Escapement mechanism with bistable leaf spring
The escapement mechanism with a leaf spring and rockers enables self-starting by accumulating and releasing energy, addressing the issue of insufficient torque in existing mechanisms, ensuring consistent balance wheel oscillations.
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Patents
- Current Assignee / Owner
- SOWIND
- Filing Date
- 2023-10-04
- Publication Date
- 2026-07-01
Smart Images
Figure IMGF0001 
Figure IMGF0002 
Figure IMGF0003
Abstract
Description
technical field
[0001] The present invention relates to the field of mechanical watchmaking. It relates, more particularly, to an escapement mechanism arranged to provide 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 cooperation with a winding rocker, a detent rocker and a locking rocker.
[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, a well-known escapement mechanism is designed to supply mechanical energy impulses from a driving source to an oscillating regulator of a watch movement via a leaf spring operating in buckling around an inflection point. The Applicant's patent EP 2105806 can be cited as an example.
[0004] Such an escapement mechanism makes it possible in particular to maintain the oscillations of the balance wheel in a constant manner throughout the duration of the power reserve, regardless of the energy source.
[0005] Various improvements have been made to this escapement mechanism to enhance its efficiency and reliability of operation, such as those described in documents CH 710925, WO 2018 / 015146, EP 3599514 or EP 3623875 also in the name of the Applicant.
[0006] A first improvement, described in patent CH 710925 or CH 710685, consisted of adding a locking lever that prevents accidental unlocking between the winding lever's resting pallets and the lugs on the winding wheel teeth. A second development, described in patent EP 3623875, involved changing the function of this locking lever so that it became a locking and releasing element for the escapement. The winding lever, driven by the escape wheels, is locked by the locking lever, which is controlled by the balance wheel via the detent lever and its jewel. The escapement's functions are thus better sequenced and secured, rebounds are eliminated, and the energy supplied by the escape spring goes directly to the balance wheel because the escape spring no longer participates in unlocking the escapement. Efficiency is improved.
[0007] However, the resulting escapement mechanisms have the drawback of not being able to self-start when the power source is wound or following a shock that has significantly slowed the balance wheel and hairspring. The torque provided by the escapement spring is then insufficient to drive the balance wheel, which remains stationary, outside the lift angle required for it to begin moving—that is, outside the angle during which the balance wheel pivot is in contact with the fork inlet. This condition allows the escapement components to position themselves so that the escapement can lock, thereby accumulating the energy of the leaf spring during a rest phase and releasing it upon the impulse triggered by the release of the balance wheel. These conditions are not met because the only connection between the escapement spring and the balance wheel and hairspring is the elasticity of the escapement spring.There is no mechanism to position the components in a way that guarantees a configuration allowing the movement to start automatically. Even when these conditions are met, the torque of the balance spring is insufficient to overcome the resistance of the wound escapement—that is, the resistance of the winding lever on the locking lever—and to disengage the mainspring. The escapement will therefore remain "hanging" in a position where the escape spring has been wound by the mainspring and the winding lever is abutting the resistance of the locking lever.
[0008] The present invention aims to remedy these drawbacks by proposing a self-starting escapement mechanism arranged to provide mechanical impulses from a driving source to an oscillating regulator of a clock movement via a leaf spring working in buckling around an inflection point. Disclosure of the invention
[0009] To this end, the invention relates to an escapement mechanism arranged to provide mechanical energy pulses from a driving source to an oscillating regulator of a clock movement by means of a leaf spring working in buckling around an inflection point, said mechanism comprising a winding rocker, a release rocker and a locking rocker for the winding rocker arranged in kinematic connection with the release rocker, said leaf spring being capable, in normal operation, by means of said winding rocker, said locking rocker and said release rocker, of accumulating the energy from the driving source transmitted by winding components during a winding phase, of then remaining in a wound state during a locking phase, and then of releasing the accumulated energy to said oscillating regulator during a pulse phase preceded by a release phase,said locking toggle comprising two locking arms, each equipped with a locking member arranged to cooperate with a respective complementary locking member of the cocking toggle to lock said cocking toggle during the locking phase.
[0010] According to the invention, each locking arm of said locking rocker comprises, at its free end, at least one inclined plane configured to cooperate with a corresponding starting inclined plane on the arming rocker during a self-starting phase in which activation of the drive source causes an angular movement of the arming rocker, the free passage of which is permitted by the locking rocker previously positioned by the release rocker under the influence of the oscillating governor at rest, said angular movement of the arming rocker causing a displacement of the locking rocker by pushing one of the starting inclined planes of the arming rocker on the corresponding inclined plane of the locking rocker, so that said locking rocker, via the release rocker, rotates the oscillating governor out of the lifting angle,The escapement mechanism positions itself in a position corresponding to a locking phase, ready to be followed by an unlocking phase and a pulse phase of normal operation.
[0011] Advantageously, the inclined planes of the locking rocker and the inclined planes of the starting rocker are configured so that, during the self-starting phase, the armature rocker, set in motion by the action of the armature mobiles themselves driven by the driving source, positions the locking rocker, via their respective inclined planes, the detent rocker and the oscillating regulator in such a way that the armature rocker is free to move until the end of the movement by one of the armature mobiles and the fall of the latter.
[0012] Thus, the release lever is moved to force the oscillating governor to move, thereby moving out of the lift angle. This is possible because the oscillating governor is close to the center line when the movement is at rest. In this configuration, the position of the locking lever prevents the winding lever from stopping on the locking mechanism of the locking lever and allows the winding lever, driven by the energy of the power source, to move to the end of its travel, driven by one of the winding arms until it falls. At this point, the locking lever forces the oscillating governor into a position outside the lift angle.The escapement gear can then rotate and rewind the leaf spring in the opposite direction, but this time the winding lever, driven by the energy of the power source, is free to move. It will lock against the locking mechanism of the locking lever in a position corresponding to a locking phase, ready to be followed by an unlocking phase and a pulse phase for normal operation. The system is then ready to be released by the oscillating regulator, which returns to the center line and receives an impulse from the leaf spring. The movement begins.
