Timepiece movement and watch comprising timepiece movement

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 utility model relates to a timepiece movement, said movement being provided with an indicator and comprising a mechanism for driving this indicator to jump, and the utility model further relates to a watch comprising a timepiece movement provided with such a mechanism. In particular, said indicator is a date indicator. BACKGROUND

[0002] The patent document EP 3828644 describes a mechanism for driving a jumping indicator, said mechanism advantageously overcoming the technical problems of the prior art by comprising a rigid drum finger and a hairspring arranged in said drum finger, said drum finger being rotatably and translationally guided by a hub passing through an oval hole in the drum, and said hairspring connecting the drum finger to a gear platform.

[0003] This driving mechanism presents several drawbacks. First, when the date ring is driven, the hairspring expands, and when the hairspring is loaded, its coil is intended to rest against the inner wall of the drum in order to limit the expansion of the hairspring and prevent said expansion from reaching the plastic range of the hairspring. This results in a sudden reduction in the effective length of the hairspring. Given the manufacturing tolerances of the various components, the loading time of the driving mechanism can vary, since the time at which the hairspring comes into contact with the inner wall of the drum can vary from one loading to the next, and so can the angular position of the contact area. This results in an inaccuracy in the 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 coil of the hairspring, which must have sufficient rigidity / hardness over its entire length, and more particularly in the part located between the contact area with the wall of the drum and the coupling member arranged at the second end of the hairspring for coupling this drum, which part ultimately needs to withstand the entire additional torque generated from the moment of contact to the moment at which the indicator jumps.

[0004] The figures in the above-mentioned documents show that the coupling member of the hairspring is arranged in a shallow recess from which it can easily emerge. The two lateral surfaces of the recess are parallel in the radial direction passing through the middle of the recess, while the coupling member has two radial sides, the angular width of which is less than the angular width of the recess, to allow this member to easily enter the recess. Furthermore, the coupling member is intended to have a large amount of play in the recess to allow this coupling member to move in the recess. Thus, a relatively small impact can easily cause the coupling member to come out of its recess. If this happens, either when the hairspring is loaded against the teeth of the date ring, or before this hairspring is loaded (the hairspring will then typically exhibit a slight expansion due to the friction exerted on the barrel), the coupling member comes out from one side of the radial driving side of the finger. In this case, the lateral wall of the barrel exerts a radial force on the coupling member, which is subjected to the friction force on this lateral wall. If the coupling member comes out of its recess when the hairspring is loaded against the teeth of the date ring, either the coupling member will then slide along the inner lateral surface and a date jump will occur until at least one revolution of the driving wheel is made and the coupling member reenters its recess (which is the best case, although this leads to the absence of a correct date display, which misses the daily jump), or the friction force is sufficient for the hairspring to expand again, thereby further increasing the friction force, until its spring coil touches the lateral wall and a date jump occurs at an indeterminate time. In the latter case, after the date jump, the hairspring will relax by driving the barrel. If this situation occurs again, the next date change will no longer occur around midnight. If the coupling member experiences some sudden angular displacement along the lateral wall (which is possible), this situation will be repeated for at least a few days, with the date increment occurring at an indeterminate and variable time. In any case, once the coupling member comes out of its recess, the date driving mechanism will stop functioning for at least a few days, a situation that is very likely in the mechanism shown in the figures of patent document EP 3828644.

[0005] The geometry of the coupling member with respect to its recess, which allows a significant amount of play and a certain mobility performance of the coupling member in the recess, generates another problem. More specifically, when the hairspring is loaded, it deforms the coil of the hairspring and causes the coupling member to rotate around itself. This rotation will make the coupling member slide against the front transverse wall of the recess, so that the point of application of the force from the hairspring to the drum finger decreases radially as the hairspring is loaded. Thus, at a given level of loading of the hairspring, the driving torque provided by the hairspring on the finger is proportionally reduced as the lever arm of the force from the hairspring to the drum finger decreases, which poses a problem because, for a given point of contact, the driving force of the finger on the teeth of the indicator also decreases by the same proportion. Since a given driving torque is required to make the indicator 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 watch movement, which loads the hairspring of the driving mechanism and therefore has to provide more torque. This also requires the hairspring to be sized more robustly than necessary.

