CLUTCH CLOCK MECHANISM

Description

Domaine technique

[0001] The present invention relates to a clutch watch mechanism. The present invention also relates to a watch movement comprising such a mechanism, as well as a timepiece, for example a chronograph watch, in particular a wrist chronograph watch, comprising such a mechanism or such a movement. Although the mechanism according to the invention can be used to produce a clutch in a chronograph watch, it is not limited to such an application, but it can also be used for any other watchmaking application which requires a clutch: for example and in a non-limiting manner, it can be used in a striking watch mechanism. Etat de la technique

[0002] A chronograph watch is a timepiece that can measure time. Typically, a chronograph watch includes at least one indicator (such as a hand) that can be started and stopped by a pusher or other control element to measure time. It can then be returned to its starting point. Chronograph watches generally also include indicators for displaying the current time in addition to displaying the measured time.

[0003] Conventional chronograph watches draw the energy necessary for the operation of the part of the movement allowing the measurement of a duration from the kinematic chain allowing the counting and display of the current time, that is to say from the kinematic chain linking an energy source, for example a barrel, to the regulating organ and the wheels of the watch, which are linked to the indicators of the watch in order to display the current hour, minutes and / or seconds.

[0004] In order to extract the energy needed to set in motion the kinematic chain enabling the measurement of a time duration, it is necessary to create a clutch between the kinematic chain which enables the current time to be counted and displayed and that which enables the measurement of a time duration.

[0005] Two main organs are used in the majority of chronograph watch mechanism operations, namely control devices and clutch devices.

[0006] The control devices can be, for example, cam or column wheel. Since they are known per se in the field of technology, they will not be described here.

[0007] Clutch devices allow the chronograph drive train to be driven by the drive train for counting and displaying the current time. In particular, clutch devices allow the chronograph drive train to be started and stopped very quickly, and also to be locked while keeping the chronograph indicators stopped.

[0008] Various types of clutch devices, including vertical, horizontal, and oscillating pinion clutch devices, are known.

[0009] Vertical clutch devices allow a so-called "vertical" clutch between the two drive trains, in particular between a wheel of one drive train and a wheel of the other drive train.

[0010] In the case of a vertical clutch, the energy transmission is not done by teeth, but by friction, for example on the faces of the wheels. The advantage of this type of clutch is that the drive of the counter which allows the measurement of a time duration is done without starting jump. On the other hand, it is expensive due to the high number of parts and its development remains quite difficult. In addition, this vertical clutch requires a certain height in the movement. In addition, its operation involves high operating forces, which can cause operational problems.

[0011] Lateral or horizontal clutch devices allow two wheels to be coupled by bringing them into contact by their periphery, in particular by their teeth. The disadvantage of this type of clutch is that when driving the chronograph wheel it is possible to have a starting jump caused by a bad alignment of the teeth of the two wheels. The gap is all the smaller the more teeth there are. However, teeth with many teeth are difficult to manufacture and more subject to wear. In this type of device, there is no oscillating movement or tilting of the elements of these devices.

[0012] There are also oscillating pinion clutch devices, which allow energy to be transmitted from one wheel of one drive train to a wheel of the other drive train using an oscillating pinion. This oscillating pinion has a first toothing which is in permanent contact with the wheel of the drive train which makes it possible to determine the current time. This oscillating pinion, under the action of an actuating device such as a rocker, oscillates or rocks, so that its second toothing comes into contact with the wheel which makes it possible to measure a duration, thus also setting it in rotation.

[0013] Similar to horizontal clutches, when using an oscillating pinion clutch, the penetration of the teeth of the oscillating pinion into those of the chronograph wheel can cause an untimely jump of the chronograph wheel and therefore of the chronograph indicator, resulting in a shift in the information.

[0014] Other clutch solutions have been developed. An example of such a solution is described in EP2085832. In the mechanism described in this document, when the user operates a column wheel via a control push button in order to stop the chronograph, clamps press on a clutch disc, thus locking a chronograph wheel. Simultaneously, an insulator drives a rotating insulator wheel, which has the effect of radially moving clutch elements using several lugs, thus stopping the chronograph mechanism. In this way, a clutch spring is no longer in contact with a drive plate, thus stopping the chronograph wheel. The clutch described comprises a radial spring and an axial or vertical conical spring, the latter being necessary for the correct operation of the reset.

[0015] When the user activates the column wheel again via the control push button to start the chronograph, the clamps move away from the clutch disc, thus releasing the chronograph wheel. Simultaneously, the insulator rotates the insulator wheel, which has the effect of radially moving the clutch elements using the lugs. In this way, the clutch spring comes into contact with the drive plate, thus starting the chronograph.

[0016] The clutch mechanism described is complex and comprises more than ten parts. In addition, the clutch disc is actuation indirectly and is done via pins. Finally, in order to achieve the coupling with the chronograph shaft, several contacts take place between the different components (drive plate → clutch elements → spring → disc → friction spring → ring → shaft), which results in a significant loss of energy.

[0017] Document EP3671370 describes another clutch mechanism, in which, when a clamp is actuated to start the chronograph, its support element moves away from a clutch disc. At this moment, elements pivot under the effect of springs. Positioned pins then abut against a chronograph wheel, which ensures the coupling and therefore the clutch.

[0018] When the clamp is actuated again to stop the chronograph, its support element comes into contact with the clutch disc, which causes certain elements of the clutch disc to pivot, thus releasing the lugs of the chronograph wheel and allowing disengagement.

