OSCILLATOR MECHANISM ON FLEXIBLE GUIDE FOR A MECHANICAL CLOCK MOVEMENT WITH A SHOCKPROOF SUSPENSION

Description

technical field

[0001] This disclosure relates to the watchmaking industry, specifically to mechanical watches with oscillators on flexible guides and a shock-absorbing mechanism associated with a flexibly guided oscillator. This disclosure also relates to a watch movement incorporating the oscillator mechanism. State of the art

[0002] A flexible-guided oscillator is shown to figures 1a and 1b .Such an oscillator consists of an inertial element 11 (such as a pendulum) and a flexible pivot 120 comprising a plurality of elastic pivot blades 12, 13. The flexible pivot 120 combines the function of a spring and the rotational guidance of the inertial element 11 around a pivot axis A substantially perpendicular to the plane of oscillation Po of the inertial element 11. To ensure this pivoting function, the rotational and translational stiffness constants in all other directions must be particularly large, especially for translations in the plane of oscillation Po. This high stiffness implies that during an impact, the mechanical stress generated by the deformation of the pivot blades 12, 13 will increase significantly for very small displacements of the inertial element 11.

[0003] The shocks that such a flexible-guided oscillator must withstand are potentially very intense, typically up to 5000 G. For such shocks, it is essential to limit the displacement of the inertial element 11 and therefore the deformation of the pivot blades 12, 13 in order to prevent their breakage. figures 1a and 1b show a fixed thrust bearing 3, against which a thrust shaft (see figures 7a and 7b , not represented at figures 1a and 1b ) comes into contact with the thrust bearing during an impact of an intensity greater than a given threshold value.

[0004] Document EP3719587A1 from this applicant describes a shock-absorbing device for protecting a mechanical clockwork oscillator with flexible guidance from shocks. In this device, a thrust shaft is rigidly connected to the inertial element 11 and housed in a fixed thrust bearing. This thrust device is implemented above and below the inertial element 11 so as to prevent in-plane and out-of-plane displacement of the inertial element, as well as torsional rotation (rotation about any axis within the plane of oscillation P₀).

[0005] In order not to disturb the oscillator 1, the clearance between the stop shaft and the stop bearing 3 must be sufficiently large, typically 50 µm, to prevent any contact between the stop shaft and the stop bearing 3 during normal operation or for low-intensity shocks that are not dangerous for the pivot blades 12, 13. Thus, ideally, the flexible pivot 120 must be sufficiently rigid to prevent any contact between the stop shaft and the stop bearing 3 for low shocks and be less rigid for higher-intensity shocks that could damage the pivot blades 12, 13, and therefore allow the inertial element 11 to move by typically 50 µm until the stop shaft meets the stop bearing 3.

[0006] For all pivots on flexible guides, the variable stiffness property is naturally observed during translations of the rocker arm in the plane of oscillation. However, some flexible pivots characterized by at least three planes of symmetry (such as in the device described in patent EP329990581 by the present applicant) will exhibit a decrease in stiffness upon a significant shock, regardless of the direction (in the plane of oscillation) and the sense of application of that shock. Flexible pivots with a single plane of symmetry (such as described in patent EP2911012B1 by the present applicant) will, on the other hand, exhibit a decrease in stiffness in certain shock orientations and an increase in others. This latter property is problematic because, when a shock is applied in certain directions of the plane, the rocker arm will not move sufficiently for the thrust axis to contact the thrust bearing before the pivot blades break.Flexible pivots with a plane of symmetry nevertheless retain great interest because they are simpler and smaller than other flexible pivots while being just as efficient in terms of sensitivity to gravity and isochronism error (watch accuracy).

