EP2570870A1 - Timepiece with permanently coupled oscillators - Google Patents

Abstract

The timepiece (1) has an oscillator (15) oscillating at frequency and connected to an energy source (9) by a gear train (5), and another oscillator (35) oscillating at another frequency and connected to another gear train (25). The latter train is connected to the former train by an elastic coupling unit (41) in order to synchronize rate of the two oscillators using the same energy source. The elastic coupling unit is formed by a spring (43) connecting a wheel of the former train to another wheel of the latter train. The two frequencies are identical and higher than 5 hertz.

Description

Field of the invention

The invention relates to a timepiece with permanently coupled oscillators and a timepiece comprising two oscillators intended to display at least one value less than or equal to the second with a better resolution and / or a better accuracy. .

Background of the invention

It is known to train timepieces whose frequency is increased to improve the resolution. However, these timepieces can be very sensitive to shocks or very greedy energy which makes them marginal.

It is therefore clear that it is easier to manufacture a template by mounting a low frequency oscillator, typically 4 Hz, to display the time and another high frequency oscillator, typically 10 or 50 Hz, independent of the first to display a measured time with better resolution. However, after several seconds, it becomes apparent that the display of the seconds of each oscillator is no longer the same, which can raise questions about the quality of the timepiece.

Summary of the invention

The object of the present invention is to overcome all or part of the disadvantages mentioned above by proposing a timepiece able to display the time with better resolution while guaranteeing a usual robustness for a mechanical watch, a reduced energy consumption and a minimal drift between the oscillators.

For this purpose, the invention relates to a timepiece comprising a first oscillator oscillating at a first frequency and connected by a first gear to a power source and a second oscillator oscillating at a second frequency and connected to a second characterized in that the second wheel is connected to the first gear by elastic coupling means to synchronize the operation of the two oscillators using the same energy source.

It is therefore understandable that even in the event of shocks, the variations of step will be minimal thanks to the construction allowing the synchronization of the two oscillators. Therefore, the timepiece according to the invention is able to display the time with better resolution and / or better accuracy while ensuring high robustness, low consumption and minimal drift between the wheels.

• les moyens de couplage élastique sont formés par un ressort reliant une roue du premier rouage avec une autre du deuxième rouage ;
• les moyens de couplage élastique relient les roues des secondes respectivement du premier rouage et du deuxième rouage ;
• l'oscillateur choisi comme référence reçoit le plus de couple de la source d'énergie et, préférentiellement, au moins 75% du couple ;
• l'oscillateur choisi comme référence possède un isochronisme de meilleure qualité que l'autre oscillateur afin de faciliter la synchronisation de ce dernier ;
• l'oscillateur choisi comme référence comporte un facteur de qualité supérieur à celui de l'autre oscillateur ;
• ledit autre oscillateur comporte un facteur de qualité inférieur à 100 afin d'obtenir une stabilisation plus rapide ;
• les première et deuxième fréquences sont identiques et, préférentiellement, sont supérieures à 5 Hz pour afficher l'heure avec une meilleure résolution et/ou une meilleure précision ;
• la première fréquence est différente de la deuxième fréquence pour modifier la résolution et/ou améliorer la précision et, préférentiellement, une des deux fréquences est au moins égale à 10 Hz et l'autre fréquence entre 1 et 5 Hz ;
• l'oscillateur choisi comme référence est le premier oscillateur ou le deuxième oscillateur ;
• la pièce d'horlogerie comporte un système de chronographe débrayable solidaire d'un des rouages ;
• la pièce d'horlogerie comporte un afficheur d'une valeur inférieure à la seconde solidaire d'un des rouages de manière permanente ou non.

According to other advantageous features of the invention:

• the elastic coupling means are formed by a spring connecting a wheel of the first wheel with another of the second wheel;
• the elastic coupling means connect the wheels of the seconds respectively of the first wheel and the second wheel;
• the oscillator chosen as a reference receives the most torque from the energy source and, preferably, at least 75% of the torque;
• the oscillator chosen as reference has an isochronism of better quality than the other oscillator to facilitate the synchronization of the latter;
• the oscillator chosen as a reference has a higher quality factor than the other oscillator;
• said other oscillator has a quality factor of less than 100 to achieve faster stabilization;
• the first and second frequencies are identical and, preferably, are greater than 5 Hz to display the time with a better resolution and / or a better accuracy;
• the first frequency is different from the second frequency for modifying the resolution and / or improving the accuracy and, preferably, one of the two frequencies is at least 10 Hz and the other frequency between 1 and 5 Hz;
• the oscillator chosen as reference is the first oscillator or the second oscillator;
• the timepiece comprises a disengageable chronograph system secured to one of the wheels;
• the timepiece comprises a display of a value less than the second integral with one of the wheels permanently or not.

