EP3483664B1 - Clockwork mechanism for displaying the lunar day and the phase of the moon, with correction system with dual drive train - Google Patents

Description

Technical area

• Le jour lunaire, dont la durée sépare deux passages successifs par un méridien donné (qui peut être figuré, dans l'horloge ou la montre équipée du mécanisme, par deux passages successifs à midi) ;
• et la phase de lune, c'est-à-dire la portion (variable) de la lune éclairée par le soleil.

The invention relates to the field of watchmaking. More precisely, it relates to a mechanism, commonly called an astronomical complication, making it possible to display both:

• The lunar day, the duration of which separates two successive passages by a given meridian (which can be represented, in the clock or the watch equipped with the mechanism, by two successive passages at midday);
• and the moon phase, that is to say the (variable) portion of the moon lit by the sun.

Technological background

The astronomical characteristics of the moon have been known for a long time, and described in particular by James Ferguson in "Astronomy explained upon Sir Isaac Newton's principles", the fifth edition of which was published in 1772.

The average value of the lunar day (separating two passages in the meridian) is 24 hours, 50 minutes, 28.328 seconds.

The ratio of the solar day to the lunar day is therefore: $$\frac{86400s}{\mathrm{89428,328}s}=0.96613682$$

As for the average value of the lunation (duration separating two full moons), it is 29 days, 12 hours, 44 minutes, 2.8 seconds.

Claiming to be inspired by Ferguson, E. Cloux, in his watchmaking course given at the Vocational School of the Vallée de Joux in 1949, drew a display mechanism for the lunar day and the moon phase, superimposed on the solar day (with an average value of 24 hours).

• Un palier 101 de lune pourvu d'une roue 102 de méridien (à 59 dents) et monté en rotation autour d'un axe X1 principal ;
• Une sphère 103 figurant la lune, montée en rotation par rapport au palier 101 de lune autour d'un axe X2 radial perpendiculaire à l'axe X1 principal, l'axe Y1 radial portant un pignon 104 de lune (à 20 dents) ;
• Un premier élément 105 tournant (à 57 dents) monté en rotation autour de l'axe X1 principal et dont on comprend qu'il doit engrener un mécanisme d'entraînement (non représenté) employé par ailleurs pour l'affichage des minutes et/ou des heures du jour solaire ;
• Un mobile 106 de lune (à deux roues solidaires de 57 dents chacune) couplant en rotation, avec réduction, le premier élément 105 tournant à la roue 102 de méridien ;
• Une roue 107 centrale (à 20 dents), solidaire du premier 105 élément tournant et engrenant le pignon 104 de lune.

The mechanism designed by E. Cloux, represented on the figure 1 , included the following:

• A moon bearing 101 provided with a meridian wheel 102 (with 59 teeth) and mounted in rotation about a main axis X1;
• A sphere 103 representing the moon, mounted in rotation relative to the bearing 101 of the moon around an axis X2 radial perpendicular to the main axis X1, the axis Y1 radial carrying a pinion 104 of the moon (with 20 teeth);
• A first rotating element 105 (with 57 teeth) rotatably mounted around the main axis X1 and of which it is understood that it must engage a drive mechanism (not shown) also used for displaying the minutes and / or hours of the solar day;
• A mobile 106 of the moon (with two integral wheels of 57 teeth each) coupling in rotation, with reduction, the first element 105 rotating to the wheel 102 of the meridian;
• A central wheel 107 (with 20 teeth), integral with the first 105 rotating element and meshing with the moon pinion 104.

This very clever mechanism makes it possible to display a passage from the moon to the meridian in 24 hours, 50 minutes, 31.58 seconds, and a lunation in 29.5 days.

We see that both are approximations of the average lunar day and the average lunation, imposed by the choice of the gear ratio: $$24h\times \frac{59}{57}=24\mathrm{<figure-callout\; id="50"\; label="h"\; filenames="imgf0004.png"\; state="\{\{state\}\}">h</figure-callout>}50\mathit{min}31.58s$$

However, the mechanism designed by E.Cloux does not include any body allowing the corrections made to be displayed. necessary either by the drifts resulting from the abovementioned approximations, or, quite simply, by the shutdown of the mechanism following the exhaustion of the energy source (most often a barrel spring in mechanical watches, which failing winding eventually relax completely).

We also know the document WO91 / 11756 A1 . This document describes a mechanism for displaying the lunar day and the moon phase, this mechanism employing a sphere, representing the moon, which is driven to pivot around two axes perpendicular to each other. The first rotation is carried out in a lunar day (approximately 24h and 50m) and the other rotation is completed in the duration of a lunation (approximately 29 days). The figure 2 of this document shows the drive train. The sphere is arranged in a bearing supported by a plate 16, which is itself driven in rotation by a gear train (10, 9, 46, 45, 42, 22) derived directly from the finishing. The rotation of the sphere relative to the plate 16 is obtained by a second chain (43, 37, 32, 30) derived from the finishing and ending on a moon pinion (30) integral with the sphere.

Finally, we mention the document EP 2,728,420 A1 . This document describes a mechanism for displaying the lunar day and the moon phase, this mechanism also employing a sphere, representing the moon, which is driven to pivot around two axes perpendicular to each other. The training of the sphere along the vertical axis is carried out "by jumps", using the fall of one end of a lever (19A) in a notch of a snail (15).

An objective of the invention is therefore to propose a solution making it possible, in a simple and reliable manner, to correct the lunar day and the lunation in a mechanism as presented above.

