Clock resonator mechanism with flexible guides and equipped with a stiffness adjustment device

Abstract

The invention relates to a rotary resonator mechanism, in particular for a timepiece, comprising a flexible guide comprising two main flexible strips and a rigid part, the main flexible strips being engaged on the one hand with the rigid part of the flexible guide and on the other hand with the oscillating mass, and an oscillating mass, the resonator mechanism comprising means for adjusting the stiffness of the resonator mechanism, the adjustment means comprising a flexible element connected on the one hand to the rigid part of the flexible guide and on the other hand to a fixed support, such that the flexible guide is suspended by the flexible element, the flexible guide and the flexible element extending substantially in the same plane to enable a rotational movement of the oscillating mass about a virtual pivot, the adjustment means also comprising prestressing means to exert a variable force or torque on the flexible element or the flexible guide so as to vary the stiffness of the flexible element. The invention also relates to a timepiece movement comprising such a resonator mechanism.

Description

Technical Field

[0001] The invention relates to a resonator mechanism, in particular for a timepiece, having a flexible guide device, which is equipped with a device for adjusting the rigidity. Background Art

[0002] Most of today's mechanical watches are equipped with a balance spring and a Swiss lever escapement. The balance spring forms the time base of the watch. It is also called a resonator.

[0003] As for the escapement, it performs two main functions:

[0004] -Maintain the reciprocating motion of the resonator;

[0005] - These reciprocating movements are counted.

[0006] In order to form a mechanical resonator, an inertial element, a guide and an elastic return element are required. Usually, a hairspring plays the role of an elastic return element of the inertial element constituting a balance wheel. Such a balance wheel is guided in rotation by a pivot that usually rotates in a smooth ruby ​​bearing.

[0007] Flexible guides are currently used as springs to form a virtual pivot. Flexible guides with a virtual pivot can significantly improve watch resonators. The simplest is a cross-stripe pivot, which comprises two guides with substantially perpendicular crossing straight strips. The two strips can be three-dimensional in two different planes, or two-dimensional in the same plane and thus welded at their intersection. However, there are non-cross-stripe guides of the RCC (Remote Centre Compliance) type, which have straight strips that do not cross. Such resonators are described in document EP2911012 or in documents EP14199039 and EP16155039.

[0008] For its operation, the balance system with hairspring must usually be able to be adjusted to improve the precision of the watch. For this purpose, devices for adjusting the stiffness of the hairspring are used, such as an index for modifying the effective length of the hairspring. Its stiffness is thus modified to adjust the accuracy of the time difference of the watch. However, the effect of conventional indexes in adjusting the time difference is still limited and it is not always effective to achieve a sufficiently fine adjustment of the order of a few seconds or tens of seconds per day.

[0009] In the case of flexible guides, there are adjustment devices comprising one or more screws arranged in the rim of the balance wheel. By acting on the screws, the inertia of the balance wheel is changed, which has the effect of changing its runout.

[0010] However, although these screws provide a wide adjustment range, the fineness of the adjustment is not precise, so it is difficult to obtain a correct adjustment of the travel time. Summary of the invention

[0011] The object of the present invention is to overcome all or part of the above-mentioned drawbacks by proposing a timepiece resonator mechanism equipped with a precision regulating device and having flexible guiding means.

[0012] To this end, the invention relates to a rotary resonator mechanism, in particular for a timepiece, comprising a flexible guide comprising two flexible strips and a rigid part, the flexible strips being engaged on the one hand with the rigid part of the flexible guide and on the other hand with the oscillating mass.

[0013] The present invention is notable in that: the mechanism includes a device for adjusting the stiffness of the resonator mechanism, the adjusting device includes a flexible element arranged in series with a flexible guiding device, the flexible element is connected to the rigid part of the flexible guiding device on the one hand and to a fixed support on the other hand, so that the flexible guiding device is suspended by the flexible element, the flexible element forms a pivot to enable the rigid part to perform a rotational movement, the flexible guiding device and the flexible element extend basically in the same plane to enable the oscillating mass body to perform a rotational movement around a virtual pivot, and the adjusting device further includes a prestressing device to apply a variable force or torque on the flexible element or the flexible guiding device, thereby changing the stiffness of the flexible element.