[0019] This clutch mechanism is complex, as it requires a clutch disc having elements arranged to pivot under the action of flexible blades and to accommodate pins that are perpendicular to the plane of the disc. Since these pins perform the clutch with the chronograph wheel, the friction surface between the chronograph wheel and each of these pins is small, which reduces the reliability of the clutch. In addition, the mechanism described includes several parts (clutch disc, several pins, etc.), which does not facilitate the assembly of the mechanism, in addition to complicating the mounting of the pins in the disc. Bref résumé de l'invention

[0020] An object of the present invention is to provide a clutch mechanism free from the limitations of known clutch mechanisms.

[0021] Another object of the invention is to provide a clutch mechanism which comprises fewer components than known clutch mechanisms.

[0022] Another object of the invention is to provide a clutch mechanism that is less bulky than known clutch mechanisms.

[0023] Another object of the invention is to provide a clutch mechanism which is easier to mount than known clutch mechanisms.

[0024] According to the invention, these aims are achieved in particular by means of the clutch mechanism according to claim 1.

[0025] The clutch clock mechanism according to the invention comprises: a shaft, a first wheel (or drive wheel) arranged to be freely rotatably mounted on the shaft and to rotate continuously about the shaft, a second wheel (or driven wheel) integral with the shaft, a clutch disc integral with the shaft, and a control device.

[0026] In this context, the expression "clutch disc (or second wheel) integral with the shaft" indicates that the disc (or second wheel) and the shaft can be driven by each other in a common movement, without necessarily being fixed (e.g. directly fixed) to each other. For example, a clutch disc frictionally connected to the shaft is also integral with the shaft.

[0027] The clutch clock mechanism according to the invention is arranged to pass, under the action of the control device, from an engaged position to a disengaged position and vice versa. In particular, in the engaged position, the first wheel drives the second wheel (the drive not necessarily being direct), and in the disengaged position the first wheel no longer drives the second wheel.

[0028] According to the invention, the clutch disc belongs to a plane perpendicular to the shaft and in this plane it comprises: a central hub cooperating with the shaft, at least two peripheral rigid clutch elements, and at least one flexible blade connecting each peripheral rigid clutch element to the central hub.

[0029] In the context of the present application, the expression "flexible blade" means a blade or beam, arranged to deform elastically in the plane of the clutch disc, for example in a bending movement.

[0030] In the context of the present application, the expression "rigid clutch elements" designates parts of the clutch disc which are not intended to be deformed during operation of the mechanism according to the invention, and whose rigidity is greater than that of the flexible blades.

[0031] In the context of the present application, the expression "peripheral rigid clutch elements" means rigid clutch elements which are at the periphery of the clutch disc and in particular which define its external diameter.

[0032] According to the invention, the flexible blades are arranged to deform in the plane of the clutch disc, so that: in the engaged position, the clutch disc has a first diameter, such that the peripheral rigid clutch elements come into contact with a surface of the first wheel, the first wheel driving the clutch disc by means of this contact, the clutch disc therefore driving the shaft, and the shaft driving the second wheel, in the disengaged position, the clutch disc has a second diameter smaller than the first diameter, such that the peripheral rigid clutch elements no longer come into contact with the surface of the first wheel.

[0033] In this context, the term "clutch disc diameter" refers to the largest dimension of the clutch disc.

[0034] Since the first wheel is arranged to be mounted freely rotatably on the shaft, its rotation in the disengaged position does not cause rotation of the shaft or of the second wheel. On the other hand, in the engaged position, the rotation of the first wheel allows rotation of the shaft, and therefore of the second wheel which is integral with the shaft, via the clutch disc.

[0035] This solution has the advantage of comprising fewer components compared to known clutch mechanisms. In fact, the clutch is achieved by a single component, namely the clutch disc, without the need for pins or a plurality of components that come into contact with each other to achieve the clutch between the first wheel and the second wheel.

[0036] Therefore, the clutch mechanism according to the invention is less bulky than known clutch mechanisms and can be used, for example, in timepieces having a reduced thickness.

[0037] In addition, due to the reduced number of its components, the clutch mechanism is easier to assemble than known clutch mechanisms.

[0038] Finally, in the clutch mechanism according to the invention, the energy transmission is done horizontally (or radially) not by teeth, but by friction. This type of mechanism will subsequently be called a horizontal (or radial) friction clutch mechanism.

[0039] In one embodiment, the peripheral rigid clutch elements move, under the action of the flexible blades, with a movement which is a substantially translational (or "quasi-translational") movement in a radial direction of the clutch disc, between the engaged position and the disengaged position. In other words, the clutch disc contracts (in the disengaged position) and expands (in the engaged position) under the action of the flexible blades.

[0040] The movement of the peripheral rigid clutch elements is a substantially translational movement because there is also a slight rotation of these elements around the central hub which is due to the deformation of the flexible blades. However, this rotation, of the order of magnitude of a few degrees, in particular less than 10°, is negligible compared to the radial translation of the peripheral rigid clutch elements.

[0041] In one embodiment, the first wheel comprises a housing arranged to receive the clutch disc at least partially in the direction of the shaft.

[0042] In one embodiment, in the engaged position, each flexible blade is substantially straight. This makes it possible to reduce the low rotation of the clutch disc due to the deformation of the flexible blades, when changing from the engaged position to the disengaged position and vice versa.

[0043] In one embodiment, the peripheral rigid clutch elements are arc-shaped and / or comprise a portion in the shape of an arc of a circle. In one embodiment, this arc of a circle has an angular opening in the range between 20° and 170°, for example in the range 30° to 120°. In one embodiment, the peripheral rigid clutch elements all have the same dimensions and / or the same shape. In another embodiment, they do not necessarily all have the same dimensions and / or the same shape.

[0044] In one embodiment, the clutch disc comprises a pair of parallel flexible blades connecting at least one peripheral rigid clutch element to the central hub. This further reduces the low rotation of the clutch disc due to the deformation of the flexible blades, when moving from the engaged position to the disengaged position and vice versa. In other words, having two parallel blades makes it possible to approach translational guidance.

