EP3234699B1 - Timepiece resonator with crossed blades - Google Patents

Description

Field of invention

The invention relates to a clockwork resonator comprising at least one mass oscillating with respect to a connecting element which it comprises and which is arranged to be fixed directly or indirectly to a structure of a clockwork movement, said at least a mass being suspended from said connecting element by crossed blades which are elastic blades which extend at a distance from each other in two parallel planes, and whose projections of the directions on one of said parallel planes intersect at the level of a virtual pivot axis of said mass, and together define a first angle which is the angle at the vertex, from said virtual pivot axis, opposite which the part of said connecting element which is located between the fasteners extends said blades crossed on said connecting element.

The invention also relates to a clock movement comprising such a resonator.

The invention also relates to a timepiece, in particular a watch, comprising such a movement, and/or such a resonator.

The invention relates to the field of time bases for mechanical timepiece mechanisms, in particular for watches.

Background of the invention

A cross-blade balance wheel is a resonator which can be used as a time base in a mechanical watch, instead of a balance-spring.

The use of crossed blades has the advantage of increasing the quality factor since there is no longer a rubbing pivot.

• le couple de rappel élastique est non-linéaire, ce qui rend le système anisochrone, c'est-à-dire que la fréquence du résonateur dépend de l'amplitude de l'oscillation;
• le centre de masse du balancier subit un mouvement résiduel qui est dû au mouvement parasite de l'axe instantané de rotation. Il en résulte que la fréquence du résonateur dépend de l'orientation de la montre dans le champ gravitationnel; c'est ce qu'on appelle l'effet des positions.

However, a balance with crossed blades has two major drawbacks:

• the elastic restoring torque is non-linear, which makes the system anisochronous, ie the frequency of the resonator depends on the amplitude of the oscillation;
• the center of mass of the balance undergoes a residual movement which is due to the parasitic movement of the instantaneous axis of rotation. It follows that the frequency of the resonator depends on the orientation of the watch in the gravitational field; this is called the position effect.

In the post F.Barrot, T. Hamaguchi, "A new mechanical regulator for an exceptional power reserve", Proceedings of the 2014 study day of the Swiss Society of Chronometry , the authors disclose an oscillator composed of a cross-bladed pendulum. They explain that "a Wittrick pivot type implementation is chosen" in order to "make the frequency of oscillation independent of the orientation of the pendulum with respect to gravity". This particular configuration where the blades intersect at seven-eighths of their length has been disclosed in the work of WHWittrick, “The properties of crossed flexure pivots and the influence of the point at which the strips cross” The Aeronautical Quarterly II(4), pages 272 to 292 (1951 ). It has the advantage of minimizing the displacements of the virtual axis of rotation and consequently of minimizing the effect of the positions. However, with an angle of 90° between the two blades, the cross-blade balance wheel used in this work is highly anisochronous, which is why the authors resorted to compensation by an additional component called the isochronism corrector. Experimental measurements show that this compensation is very difficult to achieve in practice and that it would therefore be very useful to find a geometry of the blades which cancels both the effect of the positions and the anisochronism produced by the non-linearity of the force. elastic return.

The document EP 2 911 012 A1 in the name of CSEM describes a rotary clockwork oscillator with a virtual pivot, with a balance which is connected by several flexible blades to a support, in particular in a monolithic embodiment. At least two flexible blades extend in planes perpendicular to the plane of the oscillator, and intersecting between them according to a straight line defining the geometric axis of oscillation of the oscillator, this axis crossing the two blades at seven eighths of their respective length.

This configuration of the crossing at seven-eighths of the length is already known as optimal, allowing to obtain a clean and frictionless rotation around the virtual axis of oscillation, by minimizing the displacement of this axis, according to the work of WH WITTRICK , University of Sydney, in February 1951.

If in this document EP 2 911 012 A1 CSEM, it is contemplated that the blades may originate perpendicular to the sides of an N-sided regular interior polygon, with N-order symmetry about the virtual axis of oscillation, however the only particular configuration shown is that of 'an interior square, in which the two planes comprising the blades are perpendicular to each other. According to this document, the number of slats and their arrangement is defined by a compromise between the size granted to the system, in particular from an aesthetic point of view, and the stability of the system. Apart from the rule of seven eighths already known, there is no explicit mention in the document EP 2 911 012 A1 , specific geometric parameters to be favored for the best isochronism.

