thereby avoiding the creation of internal threads in the chain links.

[0006] Therefore, the present invention relates to a component (particularly a wristband) comprising at least two groups of elements (particularly links) assembled together. According to the invention, attachment between elements in the groups and attachment between groups are achieved by gluing rather than screwing.

[0007] More specifically, the present invention relates to a component comprising at least two groups of elements assembled together, each group comprising a first element, a second element, and a third element, wherein the first element and the second element are disposed on opposite sides of the third element. The first element and the second element each include a first blind recess and a second blind recess, and the third element includes a first through-hole and a second through-hole, the first through-hole of the third element being positioned facing the first blind recess of the first element and the second element in each group, and the second through-hole of the third element in one group being positioned facing the second blind recess of the first element and the second element in the other group. Attachment within each group and attachment between the two groups are respectively provided by: - A first rod, which is installed in the first through hole of the third element and fastened at its end in the first blind recess of the first and second elements by adhesive. - The second rod is installed in the second through hole of the third element and is fastened at its end in the second blind recess of the first and second elements by the adhesive.

[0008] According to the invention, the blind recess has a specific form that ensures the anchorage of the rod within it. The first and second blind recesses define, in a conventional manner, a longitudinal region for receiving the ends of the first and second rods. According to the invention, this longitudinal region leads to at least one cavity extending laterally relative to the longitudinal region. This cavity forms a recess, where adhesive is received and secured around the end of the rod, ensuring its firm retention within the recess.

[0009] Preferably, the first blind recess and the second blind recess each define two cavities extending laterally relative to the longitudinal region, and the two cavities are respectively located on each side of the longitudinal region.

[0010] Therefore, one or more cavities enable mechanical attachment between the glue and the chain links, which allows for the secure fastening of a wide variety of assemblies.

[0011] In addition, gluing and fastening reduces the assembly cost of the wristband and simplifies the assembly process.

[0012] The absence of internal threads in the blind recess simplifies the injection molding process, which inevitably results in the injection point being located on the surface including the blind recess (i.e., on an invisible surface). This allows for the avoidance of machining steps and the direct injection of the chain link into the correct shape.

[0013] According to a specific embodiment of the present invention, the component has one or a suitable combination of the following features: - The two cavities are positioned facing each other on each side of the longitudinal region; - The longitudinal region extends on both sides of the at least one cavity; - The first and second rods include heads at their ends, the heads having cutouts on their periphery, the cutouts being filled with adhesive and positioned opposite the at least one cavity; - At least a portion of the first and second elements is made of enamel, stone, sapphire, cermet, or ceramic; - In each group, the third element is formed by a plurality of elements and an intermediate element disposed between each of the plurality of elements; - The first and / or second through holes of the third element include a non-circular cross-section corresponding to the shape of the first and second rods, respectively, in order to prevent any relative pivoting of the first, second and third elements; - The first and second through holes of the third element have circular cross-sections that correspond to the cross-sectional shapes of the first and second rods, so as to allow the third element to pivot relative to the first and second elements; - It includes at least five elements connected together; - This applies to wristbands, decorative items, or jewelry.

[0014] The present invention also relates to a method for manufacturing the component, the method comprising the steps of manufacturing at least one of a first element, a second element, and a third element by additive manufacturing or by injection and sintering; and comprising the steps of assembling and fastening the first element, the second element, and the third element by gluing.

[0015] According to a specific embodiment of the method, the first element and the second element are manufactured by injection and sintering according to the following steps: a) The step of manufacturing a precursor from a mixture of at least one material in powder form and an adhesive. b) The step of manufacturing an insert made of polymer material, the insert having at least partially a form opposite to the first and second blind recesses. c) The step of overlaying a molding precursor onto an insert made of polymer material by injection into a mold to form an unfired body, and d) The step of sintering the unsintered body to form the first element and the second element in the material.

[0016] Other features and advantages of the invention will become apparent in the following description of preferred embodiments, which are presented by way of non-limiting example with reference to the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of a component according to the invention, wherein the links are assembled by gluing.