[0014] Thanks to the invention, by acting on the prestressing means, the force or torque exerted on the flexible element is varied, which causes a change in the stiffness of the assembly comprising the flexible element and the flexible guiding means. In fact, the flexible element placed in series with the flexible guiding means provides an additional stiffness, which is added to the stiffness of the flexible guiding means. Thus, when the prestressing means exert a variable force or torque on the flexible element, they vary the stiffness of the flexible element and therefore the stiffness of the assembly comprising the flexible guiding means and the flexible element.

[0015] In other words, the flexible element is arranged in series with the flexible guide device, located between the flexible guide device and the fixed support. Such a flexible element changes the stiffness of the attachment point and provides additional flexibility for the resonator. Therefore, the effective stiffness of the resonator includes the stiffness of the flexible guide device and the stiffness of the flexible element. Thus, a variable force or torque is applied to prestress the flexible element without prestressing the flexible guide device and without moving the flexible guide device. By prestressing the flexible element, its stiffness changes, while the stiffness of the flexible guide device remains unchanged because it is not prestressed and its end does not move. By changing the stiffness of the flexible element, the stiffness of the resonator (the stiffness of the flexible guide device and the stiffness of the flexible element) changes, which thereby changes the travel time difference of the resonator. The flexible element is preferably stiffer than the flexible guide device, and the proportion of the stiffness of the flexible element in the total stiffness is smaller than that of the flexible guide device. Therefore, modifying the stiffness of the flexible element changes the stiffness of the components of the resonator and thus finely adjusts its travel time difference, which makes it possible to accurately adjust the frequency of the time base. Therefore, high precision is obtained in the travel time difference adjustment, because only one element is acted on to adjust the stiffness.

[0016] According to a particular embodiment of the invention, the prestressing means will only modify the stiffness of the flexible element, without modifying the stiffness of the main flexible strip.

[0017] According to a particular embodiment of the invention, the flexible element comprises at least one secondary flexible strip, preferably two secondary flexible strips, each of which is connected to a fixed support.

[0018] According to a particular embodiment of the invention, the prestressing means comprise a pin in contact with the secondary flexible strip.

[0019] According to a particular embodiment of the invention, the prestressing means exert a variable force or torque on the secondary flexible strip.

[0020] According to a particular embodiment of the invention, the prestressing means exert a variable force or torque on the rigid portion of the flexible guiding means.

[0021] According to a particular embodiment of the invention, the prestressing means comprises a first movable body and at least one tertiary flexible strip connected to the first movable body and to the rigid portion or the flexible element of the flexible guiding means.

[0022] According to a particular embodiment of the invention, the prestressing device comprises a plurality of four-level flexible strips and a second movable body, the four-level flexible strips connecting the second movable body to the first movable body.

[0023] According to a particular embodiment of the invention, the prestressing means comprise at least one five-level flexible strip connecting the second movable body or the first movable body to the fixed support.

[0024] According to a particular embodiment of the invention, the prestressing means comprise an eccentric screw in contact with the second movable body or the rigid part.

[0025] According to a particular embodiment of the invention, the prestressing means comprise a screw longitudinally movable against the second movable body.

[0026] According to a particular embodiment of the invention, the prestressing means comprise a rod for moving the second movable body.

[0027] According to a particular embodiment of the invention, the prestressing means comprises a first magnet integral with the rigid part or with the second movable body, and a second magnet movable relative to the first magnet.

[0028] According to a particular embodiment of the invention, the prestressing means comprises a spring connected to a rigid part, and a movable body for tensioning or compressing the spring.

[0029] According to a particular embodiment of the invention, the prestressing means are arranged in the same plane as the flexible guiding means and the flexible element.

[0030] According to a particular embodiment of the invention, the prestressing means are arranged in a plane substantially parallel to the plane of the flexible guiding means and the flexible element.

[0031] According to a particular embodiment of the invention, the flexible element comprises a third movable body, and a plurality of six-level flexible strips connecting the third movable body to the rigid portion.

[0032] According to a specific embodiment of the invention, the flexible element comprises a fourth movable body, and a plurality of seven-level strips connecting the third movable body to the fourth movable body.

[0033] According to a particular embodiment of the invention, the tertiary flexible strip is connected to the fourth movable body.

[0034] According to a particular embodiment of the invention, the two main strips of the flexible guiding means are crossed.

[0035] According to a particular embodiment of the invention, the stiffness of the flexible element is greater than the stiffness of the flexible guiding means, preferably at least five times, or even at least ten times.