Brief description of the drawings

• la figure 1 est un exemple de pièce d'horlogerie selon l'invention ;
• la figure 2 est un exemple de moyens de couplage élastique selon l'invention ;
• les figures 3 et 4 sont des simulations de synchronisation pour deux exemples de pièces d'horlogerie selon l'invention.

Other particularities and advantages will emerge clearly from the description which is given hereinafter, by way of indication and in no way limiting, with reference to the appended drawings, in which:

• the figure 1 is an example of a timepiece according to the invention;
• the figure 2 is an example of elastic coupling means according to the invention;
• the Figures 3 and 4 are synchronization simulations for two examples of timepieces according to the invention.

Detailed Description of the Preferred Embodiments

As illustrated in figures 1 and 2 the invention relates to a timepiece 1 comprising a first resonator 3 and connected by a first gear 5 via a first escapement 7 to a source of energy 9. first resonator 3 and the first escapement 7 thus form a first oscillator 15 oscillating at a first frequency f ₁ . The timepiece 1 also comprises a second resonator 23 and connected to a second gear 25 via a second escapement 27. The second resonator 23 and the second escapement 27 thus form a second oscillator 35 oscillating at a second frequency f ₂ .

Advantageously according to the invention, the second wheel 25 is permanently connected to the first wheel 5 by elastic coupling means 41 in order to synchronize the operation of the two oscillators 15, 35 with the same energy source 9. As seen in the example of the figure 1 , the energy source 9 is preferably a barrel, that is to say a source of mechanical energy accumulation.

Preferably, according to the invention, the elastic coupling means 41 are formed by a spring 43 connecting a wheel of the first gear train 5 with another of the second gear train 25. As illustrated in FIG. figure 2 , the elastic coupling means 41 connect, preferably according to the invention, the wheels of the seconds respectively of the first gear 5 and the second gear 25.

Preferably according to the invention, it can be seen that a double wheel 42 is used. As better visible at the figure 2 it is formed by a first board 45 connected via a reference 46 to the first gear 5 and a second board 47 connected directly or indirectly to the second gear 25. The two boards 45, 47 are integral with an axis 48 respectively crazy way and in a fixed way. Finally, the spring 43 of the elastic coupling means 41 is preferably mounted between the fastener 49 fixed on the stretcher of the board 45 and the flange 50 of the axis 48. It is therefore understood that the boards 45 and 47, and incidentally, the workings 5 and 25 can be angularly offset by the elastic coupling of the spring 43.

Advantageously according to the invention, the display of the time, that is to say the hours, minutes and / or seconds can be carried out indifferently from the first or second gear 5, 25.

Depending on the desired application for the timepiece, the first f ₁ and second f ₂ frequencies are identical or not. Thus, in a first embodiment, the first and second frequencies f ₁ , f ₂ are identical and preferably greater than 5 Hz to display the time with better resolution and / or better accuracy. In such an embodiment, the frequencies f ₁ , f ₂ may, for example, be equal to 10 Hz or 50 Hz to respectively display 1/20 or 1/100 of seconds.

Thus, depending on the oscillator chosen as a reference, it may be useful to mount the display of hours and minutes on the wheel of said oscillator chosen as a reference and the display of seconds on the wheel of the second. Indeed, it appeared that, during any shock, the seconds display can induce induced torque at the oscillator own to change its amplitude and therefore its progress.

In a second embodiment, the first frequency f ₁ is higher than the second frequency f _{2 in} order to display the time with a better resolution and / or a better accuracy. Similarly to the first embodiment, the first frequency f ₁ is at least 10 Hz and the second frequency f ₂ is preferably between 1 and 5 Hz. By way of example, it may be desired that a second is incremented by a single step per second, that is to say that the second frequency f ₂ is equal to 1 Hz, "in the manner" of a quartz watch.