[0018] Figure 2This is a plan view of another component according to the invention, wherein the links are assembled by gluing.

[0019] Figure 3a and 3b The illustration shows the steps for securing the rod to the chain link by gluing.

[0020] Figure 4 This is a block diagram of a method for manufacturing a chain link with a blind recess.

[0021] Figures 5a to 5c It shows according to Figure 4 A schematic cross-sectional view of the chain segment obtained by the method.

[0022] Figure 6 This is a perspective view of a link according to the present invention. Detailed Implementation

[0023] This invention relates to components, such as links intended to form wristbands, decorative items, or jewelry. More specifically, it applies to components made wholly or partially of a hard material. According to the invention, the term "hard material" means a material whose hardness is substantially equal to or greater than 600 HV, or even equal to or greater than 1000 HV; and which accepts only minimal or no plastic deformation before fracture. Examples of hard materials that may be mentioned by way of entirely non-limiting example include: enamel, stone (whether or not a gemstone, such as ruby, sapphire, or quartz), ceramics (such as metal or non-metal oxides, carbides, or nitrides), cermets, or hard metals.

[0024] The component according to the invention (shown below as a wristband) comprises at least two groups of elements assembled together. According to the invention, fastening between the elements in the groups and between the groups is achieved by gluing.

[0025] exist Figure 1 Each group 1, defined by the dashed line, includes at least three elements 3, 5, and 7, which may be formed wholly or partially of a rigid material. It includes a first lateral element 3 and a second lateral element 5, which are substantially symmetrical with respect to a third element 7 disposed between the lateral elements. It should be noted that elements 3, 5, and 7 are preferably mounted in a serrated manner.

[0026] The first and second elements 3 and 5 each include a first blind recess 2 and 4, respectively, while the third element 7 includes a first through hole 6. For example... Figure 1As shown, recesses 2, 4 and holes 6 are designed to be aligned to secure the first element 3, the second element 5, and the third element 7 together via a rod 11, which is mounted in the through hole 6 of the central third element 7 and glued at its end to recesses 2, 4. Blind recesses 2, 4 define longitudinal regions 2a, 4a for receiving the end of the rod 11 and at least one cavity 2b, 4b extending laterally relative to said longitudinal regions. Figure 3a The cavity receives adhesive 15 for providing mechanical attachment of the adhesive in the first and second components. Figure 3b Preferably, there are two lateral cavities 2b, 4b, which are disposed on both sides of the longitudinal regions 2a, 4b and preferably face each other. Also preferably, the longitudinal regions 2a, 4a extend on both sides of the cavities 2b, 4b, wherein the end of the rod 11 is supported against the end of the longitudinal regions 2a, 4a.

[0027] Furthermore, preferably, the rod 11 includes a head 11a at its end, the head 11a having a cutout 11b disposed over its entire periphery. This cutout is filled with adhesive and disposed opposite to the cavity. The rod 11 includes a main portion 10 received in the through-hole 6 of the third element 7. Figure 1 Depending on the shape of the gaps or through-holes 6 and portions 10, the first and second lateral elements 3, 5 may or may not pivot relative to the central third element 7. By way of a completely non-limiting example, the through-hole 6 may include a non-circular cross-section corresponding to the cross-sectional shape of the central portion 10 of the rod 11 to prevent any relative pivoting of the first element 3, the second element 5, and the third element 7. Alternatively, it is conceivable that the through-hole 6 includes a circular cross-section corresponding to the cross-sectional shape of the portion 10 of the rod 11 to allow the central third element 7 to pivot relative to the first and second lateral elements 3, 5.

[0028] exist Figure 2 In the variant shown, each group 31 includes five elements. This is because, in addition to the three elements 33, 35', and 37 of the elements 3, 5, and 7 of the first type group 1, the second type group 31 also includes an intermediate row having a central second element 37' and an intermediate element 35.

[0029] Groups 1 and 31 are assembled with another group and so on to form components, such as wristbands, decorative items, or jewelry. Figure 2 As shown, multiple groups 31 can be connected together by buckles 61 to form a wristband intended for mounting on the central part of a timepiece.

