Escapement mechanism with bistable leaf spring

Abstract

The present invention relates to an escapement mechanism comprising a bistable elastic blade working in buckling around a median inflection point between two fixed points, a winding rocker (10) of said bistable elastic blade, and first and second winding mobiles (40a, 40b) arranged to sequentially apply a driving torque to the winding rocker (10) so as to rotate said winding rocker (10) in one direction or the other, and a release rocker fixed to the bistable elastic blade at its inflection point and arranged to cooperate with an oscillating regulator of the clock movement at each alternation of the latter so as to transmit to it an impulse following a disarming of the blade.The said first and second winding wheels (40a, 40b) comprise a first, respectively a second, escape pinion (42a, 42b) and a first, respectively a second, winding wheel (38a, 38b), the said escape pinions (42a, 42b) being intended to mesh with a wheel (4) of the finishing gear of the watch movement to pivot simultaneously in the same direction in order to subject the said winding wheels (40a, 40b) to equal torques, the said first and second winding wheels (38a, 38b) being intended to cooperate with a corresponding winding pallet (36a, 36b) of the winding lever (10).The first and second winding wheels (38a, 38b) are configured so that the ends of their teeth have different radii chosen such that the winding angle traversed by the second winding wheel (38b) in contact with the right winding pallet (36b) during a winding of the winding rocker (10) in the counterclockwise direction is equal or substantially equal to the winding angle (αag) traversed by the first winding wheel (38a) in contact with the left winding pallet (36a) during a winding of the winding rocker (10) in the clockwise direction, so that the work of the torque supplied by the winding wheels (38a, 38b) to the winding rocker (10) is equal or substantially equal in both winding directions.

Description

Technical field

[0001] The present invention relates to the field of mechanical watchmaking. It relates, more particularly, to a bistable spring escapement mechanism formed of a blade working in buckling around a central point of inflection in cooperation with a winding lever and a detent lever to provide mechanical impulses from a driving source to an oscillating regulator of a watch movement.

[0002] The present invention also relates to a watch movement comprising such an escapement mechanism, as well as a timepiece comprising such an escapement mechanism or such a movement. State of the art

[0003] In the field of watchmaking, an escapement mechanism arranged to transmit mechanical energy pulses from a driving source to an oscillating regulator of a watch movement by means of a bistable leaf spring working in buckling around an inflection point is well known. One can cite here as an example the Applicant's patent EP 2105806.

[0004] Such an escapement mechanism makes it possible, in particular, to maintain the oscillations of the balance wheel constantly throughout the power reserve, regardless of the energy source.

[0005] Various improvements have been made to this escapement mechanism to improve its efficiency and operational reliability, such as those described in documents CH 710925, WO 2018 / 015146 or EP 3623875 also in the name of the Applicant.

[0006] In the developed escapement mechanisms, the winding of the bistable leaf spring results from the transmission of the mechanical driving torque from the motive source of the watch movement to the winding lever. This torque transmission is carried out by meshing the escape wheel teeth, or the winding wheels, with pallets or lugs provided on the winding lever.

[0007] Still with the aim of improving the efficiency of such a bistable leaf spring escapement, application WO 2018 / 002773 proposed an escapement mechanism comprising a bistable leaf spring and a single escape wheel for driving a winding lever during the winding phases, the escape wheel comprising a winding member arranged to cooperate with winding elements of the winding lever in the manner of a gear to pivot the winding lever alternately in opposite directions. Such a mechanism makes it possible to reduce the overall size of the mechanism by using a single escape wheel. In addition, the cooperation between the teeth of the winding member in the form of a star and the winding elements generates little or no friction.

[0008] However, the configuration of this escapement mechanism is such that the lever arms between the point of application of the winding force of a tooth of the winding member and the center of rotation of the winding lever during the clockwise winding phases (rotation of the winding lever in the clockwise direction) and counterclockwise winding phases (rotation of the winding lever in the counterclockwise direction) of the winding lever are different. Consequently, the driving torques applied by the escapement wheel and pinion to the winding lever in one direction and the other are different. As a result, the escapement wheel and pinion produces different thrusts on the winding lever depending on the direction of rotation of the winding lever. However, the bistable elastic blade used in the escapement mechanisms developed by the Applicant requires torques that are equal in standard and in opposite directions to be able to be wound in one direction and the other.

[0009] One of the latest improvements described in patent EP 3599514 consisted of adding a monostable elastic member to the mechanism described in application WO 2018 / 002773. Said monostable elastic member is sized to compensate for the variation in the driving torque of the winding lever by the escape wheels depending on the direction of rotation of the winding lever. This added elastic member makes it possible to compensate for the unequal thrust of the two escape wheels by storing energy during the strong thrust and by restoring energy during the weak thrust. However, the added elastic member requires having a monostable blade embedded on the one hand in a part secured to the plate while collaborating on the other hand with the winding lever. This requires providing additional connecting members. The number of parts to be used is therefore increased.

[0010] The present invention aims to overcome these drawbacks by proposing an escapement mechanism arranged to transmit mechanical impulses from a driving source to an oscillating regulator of a watch movement by means of a leaf spring working in buckling around an inflection point in which the thrust on the winding lever is equal or substantially equal in standard during winding in one direction and in the other, in order to dispense with the monostable spring and its connecting members with the adjoining parts. Disclosure of the invention

[0011] To this end, the invention relates to an escapement mechanism of a watch movement, comprising: a bistable elastic blade working in buckling around a median inflection point between two embedding points of said bistable elastic blade, a winding lever of said bistable elastic blade, movable in rotation and kinematically linked in a direction substantially perpendicular to said bistable elastic blade at two points equidistant from its pivot axis, said winding lever comprising two winding pallets, a winding wheel set, respectively two winding wheels, arranged to be subjected to a torque, respectively to torques equal in standard in the same direction or in opposite directions, provided by a wheel set of the finishing train of the watch movement, and to sequentially apply to the winding lever a driving torque so as to pivot said winding lever in one direction or the other alternately to make said bistable elastic blade pass from a stable rest state to a metastable winding state,said winding wheel(s) respectively comprising a winding wheel, the winding wheel(s) and the winding pallets being arranged so that when one of the winding pallets is in contact with the winding wheel(s), the other of the winding pallets is not in contact with the winding wheel(s), a detent lever secured to the bistable elastic blade at its median inflection point and arranged to cooperate with an oscillating regulating member of the watch movement at each alternation thereof so as to transmit an impulse to it following a disarming of the bistable elastic blade corresponding to the transition from a winding state to a rest state symmetrical to the previous stable rest state, , escapement mechanism in which the winding angle traveled by the or one of the winding wheels in contact with one of the winding pallets of the winding lever when winding said winding lever in one direction is equal or substantially equal to the winding angle traveled by the or the other winding wheel in contact with the other winding pallet of the winding lever when winding said winding lever in the other direction, so that the work of the torque supplied by the or one of the winding wheels to the winding lever when winding in one direction is equal or substantially equal to the work of the torque supplied by the or the other winding wheel to the winding lever when winding in the other direction.

[0012] Thus, the thrust of the winding wheel(s) on the winding lever is equal or substantially equal as a standard when winding the lever clockwise and when winding the lever counterclockwise, without the need to add additional components.

[0013] The present invention also relates to a watch movement comprising an escapement mechanism as defined above.

