CH719048A9 - Clockwork clutch mechanism. - Google Patents

Abstract

The present invention relates to a clockwork clutch mechanism (100) in which flexible blades of a clutch disc (5) are arranged to deform, so that – in the engaged position, the clutch disc ( 5) has a first diameter, so that peripheral rigid clutch elements come into contact with a surface of a first wheel (4), the first wheel (4) driving through this contact the clutch disc (5 ), the clutch disc (5) therefore driving a shaft (3), and the shaft (3) driving a second wheel (2), – in the disengaged position, the clutch disc (5) has a second diameter smaller than the first diameter, so that the peripheral rigid clutch elements no longer come into contact with the surface of the first wheel (4).

Description

Technical area

The present invention relates to a clockwork clutch mechanism. The present invention also relates to a timepiece movement comprising such a mechanism, as well as a timepiece, for example a chronograph watch, in particular a wristwatch chronograph, 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 horological application which requires a clutch: for example and in a non-limiting way, it can be used in a striking clockwork mechanism.

State of the art

[0002] A chronograph watch is a timepiece which makes it possible to measure duration. As a general rule, a chronograph watch comprises at least one indicator (such as a hand) which can be started, then stopped, by means of a pusher or another control member, in order to measure a duration. Then it can be returned to its starting point. In general, chronograph watches also include indicators for displaying the current time in addition to displaying the duration measured.

[0003] The usual chronograph watches take the energy necessary for the operation of the part of the movement allowing the measurement of a duration on the kinematic chain making it possible to count and display the current time, that is to say on the kinematic chain linking a source of energy, for example a barrel, to the regulating organ and to the wheels of the watch, which are linked to the indicators of the watch in order to display the hour, the minutes and/or the seconds common.

[0004] In order to collect this energy necessary to set the kinematic chain in motion allowing the measurement of a time duration, it is necessary to produce a clutch between the kinematic chain which makes it possible to count and display the current time and that which allows to measure a temporal duration.

[0005] Two main bodies are used in the majority of operations of mechanisms for chronograph watches, namely control devices and clutch devices.

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

[0007] The clutch devices make it possible to drive the kinematic chain of the chronograph by the kinematic chain making it possible to count and display the current time. In particular, the clutch devices make it possible to start and stop the chronograph kinematic chain very quickly, and also to block it by keeping the chronograph indicators stopped.

[0008] Different types of clutch devices, in particular vertical, horizontal and oscillating gear clutch devices, are known.

[0009] Vertical clutch devices allow a so-called “vertical” clutch between the two kinematic chains, in particular between a wheel of one kinematic chain and a wheel of the other kinematic chain.

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

[0011] Lateral or horizontal clutch devices make it possible to couple two wheels by bringing them into contact via their periphery, in particular via 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 misalignment of the teeth of the two wheels. The gap is all the more reduced as there are teeth. However, gears 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 kinematic chain to a wheel of the other kinematic chain using a oscillating pinion. This oscillating pinion comprises a first toothing which is in permanent contact with the wheel of the kinematic chain 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 carry out a measurement of a duration , thus also putting it in rotation.

[0013] In a similar way to horizontal clutches, during an oscillating pinion clutch, the penetration of the toothing of the oscillating pinion into that of the chronograph wheel can cause an untimely jump of the chronograph wheel and therefore of the chronograph indicator, leading to a shift in information.

[0014] Other clutch solutions have been developed. An example of such a solution is described in document EP2085832. In the mechanism described in this document, when the user actuates a column wheel via a control push button in order to stop the chronograph, pliers press on a clutch disc thus blocking a chronograph wheel. Simultaneously, an isolator drives a rotating isolator wheel, which has the effect of radially displacing clutch elements using several tenons, 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 described clutch 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 actuates the column wheel again via the control push button in order to start the chronograph, the grippers move away from the clutch disc, thus freeing the chronograph wheel. Simultaneously, the isolator drives the isolation wheel in rotation, which has the effect of radially displacing the clutch elements using the tenons. In this way, the clutch spring comes into contact with the drive plate, thus starting the chrono.

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

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

[0018] When the clamp is actuated again in order 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 disengaging the lugs of the chronograph wheel and allowing the clutch to be released.

