Timepiece movement equipped with mechanism for driving run-out indicator

Abstract

The timepiece movement (2) is equipped with an indicator (4) and comprises a mechanism (6) for driving the indicator to jump, the mechanism comprising a gear platform (8) having a first axis of rotation (20), a driving finger (12) for driving the indicator, and a hairspring (16), the hairspring has a first end attached to the gear platform for rotation therewith and a second end attached to the drive finger for rotation therewith. The mechanism comprises a rigid support (10) rotatable relative to the gear platform about a first axis of rotation (20) and a lever (26) mounted on the rigid support so as to be rotatable about a second axis of rotation (22) remote from the first axis of rotation and forming a drive finger. When the hairspring is loaded and the indicator performs the next run-out, the mechanism limits rotation of the lever in a first direction, the lever being rotatable opposite the first direction, allowing the drive finger to radially retract towards the first axis of rotation under the effect of a radial force exerted thereon.

Description

Technical Field

[0001] The present invention relates to a watch movement equipped with an indicator and including a mechanism for driving this indicator to jump, and the present invention further relates to a watch including a watch movement equipped with such a mechanism. In particular, the indicator is a date indicator. Background Art

[0002] Patent document EP 3828644 describes a mechanism for driving a jumping indicator which advantageously overcomes the technical problems of the prior art by including a rigid drum finger and a hairspring disposed in the drum finger, the drum finger being rotatably and translatably guided by a hub passing through an oval hole in the drum, and the hairspring connecting the drum finger to a gear platform.

[0003] This drive mechanism has several drawbacks. First, when the date ring is driven, the hairspring expands, and when the hairspring is loaded, its coils are intended to bear against the inner wall of the drum in order to limit the expansion of the hairspring and prevent the expansion from reaching the plastic range of the hairspring. This results in a sudden decrease in the effective length of the hairspring. Given the manufacturing tolerances of the various components, the loading time of the drive mechanism may vary because the time at which the hairspring contacts the inner wall of the drum may change from one loading to the next, and the angular position of the contact area may also change. This results in an inaccurate time at which the ring is triggered to move to the next date. Another problem stems from the fact that the driving force is transmitted to the finger via the coils of the hairspring, which must have sufficient stiffness / hardness over its entire length, and more particularly in the portion located between the contact area with the wall of the drum and the coupling member for coupling this drum disposed at the second end of the hairspring, which portion ultimately needs to withstand all the additional torque generated from the moment of contact until the moment at which the indicator jumps.

[0004] The illustration in the above-mentioned document shows that the connecting member of the hairspring is arranged in a shallow groove, and this member may be easily exposed from the shallow groove. The two lateral surfaces of the groove are parallel in the radial direction passing through the middle of the groove, and the connecting member has two radial sides. The angular width of the connecting member is smaller than the angular width of the groove to allow the member to be easily inserted into the groove. In addition, the connecting member is intended to have a large amount of play in the groove to allow the connecting member to move in the groove. Therefore, a relatively small impact may easily cause the connecting member to disengage from its groove. If this occurs, whether when the hairspring is loaded against the teeth of the date ring or before loading this hairspring (the hairspring will then typically exhibit slight expansion due to the friction applied to the drum), the connecting member will disengage from one side of the radial driving side of the finger. In this case, the lateral wall of the drum applies a radial force on the connecting member, causing the connecting member to be subject to the frictional force on this lateral wall. If the connecting member disengages from its groove when the hairspring against the teeth of the date ring is loaded, either the connecting member then slides along the inner lateral surface and date jumping will not occur until at least the driving gear makes one full rotation and the connecting member re-enters its groove (this is the best-case scenario, although this will result in the absence of the correct date display, missing the daily jump), or the frictional force is sufficient to cause the hairspring to expand again, further increasing the frictional force until its coil touches the lateral wall and date jumping occurs at an uncertain time. In the latter case, after the date jump, the hairspring will relax by driving the drum. If this happens again, the next date change will no longer occur near midnight. If the connecting member undergoes a sudden angular displacement along the lateral wall (which is possible), then this situation will repeat for at least several days, where the date increment occurs at an uncertain and varying time. In any case, once the connecting member disengages from its groove, the date driving mechanism will stop functioning for at least several days, and this situation is very likely in the mechanism shown in the illustration of patent document EP 3828644.

[0005] Another problem arises with respect to the geometric configuration of the coupling member relative to its recess, which allows for a large amount of play and a certain mobility of the coupling member within the recess. More specifically, when the hairspring is loaded, it causes the turns of the hairspring to deform and results in the coupling member rotating about itself. This rotation causes the coupling member to slide against the front transverse wall of the recess, such that as the hairspring is loaded, the point of application of the force from the hairspring to the drum finger radially decreases. Thus, at a given level of hairspring loading, the drive torque provided by the hairspring on the finger decreases proportionally with the decrease in the application of the force from the hairspring to the drum finger via the lever arm, which is problematic because for a given contact point, the driving force of the finger on the teeth of the indicator also decreases by the same proportion. Since a given drive torque is required to cause the indicator to jump, the hairspring will have to generate a greater force because the lever arm decreases during the loading of the hairspring, which has a negative impact on the performance of the timepiece movement that loads the hairspring of the drive mechanism and thus has to provide more torque. This also requires the hairspring to be dimensioned more robustly than necessary.