Summary of the invention

• un premier élément tournant monté en rotation autour d'un axe principal et engrenant un mécanisme d'entraînement,
• un palier de lune pourvu d'une roue de méridien et monté en rotation autour d'un axe principal,
• une sphère figurant la lune, montée en rotation par rapport au palier de lune autour d'un axe radial perpendiculaire à l'axe principal, l'axe radial portant un pignon de lune,
• un mobile de lune couplant en rotation, avec réduction, le premier élément tournant à la roue de méridien,
• une roue centrale, montée en rotation autour d'un axe principal sur le premier élément tournant et engrenant le pignon de lune,
• un deuxième élément tournant, engrenant le mobile de lune et monté avec friction, à une interface, sur le premier élément tournant pour lui être solidaire en rotation autour de l'axe principal tant que le couple résultant d'efforts circonférentiels différents s'exerçant respectivement sur le premier élément tournant et sur le deuxième élément tournant est inférieur à un couple de friction déterminant la limite d'adhérence à l'interface, le deuxième élément tournant ensemble avec le mobile de lune et le palier de lune formant une première chaîne cinématique en aval du premier élément tournant,
• une roue de transmission, solidaire en rotation de la roue centrale et pourvu extérieurement d'une denture et intérieurement d'au moins un sautoir en prise d'encliquetage avec une roue étoilée solidaire en rotation du deuxième élément tournant, pour coupler en rotation ce deuxième élément tournant avec la roue centrale tant que le couple résultant d'efforts circonférentiels différents s'exerçant respectivement sur la roue étoilée et sur la roue de transmission est inférieur à un couple de saut, au-delà duquel le sautoir est déporté radialement par glissement sur la roue étoilée jusqu'à s'en décliqueter, ledit au moins un sautoir et la roue étoilée étant configurés de sorte que le couple de saut est inférieur audit couple de friction, la roue de transmission ensemble avec la roue centrale et le pignon de lune formant une deuxième chaîne cinématique en aval de la roue étoilée,
• un système de correction de l'affichage du jour lunaire, qui comprend un premier élément d'entraînement apte à présenter au moins momentanément une relation d'engrènement avec la première chaîne cinématique pour forcer la rotation du palier de lune autour de l'axe principal, via un premier rouage de correction formé partiellement par au moins une partie de la première chaîne cinématique, lorsqu'un premier couple de correction, supérieur audit couple de friction, est appliqué à ce premier rouage de correction par un utilisateur, et
• un système de correction de la phase de lune, qui comprend un deuxième élément d'entraînement apte à présenter au moins momentanément une relation d'engrènement avec la deuxième chaîne cinématique pour forcer la rotation de la sphère autour dudit axe radial, via un deuxième rouage de correction formé partiellement par au moins une partie de la deuxième chaîne cinématique et indépendant de la première chaîne cinématique, lorsqu'un deuxième couple de correction, supérieur audit couple de saut, est appliqué à ce deuxième rouage de correction par un utilisateur.

To achieve the above-mentioned objective, a clock mechanism for displaying the lunar day and the moon phase is proposed, which includes:

• a first rotary element rotatably mounted around a main axis and meshing a drive mechanism,
• a moon bearing provided with a meridian wheel and mounted in rotation about a main axis,
• a sphere representing the moon, mounted in rotation relative to the moon bearing around a radial axis perpendicular to the main axis, the radial axis carrying a moon pinion,
• a moon wheel moving in rotation, with reduction, the first rotating element to the meridian wheel,
• a central wheel, mounted in rotation around a main axis on the first rotating element and meshing with the moon pinion,
• a second rotating element, meshing the moon mobile and frictionally mounted, at an interface, on the first rotating element so as to be integral in rotation about the main axis as long as the torque resulting from different circumferential forces being exerted respectively on the first rotating element and on the second rotating element is less than a friction torque determining the adhesion limit at the interface, the second element rotating together with the moon mobile and the moon bearing forming a first kinematic chain downstream of the first rotating element,
• a transmission wheel, integral in rotation with the central wheel and provided externally with a toothing and internally at least one jumper in snap engagement with a star wheel integral in rotation with the second rotating element, to couple in rotation this second rotating element with the central wheel as long as the torque resulting from different circumferential forces exerted respectively on the star wheel and on the transmission wheel is less than a jumping torque, beyond which the jumper is offset radially by sliding on the star wheel until it clicks, said at least one jumper and the star wheel being configured so that the jumping torque is less than said friction torque, the transmission wheel together with the central wheel and the moon pinion forming a second kinematic chain downstream of the star wheel,
• a system for correcting the display of the lunar day, which comprises a first drive element capable of presenting at least momentarily an engagement relationship with the first kinematic chain to force the rotation of the moon bearing around the main axis , via a first correction train formed partially by at least part of the first kinematic chain, when a first correction torque, greater than said friction torque, is applied to this first correction train by a user, and
• a moon phase correction system, which comprises a second drive element capable of presenting at least momentarily an engagement relationship with the second kinematic chain to force the rotation of the sphere around said radial axis, via a second gear train of correction partially formed by at least part of the second kinematic chain and independent of the first kinematic chain, when a second correction torque, greater said jump torque is applied to this second gear train by a user.

Thanks to this double correction system, which acts via two separate kinematic chains, it is possible to correct in a simple and reliable way the display of the lunar day and that of the moon phase.

• une position de réglage du jour lunaire, dans laquelle le pignon baladeur engrène le mobile de lune pour forcer la rotation du palier de lune autour dudit axe principal via ladite au moins une partie de la première chaîne cinématique ;
• une position de réglage de la phase de lune, dans laquelle le pignon baladeur engrène la roue de transmission pour forcer la rotation de la sphère autour dudit axe radial via ladite au moins une partie de la deuxième chaîne cinématique.

According to a main embodiment, the system for correcting the display of the lunar day and the system for correcting the moon phase comprise a joint correction device for actuating the display of the lunar day and, without actuating the display of the lunar day, the moon phase. This joint correction device comprises a sliding pinion which alone forms the first and second drive elements, this sliding pinion being able to adopt two adjustment positions, namely:

• a position for adjusting the lunar day, in which the sliding pinion meshes with the moon wheel to force the rotation of the moon bearing around said main axis via said at least part of the first kinematic chain;
• a position for adjusting the moon phase, in which the sliding pinion meshes with the transmission wheel to force rotation of the sphere around said radial axis via said at least part of the second kinematic chain.

The correction device advantageously comprises a carrying pinion which meshes with the sliding pinion, and at least one connecting rod which couples the axes of rotation of the sliding pinion and the carrying pinion.

The first rotating element comprises for example a toothed wheel which extends perpendicular to the main axis, integral with a barrel which extends along the main axis. As for the second rotating element, it then comprises an auxiliary wheel which extends perpendicular to the axis main, integral with a sleeve fitted with friction on the barrel of the first rotating element.

The friction connection between the second rotating element and the first rotating element is advantageously carried out by lanterning, which occurs, for example. in the form of a punctual deformation of the internal diameter of the tube of the second rotating element, so as to ensure friction on the conical groove produced in the barrel of the first element.

• une roue inférieure, qui engrène la roue auxiliaire du deuxième élément tournant, et
• une roue supérieure, qui engrène la roue de méridien du palier de lune.

According to a preferred embodiment, the moon mobile comprises two superimposed integral wheels, namely:

• a lower wheel, which meshes with the auxiliary wheel of the second rotating element, and
• an upper wheel, which meshes the meridian wheel of the moon bearing.

• la roue auxiliaire du deuxième élément tournant comprend 64 dents,
• la roue inférieure du mobile de lune comprend 43 dents,
• la roue supérieure du mobile de lune comprend 37 dents, et
• la roue de méridien du palier de lune comprend 57 dents.

According to a particular embodiment:

• the auxiliary wheel of the second rotating element comprises 64 teeth,
• the lower wheel of the moon wheel has 43 teeth,
• the upper wheel of the moon wheel has 37 teeth, and
• the moon bearing meridian wheel has 57 teeth.

The central wheel preferably carries a toothing in crown geared by the moon pinion; in addition, the central wheel is advantageously fitted onto the barrel of the first rotating element.

