CLOCK MOVEMENT EQUIPPED WITH A DRIVE MECHANISM OF A STEPPER INDICATOR

Description

Technical field of the invention

[0001] The present invention relates to a watch movement equipped with an indicator and comprising a mechanism for driving this indicator by jumping, as well as a watch incorporating a watch movement equipped 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 previous technical problems by the fact that it includes a rigid finger-drum, guided in rotation and translation by a hub passing through an oblong hole in the drum, and a spring arranged in this finger-drum and connecting the latter to a wheel board.

[0003] This drive mechanism has several drawbacks. First, the spring expands during the winding of the date ring, and its coil is designed to bear against the inner wall of the drum during spring loading, thus limiting the spring's expansion and preventing it from entering its plastic deformation range. This results in a sudden decrease in the spring's active length. Given the manufacturing tolerances of the various components, the winding time of the drive mechanism can vary, as the moment the spring contacts the inner wall of the drum can differ from one loading to the next, and the angular position of the contact area can also vary. This leads to inaccuracies in the timing of the ring's transition to the next date.Next, another problem arises 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 on the portion located between the contact area with the wall of the drum and the coupling element to this drum arranged at the second end of the spring, this portion having to support the entirety of an additional torque generated up to the moment of the jump of the indicator from the moment of contact.

[0004] The figures in the aforementioned document show that the spring coupling member is arranged in a shallow housing from which it can easily be dislodged. Indeed, the two lateral surfaces of the housing are parallel along a radial direction passing through the center of the housing, and the coupling member has two radial flanks. The angular width of the coupling member is designed to be less than that of the housing to allow it to enter the housing easily. Furthermore, the coupling member is designed to have significant clearance within the housing to allow for its movement. Thus, a relatively minor impact can easily cause the coupling member to be dislodged from its housing.If this occurs, whether during the spring's loading against a tooth of the date ring or before the spring is loaded (it generally exhibits slight expansion due to friction on the drum), the coupling element protrudes from the radial side of the finger's drive. In this situation, the drum's side wall exerts a radial force on the coupling element, causing it to experience friction against this side wall.If the coupling element comes out of its housing during the winding of the spring against a tooth of the date ring, it will either slide along the inner side surface and the date change will not occur at least until the drive wheel has completed one revolution and the coupling element re-enters its housing (the most favorable scenario, which nevertheless results in the loss of a correct date display, as the date has missed a daily jump), or the friction force will be sufficient for the spring to expand again, further increasing the friction force, until its coil touches the side wall and a date change occurs at an undetermined time. In this latter case, after the date change, the spring will unwind, driving the drum. If this situation recurs, then subsequent date changes will no longer occur around midnight.If the coupling element undergoes a sudden angular displacement along the side wall, which is likely, then this situation will recur for at least a few days, with the date incrementing at undetermined and variable times. In any case, the date drive mechanism is no longer functional for at least a few days once the coupling element has been removed from its housing, a highly probable event for the mechanism as shown in the figures of document EP 3828644.

[0005] The geometry of the coupling relative to its housing, which allows for considerable play and some mobility within the housing, creates another problem. When the spring is loaded, it deforms the spring coil and causes the coupling to rotate. This rotation causes the coupling to slide against the front side wall of the housing, thus reducing the point of application of the spring force on the drum finger radially as the spring is loaded. Therefore, for a given level of spring loading, the driving torque supplied by the spring to the finger decreases proportionally to the reduction in the lever arm of the spring force applied to the drum finger. This poses a problem because the driving force of the finger on the indicator tooth decreases proportionally for a given point of contact.However, since a specific driving torque is required to make the indicator jump, the spring must generate a force that increases as the lever arm decreases during spring loading. This negatively impacts the performance of the watch movement, which winds the mainspring and must therefore provide more torque. This also necessitates a more robust spring than required.

[0006] Finally, another problem with the mechanism in question arises from the fact that, during the indicator's rotation, the spring coil exerts a radial force on the drum, directed outwards in an area diametrically opposite the finger and thus roughly along the longitudinal direction of the oblong hole. This tends to pull the finger away from the ring's teeth. The finger is then more likely to slip past a tooth without the indicator being engaged, particularly during a minor impact in such a situation.It should also be noted that such a situation reduces the angular path along which the finger can drive a tooth while maintaining contact. Therefore, 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 change. The date ring may then remain stopped in an intermediate position or return to its previous stable position once the finger has passed the tooth. Furthermore, the reduced lever arm for applying the driving force to the tooth necessitates, for a given driving torque, an increase in the required driving force. This, in turn, requires an increase in the force supplied by the spring and therefore in its tension.