[0006] Finally, another problem of the mechanism comes from the fact that, when the indicator is driven, the coil of the hairspring exerts a radial force on the drum in the area diametrically opposite the finger, thus substantially along the longitudinal direction of the oval hole, which is intended to move the finger away from the teeth of the ring. Thus, in this case, especially in the case of a small impact, the finger is more likely to pass over the teeth without causing the indicator to be driven. It should also be noted that this situation reduces the angular path that the finger can pass through to drive the teeth by remaining in contact, so that the finger can pass over the teeth before it receives the driving torque over an angular distance sufficient to ensure the date jump, once the finger has passed over the teeth, the date ring remains stationary in the intermediate position or returns to its previous stable position. Furthermore, for a given driving torque, the reduction of the lever arm for the application of the driving force to the teeth requires an increase in the driving force required, which requires an increase in the force provided by the hairspring and therefore its tension. SUMMARY

[0007] The object of the present invention is to provide a mechanism for driving a jumping indicator, which overcomes at least some of the drawbacks of the prior art described above. The present invention further aims to provide a watch movement equipped with an indicator and comprising a mechanism for driving the indicator to jump, which is efficient, precise in each watch movement comprising this mechanism, and whose operation is hardly or not at all disturbed by external stresses (e.g. impacts).

[0008] In particular, the driving mechanism is intended to allow a rapid correction of the indicator by another specific mechanism peculiar to the timepiece movement, during the passage of a tooth on the outer side of the driving finger of the indicator or the successive passage of several teeth on the outer side of the driving finger of the indicator, with the additional torque due to the presence of the driving mechanism, which is minimal and does not contain a jump.

[0009] To this end, the utility model relates to a timepiece movement, said timepiece movement being equipped with an indicator and comprising a mechanism for driving the jumps of said indicator, said mechanism comprising a gear platform defining a first axis of rotation, a driving finger for driving the indicator and a hairspring formed by a first end, a coil and a second end, said first end being attached to the gear platform for rotation therewith, the second end being attached to the driving finger for rotation therewith at least during each loading of the hairspring before the jumps of the indicator and during the driving of the indicator by the mechanism during said jumps. Said mechanism comprises a rigid support rotatable with respect 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, said second axis of rotation being at a first end of the lever and the driving finger being formed on a side of the second end of said lever. The mechanism further comprises a first stop formed integrally with the rigid support, said first stop limiting 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, said lever being arranged to abut against the first stop at least when the hairspring is loaded before the jumps of the indicator and being able to rotate in a second direction opposite to the first direction to allow the driving finger to be retracted towards the first axis of rotation under the action of a force exerted on the driving finger, said force having a radial component which gradually increases.

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

[0011] In a particular alternative embodiment, the indicator is a date indicator comprising a ring of teeth. In particular, said indicator is a date ring comprising an inner ring of teeth so as to be rotatably driven by said mechanism.

[0012] Due to the drive finger (which is not formed integrally with the rigid support but can rotate about a second axis of rotation defined by the rigid support, which is remote from the gear platform and the first axis of rotation of the rigid support), the radial retraction of the drive finger in the direction of the first axis of rotation, under the action of the force exerted on it by the indicator, is in this case achieved by rotation of the lever, which can be relatively light and exhibit relatively low friction during rotation, without radial displacement of the rigid support. Thus, the force couple to be exerted by the user for the rapid correction of the indicator in the intended drive direction, via a correction device other than the mechanism, or in the anticlockwise direction (which generates rotation of the gear platform in the opposite direction to the drive direction) and through midnight for the correction of time (in particular in the case of a calendar indicator), is relatively weak, and the passage of the indicator teeth on the drive finger (retraction in a direction which is mainly radial with respect to the central axis) is less pronounced than in the prior art.