The moon bearing is, for its part, preferably mounted on the central wheel, being for example. fitted onto it with the interposition of a plain bearing.

The transmission wheel advantageously comprises a pair of diametrically opposite necklaces.

Finally, the star wheel typically comprises 29 or 30 teeth, or in a preferred variant, 59 teeth.

Brief description of the figures

• La figure 1 est une vue en coupe d'un mécanisme connu d'affichage du jour lunaire et de la phase de lune, tel que proposé par E.Cloux ;
• la figure 2 est une vue en perspective éclatée illustrant une montre équipée d'un mécanisme d'affichage du jour lunaire et de la phase de lune, selon l'invention ;
• la figure 3 est une vue en perspective, à plus grande échelle, du mécanisme d'affichage de la figure 2 ;
• la figure 4 est une vue en coupe partielle du mécanisme de la figure 3, selon le plan de coupe IV-IV ; dans un médaillon est montré un détail à plus grande échelle ;
• la figure 5 est une vue en plan du mécanisme de la figure 4 (pour rendre visibles des composants sous-jacents, on a retiré le palier de lune) ;
• la figure 6 est une vue d'un détail, à plus grande échelle, du mécanisme, pris à la fois dans le médaillon VI en haut à gauche de la figure 5;
• la figure 7 est une de dessus du mécanisme, illustrant la correction du jour lunaire ;
• la figure 8 est une vue similaire à la figure 5, illustrant la correction de la phase de lune ;
• la figure 9 est une vue d'un détail, à plus grande échelle, du mécanisme, pris dans le médaillon IX en haut à gauche de la figure 8.

Other objects and advantages of the invention will appear in the light of the description of an embodiment, given below with reference to the appended drawings in which:

• The figure 1 is a sectional view of a known mechanism for displaying the lunar day and the moon phase, as proposed by E.Cloux;
• the figure 2 is an exploded perspective view illustrating a watch equipped with a mechanism for displaying the lunar day and the moon phase, according to the invention;
• the figure 3 is a perspective view, on a larger scale, of the display mechanism of the figure 2 ;
• the figure 4 is a partial section view of the mechanism of the figure 3 , according to section plane IV-IV; in a medallion is shown a detail on a larger scale;
• the figure 5 is a plan view of the mechanism of the figure 4 (to make the underlying components visible, the moon bearing has been removed);
• the figure 6 is a view of a detail, on a larger scale, of the mechanism, taken at the same time in the medallion VI at the top left of the figure 5 ;
• the figure 7 is a top view of the mechanism, illustrating the correction of the lunar day;
• the figure 8 is a view similar to the figure 5 , illustrating the correction of the moon phase;
• the figure 9 is a view of a detail, on a larger scale, of the mechanism, taken from the medallion IX at the top left of the figure 8 .

Detailed description of the invention

On the figure 2 is shown a timepiece. It could be a clock or a pendulum, but, in the example illustrated, it is a watch 1 - and more precisely a wristwatch, suitable for being worn on the wrist. Conventionally, this watch 1 comprises a case 2 which includes a middle part 3, a base and a crystal (not shown), as well as, fixed on horns 4 of the middle part, a bracelet 5 for wearing on the wrist.

Watch 1 comprises, housed in case 2, a clockwork movement 6 which includes a plate 7 and, mounted on the plate, at least one clock mechanism 8 designed to ensure the display of the lunar day and the moon phase .

As we will see, the mechanism 8 is also designed to ensure the display of the minutes and the hour of the average solar day, but such a display is optional and could be achieved by a separate mechanism.

Mechanism 8 belongs to the family of so-called astronomical complications; it is organized around a main axis A1 perpendicular to the general plane of the plate 7.

• révolution autour de l'axe A1 principal pour donner l'indication du jour lunaire ;
• rotation autour d'un axe A3 propre (radial) pour donner l'indication de la phase de lune.

The moon is displayed in volume, in the form of a sphere 9 animated by a double movement:

• revolution around the main axis A1 to give the indication of the lunar day;
• rotation around a clean A3 axis (radial) to give the indication of the moon phase.

According to an embodiment illustrated on the figure 4 , the main axis A1 is materialized by a shaft 10 which, in this example, is formed on a mobile 11 in the center, itself mounted on the plate 7. This center mobile is here provided with a wheel 12 whose function does not intervene in the present framework.

• Une grande roue 14, pourvue d'une denture périphérique comprenant typiquement un nombre de dents Z1=72 ;
• Une roue 15 moyenne, pourvue d'une denture périphérique comprenant typiquement un nombre de dents Z2=24 ;
• Une petite roue 16, pourvue d'une denture périphérique comprenant typiquement un nombre de dents Z3=12.

As seen on the figure 4 , the display mechanism 8 is attacked by a drive mechanism 13, hereinafter called the timer mobile, which comprises several superimposed wheels integral in rotation with a common axis A2 offset relative to the main and parallel axis A1 to this one. In the example illustrated, the timer mobile 13 comprises three superimposed wheels, namely:

• A large wheel 14, provided with a peripheral toothing typically comprising a number of teeth Z1 = 72;
• A medium wheel 15, provided with a peripheral toothing typically comprising a number of teeth Z2 = 24;
• A small wheel 16, provided with a peripheral toothing typically comprising a number of teeth Z3 = 12.

The timer mobile 13 is rotated by a motor device (not shown) including a power source and a transmission. Since astronomical complications are usually associated with mechanical watches, it is preferable for the energy source to be a barrel spring associated with a spiral balance regulator. However, that the energy source is a battery associated with a quartz regulator would not depart from the scope of the present invention.

As we mentioned, the mechanism 8 is designed to display the minutes and the time of the average solar day.

For the display of the minutes, the mechanism 8 comprises a carriageway 17, mounted in rotation about the main axis A1 and provided with a pinion 18 for the minutes meshing with the large wheel 14, and with a tube 19 fitted (with the possibility of rotation) on the shaft 10 of the center mobile 11. Pavement 17 carries a 20 minute hand which, as illustrated in the figure 4 , is driven onto the tube 19, at an upper end of the latter. Pinion 18 minutes is provided with a peripheral toothing typically comprising a number of teeth Z4 = 16. Pavement 17 performs a revolution around the main axis A1 in one hour.

For the display of the hours, the mechanism 8 comprises a mobile 21 for the hours, mounted in rotation about the main axis A1 and provided with a wheel 22 for the hours meshing the wheel 15 with a medium, and a barrel 23 fitted (with the possibility of rotation) on the tube 19 of the roadway 17. The mobile 21 of the hours carries a 24 hour hand which, as illustrated in the figure 4 , is driven out of the barrel 23, at an upper end thereof.