[0014] The present invention also relates to a timepiece comprising an escapement mechanism or a watch movement as defined above. Brief description of the drawings

[0015] Other characteristics and advantages of the present invention will appear on reading the following detailed description of several embodiments of the invention, given as non-limiting examples, and made with reference to the appended drawings in which: there figure 1is an isometric view of an escapement mechanism of the invention, the bistable elastic blade not yet being buckled, according to a first embodiment of the invention; figure 2 is an isometric view of the unflapped elastic blade, its frame and the trigger lever; figure 3 is an isometric view of the winding lever used in the escapement mechanism of the invention; the Figures 4 and 5 are isometric views of the winding wheels used in the escapement mechanism of the invention; the figure 6 is a schematic view of the winding wheels and the winding lever according to the first embodiment of the invention; figure 7 is a detail view of the first winding wheel of the first embodiment; the figure 8 is a detail view of the second winding wheel of the first embodiment; the figures 9a, 10a , 11a and 12arepresent the safety and security features arranged in different positions of the escapement mechanism according to the first embodiment of the invention and the figures 9b, 10b, 10c , 11b, 12b, 12c are detailed views of the Figures 9a to 12a respectively; the Figure 13a is a schematic view of the winding wheels and the winding lever according to a second embodiment of the invention, and the Figure 13b is a detail view of the Figure 13a ; THE Figures 14a to 14d represent the safety and security features arranged in different positions of the escapement mechanism according to the second embodiment of the invention; Figure 15a is a schematic view of a winding mechanism and the winding lever according to a third embodiment of the invention, and the Figure 15b is a detail view of the Figure 15a ; THE Figures 16a to 16drepresent the safety and security features arranged in different positions of the escapement mechanism according to the third embodiment of the invention; the Figure 17a is a schematic view of the winding wheels and the winding lever according to a fourth embodiment of the invention, and the Figure 17b is a detail view of the Figure 17a ; THE Figures 18a to 18d represent the safety and security features arranged in different positions of the escapement mechanism according to the second embodiment of the invention; and the figures 19 to 31 represent different positions of the escapement mechanism of the invention according to the first embodiment during normal operation. Embodiments of the invention

[0016] In this application, it is conventionally defined that the term "right" means any element that is furthest to the right in the drawings when looking at the figures and that the term "left" means any element that is furthest to the left in the drawings when looking at the figures. Clockwise and counterclockwise are the directions of rotation as seen when looking at the figures.

[0017] In reference to the figure 1, there is shown an escapement mechanism 1 according to the invention in a first embodiment. This mechanism, in a known manner described for example in patent EP 2105806, makes it possible to maintain the oscillations of an oscillating regulating organ 2, composed for example of a balance 2a associated with a balance spring 2b, by delivering to it energy received from a driving source, such as a barrel for example (not shown), via a mobile 4 terminal of the finishing train, mobile in rotation around an axis H, by means of a bistable elastic blade 6 working in buckling around a median or central inflection point I, and whose embedding points A and B are integral with a frame 8 for fixing on a watch movement frame. The blade 6 is formed of an initially straight elastic blade, for example a silicon blade. It is buckled during assembly so that it occupies a stable rest state corresponding to first mode buckling.

[0018] The blade 6 cooperates with a winding lever 10, a detent lever 12 and a locking lever 14 in order to accumulate the energy from the driving source during winding phases, to then remain in an armed state during locking phases and to restore the accumulated energy to said oscillating regulating member 2 during impulse phases preceded by unlocking phases, during normal operation of the watch movement.

[0019] With particular reference to the figure 2, the detent lever 12 is rigidly connected to the blade 6 substantially at its central inflection point I and thus pivots around this inflection point I. The detent lever 12 is arranged to cooperate with an oscillating regulating member 2 of the watch movement at each alternation of the latter so as to transmit to it an impulse following a disarming of the bistable elastic blade 6 corresponding to the passage from a wound state to a rest state symmetrical to the previous stable rest state. For this purpose, the detent lever comprises, at one end, a detent fork 16 intended to cooperate with a double-plate 20, 21 of the balance 2a, and more particularly with a plate pin 22 driven onto the large plate 20 of the double plate. A pin 18 is also provided intended to prevent any overturning as in a free lever escapement.Thus, during normal operation of the watch movement, the detent lever 12 only starts moving around the inflection point I under the action of the plate pin 22 engaged in its detent fork 16 during the alternations of the balance 2a.

[0020] The movements of the trigger lever 12 are limited by stops in the form of pins 8a, 8b, for example, advantageously integrated in monolithic form into the frame 8.

[0021] The trigger lever 12 comprises, at the end opposite its trigger fork 16, an unlocking pin 24 secured to said trigger lever, said unlocking pin 24 cooperating with a connecting fork 26 of the locking lever 14 which will be described in detail below.

[0022] The arming lever 10 is rotatable and kinematically linked in a direction substantially perpendicular to the blade 6 at two points equidistant from the pivot axis 1' of the arming lever 10 which passes through the median or central inflection point I.

[0023] With particular reference to the figure 3, the arming lever 10 comprises a central portion 28 and two arming arms 30, 32 respectively comprising a first portion 30a, 32a and a second portion 30b, 32b. The first portions 30a, 32a extend symmetrically from the central portion 28 relative to a median or longitudinal axis of the central portion 28 passing through the. Their ends secured to the second portion 30b, 32b are kinematically connected to the blade 6, in particular in the example shown by arming tenons 34a, 34b inserted with sufficient play in eyelets 6a, 6b of the blade 6 and constituting the two equidistant points from the pivot axis the. The arming lever 10 being movable in rotation around the pivot axis l' passing through the inflection point I, said arming lever 10 and the trigger lever 12 therefore pivot around the same axis perpendicular to the plane of the figure 1passing through the inflection point I. However, the trigger lever 12 pivots coaxially with the arming lever 10 but independently.

[0024] The second portions 30b, 32b of the winding arms 30, 32 have at their free end a winding pallet 36a (left), 36b (right) respectively, intended to cooperate respectively with a first winding wheel 38a (left) of the first winding wheel set 40a (left) and a second winding wheel 38b (right) of the second winding wheel set 40b (right).

[0025] Said first and second winding mobiles 40a, 40b are arranged to sequentially apply to the winding lever 10 a driving torque so as to pivot said winding lever 10 in a clockwise direction, respectively a driving torque so as to pivot said winding lever 10 in a counterclockwise direction, alternately so that the winding lever 10 applies to the blade 6 a winding torque capable of making the bistable elastic blade 6 pass from a stable rest state to a metastable winding state.

[0026] With particular reference to Figures 4 and 5, the two left and right winding wheels 40a, 40b each comprise an escapement pinion 42a, 42b distinct from one another, each escapement pinion 42a, 42b being coaxial and integral with the winding wheel 38a, 38b respectively and being intended to mesh with the wheel 4 of the finishing gear train to pivot simultaneously in a synchronized manner in the same direction around distinct rotation axes G and R (cf. Figure 6 ) respectively in this first embodiment of the invention. Thus, the mobile 4 provides the escapement pinions 42a, 42b with a torque M equal in norm and direction (cf. figure 6 ).

[0027] Each winding wheel 40a, 40b also comprises an inertia wheel 44a, 44b coaxial and integral with the winding wheel 38a, 38b and the escapement pinion 42a, 42b.