[0036] The invention also relates to a timepiece movement comprising such a resonator mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The objects, advantages and features of the invention will become apparent upon reading a number of embodiments given by way of non-limiting examples only, with reference to the accompanying drawings, in which:

[0038] - Figure 1 schematically represents a top view of a resonator mechanism according to a first embodiment of the invention,

[0039] - Figure 2 schematically represents a top view of a resonator mechanism according to a first variant of a first embodiment of the invention,

[0040] - Figure 3 schematically represents a top view of a resonator mechanism according to a second embodiment of the present invention,

[0041] - Figure 4 schematically represents a top view of a resonator mechanism according to a first variant of a second embodiment of the invention,

[0042] - Figure 5 schematically represents a top view of a resonator mechanism according to a second variant of a second embodiment of the invention,

[0043] - Figure 6 schematically represents a top view of a resonator mechanism according to a third variant of the second embodiment of the invention,

[0044] - Figure 7 schematically represents a top view of a resonator mechanism according to a fourth variant of the second embodiment of the invention,

[0045] - Figure 8 schematically represents a top view of a resonator mechanism according to a fifth variant of the second embodiment of the invention,

[0046] - Fig. 9 schematically represents a top view of a resonator mechanism according to a sixth variant of the second embodiment of the present invention,

[0047] - Fig.10 schematically represents a top view of a resonator mechanism according to a seventh variant of the second embodiment of the invention,

[0048] - Fig.11 schematically represents a top view of a resonator mechanism according to a third embodiment of the present invention,

[0049] - Fig.12 schematically represents a top view of a resonator mechanism according to a first variant of a third embodiment of the invention,

[0050] - Fig.13 schematically represents a top view of a resonator mechanism according to a second variant of the third embodiment of the invention,

[0051] - Fig.14 schematically represents a top view of a resonator mechanism according to a third variant of a third embodiment of the invention, and

[0052] - Fig.15 Schematically represents a top view of a resonator mechanism according to a fourth variant of the third embodiment of the invention. DETAILED DESCRIPTION

[0053] Figures 1 to 15 The three embodiments of a resonator mechanism 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, in particular for a timepiece, comprise a flexible guide 5 and an oscillating mass 2. The oscillating mass 2 comprises an attachment body 3 and a balance (not shown in the figures), such as an annular balance or a bone-like straight member, which is usually used in timepieces and is assembled on the attachment body 3. The attachment body 3 has an elongated rectangular shape. The resonator mechanism 1 extends substantially in the same plane so as to enable the oscillating mass 2 to perform a rotational movement about a virtual pivot.

[0054] The flexible guide device 5 comprises two main flexible strips 4, 6 and a rigid part 7. The flexible guide device 5 extends according to a main symmetry axis. The flexible strips 4, 6 engage on the one hand with the rigid part 7 of the flexible guide device 5 and on the other hand with the attachment body 3 of the oscillating mass 2. The two main strips 4, 6 of the flexible guide device 5 cross, are preferably straight and of the same length.

[0055] According to the invention, the resonator mechanism 1 comprises means for adjusting the stiffness of the resonator mechanism. To this end, the adjusting means comprise a flexible element 12 arranged in series (i.e. arranged in succession) with the flexible guide means 5, the flexible element 12 being connected on the one hand to the rigid part 7 of the flexible guide means and on the other hand to the fixed support 11, so that the flexible guide means 5 is suspended by the flexible element 12, the flexible element 12 forming a pivot to enable the rigid part 7 to perform a rotational movement. The rigid part 7 thus performs a rotational movement due to the flexible element 12. The rotational movement of the rigid part 7 is added to the rotational movement of the oscillating mass 2 caused by the flexible guide means 5, so that the angular travel of the oscillating mass is increased by the flexible element 12.

[0056] Furthermore, the prestressing device 15 will only change the stiffness of the flexible element 12, but not the stiffness of the main flexible strips 4, 6. Thus, to adjust the resonator mechanism, only one element is acted on to simplify the adjustment. In addition, the position of the main flexible strips 4, 6 will not be changed by the prestressing device 15.

[0057] In the first two embodiments, the rigid part 7 has the shape of an arc of a circle with an inner side on which the main strips 4, 6 are joined, preferably symmetrically about the center of the arc. The flexible element 12 comprises at least one secondary flexible strip, here two secondary flexible strips 8, 9. Preferably, the secondary flexible strips 8, 9 are straight and have the same length. Each secondary flexible strip 8, 9 connects the outer side of the arc of the rigid part 7 of the flexible guide 5 with the fixed support 11. The secondary flexible strips 8, 9 are preferably arranged close to each end of the arc and symmetrically about the axis of the flexible guide 5.

