EP2450759B1 - Magnetic shock absorber - Google Patents

Description

Field of the invention

The present invention is defined by the appended claims.

The invention relates to an anti-shock device for the protection of a watch component pivotally mounted between a first end and a second end of said component, said component being made of a material at least partially permeable magnetically or at least partially magnetic at said first end and at said second end, said device comprising a first pole mass and a second pole mass arranged on either side of said first and second ends, and comprising on the one hand in the vicinity of said first end magnetic attraction means between said first end and said first pole mass on which said first end is kept resting, and on the other hand in the vicinity of said second pole mass, magnetic attraction means between said second end and said second pole mass.

The invention also relates to a magnetic pivot comprising a watch component, made of a material which is at least partially magnetically permeable or at least partially magnetic at a first end and at a second end.

The invention also relates to a timepiece movement comprising at least one such shock-proof device, or / and at least one such magnetic pivot.

The invention also relates to a timepiece comprising at least one such timepiece movement, or / and at least one such shock-proof device, or / and at least one such magnetic pivot.

The invention relates to the field of mechanical manufacturing, and more particularly to micro-mechanics, to which it is particularly well suited.

It applies more particularly to the field of watchmaking.

Background of the invention

• garantir, après le choc, un recentrage radial exact.
• réaliser une solution antichoc indépendante des frottements mécaniques, qui ont le désavantage de réduire le rendement/facteur de qualité des composants, lors d'un fonctionnement normal, c'est-à-dire en absence de chocs.

Watchmaking technique uses traditional solutions to guarantee the shock-proof functions of watch components, such as a balance. These solutions are based on the elastic response of parts acting as shock absorbers and on the mechanical friction between the shock absorbers and the component to be protected. The traditional shock absorbers are characterized in particular by a threshold acceleration below which the shock absorber is not deformed and by a function of radial recentering of the component after the impact which is relatively imprecise. The problems to be solved are then the following:

• guarantee, after impact, an exact radial recentering.
• achieve an anti-shock solution independent of mechanical friction, which has the disadvantage of reducing the efficiency / quality factor of the components, during normal operation, that is to say in the absence of shocks.

The document DE 12 11 460 B in the name of SIEMENS AG describes a mobile consisting of a rod secured to an interior tabular magnet inserted into an exterior tubular magnet. The latter is movable, in a cartridge coaxial with the two magnets, against a bearing face in abutment at one end, and against a spring held by a plug at the other end. This mobile is still guided axially on a spindle integral with this stopper. At each axial end, this mobile comprises a protective sleeve for the fragile ceramic core formed by the internal magnet. The pivoting guide means are formed by the cooperation of two tubular magnets, inner and outer. However, maintaining the mobile on the first pole mass does not correspond to a support, since there is solidarity between this mobile and the inner tubular magnet, by means of a flange and one of these two sockets. . As a result, the mobile of this patent is not free with respect to the first pole mass formed by the inner magnet, but only with respect to the second pole mass formed by the outer magnet.

The document DE 198 54 063 A1 in the name of JAGMANN VLADIMIR which describes a mobile in magnetizable material held by levitation between two magnetic pole masses generating a magnetic field of direction perpendicular to the attraction of gravity.

The document US 4308605 on behalf of AYER describes a wall timepiece, comprising an assembly with a balance arranged to pivot about a vertical axis in the direction of the gravity field. This assembly comprises a base plate, and lower and upper pivot blocks mounted on the base plate and aligned in the vertical direction, each adjustable by screw in the vertical direction but not freely movable in this vertical direction. The pivot blocks have opposing tapered recesses, a vertical balance shaft is pointed at each end and disposed in the recesses. A magnet near the upper pivot block serves to attract the shaft towards the upper pivot block against the gravitational pull, to limit the wear of the pivots.

Summary of the invention

The invention proposes, to overcome the limits of the prior art, a configuration for protecting a component, and in particular a timepiece component, pivotally mounted between holding means with or without contact.

The essential characteristic is the mobility of these holding means, the normal operating position of which is a position of stable equilibrium, these holding means are mobile, with respect to a structure, under the effect of a strong acceleration created by shock, in order to preserve the integrity of the component and its environment.

To this end, the invention relates to an anti-shock device for the protection of a watch component, according to claim 1.