[0006] Finally, another problem with the mechanism results from the fact that when the indicator is driven, the turns of the hairspring apply a radial force outwardly and thus substantially along the longitudinal direction of the oval hole on the drum in the diametrically opposite region to the finger, which is intended to move the finger away from the toothed ring of the annulus. Thus, in this situation, especially in the case of a small shock, the finger is more likely to pass over the teeth without driving the indicator. It should also be noted that this situation reduces the angular path along which the finger can drive the teeth by maintaining contact, such that the finger may pass over the teeth before it has received a drive torque over an angular distance sufficient to ensure the date jump, and once the finger has passed over the teeth, the date ring remains stationary in the intermediate position or returns to its previous stable position. Additionally, for a given drive torque, reducing the lever arm for applying the driving force to the teeth requires an increase in the required driving force, which also requires an increase in the force provided by the hairspring and thus its tension. Summary of the Invention

[0007] It is an object of the present invention to provide a mechanism for driving a jumping indicator that overcomes at least some of the drawbacks of the above prior art. The present invention further aims to provide a timepiece movement equipped with an indicator and including a mechanism for driving the indicator to jump, the mechanism being efficient, capable of being precise in each timepiece movement including this mechanism, and its operation being hardly or not at all disturbed by external stresses (e.g., shocks).

[0008] In particular, the drive mechanism is designed to allow, during the passage of one tooth or the successive passage of a plurality of teeth on the outer side of the drive finger of the indicator, another specific mechanism characteristic of a timepiece movement to rapidly correct the indicator by taking advantage of the additional torque generated by the presence of the drive mechanism, said torque being minimal and not including any sudden changes.

[0009] To this end, the invention relates to a timepiece movement equipped with an indicator and comprising a mechanism for driving the indicator to jump, said mechanism including a gear platform defining a first axis of rotation, a drive finger for driving the indicator, and a hairspring formed by a first end, a coil, and a second end, the first end being attached to the gear platform for rotation therewith, and the second end being attached to the drive finger for rotating with the drive finger at least during each loading of the hairspring before the indicator jumps and during the driving of the indicator by the mechanism during this jump. The mechanism includes: a rigid support that is rotatable relative to the gear platform about the first axis of rotation; and a lever mounted on the rigid support so as to be rotatable about a second axis of rotation remote from the first axis of rotation, the second axis of rotation being located at a first end of the lever, and the drive finger being formed on one side of its second end by the lever. The mechanism further includes a first stop formed integrally with the rigid support, the first stop restricting the rotation of the lever in a first direction corresponding to the direction in which the finger moves radially away from the first axis of rotation, the lever being arranged to bear against the first stop at least when the hairspring is loaded before the indicator jumps and being able to rotate in a second direction opposite to the first direction to allow the drive finger to be retracted towards the first axis of rotation under the action of a force applied to the drive finger, said force having a radially increasing component.

[0010] When the hairspring is loaded, the first stop makes it possible to maintain a constant radial distance between the contact point of the drive finger on the teeth of the indicator and the first axis of rotation (central axis of rotation) of the mechanism. Compared with the prior art, the leverage is thus unchanged and the mechanism is more efficient.

[0011] In a particular alternative embodiment, the indicator is a date indicator including a toothed ring. In particular, the indicator is a date ring including an internal toothed ring so as to be rotatably driven by the mechanism.

[0012] Attributed to the driving finger (the driving finger is not integrally formed with the rigid support, but can rotate about a second rotation axis defined by the rigid support, the second rotation axis being remote from the gear platform and the first rotation axis of the rigid support), under the action of the force applied by the indicator on this driving finger, the radial retraction of the driving finger in the direction of the first rotation axis is achieved in this case by the rotation of a lever, without radial displacement of the rigid support, this lever being possibly relatively light and exhibiting relatively low friction during rotation. Thus, the couple of forces to be applied by the user via a correction device other than the said mechanism allows for a rapid correction of the indicator in the expected driving direction, or for a correction of the time in the counterclockwise direction (which results in a rotation of the gear platform in a direction opposite to the driving direction) and past midnight (especially in the case of a calendar indicator), the said couple of forces being relatively weak, and the passage of the indicator teeth on the driving finger (retracting mainly in a direction radial with respect to the central axis) being less pronounced compared to the prior art.