[0007] An example of a flexible pivot on a plane of symmetry (lines drawn on the figures 1a and 1b ) is the Wittrick-type pivot. The latter is composed of two crossed pivot blades 12, 13, separated by an angle of typically 90°, linking a fixed base 16 to the inertial element 11. The configuration of the pivot blades 12, 13 implies that, during a shock and depending on the direction of application of the shock, the pivot blades 12, 13 can be either both in tension ( figure 1a ), or both under compression ( figure 1b). When a blade is subjected to tension, like a rope, it becomes more rigid. The mass of the inertial element 11 will then move very little, and the stress in the pivot blades 12, 13 will be very high if the intensity of the shock subjecting it to tension is great. Conversely, if the shock experienced by such a pivot is applied in the opposite direction ( figure 1b The blades will be compressed, which will decrease their stiffness. The mass of the rocker arm will then be able to move significantly without the stress in the blades increasing excessively: this is known as the buckling of the pivot blades. As mentioned previously, the displacement of the inertial element 11 is limited by a thrust bearing 3, which typically prevents displacements exceeding 50 µm.

[0008] However, a displacement of 50 µm can be sufficient to cause the pivot blades 12, 13 to break if the direction of the impact is such that the blades are subjected to tensile stress. Reducing the clearance by 50 µm is not advisable because the inertial element 11 would then easily come into contact with the thrust bearing 3, which would disrupt the operation of the oscillator 1 too frequently. Lengthening the pivot blades 12, 13 to reduce the maximum stress is also not beneficial, as this would degrade the oscillator's sensitivity to gravity.

[0009] Patent EP3561609B1 describes a suspension device for a flexible pivot with a plane of symmetry, allowing translation of the inertial element in the plane of oscillation until the thrust axis reaches the thrust bearing without breaking the pivot blades. However, this suspension device does not prevent pivot displacement during normal operation or under minor shocks, which is undesirable when minimizing oscillator disturbances.

[0010] To prevent these movements during minor impacts, document CH713138B1 proposes preloading the suspension system. This way, the suspension system will not move until the impact force exceeds the preload value. However, this solution requires assembling several parts, complicating implementation, increasing costs, and introducing assembly inaccuracies.

[0011] Document EP3324247A1 describes a leaf resonator for a mechanical watch movement incorporating a shock-absorbing device. The shock-absorbing device includes a first pre-stressed flexible element that allows a change in length by expansion or contraction of the pivot leaf under a force below a first threshold, and prevents expansion or contraction of this leaf when it is subjected to a force above the first threshold. In one embodiment, the threshold effect is created by the fact that one of the pivot leaves can buckle to limit the tension in the opposite leaf. Summary

[0012] This disclosure relates to a flexible-guided oscillating mechanism arranged to be fixed to the plate of a mechanical watch movement. The oscillating mechanism comprises a fixed structure, arranged to be fixed to the plate, a pivot base, an inertial element, and a flexible pivot having a plurality of elastic blades, each extending between, at one end of the blade, the pivot base, and, at the other end of the blade, the inertial element, allowing the latter to oscillate in a plane of oscillation substantially perpendicular to a pivot axis of the inertial element. A shock-absorbing suspension is connected, on one side, to the pivot base, and, on the other side, to the fixed structure, and configured to keep the pivot base substantially fixed for shock intensities below a threshold value and to deform by buckling when the oscillating mechanism is subjected to a shock of an intensity exceeding a threshold value.The pivot base can then move relative to the fixed structure through at least one translational degree of freedom in the plane of oscillation Po. The shock-absorbing suspension includes at least one rigid element that does not deform upon impact and at least one suspension element that deforms by buckling upon impact subjecting the suspension element to a compressive force exceeding the threshold value. The rigid element is connected, on one side, to the pivot blades and, on the other side, to the fixed structure via the suspension element. The shock-absorbing suspension further includes a guide configured to guide the movement of the pivot base through at least one translational degree of freedom in the plane of oscillation.

[0013] Depending on one form of execution, the threshold value is at least greater than 10 G or 50 G.

[0014] One advantage of the oscillator mechanism 1 described here compared to the state of the art is that it allows for the realization of a shock-absorbing suspension with a trigger threshold (threshold value S for buckling) without requiring a preload.

