CH714031A2 - Clock oscillator with flexible guides with long angular travel. - Google Patents

Abstract

The invention relates to a clockwork mechanical oscillator comprising, between a support (4) and an inertial element, a guide with flexible blades crossed in projection, comprising, superimposed, an upper stage comprising, between a support (48) and a higher inertial element (58), an upper primary blade (318) in a first direction (DL1) and an upper secondary blade (328) in a second direction (DL2), and a lower stage comprising, between a support and an inertial element lower, a lower primary blade in the first direction (DL1) and a lower secondary blade in the second direction (DL2), which upper stage (28) and / or lower comprises, between the support and the upper support (48), or respectively lower a translation table with elastic connection in one or two axes of freedom in the plane of oscillation, lower stiffness than that of each flexible blade.

Description

Description

Field of the invention The invention relates to a mechanical clockwork oscillator, comprising between a rigid support element and an inertia element! massive, a flexible guide with at least two first flexible blades which support said massive inertial element and are arranged to return it to a rest position, said massive inertial element being arranged to oscillate angularly according to an oscillation plane around said position of at rest, said first two flexible blades not touching and their projections on said oscillation plane crossing, in the rest position, at a crossing point, in the immediate vicinity of which or through which passes the axis of rotation of said inertial element solid perpendicular to said plane of oscillation, and the embedding of said first flexible blades with said rigid support element and said solid inertial element defining at least two directions of blades parallel to said plane of oscillation.

The invention also relates to a timepiece movement comprising at least one such mechanical oscillator.

The invention also relates to a watch comprising such a clockwork movement.

The invention relates to the field of mechanical watch oscillators comprising guides with flexible blades ensuring the functions of retaining and recalling moving elements.

BACKGROUND OF THE INVENTION The use of flexible guides, in particular with flexible blades, in mechanical clock oscillators, is made possible by production methods, such as “MEMS”, “LIGA” or similar, of micro-machinable materials, such as silicon and its oxides, which allow a very reproducible manufacture of components which have elastic characteristics constant over time and a great insensitivity to external agents such as temperature and humidity. Pivots with flexible guidance, as described in applications EP 1 419 039 or EP 16 155 039 from the same applicant, in particular make it possible to replace the pivot of a conventional balance, as well as the balance spring which is usually associated with it. By eliminating the friction of pivots, the quality factor of an oscillator can be substantially increased. However, the pivots with flexible guidance generally have a small angular travel, of the order of 10 ° to 20 °, which is very small compared to the usual amplitude of 300 ° of a balance spring, and which does not not allow their direct combination with conventional exhaust mechanisms, and in particular with usual retainers such as a Swiss anchor or the like, which require a large angular travel to ensure their proper functioning.

During the Chronometry Congress in Montreux, Switzerland, on September 28 and 29, 2016, the team of MH Kahrobaiyan discussed the increase in this angular travel in the article “Gravity insensitive flexure pivots for watch oscillators”, and it appears that the solution -complex- envisaged is not isochronous.

Document EP 3 035 127 A1 in the name of the same applicant SWATCH GROUP RESEARCH & DEVELOPMENT Ltd describes a clock oscillator comprising a time base with at least one resonator constituted by a tuning fork which comprises at least two oscillating moving parts, said movable parts being fixed to a connecting element, which comprises said oscillator, by flexible elements whose geometry determines a virtual pivot axis of position determined relative to said connecting element, around which virtual pivot axis oscillates said respective movable part , whose center of mass coincides in the rest position with said respective virtual pivot axis. For at least one said movable part, said flexible elements consist of crossed elastic blades and extending at a distance from each other in two parallel planes, and the projections of the directions on one of said parallel planes intersect at the level of said virtual pivot axis, of said movable part considered.

Document US 3,628,781 A in the name of GRIB describes a tuning fork, in the form of a double cantilever structure, to allow an accentuated rotational movement of a pair of movable elements , with respect to a fixed reference plane comprising a first elastically deformable body having at least two elastically similar elongated flexible parts, the ends of each of said flexible parts being respectively integral with enlarged rigid parts of said element, the first of said rigid parts being fixed for defining a reference plane and the second being resiliently supported to have an accentuated rotational movement relative to the first, a second elastically deformable body substantially identical to the first elastically deformable body, and means for rigidly fixing the first of said respective rigid parts of said elastically deformable bodies in relation to pitched to provide a tuning fork structure in which each of the tuning fork teeth includes the free end of one of said elastically deformable bodies.

Document EP 3 130 966 A1 in the name of ETA Manufacture Horlogère Suisse describes a mechanical clockwork movement which comprises at least one barrel, a set of gear wheels driven at one end by the barrel, and a mechanism for exhaust of a local oscillator with a resonator in the form of a balance-spring and a clock movement feedback system. The escapement mechanism is driven at another end of the gear wheel assembly. The feedback system includes at least one precise reference oscillator, combined with a path comparator to compare the path of the two oscillators, and a resonator adjustment mechanism of the local oscillator to slow or accelerate the resonator based on a result of the comparison in the market comparator.

CH 714 031 A2 The document CH 709 536 A2 in the name of ETA Manufacture Horlogère Suisse describes a clockwork regulating mechanism comprising, mounted movable, at least in pivoting relative to a plate, an escape wheel arranged to receive a driving torque via a gear train, and a first oscillator comprising a first rigid structure connected to said plate by first elastic return means. This regulating mechanism comprises a second oscillator comprising a second rigid structure connected to said first rigid structure by second elastic return means, and which comprises guide means arranged to cooperate with complementary guide means which comprises said escape wheel, synchronizing said first oscillator and said second oscillator with said train.

Patent application EP 17 183 666 by the same applicant, incorporated here by reference, describes a pivot with a large angular stroke. By using an angle between the blades of about 25 ° to 30 °, and a crossing point located about 45% of their length, it is possible to simultaneously obtain good isochronism and insensitivity to positions over a large angular stroke (up to 40 ° or more). In order to maximize the angular travel while retaining good off-plane rigidity, we tend to refine the blades while increasing their height. The use of a large value of the aspect ratio, that is to say the ratio between the height of the blade over its thickness is theoretically advantageous, but in practice we often encounter phenomena of anti-clastic curvature , which alter the properties.

