Patent Application
20240310784
This application claims priority of European patent application No. EP23161901.6 filed Mar. 14, 2023, the content of which is hereby incorporated by reference herein in its entirety.
The invention relates to a regulating system for a timepiece movement. The invention also relates to a device for modifying the stiffness of an elastic return element. The invention further relates to a timepiece movement comprising such a regulating system or such a device for modifying stiffness. The invention finally relates to a timepiece comprising such a timepiece movement or such a regulating system or such a device for modifying stiffness.
Mechanical timepiece movements are commonly provided with an oscillator in the form of an assembly constituted by an inertial element and an elastic return element, in particular a balance and a hairspring.
In order for such an assembly to constitute a time base that is sufficiently accurate to ensure the correct operation of the movement, means for adjusting the inertial element or the elastic return element are used. These may, for example, be adjustment means for varying the inertia of the inertial element, or means for acting on the stiffness of the elastic return element. In particular, the inertial element may be provided with inertia blocks or adjusting screws that can be moved to allow more or less fine adjustment of the rate of the movement, of the order of a few seconds or tens of seconds per day. These inertia blocks may, for example, be adjusted by a watchmaker when the inertial element is stationary and, more particularly, when the movement is stationary. Additionally, or alternatively, the stiffness of the elastic return element may be adjusted by modifying the effective length of said element, for example by means of an index. Although such a system has the advantage of being adjustable while the inertial element is in motion, it does not allow sufficiently accurate adjustment, with accuracy comparable to that provided by moving the inertia blocks or adjusting screws of the inertial element.
Patent application EP 4 006 648 relates to a device for adjusting the effective length of a first elastic return element linked to an inertial element, which has the particularity of being directly integrated into the first elastic return element. In particular, this document discloses a first elastic return element in the form of a hairspring whose outer end comprises a set of elastic elements. These are designed to move a clamp in a precise manner opposite the terminal part of the outer end of the hairspring. The effective length of the hairspring can thus be adjusted, modifying the stiffness of the hairspring and therefore the frequency of the oscillator, i.e., of the inertial element/hairspring assembly, by modifying the ratio k/l in which k is the stiffness of the hairspring and l the inertia of the balance. However, such a device is particularly sensitive to variations in the effective length of the hairspring. Indeed, for an oscillator with a nominal frequency of 4 Hz, for example, a modification in the stiffness of the hairspring of approximately 10% results in a rate variation of several thousand seconds per day. With such an adjustment device, it is therefore very difficult to achieve fine adjustment of the order of a few seconds or tens of seconds per day. For a given hairspring, the adjustment in length that would be needed in order to adjust the rate by approximately ten seconds per day can be estimated at a few dozen micrometers. Moreover, there is a risk that acting directly on the length of the hairspring may disrupt the operation of the oscillator. Patent FR 833 085 relates to a method for synchronizing an oscillator of a mechanical clock with an electrical reference oscillator. According to one particular embodiment shown in
Patent application EP 4 009 115 discloses an oscillator that has the particularity of comprising a first elastic return element in the form of a hairspring linked to an inertial element in the form of a balance, and a second elastic return element linked in series with the hairspring, the stiffness of this second elastic return element being capable of being modified by prestressing means designed to apply a variable force or torque to the second elastic return element without modifying the stiffness of the hairspring. The stiffness of the second elastic return element is preferably greater than that of the hairspring, meaning that modifying the stiffness of the second elastic return element allows finer adjustment of the rate than if the stiffness of the hairspring were to be acted on directly. However, this modification in the stiffness of the second elastic return element needs to be possible without varying the position of the outer end of the hairspring with respect to the axis of rotation of the balance, in particular with respect to the isochronism of the oscillator, which is difficult to achieve in practice.
Patent application EP 4 016 194 discloses a concept similar to that which forms the subject matter of application EP 4 009 115, but for a one-piece oscillator. In particular, this oscillator comprises a flexible guide formed from elastic blades, which is designed to define a virtual pivot for an inertial element, and means for adjusting the stiffness of the oscillator comprising a flexible element arranged in series with the flexible guide. These adjustment means also comprise prestressing means designed to apply a variable force or torque to the flexible element in order to vary its stiffness, without varying the positioning of the virtual pivot defined by the flexible guide, which is difficult to achieve in practice.