This clutch mechanism is complex because it requires a clutch disc having elements arranged to pivot under the action of flexible blades and to accommodate tenons which are perpendicular to the plane of the disc. Since these studs perform the clutch with the chronograph wheel, the friction surface between the chronograph wheel and each of these studs is small, which reduces the reliability of the clutch. In addition, the mechanism described comprises several parts (clutch disc, several tenons, etc.), which does not facilitate the assembly of the mechanism, in addition to being complicated by the mounting of the tenons in the disc.

Brief summary of the invention

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

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

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

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

According to the invention, these objects are achieved in particular by means of the clutch mechanism according to claim 1.

[0025] The clockwork clutch mechanism according to the invention comprises: - a shaft, - a first wheel (or drive wheel) arranged to be mounted in a freely rotatable manner on the shaft and to rotate continuously around 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 the second wheel) and the shaft can be driven one by the other. in a common movement, without necessarily being fixed (for example directly fixed) to each other. For example, a clutch disc frictionally bonded to the shaft is also integral with the shaft.

The clockwork clutch 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.

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” designates a blade or a beam, arranged to deform elastically in the plane of the clutch disc, for example according to 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 flexible blades.

[0031] In the context of the present application, the expression "peripheral rigid clutch elements" denotes 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, so that the peripheral rigid clutch elements come into contact with a surface of the first wheel, the first wheel driving by means of this contact the clutch disc, 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, so 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" means the largest dimension of the clutch disc.

[0034] Since the first wheel is arranged to be mounted in a freely rotatable manner on the shaft, its rotation in the disengaged position does not cause the rotation of the shaft nor that of the second wheel. On the other hand, in the engaged position, the rotation of the first wheel allows the rotation of the shaft, and therefore of the second wheel which is integral with the shaft, via the clutch disc.

This solution has the particular advantage of comprising fewer components compared to known clutch mechanisms. Indeed, the clutch is produced by a single component, namely the clutch disc, without the need for tenons or a plurality of components which come into contact with each other to produce the clutch between the first wheel and the second wheel.

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

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

Finally, in the clutch mechanism according to the invention the transmission of energy takes place horizontally (or radially) not by toothing, but by friction. This type of mechanism will subsequently be called a horizontal (or radial) clutch mechanism by friction.

[0039] In one embodiment, the peripheral rigid clutch elements move, under the action of the flexible blades, with a movement which is substantially a movement of translation (or "quasi-translation") 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 with respect 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.

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 passing from the engaged position to that disengaged and vice versa.

[0043] In one embodiment, the peripheral rigid clutch elements are in the shape of an arc of a circle and/or comprise a portion in the shape of an arc of a circle. In one embodiment, this circular arc has an angular opening comprised in the range between 20° and 170°, for example comprised 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 all necessarily have the same dimensions and/or the same shape.

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 makes it possible to further reduce the low rotation of the clutch disc due to the deformation of the flexible blades, when passing from the engaged position to that disengaged and vice versa. In other words, the fact of having two parallel blades makes it possible to come close to guiding in translation.

[0045] In one embodiment, the second wheel is a chorograph wheel and the central hub comprises central flexible blades, these central flexible blades being arranged to make it possible to adjust the value of the torque for which the shaft slips during a reset.

[0046] In one embodiment, the second wheel is a chorograph wheel and the central hub is arranged so that - in the engaged position, the central hub has a first diameter to come into contact with the shaft, – in the disengaged position and when the chorograph wheel is reset by a reset mechanism, the central hub has a second diameter greater than the first diameter, so that the shaft can slip on the central hub. In this embodiment therefore, in the disengaged position and when resetting, the clutch disc has a smaller external diameter than that of the engaged position, and the central hub has a larger diameter than that from the engaged position. In other words, in the disengaged position and during reset, the peripheral rigid clutch elements move radially towards the center of the disc, while the central hub moves away from the shaft. This also makes it possible to precisely adjust the friction torque for the reset, with the aim of obtaining a very small or even zero friction torque (no contact with the shaft if the central hub completely detaches from the shaft ).

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 approach in the engaged position, and move away in the disengaged position and when resetting the chorograph wheel.

In one embodiment, at least one peripheral rigid clutch element comprises a first surface and a second surface adjacent to the first surface in the direction of the shaft, so that: - in the engaged position, the first surface is in contact with the first wheel, the second surface being remote from a gripper; – in the disengaged position, the clamp comes into contact with the second surface, which moves the first surface away from the first wheel.

[0049] 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.