Claims (19)

Summary of the invention The invention proposes to develop a mechanical oscillator with flexible guides, the angular travel of which is compatible with existing exhaust mechanisms, and whose flexible guides behave regularly regardless of either their deformation. This flexible rotationally guided resonator must have the following properties: - a high quality factor; - a large angular stroke; - good isochronism; - great insensitivity to positions in space. Considering the particular case of a flexible guide with crossed blades in projection in a plane parallel to the oscillation plane, where these blades join a fixed mass and a mobile mass, the possible angular travel 9 of the pivot depends on the ratio X = D / L enters, on the one hand the distance D from the point of embedding of a blade in the fixed mass and the crossing point, and on the other hand the total length L of this same blade, in its elongation , between its two opposite recesses. The works cited above by the team of MH Kahrobaiyan show that this possible angular travel 9 is, for a given pair of blades and angle at the top given at the crossing point, here 90 °, maximum for X = D / L = 0.5, and decreases rapidly when we deviate from this value, according to a substantially symmetrical curve. However, such a pivot with crossed blades with X = D / L = 0.5 and and = 90 ° is not isochronous. The invention therefore explores the areas of favorable combinations between the angle values at the apex at the intersection of the blades, and the values of the ratio X = D / L, to obtain isochronous pivots, as well as the values optimal aspect ratio of each blade. To this end, the invention relates to a mechanical oscillator according to claim 1. And in particular the invention shows that one can obtain an isochronous oscillator with pivots which verify both the two inequalities: 0.15 <(X = D / L) <0.85, and at <60 °. Naturally, the configurations with a = 0 ° are discarded, the blades then no longer being intersecting in projection, but parallel. The invention also relates to a timepiece movement comprising at least one such mechanical oscillator. The invention also relates to a watch comprising such a clockwork movement. Brief description of the drawings [0021] Other characteristics and advantages of the invention will appear on reading the detailed description which follows, with reference to the accompanying drawings, where: fig. 1 shows, schematically, and in perspective, a first variant of a mechanical oscillator, which comprises a rigid support element, of elongated shape, for its attachment to a movement plate or the like, from which a massive inertial element is suspended by two first disjointed hoses, crossed in projection on the oscillation plane of this inertial element, which cooperates with a conventional exhaust mechanism with Swiss anchor and standard escape wheel; CH 714 031 A2 fig. 2 shows schematically and in plan the oscillator of fig. 1; fig. 3 shows schematically, and in section passing through the axis of intersection of the blades, the oscillator of FIG. 1; fig. 4 shows, schematically, a detail of FIG. 2, showing the offset between the crossing of the blades and the projection of the center of mass of the resonator, this detail with offset being applicable in the same way to the different variants described below; fig. 5 is a graph, with abscissa X = D / L between, on the one hand the distance D from the point of embedding of a blade in the fixed mass and the crossing point, and on the other hand the total length L of this same blade between its two opposite recesses, and on the ordinate the angle at the top of the crossing of the flexible blades, and which defines two curves, lower and upper, in broken lines, which limit the suitable range between these parameters to ensure the isochronism, the curve in solid line corresponding to an advantageous value; fig. 6 represents, similarly to FIG. 1, a second variant of a mechanical oscillator, where the rigid support element, of elongated shape, is also movable relative to a fixed structure, and is carried by a third rigid element, by means of a second set of flexible blades, arranged similarly to the first flexible blades, the inertial element being further arranged to cooperate with a conventional exhaust mechanism not shown; fig. 7 shows schematically and in plan the oscillator of fig. 6; fig. 8 shows schematically, and in section passing through the axis of intersection of the blades, the oscillator of FIG. 1; fig. 9 is a block diagram representing a watch which includes a movement with such a resonator; fig. 10 shows, schematically and in perspective, a guide with flexible blades crossed in projection, between a fixed structure and an inertial element; fig. 11 represents, similarly to FIG. 10, a theoretical flexible guide, each blade of which has an aspect ratio greater than that of the blades of FIG. 10; fig. 12 represents, similarly to FIG. 10, flexible guidance, equivalent in terms of elastic return to the theoretical guidance of FIG. 11, but comprising a greater number of blades, each of which has an aspect ratio of less than 10, in this variant two elementary blades of a first type are superimposed in a first direction, and cross in projection two elementary blades of a second type which are also superimposed between them and extend in a second direction; fig. 13 represents, similarly to FIG. 12, another flexible guide, the four blades of which are staggered; fig. 14 represents, similarly to FIG. 12, yet another flexible guide, the four blades of which comprise two elementary blades of a first type in a first direction, which frame two elementary blades of a second type which are superimposed between them and extend in a second direction; fig. 15 represents, similarly to FIG. 12, another flexible guide, comprising six blades superimposed by three; fig. 16 represents, similarly to FIG. 13, another flexible guide, the six blades of which are staggered; fig. 17 represents, similarly to FIG. 14, another flexible guide, the eight blades of which comprise a first and a second superposition of two elementary blades of a first type in a first direction, which surround four elementary blades of a second type which are superimposed between themselves and extend in a second direction; fig. 18 represents, similarly to FIG. 12, yet another flexible guide, with an unequal number of blades, the five blades of which comprise two elementary blades of a first type in a first direction, which frame three elementary blades of a second type which are superimposed between themselves and extend in a second direction; CH 714 031 A2 fig. 19 is identical to FIG. 13, and fig. 20 shows the breakdown of this flexible guide with four alternating blades into two subunits of pivots with two blades; fig. 21 is identical to FIG. 14, and fig. 22 shows the breakdown of this flexible guide with four blades framed into two sub-units of pivots with two blades; fig. 23 shows, schematically, and, brought back in the same plane, the upper part and the lower part of an oscillator with such a flexible guide broken down into several subunits, in the case in