In a third embodiment, the first frequency f ₁ is lower than the second frequency f _{2 in} order to display the time with a better resolution and / or a better accuracy. In this embodiment, which is the inverse of the second embodiment, the same advantages are obtained.

Simulations have been developed below to describe the synchronization between these two oscillators 15, 35. Arbitrarily, the third embodiment has been chosen for the explanation. Thus, the oscillator 15 is chosen as the reference, is of the low frequency type and is called the first oscillator. In fact, in the example below, the second oscillator will be the oscillator 35 of the high frequency type which will synchronize with the low frequency oscillator.

à laquelle la marche est nulle. De plus, comme le premier oscillateur 15 est choisi comme référence, il a toujours une marche sensiblement nulle en faisant faiblement varier son amplitude.Preferably, according to the invention, the second oscillator 35 is chosen with a strong anisochronism as a function of the amplitude, described by the slope of anisochronism Γ , as well as by the amplitude ${\mathrm{AT}}_2^0$

at which the march is null. In addition, since the first oscillator 15 is chosen as a reference, it always has a substantially zero step by slightly varying its amplitude.

The simulations show the evolution of the two oscillators 15, 35, that is to say their amplitudes and their phase shift state over time and thus make it possible to check the possibility of synchronization or not of the second oscillator 35 on the first oscillator 15.

positive lorsqu'il oscille à une amplitude supérieure à $A_2^0$

et négative lorsqu'il oscille à une amplitude inférieure à $A_2^0\mathrm{.}$

Preferably, the second oscillator 35 is constructed so that its march is zero when it oscillates at an amplitude ${\mathrm{AT}}_{}^{}$${}_2^0,$

positive when it oscillates at an amplitude greater than ${\mathrm{<figure-callout\; id="2"\; label="AT"\; filenames="imgf0003.png"\; state="\{\{state\}\}">AT</figure-callout>}}_2^0$

and negative when it oscillates at a lower amplitude than ${\mathrm{<figure-callout\; id="2"\; label="AT"\; filenames="imgf0003.png"\; state="\{\{state\}\}">AT</figure-callout>}}_2^0\mathrm{.}$

On the other hand, the elastic coupling means 41 are constructed so that the torque transmitted to the second wheel 25 remains constant if the two wheels 5, 25 rotate at the same speed, decreases if the second wheel 25 advances faster than the first wheel 5 (the spring 43 disarms) and increases if the second gear 25 advances less rapidly than the first gear 5 (the spring 43 is armed).

et dans laquelle le ressort 43 transmet, au deuxième rouage 25, le couple M₂ nécessaire à maintenir le deuxième oscillateur 35 à l'amplitude $A_2^0\mathrm{.}$

If the above conditions are satisfied, the timepiece will always evolve towards the stable situation where the second oscillator 35 oscillates at the amplitude ${\mathrm{AT}}_2^0$

and in which the spring 43 transmits, to the second wheel 25, the torque M ₂ necessary to maintain the second oscillator 35 at the amplitude ${\mathrm{AT}}_2^0\mathrm{.}$

. Comme expliqué ci-dessus, sa marche devient négative, c'est-à-dire que le deuxième oscillateur 35 prend du retard par rapport au premier oscillateur 5 choisi comme référence.Therefore, if the second oscillator 35 receives a torque less than M ₂ , its amplitude decreases, that is to say has a smaller amplitude than ${\mathrm{<figure-callout\; id="2"\; label="AT"\; filenames="imgf0003.png"\; state="\{\{state\}\}">AT</figure-callout>}}_2^0$

. As explained above, its operation becomes negative, that is to say that the second oscillator 35 is delayed relative to the first oscillator 5 chosen as reference.