The aim of the invention is to provide a regulating system that helps overcome the abovementioned problems and improve the regulating systems known from the prior art. In particular, the invention proposes a regulating system that allows fine and reliable adjustment of the oscillation frequency of an oscillator. By virtue of such a system, the adjustment may be made while the oscillator is in operation, and without affecting it.
According to a first aspect of the invention, subject matters are defined by the following propositions:
According to a second aspect of the invention, subject matters are defined by the following propositions:
According to a third aspect of the invention, subject matters are defined by the following propositions:
The appended drawings show, by way of example, two embodiments of a timepiece according to the invention.
Whatever the embodiment or the variant, a timepiece 400 is described hereinafter in detail in reference to
The timepiece 400 is, for example, a watch, in particular a wristwatch. The timepiece 400 comprises a timepiece movement 300 intended to be mounted in a timepiece case or casing in order to protect it from the outside environment.
The timepiece movement 300 may be a mechanical movement, in particular an automatic movement, or indeed a hybrid movement, i.e., a mechanical movement comprising electronic components.
The timepiece movement 300 comprises a regulating system 150.
The regulating system 150 comprises:
According to the first aspect of the invention, the regulating system 150 for a timepiece movement 300 comprises:
the elastic return system 1; 1′, 2, 3 comprising:
The first elastic return element 1; 1′ and the second elastic return element 2 are assembled in series between the inertial element 4; 4′ and the frame 6, and the third elastic return element 3 and the second elastic return element 2 are assembled in parallel between the frame 6 and the first elastic return element 1; 1′.
According to the second aspect of the invention, the regulating system 150 for a timepiece movement 300 comprises:
The elastic return system 1, 2, 3 comprises:
The first elastic return element 1 and the second elastic return element 2 are assembled in series between the assembled balance 4 and the frame 6, and the third elastic return element 3 and the second elastic return element 2 are assembled in parallel between the frame 6 and the first elastic return element 1.
Two elastic return elements of a system are said to be “in series” when they follow one after another or are linked to each other by one of their respective ends, so as to connect two separate elements, which means that, when a mechanical load of a given intensity is applied to the system, in particular to one or other of the two separate elements, each of the two elastic return elements is subjected at least substantially to this given intensity of this load.
Two elastic return elements of a system are said to be “in parallel” when they directly connect two separate elements by their two respective ends, which means that, when a deformation of a given intensity is applied to the system, each of the two elastic return elements is deformed at least substantially by this intensity.
The regulating system and/or the oscillator are specifically shaped and/or arranged to allow fine adjustment of the rate of the movement by modifying the stiffness of an elastic return element forming part of said oscillator. This adjustment may be carried out, in particular, by modifying the effective or active length of at least one elastic blade of an elastic return element forming part of said oscillator, in particular by means of a lever or a framework that can be moved in relation to the frame.
The oscillator 100, which is shown schematically in
The research undertaken by the inventors demonstrates that such an arrangement of the return elements 1, 2, 3 of the oscillator 100 allows particularly fine adjustment of the rate for carefully chosen stiffnesses k1, k2, k3. For example, for an oscillator 100 provided with a frequency of 4 Hz, and for a given stiffness k1, and when k2=20×k1 and k3=k1, a variation of ±10% in the stiffness k3 results in a rate variation in the timepiece comprising the oscillator 100 that is equal or substantially equal to ±10 secs/day.
It appears that a variation of approximately ±10% in the stiffness k3 of the third elastic return element 3 may be made possible by the use of a lever or framework that allows the effective or active length of at least one elastic blade 31 of the third elastic return element 3 to be adjusted. The lever or the framework may be operated by a watchmaker or by any autonomous device. For example, such a variation in stiffness of approximately ±10% may be caused by moving a lever or framework by an angle of a few degrees or approximately ten degrees about the axis A4.
The regulating system 150 is described hereinafter according to different embodiments and variants which involve either the use of traditional watchmaking elements such as a balance and at least one hairspring, or flexible guides and elements suitable for forming a one-piece assembly.
In the first embodiment (shown in
In the second embodiment (shown in
Different variants of these two embodiments are described hereinafter. In these variants:
Whatever the embodiment or the variant, the first elastic return element 1 may be linked respectively to the second and third elastic return elements 2, 3 by means of a connecting member 5, as shown in
Whatever the embodiment or the variant, the second and third elastic return elements 2, 3 are linked to the frame 6. The frame may be a frame of the timepiece movement 300, in particular a movement blank 6, such as a plate or a cock, in particular a balance cock.
