CH713306A2 - Watchmaking assembly comprising a mechanical oscillator associated with a device for regulating its average frequency. - Google Patents

Abstract

The watch assembly (2) comprises a mechanism, a mechanical oscillator controlling the operation of the mechanism and able to oscillate around a neutral position of its mechanical resonator (6), as well as a device for regulating the frequency of the mechanical oscillator, this control device (8) comprising a measuring device, arranged to measure a temporal drift of the mechanical oscillator relative to an auxiliary oscillator (32) and to determine whether this temporal drift corresponds to a certain advance or a delay, and a regulating pulse applying device arranged to be able to apply to the mechanical resonator, when the measured time drift corresponds to the certain advance, at least one braking pulse in a half-wave of the oscillation of the mechanical resonator intervening before the median moment at which the resonator passes through its neutral position in the alternation e n question and, when the measured time drift corresponds to a certain delay, a braking pulse in a half-alternation occurring after the median moment of the considered alternation.

Description

TECHNICAL FIELD [0001] The present invention relates to a watch assembly, in particular a timepiece, comprising: a mechanism, which at least partially forms a mechanical movement of this watch assembly; a mechanical resonator capable of oscillating around a a neutral position corresponding to its minimum potential mechanical energy state, each oscillation of this mechanical resonator defining an oscillation period and having a first alternation followed by a second alternation between two extreme positions which define the amplitude of oscillation of the mechanical resonator, - a maintenance device of the mechanical resonator forming with the latter a mechanical oscillator incorporated in the mechanical movement to control the operation of the mechanism, - a regulating device arranged to regulate the frequency of the mechanical oscillator, this device regulator comprising an osc an auxiliary scanner, generally more accurate than said mechanical oscillator, and a device arranged to be able to apply a force torque to the mechanical resonator.

In particular, the mechanical resonator is a balance spring and the maintenance device comprises a conventional exhaust, for example Swiss anchor. The auxiliary oscillator is formed in particular by a quartz resonator or by a resonator integrated in an electronic circuit.

BACKGROUND [0003] Movements forming watchmaking assemblies as defined in the field of the invention have been proposed in some previous documents. Patent CH 597 636, published in 1977, proposes such a movement with reference to FIG. . 3. The movement is equipped with a sprung balance resonator and a conventional maintenance device comprising an anchor and an escape wheel in kinematic connection with a spring-loaded barrel. This watch movement comprises a device for regulating the frequency of the mechanical oscillator. This control device comprises an electronic circuit and a magnetic assembly formed of a flat coil, arranged on a support under the beam shank, and two magnets mounted on the balance and arranged close to each other so as to both pass over the coil when the oscillator is on.

The electronic circuit comprises a time base comprising a quartz resonator and for generating a reference frequency signal FR, this reference frequency being compared with the frequency FG of the mechanical oscillator. The detection of the frequency FG is carried out via the electrical signals generated in the coil by the pair of magnets. The control circuit is arranged to be able momentarily to generate a braking torque via a magnet-coil magnetic coupling and a switchable load connected to the coil. Document CH 597 636 gives the following teaching: "The resonator thus formed must have a variable oscillation frequency according to the amplitude on either side of the frequency FR (isochronism defect)". It is therefore taught that a variation of the oscillation frequency of a non-isochronous resonator is obtained by varying its amplitude of oscillation. An analogy is made between the amplitude of oscillation of a resonator and the angular velocity of a generator comprising a rotor provided with magnets and arranged in a cog of the watch movement to regulate its operation. As a braking torque decreases the rotational speed of such a generator and thus its rotation frequency, it is here only considered to be able to reduce the oscillation frequency of a necessarily non-isochronous resonator by applying a torque braking decreasing its amplitude of oscillation.

To perform an electronic control of the frequency of the generator, respectively the mechanical oscillator, it is provided in a given embodiment that the charge is formed by a switchable rectifier via a transistor which charges a storage capacity when braking pulses, for recovering the electrical energy in order to supply the electronic circuit. The constant teaching given in document CH 597 636 is as follows: When FG> FR the transistor is conductive; a power Pa is then taken from the generator / oscillator. When FG <FR, the transistor is non-conductive; no more energy is drawn from the generator / oscillator. In other words, it regulates only when the frequency of the generator / oscillator is greater than the reference frequency FR. This regulation consists of braking the generator / oscillator in order to reduce its frequency FG. Thus, in the case of the mechanical oscillator, those skilled in the art understand that regulation is possible only when the mainspring is heavily armed and the free oscillation frequency (natural frequency) of the oscillator mechanical is greater than the reference frequency FR, as a result of a desired isochronism defect of the selected mechanical oscillator. There is therefore a double problem, namely the mechanical oscillator is selected for what is normally a defect in a mechanical movement and the electronic control is functional only when the natural frequency of this oscillator is greater than a nominal frequency.