The article of F. Barrot and T. Hamaguchi: "A new mechanical regulator for an exceptional power reserve", Proceedings of the Study Day, Swiss Society of Chronometry, September 17, 2014, pages 43-48 , discloses a resonator with oscillating mass and two crossed blades connecting it to a connecting element connected in turn to the structure of a clock movement.

Summary of the invention

The inventors having noted on the one hand that the effect of the positions depends very weakly on the angle between the two crossed blades and on the other hand that the anisochronism produced by the non-linearity of the elastic restoring force depends strongly on this angle, they demonstrated by numerical simulation that it is possible to find an angular value which simultaneously optimizes the effect of positions and isochronism.

The invention therefore proposes to eliminate the drawbacks of the prior art by proposing an optimized geometry of the blades of the balance which cancels both the effect of the positions and the anisochronism produced by the non-linearity of the elastic restoring force. . To this end, the invention relates to a clockwork resonator comprising at least one oscillating mass with respect to a connecting element which it comprises and which is arranged to be fixed directly or indirectly to a structure of a clockwork movement. , said at least one mass being suspended from said connecting element by crossed blades which are elastic blades which extend at a distance from each other in two parallel planes, and whose direction projections on one of said planes parallel lines intersect at the level of a virtual pivot axis of said mass, and together define a first angle which is the angle at the apex, from said virtual pivot axis, opposite which extends the part of said connecting element which is located between the attachments of said blades crossed on said connecting element, characterized in that said first angle is between 68° and 76°.

The invention also relates to a clock movement comprising such a resonator.

The invention also relates to a timepiece, in particular a watch, comprising such a movement, and/or such a resonator.

Brief description of the drawings

• la figure 1 représente, de façon schématisée et en plan, un résonateur à balancier à lames croisées, dans une position de repos en trait plein, et dans une position instantanée (en trait interrompu des lames croisées) où le balancier est écarté de sa position de repos ; cette figure 1 représente un cas général où l'encastrement des lames croisées est oblique dans l'élément de liaison qui les porte, lequel est fixé à la structure d'un mouvement d'horlogerie. La figure 1A représente une configuration préférée où cet encastrement est réalisé au niveau d'une surface qui est orthogonale à l'extrémité de chaque lame au niveau de son encastrement dans cet élément de liaison;
• la figure 2 est un graphique représentatif de l'art antérieur, où les lames croisées sont perpendiculaires dans la position de repos du résonateur, illustrant la variation de la constante de rappel élastique k en ordonnée, en fonction de l'angle courant θ que fait le balancier avec sa position de repos en abscisse ;
• la figure 3 et la figure 4 sont des graphiques également représentatifs du même art antérieur, et illustrent la variation des coordonnées du centre de masse, respectivement selon X, ΔX, sur la figure 3, et selon Y, ΔY, sur la figure 4 en fonction de l'angle courant θ que fait le balancier avec sa position de repos en abscisse. Ces variations des coordonnées ΔX et ΔY sont normalisées par rapport à la longueur des lames L pour que les graphiques soient sans unités;
• la figure 5 est un graphique représentatif de l'invention, où les lames croisées font entre elles un premier angle α voisin de 72° dans la position de repos du résonateur, illustrant la variation de la constante de rappel élastique k en ordonnée, en fonction de l'angle courant θ que fait le balancier avec sa position de repos en abscisse ;
• la figure 6 et la figure 7 sont des graphiques également représentatifs de l'invention, où les lames croisées font entre elles un premier angle α voisin de 72° dans la position de repos du résonateur, et illustrent la variation des coordonnées du centre de masse, respectivement selon X, ΔX, sur la figure 6, et selon Y, ΔY, sur la figure 7 en fonction de l'angle courant θ que fait le balancier avec sa position de repos en abscisse. Ces variations des coordonnées ΔX et ΔY sont normalisées par rapport à la longueur des lames L pour que les graphiques soient sans unités;
• la figure 8 illustre une variante où le résonateur à lames croisées est un résonateur à diapason ;
• la figure 9 est un détail montrant, en trait interrompu, la profondeur de la zone d'influence d'une flexion d'une lame élastique monolithique avec un élément de liaison en matériau micro-usinable dans le cas de la figure 1. La figure 9A est l'équivalent pour la figure 1A ;
• la figure 10 est un schéma-blocs représentant une pièce d'horlogerie ou une montre comportant un mouvement comportant lui-même un tel résonateur.
• la figure 11A est un graphique illustrant l'anisochronisme du balancier à lames croisées en fonction du paramètre Q = ri/L qui permet de comparer les performances de la présente invention (α = 71.2°) à l'art antérieur (α = 90°). L'anisochronisme, mesuré en secondes par jour (s/j) est la différence de marche observée pour deux amplitudes différentes (les valeurs choisies de 12° et 8° sont représentatives du domaine de fonctionnement du système considéré).
• la figure 11B est un graphique illustrant l'effet des positions sur la marche du balancier à lames croisées en fonction du paramètre Q = ri/L pour la présente invention (α = 71.2°) ainsi que pour l'art antérieur (α = 90°).