Whatever the embodiment or the variant, the third elastic return element 3 may be linked to the frame 6 by means of an adjustment element 7 of the modification device 200.
Whatever the embodiment or the variant (implementing a hairspring or a flexible guide as a first elastic return element), one advantageous way of producing the second elastic return element consists in using an RCC (Remote Center Compliance) pivot, constituted by at least two embedded blades, whose purpose is to guide the connecting member 5. The virtual center of intersection of the flexible blades that constitute the RCC pivot may advantageously coincide with a point through which the geometric axis A4 of the inertial element passes (for the first embodiment) or coincide with a point through which the geometric (and virtual) axis A4′ of the flexible guide 1′ and the inertial element passes (for the second embodiment). This configuration improves the stability of the oscillator 100; 100′ compared with any other arrangements of the three elastic return elements.
The inertial element 4; 4′, in particular the “assembled balance 4”, or more generally the oscillator 100; 100′ or the regulating system 150, regulates a finishing chain or finishing gear of the movement 300 by means of a watch escapement. Any known watch escapement structure and any known finishing gear structure may be used.
In a first variant (shown schematically in
The second elastic return element 2 comprises two elastic blades 21, 22. The two blades 21, 22 are preferably straight. They are, for example, oriented radially in relation to the pivot axis A4 of the inertial element 4.
The third elastic return element 3 is in the form of a single elastic blade 31. The blade 3 is preferably straight. The blade 31 is, for example, oriented radially in relation to the pivot axis A4 of the inertial element 4.
The blades 21, 22, 31 are linked, at each of their first ends, to the hairspring 1, at an end portion 5 of the hairspring 1, which is substantially more rigid than the blade 11 and extends the blade 11 at the distal end of the hairspring 1. These blades 21, 22, 31 are also linked, at each of their second ends, to the frame 6. In particular, the second ends of the blades 21, 22 are embedded, in particular permanently embedded, in the frame 6. Also, in particular, the second end of the blade 31 is engaged or held between two pins 81, 82 secured to the adjustment element 7 consisting of a lever 7 or a framework 7 that is linked to the frame 6 while being able to be moved in translation in relation to said frame 6. The pins allow the third blade 31 to be clamped and/or held and/or supported at the point of contact with the pins. At these points of contact, the deflection of the third blade 31 is limited, or even cancelled out. The bending of the blade thus occurs between its point of connection to the end portion 5 and the points of contact with the pins. As a result, the effective or active length of the third blade which is bending can be adjusted by moving the lever 7 or the framework 7. The effect of this is to modify the stiffness k3 of the third blade 31.
During the operation of the oscillator 100, the inertial element 4 oscillates about the axis A4, which causes expansion and compression of the blade 11, and also deflection of the blades 21, 22, 31. In particular, the blades 21, 22 define a flexible guide linking the blade 11 and the connecting member 5 of the hairspring 1 to the frame 6. In particular, in this case, the blades 21, 22 define an RCC (Remote Center Compliance) pivot linking the blade 11 and the connecting member 5 of the hairspring 1 to the frame 6. The axis of the RCC pivot preferably coincides with the geometric axis A4 about which the inertial element 4 is pivoted. Modifying the effective length of the blade 31 (and therefore its stiffness k3, as previously described) makes it possible to vary the stiffness k100 of the oscillator 100 comprising such a hairspring 1 linked in series respectively with the blades 21, 22, and the blade 31.
As previously described, this is made possible by virtue of the pins 81, 82, which provide abutments and define the effective length of the blade 31 under the effect of a translational movement of the lever 7 or the framework 7.
The research undertaken by the inventors demonstrates that such an arrangement of the blades 11, 21, 22, 31 for the oscillator 100 allows particularly fine adjustment of the rate for carefully chosen stiffnesses k1, k2, k3. For example, for an oscillator 100 having an operating frequency of 4 Hz, and for a given stiffness k1, and when k2=20×k1 and k3=k1, a variation of ±10% in the stiffness k3 results in a rate variation in the timepiece comprising the oscillator 100 that is equal or substantially equal to ±10 secs/day.
In a second variant (shown schematically in
For example, in this second variant, the connecting member 5 has a slightly more complex configuration than that of the connecting member 5 of the first variant. In particular, the connecting member 5 according to this second variant may have elbow-shaped geometry. The connecting member 5 may have a first circular or substantially circular portion extending about the axis A4 to secure the blades 21, 22 to the blade 11 (in an identical manner to the first variant) and a second straight portion oriented radially or substantially radially in relation to the axis A4, being designed to secure the blade 31 to the blade 11.