In this embodiment, when passing from the engaged position to the disengaged position, the rigid body moves in translation in a first direction in a plane of the gripper, 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 approach each other (in the disengaged position) respectively move apart (in the engaged position) during their movement, which makes it possible in particular to pinch or not the disc d 'clutch.

[0051] In one embodiment, the gripper comprises a frame which does not move during passage from the engaged position to the disengaged position.

[0052] 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.

[0053] In one embodiment, the frame is connected to each jaw via a mechanism for moving the jaws comprising: - at least one flexible blade, and - at least one rigid element in series with the flexible blade. realization, this flexible blade is deformed during the transition from the engaged position to that disengaged and vice versa, allowing the translational movement of the jaws. The combination of the flexible blade with the rigid element makes it possible to limit or even cancel a parasitic movement of rotation of the jaws.

Although the clamp and its characteristics above can be combined with the clockwork clutch mechanism according to the invention, according to an independent aspect of the invention, this clamp can be combined with another clockwork clutch mechanism according to the invention, in particular with a clockwork clutch mechanism comprising a clutch disc different from that according to the invention and/or devoid of a clutch disc.

The present invention also relates to a watch movement comprising the watch clutch mechanism according to the invention.

The present invention also relates to a timepiece, for example a chronograph watch, comprising the mechanism according to the invention or the timepiece movement according to the invention.

Brief description of figures

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which:

[0058] Figure 1A illustrates a sectional view of a clutch mechanism according to one embodiment of the invention, in the engaged position.

[0059] Figure 1B illustrates a sectional view of the clutch mechanism of Figure 1A, in the disengaged position.

[0060] Figure 2 illustrates a perspective view of a clutch mechanism according to another embodiment of the invention.

FIG. 3A illustrates a top view of a clutch disc of a clutch mechanism according to one embodiment of the invention, in the engaged position.

[0062] Figure 3B illustrates a top view of the clutch disc of Figure 3A, in the disengaged position.

[0063] FIG. 4A illustrates a top view of a clutch disc of a clutch mechanism according to another embodiment of the invention, in the engaged position.

[0064] Figure 4B illustrates a perspective view of the clutch disc of Figure 4A.

FIG. 5A illustrates a top view of a clutch disc of a clutch mechanism according to another embodiment of the invention, in the engaged position.

[0066] Figure 5B illustrates a perspective view of the clutch disc of Figure 5A.

FIG. 6A illustrates a top view of a clutch disc of a clutch mechanism according to another embodiment of the invention, in the engaged position.

[0068] Figure 6B illustrates a perspective view of the clutch disc of Figure 6A.

[0069] Figure 7 illustrates a top view of a clamp of a clutch mechanism according to another embodiment of the invention.

[0070] Figure 8 illustrates a perspective view of the clamp of Figure 7, cooperating with a control device.

[0071] Figure 9 illustrates a top view of a clamp of a clutch mechanism according to another embodiment of the invention.

[0072] Figure 10 illustrates a top view of a clamp of a clutch mechanism according to another embodiment of the invention.

[0073] Figure 11 illustrates a top view of a clamp of a clutch mechanism according to another embodiment of the invention.

Example(s) of embodiment of the invention

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 horological application which requires a clutch. For example and without limitation, the clutch mechanism according to the invention can be used in a striking watch mechanism.

[0075] Figure 1A illustrates a sectional view of a clutch mechanism 100 according to one embodiment of the invention, in the engaged position.

In the embodiment of Figure 1A, a first wheel 4 (or clutch bell) is crimped on 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 toothing 41 which is arranged so that the first wheel 4 can rotate continuously, for example by meshing with a barrel gear train (not shown).

[0077] 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. .

In the embodiment of Figure 1A, a second wheel 2, which is for example a chronograph wheel, is mounted integral 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.

[0079] The clutch mechanism 100 illustrated in Figure 1A also comprises a clamp 1, partially visible, which comprises two branches or jaws 10 controlled by a control device (not illustrated in Figure 1A), for example and so non-limiting a column wheel (as illustrated in Figure 2). The jaws 10 are arranged to come into direct contact with the clutch disc 5, in particular with an outer surface P of the peripheral rigid clutch elements 51.

In the embodiment of Figure 1A, another collar 6 cooperates with the end of the shaft 3 opposite to that cooperating with the collar 8.

[0081] When the user actuates the control device, for example via a push button (or any other control device), 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 in FIG. 1A.

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 thanks to this contact the clutch disc 5, 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.

In the embodiment of 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 make 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.

