A clock movement including a mechanism for driving a jump indicator, and a wristwatch including the clock movement

Abstract

To provide a mechanism for driving a jumping indicator.SOLUTION: A mechanism 6 for driving an indicator 4 in jumps includes: a wheel platform 8 having a first rotation axis 20; a driving finger 12 for driving the indicator 4; a spring 16; a rigid support 10 rotatable about the first rotation axis 20 to the wheel platform 8; and a lever 26 mounted on the rigid support 10 so as to be rotatable about a second rotation axis 22 apart from the first rotation axis 20, and forming the driving finger. The mechanism 6 limits rotation of the lever 26 in a first direction when the spring 16 is being loaded and the indicator 4 is making its next jump, the lever 26 being able to rotate in the opposite direction to the first direction, thus allowing the driving finger 12 to radially retract towards the first rotation axis under an action of a radial force exerted on the driving finger 12.SELECTED DRAWING: Figure 6A

Description

[Technical Field]

[0001] The present invention relates to a timepiece movement provided with an indicator and including a mechanism for jump-driving the indicator, and further to a wristwatch incorporating a timepiece movement provided with such a mechanism. More specifically, the indicator is a date indicator. [Background technology]

[0002] The patent document 1 describes a mechanism for driving a jump indicator, which advantageously overcomes the technical problems of the prior art by including a rigid drum finger rotatably and translatably guided by a hub passing through an oblong hole in the drum, and a spring disposed on the drum finger, connecting the drum finger to the wheel platform.

[0003] This drive mechanism has several drawbacks. First, the spring expands when the date ring is driven. Because the spring coils are intended to contact the inner wall of the drum when the spring is under load, the spring's expansion is limited and the spring's plastic zone is prevented from being reached. This results in a sudden decrease in the spring's effective length. Given the manufacturing tolerances of various components, the drive mechanism's load time can vary. This is because the time at which the spring comes into contact with the inner wall of the drum varies with each load, and the angular position of the contact zone also varies. This results in inaccuracies in the time that triggers the ring to move to the next date. Another problem arises from the fact that the drive force is transmitted to the finger via the spring coils. This means that the spring must be sufficiently rigid / stiff throughout its entire length, specifically the section located between the contact zone with the drum wall and the connecting element at the second end of the spring, which ultimately must be able to withstand the additional torque generated from the moment of contact to the moment the indicator jumps.

[0004] The diagram in Reference 1 shows that the spring's coupling element is positioned in a shallow recess from which it can easily emerge. The two side surfaces of the recess are parallel to the radial direction passing through the middle of the recess, and the coupling element has two radial flanks. The angular width of the coupling element is smaller than that of the recess so that it can easily enter the recess. Furthermore, the coupling element is intended to have a large amount of play in the recess so that it can move in the recess. That is, it can easily be released from its recess with a relatively small impact. In this case, either when the spring is loaded against the teeth of the date ring or before it is loaded, the spring typically shows a slight expansion due to friction with the drum, but the coupling element escapes from the side of the finger's radial drive flank. In this situation, the side wall of the drum exerts a radial force on the coupling element, which is subjected to a frictional force with the side wall. If the spring bearing against the date ring tooth is loaded and the coupling element disengages from the recess, it will then slide along the inner lateral surface, preventing a date jump until the drive wheel rotates at least once and the coupling element re-enters the recess (the best-case scenario, which would still result in the missed date jump and the correct date display being lost). Alternatively, the frictional force is sufficient to re-expand the spring, increasing it further until its coil contacts the side wall, causing a date jump at an indeterminate time. In the latter case, after the date jump, the drive of the drum relaxes the spring. If this situation recurs, the next date change will no longer occur around midnight. If the coupling element undergoes a predetermined, sudden angular displacement along the side wall (which is possible), this situation will be repeated at indeterminate and variable date increments for at least several days. In either case, the date drive mechanism will cease to function for at least several days as soon as the coupling element disengages from its recess. This is highly likely to occur in the case of the mechanism shown in the figure in Patent Document 1.

[0005] The geometry of the coupling member relative to the recess, which allows a large amount of play and a certain degree of mobility of the coupling member in the recess, creates other problems. Specifically, when the spring is loaded, the spring coils deform, causing the coupling member to rotate around itself. This rotation causes the coupling member to slide against the front wall of the recess, radially reducing the point of application of the spring's force on the drum finger as the spring is loaded. That is, for a given spring load level, the driving torque the spring exerts on the finger decreases in proportion to the reduction in the lever arm's application of the spring's force on the drum finger. This creates a problem because the finger's driving force on the indicator tooth decreases by the same factor for a given contact point. For a given driving torque required to jump the indicator, the spring must generate a force that corresponds to the reduction in the lever arm while the spring is loaded. This negatively impacts the performance of the watch movement, which must apply a large torque by loading the drive spring. This, in turn, requires the spring to be oversized.

