CH714032A2 - Process for producing a flexible guiding mechanism for mechanical clock oscillator - Google Patents

Abstract

The invention relates to a method for producing a flexible guide for oscillator with inertial element oscillating in a plane supported by flexible blades fixed on a fixed support (4) reminding it to a rest position: this guidance is determined with blades superimposed levels, each having an aspect ratio of less than 10, the number of elementary levels is decomposed into a plurality of subunits (308), each having one or two blades joining an elementary support (48, 49) and a elementary inertial element (58, 59), which is produced by etching substrates, these subunits are assembled, by joining their elementary inertial elements, the elementary supports are fixed to the support, directly or via translation tables according to one or two degrees of freedom in plane translation, of stiffness in translation less than that of the subunit.

Description

Description

FIELD OF THE INVENTION The invention relates to a method of producing a flexible guide mechanism for a mechanical oscillator comprising at least one massive inertial element arranged to oscillate in an oscillation plane, said flexible guide comprising at least two first flexible blades extending in parallel or merged planes and each of substantially rectangular section and arranged to be fixed or embedded on a fixed support and support said massive inertial element, and arranged together to return it to a rest position.

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 timepiece 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 es 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 watch movement which includes 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 feedback system for the watch movement. 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.

Document CH 709 536 A2 in the name of ETA Manufacture Horlogère Suisse describes a clockwork regulating mechanism comprising, mounted movably, at least in pivoting relative to a plate, an escapement wheel arranged to receive a motor 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 guide means com

CH 714 032 A2, an additional element which comprises said escapement 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 (25)

Summary of the invention The invention proposes to develop a method for producing a flexible guide mechanism for a mechanical clock oscillator, so that its angular travel is compatible with mechanisms of existing exhaust, and whose flexible guides behave regularly regardless of 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. And it is to achieve such an oscillator so as to guarantee the maintenance of isochronism in the extreme positions of the flexible blades it comprises, and, for this purpose, to prevent any twisting or any anticlastic curvature of these blades. To this end, the invention relates to a method of producing a flexible guide mechanism for a mechanical clock oscillator according to claim 1. Brief description of the drawings [0014] 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; 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 the X = D / L ratio 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 embedments, 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 l 'isochronism, the curve in solid line corresponding to an advantageous value; fig. 6 shows, 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; CH 714 032 A2 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; 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 represents, schematically, and, brought back in the same plane, the upper part and the lower part of an oscillator with such a flexible guidance broken down into several subunits, in the case in point an upper stage and a lower stage , 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 in 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 and lower parts of an oscillator with flexible guidance broken down into two sub-units, 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; fig. 29 is a flow diagram representing the steps of a process for producing flexible guidance according to the invention. CH 714 032 A2 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention relates to the production of 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 solid inertial element 5, a flexible guiding mechanism 200. This flexible guiding mechanism comprises at least two first flexible blades 31, 32, which support the massive inertial element 5 and are arranged to recall 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 they, in projection on the plane of oscillation, an angle at the top 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 included 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 t 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. In particular, when projected onto the plane of oscillation, 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 non-zero distance from the point of crossing 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 31.32. More particularly, the first blades 31 and 32 are straight blades. More particularly still, the angle at the top a is less than or equal to 50 °, or else 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 , CH 714 032 A2 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 plane of oscillation, 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. Similarly and in a particular way, when the pivot 1 is symmetrical relative 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 in which 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, 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 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, 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. Similarly and particularly, 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. 