[0015] This disclosure also relates to a watch movement comprising the oscillator mechanism. Brief description of the figures

[0016] Examples of implementation of the invention are given in the description illustrated by the accompanying figures, in which: there figure 1 illustrates an oscillating mechanism, comprising pivot blades connecting an inertial element to a fixed pivot base, undergoing a shock in the 0° orientation ( figure 1a ) and undergoing a shock in the 180° orientation ( figure 1b ). there figure 2illustrates an oscillating mechanism, comprising pivot blades connecting an inertial element to a pivot base comprising a suspension element, and undergoing a shock in the 0° orientation ( figure 2a ) and in the 180° orientation ( figure 2b ), according to one embodiment; the figure 3 illustrates the oscillating mechanism according to another embodiment, undergoing a shock in the 0° orientation ( figure 3a ) and in the 180° orientation ( figure 3b ); there figure 4 illustrates the oscillating mechanism in yet another embodiment, undergoing a shock in the 0° orientation ( figure 4a ) and in the 180° orientation ( figure 4b ); there figure 5 illustrates the oscillating mechanism in yet another embodiment, undergoing a shock in the 0° orientation ( figure 5a ) and in the 180° orientation ( figure 5b ); there figure 6 illustrates the oscillating mechanism in yet another embodiment, undergoing a shock in the 0° orientation ( figure 5a ), in the 180° orientation ( figure 5b ), in the 270° orientation (Figure 5c), and in the 90° orientation (Figure 5d); the figure 7 shows an overview ( figure 7a ) and partial ( figure 7b ) an example of an implementation of the oscillator mechanism; The figure 8 shows the maximum stress in the pivot blades as a function of the shock orientation in the plane of the oscillating mechanism. Example(s) of implementation method

[0017] An oscillating mechanism 1 on a flexible guide, arranged to be fixed to a plate of a mechanical watch movement, is illustrated in figures 2 to 6 ,according to one embodiment. The oscillating mechanism 1 comprises a fixed structure 16, arranged to be fixed to the plate. The oscillating mechanism 1 also comprises a pivot base 20, an inertial element 11, and a flexible pivot 120 having a plurality of elastic pivot blades 12, 13. Each pivot blade 12, 13 extends between, at a first end 121 of the pivot blade 12, 13, the pivot base 20, and, at a second end 122 of the pivot blade 12, 13, the inertial element 11, allowing the latter to oscillate in a plane of oscillation Po, substantially perpendicular to a pivot axis A of the inertial element 11.

[0018] In the various embodiments shown to figures 2 to 6The oscillating mechanism 1 comprises two pivot blades 12, 13. The two pivot blades 12, 13 intersect along a straight line that passes through a certain fraction of the length of each pivot blade 12, 13 and defines the virtual pivot axis A of the oscillating mechanism 1. This configuration corresponds to an oscillating mechanism with a plane of symmetry. However, other configurations of the pivot blades 12, 13 are possible. For example, the oscillating mechanism 1 may comprise more than two pivot blades.

[0019] A stop bearing 3, fixed relative to the oscillating mechanism 1, can be arranged to limit the displacement of the inertial element 11 relative to the pivot axis A of the oscillating mechanism 1.

[0020] According to one embodiment, a shock-absorbing suspension 200 is connected, on the one hand, to the pivot base 20, and, on the other hand, to the fixed structure 16. The shock-absorbing suspension 200 is configured to keep the pivot base 20 substantially fixed for shock intensities below a threshold value S, and to deform by buckling when the oscillating mechanism 1 undergoes a shock that exceeds a threshold value S. The shock-absorbing suspension 200 allows the pivot base 20 to move relative to the fixed structure 16 along at least one translational degree of freedom in the plane of oscillation Po, during the shock exceeding the threshold value S. In this way, following a shock stressing the flexible pivot 120, the tensile stress, which may appear in the pivot blades 12, 13, is reduced.

[0021] In one embodiment, the shock-absorbing suspension 200 comprises at least one rigid element 22, 24 that does not deform upon impact. The shock-absorbing suspension 200 also comprises at least one suspension element 23, 25, 27 that deforms by buckling upon impact subjecting the suspension element 23, 25, 27 to a compressive force exceeding the threshold value S. The rigid element 22, 24 is connected, on the one hand, to the pivot blades 12, 13 and, on the other hand, to the fixed structure 16 via the suspension element 23, 25, 27.