[0006] Finally, another problem with the mechanism in question arises from the fact that, when the indicator is actuated, the spring coil exerts a radial force on the drum, directed outward from the area diametrically opposite the finger, thus essentially in the longitudinal direction of the oblong hole. This tends to move the finger away from the tooth of the ring. Therefore, especially in the event of a small impact in such a situation, the finger is more likely to pass the tooth without actuating the indicator. It should also be noted that in such a situation, the angular path over which the finger can drive the tooth by maintaining contact is reduced, allowing the finger to pass the tooth before receiving a driving torque sufficient to ensure a jump in the date. The date ring remains stationary in an intermediate position or returns to its previous stable position as soon as the finger passes the tooth. Furthermore, reducing the lever arm that applies the driving force to the tooth requires an increase in the required driving force for a given driving torque. This in turn requires an increase in the force provided by the spring, and therefore its tension. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] European Patent Application Publication No. 3828644 Summary of the Invention

[0008] The object of the present invention is to provide a mechanism for driving a jump indicator that overcomes at least some of the drawbacks of the prior art mentioned above. It is a further object of the present invention to provide a timepiece movement provided with an indicator, which includes a mechanism for jump driving said indicator. This mechanism can be efficient and accurate in each timepiece movement that includes such a mechanism. Its operation is little or not disturbed by external stresses, such as shocks.

[0009] In more detail, the drive mechanism is intended to enable the indicator to be quickly corrected by another specific mechanism specific to the watch movement, with the additional torque generated by the presence of the drive mechanism during the passage of one tooth or successive passages of several teeth on the outer flank of the indicator's drive finger, this torque being minimal and not involving sudden fluctuations.

[0010] To this end, the present invention relates to a timepiece movement provided with an indicator, the timepiece movement including a mechanism for jump-driving the indicator. The mechanism includes a wheel platform defining a first axis of rotation, a drive finger for driving the indicator, and a spring formed by a first end, a coil, and a second end. The first end is attached to the wheel platform for rotation therewith, and the second end is attached to the drive finger for rotation therewith at least during loading of the spring prior to a jump by the indicator and during driving of the indicator by the mechanism during the jump. The mechanism includes a rigid support rotatable about the first axis of rotation relative to the wheel platform, and a lever mounted on the rigid support for rotation about a second axis of rotation spaced from the first axis of rotation. The second axis of rotation is located at a first end of the lever, and the drive finger is formed by the lever toward its second end. The mechanism includes a first stop integral with the rigid support, which limits rotation of the lever in a first direction corresponding to the direction in which the finger moves radially away from the first axis of rotation. The lever is arranged so as to abut against a first stop at least when the spring (16) is under load before the indicator jumps, and so as to be able to rotate in a second direction opposite to the first direction, thereby allowing the drive finger to be radially retracted towards the first axis of rotation under the action of a force exerted on the drive finger, the force having a gradually increasing radial component.

[0011] When the spring is under load, the first stop allows a constant radial distance to be maintained between the contact point of the drive finger on the indicator tooth and the first axis of rotation of the mechanism. In contrast to the prior art, the lever action remains constant, making the mechanism efficient.

[0012] In certain alternative embodiments, the indicator is a date indicator including teeth, in particular a date ring including internal teeth so as to be rotatably driven by said mechanism.

[0013] Thanks to the drive finger being rotatable about a second axis of rotation that is not integral with the rigid support but is defined by the rigid support and that is spaced apart from the first axis of rotation of the wheel platform and the rigid support, under the action of a force exerted on the drive finger by the indicator, a radial retreat of the drive finger in the direction of the first axis of rotation is obtained in this case by rotation of the lever without radial displacement of the rigid support. This allows the lever to be relatively light and to exhibit relatively low friction during rotation. This means that the force couple exerted by the user, via a correction device other than the mechanism, in the intended drive direction or in the case of a calendar indicator, in the counterclockwise direction (which causes the wheel platform to rotate in the opposite direction to the drive direction), is relatively weak, making the passage of the indicator tooth through the drive finger, which is mainly radially retreating relative to the central axis, less noticeable than in the prior art.