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 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 CH 714 032 A2 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 particular, 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 relative 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 of 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 all cases 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 has a ratio of aspect 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 except for 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. CH 714 032 A2 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 by a plurality of secondary blades 32 extending in a second direction of blade 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. It is also noted 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 the production of a clockwork movement 1000 comprising at least one such mechanical oscillator 100. The invention also relates to the production of 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 engraving process "DRE" front face to obtain AA, in particular engraving of the two layers in one piece; vs. engraving by engraving process "DRE" rear face to obtain BB, in particular engraving 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; 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; CH 714 032 A2 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 the 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 gluing, 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 Δ 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. 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 blade lower secondary 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 difference Δ. 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. CH 714 032 A2 Preferably, the oscillator 100 comprises, for each flexible guide mechanism 200 which 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 on 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 stage, 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 have a translation table, and the other stage may have a rigid fixing. 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. 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. [0097] 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 translation table contributes to the protection of the mechanism against strong accelerations, during a fall or impact for example. 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 deliberately exaggerate the assembly defect Δ, in order to introduce anisochronism in a controlled manner, for example to compensate for a delay in the exhaust. 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 CH 714 032 A2 linked to the rigid support element 4, or to the plate 900, but which are constrained to plane movements, reverse 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 of the 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. [0104] 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. The invention thus relates to a method of producing a flexible guide mechanism 200 for a mechanical oscillator 100 comprising at least one massive inertial element 5 arranged to oscillate in an oscillation plane, this flexible guide 200 comprising at least two first flexible blades 31, 32, extending in parallel or merged planes, and each of substantially rectangular section, and arranged to be fixed or embedded on a fixed support 4 and support this inertial element 5, and arranged together to recall it towards a rest position, according to which the following steps are carried out: - (10) the geometry of the flexible guide 200 is determined, the material of the theoretical flexible blades it contains is chosen, and the number and inclination of the theoretical flexible blades it comprises is calculated; - (20) the length L between recesses, the height H and the thickness E of each theoretical flexible blade are calculated; - (30) the aspect ratio RA = O / W of each theoretical flexible blade is calculated; - (40) for each theoretical flexible blade; whose calculated aspect ratio RA is greater than or equal to 10, this theoretical flexible blade is decomposed into a plurality of elementary blades included in superimposed levels and each having an RA aspect ratio less than 10, and the number is determined elementary levels of blades to be superimposed; - (50) we resume the calculation of the characteristics of the flexible guide 200 with these elementary blades, replacing the theoretical flexible blades, by iteration, until satisfactory characteristics are obtained; - (60) the number of elementary levels is broken down into a plurality of sub-units 308, 309, each sub-unit being either a double sub-unit comprising two blades according to two superposed and distant levels according to two parallel planes, or indeed a simple sub-unit comprising a single blade; - (70) it is determined, for each subunit, an elementary support 48, 49, and an elementary inertial element 58, 59, which join the two blades in the case of a double subunit, or that joins the blade unique in the case of a simple sub-unit; - (80) is provided, at least for each said double subunit, with an SOI substrate at two levels of said material, and this substrate is etched above and below at least when the projected shape of the two blades is distinct, and for each simple sub-unit, from a SOI substrate with one or two levels, which is etched, depending on its thickness, on one side or above and below, to obtain the different sub - constituent units of the flexible guide 200; - (90) these subunits formed from etched substrates are assembled one on the other, by joining all their elementary inertial elements, and by fixing all these elementary inertial elements to the inertial element 5, either directly or by intermediate of translation tables according to one or two degrees of freedom in translation in the plane of each subunit, the stiffness in translation of each translation table being less than that of each subunit; - (100) all the elementary supports of the subunits formed of etched substrates are fixed to the fixed support (4), either directly or via translation tables according to one or two degrees of freedom in translation in the