[0022] The shock-absorbing suspension 200 further includes a guide element 21 configured to guide the movement of the pivot base 20 along at least one degree of freedom in translation, in the plane of oscillation P o.

[0023] The suspension element 23, 25, 27 may include one or more flexible suspension blades 230.

[0024] Buckling occurs when a compressive force is applied to the suspension element 23, 25, 27, for example, to a suspension blade 230. If the applied force exceeds the buckling limit of the suspension blade 230, its compressive stiffness (which can be very high) decreases abruptly, causing the blade 230 to collapse. The buckling limit depends on the slenderness ratio of the suspension blade 230. Thus, a long, thin blade has a lower buckling limit compared to a thick, short one. This buckling limit therefore depends primarily on geometric parameters and the material, which can be precisely dimensioned and selected.

[0025] The threshold value S is at least greater than 10 G. The threshold value S can also be at least greater than 50 G.

[0026] In the particular embodiment shown to figures 2a and 2b ,The shock-absorbing suspension 200 comprises a first rigid element 22 that does not deform during the impact and a first suspension element 23. The rigid element 22 is, on the one hand, connected to the pivot blades 12, 13 and, on the other hand, to the fixed structure 16 via the first suspension element 23. The first flexible element 23 deforms by buckling during an impact subjecting the suspension element 23 to a compressive force whose intensity exceeds the threshold value S. During the impact, the pivot blades 12, 13 are subjected to a tensile force that is all the lower as the suspension element 23 protects them by deforming by buckling.

[0027] More specifically, in the example of figures 2a and 2bThe first rigid element 22 is connected to a first section 161 of the fixed structure 16 via the first suspension element 23. The suspension element 23 comprises a single suspension blade 230. The first rigid element 22 is connected to a second section 162 of the fixed structure 16 via the guide member 21.

[0028] The guide element 21 allows the translational movement of the pivot base 20, induced by buckling deformation, to be guided in the plane of oscillation Po. For example, the guide element 21 can be configured to block the movement of the pivot base 20 in directions other than the direction corresponding to the desired translational degree of freedom. For example, following an impact stressing the shock absorber 200, the latter buckles while allowing the pivot base 20, guided by the guide element 21, to move in translation along the axis of symmetry of the flexible pivot 120. In the figures 2a and 2b The guiding element 21 is represented abstractly by bearings.

[0029] THE figures 3a and 3b illustrate the oscillator mechanism 1 of the figures 2a and 2bin which the guide element 21 comprises two guide blades 210 arranged substantially parallel. It should be noted that the guide element 21 may also comprise more than two guide blades 210. The guide blade 210 is preferably dimensioned so as to minimize the rigidity of the guide element 21 in the direction of its degree of freedom in order to avoid adding additional stress to the pivot blades 12, 13. Other configurations of the guide element 21 are also possible.

[0030] In the figure 3aThe impact is directed to the right, and the pivot blades 12, 13 are subjected to a tensile force. The direction of the impact is illustrated by the arrow and corresponds to the angle 0°. The suspension element 23 buckles when the oscillating mechanism 1 experiences an impact exceeding the threshold value S. The pivot base 20 then moves in the direction of the impact, which reduces the tensile force in the pivot blades 12, 13. When the pivot base 20 is not displaced, the two guide blades 210 extend, between the second section 162 of the fixed structure 16 and the first rigid element 22, in a direction substantially perpendicular to the direction in which the first suspension element 23 deforms.When the suspension element 23 buckles, the two guide blades 210 flex in the direction of movement of the pivot base 20, thus guiding the latter in the direction corresponding to the degree of freedom in translation, here between 180° and 0°, in the plane of oscillation P o.