The invention also relates to a magnetic pivot comprising a watch component, made of a material which is at least partially magnetically permeable or at least partially magnetic at a first end and at a second end, comprising such an impact-resistant device for the protection of this component.

The invention also relates to a timepiece movement comprising at least one such shock-proof device, or / and at least one such magnetic pivot.

The invention also relates to a timepiece comprising at least one such timepiece movement, or / and at least one such shock-proof device, or / and at least one such magnetic pivot.

Brief description of the drawings

• la figure 1 représente, de façon schématisée, et en coupe longitudinale selon un axe de pivotement, un dispositif selon l'invention, appliqué à la protection d'un composant de pièce d'horlogerie ;
• la figure 2 représente, de façon schématisée, et en perspective, une pièce d'horlogerie comportant un mouvement incorporant un dispositif selon l'invention ;
• la figure 3 représente, de façon schématisée, le principe de fonctionnement d'un dispositif selon l'invention.

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

• the figure 1 represents, schematically, and in longitudinal section along a pivot axis, a device according to the invention, applied to the protection of a component of a timepiece;
• the figure 2 represents, schematically, and in perspective, a timepiece comprising a movement incorporating a device according to the invention;
• the figure 3 schematically represents the operating principle of a device according to the invention.

Detailed description of the preferred embodiments

Thus, the invention relates to an anti-shock device 10 for protecting a watch component 1 pivotally mounted between a first end 2 and a second end 3.

According to the invention, this shock-absorbing device 10 comprises, on either side of these first 2 and second 3 ends, on the one hand, means for guiding in pivoting or means for attracting the first end 2 kept in abutment. on a first pole mass 4, and on the other hand, in the vicinity of a second pole mass 6, means for guiding in pivoting the second end 2 or means for attracting this second end 2 towards the second pole mass 6.

According to the invention, the pivoting guide means or the attraction means of the first end 2 on the one hand, and the pivoting guide means or the attraction means of the second end 3 on the other hand, are movable along a direction D between stops.

This direction D is illustrated in the figures in a particular case where it is linear. It can also be curvilinear.

This shock-absorbing device comprises means for damping the movement of each of the pole masses 4, 6 or / and elastic return means of each of the pole masses 4, 6. These damping means or / and these elastic return means are arranged to absorb the energy communicated to the pole masses 4, 6 during an impact, and to return after this same impact each of the pole masses 4, 6 to a position of stable equilibrium which it occupied prior to this impact.

In a particular embodiment, as seen on the figure 1 , the anti-shock device 10 is arranged so that at least the first mass 4 or the second mass 6 comprises guide means 14, 16 arranged to cooperate, under a strong acceleration imparted to the component 1 during an impact, in sliding along the direction D, with complementary fixed guide means 15, 17 comprised of structural elements 12, 13, of the device 10. Preferably, the first mass 4 and the second mass 6 respectively comprise these guide means 14, 16.

In a particular embodiment, the shock-absorbing device 10 comprises such damping means, which are of the viscous friction type.

In a particular embodiment, the shock-absorbing device 10 comprises such damping means, which comprise a compressible fluid between the pole mass 4, 6 concerned and a stop 42, 44 which limits its travel away from component 1.

According to the invention, as visible on the figure 1 , the first pole mass 4 and the second pole mass 6 are each movable in a chamber between two stops, respectively 41 and 42, 43 and 44.

Preferably and advantageously, the shockproof device 10 comprises means for damping the movement of each of the pole masses 4, 6 in their respective chamber.

In a particular embodiment, as seen on the figure 1 , the shock-absorbing device 10 comprises such damping means, comprises a deformable shape-memory damper 23, 24 designed to dissipate the kinetic energy of an impact, and to slowly return to its initial shape after an impact.

Preferably, this deformable shape memory damper 23, 24 is made of neoprene.

In a particular embodiment, the shock-absorbing device 1 may include both damping means and elastic return means, which differ in their time constant, the return to the stable equilibrium position being slower with the damping means than with elastic return means.

In a preferred embodiment and as seen in the figures, the direction D is linear.

Component 1 is made of a material which is at least partially permeable magnetically or at least partially magnetic at a first end 2 and at a second end 3.