[0045] In one embodiment, the second wheel is a chronograph wheel and the central hub includes central flexible blades, these central flexible blades being arranged to allow adjustment of the torque value at which the shaft slips during a reset.

[0046] In one embodiment, the central hub is arranged to limit deformation of the central flexible blades.

[0047] In one embodiment, the second wheel is a chronograph wheel and the central hub is arranged such that, in the engaged position, the central hub has a first diameter to contact the shaft, in the disengaged position and when resetting the chronograph wheel by a resetting mechanism, the central hub has a second diameter larger than the first diameter, so that the shaft can slip on the central hub.

[0048] In this embodiment therefore, in the disengaged position and upon reset, the clutch disc has a smaller outer diameter than that of the engaged position, and the central hub has a larger diameter than that of the engaged position. In other words, in the disengaged position and upon reset, the peripheral rigid clutch elements move radially toward the center of the disc, while the central hub moves away from the shaft. This also allows the friction torque for the reset to be precisely adjusted, with the aim of obtaining a very small or even zero friction torque (no contact with the shaft if the central hub becomes completely detached from the shaft).

[0049] In one embodiment, the central hub comprises at least two central rigid elements defining the first diameter in the engaged position, and the second diameter in the disengaged position. In other words, the central rigid elements move towards each other in the engaged position, and move away in the disengaged position and when resetting the chronograph wheel.

[0050] In one embodiment, at least one peripheral rigid clutch element comprises a first surface and a second surface adjacent the first surface in the shaft direction, such that: in the engaged position, the first surface contacts the first wheel, the second surface being moved away from a clamp; in the disengaged position, the clamp contacts the second surface, which moves the first surface away from the first wheel.

[0051] In one embodiment, the clamp comprises: a rigid body, two jaws arranged to cooperate with the clutch disc, flexible blades connecting the rigid body to the jaws.

[0052] In this embodiment, when moving from the engaged position to the disengaged position, the rigid body moves in translation in a first direction in a plane of the clamp, causing a translational movement of the jaws in a second direction in this plane, the second direction being substantially perpendicular to the first direction, the two jaws move closer together (in the disengaged position) and move apart respectively (in the engaged position) during their movement, which in particular makes it possible to clamp the clutch disc or not.

[0053] In one embodiment, the clamp includes a frame that does not move when transitioning from the engaged position to the disengaged position.

[0054] In one embodiment, the clamp comprises: a rocker arranged to cooperate with the control device, a first flexible blade connecting the rocker to the frame, and a second flexible blade connecting the rocker to the rigid body.

[0055] In one embodiment, the frame is connected to each jaw via a jaw moving mechanism comprising: at least one flexible blade, and at least one rigid element in series with the flexible blade.

[0056] In this embodiment, this flexible blade deforms when moving from the engaged position to the disengaged position and vice versa, allowing translational movement of the jaws. The combination of the flexible blade with the rigid element makes it possible to limit or even cancel out any unwanted rotational movement of the jaws.

[0057] Although the clamp and its above characteristics can be combined with the clutch watch mechanism according to the invention, according to an independent aspect of the invention, this clamp can be combined with another clutch watch mechanism according to the invention, in particular with a clutch watch mechanism comprising a clutch disc different from that according to the invention and / or without a clutch disc.

[0058] In one embodiment, the present invention also relates to a watch movement comprising the clutch watch mechanism according to the invention.

[0059] In one embodiment, the present invention also relates to a timepiece, for example a chronograph watch, comprising the mechanism according to the invention or the watch movement according to the invention. Brief description of the figures

[0060] Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which: There figure 1A illustrates a sectional view of a clutch mechanism according to one embodiment of the invention, in the engaged position. The figure 1B illustrates a sectional view of the clutch mechanism of the figure 1A , in the disengaged position. The figure 2 illustrates a perspective view of a clutch mechanism according to another embodiment of the invention. The figure 3A illustrates a top view of a clutch disc of a clutch mechanism according to an embodiment of the invention, in the engaged position. The figure 3B illustrates a top view of the clutch disc of the figure 3A , in the disengaged position. The figure 4A illustrates a top view of a clutch disc of a clutch mechanism according to another embodiment of the invention, in the engaged position. figure 4B illustrates a perspective view of the clutch disc of the figure 4A . There figure 5A illustrates a top view of a clutch disc of a clutch mechanism according to another embodiment of the invention, in the engaged position. figure 5B illustrates a perspective view of the clutch disc of the figure 5A . There figure 6A illustrates a top view of a clutch disc of a clutch mechanism according to another embodiment of the invention, in the engaged position. figure 6B illustrates a perspective view of the clutch disc of the figure 6A . There figure 7 illustrates a top view of a clamp of a clutch mechanism according to another embodiment of the invention. The figure 8 illustrates a perspective view of the clamp of the figure 7 , cooperating with a control device. The figure 9 illustrates a top view of a clamp of a clutch mechanism according to another embodiment of the invention. The figure 10 illustrates a top view of a clamp of a clutch mechanism according to another embodiment of the invention. The figure 11 illustrates a top view of a clamp of a clutch mechanism according to another embodiment of the invention. Exemple(s) de mode de réalisation de l'invention

[0061] In the following description provided by way of example, reference will be made, for simplicity, to a clutch mechanism for a chronograph watch. It should however be understood that the invention is not limited to such an application, but also includes any other watchmaking application which requires a clutch. For example and in a non-limiting manner, the clutch mechanism according to the invention can be used in a striking watch mechanism.

[0062] There figure 1A illustrates a sectional view of a clutch mechanism 100 according to one embodiment of the invention, in the engaged position.