[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 clock movement as defined above. Brief description of the drawings
[0015] Other features and advantages of the present invention will become apparent from the following detailed description of an embodiment of the invention, given by way of non-limiting example, and made with reference to the accompanying drawings in which: there figure 1 is an isometric view of an escapement mechanism of the invention, the leaf spring not yet being flamed; the figure 2 is an isometric view of the unbuckled leaf spring, its frame, and the detent lever; the figure 3 is an isometric view of the winding lever used in the escapement mechanism of the invention, and the figure 3a is a detailed view of the central portion of the cocking lever; the figure 4 is an isometric view of the locking toggle used in the escapement mechanism of the invention; the figure 5is a top view of the end of a locking arm of the locking toggle; the figures 6 and 7 are isometric views of the winding components used in the escapement mechanism of the invention; the figures 8 to 20 represent different positions of the escapement mechanism of the invention during normal operation; and the figures 21 to 35 represent different positions of the escape mechanism of the invention during a self-start phase. Embodiments of the invention
[0016] With reference to the figure 1An escapement mechanism 1 according to the invention is shown in a preferred embodiment. This mechanism, in a known manner described for example in patent EP 2105806, maintains the oscillations of an oscillating regulator 2, composed for example of a balance wheel 2a associated with a balance spring 2b, by supplying it with energy received from a driving source, such as a mainspring barrel (not shown), via a terminal wheel 4 of the finishing gear train, such as a fifth wheel, by means of a bistable leaf spring 6 operating in buckling around a central inflection point I, and whose ends are fixed to a frame 8 for mounting on a watch movement frame. The leaf spring 6 is formed of an initially straight elastic leaf, for example a silicon leaf. It is buckled during assembly so that it occupies a stable position corresponding to first-mode buckling.
[0017] The leaf spring 6 cooperates with a winding rocker 10, a release rocker 12 and a locking rocker 14 of the winding rocker 10 arranged in kinematic connection with the release rocker 12 in order to accumulate the energy from the driving source during winding phases, to remain in a wound state during locking phases and to return the accumulated energy to said oscillating regulator 2 during impulse phases preceded by unlocking phases, during normal operation of the watch movement.
[0018] With particular reference to the figure 2The detent lever 12 is rigidly linked to the leaf spring 6 approximately at its central inflection point I and thus pivots around this inflection point I. At one end, it has a detent fork 16 designed to cooperate with a double plate 20, 21 of the balance wheel 2a, and more specifically with a plate pin 22 pressed onto the large plate 20 of the double plate. A dart 18 is also provided to prevent any reversal, as in a lever escapement. Thus, during the normal operation of the watch movement, the detent lever 12 only moves 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 wheel 2a, thereby transmitting to the latter the elastic energy accumulated during the winding phase of the leaf spring 6.
[0019] The movements of the detent rocker 12 are limited by stops in the form of 8a, 8b for example advantageously integrated in monolithic form into the frame 8.
[0020] The trigger lever 12 has at the opposite end to its trigger fork 16, a release pin 24 integral with said trigger lever, said release pin 24 cooperating with a link fork 26 of the locking lever 14 which will be described in detail below.
[0021] With particular reference to the figure 3The cocking lever 10 comprises a central portion 28 and two cocking arms 30, 32, each consisting of a first portion 30a, 32a and a second portion 30b, 32b. The first portions 30a, 32a extend symmetrically from the central portion 28. Their ends, integral with the second portion 30b, 32b, are kinematically linked to the leaf spring 6, notably in the example shown by cocking pins 34a, 34b inserted with sufficient clearance into eyelets 6a, 6b of the leaf spring 6. The cocking lever 10 is rotatable about an axis passing through the inflection point I. The cocking lever 10 and the trigger lever 12 therefore pivot about the same axis perpendicular to the plane of the figure 1 passing through the inflection point I. However, the detent rocker 12 pivots coaxially with the cocking rocker 10 but independently.
[0022] The second portions 30b, 32b of the winding arms 30, 32 have at their free end a winding beak 36a, 36b respectively, intended to cooperate with a winding star 38a, 38b of a winding mobile 40a, 40b respectively.
[0023] With particular reference to figures 6 and 7 The two winding wheels, left and right, 40a and 40b, each also include an escapement pinion 42a and 42b, coaxial and integral with the winding star 38a and 38b respectively, designed to mesh with the wheel 4 of the finishing train to rotate simultaneously and synchronously in the same direction around separate axes of rotation. Each winding wheel 40a and 40b also includes an inertia wheel 44a and 44b, coaxial and integral with the winding star 38a and 38b and the escapement pinion 42a and 42b.
[0024] The second portions 30b, 32b of the winding arms 30, 32 are not symmetrical and are configured so that the winding beak 36a, i.e. the left winding beak, is directed towards the central portion 28 of the winding rocker 10 by being furthest from the axis of rotation of the winding rocker 10 which passes through the inflection point I. The winding beak 36b, i.e. the right winding beak, is directed opposite to the winding rocker 10 by being closest to the axis of rotation of the winding rocker 10.
[0025] The indexing of the winding lugs 40a, 40b is such that when one of the winding lugs 36a, 36b is in contact with one of the winding stars 38a, 38b, the other winding lug 36a, 36b is not in contact with the other winding star 38a, 38b. Various safety features and safeguards are provided for this purpose by those skilled in the art. For example, at the end of the engagement of a tooth of the winding star 38a, 38b on the corresponding winding lug 36a, 36b, a safety drop must occur before the other tooth of the winding star 38a, 38b comes into contact with the corresponding winding lug 36a, 36b.
