Elastic mounting device for attaching a watch component to a mounting element

Description

Field of invention

[0001] The invention relates to an elastic holding member for fixing a watch component to a support element.

[0002] The invention also relates to an elastic holding member - watch component assembly and an assembly of such an assembly with the support element.

[0003] The invention also relates to a method of producing such an assembly.

[0004] The invention further relates to a timepiece movement comprising at least one such assembly.

[0005] The invention finally relates to a timepiece comprising such a movement. Background of the invention

[0006] In the state of the art, elastic holding members such as watch collets are known which participate in the assembly of hairsprings on balance shafts in a watch movement, by elastic tightening.

[0007] However, such elastic holding members have the major disadvantage of requiring complex, long and costly assembly operations when producing such assemblies because these members have holding torques on these balance shafts which are low and limited. Notable state of the art: EP3309625. Summary of the invention

[0008] The aim of the present invention is to overcome all or part of the drawbacks mentioned above by proposing an elastic holding member which has a high holding torque, in particular to facilitate / simplify the operations of mounting an assembly of an elastic holding member - watch component assembly with a support element as well as to ensure sufficient holding to guarantee holding in position in the plane and guarantee its angular position during the life of the component.

[0009] To this end, the invention relates to an elastic holding member according to claim 1 for fixing a timepiece component to a support element, comprising an opening into which said support element is capable of being inserted, the holding member comprising rigid arms and elastic arms defined between connecting zones 9 of the member 1, these arms contributing to ensuring elastic clamping of the support element in the opening, each rigid arm being provided with a single flat contact zone of the holding member capable of cooperating with a corresponding convex contact portion of the support element.

[0010] Thus, thanks to these characteristics, the elastic holding member is then able to withstand significant elastic tightening and therefore to store a significant quantity of elastic energy when it is stressed in order to restore a significant holding torque, in particular thanks to a significant rigidity of this elastic holding member induced in particular by significant volumes (or quantities) of material constituting its rigid arms which comprise the internal and external structures. It will be noted that these significant volumes of material are more precisely included in the contact zones which are placed under load (or under stress) during the insertion of the support element into this holding member.

[0011] Furthermore, it will be noted that this elastic holding member is configured so that this storage of elastic energy leads to stresses which remain admissible with regard to the material which constitutes such a holding member such as silicon. Indeed, the contact zones 8 have a flat surface which thus allows them to produce with the contact portions a contact configuration of the plano-convex type thus contributing to avoiding / preventing any damage to the holding member 1 by the appearance of breaks or even cracks.

[0012] In other embodiments: the contact zone is distributed over a convex inner face of each rigid arm of the holding member; each contact zone is defined on a convex inner face of each rigid arm of the holding member, extending over all or part of a thickness of this holding member; each contact zone is capable of cooperating with the corresponding contact portion of the support element while being in a plano-convex contact configuration; the elastic holding member comprises as many contact zones as there are contact portions; the elastic holding member comprises as many rigid arms as there are elastic arms; the rigid arms and the elastic arms are arranged in the holding member in a successive and alternating manner; each rigid arm is connected at its two opposite ends to two different elastic arms; each rigid arm has a volume of material greater than the volume of material constituting each elastic arm;each elastic arm has a cross-section that is less than a cross-section of each rigid arm; each elastic arm has a cross-section that is constant throughout the body of this elastic arm; the elastic holding member comprises an attachment point with the timepiece component; the elastic holding member is a collet for fixing the timepiece component such as a hairspring to a support element such as a balance shaft, and the elastic holding member is made of a silicon-based material.

[0013] The invention also relates to an elastic holding member - timepiece component assembly for a timepiece movement of a timepiece comprising such a holding member.

[0014] In particular, the whole is monobloc.

[0015] The invention also relates to an assembly for a watch movement of a timepiece comprising an elastic holding member - timepiece component assembly, said assembly being fixed to a support element.

[0016] The invention further relates to a timepiece movement comprising at least one such assembly.

[0017] The invention also relates to a timepiece comprising such a timepiece movement.

