Micromechanical mechanism provided with a system for actuating by impact, in particular for timepieces

Abstract

The invention relates to a micromechanical mechanism (1), particularly for a clockwork movement (3), the mechanism comprising a micromechanical device having a specific function, the device comprising a movable element (8) requiring mechanical movement to trigger its operation, characterized in that it comprises a device actuation system, the actuation system comprising a movable striker (16, 17, 18) configured to move from a firing position (19) to a striking position (21) in which it transmits to the movable element (8) a quantity of motion necessary to trigger the device, the actuation system further comprising a magnet (15) configured to attract the movable striker (16, 17, 18) to the striking position (21). The invention also relates to a clockwork movement (3) comprising such a mechanism (1).

Description

Technical field of the invention

[0001] The invention relates to a micromechanical mechanism equipped with a percussion actuation system, in particular for watchmaking.

[0002] The invention also relates to a clockwork movement comprising such a micromechanical mechanism. Technological background

[0003] In the field of watchmaking, we know of different types of complications, some of which require a specific activation device, in particular because they require a specific trigger.

[0004] For example, a striking mechanism may be combined with a traditional watch movement to serve, for example, as a minute repeater or to signal a programmed alarm time. Such a striking mechanism generally comprises at least one gong made of sapphire, quartz or a metallic material, such as steel, bronze, precious metal or metallic glass. This gong may, for example, describe at least a portion of a circle around the watch movement in the watch cage. The gong is fixed by at least one of its ends to a gong holder, which is itself secured to a watch plate.

[0005] To activate the chime, a hammer of the mechanism is mounted rotatably on the plate, for example near the gong holder, so as to strike the gong and make it vibrate. The sound produced by the gong struck by the hammer is located in the audible frequency range of 1 kHz to 20 kHz. This allows the wearer of the watch to be notified of a specific time, a programmed alarm or a minute repeater.

[0006] As shown in patent document EP 1 574 917 A1, the striking mechanism of a watch may comprise two or more gongs fixed by one of their ends to a single gong-carrier, which is itself secured to a plate. Each gong may be struck by a respective hammer. To do this, each hammer is driven by its own drive spring, which must have been previously wound, so as to drive the hammer against the gong, in order to signal a minute repeater or an alarm time. Two damping counter-springs are each provided to push back and keep the two hammers away from the gongs in a rest mode. In a striking mode, the damping counter-springs act with a significant force and slow the fall of each hammer before striking the respective gong. These counter-springs allow each hammer to be pushed back to their rest position following the strike.Eccentrics are also provided for adjusting the operation of the countersprings to essentially prevent any rebound of each hammer against the respective gong.

[0007] A disadvantage of known actuation systems is the amount of energy they require to function optimally. This energy is either provided by the barrel or by manual actuation.

[0008] For example, in the case of a chime, the hammer must be activated automatically to function, in particular thanks to the energy supplied by the barrel.

[0009] In document EP 3 079 024, a striking mechanism is known which uses magnetic activation to trigger the striking.

[0010] In the case of manual pressure, the pressure required can be relatively high, which is not pleasant for the person using the mechanism.

[0011] More generally, an actuation system may also be required that operates continuously. For example, in the case of an escapement mechanism, the movement must be maintained at a predefined frequency. However, today, there are few alternatives to an escape wheel cooperating with an anchor, which consumes significant energy. Detent escapement mechanisms are known, which do not include an anchor. However, these mechanisms are complex to implement and operate. In document EP 3 579 058, a magnetic escapement mechanism is known. The document saved at the page https: / / web.archive.org / web / 20210428223905 / https: / / www.kjmagnetics.com / blog.asp? p=gauss-guns presents a device called a Gauss gun. Summary of the invention

[0012] The invention, which is defined by the appended claim 1, therefore aims to overcome the drawbacks of the aforementioned state of the art by providing an innovative actuation system, in particular for a timepiece, with the aim of avoiding significant use of energy necessary for its operation.