[0026] Thus, when the winding star 38a of the winding mechanism 40a drives the winding beak 36a of the winding arm 30 to rotate the winding lever 10 in one direction (here clockwise) to wind the leaf spring 6, the winding mechanism 40b is not in contact with the winding beak 36b of the winding arm 32. Conversely, when the winding star 38b of the winding mechanism 40b drives the winding beak 36b of the winding arm 32b to rotate the winding lever 10 in the other direction (here counterclockwise) to wind the leaf spring 6, the escapement mechanism 40a is not in contact with the winding beak 36a of the winding arm 30.
[0027] The central portion 28 of the cocking lever 10 has, at its end opposite its center of rotation I, or tail, two resting prongs 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 in detail below. Each resting prong 46a, 46b is formed by the intersection of the curved edge of the tail of the central portion 28 with an upper inclined plane 61a, 61b forming an acute angle with the edge of the curve. Said inclined planes 61a, 61b constitute the starting inclined planes, the role of which will be explained below.
[0028] The mechanism 1 according to the invention further comprises a locking rocker 14 for the cocking rocker 10, shown more particularly in the figure 4This locking lever 14 is designed to lock the winding lever 10 when the leaf spring is wound in a metastable state as close as possible to its unstable state. The locking lever 14 is integral with a pivotally mounted axis 48 on the watch movement frame and is kinematically linked to the release lever 12. In the embodiment shown, it comprises a rod 50 extending from a central body 52 through which the axis 48 passes along a longitudinal axis. This rod 50 is provided, at one end, with the connecting fork 26 to the release lever 12 via the unlocking pin 24. For this purpose, the fork 26 of the locking lever 14 has two lugs 26a, 26b defining a space 54 between the lugs into which the unlocking pin 24 of the release lever 12 is inserted.
[0029] At its second end opposite the linkage fork 26, the locking lever 14 also has two locking arms 56a, 56b extending symmetrically from each other with respect to the longitudinal axis of the rod 50 from the central body 52. These locking arms 56a, 56b are concentric with the pivot axis 48 of the locking lever 14 so that there is no pull between the winding lever 10 and the locking lever 14. Sufficient pull is already ensured by the leaf spring 6 of the escapement.
[0030] The two locking arms 56a, 56b are each equipped with a locking member arranged to cooperate with a respective complementary locking member of the cocking lever 10 in order to block said cocking lever 10 during the locking phase.
[0031] Advantageously, the locking member consists of a resting beak 58a, 58b respectively of the locking rocker 14, and the complementary locking member of the cocking rocker 10 consists of the resting beak 46a, 46b respectively described above.
[0032] This means that during a normal operating locking phase, either the right winding star 38b is against the right winding beak 36b of the winding rocker 10 while the left rest beak 46a of the winding rocker 10 is against the left rest beak 58a of the locking rocker 14, or the left winding star 38a is against the left winding beak 36a of the winding rocker 10 while the right rest beak 46b of the winding rocker 10 is against the right rest beak 58b of the locking rocker 14, so that all the components of the escapement are immobile, only the balance wheel 2a freely completing its oscillation.
[0033] According to the invention, each locking arm 56a, 56b of the locking toggle 14 comprises at its free end, following the locking member constituted by the resting beak 58a, 58b respectively, at least one inclined plane 66a, 66b shown in the Figures 4 and 5 , configured to create a contact surface and cooperate with a starting inclined plane 61a, 61b (shown on the figure 3a) provided in correspondence on the arming lever 10 during a self-start phase in which an activation of the drive source causes an angular movement of said arming lever 10 which, by becoming a drive on the locking lever 14, causes a displacement of said locking lever 14 which pivots about its axis 48 by the push of one of the starting inclined planes 61a, 61b of the arming lever 10 moving on the inclined plane 66a, 66b of the locking lever 14 which is located opposite the corresponding starting inclined plane 61a, 61b, i.e. here the straight inclined planes 66b and the starting inclined plane 61b, so that said locking lever 14,which in turn becomes the driving force on the oscillating regulator 2 via the detent rocker 12, whose unlocking pin 24 works with the fork 26 of the locking rocker 14 and whose detent fork 16 drives the plate pin 22, causes the oscillating regulator 2 to rotate out of the lift angle (i.e., the angle during which the plate pin 22 is in contact with the inlet of the fork 16). In parallel, the escapement mechanism 1 positions itself in a position corresponding to a locking phase ready to be followed by an unlocking phase and a pulse phase of normal operation.
[0034] Preferably, the inclined planes 66a, 66b of the locking rocker 14 are of complementary shape to the corresponding starting inclined planes 61a, 61b of the arming rocker 10.
[0035] Advantageously, each locking arm 56a, 56b of the locking rocker 14 comprises successively in the direction of its free end a first segment, which forms the resting beak 58a, 58b respectively constituting the locking member of the locking rocker, and a second segment 62a, 62b, said first and second segments 58a, 62a or 58b, 62b being connected in particular by the respective inclined planes 60a, 60b.
[0036] More specifically, and in relation to the figure 5 , the first segment is of substantially circular shape concentric to the pivot axis 48 of the locking rocker 14. It has on its inner face opposite the rod 50 a surface concentric to the pivot axis 48 which constitutes the rest face of the rest beak 58a, 58b.
[0037] The second segment 62a, 62b has a thickness e' less than the thickness e of the first segment 58a, 58b. The second segment 62a, 62b has on its inner face opposite the rod 50 a surface concentric to the pivot axis 48 and to the first segment 58a, 58b and further from the rod 50 than the concentric surface of the first segment 58a, 58b.