[0030] The two groups 1 and 31 are also connected together via a rod 11', which is mounted in the second through-hole 24 in the third element 7 of group 1. Each end of the rod 11' is respectively mounted and glued into a second blind recess 27 or 28 formed in the first and second elements 3 and 5 of another adjacent group 1. The rod 11' intended to be mounted in the second through-hole 24 has a similar construction to the rod intended to be mounted in the first through-hole 6. Similarly, the blind recesses 27 and 38 have the same features as the blind recesses 2 and 4.

[0031] It should be understood that, as with the first through-hole 6, depending on the clearance left or the respective forms of the through-hole 24 and the rod 11', the central third element 7 will be able to pivot or not pivot relative to the first and second lateral elements 3, 5 that frame it. Just as with the first through-hole 6, the through-hole 24 may include a non-circular cross-section corresponding to the cross-sectional shape of the rod 11' to prevent any relative pivoting between the third element and the first and second lateral elements. On the other hand, it is conceivable that the through-hole 24 may include a circular cross-section corresponding to the cross-sectional shape of the rod 11' to allow such relative pivoting.

[0032] The method for mounting assembly 1 is explained below. Initially, components 3, 5, and 7 are manufactured with various holes or recesses 2, 4, 6, 27, 28, and 24. Preferably, at least one of components 3 and 5 with blind recesses 2, 4, 27, and 28 is manufactured by additive manufacturing or by injection and sintering according to the method described in further detail below. Next, rods 11 and 11' are respectively glued and fixed in the recesses 2 and 27 of the lateral component 3. Figure 3a and Figure 3b For example, the adhesive may have a viscosity > 400 Pa·s and a tensile strength > 40 N / mm. 2 The epoxy resin adhesive is applied. Bonding is performed by pressure deposition using a syringe. Third, the portions of rods 11 and 11' protruding from the first lateral element 3 are respectively fitted into the first through-hole 6 in the third element 7 of group 1 with respect to the first rod and into the second through-hole 24 in the third element 7 of the adjacent group 1 with respect to the second rod. Fourth, the second ends of each rod 11 and 11' protruding from the third element 7 are glued and secured to the recesses 4 and 28 of the second lateral element 5. At the end of the fourth stage, elements 2, 5, and 7 within each group are completely secured together, and these groups are also completely secured to each other.

[0033] When Figure 2When there are more than three elements in the diagram, the principle is basically the same as that of elements 37 and 37' that form the third central element. The first and second through holes in these elements 37 and 37' communicate with two through holes formed in the intermediate elements 35 of two adjacent groups 31, respectively, for receiving two rods 11 and 11' extending between the lateral elements 33 and 35' with blind recesses, respectively.

[0034] As explained above, the lateral elements 3 and 5 with blind recesses can be manufactured by additive manufacturing or by injection and sintering. The blind recesses can be directly manufactured during additive manufacturing. According to application EP 20194714, for manufacturing by injection and sintering, lateral elements with blind recesses can be manufactured by overmolding a hard material onto an insert, the insert being made of a release material and having the form of a recess. According to this application and as... Figure 4 As schematically illustrated, method 8 includes a first step (a) of manufacturing a precursor from a mixture of at least one hard material in powder form and an adhesive. In this case, the ceramic-based powder may include at least one metal oxide, metal nitride, or metal carbide. By way of example, the ceramic-based powder may include alumina, or a mixture of alumina and chromium oxide, to form synthetic ruby, zirconium oxide (which may optionally be colorable), alumina (which may optionally be colorable), silicon nitride, cermet, metal, and composites of these metals. For example, the cermet is titanium carbide or tungsten carbide. For example, the metal is tungsten, titanium, 316L stainless steel, or steel, preferably nickel-free. The adhesive is of an organic type.

[0035] Method 8 includes a second step (b) of manufacturing an insert 9 made of polymer material, which at least partially has a form opposite to the required form of the recesses of the lateral elements 3, 5. Figure 5a The polymer is selected, for example, from the following list: acrylic resins of the PVD (plasticized polyvinyl butyral), CAB (plasticized cellulose acetate butyrate), or PBMA (polybutyl methacrylate) type.