[0013] To this end, the invention relates to a micromechanical mechanism for a clockwork movement, the mechanism comprising a micromechanical device having a specific function, the device comprising a movable element needing to be moved mechanically to trigger its operation.

[0014] The mechanism comprises a system for actuating the device, the actuating system comprising a movable striker configured to move from a trigger position to a percussion position in which it transmits to the movable element a quantity of movement necessary for triggering the micromechanical device, the actuating system further comprising a magnet configured to attract the movable striker to the percussion position.

[0015] On the one hand, the attractive force of the magnet is used to bring the striker into the striking position. On the other hand, the striker transmits a necessary momentum to the movable element. Thanks to the momentum of the striker, the movable element receives sufficient energy to trigger the micromechanical device. This saves the energy required to actuate the striker and / or the movable element. In addition, the transmitted energy corresponds substantially to the momentum of the striker and is therefore relatively constant, independent of the energy of the striker actuation system, the system thus forming a constant force system.

[0016] The mechanism is remarkable in that the moving element is in contact with the magnet in its rest position.

[0017] Thanks to the invention, the actuation energy of the micromechanical device is lower. Depending on the actuation system, the barrel is less stressed, or manual actuation is easier.

[0018] Furthermore, by selecting a specific mass difference between the moving element and the striker, the speed of the moving element can be adjusted. For example, a moving element with a reduced mass can be chosen, which moves at a higher speed than the striker with a higher mass. A lighter moving element moving quickly reduces the risk of rebound after striking the gong.

[0019] According to a particular embodiment of the invention, the mobile element comprises a magnetic conductive material.

[0020] According to a particular embodiment of the invention, the striker comprises a magnetically conductive material, so as to be attracted by the magnet.

[0021] According to a particular embodiment of the invention, the striker is configured to strike the magnet so as to give an impulse to the movable element.

[0022] According to a particular embodiment of the invention, the distance between the firing position of the striker and the magnet is chosen so that the magnet attracts the striker against it in its percussion position.

[0023] According to a particular embodiment of the invention, the amount of movement transmitted by the striker is sufficiently large to overcome the retaining force of the magnet acting on the movable element, so that the movable element detaches from the magnet.

[0024] According to a particular embodiment of the invention, the mechanism comprises a flexible guide on which the movable element is mounted to allow it to move between its rest position and its impact position.

[0025] According to a particular embodiment of the invention, the flexible guide is configured to press the movable element against the magnet.

[0026] According to a particular embodiment of the invention, the actuation system comprises a flexible guide on which the striker is mounted to allow it to move between the trigger position and the percussion position.

[0027] According to a particular embodiment of the invention, the flexible guide comprises a flexible blade or a flexible neck.

[0028] According to a particular embodiment of the invention, the actuation system comprises a rotary device provided with the striker, the rotary device being configured to bring the striker into the trigger position.

[0029] According to a particular embodiment of the invention, the actuation system comprises at least one additional striker, preferably two additional strikers, arranged on the rotary device, so as to alternately bring each striker into the trigger position.

[0030] According to a particular embodiment of the invention, the rotating device comprises a rotating hub.

[0031] According to a particular embodiment of the invention, the rotary device comprises at least one arm, each arm carrying a striker.

[0032] According to a particular embodiment of the invention, the rotary device comprises several arms distributed angularly around the hub.

[0033] According to a particular embodiment of the invention, the mass of the striker is greater than that of the moving element, for example, the mass of the striker is at least twice as great as that of the moving element.

[0034] According to a particular embodiment of the invention, the micromechanical device is a bell, the device comprising at least one resonant element making it possible to emit a sound when struck, the movable element being a hammer movable between the rest position and the shock position in which it strikes the resonant element to make it vibrate.

[0035] According to a particular embodiment of the invention, the micromechanical mechanism is a regulating member provided with a balance, an escapement mechanism provided with an escape wheel and a detent lever cooperating with the escape wheel, the balance being actuated by the moving element.

[0036] According to a particular embodiment of the invention, the moving element strikes the balance in the shock position.

[0037] According to a particular embodiment of the invention, the movable element strikes the balance in the shock position, preferably with a single impact.