[0013] Secondly, the elastic deformation of the hairspring may be lower than in the prior art, thus resulting in lower stress in the hairspring, which is advantageous for the sizing of the hairspring, since the lever rotates about the second rotation axis and the driving finger moves mainly towards the first rotation axis. Due to the radial retraction of the driving finger and thus the radial retraction of the second end of this hairspring, the hairspring necessarily undergoes radial elastic deformation; however, the angular deformation of the hairspring caused by the couple of forces applied to the said second end may be much less than in the case of the prior art mechanisms. Advantageously, the interaction of the toothed ring on the finger only exerts a force on the rigid support via the lever and thus at the second eccentric rotation axis. The direction of the force exerted by the teeth of the indicator pressing on the outer side of the driving finger at the second axis generates a torque on the rigid support aimed at rotating the rigid support, the said torque being weaker than the torque in the prior art. Given the stiffness of the hairspring (which is necessary for storing energy during the normal driving of the indicator), the lever can rotate relative to the rigid support under the action of the teeth pressing on the outer side of the driving finger, without this rigid support rotating relative to the gear platform. It can thus be seen that due to the retraction of the driving finger rotating about a second rotation axis remote from the first rotation axis, the hairspring mainly undergoes radial elastic deformation. The drive mechanism of the present invention thus allows for the same retraction of the finger during correction as in the prior art, but compared to the prior art mechanisms, the drive mechanism produces a smaller elastic deformation of the hairspring, in the prior art mechanisms, the hairspring undergoes significant angular deformation in addition to radial deformation.

[0014] In an advantageous alternative embodiment, the above-described advantages of the present invention can be significantly obtained, wherein the outer side of the drive finger is arcuate, and when the lever contacts the first stop, this arcuate outer side has a dimension radial to the first axis of rotation, and this dimension monotonically increases as it approaches the drive side of the drive finger, so as to press against the lateral side of the tooth of the toothed ring during the increase of the indicator according to jerks.

[0015] According to an advantageous alternative embodiment, the hairspring and the lever are arranged such that the lever also abuts against the first stop when the hairspring is not subjected to angular stress.

[0016] According to the main embodiment, the rigid support includes a disk forming the first stop. In particular, the rigid support is constituted by such a disk.

[0017] According to a preferred embodiment, the mechanism is arranged such that when the hairspring is loaded, the hairspring contracts so as to be able to produce jerks, in particular a semi-instantaneous jerk of the indicator. By contracting the hairspring, in particular a constant radius can be obtained for applying the driving force of the finger to the teeth of the indicator against which the finger abuts, thereby optimizing this driving force and thus the driving torque required to cause the jerk of the indicator.

[0018] According to an advantageous alternative embodiment, when the coiled spring of the hairspring that is caused to contract by the load is stressed, the angular displacement of the second end of the hairspring and thus the drive finger relative to the gear platform is limited by a second stop, and the second stop defines an angular stop attached to the gear platform for rotating therewith, and the indicator and the mechanism are arranged such that during normal operation, after the angular displacement is stopped by the second stop, at the end of the loading of the hairspring before this jerk, the jerk of the indicator occurs and thus corresponds to a determined angular distance.

[0019] The present invention further relates to a watch comprising a movement according to the present invention. Description of the Drawings

[0020] The objects, advantages and features of the present invention will be described in more detail below with the aid of the drawings, which are given by way of non-limiting example, wherein:

[0021] - Figure 1 is a top view of a timepiece mechanism according to an advantageous embodiment of the present invention, the mechanism being intended to drive a jerk indicator, in particular a semi-instantaneous jerk;

[0022] - Figure 2 is Figure 1 the exploded perspective view of the timepiece mechanism in

[0023] - Figure 3 is shown in an inverted position Figure 1Perspective view of the rigid support, hairspring, and lever of the timepiece mechanism therein;

[0024] - Figure 4 is an enlarged perspective view of the lever;

[0025] - Figure 5 is similar to that shown in Figure 1 and is a view of an alternative embodiment of the timepiece mechanism shown in Figure 1 ;

[0026] - Figures 6A to 6D Partially shows a timepiece movement according to the present invention in four successive states that occur respectively when the date ring is driven by a drive mechanism, the movement including an advantageous embodiment of the drive mechanism described in the foregoing figures;

[0027] - Figure 7A and 7B Partially shows a timepiece movement in Figure 6A in two successive states that occur when the date ring is rapidly driven in the date-ring drive direction by a conventional control member;

[0028] - Figure 8A and 8B Partially shows a timepiece movement in Figure 6A in two successive states that occur when the time-display hand is driven in the counterclockwise direction, so that when the date ring is driven, the gear platform is driven in a direction opposite to the drive direction of this platform. Detailed Description

[0029] Referring to the accompanying drawings, an advantageous embodiment of a mechanism for driving an indicator jump (particularly a semi-instantaneous jump) will be described, and more particularly with reference to Figures 6A to 8B , the operation of a timepiece movement according to the present invention including such a drive mechanism will be described.

