EP2044490B1 - Electromechanical escapement device and timepiece part utilizing said device - Google Patents

Abstract

The electromechanical escapement device is associated with an electronic circuit having a quartz oscillator and calculation means suitable for calculating the difference between the period of the quartz oscillator and the period of a mechanical oscillator and releasing an escape wheel, normally controlled by said mechanical oscillator, when the difference between said periods is greater than a threshold value.

Description

The present invention relates to an electromechanical exhaust device and a timepiece using such a device.

For a mechanical timepiece, the exhaust device serves on the one hand to maintain the oscillatory movement of the mechanical oscillator comprising the balance and the hairspring and on the other hand to transmit the frequency of this oscillator to the gear train causing the time display.

Fully mechanical exhaust devices are therefore well known in the prior art. Manuals "Exhausts and stepper motors" by Charles Huguenin edited by the Federation of Technical Schools of Switzerland and "Horological Theory", ISBN 2-940025-10-X, also published by the Federation of Technical Schools of Switzerland , describe several mechanical escapement devices called "anchor", "trigger", "Graham", etc.

As mentioned above, the traditional mechanical exhaust devices transmit the frequency of the mechanical oscillator directly to the gear train causing the time display. The frequency of the mechanical oscillator, generally between 2 and 4 Hz, is unfortunately not very precise and in addition very dependent on the position of the watch. The accuracy of a mechanical watch is therefore lower than that of an electronic quartz watch.

It is also known from the document EP 1,521,142 , a timepiece having a mechanical movement associated with an electronic regulator.

An object of the present invention is to provide an electromechanical exhaust device for significantly improving the accuracy of a mechanical watch.

Another object of the invention is to propose a mechanoelectronic timepiece equipped with such an exhaust device

These objects are achieved by an electromechanical exhaust device as described in claim 1 as well as by a timepiece as described in claim 9. Alternative embodiments are described in the dependent claims.

• la figure 1 représente un schéma de principe d'une montre mécanique traditionnelle,
• la figure 2 représente un schéma de principe d'une montre mécanoélectronique utilisant un dispositif d'échappement électromécanique selon l'invention,
• la figure 3 représente une forme d'exécution d'un échappement électromécanique selon l'invention,
• la figure 4 représente des détails d'une roue d'échappement,
• la figure 5 représente des détails des mobiles tournant autour du centre 02 de la figure 3,
• la figure 6 représente des détails des mobiles tournant autour du centre 03 de la figure 3,
• la figure 7 représente des détails des mobiles tournant autour du centre 04 de la figure 3 ainsi qu'un convertisseur mécanique,
• la figure 8 illustre la position de blocage,
• la figure 9 illustre la phase de dégagement mécanique,
• la figure 10 illustre la phase de transmission d'énergie,
• la figure 11 illustre la phase de repositionnement,
• la figure 12 illustre la phase de dégagement électromagnétique, et
• la figure 13 illustre un schéma de principe d'un dispositif électronique associé.

The invention will be better understood from the following description describing a particular embodiment of the invention, as well as from the appended drawing comprising the figures in which:

• the figure 1 represents a schematic diagram of a traditional mechanical watch,
• the figure 2 represents a schematic diagram of a mechanoelectronic watch using an electromechanical exhaust device according to the invention,
• the figure 3 represents an embodiment of an electromechanical escapement according to the invention,
• the figure 4 represents details of an escape wheel,
• the figure 5 represents details of the mobiles rotating around center 02 of the figure 3 ,
• the figure 6 represents details of the mobiles rotating around the center 03 of the figure 3 ,
• the figure 7 represents details of the mobiles rotating around the center 04 of the figure 3 as well as a mechanical converter,
• the figure 8 illustrates the blocking position,
• the figure 9 illustrates the phase of mechanical release,
• the figure 10 illustrates the phase of energy transmission,
• the figure 11 illustrates the repositioning phase,
• the figure 12 illustrates the phase of electromagnetic release, and
• the figure 13 illustrates a block diagram of an associated electronic device.

The figure 1 represents a block diagram of a traditional mechanical watch in which the mechanical energy from a manual or automatic winding device is stored in a barrel spring 1 to be distributed through a set of wheels 2 to a device Exhaust 3 and a display 4.

