Patent Application
20240176298
The invention relates to an attachment monolithic part such as a collet for fastening a timepiece component on a support element.
The invention also relates to an attachment monolithic part —timepiece component assembly such as a balance spring—collet monolithic assembly.
In the prior art, attachment parts such as timepiece collets are known which are involved in assemblies of balance-springs on balance shafts in a horological movement and that being so, by elastic clamping.
Nonetheless, such attachment parts have the major drawback of imposing complex, long and expensive mounting operations, when making such assembly, as these attachment parts have hold torques on these balance shafts that are low and limited.
The present invention aims to overcome all or part of the aforementioned drawbacks by providing an attachment monolithic part which has a great hold torque in particular to facilitate/simplify the operations of mounting an assembly of an attachment monolithic part —horological component assembly with a support element as well as ensuring enough hold to guarantee holding in position in the plane and guaranteeing its angular position throughout the service life of the component.
To this end, the invention relates to an attachment monolithic part for fastening a timepiece component on a support element, comprising an opening into which said support element could be inserted, the attachment part comprising elastic arms contributing to ensuring an elastic clamping of the support element in the opening, each arm consisting of a contact portion provided with a through hole and with a connecting portion, said contact portion comprising a receiving region provided with a bearing area intended to come into contact with the support element and said connecting portion ensuring an elastic connection with another one of said arms of the part.
In other embodiments:
The invention also relates to an attachment monolithic part —timepiece component assembly for a horological movement of a watch comprising such an attachment part.
Advantageously, the assembly is monolithic.
The invention also relates to an assembly for a horological movement of a watch comprising said attachment monolithic part —timepiece component assembly, said assembly being fastened to a support element.
The invention also relates to a horological movement comprising at least one such assembly.
The invention also relates to a watch comprising such a horological movement.
The invention also relates to a method for carrying out such an assembly of an attachment monolithic part—horological component assembly with a support element, comprising:
Other particularities and advantages will clearly arise from the following description, made for indicative and non-limiting purposes, with reference to the appended drawings, wherein:
In this embodiment, this attachment monolithic part 1 also called attachment part 1 may be included in an attachment part—timepiece component assembly 120 visible in
In the context of the invention, this attachment part 1 has a thickness comprised between 50 and 150 μm. Preferably, such a thickness is in the range of 100 μm.
It should be noted that in one variant of this assembly 120, only the attachment part 1 may be made of such a so-called “fragile” material, the horological component 2 then being manufactured in another material.
This assembly 120 may be part of an assembly 130 for the horological movement 110, by being fastened to the support element 3 for example by elastic clamping. It should be noted that this assembly 130 has been imagined for applications in the watchmaking industry. Nonetheless, the invention could perfectly be implemented in other domains such as aeronautics, jewellery, or the automotive industry.
Such an attachment part 1 comprises an upper face and a lower face 10, preferably planar, respectively included in first and second planes P1 and P2 visible in
This attachment part 1 comprises outer and inner peripheral walls 9a, 9b. The outer peripheral wall 9a comprises a surface which externally delimits the contour of this attachment part 1. This peripheral wall confers an essentially hexagonal shape on this attachment part 1. As regards the inner peripheral wall 9b, it comprises a surface which delimits the opening 7 of this attachment part 1. This opening 7 defines a volume in the attachment part 1 which is smaller than that of a connecting portion of one end of the support element 3 which is intended to be arranged therein. It should be noted that this connecting portion has a circular cross-section and comprises all or part of the contact portions defined over the peripheral wall 8 of the support element 3.
As we will see later on, this inner peripheral wall 9b comprises bearing areas 13 intended to come into contact on the support element 3.
Referring to
Such arms 4 are formed by two portions 5a, 5b, a first portion so-called contact portion 5a with the support element and a second portion so-called elastic connection portion 5b with another arm 4 of the attachment part 1.
The contact portion 5a of each arm 4 is formed by two lateral regions 12b, a receiving region 12a and an outer region 12c. These regions 12a to 12c together delimit the periphery of a through hole 6 of this portion 5a.
In this configuration, the receiving region 12a is comprised between the inner peripheral wall 9b of the attachment part 1 and a portion of the periphery of the through hole 6 while being connected to the two lateral regions 12b of this contact portion 5a. This receiving region 12a is provided with an inner face 14 comprising the bearing area 13 of each elastic arm 4. This inner face 14 is formed by a portion of the inner peripheral wall 9b which is comprised in this contact portion 5a of the arm 4. In this configuration, the bearing area 13 may have:
This bearing area 13 comprises a substantially hollow or substantially concave portion in which two contact areas are included. These two contact areas are able to cooperate with the corresponding convex contact portion of the support element 3. Such contact areas are defined/comprised in the surface of this bearing area 13 while extending substantially over all or part of the thickness of the attachment part 1. In addition, these contact areas are flat each comprising a surface that is completely or partially planar. In the bearing area 13, the two contact areas are respectively included in different planes forming together an obtuse angle. These two contact areas are separate by being spaced apart from each other. In other words, the bearing area 13 comprises a connection area of the two contact areas. Preferably, this connection area has a rounded shape.