[0031] In the figure 3b The shock is directed to the left and the pivot blades 12, 13 are subjected to a compressive force. The pivot blades 12, 13 can be configured so as to buckle when the oscillating mechanism 1 experiences a shock whose intensity exceeds the threshold value S, resulting in a decrease in the stiffness of the pivot blades 12, 13 and a displacement of the inertial element 11. In such a case, the suspension element 23 is in tension, therefore it does not buckle and the pivot base 20 does not move.

[0032] THE figures 4a and 4b illustrate the oscillator mechanism 1 according to an alternative embodiment to that of figures 3a and 3bin which the suspension element 23 comprises two suspension blades 230. The two suspension blades 230 are preferably arranged substantially parallel to each other. Each of the suspension blades 230 is configured to buckle when the oscillating mechanism 1 is subjected to an impact exceeding the threshold value S. In this case, the pivot blades are in tension and the suspension blades 230 are in compression. Each of the two suspension blades 230 may advantageously have a more slender shape than the single suspension blade 230 of the suspension element 23, depending on the configuration of the figures 3a and 3b , in the case where the buckling of both suspension blades 230 is desired to be at the same threshold value S as that of the single suspension blade 230. The configuration of the suspension element 23 according to the figures 3a and 3ballows the rotational degrees of freedom of the pivot base 20 to be blocked more rigidly, which reduces the sensitivity to gravity of the oscillator mechanism 1.

[0033] Similar to figures 3a and 3b , there figure 4a shows the oscillating mechanism 1 undergoing a shock directed to the right (0°) subjecting the pivot blades 12, 13 to a tensile force. In the figure 4b The impact is directed to the left (180°) and the pivot blades 12, 13 are subjected to a compressive force. As discussed above, the pivot blades 12, 13 can then buckle when the force in the pivot blades 12, 13 is compressive and the intensity of the impact exceeds the threshold value S.

[0034] In the particular embodiment shown to figures 5a and 5bThe shock-absorbing suspension 200 comprises a first rigid element 22 and a second rigid element 24. The shock-absorbing suspension 200 also comprises a first suspension element 23 and a second suspension element 25. The first rigid element 22 is connected to the fixed structure 16 via the second suspension element 25, the second rigid element 24, and the first suspension element 23. The first suspension element 23 is configured to deform by buckling in a direction substantially parallel to, but in the opposite direction to, the buckling deformation direction of the second suspension element 25. The pivot base 20 can therefore move along one degree of freedom in translation in two orientations (0° and 180°) in the plane of oscillation Po, when the oscillating mechanism 1 is subjected to shocks in diametrically opposite orientations directed along the bisector of the angle formed by the blades 12 and 13.

[0035] More specifically, in the example of figures 5a and 5b The first rigid element 22 is connected to a first section 161 of the fixed structure 16 via the second suspension element 25, the second rigid element 24 and the first suspension element 23. The first rigid element 22 is also connected to a second section 162 of the fixed structure 16 via the guide member 21.

[0036] In this example, the suspension element 23 comprises two suspension blades 230 that are substantially parallel to each other. The guide member 21 also comprises two guide blades 210. The two guide blades 210 are arranged substantially parallel to each other. When the pivot base 20 moves, the two guide blades 210 flex in the direction of movement of the pivot base 20, thus guiding the latter in the direction corresponding to the translational degree of freedom, here between 180° and 0°, in the plane of oscillation P o .

[0037] There figure 5a This shows the oscillating mechanism 1 undergoing a shock directed to the right (0°), subjecting the pivot blades 12, 13 to a tensile force and the first flexible element 23 to a compressive force. The first flexible element 23 deforms by buckling when the shock intensity exceeds the threshold value S.

[0038] In the figure 5bThe impact is directed to the right (180°) and the pivot blades 12, 13 are subjected to a compressive force. Unlike the example of the figure 4b The pivot blades 12 and 13 do not buckle. For example, the buckling limit of the pivot blades 12 and 13 is too high (for example, in the case where the pivot blades 12 and 13 are dimensioned very short). In this configuration, the second suspension element 25, which is subjected to a compressive force, buckles, allowing the inertial element to move when the shock exceeds the threshold value S.

