Mechanism for triggering a clockwork mechanism, and timepiece comprising such a triggering mechanism

Abstract

The present invention relates to a mechanism (56) for triggering a clockwork mechanism arranged to perform a function. The invention also relates to a timepiece comprising such a triggering mechanism.

Description

[0001] TRIGGER MECHANISM OF A TIMEPIECE MECHANISM AND TIMEPIECE COMPRISING SUCH A TRIGGER MECHANISM

[0002] Technical field

[0003] The present invention relates to a trigger mechanism of a clockwork mechanism arranged to perform a function.

[0004] The present invention also relates to a timepiece comprising such a trigger mechanism.

[0005] State of the art

[0006] Publication CH 717672 describes a mechanism for triggering an animation disc, representing for example a shooting star. The control member is a ratchet wheel of a barrel of a watch movement driven in rotation at least by means of an oscillating weight and possibly also by means of a user-operable operating member. Since the trigger mechanism is managed essentially by the ratchet wheel of the barrel which imposes a substantially constant torque, the trigger mechanism is systematically triggered to start the animation.

[0007] Document CH 717672 does not provide any information on the consequences on the triggering of the animation or on the mechanism in the event that a user wishes to trigger the animation at will by actuating the operating member by applying insufficient or too much force.

[0008] Also known is document EP 2 068 210, which describes a trigger mechanism according to the preamble of the appended claim 1. This trigger mechanism makes it possible to transform a continuous movement, for example the continuous rotation of a wheel of an input mobile, into a periodic instantaneous trigger movement of an output mobile. No information is given if insufficient or too great a force is applied to this trigger mechanism.

[0009] Furthermore, watch trigger mechanisms based on other constructions are known and which are configured to be able to manage the application of insufficient force to the control member by having a functionality called "all or nothing". This means that the action linked to the trigger mechanism is only triggered if the user applies sufficient force to the control or operating member. Such "all or nothing" mechanisms are described for example in documents EP 1959317 and CH 3873. "All or nothing" mechanisms are typically based on ratchet systems whose operation is not always optimal. In addition, these mechanisms do not allow the application of too much force to the control member to be managed.

[0010] Clock trigger mechanisms are also known which are configured to be able to manage the application of a very high force to the control member by the user by having a device guaranteeing a constant output torque of the trigger mechanism. Such mechanisms are described for example in documents EP 1960844 and CH 717359. However, these mechanisms do not allow the application of too low a force to the control member to be managed.

[0011] The present invention aims to remedy these drawbacks by proposing a trigger mechanism for a watch mechanism which makes it possible to manage the application of insufficient force to the control member as well as excessive force.

[0012] Disclosure of the invention

[0013] To this end, the invention relates to a trigger mechanism of a clockwork mechanism arranged to perform a function, said trigger mechanism comprising:

[0014] - a control device comprising a control member,

[0015] - a trigger wheel mounted to rotate and comprising a trigger member intended to be driven in rotation by the control member, a trigger pilot wheel kinematically linked to the trigger member and integral in rotation with a first end of an elastic member, and a trigger output wheel integral in rotation with a second end of the elastic member and kinematically linked to an element of the watch mechanism, said trigger member being a rotary trigger cam,

[0016] - a control device kinematically linked to the trigger control wheel and arranged to block or release the trigger output wheel depending on the rotation of said trigger control wheel, the control member being arranged to exert a first rotational driving force on said trigger cam.

[0017] According to the invention, said trigger mechanism comprises a trigger rocker arranged to read the trigger cam and said trigger cam and the trigger rocker are arranged to allow said trigger rocker, when reading said trigger cam rotated by the control member:

[0018] - to store energy by exerting on said trigger cam a second rotational driving force which is antagonistic as long as the first rotational driving force is less than a predetermined threshold and,

[0019] - to restore, beyond said predetermined threshold, said energy so that said second rotational drive force exerted on the trigger cam causes a rotation of the trigger pilot wheel such that the pilot device, blocking the trigger output wheel until then, releases said trigger output wheel to perform said function.

[0020] Thus, the trigger mechanism according to the invention is of the "all or nothing" type by authorizing the rotation of the trigger output wheel which will allow the watch mechanism to perform its function only if the force applied to the control member is sufficient to cause a rotation of the trigger cam and therefore the rotation of the trigger pilot wheel necessary for the actuation of the pilot device to release the trigger output wheel in order to perform the function.

[0021] In addition, the trigger mechanism according to the invention advantageously constitutes an intermediate device which makes it possible to manage the force applied to the control member by standardizing the torque to be transmitted to the associated watch mechanism to perform its function. Thus, the watch mechanism receives from the trigger output wheel a constant torque linked to the elastic member, independent of the force applied to the control member, in particular a very significant force.

[0022] Advantageously, the trigger rocker is provided with a return spring arranged to, when the trigger rocker reads the rotating trigger cam, store and restore said energy allowing said trigger rocker to exert the second rotational driving force on the trigger cam.

[0023] Preferably, the trigger cam has n branches defining n peaks and n troughs, each branch having a rising edge and a falling edge.

[0024] Advantageously, the return spring of the trigger lever is arranged to store said energy when the trigger lever reads a rising edge of the rotating trigger cam, and to, when the trigger lever reads a falling edge of the rotating trigger cam, restore said energy allowing the trigger lever to exert the second rotational driving force on the trigger cam.

