Clock movement comprising a power reserve display device

Abstract

The invention relates to a watch movement comprising at least one barrel (11, 12) and a power reserve display device (10), the watch movement being characterized in that said device comprises: - a winding device comprising a winding gear train (15), - a reduction gear train (16) meshed with the barrel or one of the barrels (11; 12), - a differential (14) arranged so as to kinematically connect the winding gear train (15) and the barrel (11) by a first input of the differential (14), said differential (14) comprising a second input by which it is connected to the reduction gear train (16), and comprising an output, the first and second inputs and the output of the differential (14) being coaxial, - a power reserve display module (17) cooperating with the output of the differential (14).

Description

Technical field of the invention

[0001] The invention falls within the field of watchmaking and relates in particular to a watch movement comprising a power reserve display device. Technological background

[0002] In a watch movement, a power reserve indicator is a horological complication that allows the user to know the level of energy available for displaying the time or any other time indication. In other words, a power reserve indicator shows the charge level of the mainspring barrel(s) in the watch movement.

[0003] A power reserve display device includes a power reserve indicator, such as a needle, and a differential linking the indicator to the barrel(s), as described in document EP3333637.

[0004] Power reserve indicators typically contain numerous components to achieve the appropriate reduction ratios between the watch movement's mainspring barrel(s) and the power reserve indicator. These many components significantly impact the cost of the watch movements in which they are integrated. Furthermore, power reserve indicators are relatively bulky, which complicates their integration within a watch movement. Summary of the invention

[0005] The invention solves the aforementioned drawbacks by proposing for this purpose a watch movement comprising at least one barrel and a power reserve display device.

[0006] The power reserve display device includes: a winding device comprising a winding gear train, a reduction gear train meshed with the barrel(s), a differential arranged to kinematically connect the winding gear train and the barrel by a first input of the differential, said differential comprising a second input by which it is connected to the reduction gear train, and comprising an output, the first and second inputs and the output of the differential being coaxial, a power reserve display module cooperating with the output of the differential.

[0007] These characteristics advantageously allow for a reduction in the number of components in the power reserve display device, and consequently, its size.

[0008] In particular embodiments, the invention may further comprise one or more of the following features, taken individually or in all technically possible combinations.

[0009] In particular embodiments, the differential includes a satellite carried by a planet carrier wheel fixed in rotation to an axis, the planet carrier wheel constituting the first input of the differential and having an external toothing by which it meshes with the barrel and with the winding gear.

[0010] In particular embodiments, the second input of the differential is constituted by a solar wheel mounted to rotate freely on the axis.

[0011] In particular embodiments, the differential includes a ring fixed in rotation by friction with a barrel constituting the output of the differential, the latter being fitted in a movable way in rotation on the axis, said ring having an internal toothing by which it is kinematically connected to the satellite, preferably by means of a linkage carried by the planet carrier wheel and meshing with the satellite.

[0012] In particular embodiments, the power reserve display module includes a snail cam fixed to the barrel, a feeler arranged to bear against the latter and a power reserve indicator connected to the feeler so that the movement of the cam causes the movement of the power reserve indicator.

[0013] In particular embodiments, the watch movement comprises a first and a second barrel, each comprising a ratchet wheel which meshes with a transmission wheel, the first barrel including a drum by which it is connected to the differential and the second barrel including a drum by which it is connected to the reduction gear. Brief description of the figures

[0014] Other features and advantages of the invention will become apparent from the following detailed description, given by way of non-limiting example, with reference to the accompanying drawings in which: there figure 1 represents a perspective view from below of two barrels and a power reserve display device of a watch movement according to a preferred embodiment of the invention, the figure 2 represents a cross-sectional view of a differential in the power reserve display device of the figure 1 , there figure 3 represents a top-down perspective view of the differential cooperating with a power reserve display module, the figure 4 represents a perspective view from below of a barrel and a power reserve display device of a watch movement according to another embodiment of the invention.

[0015] Note that the figures are not necessarily drawn to scale for reasons of clarity. Detailed description of the invention

[0016] There figure 1 shows two barrels and a power reserve display device 10 of a watch movement according to a preferred example of the invention.