[0007] For the sake of completeness, we also mention the jump drive mechanism of a date disk, as disclosed in document CH712222A2. Summary of the invention

[0008] The invention aims to provide a mechanism for driving a jumping indicator that overcomes at least some of the drawbacks of the prior art described above. The invention also aims to provide a watch movement equipped with an indicator and comprising a jumping indicator drive mechanism that is efficient, accurate in every watch movement incorporating such a mechanism, and whose operation is minimally or not at all affected by external stresses, such as shocks.

[0009] In particular, it is planned that the drive mechanism will allow a 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, when a tooth or successively several teeth pass over the outer side of a drive finger of the indicator, which is minimal and without abrupt variation.

[0010] To this end, the invention relates to a watch movement equipped with an indicator and comprising a mechanism for driving this indicator by jump, the mechanism comprising a wheel board 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 rotationally fixed to the wheel board and the second end being rotationally fixed to the drive finger at least during each winding of the spring preceding a jump of the indicator and of the driving of the indicator by the mechanism during this jump.The mechanism includes a rigid support, which is movable in rotation about the first axis of rotation relative to the wheel board, and a rocker mounted on the rigid support so as to be movable in rotation about a second axis of rotation which is distant from the first axis of rotation, the second axis of rotation being located at one end of the rocker and the drive finger being formed by this rocker on the side of its second end.The mechanism further includes 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 movement of the finger relative to the first axis of rotation, the rocker being arranged so as to be in contact with the first stop at least when the spring is loaded 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.

[0011] The first stop ensures, during spring loading, that a constant radial distance is maintained 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 prior art, the lever arm remains constant, resulting in improved efficiency of the mechanism.

[0012] In one particular variant, the indicator is a date indicator comprising teeth. Specifically, the indicator is a date ring comprising internal teeth for its rotational drive by said mechanism.

[0013] Thanks to the drive finger which is not made of material with the rigid support but is mobile 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 retraction 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 present a relatively low friction during a rotation.Thus, the torque to be applied by a user, who makes a quick correction of the indicator, via a correction device other than said mechanism, in the intended direction of drive or a correction of the time (particularly in the case of a calendar indicator) in a counterclockwise direction (which causes a rotation of the wheel board in the opposite direction to the direction of drive) and passing through midnight, is relatively small and the passage of teeth of the indicator over the drive finger, which retracts in a mainly radial direction relative to the central axis, is less noticeable than in the prior art.

[0014] Furthermore, the elastic deformation of the spring can be less than in the prior art, thus generating lower stresses within the spring. This is advantageous for spring design, thanks to the rocker arm's rotation around the second axis of rotation, with the drive finger moving primarily towards the first axis of rotation. The spring necessarily undergoes radial elastic deformation due to the radial retraction of the drive finger and, consequently, of the second end of the spring. However, the angular deformation of the spring resulting from a torque applied to this second end can be significantly less than in the case of the prior art mechanism. Advantageously, the interaction of the teeth on the finger applies a force to the rigid support only through the rocker arm, and therefore at the off-center second axis of rotation.The force exerted by a tooth of the indicator pressing against the outer side of the drive finger, applied at the second axis, generates a torque on the rigid support, tending to rotate it, which is weaker than in the prior art. Given the spring's stiffness (necessary to store energy during normal indicator operation), the rocker arm can rotate relative to the rigid support under the action of a tooth pressing against the outer side of the drive finger, without the rigid support necessarily rotating relative to the wheel. Thus, the spring undergoes primarily radial elastic deformation due to the retraction 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 perform 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 performs in addition to a radial deformation a significant angular deformation of the spring.

[0015] The benefits of the invention set forth above are remarkably achieved in an advantageous embodiment, 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 as it approaches a drive flank which the drive finger presents to press against a lateral flank of a tooth of the gearing during an increment of the indicator by jump.

[0016] According to an advantageous variant, the spring and the rocker are arranged so that the rocker is also in contact with the first stop when the spring is not angularly constrained.

[0017] According to a principal embodiment, the rigid support includes a plate that forms the first stop. In particular, the rigid support consists of such a plate.

[0018] In a preferred embodiment, the mechanism is arranged so that the spring contracts when loaded, thereby generating a jump, specifically a semi-instantaneous jump of the indicator. The spring's contraction ensures a constant radius for the application of the finger's driving force to the indicator's tooth against which the finger presses, thus optimizing this driving force and consequently the torque required to make the indicator jump.