[0025] Advantageously, to exert the first rotational driving force on the trigger cam, the control member is a control rocker which has a hook arranged to rotate said trigger cam, preferably by gripping a top of one of its branches.

[0026] Advantageously, the trigger cam is coaxial and rotationally fixed to the trigger control wheel. This reduces the size of the mechanism.

[0027] Preferably, the trigger lever comprises a roller arranged to read the trigger cam. Such a roller makes it possible to reduce friction and facilitate reading of the trigger cam. Preferably, the elastic member is a spiral spring.

[0028] Advantageously, the piloting device comprises a piloting pinion free to rotate and kinematically linked to the trigger piloting wheel, a piloting cam secured to said piloting pinion, a piloting fork mounted to rotate and arranged to cooperate with the piloting cam, a piloting anchor secured in rotation to the piloting fork, said piloting anchor comprising two arms arranged to be able to alternately block a locking finger secured in rotation to a locking pinion arranged to be kinematically linked to the triggering output wheel.

[0029] In a preferred embodiment, the watch mechanism is a correction mechanism for at least one display member, for example a correction mechanism for a display member linked to a GMT time.

[0030] The present invention also relates to a timepiece comprising a watch mechanism arranged to perform a function and a trigger mechanism for said watch mechanism as defined above.

[0031] Brief description of the drawings

[0032] Other characteristics and advantages of the present invention will appear on reading the following detailed description of an embodiment of the invention, given by way of non-limiting example, and made with reference to the appended drawings in which:

[0033] - figure 1 is an isometric view of a trigger mechanism according to the invention used in a timepiece for correcting display organs in connection with a GMT time;

[0034] - Figure 2 is an isometric view of the differential gear;

[0035] - Figure 3 is a sectional view of the differential gear of Figure 2;

[0036] - Figure 4 is an isometric view of the phase shifting wheel; - Figure 5 is an isometric view of the lower phase shifting wheel of the phase shifting wheel of Figure 4;

[0037] - Figure 6 is a view of a display device arranged to display the difference between local time HT and GMT time used in the present invention;

[0038] - figure 7 is an isometric view of the triggering mobile;

[0039] - Figure 8 is an isometric view of the trigger control wheel of the trigger mobile of Figure 7;

[0040] - figure 9 is an isometric view of the control device;

[0041] - Figure 10 is an isometric view of the pilot pinion, pilot cam and pilot fork of the pilot device of Figure 9; and

[0042] - figures 11 to 14 are top views of the triggering mechanism according to the invention in different operating phases.

[0043] Embodiments of the invention

[0044] The present invention relates to a trigger mechanism for a watch mechanism. In the exemplary embodiment described, said watch mechanism is a mechanism for correcting a display member linked to a GMT time provided in a timepiece, the elements of which useful for understanding the invention are shown in Figure 1.

[0045] Said timepiece comprises, in a known manner, a cannon pinion 1 which integrally carries the minute display member (such as a hand, not shown), and which is kinematically linked to the driving member (not shown) of the timepiece, such as a barrel. During normal operation of the timepiece, in a conventional manner, the cannon pinion 1 is driven via the driving member and in turn drives, via a drive wheel set 2 corresponding to the timer wheel set, the hour wheel (not shown) which is arranged to drive a first local time display member HT (such as a hand, not shown) in cooperation with the minute display member.

[0046] The timepiece also includes a second display organ, symbolically represented by the reference 4, such as a hand, arranged to be able to display a GMT time of a time zone different from that of the local time HT.

[0047] It is obvious that any other suitable organ for displaying local time HT and GMT time can be used.

[0048] The timepiece also includes a correction mechanism 6 of the second display member 4 arranged to be able to correct the GMT time independently of the local time HT.

[0049] Said correction mechanism 6 will be described in more detail below.

[0050] The timepiece also comprises a drive mechanism 8 for the second display member 4 which comprises a differential gear 10 and a phase shifting wheel 12.

[0051] With particular reference to Figures 2 and 3, said differential gear 10 comprises at least one upper differential wheel set 14 arranged to be kinematically connected to the second display member 4, a lower differential wheel set 16 arranged to be kinematically connected to the drive wheel set 2 of the first display member (timer wheel set), via the phase shift wheel set 12 as described below, and an input 18 arranged to be kinematically connected to the correction mechanism 6 of the second display member 4.

[0052] More specifically, the differential gear 10 comprises a differential block 20 mounted freely in rotation, preferably on two half-axes 22a, 22b mounted pivotally on the frame of the part and secured respectively to the upper differential wheel set 14 and the lower differential wheel set 16. Said differential block 20 carries at least a first idler pinion 24a arranged to mesh with a pinion 26a secured to the half-axel 22a of the upper differential wheel set 14 and a second idler pinion 24b arranged to mesh with a pinion 26b secured to the half-axel 22b of the lower differential wheel set 16, said idler pinions 24a and 24b being mounted freely in rotation on the differential block 20.

[0053] The differential block 20 is also integral with a wheel constituting the input 18 of the differential gear 10 and arranged to be kinematically linked to the trigger mechanism as will be described below.