According to the invention, the shock-absorbing device 10 then comprises, on either side of the first 2 and second 3 ends, at a greater air gap distance, the value of a determined functional clearance J, at the center distance between the first end 2 and the second end 3, a first surface 5 of a first pole mass 4 and a second surface 7 of a second pole mass 6.

These pole masses 4, 6, are arranged to either be attracted each by a magnetic field emitted by one of the first end 2 or second end 3 of component 1, or else to generate each a magnetic field attracting one of the first end 2 or second end 3 of component 1, so that the magnetic attraction forces exerted on component 1 at its two ends 2, 3, are of different intensity, so in attracting component 1 by one of its two ends 2, 3, in direct or indirect contact on only one of the surfaces 5, 7 of the pole masses 4, 6.

Preferably, the first pole mass 4 and the second pole mass 6 are each made of a magnetic material, or magnetically permeable, and are magnetic if the component 1 is not. The first pole mass 4 and the second pole mass 6, preferably together define a direction D, on which is aligned a longitudinal axis of the component 1 joining the first end 2 and second end 3 of the latter, when the component 1 is inserted between the first polar mass 4 and second polar mass 6

The device is calculated so that the air gap distance between the first surface 5 and the second surface 7 is dimensioned so as to ensure the determined functional clearance J over the entire temperature range of use of the shockproof device 10 and of the component 1.

The principle of such a magnetic shock absorber construction for a component 1, which is shown, in a preferred but not limited to application, in the form of a balance pin, is shown in figure 3 . The axis of component 1, which is made of a magnetically permeable material, typically soft ferromagnetic, or of a magnetic material, is placed between two pole masses 4 and 6. This axis can also consist of two half-axes of such a material, each at one end 2, 3, of component 1. These pole masses 4 and 6 are magnetized if component 1 is not, they can be magnetically permeable or magnetized when component 1 is magnetized.

These pole masses 4, 6 can in particular consist of micro-magnets, the polarities of which match, and which define the pivoting of the axis of component 1. The support of this axis is guaranteed, or else by two stones interposed between the axis and the pole masses or magnets, or by a hardening treatment of the surface of the pole masses or magnets.

The two pole masses 4 and 6 are, according to the invention, each movable in a chamber bounded by stops, respectively 41, 42 on the one hand, and 43, 44 on the other hand. Their movement takes place according to an axial play, respectively h ₁ and h ₂ .

The minimum distance between the pole masses 4 and 6 is set by the stops 41 and 43 closest to the component, while the maximum distance is set by the stops 42, 44, the furthest from the component 1, here formed by the bottom cellars.

The two pole pieces 4 and 6, and component 1, are arranged so that the magnetic forces and torques exerted on the component are attractive forces, tending to attract component 1 towards contact surfaces 5 and 7 that comprise either the pole masses 4 and 6, or spacers 18, 19, interposed between these pole masses and the component 1.

The normal position of the pole masses is that represented on the figures 1 and 3 , in a position where the magnetic fields are organized around component 1 with an imbalance, so that the latter comes into contact with only one of the surfaces 5 or 7, that is to say the surface 5 in the figures, and remains at a distance J corresponding to a predetermined functional clearance of the other of these surfaces.

The mobility of the pole masses 4 and 6 is preferably hampered by damping means, or else elastic return means. The preferred damping means can take different forms: in the case of figure 1 , viscous friction means of the pole masses 4 and 6 in chambers in which they are movable, this viscous friction being able to be supplemented by the presence of a compressible fluid between the pole masses 4, 6, and their stops 42, 44, furthest from component 1.

Or, as seen on the figure 1 , in a preferred embodiment, the damping means comprise dampers 23, 24, arranged to withstand a shock while allowing axial mobility, in the z direction of the figure 1 , or the axial direction of pivoting D of the figure 3 , one or the other pole mass 4 or 6, and to slowly return them to their position prior to the shock. Therefore, elastic return means, such as springs, are also possible, however their stiffness must be calculated in order to avoid too steep a return, and a reverse impact effect on component 1, which is not desired. .

In a preferred embodiment for watchmaking, in particular for damping a balance axis as visible on the figure 3 , these dampers 23 and 24 are made of neoprene, or of silicone, or include at least one part of neoprene, or of silicone, due to the characteristics of slow return to shape of these shape memory materials.