[0006] A more recent patent application than the Swiss patent presented above also deals with the electronic regulation of a balance spring. This is the document EP 1 521 142 A1 published in 2005. The control device proposed in the latter document is similar in its general operation to that of patent CH 597 636. Indeed, it is also provided a pair of magnets mounted on the balance and a flat coil arranged below so that the two magnets pass in front of this coil during oscillations of the sprung balance. This European document gives a lesson that goes in the same direction as that of the Swiss patent. He mentions in his paragraph. [0007] In fact, in the present invention, the aim is to use, as far as possible, a mechanical clockwork movement of usual construction, by simply adding an electronic regulator which cooperates with the balance of the mechanical regulator thanks to the addition of a pair of magnets on the balance. To do this, the only element that must necessarily be modified in the mechanical movement is the balance, because of the addition of magnets. It is obviously necessary that the natural frequency of oscillation is slightly higher than the original one, so that the electronic regulator can stabilize it by brief braking of the balance, but the thus stabilized frequency must be equal to the original frequency ". By frequency of origin, one understands the wanted frequency for a precise march of the watch movement, this original frequency being determined in a precise way by the electronic regulator which incorporates a quartz oscillator. The European document adds in its paragraph [0022]: "The mechanical regulator 20 is arranged to have a slightly higher natural oscillation frequency (for example of about 1%) than the theoretical frequency of 4 Hz over the entire useful range. the armature of the spring 54, so that the stabilization of its real frequency by the servocontrol circuit can be done only by small braking pulses ". It will be noted that 1% of error on the theoretical frequency corresponds to a drift of thirty-six seconds per hour and therefore more than ten minutes per day.

In conclusion, the teaching generally given to those skilled in the art is the following: If we want to electronically regulate the frequency of a sprung balance of a classic watch movement, it is necessary to change the sprung balance for first arrange at least one magnet on it and secondly to modify its natural frequency so that this natural frequency is greater than the desired frequency. The consequence of such a teaching is clear: The mechanical resonator must be de-tuned to oscillate at a frequency that is too high to allow the regulating device to constantly reduce its frequency to a lower frequency, corresponding to the desired theoretical frequency. , by a succession of braking pulses. Consequently, the resulting clock movement is deliberately set so that a precise step depends on the electronic regulation, otherwise such a watch movement would have a very important time drift. Thus, if for one reason or another the regulating device is deactivated, in particular because of deterioration, then the watch equipped with such a movement will no longer be precise, and this to an extent that it is in fact more functional. Such a situation is problematic. SUMMARY OF THE INVENTION [0008] The problems of the prior art mentioned above in the technological background are certainly one of the main reasons why there are few or no watches on the market equipped with mechanical movements associated with a computer. control circuit to ensure a more precise running of the timepiece relative to a version with a purely mechanical oscillator.

An object of the present invention is to find a solution to the technical problems mentioned. A first objective, within the framework of the development that led to the present invention, was to produce a watch assembly comprising a mechanical movement with a mechanical oscillator and a device for regulating this mechanical oscillator, but without initially having to disrupt the mechanical oscillator. to have a timepiece which has the precision of an auxiliary electronic oscillator (in particular provided with a quartz resonator) when the regulating device is functional and the accuracy of the mechanical oscillator when this control device is deactivated or off, but with a precision that may correspond to the best standard in the latter case. In other words, it seeks to add an electronic control to a mechanical movement also the most accurate possible so that it remains functional, with the best possible operation, when the electronic control is not active.

Another object of the present invention is to provide a mechanical watch movement associated with a control device that allows intelligent management of mechanical energy available, including minimizing the regulation energy.

The present invention also aims to provide a watch assembly meeting the above mentioned goals and which is robust, that is to say, which can maintain high accuracy even after an external disturbance as a shock.