[0039] THE figures 6a to 6d illustrate the oscillator mechanism 1 according to another embodiment, in which the shock-absorbing suspension 200 comprises a first rigid element 22 and a second rigid element 24. The shock-absorbing suspension 200 also comprises a first suspension element 23, a second suspension element 25, and a third suspension element 27.

[0040] Similar to the configuration of the figures 3a and 3bThe rigid element 22 is, on the one hand, connected to the pivot blades 12, 13 and, on the other hand, to the fixed structure 16 (for example to the first section 161 of the fixed structure 16) via the first suspension element 23. The first flexible element 23 deforms by buckling during an impact whose intensity exceeds the threshold value S. The pivot blades 12, 13 are subjected to a tensile force and the first flexible element 23 is subjected to a compressive force. The rigid element 22 is also connected to the fixed structure 16 (for example to the second section 162 of the fixed structure 16), via the second suspension element 25, the second rigid element 24 and the third suspension element 27. The first suspension element 23 is configured to deform in a direction substantially perpendicular to the direction of deformation of the second suspension element 25 and third suspension element 27.The pivot base 20 can then be moved along two degrees of freedom in translation relative to the fixed structure 16, substantially perpendicular to each other, and in the plane of oscillation P o.

[0041] There figure 6a Figure 1 shows the oscillating mechanism undergoing a shock directed to the right (0°), subjecting the pivot blades 12, 13 to a tensile force. The first flexible element 23 is subjected to a compressive force and deforms by buckling when the shock intensity exceeds the threshold value S. In the figure 6b The impact is directed to the left (180°) and the pivot blades 12, 13 are subjected to a compressive force. The operation of the pivot base 20 for an impact in the 0° and 180° orientations is similar to that of the pivot base 20 in the configurations of figures 4a and 4b .

[0042] In the figure 6cThe impact is directed downwards (270°). The second flexible element 25 is subjected to a compressive force and deforms by buckling when the intensity of the impact exceeds the threshold value S. In the figure 6d , the shock is directed upwards (90°). The third flexible element 27 is subjected to a compressive force and deforms by buckling when the intensity of the shock exceeds the threshold value S. The presence of the second and third flexible elements 25, 27 allows the pivot base 20 to move in both orientations 90° and 270° and in the plane of oscillation P o .

[0043] We note that, when the shock is directed downwards (90°, figure 6c ) or upwards (270°, figure 6d ), the suspension blades 230 of the first suspension element 23 act as the guide element 21 and guide the movement of the pivot base 20 in the two opposite orientations between 270° and 90°. When the shock is directed to the right (0°, figure 6a ), the suspension blades 230 of the second and third suspension elements 25, 27 play the role of the guide element 21 and guide the movement of the pivot base 20 in the orientations towards 0°.

[0044] According to an unrepresented variant of the configuration of figures 6a-b The shock-absorbing suspension 200 may comprise only the first and second suspension elements 23, 25 and only the first rigid element 22. The rigid element 22 is then connected to the fixed structure 16 (for example to the second section 162 of the fixed structure 16) via the second suspension element 25. In this configuration, the second flexible element 25 deforms by buckling when a shock is directed downwards (270°) and when its intensity exceeds the threshold value S. The second flexible element 25 does not deform when the shock is directed upwards (90°).

[0045] It may be advantageous for each of the first, second and third flexible elements 23, 25, 27 to flare up for substantially the same threshold value S.

[0046] THE figures 7a and 7b They are setting up a possible implementation of the oscillator mechanism 1. The figure 7a shows a general view of the oscillator mechanism 1 and the figure 7b shows a partial view of the oscillating mechanism of the figure 7aThe oscillating mechanism 1 comprises the inertial element 11 (or balance wheel) and the pivot base 20. The two pivot blades 12, 13 extend at approximately 90° to each other. The pivot blades 12, 13 are connected on one side to the pivot base 20 and on the other side to the inertial element 11. The shock-absorbing suspension 200 comprises the guide member 21 having two guide blades 210, and the first suspension element 23 having a suspension blade 230. The suspension blade 230 may have a slight curvature to ensure that it deforms according to the desired buckling mode. By desired buckling mode, we mean a particular deformation mode of the suspension blade 230. For example, it may be desirable that the belly of the suspension blade 230, when it deforms in buckling, forms in a determined direction (convex, concave).