Such dampers, placed on the internal walls of guide chambers of the pole masses 4 and 6 and inside the stops, are thus used to dissipate the kinetic energy of the shock and prevent the pole masses or magnets collide with the walls or their rear stops 42, 44 during the impact, or with the stops 41, 43, closest to component 1, after the impact.

The shock absorbers can also be constructed so as to constitute the end stops themselves, as in the case of the figure 3 where they are fixed to the ends of complementary guide means 15 and 17, here bores, cooperating with guide means 14 and 16 that comprise, here in the form of cylindrical surfaces, the pole masses 4 and 6.

The use of shock absorbers is however not necessary, if the axial play and the energy of the magnets are sufficiently large, and if the magnets are subjected to a viscous friction inside the cell which guarantees the dissipation of the 'energy.

Traditional 32 and 33 radial shock absorbers, visible on the figure 3 , are advantageously placed along the axis, around spans 34, 35, of component 1, to prevent that, during an impact, the axis of component 1 can leave the region where the magnetic field is stronger . These radial shock absorbers 32 and 33 have no contact with component 1, in the normal course of the latter.

The size and energy of the magnets used, either in pole masses 4 and 6, or in component 1, or in pole masses 4 and 6 and component 1, as well as the axis profile of component 1 are optimized to produce a force of net magnetic attraction towards one of the two pole masses.

Here we describe more particularly the preferred case where the pole masses 4 and 6 are magnetic, they will also be called “magnets”.

The value of the magnetic force is proportional to the magnetization M _axis (r, z) and to the gradient of the magnetic field H produced by the two magnets: $${\overrightarrow{F}}_m={\mu }_0{\displaystyle \underset{V_{\mathit{axis}}}{\int }d\overrightarrow{r}}{\overrightarrow{M}}_{\mathit{axis}}\cdot \overrightarrow{\nabla }H$$

The integration is made on the volume of the axis V _axis . For all positions of the timepiece, hereinafter called “watch”, the axis therefore presses on the same magnet. The axis is also subjected to the magnetic torque C _m : $${\overrightarrow{\mathrm{VS}}}_m=-{\mu }_0{\displaystyle \int d\overrightarrow{r}{\overrightarrow{M}}_{\mathit{axis}}\times \overrightarrow{H}}$$

It is zero only if the axis is oriented like the field lines, therefore in the z direction. If the orientation of the axis deviates from the z direction, the restoring torque C _m reorients the axis in the correct direction.

The figure 1 thus illustrates an embodiment of a magnetic balance with axial symmetry: the balance axis 1, in soft magnetizable materials, or magnetic, is located between two permanent magnets 4 and 6 whose magnetic polarization is directed in the same direction corresponding to the z direction of the figure 3 , here under the direction reference D corresponding to a pivot axis of component 1. The support of the balance axis can be guaranteed either by two stones 18, 19, interposed between the magnets and the balance axis, or by a surface treatment of the magnets.

The magnetic interaction between axis and magnets results in a net attraction towards magnet 4 greater than gravity.

The magnets have an axial play h ₁ and h ₂ respectively, determined by the stops 41, 42 and 43, 44. The axial play allows the dissipation of the energy of the shock through the movement of the magnets. The radial dampers 32 and 33 have the function of preventing the axis from leaving the region of magnetic influence, and have no contact with the component 1 during the normal operation of the latter. This property is valid for all positions of the watch, therefore also in the vertical position.

• la force d'attraction nette entre l'axe 1 et l'aimant 4 est supérieure à la force de gravité et à la force maximale appliquée, par le dispositif mécanique avec lequel il coopère, sur le composant 1, tel que visible sur la figure 3;
• la force d'attraction magnétique entre les deux aimants 4 et 6 est suffisamment grande pour emmener toujours les aimants dans la position de distance minimale après le choc, c'est-à-dire les deux aimants en contact avec les butées.

Optimization of the geometric characteristics of parts allows two results:

• the net attractive force between the axis 1 and the magnet 4 is greater than the force of gravity and the maximum force applied, by the mechanical device with which it cooperates, on the component 1, as visible on the figure figure 3 ;
• the magnetic force of attraction between the two magnets 4 and 6 is large enough to always bring the magnets to the position of minimum distance after the impact, that is to say the two magnets in contact with the stops.