[0030] The mechanism 6 for driving the jumping indicator 4 includes: a gear platform 8 that rotates about a first axis of rotation 20; a drive finger 12 for driving the indicator; and a hairspring 16. In a main alternative embodiment, the indicator is a date indicator, in particular a date ring including an internal toothed ring 5. In other specific alternative embodiments given by way of non-limiting example, the indicator is, for example, a minutes, hours, days or months indicator. The hairspring 16 consists of a first end 17, a coil 18 and a second end 19, the first end being attached to the gear platform for rotation therewith, and the second end being attached to the drive finger 12 for rotating with the drive finger at least during each loading of the hairspring 16 before the indicator 4 jumps and during the driving of the indicator by the mechanism during said jump. The first end 17 of the hairspring is connected to a central part 24, the central part being attached to the gear platform 8 for rotation therewith. Preferably, the hairspring and the central part form the same part. The mechanism 6 includes: a rigid support 10 that is rotatable relative to the gear platform about the first axis of rotation; and a lever 26 that is mounted on the rigid support so as to be rotatable about a second axis of rotation 22, the second axis of rotation being remote from the first axis of rotation 20.

[0031] The second axis of rotation 22 is located at the first end of the lever, the lever forming a drive finger on one side of its second end. In particular, the lever has a circular outer stud 34 at its first end, the outer stud being inserted into a hole 33 formed in the rigid support such that the lever can rotate about the axis of rotation 22 defined by the hole 33, in particular allowing the drive finger 12 to retract during a rapid correction of the date or during a specific counterclockwise correction of the time past midnight, as will be explained in more detail below.

[0032] The mechanism 6 includes a central hub 32 that defines an axis that passes through a central hole in the rigid support 10 and rotatably guides this rigid support relative to the gear platform 8, the gear platform and the central part 24 being driven onto the central hub 32.

[0033] Generally speaking, the drive mechanism includes a first stop, which is integrally formed with the rigid support and limits the rotation of the lever in a first direction corresponding to the direction in which the finger moves radially away from the first rotation axis 20. The lever is arranged to be able to abut against the first stop at least when the hairspring is loaded before the indicator jumps and also preferably when the indicator is driven during this jump, and to be able to rotate in a second direction opposite to the first direction, so as to allow the drive finger to retract towards the first rotation axis 20 under the action of the tangential component of the force exerted on the drive finger by the toothed ring of the indicator with respect to the second rotation axis 22 during calibration. Preferably, the hairspring and the lever are arranged such that the lever also abuts against the first stop when the hairspring is not subjected to angular stress. According to a main alternative embodiment, the rigid support includes a disk forming the first stop. According to an advantageous alternative embodiment shown in the figure, the rigid support is disk 10.

[0034] According to a specific alternative embodiment shown in the figure, the lever 26 is formed by an arm 36 and a drive finger 12. The arm has a first height and is at least partially arranged between the gear platform and the disk. The drive finger 12 has a second height H at least in the thickened portion defining the drive side 14, and the drive side is intended to abut against the teeth of the toothed ring 5 associated with the indicator 4 (see Figures 6A to 8B ) when the indicator is driven by the mechanism 6. The second height H is greater than the first height, and for any useful angular position of the lever, the thickened portion of the drive finger does not stack on the disk, and the thickened portion axially extends at least partially over the thickness of at least one area of the disk located above the arm. When the lever abuts against the first stop 30, the drive side 14 is substantially radial to the first rotation axis 20.

[0035] According to an advantageous alternative embodiment, the disk 10 has a lateral surface, and the substantially radial area thereof defines the first stop 30. The drive finger 12 has a second height H throughout the range in the plane of the toothed ring 5 and is arranged such that at least each time the hairspring is loaded, the upper rear part of the drive finger may abut against the first stop 30, so that the drive finger is subsequently held in a fixed angular position with respect to the second rotation axis and thus in a fixed position with respect to the first rotation axis. In particular, the upper rear part defines a stop surface 15, which cooperates with the first stop 30 to limit the rotation of the lever in the first rotation direction. This stop surface 15 abuts against the first stop 30 at least each time the hairspring 16 is loaded, and the indicator then performs a jump, that is, the date jump when the time display indicates midnight.

[0036] In Figures 1 to 3In the first alternative embodiment shown, the disk 10 has an overall circular profile with a transverse cavity 38 configured to allow the drive finger 12 to enter the cavity and thus retract as the teeth pass along the outer side 13 of the drive finger, with most of the hairspring 16 always being covered by the disk. In Figure 5 In the second alternative embodiment shown, the disk 10A of the mechanism 6A includes: - a central portion defining a central hole; - a projection 58 that covers a portion of the hairspring 16 on one side of its second end 19 to hold it in the general plane of the hairspring between the gear platform 8 and the disk 10A; - a portion in the form of an annular sector that extends radially from the central portion and defines a first stop 30 at a first angular end and a hole 33 for the outer stud 34 of the lever 26 on one side of a second angular end.

