Clock movement provided with a drive mechanism for a jumping indicator

Abstract

The clockwork movement (2) is provided with an indicator (4) and comprises a mechanism (6) for its jump drive, the mechanism comprising a wheel plate (8) having a first axis of rotation (20), a drive finger (12) for the indicator and a spring (16) having a first end integral in rotation with the wheel plate and a second end integral in rotation with the drive finger. The mechanism comprises a rigid support (10), movable in rotation about the first axis of rotation (20) relative to the wheel plate, and a lever (26) mounted on the rigid support movable in rotation about a second axis of rotation (22), distant from the first axis of rotation, and forming the drive finger.The mechanism limits the rotation of the rocker in a first direction during loading of the spring and a subsequent jump of the indicator, the rocker being able to undergo a rotation in the direction opposite to the first direction, thus allowing a radial withdrawal of the drive finger, in the direction of the first axis of rotation, under the action of a radial force exerted on this drive finger.

Description

Technical field of the invention

[0001] The present invention relates to a watch movement provided with an indicator and comprising a mechanism for driving this indicator by jumping, as well as a watch incorporating a watch movement provided with such a mechanism. In particular, the indicator is a date indicator. Technological background

[0002] Document EP 3828644 describes a drive mechanism for a jumping indicator which advantageously addresses prior technical problems by the fact that it comprises a rigid drum finger, guided in rotation and translation by a hub passing through an oblong hole in the drum, and a spring arranged in this drum finger and connecting the latter to a wheel board.

[0003] This drive mechanism has several disadvantages. Firstly, the spring works by expanding when driving the date ring and its coil is designed to come into contact with the inner wall of the drum when the spring is loaded, so as to limit the expansion of this spring to avoid reaching the plastic domain of the spring. This has the consequence of suddenly reducing the active length of the spring. Given the manufacturing tolerances of the various elements, the loading time of the drive mechanism can vary, because the moment when the spring comes into contact with the inner wall of the drum can vary from one loading to another and the angular position of the contact zone can also vary. This causes an inaccuracy for the moment of triggering the transition of the ring to the next date.Then, another problem comes from the fact that the driving force is transmitted to the finger via the coil of the spring, which must therefore have sufficient rigidity / stiffness over its entire length and more particularly over the portion located between the contact zone with the wall of the drum and the coupling member to this drum arranged at the second end of the spring, this portion ultimately having to support the entirety of an additional torque generated up to the moment of the indicator jump from the instant of contact.

[0004] The figures of the aforementioned document show that the spring coupling member is arranged in a shallow housing from which this member can easily emerge. Indeed, the two lateral surfaces of the housing are parallel in a radial direction passing through the middle of the housing and the coupling member has two radial flanks, the angular width of the coupling member being provided to be less than that of the housing to allow this member to easily penetrate into the housing. In addition, it is provided that the coupling member has a large clearance in the housing, to allow mobility of this coupling member in the housing. Thus, a relatively small shock can easily result in the coupling member coming out of its housing.If this is the case, whether during loading of the spring bearing against a tooth of the date ring or before loading of this spring, which then generally presents a slight expansion due to the friction exerted on the drum, the coupling member comes out from the side of the radial driving flank of the finger. In this situation, the side wall of the drum exerts a radial force on the coupling member so that it undergoes a friction force on this side wall.If the coupling member comes out of its housing when the spring is loaded against a tooth of the date ring, it either slides along the inner side surface and the date jump will not take place at least until the drive wheel has made one revolution and the coupling member enters its housing again (the most favorable case which, however, results in the loss of a correct display of the date, which has missed a daily jump), or the friction force is sufficient for the spring to be loaded again by expansion, further increasing the friction force, until its coil touches the side wall and a date jump takes place at an undetermined time. In the latter case, after the date jump, the spring will relax, driving the drum. If this situation is repeated, then the following date changes will no longer occur around midnight.If the coupling member undergoes a certain sudden angular displacement along the side wall, which is likely, then this situation will repeat itself for at least a few days with increments of the date at indeterminate and variable times. In any case, the date drive mechanism is no longer functional for at least a few days as soon as the coupling member is removed from its housing, a very likely event for the mechanism as shown in the figures of document EP 3828644.

[0005] The geometry of the coupling member relative to its housing, allowing for a large amount of play and some mobility of this coupling member in the housing, creates another problem. Indeed, when the spring is loaded, it will deform the coil of the spring and cause the coupling member to rotate on itself. This rotation will have the effect of sliding the coupling member against the front side wall of the housing so that the point of application of the spring force on the drum finger is reduced radially as the spring is loaded. Thus, for a given spring loading level, the driving torque provided by the spring on the finger decreases proportionally to the reduction in the lever arm for applying the spring force to the drum finger, which poses a problem because the driving force of the finger on the indicator tooth decreases in the same proportion for a given contact point.However, since a given driving torque is required to make the indicator jump, the spring will therefore have to generate a force that is all the higher as the said lever arm decreases during the loading of the spring, which negatively impacts the performance of the watch movement which loads the spring of the drive mechanism and must then provide more torque. This also requires a more robust dimensioning of the spring than necessary.