[0038] According to a particular embodiment of the invention, the balance wheel comprises a release lever arranged to move the detent lever in order to release the escape wheel.

[0039] According to a particular embodiment of the invention, the device can be triggered punctually.

[0040] According to a particular embodiment of the invention, the magnet is fixed relative to the clockwork movement.

[0041] The invention also relates to a clockwork movement comprising such a micromechanical mechanism. Brief description of the figures

[0042] Other features and advantages will become clear from the description given below, for information purposes only and in no way limiting, with reference to the attached drawings, in which: there figure 1 is a schematic representation of a timepiece comprising a micromechanical percussion striking mechanism according to a first embodiment of the invention; the figure 2 is an enlarged schematic representation of the micromechanical striking mechanism of the figure 1 ; there figure 3 is a schematic representation of the micromechanical striking mechanism of the figure 1 , in which the firing pin is in the firing position; the figure 4 is a schematic representation of the micromechanical striking mechanism of the figure 1 , in which the striker is in the percussion position with the magnet and the moving element, here a hammer, in the shock position with the gong; the Figure 5is a schematic representation of the striking mechanism of the figure 1 , in which the firing pin is no longer in the percussion position or in the trigger position and the moving element has returned to the rest position; figure 6 is a schematic representation of a micromechanical percussion escapement mechanism according to a second embodiment of the invention; the figure 7 is a schematic representation of the micromechanical escapement mechanism of the figure 6 , in which the trigger lever is moved by the balance wheel; the figure 8 is a schematic representation of the micromechanical escapement mechanism of the figure 6 , in which the firing pin is in the trigger position; the figure 9 is a schematic representation of the escapement mechanism of the figure 6 , in which the striker is in the percussion position with the magnet; the figure 10is a schematic representation of the escapement mechanism of the figure 6 , in which the moving element is in a position of impact with the balance; and the figure 11 is a schematic representation of the escapement mechanism of the figure 6 , in which the pendulum is in motion. Detailed description of the invention

[0043] As explained above, the invention relates to a micromechanical mechanism, which has a specific striking function 1 in the first embodiment. By specific function is meant a micromechanical function different from the usual function linked to the display of the time.

[0044] The striking mechanism 1 is intended for a timepiece 10, such as a watch shown in the figure 1. The timepiece 10 comprises a caseband 2 and a watch movement 3, preferably mechanical, which is for example provided with a plate 4 and a barrel spring to provide the operating energy. The embodiment described below is based on the combination of the “Gauss magnetic gun” principle and the principle of conservation of momentum during a shock.

[0045] On the figures 1 to 5 , the striking mechanism 1 comprises a micromechanical device provided with a resonant element 5, for example a gong conventionally used in clockwork strikes. The resonant element 5 makes it possible to emit a sound when struck. In the figures, the resonant element 5 is a rod comprising a rectilinear portion 6. The resonant element 5 is preferably fixed to the plate 4, so as to extend above next to the plate 4, for example in a plane parallel to that of the plate 4.

[0046] Other configurations of resonant element 5 are possible. The resonant element 5 may further comprise a circular portion 7, shown in the figure 1 , in particular to run along the inner face of the middle 2.

[0047] To emit a sound, the mechanism 1 comprises a movable element 8, here a hammer, which is movable relative to the plate 4. The movable element 8 is movable between two positions, a rest position 9 distant from the resonant element 5, and a shock position 11 in which it strikes the resonant element to make it vibrate. Thus, the resonant element 5 produces a vibration which propagates in the watch. The outer part of the watch radiates these vibrations so as to emit a sound. Other embodiments are possible with various shapes of movable element and resonant element 5.

[0048] The mechanism 1 here comprises a flexible guide 12 on which the movable element 8 is mounted to allow it to move between its rest position 9 and its impact position 11. The flexible guide 12 preferably comprises a first flexible blade 13 assembled to the plate 4 on the one hand, and to the movable element 8 on the other hand. The first flexible blade 13 is preferably arranged substantially parallel to the resonant element 5 when the movable element 8 is in the rest position 9.