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

[0085] Figure 1B illustrates a sectional view of the clutch mechanism 100 of 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 FIG. 2), and causes the clamp 1 to close. A space E is created then between the surface 42 of the first wheel 4 and the clutch disc 5.

The clutch disc 5 therefore contracts radially (ie 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 spin freely on the shaft 3.

[0087] In one embodiment, the expansion of the clutch disc in the engaged position (visible in FIG. 1A) when the gripper 1 is moved apart is made possible by a slightly pre-stressed mounting of the clutch disc 5 in the first wheel 4.

In the embodiment of 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 the engaged position (FIG. 1A), the first surface F is in contact with the first wheel 4, the second surface P being remote from the gripper 1; – in the disengaged position (figure 1B), the gripper 1 comes into contact with the second surface P, which moves the first surface F away from the first wheel 4.

[0089] The operation of the clutch mechanism according to the invention is therefore based on the contraction or expansion of the clutch disc 5.

FIG. 3A illustrates a view from above of a clutch disc 5 of a clutch mechanism 100 according to one embodiment of the invention, in the engaged position, and FIG. 3B illustrates a view from above. the top of the clutch disc 5 of FIG. 3A, in the disengaged position.

The clutch disc 5 according to the invention comprises: - a cooperating central hub 53, 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.

[0092] A flexible blade 52 can be parallelepiped, or have another shape, so as to promote the desired mode of deformation and to block undesirable modes of deformation. Non-straight flexible strips 52, for example curved flexible strips, can also be imagined. The section of the flexible blades 52 is advantageously rectangular, but could also be different.

In the embodiment of Figures 3A and 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.

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

In the embodiment of Figures 3A and 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.

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

In the embodiment of Figures 3A and 3B, each rigid peripheral clutch element 51 is linked to the central core 53 via a pair of flexible blades 52 parallel to each other. This makes it possible to further reduce the slight rotation of the clutch disc 5 due to the deformation of the flexible blades 52, when passing 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.

In the embodiment of Figures 3A and 3B, the central hub 53 is substantially rigid. In another embodiment, the central hub 53 is constituted by flexible blades 52, or else also comprises flexible blades 52.

In the embodiment of Figures 3A and 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.

Advantageously, the peripheral rigid clutch elements 51 define the outer diameter of the clutch disc 5. In the engaged position, visible in FIG. 3A, a first space E1 separates a peripheral rigid clutch element 51 from the adjacent one.

In the engaged position, visible in Figure 3A, the clutch disc has a first diameter D1. In the disengaged position, visible in FIG. 3B, the flexible strips 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 come together in the disengaged position, during the contraction of the clutch disc 5.

[0102] In other words again, in the disengaged position, the clutch disc can fit into a virtual disc that is smaller than the one in which it can fit in the engaged position.

[0103] In the embodiments of FIGS. 3A and 3B, the peripheral rigid clutch elements 51 move, under the action of the flexible blades 52, with a movement which is substantially a movement of translation (or of "quasi- translation“) in a radial direction of the clutch disc 5, between the engaged position (FIG. 3A) and the disengaged position (FIG. 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.

[0104] 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 with respect to the radial translation of the peripheral rigid clutch elements 51.

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

[0106] FIG. 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 Figure 4A.

[0107] The clutch disc 5 of Figures 4A and 4B comprises a total of two first peripheral rigid clutch elements 51' and two second peripheral rigid clutch elements 51", the first and the second elements 51', 51" being arranged alternately.

[0108] In the embodiment of Figures 4A and 4B, two internal rigid clutch elements 54 extend from the central hub 53. Each internal rigid clutch element 54 is also connected both to a first and to a second peripheral rigid clutch element 51', 51" via a pair of parallel flexible blades 52, straight in the engaged position.

In the embodiment of Figures 4A and 4B, these two pairs of parallel flexible blades 52 are arranged substantially perpendicular to each other.

In the embodiment of Figures 4A and 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 torque of parallel flexible blades 52 adjacent. The advantage of the embodiment of FIGS. 4A and 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 interconnected. In this embodiment, a gripper 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 d In other words, in the embodiment of FIGS. 4A and 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.

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

FIG. 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 Figure 5A.

In the embodiment of Figures 5A and 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 nor to such a shape, provided that the shape created by the central flexible blades 530 is adapted to receive the shaft 3.

The embodiment of Figures 5A and 5B is particularly interesting in the case where the second wheel 2 is a chronograph wheel. In general, zeroing occurs when clamp 1 is closed on clutch disc 5.