[0006] Finally, another problem with the mechanism in question results from the fact that, when driving the indicator, the coil of the spring exerts a radial force on the drum directed outwards in an area diametrically opposite the finger and thus substantially in the longitudinal direction of the oblong hole, which tends to move this finger away from the teeth of the ring. The finger then risks more easily passing a tooth without driving the indicator, in particular during a small shock in such a situation.It will also be noted that such a situation decreases the angular path over which the finger can drive a tooth while remaining in contact, so that it is possible for the finger to pass the tooth before it receives a driving torque over a sufficient angular distance to ensure a date jump, the date ring remaining stopped in an intermediate position or returning back to its previous stable position once the finger has passed the tooth. In addition, the reduction in the lever arm for applying the driving force to the tooth requires, for a given driving torque, an increase in the necessary driving force, which requires an increase in the force provided by the spring and therefore its tension. Summary of the invention

[0007] The invention aims to propose a mechanism for driving a jumping indicator which solves at least some of the drawbacks of the prior art described above. The invention also aims to provide a watch movement provided with an indicator and comprising a mechanism for driving this indicator by jumping which is efficient, which can be precise in each watch movement comprising such a mechanism, and which is little or not disturbed in its operation by external constraints, for example shocks.

[0008] In particular, it is intended that the drive mechanism allows rapid correction of the indicator, by another specific mechanism of the watch movement, with an additional torque generated by the presence of the drive mechanism, during the passage of a tooth or successively of several teeth on the outer flank of a drive finger of the indicator, which is minimal and without sudden variation.

[0009] To this end, the invention relates to a watch movement provided with an indicator and comprising a mechanism for driving this indicator by jumping, the mechanism comprising a wheel plate defining a first axis of rotation, a drive finger for the indicator and a spring formed of a first end, a coil and a second end, the first end being integral in rotation with the wheel plate and the second end being integral in rotation with the drive finger at least during each loading of the spring preceding a jump of the indicator and the driving of the indicator by the mechanism during this jump.The mechanism comprises a rigid support, which is rotatable about the first axis of rotation relative to the wheel board, and a rocker mounted on the rigid support so as to be rotatable about a second axis of rotation which is distant from the first axis of rotation, the second axis of rotation being located at a first end of the rocker and the drive finger being formed by this rocker on the side of its second end.The mechanism further comprises a first stop which is integral with the rigid support and which limits the rotation of the rocker in a first direction which corresponds to a radial distance of the finger relative to the first axis of rotation, the rocker being arranged so as to bear against the first stop at least during loading of the spring before a jump of the indicator and to be able to undergo a rotation in the second direction, opposite to the first direction, and thus allow a radial withdrawal of the drive finger, in the direction of the first axis of rotation, under the action of a force exerted on this drive finger which has a progressively increasing radial component.

[0010] The first stop allows, when loading the spring, to maintain a constant radial distance between the point of contact of the drive finger on a tooth of the indicator and the first axis of rotation (central axis of rotation) of the mechanism. Thus, unlike the prior art, the lever arm remains constant and therefore a better efficiency of the mechanism is obtained.

[0011] In a particular variant, the indicator is a date indicator comprising a toothing. In particular, the indicator is a date ring comprising an internal toothing for its rotational drive by said mechanism.

[0012] Thanks to the drive finger which is not integral with the rigid support but which is movable in rotation around a second axis of rotation defined by the rigid support and distant from the first axis of rotation of the wheel board and the rigid support, a radial withdrawal of the drive finger in the direction of the first axis of rotation, under the action of a force exerted on this drive finger by the indicator, is obtained here by the rotation of the rocker without radial displacement of the rigid support, this rocker being able to be relatively light and having relatively low friction during rotation.Thus, the force torque to be applied by a user, who performs a rapid correction of the indicator, via a correction device other than said mechanism, in the intended drive direction or a correction of the time (in particular in the case of a calendar indicator) in an anticlockwise direction (which causes a rotation of the wheel plate in the direction opposite to the drive direction) and passing through midnight, is relatively low and the passage of teeth of the indicator above the drive finger, which retracts in a mainly radial direction relative to the central axis, is less perceptible than in the prior art.