point an upper stage and a stage lower, with translation tables interposed between the fixed support and the support of the blades towards the inertial element, these translation tables comprising flexible elastic guides along the directions X and Y of the bisectors at the directions in projection of the blades; fig. 24 is similar to FIG. 23, and includes an X position adjustment on a lower rigid part, so as to modify the difference between the projections of the crossings of the upper and lower blades; fig. 25 to 27 illustrate other variants of translation tables; fig. 28 shows, schematically, and in side view, the upper part and the lower part of an oscillator with a flexible guide broken down into two subunits, in this case an upper stage and a lower stage, with a translation table interposed between the fixed support and the upper support of the upper blades towards the inertial element. Detailed description of the preferred embodiments The invention relates to a mechanical clock oscillator 100, comprising at least one rigid support element 4 fixed directly or indirectly on a plate 900, and a massive inertial element 5. This oscillator 100 comprises, between the rigid support element 4 and the massive inertial element 5, a flexible guide mechanism 200. This flexible guide mechanism comprises at least two first flexible blades 31, 32, which support the massive inertial element 5 and are arranged to return it to a rest position. This massive inertial element 5 is arranged to oscillate angularly according to a plane of oscillation around this rest position. The first two flexible blades 31 and 32 do not touch, and, in the rest position, their projections on the plane of oscillation intersect at a crossing point P, in the immediate vicinity of which or through which the axis of rotation of the massive inertial element 5 perpendicular to the plane of oscillation. All the geometric elements described below are understood, unless otherwise stated, to be considered in the rest position of the oscillator when stopped. Figs. 1 to 4 illustrate a first variant with a rigid support element 4 and a massive inertial element connected by two first flexible blades 31,32. The recesses of the first flexible blades 31, 32, with the rigid support element 4 and the solid inertial element 5 define at least two directions of blades DL1, DL2, which are parallel to the plane of oscillation and which form between them, in projection on the plane of oscillation, an angle at the apex a. The position of the crossing point P is defined by the ratio X = D / L where D is the distance between the projection, on the plane of oscillation, of one of the points of embedding of the first blades 31, 32, in the first rigid support element 4 and the crossing point P, and where L is the total length of the projection, on the plane of oscillation, of the blade 31, 32, concerned. And the value of the D / L ratio is between 0 and 1, and the angle at the top a is less than or equal to 70 °. Advantageously, both the apex angle a is less than or equal to 60 °, and, for each first flexible strip 31.32, the embedding ratio D1 / L1, D2 / L2, is understood between 0.15 and 0.85, limits included. In particular, as shown in Figs. 2 to 4, the center of mass of the oscillator 100 in its rest position is distant from the crossing point P by a difference ε which is between 10% and 20% of the total length L of the projection, on the plane of oscillation of the blade 31, 32. More particularly still, the distance is between 12% and 18% of the total length L of the projection, on the plane of oscillation, of the blade 31.32. More particularly, and as illustrated in the figures, the first blades 31, 32, and their recesses together define a pivot 1 which, in projection on the plane of oscillation, is symmetrical with respect to an axis of symmetry AA passing through the crossing point P. More particularly, when the pivot 1 is symmetrical with respect to the axis of symmetry AA, in the rest position, in projection on the plane of oscillation, the center of mass of the massive inertial element 5 is located on the axis of symmetry AA of pivot 1. In projection, this center of mass may or may not coincide with the crossing point P. More particularly still, the center of mass of the massive inertial element 5 is located at a non-zero distance from the crossing point P corresponding to the axis of rotation of the massive inertial element 5, as visible on the fig. 2 to 4. CH 714 031 A2 In particular, when projected onto the oscillation plane, the center of mass of the massive inertial element 5 is located on the axis of symmetry AA of the pivot 1, and is located at a distance not null of the crossing point P which is between 0.1 times and 0.2 times the total length L of the projection, on the plane of oscillation, of the strip 31,32. More particularly, the first blades 31 and 32 are straight blades. More particularly still, the apex angle a is less than or equal to 50 °, or is less than or equal to 40 °, or even less than or equal to 35 °, or even less than or equal to 30 °. More particularly, the embedding ratio D1 / L1, D2 / L2, is between 0.15 and 0.49, terminals included, or between 0.51 and 0.85, terminals included, as shown in fig. 5. In a variant, and more particularly according to the execution according to FIG. 5, the angle at the top a is less than or equal to 50 °, and the embedding ratio D1 / L1, D2 / L2, is between 0.25 and 0.75, limits included. In a variant, and more particularly according to the execution according to FIG. 5, the apex angle a is less than or equal to 40 °, and the embedding ratio D1 / L1, D2 / L2, is between 0.30 and 0.70, limits included. In a variant, and more particularly according to the execution according to FIG. 5, the angle at the top a is less than or equal to 35 °, and the embedding ratio D1 / L1, D2 / L2, is between 0.40 and 0.60, limits included. Advantageously, and as visible in FIG. 5, the angle at the top a and the ratio X = D / L satisfy the relation: h1 (D / L) <a <h2 (D / L), with, for 0.2 <X <0.5: h1 (X) = 116-473 * (X + 0.05) + 3962 * (X + 0.05) ³ -6000 * (X + 0.05) ⁴ , h2 (X) = 128-473 * (X-0.05) + 3962 * (X-0.05) ³ -6000 * (X - 0.05) ⁴ , for 0.5 <X <0.8: h1 (X) = 116-473 * (1.05-X) + 3962 * (1.05-X) ³ -6000 * (1.05-X) ⁴ , h2 (X) = 128-473 * (0.95-X) + 3962 * (0.95-X) ³ -6000 * (0.95-X) ⁴ . More particularly, and in particular in the non-limiting embodiment illustrated by the figures, the first flexible blades 31 and 32 have the same length L, and the same distance D. More particularly, between their recesses, these first flexible blades 31 and 32 are identical. Figs. 6 to 8 illustrate a second variant of mechanical oscillator 100, where the rigid support element 4 is also movable, directly or indirectly relative to a fixed structure that this oscillator 100 comprises, and is carried by a third rigid element 6, by by means of two second flexible blades 33, 34, arranged similarly to the first flexible blades 31, 32. More particularly, in the non-limiting embodiment illustrated by the figures, the projections of the first flexible blades 31, 32, and of the second flexible