[0028] The second portions 30b, 32b of the arming arms 30, 32 are not symmetrical and are configured so that the left arming pallet 36a is directed towards the central portion 28 of the arming lever 10 while being the furthest from the axis of rotation l' of the arming lever 10 which passes through the inflection point I. The right arming pallet 36b is directed away from the arming lever 10 while being the closest to the axis of rotation l' of the arming lever 10.

[0029] The first and second winding wheels 40a, 40b and the winding pallets 36a, 36b are arranged such that when one of the winding pallets 36a, 36b is in contact with one of the winding wheels 38a, 38b, the other winding pallet 36a, 36b is not in contact with the other winding wheel 38a, 38b. In addition, safety and security features are provided as will be described below.

[0030] Thus, when the left winding wheel 38a of the left winding wheel set 40a drives the left winding pallet 36a of the left winding arm 30 to pivot the winding lever 10 in one direction (here clockwise) to wind the leaf spring 6, the right winding wheel set 40b is not in contact with the right winding pallet 36b of the right winding arm 32. Conversely, when the right winding wheel 38b of the right winding wheel set 40b drives the right winding pallet 36b of the right winding arm 32b to pivot the winding lever 10 in the other direction (here counterclockwise) to wind the leaf spring 6, the left winding wheel set 40a is not in contact with the left winding pallet 36a of the left winding arm 30.

[0031] The central portion 28 of the arming lever 10 comprises at its end opposite its center of rotation I, or tail, two resting beaks 46a, 46b, or projections, symmetrical to each other with respect to a median axis of said central portion 28, and intended to cooperate with the locking lever 14 as described below.

[0032] The mechanism 1 further comprises a locking lever 14 for the winding lever 10. This locking lever 14 is intended to operate the locking of the winding lever 10 in the winding positions of the blade 6 in which, following a counterclockwise rotation of the winding lever 10 or following a clockwise rotation of the winding lever 10, said blade 6 is armed in a metastable state as close as possible to its unstable state. The locking lever 14 is integral with an axis 48 pivotally mounted on the frame of the watch movement and is arranged in kinematic connection with the detent lever 12. It comprises at a first end, the connecting fork 26 to said detent lever 12 via the unlocking pin 24.

[0033] At its second end opposite the connecting fork 26, the locking lever 14 also comprises two locking arms 56a, 56b extending symmetrically from each other relative to the longitudinal axis of the locking lever 14.

[0034] The two locking arms 56a, 56b are each provided with a locking member arranged to cooperate with a respective complementary locking member of the arming lever 10 in order to block said arming lever 10 during the locking phase during which the blade 6 remains in a metastable arming state.

[0035] The locking member may be constituted by a locking pallet arranged to cooperate with a corresponding locking beak provided on the winding lever as described in patent EP 3 599 514. The locking member may also be constituted by a resting beak 58a, 58b respectively of the locking lever 14, and the complementary locking member of the winding lever 10 is constituted by the resting beak 46a, 46b respectively described above. Such a locking lever is described in application EP No. 23201571 filed by the applicant.

[0036] In accordance with the invention, and with reference to the figures 6 to 12c , the winding angle αad traveled by the right winding wheel 38b in contact with the right winding pallet 36b of the winding lever 10 (for example the angle αad traveled by the end of a tooth of the right winding wheel 38b shown on the Figure 11a) when winding said winding lever 10 in a counterclockwise direction, is equal or substantially equal to the winding angle αag traveled by the left winding wheel 38a in contact with the left winding pallet 36a of the winding lever 10 (for example the angle αag traveled by the end of a tooth of the left winding wheel 38a shown in the Figure 12a ) when winding said winding lever 10 in the clockwise direction, so that the work M*αad of the torque supplied by the right winding wheel 38b to the winding lever 10 when winding in the counterclockwise direction is equal or substantially equal to the work M*αag of the torque supplied by the left winding wheel 38a to the winding lever 10 when winding in the clockwise direction, the first and second winding mobiles 40a, 40b being subjected to the same torque M.

[0037] Thus, the thrust of each winding wheel 40a, 40b on the winding lever 10 is equal or substantially equal so that the winding lever 10 receives equal or substantially equal energy during the two windings in one direction and in the other.

[0038] In the first embodiment shown, the constraint of equality or substantial equality of the winding angles αag, αad at the winding wheels 38a, 38b results in a first radius Ra of the tooth tips (taken at the ends of the teeth) of the first winding wheel 38a (left) which is different, here greater than the second radius Ra' of the tooth tips (taken at the ends of the teeth) of the second winding wheel 38b (right).

[0039] Advantageously, the teeth of the left and right winding wheels 38a, 38b have a radial plane and each winding pallet 36a, 36b of the winding lever 10 comprises at its end a winding beak intended to be in contact with the radial plane of a tooth of the corresponding winding wheel 36a, 36b during winding of the winding lever 10. Such a configuration promotes thrust in the middle of winding, which is particularly advantageous since the blade 6 requires the most energy in the middle of winding.

[0040] The first and second winding mobiles 40a, 40b and the winding lever are configured so that when one of the winding pallets 36a, 36b is in contact with one of the winding wheels 38a, 38b during a locking phase, said winding pallet 38a, 38b is engaged on the tooth of said winding wheel 38a, 38b by a safety distance necessary to ensure proper operation, the other winding pallet 36a, 36b not being in contact with the other winding wheel 38a, 38b and so that when a tooth of one of the winding wheels 38a, 38b falls onto one of the winding pallets 36a, 36b following an unlocking phase, said tooth of the winding wheel 38a, 38b is engaged on said winding pallet 36a, 36b at a necessary safety distance to ensure proper operation, the reverse of the tooth of the other winding wheel 38a, 38b near the other winding pallet 36a, 36b being at a necessary safety distance from the other winding pallet 36a, 36b.

[0041] More particularly with reference to the Figures 9a and 9b , the winding lever 10 is in the locking position by the left pallet 36a, locking position in which said winding lever 10, at the end of its clockwise winding rotation, is held in the locked position by the locking lever 14, the right resting beak 46b of the winding lever 10 cooperating with the right resting beak 58b of the locking lever 14, then locking the blade 6 in a metastable state as well as the left winding wheel 38a. For this purpose, as illustrated in detail in Figure 9b , in said locking position by the left pallet 36a, the left winding pallet 36a of the second portion 30b of the winding arm 30 is engaged by a reasonable safety distance d in the tooth of the left winding wheel 38a.

[0042] The locking position by the left pallet 36a is followed by an unlocking phase of the left winding wheel 38a initiated by the release of the winding lever 10 from the locking lever 14. The tooth of the left winding wheel 38a can then push the winding pallet 36a to the end of the drive.

[0043] At the end of the driving of the tooth of the left winding wheel 38a on the left winding pallet 36a, when said tooth escapes from said pallet 36a, the tooth of the second winding wheel 38b falls onto the right winding pallet 36b of the second portion 32b of the winding arm 32. The mechanism is found in the position illustrated by the Figures 10a, 10b and 10c The tooth of the second winding wheel 38b must then be engaged at a reasonable safety distance d on the right winding pallet 36b of the winding arm 32 (cf. Figure 10c) and the reverse of the tooth of the left winding wheel 38a near the left winding pallet 36a of the winding arm 30 must be at a reasonable safety distance D from said winding pallet 36a (cf. Figure 10b ).

