DEVICE FOR AUTOMATIC WINDING OF A SPRING IN THE SPRING HOUSING OF A CLOCK MOVEMENT

Description

Technical field of the invention

[0001] The invention falls within the field of watch movements, and relates in particular to a device for the automatic winding of a watch. Technological background

[0002] Automatic winding devices for a watch's mainspring are known to allow the transmission of torque to a barrel ratchet for the purpose of winding said mainspring, regardless of the direction of rotation of the oscillating weight.

[0003] Clutch mechanisms are well known in the prior art. They comprise two clutch wheels, each consisting of a wheel mounted freely around a pinion and carrying a pawl. The wheels of the clutch wheels mesh with each other, and one of these wheels, called the "first wheel," engages with an input wheel that is fixed in rotation to the oscillating mass. The pinions are meshed with an output wheel that cooperates with the rotating barrel ratchet.

[0004] When the oscillating mass pivots in one direction, it drives the first wheel to rotate in a second direction, and the pawl it carries is configured to lock the first wheel to the pinion around which it is mounted. This pinion then transmits a torque to the output shaft, causing it to rotate in the first direction. Simultaneously, the first wheel drives the second wheel to rotate in the first direction, and the pawl on the second wheel disengages its rotation from that of the pinion around which it is mounted, the pinion being driven in the second direction by the output shaft.

[0005] Conversely, when the oscillating mass pivots in a second direction, it drives the first wheel to rotate in the first direction, the pawl it carries disengaging the first wheel from the pinion around which it is mounted. Simultaneously, the first wheel drives the second wheel to rotate in the second direction, and the pawl it carries locks its rotation to that of the pinion around which it is mounted, the pinion then driving the output shaft in the first direction.

[0006] Automatic winding devices for a mainspring are described in documents EP3104232 and EP2897000.

[0007] As is known, the mainspring can also be wound manually, by acting on a winding rod kinematically linked to the mainspring ratchet, so that its rotation, said winding rod causes the rotation of said ratchet.

[0008] During the rotation of the winding stem, the barrel ratchet drives the clutch gears into rotation via the output shaft. As the gears rotate, the pawls on each of the two clutch gears are engaged, thus disengaging the gears from the gears.

[0009] Due to the reduction ratios between the barrel ratchet, the output shaft, and the pinions, the pawls are subjected to very high angular speeds, which causes lubrication problems and premature wear of said pawls.

[0010] Furthermore, these clutch mechanisms have the disadvantage of generating significant mechanical play between the pawls and the teeth of the clutch gears when the direction of rotation of the clutch wheels changes. This play, referred to as "dead angles" by those skilled in the art, causes noise, shocks, vibrations, and premature wear of the moving parts that generate it. The dead angle also reduces the winding mechanism's ability to wind the mainspring barrel because while the rotor is moving through this angle, it cannot wind the barrel.

[0011] The blind spot is all the more important when the reduction ratio between the oscillating mass and the wheels of the clutch mechanisms is large. Summary of the invention

[0012] The invention overcomes the aforementioned drawbacks and, to this end, relates to a device for the automatic winding of a watch's mainspring, comprising an oscillating weight, an input wheel kinematically linked to the oscillating weight, two reduction wheels, and a ratchet wheel drive. Each reduction wheel has a reduction gear carrying at least four planet gears, and a transmission pinion around which the reduction wheel is mounted freely. The input wheel is kinematically linked to the two reduction wheels so that, regardless of the direction of rotation in which it is driven by the oscillating weight, it drives the two reduction wheels in opposite directions.The satellites include teeth of asymmetrical shape, so as to form pawls configured to lock in rotation, in each of said reduction gears, the transmission pinion and the reduction wheel only when said reduction wheel pivots in a predefined direction of rotation, said predefined direction of rotation being identical for both of the reduction wheels.

[0013] In particular embodiments, the invention may further comprise one or more of the following features, taken individually or in all technically possible combinations.

[0014] In particular embodiments, the input wheel and the reduction wheels are dimensioned so that between the oscillating mass and the reduction wheels a reduction ratio greater than or equal to 1 / 3 is generated, and / or the transmission pinions and the ratchet driving wheel are dimensioned so that the gear train formed between said transmission pinions and the ratchet, or the ratchet driving wheel, has a reduction ratio less than or equal to 1 / 50.

[0015] According to the invention, one of the reduction wheels is in meshing relationship with the input moving part and with the other reduction wheel.

[0016] In particular embodiments, the reduction mobiles are identical to each other.

[0017] In particular embodiments, the transmission gears have a first set of teeth cooperating with the planet gears and a second set of teeth cooperating with the ratchet driving wheel.