[0037] In the alternative embodiment shown, the drive finger 12 has an arcuate outer side 13 against which at least one tooth 5b of the toothed ring 5 of the indicator 4 can bear during rapid correction of the indicator using a correction device other than the mechanism. When the lever contacts the first stop 30, the arcuate outer side has a dimension radial to the first axis of rotation 20 that monotonically increases as the arcuate outer side approaches the drive side 14.

[0038] According to an advantageous alternative embodiment also shown in the figure, the lever 26 has a groove 42 in an inner portion 46 that runs along the drive finger 12, the groove having a transverse opening on one side of the hairspring 16. The second end 19 of the hairspring 16 extends through a member 40 that is coupled to the lever 26, the coupling member 40 being rigid and configured to be able to penetrate at least partially into the groove 42 and allow the hairspring to apply a driving couple to the rigid support 10 and the lever 26, thereby allowing the drive finger 12 to drive the indicator 4.

[0039] Preferably, the coupling member 40 is configured to be at least partially inserted into the groove 42 through the lateral opening of the groove. In particular, the groove 42 has a lateral surface 52 that is inclined in the rotational direction 50 of the gear platform 8. The indicator 4 is intended to be driven through the center of the lateral surface in the direction along the radial direction relative to the relative central rotation axis 20. The coupling member 40 has a lateral side 54 that faces the lateral surface 52. The lateral side is also inclined and skewed relative to the central rotation axis 20 in the same direction as the lateral surface. When the indicator is driven, the lateral side at least partially abuts against the lateral surface. The lateral surface and the lateral side are relatively long. This specific feature ensures that once the hairspring 16 contracts, the coupling member will be firmly held in the groove. In particular, when the hairspring is loaded, the contact point or contact area of the groove (where the hairspring force is applied via the coupling member) does not change. In addition, when the hairspring is loaded, the coupling member 40 cannot rotate about itself in the rotational direction of the gear platform.

[0040] The lever 26 advantageously has a lateral bevel 48 on the front part of the inner part 46, thereby allowing the coupling member 40 to be coupled to the lever 26, in particular the drive finger, by the following operation: by simply rotating the disk 10 relative to the gear platform 8 in the clockwise direction, the coupling member is inserted from the angular position of the coupling member upstream of the lateral bevel 48 into the groove 42.

[0041] The groove 42 is generally triangular in shape and gradually opens towards its lateral opening. The shape of the part of the coupling member 40 inserted into the groove through the lateral opening substantially corresponds to the shape of the groove. This configuration advantageously allows the coupling member to be easily inserted into the groove, but prior art information allows the member to very easily disengage in the case of an impact, even if the groove is intended to be relatively deep. However, the hairspring 16 is arranged such that when the hairspring is loaded, the rigid connection of the coupling member to the inner end 17 of the central part 24 is at a very short distance. In this case, the coupling member 40 cannot disengage from its groove in the case of an impact. In addition, when the drive finger does not interact with the toothing 5 of the indicator and the hairspring 16 is substantially relaxed, the coupling member 40 cannot laterally disengage from its groove in the case of an impact. Therefore, the mechanism 6 is arranged such that the coupling member cannot move out of the groove 42 when the hairspring is relaxed or stressed during the loading of the hairspring before the indicator jumps.

[0042] Once inserted into the recess 42, the coupling member 40 may be held in the recess by a radial force applied outwardly by the hairspring 16 to the coupling member relative to the central axis of rotation 20, although this is not mandatory. This radial force (more precisely, the radial component of the force applied by the hairspring via the coupling member to the lever) increases during rapid date change or during counterclockwise time correction through midnight because of the fact that the drive finger and the coupling member are subsequently retracted / withdrawn in the direction of the axis of rotation 20 via a clockwise rotation (the second rotation direction of the lever), such that the coupling member is thus generally held in the recess even when the hairspring 16 has a certain expansion in such a case.

[0043] When the drive finger 12 is retracted, during rapid correction of the date or time (including through midnight) in the counterclockwise direction, by rotating the lever 26 clockwise, the coupling finger moves closer to the central part 24, such that after a certain initial rotation of the lever, the coupling member can no longer disengage from its recess. During the initial rotation, the hairspring 16 can withstand a certain angular stress, which causes its expansion and theoretically allows the coupling member to disengage from its recess in case of an impact. However, if the coupling member significantly experiences an acceleration in the direction of the axis of rotation 20 of the gear platform 8, the lever is subject to a certain couple of forces that produces a rotation of the lever about its axis of rotation 22, and the drive finger subsequently follows the coupling member, such that the coupling member remains at least partially in its recess. If the acceleration occurs in a direction substantially passing through the center of gravity of the lever and its axis of rotation 22, the coupling member 40 can experience a movement that causes it to disengage from the recess 42. However, the internal projection 44 of the hairspring can be configured such that it prevents the coupling member from completely disengaging from its recess. Alternatively and advantageously, the rear part of the coupling member can be configured such that it collides with a rigid part integrally formed with the gear platform before the coupling member can completely disengage from its recess during correction. In summary, the mechanism 6 is arranged such that the coupling member 40 remains in its recess 42 during normal operation, such that the coupling member is always integrally formed with the drive finger during the normal operation, and such that in most cases, the coupling member cannot disengage from its recess during an impact, preferably not at all.