[0044] The fall of the tooth of the second winding wheel 38b onto the right winding pallet 36b of the winding arm 32 is followed by a winding phase by the right pallet 36b during which the tooth of the second winding wheel 38b arms the winding lever 10 in the counterclockwise direction by pivoting by an angle αad into a locking position by the right pallet 36b illustrated by the Figures 11a, 11bin which said winding lever 10, at the end of its counterclockwise winding rotation, is held in the locked position by the locking lever 14, the left resting beak 46a of the winding lever 10 cooperating with the left resting beak 58a of the locking lever 14, then locking the blade 6 in a metastable state as well as the second winding wheel 38b by its right winding pallet 36b. For this purpose, the right winding pallet 36b is engaged by a reasonable safety distance d on the tooth of the second winding wheel 38b, as shown in the Figure 11b .

[0045] The locking phase by the right winding pallet 36b is followed by the unlocking phase of the right winding wheel 38b, i.e. the driving of the tooth of the right winding wheel 38b onto the right winding pallet 36b and the dropping of the tooth of the left winding wheel 38a onto the left winding pallet 36a of the winding lever 10, this phase ending in the position illustrated by the Figures 12a, 12b and 12c . In the end-of-fall position, the tooth of the left winding wheel 38a must be engaged by a reasonable safety distance d on the left winding pallet 36a as shown in the Figure 12b , and the reverse of the tooth of the right winding wheel 38b near the right winding pallet 36b of the winding lever 10 must be at a reasonable safety distance D from said right winding pallet 36b, as shown in the Figure 12c The left winding wheel 38a is about to pivot through an angle αag to wind the winding lever 10 clockwise.

[0046] Advantageously, the securities d and the securities D represented on the Figures 9a to 12c are equal or substantially equal. In the embodiment described here, the safeties d and safeties D may advantageously be 3 to 6 hundredths of a millimeter.

[0047] In reference to the Figures 13a, 13b a second embodiment of the invention is shown which corresponds to an alternative embodiment of the first embodiment and in which the escapement pinions 42a, 42b of the first and second winding wheels 40a, 40b are merged into a single escapement pinion 42', and the first and second winding wheels 38a', 38b' are fixed superimposed on the same axis. An inertia wheel (not shown) similar to the inertia wheels 44a, 44b is also provided. As for the first embodiment, the radius Ra of the first winding wheel 38a' is greater than the radius Ra' of the second winding wheel 38b'.

[0048] The arming lever 10' comprises a central portion 28' and two arming arms 30', 32' kinematically linked to the bistable elastic blade 6. Said arming wheels 38a', 38b' collaborate with arming pallets 36a', 36b' respectively provided at different heights on an arming ring 31 provided at the end of the central portion 28', said arming ring 31 defining an oblong opening into which the first and second arming wheels 38a', 38b' extend.The first and second winding wheels 38a', 38b' are configured in the same way as the first and second winding wheels 38a, 38b of the first embodiment described above, the first winding wheel 38a' having a radius Ra different from the radius Ra' of the second winding wheel 38b' so that the winding angle αad, traveled by the second winding wheel 38b' in contact with the winding pallet 36b' during winding of said winding lever 10' in the counterclockwise direction, is equal or substantially equal to the winding angle αag traveled by the first winding wheel 38a' in contact with the winding pallet 36a' during winding of said winding lever 10' in the clockwise direction, making it possible to provide equal, or substantially equal, thrusts to the lever 10' of arming in both directions of arming.

[0049] As in the first embodiment, the teeth of the first and second winding wheels 38a', 38b' advantageously have a radial plane and each winding pallet 36a', 36b' of the winding lever 10' comprises at its end a winding beak intended to be in contact with the radial plane of a tooth of the corresponding winding wheel 36a', 36b' during winding of the winding lever 10'. Such a configuration promotes thrust in the middle of winding.

[0050] This second embodiment differs from the first embodiment only in the arrangement and geometry of its functional parts. The second embodiment exactly reproduces the operation of the first embodiment.

[0051] In reference to the Figure 14a, the winding lever 10' is blocked in the locking position by the locking lever 14. By means of its winding pallet 36a', it in turn blocks the first winding wheel 38a'. The winding pallet 36a' is engaged by a respectable distance d on the tooth of the first winding wheel 38a'.

[0052] In reference to the Figure 14b, following its release from the locking lever 14, the mechanism has just completed the unlocking of the first winding wheel 38a', allowing the tooth of said first winding wheel 38a' to escape from the winding pallet 36a'. Just after the tooth has been released by the winding pallet 36a', a tooth of the second winding wheel 38b' falls onto the winding pallet 36b', engaging therein by a respectable distance d. The fall allows a respectable distance D to be left between the reverse of the tooth of the first winding wheel 38a' and the winding pallet 36a'. In the position illustrated, the second winding wheel 38b' begins winding the lever 10' in the counterclockwise direction.

[0053] In reference to the Figure 14c, the second winding wheel 38b' has finished winding the winding lever 10' by pivoting by a winding angle αad, and the system is in the locking position, the winding lever 10' being blocked by the locking lever 14, and the second winding wheel 38b' being blocked by the winding pallet 36b' of the winding lever 10'. The winding pallet 36b' is engaged by a reasonable distance d on the tooth of the second winding wheel 38b'.

[0054] And finally, in reference to the Figure 14d, following the release of the winding lever 10' by the locking lever 14, the second winding wheel 38b' has just completed its disengagement from the winding pallet 36b' of the winding lever 10', leaving the tooth of the first winding wheel 38a' to fall onto the winding pallet 36a' with a respectable engagement d, as well as the tooth of the second winding wheel 38b' at a respectable distance D from the winding pallet 36b'. The first winding wheel 38a' is preparing to wind the winding lever 10' clockwise by pivoting by a winding angle αag.

[0055] For winding angles αad and αag at the winding wheels 38a', 38b' that are equal or substantially equal, knowing that said winding wheels 38a', 38b' are subjected to the same torque M, then said torque provides substantially equal work during the two windings in one direction and in the other, so that the winding lever 10' receives equal or substantially equal energy during the two windings in one direction and in the other.

[0056] In reference to the Figures 15a to 16d , a third embodiment of the invention is shown in which a single winding wheel set 49 is provided, comprising an escape pinion 51 intended to mesh with the wheel set 4 of the finishing gear train of the watch movement, a winding wheel 50, and an inertia wheel (not shown). The winding wheel 50 is intended to cooperate with winding pallets of the winding lever 52, namely a pallet called the output pallet 64a, visible on the left in the Figures 16a to 16d, and a palette called input palette 64b, visible on the right on the Figures 16a to 16d . In this embodiment, the winding wheel 50 and the winding lever 52 operate as a Clément recoil lever escapement, the terms "entry" and "exit" referring to the terminology in force for anchor escapements, in particular the Clément recoil lever escapement, the entry pallet designating the pallet through which the teeth of the winding wheel 50 enter the inner zone delimited by the two pallets, and the exit pallet designating the pallet through which the teeth of the winding wheel 50 exit said zone. The winding wheel set 49 is subjected to the torque M.