[0018] In particular embodiments, the first set of teeth has more teeth than the second set of teeth.

[0019] In particular embodiments, in each reduction gear, the satellites are distributed regularly around the transmission pinion and are each arranged in angular positions around their respective axes of rotation that are different from each other. Brief description of the figures

[0020] 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 1represents a perspective view of a watch mainspring winding device according to a preferred embodiment of the invention; the figure 2 represents a top view of a reduction device mobile of the figure 1 ; there figure 3 represents a perspective view of the reduction mobile of the figure 2 .

[0021] Note that the figures are not necessarily drawn to scale for reasons of clarity. Detailed description of the invention

[0022] There figure 1 shows a device 10 for the automatic winding of a watch's mainspring according to a preferred embodiment. As can be seen in this figure, the winding device 10 comprises an oscillating weight 11, an input wheel 12 meshing with the oscillating weight 11, two reduction wheels 13 and a ratchet-driving wheel 14 for cooperating with a ratchet (not shown in the figures).

[0023] The input element 12 is kinematically connected, via an input wheel 120 with which it is equipped, to the oscillating mass 11, such that when the latter pivots, it drives the input element 12 in rotation. Preferably, the input wheel 120 is meshed, for this purpose, with a driving wheel 110 rigidly fixed to the oscillating mass 11, i.e., without any degrees of freedom. In the preferred embodiment of the invention, the driving wheel 110 has the same number of teeth as the input wheel 120.

[0024] The input mobile 12 further comprises a pinion 121 around which the input wheel 120 is rigidly fixed, intended to transmit a rotational movement of said input mobile 12 to one of the reduction mobiles 13 with which it is meshed.

[0025] In particular, each reduction gear 13 comprises a reduction wheel 130 carrying at least four planet gears 131, and a transmission pinion 132 around which the reduction wheel 130 is mounted freely, that is, with one degree of rotational freedom. As shown in the figure 1 The input shaft 12 is kinematically connected to the two reduction wheels 130 so that, regardless of the direction of rotation in which it is driven by the oscillating mass 11, it drives the two reduction wheels 130 in rotation in opposite directions. To this end, in the preferred embodiment of the invention as shown in the figure 1 , one of the reduction wheels 130 is in mesh relationship with the input moving part 12, in particular with the pinion of the input moving part 12, and with the other reduction wheel 130.

[0026] Preferably, as seen on the figure 1The reduction mobiles 13 are identical to each other. Thus, the manufacture and assembly of the device are facilitated, and economies of scale can be achieved.

[0027] THE figures 2 And 3 represent in detail a reduction gear 13 according to the preferred embodiment of the present invention.

[0028] As shown by figure 2The satellites 131 form, in each of the reduction gears 13, pawls configured to lock the transmission pinion 132 and the reduction wheel 130 in rotation only when said reduction wheel 130 pivots in a predefined direction of rotation, here clockwise. In particular, when the reduction wheel 130 pivots clockwise, one of the satellites 131 locks itself in rotation against the transmission pinion 132 and applies a torque to teeth of the transmission pinion 132 with which it cooperates, which causes said transmission pinion 132 and the reduction wheel 130 to lock in rotation.

[0029] This technical effect is mainly due to the asymmetrical shape of the teeth of the satellites 131. In particular, when one of the satellites 131 becomes stuck in rotation, such as the one shown on the right in the figure 2, the top of one of its teeth is arranged to bear against the head of an opposite tooth of the transmission pinion 132, said head then constituting a stop.

[0030] Conversely, when the reduction wheel 130 pivots in the counterclockwise direction, the satellites 131 mesh with the transmission pinion 132, so that said reduction wheel 130 rotates around said transmission pinion 132 without applying any torque to it, that is to say, without causing it to rotate.

[0031] Advantageously, since the reduction wheels 13 are identical to each other, the predefined direction of rotation in which the satellites 131 lock the reduction wheel 130 and the transmission pinion 132 in rotation is identical for both of the reduction wheels 130. Since the reduction wheels 130 are both driven in rotation in different directions during the rotation of the oscillating mass 11, whatever the direction of rotation of the latter, one of the transmission pinions 132 is driven to pivot in the predefined direction, i.e. clockwise.

[0032] In particular, in the preferred embodiment of the invention, the transmission gears 132 comprise a first set of teeth 1320 cooperating with the planet gears 131 and forming a sun wheel, and a second set of teeth 1321 cooperating with the ratchet drive 14, the first set of teeth 1320 having a greater number of teeth than the second set of teeth 1321. The first and second sets of teeth 1320 and 1321 are advantageously fixed on the same shaft and are fixed against rotation relative to each other. In the figures, these first and second sets of teeth 1320 and 1321 are schematically represented by their reference cylinders.