[0058] The adjustment device further comprises a prestressing device 15 to exert a variable force or torque on the flexible element 12 or the flexible guiding device 5 , thereby changing the stiffness of the flexible element 12 .

[0059] In a second variant of the first embodiment, the prestressing means 15 comprise pins in contact with the secondary flexible strip.

[0060] Figure 1 and 2 1 shows a schematic diagram of a first embodiment of a rotary resonator mechanism 1 for a timepiece movement. Figure 1 As shown in the operating principle of the prestressing device 15, a variable force or torque is applied to the flexible element 12. Here, the prestressing device 15 applies a force or torque to the secondary flexible strips 8, 9. Thus, the stiffness of the secondary flexible strips 8, 9 is varied to adjust the stiffness of the assembly formed by the flexible element 12 and the flexible guide device 5.

[0061] exist Figure 2 In a variant of , the prestressing means 15 comprises pins 14, 16, here two pairs of pins, each pair of pins being arranged on both sides of each secondary flexible strip 8, 9. The two pins 14, 16 are in contact with the secondary flexible strips 8, 9 and can be moved along each strip 8, 9 to change their stiffness. Thus, the movement of the pins 14, 16 can change the stiffness of the assembly formed by the secondary flexible strips 8, 9 and the flexible guide means 5 to adjust the travel time accuracy of the resonator mechanism 1.

[0062] The operating principle of the second embodiment of the resonator mechanism 1 is Figure 3 The prestressing device 15 exerts a variable force or torque on the flexible guiding device 5, in particular on the rigid portion 7 of the flexible guiding device 5. This arrangement thus makes it possible to vary the stiffness of both the primary flexible strips 4, 6 of the flexible guiding device 5 and the secondary flexible strips 8, 9 of the flexible element 12.

[0063] Figure 4The first variant of the second embodiment shows a prestressing device 15 comprising an eccentric screw 17, the head of which is arranged in contact with the rigid part 7 of the flexible guide 5. Thus, by actuating the eccentric screw 16, the force or torque exerted on the rigid part 7 varies.

[0064] In a second variant of the second embodiment, the prestressing means 15 comprises magnets 17, 18. A first magnet 17 is arranged on the rigid part 7 of the flexible guide 5 and a second movable magnet 18 is arranged at a variable distance from the first magnet 17 so that it exerts a variable force or torque on the first magnet 17 and therefore on the rigid part 7.

[0065] Figure 6 The prestressing device 15 of the third variant comprises a spring 21 and a movable body 22, which is connected to the rigid part 7 of the flexible guide device 5 via the spring 21. Therefore, by moving the movable body 22, the spring 21 is stretched or compressed to change the force or torque applied to the rigid part 7.

[0066] exist Figures 7 to 10 In a variation of the second embodiment, the prestressing device 15 comprises a first movable body 24 and a tertiary flexible strip 25, which is preferably assembled in series to the rigid part 7 and the first movable body 24 according to the axis of symmetry of the flexible guide device. The first movable body 24 preferably has an elongated shape and is arranged on the axis of the tertiary flexible strip 25.

[0067] The prestressing device 15 comprises a second elbow-shaped movable body 27, and four quadruple flexible strips 26, here four quadruple flexible strips 26, connecting the two movable bodies 24, 27. In the rest position of the prestressing device 15, these four quadruple strips 26 are preferably substantially perpendicular to the tertiary strips 25. The quadruple flexible strips 26 are preferably parallel.

[0068] exist Figure 7 In the fourth variant of the resonator mechanism 60, the prestressing device 15 further comprises two five-level strips 28, which connect the first movable body 24 to the fixed support 31. The five-level flexible strips 28 are preferably parallel. The five-level strips 28 are substantially parallel to the four-level strips 26 and are arranged on opposite sides of the first movable body 24. The prestressing device 15 also includes a screw 29, which is arranged to contact the second movable body 27 in the longitudinal direction to apply a variable force or torque. By applying a variable force or torque on the second movable body 27, the stiffness of the resonator mechanism 60 changes.