These two properties ensure that the configuration shown is of stable equilibrium in the absence of shocks and that this position of stable equilibrium is re-obtained after a shock.

During a radial impact, the axis is maintained in the region of influence of the magnetic field by the shock absorbers 32 and 33: after the impact, the recentering is guaranteed by the magnetic interaction which returns the axis exactly to the center of the magnets by aligning them perfectly in the z direction.

• le système subit une accélération a = n g dans la direction z > 0 : dans ce cas, l'aimant 4 et l'axe, qui sont soumis à la même accélération, se déplacent solidairement, en gardant le contact grâce à l'attraction magnétique, tandis que l'aimant 6 est bloqué par sa butée 43. L'énergie cinétique du choc est dissipée par le frottement de l'aimant contre les parois latérales de l'encave et/ou l'amortisseur placé sur la butée 44. Après le choc, l'attraction magnétique emmène l'aimant 4 et l'axe 1 dans leur position d'équilibre. Le frottement et/ou l'amortisseur à l'intérieur de la butée ont la fonction d'empêcher une collision trop énergétique de l'aimant 4 contre la butée, collision qui pourrait impliquer la perte de contact de l'axe de l'aimant 4 et un choc énergétique de l'axe contre l'aimant 4. Une fois que les aimants sont retournés en contact contre les butées, l'axe est ramené exactement à sa position d'équilibre ;
• ou le système subit une accélération a = n g dans la direction z < 0 : dans ce cas, l'aimant 6 et l'axe 1 se déplacent, tandis que l'aimant 4 est bloqué par sa butée 41. L'axe 1 perd le contact avec la masse polaire 4 mais il entre rapidement en contact avec la masse polaire 6. Le choc entre l'axe et l'aimant 4 est toutefois très peu énergétique même pour une grande accélération du type a = 3500 g, parce que la distance initiale est très petite, environ 0.02 mm. En analogie avec le cas précédent, l'énergie du choc est dissipée par le mouvement de l'aimant 6, grâce au frottement et/ou à l'amortisseur 24 ou dans la chambre de mobilité de la masse polaire 6. Après le choc, l'aimant 6, toujours en contact avec l'axe, est ramené contre la butée. Dans cette condition, l'axe est soumis à une force d'attraction nette vers l'aimant 4, et donc il est ramené en contact avec celui-ci.

During an axial shock two situations are possible:

• the system undergoes an acceleration a = ng in the direction z> 0: in this case, the magnet 4 and the axis, which are subjected to the same acceleration, move together, keeping contact thanks to the magnetic attraction , while the magnet 6 is blocked by its stop 43. The kinetic energy of the impact is dissipated by the friction of the magnet against the side walls of the cell and / or the damper placed on the stop 44. Afterwards the shock, the magnetic attraction takes the magnet 4 and the axis 1 in their equilibrium position. The friction and / or the damper inside the stopper have the function of preventing a too energetic collision of the magnet 4 against the stopper, a collision which could involve the loss of contact of the axis of the magnet. 4 and an energetic shock of the axis against the magnet 4. Once the magnets are returned in contact against the stops, the axis is brought back exactly to its equilibrium position;
• or the system undergoes an acceleration a = ng in the direction z <0: in this case, the magnet 6 and the axis 1 move, while the magnet 4 is blocked by its stop 41. The axis 1 loses contact with the pole mass 4 but it quickly comes into contact with the pole mass 6. The impact between the axis and the magnet 4 is however very low in energy even for a large acceleration of the type a = 3500 g, because the initial distance is very small, about 0.02mm. By analogy with the previous case, the energy of the shock is dissipated by the movement of the magnet 6, thanks to the friction and / or the damper 24 or in the mobility chamber of the pole mass 6. After the impact, the magnet 6, still in contact with the axis, is brought back against the stop. In this condition, the axis is subjected to a net attractive force towards the magnet 4, and therefore it is brought back into contact with it.

Since the dissipative mechanisms act on the movement of the magnets and not on the axis, the dissipation due to the friction of the pendulum pivot is almost zero during normal operation. The quality factor of the regulator is therefore independent of the shock absorber function and can be much higher than for a traditional mechanical system.