blades 33, 34, on the plane of oscillation intersect at the same crossing point P. In another particular embodiment not shown, in the rest position, in projection on the oscillation plane, the projections of the first flexible blades 31, 32, and of the second flexible blades 33, 34, on the plane of oscillation intersect at two distinct points, both located on the axis of symmetry AA of pivot 1, when pivot 1 is symmetrical with respect to the axis of symmetry AA. More particularly, the recesses of the second flexible blades 33, 34, with the rigid support element 4 and the third rigid element 6, define two directions of blades parallel to the plane of oscillation and forming between them, in projection on the oscillation plane, an angle at the top of the same bisector as the angle at the top has that the first flexible blades 31,32. More particularly still, these two directions of the second flexible blades 33, 34 have the same angle at the top a as the first flexible blades 31, 32. More particularly, the second flexible blades 33, 34 are identical to the first flexible blades 31, 32, as in the nonlimiting example of the figures. More particularly, when the pivot 1 is symmetrical with respect to the axis of symmetry AA, in the rest position, in projection on the plane of oscillation, the center of mass of the massive inertial element 5 is located on the axis of symmetry AA of pivot 1. In a similar and particular way, when the pivot 1 is symmetrical with respect to the axis of symmetry AA, in the rest position, the center of mass of the rigid support element 4 is located, in projection on the plane d 'oscillation, on the axis of symmetry AA of pivot 1. In a particular variant, when the pivot 1 is symmetrical with respect to the axis of symmetry AA, in the rest position, in projection on the plane of oscillation, both the center of mass of the massive inertial element 5 and the center of mass of the rigid support element 4 are located on the axis of symmetry AA of the pivot 1. More particularly still, the projections of the center of mass of the massive inertial element 5 and of the center of mass of the support element rigid 4, on the axis of symmetry AA of pivot 1, are combined. A particular configuration illustrated by the figures for such superimposed pivots is that where the projections of the first flexible blades 31, 32, and of the second flexible blades 33, 34, on the plane of oscillation intersect at the same CH 714 031 A2 crossing point P, which also corresponds to the projection of the center of mass of the massive inertial element 5, or at least which is as close as possible to it. More particularly, this same point also corresponds to the projection of the center of mass of the rigid support element 4. More particularly still, this same point also corresponds to the projection of the center of mass of the entire oscillator 100. In a particular variant of this configuration of superimposed pivots, when the pivot 1 is symmetrical relative to the axis of symmetry AA, in the rest position, in projection on the plane of oscillation, the center of mass of the massive inertial element 5 is located on the axis of symmetry AA of pivot 1, and at a non-zero distance from the crossing point corresponding to the axis of rotation of the massive inertial element 5, which non-zero distance is between 0.1 times and 0.2 times the total length L of the projection, on the plane of oscillation, of the blade 33, 34, with a difference similar to the difference ε in fig. 2 to 4. In a similar and particular way, when the pivot 1 is symmetrical with respect to the axis of symmetry AA, the center of mass of the massive inertial element 5 is located, in projection on the plane of oscillation, on the axis of symmetry AA of the pivot 1 and at a non-zero distance from the crossing point corresponding to the axis of rotation of the rigid support element 4 which non-zero distance is between 0.1 times and 0.2 times the total length L of the projection, on the plane of oscillation, of the blade 31.32. Similarly and in a particular way, when the pivot 1 is symmetrical with respect to the axis of symmetry AA, the center of mass of the rigid support element 4 is located, in projection on the plane of oscillation, on the axis of symmetry AA of pivot 1 and at a non-zero distance from the crossing point P corresponding to the axis of rotation of the massive inertial element 5. In particular, this non-zero distance is between 0.1 times and 0.2 times the total length L of the projection, on the plane of oscillation, of the blade 33, 34. Similarly and in a particular way, when the pivot 1 is symmetrical with respect to the axis of symmetry AA, the center of mass of the rigid support element 4 is located, in projection on the plane of oscillation, on the axis of symmetry AA of the pivot 1 and at a non-zero distance from the crossing point corresponding to the axis of rotation of the rigid support element 4 which non-zero distance is between 0.1 times and 0.2 times the total length L of the projection, on the plane of oscillation, of the blade 31.32. Similarly and particularly, the center of mass of the rigid support element 4 is located on the axis of symmetry AA of the pivot 1 and at the non-zero distance from the crossing point P which is between 0.1 times and 0.2 times the total length L of the projection, on the plane of oscillation, of the blade 33, 34. More particularly, and as visible in the variant of the figures, when the pivot 1 is symmetrical with respect to the axis of symmetry AA, in projection on the plane of oscillation, the center of mass of the oscillator 100 in its rest position is located on the axis of symmetry AA. More particularly, the massive inertial element 5 is elongated in the direction of the axis of symmetry AA of the pivot 1, when the pivot 1 is symmetrical with respect to the axis of symmetry AA. This is for example the case of figs. 1 to 4 where the inertial element 5 comprises a base on which is fixed a traditional pendulum with long arms provided with sections of serge or weights in an arc of a circle. The objective is to minimize the influence of external angular accelerations around the axis of symmetry of the pivot, because the blades have a low rigidity in rotation around this axis because of the small angle a. The invention lends itself well to a monolithic execution of the blades and the massive components which they join, made of micro-machinable material or at least partially amorphous, with an implementation by “MEMS” or “LIGA” process or similar. In particular, in the case of an execution in silicon, the oscillator 100 is advantageously thermally compensated by adding silicon dioxide on flexible silicon wafers. In a variant, the blades can be assembled, for example embedded in grooves, or the like. When there are two pivots in series, as in the case of FIG. 6 to 9, the center of mass can be placed on the axis of rotation, in the case where the arrangement is chosen so that the parasitic displacements compensate each other, which constitutes an advantageous but non-limiting variant. It should be noted, however, that it is not necessary to choose