[0069] exist Figure 8In a fifth variant of the resonator mechanism 70, the prestressing device 15 further comprises two five-level strips 32 connecting the second movable body 27 to the fixed support 31. The five-level strips 32 are substantially parallel to the four-level strips and are arranged on the same side of the second element. The prestressing device 15 also comprises a screw 29, which is arranged to contact the second movable body 27 in the longitudinal direction to apply a variable force or torque. By applying a variable force or torque on the second movable body 27, the stiffness of the resonator mechanism 70 changes.

[0070] Fig. 9 and 10 The sixth variation 80 and the seventh variation 90 of the resonator mechanism of the second embodiment are similar to Figure 7 A fourth variation of the second embodiment, except that the longitudinal screw is replaced by another means for applying force or torque.

[0071] exist Fig. 9 In the embodiment, the prestressing device 15 comprises an eccentric screw 33, the head of which is in contact with the second movable body 27. Therefore, by rotating the screw, the force or torque applied to the second movable body 27 is variable.

[0072] exist Fig.10 In a seventh variant of the resonator mechanism 90 of FIG. 1 , the prestressing device 15 comprises a rod 35 connected to the second movable body 27 by a six-stage flexible strip 36 equipped with a rigid central section 34. In the rest position of the prestressing device 15, the six-stage flexible strip 36 is substantially parallel to the three-stage flexible strip 25. The rod 35 is arranged perpendicular to the six-stage flexible strip 36. The rod 35 is further connected to the second fixed support 41 by two seven-stage strips 37, 38 arranged on both sides of the rod 35. The free end 39 of the rod 35 is U-shaped, on which it can be acted by lateral actuation in order to exert a variable force or torque on the flexible element 12.

[0073] exist Figures 11 to 15In the third embodiment of the present invention, the rigid part 47 of the flexible guide 45 is elongated and arranged perpendicularly to the axis of the flexible guide 45. The flexible element 42 comprises at least one six-level flexible strip 44, here four six-level flexible strips 44, and a third L-shaped movable body 46. The six-level flexible strips 44 are arranged parallel to the axis of the flexible guide 45 and connect the rigid part 47 of the flexible guide 45 to the inner side of the base of the L. In the rest position of the flexible element 45, the stem of the L extends parallel to the six-level flexible strips 44. The flexible element 42 further comprises a fourth movable body 48 and at least one seven-level strip 49, here four seven-level flexible strips. The fourth movable body 48 is in the shape of a wide mouth U, with its inner side facing the outer side of the stem of the L. The seven-level strip 49 connects the outer side of the stem of the L to the inner side of the base of the U and is substantially perpendicular to the six-level flexible strips 44.

[0074] The flexible element also comprises at least one secondary flexible strip 51 , 52 , here two secondary flexible strips, connecting the wide mouth end of the U to a fixed support 53 of the resonator mechanism 100 .

[0075] The prestressing device 43 is configured to exert a force or torque on U.

[0076] exist Fig.12 In the first variation of the resonator mechanism 110 of the third embodiment, the prestressing device 43 further comprises a first movable body 55 and a tertiary flexible strip 54, which is preferably assembled in series perpendicular to the symmetry axis of the flexible guide device 45 to the rigid part 47 of the flexible guide device 45 and the first movable body 55. The first movable body 55 preferably has an elongated shape and is arranged on the axis of the tertiary flexible strip 54.

[0077] The prestressing device 43 comprises a second elbow-shaped movable body 57, and a quadruple flexible strip 56 connecting the first movable body 55 and the second movable body 57. Here, in the rest position of the prestressing device 43, the four quadruple strips 56 are substantially perpendicular to the tertiary strips 54. The quadruple flexible strips 56 are preferably parallel.

[0078] The prestressing device 43 further comprises two five-level flexible strips 59 connecting the first movable body 55 to the fixed support 61. The five-level flexible strips 59 are preferably parallel. The five-level strips 59 are substantially perpendicular to the three-level flexible strips 54 and are arranged on the opposite side of the four-level flexible strips 56 with respect to the first movable body 55. The prestressing device 43 further comprises a screw 58, which is arranged to contact the second movable body 57 in the longitudinal direction to apply a variable force or torque. By applying a variable force or torque on the second movable body 57, the stiffness of the resonator mechanism 110 changes.