[0049] By the elastic deformation of the first flexible blade 13, the movable element 8 passes from the rest position 9 to the impact position 11 and vice versa.

[0050] The mechanism 1 further comprises a magnet 15 fixed relative to the plate 4. The magnet 15 is preferably assembled on the plate 4. The magnet 15 is for example arranged on a promontory 14 opposite the resonant element 5.

[0051] Preferably, the magnet 15 is configured to retain the movable element 8 in its rest position 9. For this purpose, the movable element 8 comprises a magnetically conductive material, which induces an attractive force of the movable element 8 against the magnet 15.

[0052] Alternatively, a mobile element 8 may be chosen that does not comprise a magnetically conductive material. In this case, the flexible guide 12 is configured to apply a prestress to the mobile element 8, so as to press it against the magnet 8.

[0053] Thus, in the rest position 9, the movable element 8 is in contact with a front face 29 of the magnet 15. The movable element 8 keeps this position permanently, except when it strikes the resonant element 5. The flexible guide 12 is assembled to the plate 4 between the promontory 14 and the resonant element 5. Thus, the movable element 8 can move between the magnet 15 and the resonant element 5 thanks to the flexible guide 12.

[0054] The front face 29 preferably has a substantially flat surface. The movable element 8 has, for example, a cylindrical or spherical shape. These rounded shapes make it easier to separate the movable element 8 from the front face 29 of the magnet 15.

[0055] According to the invention, the mechanism 1 comprises a system for actuating the mobile element 8. This system is configured to cause the movement of the mobile element 8 from its rest position 9 to its impact position 11. In particular, it serves to separate the mobile element 8 from the magnet 15 and to allow it to reach the resonant element 5. The actuating system comprises the magnet 15.

[0056] To this end, the actuation system 20 comprises at least one movable striker 16, 17, 18 configured to transmit to the movable element 8 a sufficient quantity of movement for it to move from its rest position 9 to its impact position 11 and to vibrate the resonant element 5.

[0057] The striker 16, 17, 18 is configured to move from a trigger position 19 to a percussion position 21 in which it transmits a quantity of movement to the movable element 8.

[0058] In, the embodiment of the figures 1 to 5 , the actuation system comprises a rotary device 20 provided with three movable strikers 16, 17, 18.

[0059] The rotary device 20 comprises a hub 22 and three arms 23, 24, 25, distributed angularly around the hub 22, and are connected to the hub 22 by one end. Each arm 23, 24, 25 carries a movable striker 16, 17, 18 arranged at the opposite end of the arm 23, 24, 25 relative to the hub 22. The arms 23, 24, 25 are preferably arranged in the same plane substantially perpendicular to the axis of the hub 22. This plane also preferably passes through the magnet 15, the movable element 8 and the resonant element 5.

[0060] The system may include a greater or lesser number of arms and strikers than those illustrated in the described embodiment.

[0061] Each movable striker 16, 17, 18 is mounted on an arm 23, 24, 25 so as to form an angle with the arm 23, 24, 25. The angle is typically between 30 and 60°, when the movable striker 16, 17, 18 is in the trigger position 19, and the angle is typically between 60 and 90°, when the movable striker 16, 17, 18 is in the percussion position 21. An arm may, for example, be an oblong body, a gear tooth or a plate.

[0062] Preferably, each movable striker 16, 17, 18 is mounted on the arm 23, 24, 25 by a flexible guide to enable it to move relative to the arm 23, 24, 25, and to move from the trigger position 19 to the percussion position 21. The flexible guide here comprises a second flexible blade 26 assembled to the movable striker 16, 17, 18 on the one hand, and on the other hand to the end of the arm 23, 24, 25.

[0063] Each movable striker 16, 17, 18 comprises a contact face 31, 32, 33, which is intended to come into contact with the magnet 15, when it passes from the trigger position 19 to the percussion position 21. The contact faces 31, 32, 33 of the movable strikers 16, 17, 18 are preferably rounded, to allow easier detachment when the movable striker 16, 17, 18 returns to its trigger position.