The hour wheel 22 is provided with a peripheral toothing typically comprising a number of teeth Z5 = 64, so that the reduction ratio (i.e. the ratio of the rotational speeds) between the hour wheel 22 and the pinion 18 minutes is: $$\frac{Z4}{\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="imgf0002.png"\; state="\{\{state\}\}">Z</figure-callout>}1}\times \frac{Z2}{\mathrm{<figure-callout\; id="5"\; label="Z"\; filenames="imgf0002.png"\; state="\{\{state\}\}">Z</figure-callout>}5}=\frac{16}{72}\times \frac{24}{64}=\frac{1}{12}$$

In this way, the hour mobile 21 performs a revolution around the main axis A1 in 12 hours.

For the display of the lunar day and the moon phase, the mechanism 8 comprises, firstly, a first rotating element 25 rotatably mounted around the main axis A1 and meshing the moving body 13 of the timer.

More specifically, in the example illustrated in particular on the figure 4 , the first rotating element 25 comprises a toothed wheel, called the solar wheel 26 (or 24 hour wheel), which extends perpendicular to the main axis A1, and a barrel 27, integral with the solar wheel and which extends along the main A1 axis. According to an embodiment illustrated on the figure 4 , the barrel 27 is fitted (with the possibility of rotation) on the barrel 23 of the 21 hour mobile.

In the example illustrated, the barrel 27 is stepped, and comprises a lower stage 28, of which the solar wheel 26 is integral, and an upper stage 29, of diameter smaller than that of stage 28 lower. The lower floor and the upper floor are separated by a shoulder 30.

The solar wheel 26 meshes with the small wheel 16 of the timer mobile 13. This solar wheel is provided with a peripheral toothing typically comprising a number of teeth Z6 = 64, so that the reduction ratio between the first rotating element 25 and the moving part 21 of the hours is: $$\frac{Z5}{Z2}\times \frac{Z3}{\mathrm{<figure-callout\; id="6"\; label="Z"\; filenames="imgf0005.png"\; state="\{\{state\}\}">Z</figure-callout>}6}=\frac{64}{24}\times \frac{12}{64}=\frac{1}{2}$$

In this way, the first rotating element 25 performs a revolution around the main axis A1 in 24 hours. In other words, the first rotating element can serve as a measure of the average solar day. It can also be used to display the average solar day. Thus, in the illustrated embodiment (cf. figure 3 ), the first rotating element carries, at an upper end of the upper stage 29 of the barrel 27, a solar hand 31 (also called 24 hour hand), which to represent the sun can be round in shape and / or have an opening circular.

The mechanism 8 comprises, secondly, a moon bearing 32 rotatably mounted around the main axis A1. The moon bearing is provided with a meridian wheel 33. The moon bearing is also provided with a moon cover 34, fixed on the meridian wheel so as to be integral with it in rotation. Alternatively, the meridian wheel and the moon cover form a single piece.

The meridian wheel 33 is provided with a peripheral toothing typically comprising a number of teeth Z7 = 57.

• Un hémisphère 36 sombre (grisé sur les dessins), figurant la portion de la face de la lune non éclairée par le soleil ;
• Un hémisphère 37 clair (blanc sur les dessins), figurant la portion de la lune éclairée par le soleil.

As seen on the figure 4 , the moon bearing 32 is hollow, and has an internal cavity 35 formed in the moon cover 34. The mechanism 8 comprises, thirdly, a sphere 9 representing the moon, mounted in rotation relative to the moon bearing 32 around an axis A3 radial, perpendicular to the main axis A1. The sphere 9 advantageously comprises two hemispheres of contrasting colors, namely:

• A dark hemisphere 36 (grayed out on the drawings), representing the portion of the face of the moon not lit by the sun;
• A clear hemisphere 37 (white in the drawings), representing the portion of the moon lit by the sun.

The hemispheres 36, 37 can be made distinct by applying a paint. However, according to a preferred embodiment, the hemispheres are hemispherical caps made of different materials and assembled to form the sphere 9. Thus, the dark hemisphere 36 can be made of biotite mica, obsidian or any other mineral of dark color, while the light hemisphere 37 can be made of metal (eg silver or gray gold), or in a light mineral (eg moonstone).

Furthermore, in the example illustrated, the radial axis A3 is formed by a pin 38 which passes through the sphere 9 and is integral with it in rotation. At an internal end, the spindle is mounted in a sheath 39 fitted into a hole 40 made in the bearing 32 of the moon.

As seen on the figure 4 , the radial axis A3 (that is to say the spindle 38) carries, at an internal end, a moon pinion 41, which is integral with it in rotation. The moon pinion is housed in the internal cavity 35 of the moon bearing 32.

The moon pinion 41 is provided with a peripheral toothing typically comprising a number of teeth Z8 = 14.

The mechanism 8 comprises, fourthly, a second rotating element 42, mounted in rotation about the main axis A1. According to an embodiment illustrated on the figure 4 , the second rotating element comprises an auxiliary wheel 43, which extends perpendicular to the main axis A1, and a bush 44 integral with the auxiliary wheel and which extends along the axis A1 main. The auxiliary wheel 43 is provided with a peripheral toothing typically comprising a number of teeth Z9 = 64 teeth.

The second rotating element 42 is mounted on the first rotating element 25 with friction at their interface, denoted 45 (the interface is the surface where the first rotating element and the second rotating element make contact).

More specifically, the sleeve 44 is frictionally fitted onto the barrel 27 of the first rotating element. More precisely still, the sleeve is fitted with friction on the lower stage 28 of the barrel. This friction mounting aims to make the second rotating element 42 integral (in rotation about the main axis A1) with the first rotating element 25, as long as the torque, denoted C1, resulting from different circumferential forces acting respectively on the first rotating element and on the second rotating element is less than a friction torque, denoted CF, determining the adhesion limit at the interface 45.

• tant que C1 < CF, le premier élément 25 tournant et le deuxième élément 42 tournant sont solidaires en rotation, sans glissement à leur interface 45, et se comportent comme une pièce monobloc ;
• dès lors que C1 ≥ CF, la limite d'adhérence à l'interface 45 entre le premier élément 25 tournant et le deuxième élément 42 tournant est atteinte, et ils se désolidarisent en rotation, de sorte que le deuxième élément tournant peut pivoter indépendamment du premier élément tournant autour de l'axe A1 principal, avec glissement à l'interface 45.

In other words:

• as long as C1 <CF, the first rotating element 25 and the second rotating element 42 are integral in rotation, without sliding at their interface 45, and behave like a single piece;
• as soon as C1 ≥ CF, the adhesion limit at the interface 45 between the first rotating element 25 and the second rotating element 42 is reached, and they separate in rotation, so that the second rotating element can pivot independently of the first element rotating around the main axis A1, with sliding at interface 45.

The friction connection at the interface 45 between the second rotating element and the first rotating element can, in practice, be carried out by a lanterning 46, which is for example, as illustrated in the detail medallion of the figure 4 , in the form of a conical groove made in the barrel 27 of the first rotating element.

