EP3765919B1 - Variable geometry timepiece display mechanism with elastic needle - Google Patents

Description

Field of the invention

The invention relates to a timepiece display mechanism with variable geometry, comprising at least one elastic needle which comprises a first drive barrel secured to a first end of a flexible blade, and a second drive barrel secured of another end of said flexible blade, and which comprises a vertex or display index which, in a free unconstrained state of said elastic needle in which both said first barrel and said second barrel are not subject to any constraint and are spaced from each other, is spaced from said first barrel and said second barrel, the service position of said elastic needle being a constrained position where said first barrel and said second barrel are coaxial with each other around an output axis, said display mechanism comprising first means for driving said first barrel around said output axis, and second means for driving said second barrel around said output axis, said first means for drive and second drive means being arranged to deform said flexible blade, by varying the angular position of said second barrel relative to the angular position of said first barrel around said output axis, and to vary the radial position of said vertex or index display relative to said output axis.

The invention also relates to a clock movement comprising at least one such display mechanism.

The invention also relates to a timepiece comprising at least one such clock movement, and/or comprising at least one such display mechanism.

The invention also relates to a scientific device comprising at least one such clockwork movement, and/and comprising at least one such display mechanism.

The invention relates to the field of analog display mechanisms using mobile mechanical components, for timepieces or scientific devices.

Background of the invention

The documents EP2863274 And EP3159751 in the name of MONTRES BREGUET SA describe different arrangements of elastic hands, allowing the adaptation of a display on a timepiece to the shape of its case or its dial, thanks to a radial extension obtained by controlling such an elastic needle comprising flexible segments driven distinctly.

Summary of the invention

The invention aims to provide a reliable and highly robust solution to the problem of providing a variable radial extension indicator depending on its position and its control.

To this end, the invention relates to a timepiece display mechanism comprising at least one such elastic needle, which comprises a first drive barrel secured to at least one flexible blade, according to claim 1.

The invention also relates to a clock movement comprising at least one such display mechanism.

The invention also relates to a timepiece comprising at least one such clock movement, and/or comprising at least one such display mechanism.

The invention also relates to a scientific device comprising at least one such clockwork movement, and/and comprising at least one such display mechanism.

Summary description of the drawings

• la figure 1 représente, de façon schématisée et en vue en plan, une montre, en particulier une montre pour dame de forme ovale, comportant un mécanisme d'affichage selon l'invention, comportant une aiguille élastique à longueur variable, dont l'extrémité distale, qui est formée par un sommet entre deux lames flexibles, est agencée pour parcourir une trajectoire non circulaire; cette aiguille élastique est représentée dans une position à douze heures, dans laquelle l'aiguille élastique a une forme d'amande, et où le sommet est dans sa position la plus éloignée d'un axe de sortie;
• la figure 2 représente, de façon similaire à la figure 1, la même montre, dans une position à six heures de l'aiguille élastique qui a alors une forme de coeur, et où le sommet est dans sa position la plus proche d'un axe de sortie;
• la figure 3 représente, de façon similaire à la figure 1, la même montre, dans la même position et dans la forme en amande de l'aiguille élastique, cette vue montre une trajectoire du sommet qui, par rapport à l'axe de sortie, est en élongation sur un angle de 120° de huit heures à douze heures, et en raccourcissement sur un autre angle de 120°de douze heures à quatre heures ; cette même trajectoire est sensiblement circulaire par rapport à un axe excentré circulaire, sur un angle d'environ 240°, de la position à huit heures à la position à douze heures, et de cette dernière à la position à quatre heures ;
• la figure 4 représente, de façon similaire à la figure 2, la même montre, où le sommet de l'aiguille est dans la position à quatre heures, et où la forme de cette aiguille élastique est désormais une forme de coeur, après un changement de forme intervenu avant cette position à quatre heures ;
• la figure 5 représente, de façon similaire à la figure 4, la même montre, où le sommet de l'aiguille est dans la position à huit heures, et où sa forme est toujours le même coeur, le sommet a parcouru, entre les représentations de la figure 4 et de la figure 5, un cercle ici centré sur l'axe de sortie, et avant un nouveau changement de forme après cette position à huit heures, pour retrouver la forme en amande de la figure 3 ;
• la figure 6 représente, de façon schématisée et en vue en plan, l'aiguille élastique des figures 1 à 5, dans une position de service contrainte, où deux canons d'extrémité qu'elle comporte, aux extrémités de ses deux lames flexibles, sont alignés et superposés l'un à l'autre, chacun entraîné par un mobile différent ;
• la figure 7 est une variante de la figure 6, où le sommet comporte un oeil agencé pour permettre une visualisation particulière sur un cadran ;
• la figure 8 représente, de façon similaire à la figure 1, la même montre, dans la même position et dans une forme à vide, en amande, de l'aiguille élastique, laquelle est libre, dans un état non contraint, et fixée à un mobile d'entraînement par un seul de ses canons ;
• la figure 9 est une vue de gauche de la montre de la figure 8 ;
• la figure 10 représente, de façon similaire à la figure 1, la même montre, dans la même position et où l'aiguille élastique comporte un élément sécable reliant ses deux canons d'extrémité et facilitant son assemblage sur le mouvement d'horlogerie, ainsi que la manipulation du deuxième canon pour sa mise en place au-dessus du premier, avant la rupture par l'horloger des attaches fragiles reliant l'élément sécables aux deux canons ;
• la figure 11 est un schéma de principe, en perspective éclatée, d'un mécanisme d'affichage selon l'invention, où une prise de mouvement, en partie inférieure de la figure, est agencée pour entraîner deux trains de rouages, le premier pour entraîner le premier canon, et le deuxième pour entraîner le deuxième canon; les flèches illustrent la transmission du mouvement; les trains de rouage comportent des rouages de forme, qui sont agencés pour accélérer, stabiliser, ou ralentir la rotation de l'un des canons par rapport à l'autre; l'aiguille élastique est représentée dans un état entièrement libre, sans élément sécable; cette vue montre, encore, une aiguille classique, coaxiale à l'aiguille élastique, pour l'affichage d'une autre information, notamment horaire ;
• la figure 12 est une vue en perspective d'un mécanisme d'affichage selon une variante de l'invention, dans laquelle un mobile d'entrée, agencé pour coopérer avec un mobile de sortie du mouvement d'horlogerie, est coaxial à un arbre d'entraînement, et à une chaussée sur laquelle le premier canon est représenté monté, le deuxième canon étant représenté dans l'état libre de l'aiguille élastique avant son positionnement coaxial au premier canon sur l'arbre d'entraînement ; chaque roue de forme comporte un repérage angulaire de façon à assurer correctement l'effet de rouage de forme ;
• la figure 13, similaire à la figure 12, illustre le positionnement d'un plan de coupe, selon lequel est effectuée la coupe de la figure 14 ;
• la figure 14 est une coupe partielle, selon le plan visualisée en figure 13, d'un mouvement d'horlogerie entraînant un mécanisme selon l'invention ;
• la figure 15 illustre, en vue en plan, un train de rouage à deux étages de façon à pondérer la course angulaire de chaque étage, et où chaque étage comporte un rouage de forme;
• la figure 16 est une vue en plan d'un mécanisme d'affichage selon une variante de l'invention, dans laquelle un mobile d'entrée, agencé pour coopérer avec un mobile de sortie du mouvement d'horlogerie, est distinct de l'axe de sortie, et où chaque train de rouage comporte deux étages de façon à pondérer la course angulaire de chaque étage, et où chaque étage comporte un rouage de forme;
• les figures 17 à 20 illustrent la construction des rouages de forme :
• la figure 17 illustre le choix d'une loi d'espace pour faire varier la longueur radiale de l'aiguille en fonction de l'écart angulaire entre ses deux canons, cette figure illustre l'angle de sortie en fonction de l'angle d'entrée ;
• la figure 18 illustre le calcul des profils primitifs des dentures, selon l'entraxe choisi pour leur réalisation ;
• la figure 19 illustre le calcul de la denture menante, en fonction du nombre de dents défini ;
• la figure 20 illustre le calcul de la denture menée, ce qui permet ensuite le taillage des deux roues au profil ainsi défini ;
• la figure 21, similaire à la figure 17 mais renversée, illustre trois zones successives de rallongement radial de l'aiguille, stabilisation de la longueur de l'aiguille, et de raccourcissement de l'aiguille ;
• la figure 22 est une vue en plan, de la superposition des trois états illustrés par les figures 3 à 5, et les flèches mettent en évidence une phase de contraction CO de l'aiguille entre les positions à douze heures et à quatre heures de son sommet, une phase de stabilité ST à élongation constante entre les positions à quatre heures et à huit heures, et une phase de détente DE entre les positions à huit heures et à douze heures ;
• la figure 23 est un diagramme montrant en ordonnée l'évolution du couple entre les segments flexibles de l'aiguille élastique, en fonction de l'angle parcouru, avec une première zone de réduction de longueur de l'aiguille élastique avec consommation de couple, une deuxième phase de maintien de la longueur de l'aiguille à couple sensiblement constant, et une troisième phase de rallongement de l'aiguille avec restitution du couple ;
• la figure 24 est un diagramme montrant en ordonnée l'évolution du couple sur un canon, en fonction de l'angle de rotation d'un canon ;
• la figure 25 est un diagramme montrant en ordonnée l'extension radiale de l'aiguille, en fonction de l'angle de rotation d'un canon ;
• la figure 26 représente, en vue en plan, un rouage de forme comportant deux roues non de révolution, et comportant des repères pour leur indexage relatif l'une par rapport à l'autre ;
• la figure 27 représente une telle roue, avec une denture en développante, agrandie en loupe ;
• la figure 28 représente une telle roue, avec une denture en sinus, agrandie en loupe ;
• la figure 29 illustre, en perspective éclatée, un mécanisme d'affichage selon l'invention, limité aux canons de l'aiguille élastique qui n'est pas représentée ; ce mécanisme comporte deux différentiels portés par un châssis porte-satellite mobile entre deux flasques fixes porteurs de cames d'entrée des différentiels, et l'ensemble ainsi représenté constitue un bloc additionnel adaptable sur un mouvement existant ; les deux canons de l'aiguille élastique sont ici coaxiaux autour d'une chaussée agencée pour constituer une sortie d'un tel mouvement.