The exhaust device 3 serves on the one hand to maintain the movement of the mechanical oscillator 5 comprising a balance and a hairspring and on the other hand to transmit the frequency of this oscillator to the gear 2 causing the time display 4. A each oscillation period of the mechanical oscillator 5, the gear 2, linked to the display 4, advances by a fixed angle and, therefore, the speed of rotation of the gear 2 is proportional to the frequency of the mechanical oscillator 5, making the accuracy of the display 4 is directly dependent on this frequency.

The frequency of a mechanical oscillator, generally between 2 and 4 Hz, is unfortunately not very precise and, moreover, very dependent on the position of the watch. The accuracy of a traditional mechanical watch is therefore lower than that of an electronic quartz watch.

• la première est d'entretenir le mouvement d'oscillation de l'oscillateur mécanique 11,
• la deuxième est de transmettre la fréquence de l'oscillateur 11 au rouage 7 entraînant l'affichage horaire 8,
• la troisième est de transformer une partie de l'énergie mécanique reçue en énergie électrique pour alimenter le dispositif électronique 10 qui possède une base de temps à quartz,
• finalement la dernière fonction du dispositif d'échappement électromécanique 9 est de faire avancer le rouage 7 lorsqu'il reçoit des impulsions électriques de correction provenant du dispositif électronique 10.

The figure 2 represents a schematic diagram of a mechanoelectronic watch using an electromechanical exhaust device according to the invention. The mechanical energy stored in a mainspring 6 is distributed through a set of wheels 7 to an electromechanical exhaust device 9 and to a display 8. The electromechanical exhaust device 9 according to the invention has multiple functions:

• the first is to maintain the oscillation movement of the mechanical oscillator 11,
• the second is to transmit the frequency of the oscillator 11 to the wheel 7 causing the time display 8,
• the third is to convert a portion of the mechanical energy received into electrical energy to power the electronic device 10 which has a quartz time base,
• finally the last function of the electromechanical exhaust device 9 is to advance the gear 7 when it receives electrical correction pulses from the electronic device 10.

It can be seen from this diagram that the barrel spring 6, the gear 7, the display 8 as well as the mechanical oscillator 11 are identical components to those of the same names in the figure 1 .

At each oscillation period of the mechanical oscillator 11, the gear 7 linked to the display 8 and the electromechanical exhaust device 9 advance by a fixed angle and transmit, through an electromechanical converter described below. of the device 9, the electrical energy and the oscillation period of the mechanical oscillator 11 to the electronic device 10. This electronic device 10 has an electric energy accumulator and a quartz time base taken as reference time base ; he compares the periods of mechanical oscillation with a reference period. When the sum of the differences between these periods exceeds a certain limit, the electronic device 10 sends electrical correction pulses through an electromechanical converter to advance the electromechanical exhaust device 9 as well as the gear 7 and the display 8.

It can be seen that, unlike a traditional mechanical escapement whose movement is synchronous with that of the mechanical oscillator, the electromechanical escapement 9 according to the invention advances at each period of the mechanical oscillator 11 and also, so independent of the mechanical oscillator 11, when it receives pulses coming from the electronic circuit 10.

To obtain a good operation of the timepiece according to the figure 2 , just set the period of the mechanical oscillator 11 slightly larger than that of the reference time base of the quartz timebase. The electronic circuit 10 measures the difference between these periods and sends a set of correction pulses to catch up. In practice setting the period of a mechanical oscillator with an accuracy of one per thousand is easily achievable.

The figure 3 represents an embodiment of an electromechanical exhaust device according to the invention. This device comprises several mobiles rotating around 4 centers O1, O2, O3 and O4.

The escape wheel 12, shown in detail at the figure 4 , around the center O1 and is provided with pins 121. In this example the number of pins is equal to 8, but the choice of another number of pins is also possible.

Two superimposed mobiles rotate simultaneously around the center 02: a locking means 14 and a toothed wheel 13, these two mobiles being represented in detail in FIG. figure 5 . The mechanical oscillator 11, comprising the balance and the spiral, rotates around the center 03. On the figure 3 as well as on the detail drawing of the figure 6 it represents only the plate 15, integral with the balance, and comprising the pulse lever 151 and the release pin 152.

Three superposed mobiles rotate simultaneously around the center 04: a mechanical release means 16, a toothed wheel 17 meshing with the toothed wheel 13 and a rotor 182 of the electromechanical converter, made of a permanent magnet. The figure 7 represents the details of these mobiles as well as the electromechanical converter 18 having, in addition to the rotor 182, a stator 181 of soft magnetic material provided with the cells 184, and a coil 183.

