Timepiece mechanism with counting chain

Abstract

Method of assembling a mechanism or a clock part, characterized in that it comprises the following steps: - a step of supplying a frame (80, 81), - a step of mounting a drive wheel (20) on the frame (80, 81), - a step of mounting an hour counter (40) on the frame (80, 81), and - a step of assembling: • a wheel (30') meshing with the drive wheel and with the hour wheel, or • an epicyclic gear train (31, 32, 33, 34) meshing with the drive wheel and with the hour wheel.

Description

[0001] The invention relates to a clockwork mechanism. The invention also relates to a timepiece comprising such a mechanism. The invention further relates to a method for assembling such a mechanism.

[0002] Document EP2515186 describes the arrangement of an epicyclic gear train within a finishing gear train, with the aim of reducing the number of moving parts and thus increasing the transmission efficiency. A mainspring barrel drives this epicyclic gear train via the planet carrier(s). The planet(s) mounted on the planet carrier(s) mesh simultaneously with a first planet gear fixed to the movement frame and with a second planet gear. This second planet gear includes a wheel kinematically connected to the escapement pinion.

[0003] Document EP0195742 describes an astronomical watch comprising an epicyclic gear train that achieves the transmission ratios necessary for displaying at least one astronomical quantity. A first planet gear and the satellite carrier are driven by the main movement. The other planet gears, driven by different satellites and gears carried by the satellite carrier, enable the display of the various astronomical time quantities.

[0004] Document EP3368950 describes a countdown chronograph mechanism that reverses the direction of rotation of the chronograph seconds display depending on the chronograph display mode. Specifically, when a countdown is programmed by the user, the chronograph seconds display rotates counterclockwise. At the end of the countdown, the direction of rotation of the chronograph seconds display automatically reverses to the conventional direction. This is achieved by an epicyclic gear train arranged upstream of a clutch device that kinematically links the finishing gear train to the chronograph counting chain.This epicyclic gear train comprises a first planetary gear driven by the finishing gear train, a second planetary gear designed to drive the chronograph seconds hand via a clutch mechanism, and a satellite carrier including a satellite that meshes simultaneously with the planetary gears. The satellite carrier is designed to be stopped by a countdown mechanism depending on the chronograph display mode. In other words, the direction of rotation of the chronograph seconds display is determined by the rotation of the satellite carrier.

[0005] Document EP0772104 discloses a chronograph counter chain architecture. This counter chain connects a chronograph hour counter wheel to a chronograph minute counter wheel. It is driven at one step per minute by a finger within a chronograph clutch wheel. This architecture employs very few wheels, resulting in high efficiency compared to known state-of-the-art counter chains while maintaining a relatively small footprint. Furthermore, it also results in minimal backlash, which can be controlled by a single indexing device for the entire counter chain.

[0006] For reasons of performance and chronometric precision, chronograph counter chains are generally linked to the seconds wheel of the main movement's finishing gear train via a clutch mechanism. Starting with the seconds wheel, which completes one revolution per minute, the required gear ratio to achieve a 12-hour display (one revolution every 12 hours) is 720, and 1440 for a 24-hour display (one revolution every 24 hours).

[0007] To achieve such a high gear ratio, numerous moving parts must be arranged in the counting chain, which adds considerable bulk to a watch movement, particularly a chronograph module. Furthermore, the blanks designed to rotate the moving parts of such a counting chain can hardly rotate the moving parts of a counting chain with a lower gear ratio. This necessitates developing separate blanks to rotate the display moving parts over 12 hours and other blanks to rotate them over 24 hours.

[0008] The aim of the invention is to provide a clockwork mechanism that improves upon devices known in the prior art. In particular, the invention proposes a clockwork mechanism that achieves a high gear ratio with a compact design. The invention further proposes an assembly method for producing, using the same blanks, a clockwork mechanism capable of displaying a chronograph over 12 or 24 hours.

[0009] According to a first aspect of the invention, an assembly method according to the invention is defined by claim 1.

[0010] Different modes of execution of the assembly process are defined by claims 2 and 3.

