Driving mechanism for a timepiece

Abstract

The present invention relates to an actuation mechanism for a timepiece comprising a pivoting rocker (1), the rocker comprising a flexible actuating arm (2) having an active end (23) arranged to cooperate with the teeth of a moving part (4) when the rocker (1) pivots in a first direction. The actuation mechanism further comprises a fixed stop (6) for mounting on a fixed part of the timepiece. The flexible actuating arm (2) of the rocker (1) includes a rigid portion (22) having a contact area (221) arranged to cooperate with the fixed stop (6) such that the contact area (221) bears against the fixed stop (6) when the rocker (1) pivots in the first direction and the active end (23) cooperates with a tooth of the moving part (4).

Description

[0001] The present invention relates to an actuating mechanism for a timepiece comprising in particular a pivotally mounted lever arranged to actuate a wheel set, in particular a star, when the lever pivots in a first direction while the lever does not actuate said star when it pivots in the other direction. The present invention relates in particular to a corrector or correction mechanism, namely an actuating mechanism designed to be controlled by a user to correct an indication displayed by the timepiece.

[0002] A corrector or correction mechanism is an actuating mechanism comprising a small button which is most often embedded in the case of a timepiece, and which is arranged to cooperate with a mobile, generally a star, to correct one of the indications displayed by the timepiece. The user of the watch or a watchmaker can operate the corrector either with the finger or with a special tool called a "push button". In general, the corrector is in the form of a lever pivotally mounted around an axis, connected to a button which can be actuated from outside the timepiece for its pivoting and subjected to the action of a return spring to return the lever to its rest position. The lever also comprises a beak which is arranged to cooperate with the teeth of a mobile connected to an indicator member. The position of the mobile is generally indexed by a jump spring.

[0003] The use of correctors similar to the one described above is not without problems. First of all, remember that it is generally not recommended to use the correctors of a calendar watch between 8:30 p.m. and 3:30 a.m. Indeed, the incrementation of the date indicators by the movement of a calendar watch usually takes place during a period that can last several hours and is centered around midnight (dragging mechanism). Under these conditions, if a user decides to activate the corrector of a date indicator during this period, the opposing forces exerted by the calendar drive mechanism, on the one hand, and by the corrector, on the other hand, risk causing the breakage of a part of the mechanism or a phase shift.

[0004] To avoid this kind of problem, the calendar of some well-known complication watches is equipped with one-way drive organs. These drive organs, which most often operate like pawls, are arranged to automatically disengage when a user activates the corrector of the star they are in the process of incrementing. One-way drive organs do indeed prevent breakage when a user activates a corrector around midnight. However, their implementation also comes with a number of drawbacks. In particular, disengaging a drive organ causes it to de-index from the toothing with which it cooperates.

[0005] Furthermore, if the star cannot return to its original position at all, whether it is permanently blocked or only at certain times, then the corrector cannot return to its original position. Indeed, to return to its original position, the corrector must push the star it has just incremented back. This leaves a problem, as it is understandable that a situation in which the user can only make one correction is undesirable.

[0006] To remedy this problem, attempts were made to make the beak or active end of the corrector cooperating with the mobile to be driven retractable.

[0007] A first solution consists of equipping the beak or the active end of the corrector's rocker with a ratchet designed to allow the corrector to return backwards. This solution, although simple, has the disadvantage of being cumbersome, particularly in height.

[0008] Another solution consists of using an elastic active end of the corrector. For example, patent document EP 3 489 766 A1 describes a corrector whose actuating arm separates into two branches, one of the two branches being flexible and the other rigid. One end of the flexible branch is arranged to push a tooth of a star wheel when the actuating arm pivots from its rest position to its tilted position. The trajectory of the rigid branch, for its part, always remains outside the trajectory of the teeth of the star wheel. The flexible branch has a support zone which is intended to come to bear against a support surface presented by the rigid branch, when the end of the flexible branch pushes the tooth of the star wheel. This corrector of the prior art has the advantage of being able to return to the rest position without pushing the star wheel backwards.However, its long, angled flexible arm presents risks of torsional deformation when subjected to torque. In addition, given the shape of the flexible arm, any twist, even slight, causes an upward or downward shift of the end of the flexible arm which is designed to push a tooth of the star, so that this end risks passing above or below the teeth of the star, thus compromising the correct operation of the corrector. Finally, the rocker of this corrector with its arm separated into two arms is relatively bulky and complex to machine.

[0009] Document EP 3 734 372 describes an actuating device comprising a rocker with a pawl and guide means for positioning the pawl. The guide means comprise an opening fixed on the frame and an orienting element both cooperating with a guide fixed on the pawl.