• grâce aux alvéoles 184, le rotor 182 possède deux positions d'équilibre stables alignées sur l'axe S1-S2 en l'absence de courant dans la bobine 183,
• lorsqu'on fournit un courant à la bobine 183 avec la polarité appropriée, le rotor 182 tourne dans le sens antihoraire indiqué par la flèche F,
• finalement, lorsque le rotor 182 du convertisseur 18 est entraîné par la roue d'échappement 12, par l'intermédiaire des roue dentées 13 et 17, ce convertisseur 18 fonctionne en génératrice et fournit une tension aux bornes B1 et B2 de la bobine 183.

The electromechanical converter 18 has several distinct functions:

• thanks to the cells 184, the rotor 182 has two stable equilibrium positions aligned on the axis S1-S2 in the absence of current in the coil 183,
• when a current is supplied to the coil 183 with the appropriate polarity, the rotor 182 rotates counterclockwise indicated by the arrow F,
• finally, when the rotor 182 of the converter 18 is driven by the escape wheel 12, via the gear wheels 13 and 17, the converter 18 operates as a generator and supplies a voltage across the terminals B1 and B2 of the coil 183.

• Phase de blocage : la plupart du temps, lorsque le plateau 15 de l'oscillateur mécanique 11 n'a pas de contact mécanique avec la roue d'échappement 12 par l'intermédiaire du levier d'impulsion 151 ou avec le moyen de dégagement 16 par l'intermédiaire de la goupille de dégagement 152, la roue d'échappement 12 se trouve en position de blocage. La figure 8 illustre cette position de blocage. Dans cette figure, la roue d'échappement 12 est soumise à un couple provenant du barillet 6 dans le sens indiqué par la flèche F2. Grâce à la forme du moyen de blocage 14 et au couple de positionnement magnétique provenant du rotor 182 via les roues 17 et 13, la roue d'échappement 12 est bloquée dans cette position pendant que le plateau 15 de l'oscillateur mécanique 11 continue son mouvement.
• Phase de dégagement mécanique : la figure 9 illustre la phase de dégagement mécanique. Dans cette figure, la goupille 152 du plateau 15, tournant dans le sens de la flèche F3, actionne le moyen de dégagement 16 et, par l'intermédiaire des roues 17 et 13, libère la goupille 121 du moyen de blocage 14. La roue d'échappement 12 peut tourner, sous l'effet du couple transmis par le barillet 6 dans le sens de la flèche F2.
• Phase de transmission d'énergie : dans cette phase la roue d'échappement 12 transmet l'énergie à l'oscillateur mécanique 11 ainsi qu'au convertisseur électromécanique 18. La figure 10 illustre cette phase de transmission d'énergie. Après la phase de dégagement mécanique, la roue d'échappement 12 tourne dans le sens de la flèche F2, l'une des goupilles 121 de cette roue actionnant le levier d'impulsion 151 du plateau 15 pour fournir l'énergie destinée à l'entretien du mouvement de l'oscillateur 11. La goupille 121 précédant celle mentionnée ci-dessus dans le sens de rotation, actionne le moyen de blocage 14, lequel transmet l'énergie mécanique par l'intermédiaire des roues 13 et 17 au convertisseur électromécanique 18 qui la transforme en énergie électrique aux bornes de la bobine 183.
• Phase de repositionnement : cette phase est illustrée par la figure 11. Après la phase de transmission d'énergie, le moyen de blocage 14 et la roue 13 continuent de tourner dans le même sens indiqué par la flèche F4 et, sous l'effet du couple de positionnement magnétique, retrouvent une nouvelle position de blocage à 180 degrés par rapport à la position de blocage précédente. Dans cette phase, la roue d'échappement 12 continue à fournir l'énergie à l'oscillateur mécanique 11 par l'intermédiaire du levier d'impulsion 151 du plateau 15.
• Phase de dégagement électromagnétique : cette phase est illustrée par la figure 12. Une des particularités du dispositif d'échappement électromécanique selon l'invention est qu'il est apte à libérer la roue d'échappement 12 de la position de blocage, de façon indépendante de la fréquence de l'oscillateur mécanique 11. Pour ce faire, il suffit d'envoyer un jeu d'impulsions électriques à la bobine 183 du convertisseur électromécanique 18. L'interaction entre le champ magnétique créé par le courant dans la bobine 183 et le champ magnétique de l'aimant du rotor 182 engendre un couple électromagnétique dans le sens de la flèche F5, supérieur au couple de positionnement, qui actionne le moyen de blocage 14 dans le sens opposé par l'intermédiaire des roues 13 et 17. La phase de dégagement électromagnétique s'effectue généralement en dehors des phases de dégagement mécanique, de transmission d'énergie et de repositionnement. Pendant cette phase, la vitesse angulaire de l'oscillateur mécanique 11 est pratiquement nulle. Dans cette phase de dégagement électromagnétique, la roue d'échappement 12 ne transmet aucune énergie à l'oscillateur mécanique 11.