plane of each sub-unit, the translational stiffness of each translation table being less than that of each sub-unit. In a first variant, the flexible guide 200 is calculated with only theoretical coplanar, parallel and / or divergent blades. In a second variant, this flexible guide 200 is calculated with only pairs of blades crossed in projection, on at least two different and distinct levels. In a mixed variant, the flexible guide 200 is calculated with both a first group of theoretical coplanar blades, parallel and / or divergent, and a second group of pairs of blades crossed in projection, on at least two different levels and separate. More particularly, when one chooses divergent flexible blades or flexible d blades by crossed pairs in projection, their point of divergence or their crossing point, in projection on the plane of oscillation, defines the virtual pivot axis. of the inertial element 5. More particularly, in the second variant, when choosing flexible blades in crossed pairs in projection, which extend at a distance from each other in two planes parallel to the plane of oscillation of the inertial element 5, and whose projections of the directions on the plane of oscillation intersect at a virtual pivot axis O of CH 714 032 A2 the inertial element 5 and together define a first angle a which is the angle at the top, from this virtual pivot axis O, on which face extends the part of the fixed support 4 which is located between the attachments of the blades crossed on the fixed support 4, this first angle is chosen to be between 70 ° and 74 °. More particularly still, this first angle is chosen to be equal to 71.2 °. Still in this second variant, the flexible blades are advantageously dimensioned with an inner radius ri which is the distance between the virtual pivot axis O and their point of attachment to the fixed support element 4, with a radius exterior re which is the distance between the virtual pivot axis O and their point of attachment to the inertial element 5 and with a total length L with L = ri + re, such as a first ratio Q such that Q = ri / L, either between 0.12 and 0.13, or such that a second ratio Qm such that Qm = (ri + e / 2) / (ri + e / 2 + re), or between 0.12 and 0.13. More particularly, this first Q ratio or this second Qm ratio equal to 0.1264 is chosen. Advantageously, when choosing flexible blades in crossed pairs in projection, which extend at a distance from each other in two planes parallel to the plane of oscillation of the inertial element 5, and whose projections directions on the oscillation plane intersect at a virtual pivot axis O of the inertial element 5, with the recesses of the flexible blades with the fixed support 4 and the inertial element 5 defining two directions of blades DL1 , DL2, parallel to the oscillation plane, the flexible guide mechanism 200 is produced comprising, superimposed on one another: at least one 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 blade direction DL1 and an upper secondary blade 328 extending in a second blade direction DL2 crossed in projection at an upper crossing point PS, - And at least one 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 blade direction DL1 and a lower secondary blade 329 extending in a second blade direction DL2 crossed in projection at a lower crossing point PI; and this upper stage 28 and / or this lower stage 29 is produced comprising, between on the one hand the fixed support 4 and on the other hand the upper support 48, or respectively the lower support 49, and / or between on the one hand the inertial element 5 and on the other hand the upper elementary inertial element 58, or respectively the lower elementary inertial element 59, a translation table 308, 309, which comprises at least one elastic connection according to one or two axes of freedom in the plane of oscillation, and whose stiffness in translation is less than that of each flexible blade. More particularly, and as visible in FIGS. 23 and 24, the upper stage 28 and the lower stage 29 are produced, each comprising, between the fixed support 4 and the upper support 48, and respectively the lower support 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 in translation is less than that of each flexible blade. In particular, the elastic connection of the upper translation table 308, or respectively of the lower translation table 309, is produced along one or two axes of freedom in the plane of oscillation, in the form of a elastic connection along the axes X and Y of the bisectors of the angles formed between them by the projections of the flexible blades of the flexible guide mechanism 200 on the plane of oscillation. In a variant, flexible blades are chosen in crossed pairs in projection, which extend at a distance from each other in two planes parallel to the plane of oscillation of the inertial element 5, and whose projections of the directions on the oscillation plane intersect at a crossing point P near the virtual pivot axis O of the inertial element 5. The recesses of the flexible blades with the fixed support 4 and the inertial element 5 define two directions of blades DL1, DL2, parallel to the plane of oscillation. The flexible guide mechanism 200 is produced with the two blade directions DL1, DL2, parallel to the plane of oscillation and forming between them, in the rest position, in projection on the plane of oscillation, an angle at the apex a, the position of the crossing point P being 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 fixed support 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, and with the center of mass of the oscillator 100 in its position rest distant from the crossing point P by a difference t which is between 12% and 18% of the total length L, with the value of the ratio D / L between 0 and 1, with the angle at the top a less than or equal to 60 °, and with, for each first flexible blade 31, 32, the embedding ratio D1 / L1, D2 / L2, included e between 0.15 and 0.85, terminals included. In any of these process variants, it may be