such an arrangement, and such an oscillator operates with two pivots in series without positioning the center of mass on the axis of rotation. Of course, even if the illustrated embodiments correspond to particular geometrical configurations of alignment, or of symmetry, it is understood that it is also possible to stack two different pivots, or with different crossing points, or with centers of non-aligned masses, or to implement a greater number of sets of blades in series, with intermediate masses, to further increase the amplitude of the balance. The illustrated variants include all the pivot axes, blade crossings, and centers of mass, coplanar, which is a special advantageous but not limiting case. We understand that it is thus possible to obtain an angular travel which is large: in any case greater than 30 °, it can even reach 50 ° or even 60 °, which makes it compatible in combination with all usual mechanical exhausts, Swiss anchor, detent, co-axial, or other. It is also a question of determining a practical solution which is equivalent to the theoretical use of a large value of the aspect ratio of the blades. For this purpose, it is advantageous to subdivide the blades lengthwise, by replacing a single blade with a plurality of elementary blades whose overall behavior is equivalent, and where each of the elementary blades CH 714 031 A2 has an aspect ratio limited to a threshold value. We thus reduce, compared to a single reference blade, the aspect ratio of each elementary blade, to find the optimum of isochronism and insensitivity to positions. Each blade 31.32, has an aspect ratio RA = O / W, where H is the height of the blade 31.32, perpendicular both to the plane of oscillation and to the elongation of the blade 31.32, along the length L, and where E is the thickness of the blade 31, 32, in the plane of oscillation and perpendicular to the elongation of the blade 31.32, along the length L. Preferably, the aspect ratio RA = O / W is less than 10 for each blade 31.32. More particularly, this aspect ratio is less than 8. And the total number of flexible blades 31, 32 is strictly greater than two. More particularly, the oscillator 100 comprises a first number N1 of first blades called primary blades 31 extending in a first direction of blade DL1, and a second number N2 of first secondary blades 32 extending in a second direction DL2 blade, the first number N1 and the second number N2 each being greater than or equal to two. More particularly, the first number N1 is equal to the second number N2. More particularly still, the oscillator 100 comprises at least one pair formed by a primary blade 31 extending in a first direction of blade DL1, and a secondary blade 32 extending in a second direction of blade DL2. And, in each pair, the primary blade 31 is identical to the secondary blade 32 in the orientation. In a particular variant, the oscillator 100 has only pairs each formed by a primary blade 31 extending in a first direction of blade DL1, and a secondary blade 32 extending in a second direction DL2 blade, and in each pair, the primary blade 31 is identical to the secondary blade 32 to the orientation. In another variant, the oscillator 100 comprises at least one group of blades formed by a primary blade 31 extending in a first blade direction DL1, and a plurality of secondary blades 32 extending according to a second blade direction DL2. And, in this case, in each group of blades, the elastic behavior of the primary blade 31 is identical to the elastic behavior resulting from the accumulation of the plurality of secondary blades 32 except for the orientation. We also note that, if the behavior of a flexible blade depends on its aspect ratio RA, it also depends on the value of the curvature which is printed on it. Its deformation depends on both the value of the aspect ratio and the local value of the radius of curvature, in particular at embedding. This is the reason why, preferably, a symmetrical arrangement of the blades is adopted in planar projection. The invention also relates to a clockwork movement 1000 comprising at least one such mechanical oscillator 100. The invention also relates to a watch 2000 comprising at least one such clockwork movement 1000. A suitable manufacturing process consists in carrying out the following operations for the different types of pivots below: For a type of AABB pivot: at. use a substrate with at least four layers, resulting for example but not limited to the assembly of two SOI wafers; b. engraving by “DRIE” engraving process on the front face to obtain AA, in particular engraving the two layers in one piece; vs. engraving by engraving process "DRIE" back face to obtain BB, with in particular engraving of the two layers in one piece; d. Partially separate the four layers by etching the buried oxide. The high precision of the “DRIE” process, that is to say deep reactive ion etching (in English Deep Reactive Ion Etching DRIE) guarantees very good positioning and alignment precision, less than or equal to 5 micrometers, thanks to an optical alignment, which guarantees a very good alignment face to face. Of course, equivalent methods can be used depending on the material chosen. It is possible to use substrates with a higher number of layers, in particular a substrate with six available layers, for example by assembling two DSOIs, to obtain a structure of the AAABBB type. A variant for obtaining the same type of AABB pivot consists in: at. use two standard two-layer SOI substrates; CH 714 031 A2 b. etching by “DRIE” etching process the first substrate, on the front face to obtain A, on the rear face to obtain A; vs. etching by “DRIE” etching process the second substrate, on the front face to obtain B, on the rear face to obtain B; as an alternative to operations b and c, it is possible, on the first substrate and on the second substrate, to carry out etching in addition to the two layers at once, without effecting etching on the front and rear sides; d. perform the "wafer to wafer" assembly of the two substrates or "piece by piece" of the individual components, to obtain AABB. The correct alignment of the geometries is then linked to the specification of the "wafer to wafer" bonding machine or to the "piece to piece" process, in a manner well known to the skilled person. For a type of ABAB pivot: at. use two standard two-layer SOI substrates; b. etching by “DRIE” etching process the first substrate, on the front face to obtain A, on the rear face to obtain B; vs. engraving by “DRIE” etching process the second substrate, on the front face to obtain A, on the rear face to obtain B; d. perform the "wafer to wafer" assembly of the two substrates or "piece by piece" of the individual components, to obtain ABAB. As before, The correct alignment of the geometries is linked to the specification of the "wafer to wafer" bonding machine or to the "piece to piece" process. Many other process variants can be implemented, depending on the number of blades and the equipment available. The standard methods of manufacture by DRIE etching of silicon do not yet allow the easy production of a monolithic pivot having more than