[0044] Preferably, the mechanism 6 is arranged such that the hairspring 16 contracts when the hairspring is loaded, so as to be able to produce an indicator jump. Preferably, when the coiled spring 18 of the contracted hairspring is stressed due to the loading of the hairspring, the angular displacement of the second end 19 of the hairspring 16 relative to the gear platform 8 and thus the angular displacement of the drive finger 12 coupled to the coupling member 40 relative to the gear platform 8 are limited by the second stop 28, which defines an angular stop attached to the gear platform 8 for rotation therewith. The indicator and the mechanism are arranged such that, during normal operation, before the angular displacement is stopped by the second stop and before this jump, at the end of the hairspring loading before this jump, no jump of the indicator occurs, and thus it corresponds to a determined angular distance α (see Figure 6A ).

[0045] In the alternative embodiment shown, the hairspring 16 includes an internal projection 44 arranged along the coiled spring 18 on one side of its second end 19, and the internal projection is arranged to abut against the second stop 28 (angular stop), thereby ending the loading of the hairspring and then causing the indicator 4 to jump to its next stable position, i.e., to the next date in the case of a date indicator.

[0046] Figures 6A to 8B The operation of the timepiece movement 2 is shown in more detail, in particular the mechanism 6 for driving the date ring 4 included in this timepiece movement. The central hub 32 is not shown in these figures so as not to clutter the drawings, but it is clearly necessary for the functionality of the mechanism 6.

[0047] Figures 6A to 6D Four consecutive states of the mechanism 6 for driving the date ring 4 to jump, in particular a semi-instantaneous jump, are shown. Figures 6A to 6D The mechanism 6 and the date ring 4 are shown respectively when the ring is driven to change to the next date at midnight:

[0048] - when the drive finger 12 is in contact with the tooth 5a of the ring 4 and the hairspring 16 is substantially angularly relaxed (i.e., not angularly stressed);

[0049] - after the end of the loading of the hairspring 16, at which time the internal projection 44 of the hairspring abuts against the angular stop 28 after undergoing an angular displacement α relative to the gear platform 8;

[0050] - during the date jump produced by the mechanical energy stored in the contracted hairspring being applied to the assembly; and

[0051] - at the end of the jump, at which time the date ring 4 has substantially reached its next stable position.

[0052] It should be noted that, in a particular embodiment, during normal operation, the jerk of the indicator occurs before the angular displacement of the hairspring is stopped by the angular stop 28. In this case, the angular stop is a hairspring protection stop. In another particular embodiment, the drive mechanism does not have any angular stops. During the loading period, the hairspring contracts and the turns of the hairspring remain free to expand between the two ends of the hairspring.

[0053] It should be noted that, in order to prevent the teeth 5a of the indicator 4 from passing below or above the drive finger 12 when the indicator is driven, it is stipulated that the height (including the clearance) between the gear platform 8 and the lower side of the toothed ring 5 is constantly maintained between the lower limit height and the upper limit height (including the clearance) of the drive finger from the gear platform. To this end, in an advantageous alternative embodiment, the lower limit height of the finger is less than the thickness of the teeth of the toothed ring 5. Preferably, in a watch comprising a watch movement 2, the upper limit height of the finger and the distance between the dial covering the drive mechanism and the indicator are also designed to be less than the thickness of the teeth of the toothed ring 5. The greater height of the finger 12 makes it possible to easily prevent the tooth 5a from passing below or above the finger 12, and the greater height can at least rise from the lower side of the hairspring 16 above the disc 10 defining the upper surface of the mechanism 6.

[0054] Figure 7A and 7B shows the behavior of the mechanism 6 during the rapid correction of the date ring 4 at night by means of a control member that can be operated by the user in a conventional manner. At night, the gear platform 8 and the disc 10 are initially in Figure 7A the configuration shown, such that the finger 12 is located between the tooth 5a and the tooth 5b preceding the tooth 5a with respect to the direction of rotation 60, so that the finger 12 is in the path of the tooth 5b of the indicator. The ring 4 is intended to advance rapidly in the direction of rotation 60 corresponding to the single direction of rotation of the date ring. As Figure 7B shown, the tooth 5b of the toothed ring 5 contacts the arcuate outer side 13 of the finger 12 when the ring 4 rotates, and then exerts a gradually increasing radial force on this finger, which causes the lever 26 to rotate clockwise about its axis of rotation 22 and thus causes the finger 12 to move towards the central hub of the disc 10, so that the finger retracts towards the axis of rotation 20. This retraction becomes possible through the configuration of the drive finger 12 and the profile of the transverse cavity 38 provided in the disc 10, and through the arrangement of the hairspring 16 and its attached central part 24, and through the configuration of the internal projection 44. As Figure 7B visible, when the tooth 5b passes by, the finger 12 retracts, thus allowing the tooth to follow the outer side 13 of the finger until the tooth projects angularly beyond the finger.