advantageous to produce the flexible guide 200 with a first number N1 of first blades called primary blades 31 extending in a first blade direction DL1, and a second number N2 of first blades called secondary blades 32 extending in a second direction of blade DL2, the first number N1 and the second number N2 each being greater than or equal to two. This arrangement makes it possible to limit the height of the blades, which is advantageous for their operation. More particularly, but not necessarily, the first number N1 is chosen equal to the second number N2. More particularly, the flexible guide 200 is produced with 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 with, in each pair, the primary blade 31 identical to the secondary blade 32 except for the orientation. More particularly still, the flexible guide 200 is produced comprising only such pairs each formed CH 714 032 A2 of a primary blade 31 extending in a first direction of blade DL1, and of a secondary blade 32 extending in a second direction of blade DL2, and with, in each pair, the primary blade 31 identical to the secondary blade 32 except for the orientation. In particular, the flexible guide 200 is produced with at least one group of blades formed by a primary blade 31 extending in a first blade direction DL1, and by a plurality of secondary blades 32 extending according to a second direction of blade DL2, and with, in each group of blades, the elastic behavior of the primary blade 31 identical to the elastic behavior resulting from the plurality of secondary blades 32 except for the orientation. In a particular embodiment, the flexible guide 200 is produced with a first number of first blades called primary blades 31 extending in a first blade direction DL1, and a second number N2 of first blades called secondary blades 32 s' extending in a second direction of blade DL2, with the two directions of blades DL1, DL2, parallel to the plane of oscillation and forming between them, in the rest position, in projection on this plane of oscillation, an angle at the apex a, the two directions of blades DL1, DL2, crossing, in projection on the plane of oscillation, at a crossing point P whose position is defined by the ratio X = D / L, where D is the distance between the projection, on the oscillation plane, from one of the points of embedding of the first blades 31, 32, in the fixed support 4 and the crossing point P, and where L is the total length of the projection, on the plane d oscillation, of the blade 31.32, in its th length, and with the embedding ratio D1 / L1, D2 / L2, between 0.15 and 0.49, limits included, or between 0.51 and 0.85, limits included. More particularly, the angle at the apex (a) less than or equal to 50 ° is chosen, and the embedding ratio (D1 / L1; D2 / L2) between 0.25 and 0.75, limits included. More particularly, we choose the angle at the top (a) less than or equal to 40 °, and the embedding ratio (D1 / L1; D2 / L2) between 0.30 and 0.70, limits included. More particularly, the angle at the apex (a) less than or equal to 35 ° is chosen, and said embedding ratio (D1 / L1; D2 / L2) between 0.40 and 0.60, limits included. More particularly, we choose the angle at the top (a) less than or equal to 30 °. In this same variant where the embedding ratio D1 / L1, D2 / L2, is between 0.15 and 0.49, limits included, or between 0.51 and 0.85, limits included, more particularly the angle at the apex is chosen. and the ratio X = D / L satisfying 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 Ό5-Χ) + 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 . In any of these process variants, the flexible guide 200 is produced more particularly with a total number of flexible blades strictly greater than two. More particularly, the flexible guide 200 is produced with straight and flat flexible blades at rest. More particularly still, the flexible guide 200 is produced with all of its straight and flat flexible blades at rest. In sum, the invention allows the production of flexible guides for oscillators of different geometries, with coplanar blades: vee, parallel, or other, or in offset planes, in particular crossed blades in projection, or other. The invention makes it possible to ensure the regular behavior of these blades over their entire range of use, and therefore to guarantee the isochronism of the oscillators suitably designed and comprising such blades. Naturally, if the invention is preferably applied to flexible guides having several blades, and which provide the best isochronism results, the production method is also applicable to guides comprising a single blade. claims 1. Method for producing a flexible guide mechanism (200) for a mechanical oscillator (100) comprising at least one massive inertial element (5) arranged to oscillate in an oscillation plane, said flexible guide (200) comprising at least two first flexible blades (31,32) extending in parallel or merged planes and each of substantially rectangular section and arranged to be fixed or embedded on a fixed support (4) and support said inertial element (5), and arranged together to recall it to a rest position, according to which the following steps are carried out: - (10) determining the geometry of said flexible guide (200), choosing the material of the theoretical flexible blades that it comprises, and calculating the number and the inclination of the theoretical flexible blades that it comprises; - (20) the length L between recesses, the height H and the thickness E of each said theoretical flexible blade are calculated; - (30) the aspect ratio RA = H / E of each said theoretical flexible blade is calculated; - (40) for each said theoretical flexible blade; whose calculated aspect ratio RA is greater than or equal to 10, this theoretical flexible blade is decomposed into a plurality of elementary blades included in superpo levels CH 714 032 A2 ses and each having an aspect ratio RA of less than 10, and the number of elementary levels of blades to be superimposed is determined; - (50) the calculation of the