[0054] With particular reference to Figures 4 and 5, the phase shift wheel 12 comprises a lower phase shift wheel 28 arranged to be kinematically connected to the drive wheel 2 of the first display member, and more particularly to the timer wheel 2a. The lower phase shift wheel 28 is also arranged to be kinematically connected to the lower differential wheel 16 of the differential gear 10, for example by means of two stepped idler pinions 30a, 30b secured to each other, the pinion 30a being arranged to cooperate with the lower phase shift wheel 28 and the pinion 30b being arranged to cooperate with the lower differential wheel 16, as shown in Figure 1.

[0055] The phase shifting wheel 12 also comprises an upper phase shifting wheel 32, coaxial with the lower phase shifting wheel 28, and arranged to drive the second display member 4 and to be kinematically linked to the upper differential wheel 14 of the differential gear 10.

[0056] The upper phase shift wheel 32 is also kinematically linked to the lower phase shift wheel 28 in a disengageable manner so that said upper phase shift wheel 32 is uncoupled from the lower phase shift wheel 28 during a correction of the GMT time independently of the local time HT by the correction mechanism 6 while allowing, after correction, a repositioning of the second display member 4 synchronized with the positioning of the first display member.

[0057] The upper phase shift wheel 32 is kinematically connected to the lower phase shift wheel 28 in a disengageable manner by means of a phase cam 34 secured to the lower phase shift wheel 28, coaxial with said lower phase shift wheel 28, and a hammer 36 provided with a phase shift spring 38 carried by the upper phase shift wheel 32, said hammer 36 being arranged to cooperate with said phase cam 34. More particularly, the hammer 36 is pivotally mounted on the upper phase shift wheel 32 by means of a pivot axis mounted securely on said upper phase shift wheel 32.

[0058] The hammer 36 comprises a first end 36a provided with a roller 40 cooperating with the phasing cam 34 to facilitate its reading, and a second end 36b which cooperates with a first end 38a of the phase shift spring 38. The second end 38b of the phase shift spring 38 is pivotally mounted on the upper phase shift wheel 32 by means of a pivot axis mounted integrally on said upper phase shift wheel 32.

[0059] The timepiece may also comprise a display device 42 shown in FIG. 6, arranged to display the difference between local time HT and GMT.

[0060] Said display device 42 comprises a fixed dial 44, an indicator 46 mounted fixedly on the dial 44 and arranged to define the local time HT as a reference, and a third display member 48 mounted to rotate relative to said dial 44 in order to be able to move it, the position of the third display member 48 on the dial 44 relative to the indicator 46 indicating the difference between the local time HT and the GMT time. In operating mode, the third display member 48 is fixed. The dial 44 comprises graduations to indicate, by means of the third display member 48, the time difference between the local time HT and the GMT time. For example, the fixed dial 44 can be graduated from 0 to -12 on one side of the 0 indicated by the fixed indicator 46 and from 0 to +12 on the other side of the 0, making it possible to directly indicate to the user the time difference from Oh to 12h in one direction or the other by means of the third display member 48.In the example of Figure 6, the third display member 48 indicates an offset of - 11 hours on the dial 44 informing the user that the local time HT is 11 hours ahead of GMT.

[0061] Said display device 42 may also comprise a day / night disc 50 comprising two angular sectors 52 and 54 extending on either side of an axis of symmetry of the disc over 180°. The disc 50 is driven clockwise by the clockwork movement of the timepiece by one revolution per 24 hours. The position of the indicator 46 and the third display member 48 above the day / night disc 50 makes it possible to indicate at a given instant whether it is day or night respectively at local time HT and at GMT time.

[0062] Such a display device 42 is described in the applicant's application CH 2021 / 0070690.

[0063] To enable correction of the difference between the local time HT and the GMT time displayed during a correction of the second display member 4 of the GMT time, i.e. a correction of the third display member 48, independently of the local time HT, the display device 42, and more particularly said third display member 48, is kinematically linked to the trigger mechanism, as will be detailed below, in order to be able to be corrected by the correction mechanism 6 of the second display member 4.

[0064] The correction mechanism 6 of the second display member 4 comprises a trigger mechanism 56.

[0065] With reference to figures 1, and 7 to 10, said trigger mechanism 56 comprises a control device comprising a control member 58 intended to be accessible to a user, via for example a push button, to perform the function of the associated clock mechanism, here the function of correcting the second display member 4 of the GMT time and, if present, of the third display member 48 indicating the time difference between the local time HT and the GMT time, independently of the local time HT.

[0066] Advantageously, the control member 58 is a control rocker pivotally mounted on the frame and equipped with its return spring 60. The control rocker is set in motion by the user via, for example, a push button (not shown).

[0067] The trigger mechanism 56 also comprises a trigger wheel set 62, visible in particular in FIG. 7, arranged to be mounted so as to be able to rotate on the frame of the part. The trigger wheel set 62 comprises a trigger member 64 intended to be driven in rotation, directly or indirectly, by the control member 58, a trigger pilot wheel 66 kinematically linked to the trigger member 64 and integral in rotation with a first end of an elastic member 68, and a trigger output wheel 70 integral in rotation with a second end of the elastic member 68 and kinematically linked to an element of the watch mechanism to be triggered. Advantageously, the elastic member is a spiral spring.