[0063] In the embodiment of the figure 1A , a first wheel 4 (or clutch bell) is crimped onto a ring 7 which is mounted in a freely rotatable manner on the axis 3 between a collar 8 and the ring 7. This first wheel 4 is provided with peripheral teeth 41 which are arranged so that the first wheel 4 can rotate continuously, for example by meshing with a barrel train (not shown).

[0064] The presence of the collar 8 and the ring 7 is not necessary, and any other element which can allow the first wheel 4 to be mounted in a freely rotatable manner on the shaft 3 can be used instead.

[0065] In the embodiment of the figure 1A , a second wheel 2, which is for example a chronograph wheel, is mounted integrally with the shaft 3, for example clamped to the shaft 3. In one embodiment, the second wheel 2 is driven by the shaft 3 in a common movement. Following the direction A of the shaft 3, relative to the clutch disc 5 the second wheel is mounted on the shaft 3 on the opposite side of the first wheel 4. The second wheel 2 is not in direct contact with the clutch disc 5 nor with the first wheel 4.

[0066] The clutch mechanism 100 illustrated in the figure 1A also includes a clamp 1, partially visible, which comprises two branches or jaws 10 controlled by a control device (not shown in the figure 1A ), for example and without limitation a column wheel (as illustrated in the figure 2 ). The jaws 10 are arranged to come into direct contact with the clutch disc 5, in particular with an external surface P of the peripheral rigid clutch elements 51.

[0067] In the embodiment of the figure 1A , another collar 6 cooperates with the end of the shaft 3 opposite that cooperating with the collar 8.

[0068] When the user actuates the control device, for example via a push button (or any other control member), the clamp 1 moves away from the clutch disc 5. The clutch disc, and in particular its surface F, then comes into contact with a cylindrical (internal) surface 42 of the first wheel 4, visible on the figure 1A .

[0069] In this position, the clutch disc 5 has a first diameter so that its peripheral rigid clutch elements 51, and in particular their surface F, come into contact with the surface 42 of the first wheel 4. The first wheel 4 drives the clutch disc 5 thanks to this contact, the clutch disc 5 therefore driving the shaft 3, and the shaft 3 driving the second wheel 2, by producing a radial friction clutch. The coupling of the shaft 3 and therefore of the second wheel 2 is then carried out.

[0070] In the embodiment of the figure 1A , the first wheel 4 comprises a housing 40 arranged to receive at least partially in the direction A of the shaft 3 the clutch disc 5, so as to achieve contact between the peripheral rigid clutch elements 51 of the clutch disc 5 and at least a portion of the surface 42 axially delimiting this housing 40. In one embodiment, this housing is substantially cylindrical.

[0071] In the embodiment of the figure 1A , the clamp 1 acts on the surface F of the clutch disc 5 which is not received in this housing 40.

[0072] There figure 1B illustrates a sectional view of the clutch mechanism 100 of the figure 1A , in the disengaged position. In this case, another pressure on a control member (not shown) acts on the control device (for example the column wheel 9 of the figure 2 ), and causes the clamp 1 to close. A space E is then created between the surface 42 of the first wheel 4 and the clutch disc 5.

[0073] The clutch disc 5 therefore contracts radially (i.e. in a plane perpendicular to the shaft 3) thereby blocking the axis 3 and the second wheel 2, which therefore stops. The first wheel 4 continues to rotate freely on the shaft 3.

[0074] In one embodiment, the expansion of the clutch disc in the engaged position (visible in figure 1A ) when the clamp 1 is spread is made possible by a slightly pre-stressed mounting of the clutch disc 5 in the first wheel 4.

[0075] In the embodiment of the figures 1A And 1B , at least one peripheral rigid clutch element 51 comprises a first surface F and a second surface P adjacent to the first surface F in the direction A of the shaft, so that: in engaged position ( figure 1A ), the first surface F is in contact with the first wheel 4, the second surface P being distant from the clamp 1; in the disengaged position ( figure 1B ), the clamp 1 comes into contact with the second surface P, which moves the first surface F away from the first wheel 4.

[0076] The operation of the clutch mechanism according to the invention is therefore based on the contraction or expansion of the clutch disc 5.

[0077] There figure 3A illustrates a top view of a clutch disc 5 of a clutch mechanism 100 according to an embodiment of the invention, in the engaged position, and the figure 3B illustrates a top view of the clutch disc 5 of the figure 3A , in the disengaged position.

[0078] The clutch disc 5 according to the invention comprises: a central hub 53 cooperating, in particular being arranged to come into direct contact, with the shaft 3, at least two peripheral rigid clutch elements 51, and at least one flexible blade 52 connecting each peripheral rigid clutch element 51 to the central hub 53.

[0079] A flexible blade 52 may be parallelepipedal, or have another shape, so as to promote the desired deformation mode and to block undesirable deformation modes. Non-rectilinear flexible blades 52, for example curved flexible blades, may also be imagined. The section of the flexible blades 52 is advantageously rectangular, but could also be different.

[0080] In the embodiment of the figures 3A et 3B , the clutch disc 5 comprises three peripheral rigid clutch elements 51, this number being a good compromise between the length of the peripheral rigid clutch elements 51, which must be large enough to achieve good friction with the first wheel 4, and at the same time which must be small enough to achieve efficient closing of the clutch disc 5 in the disengaged position.

[0081] In another embodiment, the number of peripheral rigid clutch elements 51 is 2N + 1, where N is an integer equal to or greater than 1.

[0082] In the embodiment of the figures 3A et 3B , the peripheral rigid clutch elements 51 all have the same shape (in an arc of a circle) and the same dimensions. The section of the peripheral rigid clutch elements 51 is advantageously rectangular, but could also be different.

[0083] In another embodiment (not shown), the peripheral rigid clutch elements 51 do not all necessarily have the same shape or dimensions.