[0014] Second, the spring's elastic deformation can be smaller than in the prior art, resulting in less stress on the spring, which is advantageous for spring sizing. This is due to the rotation of the lever about the second axis of rotation, along which the drive finger moves primarily toward the first axis of rotation. While the spring necessarily undergoes radial elastic deformation due to the radial retraction of the drive finger and thus the second end of the spring, the angular deformation of the spring resulting from the force couple applied to this second end can be much smaller than in the prior art mechanisms. Advantageously, the interaction of the teeth with the finger applies a force to the rigid support only through the lever and thus at the second, offset axis of rotation. The direction of the force applied at the second axis, resulting from the indicator teeth pressing against the outer flank of the drive finger, generates a torque on the rigid support that tends to rotate it, but this torque is weaker than in the prior art. Taking into account the stiffness of the spring (which is necessary to store energy during normal operation of the indicator), the lever can rotate relative to a rigid support under the action of the tooth pressing against the outer flank of the drive finger, but this rigid support does not have to rotate relative to the wheel platform. It can be seen that the spring undergoes mainly radial elastic deformation due to the retraction of the drive finger due to rotation about a second axis of rotation away from the first axis of rotation. That is, the drive mechanism of the present invention allows the same retraction of the finger during correction as the prior art, but generates a smaller elastic deformation of the spring compared to prior art mechanisms in which the spring undergoes significant angular deformation in addition to radial deformation.

[0015] The benefits of the invention described above are particularly achieved in an advantageous alternative embodiment, in which the outer flank of the driving finger is arched, and this arched outer flank has a radial dimension relative to the first axis of rotation while the lever is in contact with the first stop, which radial dimension monotonically increases as it approaches the driving flank of the driving finger so as to press against the lateral flank of the tooth of the toothing during the indicator increment in the jump.

[0016] According to an advantageous alternative embodiment, the spring and the lever are arranged in such a way that the lever abuts against the first stop even when the spring is not subjected to angular stress.

[0017] According to the main embodiment, the rigid support comprises a plate forming the first stop, in particular the rigid support is constituted by such a plate.

[0018] According to a preferred embodiment, the mechanism is arranged so that when loaded, this spring contracts in order to be able to generate a jump, in particular a semi-instantaneous jump of the indicator, by which in particular a constant radius is obtained for applying the driving force of the finger to the tooth of the indicator against which it rests, thereby making it possible to optimize this driving force and therefore the driving torque required to jump the indicator.

[0019] According to an advantageous alternative embodiment, when the contracted coil is stressed as a result of the spring loading, the angular displacement of the second end of the spring relative to the wheel platform, and therefore the angular displacement of the drive finger, is limited by a second stop defining an angular stop mounted to the wheel platform for rotation therewith, the indicator and mechanism being arranged such that a jump by the indicator occurs at the end of the spring loading preceding this jump, in normal operation after said angular displacement has been stopped by the second stop and thus corresponds to the determined angular distance.

[0020] The invention further relates to a watch incorporating a movement according to the invention. [Brief explanation of the drawings]

[0021] The objects, advantages and features of the present invention are explained in detail below with the aid of the accompanying drawings, given as non-limiting examples.

[0022] [Figure 1]1 is a top view of a timepiece mechanism according to an advantageous embodiment of the invention, which mechanism is intended to drive a jump indicator, in particular in a semi-instantaneous jump. [Figure 2] FIG. 2 is an exploded perspective view of the timepiece mechanism of FIG. 1. [Figure 3] 2 is a perspective view of the rigid supports, springs and levers of the clockwork mechanism of FIG. 1 shown in an inverted position; FIG. [Figure 4] FIG. [Figure 5] 1, but of an alternative embodiment of the clock mechanism shown in FIG. [Figure 6A] 6A to 6D show a portion of a timepiece movement according to the invention, which incorporates an advantageous embodiment of the drive mechanism described in the previous figures, and each of which shows four successive states that can occur when the date ring is driven by the drive mechanism. [Figure 6B] 6A to 6D show a portion of a timepiece movement according to the invention, which incorporates an advantageous embodiment of the drive mechanism described in the previous figures, and each of which shows four successive states that can occur when the date ring is driven by the drive mechanism. [Figure 6C] 6A to 6D show a portion of a timepiece movement according to the invention, which incorporates an advantageous embodiment of the drive mechanism described in the previous figures, and each of which shows four successive states that can occur when the date ring is driven by the drive mechanism. [Figure 6D] 6A to 6D show a portion of a timepiece movement according to the invention, which incorporates an advantageous embodiment of the drive mechanism described in the previous figures, and each of which shows four successive states that can occur when the date ring is driven by the drive mechanism. [Figure 7A] 7A and 7B each partially show the timepiece movement in FIG. 6A in two successive states which occur when the date ring is rapidly driven in the date ring driving direction by a conventional control member. [Figure 7B]7A and 7B each partially show the timepiece movement in FIG. 6A in two successive states which occur when the date ring is rapidly driven in the date ring driving direction by a conventional control member. [Figure 8A] 8A and 8B each partially show the timepiece movement of FIG. 6A in two successive states that arise when the hour hand is driven counterclockwise and thus the wheel platform is driven in a direction opposite to the driving direction of this platform when the date ring is driven. [Figure 8B] 8A and 8B each partially show the timepiece movement of FIG. 6A in two successive states that arise when the hour hand is driven counterclockwise and thus the wheel platform is driven in a direction opposite to the driving direction of this platform when the date ring is driven. DETAILED DESCRIPTION OF THE INVENTION

[0023] With reference to the accompanying drawings, an advantageous embodiment of a mechanism for driving an indicator with jumps, in particular with semi-instantaneous jumps, will be described, and in more detail with reference to Figures 6A to 8B, the operation of a timepiece movement according to the invention incorporating such a driving mechanism will be described.