[0036] The third step (c) includes overlaying the molded precursor 16 onto the insert 9 made of polymer material to form an unfired body 14. Figure 5b Overmolding is achieved, in particular, by injection into a mold. Taking into account the shrinkage coefficient of the part, the mold at least partially takes on the form of the desired part. The precursor is injected into the mold through a tube and then through a circuit used to distribute the precursor throughout the mold. Thus, the precursor takes the form of the mold, i.e., the form of a lateral element. Alternatively, injection can be performed via a disc or through a channel. The unbaked body takes the form of the mold and at least partially takes the form of an insert, overmolding the unbaked body onto the insert.

[0037] In step d), the unburned body is processed to remove unwanted portions of the injection-manufactured unburned body. For example, nozzles or channels formed by the tubing or dispensing circuit of the injection system are removed. This yields the processed unburned body.

[0038] In step e), the polymer insert 9 is removed by thermal stripping. Preferably, the unburned body overmolded on the insert is immersed in an alcohol bath at 80°C. The alcohol bath dissolves the polymer insert, thereby obtaining an unburned body with the desired shape given by the insert. Alternatively, thermal stripping can be performed to remove the polymer insert. Therefore, the body overmolded on the insert is heated to a high temperature to cause the polymer to disappear. The polymer insert is thus removed from the unburned body. The insert leaves a positive shape in the unburned body 14, namely the shape of the blind recesses 2, 4, 27, and 28. Figure 5c ).

[0039] The function of step f) is to sinter the processed unburned bulk material to form the bulk of the future part in the at least one hard material. Sintering includes heating the precursor to cause the powder particles to agglomerate. During sintering, the unburned bulk material hardens while shrinking, thereby producing a hard bulk material with a sintering coefficient. Preferably, according to the invention, the sintering step may include pyrolysis. Through this step, the bulk of the obtained part is substantially hardened. Therefore, the bulk of the part has a defined form, such as... Figure 6 As shown in the diagram.

[0040] However, a seventh step (g) is still required to glaze and / or polish the hard material. This improves the aesthetic appearance of the lateral element.

[0041] Next, the lateral components are assembled in each group according to the assembly method described above.

[0042] In variations, blind recesses can be manufactured by injection and sintering, and by additive manufacturing, either by machining in an unsintered body or in a hard body after sintering.

[0043] The central element 7 can also be manufactured by additive manufacturing or by injection and sintering.

Claims

1. A component (21, 51) comprising elements (3, 5, 7, 33, 35, 35', 37, 37') assembled together in at least two groups (1, 31), each group (1, 31) comprising a first element (3, 33), a second element (5, 35'), and a third element (7, 37, 37'), wherein the first element (3, 33) and the second element (5, 35') are disposed on both sides of the third element (7, 37, 37'), the first element (3, 33) and the second element (5, 35') each comprising a first blind recess (2, 4) and a second blind recess (27, 28), and the third element (7, 37, 37') comprises... The third element (7, 37, 37') includes a first through hole (6) and a second through hole (24), wherein the first through hole (6) of the third element (7, 37, 37') is positioned to face the first blind recess (2, 4) of the first element (3, 33) and the second element (5, 35') in each group (1, 31), and the second through hole (24) of the third element (7, 37, 37') of the group (1, 31) is positioned to face the second blind recess (27, 28) of the first element (3, 33) and the second element (5, 35') in the other group (1, 31), wherein attachment within each group (1, 31) and attachment between the two groups (1, 31) are provided by the following: - A first rod (11) is installed in the first through hole (6) of the third element (7, 37, 37') and fastened at its end in the first blind recess (2, 4) of the first element (3, 33) and the second element (5, 35'). - A second rod (11') is installed in the second through hole (24) of the third element (7, 37, 37') and is fastened at its end to the second blind recesses (27, 28) of the first element (3, 33) and the second element (5, 35'). The components (21, 51) are characterized in that: - The first rod (11) and the second rod (11') are respectively fastened to the first blind recess (2, 4) and the second blind recess (27, 28) with glue (15). - The first blind recess (2, 4) and the second blind recess (27, 28) form longitudinal regions (2a, 4a) for receiving the ends of the first rod (11) and the second rod (11'), respectively. The longitudinal regions (2a, 4a) lead to at least one cavity (2b, 4b) extending laterally relative to the longitudinal regions (2a, 4a). The cavities (2b, 4b) receive the adhesive (15) and provide mechanical attachment of the adhesive (15) in the first element (3, 33) and the second element (5, 35'). Furthermore, the longitudinal regions (2a, 4a) form longitudinal regions (2a, 4a) for receiving the ends of the first rod (11) and the second rod (11'), respectively. (a, 4a) leads to two cavities (2b, 4b) extending laterally relative to the longitudinal regions (2a, 4a), the two cavities (2b, 4b) being positioned on each side of the longitudinal regions (2a, 4a), the first rod (11) and the second rod (11') including heads (11a, 11'a) at their ends, the heads (11a, 11'a) having cutouts (11b, 11'b) on their periphery, the cutouts (11b, 11'b) being filled with the adhesive (15) and positioned opposite the at least one cavity (2b, 4b).