The other end of the blade 31 is preferably embedded in the frame 6. However, the effective or active length of this blade 31, which moves to either side of its rest position under the effect of the oscillations of the inertial element 4 about the geometric axis A4, is defined by pins 81 and 82 that are secured to a lever or framework 7 that can rotate in relation to the frame 6. As in the first variant, the pins 81 and 82 provide points of abutment against the blade 31 and thus define one end of the effective or active length of this blade 31, i.e., they define the length of the blade 31 that is effectively subjected to bending.
In a third variant (shown in
In particular, the second elastic return element 2 and the connecting member 5 are integral with an intermediate member 61 that is fixed or attached to the rest of the frame 6. The intermediate member 61 therefore forms part of the frame 6. More generally, the second elastic return element 2 and the connecting member 5 are included within the same intermediate member 61 fixed to the rest of the frame 6.
This intermediate member 61, which is shown specifically in
In particular, these two pairs of blades are arranged symmetrically with respect to a plane P passing through the geometric axis A4 of the staff 42 that is linked to the balance 41, the staff 42 passing through a central opening 610 of the member 61.
The pair of blades 21a, 21b elastically links a first portion or plate 51 to the intermediate member 61. The pair of blades 22a, 22b elastically links a second portion or plate 52 to the intermediate member 61. The portions or plates 51 and 52 together constitute the connecting member 5. The plates 51, 52 are therefore respectively secured to the pairs of blades 21a, 21b and 22a, 22b.
Each of these plates 51, 52 is intended to be fastened respectively to a first respective end 13a, 33a and to a second respective end 13b, 33b of the hairsprings 1 and 3. The hairsprings 1, 3 are thus linked to the plates 51, 52 constituting the connecting member 5. These plates are themselves linked to the frame 6 by the elastic blades 21a, 21b and 22a, 22b.
The member 61 fastened to the rest of the cock 6 can thus constitute a support for the hairsprings 1 and 3.
In particular, the first ends 13a, 13b and second ends 33a, 33b are each in the form of studs or pins intended to be fitted, in particular driven, into openings 53a, 53b respectively formed at each of the plates 51, 52. Alternatively, the two plates could comprise studs and the connecting means of the hairsprings could comprise openings for receiving or driving these studs into.
Each of the plates 51, 52 is formed in the continuation of the blades 21a, 21b and 22a, 22b which are each, in this case, U-shaped or substantially U-shaped. Alternatively, the elastic blades 21a, 21b and 22a, 22b may each be V-shaped or substantially V-shaped or W-shaped or substantially W-shaped, for example. Alternatively, the elastic blades 21a, 21b and 22a, 22b may each be shaped in such a way as to achieve the required stiffness value, for example.
In particular, the structures 21a, 21b, 51 and 22a, 22b, 52 constitute unitary or single-piece elements. More generally, these structures are included within the intermediate member 61, the latter forming a one-piece assembly. The unitary assembly may incorporate the two plates 51, 52.
The pairs of studs 13a, 13b and 33a, 33b are respectively secured to a connecting means 12, 32 formed respectively in the continuation of the blades 11, 31 of the hairsprings 1, 3, at their distal end. In particular, these two pairs of studs are arranged symmetrically with respect to the abovementioned plane P, meaning that they are each able to cooperate with the pairs of elastic blades 21a, 21b and 22a, 22b by means of the plates 51, 52 that form the connecting member 5.
The first connecting means 12 is arranged at a first distal end of the first blade 11 and links the first hairspring 1 to the second elastic return element 2, in particular by means of the connecting member 5.
The second connecting means 32 is arranged at a second distal end of the third blade 31 and links the second hairspring 3 to the second elastic return element 2, in particular by means of the connecting member 5.
Each of these pairs of elastic blades 21a, 21b and 22a, 22b defines a flexible guide for the hairsprings 1 and 3, in particular an RCC pivot (the virtual center of which coincides with the axis A4), while linking the hairsprings 1 and 3 by means of the portions 51, 52.