[0064] When the rotary device 20 rotates, it positions one of the movable strikers 16, 17, 18 opposite the magnet 15. The movable striker 16, 17, 18 then moves from the trigger position 19 to the percussion position 21 according to a radial displacement. Once the percussion has been carried out, the rotary device 20 continues to rotate in order to prevent the movable striker 16, 17, 18 from remaining against the magnet 15. The geometry of the movable strikers 16, 17, 18 is produced so as to require the least possible torque on the rotary device 20. For example, a contact face 32 is chosen having a ramp shape tangential to the rotary movement.

[0065] The rotary device 20 is actuated by rotating the hub 22 around its axis, so that the arms 23, 24, 25 rotate around the axis of the hub 22. Thus, the movable strikers 16, 17, 18 also rotate around the axis of the hub 22 while remaining in the trigger position 19. In other words, the movable strikers 16, 17, 18 remain in the same position relative to the arms 23, 24, 25, which carry them.

[0066] To rotate, the means 22 is mechanically connected to the barrel of the movement by means of gear means, not shown in the figures. These gear means comprise for example an actuation system configured to determine the strikes to be executed according to the time displayed by the movement 3, to serve in particular as minute repeaters or to signal a programmed alarm time. Thus, when one or more strikes are to sound, the actuation system triggers the rotation of the hub 22.

[0067] The rotary device 20 is configured to bring the striker into the trigger position 19 in front of the magnet 15. The figure 3 shows an example in which the striker is in the trigger position 19 closest to the magnet 15. The magnet 15 has an opposite face 30 oriented towards the rotating device 20, so that the opposite face 30 of the magnet 15 and a contact face 31, 32, 33 of a movable striker 16, 17, 18 are opposite each other when the rotating device 20 rotates. The opposite face 30 preferably has a substantially flat surface.

[0068] The attractive force of the magnet 15 and the distance between the contact face 31, 32, 33 of the movable striker 16, 17, 18 in the trigger position 19 and the opposite face 30 of the magnet 15 are chosen so that the magnet 15 attracts the striker 16 against its opposite face 30, when it passes in front of its opposite face 30. Thus, the magnetic potential energy produced by the magnet 15 acting on the movable striker 16, 17, 18 is transformed into kinetic energy by the movable striker 16, 17, 18. This kinetic energy is transmitted to the movable element 8 by the impact of the movable striker 16, 17, 18.

[0069] Indeed, when the movable striker 16, 17, 18 is attracted by the magnet 15, it is accelerated and strikes the magnet 15. When the movable striker 16, 17, 18 collides with the opposite face 30 of the magnet 15, at least part of its momentum is transmitted to the movable element 8 through the magnet 15, the movable element 8 being arranged against the front face 29 of the magnet in the rest position.

[0070] This principle of motion transmission combined with magnetic attraction is known as the "Gauss cannon". The attraction of the magnet 15 guarantees a minimum intensity with each strike of the moving element 8. The resulting strike is more constant throughout the duration of the strike, regardless of the barrel torque.

[0071] As shown in the figure 4 , each movable striker 16, 17, 18 is configured to strike the magnet 15 so as to give an impulse to the movable element.

[0072] Furthermore, the movable strikers 16, 17, 18 and the rotating device 20 are configured so that the amount of movement transmitted to the movable element 8 by the striker 16, 17, 18 is greater than the retaining force of the magnet acting on the movable element 8, so that the movable element detaches from the magnet 15 and strikes the resonant element 5 with sufficient force, as shown in figure 4 .

[0073] As shown on the Figure 5 , the magnet 15 and the movable element 8 are further configured so that the front face 29 attracts the movable element 8 against it, after it has struck the resonant element 5. Thus, the movable element 8 returns to its rest position 9, and can be actuated again by the following movable striker 16, 17, 18. This also prevents the movable element 8 from bouncing and striking the resonant element 5 again in an inopportune manner.

[0074] In the case of a movable element 8 not comprising magnetically conductive material, the flexible guide 12 brings the movable element back against the magnet 15.