characteristics of said flexible guide (200) is resumed with said elementary blades, in substitution for said theoretical flexible blades, until satisfactory characteristics are obtained; - (60) the said number of elementary levels is broken down into a plurality of subunits (308, 309), each said subunit being either a double subunit comprising two blades according to two superimposed and distant levels along two planes parallel, or a simple sub-unit comprising a single blade; - (70) it is determined, for each sub-unit, an elementary support (48, 49) and an elementary inertial element (58, 59) which said two blades join in the case of a double sub-unit, or which joint said single blade in the case of a single sub-unit; - (80) is provided, at least for each said double subunit, with an SOI substrate at two levels of said material, and this substrate is etched above and below at least when the shape in projection of said two blades is distinct, and for each simple sub-unit, from a SOI substrate with one or two levels, which is etched, depending on its thickness, on one side or above and below, to obtain the different sub - constituent units of said flexible guide (200); - (90) assembling on each other said subunits formed of etched substrates, by joining all their said elementary inertial elements, and by fixing all these elementary inertial elements to said inertial element (5), either directly or by 'intermediate translation tables according to one or two degrees of freedom in translation in the plane of each said subunit, the stiffness in translation of each said translation table being less than that of each said subunit; - (100) all said elementary supports of said subunits formed of substrates etched to said fixed support (4) are fixed, either directly or via translation tables according to one or two degrees of freedom in translation in the plane of each said sub-unit, the stiffness in translation of each said translation table being less than that of each said sub-unit. 2. Method according to claim 1, characterized in that said flexible guide (200) is calculated with only theoretical plates which are coplanar, parallel and / or divergent. 3. Method according to claim 1, characterized in that said flexible guide (200) is calculated with only pairs of blades crossed in projection, on at least two different and distinct levels. 4. Method according to claim 1, characterized in that said flexible guide (200) is calculated with both a first group of coplanar theoretical blades, parallel and / or divergent, and a second group of pairs of blades crossed in projection, on at least two different and distinct levels. 5. Method according to one of claims 1 to 4, characterized in that, when one chooses said divergent flexible blades or said flexible blades in crossed pairs in projection, their point of divergence or their crossing point, in projection on the oscillation plane defines the virtual pivot axis of said inertial element (5). 6. Method according to one of claims 1 to 5, characterized in that, when choosing said flexible blades by crossed pairs in projection, which extend at a distance from each other in two planes parallel to the plane of oscillation of said inertial element (5), and whose projections of the directions on said plane of oscillation intersect at a virtual pivot axis (O) of said inertial element (5) and together define a first angle (a ) which is the angle at the top, from said virtual pivot axis (O), face on which extends the part of said fixed support (4) which is located between the fasteners of said crossed blades on said fixed support (4), chooses said first angle between 70 ° and 74 °. 7. Method according to claim 6, characterized in that said first angle (a) is chosen equal to 71.2 °. 8. Method according to claim 6 or 7, characterized in that said flexible blades are dimensioned with an internal radius (ri) which is the distance between said virtual pivot axis (O) and their point of attachment to said element of fixed support (4), with an external radius (re) which is the distance between said virtual pivot axis (O) and their point of attachment to said inertial element (5) and with a total length (L) with L = ri + re, such that a first ratio (Q) such that Q = ri / L, is between 0.12 and 0.13, or such that a second ratio (Qm) such that Qm = (ri + e / 2) / (ri + e / 2 + re), i.e. between 0.12 and 0.13. 9. Method according to claim 8, characterized in that one chooses said first ratio (Q) or said second ratio (Qm) equal to 0.1264. 10. Method according to one of claims 1 to 5, characterized in that, when one chooses said flexible blades by crossed pairs in projection, which extend at a distance from each other in two planes parallel to the plane of oscillation of said inertial element (5), and whose projections of the directions on said plane of oscillation intersect at a virtual pivot axis (O) of said inertial element (5), with the recesses of said flexible blades with said fixed support (4) and said inertial element (5) defining two directions of blades (DL1; DL2) parallel to said plane of oscillation, said flexible guide mechanism (200) is produced comprising, superimposed on each other , at least one 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 blade direction (DL1) and a secondary blade upper (328) CH 714 032 A2 extending in a second direction of blade (DL2) crossed in projection at an upper crossing point (PS), and at least one 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 blade direction (DL1) and a lower secondary blade (329) extending in a second blade direction (DL2) crossed in projection at a lower crossing point (PI), and in that said upper stage (28) and / or said lower stage (29) comprising, between said fixed support (4) and said upper support (48), or respectively said lower support (49), and / or between said inertial element (5) and said upper elementary inertial element (58), or respectively said lower elementary inertial element (59), a translation table (308; 309) comprising at least one elastic link e along one or two axes of freedom in the plane of oscillation, and whose stiffness in translation is less than that of each said flexible blade. 