In the construction example shown in
The modification device 200 may, for example, be arranged between the hairspring 3 and the frame 6, in particular the balance cock 6 (according to the vertical direction z). As described in the preceding variants and as can be seen, more particularly, in
Advantageously, the blades 11 and 31 of the hairsprings 1, 3 may be similar or substantially similar, or indeed identical. Therefore, advantageously, k3=k1. For example, for an oscillator 100 provided with a frequency of 4 Hz, and for a given stiffness k1 that is equal to k3, and when k2=20×k1, a variation of ±10% in the stiffness k3 results in a rate variation in the timepiece comprising the oscillator 100 that is equal or substantially equal to ±10 secs/day.
Such a variant has the advantage of using traditional watchmaking elements (for example, the hairsprings 1, 3, the assembled balance 4) while facilitating assembly by means of the specific configuration of the intermediate member 61, which has the advantage of combining the functions of the second elastic return element 2 and the connecting member 5.
A collet 14 is preferably arranged at a first proximal end of the first blade 11 and fastened to the staff 42 secured to the balance 41.
Advantageously, the collet 14, the first blade 11 and the first connecting means 12 form a one-piece assembly. Similarly, advantageously, the second proximal end 34, the second blade 31 and the second connecting means 32 may form a one-piece component.
Moreover, the balance 41, the staff 42 and the hairspring 1 (fastened to the staff 42 by means of the collet 14, for example) have the advantage that they can be assembled directly on a frame 6 if allowing adjustment by means of a modification device 200 is not desirable. Therefore, this assembly 41, 42, 1 may constitute a standardized assembly that can be incorporated both into a conventional movement and into a movement 300 provided with a modification device 200.
Optionally, the balance 41 may comprise movable screws or inertia blocks in order to allow fine adjustment of the rate of the movement, of the order of a few seconds per day. These screws or inertia blocks are, for example, movably fastened to a felloe 410 of the balance 41. These screws or inertia blocks may, for example, be adjusted by a watchmaker when the balance is stationary, using a key or screwdriver to move them (towards or away from the axis A4). These tools are generally provided with means for indicating the extension or retraction of the screw or the inertia block, in order to allow particularly fine adjustment of the rate of the movement.
In the third variant, which is more particularly shown in
According to the procedure described in this document, the third variant of the first embodiment allows fine adjustment of the rate of the movement by modifying the stiffness k3 of the elastic blade 31 of the hairspring 3, in particular by modifying the effective length of the elastic blade 31 of the hairspring 3, in particular by means of pins 81, 82 secured to a lever 7 or framework 7 and providing an abutment for said blade. This solution can be implemented in order to adjust the rate while the balance or the oscillator is in operation. Alternatively, this solution can be implemented while the balance is stationary, for example during the assembly or repair of the timepiece movement. In this latter case, a possible step of putting the timepiece in beat, comprising an operation of moving the intermediate member 61 in relation to the rest of the frame 6, may be carried out in advance. The operation of moving the intermediate member 61 is preferably an operation of rotating the intermediate member 61 about the geometric axis A4 in relation to the rest of the frame 6.
Optionally, preliminary or additional adjustment of the rate may be carried out by means of the inertia blocks 43a, 43b and 44a, 44b, while the balance is stationary, for example during the assembly or repair of the timepiece movement.
Therefore, such a third variant allows the implementation of a method for adjusting an oscillator of a regulating system, the method comprising:
Preferably, the first optional step may be carried out prior to the second step, in particular before the entire regulating system or oscillator is assembled. Advantageously, the first step is carried out while the balance is stationary. Advantageously, the second step can be carried out while the balance is in operation. Alternatively, the second step may be carried out while the balance is stationary. Optionally, a possible step of putting the timepiece in beat, comprising an operation of rotating the intermediate member 61, may be carried out prior to the second step.
A fourth variant (shown in
Indeed, the research undertaken by the inventors also shows that, for an oscillator 100 provided, for example, with a frequency of 4 Hz, and for a given stiffness k1, and for a second stiffness k2 and a third stiffness k3 that are similar or of the same order, substantially greater than the stiffness k1, of approximately 125×k1, a variation of ±10% in the stiffness k3 results in a rate variation in the timepiece comprising the oscillator 100 that is equal or substantially equal to ±15 secs/day.
In a fifth variant (shown schematically in
The effective length of the curved elastic blade 31 is again adjusted by pins 81, 82 of a lever 7 or framework that can be rotated with respect to the frame 6.