[0075] By continuing to rotate, the rotation device 20 pulls on the movable striker 16, 17, 18 so that it detaches from the opposite face 30 of the magnet 15. At the same time, as the hub 22 rotates, the next movable striker 16, 17, 18 moves closer to the magnet 15.

[0076] The rotating device 20 is actuated by the movement, when a ringing is required. Thus, the ringing sounds automatically thanks to the movable strikers 16, 17, 18, the magnet 15, the movable element 8 and the resonant element 5.

[0077] In operation, each movable striker 16, 17, 18 strikes the magnet 15 one after the other, to produce a sound each time. With each percussion of a movable striker 16, 17, 18, the movable element 8 strikes the resonant element 5, and returns to the rest position 9 against the magnet 15 between two successive percussions.

[0078] Depending on the number of rings to be emitted, the rotating device is activated for a predefined time.

[0079] Preferably, the rotation is carried out at a constant speed so that the ringing strokes are emitted periodically at the same frequency.

[0080] The rotation speed can also be varied to emit a particular ringing sound.

[0081] THE figures 6 to 11represent a second embodiment of the invention, in which the micromechanical mechanism 10 is a regulating member for a watch movement. The micromechanical device comprises a detent escapement mechanism, a movable element 8 and a balance plate 36. The escapement mechanism comprises a rotating escape wheel 34 provided with peripheral teeth 35 capable of cooperating with a notch 42 for stopping the rotation of the escape wheel 34. The escape wheel 34 is preferably mechanically connected to means for driving the movement, for example a barrel.

[0082] The escapement mechanism further comprises a detent lever 40 cooperating with the balance wheel 36. When it is actuated, the balance wheel 36 performs an alternating movement in the clockwise and counterclockwise directions.

[0083] The trigger lever 40 includes the stop notch 42 for retaining the escape wheel 34.

[0084] The detent lever 40 further comprises a flexible blade 41 at one end, the flexible blade being able to cooperate with the balance wheel plate 36 to allow the balance wheel to disengage the detent lever during its counterclockwise rotation. The flexible blade 41 is fixed on the detent lever 40 and is arranged longitudinally in the extension of the detent lever 40. The detent lever 40 comprises a lug 43 at its end in order to retain the flexible blade 41 during a movement to the right. When the balance wheel plate 36 rotates clockwise, the flexible blade 41 can move away from the lug 43 without the detent lever 40 moving. When the balance wheel plate rotates counterclockwise, the blade 41 presses against the lug 43 and angularly displaces the detent lever so as to disengage the stop notch 42 from the escape wheel 34.

[0085] The balance wheel 36 has a circular shape, for example a disc, and is provided with a clearance lift 37 and an impulse lift 38 arranged at the periphery of the disc 36, and extending on two different levels above the disc, preferably close to each other. Here, the clearance lift 37 extends above the impulse lift 38.

[0086] During a counterclockwise rotation, the release lever 37 allows the detent lever 40 to be moved to release the stop notch 42 from the tooth 35 of the escape wheel 34 so that the latter can rotate.

[0087] The impulse lift 38 makes it possible to receive an impulse from the moving element 8 to cause the rotation of the balance wheel 36, here in the counterclockwise direction.

[0088] The trigger rocker 40 extends longitudinally, and is arranged at the level of the release lift 37, and the movable element 8 is arranged at the level of the impulse lift 38. Thus, the trigger rocker 40 is above the movable element 8.

[0089] The detent lever 40 is arranged tangentially to the escape wheel 34, obliquely to the balance wheel plate 36 at its end 41. The detent lever 40 is held by a flexible blade 39 in the extension of the second end.

[0090] The actuation system 20 is identical to the first embodiment. The rotary device 20 is mounted on the escape wheel 34 in a plane parallel to that of the escape wheel 34. Thus, when the escape wheel 34 rotates, the rotary device 20 also rotates.

[0091] The rotary device 20 is configured to bring a striker 16, 17, 18 into the trigger position 19 in front of the magnet 15. The actuating mechanism operates in a similar manner to that of the first embodiment.