two distinct levels. It is therefore easier to make separate parts which are then assembled. However, sensitivity to assembly errors requires greater precision than a micrometer, in order to obtain optimal isochronism and / or position insensitivity properties. In order to solve this problem, it is necessary to adopt a manufacturing strategy which is described below. In a first step, it is a question of assembling with great precision two blades having different directions. The invention proposes to divide the flexible guide, or pivot, into subunits composed of pivots with two blades, for example an upper subunit and a lower subunit, in the case of a flexible guide comprising four blades , as seen in fig. 19, with four alternating blades, which we break down into two sub-units of pivots with two blades. Figs. 21 and 22 illustrate a similar decomposition in the case of framed blades rather than alternating blades. Each sub-unit is manufactured by two-level DRIE etching (SOI wafer attacked from above and from below) in order to guarantee sufficient alignment precision. The upper subunit is then assembled to the lower subunit. This assembly can be carried out by any traditional method: alignment pinning and screwing, or bonding, or "wafer fusion bonding", or welding, or soldering, or any other method known to those skilled in the art. The assembly defect is manifested by a small offset A of the axes of rotation of the upper and lower subunits. So the rotational movement of the resonator dictated by the upper subunit is not in agreement with the rotational movement dictated by the lower subunit. To prevent this offset from producing an over-stress, the mechanism includes at least one translation table, the free movement of which makes it possible to absorb the discrepancy between the two rotations of distinct axes. At least one of the translation tables must be flexible enough so that the movement mismatch does not degrade the isochronism. In the case where two identical translation tables are introduced, as shown in fig. 23, they must be flexible enough so that the discord of movement does not degrade the isochronism, and rigid enough so that the position of the pivot is well determined. The calculations show that these conditions are not contradictory if the offset between the axes of rotation is less than 10 micrometers, which is achievable by traditional assembly. Naturally, the precision of such an assembly can be improved with complementary engravings, of the tenon-mortise type, or with a plurality of tenon-mortise assemblies forming between them a non-zero angle, or any other arrangement known in precision mechanics. More particularly, as visible in the figures, the flexible guide mechanism 200 comprises, superimposed one on the other, at least one upper stage 28 and at least one lower stage 29. The upper subunit comprises an upper stage 28, which comprises, between an upper support 48 and an upper inertial element 58, at least one upper primary blade 318 extending in a first direction of upper blade DL1S and a blade upper secondary 328 extending in a second upper blade direction DL2S, crossed in projection at an upper crossing point PS. CH 714 031 A2 The lower subunit comprises a lower stage 29, which comprises, between a lower support 49 and a lower inertial element 59, at least one lower primary blade 319 extending in a first direction of lower blade DL11 and a lower secondary blade 329 extending in a second direction of lower blade DL2I crossed in projection at a lower crossing point PI, distant at rest from the upper crossing point PS by a distance A. And at least the upper stage 28 or the lower stage 29 comprises, between the plate 900 and the upper support 48, or respectively the lower support 49, an upper translation table 308, or respectively a lower translation table 309, which comprises at least one elastic connection which allows translation along one or two axes of freedom in the plane of oscillation, and whose stiffness in translation along these two axes is less than that of each flexible blade 31, 32, 333 , 34, 318, 319, 328, 329, which includes the flexible guide mechanism 200. Note that this elastic connection does not allow rotations with an axis parallel to that of the resonator. Note that it is not necessary for the upper directions DL1S and DL2S of the upper stage 28 to be identical to the lower directions DL1I and DL2I of the lower stage 29. Preferably, they have the same bisectors. More particularly, the point P through which passes the axis of rotation of the inertial element 5 is located between the upper crossing point PS and the lower crossing point PI, exactly in the middle if the flexible guide mechanism 200 comprises two upper 308 and lower 309 translation tables which are identical. In a variant, this point P is located exactly on the lower crossing point PI if the lower stage 29 does not have a translation table, or on the upper crossing point PS if the upper stage 28 does not have a table of translation. Preferably, the oscillator 100 comprises, for each flexible guide mechanism 200 that it comprises, a massive inertial element 5 is unique. More particularly, the flexible guide mechanism 200 is unique, and the massive inertial element 5 is unique. Naturally, the preferred configuration of the translation tables 308 and 309 illustrated by the figures is not limiting. These translation tables 308 and 309 can also be located between the inertial element 5 and the recesses on the inertial element side. If we define by X and Y the axes of the bisectors of the angles which the projections of the flexible blades make between them on a common parallel plane, the combination of the tables in translation, along the X axis and along the axis Y, must be more flexible than the flexible pivot along the same axes. This rule is valid whatever the number of stages, the cumulation due to the combination of all the tables, in translation, along the X axis and along the Y axis, must be more flexible than the flexible pivot. The elastic connection of the upper translation table 308, or respectively of the lower translation table 309, along one or two axes of freedom in the plane of oscillation, is thus preferably an elastic connection along these axes X and Y. The additional storage of elastic energy in the translation table (s), which results from the movement variance, is added to the main energy storage of the pivot, and tends to disturb the isochronism, unless the value of additional storage is much less than that of primary storage. This is why the elastic connections in the travel tables must be much more flexible than those of the flexible pivot. More particularly, the upper stage 28 and the lower stage 29 each comprise, between the plate 900 and the upper support 48, and respectively the lower support 49, an upper translation table 308, or respectively a translation table lower 309, comprising at least one elastic connection along one or two axes of freedom in the plane of oscillation, and the stiffness of which is less than that of each flexible blade. When there is a translation table per floor, they are not necessarily