[0010] Document WO 2012 / 127054 describes an instantaneous drive mechanism comprising a mobile and a pivoting lever comprising a spring intended to act on a retractable finger. The spring bears on a cam fixed to the frame and the retractable finger comprises an extension cooperating with a pin fixed to the frame. An aim of the present invention is therefore to overcome the drawbacks of the correctors of the prior art described below. In particular, an aim of the present invention is to provide an actuating mechanism, in particular a correction mechanism, comprising, among other things, a rocker which allows reliable actuation of a mobile when the rocker pivots in a first direction as well as the pivoting of the rocker in a second direction without driving the mobile and this, at any time, and without limiting the number of successive actuations of the mechanism.Another object of the present invention is to provide an actuating mechanism, in particular a correction mechanism, which is robust, efficient, space-saving and easy to produce.

[0011] The present invention relates to an actuating mechanism according to claim 1.

[0012] The attached figures illustrate schematically and by way of example an embodiment of the actuating mechanism according to the invention.

[0013] THE figures 1 to 5 are schematic plan views of a corrector which corresponds to a particular embodiment of the actuating mechanism of the invention, the corrector being shown at four successive times during its pivoting from its rest position ( figure 1 ) towards its tilted position.

[0014] There figure 6 is a schematic plan view of the corrector of the figures 1 to 5at a particular moment of its return to the rest position after having activated the rotating star.

[0015] Schematic plan views of the figures 1 to 6attached illustrate an actuating mechanism for a timepiece according to one embodiment of the invention. The actuating mechanism shown in the figures is intended to equip a movement of a timepiece and is designed to be controlled by a user to correct an indication displayed by the timepiece. Such an actuating mechanism controllable from outside the timepiece is known as a “corrector” or “correction mechanism”. It is important to note, however, that not all actuating mechanisms according to the invention are correctors. For example, there are also actuating mechanisms that perform the function of an automatic drive member for a display mechanism (a calendar mechanism for example) driven by the movement of a timepiece.

[0016] The corrector represented in the figures 1 to 6includes a control member that can be operated manually from outside the timepiece (control member not shown, symbolized by an arrow in the figures 2 to 4 ) as well as a rocker 1 comprising an arm 2 and subject to the action of a return spring 3 (visible only on the figures 1 And 6 ). The actuating mechanism further comprises a mobile to be actuated. In the illustrated embodiment, this is a star 4 which has seven teeth. In the present example, the star 4 could for example carry a member indicating the days of the week (not shown). The position of the star 4 is indexed by a jumper spring 5 (visible only on the figures 1 And 6 ) which is recalled against the teeth of star 4.

[0017] The rocker 1 of the corrector is pivotally mounted about an axis A and has a bulge 11 with which the control member is arranged to cooperate. The arm 2 of the rocker 1 is flexible and comprises an elastic part 21 and a rigid part which is constituted by a rigid shoe 22. The junction between the elastic part 21 and the shoe 22 forms an elbow preferably having an acute angle. The tip 23 of the elbow forms the active end of the rocker 1 and is arranged to push back a tooth of the star 4 when the rocker 1 pivots from its rest position (shown in the figure 1 ) towards its tilted position (rotates counterclockwise in the figures).

[0018] According to the invention, the corrector further comprises a fixed stop 6 mounted on a fixed part of the movement of the timepiece comprising the corrector. This fixed stop may have any suitable shape such as a stud, a pin or any element having a rigid and fixed bearing surface.

[0019] The shoe 22 of the arm 2 of the lever 1 comprises a support zone 221 which comes to bear against the fixed stop 6 when the tip 23 of the arm 2 pushes a tooth of the star 4 against the action of the jumper spring 5. Indeed, in this situation, the tooth of the star 4 exerts a reaction force on the tip 23. The arm 2 of the lever 1 and in particular the elastic part 21 are arranged so that said reaction force causes the bending of the elastic part 21 of the arm 2. Within the limit of small deformations, the bending of the elastic part 21 of the arm 2 results in a rotation of the end of the elastic part 21 as well as of the shoe 22 (in a direction corresponding to the clockwise direction in the figures). This rotation causes the portion of the edge of the shoe 22 which is located opposite the fixed stop 6, in other words, the backing zone 221, to come into contact with this fixed stop 6, as shown in the figure 3. When the arm 2 of the rocker is in the configuration shown in the figure 3 - that is to say the support zone 221 of the shoe 22 in abutment against the fixed stop 6 - the shoe 22 cannot rotate in the clockwise direction. It will be noted that the elastic part 21 must be sufficiently flexible so that the force necessary to bring the shoe 22 into abutment against the fixed stop 6 is less than the force necessary to lift the jumper spring 5 from the star 4.