[0013] Secondly, the elastic deformation of the balance spring can be lower than in the prior art, thus generating lower stresses in the balance spring, which is advantageous for the dimensional definition of the balance spring, since the lever rotates about the second axis of rotation and the drive finger moves mainly towards the first axis of rotation. The balance spring necessarily undergoes radial elastic deformation due to the radial retraction of the drive finger and thus of the second end of the balance spring; however, the angular deformation of the balance spring caused by the force couple exerted on said second end can be much lower than in the case of the mechanism of the prior art. Advantageously, the interaction of the gear ring on the finger is exerted by the lever only on the rigid support and thus at the second eccentric axis of rotation. The direction of the forces generated by the teeth of the indicator pressing on the outer side of the drive finger at the second axis of rotation generates a torque on the rigid support, intended to rotate the rigid support, which is weaker than in the prior art. Given the stiffness of the balance spring, which is necessary to store energy during normal driving of the indicator, the lever can rotate with respect to the rigid support under the action of the teeth pressing on the outer side of the drive finger without the rigid support rotating with respect to the gear platform. It can thus be seen that, since the drive finger retracts about a second axis of rotation which is remote from the first axis of rotation, the balance spring mainly undergoes radial elastic deformation. The drive mechanism of the application thus allows the same retraction of the finger during correction as in the prior art, but generates a smaller elastic deformation of the balance spring than the mechanism of the prior art, in which the balance spring undergoes not only radial deformation but also significant angular deformation.

[0014] The above-mentioned advantages of the present application can be obtained significantly in an advantageous alternative embodiment, wherein the outer side of the driving finger is curved, which curved outer side has a dimension radial to the first rotation axis when the lever is in contact with the first stop, said dimension increasing monotonously as it approaches the driving side of the driving finger, so as to press against the lateral side of the teeth of the toothed ring during the increase of the indicator according to the jump.

[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 an angular stress.

[0016] According to a main embodiment, the rigid support comprises a disc forming the first stop. In particular, said rigid support consists of such a disc.

[0017] According to a preferred embodiment, the mechanism is arranged such that, when the hairspring is loaded, said hairspring contracts so as to be able to generate a jump, in particular a semi-instantaneous jump 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 indicator teeth against which the finger abuts, thereby optimizing this driving force and thus the driving torque required to cause the jump of the indicator.

[0018] According to an advantageous alternative embodiment, when the coil spring, which is contracted by the hairspring, is stressed, the angular displacement of the second end of the hairspring and thus of the driving finger relative to the gear platform is limited by a second stop, said second stop defining an angular stop attached to the gear platform for rotation therewith, said indicator and said mechanism being arranged such that, in normal operation, after said angular displacement is stopped by the second stop, at the end of the loading of the hairspring before this jump, the jump of the indicator occurs and thus corresponds to a determined angular distance.

[0019] The present application further relates to a watch comprising a movement according to the present application. BRIEF DESCRIPTION OF DRAWINGS

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

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

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

[0023] - Figure 3 is the mechanism of Figure 1perspective view of the rigid support, the balance spring and the lever of the timepiece movement in

[0024] - Figure 4 is a magnified perspective view of the lever;

[0025] - Figure 5 is a view similar to Figure 1 showing an alternative embodiment of the timepiece movement in Figure 1 ;

[0026] - Figures 6A to 6D partially shows a timepiece movement according to the application in four successive states respectively appearing when the date ring is driven by the driving mechanism, the movement comprising the advantageous embodiment of the driving mechanism described in the preceding figures;

[0027] - Figure 7A and 7B partially shows a timepiece movement in Figure 6A in two successive states respectively appearing when the date ring is rapidly driven by the conventional control member in the date ring driving direction;

[0028] - Figure 8A and 8B partially shows a timepiece movement in Figure 6A in two successive states respectively appearing when the time display hands are driven in the counter-clockwise direction, the gear platform thus being driven in the opposite direction to the driving direction of this platform when the date ring is driven. DETAILED DESCRIPTION

[0029] With reference to the appended figures, one advantageous embodiment of a mechanism for driving an indicator jump, in particular 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 application comprising such a driving mechanism will be described.