[0068] In the example described, the trigger output wheel 70 is kinematically linked to the wheel constituting the input 18 of the differential gear 10 to allow the correction of the second display member 4 of the time GMT independently of the local time HT. If the third display member 48 is present, the trigger output wheel 70 is also kinematically linked to said third display member 48 to allow the correction of said third display member 48 at the same time as the correction of the second display member 4.

[0069] The trigger mechanism 56 also comprises a pilot device 72, shown in FIGS. 9 and 10, kinematically linked to the trigger pilot wheel 66 and arranged to block or release the trigger output wheel 70 depending on the rotation of said trigger pilot wheel 66.

[0070] Advantageously, the control device 72 comprises a control pinion 74 mounted freely rotatable on the frame and arranged to be kinematically linked to the trigger control wheel 66.

[0071] The control device 72 also comprises a control cam 76 secured to said control pinion 74 and constituting an eccentric member relative to the control pinion 74, more particularly relative to its axis of rotation. The control device 72 further comprises a control fork 78 mounted to rotate on the frame about an axis 80 and arranged to cooperate with said control cam 76 in order to be pivoted alternately in one direction or the other.

[0072] The control device 72 also comprises a control anchor 82 mounted to rotate on the axis 80 and arranged to be integral in rotation with the control fork 78 by means, for example, of a tenon 84 integral with the control anchor 82 and the control fork 78. Said control anchor 82 comprises two arms 82a, 82b arranged to be able to alternately block a blocking finger 86 integral in rotation with a blocking pinion 88 mounted free in rotation on the frame and arranged to be kinematically linked to the trigger output wheel 70. When the blocking finger 86 is blocked by one of the arms 82a, 82b, the blocking pinion 88 is blocked and prevents the rotation of the trigger output wheel 70.When the pilot anchor 82 pivots, releasing the locking finger 86, the locking pinion 88 is free to rotate and releases the trigger output wheel 70 to allow its rotation under the effect of the energy released by the elastic member 68.

[0073] Advantageously, the pilot pinion 74, the locking finger 86 and the locking pinion 88 are aligned along the same axis.

[0074] Advantageously, the trigger member 64 is a rotary trigger cam. Preferably, said trigger cam 64 has n branches 64a defining n peaks and n troughs. For this purpose, each of the branches 64a comprises a rising edge and a falling edge. In the example shown, the trigger cam comprises four branches 64a.

[0075] Advantageously, the trigger cam 64 is coaxial and integral in rotation with the trigger pilot wheel 66. The trigger cam 64 can be made integral with the trigger pilot wheel 66 by means, for example, of a cylindrical counterform 90 integral with the trigger pilot wheel 66 and coaxial with the trigger cam 64 and the trigger pilot wheel 66. The counterform 90 comprises four lugs 90a, as shown in FIG. 8 and is arranged to fit into a corresponding opening 64b provided in the center of the trigger cam 64, the lugs 90a bearing against the inner wall of the opening 64b.

[0076] The trigger output wheel 70 is mounted to rotate freely on the counterform 90, between the trigger cam 64 and the trigger pilot wheel 66, coaxially with said trigger cam 64 and said trigger pilot wheel 66. The spiral spring 68 is positioned between the trigger output wheel 70 and the trigger pilot wheel 66, one of its ends being secured to the trigger output wheel 70, its other end being secured to the trigger pilot wheel 66.

[0077] Advantageously, the control member 58, here the control rocker, is arranged to exert on said trigger cam 64, directly or indirectly, a first rotational driving force making it possible to initiate the rotation of said trigger cam 64. For this purpose, the control rocker advantageously has, on the side of its end which cooperates with the trigger cam 64, an arm 92, visible in FIGS. 1 and 11 in particular, pivotally mounted on said control rocker 58 and terminated at its free end by a hook 92a (see Figure 11). Said hook 92a is arranged to rotate said trigger cam 64, for example by gripping a tip of one of its branches 64a. As will be seen below, the hook 92a makes it possible more particularly to exert on said trigger cam 64 a first driving force making it possible to initiate the rotation of said trigger cam 64.

[0078] Advantageously, the trigger mechanism 56 also comprises a trigger rocker 94 pivotally mounted on the frame, and arranged to read the trigger cam 64 via a reading member. The trigger cam 64 and the trigger rocker 94 are arranged to allow the trigger rocker 94, when reading said trigger cam 64 driven in rotation initiated by the control member 58, here the control rocker:

[0079] - to store energy by exerting on said trigger cam 64 a second rotational driving force which is antagonistic as long as the first rotational driving force is less than a predetermined threshold and,

[0080] - to restore, beyond said predetermined threshold, said energy so that said second rotational driving force exerted on the trigger cam 64 makes it possible to complete the rotation of the trigger cam 64 by causing a rotation of the trigger pilot wheel 66 such that the pilot device 72, blocking the trigger output wheel 70 until then, releases said trigger output wheel 70 to perform said function. For this purpose, the trigger rocker is advantageously provided with a return spring 96 arranged to, when the trigger rocker 94 reads the rotating trigger cam 64, store and restore said energy allowing said trigger rocker 94 to exert said second rotational driving force on the trigger cam 64.

[0081] More particularly, the return spring 96 is arranged to store said energy when the trigger lever 94 reads a rising edge of a branch 64a' of the rotating trigger cam, and to, when the trigger lever 94 reads the falling edge of the branch 64a' of the rotating trigger cam 64, restore this energy allowing the trigger lever 94 to exert the second rotational driving force on said trigger cam 64.