identical to each other. A variant consists in using two different translation tables, the first being flexible so that the movement variance does not degrade the isochronism, and the second being rigid in order to ensure the positioning of the pivot. In another variant, a stage may include a translation table, and the other stage may have a rigid attachment. The upper inertial element 58 and the lower inertial element 59 constitute all or part of the massive inertial element 5, and are rigidly connected, directly or indirectly, with one another. The upper support 48 and the lower support 49 are linked, as the case may be, directly or through an upper translation table 308, or respectively a lower translation table 309, to an upper rigid part 480, respectively a lower rigid part 490, which they are rigidly linked to the rigid support element 4, or to the plate 900. [0102] Figs. 23 and 24 show an example of such a connection. An upper translation table 308 comprises, between the upper support 48 and an upper intermediate mass 68, first flexible elastic connections 78 extending in the direction X, and, between the upper intermediate mass 68 and the upper rigid part 480, second flexible elastic connections 88 extending in the direction Y. In the same way a lower translation table 309 comprises, between the lower support 49 and a lower intermediate mass 69, first flexible elastic connections 79 extending in the direction X , and, between the lower intermediate mass 69 and the lower rigid part 490, second flexible elastic connections 89 extending in the direction Y. Thus, the movement of the translation table, or advantageously of the translation tables, makes it possible to absorb the possible discrepancy between the rotations of the upper subunit and of the lower subunit. In addition, each table CH 714 031 A2 of translation helps protect the mechanism against strong acceleration, for example when falling or percussion. It is understood that the assembly as described above in the context of the first approach makes it possible to make the added anisochronism negligible, provided that the assembly defect Δ is sufficiently small. Conversely, one can decide to voluntarily exaggerate the assembly defect Δ, in order to introduce anisochronism in a controlled manner, for example to compensate for an exhaust delay. It is then advantageous to make mobile, and adjustable, at least one of the recesses in the plate, that is to say the upper support 48 and / or the lower support 49 in the case of the particular non-limiting variant illustrated. . In fact, by adjusting the relative position of these two recesses, the rigidity of the translation tables 308, 309 is modified, which has the effect of allowing the adjustment of the added anisochronism. Such an adjustment can be easily carried out with the combination of a groove and an eccentric, or by any other solution known to the watchmaker. In sum, by moving the position of at least one of the recesses on the plate, as visible in FIG. 24, it is possible to adjust the anisochronism produced by the assembly defect Δ. This particular arrangement with at least one translation table makes it possible, in short, to guarantee alignment between the upper and lower stages, and to avoid the great stresses which the blades would undergo if the upper and lower stages did not follow the same trajectory. Yet another alternative consists in equipping the mechanism with an upper translation table 308 and a lower translation table 309, with an upper support 48 and a lower support 49 which are no longer rigidly connected to the support element. rigid 4, or to the plate 900, but which are constrained to planar, reverse movements in X and in Y, by a crankshaft type connection or the like, relative to a fixed axis of the rigid support element 4, or plate 900. This solution has the advantage of making it possible to adjust the anisochronism without slightly moving the axis of rotation of the resonator. It is understood that the translation tables, which constitute flexible guides in translation, can be produced in many different ways. Those skilled in the art will find examples in the following references: [1] S.Henein, Design of flexible guides. PPUR, [2] Larry L. Howell, Handbook of compliant mechanisms, WILEY), or [3] Zeyi Wu and Qingsong Xu, Actuators 2018. Such non-limiting examples are illustrated in figs. 25 to 27. [0110] FIG. 28 illustrates a simplified example with a translation table with collar connection: the upper support 48 is linked to an intermediate element 488 suspended by a first elastic collar 880 from a second intermediate element 889 from a second collar 890 which performs the elastic connection with the lower rigid part 490, rigidly linked to the plate 900. In this example the upper inertial element 58 and the lower inertial element 59 are linked to another intermediate element 589 to constitute with it the massive inertial element 5. claims 1. Mechanical clock oscillator (100), comprising, between a rigid support element (4) fixed directly or indirectly on a plate (900), and a massive inertial element (5), a flexible guide mechanism (200) comprising at least two first flexible blades (31; 32) which support said massive inertial element (5) and are arranged to return it to a rest position, said massive inertial element (5) being arranged to oscillate angularly according to a plane of oscillation around said rest position, said two first flexible blades (31; 32) not touching and their projections on said oscillation plane intersecting, in rest position, at a crossing point (P), in the vicinity of which passes the axis of rotation of said solid inertial element (5) perpendicular to said plane of oscillation, characterized in that said flexible guide mechanism (200) comprises, superposed one on the other, at least one stage upper (28) which comprises, between an upper support (48) and said massive inertial element (5) at least one upper primary blade (318) extending in a first upper blade direction (DL1S) and an upper secondary blade ( 328) extending in a second upper blade direction (DL2S) crossed in projection at an upper crossing point (PS), and at least one lower stage (29) which comprises, between a lower support (49) and said element massive inertial (5) at least one lower primary blade (319) extending in a first lower blade direction (DL11) and a lower secondary blade (329) extending in a second lower blade direction (DL2I) crossed in projection at a lower crossing point (PI), and in that at least said upper stage (28) or said lower stage (29) comprises, between said plate (900) and said upper support (48), or respectively said supp lower ort (49), or between said massive inertial element (5) and the recesses of said flexible blades (31; 32) on the side of said massive inertial element (5), a translation table (308; 309) comprising at least one elastic connection along one or two axes of freedom in the plane of oscillation, and whose stiffness in translation is less than that of the pivot of the upper stage and also that of the pivot of the lower stage. 