The operation of the electromechanical exhaust device according to the invention comprising several main phases is described below:

• Blocking phase: most of the time, when the plate 15 of the mechanical oscillator 11 has no mechanical contact with the escape wheel 12 via the pulse lever 151 or with the release means 16 by means of the release pin 152, the escape wheel 12 is in the locking position. The figure 8 illustrates this blocking position. In this figure, the escape wheel 12 is subjected to a torque from the barrel 6 in the direction indicated by the arrow F2. Due to the shape of the locking means 14 and the magnetic positioning torque from the rotor 182 via the wheels 17 and 13, the wheel exhaust 12 is locked in this position while the plate 15 of the mechanical oscillator 11 continues its movement.
• Mechanical release phase: the figure 9 illustrates the phase of mechanical clearance. In this figure, the pin 152 of the plate 15, rotating in the direction of the arrow F3, actuates the release means 16 and, through the wheels 17 and 13, releases the pin 121 of the locking means 14. The wheel exhaust 12 can rotate, under the effect of the torque transmitted by the barrel 6 in the direction of the arrow F2.
• Energy transmission phase: in this phase, the escape wheel 12 transmits the energy to the mechanical oscillator 11 as well as to the electromechanical converter 18. figure 10 illustrates this phase of energy transmission. After the mechanical release phase, the escape wheel 12 rotates in the direction of the arrow F2, one of the pins 121 of this wheel operating the pulse lever 151 of the plate 15 to provide the energy for the maintenance of the movement of the oscillator 11. The pin 121 preceding that mentioned above in the direction of rotation, actuates the locking means 14, which transmits the mechanical energy through the wheels 13 and 17 to the electromechanical converter 18 which transforms it into electrical energy at the terminals of the coil 183.
• Repositioning phase: this phase is illustrated by the figure 11 . After the energy transmission phase, the locking means 14 and the wheel 13 continue to rotate in the same direction indicated by the arrow F4 and, under the effect of the magnetic positioning torque, find a new locking position 180 degrees to the previous lock position. In this phase, the escape wheel 12 continues to supply energy to the mechanical oscillator 11 via the pulse lever 151 of the plate 15.
• Electromagnetic release phase: this phase is illustrated by the figure 12 . One of the peculiarities of the electromechanical exhaust device according to the invention is that it is able to release the escape wheel 12 from the locking position, independently of the frequency of the mechanical oscillator 11. To do this, it is sufficient to send a set of electrical pulses to the coil 183 of the electromechanical converter 18. The interaction between the magnetic field created by the current in the coil 183 and the magnetic field of the rotor magnet 182 generates an electromagnetic torque in the direction of the arrow F5, greater than the positioning torque, which actuates the locking means 14 in the opposite direction through the wheels 13 and 17. The electromagnetic clearance phase is generally performed outside the release phases mechanical, energy transmission and repositioning. During this phase, the angular velocity of the mechanical oscillator 11 is practically zero. In this phase of electromagnetic release, the escape wheel 12 transmits no energy to the mechanical oscillator 11.

• des moyens de charge 100,
• des moyens d'accumulation d'énergie 101,
• des moyens 102 de mise en forme de la tension provenant de la bobine 183,
• des moyens 103 de mesure de la période de l'oscillateur mécanique 11 basés sur une base de temps de référence provenant d'un oscillateur à quartz 104,
• des moyens 105 de calcul et de fourniture d'un jeu d'impulsions électriques de correction.

The figure 13 represents the schematic diagram of the electronic device 10 of the figure 2 . This device comprises:

• charging means 100,
• energy storage means 101,
• means 102 for shaping the voltage coming from the coil 183,
• means 103 for measuring the period of the oscillator mechanical 11 based on a reference time base from a crystal oscillator 104,
• means 105 for calculating and supplying a set of electrical correction pulses.