[0038] The aforementioned first and second segments 58a, 62a or 58b, 62b are connected by: inclined planes 60a, 60b comprising a first inclined plane 64 arranged to form a chamfer for the supplementary locking member of the cocking lever, i.e. the resting beak 46a, 46b, and a second inclined plane 66a, 66b forming an obtuse angle with the surface concentric to the pivot axis 48 of the first segment 58a, 58b, chosen so that the contact of the starting inclined plane 61a, 61b of the cocking lever 10 in angular motion with said second inclined plane 66a, 66b causes a rotation of the locking lever 14 about the pivot axis 48, the inclined planes 66a, 66b of the locking lever 14 preferably being complementary in shape to the corresponding starting inclined planes 61a, 61b, and a recess 68 configured to allow the supplementary locking member (i.e. the resting beak 46a, 46b) of the cocking lever 10 to be able to engage in order to allow said cocking lever 10 to complete its travel.
[0039] In a particularly advantageous way, the inclined planes, here the right inclined plane 66b, of the locking rocker 14 are configured so that, during the self-start phase, the winding rocker 10 (whose angular movement has enabled the leaf spring 6 to accumulate energy from the driving source and to position, via the release rocker 12, the locking rocker 14 so that the starting inclined plane, here 61b, of the winding rocker 10 in angular movement can push on the inclined plane 66b of the locking rocker 14 opposite), positions the locking rocker 14, the release rocker 12 and the oscillating regulator 2 in such a way that the winding rocker 10, driven by the energy of the driving source, is free to move until the end of the winding phase, driven by one of the winding articulators 40a, 40b, here the arming mechanism 40a, and its fall.
[0040] Furthermore, in a particularly advantageous manner, the inclined planes 66a, 66b of the locking lever 14 are configured to push on the corresponding starting inclined planes 61a, 61b of the winding lever 10 in order to move said winding lever 10 away from the locking elements (i.e., the resting beak 58a, 58b) of the locking lever 14 when the driving energy becomes insufficient to drive the winding lever 10. Indeed, when the driving energy becomes insufficient, the rocker arm 2a will still perform a few cycles and drive the locking lever 14 with it, as well as the leaf spring 6, which will impose a position on the winding lever 10. The inclined planes 66a, 66b of the locking lever 14 will act as a driving force on the winding lever 10, gently moving it away.Without these inclined planes 66a, 66b, the locking lever 14, under the action of the kinetic energy of the moving balance wheel 2a, would lock abruptly on the winding lever 10, which could damage the locking lever 14 or its fork 26, the winding lever 10, the detent lever 12 or the plate pin 22. Thus, thanks to the inclined planes 66a, 66b, the locking lever 14 does not lock on the resting jaws 46a, 46b of the winding lever 10 when the latter is no longer under the influence of the driving force of the winding stars 38a, 38b at the end of the power reserve.
[0041] According to another aspect of the invention, each locking arm 56a, 56b comprises, on the surface of the second segment 62a, 62b concentric with the pivot axis 48, a groove 70a, 70b extending perpendicularly to the upper and lower faces of the locking arm 56a, 56b and arranged to constitute a capillary point for a lubricant. The portion of the second segment 62a, 62b between the notch 68 and the groove 70a, 70b respectively advantageously constitutes a stop 71a, 71b for the resting jaws 46a, 46b of the cocking lever 10 in order to prevent excessive angular displacement of said cocking lever 10. Grooves 72a, 72b constituting a capillary point for a lubricant are also provided at the top of the arm portions constituting the resting jaws 58a, 58b.
[0042] The 71a, 71b stops are a safety stop to prevent excessive angular movement of the winding rocker 10, during a phase where said winding rocker 10 is free, that is to say between the end of the winding by one winding star 38a, 38b, and the beginning of the winding by the other star 38a, 38b, and at the moment when the leaf spring 6 is in its natural buckling position.
[0043] The 71a, 71b cleats also allow the winding rocker 10 to always be able to remain in an angular position which allows the winding stars 38a, 38b, of the winding mobiles 40a, 40b, to come into contact with the winding beaks 36a, 36b of the winding rocker 10.
[0044] The stops 71a, 71b limit excessive angular displacement of the cocking lever 10, which allows the inclined planes 66a, 66b of the locking lever 14 to always act as drive points on the cocking lever 10 in the event of a shock or start-up. Without this stop, during a shock, the cocking lugs 34a, 34b of the cocking lever 10 could strike the inside of the eyelets 6a, 6b of the leaf spring 6 and force it beyond its natural buckling position.
[0045] According to another aspect of the invention, the locking lever 50 has a length (along its longitudinal axis) between its pivot center passing through the pivot axis 48 and the functional portion of the space between the lugs 54 that is greater than or equal to twice the length of the release lever 12 between its inflection point I and the unlocking pin 24. In other words, the point of contact between the locking lever 14 and the release lever 12 is located in a proportion of 2 / 3 - 1 / 3 of the total center distance (distance between the pivot center of the locking lever 14 and the inflection point I of the release lever 12). In prior art escapement mechanisms, the length of the locking lever 14's rod is less than half the length of the release lever 12.
[0046] Increasing the length of the locking lever 50, and therefore shortening the location of the unlocking pin 24 on the trigger lever 12, allows for a longer lever arm which has two effects: decrease in the angle traveled by the locking lever, and therefore decrease in the torque required by the balance wheel 2a to overcome the release of the escapement, this reduces losses and increases the amplitude of the balance wheel; increase in the angle traveled by the balance wheel 2a when the locking lever is driving during the self-start phase.
[0047] The normal operation of the escapement mechanism 1 according to the invention is explained below with reference to figures 8 to 20 .