2. Mechanical oscillator (100) according to claim 1, characterized in that said upper stage (28) and said lower stage (29) each comprise, between said plate (900) and said upper support (48), and respectively said support lower (49), a translation table (308; 309) comprising at least one elastic connection along one or two axes of freedom in the plane of oscillation, and whose stiffness is less than that of the pivot of the upper stage and also to that of the pivot of the lower floor. CH 714 031 A2 3. Mechanical oscillator (100) according to claim 1 or 2, characterized in that said elastic connection of said upper translation table (308), or respectively of said lower translation table (309), along one or two axes of freedom in said oscillation plane, is an elastic connection along the axes X and Y of the bisectors of the angles which the projections of the flexible blades of said flexible guide mechanism (200) make between them on a common parallel plane. 4. Mechanical oscillator (100) according to one of claims 1 to 3, characterized in that said two blade directions (DL1; DL2) parallel to said plane of oscillation and forming between them, in the rest position, projected onto said plane of oscillation, an angle at the apex a, the position of said crossing point (P) being defined by the ratio X = D / L where D is the distance between the projection, on said plane of oscillation, of the one of the points of embedding of said first blades (31; 32) in said first rigid support element (4) and said crossing point (P), and where L is the total length of the projection, on said plane of oscillation , of said blade (31; 32), and in that the center of mass of said oscillator (100) in its rest position is distant from said crossing point (P) by a gap (ε) which gap (ε) is between 12% and 18% of said total length L of the projection, on said oscillation plane, of said blade (31 ; 32), in that the value of said D / L ratio is between 0 and 1, in that said apex angle (a) is less than or equal to 60 °, and in that, for each said first flexible blade (31; 32), the installation ratio (D1 / L1; D2 / L2) is between 0.15 and 0.85, limits included. 5. Mechanical oscillator (100) according to one of claims 1 to 3, characterized in that each said blade (31; 32) has an aspect ratio RA = O / W, where H is the height of said blade ( 31; 32) perpendicular both to the plane of oscillation and to the elongation of said blade (31; 32) along said length L, and where E is the thickness of said blade (31; 32) in the plane d oscillation and perpendicular to the elongation of said blade (31; 32) along said length L, and in that said aspect ratio RA = O / W is less than 10 for each said blade (31; 32), and in that the total number of said flexible blades (31; 32) is strictly greater than two. 6. Mechanical oscillator (100) according to claim 5, characterized in that said oscillator (100) comprises a first number N1 of said first blades called primary blades (31) extending in a first blade direction (DL1), and a second number N2 of said first blades said secondary blades (32) extending in a second blade direction (DL2), said first number N1 and said second number N2 each being greater than or equal to two. 7. Mechanical oscillator (100) according to claim 6, characterized in that said first number N1 is equal to said second number N2. 8. Mechanical oscillator (100) according to claim 6 or 7, characterized in that said oscillator comprises at least one pair formed by a said primary blade (31) extending in a first blade direction (DU), and d 'a said secondary blade (32) extending in a second blade direction (DL2), and in that, in each pair, said primary blade (31) is identical to said secondary blade (32) except for the orientation . 9. Mechanical oscillator (100) according to claim 8, characterized in that said oscillator comprises only said pairs each formed by a said primary blade (31) extending in a first blade direction (DL1), and d 'a said secondary blade (32) extending in a second blade direction (DL2), and in that, in each pair, said primary blade (31) is identical to said secondary blade (32) except for the orientation . 10. Mechanical oscillator (100) according to claim 6 or 8 according to 6, characterized in that said oscillator comprises at least one group of blades formed of a said primary blade (31) extending in a first blade direction (DL1 ), and of a plurality of said secondary blades (32) extending in a second blade direction (DL2), and in that, in each said group of blades, the elastic behavior of said primary blade (31) is identical to the elastic behavior resulting from said plurality of secondary blades (32) except for the orientation. 11. Mechanical clock oscillator (100), according to one of claims 1 to 10, characterized in that said two blade directions (DL1; DL2) parallel to said oscillation plane form between them, in the rest position, in projection on said oscillation plane, an angle at the apex a, the position of said crossing point (P) being defined by the ratio X = D / L, where D is the distance between the projection, on said oscillation plane , from one of the points of embedding of said first blades (31; 32) in said first rigid support element (4) and said crossing point (P), and L is the total length of the projection, on said plane of oscillation, of said blade (31; 32) in its elongation, and in that said embedding ratio (D1 / L1; D2 / L2) is between 0.15 and 0.49, limits included, or between 0.51 and 0.85, terminals included. 12. Mechanical oscillator (100) according to claim 11, characterized in that said apex angle (a) is less than or equal to 50 °, and characterized in that said embedding ratio (D1 / L1; D2 / L2) is between 0.25 and 0.75, limits included. 13. Mechanical oscillator (100) according to claim 12, characterized in that said apex angle (a) is less than or equal to 40 °, in that said embedding ratio (D1 / L1; D2 / L2) is understood between 0.30 and 0.70, limits included. 14. Mechanical oscillator (100) according to claim 13, characterized in that said apex angle (a) is less than or equal to 35 °, in that said embedding ratio (D1 / L1; D2 / L2) is understood between 0.40 and 0.60, limits included. CH 714 031 A2 15. Mechanical oscillator (100) according to one of claims 11 to 14, characterized in that said apex angle (a) is less than or equal to 30 °. 16. Mechanical oscillator (100) according to one of claims 11 to 15, characterized in that said apex angle (a) and said ratio X = D / L satisfy the relation: h1 (D / L) <a <h2 (D / L), with, for 0.2 <X <0.5: h1 (X) = 116-473 * (X + 0.05) + 3962 * (X + 0.05) ³ -6000 * (X + 0.05) ⁴ , h2 ( X) = 128-473 * (X-0.05) + 3962 * (X-0.05) ³ -6000 * (X-0.05) ⁴ , for 0.5 <X <0.8: h1 (X) = 116-473 * (1.05- X) + 3962 * (1.05 - X) ³ -6000 * (1 Ό5-Χ) ⁴ , h2 (X) = 128-473 * (0.95-X) + 3962 * (0.95-X) ³ -6000 * (0.95 -X) ⁴ . 17. Mechanical oscillator (100) according to one of claims 1 to 16, characterized in that said flexible blades are straight blades 18. Clock movement (1000) comprising at least one mechanical oscillator (100) according to one of claims 1 to 17. 19. Watch (2000) comprising at least one clockwork movement (1000) according to claim 18. CH 714 031 A2 CH 714 031 A2