For this purpose, the present invention relates to a watch assembly as defined above in the field of the invention and wherein the mechanical oscillator defines, when activated, alternations which each have a passage of the mechanical resonator by its neutral position at a median time and a certain duration between an initial instant and a final instant respectively defined by the two extreme positions occupied by the mechanical resonator respectively at the beginning and at the end of the alternation considered. The device for regulating the average frequency of the mechanical oscillator comprises an auxiliary oscillator, a device for applying regulation pulses to the mechanical resonator, a measuring device arranged to measure the time drift of the mechanical oscillator relative to the auxiliary oscillator and an electronic control circuit connected to the measuring device and arranged to control the regulating pulse application device. The measuring device and the electronic control circuit are arranged to determine whether the measured time drift corresponds to at least some advance. The regulation pulse application device is arranged in such a way as to be able to generate on command control pulses each exerting a certain force torque on the mechanical resonator. This watch assembly is characterized in that the measuring device and the electronic control circuit are arranged to be able to further determine if the time drift corresponds to at least a certain delay, and that the electronic control circuit and the device for applying regulation pulses are arranged to be able to apply selectively to the mechanical resonator: - following a determination of at least some advance, a first braking pulse of which at least the major part intervenes between the initial moment and the median moment of an alternation or / and a first driving impulse of which at least the major part intervenes between the median moment and the final moment of an alternation, - following a determination of at least some delay , a second braking pulse of which at least the major part intervenes between the median instant and the final moment of an alternation or / and a second driving pulse of which at least the major part intervenes between the initial moment and the median moment of an alternation.

In a particular variant, the electronic control circuit and the regulation pulse application device are arranged to be able to selectively apply to the mechanical resonator in a plurality of alternations: - following a determination of at least one some advance, respectively a plurality of first braking pulses, each similar to the first braking pulse, or / and a plurality of first driving pulses, each similar to the first driving pulse, - following a determination of at least some delay, respectively a plurality of second braking pulses, each similar to the second braking pulse, or / and a plurality of second driving pulses, each similar to the second driving pulse.

By "selectively apply regulation pulses to the mechanical resonator", it is understood that the watch assembly according to the invention allows the application of the various pulses mentioned in the alternation, respectively alternations in question; but that, first, the regulating device applies such regulation pulses only when one of the two conditions relating to the time drift is filled and, secondly, the regulating device selects a single pulse between a first braking pulse and a second one. braking pulse, respectively between a first driving pulse and a second driving pulse as a function of the two conditions relating to the time drift, namely as a function of the fact of the determination of at least some advance or at least some delay .

The present invention is remarkable in that it takes advantage of a particular physical phenomenon and surprising mechanical oscillators. The inventors have arrived at the following observation: Contrary to the general education in the horological field, it is possible not only to reduce the frequency of a mechanical oscillator by braking pulses, but it is also possible to increase the frequency such a mechanical oscillator also by braking pulses. Indeed, as demonstrated by the document EP 1 521 142 A1 published in 2005, the skilled person expects to be able to practically only reduce the frequency of a mechanical oscillator by braking pulses and, as corollary, to be able only to increase the frequency of such a mechanical oscillator by the application of driving pulses during a supply of energy to this oscillator. Such intuition, which has imposed itself in the field of watchmaking and therefore comes first on board in the mind of a person skilled in the art, proves false for a mechanical oscillator. Although such behavior is correct for a micro-generator, whose rotor turns continuously in the same direction, this is not true for a mechanical oscillator because it oscillates.

Thus, thanks to the characteristics of the watch movement according to the invention, it is possible to regulate via an auxiliary oscillator comprising for example a quartz resonator, a mechanical oscillator which is otherwise very precise, that it momentarily exhibits a frequency slightly too high or too low. To do this, it is planned to select, depending on the operation of the mechanism in question and therefore the frequency of the mechanical oscillator that paces this step, the moment to apply either a braking pulse or a driving pulse ( we do not deal here first with the question of the source of electrical energy to generate motor impulses). The regulation of the frequency consists in momentarily varying the instantaneous frequency of the mechanical oscillator so that its average frequency over the duration is equal to that of the auxiliary oscillator. It is a very precise regulation that eliminates any temporal drift of the operation of the mechanism in question.