[0115] In order to solve the torque problems during the reset, these central flexible blades 530 form a friction system at 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 value of the torque for which the shaft 3 slips during the reset.

In the embodiment of Figures 5A and 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 a rigid clutch element internal 54. The (the) flexible blades 52 is (are) connected (s) also to the rigid peripheral clutch element 51 corresponding.

Although in the embodiment of Figures 5A and 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 considered.

FIG. 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 Figure 6A.

In the embodiment of Figures 6A and 6B, the second wheel (not shown) is a chorograph wheel and the central hub 53 is arranged so that - in the engaged position (visible in Figures 6A and 6B), the central hub 53 has a first diameter to come into contact with the shaft 3, – in the disengaged position and when the chorograph wheel is reset by a reset 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.

[0120] In this embodiment, in the disengaged position and during the reset, 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 from the engaged position. In other words, in the disengaged position and during reset, the peripheral rigid clutch elements 51 move radially towards the center C of the clutch disc 5 and therefore towards the shaft 3, while its hub central 53 deviates from the shaft 3. This also makes it possible to precisely adjust the friction torque for the reset.

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 FIGS. 6A and 6B), and move away in the disengaged position and when the chronograph wheel is reset (not shown).

In the embodiment of Figures 6A and 6B, the central hub 53 comprises central rigid elements 531. In the illustrated embodiment, there are three of them and define a substantially circular opening (they have a slightly curved), 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 adapted to receive the shaft 3.

In the embodiment of FIGS. 6A and 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 element 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.

Each pair of parallel blades 52', 52" in FIGS. 6A and 6B can be replaced by a single flexible blade.

Although in the embodiment of 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 or greater than two can be considered.

[0126] 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 included in the range of 0 .04N. mm at 0.09N. mm.

In one embodiment, it is possible to change the range of the 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 blades, etc.

[0128] Figure 7 illustrates a top view of a clamp 1 of a clutch mechanism 100 according to another embodiment of the invention.

In the embodiment of Figure 7, the clamp 1 comprises: - a rigid body 13, which in the example shown is D-shaped, but which could have another shape, for example and in a way not limiting a C, U or V shape, - two jaws 10 arranged to cooperate with the clutch disc 5 (not shown); 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.

When passing 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 gripper 1, causing the jaws to move in translation 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 approaching (in the disengaged position) respectively moving away (in the engaged position) when their displacement.

The gripper 1 can also comprise an outer frame 14 which does not move during passage from the engaged position to the disengaged position. In the embodiment of 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 Figure 7, the frame 14 comprises holes 140 of different dimensions, which allow its fixing 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.

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 trajectory. In one embodiment, this movement is obtained by means of two mechanisms for moving the jaws 120 arranged between the frame 14 and the jaws 10.

Each mechanism for moving the jaws 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.

In the embodiment of Figure 7, each mechanism for moving the jaws 120 comprises a rigid element 17 disposed between two flexible blades 12.

[0135] 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 rocker 19 to rigid body 13.

In general, the mechanism for moving the jaws 120, and in particular the flexible blade(s) 12, deform(s) when passing from the engaged position to the disengaged position and vice versa, allowing the quasi-linear guidance of the jaws 10.

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 in FIG. and acts as a lever, allowing a change of direction at the other end of rocker 9 (arrow C in FIG. 7). The flexible blade 17 makes it possible to compensate for the effect of the rotation of the rocker 19.

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 mechanisms for moving the jaws 120 allow a quasi-linear guiding of the jaws 10.

[0139] Figure 8 illustrates a perspective view of the clamp 1 of Figure 7, cooperating with a control device, for example a column wheel 9.

In the example of 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).

[0141] When the column wheel 9 rotates, the rocker 19 begins to pivot driving the rigid body 13 downwards (namely towards the rocker 19) with a translational movement in the direction R. The flexible blades 16, which on Figure 8 are oriented at 45 ° allow to move the jaws 10 through the two mechanisms 120 with parallel blades in the direction M1, M2.

[0142] Other non-limiting examples of clamps 1 are illustrated in Figures 9 to 11.

[0143] Figure 9 illustrates 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 lever 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 in this case comprise 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 FIG. 9, the frame comprises part 13″ and the two flexible blades 23 located on either side of part 13′.

[0144] Figure 10 illustrates 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".