2. The components (21, 51) according to claim 1, characterized in that, The two cavities (2b, 4b) are positioned facing each other on each side of the longitudinal region (2a, 4a).

3. The component (21, 51) according to claim 1 or 2, characterized in that, The longitudinal regions (2a, 4a) extend on both sides of the at least one cavity (2b, 4b).

4. The component (21, 51) according to claim 1 or 2, characterized in that, At least a portion of the first and second elements (3, 5, 33, 35') is made of enamel, stone, sapphire, cermet, or ceramic.

5. The component (21, 51) according to claim 1 or 2, characterized in that, In each group, the third element (7, 37, 37') is formed by a plurality of elements (37, 37') and an intermediate element (35) disposed between each of the plurality of elements (37, 37').

6. The component (21, 51) according to claim 1 or 2, characterized in that, The first through hole (6) and / or the second through hole (24) of the third element (7, 37, 37') have a non-circular cross-section corresponding to the shapes of the first and second rods (11, 11') respectively, in order to prevent any relative pivoting of the first, second and third elements (3, 5, 33, 35', 7, 37', 37).

7. The component (21, 51) according to claim 1 or 2, characterized in that, The first through-hole (6) and the second through-hole (24) of the third element (7, 37, 37') have circular cross-sections corresponding to the cross-sectional shapes of the first and second rods (11, 11') to allow the third element (7, 37, 37') to pivot relative to the first and second elements (3, 5, 33, 35').

8. The component (21, 51) according to claim 1 or 2, characterized in that, It includes at least five groups (1, 31) connected together.

9. The component (21, 51) according to claim 1 or 2, characterized in that, This applies to wristbands, decorative items, or jewelry.

10. A method for manufacturing a component (21, 51) according to any one of claims 1 to 9, characterized in that, The method includes the step of manufacturing at least one of the first element (3, 33), the second element (5, 35'), and the third element (7, 37, 37') by additive manufacturing or by injection and sintering; and wherein the method includes the step of assembling and fastening the first element (3, 33), the second element (5, 35'), and the third element (7, 37, 37') by gluing.

11. The manufacturing method according to claim 10, characterized in that, The first element (3, 33) and the second element (5, 35') are manufactured by injection and sintering according to the following steps: a) The step of manufacturing the precursor (16) from a mixture of at least one material in powder form and an adhesive. b) The step of manufacturing an insert (9) made of polymer material, said insert (9) having at least partially a form opposite to the first blind recess (2, 4) and the second blind recess (27, 28), c) The step of overmolding the precursor (16) onto the insert (9) made of polymer material by injection into a mold to form an unfired body (14), and d) The step of sintering the unsintered body (14) to form the first element (3, 33) and the second element (5, 35') in the material.

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