The inventors have observed that the effect produced by a control pulse on a mechanical resonator depends on the moment when it is applied in an alternation relative to the moment when this mechanical resonator passes through its neutral position. According to this principle, brought to light by the inventors and used in a watch assembly according to the invention, a braking pulse applied, in any alternation between the two extreme positions of the mechanical resonator, substantially before the passage of the mechanical resonator by its neutral position. (rest position) produces a negative temporal phase shift in the oscillation of this resonator and therefore a delay in the operation of the mechanism clocked by the resonator, while a braking pulse applied in this alternation substantially after the passage of the mechanical resonator by its neutral position produces a positive temporal phase shift in the oscillation of this resonator and thus an advance in the operation of the mechanism. It is thus possible to correct a frequency that is too high or a frequency that is too low only by means of braking pulses. In summary, the application of a braking torque during an alternation of the oscillation of a sprung balance causes a negative or positive phase shift in the oscillation of this sprung balance depending on whether this braking torque is applied respectively before or after the sprung balance has passed through its neutral position.

Conversely, it is observed that a driving pulse applied, in any alternation, substantially before the passage of the mechanical resonator by its neutral position produces a positive temporal phase shift in the oscillation of the mechanical resonator (positive time drift) and therefore a advance in the operation of the mechanism clocked by the resonator, whereas a driving pulse applied in this alternation substantially after the passage of the mechanical resonator by its neutral position produces a negative temporal phase shift in the oscillation of this resonator (negative time drift) and therefore a delay in the operation of the mechanism.

In a main embodiment of the invention, the control device comprises a device for determining the temporal positions of the mechanical resonator, this determination device being arranged to be able to determine, in an alternation of the oscillation of the mechanical resonator. at least a first moment which occurs before the median instant and after the initial moment of this alternation and, also in an alternation of the oscillation of the mechanical resonator, at least a second instant which occurs after the median instant and before the final moment of this alternation. The electronic control circuit of the regulating device is arranged to be able to selectively trigger a first braking pulse or a second driving pulse substantially at the first instant and a second braking pulse or a first driving pulse substantially at the second instant.

In particular, the electronic control circuit and the regulation pulse application device are arranged to be able to apply to the mechanical resonator, when the measured time drift corresponds to a certain advance, a braking pulse in a half-wave of the oscillation of the mechanical resonator occurring before the median instant at which the resonator passes through its neutral position in the considered alternation and, when the measured temporal drift corresponds to a certain delay, a braking pulse in a half-alternation occurring after the median moment of the considered alternation. By "median moment", we understand a moment intervening substantially in the middle of the alternations. This is precisely the case when the mechanical oscillator oscillates freely. On the other hand, for the alternations during which regulation pulses are provided, it will be noted that this median instant no longer corresponds exactly to the middle of the duration of each of these alternations due to the disturbance of the mechanical oscillator generated by the device. regulation.

In a particular embodiment of the invention, the regulation device comprises a magnetic system formed of at least one magnet and at least one coil, this at least one magnet and this at least one coil being arranged either respectively on the mechanical resonator and on a support of this mechanical resonator, or respectively on the support of the mechanical resonator and on this mechanical resonator.

In a main embodiment of the invention, the mechanical resonator comprises a rocker and elastic means associated with the rocker to exert on it a return force when it deviates angularly from a rest position, which defines the neutral position of the resonator. This resonator is excited by a maintenance device conventionally comprising an escapement kinematically connected to a barrel provided with a spring, the escapement being capable of supplying the mechanical resonator with a mechanical torque for maintaining its oscillation.

The invention also relates to a method of regulating a mechanical oscillator which is implemented in a watch assembly according to the invention, the method defined in appended claims of which it is the subject.