The second rotating element 42 is provided with a star wheel 47. This peripheral-shaped star wheel 47 is, for example. cut externally in the socket 44. It includes a series of triangular teeth 48, which are here 30 in number but could be 29 in number, or 59 in number (which corresponds to the approximate number of half-days in one lunation).

The mechanism 8 comprises, fifthly, a central wheel 49, mounted on the first rotating element 25 and in gear engagement with the moon pinion 41. This central wheel advantageously carries a toothing 50 in a crown (that is to say whose teeth extend parallel to the main axis A1) meshed by the pinion 41 of the moon. This toothing is e.g. cycloidal and includes a number of teeth Z10 equal to the number of teeth Z8 of the moon pinion (that is, here, Z10 = 14).

In the example illustrated on the figure 4 , the central wheel 49 is fitted onto the barrel 27 of the first rotating element 25. More specifically, the central wheel is fitted onto the shoulder 30. The interface between the central wheel and the first rotating element is sliding, so that the central wheel can rotate independently of the first rotating element.

According to a preferred embodiment illustrated on the figure 4 , the moon bearing 32 is mounted on the central wheel 49. To allow the rotation of the moon bearing 32 relative to the central wheel, a smooth bearing 51 is interposed between them.

The mechanism 8 comprises, in the sixth place, a mobile 52 of the moon which couples in rotation, with reduction, the first element 25 turning to the wheel 33 of the meridian (and therefore to the bearing 32 of the moon) to allow the rotation of the moon landing by the first rotating element 25. More specifically, the moon mobile 52 couples in rotation the second rotating element 42 (integral in rotation with the first rotating element 25 as long as C1 <CF) with the meridian wheel.

• Une roue 53 inférieure, qui engrène la roue 43 auxiliaire du deuxième élément 42 tournant ;
• Une roue 54 supérieure, qui engrène la roue 33 de méridien du palier 32 de lune.

The moon mobile 52 is offset, mounted in rotation about an axis A4 parallel to the main axis A1. According to an embodiment illustrated on the figure 4 , the moon mobile comprises two superimposed integral wheels, namely:

• A lower wheel 53, which meshes the auxiliary wheel 43 of the second rotating element 42;
• A wheel 54 upper, which meshes the wheel 33 of the meridian of the bearing 32 of the moon.

The lower wheel 53 is provided with a peripheral toothing typically comprising a number of teeth Z11 = 43. The upper wheel 54 is provided with a peripheral toothing typically comprising a number of teeth Z12 = 37 teeth. In this way, the reduction ratio, denoted R, from the solar wheel 26 to the meridian wheel 33 (equal to the ratio of the speeds of rotation of the moon bearing 32 and the first rotating element 25) is: $$R=\frac{Z9}{Z11}\times \frac{Z12}{Z7}=\frac{64}{43}\times \frac{37}{57}=0.96613627$$

This reduction report provides the value of the displayed average lunar day, noted D: $$J=\frac{24h}{R}=24\mathrm{<figure-callout\; id="50"\; label="h"\; filenames="imgf0004.png"\; state="\{\{state\}\}">h</figure-callout>}50\mathit{min}\mathrm{28,378}s$$

It is an excellent approximation of the actual average lunar day. In fact, the delay from the lunar day displayed to the actual lunar day is only 5 / 100th of a second per solar day (i.e. one day of delay every eight years).

The display of the lunar day is ensured by the circular path (that is to say the revolution) of the sphere 9 around the main axis A1. The passage from the moon to the zenith is represented by the passage of the sphere 9 at twelve o'clock.

According to a preferred embodiment, illustrated in dotted lines on the figure 3 , the watch is advantageously provided with a bar 55, visible to the wearer, and which represents the terrestrial horizon line.

The course of approximately 180 ° of the sphere 9 above the bar 55 (from the point of view of the wearer) represents the course of the moon in the visible sky (lunar day), while the course of approximately 180 ° of the sphere 9 below the bar shows the course of the moon in the invisible sky (lunar night).

The moon mobile 52 is advantageously mounted on a bridge 56 itself fixed on the plate 7. Its axis A4 of rotation is for example. formed by a screw in helical engagement with the bridge 56.

The mechanism 8 comprises, in seventh place, a transmission wheel 57 secured to the central wheel 49, designed to secure the latter in rotation to the second element 42 rotating in normal operation of the mechanism 8, and to allow their relative rotation on the contrary during a correction of the display, under conditions which will be set out below.

The transmission wheel 57 is provided externally with a toothing 58 and internally with at least one jumper 59.

According to an embodiment illustrated on the figure 8 , the transmission wheel 57 is provided with a pair of diametrically opposite jumpers 59. This number is not limitative. Thus, three necklaces distributed at 120 ° could be provided.

As illustrated on figure 6 and figure 9 , the (or each) jumper 59 comprises a spring blade 60 (curve in the example illustrated), which extends in a notch 61 formed in the transmission wheel 57. When viewed from above, the leaf spring 60 extends from a fixed end 61 to a free end 63 counterclockwise (cf. figure 6 ). The jumper 59 is also provided, at the free end of the spring blade, with a triangular head 64 of size and shape complementary to the space separating two neighboring teeth 48 from the star-shaped wheel 47.

The (or each) jumper 59 is in snap engagement (by its head 64) with the star wheel 47. In its position of equilibrium (in the absence of any constraint), the jumper 59 would occupy a position in which the head 64 would be spaced from the main axis A1 by a distance less than the radius of the star wheel.

In normal operation, the (or each) jumper 59 is snapped on by its head 64 between two teeth 48 adjacent to the star-shaped wheel 47. The jumper 59 is held in this position by its own elastic return force which tends to urge the head 64 towards the main axis A1.

In normal operation, the second rotating element 42, integral with the first rotating element (and therefore driven by it in rotation) rotates around the main axis A1 in a clockwise direction (when seen from above). The star wheel 47 therefore exerts on the head 64 of (or each) jumper 59 an effort which urges the latter into bracing, which tends to hold the head 64 between two teeth 48 adjacent to the star wheel. Under these conditions, the second rotating element (with the first rotating element) and the transmission wheel 57 (with the central wheel 49) are integral in rotation about the main axis A1, and jointly rotate clockwise around that -this ( figure 6 ).

The central wheel 49 is made integral with the transmission wheel 57 for example by means of feet 65, projecting from the central wheel, driven into holes drilled in the transmission wheel 57. Alternatively, this attachment can be achieved by screwing.

During a correction of the moon phase display, a driving torque is applied to the transmission wheel 57 to drive it in rotation around the main axis A1 (counterclockwise when viewed from above, cf. . figure 8 and figure 9 ), however, without this rotation being transmitted by the star wheel 47 to the second rotating element 42.