In an alternative configuration, the component axis can itself be a permanent magnet, thus maximizing magnetic forces and torques.

• le recentrage radial de l'axe est toujours garanti exact après le choc ;
• la position d'équilibre axial, et de fonctionnement idéal, est toujours rattrapée après le choc ;
• la résistance aux chocs est supérieure à celle des antichocs traditionnels ;
• les frottements et la dissipation d'énergie sont minimisés ;
• le nombre de composants est limité comparé à d'autres solutions ;
• le système peut être intégré à d'autres éléments magnétiques. A cet effet il comporte avantageusement des moyens de blindage 20 visibles sur la figure 1.

The advantages deriving from the characteristics of the invention are substantial:

• the radial recentering of the axis is always guaranteed exact after the impact;
• the position of axial equilibrium, and of ideal operation, is always recovered after the shock;
• impact resistance is higher than that of traditional shock absorbers;
• friction and energy dissipation are minimized;
• the number of components is limited compared to other solutions;
• the system can be integrated with other magnetic elements. For this purpose it advantageously comprises shielding means 20 visible on the figure 1 .

The determined functional clearance J is strictly positive. Preferably, the determined functional clearance J is greater than or equal to 0.020 mm.

The choice of the magnetic permeability of the material of component 1, and the determination of the magnetization, as the case may be, of the first mass 4 and of the second mass 6 on the one hand, or / and of component 1 on the other hand , are preferably carried out so that the magnetic fields attracting the first end 2 and second end 3 each exert on the component 1 attractive forces greater than ten times the force of attraction of gravity on the component 1.

Preferably, the magnetic field density in the vicinity of the first surface 5 and of the second surface 7 is greater than or equal to 100,000 A / m.

The anti-shock device 10 also advantageously comprises shielding means 20 arranged to prevent the action of any magnetic field with a radial component with respect to the direction D, in the vicinity of the first 5 and second 7 contact surfaces.

In the embodiment of the figure 1 , these shielding means 20 comprise at least one tubular part 21, 22 oriented in the direction D and surrounding the first mass 4 and the second mass 6, and at least the second end 3 of the component 1.

In a particular embodiment, at least the first surface 5 comprises a hard coating or is constituted by a hard surface of a spacer 18 interposed between the first mass 4 and the component 1. Similarly, a spacer 19 can be interposed between the second mass 6 and component 1.

In a particular variant, the anti-shock device 10 comprises means for looping the magnetic field between the first mass 4 and the second mass 6.

The invention also relates to a magnetic pivot 100 comprising a watch component 1, made of at least partially permeable material. magnetically or at least partially magnetic at a first end 2 and at a second end 3, and comprising such an anti-shock device 10.

Preferably, this magnetic pivot 100 comprises access means for inserting the component 1 into the air gap, or is made removable into several parts comprising means of cooperation between them or / and with a bridge 31 or / and a plate 30 to allow the component 1 to be mounted, resting by its first end 2 on a first part comprising the first surface 5 and the first mass 4, prior to the mounting of a second part comprising the second surface 7 and the second mass 6 .

Advantageously, a magnetic pivot 100 as shown in figure 1 comprises a component 1 which has a tapered part, of revolution around the direction D which is linear, and of decreasing section from the center of gravity of component 1 towards the second end 3, so as to improve the magnetic field gradient in the vicinity of the second surface 7, and to facilitate the centering of the second end 3 on the direction D.

In the case where the component 1 is driven by a pivoting movement around the direction D, the magnetic pivot 100 advantageously comprises a component 1 which is dynamically balanced, for its maximum pivoting speed, around a longitudinal axis joining the first end 2 and second end 3.

Preferably, the first end 2 of the component 1 is arranged with a point contact surface with the first surface 5, the point contact surface being locally spherical or conical.

Advantageously, the first surface 5 comprises a receiving surface arranged to cooperate with the first end 2, the receiving surface being hollow and locally spherical or conical.

In a preferred application to an oscillator, component 1 is a balance whose pivot axis coincides with direction D.