[0082] For this purpose, the trigger rocker 94 advantageously has, on the side of its end which cooperates with the trigger cam 64, an arm 98, visible in figures 1 and 11 in particular, having at its free end a roller 100 (see figure 11) constituting the reading member arranged to read the trigger cam 64 by following the rising edge and the falling edge of each branch 64a.

[0083] The various elements of the trigger mechanism 56 are dimensioned and configured so that the function linked to the watch mechanism is only performed when said control lever 58 exerts on the trigger cam 64 a first necessary and sufficient rotational driving force at least equal to a predetermined threshold set by the construction of the elements of the trigger mechanism 56, and in particular dependent on the force of the return spring 96. The rotation of said trigger cam 64 is such that, when the trigger lever 94 reads a rising edge of one of the branches 64a of the rotating trigger cam 64, the return spring 96 of the trigger lever 94 is armed and stores energy.This energy is then restored when the trigger rocker 94 reads a falling edge of said branch 64a of the rotating trigger cam 64, thus allowing the trigger rocker 94 to exert a second rotational driving force on the trigger cam 64 to drive the trigger cam 64 in a complementary rotation phase with the trigger pilot wheel 66 associated with it. By this means, the pilot device 72 which blocked the trigger output wheel 70 is actuated so as to release said trigger output wheel 70 and allow its rotation, driven by the energy released by the elastic member 68, in order to perform the function.

[0084] In more specific connection with the correction mechanism 6 of the second display member 4 of the GMT time and, if present, of the third display member 48 indicating the time difference between the local time HT and the GMT time, independently of the local time HT, described above, the operation of the correction mechanism 6 and its trigger mechanism 56 is described below with reference to FIGS. 11 to 14.

[0085] During normal operation of the timepiece, the trigger mechanism 56 is in the rest state shown in Figure 11. In this initial rest state, the trigger mechanism 56 is such that the roller 100 of the trigger lever 98 is positioned in a stable rest position in a hollow at the foot of a rising flank towards the top of one of the branches 64a' of the trigger cam 64. The hook 92a of the control lever is preferably positioned at the top of one of the branches 64a of the trigger cam 64. The locking finger 86 is locked by the arm 82a of the pilot anchor 82 of the pilot device 72 so that the trigger output wheel 70 is locked in rotation, retained by the locking pinion 88.

[0086] The driving member of the timepiece drives the cannon pinion 1 which in turn drives the minute display member as well as the hour wheel, via the timer wheel set 2. The hour wheel drives the first local time display member HT in a standard manner. The timer wheel 2a also drives the lower phase shift wheel 28 of the phase shift wheel set 8, as well as the upper phase shift wheel 32, then coupled to the lower phase shift wheel 28 by the phasing cam 34 / hammer 36 assembly. The second GMT time display member 4 is then driven in a synchronized manner with the first local time display member HT.In this state, the lower phase shift wheel 28 continuously drives the lower differential wheel 16 of the differential gear 10 via two stepped idler pinions 30a, 30b and the upper phase shift wheel 32 continuously drives the upper differential wheel 14 of the differential gear 10. The input wheel 18 of the differential gear 10 being blocked by the trigger mechanism 56, the differential block 20 does not rotate. The idler pinions 24a and 24b are also continuously driven via the pinions 26a, 26b secured to their respective half-axis 22a, 22b. The trigger output wheel 70 being blocked, the third display member 48 remains fixed.

[0087] When correcting the second display member 4 and, if present, the third display member 48, independently of the local time HT, the user actuates the control member 58, here the control rocker, via for example a push button of the control device according to a force F represented in FIG. 12 by an arrow. When the control rocker pivots, its hook 92a grips the top of the branch 64a of the trigger cam 64 to initiate and rotate said trigger cam 64. During this rotation of the trigger cam 64, the roller 100 of the trigger rocker 94 reads said trigger cam 64 by following the rising edge of another branch 64a' of the trigger cam 64, which has the effect of arming the return spring 96 of the trigger rocker 94.At the same time, the rotation of the trigger cam 64 causes the rotation of the trigger pilot wheel 66 which is integral with it, which has the effect of arming the trigger spring 68 which can be potentially pre-armed, the trigger output wheel 70 still being blocked by the pilot device 72. Indeed, during this arming phase, the elements of the trigger mechanism 56 are dimensioned so that the rotation of the trigger pilot wheel 66 causes a rotation of the pilot pinion 74 and its pilot cam 76, and therefore of the pilot fork 78 and the pilot anchor 82 but not sufficiently for the arm 82a to release the locking finger 86, as shown in Figure 12.

[0088] During the next triggering phase shown in Figure 13, the roller 100 of the trigger lever 94 continues to read the trigger cam 64, which continues its rotation, passing the top of the branch 64a' and following the descending edge of said branch 64a' of the trigger cam 64, so that the return spring 96 of the trigger lever 94 redistributes the stored energy to the trigger lever 94 which becomes the motor of the trigger cam 64. As the rotation of the trigger cam 64 continues, the trigger spring 68 continues to be armed.