[0013] Then, the elastic deformation of the spring can be lower than in the prior art and therefore generate lower stresses in the spring, which is an advantage for the dimensioning of the spring, this thanks to the rotation of the rocker about the second axis of rotation with the drive finger moving mainly towards the first axis of rotation. The spring necessarily undergoes a radial elastic deformation due to the radial withdrawal of the drive finger and therefore of the second end of this spring, but the angular deformation of the spring resulting from a force torque applied to this second end can be much lower than in the case of the mechanism of the prior art. Advantageously, the interaction of the teeth on the finger applies a force to the rigid support only through the rocker, and therefore at the level of the second off-center axis of rotation.The direction of the force, generated by a tooth of the indicator pressing on the outer flank of the drive finger, which is applied at the second axis generates a torque on the rigid support, tending to rotate it, which is lower than in the prior art. Given the rigidity of the spring (necessary to store energy during normal driving of the indicator), the rocker can rotate relative to the rigid support, under the action of a tooth pressing on the outer flank of the drive finger, without this rigid support necessarily rotating relative to the wheel plate. It can thus be seen that the spring undergoes a mainly radial elastic deformation due to the withdrawal of the drive finger by rotation around the second axis of rotation, which is distant from the first axis of rotation.The drive mechanism of the invention therefore makes it possible to carry out the same withdrawal of the finger, during a correction, as in the prior art, but it generates a weaker elastic deformation of the spring relative to the mechanism of the prior art where the spring carries out, in addition to a radial deformation, a significant angular deformation of the spring.

[0014] The benefits of the invention set out above are obtained in a remarkable manner in an advantageous variant, in which the outer flank of the drive finger is arched, this arched outer flank having, while the rocker is in contact with the first stop, a radial dimension to the first axis of rotation which is monotonically increasing when approaching a drive flank that the drive finger presents to press against a lateral flank of a tooth of the toothing during an incrementation of the indicator by jump.

[0015] According to an advantageous variant, the spring and the rocker are arranged so that the rocker also bears against the first stop when the spring is not angularly constrained.

[0016] According to a main embodiment, the rigid support comprises a plate which forms the first stop. In particular, the rigid support is constituted by such a plate.

[0017] According to a preferred embodiment, the mechanism is arranged so that the spring works in contraction when this spring is loaded in order to be able to generate a jump, in particular a semi-instantaneous jump of the indicator. The work of the spring in contraction makes it possible in particular to ensure a constant radius for the application of the driving force of the finger on the tooth of the indicator against which the finger presses, which makes it possible to optimize this driving force and therefore the driving torque to be provided to make a jump of the indicator.

[0018] According to an advantageous variant, an angular displacement of the second end of the spring, and thus of the drive finger, relative to the wheel board is limited, during a stress of the coil in contraction resulting from the loading of the spring, by a second stop, defining an angular stop integral in rotation with the wheel board, the indicator and the mechanism being arranged so that a jump of the indicator occurs, in normal operation, after said angular displacement is stopped by the second stop, at the end of a loading of the spring preceding this jump, and then corresponds to a determined angular distance.

[0019] The invention also relates to a watch incorporating a movement according to the invention. Brief description of the figures

[0020] The aims, advantages and characteristics of the invention will be described below in more detail with the aid of the appended drawings, given as non-limiting examples, in which: there Figure 1 is a top view of a clockwork mechanism, according to an advantageous embodiment of the invention, provided for driving a jumping indicator, in particular by semi-instantaneous jumping; Figure 2 is an exploded perspective view of the clockwork mechanism of the Figure 1 ; there Figure 3 is a perspective view of a rigid support, a spring and a lever of the clockwork mechanism of the Figure 1 , shown in an inverted position; the Figure 4 is an enlarged perspective view of the seesaw; Figure 5 is a view, similar to that of the Figure 1 , of a variant embodiment of the clockwork mechanism of the Figure 1 ; THE Figures 6A to 6Dpartially show a clockwork movement according to the invention, incorporating the advantageous embodiment of the drive mechanism described in the preceding figures, respectively in four successive states occurring during the driving of a date ring by the drive mechanism; Figures 7A and 7B partially show the clockwork of the Figure 6A respectively in two successive states occurring during rapid driving of the date ring, by a standard control member, in the direction of driving of the date ring; Figures 8A and 8B partially show the clockwork of the Figure 6A respectively in two successive states occurring when the time display hands are driven counterclockwise and therefore the wheel plate in the opposite direction to the direction in which this wheel plate is driven when the date ring is driven. Detailed description of the invention

[0021] With reference to the attached figures, an advantageous embodiment of a mechanism for driving an indicator by jump, in particular by semi-instantaneous jump, will be described, and more particularly with reference to Figures 6A to 8B , the operation of a watch movement according to the invention incorporating such a drive mechanism will be described.