[0145] In the embodiment of Figure 10, rocker 19' cooperates with first rigid body 13' via a second rocker 19".

[0146] Figure 11 illustrates a top view of a clamp 1 of a clutch mechanism 100 according to another embodiment of the invention. In this case the movement mechanism of the jaws 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 movement into translation of the rigid body 13 in a first direction in the plane of the clamp 1, in a translational movement of the jaws in a second direction in this plane, the second direction being substantially perpendicular to the first direction.

The flexible blades and/or the rigid bodies of the clutch disc 5 or of 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 a variant, the nanotubes are carbon nanotubes. Alternatively, 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 a 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 of synthetic diamond (in particular synthetic diamond obtained by a process of chemical vapor deposition ), titanium, titanium alloy (in particular an alloy from the Gum metal (R) family) or an alloy from the Elinvar family, in particular Elinvar (R), Nivarox (R), Thermelast ( R), Nl-Span-C (R) and Precision C (R), in shape memory alloy, in particular in Nitinol, in plastic or in any other material having a Young's modulus very little sensitive to variations in temperature.

Reference numbers used in the figures

[0148] 1 Clamp 2 Second wheel 3 Shaft 4 First wheel 5 Clutch disc 6 Collar 7 Ring 8 Collar 9 Control device 10 Jaws 13, 13', 13" Rigid body 14 Frame 15 Housing 16 Flexible blade of the clamp 17 Flexible blade linking the rocker to the rigid body 18 Flexible blade (pivot lever) 19, 19' Rocker 23 Flexible blade 40 Housing of the first wheel 41 Toothing 51, 51', 51" Peripheral rigid clutch element 52, 52', 52 " Flexible blade 53 Central hub 54 Internal rigid clutch element 55 Intermediate rigid clutch element 56', 56" Flexible blade 100 Clockwork clutch mechanism 120 Mechanism for moving the jaws 140 Holes 190 Rocker head 530 Central flexible blade 531 Central rigid element A Direction of the shaft C Center of the clutch disc D1 First diameter of the clutch disc D2 Second diameter of the clutch disc E, E1, E2 Space F Contact surface with the clutch disc M1 , M2 Direction of movement of the jaws P Contact surface with the gripper R Direction of movement of the rigid part

Claims (16)

1. Clockwork clutch mechanism (100), comprising – a tree (3), – a first wheel (4) arranged to be freely rotatably mounted on the shaft (3) and to rotate continuously around the shaft (3), – a second wheel (2) integral with the shaft (3), – a clutch disc (4) integral with the shaft (3), – a control device (9), in which the mechanism (100) is arranged to pass, 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), – 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 thanks to this contact the clutch disc (5), 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, wherein the peripheral rigid clutch elements (51) are arranged to move, under the action of the flexible blades (52), with a substantially translational movement in one direction. radial 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) are in the shape of an arc of a circle and/or comprise a portion in the shape of an arc of a circle . 6. The mechanism (100) according to one of claims 1 to 5, wherein 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 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 to come into contact with the shaft (3), – in the disengaged position and when the chorograph wheel is reset by a reset mechanism, the central hub (3) has a second diameter larger than the first diameter, so that the shaft ( 3) can slip on the central hub (53). 9. The mechanism according to claim 98, wherein 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 resetting the the chronograph wheel. 10. The mechanism (100) according to one of claims 1 to 9, 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), so 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 gripper (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). 11. The mechanism (100) according to claim 10, 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) moves in translation in a first direction R) in a plane of the gripper, by causing the jaws (10) to move in translation 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) approaching respectively moving away during their movement. 12. The mechanism (100) according to one of claims 10 or 11, the clamp (1) comprising a frame (14) which does not move when passing from the engaged position to that disengaged. 13. The mechanism (100) according to one of claims 11 or 12, the clamp (1) comprising a rocker (19) arranged to cooperate with the control device, (9) and a first flexible blade (17) connecting the rocker (19) to the frame (14), and a second flexible blade (18) connecting the rocker (19) to the rigid body (13). 14. The mechanism (100) according to one of claims 12 or 13, the frame (14) being connected to each jaw via a mechanism for moving the jaws (120) comprising: – at least one flexible blade (12), - at least one rigid element (17) in series with the flexible strip (12). 15. Watch movement comprising the watch mechanism (100) according to one of claims 1 to 14. 16. Timepiece, for example chronograph watch, comprising the mechanism according to one of claims 1 to 14 or the timepiece movement according to claim 15.