[0020] The characteristics which have just been described, concerning the corrector of the present example, allow it to have the following operation. When the corrector is in the rest position (position shown in figure 1 ) and the user operates the control member from outside the timepiece, he pivots the lever 1 against the return spring 3. By pivoting, the tip 23 of the arm 2 meets one of the teeth of the star 4. The figure 2illustrates this contact just before the deformation of the arm 2 of the rocker 1. The reaction force exerted by the tooth of the star 4 on the arm 2 causes its elastic part 21 to flex in a first direction until the support zone 221 of the shoe 22 comes to abut against the fixed stop 6. The situation then corresponds to that which is represented in the figure 3. The lever 1 continues its rotation and the arm 2 and its tip 23 now behave rigidly, which allows the lever 1 to drive the star 4 in rotation. The rotation of the star 4 causes one of the teeth to lift the jump spring 5, which thus rises until the tip of its inclined plane has crossed the top of the tooth and passed over the other slope. As soon as the inclined plane of the jump spring 5 is thus in a position to begin the descent on the opposite slope of the tooth, the force that the inclined plane exerts on the top of the tooth no longer opposes the rotation of the star 4, but on the contrary produces a torque which stresses the star 4 in the direction in which it is already driven. The disappearance of the torque which until then opposed the rotation of the star 4 allows the elastic part 21 of the arm 2 of the rocker 1 to straighten up by moving the shoe 22 away from the fixed stop 6 ( Figure 5 ).

[0021] When, after actuating the corrector, the user releases the control member, the rocker 1 of the corrector is returned towards its rest position by the spring 3. However, the passage that the tip 23 must take to return to the rest position is now blocked by the tooth of the star 4 which follows the one that the corrector has just pushed forward. In accordance with the present invention, the arm 2 of the corrector is capable of returning to the rest position, even in cases where the automatic incrementing mechanism of the star 4 blocks the rotation of the latter towards the rear. Indeed, it is possible to move the tip 23 and the shoe 22 away from the path of the teeth of the star 4 by bending the elastic part 21 of the arm 2 in a second direction as shown in the figure 6. The bending of the elastic part 21 of the arm 2 in this second direction results in a rotation of the tip 23 as well as of the shoe 22 (in a direction corresponding to the counterclockwise direction as shown in the figures). It will be understood that the pressure of the top of the tooth on the shoe 22 gradually bends the elastic part 21 of the arm 2 until the tip 23 has passed the tooth. This behavior is made possible by the fact that the force necessary to bend the arm 2 is less than the force necessary to lift the jumper spring 5 high enough for the tip of its inclined plane to cross the top of a tooth. Then, as soon as the tip 23 has passed the tooth, the elastic part 21 of the arm 2 is free to straighten and the rocker 1 can return to its rest position ( figure 1 ).

[0022] Thus, an actuation mechanism is produced, and in particular a correction mechanism which is efficient, reliable, compact, space-saving and simple to produce and which can be actuated at any time and successively, without waiting time between two actuations.

[0023] A person skilled in the art is able to determine the dimensioning of the flexible arm, its active end and the support zone which cooperates with the fixed stop so as to allow the driving of a mobile when the rocker pivots from its rest position into its tilted position and the retraction of said active end without driving the mobile when the rocker pivots from its tilted position to its rest position. Preferably, the dimensioning of the flexible arm allows retraction without increasing the angular travel necessary for the pivoting of the mobile to be actuated.

[0024] In the above embodiment, the rocker 1 drives the star 4 when it pivots from its rest position to its tilted position and does not drive the star 4 when it pivots from its tilted position to its rest position. Of course, as a variant, the mechanism could be arranged so that the rocker 1 drives the star 4 when it pivots from its tilted position to its rest position while it does not drive the star 4 when the rocker pivots from its rest position to its tilted position.

[0025] Generally, the actuating mechanism according to the invention comprises a pivotally mounted lever. The lever comprises a flexible actuating arm comprising an active end arranged to cooperate with the teeth of a mobile to be actuated when the lever pivots in a first direction. The actuating mechanism further comprises a fixed stop intended to be mounted on a fixed part of the timepiece. The actuating arm of the lever comprises a rigid portion having a support zone arranged to cooperate with the fixed stop so that the support zone comes to bear on the fixed stop when the lever pivots in the first direction and the active end cooperates with the teeth of the mobile to be actuated.

[0026] Preferably, the actuating mechanism comprises a control member manually actuable from outside the timepiece, and the lever comprises a control element arranged to cooperate with the control member to pivot the lever when the control member is actuated from outside the timepiece.

[0027] Preferably, the mobile to be actuated is subjected to the action of an elastic indexing force arranged to determine angular positions of said mobile, said elastic force being arranged to return the mobile to an indexed angular position when the mobile deviates from said indexed angular position. The actuating arm of the rocker has sufficient stiffness to enable it to push one of the teeth of the toothing of the mobile to be actuated with sufficient force to overcome the holding torque of the elastic indexing force when the backing zone of the actuating arm is pressed against the fixed stop.