[0022] The mechanism 6 for driving a jumping indicator 4 comprises a wheel plate 8 rotating around a first axis of rotation 20, a drive finger 12 for the indicator and a spring 16. In a main variant, the indicator is a date indicator, in particular a date ring comprising an internal toothing 5. In other particular variants, given as non-limiting examples, the indicator is for example an indicator of the minutes, hours, days or months. The spring 16 is formed of a first end 17, a coil 18 and a second end 19, the first end being integral in rotation with the wheel plate and the second end being integral in rotation with the drive finger 12 at least during each loading of the spring 16 preceding a jump of the indicator 4 and the driving of the indicator by the mechanism during this jump.The first end 17 of the spring is connected to a central part 24 which is integral in rotation with the wheel board 8. Preferably the spring and the central part form a single piece. The mechanism 6 comprises a rigid support 10, which is movable in rotation around the first axis of rotation relative to the wheel board, and a rocker 26 mounted on the rigid support so as to be movable in rotation around a second axis of rotation 22 which is distant from the first axis of rotation 20.

[0023] The second axis of rotation 22 is located at a first end of the lever, which forms the drive finger on the side of its second end. In particular, the lever has at its first end a circular stud 34 which is inserted into a hole 33, provided in the rigid support, so that the lever can undergo a rotation around the axis of rotation 22 defined by this hole 33, in particular to allow the drive finger 12 to retract during a rapid correction of the date or a certain counterclockwise correction of the time passing through midnight, as will be explained in more detail later.

[0024] The mechanism 6 comprises a central hub 32 defining a shaft which passes through a central hole of the rigid support 10 and guides this rigid support in rotation relative to the wheel board 8, the latter and the central part 24 being driven onto the central hub 32.

[0025] Generally, the drive mechanism comprises a first stop which is integral with the rigid support and which limits the rotation of the rocker in a first direction which corresponds to a radial distance of the finger relative to the first axis of rotation 20, the rocker being arranged so as to bear against the first stop at least during loading of the spring before a jump of the indicator and, preferably, also during the driving of the indicator during this jump, and to be able to undergo a rotation in the second direction, opposite to the first direction, and thus allow a radial withdrawal of the drive finger, in the direction of the first axis of rotation 20, under the action of a tangential component, relative to the second axis of rotation 22, of a force exerted on this drive finger by the teeth of the indicator during a correction.Preferably, the spring and the rocker are arranged so that the rocker also bears against the first stop when the spring is not angularly constrained. In a main variant, the rigid support comprises a plate which forms the first stop. In an advantageous variant shown in the figures, the rigid support is the plate 10.

[0026] According to a particular variant shown in the figures, the rocker 26 is formed by an arm 36 and the drive finger 12, the arm having a first height and being arranged at least partially between the wheel board and the plate. The drive finger 12 has a second height H at least in a thick part defining a drive flank 14 intended to come to bear against a tooth of a set of teeth 5 associated with the indicator 4 ( Figures 6A to 8B) when the indicator is driven by the mechanism 6. The second height H is greater than the first height and the thick part of the drive finger is not superimposed on the plate for any useful angular position of the rocker, this thick part extending axially at least partially over the thickness of at least one region of the plate located above the arm. The drive flank 14 is substantially radial to the first axis of rotation 20 when the rocker is bearing against the first stop 30.

[0027] According to an advantageous variant, the plate 10 has a lateral surface of which a substantially radial zone defines the first stop 30. The drive finger 12 has the second height H over its entire extent in the plane of the teeth 5 and is arranged in such a way that its rear upper portion can come to bear against the first stop 30 at least during each loading of the spring, so as to then be 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.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 direction of rotation, this stop surface 15 bearing against the first stop 30 at least during each loading of the spring 16 and a following jump of the indicator, namely a date jump when the time display indicates midnight.

[0028] In the first variant represented in figures 1 to 3 , the plate 10 has a general circular profile with a lateral recess 38, configured to allow the drive finger 12 to penetrate into this recess when a tooth passes along an external flank 13 of this drive finger and thus to retract, the major part of the spring 16 being covered at all times by the plate. In a second variant shown in the Figure 5, the plate 10A of the mechanism 6A comprises: - A central part defining the central hole; - a projecting part 58 which covers a part of the spring 16 on the side of its second end 19 to keep it in the general plane of the spring between the wheel board 8 and the plate 10A; - a part in the form of an annular sector which extends radially from the central part and which defines, at a first angular end, the first stop 30 and, on the side of the second angular end, the hole 33 for the stud 34 of the rocker 26.