Other characteristics and advantages of the invention will appear on reading the detailed description which follows, with reference to the appended drawings, where:

• there figure 1 represents, schematically and in plan view, a watch, in particular a ladies' watch of oval shape, comprising a display mechanism according to the invention, comprising an elastic needle of variable length, the distal end of which, which is formed by a vertex between two flexible blades, is arranged to travel a non-circular trajectory; this elastic needle is shown in a position at twelve o'clock, in which the elastic needle has an almond shape, and where the top is in its position furthest from an output axis;
• there figure 2 represents, similarly to the figure 1 , the same watch, in a position at six o'clock of the elastic hand which then has a heart shape, and where the top is in its position closest to an output axis;
• there Figure 3 represents, similarly to the figure 1 , the same watch, in the same position and in the almond shape of the elastic needle, this view shows a trajectory of the apex which, relative to the exit axis, is elongated over an angle of 120° of eight hours to twelve o'clock, and shortening on another angle of 120° from twelve o'clock to four o'clock; this same trajectory is substantially circular relative to an eccentric circular axis, over an angle of approximately 240°, from the eight o'clock position to the twelve o'clock position, and from the latter to the four o'clock position;
• there figure 4 represents, similarly to the figure 2 , the same watch, where the top of the hand is in the position at four o'clock, and where the shape of this elastic hand is now a heart shape, after a change in shape occurring before this position at four o'clock;
• there figure 5 represents, similarly to the figure 4 , the same watch, where the top of the hand is in the position at eight o'clock, and where its shape is always the same heart, the top has traveled, between the representations of the figure 4 and some figure 5 , a circle here centered on the exit axis, and before a new change of shape after this position at eight o'clock, to find the almond shape of the Figure 3 ;
• there Figure 6 represents, schematically and in plan view, the elastic needle of the figures 1 to 5 , in a constrained service position, where two end barrels that it includes, at the ends of its two flexible blades, are aligned and superimposed on one another, each driven by a different mobile;
• there Figure 7 is a variant of the Figure 6 , where the top has an eye arranged to allow particular viewing on a dial;
• there figure 8 represents, similarly to the figure 1 , the same watch, in the same position and in an empty, almond-shaped shape, of the elastic hand, which is free, in an unconstrained state, and fixed to a drive mobile by only one of its barrels;
• there Figure 9 is a left view of the watch of the figure 8 ;
• there Figure 10 represents, similarly to the figure 1 , the same watch, in the same position and where the elastic hand has a breakable element connecting its two end barrels and facilitating its assembly on the watch movement, as well as the manipulation of the second barrel for its installation above the first, before the watchmaker breaks the fragile fasteners connecting the breakable element to the two barrels;
• there Figure 11 is a block diagram, in exploded perspective, of a display mechanism according to the invention, where a power take-off, in the lower part of the figure, is arranged to drive two sets of cogs, the first to drive the first cannon, and the second to drive the second cannon; the arrows illustrate the transmission of movement; the gear trains comprise shaped gears, which are arranged to accelerate, stabilize, or slow down the rotation of one of the guns relative to the other; the elastic needle is shown in a completely free state, without breakable elements; this view shows, again, a conventional needle, coaxial with the elastic needle, for displaying other information, in particular time;
• there Figure 12 is a perspective view of a display mechanism according to a variant of the invention, in which an input mobile, arranged to cooperate with an output mobile of the clock movement, is coaxial with a drive shaft , and to a roadway on which the first barrel is shown mounted, the second barrel being shown in the free state of the elastic needle before its positioning coaxial with the first barrel on the drive shaft; each shape wheel has an angular marking so as to correctly ensure the shape cog effect;
• there Figure 13 , similar to the Figure 12 , illustrates the positioning of a cutting plane, according to which the cutting of the Figure 14 ;
• there Figure 14 is a partial section, according to the plan visualized in Figure 13 , a clockwork movement driving a mechanism according to the invention;
• there Figure 15 illustrates, in plan view, a two-stage gear train so as to weight the angular travel of each stage, and where each stage comprises a shaped gear train;
• there Figure 16 is a plan view of a display mechanism according to a variant of the invention, in which an input mobile, arranged to cooperate with an output mobile of the clock movement, is distinct from the output axis , and where each gear train has two stages so as to weight the angular travel of each stage, and where each stage comprises a shaped cog;
• THE figures 17 to 20 illustrate the construction of shape cogs:
• there Figure 17 illustrates the choice of a space law to vary the radial length of the needle as a function of the angular difference between its two barrels, this figure illustrates the exit angle as a function of the entry angle;
• there Figure 18 illustrates the calculation of the original profiles of the teeth, according to the distance chosen for their production;
• there Figure 19 illustrates the calculation of the driving teeth, based on the defined number of teeth;
• there Figure 20 illustrates the calculation of the driven teeth, which then allows the cutting of the two wheels to the profile thus defined;
• there Figure 21 , similar to the Figure 17 but reversed, illustrates three successive zones of radial lengthening of the needle, stabilization of the length of the needle, and shortening of the needle;
• there Figure 22 is a plan view of the superposition of the three states illustrated by the figures 3 to 5 , and the arrows highlight a phase of CO contraction of the hand between the positions at twelve o'clock and four o'clock from its top, a phase of ST stability with constant elongation between the positions at four o'clock and at eight o'clock, and a DE relaxation phase between the eight o'clock and twelve o'clock positions;
• there Figure 23 is a diagram showing on the ordinate the evolution of the torque between the flexible segments of the elastic needle, as a function of the angle traveled, with a first zone of reduction in length of the elastic needle with torque consumption, a second phase maintaining the length of the needle at a substantially constant torque, and a third phase of lengthening the needle with restitution of the torque;
• there Figure 24 is a diagram showing on the ordinate the evolution of the torque on a barrel, as a function of the angle of rotation of a barrel;
• there Figure 25 is a diagram showing on the ordinate the radial extension of the needle, as a function of the angle of rotation of a barrel;
• there Figure 26 represents, in plan view, a shaped cog comprising two wheels not of revolution, and comprising marks for their relative indexing relative to each other;
• there figure 27 represents such a wheel, with involute teeth, enlarged like a magnifying glass;
• there Figure 28 represents such a wheel, with sinus teeth, enlarged like a magnifying glass;
• there Figure 29 illustrates, in exploded perspective, a display mechanism according to the invention, limited to the barrels of the elastic needle which is not shown; this mechanism comprises two differentials carried by a mobile satellite carrier frame between two fixed flanges carrying differential input cams, and the assembly thus represented constitutes an additional block adaptable to an existing movement; the two barrels of the elastic needle are here coaxial around a roadway arranged to constitute an exit from such a movement.