.It is therefore understood that the second wheel 25 will rotate more slowly than the first wheel 5 by arming the coupling spring 43, that is to say by increasing the torque transmitted to the second wheel 25. Therefore, the increasing torque, the amplitude of the second oscillator 25 is corrected automatically. It is therefore noted that both the torque and the amplitude of the second oscillator 35 synchronize structurally with the stable torque M ₂ and the stable amplitude ${\mathrm{AT}}_2^0$

.

ce qui signifie que la marche du deuxième oscillateur 35 sera positive. Le deuxième rouage 25 prend donc de l'avance sur le premier rouage 5 en désarmant le ressort 43. Par conséquent, le couple sur le deuxième rouage 25 va diminuer vers le couple stable M₂ et, l'amplitude du deuxième oscillateur 35, tendre à nouveau vers l'amplitude stable $A_2^0\mathrm{.}$

Similarly, if the received torque exceeds the torque M ₂ then the amplitude of the second oscillator 35 becomes greater than the value ${\mathrm{AT}}_2^0,$

which means that the step of the second oscillator 35 will be positive. The second gear 25 is therefore ahead of the first gear 5 by disarming the spring 43. Therefore, the torque on the second gear 25 will decrease towards the stable torque M ₂ and, the amplitude of the second oscillator 35, soft again towards stable amplitude ${\mathrm{AT}}_2^0\mathrm{.}$

So we see that whatever the situation in which we are, either at the start of the watch or after a shock, the system will always evolve to stabilize on the stable situation where the torque on the second wheel 25 is M ₂ and the amplitude of the second oscillator 35 is ${\mathrm{AT}}_2^0\mathrm{.}$

• la « taille » des deux oscillateurs 15, 35 (par exemple les inerties I ₁, I ₂ si les résonateurs 3, 23 sont du type balancier - spiral) ;
• les facteurs de qualité des deux oscillateurs 15, 35 : Q₁, Q₂ (qui est fonction de la taille de l'oscillateur) ;
• la pente d'anisochronisme du deuxième oscillateur : Γ ;
• l'amplitude du deuxième oscillateur pour laquelle sa marche est nulle : $A_2^0$
  
  ;
• le couple M ₂ du ressort 43 ;
• la rigidité angulaire K du ressort 43.

In a preferred manner according to the invention, it is assumed that the torque of the barrel 9 and the frequency f ₁ , f ₂ of the two oscillators 15, 35 are given parameters. We therefore understand that the parameters still to choose are:

• the "size" of the two oscillators 15, 35 (for example the inertias I ₁ , I ₂ if the resonators 3, 23 are of the balance-spring type);
• the quality factors of the two oscillators 15, 35: Q ₁ , Q ₂ (which is a function of the size of the oscillator);
• the anisochronism slope of the second oscillator: Γ;
• the amplitude of the second oscillator for which its progress is null: ${\mathrm{AT}}_2^0$
  
  ;
• the torque M ₂ of the spring 43;
• the angular rigidity K of the spring 43.

• fraction du couple total que l'on souhaite transmettre au deuxième oscillateur, ce qui donne la valeur du couple M₂. Selon l'invention, le premier oscillateur 15, reçoit le plus de couple par la source d'énergie 9 et, préférentiellement, au moins 75%.
• amplitude $A_{}^{}$${}_2^0$
  
  du deuxième oscillateur à laquelle on veut qu'il se stabilise (il faudra donc construire le deuxième oscillateur de façon à ce que sa marche soit sensiblement nulle à cette amplitude) ;
• taille du deuxième oscillateur (par exemple son inertie) pour que l'amplitude de stabilisation soit $A_{}^{}$${}_2^0$
  
  lorsqu'il reçoit le couple M ₂ (par l'intermédiaire du facteur de qualité) ;
• taille du premier oscillateur (par exemple son inertie) pour que l'amplitude de stabilisation soit acceptable (par l'intermédiaire du facteur de qualité) ;
• pente d'anisochronisme Γ du deuxième oscillateur 35 ;
• rigidité K du ressort 43.

Preferably, according to the invention, the parameters are chosen as follows:

• fraction of the total torque that it is desired to transmit to the second oscillator, which gives the value of the torque M ₂ . According to the invention, the first oscillator 15 receives the most torque from the energy source 9 and, preferably, at least 75%.
• amplitude ${\mathrm{AT}}_2^0$
  
  the second oscillator at which one wants it to stabilize (it will be necessary to build the second oscillator so that its march is substantially zero at this amplitude);
• size of the second oscillator (for example its inertia) so that the amplitude of stabilization is ${\mathrm{AT}}_2^0$
  
  when he receives the torque M ₂ (via the quality factor);
• size of the first oscillator (for example its inertia) so that the stabilization amplitude is acceptable (via the quality factor);
• anisochronism slope Γ of the second oscillator 35;
• stiffness K of the spring 43.