[0057] In this embodiment, the winding lever 52 comprises a drive arm 60 extending towards the winding wheel 50 and carrying two circular arm portions 62a, 62b having at their free end one of the winding pallets 64a, 64b respectively. Said arm portions 62a, 62b are symmetrical with respect to the longitudinal axis of the drive arm 60. The winding pallets 64a, 64b are non-symmetrical and non-concentric with respect to the longitudinal axis of the drive arm 60 and each comprise a winding zone intended to be in contact with a tooth of the winding wheel 50 during winding of the winding lever 52.In this embodiment, said winding zones of the winding pallets 64a, 64b are configured such that the winding angle αad traveled by the winding wheel 50 in contact with the winding zone of the input winding pallet 64b during the winding of the winding lever 52 in the clockwise direction, is equal or substantially equal to the winding angle αag traveled by the winding wheel 50 in contact with the winding zone of the output winding pallet 64a during the winding of the winding lever 52 in the counterclockwise direction, such that the work of the torque supplied by the winding wheel 50 to the winding lever 52 during winding in one direction is equal or substantially equal to the work of the torque supplied by said winding wheel 50 to the winding lever 52 during of an armament in the other direction.

[0058] In this embodiment, the winding lever 52 comprises a central portion 54 carrying two winding arms 56, 58 kinematically linked to the bistable elastic blade 6 and the drive arm 60 projecting from the central portion 54 in the direction of the winding wheel 50.

[0059] Advantageously, the arming area of ​​each arming pallet 64a, 64b has the shape of a curve.

[0060] Preferably, the winding zone of each winding pallet 64a, 64b has an S-shaped curve. Such an S-shape advantageously makes it possible to obtain a thrust from the winding wheel 50 on the winding lever 52 which is stronger in the middle of winding than at the beginning and end of winding.

[0061] THE Figures 16a to 16d illustrate the operation of this third embodiment. The illustrated positions represent, in order, the same characteristic positions of winding wheel and winding lever as those illustrated for example in Figures 14a to 14d for the second embodiment with coaxial winding wheels.

[0062] According to the Figure 16a , the system is locked, a tooth of the winding wheel 50 being engaged by the distance d on the input winding pallet 64b.

[0063] According to the Figure 16b , the system has just completed unlocking and enters the winding phase in the counterclockwise direction, the tooth of the winding wheel 50 pushing on the inclined winding zone of the output winding pallet 64a. The fall preceding the illustrated position makes it possible to provide a comfortable distance D between the tooth of the winding wheel 50 and the input winding pallet 64b.

[0064] According to the Figure 16c , the system is locked, the tooth of the winding wheel 50 being engaged on the output pallet 64a by a comfortable distance d. The winding wheel 50 has just completed the winding of the winding lever 52 by traveling through the winding angle αag.

[0065] According to the figure 16d , the system completes the unlocking by the output pallet 64a and the fall onto the input pallet 64b, the fall of the tooth of the winding wheel 50 onto the input pallet 64b leaving a comfortable distance D between the tooth of the winding wheel 50 and the output pallet 64a. The winding wheel 50 is preparing to arm the winding lever 52 traveling through the winding angle αad.

[0066] For equal or substantially equal winding angles αad and αag at the winding wheel 50, the torque M provides equal or substantially equal work during the two windings, so the lever receives equal or substantially equal energy.

[0067] In reference to the figures 17a, 17ba fourth embodiment of the invention is shown in which a first and a second winding wheel set 70a, 70b are provided comprising a first, respectively a second drive wheel 72a, 72b and a first, respectively a second winding wheel 74a, 74b, the first drive wheel 72a (left) being integral with the first winding wheel 74a (left) and the second drive wheel 72b (right) being integral with the second winding wheel 74b (right). Said first and second drive wheels 72a, 72b are identical, symmetrical with respect to the longitudinal axis of the winding lever 76 and arranged to mesh with each other. The first and second winding wheels 74a, 74b are also identical, symmetrical with respect to the longitudinal axis of the winding lever 76.In addition, the escapement mechanism comprises an intermediate escapement pinion 78 intended to mesh with the wheel set 4 of the finishing gear train of the watch movement and arranged to be secured to one of the first and second drive wheels, here the first drive wheel 72a.

[0068] In this embodiment, said first and second winding wheels 70a, 70b are therefore identical, arranged to be subjected to torques M equal in norm and in opposite directions, and arranged symmetrically with respect to the longitudinal axis of the winding lever 76.

[0069] The first and second winding wheels 74a, 74b are intended to cooperate with the corresponding winding pallet 80a, 80b of the winding lever 76.

[0070] In this embodiment, the arming pallets 80a, 80b are symmetrical with respect to the longitudinal axis of the arming lever 76.

[0071] Said arming lever 76 comprises a central portion 82 carrying the two arming pallets 80a, 80b and two arming arms 84, 86 kinematically linked to the bistable elastic blade 6, said arming pallets 80a, 80b and the arming arms 84, 86 being symmetrical with respect to the longitudinal axis of the central portion 82.

[0072] Due to the symmetry of the winding wheels 74a, 74b and the winding pallets 80a, 80b, the winding angle αad, traveled by the second right winding wheel 74b in contact with the right winding pallet 80b of the winding lever 76 during the winding of said winding lever 76 in the counterclockwise direction, is equal in absolute value and opposite in direction to the winding angle αag traveled by the first left winding wheel 74a in contact with the left winding pallet 80a of the winding lever 76 during the winding of said winding lever 76 in the clockwise direction, so that the work of the torque supplied by one of the first and second winding wheels 74a, 74b to the winding lever 76 during winding in one direction is equal to the work of the torque supplied by the other winding wheel 74a, 74b to the winding lever 76 when winding in the other direction.

[0073] Thus, in this embodiment, the first and second winding wheels 74a, 74b and the winding lever 76 operate according to the so-called double Volet wheel principle.

[0074] Advantageously, the teeth of the first and second winding wheels 74a, 74b have a radial plane and each winding pallet 80a, 80b of the winding lever 76 comprises at its end a winding beak intended to be in contact with the radial plane of a tooth of the corresponding winding wheel 74a, 74b during winding of the winding lever 76. Such a configuration promotes thrust in the middle of winding.

[0075] THE Figures 18a to 18d illustrate the operation of this fourth embodiment in which the two winding wheels 74a, 74b are forced to rotate in opposite directions and are subjected to torques M equal in absolute value and of opposite sign. Points a) to d) correspond, in order, to the phases of the previous embodiments.

[0076] According to the Figure 18a , the system is in locking of the right winding wheel 74b, the right winding pallet 80b being engaged by a respectable distance d on the tooth of the right winding wheel 74b.

[0077] According to the Figure 18b , the system has just completed the unlocking of the right winding wheel 74b as well as the fall of the tooth of the left winding wheel 74a onto the left pallet 80a and enters the winding phase in the clockwise direction of the lever by the left winding wheel 74a, the radial plane of the tooth of the left winding wheel 74a pushing the beak of the left winding pallet 80a. The fall preceding the illustrated position makes it possible to arrange a comfortable distance D between the tooth of the right winding wheel 74b and the right winding pallet 80b.

[0078] According to the figure 18c, the system is locked by the left pallet 80a, said left pallet 80a being engaged on the radial plane of the tooth of the left winding wheel 74a by a comfortable distance d. The left winding wheel 74a has just completed the winding of the winding lever 76 by traveling through the winding angle αag.

[0079] According to the figure 18d , the system completes the unlocking of the left winding wheel 74a and the fall of the right winding wheel 74b onto the right pallet 80b with a respectable engagement d, the fall leaving a comfortable distance D between the tooth of the left winding wheel 74a and the left winding pallet 80a. The right winding wheel 74b is preparing to arm the winding lever 82 by the winding angle α ad.