[0024] The mechanism 6 for driving the jump indicator 4 includes a wheel platform 8 that rotates about a first axis of rotation 20, a drive finger 12 that drives the indicator, and a spring 16. In a primary alternative embodiment, the indicator is a date indicator, specifically a date ring including internal teeth 5. In other specific alternative embodiments, given by way of non-limiting example, the indicator is, for example, an indicator for minutes, hours, days, or months. The spring 16 is formed by a first end 17, a coil 18, and a second end 19. The first end is attached to the wheel platform with which it rotates, and the second end is attached to the drive finger 12 with which it rotates, at least during each loading of the spring 16 prior to a jump by the indicator 4 and during the driving of the indicator by the mechanism during this jump. The first end 17 of the spring is connected to a central portion 24 that is mounted for rotation on the wheel platform 8. Preferably, the spring and central portion form one and the same part. The mechanism 6 includes a rigid support 10 rotatable about a first axis of rotation 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 spaced from the first axis of rotation 20.

[0025] The second pivot point 22 is located at a first end of the lever, which forms a drive finger on the side of its second end. In particular, the lever has at its first end a circular stud 34 inserted into a hole 33 made in the rigid support. The lever is rotatable about the pivot point 22 defined by this hole 33, allowing the drive finger 12 to be retracted, in particular during a rapid correction of the date or during a predetermined counterclockwise correction of the time past midnight, as will be explained in more detail below.

[0026] The mechanism 6 includes a central hub 32 that defines a shaft that passes through a central bore of the rigid support 10 and rotatably guides the rigid support relative to the wheel platform 8. The rigid support 10 and the central portion 24 are driven into the central hub 32.

[0027] Typically, the drive mechanism includes a first stop integral with the rigid support, which limits the rotation of the lever in a first direction corresponding to the movement of the finger radially away from the first axis of rotation 20. The lever is arranged to abut against the first stop at least when the spring is loaded before the indicator jumps, and preferably also when the indicator is driven during this jump, and to be able to rotate in a second direction opposite to the first direction. This causes the drive finger to retract toward the first axis of rotation 20 under the action of a tangential component, relative to the second axis of rotation 22, of the force exerted on the drive finger by the indicator tooth during correction. Preferably, the spring and lever are arranged such that the lever also abuts against the first stop even when the spring is not subjected to angular stress. According to a main alternative embodiment, the rigid support includes a plate forming the first stop. According to an advantageous alternative embodiment shown in the figures, the rigid support is a plate 10.

[0028] According to the particular alternative embodiment shown in the figures, the lever 26 is formed by an arm 36 and a drive finger 12. The arm has a first height and is at least partially disposed between the wheel platform and the plate. The drive finger 12 has a second height H at a thickened portion that defines a drive flank 14. The drive flank 14 is intended to abut a tooth of the toothing 5 associated with the indicator 4 (FIGS. 6A to 8B) when the indicator is actuated by the mechanism 6. The second height H is greater than the first height, such that the thickened portion of the drive finger is not superimposed on the plate for any useful angular position of the lever, and this thickened portion extends axially at least partially beyond 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 lever abuts the first stop 30.

[0029] According to an advantageous alternative embodiment, the plate 10 has a lateral surface, a substantially radial area of ​​which defines a first stop 30. The drive finger 12 has a second height H over its entire extent in the plane of the toothing 5 and is arranged so that its rear upper part can abut against the first stop 30 at least every time the spring is loaded. As a result, the drive finger 12 is held in a fixed angular position relative to the second axis of rotation and, therefore, in a fixed position relative to the first axis of rotation. In particular, the rear upper part defines a stop surface 15 which, in cooperation with the first stop 30, limits the rotation of the lever in the first direction of rotation. This stop surface 15 abuts against the first stop 30 at least every time the indicator performs a jump, i.e., a date jump when the time display shows midnight, after the spring 16 is loaded.

[0030] In a first alternative embodiment shown in Figures 1 to 3, the plate 10 has a generally circular outer shape with lateral cavities 38 configured to allow the drive finger 12 to enter and thus retract into this cavity as the tooth passes along the outer flank 13 of this drive finger, with the majority of the spring 16 always covered by the plate. In a second alternative embodiment shown in Figure 5, the plate 10A of the mechanism 6A includes: a central portion defining a central hole; a protrusion 58 that covers part of the spring 16 at its second end 19 to hold it in the general plane of the spring between the wheel platform 8 and the plate 10A; and a portion in the form of an annular sector extending radially from the central portion and defining a first stop 30 at the first angular end and a hole 33 for a stud 34 of the lever 16 at the second angular end.