• le couple transmis au rouage 25 ne devienne jamais nul ;
• la marche du deuxième oscillateur 35 reste proche de sa fréquence de zéro ;
• l'écart d'état entre les deux oscillateurs 15, 35 soit faible au
  « démarrage » ;
• le temps de stabilisation soit suffisamment court.

Advantageously according to the invention, it is also preferred to "adjust" K and Γ so that:

• the torque transmitted to the wheel 25 never becomes zero;
• the operation of the second oscillator 35 remains close to its frequency of zero;
• the difference in state between the two oscillators 15, 35 is small at
  " start-up ";
• the stabilization time is sufficiently short.

Empirically, it has been shown that it is preferable that the K.Γ product be kept identical to have the same stabilization time in the continuous approximation. Thus, increasing K (and thus decreasing Γ all the same) makes it possible to reduce the amplitude and torque fluctuations (thus preventing the pair from being canceled). On the other hand, it also increases the maximum state difference before stabilization, as well as instantaneous walking, which can become extreme. We must therefore find a compromise between these two effects.

It has also been found that increasing the frequency of the synchronizing oscillator (above the second oscillator 35) makes it possible to reduce the stabilization time. Finally, during the tests, it has been shown that reducing the quality factor of the oscillator that synchronizes (above the second oscillator) also makes it possible to reduce the stabilization time.

The Figures 3 and 4 are simulations performed as an example of execution. In the figure 3 , f ₁ = 4 Hz, f ₂ = 10 Hz, Q ₁ = 200, Q ₂ = 50 and, in the figure 4 , f ₁ = 4 Hz, f ₂ = 50 Hz, Q ₁ = 200, Q ₂ = 50 with for each simulation a product K.Γ identical.

choisi du deuxième oscillateur est d'environ ⅓. Ainsi au bout de respectivement 2 et 1,5 secondes, chaque oscillateur se stabilise à son amplitude synchronisée.Part A of each figure corresponds to the amplitude fraction of each oscillator relative to the reference amplitude if it received the entire torque of the energy source. We note that for the examples of the figures the amplitude ${\mathrm{AT}}_2^0$

chosen from the second oscillator is about ⅓. Thus after 2 and 1.5 seconds respectively, each oscillator stabilizes at its synchronized amplitude.

Part B of each figure corresponds to the fraction of torque that each oscillator receives from the energy source. Note that for the examples of the figures the proportion of torque chosen for the second oscillator is about 10%. Thus at the end of respectively 2 and 1.5 seconds, each oscillator receives in a stabilized manner its proportion of torque.

Part C of each figure corresponds to the operation of the second oscillator. We note that after 5.5 and 2 seconds respectively, the second oscillator stabilizes around its zero step.

Finally, the part D of each figure corresponds to the difference of state in seconds between each oscillator. We note that after 5 and 2 seconds respectively, the difference stabilizes at its zero value.

In view of the AD parts of Figures 3 and 4 , we thus perfectly find the conclusions stated above. It is therefore understandable that even in the event of shocks, the variations of step will be minimal thanks to the construction allowing the synchronization of the two oscillators. Therefore, the timepiece according to the invention is capable of displaying the time with a better resolution and / or a better precision while guaranteeing a great robustness, a low consumption and a minimal drift between the workings 5, 25 .

Moreover, during the tests, it has been found that in addition to the fact that the first oscillator chosen as a reference preferably has an isochronism of better quality than the second oscillator in order to facilitate the synchronization of the latter, the second oscillator comprises preferred way a quality factor lower than that of the first oscillator and, preferably, less than 100 in order to obtain a faster stabilization, that is to say typically less than 2 seconds.

Of course, the present invention is not limited to the illustrated example but is susceptible of various variations and modifications that will occur to those skilled in the art. In particular, the oscillator chosen as reference can indifferently be the first oscillator 15 or the second oscillator 35 without the conclusions relating respectively to the first oscillator and the second oscillator differ.

Thus, unlike the example above, the oscillator chosen as a reference could be the second oscillator 35 chosen at high frequency in order to form a precision timepiece. In this case, the display of the time will preferably be performed from the first gear 5 of the first oscillator selected low frequency to limit the propagation of torque induced by any shock at the second oscillator 35 selected at high frequency.