Detailed description of the preferred embodiments

The invention relates to a display indicator for a timepiece or for a scientific device.

The documents EP2863274 And EP3159751 in the name of MONTRES BREGUET SA describe a watch display using an elastic needle, and their characteristics can be directly used for the production of a display mechanism according to the present.

The invention is described here in the particular, but non-limiting, case of a rotary indicator, and in particular of an elastic needle. However, the principle is applicable to an indicator with a mobility trajectory other than circular, for example to a linear cursor, or other, particularly in space. The invention is more precisely described for this application of a flexible indicator with a needle, but it is applicable to other shapes of indicators, in plan or even in three dimensions.

In the same way, drive means comprising cogs are described below, but the invention is equally applicable to analog display means for an electronic or electrical device, a quartz watch or the like.

The principle of the invention is to produce a display mechanism, of which at least one indicator, in particular a hand, for example the minute hand for a watch, has a variable length, or a variable radial extension, or a shape variable.

The invention relates to a timepiece display mechanism 10 with variable geometry, which comprises at least one elastic needle 1. This elastic needle 1 comprises a first drive barrel 2, which is integral with at least one blade flexible 3 in one piece, and a single flexible blade 3 in the particular and non-limiting case of the figures.

The display mechanism 10 comprises an input mobile 71, which is arranged to be pivoted around an input axis by a movement 20, and which defines an input angle with respect to a reference direction .

The elastic needle 1 comprises a first drive barrel 2 secured to a first end of a flexible blade 3, and a second drive barrel 4 secured to another end of this flexible blade 3, and the needle elastic 1 comprises a vertex or display index which, in a free, unconstrained state of this elastic needle 1 in which both the first barrel 2 and the second barrel 4 are not subject to any constraint and are spaced apart from each other. the other, is distant from the first barrel 2 and the second barrel 4. The service position of this elastic needle 1 is a constrained position where the first barrel 2 and the second barrel 4 are coaxial with each other around 'an output axis D.

The display mechanism 10 comprises first means 11 for driving the first barrel 2 around the output axis D, and second means 13 for driving the second barrel 4 around this output axis D.

These first drive means 11 and second drive means 13 are arranged to deform the flexible blade 3, by varying the angular position of the second barrel 4 relative to the angular position of the first barrel 2 around the exit axis D, and to vary the radial position of the vertex or display index relative to the output axis D.

In a particular embodiment, the elastic needle 1, and more particularly its flexible blade 3, comprises a plurality of flexible segments 5, 5A, 5B, which are joined end to end at at least one vertex 6, arranged to constitute such an index, and preferably two successive flexible segments are joined by such a vertex.

In the case of the figures, a first flexible segment 5A of the flexible blade 3 extends between the first barrel 2 and a first vertex 6.

More particularly the invention is illustrated in the most common case where the needle comprises two flexible segments 5 joined by a single vertex 6, which is used for the display.

The display mechanism 10 comprises first means 11 for driving the first barrel 2 around an output axis D, and comprises second means 12 for placing at least the first flexible segment 5 under stress: these second means 12 are arranged to vary the position of at least the first vertex 6 relative to the output axis D. The first vertex 6 is thus at a variable distance from the first barrel 2, depending on the forces applied to the flexible blade 3 by the second means 12 for placing under stress.

THE figures 1 to 5 show a particular case of such a mechanism, with an elastic needle 1 comprising a single vertex 6, which follows over an upper part of its stroke an eccentric circle relative to the output axis, and over a lower part of its stroke another circle centered on the output axis. Naturally this is a special case, and the mechanism 10, for the same oval-shaped watch, can also be dimensioned to follow the contour of the box, or any other contour highlighting the product.

According to the invention, the first drive means 11 and/or the second means 12 for placing under stress, and in particular the second drive means 13 which they comprise, comprise a first cog of shape 111 and/or respectively a second shaped cog 131, which is arranged or which are arranged to accelerate or stabilize in speed or slow down at least the first barrel 2, and/or the second barrel 4, over part of its angular travel.

More particularly, the first drive means 11 and the second means 12 for placing under stress, and in particular the second drive means 13 which they comprise, comprise at least one first cog of shape 111 and respectively at least one second cog. of shape 131 which are arranged to accelerate or stabilize in speed or slow down the first barrel 2, and respectively the second barrel 4, over at least part of the angular travel of the first barrel 2, and respectively of the second barrel 4.

In a particular realization, illustrated by the figures 1 to 5 , the first drive means 11 and the second stressing means 12 are arranged to drive the elastic needle 1 over its entire angular travel around the output axis D, and give it, in projection on a display plane P or on a dial, and at different angular positions of the elastic needle 1, at least a first shape where the flexible segments 5: 5A, 5B, which the flexible blade 3 comprises do not cross outside of the first canon 2, and at least one second shape where the flexible segments 5: 5A, 5B, which the flexible blade 3 comprises, intersect outside the first barrel 2. In the particular and non-limiting case illustrated by the figures, this first shape is an almond shape, and this second shape is a heart shape. In another variant where the elastic needle 1 travels the surface defined by an ellipse, this needle can successively occupy, on its revolution, an alternation of first shapes and second shapes, for example an almond shape on each of the two ends of the major axis of the ellipse, and a heart shape on each of the two ends of the minor axis of the ellipse.