[0029] In the variants shown, the drive finger 12 has an arcuate outer flank 13 against which at least one tooth 5b of the toothing 5 of the indicator 4 can press during a rapid correction of the indicator by a correction device other than the mechanism, the arcuate outer flank having, while the rocker is in contact with the first stop 30, a radial dimension to the first axis of rotation 20 which is monotonically increasing as it approaches the drive flank 14.

[0030] According to an advantageous variant, also shown in the figures, the rocker 26 has, in an inner portion 46 running along the drive finger 12, a housing 42 having a lateral opening on the side of the spring 16. The second end 19 of the spring 16 is extended by a coupling member 40 to the rocker 26, this coupling member 40 being rigid and configured so as to be able to penetrate at least partially into the housing 42 and allow the spring to apply a driving force torque to the rigid support 10 and to the rocker 26 so as to then allow the drive finger 12 to drive the indicator 4.

[0031] Preferably, the coupling member 40 is configured to be able to penetrate at least partially into the housing 42 through the lateral opening of this housing. In particular, the housing 42 has a lateral surface 52 oriented obliquely in the direction of rotation 50 of the wheel plate 8, provided for driving the indicator 4, relative to a radial direction, relative to the central axis of rotation 20, passing through the middle of this lateral surface, and the coupling member 40 has a lateral flank 54, opposite the lateral surface 52, which is also inclined obliquely, relative to the central axis of rotation 20, in the same direction as the lateral surface and which presses at least partially against this lateral surface during said driving of the indicator. The lateral surface and the lateral flank have a relatively great length.This particular feature makes it possible to ensure good retention of the coupling member in the housing as soon as the spring 16 is put under tension in contraction. In particular, the contact point or the contact zone of the housing on which the force of the spring is exerted, via the coupling member, does not vary during loading of the spring. In addition, the coupling member 40 cannot undergo rotation on itself, in the direction of rotation of the wheel board, during loading of the spring.

[0032] The rocker 26 advantageously has a lateral ramp 48 on the front part of the inner portion 46 allowing coupling of the coupling member 40 with the rocker 26, in particular with the drive finger, via an introduction of this coupling member into the housing 42, from an angular position of this coupling member located upstream of the lateral ramp 48, by a simple rotation of the plate 10 in a clockwise direction relative to the wheel board 8.

[0033] The housing 42 has a generally triangular shape and opens gradually towards its lateral opening. The shape of the part of the coupling member 40 which is inserted into the housing via the lateral opening corresponds substantially to that of the housing. This configuration advantageously allows the coupling member to be easily inserted into the housing, but would a priori allow this member to come out quite easily in the event of an impact, although the housing is provided to be relatively deep. However, the spring 16 is arranged so that when this spring is loaded, the coupling member is a short distance from the inner end 17 of the spring which is rigidly connected to the central part 24. In this situation, the coupling member 40 cannot come out of its housing in the event of an impact.Furthermore, when the drive finger is not interacting with the toothing 5 of the indicator and the spring 16 is then substantially relaxed, the coupling member 40 cannot come out laterally from its housing during an impact. Thus, the mechanism 6 is arranged in such a way that, when the spring is relaxed or stressed during a loading of this spring preceding a jump of the indicator, the coupling member cannot come out of the housing 42.

[0034] Once inserted into the housing 42, the coupling member 40 may be held, but not necessarily, in this housing by a radial force, relative to the central axis of rotation 20, applied outwards by the spring 16 to this coupling member. This radial force (more precisely, the radial component of the force applied by the spring to the lever via the coupling member) is increased during a rapid date change or during a time correction in the counterclockwise direction and passing through midnight, by the fact that the drive finger and the coupling member then undergo a recoil / withdrawal in the direction of the axis of rotation 20 via a clockwise rotation (second direction of rotation of the lever), so that the coupling member is thus normally held in the housing even when the spring 16 is somewhat forced into expansion in such a situation.

[0035] When the drive finger 12 retracts, by a rotation of the lever 26 in the clockwise direction, during a rapid correction of the date or the time in an anticlockwise direction with passage through midnight, the coupling finger approaches the central part 24 so that the coupling member can no longer, after a certain initial rotation of the lever, come out of its housing. During the initial rotation, the spring 16 can undergo a certain angular stress in expansion and theoretically allow the coupling member to come out of its housing in the event of an impact. However, if the coupling member undergoes an acceleration substantially in the direction of the axis of rotation 20 of the wheel plate 8, the lever then undergoes a certain force torque, which causes a rotation of this lever around its axis of rotation 22, and the drive finger then follows the coupling member so that the latter remains at least partly in its housing.If the acceleration is in a direction passing substantially through the center of gravity of the rocker and its axis of rotation 22, the coupling member 40 can undergo an exit movement from the housing 42. However, an internal projecting part 44 of the spring can be configured so as to prevent the coupling member from being able to come out completely from its housing. Alternatively, advantageously, a rear part of the coupling member can be configured so as to collide, during a correction, with a rigid part secured to the wheel board before being able to come out completely from its housing.In conclusion, the mechanism 6 is arranged so that the coupling member 40 remains in its housing 42 during normal operation, so that this coupling member is at all times secured to the drive finger during normal operation, and that it cannot in most cases come out of its housing during impacts, preferably in no case.