[0030] The mechanism 6 for driving the jumping indicator 4 comprises a gear platform 8 rotating about a first axis of rotation 20, a driving 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 comprising an inner toothing 5. In other particular alternative embodiments given by way of non-limiting example, the indicator is for example a minute, hour, day or month indicator. The hairspring 16 is made up of a first end 17 attached to the gear platform for rotation therewith, a coil 18 and a second end 19 attached to the driving finger 12 for rotation therewith at least during each loading of the hairspring 16 before the jump of the indicator 4 and during said jump by the mechanism. The first end 17 of the hairspring is connected to a central portion 24 attached to the gear platform 8 for rotation therewith. Preferably, the hairspring and the central portion form one and the same portion. The mechanism 6 comprises a rigid support 10 rotatable about the first axis of rotation with respect to the gear platform, and a lever 26 mounted on said rigid support so as to be rotatable about a second axis of rotation 22, said second axis of rotation being distant from the first axis of rotation 20.

[0031] The second axis of rotation 22 is located at a first end of the lever which forms the driving finger on one side of a second end thereof. In particular, the lever has a circular outer stake 34 at its first end which is inserted into a hole 33 formed in the rigid support so that the lever can rotate about the axis of rotation 22 defined by said hole 33, in particular allowing the driving finger 12 to retract during a rapid correction of the date or during a particular anticlockwise correction of the time past midnight, as will be explained in more detail hereafter.

[0032] The mechanism 6 comprises a central hub 32 which defines a shaft which passes through a central hole in the rigid support 10 and which rotatably guides this rigid support with respect to the gear platform 8, said gear platform and the central portion 24 being driven onto the central hub 32.

[0033] Generally, the drive mechanism comprises a first stop which is formed integrally with the rigid support and which limits the rotation of the lever in a first direction corresponding to the direction in which the fingers move radially away from the first rotation axis 20, the lever being arranged to be able to bear against the first stop at least when the hairspring is being wound up before the jump of the indicator and also preferably when the indicator is being 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 fingers to retract towards the first rotation axis 20 during the correction under the action of the tangential component of the force exerted by the rim of the indicator on the drive fingers with respect to the second rotation axis 22. Preferably, the hairspring and the lever are arranged so that the lever also bears against the first stop when the hairspring is not subjected to an angular stress. According to a main alternative embodiment, the rigid support comprises a disc which forms the first stop. According to an advantageous alternative embodiment illustrated in the figures, the rigid support is a disc 10.

[0034] According to a particular alternative embodiment illustrated in the figures, the lever 26 is formed by an arm 36 having a first height and at least partly arranged between the gearwheel platform and the disc, and a drive finger 12. The drive finger 12 has a second height H at least in the thickened portion which defines the drive side 14 intended to bear against the teeth of the rim 5 associated with the indicator 4 (see Figures 6A to 8B ) when the indicator is driven by the mechanism 6. This 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 up on the disc, at least partly extending axially over the thickness of at least one region of the disc situated above the arm. When the lever bears 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 disc 10 has a lateral surface whose substantially radial region defines the first stop 30. The drive finger 12 has the second height H over the entire extent of the rim 5 in the plane thereof and is arranged so that at least each time the hairspring is wound up, the rear upper portion of the drive finger can bear against the first stop 30, so that the drive finger is then held in a fixed angular position with respect to the second rotation axis and consequently in a fixed position with respect to the first rotation axis. In particular, the rear upper portion 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 bearing against the first stop 30 at least each time the hairspring 16 is wound up and the indicator subsequently performs a jump, i.e. a date jump when the time indicates midnight.

[0036] In Figures 1 to 3In the first alternative embodiment shown, the disc 10 has a generally circular profile with a transverse cavity 38 configured to allow the drive finger 12 to enter said cavity and thus retract when the tooth passes along the outer side 13 of said drive finger, with the majority of the hairspring 16 being covered by the disc at all times. In the second alternative embodiment shown, the disc 10A of the mechanism 6A comprises: - a central portion defining a central hole; - a raised piece 58 covering the portion of the hairspring 16 on one side of its second end 19, to keep it in the general plane of the hairspring between the toothed platform 8 and the disc 10A; - a portion in the form of an annular sector extending radially from the central portion and defining 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. Figure 5

[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 bezel 5 of the indicator 4 can be pressed during rapid correction of the indicator using a correction device other than said mechanism, the arcuate outer side having a dimension radially to the first rotation axis 20 which monotonically increases as the arcuate outer side approaches the drive side 14.