More particularly, and as taught by the documents EP2863274 And EP3159751 the elastic needle 1 comprises a second drive barrel 4 also integral with the flexible blade 3. The second means 12 for placing under stress then comprise second means 13 for driving the second barrel 4 in a mounted and constrained state of the elastic needle 1. In this mounted state of the elastic needle, both the first barrel 2 is, advantageously but not necessarily in a pre-stressed operating state, driven by the first drive means 11, and the second barrel 4 is, advantageously but not necessarily in a pre-stressed operating state, driven by the second drive means 13. And at least one of the vertices 6 is, in a free, unconstrained state of the elastic needle 1 in which both the first barrel 2 and the second barrel 4 are not subject to any constraint, distant from the first barrel 2 and the second barrel 4, which first barrel 2 and second barrel 4 are spaced from each other in this free state of the elastic needle 1.

In the particular case of the figures where the flexible blade 3 only comprises a first flexible segment 5A and a second flexible segment 5B, this vertex 6 which joins them is unique. Thus, more particularly, this first flexible segment 5A carries the first barrel 2 at a first end 52, this second flexible segment 5B joined to the first flexible segment 5A carries the second barrel 4 at a second end 54. And, in the free state of the elastic needle 1, the first end 52 and the second end 54 are spaced apart from each other, or form a non-zero angle with each other from the junction vertex 6 of the first flexible segment 5A and the second flexible segment 5B.

More particularly, the outlet of the second drive means 13 of the second barrel 4 is coaxial with the outlet of the first drive means 11 of the first barrel 2, in the mounted state of the elastic needle 1. This arrangement is however not obligatory, in particular in the case of a retrograde display, where the axes of the first barrel 2 and the second barrel 4 can be distinct.

According to the invention, the first drive means 11 and the second drive means 13 comprise an accelerator or retarder device, which is arranged to accelerate or stabilize in speed or slow down at least the first barrel 2 and/or said second barrel 4 over at least part of its angular travel.

In a variant, the first barrel 2 has an advance or a delay relative to the value of the entry angle which is symmetrical to the delay or advance of the second barrel 4 relative to the entry angle, so that the first vertex 6 always displays, with respect to the output axis D and the reference, an angle equal to the entry angle.

In another variant, the first barrel 2 has an advance or a delay with respect to the value of the entry angle which is, in absolute value, different from the delay or the advance of the second barrel 4 with respect to the entry angle, so that the first vertex 6 displays, relative to the output axis D and to the reference, a variable angle relative to the entry angle throughout its travel. This particular arrangement of advance and/or delay relative to the input barrel allows the hand to point the time (or another display) exactly on the dial, and in particular for a non-regular display, for example a square trajectory where the time is separated into twelve equidistant segments on the square trajectory, which cannot be managed in the same way as twelve indexes separated by 30°.

In yet another variant, the needle 1 is arranged to perform a total non-retrograde stroke, and, over the total stroke, the average speed of the first barrel 2 is equal to the average speed of said second barrel 4.

• si les bras de l'aiguille sont symétriques, il faut une avance et retard symétriques, en sorte que l'aiguille pointe l'heure juste ;
• si les bras de l'aiguille sont asymétriques, il faut une avance et retard en sorte que l'aiguille pointe l'heure juste ;
• on part du principe que l'aiguille pointe l'heure juste. On peut aussi avoir une graduation qui n'est pas séparée tous les 30° comme expliqué ci-dessus.

Many configurations can be considered:

• if the arms of the hand are symmetrical, it is necessary to advance and delay symmetrically, so that the hand points the correct time;
• if the arms of the hand are asymmetrical, it is necessary to advance and delay so that the hand points the correct time;
• we assume that the hand points to the correct time. We can also have a graduation which is not separated every 30° as explained above.

In a particular embodiment which will be detailed below, the accelerator or retarder device comprises a first cog of shape 111 and/or respectively a second cog of shape 131.

In another particular embodiment which will be detailed later, the accelerator or retarder device comprises a device with a first differential 912 on the drive train of the first barrel 2 and/or a second differential 914 on the drive train of the second barrel, and at least one cam 902, 904, constituting an input to such a differential 912, 914.

In yet another embodiment, the accelerator or retarder device comprises simple cogs arranged suitably to carry out the required accelerations or decelerations.

More particularly, and as visible on the figures 11 to 20 , the first drive means 11 and the second drive means 13 comprise, respectively, at least one first gear of shape 111 and at least one second gear of shape 131, which are each arranged or which are arranged to accelerate or stabilize in speed or slow down the first barrel 2 and respectively the second barrel 4 over part of its angular travel. By shaped cog we mean here that at least one wheel of the cog does not rotate; more particularly, at least two opposing wheels of this cog are not of revolution, and are arranged to mesh permanently with minimal play with one another at constant center distance.

More particularly, the first shaped cog 111 and the second shaped cog 131 are arranged to accelerate or respectively brake the first barrel 2, and to brake or respectively accelerate the second barrel 4 over at least part of the angular travel of the elastic needle 1, or even on only part of the angular travel of the elastic needle 1. Stated differently, one of the guns takes an angular advance relative to the entry angle, while the other gun takes a delay angular relative to the entry angle.

Thus, in a particular embodiment of the invention, the first barrel 2 has an advance or a delay relative to the value of said entry angle which is symmetrical to the delay or advance of the second barrel 4 relative to this same entry angle, so that the first vertex 6 always displays, with respect to the exit axis D and the reference direction, an angle equal to the entry angle.

Thus, considering the realization according to the figures 3 to 5 , with a total CAT angular travel of 360°, from a position in Figure 3 where the top 6 of the hand 1 is at twelve o'clock, to move into the position at four o'clock of the figure 4 , by rotating clockwise, the second barrel 4 of the second flexible segment 5B slowed down by 60°, and the first barrel 2 of the first flexible segment 5A accelerated by 60°. In fact, none of the flexible segments 5 of hand 1 alone indicates the time; it is only the result of the rotation of the two barrels which determines a time indication by the top 6 of hand 1. Between the position of the figure 4 and at the eight o'clock position of the figure 5 , the guns remain synchronous with their offset. To move from the eight o'clock position of the figure 5 to that at twelve o'clock Figure 3 , it is the opposite, the second barrel 4 of the second flexible segment 5B has accelerated by 60°, and the first barrel 2 of the first flexible segment 5A has slowed down by 60°.

The invention is illustrated in the figures by the particular case of a continuous watch display displaying a complete revolution, it is understood that the invention is applicable to any display, in particular a retrograde display.

According to the invention, the first shaped cog 111 and the second shaped cog 131 are arranged to symmetrically control the first barrel 2 and the second barrel 4, so that the first flexible segment 5A and the second flexible segment 5B are symmetrical with respect to a radial coming from the output axis D and passing through the vertex 6 of junction between the first flexible segment 5A and the second flexible segment 5B, over at least part of the angular stroke of the elastic needle 1 This configuration is not limiting, but it offers the advantage of subjecting the first flexible segment 5A and the second flexible segment 5B to symmetrical constraints.

More particularly, the first cog of shape 111 and the second cog of shape 131 each comprise at least one pair of wheels arranged to cooperate in meshing with one another and whose geometric supports, i.e. say the primitive curves, the teeth are not of revolution.