[0055] As has been explained, the interaction of the ring gear 5 on the drive finger 12 only exerts a force on the disk 10 through the lever 26, and thus a force is exerted at the second axis of rotation 22. The direction of the force (exerted at the second axis of rotation) generated by the teeth 5a or 5b of the indicator pressing on the outer side 13 of the drive finger creates a torque on the disk, thereby aiming to rotate the said disk, and the torque is weaker than that in the prior art. Given the rigidity of the hairspring 16, under the action of the teeth pressing on the outer side of the drive finger, the lever 26 can rotate relative to the disk without causing this rigid support to rotate significantly relative to the gear platform. It can be seen that since the drive finger 12 retracts by rotating about the second axis of rotation 22 away from the first axis of rotation 20 (the central axis of rotation of the mechanism), the hairspring mainly undergoes radial elastic deformation relative to the central axis of rotation 20. During calibration, the drive mechanism 6 thus allows the same retraction of the finger as in the prior art, but the drive mechanism produces less elastic deformation of the hairspring 16 compared to the mechanism in the prior art, in which the hairspring undergoes significant angular deformation in addition to radial deformation. Therefore, during the said calibration, the work that must be provided by the date ring 4 to the mechanism 6 to allow the tooth 5b to pass over the drive finger 12 (in the plane perpendicular to the axes of rotation 20 and 22) is less than in the case of a drive finger with a similar profile, but the drive finger with a similar profile is fixed relative to a disk having an oval hole through which the central axis passes, which axis is formed in particular by the hub, as in the prior art.

[0056] As the finger 12 moves radially, the hairspring 16 contracts radially, and the coupling member 40 moves closer to the central part 24. It should be noted that during the rapid calibration of the date ring, the hairspring 16 (more precisely, its coils 18) also expands slightly and is simultaneously subjected to a radial stress, and the hairspring is subjected to this radial stress in the direction of the axis of rotation of the gear platform. However, given the profile of the outer side 13 of the finger 12 and the rotation of the said finger in the direction of the axis of rotation 20 (the first axis of rotation, which is the central axis of rotation) as explained above, the stress of the expanded hairspring is relatively small or even practically zero, depending on the configuration of the system. This is very advantageous for the design of the hairspring 16, which can thus be arranged to be able to withstand the contraction that occurs when the indicator 4 is driven by the device 6 as well as possible, without having to also ensure that the hairspring functions properly for significant expansion stress.

[0057] Figure 8A and 8BShows the behavior of mechanism 6 during the correction of the time displayed by the timepiece mechanism, which rotates the gear platform 8 counterclockwise past midnight. In this case, the date ring 4 remains stationary in a stable position, in which it is when the time is corrected. The successive states of mechanism 6 are similar to the successive states that occur during the rapid correction of the date display described above. When the gear platform 8 and thus the assembly formed by the disk 10 and the lever 26 rotate in a direction opposite to the normal rotation direction (corresponding to the clockwise direction of the time display), the arcuate outer side 13 of the finger 12 abuts against the teeth 5a of the toothed ring 5( Figure 8A ), and the disk 10 continues to rotate. However, due to the small expansion of the hairspring, at least in the initial stage, the disk rotates slightly more slowly than the gear platform, while driving the finger to move radially towards the axis of rotation 20 via the clockwise rotation of the lever 26 that penetrates deeper into the transverse cavity 38, so that the finger retracts as the stationary tooth 5a runs along the outer side 13 of the finger.

[0058] Mechanism 6 is configured to prevent jamming during rapid date correction or counterclockwise time correction.

[0059] The invention further relates to a watch comprising a timepiece movement 2 according to the invention, the movement being housed in a watch case which also houses a dial arranged so as to allow the display of data items that vary over time by jumping, in particular the date.

Claims

1. A watch movement (2), the watch movement being equipped with an indicator (4) and comprising a mechanism (6) for driving the indicator to jump, the mechanism comprising: a gear platform (8) rotating about a first axis of rotation (20); a drive finger (12) for driving the indicator; and a balance spring (16) formed by a first end (17), a spring coil (18) and a second end (19), the first end being attached to the gear platform for rotation therewith and the second end being attached to the drive finger for rotation therewith at least during each loading of the balance spring before the indicator jumps and during the driving of the indicator by the mechanism during the jumps; characterized in that the mechanism (6) comprises a rigid support (10) and a lever (26), the rigid support being rotatable relative to the gear platform about a first axis of rotation (20), the lever being mounted on the rigid support so as to be rotatable about a second axis of rotation (22) remote from the first axis of rotation, the second axis of rotation being located at a first end of the lever, and a drive finger (12) is formed by the lever on one side of its second end, the mechanism (6) comprising a first stop (30) which is integrally formed with the rigid support (10) and which limits the rotation of the lever in a first direction corresponding to the direction in which the drive finger moves radially away from the first rotation axis (20), the lever being arranged to abut against the first stop at least when the hairspring (16) is loaded and being rotatable in a second direction opposite to the first direction to allow the drive finger to be radially retracted towards the first rotation axis under the action of a force exerted on the drive finger, the force having a gradually increasing radial component.