[0048] There figure 8Figure 14 represents the escapement mechanism according to the invention after an impulse phase. The balance wheel 2a, having already received an impulse, oscillates freely along its additional ascending arc. The leaf spring 6 is in its stable first-order state and is at rest, unwound. The winding lever 10 is positioned so that the right winding star 38b of the right winding wheel 40b is at the beginning of the winding path of the right winding beak 36b of the winding lever 10. The left winding beak 36a of the winding lever 10 has released the tooth of the left winding star 38a of the left winding wheel 40a.
[0049] This is followed by a winding phase of the winding lever 10 by the right-hand winding star 38b, the energy being transmitted from the driving source to the mobile 4 which rotates counterclockwise, driving the two winding mobiles 40a, 40b simultaneously clockwise via their escape pinion 42a, 42b. Only the right-hand winding mobile 40b can transmit energy to the winding lever 10 via the right-hand winding star 38b and the right-hand winding beak 36b, creating a driving torque so as to rotate the winding lever 10 counterclockwise. The winding lever 10 then pivots around its axis I, winding the flamed leaf spring 6 via the winding tenons 34a, 34b inserted into the eyelets 6a, 6b of the leaf spring 6. The trigger lever 12 rests against the stop 8a. With the balance wheel 2a in its additional arc, the plate pin 22 is outside the entrance of the trigger fork 16 of the trigger lever.Under these conditions, the winding of the leaf spring 6 will press the trigger lever 12 against the stop 8a.
[0050] With reference to the figure 9 At the end of the winding phase, the leaf spring 6 deformed, transitioning from first-order buckling to near second-order buckling, while being wound in a metastable state, as close as possible to its unstable state. The right winding star 38b abuts the right winding beak 36b of the winding lever 10, and the left resting beak 46a of the winding lever 10 is locked against the left resting beak 58a of the left locking arm 56a of the locking lever 14, as shown in the detail in the Figure 10on which the terminal wheel 4, here the fifth wheel, is not shown. The escapement mechanism 1 is then in its locking phase in which all the escapement components are stationary. Only the balance wheel 2a completes its oscillation freely along its additional arc, the balance wheel pin 22 being close to its point of contact with the detent fork 16 of the detent lever 12.
[0051] Then come the unlocking and impulse phases, in reference to the figure 11 and to the figure 12 on which the terminal mobile 4 is not shown.
[0052] The balance wheel's pivot pin 22, extending from its descending arc, enters the detent fork 16 of the detent lever 12, causing the lever to rotate so that the detent lever 12 disengages from the stop 8a. This movement of the detent lever 12 forces the leaf spring 6 to move beyond its metastable state. The instantaneous movement of the leaf spring 6, with its eyelets 6a and 6b, from its metastable state to a second-order flared state causes the detent lever 12 to rotate counterclockwise around the inflection point I. This detent lever 12 then becomes the driving force and drives the balance wheel's pivot pin 22, thus beginning to transmit the impulse to the balance wheel 2a. Meanwhile, 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 the figure 12 .
[0053] In the middle of the impulse phase shown on the figure 13 The leaf spring 6 is supplying its impulse to the balance wheel 2a via the fork of the detent rocker 12. Said detent rocker 12, rotating counterclockwise around the inflection point I, drives the balance wheel 2a clockwise via its fork and the pallet fork pin 22, and the locking rocker 14 clockwise around its axis 48 via the unlocking pin 24 inserted into the fork 26 of the locking rocker 14. Therefore, as shown in the detail at the figure 14In which the terminal mobile 4 is not shown, the left-hand resting beak 58a of the locking lever 14 has moved and released the left-hand resting beak 46a of the winding lever 14. Said winding lever 14 no longer holds the driving force of the gear train because it is free. The gear train is therefore free but is not yet rotating because the inertia of the wheels 44a, 44b prevents it from doing so.
[0054] At the end of the impulse phase shown on the figure 15Under the influence of the leaf spring 6, the trigger lever 12 moved counterclockwise until it came to rest against the stop 8b, carrying with it the balance wheel 2a via the trigger fork 16 and the balance wheel 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, also moved clockwise, away from the left resting beak 46a of the winding lever 10, as shown in the detail at the figure 16on which the terminal mobile 4 is not shown. The locking lever 14 has released the winding lever 10, which, now unlocked, offers no further resistance, the winding lugs 34a, 34b of the winding lever 10 no longer being in contact with the eyelets 6a, 6b of the leaf spring 6 following the passage of said leaf spring 6 into its stable state of the first inverse order of that of the figure 8 The gear, having overcome the inertia preventing it from rotating during the impulse, can begin to rotate, and the moving part 4 can resume its rotation in the counterclockwise direction.
[0055] With reference to the figure 17The balance wheel 2a continues its oscillation along its additional ascending arc. The freed gear train has begun to rotate, driven by the mobile 4 which rotates counterclockwise, simultaneously driving the winding mobiles 40a and 40b clockwise. The winding star 38b pushes the right winding beak 36b of the winding lever 10 until it reaches point-to-point alignment, as shown in the detail at the figure 18 The cocking lever 10 then rotates counterclockwise, without cocking the leaf spring 6, its cocking lugs 34a, 34b no longer being in contact with the eyelets 6a, 6b of the leaf spring 6. The left resting beak 46a of the cocking lever 10 approaches the left notch 71a of the left locking arm 56a of the locking lever 14 without touching it, thanks to a safety mechanism designed for this purpose, and fits into the recess 68 under the inclined planes 60a, as shown in the detail in the figure 18on which the terminal mobile 4 is not shown.