• il comporte un composant 1 comportant une partie sensiblement arbrée en matériau perméable magnétiquement, et la première masse 4 et la deuxième masse 6 sont chacune en matériau magnétique ;
• il comporte un composant 1 comportant une partie sensiblement arbrée en matériau magnétique, et la première masse 4 et la deuxième masse 6 sont chacune en matériau perméable magnétiquement ;
• il comporte un composant 1 comportant une partie sensiblement arbrée en matériau magnétique, et la première masse 4 et la deuxième masse 6 sont chacune en matériau magnétique.

It will be understood that such a magnetic pivot 100 equipped with such an anti-shock device 10 can then adopt different configurations:

• it comprises a component 1 comprising a substantially shafted part made of a magnetically permeable material, and the first mass 4 and the second mass 6 are each made of magnetic material;
• it comprises a component 1 comprising a substantially shafted part made of magnetic material, and the first mass 4 and the second mass 6 are each made of a magnetically permeable material;
• it comprises a component 1 comprising a substantially shafted part of magnetic material, and the first mass 4 and the second mass 6 are each made of magnetic material.

The invention also relates to a clockwork movement 1000 comprising at least one such shockproof device 10, or / and at least one such magnetic pivot 100.

The invention also relates to a timepiece comprising at least one such timepiece movement 1000, or / and at least one such shock-proof device 10, or / and at least one such magnetic pivot 100.

Advantageously, the first surface 5 comprises a receiving surface arranged to cooperate with the first end 2, the receiving surface being hollow and locally spherical or conical.

In a preferred application to an oscillator, component 1 is a balance whose pivot axis coincides with direction D.

• il comporte un composant 1 comportant une partie sensiblement arbrée en matériau perméable magnétiquement, et la première masse 4 et la deuxième masse 6 sont chacune en matériau magnétique ;
• il comporte un composant 1 comportant une partie sensiblement arbrée en matériau magnétique, et la première masse 4 et la deuxième masse 6 sont chacune en matériau perméable magnétiquement ;
• il comporte un composant 1 comportant une partie sensiblement arbrée en matériau magnétique, et la première masse 4 et la deuxième masse 6 sont chacune en matériau magnétique.

It will be understood that such a magnetic pivot 100 equipped with such an anti-shock device 10 can then adopt different configurations:

• it comprises a component 1 comprising a substantially shafted part made of a magnetically permeable material, and the first mass 4 and the second mass 6 are each made of magnetic material;
• it comprises a component 1 comprising a substantially shafted part made of magnetic material, and the first mass 4 and the second mass 6 are each made of a magnetically permeable material;
• it comprises a component 1 comprising a substantially shafted part of magnetic material, and the first mass 4 and the second mass 6 are each made of magnetic material.

The invention also relates to a clockwork movement 1000 comprising at least one such shockproof device 10, or / and at least one such magnetic pivot 100.

The invention also relates to a timepiece comprising at least one such timepiece movement 1000, or / and at least one such shock-proof device 10, or / and at least one such magnetic pivot 100.

Claims (18)