Even more particularly, the first drive means 11 and/or the second drive means 13 comprise at least a first gear stage 115, 135, and a second gear stage 116, 136, which are arranged to each control a part of the shape transformation of the elastic needle 1 over at least part of its angular travel, with a weighting per floor. This weighting makes it possible to distribute part of the deformation on each of the stages, which allows, in each shaped cog, to maintain wheels whose geometry is close to a circular geometry, so as to allow suitable meshing of the teeth, and prevent their wear. Indeed, the shaped cogs are not circular, but must not be too deformed, that is to say that their shape must allow meshing without bracing, and without too much sensitivity to variations in center distance and manufacturing tolerances. We can thus avoid the interference defects that cut teeth would present if the original curves of the teeth moved too far from the circular shape. It is therefore a question of defining a compromise between a shape that is sufficiently non-circular to operate the needle, and a shape that is resistant to use. The distribution over several stages makes it possible to fulfill these conditions: each stage participates in the deformation of the needle, but its primitive curves remain close to a circular shape, this is what we call here the weighting by stage, the overall accumulation of these stepped cogs making it possible to ensure the desired deformation at the level of the needle.

The figures illustrate non-limitatively a variant with two stages of gears, but this number of two is not limiting, only the total thickness of the movement and the loss of efficiency due to friction limit the number of stages.

More particularly, both the first gear stage 115, 135, and the second gear stage 116, 136, respectively comprise a first gear train of shape 111 and a second gear train of shape 131.

THE figures 11 to 20 detail certain particular arrangements of such shaped cogs.

• un premier train de rouage comporte des roues folles 79 et 80 autour d'un premier axe DA et des roues 73, 78, et 81 autour de l'axe principal de pivotement D pour entraîner le premier canon 2,
• et un deuxième train de rouage comporte des roues folles 74, 75, autour d'un deuxième axe DB et une roue 76 autour de l'axe principal de pivotement D pour entraîner le deuxième canon 4.

There Figure 11 schematizes the operation of such a mechanism 10, the arrows symbolize the transmission of the movement to the guns, from a power take-off 21 at the level of a clockwork movement 20, which can be both mechanical and electronic, symbolized in part lower of the figure, and which is arranged to drive two sets of cogs via the same input mobile 71:

• a first gear train comprises idler wheels 79 and 80 around a first axis DA and wheels 73, 78, and 81 around the main pivot axis D to drive the first barrel 2,
• and a second gear train comprises idler wheels 74, 75 around a second axis DB and a wheel 76 around the main pivot axis D to drive the second barrel 4.

We notice that the entire cog is under tension, due to the elastic needle taking up play due to its preload.

There Figure 11 shows, again, a classic needle 101, coaxial with the elastic needle 1, for displaying other information, in particular time.

THE figures 12 to 14 illustrate more precisely a display mechanism 10 according to a variant of the invention, for displaying the minutes with the elastic hand 1. In this variant, an input mobile 71 is arranged to cooperate with an output mobile 21 of the clockwork movement 20, along an input axis D0, and is guided on a fixed tube 70. This input mobile 71, which is a roadway, is arranged to drive, directly or through a lantern by friction allowing time setting adjustment, a driving roadway 72 which is coaxial with it.

This driving roadway 72 is of revolution, and drives a first wheel of shape 78, which meshes with a second wheel of complementary shape 79 mounted loosely (with clearance compensation) around the first axis DA, and which is pivotally secured to a third wheel of shape 80, which meshes with a fourth idler wheel of complementary shape 81, which here pivots around the output axis D of the guns, and which includes a roadway 82 for fixing the first gun 2.

The same driving road 72 drives a fifth wheel of shape 73, which meshes with a sixth wheel of complementary shape 74 mounted loosely around the second axis DB, and which is pivotally integral with a seventh wheel of shape 75, which meshes with a eighth idler wheel of complementary shape 76, which here pivots around the output axis D of the guns, and is integral with a shaft 77 on which the second gun 4 is fixed.

Each shape wheel has an angular marking so as to correctly ensure the indexing of the shape cog, as detailed in Figure 26 which details a shaped cog comprising two wheels 75 and 76 not of revolution, and comprising marks 275 and 276 for their relative indexing with respect to each other, as well as oblongs 175 and 176 facilitating their installation, this which makes it possible in particular to secure them and index them by means of a pin or the like.

The driving road 72 also drives a ninth wheel 91 which comprises a mobile pivoting around an hour axis DH, which comprises a pinion 92 driving the wheel 93 of an hour road 94 receiving the hour hand 100.

• un premier train de rouage comporte un premier étage avec une première roue de forme 101 pivotant autour de l'axe d'entrée D0, qui engrène avec une deuxième roue de forme complémentaire 102, montée folle autour d'un premier axe secondaire D1. Cette deuxième roue de forme complémentaire 102 est solidaire en pivotement d'une troisième roue de forme 103, qui engrène avec une quatrième roue de forme complémentaire 104, montée pivotante sur l'axe de sortie D, et conçue pour la fixation d'un des deux canons ;
• un deuxième train de rouage, isolé sur la figure 16, comporte un premier étage avec une première roue de forme 201 pivotant autour de l'axe d'entrée D0, qui engrène avec une deuxième roue de forme complémentaire 202, montée folle autour d'un deuxième axe secondaire D2. Cette deuxième roue de forme complémentaire 202 est solidaire en pivotement d'une troisième roue de forme 203, qui engrène avec une quatrième roue de forme complémentaire 204, montée pivotante sur l'axe de sortie D, et conçue pour la fixation de l'autre canon.

THE figures 15 and 16 illustrate a variant of the invention, in which an input mobile, arranged to cooperate with an output mobile of the clock movement, pivots around an input axis D0 which is here distinct from the output axis D, and where each gear train has two stages so as to weight the angular travel of each stage, and where each stage comprises a gear of shape:

• a first gear train comprises a first stage with a first wheel of shape 101 pivoting around the input axis D0, which meshes with a second wheel of complementary shape 102, mounted loosely around a first secondary axis D1. This second wheel of complementary shape 102 is pivotally integral with a third wheel of shape 103, which meshes with a fourth wheel of complementary shape 104, pivotally mounted on the output axis D, and designed for fixing one of the two cannons;
• a second gear train, isolated on the Figure 16 , comprises a first stage with a first wheel of shape 201 pivoting around the input axis D0, which meshes with a second wheel of complementary shape 202, mounted loosely around a second secondary axis D2. This second wheel of complementary shape 202 is pivotally integral with a third wheel of shape 203, which meshes with a fourth wheel of complementary shape 204, pivotally mounted on the output axis D, and designed for fixing the other canon.

The case of a construction with radial symmetry of movement between the two flexible segments of the same needle 1 uses two similar sets of cogs of identical shape, one mounted right side up, the other upside down.

THE figures 17 to 20 illustrate the construction of the shape cogs, which begins with the choice of a space law to vary the radial length of the needle as a function of the angular distance between its two barrels, the figure17 illustrates the exit angle versus the entry angle for one of the two needle barrels. This space law allows the calculation of the original profiles of the teeth, according to the distance chosen for their production, as visible on the Figure 18 . The calculation of the leading teeth is then carried out according to the number of teeth defined, and the type of profile chosen, in particular involute or sinus type, depending on the Figure 19 , Then the calculation of the driven teeth, according to the Figure 20 , then allows the cutting of the two wheels to the profile thus defined;
THE figures 17 and 20 illustrate the law of space, with three successive zones of radial extension of the needle, stabilization of the length of the needle where the ratio between the exit angle of one of the two barrels and the entry angle into the mechanism is substantially constant, and shortening of the needle.