[0011] According to a second aspect of the invention, objects are defined by the following propositions. 1. A watch mechanism (110), in particular a watch movement or chronograph module, comprising: a frame (80, 81), and a counting chain (100) including an epicyclic gear train (31, 32, 33, 34) including a first planet gear (33) fixed to the frame. 2. A watch mechanism according to Proposition 1, characterized in that the mechanism includes a clutch device (10) arranged upstream of the counting chain for mechanically linking a finishing gear (90) to the counting chain (100). 3. A watch mechanism according to Proposition 2, characterized in that the clutch device includes a vertical clutch wheel. 4. A clockwork mechanism according to any one of propositions 1 to 3, characterized in that the epicyclic gear train (31, 32, 33, 34) comprises a second planetary gear (34) output from the epicyclic gear train arranged to drive, directly or indirectly, a counter (40) of the counting chain (100) by means of gears. 5.A clockwork mechanism according to proposition 4, characterized in that the second planet gear (34) is arranged to drive, directly or indirectly, an hour counter (40), in particular an hour counter completing one revolution per 24 hours. 6. A clockwork mechanism according to any one of propositions 1 to 5, characterized in that the epicyclic gear train (31, 32, 33, 34) comprises an input planet carrier (31) of the epicyclic gear train arranged to be driven, directly or indirectly, by a drive wheel (20). 7. A clockwork mechanism according to one of propositions 1 to 6, characterized in that the epicyclic gear train is of type 4 and / or in that the epicyclic gear train (31, 32, 33, 34) comprises a satellite (32) including a first gear (32a) meshing with a pinion (33a) of the first planet gear (33) and a second gear (32b) meshing with the second planet gear. 8.9. Clockwork mechanism according to any one of propositions 1 to 7, characterized in that the satellite carrier consists of a toothed wheel comprising a plate on which the satellite is pivoted. 10. Clockwork mechanism according to any one of propositions 1 to 8, characterized in that the first and second planetary gears are arranged on either side of the satellite carrier. 11. Clockwork mechanism according to any one of propositions 1 to 9, characterized in that the mechanism, in particular the clutch device, comprises a driving finger (12) for driving the counting chain (100). 12. Clockwork mechanism according to any one of propositions 1 to 10, characterized in that the counting chain is an hour counting chain and / or in that the counting chain is a minute counting chain, the hour counting elements and the minute counting elements being kinematically linked, in particular by gearing. 13.Timepiece (120), in particular wristwatch, comprising a mechanism according to one of propositions 1 to 11.

[0012] The attached drawings represent, as an example, one method of manufacturing a timepiece. There figure 1 is a top view of one embodiment of a timepiece. figure 2 This is a top view of a first embodiment of a chain counting mechanism. figure 3 is a cross-sectional view unfolded along line II of the figure 2 . There figure 4 is a top view of a second embodiment of a chain counting mechanism. figure 5 is a cross-sectional view unfolded along line II-II of the figure 4 . There figure 6 is a detailed cross-sectional view, particularly of a moving part of the first embodiment. figure 7 is an exploded view, in particular of a mobile of the first embodiment.

[0013] An embodiment of a timepiece 120 is described below with reference to figures 1 , 2 , 3 , 6 et 7 .

[0014] The timepiece 120 is, for example, a watch, in particular a wristwatch.

[0015] The timepiece 120 includes a timepiece mechanism 110. The timepiece mechanism may be a watch movement intended to be mounted in a timepiece case in order to protect it from the external environment.

[0016] The 110 watch movement can be an electronic movement or a mechanical movement, including an automatic movement.

[0017] Alternatively, the 110 watch mechanism can be included in the watch movement. Specifically, the watch mechanism can be a chronograph module.

[0018] The 110 watch mechanism includes: a frame 80, 81, and a counting chain 100 comprising an epicyclic train 31, 32, 33, 34 including a first planetary 33 fixed to the frame.

[0019] The counting chain preferably includes the following elements: a drive unit 20 comprising a wheel 20a and a pinion 20b of the drive unit, pivoting about an axis A2, a minute counter unit 50 in the form of a gearbox 50, pivoting about an axis A5, a minute counter 60 including in particular a wheel 60a of the minute counter, pivoting about an axis A6, a first portion of the epicyclic gear train in the form of a pinion 33a of the first planetary gear 33, a second portion of the epicyclic gear train in the form of an hour counter unit 30 comprising: ∘ a planet carrier 31 including a wheel 31a, ∘ a planet 32 ​​including a first and a second gearbox, respectively 32a and 32b, ∘ a second planetary gear 34 including a wheel 34a and a pinion 34b, an hour counter 40 including in particular a wheel 40a of the hour counter, pivoting around an A4 axis, an indexing device 70, for example in the form of a jumper,a first frame element 80, and a second frame element 81.