[0028] Preferably, the actuating arm comprises an elastic portion, having the shape of a spring blade and a rigid heel, the heel forming an elbow with the elastic portion, the tip of said elbow forming the active end of the actuating arm.

[0029] Preferably, the flexible actuating arm is arranged to deform without driving the mobile to be actuated when the rocker pivots in a second direction opposite to the first and the active end comes into contact with a tooth of the mobile to be actuated. The actuating arm therefore has a stiffness chosen so that it can deform without overcoming the elastic indexing force of the mobile to be actuated when the rocker pivots in the second direction and the active end comes into contact with a tooth of the mobile to be actuated. IlIt is possible, depending on the arrangement of the mechanism, that the mobile to be actuated does not remain completely immobile when the rocker pivots in the second direction and that the active end comes into contact with a tooth of the mobile to be actuated. Said mobile can in fact shift or pivot slightly but never sufficiently to change its indexed angular position or to make an angular step which would cause the function controlled by the mobile to be actuated to pass.

[0030] It will further be understood that various modifications and / or improvements obvious to a person skilled in the art may be made to the embodiments which are the subject of the present description without departing from the scope of the present invention defined by the appended claims.

Claims

1. Actuating mechanism for a timepiece comprising a lever (1) mounted in a pivoting manner, the lever comprising a flexible actuating arm (2) comprising an active end (23) arranged to cooperate with the tooth arrangement of a mobile to be actuated (4) when the lever (1) pivots in a first direction, the actuating mechanism further comprising a fixed stop (6) intended to be mounted on a fixed part of the timepiece, the flexible actuating arm (2) of the lever (1) comprising a rigid portion (22) having a bearing zone (221) arranged to cooperate with the fixed stop (6) so that the bearing zone (221) comes to bear against the fixed stop (6) when the lever (1) pivots in the first direction and the active end (23) cooperates with a tooth of the tooth arrangement of the mobile to be actuated (4).

2. Actuating mechanism as claimed in the preceding claim, characterised in that it comprises a control member which can be actuated manually from outside the timepiece, and in that the lever (1) comprises a control element (11) arranged to cooperate with the control member in order to cause the lever (1) to pivot when the control member is actuated from outside the timepiece.

3. Actuating mechanism as claimed in any one of the preceding claims, characterised in that the lever (1) is subject to the action of a return spring (3) which tends to return the lever (1) to a resting position.

4. Actuating mechanism as claimed in any one of the preceding claims, characterised in that the mobile to be actuated (4) is subject to the action of an elastic indexing force (5) arranged to determine angular positions of said mobile (4), said elastic indexing force (5) being arranged to return the mobile (4) to an indexed angular position when the mobile moves away from said indexed angular position; and in that the flexible actuating arm (2) a has a level of stiffness such that • said arm cannot push one of the teeth of the tooth arrangement of the mobile to be actuated (4) with sufficient force to overcome the couple of the elastic indexing force (5) when the lever (1) pivots in the first direction and as long as the bearing zone (221) of the flexible actuating arm (2) is not being pressed against the fixed stop (6), and such that • said flexible actuating arm (2) can push one of the teeth of the tooth arrangement of the mobile to be actuated (4) with sufficient force to overcome the couple of the elastic indexing force (5) when the bearing zone (221) of the flexible actuating arm (2) is being pressed against the fixed stop (6) and the lever (1) pivots in the first direction.

5. Actuating mechanism as claimed in the preceding claim, characterised in that the flexible actuating arm (2) is arranged to be deformed without bringing about a change in angular position of the mobile to be actuated (4) when the lever (1) pivots in a second direction opposite to the first and the active end (23) comes into contact with a tooth of the mobile to be actuated (4), the flexible actuating arm (2) having a level of stiffness such that it can be deformed without overcoming the elastic indexing force (5) of the mobile to be actuated (4) when the lever (1) pivots in the second direction and the active end (23) comes into contact with a tooth of the mobile to be actuated (4).

6. Actuating mechanism as claimed in any one of the preceding claims, characterised in that the flexible actuating arm comprises an elastic portion (21), being in the form of a leaf spring, and in that said rigid portion (22) forms a bend with the elastic portion (21), the point (23) of said bend forming the active end of the actuating arm.

7. Actuating mechanism as claimed in any one of the preceding claims, characterised in that the mobile to be actuated is a star (4).

8. Actuating mechanism as claimed in the preceding claim, characterised in that the mobile to be actuated (4) is subject to the action of an elastic indexing force (5) arranged to determine angular positions of said mobile (4), said elastic indexing force (5) being arranged to return the mobile (4) to an indexed angular position when the mobile moves away from said indexed angular position; and in that a jumper spring (5) is arranged to exert said elastic indexing force.

9. Timepiece fitted with an actuating mechanism as claimed in any one of the preceding claims.

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