[0092] THE figures 6 to 11 show different stages of the dynamics of the micro-mechanism, which is described below.

[0093] On the figure 6 , the stop notch 42 of the trigger lever 40 blocks the rotation of the escape wheel 34. The movable element 8 is in contact with the magnet 15 in its rest position 9. The strikers 16, 17, 18 of the rotary device are in positions which do not allow the movable element 8 to be actuated.

[0094] The balance wheel 36 rotates around its axis of rotation in a clockwise direction, according to the arrow indicated.

[0095] The balance wheel 36 rotates alternately clockwise / counterclockwise with each actuation at a predefined frequency.

[0096] As shown on the figure 7 , when moving counterclockwise, the release lever 37 comes into contact with the flexible blade 41 of the detent lever 40. Thus, the detent lever 40 is moved laterally, so that the stop notch 42 shifts from the tooth 35 in order to release the escape wheel 34.

[0097] Thus, the escape wheel 34 can rotate around its axis of rotation. On the figure 8 , the rotation of the escape wheel 34 brings a striker 16 into the trigger position 19 to actuate the actuation system 20. Attracted by the magnet 8, the striker 16 moves into the percussion position 21 against the magnet 15, and transmits a quantity of movement to the movable element 8, as shown in figure 9 .

[0098] On the figure 10, when the movable element 8 receives the momentum via the magnet 15, the movable element 8 strikes the impulse lift 38 of the balance wheel 36 in the shock position 11. The energy transmitted to the balance wheel 36 is received in the form of a single point shock. This form of impulse is advantageous, from a chronometric point of view, as is known to those skilled in the art.

[0099] Thus, at least part of the momentum transmitted by the striker 16 to the movable element 8 is supplied to the balance wheel 36. The momentum is sufficient for the balance wheel 36 to continue its rotation and maintain its amplitude, here in the counterclockwise direction, as shown in figure 11 .

[0100] A balance spring, not shown in the figures, applies this return force to the balance wheel, so that the balance wheel plate 36 then rotates clockwise, after reaching its extreme counterclockwise position.

[0101] Clockwise, the release lever 37 comes into contact with the flexible blade 41, which flexes to allow the release lever 37 to pass. Indeed, in this direction, the flexible blade 41 is not retained by a lug. The escape wheel 34 is not affected by the flexing of the flexible blade 41. The passage of the lever 37 only lifts the blade 41 without any given impulse, this empty passage being called a “lost stroke” by those skilled in the art.

[0102] Thus, as shown in the figure 6 , the balance wheel 36 continues its rotation clockwise, up to an extreme clockwise position.

[0103] Finally, the balance spring exerts a restoring force to bring the balance wheel 36 back counterclockwise, until the release lever 37 is retained by the flexible blade 41 of the detent lever 40, as shown in figure 7 .

[0104] During the rotations of the balance wheel 36, the movable element 8 returns against the magnet 15, while the detent lever 40 returns to its initial position, the stop notch 42 blocking the escape wheel 36 by contact with the next peripheral tooth 35 of the escape wheel 34.

[0105] The actuating mechanism maintains the movement of the balance wheel, and consequently the movement of the regulating organ and the escapement mechanism. The frequency of the balance wheel determines the operating frequency of the regulating organ. Thus, it is possible to maintain the oscillation with a Gaussian cannon-type system.

[0106] Of course, the present invention is not limited to the illustrated examples of striking mechanism and regulating organ, but it is susceptible to various variants and modifications which will appear to those skilled in the art.

[0107] In particular, the actuation system may be adapted to other types of micromechanical devices comprising a moving element. For example, the moving element may be a date-type display disc.

[0108] The actuation system can be connected to a push button on the timepiece. By pressing the push button, via a mechanical relay, such as gears, the striker is placed in the trigger position, for example by rotating the hub. Thus, such an actuation system can be used to trigger a micromechanical device manually on demand.