[0084] In the embodiment of the figures 3A et 3B , each peripheral rigid clutch element 51 is connected to the central core 53 via a pair of flexible blades 52 parallel to each other. This makes it possible to further reduce the small rotation of the clutch disc 5 due to the deformation of the flexible blades 52, when changing from the engaged position to the disengaged position and vice versa. However, the presence of this pair of flexible blades 52 is not necessary, a single flexible blade 52 connecting each peripheral rigid clutch element 51 to the central hub 53 being sufficient for the operation of the clutch mechanism 100 according to the invention.

[0085] In the embodiment of the figures 3A et 3B , the central hub 53 is substantially rigid. In another embodiment, the central hub 53 is constituted by flexible blades 52, or also comprises flexible blades 52.

[0086] In the embodiment of the figures 3A et 3B , the flexible blades 52 connect a free end of each peripheral rigid clutch element 51 to the central hub 53. In another embodiment (not shown), the flexible blades 52 connect another portion of each peripheral rigid clutch element 51 (for example a central portion) to the central hub 53.

[0087] Advantageously, the peripheral rigid clutch elements 51 define the external diameter of the clutch disc 5. In the engaged position, visible on the figure 3A , a first space E1 separates a peripheral rigid clutch element 51 from the adjacent one.

[0088] In engaged position, visible on the figure 3A , the clutch disc has a first diameter D1. In the disengaged position, visible on the figure 3B , the flexible blades 52 deform under the action of the clamp 1 so that the clutch disc 5 has a second diameter D2 smaller than the first diameter D1. The maximum dimension D2 of the clutch disc in the disengaged position is therefore smaller than the maximum dimension D1 of the clutch disc in the engaged position. The clutch disc 5 in other words contracts, and the space E2 between a peripheral rigid clutch element 51 and the adjacent one decreases (E2 < E1). In other words, the peripheral rigid clutch elements 51 move closer together in the disengaged position, when the clutch disc 5 contracts.

[0089] In other words, in the disengaged position, the clutch disc can fit into a smaller virtual disc than the one it can fit into in the engaged position.

[0090] In the embodiments of the figures 3A et 3B , the peripheral rigid clutch elements 51 move, under the action of the flexible blades 52, with a movement which is a substantially translational (or “quasi-translational”) movement in a radial direction of the clutch disc 5, between the engaged position ( figure 3A ) and the disengaged one ( figure 3B ). In other words, the clutch disc 5 contracts (in the disengaged position) and expands (in the engaged position) under the action of the flexible blades 52.

[0091] The movement of the peripheral rigid clutch elements 51 is a substantially translational movement because there is also a slight rotation around the center C of the clutch disc 5 due to the deformation of the flexible blades 52. However, this rotation, of the order of magnitude of a few degrees, in particular less than 10°, is negligible compared to the radial translation of the peripheral rigid clutch elements 51.

[0092] In one embodiment, in the engaged position, each flexible blade 52 is substantially straight or rectilinear, as for example visible in the figure 3A .

[0093] There figure 4A illustrates a top view of a clutch disc 5 of a clutch mechanism 100 according to another embodiment of the invention, in the engaged position. figure 4B illustrates a perspective view of the clutch disc 5 of the figure 4A .

[0094] The clutch disc 5 of the figures 4A et 4B comprises in total two first peripheral rigid clutch elements 51' and two second peripheral rigid clutch elements 51", the first and second elements 51', 51" being arranged alternately.

[0095] In the embodiment of the figures 4A et 4B , two internal rigid clutch elements 54 extend from the central hub 53. Each internal rigid clutch element 54 is also connected to both a first and a second peripheral rigid clutch element 51', 51" via a pair of parallel flexible blades 52, straight in the engaged position.

[0096] In the embodiment of the figures 4A et 4B , these two pairs of parallel flexible blades 52 are arranged substantially perpendicular to each other.

[0097] In the embodiment of the figures 4A et 4B , each pair of parallel flexible blades 52 is connected to the corresponding peripheral rigid clutch element 51 via an intermediate rigid clutch element 55 which is substantially perpendicular to the adjacent pair of parallel flexible blades 52. The advantage of the embodiment of the figures 4A et 4B lies in the fact that the actuation of the disc 5 can be carried out on any peripheral rigid clutch element 51 of the disc 5 and at least on a single element 51, because all the elements 51 are connected to each other. In this embodiment, a clamp 1 is not necessary to actuate the clutch, because this actuation can also be carried out for example by an arm with a single point of contact with a peripheral rigid clutch element 51. In other words, in the embodiment of the figures 4A et 4B , the radial displacement of a single element 51 causes the displacement of all the other elements 51. In this case the clutch disc 5 has, on a macroscopic scale, a behavior similar to that of auxetic materials.

[0098] In the embodiment of the figures 4A et 4B , each intermediate rigid clutch element 55 associated with a peripheral rigid clutch element 51" (on the left and on the right of the figures 4A et 4B ) is connected via a first flexible blade 56' to one end of an adjacent first peripheral rigid clutch element 51', and via a second flexible blade 56" to one end of an adjacent second peripheral rigid clutch element 51'.

[0099] There figure 5A illustrates a top view of a clutch disc 5 of a clutch mechanism 100 according to another embodiment of the invention, in the engaged position. figure 5B illustrates a perspective view of the clutch disc 5 of the figure 5A .

[0100] In the embodiment of the figures 5A et 5B , the central hub 53 comprises central flexible blades 530. In the illustrated embodiment, they are three in number and define a substantially triangular opening; it should however be understood that this embodiment is not limited to such a number or to such a shape, provided that the shape created by the central flexible blades 530 is adapted to receive the shaft 3.