[0020] The counting chain is advantageously an hour counting chain. The counting chain can also be a minute counting chain. In this case, the hour counting elements and the minute counting elements are advantageously kinematically linked, particularly by gears.

[0021] The first and second planetary bodies 33, 34, as well as the satellite carrier 31, are coaxial along an axis A3. The satellite 32 pivots in the satellite carrier 31 along an axis A8 parallel or substantially parallel to the axis A3.

[0022] The planet carrier 31 preferably constitutes the input of the epicyclic gear train. The second planet gear 34 preferably constitutes the output of the epicyclic gear train. The epicyclic gear train is preferably of type 4, namely that the first planet gear has external teeth and the second planet gear has external teeth. The planet 32 ​​may include a first transfer gear 32a meshing directly with the first planet gear 33 and a second transfer gear 32b meshing directly with the second planet gear.

[0023] Preferably, the planet carrier consists of a gear comprising a plate on which the planet is pivoted. Even more preferably, the first and second planet gears are arranged on either side of the planet carrier, in particular on the plate of the gear constituting the planet carrier. Even more preferably, the gears 32a and 32b are arranged on either side of the planet carrier.

[0024] The pinion 33a of the first planetary gear 33 is fixed relative to the first and second frame elements 80, 81. In particular, the first planetary gear is fixed to the frame regardless of the state (engaged, disengaged) of the clutch mechanism, that is, regardless of the state (stationary, moving) of the counting chain. The second planetary gear 34 is pivoted relative to the first and second frame elements 80, 81. The satellite carrier 31 is, in turn, pivoted around the second planetary gear 34. The hour-counting mechanism 30 thus comprises a satellite carrier 31 and a second planetary gear 34, the satellite carrier and the second planetary gear being rotationally mobile relative to each other.

[0025] The second planetary gear 34 is arranged to drive, directly or indirectly, the hour counter 40 by means of a gear, in particular an hour counter completing one revolution every 24 hours. In the embodiment shown in the figures 1 , 2 And 3 The second planetary gear 34 is arranged to drive, by means of gears, the hour counter 40 directly. Alternatively, the hour counter could be driven, by means of gears, by the second planetary gear, via an intermediate element such as a gearbox.

[0026] The counting chain is kinematically linked to a finishing gear 90 of a watch movement by means of a clutch device comprising a clutch wheel 10. This clutch wheel 10 pivots about an axis A1. It includes, in particular, a clutch pinion 11 meshing with the finishing gear and a retractable driving finger 12 designed to drive the counting chain 100 according to the chronograph's state.

[0027] The clutch mobile 10 therefore allows the finishing gear 90 to be mechanically linked to the counting chain 100.

[0028] Preferably, the clutch mobile 10 is in the form of a vertical clutch mobile. By "vertical clutch mobile", we mean a clutch mobile comprising a first element and a second element that rotate about the axis A1 and move relative to each other by translation along the axis A1 to go from an engaged state to a disengaged state.

[0029] In other words, the clutch mobile 10 allows the finishing gear 90 to be kinematically linked to the chronograph counting chain according to its configuration, the latter being able to present two distinct states, engaged or disengaged depending on the state of the chronograph, if it is respectively running or stopped.

[0030] When the chronograph is running, the drive finger 12 advances the chronograph counter chain by one step per minute. More specifically, the drive finger 12 actuates the wheel 20a of the drive wheel 20, which in turn drives the minute counter wheel 50, as well as the wheel 60a of the minute counter 60.

[0031] In its rotation, the moving part 20 also drives the moving part 30, which counts the hours. In the embodiment shown in the figures 1 , 2 And 3The moving part 20 is arranged so as to drive, by means of gears, the satellite carrier 31 directly. More specifically, the pinion 20b of the moving part 20 drives the wheel 31a of the satellite carrier 31 and thus the satellite 32 pivoted in the satellite carrier 31 along the axis A8 parallel or substantially parallel to the axis A3. Alternatively, the satellite carrier 31 could be driven, by means of gears, by the moving part 20, via an intermediate element such as a gearbox.