The second rotating element 42, mounted in friction on the first rotating element 25, provides resistance to the rotation of the transmission wheel 57, and the torque resulting from the circumferential forces is denoted by C2. different which are exerted respectively on the second rotating element 42 and on the transmission wheel 57.

• demeurer encliqueté avec la roue 47 étoilée tant que le couple C2 est inférieur à un couple CS de saut ;
• être déporté radialement par glissement sur la roue 47 étoilée (et plus précisément par glissement de la tête 64 sur les dents 48) jusqu'à s'en décliqueter, comme illustré en pointillés sur la figure 9, dès lors que le couple C2 est supérieur au couple CS de saut. On notera que ce déport radial est permis par la flexibilité de la lame ressort 60.

This is where the elasticity of the jumper (s) comes in. Each jumper 59 is indeed tared - that is to say dimensioned - for:

• remain engaged with the star wheel 47 as long as the torque C2 is less than a jump torque CS;
• be offset radially by sliding on the star-shaped wheel 47 (and more precisely by sliding the head 64 over the teeth 48) until it clicks, as shown in dotted lines on the figure 9 , as soon as the couple C2 is greater than the jump couple CS. It will be noted that this radial offset is allowed by the flexibility of the leaf spring 60.

The jump torque CS is less than the friction torque CF, that is: $$\mathrm{CS}<\mathrm{CF}$$

As a result, the application of the only torque C2 can never cause the second rotating element 42 to slip relative to the first rotating element 25. The first element and the second rotating element therefore remain integral in rotation (and therefore fixed) during a correction of the moon phase.

In normal operation, the central wheel 49 (with the toothing 50 in a crown) rotates integrally with the second rotating element (and therefore with the first rotating element) at the rate of one complete revolution around the main axis A1 in 24 hours.

Given the reduction ratio R presented above, the moon bearing 32 (with the sphere 9) performs its own complete revolution more slowly (in 24 h, 50 min, 28.378 s), and, taking into account the fact that the pinion 41 of the lunar moon and the teeth 50 in the crown include the same number of teeth (Z8 = Z10), the sphere 9 is slowly driven in rotation around the radial axis A3 (clockwise when the mechanism 8 is observed by the edge, in the direction of the A3 radial axis).

The sphere 9 performs a complete rotation around its axis A3 in a number L of days corresponding to the value of the lunation displayed, that is: $$L=\frac{1}{1-R}=29.53012048=29j12\mathrm{<figure-callout\; id="43"\; label="h"\; filenames="imgf0004.png,imgf0006.png"\; state="\{\{state\}\}">h</figure-callout>}43\mathit{min}22.4s$$

It is an excellent approximation of the actual lunation, with a delay of around 7 minutes per month (one day late every 17 years only).

We have seen that the differences between the displayed lunar day and the real lunar day, on the one hand, and the displayed moon phase and the real moon phase on the other hand, are small. A correction of the lunar day and a correction of the lunation would be necessary after uninterrupted operation of watch 1 for several years.

Moreover, wearers who are diligent enough not to let the power reserve of a mechanical watch run out are rare. Corrections due to the need to readjust the displays after stopping watch 1 due to the distraction of the wearer are therefore more frequent than corrections due to the need to make up for the delays accumulated by mechanism 8 during a uninterrupted operation.

To correct the display of the lunar day, the mechanism 8 is equipped with a correction device 66 comprising a pinion 67 capable of meshing the moon mobile 52 to force the rotation of the moon bearing 32 around the main axis A1 via a first correction train which bypasses the transmission wheel 57 and which includes the moon wheel 52 and the meridian wheel 33.

To correct the display of the moon phase, the mechanism 8 is equipped with a correction device 66 which includes a pinion 67 capable of meshing the transmission wheel 57 to force the rotation of the sphere 9 around the axis A3 radial via a second train which comprises the transmission wheel, the central wheel 49, and the moon pinion 41.

The mechanism 8 could include two separate correction devices for separately correcting the display of the lunar day and the display of the moon phase. To activate them separately, watch 1 could be equipped with two separate winders that the wearer (or a watchmaker) would handle independently of one another.

However, in a preferred embodiment illustrated in the drawings, and more particularly in the figure 5 , figure 7 and figure 8 , the mechanism 8 comprises a single device 66 for correcting the display of the lunar day and the moon phase.

• Une position de réglage du jour lunaire, dans laquelle le pignon 67 baladeur engrène le mobile 52 de lune pour forcer la rotation du palier 32 de lune autour de l'axe A1 principal via la première chaîne cinématique (figure 7) ;
• Une position de réglage de la phase de lune, dans laquelle le pignon 67 baladeur engrène la roue 57 de transmission pour forcer la rotation de la sphère 9 autour de l'axe A3 radial via la deuxième chaîne cinématique (figure 8).

This correction device 66 comprises a sliding pinion 67 capable of adopting two adjustment positions, namely:

• A lunar day setting position, in which the sliding pinion 67 meshes with the moon mobile 52 to force the rotation of the moon bearing 32 around the main axis A1 via the first kinematic chain ( figure 7 );
• A moon phase adjustment position, in which the sliding pinion 67 meshes with the transmission wheel 57 to force the rotation of the sphere 9 around the radial axis A3 via the second kinematic chain ( figure 8 ).

In the example illustrated on figure 7 and figure 8 , the correction device 66 comprises a carrying pinion 68 which meshes with the sliding pinion 67, and at least one connecting rod 69 which couples the axes of rotation of the sliding pinion and the carrying pinion. In practice, the correction device 66 comprises a pair of superimposed rods 69, arranged on either side of the carrier pinion and the sliding pinion.

The carrier pinion 68 is mounted on the bridge 56 in rotation about an axis A5 parallel to the main axis A1 and advantageously formed by a screw in helical engagement with the bridge 56.

The correction device 66 comprises a winder 70 provided with a rod 71 mounted as a pivot sliding around and along an axis A6 of the winder perpendicular to the main axis A1, and a crown 72 integral in rotation with the rod 71. The rod passes through the middle part 3, the crown being accessible to the wearer.

According to a particular embodiment illustrated on the figure 8 , the correction device 66 comprises a phase return gear (hereinafter more simply called phase return 73) which meshes the transmission wheel 57 and via which, in the moon phase adjustment position, the pinion 67 player meshes with the transmission wheel. The phase gear is rotatably mounted on the bridge around an A7 axis in the form of a screw in helical engagement with the bridge 56.

• une position de correction (figure 7 et figure 8) dans laquelle le pignon 76 coulant est accouplé au pignon 68 porteur, et
• une position de libération dans laquelle le pignon 76 coulant est désaccouplé du pignon 68 porteur (et dans laquelle le pignon 75 de remontoir est accouplé à un pignon de remontoir non représenté, via lequel le ressort de barillet de la montre 1 est réarmé par rotation de la couronne 72 de remontoir).