11. Method according to claim 10, characterized in that said upper stage (28) and said lower stage (29) each comprise, between said fixed support (4) 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 in translation is less than that of each said flexible blade. 12. Method according to claim 10 or 11, characterized in that one carries out 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 plane of oscillation, in the form of 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 said plane of oscillation. 13. Method according to one of claims 1 to 5, characterized in that, when one chooses said flexible blades by crossed pairs in projection, which extend at a distance from each other in two planes parallel to the plane of oscillation of said inertial element (5), and whose projections of the directions on said plane of oscillation intersect at a crossing point (P) near the virtual pivot axis (O) of said inertial element (5), with the recesses of said flexible blades with said fixed support (4) and said inertial element (5) defining two directions of blades (DL1; DL2) parallel to said plane of oscillation, said flexible guide mechanism (200 ) with said two directions of blades (DL1; DL2) parallel to said plane of oscillation and forming between them, in the rest position, in projection on 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 oscillation plane, of one of the embedding points of said first blades (31; 32) in said fixed support (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 with the center of mass of said oscillator (100) in its rest position distant from said crossing point (P) by a difference (ε) which is between 12% and 18% of said total length L, with the value of said ratio D / L included between 0 and 1, with said apex angle (a) less than or equal to 60 °, and with, for each said first flexible blade (31; 32), the embedding ratio (D1 / L1; D2 / L2) included between 0.15 and 0.85, limits included. 14. Method according to one of claims 1 to 13, characterized in that said flexible guide (200) is produced with 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 direction of blade (DL2), said first number N1 and said second number N2 each being greater than or equal to two. 15. The method of claim 14, characterized in that said first number N1 is chosen equal to said second number N2. 16. Method according to claim 14 or 15, characterized in that said flexible guide (200) is produced with at least one pair formed by a said primary blade (31) extending in a first blade direction (DL1) , and of a said secondary blade (32) extending in a second direction of blade (DL2), and with, in each pair, said primary blade (31) identical to said secondary blade (32) except for the orientation . 17. Method according to claim 16, characterized in that the said flexible guide (200) is carried out comprising only said pairs each formed of a said primary blade (31) extending in a first blade direction (DL1) , and of a said secondary blade (32) extending in a second direction of blade (DL2), and with, in each pair, said primary blade (31) identical to said secondary blade (32) except for the orientation . 18. Mechanical oscillator (100) according to claim 14, or according to claim 16 according to claim 14, characterized in that said flexible guide (200) is produced with 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 with, in each said group of blades, the elastic behavior of said primary blade (31) identical to the elastic behavior resulting from said plurality of secondary blades (32) except for the orientation. 19. Mechanical clock oscillator (100), according to one of claims 1 to 18, characterized in that said flexible guide (200) is produced with a first number of said first blades called primary blades (31) s' extending along a first blade direction (DL1), and a second number N2 of said first blades, said blades CH 714 032 A2 secondary (32) extending in a second blade direction (DL2), with said two blade directions (DL1; DL2) parallel to said plane of oscillation forming between them, in the rest position, projecting onto said oscillation plane, an angle at the apex a, said two directions of blades (DL1; DL2) intersecting, in projection on said oscillation plane, at a crossing point (P) whose position is defined by the ratio X = D / L, where D is the distance between the projection, on said oscillation plane, of one of the points of embedding of said first blades (31; 32) in said fixed support (4) and said point of crossing (P), and where L is the total length of the projection, on said oscillation plane, of said strip (31; 32) in its elongation, and with said embedding ratio (D1 / L1; D2 / L2 ) between 0.15 and 0.49, limits included, or between 0.51 and 0.85, limits included. 20. The method as claimed in claim 19, characterized in that said apex angle (a) is chosen to be less than or equal to 50 °, and said embedding ratio (D1 / L1; D2 / L2) between 0.25 and 0.75, terminals included. 21. The method as claimed in claim 20, characterized in that said apex angle (a) is less than or equal to 40 °, and said embedding ratio (D1 / L1; D2 / L2) between 0.30 and 0.70, terminals included. 22. The method as claimed in claim 21, characterized in that said apex angle (a) is less than or equal to 35 °, and said embedding ratio (D1 / L1; D2 / L2) between 0.40 and 0.60, terminals included. 23. Method according to one of claims 19 to 22, characterized in that said apex angle (a) is chosen to be less than or equal to 30 °. 24. Method according to one of claims 19 to 23, characterized in that said apex angle (a) is chosen and said ratio X = D / L satisfying the relationship: 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 . 25. Method according to one of claims 1 to 24, characterized in that said flexible guide (200) is produced with a total number of said flexible blades strictly greater than two. CH 714 032 A2 CH 714 032 A2