Other characteristics and advantages of the invention will appear on reading the detailed description which follows, with reference to the appended drawings, where:

• there figure 1 represents, schematically and in plan, a resonator with a balance beam with crossed blades, in a rest position in solid line, and in an instantaneous position (in broken line of the crossed blades) where the balance wheel is moved away from its rest position; this figure 1 represents a general case where the embedding of the crossed blades is oblique in the connecting element which carries them, which is fixed to the structure of a clock movement. There Figure 1A represents a preferred configuration where this embedding is carried out at the level of a surface which is orthogonal to the end of each blade at the level of its embedding in this connecting element;
• there picture 2 is a graph representative of the prior art, where the crossed blades are perpendicular in the rest position of the resonator, illustrating the variation of the elastic spring constant k on the ordinate, as a function of the current angle θ that the balance wheel makes with its rest position on the abscissa;
• there picture 3 and the figure 4 are graphs also representative of the same prior art, and illustrate the variation of the coordinates of the center of mass, respectively according to X, ΔX, on the picture 3 , and according to Y, ΔY, on the figure 4 as a function of the current angle θ that the balance makes with its rest position on the abscissa. These variations of the ΔX and ΔY coordinates are normalized with respect to the length of the blades L so that the graphs are unitless;
• there figure 5 is a graph representative of the invention, where the crossed blades make between them a first angle α close to 72° in the rest position of the resonator, illustrating the variation of the elastic spring constant k on the ordinate, as a function of the current angle θ that the balance makes with its rest position on the abscissa;
• there figure 6 and the figure 7 are graphs also representative of the invention, where the crossed blades make between them a first angle α close to 72° in the rest position of the resonator, and illustrate the variation of the coordinates of the center of mass, respectively according to X, ΔX, on the figure 6 , and according to Y, ΔY, on the figure 7 as a function of the current angle θ that the balance makes with its rest position on the abscissa. These variations of the ΔX and ΔY coordinates are normalized with respect to the length of the blades L so that the graphs are unitless;
• there figure 8 illustrates a variant where the resonator with crossed blades is a tuning fork resonator;
• there figure 9 is a detail showing, in broken line, the depth of the zone of influence of a bending of a monolithic elastic blade with a connecting element in micro-machinable material in the case of the figure 1 . There figure 9A is the equivalent for Figure 1A ;
• there figure 10 is a block diagram representing a timepiece or a watch comprising a movement itself comprising such a resonator.
• there figure 11A is a graph illustrating the anisochronism of the cross-blade balance as a function of the parameter Q=ri/L which makes it possible to compare the performances of the present invention (α=71.2°) with the prior art (α=90°). The anisochronism, measured in seconds per day (s/d) is the rate difference observed for two different amplitudes (the chosen values of 12° and 8° are representative of the operating range of the system considered).
• there figure 11B is a graph illustrating the effect of the positions on the rate of the cross-blade balance as a function of the parameter Q=ri/L for the present invention (α=71.2°) as well as for the prior art (α=90°).

Detailed Description of Preferred Embodiments

The designation “center of mass” used here can also be understood under the designation “center of inertia”.

The invention relates to a clockwork resonator 100 comprising at least one mass 1 oscillating with respect to a connecting element 2 that this resonator comprises. This connecting element 2 is arranged to be fixed directly or indirectly to a structure of a timepiece movement 200.

This at least one mass 1 is suspended from the connecting element 2 by crossed blades 3, 4, which are elastic blades which extend at a distance from one on the other in two parallel planes, and whose projections of the directions on one of these parallel planes intersect at the level of a virtual pivot axis O of the mass 1, and together define a first angle a which is the angle at the top, from this virtual pivot axis O, opposite which extends the part of the connecting element 2 which is located between the attachments of the crossed blades 3, 4, on the connecting element 2.