BRIEF DESCRIPTION OF THE DRAWINGS [0024] The invention will be described in more detail below with reference to the accompanying drawings, given by way of non-limiting examples, in which: FIG. 1 is a top view of a watch assembly according to the invention, FIG. 2 is an enlarged view of the pendulum of the movement of FIG. 1 with the magnetic system of a positive control device, FIG. 3 represents, for a variant of the watch assembly of FIG. 1, the tension induced in the coil of the magnetic magnet-coil system when the spring balance oscillates and the application of a first braking pulse in a certain alternation before the balance-spring passes through its neutral position, as well as the angular speed of the beam and its angular position in a time interval in which the first braking pulse occurs, FIGS. 4A to 4C show, for the watch ensemble considered in FIG. 3, the pendulum at three particular moments of an alternation of the oscillating balance-spring during which the first braking pulse is provided, FIG. 5 is a figure similar to that of FIG. 3 with the application of a second braking pulse in a certain alternation after the sprung balance has passed through its neutral position, FIGS. 6A to 6C show the pendulum at three particular moments of an alternation of the oscillating balance-spring during which the second braking pulse is provided, FIG. 7 is a figure similar to that of FIG. with, instead of a braking pulse, the application of a first driving pulse before the sprung balance passes through its neutral position, FIG. 8 is a figure similar to that of FIG. 7 with the application of a second driving pulse after the sprung balance has passed through its neutral position, FIG. 9 represents, for a watch ensemble similar to that of FIG. 1, the voltage induced in the bobbin of the magnetic magnet-coil system when the sprung balance oscillates and the application of a first braking pulse to the sprung balance before it passes through its neutral position in a certain alternation , fig. 10A shows the approximate angular position of the balance when applying a braking pulse according to FIG. 9, FIG. 10B shows the pendulum of FIG. 10A during its passage through the neutral position of the resonator, FIG. 10C shows the approximate angular position of the balance when applying a braking pulse according to FIG. 11, fig. 11 is a figure similar to that of FIG. 9 but with the application of a braking pulse to the ba-spiral-spiral after it has passed through its neutral position in a certain alternation, FIG. 12 shows the diagram of a first embodiment of a device for regulating the mechanical oscillator, FIG. 13 shows various electrical signals involved in the control device of FIG. 12, FIG. 14 is a flowchart of a mode of operation of the control device of FIG. 12, FIG. 15 shows the diagram of a variant of the first embodiment of the regulating device, FIG. 16 shows various electrical signals involved in the control device of FIG. 15, FIG. 17 is a flowchart of a mode of operation of the regulating device of FIG. 5, fig. 18 shows the diagram of a second embodiment of a device for regulating the mechanical oscillator, FIG. 19 shows various electrical signals involved in the control device of FIG. 18, FIG. 20 is a flow diagram of an operating mode of the control device of FIG. 18, FIG. 21 is a top view of an alternative embodiment of a mechanical resonator incorporated in a watch assembly, FIG. 22 is a cross section of the mechanical resonator of FIG. 21 according to line XXII-XXII.

Detailed Description of the Invention [0025] Referring to FIGS. 1 and 2, a watch assembly object of the present invention will be described below. Fig. 1 is a partial plan view of a watch assembly 2 comprising a mechanical movement 4, equipped with a mechanical resonator 6, and a regulating device 8. The maintenance means 10 of the mechanical resonator are conventional. They include a barrel 12 with a motor spring, an exhaust 14 formed of an escape wheel and a pallet anchor, and an intermediate gear 16 kinematically connecting the barrel to the escape wheel. The resonator 6 comprises a rocker 18 and a conventional coil spring, the rocker being pivotally mounted about an axis of rotation 20 between a plate and a bridge. The mechanical resonator 6 and the maintenance means 10 (also called excitation means) together form a mechanical oscillator. It will be noted that, in general, only the escapement as maintenance means / excitation means of this mechanical oscillator, the energy source and an intermediate gear train are included in the definition of a mechanical clock oscillator. being considered separately. The sprung balance oscillates about the axis 20 when it receives mechanical impulses from the exhaust whose escape wheel is driven by the barrel. The wheel 16 is part of a mechanism of the watch movement whose running is clocked by the mechanical oscillator. This mechanism comprises, in addition to the wheel 16, other mobiles and analog indicators (not shown) kinematically connected to the wheel 16, the displacement of these analog indicators being paced by the mechanical oscillator. Various mechanisms known to those skilled in the art can be provided.