[0019] 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 constraint of the contracting coil resulting from the loading of the spring, by a second stop, defining an angular stop fixed in rotation to 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.

[0020] The invention also relates to a watch incorporating a movement according to the invention. Brief description of the figures

[0021] The aims, advantages and features of the invention will be described in more detail below with reference to the accompanying drawings, given by way of non-limiting examples, in which: there Figure 1 is a top view of a clockwork mechanism, according to an advantageous embodiment of the invention, designed for driving a jumping indicator, in particular by semi-instantaneous jumping; the 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 rocker of the clockwork mechanism of the Figure 1 shown in an inverted position; the Figure 4 is an enlarged view of the seesaw in perspective; the Figure 5 is a view, similar to that of the Figure 1 , of a variant implementation 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 drive of a date ring by the drive mechanism; Figures 7A and 7B partially show the clockwork mechanism of the Figure 6A respectively in two successive states occurring during a rapid drive of the date ring, by a conventional control device, in the direction of drive of the date ring; the Figures 8A and 8B partially show the clockwork mechanism of the Figure 6A respectively in two successive states occurring during a drive of the time display hands in the counterclockwise direction and therefore of the wheel board in the opposite direction to the drive direction of this wheel board during the drive of the date ring. Detailed description of the invention

[0022] With reference to the attached figures, an advantageous embodiment of a jump-driven indicator mechanism will be described, particularly a semi-instantaneous jump-driven mechanism, and more specifically with reference to the Figures 6A to 8B , we will describe the operation of a clock movement according to the invention incorporating such a drive mechanism.

[0023] The mechanism 6 for driving a jumping indicator 4 comprises a wheel 8 rotating about 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 internal teeth 5. In other specific variants, given by way of non-limiting examples, the indicator is, for example, a minute, hour, day, or month indicator. The spring 16 is formed of a first end 17, a coil 18, and a second end 19, the first end being rotationally fixed to the wheel and the second end being rotationally fixed to the drive finger 12 at least during each winding of the spring 16 preceding a jump of the indicator 4 and the drive 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 rotationally fixed to the wheel plate 8. Preferably, the spring and the central part form a single unit. The mechanism 6 comprises a rigid support 10, which is rotatable about the first axis of rotation relative to the wheel plate, 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 20.

[0024] The second axis of rotation 22 is located at one end of the rocker, which forms the drive finger on the side of its second end. In particular, the rocker has at its first end a circular stud 34 which is inserted into a hole 33, provided in the rigid support, so that the rocker can undergo a rotation about 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.

[0025] The mechanism 6 includes a central hub 32 defining a shaft which passes through a central hole in 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.

[0026] In general, the drive mechanism includes a first stop which is fixed to the rigid support and which limits the rotation of the rocker in a first direction which corresponds to a radial movement of the finger relative to the first axis of rotation 20, the rocker being arranged so as to be in contact with the first stop at least when the spring is loaded before a jump of the indicator and, preferably, also when the indicator is driven 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 embodiment, the rigid support includes a plate that forms the first stop. In an advantageous embodiment shown in the figures, the rigid support is plate 10.

[0027] 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 pad. The drive finger 12 has at least a second height H in a thick part defining a drive flank 14 intended to bear against a tooth of a toothing 5 associated with the indicator 4 ( Figures 6A to 8B) during the indicator's drive by 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 a 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 supported against the first stop 30.

[0028] According to an advantageous variant, the plate 10 has a lateral surface of which a substantially radial area 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 so that its upper rear portion can come to rest against the first stop 30 at least during each loading of the spring, so as to 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 upper rear portion defines a stop surface 15 which cooperates with the first stop 30 to limit the rotation of the rocker in the first direction of rotation, this stop surface 15 being in contact with the first stop 30 at least during each loading of the spring 16 and of a subsequent jump of the indicator, namely of a date jump when the time display indicates midnight.

[0029] In the first variant represented at figures 1 to 3 The plate 10 has a generally circular profile with a lateral recess 38, configured to allow the drive finger 12 to enter this recess when a tooth passes along an outer flank 13 of this drive finger and thus retract, with most 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 maintain it in the general plane of the spring between the wheel board 8 and the plate 10A; - a part in the shape 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.