[0018] The invention also relates to a method for producing an assembly of an elastic holding member - watch component assembly with a support element according to the preceding claim, comprising: a step of inserting the support element into the opening of the elastic holding member of said assembly, said step comprising a sub-step of elastic deformation of the elastic holding member provided with a phase of displacement of the rigid arms of the elastic holding member inducing a double elastic deformation of the elastic arms of this elastic holding member, and a step of fixing the holding member on the support element comprising a sub-step of carrying out a radial elastic clamping of the holding member on the support element. Summary description of the drawings

[0019] Other features and advantages will become clear from the description given below, for information purposes only and in no way limiting, with reference to the attached drawings, in which: there figure 1is a front view of an elastic holding member for fixing a watch component to a support element which is here in a stressed state, according to one embodiment of the invention; figure 2 is a perspective view of the elastic holding member for fixing the watch component to the support element which is here in a rest state, according to the embodiment of the invention; figure 3 is a sectional view along III-III of the figure 2 ; there figure 4 is a larger scale view of part A of the figure 2 ; there Figure 5 represents a timepiece comprising a timepiece movement provided with at least one assembly comprising an elastic holding member - timepiece component assembly fixed to a support element, according to one embodiment of the invention, and the figure 6represents a method of producing such an assembly of an elastic holding member - watch component assembly with a support element. Detailed Description of Preferred Embodiments

[0020] THE figures 1 to 4 present an embodiment of the elastic holding member 1 for fixing a watch component 2 to a support element 3. For example, the elastic holding member 1 may be a collet for fixing the watch component 2 such as a hairspring to a support element 3 such as a balance shaft.

[0021] In this embodiment, this holding member 1 can be included in an assembly 120 elastic holding member - watchmaking component visible on the Figure 5and which is intended to be arranged in a timepiece movement 110 of a timepiece 100. Such an assembly 120 may be a single-piece part made of a so-called “fragile” material, preferably a micro-machinable material. Such a material may comprise silicon, quartz, corundum or even ceramic.

[0022] It will be noted that in a variant of this assembly, only the elastic holding member 1 can be made of such a so-called “fragile” material, the watch component 2 then being made of another material.

[0023] This assembly 120 may be part of an assembly 130 for the watch movement 110, being fixed to the support element 3 for example by elastic clamping. It will be noted that this assembly 130 was designed for applications in the watchmaking field. However, the invention can be perfectly implemented in other fields such as aeronautics, jewelry, or even the automobile industry.

[0024] Such a holding member 1 comprises an upper face and a lower face 12, preferably flat, included respectively in first and second planes P1 and P2 visible on the figure 2, as well as external and internal structures 4a, 4b. These external and internal structures 4a, 4b respectively comprise external and internal peripheral walls of this holding member 1 and have different shapes. More specifically, with regard to the external structure 4a, it may have a generally hexagonal shape, notably comprising parts having convex shapes. Each of these parts is included in a connecting zone 9 connecting an elastic arm 7 to a rigid arm 6. The elastic arms 7 and rigid arms 6 each being an elongated part which connects parts of the holding member 1 together. In other words, a rigid arm or an elastic arm extends longitudinally between two connecting zones 9 included in each of these arms 6, 7.In this context, when speaking of the elastic arms 7, the parts of the member 1 which are connected to each other are the rigid arms 6, this connection being made at the connection zones 9. Similarly, when speaking of the rigid arms 6, the parts of the member 1 which are connected to each other are the elastic arms 7, this connection being made evidently at the connection zones 9. It is therefore understood that each rigid arm is directly connected at each of its two opposite ends to an elastic arm. It will be noted that each rigid and elastic arm which are directly connected to each other comprise the connection zone 9 which they share and at which the end of one is directly connected to the end of the other. In addition, it is therefore understood that the elastic and rigid arms are arranged successively and alternately in the holding member.Each rigid arm is connected to two different elastic arms, which elastic arms are connected “directly” to the other rigid arms of the member 1. This external structure 4a is in particular intended to be connected to the timepiece component 2 via at least one attachment point 11 arranged in the external peripheral wall of the holding member 1. Concerning the internal structure 4b, it has a non-triangular shape. This internal structure 4b which comprises the internal peripheral wall of this holding member 1, participates in defining an opening 5 of such a holding member 1 in which the support element 3 is intended to be inserted. This opening 5 defines a volume in the holding member 1 which is less than that of a connecting part of one end of the support element 3 which is intended to be arranged there.It will be noted that this connecting part has a circular cross-section and comprises all or part of the contact portions 10 defined on the peripheral wall 13 of the support element 3. It will be noted that this support element 3 has a radius of curvature R1 visible on the . figure 1 .