Fig. 3 2 is a horizontal sectional view of the rocker arm 18 with a coil 28 of an electromagnetic system which partly forms the regulating device 8. The coil 28 is preferably of the wafer type (disc shape having a relatively small thickness ). The rocker 18 carries, preferably in an area located near its outer diameter defined by its serge, a pair of bipolar magnets 22 and 24 having axially oriented magnetization axes with reversed polarities. These magnets are arranged close to each other, advantageously at a distance allowing an addition of their respective interactions with the coil 28 with regard to the voltage induced therein (more precisely at a central lobe of the an induced voltage pulse generated during a passage of this pair of magnets above the coil). In a variant, a single bipolar magnet is provided with a magnetization axis parallel to the general plane of the balance and oriented tangentially to a geometric circle centered on the axis of rotation 20. The voltage signal induced in the coil may have substantially a same profile as for the pair of magnets described above, but with a lower amplitude since only a portion of the magnetic flux of the magnet passes through the coil. It should be noted that it is preferable to confine the magnetic flux of the magnets by a shield formed by parts of the balance, in particular by magnetic parts arranged on both sides of the magnets in the axial direction. An alternative embodiment is shown in FIGS. 21 and 22. It will be described at the end of the description.

The rocker 18 defines a half-axis 26 from its axis of rotation 20 and perpendicular thereto. This half-axis 26 passes in the middle of the pair of magnets 22 and 24. When the sprung balance is in its rest position, the half-axis 26 defines a neutral position (angular rest position of the sprung balance) around of which the balance spring can oscillate at a certain frequency, in particular at a free frequency FO corresponding to the oscillation frequency of the undisturbed mechanical oscillator, that is to say not subject to external force torques ( other than the one intermittently supplied via the exhaust). In figs. 1 and 2, the resonator 6 is shown in its neutral position. Note that it is arranged so that, in its neutral position, the half-axis 26 substantially intersects the central axis of the coil 28. In other words, in projection in the general plane of the balance, the center of the coil 28 is aligned on the half-axis 26 when the resonator is in its neutral position.

The mechanical resonator 6 is a member for controlling the operation of a mechanism comprising the gear train 16, this mechanical resonator being able to oscillate around a neutral position, corresponding to a minimum potential mechanical energy state of the resonator. Each oscillation of this mechanical resonator defines an oscillation period and it has a first alternation followed by a second alternation between two extreme positions defining the oscillation amplitude of the mechanical resonator (note that we consider here the oscillating resonator and therefore the mechanical oscillator as a whole, the oscillation amplitude of the sprung balance being defined among other things by the maintenance means). Each alternation has a passage of the mechanical resonator by its neutral position at a median time and a certain duration between an initial moment and a final instant which are respectively defined by the two extreme positions occupied by the mechanical resonator respectively at the beginning and at the end of this alternation.

The device 8 for regulating the frequency of the mechanical oscillator comprises an electronic circuit 30 and an auxiliary oscillator 32, this auxiliary oscillator comprising a clock circuit and for example a quartz resonator connected to this clock circuit . Note that in a variant, the auxiliary oscillator is integrated in the electronic circuit. The control device further comprises the magnetic system described above, namely the coil 28 which is electrically connected to the electronic circuit 30 and the pair of bipolar magnets mounted on the balance. Advantageously, the various elements of the regulating device 8, with the exception of the pair of magnets, are arranged on a support 34 with which they form a mechanically independent module of the watch movement. Thus, this module can be assembled or associated with the mechanical movement 4 that during their assembly in particular in a watch case. In particular, as shown in FIG. 1, the aforementioned module is attached to a casing ring 36 which surrounds the watch movement. It is understood that the control module can be associated with the watch movement once the latter fully assembled and adjusted, the assembly and disassembly of this module can occur without having to intervene on the mechanical movement itself.

The control device 8 is arranged so as to generate, when the mechanical oscillator is activated, successive control pulses each exerting a force torque on the mechanical resonator. These regulation pulses are supplied to the mechanical resonator via the magnetic coupling between the pair of magnets 22, 24 and the coil 28, in particular by a short-circuit of this coil when the pair of magnets passes above. It will be noted that, in order to obtain a higher induced voltage in the regulation device and therefore a stronger magnetic coupling between this device and the mechanical resonator, two or more coils can be provided, angularly offset relative to the axis of rotation. of the pendulum and connected in series, these coils cooperating with a corresponding number of pairs of magnets arranged on the balance and having one or corresponding offset / s / s / s.