There Figure 22 shows the superposition of the three states illustrated by the figures 3 to 5 , and the arrows highlight a phase of contraction CO of the hand 1 between the positions at twelve o'clock and at four o'clock of its summit 6, a phase of stability ST with constant elongation between the positions at four o'clock and at eight o'clock , and a DE relaxation phase between the eight o'clock and twelve o'clock positions. This weighting is made possible by the use of shaped gears, and in particular mechanisms with several stages of shaped gears, which make it possible to impose sufficient angular deflections on the barrels, to authorize significant changes in shape, and in particular to be able to cross the flexible segments as in the shape of a heart. These shaped cogs make it possible to safely slow down one barrel relative to the other.

The wheel of Figure 27 is an example of optimization case of this Figure 22 ; to correct the trajectories on angles of 140°-80°-140° as illustrated, instead of 120°-120°-120° which would be more balanced, it is necessary, without weighting per particular floor, that is to say -say if the upper stage and the lower stage each carry out half of the angular transformation, to design wheels with very strong deformations, and very inclined teeth, difficult to machine, and fragile. Another weighting, for example 20% of the deformation on the lower level and 80% on the upper level allows to have wheels closer to a round shape, easier to machine, and with teeth close to the standard , therefore with better kinematic and tribological parameters, and less wear.

There Figure 23 shows the evolution of the torque between the flexible segments of the elastic needle, as a function of the angle traveled, with a first zone of reduction in length of the elastic needle with torque consumption, a second phase of maintaining the length of the needle at substantially constant torque, and a third phase of extension of the needle with restitution of the torque, the Figure 24 illustrates the evolution of the torque on a barrel, as a function of the angle rotation of a cannon, and the Figure 25 shows the radial extension of the needle, as a function of the angle of rotation of a barrel.

The elastic needle 1 can be made in different ways.

In a variant, in the free state, the elastic needle 1 extends over a single plane level comprising the first barrel 2 and the second barrel 4, and the elastic needle 1 is then arranged to be mounted twisted in a position service under stress in which the first barrel 2 and the second barrel 4 are superimposed on one another.

In a variant, in the free state, the elastic needle 1 extends over a first plane level comprising the first barrel 2 and over a second plane level comprising the second barrel 4, and comprises a connection zone between the first level plane and the second plane level at the level of a vertex 6 between a first flexible segment 5A carrying the first barrel 2 and a second flexible segment 5B joined to the first flexible segment 5A and carrying the second barrel 4, and the elastic needle 1 is arranged to be mounted without twisting in a service position under stress in which the first barrel 2 and the second barrel 4 are superimposed on one another. In another particular variant, when the elastic needle 1 has more than two flexible segments 5, in the free state, the elastic needle 1 extends over, at most, as many parallel levels as there are flexible segments 5, and is arranged to be mounted without twisting in a service position under stress in which the first barrel 2 and the second barrel 4 are superimposed on one another.

According to the invention, to facilitate assembly, as illustrated in the Figure 10 , in the free state, the elastic needle 1 comprises a breakable element 24 joining the first barrel 2 and the second barrel 4, to facilitate the mounting of the elastic needle 1 on a drive mobile of the first barrel 2 or the second barrel 4, this breakable element 24 being arranged to be broken and allow the passage of the elastic needle 1 into a service position under stress in which the first barrel 2 and the second barrel 4 are superimposed on each other .

There Figure 7 illustrates a particular variant where the elastic needle 1 comprises at least one eye 60, which is arranged to constitute a window for reading an indication appearing on a dial 61 which the mechanism 10 comprises, and in front of which the needle extends elastic 1, or which comprises a clockwork movement 20, on which the mechanism 10 is arranged to be attached. For example this eye allows to visualize a city in a GMT application, or to distinguish the morning time from 0 to 12 from the afternoon time from 13 to 24, in a particular application where the training of the display mechanism is made on two revolutions, the first with a certain extension of the elastic hand 1 for the display of the morning hours, and the second with a different extension for the display of the afternoon hours; of course this variant can also accommodate a display via the top 6 of the needle 1, the presence of such an eye 60 provides reading comfort to the user. There Figure 7 further illustrates two indexes, interior and exterior, on either side of this eye 60, which also allow particular readings, depending on the dial configuration adopted. One of the great advantages of the invention is to allow great freedom of design of the dial, and the transfer of certain display zones outside of unavailable zones, for example due to the presence of a tourbillon, or even of another complication.

Advantageously, the needle 1 is made of micro-machinable material according to a “LIGA” process, in particular of nickel-phosphorus NiP ₁₂ or similar. Such a needle can be gold, or receive another coloring, the adhesion being satisfactory on such a material. Needle 1 can be colored by different processes: PVD, CVD, ALD, galvano, paint, lacquer, or other coating or ionization.

The needle 1 may include a gem setting or similar, and/or a decoration by guilloché, engraving, bevelling, or even enamelling, the latter being reserved for areas with low deformation such as the circumference of the barrels, an eye circumference, the tip, or similar.

More particularly, the mechanism 10 constitutes an additional module, which is arranged to be attached to a clock movement 20, and the first drive means 11 and the second stressing means 12 comprise a common input 71, which is arranged to be driven by a single output 21 that the movement 20 includes, such as the roadway which rotates in one hour, or the minute mobile.

In a variant, in addition to or in place of the shaped cogs, the mechanism 10 comprises, on the one hand the input mobile 71 arranged to be driven by the movement 20, and on the other hand the first barrel 2 and /or the second barrel 4, at the level of at least one stage, a cam 902, 904. This cam is arranged to control a differential 912, 914, a first input of which is in particular constituted by the input mobile 71 or by a mobile, of which a second input is a mobile, in particular a rake controlled by this cam 902, 904, and whose output meshes with the movement transmission gear to the first barrel 2 or respectively to the second barrel 4.

In a first application of this variant, the mechanism 10 comprises, between the input mobile 71 and the first barrel 2 at at least one stage, a single cam 902 arranged to control a first differential 912 of which a first input is constituted by the input mobile 71, a second input of which is a first mobile or a first rake controlled by the cam 902, and whose output meshes with the cog for transmitting the movement to the first barrel 2, and between the mobile of input 71 and the second barrel 4, the same single cam 902 arranged to control a second differential 914, a first input of which is constituted by the input mobile 71, a second input of which is a second mobile or a second rake controlled by the cam 902, and whose output meshes with the movement transmission gear to the second barrel 4.

In a second application of this variant, the mechanism 10 comprises, between the input mobile 71 and the first barrel 2 at at least one stage, a first cam 902 arranged to control a first differential 912 of which a first input is constituted by the input mobile 71, a second input of which is a first mobile or first rake controlled by the first cam 902, and whose output meshes with the cog for transmitting the movement to the first barrel 2; and, between the input mobile 71 and the second barrel 4, a second cam 904 driven by the input mobile and arranged to control a second differential 914, a first input of which is constituted by the input mobile 71, one of which second input is a second rake controlled by the second cam 904, and whose output meshes with the gear train transmitting the movement to the second barrel 4.