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

[0039] ​Preferably, the coupling member 40 is configured to be able to pass at least partially into the recess 42 through the lateral opening thereof. In particular, the recess 42 has a lateral surface 52 oriented obliquely in the direction of rotation 50 of the gear platform 8, the indicator 4 is intended to be driven through the center of said lateral surface in a radial direction with respect to the relative central rotation axis 20, and the coupling member 40 has a lateral side 54 facing the lateral surface 52, which is also obliquely skewed with respect to the central rotation axis 20 in the same direction as the lateral surface, and which, when the indicator is driven, rests at least partially against said lateral surface. Said lateral surface and lateral side are relatively long. This particular feature ensures that, once the hairspring 16 is contracted, the coupling member is firmly held in the recess. In particular, the point or area of contact of the recess, against which the hairspring force is exerted via the coupling member, does not change when the hairspring is loaded. Furthermore, the coupling member 40 cannot rotate about itself in the direction of rotation of the gear platform when the hairspring is loaded.

[0040] The lever 26 advantageously has a lateral ramp 48 on the front of the inner portion 46, allowing the coupling of the coupling member 40 to the lever 26, in particular the driving finger, by simply rotating the disc 10 with respect to the gear platform 8 in the clockwise direction, inserting this coupling member into the recess 42 from an angular position of the coupling member upstream of the lateral ramp 48.

[0041] The recess 42 is generally triangular in shape and opens gradually towards its lateral opening. The shape of the part of the coupling member 40 inserted into the recess through the lateral opening substantially corresponds to the shape of the recess. This configuration advantageously allows the coupling member to be easily inserted into the recess, but a priori (prior art) allows said member to be very easily disengaged in the event of an impact, even if the recess is intended to be relatively deep. However, the hairspring 16 is arranged such that, when said hairspring is loaded, the rigid connection of the coupling member to the inner end 17 of the hairspring, which is rigidly connected to the central portion 24, is at a very short distance. In this case, the coupling member 40 cannot disengage from its recess in the event of an impact. Furthermore, the coupling member 40 cannot disengage laterally from its recess in the event of an impact when the driving finger is not interacting with the rim 5 of the indicator and the hairspring 16 is substantially relaxed. Thus, the mechanism 6 is arranged such that said coupling member cannot move out of the recess 42 when the hairspring is relaxed or stressed during the loading of this hairspring before the jump of the indicator.

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

[0043] When the driving finger 12 is retracted, during a rapid correction of the date or time in the counterclockwise direction (including past midnight), by rotating the lever 26 in the clockwise direction, the coupling finger moves closer to the central portion 24, so 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 be subjected to a certain angular stress, causing it to expand and theoretically allowing the coupling member to disengage from its recess in the event of an impact. However, if the coupling member experiences a significant acceleration in the direction of the rotation axis 20 of the gear platform 8, a couple is exerted on the lever, which generates a rotation of said lever around its rotation axis 22, and the driving finger subsequently follows the coupling member, so 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 rotation axis 22, the coupling member 40 can experience a movement that causes it to disengage from the recess 42. However, the inner protrusion 44 of the hairspring can be configured so that the coupling member is prevented from completely disengaging from its recess. Alternatively and advantageously, the rear portion of the coupling member can be configured so that, before the coupling member can completely disengage from its recess during the correction, it collides with a rigid portion formed integrally with the gear platform. In any case, the mechanism 6 is arranged so that the coupling member 40 remains in its recess 42 during normal operation, so that said coupling member is always integral with the driving finger during said normal operation, and so that in most cases said coupling member cannot disengage from its recess during an impact, preferably cannot disengage from its recess at all.

[0044] Preferably, the mechanism 6 is arranged so that the hairspring 16 contracts when it is loaded, so as to be able to generate an indicator jump. Preferably, when the contracted coil 18 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 of the driving finger 12 coupled to the coupling member 40 relative to the gear platform 8 is limited by a second stop 28 defining an angular stop attached to the gear platform 8 for rotation therewith, the indicator and mechanism being arranged so that, in normal operation, before said angular displacement is stopped by the second stop, at the end of the loading of the hairspring before this jump, no jump of the indicator occurs, thus corresponding to a determined angular distance a (see Figure 6A ).