[0031] Referring to FIGS. 3 to 8, first of all we will describe various observed physical phenomena on the basis of which the regulation principle implemented in the watch assembly according to the invention is based. A watch ensemble similar to that of FIG. 1, but with the following two differences: 1) The mechanical resonator 40, of which only the rocker 42 has been shown in FIGS. 4A-4C and 6A-6C, carries a single bipolar magnet 44 whose magnetization axis is substantially parallel to the axis of rotation 20 of the balance, that is to say it has an axial orientation; 2) The coil 28 is fixedly arranged on a support with its center angularly offset by a non-zero angle relativement relative to the reference half-axis 48 corresponding to the position of a median half-axis 46 when the mechanical resonator 40 is in its neutral position (minimum potential mechanical energy state), the median half-axis passing through the center of rotation 20 and the center of the magnet 44. In the example discussed here, the angle 6 between the half-axis 48 and the half axis 50, connecting the center of rotation 20 to the center of the coil, has a value of about 90 °. The two half-axes 48 and 50 are fixed relative to the watch movement, while the medial half-axis 46 oscillates with the balance and gives the angular position β of the magnet mounted on this balance relative to the reference half-axis, which last defining the zero angular position for the mechanical resonator. More generally, the angular offset Θ is such that an induced voltage signal generated in the coil at the passage of the magnet facing this coil is located, during a first alternation of any oscillation, before the passage of the half-axis median by the reference half-axis and, during a second alternation of any oscillation, after the passage of this medial half-axis by the reference half-axis.

FIG. 3 shows four graphs. The first graph gives the voltage in the coil 28 as a function of time when the resonator 40 oscillates, that is to say when the mechanical oscillator of the watch assembly is activated. The second graph indicates the time tP1 at which a braking pulse is applied to the resonator 40 to make a correction in the operation of the mechanism clocked by the mechanical oscillator. The instant of the application of a pulse of rectangular shape (that is to say of a binary signal) is considered here as the temporal position of the middle of this pulse. There is a variation of the oscillation period during which the braking pulse occurs and thus a point variation of the frequency of the mechanical oscillator. In fact, as seen in the last two graphs of FIG. 3, which respectively show the angular velocity (values in radians per second: [rad / s]) and the angular position (values in radian: [rad]) of the pendulum over time, the temporal variation relates to the only alternation during from which intervenes the braking pulse. It will be noted that each oscillation has two successive alternations which are defined in the present text as the two half-periods during which the rocker is respectively subjected to an oscillation movement in one direction and then an oscillation movement in the other direction. In other words, as already explained, an alternation corresponds to a rocking of the rocker in one direction or the other direction between its two extreme positions defining the amplitude of oscillation.

By braking pulse, it includes an application, substantially during a limited period of time, a certain force torque to the mechanical resonator which brakes, that is to say a torque force that s opposes the oscillation motion of this mechanical resonator. It will be noted that the braking torque may be of various natures, in particular magnetic, electrostatic or mechanical. In the embodiment described, the braking torque is obtained by the magnet-coil coupling and therefore corresponds to a magnetic braking torque exerted on the magnet 44 via the coil 28 which is controlled by the control device according to the invention. invention. Such braking pulses can be generated by momentarily short-circuiting the coil. This action is recognizable on the graph of the coil voltage in the time zone during which the braking pulse is applied, this time zone being provided at the occurrence of a voltage pulse induced in the coil by the passage of the magnet. It is obviously in this time zone that the magnet-coil coupling allows a contactless action via a magnetic torque on the magnet fixed to the balance. Indeed, it is observed that the coil voltage goes down to zero during the braking pulse (the voltage induced in the coil 28 by the magnet 44 being shown in phantom in the aforementioned time zone). It will be noted that the braking torque can, depending on its intensity and the instant of its application, stop the sprung balance during a braking pulse, that is to say momentarily stop it.

In figs. 3, 5, 7 and 8, the oscillation period TO corresponds to a "free" oscillation (that is to say without application of regulation pulses) of the mechanical oscillator of the watch assembly. Each of the two alternations of an oscillation period has a duration TO / 2 without disturbance or external stress (in particular by a regulation pulse). The time t = 0 marks the beginning of a first alternation. It will be noted that the "free" frequency FO of the mechanical oscillator is here approximately equal to four Hertz (FO = 4 Hz), so that the period TO = approximately 250 ms.

[0035] With reference to FIGS. 3 and 4A-4C, we will describe the behavior of the mechanical oscillator in a first case. After a first period TO begins a new period T1, respectively a new alternation A1 during which occurs a braking pulse P1. At the initial time tbi begins the alternation A1, the resonator 40 then being in the state of FIG. 4A where the magnet 44 occupies an angular position β corresponding to an extreme position (maximum positive angular position Am). Then comes the braking pulse P1 at time t1 which is located before the median moment tNi at which the resonator passes through its neutral position, FIGS. 4B, 4C representing the resonator respectively at the two successive instants tPi and tNi. Finally the alternation A1 ends at the final time tP1.