[0032] Mobile 30 is illustrated in cross-section in fig 6 and in exploded view in the figure 7 As described in the references, particularly in these figures, the first gear 32a of the satellite 32 meshes with the pinion 33a of the first planetary gear 33 at a first level P1 or at the level of a first plane P1. Thus, during the rotation of the satellite carrier 31, the satellite 32 rotates around the axis A3 and also rotates about its own axis A8. The second gear 32b of the satellite 32 is rotationally fixed to the first gear 32a. The second gear 32b is arranged at a second level P2 or at the level of a second plane P2 and meshes with the wheel 34a of the second planetary gear 34. The pinion 34b, rotationally fixed to the wheel 34a, then drives the wheel 40a of the hour counter 40.

[0033] The second planetary gear 34 is, for example, pivoted by stones arranged along axis A3. The first stone 33b is mounted in the first planetary gear 33, which is fixed to the first frame element 80. The second stone 81a is fixed to the second frame element 81. The planet carrier, for its part, pivots around a portion of the second planetary gear 34, more specifically around a portion of the pinion 34b of the second planetary gear 34. The planet 32 ​​pivots along axis A8, preferably in a stone 31b fixed to the planet carrier 31.

[0034] Advantageously, the entire counting chain, particularly the minute counter 60 and the hour counter 40, are indexed by a single indexing device 70. This indexing device 70 includes, for example, a lever 71 designed to cooperate with the teeth of the return gear 50 included in the chain kinematically linking the minute counter 60 and the hour counter 40. The return of the lever 71 is ensured by an elastic return element 72, one end of which is fixed to the lever 71 and the other end of which is designed to cooperate with the first frame element 80 of the movement.

[0035] The hour counter 30, in the form of a portion of an epicyclic gear train, advantageously allows for a higher reduction ratio in the chronograph's counting chain, thus enabling, for example, a 24-hour display on the hour counter 40 instead of 12 hours. The overall dimensions resulting from the arrangement of this epicyclic gear train remain identical or substantially identical to those of a single-axis movement with a pinion and a wheel, as described below with reference to the figures 4 And 5 .

[0036] In a second embodiment shown on the figures 4 And 5The counting chain differs from the first embodiment of the counting chain only in that the moving part 30, pivoted about axis A3, is replaced by a moving part 30' for counting hours, comprising only a wheel 31a' and a pinion 34b'. The wheel 31a' and the pinion 34b' are fixed to each other. The wheel 31a' meshes with the moving part 20, specifically with the pinion 20b of the moving part 20. The pinion 34b', in turn, meshes with the counter 40, specifically with the wheel 40a of the counter 40.

[0037] Furthermore, the second embodiment of the counting chain can also differ from the first embodiment of the counting chain in that the first planetary gear 33 is replaced by a core 33'. Indeed, the pinion 33a of the first planetary gear 33 fixed to the first frame element 80 of the watch movement is no longer needed here, it can be replaced by a core 33a' also fixed to the first frame element 80 of the watch movement.

[0038] Comparing the two counting chains, with and without an epicyclic gear train, described with reference to the figures, it can be seen that the space required for implementing the two variants 30 and 30' of the hour counter wheel is identical or nearly identical. It is thus possible to obtain a common counting chain architecture that can, for example, display the hour counter over 12 hours without an epicyclic gear train, and for example, display the hour counter over 24 hours by simply replacing the wheel 30' with the wheel 30 and the core 33a' with the pinion 33a. As a point of note, the planetary gear 33, in particular the first stone 33b mounted in the first planetary gear 33, can allow the pivoting of both the wheel 30 and the wheel 30'. Alternatively, the first stone 33b can be directly mounted in the first frame element 80.

[0039] Thus, the invention also relates to a method of assembling a mechanism or a clock part, one embodiment of which is described below with reference to the figures.

[0040] The assembly process includes the following steps: a step of supplying a frame 80, 81, a step of mounting a drive unit 20 on the frame 80, 81, a step of mounting an hour counter 40 on the frame 80, 81, and a step of mounting: a unit 30' meshing with the drive unit and with the hour unit, or an epicyclic train 31, 32, 33, 34 meshing with the drive unit and with the hour unit.

[0041] The preceding formulation should not be interpreted as characterizing two alternative mounting methods, but as a single mounting method in which, using in particular the same frame, the same drive mechanism, and the same hour hand, it is possible to obtain two distinct mechanisms depending on whether an epicyclic gear train or a mechanism comprising only a pinion and a wheel is used. In particular, it is possible to obtain a mechanism such as the one described with reference to the figures 2 And 3 or a mechanism such as described with reference to figures 4 And 5 .