[0017] As seen on the figure 1 The watch movement according to the invention comprises a first barrel 11 and a second barrel 12 kinematically connected to each other by a transmission wheel 13 and each comprising a barrel spring, in a manner known per se to a person skilled in the art.

[0018] More specifically, the first and second barrels 11 and 12 each have a drum 110 and 120, and a ratchet wheel 111 and 121 preferentially engaging one or the other with the transmission wheel 13.

[0019] The drum 110 of the first barrel 11 cooperates with a pawl 112 such that said drum 110 is blocked from rotating in one direction by the pawl, only the ratchet wheel 111 being driven in rotation by the unwinding of the mainspring. The spring of the second barrel 12 also unwinds during the operation of the watch movement in a manner known as such, and drives a finishing gear (not shown in the figures) in rotation via the drum 120. These rotations are symbolized by the thin arrows on the figure 1 .

[0020] The power reserve indicator 10 includes a differential 14 kinematically interposed between a winding gear 15 of a winding device and the first barrel 11. In other words, the differential 14 is arranged so as to kinematically connect the winding gear 15 and the first barrel 11. The winding gear 15 is preferably made up of only two rotating components, as can be seen on the figure 1 .

[0021] The winding mechanism can be operated by means of a winding crown connected to a winding stem, and / or by means of an oscillating weight. The winding mechanism is known as such to those skilled in the art, and is therefore not described in further detail in the following text.

[0022] In particular, the differential 14 cooperates with the winding gear 15 and with the drum 110 of the first barrel 11 via a first input constituted, in the embodiment of the invention shown in the figures 1 and 2 , by a 140 satellite carrier wheel.

[0023] The winding of the springs of the first and second barrels 11 and 12 is thus achieved by driving the drum 110 of the first barrel 11 by the planet carrier wheel 140, in a given direction of rotation, for example clockwise, symbolized by the thick arrows on the figure 1 , following an action on the winding gear 15 in a winding direction. The planet carrier wheel 140 has external teeth provided for this purpose, cooperating with teeth on the drum 110 of the first barrel 11.

[0024] The differential 14 also includes a second input through which it is connected to the second barrel 12 by means of a reduction gear 16. The second input consists of a sun wheel 141 mounted to rotate relative to the planet carrier wheel 140. In particular, the differential 14 has a shaft 142 on which the planet carrier wheel 140 is mounted and on which the sun wheel 141 is mounted to rotate freely, as shown in the diagram. figure 2 .

[0025] As shown in particular by figure 2 In one embodiment of the invention, the solar wheel 141 meshes with a satellite 143 carried by the satellite carrier wheel 140. The differential 14 includes a ring 144 kinematically connected to the satellite 143 preferably by means of a gearbox 145 freely rotated by the satellite carrier wheel 140. In particular, the gearbox 145 meshes with an internal toothing of the ring 144.

[0026] More specifically, the satellite 143 preferentially comprises a pinion engaging with the solar wheel 141 and a wheel engaging with the gearbox 145.

[0027] In the particular example shown in the figures, the crown 144 is arranged coaxially with the planet carrier wheel 140 and is rotationally fixed by friction with a barrel 147 itself mounted in a movably rotational manner on the axis 142.

[0028] The barrel 147 forms the output of the differential 14. Advantageously, the first and second inputs and the output of the differential 14 are arranged coaxially with each other, as can be seen on the figure 2 This feature reduces the volume occupied by the differential within the watch movement. This particularly compact arrangement reduces the volume required within the watch movement to integrate the differential 14.

[0029] The power reserve display device 10 includes a power reserve display module 17 cooperating with the output of the differential 14, as shown in detail on the figure 3 .

[0030] In an example of an embodiment of the invention not shown in the figures, the power reserve display module 17 includes an indicator, such as a needle or a disc, fixed to the barrel 147 for example by means of a lug.