In addition, the oscillator, which preferably comprises a frequency at least equal to 10 Hz, may be a Clifford type oscillator (see for example the document CH386344 incorporated by reference herein) instead of the one disclosed above. In addition, the oscillator, which has a frequency of between 1 and 5 Hz, will preferably be of the sprung-balance type and, its escapement, of the Swiss anchor type.

Of course, the elastic coupling means can not be limited to a double wheel 42 cooperating with a spring 43 as illustrated in FIGS. figures 1 and 2 . Other elastic coupling means can be envisaged, for example those disclosed in the document PCT / EP2011 / 061244 incorporated by reference in this application.

Advantageously according to the invention, it is understood that the timepiece can therefore structurally comprise a display of a value less than the second integral with the gear 5, 25 whose oscillator is at high frequency, this permanently or not ( that is to say via a possible clutch). Thus, the value can go down to, for example, 1/20 of a second, if the oscillator beats at least 10 Hz or 1/100 of a second if the oscillator beats at least 50 Hz. The timepiece may even include a disengageable chronograph system also integral with the first or second gear 5, 25.

Finally, it is likely to further optimize the behavior of the system by having an anisochronism of the second oscillator that is not linear. By way of example, the second oscillator may comprise a weak anisochronism around the equilibrium amplitude and a strong anisochronism far from the amplitude of equilibrium, or vice versa.

Claims (16)

Timepiece (1) comprising a first oscillator (15) oscillating at a first frequency ( f ₁ ) and connected by a first gear (5) to a power source (9) and a second oscillator (35) oscillating at a second frequency ( f ₂ ) and connected to a second wheel (25) characterized in that the second wheel (25) is connected to the first wheel (5) by elastic coupling means (41) to synchronize the running of the two oscillators (15, 35) using the same energy source (9). Timepiece (1) according to the preceding claim, characterized in that the elastic coupling means (41) are formed by a spring (43) connecting a wheel of the first gear (5) with another of the second gear (25) . Timepiece (1) according to the preceding claim, characterized in that the elastic coupling means (41) connect the wheels of the second respectively of the first gear (5) and the second gear (25). Timepiece (1) according to one of the preceding claims, characterized in that the oscillator (15, 35) chosen as a reference receives the most torque from the energy source (9). Timepiece (1) according to the preceding claim, characterized in that the oscillator (15, 35) chosen as a reference receives at least 75% of the torque supplied by the energy source (9). Timepiece (1) according to one of the preceding claims, characterized in that the oscillator (15, 35) chosen as a reference has an isochronism of better quality than the other oscillator (35, 15) to facilitate the synchronization of the latter. Timepiece (1) according to one of the preceding claims, characterized in that the oscillator (15, 35) chosen as a reference has a quality factor (Q ₁ , Q ₂ ) greater than that of the other the other oscillator. Timepiece (1) according to the preceding claim, characterized in that said other oscillator (15, 35) has a quality factor of less than 100 to obtain a faster stabilization. Timepiece (1) according to one of the preceding claims, characterized in that the first ( f ₁ ) and second ( f ₂ ) frequencies are identical. Timepiece (1) according to the preceding claim, characterized in that the two frequencies ( f ₂ , f ₁ ) are greater than 5 Hz to display the time with better resolution and / or better accuracy. Timepiece (1) according to one of claims 1 to 8, characterized in that the first frequency ( f ₁ ) is different from the second frequency ( f ₂ ) to change the resolution and / or improve the accuracy. Timepiece (1) according to the preceding claim, characterized in that one of the two frequencies ( f ₁ , f ₂ ) is at least 10 Hz and the other frequency ( f ₂ , f ₁ ) between 1 and 5 Hz. Timepiece (1) according to one of the preceding claims, characterized in that the oscillator chosen as reference is the second oscillator (35). Timepiece (1) according to one of claims 1 to 12, characterized in that the oscillator chosen as a reference is the first oscillator (15). Timepiece (1) according to one of the preceding claims, characterized in that it comprises a disengageable chronograph system secured to one of the workings (5, 25). Timepiece (1) according to one of the preceding claims, characterized in that it comprises a display of a value less than the second secured to one of the wheels (5, 25) permanently or not.

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