[0089] The elements of the trigger mechanism 56 are dimensioned so that when the roller 100 descends along the flank of the trigger cam 64, the rotation of said trigger cam 64 and the trigger pilot wheel 66 has caused sufficient rotation of the pilot pinion 74, its pilot cam 76, the pilot fork 78 and the pilot anchor 82 so that the arm 82a has pivoted sufficiently to disengage from the locking finger 86 and release it, as shown in FIG. 13.

[0090] With the locking finger 86 released, the locking pinion 88 is free to pivot so that it no longer blocks the release output wheel 70 which is released. Said release output wheel 70 is then driven into rotation under the effect of the energy stored by the release spring 68.

[0091] When the third display member 48 indicating the time difference between the local time HT and the GMT time is present, the rotation of the released trigger output wheel 70 directly drives the third display member 48 kinematically linked to said trigger output wheel 70 for its correction, in order to move the third display member 48 in steps until the desired time difference is displayed on the dial 44.

[0092] In parallel, the rotation of the released trigger output wheel 70 causes the rotation of the input wheel 18 of the differential gear 10 to carry out the correction of the second display member 4.

[0093] For this purpose, the rotational drive of the input wheel 18 of the differential gear 10 causes the rotation of the differential block 20 so that the idler pinion 24a, respectively 24b, causes the rotation of the half-axis 22a, respectively 22b, via the pinion 26a, respectively 26b, and therefore the rotation of the upper differential wheel set 14 and the lower differential wheel set 16 respectively. The lower differential wheel set 16 then constitutes a first output of the differential gear 10 kinematically linked to the lower phase shift wheel 28 of the phase shift wheel set 12 and to the timer wheel set 2. The rotation of the lower differential wheel set 16 makes it possible to take up the gear play of the differential gear 10 up to the cannon 1 and then be blocked.This blocking forces the upper differential wheel 14 to drive the upper phase shift wheel 32 by constituting the second output of the differential gear 10 kinematically linked to the upper phase shift wheel 32 of the phase shift wheel 12. The rotation of the upper differential wheel causes the upper phase shift wheel 32 to be disengaged from the lower phase shift wheel 28 by means of the phasing cam 34 / hammer 36 assembly, the rotation of the upper phase shift wheel 32 causing the rotation of the second display member 4 for its correction.

[0094] The differential block 20 rotates in steps of an angle defined by the trigger cam 64 and its gear ratio with the trigger output wheel 70. These steps define the offset of the third display member 48 indicating here the time difference between the local time HT and the GMT time, and the phase shift angle of the phase shift wheel 12 to correct the second display member 4 of the GMT time. In the phase shift wheel 12, the correction angle of the upper phase shift wheel 32 corresponds to a step of the phasing cam 34.

[0095] Thus, the correction mechanism 6 makes it possible to carry out a correction in steps of the second display member 4 of the GMT time, and simultaneously of the third display member 48 if it is present, independently of the local time HT, that is to say independently of the first display member of the local time HT and of the display member of the minutes.

[0096] The phasing cam 34 / hammer 36 assembly of the phase shifting wheel set 12 makes it possible to precisely reposition the second display member 4 of the GMT time relative to the position of the first display member after each correction of said second display member 4. Indeed, by leaving a hollow of the phasing cam 34 to reposition itself precisely in the following hollow, the roller 40 of the hammer 36 mounted on the upper phase shifting wheel 32 of the phase shifting wheel set 12 is positioned so that the position of said second display member 4 of the GMT time remains perfectly synchronized with the position of the first display member of the local time HT relative to the position of the minute display member.

[0097] The phase shift wheel 12 also advantageously makes it possible to take up the play in the differential gear 10 to avoid too much play between the timer wheel 2 and the indication driven by the upper phase shift wheel 32, here the second GMT time display member 4. In addition, since the indication is driven by the upper phase shift wheel 32 of the phase shift wheel 12, the latter also makes it possible to avoid continuously passing torque into the differential gear 10 to drive said indication.

[0098] After unlocking the locking finger 86, the trigger rocker 94 continues its repositioning in the hollow of the trigger cam 64. In order to increase the energy given for unlocking the phase shift of the phase shifting wheel 12, it could be possible to provide during this triggering phase a rigid connection (with an eyelet and a pin for example) between the triggering pilot wheel 66 and the triggering output wheel 70.

[0099] In parallel during this triggering phase, the control rocker finishes its movement (still under the effect of the user) until it comes against a stop (not illustrated) to no longer give energy to the trigger cam 64.

[0100] During the next blocking phase shown in Figure 14, the blocking finger 86, which pivoted with the blocking pinion 88 during the correction phase, comes into abutment on the other arm 82b of the pilot anchor 82 once the phase shift has been achieved. The trigger output wheel 70 is again blocked. The blocking of the blocking finger 86 by the pilot anchor 82 is carried out alternately by the arm 82a and the arm 82b at each sufficient actuation of the control member 58 for the performance of the associated function.

[0101] When the user releases the push button of the control member 58, here the control rocker, the hook 92a of the control rocker repositions itself in the hollow behind the branch 64a of the trigger cam 64 (namely downstream of the branch 64a), ready to grasp the top of the next branch 64a', as shown in Figure 14. The roller 100 of the trigger rocker 94 returns to its stable rest position in the hollow behind the branch 64a'.