[0056] Then, with reference to the figure 19 The balance wheel 2a continues its oscillation along its additional ascending arc. The winding wheels 40a and 40b continue their clockwise rotation so that the right winding star 38b leaves the right winding beak 36b of the winding lever 10. As a result, the gear train drops and the left winding star 38a comes into contact with the left winding beak 36a of the winding lever 10, as shown in the detail at the Figure 20 on which the terminal mobile 4 is not shown. The cycle driven by the right winding star 38b is complete. From this point, a new cycle will begin as described above, but in the opposite direction, driven by the left winding star 38a, so that the winding rocker 10 will wind the leaf spring 6 by moving clockwise.
[0057] During a stop phase, when the watch movement has stopped at the end of its power reserve due to lack of driving force, the components of the escapement mechanism of the invention behave as follows: the leaf spring 6 is in its natural position, flared at rest and uncocked, as shown on the figures 8 Or 19 ; the cocking lever 10, via the cocking lugs 34a, 34b, which are located inside eyelets 6a, 6b, is in a position imposed by the leaf spring 6. The cocking stars 38a, 38b of the cocking mechanisms 40a, 40b are in a position identical to that of the figures 8 Or 19Indeed, without sufficient driving force, they will only be able to rest against one or the other of the cocking lugs 36a, 36b of the cocking lever 10 without managing to move it because the latter, via its cocking lugs 34a, 34b, is in a position imposed by the leaf spring 6; the trigger lever 12 and the locking lever linked by the unlocking pin 24 are under the influence of the leaf spring 6 in a stable position identical to that of the figures 8 Or 19The detent lever 12, wishing to be pressed against one or the other of the stops 8a, 8b; the balance wheel 2a, under the influence of the balance spring 2b, would like to be on the center line. The balance wheel pin 22 being in the lug opening of the detent fork 16 of the detent lever 12, said detent lever 12 is only slightly detached from the stop 8a or 8b, because the leaf spring 6 is not strong enough to completely counteract the torque of the balance spring 2b. At the moment when the driving force becomes insufficient, the balance wheel 2a, thanks to its stored kinetic energy, will still perform a few more oscillations and drive the leaf spring 6 until all the elements of the mechanism come to a complete stop. The cocking lever 10, positioned by the leaf spring 6 via its cocking tenons 34a, 34b and the eyelets 6a, 6b, can be found on the passage of the resting beaks 58a, 58b of the locking lever 14.Advantageously, thanks to its inclined planes 66a, 66b, the locking lever 14 will push the inclined planes of the resting beaks 46a, 46b of the cocking lever 10 and release it towards its central position so as not to damage anything.
[0058] The exhaust mechanism 1 is in position to begin a self-starting phase according to the invention, explained below with reference to figures 21 to 35 .
[0059] With reference to the figure 21 The elements of the escapement mechanism 1 are in position as described above in a stop phase: the mobile 4 and the winding mobiles 40, 40 are at rest, the position of the winding rocker 10 is influenced by the leaf spring 6 and the position of the detent rocker 12 is slightly detached from the struts, here the strut 8b, under the influence of the balance spring 2b. The balance wheel 2a is at rest.
[0060] With reference to the figure 22When a user powers the drive, for example by winding a barrel, the moving part 4 begins to rotate counterclockwise. The winding parts 40a, 40b begin to rotate clockwise until one of the winding stars 38a or 38b meets the corresponding winding beak 36a, 36b of the winding rocker 10. Here, it is the right-hand winding star 38b that will meet the right-hand winding beak 36b of the winding rocker 10 so that the winding rocker 10 is pushed counterclockwise. With the spring-blade 6 already positioned on this side, the cocking lugs 34a and 34b of the cocking lever 10 can move freely within the eyelets 6a and 6b, bringing the right-hand cocking star 38b to the end of its travel. The locking lever 14 is positioned by the trigger lever 12.Since this is not supported against the 8a, 8b cleats under the influence of the spiral 2b as described above, the left rest beak 46a of the winding lever 10 does not come into contact with the left rest beak 58a of the locking arm 56a of the locking lever 14 by fitting into the recess 68 near its second inclined plane 66, as shown in the detail at the . figure 23 on which the terminal mobile 4 is not shown. Thus, the locking rocker 14 leaves the winding rocker 10 free. It should also be noted that following a shock or disturbance, the winding rocker 10, by its inclined starting planes 61a, 61b, can disengage the locking rocker by working on its inclined planes 66a, 66b so as to impart a small movement to the rocker 2a.
[0061] With reference to the figure 24Following the end of the winding of the right winding star 38b, it leaves the right winding beak 36b of the winding rocker 10. As a result, the gear falls until a tooth of the left winding star 38a comes into contact with the left winding beak 36a of the winding rocker 10. The left winding star 38a then drives the winding rocker 10 until the winding tenons 34a, 34b of the winding rocker 10 come into contact with the eyelets 6a, 6b of the leaf spring 6.
[0062] An initial arming phase of the self-starting phase can begin with reference to the figure 25The left winding star 38a is driven by the left winding wheel 40a and works with the left winding beak 36a of the winding lever 10, so that said winding lever 10 will move clockwise. Said winding lever 10 will begin to wind the leaf spring 6 in a clockwise motion by means of its winding lugs 34a, 34b working in the eyelets 6a, 6b of the leaf spring 6. The release lever 12, under the influence of the torque of the balance spring 2b, is not pressed against the lugs 8a, 8b, as explained above. This forces the detent lever 12 to pivot around the inflection point I to follow the clockwise movement of the leaf spring 6, driving the balance wheel 2a via the platform pin 22 caught in the detent fork 16. The balance wheel 2a will begin to rotate counterclockwise towards the center line.