According to the invention, as will be explained below, this first angle a is between 68° and 76°.

More particularly, and in a non-limiting way, the mass 1 is a pendulum, as visible on the figures 1 and 1A , which illustrate, in full line, the geometry of a resonator 100 with a cross-blade balance, in its rest position.

A pendulum 1 is kept fixed to a connecting element 2 by two crossed blades 3 and 4. These crossed blades 3 and 4 are elastic blades which extend at a distance from each other in two parallel planes, and of which the projections of the directions on one of these parallel planes intersect at a virtual pivot axis O of this balance 1. These crossed blades allow the rotation of this balance 1, and substantially prevent the translation of the balance 1 in the three directions XYZ, and also provide good resistance to small shocks. There figure 1 represents a general case where the embedding of the crossed blades 3, 4 is oblique in the connecting element 2 which carries them. There Figure 1A represents a preferred configuration where this recess is made at a surface which is orthogonal to the end of each blade 3, 4, to its recess.

The origin of the coordinates O is placed at the intersection of blades 3 and 4 when resonator 100 is in its rest position. The instantaneous center of rotation as well as the center of mass of the balance wheel are also located at the origin O when the balance wheel is in its rest position. The bisector of the first angle a defines a direction X with which the projections of the two blades 3 and 4 in one of said parallel planes form an angle β which is half of the first angle α.

In the preferred embodiment of the figure 1 , the resonator 100 is symmetrical with respect to the axis OX.

In the prior art, the first angle α has a value of 90°.

On the figure 1 , the inner radius ri is the distance between the point O and the embedding of the slats 3 and 4 in the connecting element 2. The outer radius re is the distance between the point O and the embedding of the slats 3 and 4 in the pendulum 1. Note that the roles of ri and re can be exchanged depending on whether one places oneself in the referential of the connecting element or in that of the pendulum. All the following formulas remain valid since it is the relative rotational movement that counts.

The total length L of each of the blades is, in this symmetrical construction, L = ri + re.

The first angle α is the angle between the two blades 3 and 4 when the pendulum resonator 100 is in its rest position. This first angle α is the apex angle (at O) which defines the opening of the blades 3 and 4 with respect to the connecting element 2, and facing which extends the part of this connecting element 2 which is located between the attachments of the cross blades 3 and 4 on the latter.

The elastic return torque that the blades exert on the balance can be written M=k.θ, where k is the elastic return constant and θ is the current angle that the balance 1 makes with respect to its rest position. THE figures 1 and 1A show an instantaneous value θi of the current angle θ, corresponding to the deviation of a point M towards its instantaneous position Mi, corresponding to bent positions 3i and 4i of the blades 3 and 4, shown in broken line on the figures 1 and 1A .

As the torque is non-linear, the elastic spring constant varies with the angle of the pendulum k(θ) = M/θ.

The variation of the elastic spring constant k as a function of the current angle of the balance wheel θ is represented at figure 2 for the prior art. We see that the elastic restoring force is linear for the ratio Q= ri/L = 0.10.

The displacement of the center of mass of the balance wheel (ΔX, ΔY) as a function of the angle of the balance wheel θ is shown in figures 3 and 4 for the same prior art. The different curves correspond to different Q=ri/L ratios. It can be seen that, in the prior art, the displacement along X is minimum for ri/L comprised between 0.12 and 0.13.

We therefore observe, on all the figures 2 to 4 representative of the prior art, that there is no value of the ratio Q = ri/L for which we have simultaneously a linear return torque and a substantially zero displacement ΔX.

Consequently, in the constructions of the prior art, for α = 90°, it is not possible to have a system that is simultaneously isochronous (linear elastic restoring force) and independent of the positions (zero displacement of the center of mass according to X).

The invention sets out to determine a geometry for which such a resonator can be both isochronous and independent of the positions.

The study carried out within the framework of the invention makes it possible to determine suitable values.

For a first angle a close to 72°, and for a ratio Q=ri/L comprised between 0.12 and 0.13, the system is simultaneously isochronous and independent of the positions.

Indeed, for a first angle α close to 72°, the variation of the elastic spring constant k as a function of the current angle θ of the balance wheel is represented at figure 5 . We see that the elastic restoring force is linear for Q = ri/L between 0.12 and 0.13.

Similarly, for a first angle α close to 72°, the displacement of the center of mass of the balance according to X as a function of the current angle θ of the balance is shown in figure 6 . The different curves correspond to different ri / L ratios. We see that the displacement along X is canceled for Q = ri/L between 0.12 and 0.13.