[0031] In the illustrated alternative embodiment, the drive finger 12 has an arched outer flank 13 against which at least one tooth 5 of the toothing 5 of the indicator 4 can press during rapid correction of the indicator using a correction device other than the mechanism. The arched outer flank has a radial dimension relative to the first axis of rotation 20 when the lever contacts the first stop 30. This dimension increases monotonically as the drive flank 14 is approached.

[0032] According to an advantageous alternative embodiment, also shown in the figures, the lever 26 has, in an inner part 46 extending alongside the drive finger 12, a recess 42 with a lateral opening on the side of the spring 16. The second end 19 of the spring 16 is extended by a member 40 connecting with the lever 26. This connecting member 40 is rigid and is configured so that it can at least partially enter the recess 42. This allows the spring to apply a drive couple to the rigid support 10 and the lever 26, which then allows the drive finger 12 to drive the indicator 4.

[0033] Preferably, the coupling member 40 is configured so that it can at least partially enter the recess 42 through a lateral opening of the recess. Specifically, the recess 42 has a lateral surface 52 that is obliquely oriented in the rotational direction 50 of the wheel platform 8. In this rotational direction 50, the indicator 4 is intended to be driven radially, relative to the central rotation axis 20, and through the center of the lateral surface. The coupling member 40 has lateral flanks 54 facing the lateral surface 52, which are also obliquely inclined in the same direction as the lateral surface relative to the central rotation axis 20 and at least partially abut against the lateral surface when the indicator is driven. The outer surface and flanks are relatively long. This special feature ensures that the coupling member is firmly held in the recess as soon as the spring 16 is compressed. Specifically, the contact point or contact zone of the recess, at which the spring force is exerted via the coupling member, does not change when the spring is under load. Furthermore, when the spring is under load, the linkage member 40 cannot rotate about itself in the direction of rotation of the wheel platform.

[0034] The lever 26 advantageously has a lateral ramp 48 in the front part of the inner part 46, and from the angular position of this connecting member located upstream of this lateral ramp 48, the connecting member 40 can be connected to the lever 26, in particular to the drive finger, by inserting the connecting member into the recess 42 simply by rotating the plate 10 clockwise relative to the wheel platform 8.

[0035] The recess 42 is typically triangular in shape and gradually opens toward its side opening. The shape of the portion of the connecting member 40 inserted into the recess from the side opening substantially corresponds to the shape of the recess. This configuration advantageously allows the connecting member to be easily inserted into the recess, but also makes it very easy for the connecting member to come out in the event of an impact, despite the a priori intention that the recess be relatively deep. However, the spring 16 is arranged so that, when the spring is under load, the connecting member is a short distance from the inner end 17 of the spring, which is rigidly connected to the central portion 24. In this situation, the connecting member 40 will not come out of its recess, even in the event of an impact. Furthermore, when the spring 16 is substantially relaxed without the drive finger interacting with the indicator tooth 5, the connecting member 40 will also not be able to escape laterally from its recess in the event of an impact. That is, the mechanism 6 is arranged so that the connecting member cannot come out of the recess 42 even if the spring is relaxed or stressed during the spring's loading before the indicator jumps.

[0036] Once inserted into recess 42, coupling member 40 can, although not necessarily, be held in this recess by a radial force exerted by spring 16 outward towards this coupling member relative to pivot point 20. This radial force (or more precisely the radial component of the force exerted by the spring via the coupling member on the lever) is increased by the fact that during a rapid date change or counterclockwise time correction past midnight, the drive finger and coupling member are retracted / pulled in towards pivot point 20 via clockwise rotation (second rotation direction of the lever), so that in such circumstances the coupling member is usually held in the recess in this way, even when spring 16 is somewhat expanded.

[0037] During a rapid counterclockwise date or time adjustment, including passing midnight, when the drive finger 12 is retracted by clockwise rotation of the lever 26, the coupling finger moves closer to the center portion 24 so that the coupling member can no longer escape from its recess after a predetermined initial rotation of the lever. During the initial rotation, the spring 16 expands under a predetermined angular stress, which could theoretically allow the coupling member to escape from its recess in the event of an impact. However, when the coupling member is subjected to acceleration substantially in the direction of the rotation axis 20 of the wheel platform 8, the lever experiences a predetermined force couple. This couple causes the lever to rotate about its rotation axis 22, and the drive finger follows the coupling member, so that the coupling member remains at least partially within its recess. If acceleration occurs in a direction substantially passing through the center of gravity of the lever and its rotation axis 22, the coupling member 40 may be subjected to movement out of the recess 42. However, the internal protrusion 44 of the spring can be configured to prevent the coupling member from completely escaping from its recess. Alternatively, it may be advantageously configured so that the rear of the coupling member collides with a rigid part integral with the wheel platform during correction before being able to fully exit its recess. In conclusion, the mechanism 6 is arranged so that the coupling member 40 remains in its recess 42 during normal operation, so that this coupling member is always integral with the drive finger during normal operation and in most cases is unable to exit the recess on impact, preferably not at all.