According to the second embodiment, the first elastic return element 1′ is in the form of a flexible guide 1′ designed to elastically return, and also to guide, and in particular to pivot, an inertial element 4′ about an axis A4′. To this end, the first elastic return element 1′ may comprise two blades 11′ and 12′ that intersect in such a way as to form, for example, a Wittrick pivot. In particular, these blades 11′ and 12′ are arranged in two distinct parallel planes. These blades 11′, 12′ are linked, at each of their first ends, to a connecting member 5. These blades 11′, 12′ are also linked, at each of their second ends, to an oscillating mass 41′. Therefore, the inertial element 4′ may comprise the oscillating mass 41′, and also the blades 11′ and 12′ forming the first elastic return element 1′ and a guide element 42′.
According to a first variant of the second embodiment (shown in
The blades 11′, 12′ and 21, 22 and 31 are linked to each other, at each of their first ends, by means of a connecting member 5. The blades 21, 22, 31 are also linked, at each of their second ends, to the frame 6. In particular, the second ends of the blades 21, 22 are permanently embedded in the frame 6, and the second end of the blade 31 is engaged between two projections 81, 82 secured to a framework 7 of a modification device 200, which is linked to the frame 6 while being able to be moved in translation in relation to said frame 6.
During the operation of the oscillator 100′, the mass 41′ oscillates about the axis A4′, which causes bending of the blades 11′ and 12′, and also deflection of the blades 21, 22, 31. In particular, the blades 21, 22 define a flexible guide linking the blades 11′, 12′ and the connecting member 5 to the frame 6. In particular, the blades 21, 22 define an RCC pivot linking the blades 11′, 12′ and the connecting member 5 to the frame 6. The axis of the RCC pivot preferably coincides with the geometric (and virtual) axis A4′ about which the inertial element 4′ is pivoted. Modifying the effective length of the blade 31 makes it possible to vary the stiffness k100′ of the oscillator 100′ comprising such a first elastic return element 1′ linked in series respectively with the blades 21, 22, and the blade 31.
The research undertaken by the inventors has demonstrated that such an arrangement of blades 11′, 12′, 21, 22, 31 for an oscillator 100′ allows particularly fine adjustment of the rate for carefully chosen stiffnesses k1′, k2, k3. For example, for an oscillator 100′ provided with a frequency of 10 Hz, and for a given stiffness k1′, and when k2=20×k1′ and k3=k1′, a variation of ±10% in the stiffness k3 results in a rate variation in the timepiece comprising the oscillator 100 that is equal or substantially equal to ±10 secs/day.
A second variant of the second embodiment (shown in
To this end, the connecting member 5 has a slightly more complex configuration than that of the connecting member 5 of the first variant. In particular, the connecting member 5 according to this second variant has elbow-shaped geometry. Two first circular or substantially circular portions extend about the axis A4′ to secure the blades 21, 22 to the blades 11′ and 12′, and a second straight portion, oriented radially or substantially radially in relation to the axis A4′, is designed to secure the blade 31 to the blades 11′, 12′.
The other end of the blade 31 is embedded in the frame 6. However, the effective length of this blade 31, which moves to either side of its rest position under the effect of the oscillations of the inertial element 4′ about the virtual axis A4′, is defined by the pins 81 and 82 that are secured to the rotary lever 7 mechanically linked to the frame 6.
Whatever the embodiment or the variant, the oscillator 100, 100′ may be a one-piece component or constituted by an assembly of elements.
The hairsprings 1, 3 described in this document preferably comprise a single blade. Naturally, it is entirely possible to implement at least one hairspring comprising several blades, such as two blades, in one or more planes.
Whatever the embodiment or the variant, the oscillator 100; 100′ may comprise one or more other elastic return elements in addition to the first, second and third elastic return elements described in the document. For example, the oscillator 100; 100′ could comprise at least one fourth elastic return element for thermocompensation purposes or in order to fine-tune the correction of the rate. This could, for example, be arranged in parallel with the second and third elastic return elements.
Whatever the embodiment or the variant, the elastic return elements may comprise, at least partially, monocrystalline silicon of any orientation, polycrystalline silicon, amorphous silicon, amorphous silicon dioxide, doped silicon of any type and level of doping, or indeed porous silicon. They may also comprise silicon carbide, glass, ceramic, a composite material, or quartz. Alternatively, the elastic return elements may be constructed from metal or a metal alloy, in particular a paramagnetic metal alloy such as an alloy made from Nb—Zr or Nb—Ti.