The electrical signal from the coil 183 during the energy transmission phase is sent to the charging means 100, which stores the energy in a capacitor or other energy accumulator 101. This signal is also sent to the setting means. 102, which transmit the information to the means 103 for measuring the period of the mechanical oscillator 11, based on a reference time base from a crystal oscillator 104. The means 105 calculate the sum of the errors of the mechanical period and send a set of electrical pulse correction coil 183 when this sum exceeds a certain limit.

A particular embodiment of the electromechanical exhaust device has been described above, it is obvious that alternative construction can be envisaged. In particular the mechanical connection between the mechanical locking means, the mechanical release means and the rotor, described here in the form of two toothed wheels, may be different from those described, provided that they provide the same function. Other construction variants, which can be envisaged by those skilled in the art, are also to be considered.

Thus, a timepiece equipped with an electromechanical exhaust device as described above has its operating accuracy significantly improved since it depends on the accuracy of the quartz oscillator.

Claims (9)

1. A system comprising an electromechanical escapement device (9) and an electronic circuit (10) as components of a mechanical clockwork including a mechanical oscillator (11), said electromechanical escapement device (9) comprising:

   - an escapement wheel (12),

   - mechanical blocking means (14) mounted on a shaft (02),

   - mechanical disengagement means (16) mounted on another shaft (04),

   - an electromechanical converter (18) comprising a stator (181) made of a magnetic material, a rotor (182) made of permanent magnet and a coil (183),

   - mechanical driving means (13, 17) connecting both said shafts(02, 04) as well as the rotor (182),

   - the blocking means (14) being capable of periodically immobilizing the escapement wheel (12) according to well determined angular positions,

   - the mechanical disengagement means (16) being capable of releasing the escapement wheel (12) until a next blocking position, synchronously with the mechanical oscillator (11),

   - the escapement wheel (12) being capable, during its pivoting between two successive blocking positions, of providing the energy required for the mechanical oscillator (11) in order to sustain its oscillatory movement on the one hand, and to pivot the blocking device (14) on the other hand, causing pivoting of the rotor (182) via mechanical driving means (13, 17), thereby providing electric energy to the coil (183),

   - said electromechanical escapement device (9) being associated with an electronic circuit (10) including a quartz time base (104), said electronic circuit being capable of providing a set of electric pulses to the coil (183), so as to control pivoting of the rotor (182) causing pivoting of the blocking means (14) and release of the escapement wheel (12) until its next blocking position, characterized in that said release of the escapement wheel is accomplished independently of the frequency of the mechanical oscillator (11).
2. The electromechanical escapement device (9) according to claim 1, characterized in that the rotor (182) has a positioning torque determining two stable equilibrium positions (S1-S2) in the absence of current in the coil (183).
3. The electromechanical escapement device (9) according to claim 2, characterized in that the stable equilibrium positions (S1-S2) are determined by two cells (184) made in the periphery of the housing of the rotor (182) in the stator (181).
4. The electromechanical escapement device (9) according to claim 2, characterized in that the voltage provided by the coil (183) for pivoting the rotor (182) provides a greater electromagnetic torque than the positioning torque.
5. The electromechanical escapement device (9) according to claim 1, characterized in that the electronic circuit (10), which is associated with it, further comprises:

   - energy accumulation means (101) supplied with electric energy during the pivoting of the escapement wheel (12) via charging means (100),

   - means for shaping the voltage from the supply coil (183),

   - means for measuring the oscillation period of the mechanical oscillator (11),

   - calculation means (105) capable of calculating the sum of the differences between the oscillation period of the mechanical oscillator (11) and the period provided by the quartz time base (104) and of providing a set of electric pulses to the coil (183) when this difference exceeds a determined limit.
6. The electromechanical escapement device (9) according to claim 5, characterized in that the associated electronic circuit is capable of providing the set of electric pulses to the coil (183) only when the oscillation angular velocity of the mechanical oscillator (11) is substantially lower than its maximum value.
7. The electromechanical escapement device (9) according to claim 5, characterized in that the associated electronic circuit is capable of providing the set of electric pulses to the coil (183) only when the escapement wheel (12) is in the blocked position.
8. The electromechanical escapement device (9) according to claim 5, characterized in that the oscillation period of the mechanical oscillator (11) is greater than the oscillation period of the quartz time base (104).
9. A clock timepiece including a mechanical clockwork equipped with an electromechanical escapement device (9) according to any of the preceding claims.

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