[0045] In the alternative embodiment shown, the hairspring 16 comprises an internal protrusion 44 arranged on one side of the second end 19 of the coil 18, arranged to abut against the second stop 28 (angular stop), 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 watch movement 2 is shown in more detail, in particular the mechanism 6 for driving the date ring 4 comprised in this watch movement. The central hub 32 is not shown in these figures so as not to make the figures too cumbersome, but it is obviously necessary for the functionality of the mechanism 6.

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

[0048] - when the driving finger 12 is in contact with the teeth 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 protrusion 44 of the hairspring abuts against the angular stop 28 after having undergone an angular displacement a relative to the gear platform 8;

[0050] - during the date jump generated by the mechanical energy stored in the contracted hairspring applied to said 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, in normal operation, the jump 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 driving mechanism does not have any angular stop. During the loading period, the hairspring contracts and the coil of said hairspring remains free to expand between the two ends of the hairspring.

[0053] It should be noted that, in order to prevent the tooth 5a of the indicator 4 from passing from below or above the driving finger 12 when the indicator is driven, it is provided that the height between the gear platform 8 and the underside of the toothed ring 5, including the play, is constantly maintained between the lower and upper limit heights of the driving finger from the underside of the gear platform, including the play. 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 the timepiece movement 2, the upper limit height of the finger and the distance between the finger and the dial covering the driving 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, which can rise at least from the underside of the hairspring 16 above the upper surface of the defining mechanism 6, makes it easy to prevent the tooth 5a from passing from below or above the finger 12.

[0054] Figure 7A and 7B It is shown that during the rapid correction of the date ring 4, the mechanism 6 in the evening by means of the action of control members which can be operated by the user in a conventional manner, the gear platform 8 and the disc 10 are for example initially in the position Figure 7A In the configuration shown, the finger 12 is located between the tooth 5a and the tooth 5b which precedes 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 along a direction of rotation 60 corresponding to a single direction of rotation of the date ring. As Figure 7B As shown in the figure, the tooth 5b of the toothed ring 5, when the ring 4 is rotated, comes into contact with the arcuate outer side 13 of the finger 12, then exerts on this finger a gradually increasing radial force, 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 is made possible by the configuration of the driving finger 12 and the profile of the transverse cavity 38 provided in the disc 10, and by the arrangement of the hairspring 16 and the central portion 24 to which it is attached, and by the configuration of the internal projection 44. As Figure 7B As can be seen in the figure, when the tooth 5b passes, the finger 12 retracts, allowing said tooth to follow the outer side 13 of the finger until said tooth projects angularly beyond the finger.

[0055] As already explained, the interaction of the toothed ring 5 on the driving finger 12 only exerts a force on the disc 10 through the lever 26, thus at the second rotation axis 22. The direction of the force (exerted at the second rotation axis) generated by the tooth 5a or 5b of the indicator pressed on the outer side 13 of the driving finger generates a torque on the disc, which aims to rotate said disc, which is weaker than the torque in the prior art. Given the stiffness of the hair spring 16, under the action of the tooth pressed on the outer side of the driving finger, the lever 26 can rotate with respect to the disc without making this stiff support rotate significantly with respect to the gear platform. It can be seen that, since the driving finger 12 is retracted by rotating around the second rotation axis 22, which is away from the first rotation axis 20 (central rotation axis of the mechanism), the hair spring mainly undergoes a radial elastic deformation with respect to the central rotation axis 20. During the correction, the driving mechanism 6 thus allows the same retraction of the finger as in the prior art, but the driving mechanism generates less elastic deformation of the hair spring 16 than in the mechanism of the prior art, in which the hair spring undergoes a significant angular deformation in addition to a radial deformation. Thus, during the correction described, the work that must be provided to the mechanism 6 by the date ring 4 in order to allow the tooth 5b to pass above the driving finger 12 (in a plane perpendicular to the rotation axes 20 and 22) is less than in the case of a driving finger with a similar profile, but which is fixed with respect to a disc having a central axis passing through an elliptical hole, said axis being formed in particular by a hub, as in the prior art.

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

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

[0058] The mechanism 6 is configured to prevent jamming during the rapid correction of the date or the counterclockwise correction of the time.