We therefore observe that for a first angle α close to 72°, and a ratio Q = ri/L between 0.12 and 0.13 we simultaneously have a linear return torque and a zero displacement of the center of mass along X, which is a considerable advantage.

This characteristic of the first angle value α constitutes the essential characteristic of the invention, and is in no way fortuitous, since this value is the only one which makes it possible to simultaneously guarantee isochronism and the cancellation of the effect of the positions. To clearly illustrate these remarks, we have simulated the anisochronism of the crossed-blade balance, that is to say the rate difference (in seconds per day) observed for two different amplitudes (we have chosen 12° and 8° which are representative of the operating domain of the system under consideration). The results are represented in the graph of the figure 11A as a function of the parameter Q=ri/L, both for the prior art (α=90°) and for the present invention (α=71.2°). It can be seen that the anisochronism strongly depends on the angle a as well as on the parameter Q=ri/L. The prior art, with a parameter Q=0.125 and an angle α=90°, is highly anisochronous since the rate variation is approximately 17 s/d. On the other hand, according to the present invention, the cross-blade balance is isochronous for α=71.2°. For completeness, we have also simulated the effect of the positions on the cross-blade balance, i.e. the difference in rate observed between the horizontal position (X and Y axes horizontal) and the vertical position (Y axis horizontal and X axis aligned with gravitation). The results are represented in the graph of the figure 11B as a function of the parameter Q=ri/L, both for the prior art (α=90°) and for the present invention (α=71.2°). It can be seen that the effect of the positions depends weakly on the angle a and strongly on the parameter Q = ri/L. This explains our approach which consists in using a to optimize the isochronism and Q to minimize the effect of the positions. Note that the optimal value of Q=ri/L depends weakly on the angle α, it is 0.1264 for the present invention (α=71.2°) and 0.1270 for the prior art (α=90°). Finally, it is important to note that the choice of α = 71.2° is the only one which makes it possible to make the system both isochronous and independent of the positions.

In summary, the prior art is very far from optimum isochronism, and the present invention consists in using the appropriate angle value to achieve optimum isochronism.

In practice, this optimal geometric configuration may vary very slightly, depending on the width of the blades 3 and 4, and the amplitude of the oscillation of the balance, as well as the manufacturing tolerances.

THE figures 9 and 9A illustrate a phenomenon which, depending on the nature of the material of the crossed blades, can very slightly modify the estimate of the total length L of blades 3 and 4: when the influence of the bending of the blades manifests itself deep in the element of connection (in the case for example of a monolithic execution in silicon or similar), it can be estimated that this depth corresponds approximately to half the thickness of the blade. It is then necessary to correct the value ri by replacing it with the value rim=ri+e/2, e being the thickness of the blade 3 or 4 considered.

The total length is to be corrected accordingly: Lm = ri + e/2 + re, and the ratio Q is to be corrected in the same way: Qm = (ri+e/2)/(ri+e/2+re) , which must be between 0.12 and 0.13.

In practice, the suitable values of the first angle α are between 68° and 76°, and preferably as close as possible to 71.2°, and those of the ratio Q=ri/L are between 0.12 and 0.13.

In a particular variant, the resonator 100 is monolithic.

More particularly, the resonator 100 is made of a micro-machinable material which can be produced using “MEMS” or “LISA” technologies, or of silicon or silicon oxide, or of at least partially amorphous metal, or of metallic glass, or of quartz, or in DLC.

In one of these cases, it is the ratio Qm =(ri+e/2)/(ri+e/2+re), which must be between 0.12 and 0.13. More particularly, this ratio Qm is chosen equal to 0.1264.

In an advantageous variant, the first angle α is between 70° and 76°.

More particularly still, the first angle α is between 70° and 74°. More particularly still, the first angle α is equal to 71.2°.

We also note that the displacement of the center of mass along Y does not affect the resonator's operation, for reasons of parity of the function ΔY(θ), as visible on the figure 7 . In other words, for this cross-bladed balance resonator, it suffices to cancel the displacement ΔX for the operation to be independent of the positions.

The invention also relates to a clock movement 200 comprising at least one such resonator 100.

The invention also relates to a timepiece 300, in particular a watch, comprising such a movement 200, and/or such a resonator 100.

The invention thus makes it possible to make a balance resonator with crossed blades simultaneously isochronous and independent of the positions.