This document describes solutions using pivoted inertial elements. Naturally, the concept of the invention can also be applied to an inertial element designed, for example, to be moved in translation.
In this document, the oscillation frequency of the inertial element may be between 3 Hz and 8 Hz, typically being 4 Hz. This frequency can of course be chosen depending on the specific requirements of the timepiece, and this frequency may also be equal to or greater than 8 Hz, for example being 10 Hz or between 10 Hz and 100 Hz, or indeed equal to or greater than 100 Hz.
Advantageously, whatever the embodiment or the variant, the stiffnesses k1, k2 and k3 are such that:
In particular, whatever the embodiment or the variant, the stiffnesses k1, k2 and k3 may be such that:
Alternatively, whatever the embodiment or the variant, the stiffnesses k1, k2 and k3 may be such that:
In a particular variant, the second elastic return element 2 is a curved blade 21. Advantageously, this curved blade may be formed in the continuation of a blade 11 of a hairspring 1 forming the first elastic return element 1.
In the different embodiments and variants that are described, the first, second and third elastic return elements are linked to each other by a connecting member 5. This connecting member 5 may
Whatever the embodiment or the variant, the inertial element 4; 4′ and the first, second and third elastic return elements may be made in a single piece or may form a one-piece assembly.
The invention also relates to an adjustment device 200 per se. The device can be used to adjust a regulating system 150; 150′ as described previously or an oscillator 100; 100′ as described previously. The adjustment device 200 may in particular be a device for modifying the stiffness k3 of a third elastic return element 3. This modification in stiffness may in particular be achieved by modifying an active or effective length of the third elastic return element 3, in particular by modifying an active or effective length of at least one blade 31 of the third elastic return element 3.
In the solutions described above, the adjustment device is a device 200 for modifying the stiffness of an elastic return element that can be used, more particularly, to modify the active or effective length of the elastic return element.
Advantageously, whatever the embodiment or the variant, the lever or the framework 7 may be an element that can be moved in relation to the frame and provides an abutment or a support for the third elastic return element. In particular, the abutment or support may be provided by surfaces, in particular cylindrical surfaces, of pins 81, 82 arranged to bear against the third elastic return element, and in particular against an elastic blade of the third elastic return element.
The invention also relates to a method for adjusting the oscillator 100; 100′ of the regulating system 150; 150′ described above or the timepiece movement 300 described above or the timepiece 400 described above.
The method comprises a step of modifying the third stiffness k3 of the third elastic return element 3.
This modification in the third stiffness k3 of the third elastic return element 3 may be a modification of an active length of the third elastic return element 3, in particular a modification of an active length of at least one blade 31 of the third elastic return element 3. This modification is preferably carried out using an adjustment device as described above. Such an adjustment device makes it possible, in particular, to limit, or indeed cancel out, the deformation of the third elastic return element 3 at a point of the third elastic return element 3, this point being movable along the third elastic return element 3.
In addition to a possible adjustment of the rate of the movement by adjusting the inertia of a balance of an oscillator, the solutions described in this document allow fine adjustment of the rate of the movement by modifying the stiffness of a given elastic return element forming part of an oscillator, in particular by modifying the effective length of at least one elastic blade of an elastic return element forming part of said oscillator, in particular by means of a lever or framework that is movable and provides an abutment for an elastic blade. The proposed solution can also be implemented in order to adjust the rate while the oscillator is in operation.
In the described solutions, the oscillator has the particularity of comprising a first elastic return element linked to an inertial element, a second elastic return element linked in series with the first elastic return element, and a third elastic return element also linked in series with the first elastic return element, in parallel with the second elastic return element 2, the stiffness of this third elastic return element being modifiable by means of an additional device for modifying the stiffness of the third elastic return element. Advantageously, the stiffness of this third elastic return element may be modified by adjusting the effective length of at least one elastic blade of said third elastic return element, in particular by means of an additional device for modifying the effective length of the third elastic return element that may be in the form of a movable lever or framework. This movable lever or framework advantageously comprises pins or projections that clamp and/or hold and/or support the third blade 31 at the point of contact with the pins or projections. At these points of contact, the deflection of the third blade 31 is limited, or even cancelled out. Advantageously, this lever or framework comprises a pair of two pins or two projections. Naturally, this lever or framework may comprise more than two pins or two projections.
| Number | Date | Country | Kind |
|---|---|---|---|
| 23161901.6 | Mar 2023 | EP | regional |