[0063] Unlike a normal operating cycle during which the winding of the leaf spring 6 presses the detent lever 12 against one of the lugs 8a, 8b, due to the balance wheel 2a being in its additional arc, the plate pin 22 being outside the entrance of the detent fork 16 as described above in relation to the figures 8 to 10 , the winding of the leaf spring 6 during the self-starting phase moves the detent rocker 12 in the direction of the winding of the leaf spring 6. The spiral 2b also helps to detach the detent rocker 12 from the 8a, 8b stoons because its torque tends to bring the balance wheel 2a back onto the center line.
[0064] With reference to the figure 26The winding of the leaf spring 6 in the clockwise direction continues, the left winding star 38a rotating clockwise pushing the left winding beak 36a of the winding lever 10, so that said winding lever 10 will move clockwise. The leaf spring 6 carries with it the detent lever 12 clockwise, which itself moves the locking lever 14 counterclockwise so that said locking lever 14 is positioned so that the right resting beak 46b of the winding lever 10, in clockwise angular motion, can push the first chamfered inclined plane 64 of the inclined planes 60b of the right locking arm 56b opposite the locking lever 14, i.e., here the first right inclined plane 64, as shown in the detail at the figure 27 .
[0065] With reference to the detailed view of the figure 28In which the terminal mobile 4 is not shown, the winding rocker 10 continues its clockwise rotation, still under the action of the left winding star 38a pushing the left winding beak 36a of the winding rocker 10. Thus, the right-hand inclined starting plane 61b of the winding rocker 10, now acting as a drive, pushes on the second right-hand inclined plane 66b of the locking rocker 14, which will drive it counterclockwise. The locking rocker 14 in turn becomes a drive, its movement being transmitted to the release rocker 12 and the balance wheel 2a via the fork 26 and the release pin 24, then via the release fork 16 and the plate pin 22. Thus, the release rocker 12 becomes a drive under the action of the locking rocker 14, itself pushed by the winding rocker 10.The detent rocker 12, which has become a driving force, moves the balance wheel 2a counterclockwise out of the lifting angle by means of its detent fork 16 working with the plate pin 22, which sets in motion said oscillating regulator 2, the balance wheel 2a beginning to rotate.
[0066] With reference to the figure 29 , the trigger lever 12 continues to rotate clockwise and, if the winding of the leaf spring 6 by the winding lugs 34a, 34b inserted into the eyelets 6a, 6b of the leaf spring 6 is sufficient, forces said leaf spring 6 to pass beyond its instability to return to a stable mode inverse to the stable mode shown on the figure 26 .
[0067] Upon returning to its stable position, the leaf spring 6 becomes the driving force on the detent rocker 12, which, via its detent fork 16 working with the balance wheel pin 22, gives an impulse to the balance wheel 2a, which facilitates its self-starting, as shown in the figure 30 The trigger lever 12 is momentarily pressed against the left stop 8.
[0068] The inclined planes 66a, 66b of the locking rocker 14 and the starting inclined planes 61a, 61b of the winding rocker 10 are configured so that the winding rocker 10 imposes on the locking rocker 14, the detent rocker 12 and the oscillating regulator 2 an ideal position to be reached, the balance wheel 2a then being forced into a position outside the lifting angle and the winding rocker 10 then being free to move.
[0069] More specifically in relation to the figure 31, the trigger lever 12, having rested against the left stop 8a, puts the locking lever 14 into position in order to allow the right rest beak 46b of the cocking lever 10 to pass through which can engage in the right notch 68 of the right locking arm 56b. Thus, the winding lever 10 cannot stop on the right-hand resting beak 58b of the locking lever 14. The winding lever 10 can then move freely, driven by the main gear, while forcing the balance wheel 2a into a position outside the lift angle maintained by the winding lever 10, the locking lever 14, and the release lever 12, until the left-hand winding star 38a, driven by the moving part 4, completes its movement on the left-hand winding beak 36a of the winding lever 10 and falls until the right-hand winding star 38b comes into contact with the right-hand winding beak 36b of the winding lever 10, as shown in the figure 32 .
[0070] The escapement gear driven by the power source can then rotate so that the right-hand winding star 38b, driven by the moving part 4, winds the winding lever 10 counterclockwise by its right-hand winding beak 36b until the left-hand resting beak 46a of the winding lever 10 comes to rest against the left-hand resting beak 58a of the left-hand locking arm 56a of the locking lever 14, as shown in the figure 33 and in detail figure 34 During this movement of the winding lever 10, its winding lugs 34a, 34b have wound the leaf spring 6 via its eyelets 6a, 6b. The leaf spring 6 is now wound close to being unstable. The escapement mechanism is then in a position corresponding to a locking phase ready to be followed by an unlocking phase and an impulse phase of normal operation. The balance wheel 2a is still in its ascending supplementary arc.
[0071] With reference to the figure 35The gear train is now stopped and the leaf spring 6 is wound close to being unstable. The clockwise return of the balance wheel 2a will bring the balance wheel pivot 22 into the detent fork 16 and release the leaf spring 6 so that it can impart its impulse to the balance wheel 2a. This configuration is identical to that described in the figure 11 which corresponds to a classic pulse of normal operation. From this point on, the exhaust has completed its self-start phase and will operate in a classic manner, as described above with reference to figures 8 to 20 .