[0080] For winding angles αad and αag at the first and second winding wheels 74a, 74b that are equal or substantially equal, the torque M provides equal or substantially equal work during the two windings, so the winding lever 76 receives equal or substantially equal energy.

[0081] The normal operation of the escapement mechanism 1 according to the first embodiment of the invention is explained below with reference to figures 19 to 31 .

[0082] There figure 19represents the escapement mechanism 1 according to the invention after an impulse phase. The balance 2a, having already received an impulse, oscillates freely along its ascending supplementary arc. The blade 6 is buckled in its first-order stable state. It is at rest unwound. The winding lever 10 is positioned so that the second right winding wheel 38b of the right winding wheel set 40b is at the start of the drive of the right winding pallet 36b of the winding lever 10. The left winding pallet 36a of the winding lever 10 has released the tooth of the left winding wheel 38a of the left winding wheel set 40a, said drop ensuring a safety distance D, in a position similar to that of the figures 10a, 10b, 10c .

[0083] This is followed by a winding phase of the lever 10 by the right winding wheel 38b, the energy being transmitted from the driving source to the wheel set 4 which rotates counterclockwise, driving the two winding wheels 40a, 40b simultaneously in the clockwise direction via their escape pinion 42a, 42b, providing them with an equal torque M. Only the right winding wheel set 40b can transmit the energy to the winding lever 10 via the right winding wheel 38b and the right winding pallet 36b, creating a driving torque so as to pivot said winding lever 10 in the counterclockwise direction. The arming lever 10 then pivots around its axis 1', arming the buckled blade 6 by means of the arming tenons 34a, 34b inserted into the eyelets 6a, 6b of the leaf spring 6. The trigger lever 12 bears against the stop 8a of the pins.With the balance 2a in its additional arc, the plate pin 22 is outside the entry of the trigger fork 16 of the trigger lever. Under these conditions, the winding of the blade 6 will press the trigger lever 12 against the stop 8a of the skewers.

[0084] In reference to the figure 20 , at the end of the arming phase, the blade 6 has deformed to pass from a first-order buckling to a buckling close to the second order, being armed in a metastable state, as close as possible to its unstable state. The second right arming wheel 38b is in abutment on the right arming pallet 36b of the arming lever 10, said right arming pallet 36b being engaged by the safety distance d on the tooth of the second right arming wheel 38b in a position similar to that of the Figures 11a, 11bThe left resting beak 46a of the arming lever 10 is locked in abutment against the left resting beak 58a of the left locking arm 56a of the locking lever 14, as shown in detail at figure 21 on which the terminal mobile 4 is not shown. The escapement mechanism 1 is then in its locking phase by the right pallet 36b, a locking phase in which all the components of the escapement are immobile. Only the balance 2a freely completes its oscillation along its additional arc, the plate pin 22 being close to its entry into contact with the detent fork 16 of the detent lever 12.

[0085] Then come the phases of unlocking the right wheel 38b and impulse in reference to the figure 22 and to the figure 23 on which the mobile terminal 4 is not shown.

[0086] The plate pin 22 of the balance 2a has entered the detent fork 16 of the detent lever 12 causing it to rotate so that the detent lever 12 comes off the stop 8a of the pins. This movement of the detent lever 12 forces the movement of the blade 6 beyond its metastable state. The instantaneous movement of the blade 6, with its eyelets 6a, 6b, from its metastable state to a second-order buckled state causes the rotation of the detent lever 12 around the inflection point I in the counterclockwise direction. Said detent lever 12 becomes a driving force and will drive the plate pin 22 with it to begin transmitting the impulse to the balance 2a. During this time, the gear train is still stopped because the left resting beak 46a of the winding lever 10 is still in contact with the left resting beak 58a of the locking lever 14, as shown in the detail at figure 23 .

[0087] In the middle of the impulse phase shown in the figure 24 , the blade 6 is transmitting its impulse to the balance 2a via the fork of the detent lever 12. The detent lever 12 rotating counterclockwise around the inflection point I, it drives on the one hand the balance 2a in the clockwise direction by its fork and the plate pin 22, and on the other hand the locking lever 14 around its axis 48 in the clockwise direction via the unlocking pin 24 inserted in the fork 26 of the locking lever 14. Consequently, as shown in the detail at figure 25 on which the terminal mobile 4 is not shown, the left resting beak 58a of the locking lever 14 has moved and released the left resting beak 46a of the winding lever 14. Said winding lever 14 no longer retains the driving force of the gear train because it is free. The gear train is therefore released, but its acceleration is moderated by the inertia of the wheels 44a, 44b which prevents it from prematurely unlocking the lever.

[0088] At the end of the impulse phase shown in the figure 26 , under the influence of the blade 6, the trigger lever 12 has moved counterclockwise until it comes to bear against the stop 8 of the skewers, carrying with it the balance 2a via the trigger fork 16 and the plate pin 22. The locking lever 14 under the influence of the trigger lever 12 via the unlocking pin 24 inserted in the fork 26 of the locking lever 14 has also moved clockwise, moving away from the left resting beak 46a of the winding lever 10, as shown in the detail at figure 27 on which the terminal mobile 4 is not shown. The locking lever 14 has released the arming lever 10 which, then unlocked, no longer offers any resistance, the arming tenons 34a, 34b of the arming lever 10 no longer being in contact with the eyelets 6a, 6b of the blade 6 following the passage of said blade 6 into its stable state of the first order inverse to that of the figure 19 The gear train having gained speed can complete the unlocking after the blade 6 has finished supplying its energy to the balance wheel 2a via the detent fork 16 and the plate pin 22.

[0089] In reference to the figure 28 , the balance wheel 2a continues its oscillation along its additional ascending arc. The released gear train has started to rotate, driven by the wheel set 4 which rotates counterclockwise, simultaneously driving the winding wheels 40a, 40b in the clockwise direction. The right winding wheel 38b pushes the right winding pallet 36b of the winding lever 10 until it reaches beak on beak, as shown in the detail at figure 29 . The arming lever 10 then rotates counterclockwise, without arming the blade 6, its arming tenons 34a, 34b no longer being in contact with the eyelets 6a, 6b of the blade 6. The left resting beak 46a of the arming lever 10 approaches the left resting beak 58a of the left locking arm 56a of the locking lever 14 without touching it thanks to an operating safety device provided for this purpose, as shown in detail at figure 29 on which the mobile terminal 4 is not shown.

[0090] Then, in reference to the figure 30 , the balance 2a continues its oscillation along its additional ascending arc. The winding mobiles 40a, 40b continue their rotation in the clockwise direction so that the right winding wheel 38b leaves the right winding pallet 36b of the winding lever 10. As a result, the gear train is momentarily released from the winding lever 10 and the tooth of the left winding wheel 38a falls onto the left winding pallet 36a of the winding lever 10, as shown in the detail at figure 31 on which the terminal mobile 4 is not shown. At the end of the fall, the tooth of the left winding wheel 38a is engaged by the safety distance d on the left winding pallet 36a corresponding to the position illustrated by the figure 12a , and the reverse of the tooth of the right winding wheel 38b is at the safety distance D from the right winding pallet 36b corresponding to the position illustrated by the figure 12c . The cycle driven by the right winding wheel 38b is completed. From this moment, a new cycle will resume as described above, but in the opposite direction by being driven by the left winding wheel 38a, so that the winding lever 10 will wind the blade 6 by moving clockwise. The winding phase by the left winding wheel 38a is then initiated, the energy being transmitted from the driving source to the wheel set 4 which rotates counterclockwise, driving the two winding wheels 40a, 40b simultaneously in the clockwise direction via the escapement pinion 42a, 42b, providing them with an equal torque M. Only the left winding wheel 40a can transmit energy to the winding lever 10 via the left winding wheel 38a and the left winding pallet 36a, creating a driving torque so as to pivot said winding lever 10 in a clockwise direction.