[0101] The method of realization of the figures 5A et 5B is particularly interesting in the case where the second wheel 2 is a chronograph wheel. In general, the zeroing occurs at the moment when the clamp 1 is closed on the clutch disc 5.

[0102] In order to solve the torque problems during the reset, these central flexible blades 530 form a friction system in the center of the disc. The level of penetration on the diameter of the shaft 3 and / or the flexibility of the three central blades 530 make it possible to precisely adjust the torque value for which the shaft 3 slips during the reset.

[0103] In the embodiment of the figures 5A et 5B , each central blade 530 is connected to at least one flexible blade 52 (or to a pair of parallel flexible blades in the illustrated embodiment) via an internal rigid clutch element 54 of the central hub 53. The flexible blade(s) 52 is (are) also connected to the corresponding peripheral rigid clutch element 51.

[0104] In one embodiment, the central hub 53 is arranged so as to limit the deformation of the central blades 530, in particular when the clamp 1 is actuated. In other words, in this embodiment, the central hub 53, and in particular the part of the central hub 53 which is close to the central blades 530, acts as a stop for the central blades 530.

[0105] Although in the embodiment of the figures 5A et 5B , the number of peripheral rigid clutch elements 51 is three, this number is not limiting and another number of peripheral rigid clutch elements 51 equal to or greater than two can be envisaged.

[0106] There figure 6A illustrates a top view of a clutch disc 5 of a clutch mechanism 100 according to another embodiment of the invention, in the engaged position. figure 6B illustrates a perspective view of the clutch disc 5 of the figure 6A .

[0107] In the embodiment of the figures 6A et 6B , the second wheel (not shown) is a chronograph wheel and the central hub 53 is arranged so that, in engaged position (visible on the figures 6A et 6B ), the central hub 53 has a first diameter to come into contact with the shaft 3, in the disengaged position and when resetting the chronograph wheel by a resetting mechanism (not shown), the central hub 53 has a second diameter larger than the first diameter, so as to either reduce the friction torque and the contact forces on the central hub 53 (and for example allow slippage), or to completely eliminate contact with the central hub 53. There are therefore two different possible operations with this mechanism.

[0108] In this embodiment, in the disengaged position and upon resetting, the clutch disc 5 has a smaller diameter than that of the engaged position, and the central hub 53 has a larger diameter than that of the engaged position. In other words, in the disengaged position and upon resetting, the peripheral rigid clutch elements 51 move radially toward the center C of the clutch disc 5 and thus toward the shaft 3, while its central hub 53 moves away from the shaft 3. This also allows the friction torque for resetting to be precisely adjusted.

[0109] To do this, the central hub 53 comprises at least two central rigid elements 531 defining the first diameter of the central hub 53 in the engaged position, and the second diameter in the disengaged position. In other words, the central rigid elements 531 come together in the engaged position (visible in the figures 6A et 6B ), and move away in the disengaged position and when resetting the chronograph wheel (not shown).

[0110] In the embodiment of the figures 6A et 6B , the central hub 53 comprises central rigid elements 531. In the illustrated embodiment, they are three in number and define a substantially circular opening (they have a slightly curved shape), however this embodiment is not limited to such a number or to such a shape, provided that the shape created by the central rigid elements 530 is suitable for receiving the shaft 3.

[0111] In the embodiment of the figures 6A et 6B, each central rigid element 531 is connected via an internal rigid clutch element 54 to two pairs of parallel flexible blades 52', 52": a first pair connects the internal rigid clutch element 54 to an adjacent internal rigid clutch element 54, and a second pair 52" connects the internal rigid clutch element 54 to a peripheral rigid clutch element 51.

[0112] Each pair of parallel blades 52', 52" of the Figures 6A and 6B can be replaced with a single flexible blade.

[0113] Although in the embodiment of the Figures 6A and 6B , the number of peripheral rigid clutch elements 51 is three, this number is not limiting and another number of peripheral rigid clutch elements equal to or greater than two can be envisaged.

[0114] In one embodiment, the overall torque of the clutch disc 5, including the torque related to friction with the first wheel 4 and the torque related to the deformation of the flexible blades 52, is in the range of 0.04 N mm to 0.09 N mm.

[0115] In one embodiment, it is possible to change the range of friction torques, by modifying at least one of the following parameters: the thickness of the blades, the length of the blades, the material used for the blades, the shape of the blades, etc.

[0116] There Figure 7 illustrates a top view of a clamp 1 of a clutch mechanism 100 according to another embodiment of the invention.

[0117] In the embodiment of the Figure 7 , clamp 1 includes: a rigid body 13, which in the illustrated example is D-shaped, but which could have another shape, for example and in a non-limiting manner a C, U or V shape, two jaws 10 arranged to cooperate with the clutch disc 5 (not illustrated); in particular, the clutch disc 5 is arranged to be received in the housing 15 defined by the jaws 10, flexible blades 16 connecting the rigid body 13 to the jaws 10.

[0118] When moving from the engaged position to the disengaged position, the rigid body 13 moves in translation in a first direction R in a plane of the clamp 1, causing a translational movement of the jaws in a second direction M1, M2 (M1 having a direction opposite to M2) in this plane, the second direction M1, M2 being substantially perpendicular to the first direction R, the two jaws 10 moving closer (in the disengaged position) and moving away respectively (in the engaged position) during their movement.

[0119] The clamp 1 may also comprise an external frame 14 which does not move when changing from the engaged position to the disengaged position. In the embodiment of the Figure 7 , the frame 14 has a U shape and defines a space receiving the jaws 10 and the rigid body 13. In the embodiment of the Figure 7 , the frame 14 comprises holes 140 of different dimensions, which allow it to be fixed in a movement. However, the presence of these holes 140 is not necessary and any other means of fixing the clamp 1 to the movement can be used by those skilled in the art.