[0036] Preferably, the mechanism 6 is arranged so that the spring 16 works in contraction when this spring is loaded in order to be able to generate a jump of the indicator. Preferably, an angular displacement of the second end 19 of the spring 16, and thus of the drive finger 12 coupled to the coupling member 40, relative to the wheel board 8 is limited, during a stress of the coil 18 in contraction resulting from the loading of the spring, by a second stop 28, defining an angular stop integral in rotation with the wheel board 8, the indicator and the mechanism being arranged so that a jump of the indicator does not occur, in normal operation, before said angular displacement is stopped by the second stop, at the end of a loading of the spring preceding this jump, and then corresponds to a determined angular distance a (see Figure 6A ).

[0037] In the variant shown, the spring 16 comprises an internal projecting part 44 arranged along the coil 18 on the side of its second end 19, this internal projecting part being arranged to come into contact with the second stop 28 (angular stop) and thus end the loading of the spring, then trigger a jump of the indicator 4 to its next stable position, namely to the next date in the case of a date indicator.

[0038] Subsequently, it is exposed, with the help of the Figures 6A to 8B , in more detail the operation of a watch movement 2, in particular the mechanism 6 for driving a date ring 4 incorporated in this watch movement. The central hub 32 has not been shown in these figures so as not to overload the drawing, but it is obviously necessary for the mechanism 6 to be functional.

[0039] To Figures 6A to 6Dare represented four successive states of the mechanism 6 for driving the date ring 4 by jump, in particular by semi-instantaneous jump. These Figures 6A to 6D show the mechanism 6 and the date ring 4, during a drive of this ring for the passage to a following date at midnight, respectively: At the moment when the drive finger 12 comes into contact against a tooth 5a of the ring 4 and when the spring 16 is substantially angularly relaxed (i.e. not angularly stressed); At the end of the loading of the spring 16 when the internal projecting part 44 of the spring comes to bear against the angular stop 28 after having undergone the angular displacement α relative to the wheel plate 8; During the date jump generated by the supply of the mechanical energy stored in the contracted spring to said assembly; and At the end of the jump when the date ring 4 has substantially reached its next stable position.

[0040] It will be noted that in a particular embodiment, in normal operation, a jump of the indicator occurs before the angular movement of the spring is stopped by the angular stop 28. The angular stop is in this case a spring protection stop. In another particular embodiment, the drive mechanism does not have an angular stop. The spring works in contraction and the coil of this spring remains free in its development between the two ends of the spring during loading periods.

[0041] It will be noted that, in order to prevent a tooth 5a of the indicator 4 from passing over or under the drive finger 12 when driving the indicator, it is provided that the height between the wheel plate 8 and the underside of the teeth 5, including clearance, remains constantly located between the lower height and the upper height of the drive finger relative to the wheel plate, including clearance. For this purpose, in an advantageous variant, the lower height of the finger is provided to be smaller than the thickness of the teeth of the teeth 5. Preferably, in a watch incorporating the watch movement 2, the distance between the upper height of the finger and a dial covering the drive mechanism and the indicator is also provided to be smaller than the thickness of the teeth of the teeth 5.The great height of the finger 12, which can rise at least from below the spring 16 to above the plate 10 which defines the upper surface of the mechanism 6, easily makes it possible to avoid the passage of a tooth 5a under or over the finger 12.

[0042] THE Figures 7A and 7B concern the behavior of the mechanism 6 during a rapid correction of the date ring 4, via a control member that can be manipulated by a user in a conventional manner, in the evening when the wheel board 8 and the plate 10 are for example initially in the configuration of the Figure 7A , so that the finger 12 is located between the tooth 5a and the tooth 5b which precedes it relative to the direction of rotation 60, so that the finger 12 is in the path of the tooth 5b of the indicator. The rapid advance of the ring 4 is provided in the direction of rotation 60 corresponding to the single direction of rotation of the date ring. As shown in Figure 7B, the tooth 5b of the toothing 5 comes into contact with the arcuate outer flank 13 of the finger 12 when the ring 4 is rotated and then exerts on this finger a progressively radial force which causes a rotation of the rocker 26, around its axis of rotation 22, in the clockwise direction and thus a movement of the finger 12 in the direction of the central hub of the plate 10, so that the finger undergoes a withdrawal in the direction of the axis of rotation 20. This withdrawal is made possible by the configuration of the drive finger 12 and the profile of the lateral recess 38 provided in the plate 10, as well as by the arrangement of the spring 16 and of the central part 24 to which it is fixed and by the configuration of the internal projecting part 44. As can be seen in the Figure 7B , the finger 12 retracts when passing the tooth 5b, leaving this tooth to follow the outer flank 13 of the finger until this tooth angularly exceeds the finger.