The correction device 66 also comprises a shuttle 74 provided with a winding pinion 75 (for example with Breguet teeth) and a sliding pinion 76, mounted as a pivot sliding around and along the axis A6 of winding , and coupled to the winder 70 e.g. by a classic pull and rocker mechanism (not shown), between:

• a correction position ( figure 7 and figure 8 ) in which the sliding pinion 76 is coupled to the carrying pinion 68, and
• a release position in which the sliding pinion 76 is uncoupled from the carrying pinion 68 (and in which the winding pinion 75 is coupled to a winding pinion not shown, via which the barrel spring of watch 1 is reset by rotation of the winding crown 72).

The transmission of the rotation of the winder 70 to the carrier pinion 68 is advantageously via a gear train, which typically comprises a first gear 77, meshed by the sliding gear 76, and a second gear 78, interposed between the first gear and the gear carrier.

Finally, according to an embodiment illustrated in particular on the figure 2 and figure 4 , the mechanism 8 comprises a cover 79 in the form of a disc secured to the moon bearing 32 (and for example sandwiched between the meridian wheel 33 and the moon cover 34). The cover 79 has an opening 80 with a circular outline in which the sphere 9 is housed. This cover, which rotates with the moon bearing 32, is intended to symbolize the sky. To this end, in the example illustrated, the cover 79 carries symbols 81 (engraved, painted, or even projecting) representing a star constellation.

The correction of the display of the lunar day induces a rotation of the sphere 9 around its axis A3 and consequently a modification of the display of the moon phase. This is why The correction of the lunar day display must precede the correction of the moon phase display.

Before any correction, the shuttle 74 should be placed in the correction position, by pulling (conventionally for the wearer or the watchmaker) on the winding crown 72, which pushes the pinion 76 flowing towards the first return 77 for put them into gear.

To correct the display of the lunar day, the winding crown 72 must be turned in a determined direction which depends on the number of pinions in the gear train 77, 78. In the embodiment illustrated in the figure 7 , the winding crown must be turned clockwise when viewed along the A6 winding axis.

The rotation of the winding crown 72 then drives, via the gear train 77, 78, the carrier pinion 68 clockwise (when seen from above), which tends to rotate the links 69 also clockwise and causes (or maintains) the setting of gear of the sliding pinion 67 with the moon mobile 52.

• Le pignon 67 baladeur, engrené par le pignon 68 porteur, dans le sens antihoraire,
• Le mobile 52 de lune, engrené par le pignon 67 baladeur, dans le sens horaire,
• Le palier 32 de lune, dont la roue 33 de méridien est engrenée par la roue 54 supérieure du mobile de lune, dans le sens antihoraire.

The clockwise rotation of the carrier pinion 68 then successively rotates:

• The sliding pinion 67, meshed by the carrying pinion 68, counterclockwise,
• The moon mobile 52, meshed by the sliding pinion 67, clockwise,
• The moon bearing 32, the meridian wheel 33 of which is meshed by the upper wheel 54 of the moon mobile, in the counterclockwise direction.

As a result, the sphere 9 is driven in a movement of revolution around the main axis A1 in the counterclockwise direction. All these movements are illustrated by arrows on the figure 7 .

It will be noted that, during the correction of the lunar day, the resulting torque C2 which is exerted on the auxiliary wheel 43 exceeds the friction torque CF, so that, while the first rotating element 25 remains fixed in rotation around the axis A1 (because it is blocked by the timer mobile 13), the lanterning 46 gives way and allows the auxiliary wheel to slide relative to the barrel 27 at their interface 45.

The rotation of the winding crown 72 is stopped when the angular position of the radial axis A3 of the sphere 9 around the main axis A1 is decreed correct, which completes the correction of the display of the lunar day.

It is then necessary to correct the display of the moon phase. To do this, the winding crown 72 must be turned in the opposite direction to the direction followed when correcting the display of the lunar day. In the example illustrated on the figure 8 , the winding crown 72 must be turned counterclockwise when viewed along the A6 winding axis.

The rotation of the winding crown 72 drives, via the gear train 77, 78, the pinion 68 carrying counterclockwise (when seen from above), which causes the connecting rods 69 to also tilt counterclockwise until it causes the worm gear pinion gear 67 with the phase gear 73.

• Le pignon 67 baladeur, engrené par le pignon 68 porteur, dans le sens horaire,
• Le renvoi 73 de phase, engrené par le pignon baladeur, dans le sens antihoraire.

The rotation of the winding crown 72 continuing, the counterclockwise rotation of the carrier pinion 68 successively rotates:

• The sliding pinion 67, meshed by the carrying pinion 68, clockwise,
• The phase return 73, meshed by the sliding pinion, counterclockwise.

As soon as the torque C2 reaches the jump torque CS (which the wearer's or watchmaker's fingers are able to produce), the transmission wheel 57, the toothing of which 58 is meshed by the phase gear 73, is itself rotated clockwise. All these movements are illustrated by arrows on the figure 8 .

However, the jump torque CS is less than the friction torque CF of the second element 42 rotating on the first element 25 rotating. Consequently, in spite of the rotation of the transmission wheel 57, the second rotating element remains fixed, since it is integral in rotation with the first rotating element, which is blocked by the timer mobile 13.

Consequently, the jumper (s) 59 is (are) offset (s) radially and jumps (s) from one tooth to another as the rotation of the transmission wheel 57, as illustrated in dotted lines on the figure 9 .

The central wheel 49, integral in rotation with the transmission wheel 57, is driven, with its toothing 50, in rotation about the axis A1 in a clockwise direction. As the moon bearing 32 remains fixed, this rotation of the central wheel causes, via the moon pinion 41 which it meshes, the rotation of the sphere 9 around its radial axis A3, clockwise (when seen according to the 'axis A3). In a first variant, by adding for example an additional mobile to the gear train for correcting the moon phase between the transmission wheel and the sliding pinion, the sphere then rotates counterclockwise, which corresponds to its direction of rotation in operation. normal. In a second variant, by accepting during a correction of the lunar day that the sphere 9 is driven in a movement of revolution around the main axis A1 in the clockwise direction, then the additional mobile can be introduced into the kinematic chain of the correction device 66. As an alternative, in a third variant, provision is made to remove a mobile in the kinematic chain of the correction device 66. Finally, it is also possible to obtain a correction of the moon phase by reversing the relative position of the moon mobile and the transmission wheel, the correction of the moon phase being thus effected by a rotation of the crown in the clockwise while the correction of the lunar day is performed by rotating the crown counterclockwise.

When the star-shaped wheel 47 comprises 29 or 30 teeth, each jump of the jumper (s) 59 from one tooth 48 to the other corresponds to a correction of one day. When the star wheel has 59 teeth, each jump of the jumper (s) from one tooth to another corresponds to a correction of half a day. The wearer or the watchmaker is informed of this correction (of one day or, respectively, of half a day) by the audible click accompanying the jump of the jumper (s).