2. The watch movement according to claim 1, characterized in that: The balance spring (16) and the lever (26) are arranged such that the lever also abuts against the first stop when the balance spring is not under angular stress.

3. The watch movement according to claim 1 or 2, characterized in that: The rigid support comprises a disk (10) rotatably guided about the first axis of rotation (20) by a shaft (32) attached to the gear platform for rotation therewith, the disk forming the first stop (30).

4. The watch movement according to claim 3, characterized in that: The lever is formed by an arm (36) having a first height and being arranged at least partially between the gear platform (8) and the disk (10), and a drive finger (12), the arm having a second height (H) at least in a thickened portion, the thickened portion defining a drive side (14) intended to abut against a tooth (5a) of a toothed ring (5) associated with the indicator (4) when the indicator is driven by the mechanism (6), the second height being greater than the first height, and the thickened portion of the drive finger not being stacked on the disk for any useful angular position of the lever, the thickened portion extending axially at least partially over the thickness of at least one region of the disk situated above the arm.

5. The watch movement according to claim 4, characterized in that: The disc (10) has a transverse surface, a region (30) of which defines the first stop, the drive finger being arranged so that, at least each time the balance spring is loaded, the upper rear portion of the thickened portion of the drive finger can come into contact with the first stop (30), so that the drive finger is thereby held in a fixed angular position relative to the second axis of rotation and, therefore, in a fixed position relative to the first axis of rotation.

6. The watch movement according to claim 4 or 5, characterized in that: The disc (10) has a generally circular profile with a transverse cavity (38) configured to allow the drive finger (12) to enter the cavity and thus retract when the teeth (5a, 5b) pass along the outer side (13) of the drive finger, wherein a large part of the balance spring (16) is always covered by the disc.

7. A timepiece movement according to any one of claims 4 to 6, characterized in that: The drive finger (12) has an arcuate outer side surface (13) against which at least one tooth (5a) of the toothed ring (5) can be pressed during a rapid correction of the indicator using a correction device other than the mechanism, and which has a dimension radial to the first rotation axis when the lever is in contact with the first stop (30) that increases monotonically as the arcuate outer side surface approaches the drive side surface (14).

8. A timepiece movement according to any one of the preceding claims, characterised in that The mechanism (6) is arranged so that the balance spring (16) contracts when it is loaded, so as to be able to generate a beat through the indicator (4).

9. The watch movement according to claim 8, characterized in that: The balance spring (16) comprises an internal projection (44) arranged along the coil (18) on the side of its second end (19), arranged to abut against a second stop (28) defining an angular stop attached to the gear platform (8) for rotation therewith, at the end of loading of the balance spring and before the indicator jumps.

10. A timepiece movement according to any one of the preceding claims, characterised in that The first end (17) of the balance spring (16) is connected to a central part (24) which is attached to the gear platform (8) for rotation therewith.

11. A timepiece movement according to any one of the preceding claims, characterised in that The lever (26) has a groove (42) in its inner part on one side of the drive finger, the groove having a lateral opening on one side of the balance spring (16); and Characterized in that the second end (19) of the balance spring is extended by a member (40) for coupling with the lever (26), said coupling member (40) being rigid and configured to be able to penetrate at least partially into said groove through said transverse opening and to allow the balance spring to apply a driving force couple to the lever, thereby allowing the driving finger to drive said indicator.

12. The watch movement according to claim 11, characterized in that The groove (42) has a transverse surface (52) oriented obliquely in the rotational direction (50) of the gear platform (8), the indicator being intended to be driven through the center of the transverse surface in said direction relative to a radial direction relative to a first rotational axis, and the coupling member (40) has a transverse side face (54) facing the transverse surface, the transverse side face also being obliquely skewed relative to the first rotational axis in the same direction as the transverse surface, and the transverse side face at least partially abuts against the transverse surface when the indicator is driven.

13. A timepiece movement according to any one of the preceding claims, characterised in that The indicator (4) is a minute indicator, an hour indicator, a date indicator, a day indicator or a month indicator.

14. The watch movement according to claim 13, characterized in that: The indicator (4) is a date ring.

15. A watch, characterized in that: The watch comprises a timepiece movement (2) according to any one of the preceding claims.

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