Claims

1. Micromechanical mechanism (1) for an horological movement (3), the mechanism including a micromechanical device having a specific function, the device including a mobile element (8) needing to be moved mechanically to trigger its operation, the mechanism comprising a system for actuating the device, the actuation system including a mobile striker (16, 17, 18) configured to go from a release position (19) to a percussion position (21) in which it transmits to the mobile element (8) a momentum necessary for the release of the micromechanical device, the actuation system further including a magnet (15) configured to attract the mobile striker (16, 17, 18) in a percussion position (21), the mobile element (8) being in contact with the magnet (15) in its rest position (9).

2. Micromechanical mechanism according to claim 1, characterised in that the mobile striker (16, 17, 18) is configured to strike the magnet (15) in such a way as to give an impulse to the mobile element (8) via the magnet (15).

3. Micromechanical mechanism according to claim 2, characterised in that the distance between the release position (19) of the mobile striker (16, 17, 18) and the magnet (15) is chosen so that the magnet (15) attracts the mobile striker (16, 17, 18) against it in its percussion position (21).

4. Micromechanical mechanism according to claim 3, characterised in that the momentum transmitted by the mobile striker (16, 17, 18) overcomes the magnetic retaining force of the magnet (15) acting on the mobile element (8), so that the mobile element (8) detaches from the magnet (15).

5. Micromechanical mechanism according to any one of the previous claims, characterised in that it comprises a flexible guide (12) on which the mobile element (8) is mounted to allow it to move between its rest position (9) and its shock position (11).

6. Micromechanical mechanism according to any one of the previous claims, characterised in that the actuation system comprises a flexible guide on which the mobile striker (16, 17, 18) is mounted to allow it to move between the release position (19) and the percussion position (21).

7. Micromechanical mechanism according to claim 6, characterised in that the flexible guide (12) includes a flexible blade (13, 26, 27, 28) or a flexible neck.

8. Micromechanical mechanism according to any one of the previous claims, characterised in that the actuation system comprises a rotary device (20) provided with the mobile striker (16, 17, 18), the rotary device being configured to bring the mobile striker (16, 17, 18) into the release position (19).

9. Micromechanical mechanism according to claim 8, characterised in that the actuation system comprises at least one additional striker (16, 17, 18), preferably two additional strikers, arranged on the rotary device (20), in such a way as to alternatingly bring each mobile striker (16, 17, 18) into the release position (19).

10. Micromechanical mechanism according to any one of claims 8 and 9, characterised in that the rotary device (20) comprises a hub (22).

11. Micromechanical mechanism according to claim 10, characterised in that the rotary device (20) comprises at least one arm (22, 23, 24), each arm (22, 23, 24) carrying a mobile striker (16, 17, 18).

12. Micromechanical mechanism according to claim 11, characterised in that the rotary device (20) comprises several arms (22, 23, 24) distributed angularly around the hub (22).

13. Micromechanical mechanism according to any one of the previous claims, characterised in that the micromechanical mechanism is a striking-work, the device (1) including at least one resonating element (5) allowing to emit a sound when it is struck, and a hammer as an element (8) mobile between the rest position (9) and the shock position (11) in which it strikes the resonating element (5) to make it vibrate.

14. Micromechanical mechanism according to any one of claims 1 to 12, characterised in that the micromechanical mechanism (10) is a setting member provided with a balance, an escapement mechanism provided with an escapement wheel (34) and a detent lever (40) cooperating with the escapement wheel (34), the balance being actuated by the mobile element (8).

15. Micromechanical mechanism according to claim 14, characterised in that the mobile element (8) strikes the balance in a shock position (11).

16. Micromechanical mechanism according to claim 14 or 15, characterised in that the mobile element (8) strikes the balance in a shock position (11), preferably with a single impact.

17. Micromechanical mechanism according to any one of claims 14 to 16, characterised in that the balance comprises an unlocking gathering-pallet (37) arranged to move the detent lever (40) in order to free the escapement wheel (34).

18. Horological movement (3), characterised in that it comprises a micromechanical mechanism (1) according to any one of the previous claims.

Images