[0047] The oscillating mechanism 1 also includes a thrust shaft 14 connected to the inertial element 11 by a rigid link 15. The thrust shaft 14 is housed in a thrust bearing 3, which is fixed relative to the oscillating mechanism 1. The thrust shaft 14 and the thrust bearing 3 can be arranged on either side of the oscillating mechanism 1, relative to the plane of oscillation Po (see the figure 7b ). The radial play between the thrust axis 14 and the thrust bearing 3 is typically about 50 µm.

[0048] According to a particular embodiment, each of the pivot blades 12, 13 has a length of approximately 2 mm, a height of approximately 0.2 mm, and a thickness of approximately 10 µm. The suspension blade 230 has a length of approximately 2 mm, a height of approximately 0.2 mm, and a thickness of approximately 10 µm. Each of the guide blades 210 has a length of approximately 1 mm, a height of approximately 0.4 mm, and a thickness of approximately 10 µm. The material used to fabricate the structure can be silicon, for example, shaped by a deep groove etching (DRIE) process.

[0049] One advantage of the oscillating mechanism 1 described here, compared to the state of the art, is that it allows for the implementation of a shock-absorbing suspension with a trigger threshold (shock intensity with a threshold value S for buckling) without requiring preloading of this shock-absorbing suspension. The pivot base 20 can then remain stable during normal operation of the oscillating mechanism 1 under low shocks (below the threshold value S). The oscillating mechanism 1 does not require the addition of extra parts or assembly steps.

[0050] There figure 8 shows, in the case where the pivot of the figure 7aThe pivot blades 12 and 13 are made of silicon, and the maximum stress in them depends on the orientation of the shock in the plane of oscillation Po, when the inertial element 11 is pivoted at an angle of 14° (corresponding to a maximum angle) and subjected to a 5000 G shock. It should be noted that the maximum stress that silicon can withstand is around 1000 MPa. In the absence of the suspension element 23, 25, 27, the pivot blades 12 and 13 are likely to break under any shock experienced by the oscillating mechanism 1 with an orientation between 0° and + / -80°. Between + / -80° and + / -180°, the pivot blades 12 and 13 buckle, and the stress remains below 1000 MPa. In the presence of the suspension element 23, 25, 27, the maximum stress in the pivot blades 12, 13 remains below 1000 MPa regardless of the orientation of the shock suffered by the oscillating mechanism 1.

[0051] This disclosure also relates to a watch movement comprising the oscillator mechanism 1. Reference numbers used in the figures

[0052] 1 oscillator mechanism 3 thrust bearing 11 inertial element, pendulum 12, 13 pivot blade 120 flexible pivot 121 first end 122 second end 14 thrust axis 15 rigid link 16 fixed structure 161 first section of the fixed structure 162 second section of the fixed structure 20 pivot base 200 shock-absorbing suspension 21 guide element 210 guide blade 22 rigid element, first rigid element 23 suspension element, first suspension element 230 suspension blade 24 rigid element, second rigid element 25 suspension element, second suspension element 27 suspension element, third suspension element A pivot axis P o plane of oscillation