In particular, these contact areas are intended to cooperate with the contact portions according to a plane-convex or plane-cylinder type contact configuration when considering the cylindrical shape of the support element 3. In this configuration, the planar surface of each contact area cooperates with the convex-shaped corresponding contact portion of the support element 3. It should be pointed out herein that this convex shape of each contact portion 10 is assessed with respect to the planar surface of each corresponding contact area opposite which this portion 10 is arranged. It should be noted that this planar surface of each contact area forms a plane tangent to the diameter of the support element 3. In other words, the planar surface is perpendicular to the diameter and therefore to the radius of the support element.
In this configuration, the presence of two flat contact areas in each bearing area 13 of the attachment part 1 allows performing a contact pressure between this attachment part 1 and the support element 3 when making a mechanical connection therebetween and that being so, while considerably reducing the intensity of the stresses at these contact areas and the corresponding contact portions of the support element 3 during assembly and/or fastening of this attachment part 1 with the support element 3, which stresses being likely to damage the attachment part 1 by apparition of breakups/fractures or cracks.
In this configuration, the presence of this bearing area 13 in the inner face 8 of each contact portion 5a allows performing a contact pressure between the attachment part 1 and the support element 3 when making a mechanical connection therebetween and that being so, while considerably reducing the intensity of stresses at this bearing area 13 and the corresponding contact portion of the support element 3 during the assembly and/or fastening of this part 1 with the support element 3, which stresses are likely to damage said attachment part by the apparition of breakups/fractures or cracks.
As we have seen, these contact portions 5a therefore comprise the only bearing areas 13 of the attachment part 1 with the support element 3 which may be defined in all or part of the inner faces of these contact portions 5a. Referring to
Each contact portion 5a also comprises an outer region 12c. This region 12c is comprised between the outer peripheral wall 9a of the attachment part 1 and a portion of the periphery of the through hole 6 while also being connected to the two lateral regions 12b.
This contact portion 5a also includes the two lateral regions 12b, each being comprised between one end of an elastic connecting portion 5b, a portion of the outer peripheral wall 9a and a portion of the periphery of the through hole 6. It should be noted that these two lateral regions 12b also connect the receiving 12a and outer 12c regions together.
In this attachment part 1, the contact portion 5a of each arm 4 therefore comprises the through hole 6, also called hollow, which is defined across the thickness of this attachment part 1. This through hole 6 opens into both the upper and lower faces 10 of the attachment part 1. One could also say that this through hole 6 opens at one end into the upper face of the contact portion 5a and at another end into the lower face 10 of this portion 5a. This hole 6 extends according to the direction of the axis of revolution A and that being so, from the upper face towards the lower face 10 or vice versa. In other words, this through hole 6 connects these two faces together. This through hole 6 defines an empty volume or a matter-free volume. Hence, it should be understood that this volume corresponds to a variable or configurable volume. This volume comprises an open enclosure delimited by a peripheral wall of this hole 6. Such a through hole 6 represents between about 20 and 80 percents of the body of the contact portion 5a of the arm 4. Preferably, this through hole 6 represents 30 percents of this body.
Under these conditions, it should be noted that each contact portion 5a is configured to modify the volume defined by this through hole when this contact portion 5a is stressed by the support element 3.
As we have mentioned before, each arm 4 is further made up of the contact portion 5a, of the elastic connecting portion 5b. This connecting portion 5b allows connecting each arm 4 together and in particular the contact portions 5a of these arms 4. This connecting portion 5b has an elongate shape and therefore connects the contact portions 5a together. In other words, this connecting portion 5b extends longitudinally between two contact portions 5a.
The connecting portion 5b of each arm 4 has a cross-section which is constant or substantially constant all over the body of this elastic arm 4 while the cross-section of the contact portion 5a of this arm 4 is not constant/variable.
This connecting portion 5b is configured to achieve a dual deformation, a first deformation so-called “torsion elastic deformation” and a second deformation so-called “tensile deformation” or “extension elastic deformation”.
During this first deformation, the connecting portion 5b of each arm 4 is driven at both of its ends according to the same direction of rotation B4 by the moving contact portions 5a, to which portions 5a such ends are connected. One could notice that only one portion of the body of the connecting portion 5b is deformable in torsion, herein the ends of this portion 5b. In particular, such a first deformation contributes in improving the insertion of the support element 3 into the opening 5 of the attachment part 1 while contributing to avoiding any breakup of this part 1 and/or any apparition of a crack in this part 1 upon assembly thereof with the support element 3.
During the second deformation, the connecting portion 5b of each arm 4 is pulled at both of its ends according to the longitudinal direction B3 in opposite directions by the moving contact portions 5a, to which portions 5a such ends are connected. In particular, such a second deformation contributes to making the attachment part 1 store a large amount of elastic energy.
It should be noted that the first and second elastic deformations of the connecting portions 5b of these arms 4 may be carried out simultaneously or substantially simultaneously, or successively or substantially successively. It should be noted that when the first and second deformations are carried out simultaneously, then this is referred to as toroidal torsion deformation coupled with a radial expansion.