[0091] According to the invention, the winding angles αad and αag at the winding wheels 38a, 38b respectively are equal or substantially equal, due in this embodiment to the radii Ra and Ra' of the first and second winding wheels 38a, 38b being different. Thus, the thrust of the winding wheel set 40a on the winding lever during the clockwise winding phase of the winding lever 10 is equal or substantially equal to the thrust of the winding wheel set 40b on the winding lever 10 during the counterclockwise winding phase of the winding lever 10.

[0092] The clockwise winding phase of the lever 10 is followed by the locking phase of the left winding wheel 38a in which the left winding wheel 38a is in abutment on the left winding pallet 36a of the winding lever 10, said left winding pallet 36a being engaged by the safety distance d on the tooth of the left winding wheel 38a in a position similar to that of the figures 9a, 9b . The cycle on the left winding wheel 38a continues with the phases of unlocking the left winding wheel 38a and impulse in the same way as described above for the previous cycle until the left winding wheel 38a leaves the left winding pallet 36a of the winding lever 10. As a result, the gear train drops and the tooth of the right winding wheel 38b drops onto the right winding pallet 36b of the winding lever 10 and is at the start of the drive of said right winding pallet 36b. We find the position of the figure 19 and figures 10a, 10b, 10c. And the cycles on the right 38b and left 38a winding wheels are linked alternately, the escapement mechanism according to the invention making it possible to have thrusts of the winding mobiles 40a, 40b on the winding lever 10 equal or substantially equal in both directions of rotation of the winding lever 10.

Claims

1. Escapement mechanism (1) of a watch movement, comprising: - a bistable elastic blade (6) working in buckling around a median inflection point (I) between two embedding points (A, B) of said bistable elastic blade (6), - a winding lever (10, 10', 52, 76) of said bistable elastic blade (6), movable in rotation and kinematically linked in a direction substantially perpendicular to said bistable elastic blade (6) at two points equidistant from its pivot axis (l'), said winding lever (10, 10', 52, 76) comprising two winding pallets (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b), - a winding wheel set (49), respectively two winding wheel sets (40a, 40b;70a, 70b), arranged to be subjected to a torque, respectively to torques equal in standard in the same direction or in opposite directions, provided by a mobile (4) of the finishing train of the watch movement, and to sequentially apply to the winding lever (10, 10', 52, 76) a driving torque so as to pivot said winding lever (10, 10', 52, 76) in one direction or the other alternately to cause said bistable elastic blade (6) to pass from a stable rest state to a metastable winding state, said winding mobile(s) (40a, 40b; 49; 70a, 70b) respectively comprising a winding wheel (50; 38a, 38b; 38a', 38b'; 74a, 74b), the winding wheel(s) (40a, 40b; 49; 70a, 70b) and the winding pallets (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b) being arranged so that when one of the winding pallets (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b) is in contact with the winding wheel (50) or one of the winding wheels (38a, 38b;38a', 38b'; 74a, 74b), the other of the winding pallets (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b) is not in contact with the winding wheel (50) or the other winding wheel (38a, 38b; 38a', 38b'; 74a, 74b), - a detent lever (12) secured to the bistable elastic blade (6) at its median inflection point (I) and arranged to cooperate with an oscillating regulating member (2) of the watch movement at each alternation thereof so as to transmit to it an impulse following a dewinding of the bistable elastic blade (6) corresponding to the transition from a winding state to a rest state symmetrical to the previous stable rest state, escapement mechanism in which the angle of arming traveled by the arming wheel (50) or one of the arming wheels (38a, 38b; 38a', 38b'; 74a, 74b) in contact with one of the arming pallets (36a, 36b; 36a', 36b'; 64a, 64b;80a, 80b) of the winding lever (10, 10', 52, 76) during winding of said winding lever (10, 10', 52, 76) in one direction is equal or substantially equal to the winding angle traveled by the winding wheel (50) or the other winding wheel (38a, 38b; 38a', 38b'; 74a, 74b) in contact with the other winding pallet (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b) of the winding lever (10, 10', 52, 76) during winding of said winding lever (10, 10', 52, 76) in the other direction, so that the work of the torque provided by the or one of the winding wheels (50, 38a, 38b; 38a', 38b'; 74a, 74b) to the winding lever (10, 10', 52, 76) during winding in one direction is equal or substantially equal to the work of the torque provided by the or the other winding wheel (50, 38a, 38b; 38a', 38b'; 74a, 74b) to the winding lever (10, 10', 52, 76) during winding in the other direction.; 2. Escapement mechanism (1) according to claim 1, characterized in thatit comprises a first and a second winding wheel set (40a, 40b) arranged to be subjected to torques equal in standard and in the same direction, said first and a second winding wheel set (40a, 40b) comprising a first, respectively a second escapement pinion (42a, 42b) and a first, respectively a second winding wheel (38a, 38b), said first and second escapement pinions (42a, 42b) being arranged to mesh with the wheel set (4) of the finishing gear train of the watch movement to pivot simultaneously in the same direction, said first and second winding wheels (38a, 38b) being intended to cooperate with the corresponding winding pallet (36a, 36b) of the winding lever (10), and in thatthe first and second winding wheels (38a, 38b) are configured so that the ends of their teeth have a first radius (Ra), respectively a second radius (Ra'), different from each other and chosen such that the winding angle (αad), traveled by the second winding wheel (38b) in contact with the right winding pallet (36b) of the winding lever (10) during winding of said winding lever (10) in the counterclockwise direction, is equal or substantially equal to the winding angle (αag) traveled by the first winding wheel (38a) in contact with the left winding pallet (36a) of the winding lever (10) during winding of said winding lever (10) in the clockwise direction, so that the work of the torque provided by one of the first and second winding wheels (38a, 38b) to the winding lever (10) when winding in a direction that is equal or substantially equal to the work of the torque provided by the other winding wheel (38a,38b) to the arming lever (10) when arming in the other direction., 3. Escapement mechanism (1) according to the preceding claim, characterized in that said first and second escapement pinions (42a, 42b) of the first and second winding wheels (40a, 40b) are distinct and are arranged to pivot simultaneously in the same direction around distinct axes of rotation.

4. Escapement mechanism (1) according to one of claims 2 and 3, characterized in that the arming lever (10) comprises a central portion (28) and two arming arms (30, 32) respectively comprising first portions (30a, 32a) extending symmetrically from the central portion (28) and second portions (30b, 32b) having at their free end the arming pallet (36a, 36b).

5. Escapement mechanism (1) according to the preceding claim, characterized in thatfor each arming arm (30, 32), the end of the first portion (30a, 32a) secured to the second portion (30b, 32b) is kinematically linked to the bistable elastic blade (6).

6. Escapement mechanism (1) according to one of claims 4 and 5, characterized in that the second portions (30b, 32b) of the winding arms (30, 32) are not symmetrical and are configured so that the left winding pallet (36a) which cooperates with the first winding mobile (40a) is directed towards the central portion (28) of the winding lever (10) being the furthest from the axis of rotation (I') of the winding lever (10) and the right winding pallet (36b) which cooperates with the second winding mobile (40b) is directed away from the winding lever (10) being the closest to the axis of rotation (I') of the winding lever (10).