Claims

1. Oscillating mechanism (1) on flexible guiding arranged to be fixed on a plate of a mechanical watch movement, the oscillating mechanism comprising: a fixed structure (16), arranged to be fixed on the plate; a pivot base (20); an inertial element (11); and a flexible pivot (120) comprising a plurality of elastic pivot blades (12, 13), each extending between, at a first end (121) of the pivot blade (12, 13), the pivot base (20), and, at a second end (122) of the pivot blade (12, 13), the inertial element (11), allowing the latter to oscillate in an oscillation plane Po, substantially perpendicular to a pivoting axis (A) of the inertial element (11); a shock-absorbing suspension (200) which is linked, on one hand to the pivot base (20) and, on the other hand, to the fixed structure (16), and configured to maintain the pivot base (20) substantially fixed for shock intensities below a threshold value (S) and to deform by buckling when the oscillating mechanism (1) undergoes a shock of an intensity that exceeds a threshold value (S), so that the pivot base (20) can move according to at least one degree of freedom in translation in the oscillation plane Po relative to the fixed structure (16); wherein the shock-absorbing suspension (200) comprises at least one rigid element (22, 24) that does not deform during the shock and at least one suspension element (23, 25, 27) that deforms by buckling during a shock subjecting the suspension element (23, 25, 27) to a compressive force whose intensity exceeds the threshold value (S); and the rigid element (22, 24) being, on one hand, connected to the pivot blades (12, 13) and, on the other hand, to the fixed structure (16) by means of the suspension element (23, 25, 27); characterized in that the shock-absorbing suspension (200) further comprises a guiding member (21) configured to guide the displacement of the pivot base (20) according to at least one degree of freedom in translation in the oscillation plane Po.

2. Oscillating mechanism according to claim 1, wherein said threshold value (S) is at least greater than 10 G or 50 G.

3. Oscillating mechanism according to claim 1 or 2, wherein said shock-absorbing suspension (200) comprises a first suspension element (23) and a first rigid element (22), so that the pivot base (20) can move according to one degree of freedom in translation in the oscillation plane Po and in a single direction.

4. Oscillating mechanism according to claim 1 or 2, wherein said at least one rigid element comprises a first and a second rigid element (22, 24), and said at least one suspension element comprises a first and a second suspension element (23, 25).

5. Oscillating mechanism according to claim 4, wherein the first rigid element (22) is connected, on one hand, to the fixed structure (16) by means of the second suspension element (25), the second rigid element (24) and the first suspension element (23); and wherein the first suspension element (23) is configured to deform in a direction substantially parallel to the direction of deformation of the second suspension element (25), so that the pivot base (20) can move in the oscillation plane Po according to one degree of freedom in translation in two orientations, when the oscillating mechanism (1) undergoes shocks in diametrically opposite orientations.

6. Oscillating mechanism according to any one of claims 3 to 5, wherein the first rigid element (22) is connected to the fixed structure (16) by means of the guiding member (21).

7. Oscillating mechanism according to any one of claims 1 to 6, wherein the guiding member (21) comprises at least two flexible suspension blades (210).

8. Oscillating mechanism according to claim 4, wherein the first rigid element (22) is, on one hand, connected to the pivot blades (12, 13) and, on the other hand, to the fixed structure (16) by means of the first suspension element (23); wherein the first rigid element (22) is also connected to the fixed structure (16) by means of the second suspension element (25) and the second rigid element (24); and wherein the first suspension element (23) is configured to deform in a direction substantially perpendicular to the direction of deformation of the second suspension element (25), so that the pivot base (20) can move in the oscillation plane Po according to two degrees of freedom in translation relative to the fixed structure (16) and substantially perpendicular to each other.

9. Oscillating mechanism according to claim 8, wherein the first suspension element (23) performs the function of the guiding member (21) when the second suspension element (25) is deformed by buckling, and the second suspension element (25) performs the function of the guiding member (21) when the first suspension element (23) is deformed by buckling.

10. Oscillating mechanism according to claim 8, wherein said at least one flexible element further comprises a third suspension element (27); and wherein the first rigid element (22) is connected to the fixed structure (16) by means of the second suspension element (25), the second rigid element (24), and the third suspension element (27), so that the pivot base (20) can move in diametrically opposite orientations depending on whether the second suspension element (25) or the third suspension element (27) is deformed by buckling.

11. Oscillating mechanism according to claim 10, wherein the second and third suspension elements (25, 27) perform the function of the guiding member (21) when the first suspension element (23) is deformed by buckling.

12. Oscillating mechanism according to any one of claims 1 to 11, wherein said at least one suspension element (23, 25, 27) comprises at least one flexible blade.

13. Watch movement comprising at least one oscillating mechanism (1) according to any one of claims 1 to 12.