Once the corrections for the display of the lunar day and of the display of the moon phase have been completed, the wearer pushes the winding crown 72, which translates the shuttle 74 by uncoupling the pinion 76 flowing from the first return 77.

During the normal operation of watch 1, it is not a problem that the sliding pinion 67 remains meshed with the moon mobile 52 (as illustrated in the figure 5 ) or with the phase return 73, since the winder 70 is uncoupled from the carrier pinion 68.

We see that the correction device 66 presented above allows, in a simple, effective, precise and reliable manner, to correct the lunar day and the moon phase in the mechanism 8. For the wearer or the watchmaker, only the direction of rotation determines the correction applied.

Claims (15)

1. Timepiece mechanism (8) for displaying the lunar day and the moon phase, which includes:

   - a first rotating element (25) rotatably mounted about a main axis (A1) and meshing with a drive mechanism (13),

   - a moon bearing (32) provided with a meridian wheel (33) and rotatably mounted about the main axis (A1),

   - a sphere (9) representing the moon, rotatably mounted relative to the moon bearing about a radial axis (A3) perpendicular to the main axis, the radial axis bearing a moon pinion (41),

   - a moon wheel set (52) rotationally coupling, with gear reduction, the first rotating element to the meridian wheel,

   - a central wheel (49), rotatably mounted about the main axis (A1) on the first rotating element and meshing with the moon pinion,

   said mechanism (8) being characterized in that the mechanism includes:

   - a second rotating element (42), meshing with the moon wheel set (52) and friction mounted, at an interface (45), on the first rotating element (25) to rotate integrally therewith about the main axis (A1) while the torque (C1) resulting from various circumferential forces respectively exerted on the first rotating element and on the second rotating element is lower than a friction torque (CF) determining the maximum adhesion force at the interface (45), the second rotating element together with the moon wheel set and the moon bearing forming a first kinematic chain downstream of the first rotating element,

   - a transmission wheel (57), integral in rotation with the central wheel (49) and provided externally with a toothing (58) and internally with at least one jumper spring (59) engaging and meshing with the toothing of a star wheel (47) integral in rotation with the second rotating element, to rotationally couple said second rotating element to the central wheel while the torque (C2) resulting from various circumferential forces exerted respectively on the star wheel and on the transmission wheel (57) is lower than a jump torque, beyond which the jumper spring (59) is radially shifted by sliding over the star wheel (47) until it is disengaged therefrom, said at least one jumper spring and the star wheel being configured such that the jump torque is lower than said friction torque, the transmission wheel together with the central wheel and the moon pinion forming a second kinematic chain downstream of the star wheel,

   - a system for correcting the lunar day display, which includes a first drive element (67) capable of having, at least momentarily, a meshing relationship with the first kinematic chain in order to force rotation of the moon bearing (32) about the main axis (A1), via a first correction train partially formed by at least one portion of the first kinematic chain, when a first correction torque, greater than said friction torque, is applied to said first correction train by a user, and

   - a system for correcting the moon phase, which includes a second drive element (67) capable of having, at least momentarily, a meshing relationship with said second kinematic chain in order to force rotation of the sphere (9) about the radial axis (A3), via a second correction train partially formed by at least one portion of the second kinematic chain and independent of the first kinematic chain, when a second correction torque, greater than said jump torque, is applied to said second correction train by a user.
2. Mechanism (8) according to claim 1, characterized in that the lunar day display correction system and the moon phase correction system include a joint correction device (66) for activating the lunar day display, and without activating the lunar day display, the moon phase, said joint correction device includes a sliding pinion (67) which alone forms the first and second drive elements, said sliding pinion being able to adopt two adjustment positions, namely:

   - a lunar day adjustment position, in which the sliding pinion meshes with the moon wheel set (52) to force rotation of the moon bearing (32) about the main axis (A1) via said at least one portion of the first kinematic chain;

   - a phase adjustment position, in which the sliding pinion meshes with the transmission wheel (57) to force rotation of the sphere (9) about the radial axis (A1) via said at least one portion of the second kinematic chain.
3. Mechanism (8) according to claim 2, characterized in that the joint correction device (66) includes a carrier pinion (68) which meshes with the sliding pinion (67) and at least one connecting rod (69) which joins the axes of rotation of the sliding pinion (67) and of the carrier pinion.
4. Mechanism (8) according to any of the preceding claims, characterized in that the star wheel (47) and the second rotating element (42) are coaxial and integral and in that the transmission wheel (57) and the central wheel (49) are coaxial and integral.
5. Mechanism (8) according to any of the preceding claims, characterized in that the first drive element is able to mesh with the moon wheel set at least during a correction of the lunar day display; and in that the second drive element is able to mesh with the transmission wheel at least during a correction of the moon phase.
6. Mechanism (8) according to any of the preceding claims, characterized in that the first rotating element (25) includes a toothed wheel (26) which extends perpendicularly to the main axis (A1), integral with a pipe (27) that extends along the main axis.
7. Mechanism according to claim 6, characterized in that the second rotating element (42) includes an auxiliary wheel (43) which extends perpendicularly to the main axis (A1), integral with a sleeve (44) which is friction fitted onto the pipe (27) of the first rotating element (25).
8. Mechanism (8) according to claim 7, characterized in that the moon wheel set (52) includes two superposed integral wheels, namely:

   - a lower wheel (53), which meshes with the auxiliary wheel (43) of the second rotating element (42);

   - an upper wheel (54), which meshes with the meridian wheel (33) of the moon bearing (32).
9. Mechanism (8) according to claim 8, characterized in that:

   - the auxiliary wheel of the second rotating element has 64 teeth,

   - the lower wheel of the moon wheel set has 43 teeth,

   - the upper wheel of the moon wheel set has 37 teeth,

   - the meridian wheel of the moon bearing has 57 teeth.
10. Mechanism (8) according to any of the preceding claims, characterized in that the central wheel (49) carries a crown toothing (50) meshed with the moon pinion (41).
11. Mechanism (8) according to any of the preceding claims, characterized in that the central wheel (49) is mounted for free rotation on the first rotating element (25).
12. Mechanism (8) according to any of the preceding claims, characterized in that the moon bearing (32) is mounted for free rotation on the central wheel (49).
13. Mechanism (8) according to claim 12, characterized in that the moon bearing (32) is fitted onto the central wheel with insertion of a smooth bearing (51).
14. Mechanism (8) according to any of the preceding claims, characterized in that the transmission wheel (57) includes a pair of diametrically opposite jumper springs (59).
15. Mechanism (8) according to any of the preceding claims, characterized in that the star wheel (47) has 29, 30 or 59 teeth.

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