[0025] This holding member 1 comprises the rigid arms 6 and elastic arms 7 connecting the external and internal structures 4a, 4b together. It will be noted that this holding member 1 comprises as many rigid arms 6 as elastic arms 7. The rigid arms 6 are here non-deformable or almost non-deformable and play a role as stiffening elements of the holding member 1. With regard to the elastic arms 7, they are capable of deforming mainly in tension but also in torsion. These rigid arms 6 and these elastic arms 7 are defined or distributed successively and alternately in this holding member 1. In other words, these rigid arms 6 are connected to each other by said elastic arms 7. More precisely, each elastic arm 7 is connected at its two opposite ends at the level of connection zones 9 to two different rigid arms 6. Such rigid and elastic arms 6, 7 include, in a non-limiting and non-exhaustive manner: internal faces included in the internal structure 4b and which together participate in defining the internal peripheral wall of the holding member 1 and therefore also the opening 5 of this holding member 1, and external faces included in the external structure 4a and which together define the external peripheral wall of this holding member 1.

[0026] It will be noted that the inner faces of the elastic arms 7 are essentially flat and the inner faces of the rigid arms 6 are non-flat, for example being convex in shape. In the present embodiment, the convex inner face of each rigid arm 6 therefore comprises the flat contact zone 8. This contact zone 8 is capable of cooperating with the corresponding contact portion 10 of the support element 3. Such a contact zone 8 is defined in the inner face, extending substantially over all or part of the thickness of the holding member 1. In addition, this contact zone 8 is flat, comprising a surface which is wholly or partly flat.It will be noted that the contact zones 8 of the rigid arms 6 are provided in particular to cooperate with the contact portions 10 according to a planar-convex type contact configuration in which configuration where the flat surface of each contact zone 8 cooperates with the corresponding convex contact portion 10 of the support element 3. It should be noted here that this convex shape of each contact portion 10 is assessed relative to the flat surface of each corresponding contact zone 8 with respect to which this portion 10 is arranged. It will be noted that the flat surface of the contact zone 8 forms a plane tangent to the diameter of the support element. In other words, the flat surface is perpendicular to the diameter and therefore to the radius R1 of the support element.

[0027] In this configuration, the presence of this flat contact zone 8 in the inner face of each rigid arm 6 makes it possible to exert contact pressure between the holding member 1 and the support element 3 when creating a mechanical connection between them, while significantly reducing the intensity of the stresses at the level of this contact zone 8 and the corresponding contact portion 10 of the support element 3 during the assembly and / or fixing of this holding member 1 with the support element 3, which stresses are likely to damage the holding member 1 by the appearance of breaks / fractures or even cracks.

[0028] In the state of the art, this contact pressure is estimated from the Hertz pressure equation, conventionally but not exclusively implemented for determining a contact pressure between cylindrical or spherical parts having different diameters or radii of curvature. In the present case, this Hertz pressure is defined according to the following equation: P = E *F π LR 1 2 With : E* which is an equivalent modulus of elasticity; F which is the radial force also called pressure force or radial load or contact force undergone by the contact zones 8; L which is the guide length corresponding to the length of each contact zone, i.e. the thickness of the holding member 1; R which is the relative radius of curvature defined by the following equation: R = R 1 R 2 R 1 + R 2 when the contact zone 8 and the corresponding contact portion 10 of the support element 3 have different radii of curvature R 2 and R 1 and are in a convex-convex type contact configuration.

[0029] In the present embodiment, the contact zone 8 of each rigid arm 6 is flat and therefore does not have a radius of curvature R 2 . Such a contact zone 8 is capable of cooperating with the corresponding contact portion 10 of the support element 3 in the plano-convex type contact configuration.

[0030] Thus, in such a contact configuration, the contact pressure defined by the Hertz pressure equation is lower than that relating to convex-convex type contact configurations in which the contact zone 8, which then has a radius of curvature R 2, is capable of cooperating with the corresponding contact portion 10 of the support element 3. This contact pressure present in the plano-convex type contact configuration is lower than those implemented in the other configurations described previously, in particular due to the higher value in this context of the relative radius of curvature R resulting from the absence of a radius of curvature for each flat contact zone 8 of the holding member 1 of the present embodiment.