[0031] In another example of an embodiment of the invention, visible in particular on the figure 3 , the power reserve display module 17 may include a snail cam 146 driven onto the barrel 147, that is to say, it is fixed in rotation by friction with the crown 144.

[0032] Advantageously, the crown 144 is constrained against the snail cam 146 by a friction spring 149, such as a convex or concave washer, held axially against a radial lip of the barrel 147, as visible in the cross-sectional view of the figure 2 Alternatively, the crown 144 can be formed by a friction wheel (not shown in the figures), and thus can comprise a rim to which two elastic arms are connected by their ends, the elastic arms being arranged relative to each other so as to define a hole in which the barrel 147 is engaged.

[0033] In the example implementation shown on the figure 3A pin 148 is fixed to the snail cam 146 and extends along an axis parallel to the axis 142. The pin 148 is designed to move, during the rotation of the snail cam 146, in a groove provided for this purpose in a structure of the watch movement, for example, a bridge or a mainplate. This groove (not shown in the figures) extends in a curvilinear direction centered on the axis 142, between two ends. The pin 148 rests against one of these ends respectively as a result of the complete winding or unwinding of the mainsprings of the first and second barrels 11 and 12, which causes the crown 144 to slide relative to the barrel 147 and the snail cam 146.

[0034] In this embodiment of the invention, the power reserve display module 17 further comprises a rake 171 arranged to bear against the profile of the snail cam 146 by means of a feeler 170, and an indicator pinion 172 on which the indicator is fixed so as to show the power reserve. The indicator pinion 172 is meshed with the teeth of the rake 171 so that the movement of the feeler 170 on the profile of the snail cam 146 causes it to rotate.

[0035] The power reserve indicator module 17 also includes a return spring 173 arranged to cooperate with the indicator pinion 172 so as to constrain the feeler 170 against the profile of the snail cam 146 and to take up gear backlash. As shown in the Figures 1 And 3 , the return spring 173 is in particular arranged to bear against a pin fixed to a radial lip of the indicator pinion 172.

[0036] In summary, when the winding gear 15 is wound in the direction of winding, symbolized by the thick arrows on the figure 1 The drum 110 of the first barrel 11 is driven in rotation by the planet carrier wheel 140, itself driven in rotation by the winding gear train 15. On the other hand, the planet carrier wheel 140 drives the satellite 143 and the gear train 145 in a circular movement centered around the axis 142 of the differential 14. It should be noted that during the rotation of the planet carrier wheel 140, the satellite 143 also pivots around its axis to the extent that it meshes with the sun wheel 141.

[0037] The rotation of the satellite 143 explained previously causes the rotation of the linkage 145 around its axis, which in turn causes the rotation of the crown 144, and consequently, that of the snail cam 146. The feeler 170 cooperating with the snail cam 146 drives the power reserve indicator so as to indicate an increase in the power reserve.

[0038] At the same time, the ratchet wheel 121 of the second barrel 12 is driven in rotation by the ratchet wheel 111 of the first barrel 11 via the transmission wheel 13, so that the spring of the second barrel 12 is gradually wound.

[0039] Once the mainspring of the second barrel 12 is sufficiently wound, it drives the drum 120 of the second barrel 12 in rotation, thereby triggering the actuating mechanism of the finishing train and thus setting the watch movement in motion. The rotation of the drum 120 of the second barrel 12 causes the rotation of the sun wheel 141 via the reduction gear 16.

[0040] Furthermore, when the winding gear train 15 is not under load and the springs of the first and second barrels 11 and 12 are unwound—that is, when the watch movement is running—the drum 120 of the second barrel 12 transmits, via the reduction gear train 16, a rotational motion to the sun wheel 141 as described previously, and the satellite wheel 140 is then stationary. The satellite 143, the intermediate gear 145, and the crown 144 are driven in rotation around their respective axes. The rotation of the crown 144 causes, by friction, that of the snail cam 146, which in turn moves the feeler 170, thus driving the power reserve indicator to signal a decrease in the power reserve.