[0043] As already explained previously, the interaction of the toothing 5 on the drive finger 12 applies a force to the pad 10 only through the rocker 26, and therefore at the second axis of rotation 22. The direction of the force, generated by a tooth 5a or 5b of the indicator pressing on the outer flank 13 of the drive finger, which is applied at the second axis of rotation generates a torque on the pad, tending to rotate it, which is lower than in the prior art. Given the rigidity of the spring 16, the rocker 26 can rotate relative to the pad, under the action of a tooth pressing on the outer flank of the drive finger, without this rigid support performing a significant rotation relative to the wheel board.It is noted that the spring undergoes a mainly radial elastic deformation, relative to the central axis of rotation 20, due to the withdrawal of the drive finger 12 by rotation around the second axis of rotation 22, which is distant from the first axis of rotation 20 (central axis of rotation of the mechanism). The drive mechanism 6 therefore makes it possible to carry out the same withdrawal of the finger, during a correction, as in the prior art, but it generates a lower elastic deformation of the spring 16 than in the mechanism of the prior art where the spring undergoes, in addition to a radial deformation, a significant angular deformation.Thus, the work that must be provided by the date ring 4 to the mechanism 6 to allow the passage of a tooth 5b over the drive finger 12 (in a plane perpendicular to the axes of rotation 20 and 22), during the correction in question, is less than in the case of a drive finger with a similar profile but fixed relative to a plate having an oblong hole crossed by a central shaft, in particular formed by a hub, as in the prior art.

[0044] During the radial movement of the finger 12, the spring 16 contracts radially and the coupling member 40 approaches the central part 24. It will be noted that the spring 16, more precisely its coil 18, is also forced to expand a little during the rapid correction of the date ring, simultaneously with the radial stress that the spring undergoes in the direction of the axis of rotation of the wheel plate. However, given the profile of the outer flank 13 of the finger 12 and the rotation of this finger in the direction of the axis of rotation 20 (first axis of rotation, which is central) as explained above, the stress of the expanding spring is relatively small, or even almost zero depending on the configuration of the system.This is very advantageous for the production of the spring 16 which can thus be arranged to be able to best withstand the contraction occurring during driving of the indicator 4 by the device 6, without having to also ensure appropriate behavior of this spring for a significant expansion constraint.

[0045] THE Figures 8A and 8Bconcern the behavior of the mechanism 6 during a correction of a time displayed by the watch mechanism, which rotates the wheel plate 8, in an anticlockwise direction passing through midnight. In this case, the date ring 4 remains stationary in the stable position in which it is found during this time correction. The succession of states of the mechanism 6 is similar to that which takes place during the rapid correction of the date display described previously. During rotation of the wheel plate 8, and thus of the assembly formed by the plate 10 and the lever 26, in a direction opposite / inverse to the normal direction of rotation (corresponding to the clockwise direction of the time display), the arcuate outer flank 13 of the finger 12 comes to bear against a tooth 5a of the teeth 5 ( Figure 8A) and the plate 10 continues its rotation, however a little more slowly than the wheel board due to a small expansion of the spring at least in an initial phase, while the drive finger moves radially in the direction of the axis of rotation 20 via a clockwise rotation of the rocker 26 which penetrates deeper into the lateral recess 38, so that this finger retracts while the stationary tooth 5a runs along the outer flank 13 of the finger.

[0046] Mechanism 6 is configured to prevent jamming during rapid date correction or counterclockwise time correction.

[0047] The invention also relates to a watch comprising a watch movement 2 according to the invention incorporated in a case, this case also incorporating a dial arranged so as to allow the display of data evolving temporally by jumps, in particular the date.