[0030] In the variants shown, the drive finger 12 has an arched outer flank 13 against which at least one tooth 5b of the teeth 5 of the indicator 4 can press during a rapid correction of the indicator by a correction device other than the mechanism, the arched 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.

[0031] According to an advantageous variant, also shown in the figures, the rocker 26 has, in an inner portion 46 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 allow the drive finger 12 to drive the indicator 4.

[0032] 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, intended 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 bears at least partially against this lateral surface during said drive of the indicator. The lateral surface and the lateral flank have a relatively large length.This particular feature ensures that the coupling member remains securely in the housing as soon as the spring 16 is compressed. Specifically, the point or contact area of ​​the housing on which the spring force is exerted, via the coupling member, does not change during spring loading. Furthermore, the coupling member 40 cannot rotate about its own axis in the direction of rotation of the wheel plate during spring loading.

[0033] 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.

[0034] The housing 42 has a generally triangular shape and opens gradually towards its lateral opening. The shape of the portion of the coupling member 40 that inserts into the housing through the lateral opening closely matches that of the housing. This configuration advantageously allows the coupling member to insert easily into the housing, but would theoretically allow it to dislodge quite easily in the event of an impact, even though the housing is relatively deep. However, the spring 16 is arranged so that, when the spring is loaded, the coupling member is close to the inner end 17 of the spring, which is rigidly connected to the central portion 24. In this situation, the coupling member 40 cannot dislodge from its housing in the event of an impact.Furthermore, when the drive finger is not interacting with the teeth 5 of the indicator and the spring 16 is therefore substantially relaxed, the coupling member 40 cannot move laterally out of its housing during an impact. Thus, the mechanism 6 is arranged so that, when the spring is relaxed or compressed during a spring loading process preceding a jump of the indicator, the coupling member cannot move out of the housing 42.

[0035] Once inserted into the housing 42, the coupling member 40 can be held, but not necessarily, in this housing by a radial force, relative to the central rotation axis 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 rocker via the coupling member) is increased during a rapid date change or during a counterclockwise time correction passing through midnight, because the drive finger and the coupling member then undergo a recoil / withdrawal in the direction of the rotation axis 20 via a clockwise rotation (the second direction of rotation of the rocker), so that the coupling member is thus normally held in the housing even when the spring 16 is slightly constrained in expansion in such a situation.

[0036] When the drive finger 12 retracts, by a clockwise rotation of the rocker 26, during a rapid counterclockwise correction of the date or time with a passage through midnight, the coupling finger moves closer to the central part 24 so that the coupling member can no longer, after a certain initial rotation of the rocker, come out of its housing. During the initial rotation, the spring 16 can undergo a certain expanding angular stress and theoretically allow the coupling member to come out of its housing in the event of an impact. However, if the coupling member is subjected to a significant acceleration in the direction of the rotation axis 20 of the wheel plate 8, the rocker then experiences a certain torque, which causes the rocker to rotate about its rotation axis 22, and the drive finger then follows the coupling member so that the latter remains at least partially in its housing.If the acceleration is along a direction passing substantially through the center of gravity of the rocker arm and its axis of rotation 22, the coupling member 40 may move out of its housing 42. However, an internal projecting portion 44 of the spring can be configured to prevent the coupling member from fully exiting its housing. Alternatively, and advantageously, a rear portion of the coupling member can be configured to collide, during a correction, with a rigid part attached to the wheel plate before it can fully exit its housing.In conclusion, the mechanism 6 is arranged so that the coupling member 40 remains in its housing 42 in normal operation, so that this coupling member is at all times attached to the drive finger in normal operation, and that it cannot in most cases come out of its housing during shocks, preferably in no case.

[0037] Preferably, the mechanism 6 is arranged so that the spring 16 works in contraction during a spring loading 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 plate 8, is limited, during a contraction stress on the coil 18 resulting from the spring loading, by a second stop 28, defining an angular stop rotationally fixed to the wheel plate 8. The indicator and the mechanism are 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 spring loading preceding this jump, and then corresponds to a predetermined angular distance α (see Figure 6A ).

[0038] In the variant shown, the spring 16 includes an internal protruding part 44 arranged along the coil 18 on the side of its second end 19, this internal protruding part being arranged to bear against 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.

[0039] The following is then explained, using the Figures 6A to 8B , in more detail the operation of a clock movement 2, in particular the mechanism 6 for driving a date ring 4 incorporated in this clock movement. The central hub 32 has not been shown in these figures to avoid cluttering the drawing, but it is obviously necessary for the mechanism 6 to function.