[0079] exist Fig.13 In the second variant of the resonator mechanism 120 of the third embodiment of the present invention, the prestressing device 43 is similar to the prestressing device in the first variant, but is offset toward the flexible guide device 45. The flexible element 42 further includes an intermediate body 64 on which the tertiary flexible strip 54 is engaged. The intermediate body 64 is in the shape of an arc of a circle and is assembled at the wide mouth end of the U-shaped fourth movable body 48. The tertiary flexible strip 54 is engaged with the inner side of the arc of a circle. Therefore, the prestressing device 43 is arranged in a plane substantially parallel to the planes of the flexible guide device 45 and the flexible element 42.

[0080] exist Fig.14 In the third variation of the resonator mechanism 130 of the third embodiment shown, the prestressing device 43 comprises a stud 65 assembled on the base of the U-shaped fourth movable body 48, a first L-shaped movable body 66 and a tertiary flexible strip 67 connecting the stud 65 to the inner base of the L. The tertiary flexible strip 67 is preferably arranged above the septenary flexible strip 49. The prestressing device 43 further comprises a second L-shaped movable body 69 and a quaternary flexible strip 68 connecting the outer side of the stem of the L of the first movable body 66 to the inner side of the stem of the L of the second movable body 69. The quaternary flexible strips 68 are preferably parallel.

[0081] The prestressing device 43 further comprises at least one five-level flexible strip 72, preferably four five-level flexible strips 72, which connect the inner side of the stem of the L of the second movable body 69 to the fixed support 73. The five-level flexible strips 72 are preferably parallel. The fixed support 73 has an arc shape, at the ends of which the secondary flexible strips 51, 52 are joined. The fixed support 73 also comprises an additional central section 74, on which the five-level strips 72 are joined.

[0082] The prestressing device 43 also comprises a screw 71 arranged in longitudinal contact with the second movable body 69 to apply a variable force or torque. By applying a variable force or torque on the second movable body 69, the stiffness of the resonator mechanism 130 varies.

[0083] The column 65, the tertiary flexible strip 67, the first movable body 66, the quadruple flexible strip 68, the second movable body 69, the fifth flexible strip 72, the screw 71 and the additional central section 74 are arranged in an upper level of the resonator mechanism 130, and the plane in which the upper level is located is basically parallel to the plane including the other parts of the mechanism 130.

[0084] Fig.15The fourth variant of the resonator mechanism 140 of the third embodiment shown is similar to the second variant, except for the intermediate body 75 having an L shape. The stem of the L is assembled on the fourth U-shaped movable body 48, while the base of the L is bent over the flexible element 42. The tertiary flexible strip 54 is connected to the free end of the base of the L on the outside. Thus, the screw 58, the first movable body 55 and the second movable body 57 as well as the quaternary strip 56 and the quinary strip 59 are arranged vertically with respect to their respective positions of the second variant of the second embodiment.

[0085] In the described embodiments, the flexible strips are preferably straight. Furthermore, flexible strips of the same type preferably have the same length. The flexible strips may be continuously flexible or have only flexible sections.

[0086] The invention also relates to a timepiece movement (not shown) comprising a rotary resonator mechanism 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140 such as described above.

[0087] Naturally, the invention is not limited to the embodiments described with reference to the drawings, and various modifications are conceivable without departing from the scope of the invention.

Claims

1. A rotary resonator mechanism (1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140) for a timepiece, comprising a flexible guide (5, 45) and an oscillating mass (2), the flexible guide (5, 45) comprising at least two main flexible strips (4, 6) and a rigid part (7, 47), the main flexible strips (4, 6) being engaged on the one hand with the rigid part (7, 47) of the flexible guide (5, 45) and on the other hand with the oscillating mass (2), characterized in that The resonator mechanism comprises an adjustment device for adjusting the stiffness of the resonator mechanism (1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140), the adjustment device comprising a flexible element (12, 42) arranged in series with the flexible guide device (5, 45), the flexible element (12, 42) being connected on the one hand to a rigid part (7, 47) of the flexible guide device (5, 45) and on the other hand to a fixed support (11, 53) so that the flexible guide device (5, 45) is suspended by the flexible element (12, 42), the flexible element (12, 42) being arranged in series with the flexible guide device (5, 45). The member (12, 42) forms a pivot to enable the rigid part (7, 47) to perform a rotational movement, the rotational movement of the rigid part (7, 47) being added to the rotational movement of the oscillating mass (2), the flexible guide device (5, 45) and the flexible element (12, 42) extending substantially in the same plane to enable the oscillating mass (2) to perform a rotational movement around a virtual pivot, the adjustment device further comprising a prestressing device (15, 43) to apply a variable force or torque to the flexible element (12, 42) or the flexible guide device (5, 45) to change the stiffness of the flexible element (12, 42).