[0120] The two jaws 10 in the disengaged position therefore close concentrically on the clutch disc 5 (not shown). These jaws move in translation along a substantially rectilinear path. In one embodiment, this movement is obtained by means of two jaw movement mechanisms 120 arranged between the frame 14 and the jaws 10.

[0121] Each jaw moving mechanism 120 comprises two elements in parallel, each element comprising: at least one flexible blade 12, at least one rigid element 17 in series with the flexible blade 12.

[0122] In the embodiment of the Figure 7 , each jaw movement mechanism 120 comprises a rigid element 17 arranged between two flexible blades 12.

[0123] In one embodiment, the clamp 1 comprises: a rocker 19 arranged to cooperate with the control device 9, a first flexible blade 18 connecting the rocker 19 to the frame 14, and a second flexible blade 17 connecting the rocker 19 to the rigid body 13.

[0124] In general, the mechanism for moving the jaws 120, and in particular the flexible blade(s) 12, deform(s) when moving from the engaged position to the disengaged position and vice versa, allowing the jaws 10 to be guided almost linearly.

[0125] The rocker 19 is pushed in correspondence of its head 190 by a control device, for example a column wheel 9, in the direction of the arrow B of the Figure 7 The first flexible blade 18 allows a pivot to be made and acts as a lever, allowing a change of direction at the other end of the rocker 9 (arrow C of the Figure 7 ). The flexible blade 17 makes it possible to compensate for the effect of the rotation of the rocker 19.

[0126] The flexible blades 16 make it possible to obtain a trajectory inversion, that is to say they make it possible to transform the movement of the rigid body 13 in the direction R into a movement of the jaws 10 in the direction M1, M2. The jaw movement mechanisms 120 allow quasi-linear guidance of the jaws 10.

[0127] There figure 8 illustrates a perspective view of the clamp 1 of the Figure 7 , cooperating with a control device, for example a column wheel 9.

[0128] In the example of the figure 8 , the head 190 of the rocker 19 is at the bottom of a column of the column wheel 9. In this case, the clamp 1 is therefore not controlled and it is open (engaged position).

[0129] When the column wheel 9 rotates, the rocker 19 begins to pivot, driving the rigid body 13 downwards (i.e., towards the rocker 19) with a translational movement in the direction R. The flexible blades 16, which on the figure 8 are oriented at 45° allow the jaws 10 to be moved by means of the two mechanisms 120 with parallel blades in the direction M1, M2.

[0130] Other non-limiting examples of clamps 1 are illustrated in the figures 9 to 11 .

[0131] There figure 9illustrates a top view of a clamp 1 of a clutch mechanism 100 according to another embodiment of the invention. In this embodiment, the clamp 1 comprises a first rigid body 13' in the shape of a U and connected to the rocker 19 via the flexible blade 17, and a second rigid body 13" opposite the first 13' and in the shape of a C. The mechanisms for moving the jaws 120 comprise in this case two flexible blades, which are not necessarily parallel, one flexible blade connecting the first rigid body 13' to a jaw 10 and the other flexible blade connecting the second rigid body 13" to this jaw 10. In the embodiment of the figure 9 , the frame includes the 13" part and the two flexible blades 23 located on either side of the 13' part.

[0132] There Figure 10illustrates a top view of a clamp 1 of a clutch mechanism 100 according to another embodiment of the invention. In this case too, the clamp 1 comprises a first rigid body 13' in the shape of a U and connected to the rocker 19 via the flexible blade 17, and a second rigid body 13" opposite the first 13' and in the shape of a C. A flexible blade 16 connects each of the jaws 10 to the first rigid body 13', a pair of parallel flexible blades 120 connecting each of the jaws 10 to the second rigid body 13".

[0133] In the embodiment of the Figure 10 , the rocker 19' cooperates with the first rigid body 13' via a second rocker 19".

[0134] There Figure 11illustrates a top view of a clamp 1 of a clutch mechanism 100 according to another embodiment of the invention. In this case the jaw displacement mechanism 120 connecting each jaw 10 to the rigid body 13 comprises a specific arrangement of rigid bodies and flexible blades, allowing the transformation of the translational displacement of the rigid body 13 in a first direction in the plane of the clamp 1, into a translational displacement of the jaws in a second direction in this plane, the second direction being substantially perpendicular to the first direction.

[0135] The flexible blades and / or the rigid bodies of the clutch disc 5 or the clamp 1 belong to the same plane, which is that of a planar plate. The plate can be produced by photolithography from a wafer, for example a silicon wafer, by laser cutting, by LIGA, etc. In one embodiment, the clutch disc 5 or the clamp 1 is made of a composite material comprising a forest of juxtaposed nanotubes held by a matrix. In one variant, the nanotubes are carbon nanotubes. In one variant, the matrix comprises amorphous carbon. In other variants, the nanotubes are made of other materials, for example boron nitride (“boron nitride nanotubes”, BNNT) or silicon. In one variant, the clutch disc 5 or the clamp 1 is made of steel.In another variant, the clutch disc 5 or the clamp 1 is made of glass, sapphire or alumina, of diamond, in particular synthetic diamond (in particular synthetic diamond obtained by a chemical vapor deposition process), of titanium, of titanium alloy (in particular an alloy of the Gum metal (R) family) or an alloy of the elinvar family, in particular Elinvar (R), Nivarox (R), Thermelast (R), NI-Span-C (R) and Precision C (R), of shape memory alloy, in particular Nitinol, of plastic or of any other material having a Young's modulus which is very insensitive to temperature variations. Reference numbers used in the figures