[0040] To Figures 6A to 6DFour successive states of the mechanism 6 for driving the date ring 4 by jump are represented, notably by semi-instantaneous jump. Figures 6A to 6D show mechanism 6 and date ring 4, during a training of this ring for the transition to the next date at midnight, respectively: At the moment when the drive finger 12 comes into contact with a tooth 5a of the ring 4 and the spring 16 is substantially relaxed angularly (i.e. not constrained angularly); At the end of the loading of the spring 16 when the inner protruding part 44 of the spring comes into contact with 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 said assembly; and At the end of the jump when the date ring 4 has reached substantially its next stable position.

[0041] It should be noted that in one particular embodiment, during normal operation, the indicator jumps before the angular displacement of the spring is stopped by the angular stop 28. In this case, the angular stop acts as a spring protection stop. In another particular embodiment, the drive mechanism does not have an angular stop. The spring operates in contraction, and its coil remains free to extend between the two ends of the spring during the loading periods.

[0042] It should be noted that, in order to prevent a tooth 5a of the indicator 4 from passing over or under the drive finger 12 during the indicator's operation, the height between the wheel plate 8 and the underside of the teeth 5, including any clearance, is constantly maintained between the lower and upper heights of the drive finger relative to the wheel plate, including any clearance. To this end, in an advantageous embodiment, the lower height of the finger is made 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 made smaller than the thickness of the teeth of the teeth 5.The great height of the finger 12, which can rise at least from the underside of the spring 16 to above the plate 10 which defines the upper surface of the mechanism 6, makes it easy to avoid the passage of a tooth 5a under or over the finger 12.

[0043] THE Figures 7A and 7B concern the behavior of mechanism 6 during a rapid correction of the date ring 4, via a control device that can be operated 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 finger 12 is located between tooth 5a and the preceding tooth 5b relative to the direction of rotation 60, meaning that finger 12 is in the path of tooth 5b of the indicator. The rapid advance of ring 4 is provided in the direction of rotation 60 corresponding to the single direction of rotation of the date ring. As shown in the Figure 7B, tooth 5b of the gear teeth 5 comes into contact with the arched outer flank 13 of the finger 12 during the rotation of the ring 4 and then exerts on this finger a progressively radial force which causes the rocker 26 to rotate clockwise around its axis of rotation 22 and thus causes the finger 12 to move towards the central hub of the plate 10, so that the finger retracts towards the axis of rotation 20. This retraction 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 the central part 24 to which it is attached and by the configuration of the inner projecting part 44. As can be seen in the Figure 7B , finger 12 retracts as tooth 5b passes, allowing this tooth to follow the outer side 13 of the finger until this tooth protrudes angularly beyond the finger.

[0044] As previously explained, the interaction of the teeth 5 on the drive finger 12 applies a force to the pad 10 only through the rocker arm 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 weaker than in the prior art. Given the rigidity of the spring 16, the rocker arm 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 undergoing significant rotation relative to the wheel plate.It is observed that the spring undergoes primarily radial elastic deformation, relative to the central axis of rotation 20, due to the retraction of the drive finger 12 by rotation around the second axis of rotation 22, which is distant from the first axis of rotation 20 (the central axis of rotation of the mechanism). The drive mechanism 6 thus allows for the same retraction of the finger during a correction as in the previous art, but it generates a smaller elastic deformation of the spring 16 than in the previous art mechanism where the spring undergoes, in addition to radial deformation, significant angular deformation.Thus, the work to be done by the date ring 4 on 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 through which a central shaft passes, in particular formed by a hub, as in the prior art.

[0045] During the radial movement of finger 12, spring 16 contracts radially and the coupling member 40 moves closer to the central part 24. It should be noted that spring 16, more precisely its coil 18, is also subjected to slight expansion during the rapid correction of the date ring, simultaneously with the radial stress exerted on the spring in the direction of the wheel's rotation axis. However, given the profile of the outer flank 13 of finger 12 and the rotation of this finger in the direction of the rotation axis 20 (the first rotation axis, which is central) as described above, the expansion stress on the spring is relatively small, or even negligible depending on the system configuration.This is very advantageous for the realization of the spring 16 which can thus be arranged to best withstand the contraction occurring during a drive of the indicator 4 by the device 6, without having to also ensure appropriate behavior of this spring for a significant expansion stress.