[0033] Advantageously, in each reduction gear 13, the satellites 131 are regularly distributed around the transmission pinion 132 and are each arranged in angular positions, around their respective axes of rotation, that are different from one another. As can be seen on the figure 2Each satellite 131 has a different orientation so that the engagement of the teeth of the satellites 131 between the teeth of the transmission pinion 132 is different for each of said satellites 131. This ensures that, during a change in the direction of rotation of the reduction gear 130, the mechanical backlash existing between the teeth of the satellite 131, which would otherwise apply a torque to the teeth of the transmission pinion 132, particularly the first tooth 1320, and thus the dead angle, is minimized. Furthermore, the dead angle is also reduced by the number of satellites 131.

[0034] Preferably, the input wheel 12 and the reduction wheels 130 are dimensioned so that between the oscillating mass 11 and the reduction wheels 130 a reduction ratio greater than or equal to 1 / 3 is generated, preferably a reduction ratio of 1 / 5. Furthermore, the transmission pinions 132 and the ratchet driving wheel 14 are dimensioned so that the gear train formed between said transmission pinions 132 and the ratchet, or between said transmission pinions 132 and the ratchet driving wheel 14, has a reduction ratio less than or equal to 1 / 50, preferably a reduction ratio equal to 1 / 25.

[0035] The invention therefore offers the advantage of limiting the rotational speed of the satellites 131 for a given rotational speed of the oscillating mass 11 in the case of automatic winding, and for a given rotational speed of the ratchet wheel in the case of manual winding via a winding stem. This arrangement extends the lifespan of the satellites 131 while eliminating any vibrations that might result from excessive rotational speed.

[0036] The arrangement and dimensioning of the input wheels 12, the reduction wheels 130, the transmission pinion 132 and the ratchet drive wheel 14 as previously described are advantageously permitted by the reduction of the blind spot resulting from the number of satellites 131.

[0037] More generally, it should be noted that the implementation and realization methods considered above have been described as non-limiting examples, and that other variants are therefore conceivable.

[0038] In particular, the satellites 131 have been described in the form of toothed wheels in this text, but they can take the form of any other type of ratchet. Furthermore, the winding device 10 according to the invention can include other reducing elements, and the input element 12, reduction element 13, and ratchet drive element 14 can be arranged differently from the arrangement described and shown in the figures.

Claims

1. Device (10) for automatic winding of a barrel spring of a watch comprising an oscillating mass (11), an entry disk (12) kinematically linked to the oscillating mass (11), two reduction disks (13) and a ratchet driving disk (14), each reduction disk (13) including a reduction wheel (130) bearing at least four planetary wheels (131), and a transmission pinion (132) about which the reduction wheel (130) is loosely mounted, the entry disk (12) being kinematically linked to the two reduction wheels (130) such that, regardless of the direction of rotation wherein it is driven by the oscillating mass (11), it rotates the two reduction wheels (130) in mutually different directions, the planetary wheels (131) comprising teeth of asymmetric shape, so as to form ratchets configured to connect in rotation, in each of said reduction disks (13), the transmission pinion (132) and the reduction wheel (130) only when said reduction wheel (130) pivots in a predefined direction of rotation, said predefined direction of rotation being identical for either of the reduction wheels (130), in which one of the reduction wheels (130) is in mesh with the entry disk, the device (10) for winding being characterised in that said one of the reduction wheels (130) which is in mesh with the entry disk (12) is in mesh with the other reduction wheel (130).

2. Device (10) according to claim 1, wherein the entry disk (12) and the reduction wheels (130) are dimensioned such that, between the oscillating mass (11) and the reduction wheels (130), a reduction ratio greater than or equal to 1:3 is generated, and / or wherein the transmission pinions (132) and the ratchet driving disk (14) are dimensioned such that the geartrain formed between said transmission pinions (132) and the ratchet has a reduction ratio less than or equal to 1 / 50.

3. Device (10) according to one of claims 1 or 2, wherein the reduction disks (13) are identical to one another.

4. Device (10) according to one of claims 1 to 3, wherein the transmission pinions (132) include a first toothing (1320) cooperating with the planetary wheels (131) and a second toothing (1321) cooperating with the ratchet driving disk (14).

5. Device (10) according to claim 4, wherein the first toothing (1320) includes more teeth than the second toothing (1321).

6. Device (10) according to one of claims 1 to 5, wherein, in each reduction disk (13), the planetary wheels (131) are distributed regularly about the transmission pinion (132) and are each arranged in mutually different angular positions, about the respective axes of rotation thereof.