[0059] The utility model further relates to a watch comprising the timepiece movement 2 according to the utility model, the movement is loaded into the watch case, the watch case also is equipped with the watch dial, the watch dial is arranged so as to allow the display of the data item which changes with time by jumping, particularly the date.

Claims

1. A timepiece movement (2) equipped with an indicator (4) and comprising a mechanism (6) for driving the jumps of the indicator, the mechanism comprising: a gear platform (8) rotating about a first axis of rotation (20); a driving finger (12) for driving the indicator; and a hairspring (16) formed by a first end (17) attached to the gear platform for rotation therewith, and a second end (19) attached to the driving finger for rotation therewith at least during each loading of the hairspring before and during the jump of the indicator by the mechanism; characterized in that the mechanism (6) comprises a rigid support rotatable about the first axis of rotation (20) with respect to the gear platform, 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, the second axis of rotation being located at a first end of the lever, and the driving finger (12) being formed by the lever on a side of a second end thereof, the mechanism (6) comprising a first stop (30) formed integrally with the rigid support and limiting the rotation of the lever in a first direction corresponding to the direction in which the driving finger moves radially away from the first axis of rotation (20), the lever being arranged to bear against the first stop at least when the hairspring (16) is loaded, and being able to rotate in a second direction opposite to the first direction to allow the driving finger to retract radially towards the first axis of rotation under the action of a force exerted on the driving finger, the force having a radial component which gradually increases.

2. A timepiece movement according to claim 1, characterised in that, the hairspring (16) and the lever (26) are arranged so that the lever also bears against the first stop when the hairspring is not under angular stress.

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

4. A timepiece movement according to claim 3, characterized in that, the lever is formed by an arm (36) having a first height and arranged at least partly between the gear platform (8) and the disc (10), and a driving finger (12) having a second height (H) at least in a thickened portion defining a driving flank (14) intended to bear 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 for any useful angular position of the lever, the thickened portion of the driving finger does not stack on the disc, the thickened portion extending axially at least partly over the thickness of at least one region of the disc located above the arm.

5. A timepiece movement according to claim 4, characterised in that, The disc (10) has a lateral surface, one region of which defines the first stop, the driving finger being arranged so that at least at each time the hairspring is loaded, the rear upper part of the thickened portion of the driving finger can abut against the first stop (30), so that the driving finger is thus held in a fixed angular position relative to the second axis of rotation, and thus in a fixed position relative to the first axis of rotation.

6. A timepiece movement according to claim 4 or 5, characterized in that, The disc (10) has a generally circular profile with a lateral cavity (38) configured to allow the driving finger (12) to enter the cavity and thus retract when the teeth (5a, 5b) pass along the external side (13) of the driving finger, wherein the majority of the hairspring (16) is always covered by the disc.

7. A timepiece movement according to any one of Claims 4 to 6, characterized in that, The driving finger (12) has an arcuate external side (13) against which at least one tooth (5a) of the ring gear (5) can press during a rapid correction of the indicator using a correction device other than the mechanism, the arcuate external side having a dimension radial to the first axis of rotation which monotonically increases as the arcuate external side approaches the driving side (14).

8. A watch movement according to any one of the preceding claims, characterised in that, The mechanism (6) is arranged so that the hairspring (16) retracts when it is loaded, so as to be able to generate a jump by the indicator (4).

9. A timepiece movement according to claim 8, characterised in that, The hairspring (16) comprises an internal protrusion (44) arranged on one side of the second end (19) of the coil (18), the internal protrusion being arranged against a second stop (28) which defines an angular stop attached to the gear platform (8) for rotation therewith, at the end of the loading of the hairspring and before the jump by the indicator.

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

11. Watch movement according to any one of the preceding claims, characterized in that, The lever (26) has a recess (42) in an internal portion on one side of the driving finger, the recess having a lateral opening on one side of the hairspring (16); And characterized in that the second end (19) of the hairspring is extended by a member (40) for coupling with the lever (26), the coupling member (40) being rigid and configured to be able to pass at least partially into the recess through the lateral opening, and to allow the hairspring to exert a driving force couple to the lever, allowing the driving finger to drive the indicator.

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

13. A watch 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. A timepiece 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. The watch comprises a timepiece movement (2) according to any one of the preceding claims.

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