[0046] THE Figures 8A and 8Bconcern the behavior of mechanism 6 during a correction of the time displayed by the clock mechanism, which rotates the wheel 8 counterclockwise through midnight. In this case, the date ring 4 remains stationary in the stable position it is in during this time correction. The succession of states of mechanism 6 is similar to that which occurs during the rapid correction of the date display described previously. During the rotation of the wheel 8, and thus of the assembly formed by the plate 10 and the rocker 26, in the opposite direction to the normal direction of rotation (corresponding to the clockwise direction of the time display), the arched outer flank 13 of the finger 12 comes into contact with a tooth 5a of the teeth 5 ( Figure 8A) and the plate 10 continues its rotation, however a little slower 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 as the stationary tooth 5a runs along the outer flank 13 of the finger.

[0047] Mechanism 6 is configured to prevent jamming during rapid date correction or during counter-clockwise time correction.

[0048] 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 to allow the display of data evolving temporally by jumps, in particular the date.

Claims

1. Horological movement (2) provided with an indicator (4) and comprising a mechanism (6) for driving this indicator in jumps, the mechanism comprising a wheel platform (8) rotating about a first axis of rotation (20), a driving finger (12) for driving the indicator, and a spring (16) formed by a first end (17), a coil (18) and a second end (19), the first end being attached to the wheel platform for rotation therewith, and the second end being attached to the driving finger for rotation therewith at least during each loading of the spring preceding a jump by the indicator and the driving of the indicator by the mechanism during this jump; characterised in that the mechanism (6) comprises a rigid support (10), which is rotatable about the first axis of rotation (20) relative to the wheel platform, and a lever (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 lever, and the driving finger (12) being formed by this lever 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 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 so as to bear against the first stop at least when the spring (16) is loaded, and to be able to rotate in the second direction, opposite to the first direction, and thus to allow the driving finger to be radially retracted, towards the first axis of rotation, under the action of a force exerted on this driving finger and having a gradually increasing radial component.

2. Horological movement according to claim 1, characterised in that the spring (16) and the lever (26) are arranged in such a way that the lever also bears against the first stop when the spring is not under angular stress.

3. Horological movement according to claim 1 or 2, characterised in that the rigid support comprises a plate (10) which is rotatably guided about the first axis of rotation (20) by a shaft (32) attached to the wheel platform for rotation therewith, the plate forming the first stop (30).

4. Horological movement according to claim 3, characterised in that the lever is formed by an arm (36) and the driving finger (12), the arm having a first height and being arranged at least partially between the wheel platform (8) and the plate (10), the driving finger having a second height (H) at least in a thick part defining a drive flank (14) intended to bear against a tooth (5a) of a toothing (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 driving finger not being stacked on the plate for any useful angular position of the lever, this thick part extending axially at least partially over the thickness of at least one region of the plate located above the arm.

5. Horological movement according to claim 4, characterised in that the plate (10) has a lateral surface, one zone (30) of which defines the first stop, the driving finger being arranged so that a rear upper portion of the thick part of this driving finger can come to bear against the first stop (30) at least each time the spring is loaded, in such a way that it 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. Horological movement according to claim 4 or 5, characterised in that the plate (10) has a profile that is circular overall with a lateral cavity (38), configured to allow the driving finger (12) to enter this cavity when a tooth (5a, 5b) passes along an outer flank (13) of the driving finger and thus to retract, with the most part of the spring (16) being covered at all times by the plate.

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

8. Horological movement according to any one of the preceding claims, characterised in that the mechanism (6) is arranged so that the spring (16) contracts when this spring is loaded in order to be able to generate a jump by the indicator (4).

9. Horological movement according to claim 8, characterised in that the spring (16) comprises an internal projection (44) arranged along the coil (18) on the side of its second end (19), this internal projection being arranged to come to bear against a second stop (28), defining an angular stop that is attached to the wheel platform (8) for rotation therewith, at the end of the loading of the spring and before the indicator makes a jump.

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

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

12. Horological movement according to claim 11, characterised in that the recess (42) has a lateral surface (52) oriented obliquely in the direction of rotation (50) of the wheel platform (8), in which direction the indicator is intended to be driven, relative to a radial direction, relatively to the first axis of rotation, passing through the centre of this lateral surface, and the coupling member (40) has a lateral flank (54), facing 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 bears at least partially against this lateral surface when the indicator is driven.

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

14. Horological movement according to claim 13, characterised in that the indicator (4) is a date ring.

15. Watch characterised in that it comprises a horological movement (2) according to any one of the preceding claims.