[0031] In the plano-convex type contact configuration where the contact zone 8 of each rigid arm 6 is capable of cooperating with the corresponding contact portion 10 of the support element 3, the contact pressure is lower than those of these other contact configurations by at least 25%.

[0032] In this embodiment, the rigid and elastic arms 6, 7 connect the external and internal structures 4a, 4b together, each comprising a part of these external and internal structures 4a, 4b. In this holding member 1, these rigid and elastic arms 6, 7 essentially make it possible to achieve a fixing of the elastic clamping type of the support element 3 in the opening 5 formed in this holding member 1 which is defined by the internal structure 4b and in particular by the internal peripheral wall of this holding member 1.

[0033] As we have seen, these rigid arms 6 therefore comprise the only contact zones 8 of the holding member 1 with the support element 3 which can be defined in all or part of the inner faces of these rigid arms 6. The contact zone 8 of each rigid arm 6, otherwise called “contact interface”, is provided to cooperate with a peripheral wall 13 of the connecting part of the support element 3, in particular with the corresponding contact portion 10 defined in this peripheral wall 13 of the support element 3. In this context, the holding member 1 then comprises three contact zones 8 which participate in achieving precise centering of the timepiece component 2, for example a hairspring, in the timepiece movement 110.

[0034] In reference to the figure 3, in this holding member 1, each rigid arm 6 has a volume of material which is substantially greater or strictly greater than the volume of material constituting each elastic arm 7. Furthermore, it will be noted that the elasticity or rigidity of an arm in this holding member 1 is defined relative to the contact zones 8 of this member 1, more precisely relative to the intensity of the deformation of these rigid or elastic arms when a force is applied to these contact zones 8. It will in fact be noted that the external and internal structures 4a, 4b, and in particular the internal and external peripheral walls, are separated from each other in this holding member 1 by a variable gap E which then changes depending on whether these structures are included, for example, in a rigid arm 6 or an elastic arm 7.Indeed, this gap E is a maximum gap E1 when it is defined between parts of the inner and outer peripheral walls included in each rigid arm 6, i.e. the maximum gap E1 present between the inner and outer faces of this rigid arm 6. In particular for each rigid arm 6, this maximum gap E1 is defined between the contact zone 8 of each rigid arm 6 and an opposite part of the outer peripheral wall of this rigid arm 6. Furthermore, this gap E is a minimum gap E2 when it is defined between parts of the outer and inner peripheral walls included in the elastic arms 7, i.e. the minimum gap E2 present between the inner and outer faces of this elastic arm 7.

[0035] It is therefore understood here that each elastic arm 7 has a cross-section which is less than a cross-section of each rigid arm 6. In other words, the cross-section of each elastic arm 7 has a surface area which is less than a surface area of ​​the cross-section of each rigid arm 6. It will be noted that the cross-section of the elastic arm 7 is constant or substantially constant throughout the body of this elastic arm 7 whereas the cross-section of the rigid arm 6 is inconstant / variable throughout the body of this rigid arm 6. In addition, it will be noted that: the cross-section of each rigid arm 6 is preferably a solid or partially solid section which is perpendicular to the longitudinal direction in which the body of this rigid arm 6 extends, and the cross-section of each elastic arm 7 is preferably a solid or partially solid section which is perpendicular to the longitudinal direction in which the body of this elastic arm 7 extends.

[0036] Such a configuration of the rigid and elastic arms 6, 7 allows the holding member 1 to store a greater quantity of elastic energy for the same tightening compared to the holding members of the state of the art. Such a quantity of elastic energy stored in the holding member 1 then makes it possible to obtain a greater holding torque of the holding member on the support element 3 in the assembly 130 of the assembly 120 holding member - timepiece component with this support element 3. In addition, it will be noted that such a configuration of the holding member 1 makes it possible to store elastic energy ratios which are 6 to 8 times greater than those of the holding members of the state of the art.

[0037] It will be noted that the arrangement of the rigid and elastic arms 6, 7 in the holding member 1 allows, during insertion with tightening, a deformation of each elastic arm 7 making it possible to accommodate the deformation of the entire holding member 1 with the geometry of the connecting part of the support element 3 on which it is assembled. In addition, the mode of deformation that each elastic arm undergoes is a toroidal torsion coupled with a radial expansion.