The use of a cam allows highly non-circular trajectories, and also with needle jumps. The use of a single cam for the two differentials makes it possible to perform a simultaneous jump of the two guns, for example at midnight; the first differential adds the cam information for the first barrel, and the second differential subtracts the information for the second barrel.

In another particular variant, at least one wheel included in the cog mechanism arranged between on the one hand the input mobile 71 arranged to be driven by a movement 20, and on the other hand the first barrel 2 and/or the second barrel 4, at the level of at least one stage, has incomplete teeth, each missing tooth allowing relaxation of the elastic needle 1, by rotation of only one of the barrels 2, 4, during the passage of the space corresponding to a missing tooth, or missing teeth, so as to control a recoil of the top 6 of the elastic needle 1.

In particular, it is then possible to use a cog comprising one or more, or even all, of the circular wheels, of which at least one circular wheel is devoid of one or more teeth to allow the needle to relax, and to make a jump. at the end of the so-called display spiral path carried out by the top 6 of the needle 1. If for example the first barrel rotates faster than the second barrel, and if the driving road 72 is locally devoid of teeth, the needle tends to contract, for example over two revolutions, and, when the missing teeth release the first barrel, the needle tightens but the second barrel does not move, the top of the needle moves back. The advantage of such a variant is that it allows conventional wheel machining.

There Figure 24 shows the very low level of torque consumption for the deformation of such a needle 1 in LIGA, during its shortening, which has only a very slight influence on the progress of the movement. Due to the proximity of the exhaust, it is nevertheless advantageous to reduce this disturbance as much as possible, which can be obtained with very thin flexible segments 5, typically less than 100 micrometers in width and 200 micrometers in height for a LIGA construction. We understand on the Figure 24 , where we see that the torque curve as a function of angle is U-shaped with a very flat bowl, that it is advantageous, during design, to choose an angular range of deformation corresponding to the lowest level of the torque curve, so as to minimize the induced parasitic torque, and therefore to minimize the disturbance to the running of the watch. A staged design with particular weighting helps to choose the optimal angular domains. The correct choice of this angular range also makes it possible to thicken the segments 5 of the needle 1 to make it more visible, without significantly increasing its disruptive torque.

For comparison, the disturbance induced on the step is less than that caused by a change of date at midnight for a date mechanism.

The invention is illustrated in the figures with a simple form, but it can be adapted with very different needle shapes. For example an asymmetrical needle, composed of two vees nested one inside the other and in the same direction, each arm of each vee being attached to one of the barrels, and the extreme end of the other arm being linked to the similar end of the other vee. Or a double-armed needle, with two segments joining a first vertex and fixed to the two barrels, and two other segments joining a second vertex distant from the first, and fixed to the same barrels. Or a needle comprising thickened zones on a central zone of the flexible segments, for better visualization of the needle.

The invention also relates to a clock movement 20 comprising at least one such display mechanism 10.

The invention also relates to a timepiece 30 comprising at least one timepiece movement 20, and/or comprising at least one such display mechanism 10. More particularly, 21 this timepiece 30 is a watch.

The invention also relates to a scientific device comprising at least one clockwork movement 20, and/or comprising at least one such display mechanism 10.

Claims (26)