[0102] It is easily understood that if the user does not apply sufficient force to the control member 58, there is no correction, the correction mechanism not being triggered. Indeed, as described above, the different elements of the trigger mechanism 56 are dimensioned and configured so that a first force, driving the control rocker 58 in rotation exerted on the trigger cam 64, greater than or equal to the predetermined threshold, generates a second force driving the control rocker 94 in rotation.This second driving force makes it possible to obtain a necessary and sufficient rotation of said trigger cam 64 (and therefore of the associated trigger pilot wheel 66, of the pilot pinion 74, of its pilot cam 76, of the pilot fork 78 and of the pilot anchor 82) to release the locking finger 86 and thus the trigger output wheel 70 in order to carry out the function, here the correction by steps of the second display member 4 of the GMT time, and of the third display member 48 if it is present, independently of the local time HT.

[0103] If the force applied by the user is too weak, the first rotational driving force exerted by the control rocker will be less than the predetermined threshold of the driving force causing a necessary and sufficient rotation of said trigger cam 64 to release the locking finger 86, so that the rotation of the pilot anchor 82 will not be sufficient to release the locking finger 86. Consequently, the trigger output wheel 70 will remain blocked and the function cannot be performed.

[0104] If the force applied by the user is sufficient for the first rotational drive force exerted by the control lever to be greater than or equal to the predetermined threshold of the necessary and sufficient rotational drive force, the rotation of the trigger cam 64 will be sufficient for the pilot anchor 82 to pivot sufficiently to release the blocking finger 86 and thus the trigger output wheel 70 so as to perform the function. The trigger mechanism of the invention is therefore of the "all or nothing" type by allowing the rotation of the trigger output wheel 70 which will allow the watch mechanism to perform its function only if the force applied to the control member 58 is sufficient to cause a rotation of the trigger cam 64 and therefore the rotation of the trigger pilot wheel 66 necessary for the actuation of the pilot device 72 to release the trigger output wheel 70.

[0105] In addition, the trigger mechanism 56 according to the invention advantageously constitutes an intermediate device which makes it possible to manage the force applied to the control member 58 by standardizing the torque to be transmitted to the watch mechanism to perform its function. Thus, the watch mechanism receives from the trigger output wheel 70 a constant torque linked to the characteristics of the elastic member 68, independent of the force applied to the control member 58 by the user. In particular, even if the user applies a very significant force to the push button, he cannot give momentum to said watch mechanism.

[0106] Thus, the trigger mechanism according to the present invention makes it possible to manage both the application to the control member 58 of an insufficient force, by being of the “all or nothing” type, and of an excessive force, by making it possible to carry out the “constant force” function.

[0107] The advantage of the trigger mechanism according to the present invention is that the user provides the necessary impulse to trigger the mechanism and that it is the said mechanism which then performs the function itself. Thus, the user cannot provide momentum to the correction mechanism, even if he presses the push button strongly.

[0108] In addition, the use of the rotating locking finger 86 between two stops constituted by the arms 82a, 82b of the pilot anchor 82 and the locking pinion 88 secured to the locking finger 86 makes it possible to precisely control the angles of rotation of the correction gear train when correcting the second display member 4 of the GMT time, and the third display member 48 if it is present, independently of the local time HT. This makes it possible to reinforce the precision of the repositioning of the second display member 4 of the GMT time and the third display member 48 if it is present, after their correction.

[0109] The example described above is related to a correction mechanism of a display member linked to a GMT time. It is obvious that the trigger mechanism according to the invention can be used in a watch mechanism arranged to perform another function, said watch mechanism being for example a mechanical animation arranged to be triggered on demand by the user and controlled by the upper phase shift wheel 32 of the phase shift wheel set 12.

Claims

Claims 1. Trigger mechanism (56) of a clockwork mechanism arranged to perform a function, said trigger mechanism (56) comprising: - a control device comprising a control member (58), - a trigger wheel set (62) mounted to rotate and comprising a trigger member intended to be driven in rotation by the control member (58), a trigger pilot wheel (66) kinematically linked to the trigger member and integral in rotation with a first end of an elastic member (68), and a trigger output wheel (70) integral in rotation with a second end of the elastic member (68) and kinematically linked to an element of the watch mechanism, said trigger member being a rotating trigger cam (64), - a control device (72) kinematically linked to the trigger control wheel (66) and arranged to block or release the trigger output wheel (70) depending on the rotation of said trigger control wheel (66), the control member being arranged to exert on said trigger cam (64) a first rotational driving force, characterized in that said trigger mechanism (56) comprises a trigger rocker (94) arranged to read the trigger cam (64), and in that said trigger cam (64) and the trigger rocker (94) are arranged to allow said trigger rocker (94), when reading said trigger cam (64) driven in rotation by the control member: - to store energy by exerting on said trigger cam (64) a second rotational driving force which is antagonistic as long as the first rotational driving force is less than a predetermined threshold and, - to restore, beyond said predetermined threshold, said energy so that said second rotational driving force exerted on the trigger cam (64) causes the trigger pilot wheel (66) to rotate such that the pilot device (72), previously blocking the trigger output wheel (70), releases said trigger output wheel (70) to perform said function.

2. Trigger mechanism (56) according to claim 1, characterized in that the trigger rocker (94) is provided with a return spring (96) arranged to, when the trigger rocker (94) reads the rotating trigger cam (64), store and restore said energy allowing said trigger rocker (94) to exert on the trigger cam (64) the second rotational driving force.