2. The resonator mechanism according to claim 1, characterized in that The prestressing device (15, 43) only changes the stiffness of the flexible element (12, 42) but does not change the stiffness of the main flexible strip (4, 6).

3. The resonator mechanism according to claim 1 or 2, characterized in that: The flexible element (12, 42) comprises at least one secondary flexible strip (8, 9, 52, 53), each secondary flexible strip (8, 9, 52, 53) being connected to the fixed support (11, 53).

4. The resonator mechanism according to claim 3, characterized in that The prestressing means (15) comprises pins (14, 16) in contact with the secondary flexible strips (8, 9).

5. The resonator mechanism according to claim 3, characterized in that The prestressing device (15) exerts a variable force or torque on the secondary flexible strips (8, 9).

6. The resonator mechanism according to claim 3, characterized in that The prestressing device (15) exerts a variable force or torque on the rigid part (7) of the flexible guiding device (5).

7. The resonator mechanism according to claim 6, characterized in that The prestressing device (15, 43) comprises a first movable body (24, 55, 66) and at least one tertiary flexible strip (25, 54, 67) connected to the first movable body (24, 55, 66) and to the rigid part (7, 47) of the flexible guide device (5, 45) or to the flexible element (42).

8. The resonator mechanism according to claim 7, characterized in that The prestressing device (15, 43) comprises a plurality of four-level flexible strips (26, 56, 68) and a second movable body (27, 57, 69), wherein the four-level flexible strips (26, 56) connect the second movable body (27, 37, 57, 69) to the first movable body (24, 55, 66).

9. The resonator mechanism according to claim 8, characterized in that The prestressing device (15, 43) comprises at least one five-stage flexible strip (28, 32, 59, 72) connecting the second movable body (37, 69) or the first movable body (24, 55) to a fixed support (31, 61, 73).

10. The resonator mechanism according to claim 8, characterized in that The prestressing means (15, 43) comprises an eccentric screw (17) in contact with the second movable body (27) or the rigid part (7).

11. The resonator mechanism according to claim 8, characterized in that The prestressing device (15, 43) comprises a screw (29, 58, 71) which is longitudinally movable against the second movable body (27, 37, 57, 69).

12. The resonator mechanism according to claim 8, characterized in that The prestressing device (15, 43) comprises a rod (35) for moving the second movable body (27).

13. The resonator mechanism according to claim 8, characterized in that The prestressing device (15) comprises a first magnet (17) integral with the rigid part (7) or with the second movable body, and a second magnet (18) movable relative to the first magnet (17).

14. The resonator mechanism according to claim 1 or 2, characterized in that: The prestressing device (15) comprises a spring (21) connected to the rigid part (7), and a movable body (23) for stretching or compressing the spring (21).

15. The resonator mechanism according to claim 1 or 2, characterized in that: The prestressing means (15, 43) is arranged in the same plane as the flexible guiding means (5, 45) and the flexible element (12).

16. The resonator mechanism according to claim 1 or 2, characterized in that: The prestressing means (43) is arranged in a plane substantially parallel to the plane of the flexible guiding means (45) and the flexible element (12).

17. The resonator mechanism according to claim 9, characterized in that The flexible element (42) includes a third movable body (46), and a plurality of six-level flexible strips (44) connecting the third movable body (46) to the rigid portion (47).

18. The resonator mechanism according to claim 17, characterized in that The flexible member (42) includes a fourth movable body (48), and a plurality of seven-level strips (49) connecting the third movable body (46) to the fourth movable body (48).

19. The resonator mechanism according to claim 18, characterized in that The tertiary flexible strip (54, 67) is connected to the fourth movable body (48).

20. The resonator mechanism according to claim 1 or 2, characterized in that The two main flexible strips (4, 6) of the flexible guiding device (5, 45) are crossed.

21. The resonator mechanism according to claim 1 or 2, characterized in that The rigidity of the flexible element (12, 42) is greater than the rigidity of the flexible guiding device (5, 45).

22. A timepiece movement comprising a resonator mechanism (1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140) according to any one of the preceding claims.

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