[0038] Preferably, the mechanism 6 is arranged so that the spring 16 contracts when it is loaded, allowing a jump by the indicator to occur. Preferably, when stress is applied to the contracted coil 18 as a result of spring loading, the angular displacement of the second end 19 of the spring 16, and thus of the drive finger 12 connected to the connecting member 40, relative to the wheel platform 8 is limited by a second stop 28 defining an angular stop mounted for rotation therewith to the wheel platform 8. The indicator and mechanism are arranged so that, in normal operation, a jump by the indicator does not occur before, at the end of the spring loading preceding this jump, said angular displacement is stopped by the second stop and thus corresponds to the determined angular distance α (see FIG. 6A ).

[0039] In the alternative embodiment shown, spring 16 includes an internal protrusion 44 located along coil 18 at its second end 19. This internal protrusion is positioned to abut second stop 28 (angular stop), thus terminating the spring's load, which causes indicator 4 to then jump to its next stable position, i.e., to the next date in the case of a date indicator.

[0040] 6A to 8B show in detail the operation of the watch movement 2, and in particular the mechanism 6 incorporated therein that drives the date ring 4. The central hub 32 is not shown in these figures to avoid overloading the drawings, but it is clearly necessary for the functioning of the mechanism 6.

[0041] 6A to 6D show four successive states of the mechanism 6 driving the date ring 4 during a jump, in particular a semi-instantaneous jump. Each of FIGS. 6A to 6D shows the state when this ring is driven to change to the next date at midnight, i.e. When the drive finger 12 contacts the tooth 5a of the ring 4 and the spring 16 is substantially angularly relaxed (i.e., unstressed), Once the inner projection 44 of the spring has been subjected to an angular displacement α relative to the wheel platform 8 and has come into contact with the angular stop 28, the load of the spring 16 is terminated. During the date jump caused by the mechanical energy stored in the contracted spring being applied to said assembly, and When the jump ends and the date ring 4 reaches its next stable position, Showing the mechanism 6 and the date ring 4.

[0042] It should be noted that in certain embodiments, during normal operation, the indicator jumps before the angular displacement of the spring is stopped by the angular stop 28. In such cases, the angular stop becomes a spring protection stop. In other specific embodiments, the drive mechanism does not have an angular stop. The spring contracts and the coils of the spring are free to expand between the ends of the spring during the loading period.

[0043] It should be noted that, in order to prevent the tooth 5 a of the indicator 4 from passing above or below the driving finger 12 when the indicator is driven, the height, including play, between the wheel platform 8 and the underside of the tooth 5 is set so as to always remain between the lower and upper heights, including play, of the driving finger from the wheel platform. To this end, in an advantageous alternative embodiment, the lower height of the finger is smaller than the thickness of the tooth of the toothing 5. Preferably, in a watch incorporating the timepiece movement 2, the distance between the upper height of the finger and the dial covering the drive mechanism and the indicator is also designed to be smaller than the thickness of the tooth of the toothing 5. The large height of the finger 12 can rise at least from the underside of the spring 16 to above the plate 10 that defines the upper side of the mechanism 6, making it easy to prevent the tooth 5 a from passing above or below the finger 12.

[0044] 7A and 7B illustrate the behavior of mechanism 6 during rapid adjustment of date ring 4 by a user-operable control member in a conventional manner. For example, in the evening, when wheel platform 8 and plate 10 are initially in the configuration shown in FIG. 7A , finger 12 is positioned between tooth 5a and the preceding tooth 5b in the direction of rotation 60, so that finger 12 is in the path of indicator tooth 5b. Ring 4 is intended to rapidly advance in direction of rotation 60, which corresponds to the single direction of rotation of the date ring. As shown in FIG. 7B , as ring 4 rotates, tooth 5b of toothing 5 contacts the arched outer flank 13 of finger 12, exerting a progressive radial force on said finger. This causes lever 26 to rotate clockwise about its axis of rotation 22, moving finger 12 toward the central hub of plate 10 and retracting the finger toward axis of rotation 20. This retraction is made possible by the configuration of drive finger 12, the contour of lateral cavity 38 in plate 10, the location of spring 16 and its attached central portion 24, and the configuration of internal projection 44. As can be seen in Figure 7B, as finger 12 retracts as tooth 5b passes, the tooth is allowed to follow outer flank 13 of the finger until it angularly projects beyond the finger.