Claims

1. Clock movement (2) provided with an indicator (4) and comprising a mechanism (6) for driving this indicator by jumping, the mechanism comprising a wheel plate (8) rotating around a first axis of rotation (20), a drive finger (12) for the indicator and a spring (16) formed of a first end (17), a coil (18) and a second end (19), the first end being integral in rotation with the wheel plate and the second end being integral in rotation with the drive finger at least during each loading of the spring preceding a jump of the indicator and the driving of the indicator by the mechanism during this jump; characterized in thatthe mechanism (6) comprises a rigid support (10), which is rotatable about the first axis of rotation (20) relative to the wheel board, and a rocker (26) mounted on the rigid support so as to be rotatable about a second axis of rotation (22) which is distant from the first axis of rotation, the second axis of rotation being located at a first end of the rocker and the drive finger (12) being formed by this rocker on the side of its second end, the mechanism (6) comprising a first stop (30) which is integral with the rigid support (10) and which limits the rotation of the rocker in a first direction corresponding to a radial distance of the drive finger relative to the first axis of rotation (20), the rocker being arranged so as to bear against the first stop at least when the spring (16) is loaded and to be able to undergo rotation in the second direction, opposite to the first direction,and thus allow a radial withdrawal of the drive finger, towards the first axis of rotation, under the action of a force exerted on this drive finger and having a progressively increasing radial component.

2. Watch movement according to claim 1, characterized in that the spring (16) and the rocker (26) are arranged so that the rocker also bears against the first stop when the spring is not angularly constrained.

3. Watch movement according to claim 1 or 2, characterized in that the rigid support comprises a plate (10) which is guided in rotation, around the first axis of rotation (20), by a shaft (32) integral in rotation with the wheel board, the plate forming the first stop (30).

4. Watch movement according to claim 3, characterized in thatthe rocker is formed by an arm (36) and the drive finger (12), the arm having a first height and being arranged at least partially between the wheel board (8) and the plate (10), the drive finger having a second height (H) at least in a thick part defining a drive flank (14) intended to come into contact with a tooth (5a) of a set of teeth (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 thick part of the drive finger not being superimposed on the plate for any useful angular position of the rocker, this thick part extending axially at least partially over the thickness of at least one region of the plate located above the arm.

5. Watch movement according to claim 4, characterized in thatthe plate (10) has a lateral surface of which a zone (30) defines the first stop, the drive finger being arranged so that an upper rear portion of the thick part of this drive finger can come to bear against the first stop (30) at least during each loading of the spring, so as to then be maintained 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. Watch movement according to claim 4 or 5, characterized in that the plate (10) has a general circular profile with a lateral recess (38), configured to allow the drive finger (12) to penetrate into this recess when a tooth (5a, 5b) of the teeth passes along an external flank (13) of the drive finger and thus to retract, the major part of the spring (16) being covered at all times by the plate.

7. Watch movement according to any one of claims 4 to 6, characterized in that the drive finger (12) has an arcuate outer flank (13) against which at least one tooth (5a) of the toothing (5) can press during a rapid correction of the indicator by a correction device other than the mechanism, the arcuate outer flank having, while the rocker is in contact with the first stop (30), a radial dimension to the first axis of rotation which is monotonically increasing as it approaches the drive flank (14).

8. Watch movement according to any one of the preceding claims, characterized in that the mechanism (6) is arranged so that the spring (16) works in contraction when this spring is loaded in order to be able to cause the indicator (4) to jump.

9. Watch movement according to claim 8, characterized in thatthe spring (16) comprises an internal projecting part (44) arranged along the coil (18) on the side of its second end (19), this projecting part being arranged to come into contact with a second stop (28), defining an angular stop integral in rotation with the wheel board (8), at the end of the loading of the spring and before a jump of the indicator occurs.

10. Watch movement according to any one of the preceding claims, characterized in that the first end (17) of the spring (16) is connected to a central part (24) which is rotationally fixed to the wheel board (8).

11. Watch movement according to any one of the preceding claims, characterized in that the rocker (26) has, in an inner portion on the drive finger side, a housing (42) having a lateral opening on the spring (16) side; and in thatthe second end (19) of the spring is extended by a member (40) for coupling to the rocker (26), this coupling member (40) being rigid and configured so as to be able to penetrate at least partially into the housing through the lateral opening and allow the spring to apply a driving force torque to the rocker and thus to the driving finger to drive the indicator.

12. Watch movement according to claim 11, characterized in thatthe housing (42) has a lateral surface (52) oriented obliquely in the direction of rotation (50) of the wheel board (8), provided for driving the indicator, relative to a radial direction, relative to the first axis of rotation, passing through the middle of this lateral surface, and the coupling member (40) has a lateral flank (54), opposite the lateral surface, which is also inclined obliquely, relative to the first axis of rotation, in the same direction as the lateral surface and which presses at least partially against this lateral surface during said driving of the indicator.

13. Watch movement according to any one of the preceding claims, characterized in that indicator (4) is an indicator of minutes, hours, dates, days or months.

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

15. Watch characterizedin that it comprises a clockwork movement (2) according to any one of the preceding claims.

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