The invention is applicable to other configurations of resonators with crossed blades, in particular in a structure of the tuning fork type, as visible on the figure 8 . The use of several oscillating masses is advantageous since it makes it possible to minimize the losses on embedding. Indeed, a single pendulum causes a reaction force to the embedding and therefore losses. It is possible to cancel these losses by combining several oscillating masses so that the sum of their reactions to embedding is zero. In particular, the resonator 100 may comprise at least two oscillating masses, in particular two as shown in this figure, the opposite movements of which cause reactions to the embedding which compensate each other. In this particular non-limiting embodiment, two rockers 1 are each kept fixed to a common connecting element 2 by two crossed blades 3 and 4 arranged according to the characteristics described above. Here, the resonator 100 is, advantageously, entirely symmetrical with respect to the Y axis. Other variant embodiments are naturally possible.

Claims (15)

1. Timepiece resonator (100) comprising at least one weight (1) oscillating with respect to a connecting element (2) comprised in said resonator and which is arranged to be directly or indirectly secured to a structure of a timepiece movement (200), said at least one weight (1) being suspended from said connecting element (2) by crossed strips (3, 4) which are resilient strips that extend at a distance from each other in two parallel planes, and the projections of the directions of said strips on one of said parallel planes intersect at a virtual pivot axis (O) of said weight (1), and define together a first angle (α) which is the apex angle, from said virtual pivot axis (O), opposite which there extends the portion of said connecting element (2) that is located between the attachments of said crossed strips (3, 4) to said connecting element (2), characterized in that said first angle (α) is comprised between 68° and 76°.
2. Resonator (100) according to claim 1, characterized in that said first angle (α) is comprised between 70° and 76°.
3. Resonator (100) according to claim 2, characterized in that said first angle (α) is comprised between 70° and 74°.
4. Resonator (100) according to claim 3, characterized in that said first angle (α) is equal to 71.2°.
5. Resonator (100) according to one of claims 1 to 4, characterized in that said strips (3, 4) are dimensioned with an inner radius (ri) between said virtual pivot axis (O) and the point of attachment of said strips to said connecting element (2), with an outer radius (re) between said virtual pivot axis (O) and the point of attachment of said strips to said weight (1), and with a total length (L) such that L = ri + re, so that a ratio (Q) such as Q = ri/L, is comprised between 0.12 and 0.13.
6. Resonator (100) according to one of claims 1 to 4, characterized in that said strips (3, 4) are dimensioned with an inner radius (ri) between said virtual pivot axis (O) and the point of attachment of said strips to said connecting element (2), with an outer radius (re) between said virtual pivot axis (O) and the point of attachment of said strips to said weight (1), with a thickness (e) in the plane of each said strip (3, 4), such that a ratio (Qm) such as Qm = (ri+e/2)/(ri+e/2+re), is comprised between 0.12 and 0.13.
7. Resonator (100) according to claim 5 or 6, characterized in that said ratio (Qm) is equal to 0.1264.
8. Resonator (100) according to one of claims 1 to 7, characterized in that, in projection on one of said parallel planes, said resonator (100) is symmetrical with respect to the bisector (OX) of said first angle (α) when the resonator is in the rest position.
9. Resonator (100) according to one of claims 1 to 8, characterized in that said at least one weight (1) is a balance wheel.
10. Resonator (100) according to one of claims 1 to 9, characterized in that said crossed strips (3, 4) are each anchored in said connecting element (2) on a surface of said connecting element (2) which is orthogonal to the end of said strip (3, 4) concerned at the anchoring point thereof.
11. Resonator (100) according to one of claims 1 to 10, characterized in that said resonator (100) includes at least two oscillating weights, each being fixed to a said common connecting element (2) by two crossed strips (3, 4), the resonator being entirely symmetrical with respect to an axis Y, in a tuning fork structure.
12. Resonator (100) according to one of claims 1 to 11, characterized in that said resonator (100) is in one-piece.
13. Resonator (100) according to claim 12, characterized in that said resonator (100) is made of silicon or of silicon oxide or of metallic glass or of quartz or of DLC.
14. Timepiece movement (200) comprising a structure to which is fixed, directly or indirectly, a least one connecting element (2) comprised in a said resonator (100) according to one of claims 1 to 13.
15. Timepiece (300) or watch, including a movement (200) according to claim 14, and/or at least one said resonator (100) according to one of claims 1 to 13.

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