[0045] As already explained, the interaction of the tooth 5 with the drive finger 12 exerts a force on the plate 10 only through the lever 26, and thus at the second axis of rotation 22. The direction of the force exerted at the second axis of rotation, caused by the indicator tooth 5a or 5b pressing against the outer flank 13 of the drive finger, generates a torque on the plate that tends to rotate it, but this torque is weaker than in the prior art. Given the stiffness of the spring 16, the lever 26 can rotate relative to the plate under the action of the tooth pressing against the outer flank of the drive finger, without this rigid support rotating significantly relative to the wheel platform. As can be seen, the spring undergoes elastic deformation primarily radial to the axis of rotation 20 due to the retraction of the drive finger 12 by rotation about the second axis of rotation 22, away from the first axis of rotation 20 (the central axis of rotation of the mechanism). That is to say, the drive mechanism 6 allows the same retraction of the finger during correction as in the prior art, but generates a smaller elastic deformation of the spring 16 than in the prior art mechanisms, in which the spring undergoes significant angular deformation in addition to radial deformation. That is to say, the work that must be supplied to the mechanism 6 by the date ring 4 to allow the tooth 5b to pass the drive finger 12 (in a plane perpendicular to the rotation axes 20 and 22) during the correction in question is less than in the case of a drive finger having a similar geometry, but in particular fixed against a plate having an oblong hole through which passes the central shaft formed by the hub, as in the prior art.

[0046] As the finger 12 moves radially, the spring 16 contracts radially, bringing the connecting member 40 closer to the central portion 24. It should be noted that the spring 16, and more precisely its coil 18, is slightly expanded simultaneously with the radial stress it experiences in the direction of the wheel platform's axis of rotation during the quick correction of the date ring. However, taking into account the geometry of the outer flank 13 of the finger 12 and its rotation in the direction of the aforementioned axis of rotation 20 (the central first axis of rotation), the expanding spring stress is relatively small, or even practically zero, depending on the system configuration. This is highly advantageous for the design of the spring 16. The spring 16 can therefore be arranged to withstand as much as possible the contraction that occurs when the indicator 4 is driven by the device 6, without the need to ensure that the spring behaves appropriately under significant expansion stresses.

[0047] 8A and 8B show the behavior of mechanism 6 during the correction of the time displayed by the watch mechanism. This causes wheel platform 8 to rotate counterclockwise past midnight. In this case, date ring 4 remains stationary in the stable position in which the time was corrected. The sequence of states of mechanism 6 is similar to the sequence occurring during the rapid correction of the date display described above. When wheel platform 8, and thus the assembly formed by plate 10 and lever 26, rotates in the direction opposite to the normal direction of rotation (corresponding to the clockwise direction of the time display), arched outer flank 13 of finger 12 abuts against tooth 5a of toothing 5 (FIG. 8A). Plate 10 continues to rotate, but at least initially, due to the slight expansion of the spring, it rotates a little slower than the wheel platform. Meanwhile, the driving finger moves radially towards the axis of rotation 20 via clockwise rotation of the lever 26 which penetrates deeper into the lateral cavity 38, so that the finger retracts while the stationary tooth 5a extends along the outer flank 13 of the finger.

[0048] The mechanism 6 is configured to prevent blocking during rapid date adjustment or counterclockwise time adjustment.

[0049] The invention further relates to a wristwatch comprising a watch movement 2 according to the invention. This movement is incorporated into a case which also incorporates a dial arranged to display data that changes over time by jumps, in particular the date.

Claims

1. A timepiece movement (2) provided with an indicator (4) and including a mechanism (6) for jump-driving said indicator (4), The mechanism (6) includes a wheel platform (8) rotating about a first axis of rotation (20), a drive finger (12) for driving the indicator (4), and a spring (16) formed by a first end (17), a coil (18) and a second end (19), the first end (17) being attached to the wheel platform (8) for rotation therewith, and the second end (19) being attached to the drive finger (12) for rotation therewith at least during loading of the spring (16) prior to a jump by the indicator (4) and during driving of the indicator (4) by the mechanism (6) during the jump; The feature is that the mechanism (6) includes a rigid support (10) rotatable about the first axis of rotation (20) relative to the wheel platform (8), and a lever (26) mounted on the rigid support (10) so as to be rotatable about a second axis of rotation (22) spaced apart from the first axis of rotation (20), the second axis of rotation (22) being located at a first end of the lever (26), the drive finger (12) being formed by the lever (26) on the side of the second end of the lever (26), the mechanism (6) including a first stop (30) integral with the rigid support (10), the drive finger (12) being attached to the first axis of rotation (22) a first stop (30) that limits rotation of the lever (26) in a first direction corresponding to a direction of movement radially away from a rotation axis (20); the lever (26) is arranged to abut against the first stop (30) at least when the spring (16) is under load and to be able to rotate in a second direction opposite to the first direction, thereby allowing the drive finger (12) to be radially retracted toward the first rotation axis (20) under the action of a force exerted on the drive finger (12), the force having a gradually increasing radial component.