1. Variable-geometry timepiece display mechanism (10) comprising at least one resilient hand (1) which comprises a first drive pipe (2) integral with a first end of a flexible strip (3), and a second drive pipe (4) integral with another end of said flexible strip (3), and which comprises a display index or tip which, in an unstressed free state of said resilient hand (1) wherein both said first pipe (2) and said second pipe (4) are not subjected to any stress and are remote from one another, is remote from said first pipe (2) and from said second pipe (4), the operating position of said resilient hand (1) being a stressed position where said first pipe (2) and said second pipe (4) are coaxial to one another about an output axis (D), said display mechanism (10) comprising first means (11) for driving said first pipe (2) about said output axis (D), and second means (13) for driving said second pipe (4) about said output axis (D), said first drive means (11) and second drive means (13) being arranged so as to deform said flexible strip (3), by varying the angular position of said second pipe (4) relative to the angular position of said first pipe (2) about said output axis (D), and so as to vary the radial position of said display index or tip relative to said output axis (D), wherein said first drive means (11) and/or said second drive means (13) comprise an accelerator or decelerator device, which is arranged such that it accelerates, or stabilises the speed of, or slows down at least said first pipe (2) and/or said second pipe (4) over at least part of the angular travel thereof, wherein said accelerator or decelerator device comprises a first shaped gear train (111) and/or respectively a second shaped gear train (131), and wherein said first shaped gear train (111) and said second shaped gear train (131) are arranged such that they symmetrically control said first pipe (2) and said second pipe (4), such that said flexible strip (3) is symmetrical relative to a radial originating from said output axis (D) and passing by way of said tip or index, over at least part of the angular travel of said resilient hand (1), characterised in that in the free state, said resilient hand (1) comprises a divisible element (24) joining said first pipe (2) and said second pipe (4), in order to facilitate the assembly of said resilient hand (1) on a drive wheel set of said first pipe (2) or of said second pipe (4), said divisible element (24) being arranged such that it can be broken and allow for the passage of said resilient hand (1) into a stressed operating position wherein said first pipe (2) and said second pipe (4) are superimposed on one another.
2. Mechanism (10) according to claim 1, characterised in that said resilient hand (1) comprises a plurality of flexible segments (5; 5A; 5B) that are joined end-to-end at at least one tip, a first flexible segment (5A) whereof extends between said first pipe (2) and a first tip (6) forming a said index, and on the other hand said second pipe (4), said display mechanism (10) comprising an input wheel set (71), arranged so as to be driven such that it pivots about an input axis by a movement (20), and which defines an input angle with a reference, and comprising said first means (11) for driving said first pipe (2), and second means (12) for stressing at least said first flexible segment (5), which are arranged so as to vary the position of at least said first tip (6) relative to said output axis (D), said first tip (6) being at a variable distance from said first pipe (2), as a function of the forces applied to said flexible strip (3) by said second stressing means (12), wherein said second stressing means (12) comprise said second means (13) for driving said second pipe (4) in an assembled and stressed state of said resilient hand (1) in which both said first pipe (2) is driven by said first drive means (11), and said second pipe (4) is driven by said second drive means (13), characterised in that said first shaped gear train (111) and said second shaped gear train (131) are arranged such that they symmetrically control said first pipe (2) and said second pipe (4), such that said first flexible segment (5A) and said second flexible segment (5B) are symmetrical relative to a radial originating from said output axis (D) and passing by way of said tip (6) at which said first flexible segment (5A) and said second flexible segment (5B) are joined, over at least part of the angular travel of said resilient hand (1).
3. Mechanism (10) according to claim 1 or 2, characterised in that said hand (1) is arranged such that it travels a total non-retrograde path and that, over said total path, the average speed of said first pipe (2) is equal to the average speed of said second pipe (4).
4. Mechanism (10) according to one of claims 1 to 3, characterised in that said accelerator or decelerator device comprises a device with a first differential gear (912) on the drive gear train of said first pipe (2) and/or a second differential gear (914) on the drive gear train of said second pipe, and at least one cam (902, 904) forming an input of a said differential gear (912, 914).
5. Mechanism (10) according to one of claims 1 to 4, characterised in that said first drive means (11) and/or said second drive means (13) comprise at least one first gear train stage (115; 135) and one second gear train stage (116; 136), arranged such that each controls a part of the shape transformation of said resilient hand (1) over part of the angular travel thereof, with distribution per stage.
6. Mechanism (10) according to one of claims 1 to 5, characterised in that said first drive means (11) and said second drive means (13) respectively comprise at least one first shaped gear train (111) and/or at least one second shaped gear train (131), each arranged so as to accelerate or stabilise the speed of, or slow said first pipe (2), and respectively said second pipe (4), over at least part of the angular travel of said first pipe (2), and respectively of said second pipe (4).
7. Mechanism (10) according to claim 2 and one of claims 1 to 6, characterised in that said first drive means (11) and said second stressing means (12) are arranged so as to drive said resilient hand (1) over the entirety of the angular travel thereof about said output axis (D), and provide it, in projection on a display plane P or on a dial, and at different angular positions of said resilient hand (1), with at least one first shape in which said flexible segments (5; 5A; 5B) comprised in said flexible strip (3) do not cross paths outside of said first pipe (2), and at least one second shape in which said flexible segments (5; 5A; 5B) comprised in said flexible strip (3) cross paths outside of said first pipe (2).
8. Mechanism (10) according to claim 7, characterised in that said first shape is an almond shape, and said second shape is a heart shape.
9. Mechanism (10) according to claim 2 and one of claims 1 to 8, characterised in that said first flexible segment (5A) bears said first pipe (2) at a first end (52), and a second flexible segment (5B) joined to said first flexible segment (5A) bears said second pipe (4) at a second end (54), and in that, in said free state of said resilient hand (1), said first end (52) and said second end (54) are remote from one another, or form a non-zero angle with one another from said tip (6) at which said first flexible segment (5A) and said second flexible segment (5B) are joined.
10. Mechanism (10) according to one of claims 1 to 9, characterised in that the output of said second drive means (13) of said second pipe (4) is coaxial to the output of said first drive means (11) of said first pipe (2).
11. Mechanism (10) according to one of claims 1 to 10, characterised in that said first shaped gear train (111) and said second shaped gear train (131) are arranged so as to accelerate or respectively brake said first pipe (2), and to brake or respectively accelerate said second pipe (4) over only part of the angular travel of said resilient hand (1).
12. Mechanism (10) according to one of claims 1 to 11, characterised in that said first shaped gear train (111) and/or said second shaped gear train (131) comprise at least one pair of wheels arranged such that they engage by gearing with one another and the primitive curves of the toothings whereof are not axisymmetric.
13. Mechanism (10) according to claim 5 and one of claims 1 to 12, characterised in that said first gear train stage (115; 135) and said second gear train stage (116; 136) respectively comprise a said first shaped gear train (111) and a said second shaped gear train (131).
14. Mechanism (10) according to claim 2 and one of claims 1 to 13, characterised in that in the free state, said resilient hand (1) extends over a first planar level comprising said first pipe (2) and over a second planar level comprising said second pipe (4), and comprises a connecting area between said first planar level and said second planar level at one said tip (6) between a first flexible segment (5A) bearing said first pipe (2) and a second flexible segment (5B) joined to said first flexible segment (5A) and bearing said second pipe (4), and in that said resilient hand (1) is arranged such that it is mounted in a non-twisted manner in a stressed operating position wherein said first pipe (2) and said second pipe (4) are superimposed on one another.
15. Mechanism (10) according to claim 2 and one of claims 1 to 14, characterised in that in the free state, said resilient hand (1) extends over as many parallel levels as there are said flexible segments (5), and is arranged such that it is mounted in a non-twisted manner in a stressed operating position wherein said first pipe (2) and said second pipe (4) are superimposed on one another.
16. Mechanism (10) according to one of claims 1 to 14, characterised in that in the free state, said resilient hand (1) extends over a single planar level comprising said first pipe (2) and said second pipe (4), and in that said resilient hand (1) is arranged such that it is mounted in a twisted manner in a stressed operating position wherein said first pipe (2) and said second pipe (4) are superimposed on one another.
17. Mechanism (10) according to one of claims 1 to 16, characterised in that said resilient hand (1) comprises at least one eye (60) arranged such that it forms an aperture for reading information appearing on a dial (61) comprised in said mechanism (10), and in front of which said resilient hand (1) extends, or comprised in a horological movement (20) on which said mechanism (10) is arranged for attachment thereto.
18. Mechanism (10) according to one of claims 1 to 17, characterised in that said first drive means (11) and said second stressing means (12) comprise a common input (71) arranged so as to be driven by a single output (21) comprised in said movement (20).
19. Mechanism (10) according to claims 4 and 5, and according to one of claims 1 to 19, characterised in that said mechanism (10) comprises, between on the one hand an input wheel set (71) arranged so as to be driven by a movement (20), and on the other hand said first pipe (2) and/or said second pipe (4), at at least one said stage, a cam (902, 904) arranged such that it controls a differential gear (912, 914), a first input whereof is formed by said input wheel set (71), a second input whereof is a wheel set or a rack controlled by said cam (902, 904), and the output whereof gears with the gear train for transmitting the movement to said first pipe (2) or respectively to said second pipe (4).
20. Mechanism (10) according to claim 19, characterised in that said mechanism (10) comprises, between said input wheel set (71) and said first pipe (2), at the level of at least one said stage, a single cam (902) arranged such that it controls a first differential gear (912), a first input whereof is formed by said input wheel set (71), a second input whereof is a first rack controlled by said cam (902), and the output whereof gears with the gear train for transmitting the movement to said first pipe (2), and between said input wheel set (71) and said second pipe (4), the same said single cam (902) arranged such that it controls a second differential gear (914), a first input whereof is formed by said input wheel set (71), a second input whereof is a second rack controlled by said cam (902), and the output whereof gears with the gear train for transmitting the movement to said second pipe (4).
21. Mechanism (10) according to claim 19, characterised in that said mechanism (10) comprises, between said input wheel set (71) and said first pipe (2), at the level of at least one said stage, a first cam (902) arranged such that it controls a first differential gear (912), a first input whereof is formed by said input wheel set (71), a second input whereof is a first rack controlled by said first cam (902), and the output whereof gears with the gear train for transmitting the movement to said first pipe (2), and between said input wheel set (71) and said second pipe (4), a second cam (904) driven by the input wheel set and arranged such that it controls a second differential gear (914), a first input whereof is formed by said input wheel set (71), a second input whereof is a second rack controlled by said second cam (904), and the output whereof gears with the gear train for transmitting the movement to said second pipe (4).
22. Mechanism (10) according to claim 5 and according to one of claims 1 to 21, characterised in that at least one wheel comprised in the gear train mechanism arranged between, on the one hand, an input wheel set (71) arranged such that it is driven by a movement (20) and, on the other hand, said first pipe (2) and/or said second pipe (4), at the level of at least one said stage, comprises an incomplete toothing, each missing tooth allowing said resilient hand (1) to relax, by rotation of only one of said pipes (2; 4), during the passage of the space corresponding to a missing tooth, so as to control a recoil of the tip (6) of said resilient hand (1).
23. Horological movement (20) comprising at least one display mechanism (10) according to one of claims 1 to 22.
24. Timepiece (30) comprising at least one horological movement (20) according to claim 23.
25. Timepiece (30) according to claim 24, characterised in that said timepiece (30) is a watch.
26. Scientific apparatus comprising at least one horological movement (20) according to claim 23.

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