[0038] In reference to the Figure 5, the invention also relates to a method for producing the assembly 130 of the assembly 120 elastic holding member - watchmaking component with the support element 3. This method comprises a step 13 of inserting the support element 3 into the opening 5 of the holding member 1. During this step 13, the end of the support element is presented at the entrance of the opening 5 defined in the lower face 12 of the holding member 1 in anticipation of the introduction of the connecting part of this support element 3 into the volume defined in this opening 5. This step 13 comprises a sub-step 14 of elastic deformation of the holding member 1 in particular of a central zone of this holding member 1 comprising said opening 5 resulting from the application of a contact force on the contact zones 8 of the rigid arms 6 by the contact portions 10 of the peripheral wall 13 of the connecting part of the support element 3.This elastic deformation of the central zone in fact causes a deformation of the lower face 12 of the holding member 1 which then has an essentially concave shape, in particular at the level of a part of this face 12 included in the central zone of the holding member 1. In other words, when the central zone of the holding member 1 is deformed, this lower face 12 is no longer flat and is then no longer entirely included in the second plane P2.

[0039] As previously mentioned, this elastic deformation of the holding member 1 results from the application of the contact force to the contact zones 8 of the rigid arms 6 by the contact portions 10 of the peripheral wall 13 of the support element 3. Such a deformation sub-step 14 comprises a phase of displacement 15 of the rigid arms 6 under the action of the contact force applied to them. Such a displacement of the rigid arms 6 is carried out in a direction between a radial direction B1 relative to a central axis C common to the support element 3 and to the holding member 1, and a direction B2 coinciding with this central axis C. It will be noted that this direction B2 is perpendicular to the direction B1 and is oriented in a defined direction from the lower face 12 towards the upper face. The contact force is preferably perpendicular or substantially perpendicular to said contact zone 8.During the course of this phase 12, the rigid arms 6 thus moving under the action of this contact force, generate a double elastic deformation of the elastic arms 7.

[0040] A first deformation otherwise called “ elastic torsional deformation » of these elastic arms 7. During this torsional deformation, each elastic arm 7 is driven at its two ends in the same direction of rotation B4 by the rigid arms 6 in movement, to which arms 6 of such ends are connected. It will be noted that only a part of the body of these elastic arms 7 is deformable in torsion here the ends of these arms 7. Such a first deformation contributes in particular to improving the insertion of the support element 3 into the opening 5 of the holding member 1 by helping to avoid any breakage of the holding member 1 and / or any appearance of a crack in this member 1 during its assembly with the support element 3.

[0041] A second deformation otherwise called "tensile deformation" or even "elastic deformation in extension" elastic arms 7. During this extension deformation, each elastic arm 7 is pulled at its two ends in the longitudinal direction B3 in opposite directions by the rigid arms 6 in movement, to which arms 6 of such ends are connected. Such a second deformation contributes in particular to the holding member 1 storing a significant quantity of elastic energy.

[0042] This double elastic deformation of the elastic arms 7 can be carried out simultaneously or substantially simultaneously, or even successively or substantially successively. It will be noted in the context of the implementation of the deformation phase that when this double elastic deformation is carried out successively or substantially successively, the first deformation can then be carried out before the second deformation.

[0043] This method then comprises a step 16 of fixing the holding member 1 to the reinforcing element 3. Such a fixing step 16 comprises a sub-step 17 of carrying out radial elastic clamping of the holding member 1 on the support element 3. It is therefore understood that in such a state of stress, the holding member 1 stores a significant quantity of elastic energy which contributes to giving it a substantial holding torque, in particular allowing optimal turning by elastic clamping.