Claims
1. An escapement mechanism (1) arranged to provide mechanical impulses from a driving source to an oscillating regulator (2) of a watch movement by means of a leaf spring (6) working in buckling mode around an inflexion point (I), said mechanism comprising a winding lever (10), a detent lever (12) and a locking lever (14) of the winding lever (10) arranged in kinematic linkage with the detent lever (12), said leaf spring (6) being likely, in normal operation, by means of said winding lever (10), said locking lever (14) and said detent lever (12), to accumulate the energy originating from the driving source transmitted by winding wheels and pinions (40a, 40b) during a winding phase, to then remain in a wound state during a locking phase, and to then restore the accumulated energy to said oscillating regulator (2) during an impulse phase preceded by an unlocking phase, said locking lever (14) comprising two locking arms (56a, 56b) which are each equipped with a locking member (58a, 58b) arranged to cooperate with a respective complementary locking member (46a, 46b) of the winding lever (10) in order to block said winding lever (10) during the locking phase, characterised in that each locking arm (56a, 56b) of said locking lever (14) includes, at its free end, at least one inclined plane (66a, 66b) configured to cooperate with an inclined starting plane (61a, 61b) provided in correspondence on the winding lever (10) during a self-starting phase during which an activation of the driving source causes the winding lever (10) to start an angular movement, the free passage of which winding lever is allowed by the locking lever (14) which, until then, is positioned by the detent lever (12) under the influence of the stopped oscillating regulator (2), said angular movement of the winding lever (10) causing a displacement of the locking lever (14) by pushing one of the inclined starting planes (61a, 61b) of the winding lever (10) onto the corresponding inclined plane (66a, 66b) of the locking lever (10), such that said locking lever (14), by means of the detent lever (12), rotates the oscillating regulator (2) out of the lift angle, the escapement mechanism (1) positioning itself in a position corresponding to a locking phase ready to be followed by an unlocking phase and an impulse phase of normal operation.
2. The escapement mechanism (1) according to Claim 1, characterised in that the inclined planes (66a, 66b) of the locking lever (14) and the inclined starting planes (61a, 61b) of the winding lever (10) are configured so that, during the self-starting phase, the winding lever (10) positions the locking lever (14), the detent lever (12) and the oscillating regulator such that the winding lever (10), driven by the energy of the driving source, is free to be displaced up until the end of leading by one of the winding wheels and pinions (40a, 40b) and the fall of the latter.
3. The escapement mechanism (1) according to any one of the preceding claims, characterised in that the inclined planes (66a, 66b) of the locking lever (14) are configured to push onto the corresponding inclined starting plane (61a, 61b) of the winding lever (10) in order to move said winding lever (10) away from the locking members (58a, 58b) of the locking lever (14) when the driving energy becomes insufficient to drive the winding lever (10).
4. The escapement mechanism (1) according to any one of the preceding claims, characterised in that the locking lever (14) comprises a rod (50) equipped at a first end with a linking fork (26) to the detent lever (12), the two locking arms (56a, 56b) extending from a second end symmetrically with respect to the longitudinal axis of the rod (50).
5. The escapement mechanism (1) according to Claim 4, characterised in that the fork (26) of the locking lever (14) includes two horns (26a, 26b) delimiting an inter-horn space (54) in which an unlocking pin (24) which is integral with the detent lever (12) cooperates.
6. The escapement mechanism (1) according to Claim 5, characterised in that the rod (50) of the locking lever (14) has a length between its pivot centre which passes through the pivot axis (48) and the functional part of the inter-horn space (54) which is greater than or equal to twice the length of the detent lever (12) between its inflexion point (I) and the unlocking pin (24).
7. The escapement mechanism (1) according to any one of Claims 4 to 6, characterised in that each locking arm (56a, 56b) of the locking lever (14) successively comprises, in the direction of its free end, a first segment having, on its inner face facing the rod (50), a surface concentric with the pivot axis (48) of the locking lever (14) and a second segment (62a, 62b) of lesser thickness, having on its inner face facing the rod (50), a surface concentric with the pivot axis (48) of the locking lever (14), the first segment forming a locking beak constituting the locking member (58a, 58b), said first and second segments being connected by a first inclined plane (64) to form a chamfer for the complementary locking member (46a, 46b) of the winding lever (10), a second inclined plane (66) forming an obtuse angle with the surface concentric with the pivot axis (48) of the locking lever (14) of the first segment chosen so that the contact of the inclined starting plane (61a, 61b) of the winding lever (10) in movement with said second inclined plane (66) causes a rotation of the locking lever (14) about its pivot axis (48), and a recess (68) configured to allow the complementary locking member (46a, 46b) of the winding lever (10) to be able to engage therein.
8. The escapement mechanism (1) according to the preceding claim, characterised in that each locking arm (56a, 56b) comprises, on the surface concentric with the pivot axis (48) of the locking lever (14) of the second segment (62a, 62b), a groove (70a, 70b) extending perpendicularly to the upper and lower faces of the locking arm (56a, 56b), the portion of said second segment (62a, 62b) between the recess (68) and the groove (70a, 70b) being arranged to constitute a banking (71a, 71b) to prevent an excessive angular displacement of the winding lever (10).
9. The escapement mechanism (1) according to any one of the preceding claims, characterised in that it comprises two winding wheels and pinions (40a, 40b) each comprising an escapement pinion (42a, 42b) intended to mesh with a wheel and pinion (4) of the finishing gear of the watch movement to pivot simultaneously in a same direction around distinct axes of rotation and a winding star (38a, 38b) intended to cooperate with a winding beak (36a, 36b) provided at the end of a winding arm (30, 32) of the winding lever (10), the indexing of these winding wheels and pinions (40a, 40b) being such that when one of the winding beaks (36a, 36b) is in contact with one of the winding stars (38a, 38b), the other winding beak (36a, 36b) is not in contact with the other winding star (38a, 38b).
10. The escapement mechanism (1) according to the preceding claim, characterised in that each winding wheel and pinion (40a, 40b) comprises an inertia wheel (44a, 44b).
11. A watch movement comprising an escapement mechanism (1) according to any one of Claims 1 to 10.
12. A timepiece comprising an escapement mechanism (1) according to any one of Claims 1 to 10 or a watch movement according to Claim 11.