[0042] In particular, the mounting step of the moving part 30' may include the mounting of the core 33' in which the moving part is pivoted. Alternatively, the mounting step of the moving part 30' may include the mounting of the first planetary gear 33 in which the moving part 30' is pivoted.

[0043] In particular, the assembly step of the epicyclic train 31, 32, 33, 34 may include the attachment to the frame of the first planetary gear 33 of the epicyclic train.

[0044] The epicyclic gear train solution described above includes a first planetary gear fixed to the watch movement frame. This solution could function similarly if the part of the epicyclic gear train fixed to the frame were the second planetary gear. The epicyclic gear train could also be driven by one of the planetary gears instead of being driven by the planet carrier.

[0045] Regardless of the embodiment or variant, the construction of the epicyclic gear train could be different. The epicyclic gear train could include internal teeth, for example on at least one of the planetary gears and / or the planet carrier.

[0046] Regardless of the embodiment or variant, the epicyclic gear train could also be spherical, for example, with bevel gears on the planetary gears and / or the satellite(s). The axis(es) of rotation of the satellite(s) would then be perpendicular or substantially perpendicular to the A3 axis of the epicyclic gear train.

[0047] Regardless of the embodiment or variant, the epicyclic gear train could be of the differential ball type and operate by friction by replacing the satellite(s) of the satellite carrier with balls.

[0048] Regardless of the embodiment or variant, the epicyclic gear train could also include several satellites arranged along different axes. These satellites could be mounted between the two planetary gears in parallel and / or in series.

[0049] These solutions can of course work for all transmission ratios within the epicyclic gear train.

[0050] In the solutions described above, the counting chain can advance one step every minute under the action of a driving finger of a clutch device. However, regardless of the embodiment or variant, the counting chain could also be driven continuously, without skipping, in a dragging or semi-dragging manner.

[0051] In the solutions described above, the clutch mechanism is mounted in parallel with the finishing chain. In an alternative design, the chronograph clutch mechanism could be arranged directly within the finishing gear train that connects the mainspring barrel to the regulating organ.

[0052] In the solutions described above, the clutch mechanism includes a vertical clutch wheel. The clutch mechanism could also take other forms, such as a horizontal clutch or an oscillating pinion. The chronograph counter chain could also be directly linked to the mainspring barrel, for example. In this case, the clutch mechanism could be a friction device.

[0053] To ensure that the hour-counting wheel 30 is interchangeable with the hour-counting wheel 30', the planet carrier wheel 31a has the same number of teeth as the hour-counting wheel 31a'. Similarly, the pinion 34b of the second planet gear has the same number of teeth as the pinion 34b' of the hour-counting wheel. However, this does not limit the design. The construction could be implemented with other gear configurations and / or assemblies.

[0054] In the solutions described above, the counting chain is an hour counting chain. However, more generally, the epicyclic gear reducer could be used in any other counting chain including, for example, a second counter, a minute counter, or a countdown chain.

[0055] Throughout this document, the term "two fixed elements" means that these two elements are attached to each other. In other words, it means that there is a fixed or complete connection between them.

[0056] Thanks to the invention, an epicyclic gear train is advantageously arranged in a counting chain. It makes it possible to obtain a "24-hour" chronograph display in place of the "12-hour" display, with a particularly simple and compact solution, to the point that it is possible to simply replace one of the moving parts of the chronograph counting chain, and possibly a core, with this epicyclic gear train to switch from a "12-hour" display to a "24-hour" display.

[0057] The distinctive feature of the solution proposed here is that one of the planetary gears of the epicyclic gear train is fixed to the frame.

Claims

1. Method of assembling a mechanism or a clockwork part, characterized in that It includes the following steps: - a step of supplying a frame (80, 81), - a step of mounting a drive unit (20) on the frame (80, 81), - a step of mounting an hour meter (40) on the frame (80, 81), and - a step of mounting: • a unit (30') meshing with the drive unit and with the hour unit, or • an epicyclic gear train (31, 32, 33, 34) meshing with the drive unit and with the hour unit.

2. Assembly method according to the preceding claim, characterized in that the mobile assembly step (30') includes the assembly of a core (33') in which the mobile is pivoted.

3. Assembly method according to claim 1, characterized in that The assembly step of the epicyclic train (31, 32, 33, 34) includes the fixing to the frame of a first planetary gear (33) of the epicyclic train.

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