2. 2. A timepiece movement (2) according to claim 1, characterized in that the spring (16) and the lever (26) are arranged in such a way that the lever (26) also abuts the first stop (30) when the spring (16) is not subjected to angular stress.

3. 3. A timepiece movement (2) according to claim 1 or 2, characterized in that the rigid support (10) comprises a plate (10) rotatably guided about the first axis of rotation (20) by a shaft (32) mounted to the wheel platform (8) for rotation therewith, the plate (10) forming the first stop (30).

4. 4. A timepiece movement (2) according to claim 3, characterized in that the lever (26) is formed by an arm (36) and the driving finger (12), the arm (36) having a first height and being arranged at least partially between the wheel platform (8) and the plate (10), the driving finger (12) having at least a second height (H) in a thickened portion defining a driving flank (14) intended to abut against a tooth (5 a) of a toothing (5) associated with the indicator (4) when the indicator (4) is driven by the mechanism (6), the second height (H) being greater than the first height, the thickened portion of the driving finger (12) not being stacked on the plate (10) for any useful angular position of the lever (26), and this thickened portion extending axially at least partially beyond the thickness of at least one region of the plate (10) located above the arm (36).

5. 5. A timepiece movement (2) according to claim 4, characterized in that the plate (10) has a lateral surface, one zone (30) of which defines the first stop (30), the driving finger (12) is arranged so that the rear upper part of the thickened part of the driving finger (12) abuts against the first stop (30) at least every time the spring (16) is loaded, and the driving finger (12) is held in a fixed angular position relative to the second axis of rotation (22) and thus in a fixed position relative to the first axis of rotation (20).

6. 5. A timepiece movement (2) according to claim 4, characterized in that the plate (10) has a generally circular outer shape with lateral cavities (38) configured to allow the drive finger (12) to enter, and thus retract, into the lateral cavities (38) as the teeth (5a, 5b) pass along the outer flanks (13) of the drive finger (12), with the majority of the spring (16) always covered by the plate (10).

7. 5. A timepiece movement (2) according to claim 4, characterized in that the drive finger (12) has an arched outer flank (13) against which at least one tooth (5a) of the toothing (5) can press during quick correction of the indicator (4) using a correction device other than the mechanism (6), and the arched outer flank (13) has a radial dimension relative to the first axis of rotation (20) that monotonically increases as it approaches the drive flank (14) when the lever (26) is in contact with the first stop (30).

8. 3. A timepiece movement (2) according to claim 1 or 2, characterized in that the mechanism (6) is arranged so that the spring (16) contracts when subjected to a load, so as to enable the indicator (4) to generate a jump.

9. 9. A timepiece movement (2) according to claim 8, characterized in that the spring (16) includes an internal protrusion (44) arranged along the coil (18) on the side of the second end (19), the internal protrusion (44) being arranged so as to abut against a second stop (28) defining an angular stop mounted to the wheel platform (8) for rotation therewith at the end of the load of the spring (16) and before the indicator (4) makes a jump.

10. 3. A clock movement (2) according to claim 1 or 2, characterized in that the first end (17) of the spring (16) is connected to a central part (24) mounted to the wheel platform (8) for rotation therewith.

11. the lever (26) has, in its inner part on the side of the driving finger (12), a recess (42) with a lateral opening on the side of the spring (16); The second end (19) of the spring (16) is expanded by a connecting member (40) that connects with the lever (26), and the connecting member (40) is configured to be rigid and to be able to at least partially enter the recess (42) through the side opening, thereby allowing the spring (16) to apply a driving couple to the lever (26), and thus allowing the driving finger (12) to drive the indicator (4). A clock movement (2) according to claim 1 or 2, characterized in that

12. 12. The timepiece movement (2) according to claim 11, characterized in that the recess (42) has a lateral surface (52) oriented obliquely to the direction of rotation (50) of the wheel platform (8), the indicator (4) is intended to be driven in the direction of rotation (50) relative to a radial direction relative to the first axis of rotation (20) so as to pass through the center of the lateral surface (52), and the connecting member (40) has a lateral flank (54) facing the lateral surface (52), the lateral flank (54) also inclined obliquely relative to the first axis of rotation (20) in the same direction as the lateral surface (52) and at least partially abutting the lateral surface (52) when the indicator (4) is driven.

13. 3. A timepiece movement (2) according to claim 1 or 2, characterized in that the indicator (4) is a minute indicator, an hour indicator, a date indicator, a day of the week indicator or a month indicator.

14. 14. A clock movement (2) according to claim 13, characterized in that the indicator (4) is a date ring.

15. A wristwatch, characterized in that it includes a clock movement (2) according to claim 1 or 2.

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