Claims

1. An elastic retaining member (1) for fixing a timepiece component (2) on a support element (3), comprising an opening (5) into which said support element (3) can be inserted, the retaining member (1) comprising rigid arms (6) and elastic arms (7) defined between connection areas (9) of the member (1), these arms contributing to ensure elastic clamping of the support element (3) in the opening (5), such a retaining member (1) comprising an outer structure (4a) capable of being connected to said timepiece component via at least one point of attachment (11) arranged in an outer peripheral wall of the retaining member (1) and an inner structure (4b) comprising an inner peripheral wall of this retaining member (1), which contributes to defining said opening in such a retaining member (1), into which the support element is intended to be inserted, the rigid arms (6) and the elastic arms (7) connecting the outer structure (4a) and inner structure (4b) to one another and the outer structure (4a) having an overall hexagonal shape comprising convexly-shaped parts, each rigid arm (6) being provided with a single flat contact area (8) of the retaining member (1) able to cooperate with a corresponding convex contact portion (10) of the support element (3), each elastic arm (7) being able to deform by way of: - a first torsional elastic deformation, and - a second tensile or extensional elastic deformation, in this retaining member (1) when the support element (3) is inserted into the opening (5), this support element (3) applies a contact force on the contact areas (8) of the rigid arms (6), such that the rigid arms (6) are displaced, and the displacement of these rigid arms (6) causes the double elastic deformation of the elastic arms (7).

2. The elastic retaining member (1) according to the preceding claim, characterised in that the contact area (8) is distributed over a convex inner face of each rigid arm (6) of the retaining member (1).

3. The elastic retaining member (1) according to any one of the preceding claims, characterised in that each contact area (8) is defined on a convex inner face of each rigid arm (6) of the retaining member (1), extending over all or part of a thickness of this retaining member (1).

4. The elastic retaining member (1) according to any one of the preceding claims, characterised in that each contact area (8) is able to cooperate with the corresponding contact portion (10) of the support element (3) being in a plano-convex-type contact configuration.

5. The elastic retaining member (1) according to any one of the preceding claims, characterised in that it comprises as many contact areas (8) as there are contact portions (10).

6. The elastic retaining member (1) according to any one of the preceding claims, characterised in that it comprises as many rigid arms (6) as there are elastic arms (7).

7. The elastic retaining member (1) according to any one of the preceding claims, characterised in that the rigid arms (6) and the elastic arms (7) are arranged successively and alternately in the retaining member (1).

8. The elastic retaining member (1) according to any one of the preceding claims, characterised in that each rigid arm (6) is connected at its two opposite ends to two different elastic arms (7).

9. The elastic retaining member (1) according to any one of the preceding claims, characterised in that each rigid arm (6) has a volume of material greater than the volume of material constituting each elastic arm (7).

10. The elastic retaining member (1) according to any one of the preceding claims, characterised in that each elastic arm (7) has a cross section which is smaller than a cross section of each rigid arm (6).

11. The elastic retaining member (1) according to any one of the preceding claims, characterised in that each elastic arm (7) has a cross section which is constant throughout the body of this elastic arm (7).

12. The elastic retaining member (1) according to any one of the preceding claims, characterised in that it comprises a point of attachment (11) with the timepiece component (2).

13. The elastic retaining member (1) according to any one of the preceding claims, characterised in that it is a collet for fixing the timepiece component (2) such as a balance-spring to a support element (3) such as a balance shaft.

14. The elastic retaining member (1) according to any one of the preceding claims, characterised in that it is made of a silicon-based material.

15. An elastic retaining member - timepiece component assembly (120) for a horological movement (110) of a timepiece (100) comprising a retaining member (1) according to any one of the preceding claims.

16. The assembly (120) according to the preceding claim, characterised in that it is made in one piece.

17. An assemblage (130) for a horological movement (110) of a timepiece (100) comprising an elastic retaining member - timepiece component assembly (120) according to any one of claims 15 and 16, said assembly (120) being fixed to a support element (3).

18. A horological movement (110) comprising at least one assemblage (130) according to the preceding claim.

19. A timepiece (100) comprising a horological movement (110) according to the preceding claim.

20. A method for producing an assemblage (130) of an elastic retaining member - timepiece component assembly (120) with a support element (3) according to the preceding claim, comprising: - a step (13) of inserting the support element (3) into the opening (5) of the elastic retaining member (1) of said assembly (120), said step (13) comprising a sub-step (14) of elastically deforming the elastic retaining member (1) provided with a phase of displacing (15) the rigid arms (6) of the elastic retaining member inducing a double elastic deformation of the elastic arms (7) of this elastic retaining member (1), and - a step (16) of fixing the retaining member (1) on the support element (3) comprising a sub-step (17) of performing a radial elastic clamping of the retaining member (1) on the support element (3).