3. Trigger mechanism (56) according to one of the preceding claims, characterized in that the trigger cam (64) has n branches (64a, 64a') defining n peaks and n troughs, each branch (64a, 64a') having a rising edge and a falling edge.

4. Trigger mechanism (56) according to claims 2 and 3, characterized in that the return spring (96) of the trigger rocker (94) is arranged to store said energy when the trigger rocker (94) reads a rising edge of the rotating trigger cam (64), and to, when the trigger rocker (94) reads a falling edge of the rotating trigger cam (64), restore said energy allowing the trigger rocker (94) to exert on the trigger cam (64) the second rotational driving force.

5. Trigger mechanism (56) according to one of claims 3 and 4, characterized in that, to exert the first rotational driving force on the trigger cam (64), the control member is a control rocker (58) which has a hook (92a) arranged to rotate said trigger cam (64), preferably by gripping a top of one of its branches (64a).

6. Trigger mechanism (56) according to one of the preceding claims, characterized in that the trigger cam (64) is coaxial and integral in rotation with the trigger control wheel (66).

7. Trigger mechanism (56) according to one of the preceding claims, characterized in that the trigger rocker (94) comprises a roller (100) arranged to read the trigger cam (64).

8. Trigger mechanism (56) according to one of the preceding claims, characterized in that the elastic member (68) is a spiral spring.

9. Trigger mechanism (56) according to one of the preceding claims, characterized in that the pilot device (72) comprises a pilot pinion (74) free to rotate and kinematically linked to the trigger pilot wheel (66), a pilot cam (76) integral with said pilot pinion (74), a pilot fork (78) mounted so as to be able to rotate and arranged to cooperate with the pilot cam (76), a pilot anchor (82) integral in rotation with the pilot fork (78), said pilot anchor (82) comprising two arms (82a, 82b) arranged to be able to alternately block a locking finger (86) integral in rotation with a locking pinion (88) arranged to be kinematically linked to the trigger output wheel (70).

10. Trigger mechanism (56) according to one of the preceding claims, characterized in that the clockwork mechanism is a correction mechanism (6) of at least one display member (4).

11. Timepiece comprising a watch mechanism arranged to perform a function and a trigger mechanism (56) for said watch mechanism according to one of claims 1 to 10.

12. Timepiece according to claim 11 comprising at least a first display member arranged to display a local time HT, a drive wheel (2) of the first display member, a second display member (4) arranged to be able to display a GMT time of a time zone different from that of the local time HT, a drive mechanism (8) of the second display member (4), and a correction mechanism (6) of the second display member (4) arranged to be able to correct the GMT time independently of the local time HT, characterized in that said correction mechanism (6) comprises said trigger mechanism (56).

13. Timepiece according to claim 12, characterized in that the drive mechanism (8) of the second display member (4) comprises a differential gear (10) which comprises at least one upper differential wheel set (14) arranged to be kinematically connected to the second display member (4), a lower differential wheel set (16) arranged to be kinematically connected to the drive wheel set (2) of the first display member, and an input (18) arranged to be kinematically connected to the correction mechanism (6) of the second display member (4).

14. Timepiece according to claim 13, characterized in that the differential gear (10) comprises a differential block (20) mounted freely in rotation on two half-axes (22a, 22b) secured respectively to the upper differential wheel set (14) and to the lower differential wheel set (16), said differential block (20) carrying at least a first idler pinion (24a) arranged to mesh with a pinion (26a) secured to the half-axe (22a) of the upper differential wheel set (14) and a second idler pinion (24b) arranged to mesh with a pinion (26b) secured to the half-axe (22b) of the lower differential wheel set (16), said differential block (20) also being secured to a wheel constituting the input (18) of the differential gear (10) arranged to be kinematically linked to the release output wheel (70) of the release mechanism (56).

15. Timepiece according to one of claims 13 and 14, characterized in that the drive mechanism (8) of the second display member (4) comprises a phase shift wheel (12) comprising a lower phase shift wheel (28) arranged to be kinematically linked to the drive wheel (2) of the first display member and to be linked kinematically to the lower differential wheel (16), and an upper phase shift wheel (32) arranged to drive said second display member (4) and to be kinematically linked to the upper differential wheel (14), said upper phase shift wheel (32) being kinematically linked to the lower phase shift wheel (28) in a disengageable manner so that said upper phase shift wheel (32) is uncoupled from the lower phase shift wheel (28) during a correction of the GMT time independently of the local time HT by the correction mechanism (6) while allowing, after correction, a repositioning of the second display member (4) synchronized with the positioning of the first display member.

16. Timepiece according to claim 15, characterized in that the phase shifting wheel (12) comprises a phase cam (34) secured to the lower phase shifting wheel (28) and a hammer (36) provided with a phase shifting spring (38) carried by the upper phase shifting wheel (32), said hammer (36) being arranged to cooperate with said phase cam (34).

17. Timepiece according to one of claims 12 to 16, characterized in that it comprises a display device (42) arranged to display the difference between the local time HT and the GMT time, said display device (42) being kinematically linked to the trigger output wheel (70) of the trigger mechanism (56) so as to be able to be corrected during a correction of the second display member (4) of the GMT time, independently of the local time HT, by the correction mechanism (6) of the second display member (4).

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