[0136] 1Clamp 2Second wheel 3Shaft 4First wheel 5Clutch disc 6Collar 7Ring 8Collar 9Control device 10Jaws 13, 13', 13"Rigid body 14Frame 15Housing 16Flexible blade of the clamp 17Flexible blade connecting the rocker to the rigid body 18Flexible blade (pivot lever) 19, 19'Rocker 23Flexible blade 40Housing of the first wheel 41Teeth 51, 51', 51"Peripheral rigid clutch element 52, 52', 52"Flexible blade 53Central hub 54Internal rigid clutch element 55Intermediate rigid clutch element 56', 56"Flexible blade 100Clutch clockwork mechanism 120Mechanism jaw displacement 140Holes 190Rocker head 530Central flexible blade 531Central rigid element AShaft direction CCenter of clutch disc D1First diameter of clutch disc D2Second diameter of clutch disc E, E1, E2Gap FSurface of contact with clutch disc M1,M2Direction of movement of the jaws PSurface of contact with the gripper RDirection of movement of the rigid part,

Claims

1. Clockwork clutch mechanism (100), comprising - a shaft (3), - a first wheel (4) arranged to be freely rotatably mounted on the shaft (3) and to rotate continuously around the shaft (3), - a clutch disc (5) integral with the shaft (3) - a control device (9), in which the mechanism (100) is arranged to move, under the action of the control device (9), from an engaged position to a disengaged position and vice versa, in which the clutch disc (5) belongs to a plane perpendicular to the shaft (3) and in this plane it comprises - a central hub (53) cooperating with the shaft (3), characterised in that the clockwork clutch mechanism (100) comprises - a second wheel (2) integral with the shaft (3), and in that the clutch disc (5) comprises, in the plane perpendicular to the shaft (3): - at least two peripheral rigid clutch elements (51), and - at least one flexible blade (52) connecting each peripheral rigid clutch element (51) to the central hub (53), and in which the flexible blades (52) are arranged to deform in said plane, so that - in the engaged position, the clutch disc (5) has a first diameter (D1), so that the peripheral rigid clutch elements (51) come into contact with a surface (42) of the first wheel (4), the first wheel (4) driving the clutch disc (5) as a result of this contact, the clutch disc (5) therefore driving the shaft (3), and the shaft (3) driving the second wheel (2), - in the disengaged position, the clutch disc (5) has a second diameter (D2) smaller than the first diameter (D1), so that the peripheral rigid clutch elements (51) no longer come into contact with the surface (42) of the first wheel (4).

2. The mechanism (100) according to claim 1, in which the peripheral rigid clutch elements (51) are arranged to move, under the action of the flexible blades (52), with a substantially translational movement in a radial direction of the clutch disc (5).

3. The mechanism (100) according to one of claims 1 or 2, wherein the first wheel (4) comprises a housing (40) arranged to receive at least partially in the direction (A) of the shaft (3) the clutch disc (5).

4. The mechanism (100) according to one of claims 1 to 3, wherein in the engaged position, each flexible blade (42) is substantially straight.

5. The mechanism (100) according to one of claims 1 to 4, wherein the peripheral rigid clutch elements (51) have an arc of a circle shape and / or comprise an arc of a circle shaped portion.

6. The mechanism (100) according to one of claims 1 to 5, in which at least one peripheral rigid clutch element (51) is connected to the central hub (53) by a pair of parallel flexible blades (52).

7. The mechanism (100) according to one of claims 1 to 6, the second wheel (2) being a chronograph wheel, the central hub (53) comprising central flexible blades (530).

8. The mechanism (100) according to claim 7, the central hub (53) being arranged to limit the deformation of the central flexible blades (530).

9. The mechanism (100) according to one of claims 1 to 6, the second wheel (2) being a chronograph wheel, the central hub (53) being arranged so that, - in the engaged position, the central hub (53) has a first diameter for coming into contact with the shaft (3), - in the disengaged position and when the chronograph wheel is reset by a reset mechanism, the central hub (53) has a second diameter larger than the first diameter, so that the shaft (3) can slide on the central hub (53).

10. The mechanism according to claim 9, in which the central hub (3) comprises at least two central rigid elements (531) defining the first diameter in the engaged position, and the second diameter in the disengaged position and when the chronograph wheel is reset to zero.

11. The mechanism (100) according to one of claims 1 to 10, wherein at least one peripheral rigid clutch element (51) comprises a first surface (F) and a second surface (P) adjacent to the first surface (F) in the direction (A) of the shaft (3), such that : - in the engaged position, the first surface (F) is in contact with the first wheel (4), the second surface (P) being remote from a clamp (1); - in the disengaged position, the clamp (1) comes into contact with the second surface (P), which moves the first surface (F) away from the first wheel (4).

12. The mechanism (100) according to claim 11, the clamp (1) comprising : - a rigid body (13), - two jaws (10) arranged to cooperate with the clutch disc (5), - flexible blades (12, 16) connecting the rigid body (13) to the jaws (10), in which, when passing from the engaged position to the disengaged position, the rigid body (13) is displaced in translation in a first direction (R) in a plane of the clamp, causing a displacement in translation of the jaws (10) in a second direction (M1, M2) in said plane, the second direction (M1, M2) being substantially perpendicular to the first direction (R), the two jaws (10) moving towards each other respectively away from each other during their displacement.

13. The mechanism (100) according to one of claims 11 or 12, the clamp (1) comprising a frame (14) which does not move when moving from the engaged position to the disengaged position.

14. The mechanism (100) according to claim 13, the clamp (1) comprising a lever (19) arranged to cooperate with the control device (9) and a first flexible blade (17) connecting the lever (19) to the frame (14), and a second flexible blade (18) connecting the lever (19) to the rigid body (13).

15. The mechanism (100) according to one of claims 13 or 14, the frame (14) being connected to each jaw via a jaw displacement mechanism (120) comprising : - at least one flexible blade (12), - at least one rigid element (17) in series with the flexible blade (12).