As mentioned before, the attachment part 1 comprises several elastic arms 4, in particular three in the embodiment that is described herein. In other words, this attachment part 1 comprises three receiving regions 12a comprising the bearing areas 13 intended to come into contact with said support element 3 at its corresponding contact portions. These bearing areas 13 are arranged over the periphery of the opening 7 of this attachment part 1. Each of these receiving areas 12a and therefore of the bearing areas 13, is configured to carry out a radial movement relative to the axis of revolution A of the body of the attachment part 1 while causing a reduction in the volume defined by the through hole 6, the thickness of this body when said contact portion 5a is stressed by the support element 3.
Moreover, in each contact portion 5a, the two lateral regions 12b, the receiving region 12a and the outer region 12c border/surround/delimit the through hole 6. More specifically, these regions 12a to 12c are configured to be deformed in different manners as they are stressed by insertion of the support element 3 into the opening 7 of said part 1. Indeed, for each contact portion 5a, each of these regions 12a to 12c has a deformation coefficient Crr, Crl, Cre whose value decreases, as this region 12a, 12b, 12c is brought away from the bearing area 13 of the receiving region 12a. In other words, the deformation coefficient Crr, also called deformation average coefficient Crr of the receiving region 12a has a high value or a higher value than the value of the coefficient Crl of the two lateral regions 12b and of that of the coefficient Cre of the outer region 12c. In addition, the coefficients Cri of the two lateral regions 12b have similar or substantially similar values which are higher than that of the coefficient Cre of the outer region 12c. In other words, the relationship between these deformation average coefficients Crr, Crl, and Cre of these regions 12a, 12b, 12c may be defined according to the following mathematical formula:
C
rr
>C
rl
>C
re
It should be noted that the deformations of these regions 12a, 12b, 12c cause a radial movement relative to the axis of revolution A of each of them. Of course, the amplitude/the intensity of these radial movements depend on the average deformation coefficients Crr, Crl, Cre of these regions 12a, 12b, 12c.
In this configuration, the elasticity or the flexibility of the attachment part 1, is defined by the combination of the deformations of the contact portions 5a and of the connecting portions 5b, more specifically compared to the intensity of these deformations during the application of a force F on the bearing areas of this part 1.
It should be noted that the through holes 6 of the arms 4 of the attachment part 1 are configured so as to control the movement of the contact portions 5a, in particular to reduce this movement, so that these portions 5a could, by cooperating with the connecting portions 5b, store as much elastic energy as possible when driving the attachment part 1 on the support element 3 and thus increase holding of this part 1 on this element 3.
Such a configuration of the elastic arms 4 enables the attachment part 1 to store a larger amount of elastic energy for the same clamping in comparison with the attachment parts 1 of the prior art. Such an amount of elastic energy stored in this part 1 then allows obtaining a greater holding torque of the attachment part 1 on the support element 3 in the assembly 130 of the attachment part—timepiece component assembly 120 with this support element 3. Complementarily, it should be noted that such a configuration of the attachment part 1 allows storing elastic energy ratios that are 6 to 8 times greater than those of the attachment parts of the prior art.
Furthermore, one could notice that the arrangement of the elastic arms 4 in the attachment part 1 enables, during insertion with clamping, a deformation of each elastic arm 4 allowing accommodating for the deformation of the entire attachment part 1 with the geometry of the connecting portion of the support element 3 on which assembly is done.
Referring to
As we have described before, this elastic deformation of the attachment part 1 results from the application of the contact force F on the bearing areas 13 of the elastic arms 4 by the contact portions of the peripheral wall 8 of the support element 3. Such a deformation substep 21 comprises a phase 22 of moving the elastic arms 4, and in particular the contact portions 5a, by the action of the contact force F applied thereon. Such a movement of the elastic arms 4 is carried out according to a direction comprised between a radial direction B1 relative to an axis of revolution A common to the support element 3 and to the attachment part, and a direction B2 coincident with this axis A. It should be noted that this direction B2 is perpendicular to the direction B1 and is oriented according to a way defined from the lower face 10 towards the upper face. Preferably, the contact force F is perpendicular or substantially perpendicular to said bearing area 13. It should be noted that in the context of the implementation of the deformation substep, each elastic arm 4 is subjected to a triple deformation, a deformation of its contact portion 5a and a dual deformation of its connecting portion 5b. This triple elastic deformation is carried out simultaneously or successively.
Afterwards, this method comprises as step 23 of fastening the attachment part 1 on the reinforcing element 3. Such a fastening step 23, in particular by radial elastic clamping, comprises a substep 24 of carrying out a radial elastic clamping of the attachment part 1 on the support element 3. Hence, it should be understood that in such a stressed state, the attachment part 1 stores a large amount of elastic energy which contribute to conferring thereon a considerable holding torque enabling in particular an optimum pinning up by elastic clamping.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22209692.7 | Nov 2022 | EP | regional |