[0041] The arrangement of the differential 14 advantageously allows a large reduction in gearing between the rotation of the power reserve indicator and that of the drum 110 of the first barrel 11 when the planet carrier wheel 140 is driven during the winding of the springs of the first and second barrels 11 and 12. As an example, the power reserve indicator can be driven by a fraction of a turn, for example between 0.1 and 0.2 turns, when the drum 110 of the first barrel 11 is driven by several tens of turns, for example between 25 and 30 turns.

[0042] Similarly, when unloading the springs of the first and second barrels 11 and 12, thanks to the reduction gear 16 and the arrangement of the differential 14, the drum 120 of the second barrel 12 can make several tens of turns, for example between 25 and 30 turns, and cause the power reserve indicator to make a fraction of a turn, for example between 0.1 and 0.2 turns.

[0043] In another example of an embodiment of the invention shown in the figure 4 It is conceivable that the watch movement according to the invention comprises a single barrel 11 including a barrel spring in a manner known per se to those skilled in the art. The barrel 11 also includes a drum 110 and a ratchet wheel 111.

[0044] In the example shown on the figure 4 The ratchet wheel 111 is kinematically linked to the planet carrier wheel 140 so that it is driven in rotation by the latter, following a winding action on the winding train 15. This feature allows the mainspring of the barrel 11 to be wound. In this embodiment of the invention, a linkage 113 is interposed between the ratchet wheel 111 and the planet carrier wheel 140.

[0045] Similar to what has been described previously, the ratchet wheel 111 cooperates with a pawl 112 so that it is blocked in one direction of rotation by the latter. Only the drum 110 is then driven in rotation by the unwinding of the mainspring.

[0046] The drum 110 is connected to the second input of the differential 14, i.e. the sun wheel 141, via the reduction gear 16.

[0047] More generally, it should be noted that the implementation and execution methods considered above have been described as non-limiting examples, and that other variants are therefore conceivable.

[0048] In particular, it is conceivable that the power reserve display module 17 includes at least one return wheel engaging with a moving part carrying a power reserve indicator in order to relocate the power reserve display.

Claims

1. A watch movement comprising at least one mainspring barrel (11, 12) and a power reserve indicator (10), the watch movement being characterized in that said device comprises: - a winding device including a winding gear train (15), - a reduction gear train (16) meshed with the barrel(s) (11; 12), - a differential (14) arranged to kinematically connect the winding gear train (15) and the barrel (11) by a first input of the differential (14), said differential (14) including a second input by which it is connected to the reduction gear train (16), and including an output, - a power reserve display module (17) cooperating with the output of the differential (14).

2. Watch movement according to claim 1, in which the differential (14) comprises a satellite (143) carried by a planet carrier wheel (140) fixed in rotation to an axis (142), the planet carrier wheel (140) constituting the first input of the differential and comprising an external toothing by which it meshes with the barrel (11) and with the winding gear (15).

3. Clock movement according to claim 2, in which the second input of the differential (14) is constituted by a sun wheel (141) mounted movably in rotation on the axis (142).

4. Watch movement according to claim 3, in which the differential (14) comprises a crown (144) fixed in rotation by friction with a barrel (147) constituting the output of the differential, the latter being fitted in a movably rotational manner on the axis (142), said crown (144) having an internal toothing by which it is kinematically connected to the satellite (143).

5. Watch movement according to claim 3, in which the crown (144) is kinematically connected to the satellite (143) by means of a linkage (145) carried by the planet carrier wheel (140) and meshing with the satellite (143).

6. Watch movement according to claim 4 or 5, wherein the power reserve display module (17) comprises a snail cam (146) integral with the barrel (147), a feeler (170) arranged to bear against the latter and a power reserve indicator connected to the feeler (170) such that the movement of the cam causes the movement of the power reserve indicator.

7. Watch movement according to any one of claims 1 to 6, comprising a first and a second barrel (11, 12) each having a ratchet wheel (111, 121) meshing with a transmission wheel (13), the first barrel (11) comprising a drum (110) by which it is connected to the differential (14) and the second barrel (12) comprising a drum (120) by which it is connected to the reduction gear (16).

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