7. Escapement mechanism (1) according to claim 2, characterized in thatthe escapement pinions (42a, 42b) of the first and second winding wheels (40a, 40b) are merged.

8. Escapement mechanism (1) according to the preceding claim, characterized in that the arming lever (10') comprises a central portion (28'), two arming arms (30', 32') kinematically linked to the bistable elastic blade (6) and an arming ring (31) carrying the arming pallets (36a', 36b').

9. Escapement mechanism (1) according to claim 1, characterized in thatit comprises a first and a second winding wheel set (70a, 70b) comprising a first, respectively a second winding wheel (74a, 74b), said first and second winding wheel set (70a, 70b) being identical and arranged to be subjected to torques equal in standard and in opposite directions, arranged symmetrically with respect to the longitudinal axis of the winding lever, said first and second winding wheels (74a, 74b) being intended to cooperate with the corresponding winding pallet (80a, 80b) of the winding lever (76), and in thatthe winding pallets (80a, 80b) are symmetrical with respect to the longitudinal axis of the winding lever (76), such that the winding angle (αad), traveled by the second winding wheel (74b) in contact with the right winding pallet (80b) of the winding lever (76) when winding said winding lever (76) in the counterclockwise direction, is equal in absolute value and opposite in direction to the winding angle (αag) traveled by the first winding wheel (74a) in contact with the left winding pallet (80a) of the winding lever (76) when winding said winding lever (76) in the clockwise direction, such that the work of the torque supplied by one of the first and second winding wheels (74a, 74b) to the winding lever (76) when winding in one direction is equal to the work of the torque supplied by the other winding wheel (74a, 74b) to the winding lever (76) when winding in the other direction.

10. Escapement mechanism (1) according to claim 9, characterized in thatthe first and second winding wheels (70a, 70b) comprise a first, respectively a second drive wheel (72a, 72b), said first and second drive wheels (72a, 72b) being identical, symmetrical with respect to the longitudinal axis of the winding lever (76) and arranged to mesh with each other, and in that the escapement mechanism comprises an intermediate escapement pinion (78) intended to mesh with the wheel (4) of the finishing gear of the watch movement and arranged to be secured to one of the first and second drive wheels (72a, 72b).

11. Escapement mechanism (1) according to one of claims 9 and 10, characterized in that the winding lever (76) comprises a central portion (82) carrying the two winding pallets (80a, 80b) and two winding arms (84, 86) kinematically linked to the bistable elastic blade (6), said winding pallets (80a, 80b) and the winding arms (84, 86) being symmetrical with respect to the longitudinal axis of the central portion (82).

12. Escapement mechanism according to one of the preceding claims, characterized in that the teeth of the first and second winding wheels (38a, 38b, 38a', 38b', 74a, 74b) have a radial plane and in that each winding pallet (36a, 36b; 36a', 36b'; 80a, 80b) of the winding lever (10, 10', 76) comprises at its end a winding beak intended to be in contact with the radial plane of a tooth of the corresponding winding wheel (38a, 38b, 38a', 38b', 74a, 74b) during winding of the winding lever (10, 10', 76).

13. Escapement mechanism (1) according to claim 1, characterized in that it comprises a single winding wheel (49) comprising an escape pinion (51) intended to mesh with the wheel (4) of the finishing gear of the watch movement and a winding wheel (50) intended to cooperate with the winding pallets (64a, 64b) of the winding lever (52), namely an input pallet (64b) and an output pallet (64a), and in thatthe winding lever (52) comprises a drive arm (60) extending towards the winding wheel (50) and carrying two (circular) arm portions (62a, 62b) having at their free end one of the winding pallets (64a, 64b), said arm portions (62a, 62b) being symmetrical with respect to the longitudinal axis of the drive arm (60) and the winding pallets (64a, 64b) being non-symmetrical and non-concentric with respect to the longitudinal axis of the drive arm (60) and each comprising a winding zone intended to be in contact with a tooth of the winding wheel (50) during winding of the winding lever (52), said winding zones of the winding pallets (64a, 64b) being configured in such a way so that the winding angle (αad), traveled by the winding wheel (50) in contact with the winding zone of the input winding pallet (64b) when winding the winding lever (52) in a clockwise direction,is equal or substantially equal to the winding angle (αag) traveled by the winding wheel (50) in contact with the winding zone of the output winding pallet (64a) when winding the winding lever (52) in the counterclockwise direction, so that the work of the torque supplied by the winding wheel (50) to the winding lever (52) when winding in one direction is equal or substantially equal to the work of the torque supplied by said winding wheel (50) to the winding lever (52) when winding in the other direction., 14. Escapement mechanism according to claim 13, characterized in that the winding lever (52) comprises a central portion (54) carrying two winding arms (56, 58) kinematically linked to the bistable elastic blade (6) and the drive arm (60) projecting from the central portion (54) in the direction of the winding wheel (50).

15. Escapement mechanism according to one of claims 13 and 14, characterized in thatthe arming area of ​​each arming pallet (64a, 64b) has the shape of a curve.

16. Escapement mechanism according to the preceding claim, characterized in that the arming area of ​​each arming pallet (64a, 64b) has an S-curve shape.

17. Escapement mechanism according to one of the preceding claims, characterized in that it comprises a locking lever (14) of the arming lever (10, 10', 52, 76) arranged in kinematic connection with the trigger lever (12) and comprising two locking arms (56a, 56b) each provided with a locking member (58a, 58b) arranged to cooperate with a respective complementary locking member (46a, 46b) of the arming lever (10, 10', 52, 76) to block said arming lever (10, 10', 52, 76) during a locking phase during which the bistable elastic blade (6) remains in a metastable arming state.

18. Escapement mechanism according to the preceding claim, characterized in thatthe winding mobile(s) (40a, 40b; 49; 70a, 70b) and the winding lever (10, 10', 52, 76) are configured so that when one of the winding pallets (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b) is in contact with the one or more winding wheels (50; 38a, 38b; 38a', 38b'; 74a, 74b) during a locking phase, said winding pallet (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b) is engaged on the tooth of said winding wheel (50; 38a, 38b; 38a', 38b'; 74a, 74b) by a safety distance necessary to ensure proper operation, the other winding pallet (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b) not being in contact with the or the other winding wheel (50; 38a, 38b; 38a', 38b'; 74a, 74b) and so that when a tooth of the or one of the winding wheels (50; 38a, 38b; 38a', 38b'; 74a, 74b) falls on one of the winding pallets (36a, 36b; 36a', 36b'; 64a, 64b;80a, 80b) following an unlocking phase, said tooth of said winding wheel (50; 38a, 38b; 38a', 38b'; 74a, 74b) is engaged on said winding pallet (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b) by a safety distance necessary to ensure proper operation, the reverse of the tooth of the or the other winding wheel (50; 38a, 38b; 38a', 38b'; 74a, 74b) close to the other winding pallet (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b being at a necessary safety distance from said other armour palette (36a, 36b; 36a', 36b'; 64a, 64b; 80a, 80b).; 19. Watch movement comprising an escapement mechanism (1) according to one of claims 1 to 18.

20. Timepiece comprising an escapement mechanism (1) according to one of claims 1 to 18 or a watch movement according to claim 19.

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