1. Anti-shock device (10) for the protection of a timepiece component (1) pivotally mounted between a first end (2) and a second end (3) of said component (1), said component (1) being made of material that is at least partially magnetically permeable or at least partially magnetic at said first end (2) and at said second end (3), said device (10) including a first pole piece (4) and a second pole piece (6) disposed on both sides of said first (2) and second (3) ends, said device (10) including, on both sides of said first (2) and second (3) ends, on one hand, means for attracting said first end (2) to keep said first end (2) abutting on said first pole piece (4), and on the other, in proximity to said second pole piece (6), means for attracting said second end (3) towards said second pole piece (6), such that said means for attracting said first end (2), on one hand, and said means for attracting said second end (3), on the other, can move along a direction (D) between stop members, and said device (10) includes, on both sides of said first (2) and second (3) ends, at a greater air-gap distance, by the value of a determined operational play (J), than the distance of centres between said first end (2) and said second end (3), a first surface (5) of said first pole piece (4) and a second surface (7) of said second pole piece (6), characterised in that said first pole piece (4) and said second pole piece (6) are arranged either to be each attracted by a magnetic field transmitted by said first end (2) and respectively said second end (3), or indeed to each generate a magnetic field attracting said first end (2) and respectively said second end (3), such that the magnetic attraction forces being exerted on said component (1) at the two ends (2; 3) thereof are of different intensity, so as to attract said component (1) via one of the said two ends thereof, in direct or indirect contact onto only one of said surfaces (5; 7) of said pole pieces (4; 6), and said first pole piece (4) and said second pole piece (6) can each move inside a chamber between two stop members (41, 42; 43, 44) along said direction (D), and said device (10) includes means for dampening the movement of each of said pole pieces (4; 6) inside the respective chamber thereof and/or means for elastically returning each of said pole pieces (4; 6), said damping means and/or said elastic return means being arranged to absorb the energy transmitted to said pole pieces (4; 6) in the event of a shock, and to return after said shock each of said pole pieces (4; 6) to the position of stable equilibrium occupied thereby prior to said shock.
2. Anti-shock device (10) according to claim 1, characterised in that said device (10) includes means for dampening the movement of each of said pole pieces (4; 6).
3. Anti-shock device (10) according to claim 1, characterised in that said device (10) includes means for elastically returning each of said pole pieces (4; 6).
4. Anti-shock device (10) according to claim 1, characterised in that said device (10) includes means for dampening the movement of each of said pole pieces (4; 6) and said means for elastically returning each of said pole pieces (4; 6).
5. Anti-shock device (10) according to one of claims 1 to 4, characterised in that at least said first pole piece (4) or said second pole piece (6) includes guide means (14; 16) arranged to cooperate, under a strong acceleration imparted to said component (1) in the event of a shock, by sliding along a direction (D), with complementary fixed guide means (15; 17) included in said device (10)
6. Anti-shock device (10) according to one of claims 1 to 5, characterised in that said device (10) includes said damping means, which are of the viscous friction type.
7. Anti-shock device (10) according to one of claims 1 to 5, characterised in that said device (10) includes said damping means, which include a compressible fluid between said pole piece (4; 6) concerned and the stop member (42; 44) which limits the travel thereof to the opposite side to said component (1).
8. Anti-shock device (10) according to one of claims 1 to 5, characterised in that said device (10) includes said damping means, which include a deformable shape memory shock-absorber (23, 24), arranged to dissipate the kinetic energy from a shock, and to slowly return to the initial shape thereof after a shock.
9. Anti-shock device (10) according to claim 8, characterised in that said deformable shape memory shock-absorber (23, 24) is made of neoprene.
10. Anti-shock device (10) according one of claims 1 to 9, characterised in that said direction (D) is linear.
11. Anti-shock device (10) according to one of claims 1 to 10, characterised in that said device (10) includes shielding means (20), arranged to prevent the action of any magnetic field with a radial component relative to said direction (D), in proximity to first (5) and second (7) contact surfaces.
12. Anti-shock device (10) according to claim 11, characterised in that said shielding means (20) include at least one tubular part (21; 22), centred on said direction (D) and surrounding said first piece (4) and said second piece (6) and at least said second end (3) of said component (1).
13. Magnetic pivot (100) including a timepiece component (1), made of a material that is at least partially magnetically permeable or at least partially magnetic at a first end (2) and at a second end (3), characterised in that it includes an anti-shock device (10) according to one of claims 1 to 12, for the protection of said timepiece component (1).
14. Magnetic pivot (100) according to claim 13, characterised in that said pivot (100) includes one said component (1) including a substantially spindle-shaped part made of magnetically permeable material, and in that said first pole piece (4) and said second pole piece (6) are each made of magnetic material.
15. Magnetic pivot (100) according to claim 13, characterised in that said pivot (100) includes one said component (1) including a substantially spindle-shaped part made of magnetic material, and in that said first pole piece (4) and said second pole piece (6) are each made of magnetically permeable material.
16. Magnetic pivot (100) according to claim 13, characterised in that said pivot (100) includes one said component (1) including a substantially spindle-shaped part made of magnetic material, and in that said first pole piece (4) and said second pole piece (6) are each made of magnetic material.
17. Timepiece movement (1000) including at least one anti-shock device (10) according to one of claims 1 to 12, or/and at least one magnetic pivot (100) according to one of claims 13 to 16.
18. Timepiece including at least one timepiece movement (1000) according to claim 17, or/and at least one anti-shock device (10) according to one of claims 1 to 12, or/and at least one magnetic pivot (100) according to one of claims 13 to 16.

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