In the first case, the braking pulse is generated between the beginning of an alternation and the passage of the resonator by its neutral position in this alternation. As expected, the angular velocity in absolute value decreases at the moment of the braking pulse P1. This induces a negative time phase shift TCi in the oscillation of the resonator, as shown by the two graphs of the angular velocity and the angular position in FIG. 3, a delay relative to the undisturbed theoretical signal (shown in broken lines). Thus, the duration of the alternation A1 is increased by a time interval Td. The oscillation period T1, comprising the alternation A1, is therefore extended relative to the value TO. This causes a specific decrease in the frequency of the mechanical oscillator and a momentary slowing of the operation of the associated mechanism.

[0037] Referring to FIGS. 5 and 6A-6C, we will describe the behavior of the mechanical oscillator in a second case. The graphs of fig. 5 represent the temporal evolution of the same variables as in fig. 3. After a first period TO begins a new period T2, respectively an alternation A2 during which a braking pulse P2 occurs. At the initial time tD1 begins the alternation A2, the resonator 40 then being in an extreme position (maximum negative angular position not shown). After a quarter period (TO / 4) corresponding to half a half cycle, the resonator reaches its neutral position at the median time tN2 (configuration shown in Fig. 6A). Then comes the braking pulse P2 at the instant tP2 which is located after the median moment tN2 at which the resonator passes through its neutral position in the alternation A2. Finally, this alternation ends at the final time tf2 at which the resonator again occupies an extreme position (maximum positive angular position). Figs. 6B, 6C represent the resonator respectively at the two successive instants tN2 and tF2. It will be noted in particular that the configuration of FIG. 6A differs from the configuration of FIG. 4C by the opposite directions of the respective oscillation movements. Indeed, in fig. 4C, the pendulum rotates in a clockwise direction when it passes through the neutral position in the alternation A1, whereas in FIG. 6A this balance rotates counterclockwise when passing through the neutral position in alternation A2.

In the second case considered, the braking pulse is generated, in an alternation, between the median instant at which the resonator passes through its neutral position and the final instant at which this alternation ends and at which the resonator occupies a extreme position. As expected, the angular speed in absolute value decreases at the moment of the braking pulse P2. Remarkably, the braking pulse here induces a positive temporal phase shift T o in the oscillation of the resonator, as shown by the two graphs of the angular velocity and the angular position in FIG. 5, an advance relative to the undisturbed theoretical signal (shown in broken lines). Thus, the duration of the alternation A2 is reduced by the time interval TC2. The oscillation period T2 comprising the alternation A2 is therefore shorter than the value TO. This therefore generates a point increase in the frequency of the mechanical oscillator and a momentary acceleration of the operation of the associated mechanism.

With reference to FIGS. 7 and 8, the behavior of the mechanical oscillator of a watch assembly according to the invention will be described when motor pulses other than those provided by its usual maintenance device comprising an escapement are applied thereto. It will be noted that the graphs of FIGS. 7 and 8 represent the temporal evolution of the same variables as in figs. 3 and 5. Motive impulse includes an application, substantially during a limited period of time, of a certain torque of force to the mechanical resonator in the direction of the oscillation movement of this mechanical resonator. The motor torque is also obtained by the magnet-coil coupling of the intended magnetic system. It therefore corresponds to a magnetic motor torque exerted on the magnet 44 via the coil 28, the latter being controlled by the regulating device according to the invention. Such driving pulses require the application of a sufficient voltage in the coil by the regulating device. This action is recognizable in figs. 7 and 8 on the graph of the coil voltage in the time zone during which the driving pulse is supplied, this time zone being provided at the occurrence of a voltage pulse induced in the coil by the passage of the magnet. It is observed that the coil voltage takes during the driving pulse a negative value, greater in absolute value than that of the negative half cycle (an alternation of the induced voltage is defined between two passages by the zero value) of the induced voltage (shown in broken lines in the time zone). Thus, a motor torque is generated on the spring balance of the resonator.

Note that a motor torque can also be produced by the application of a positive voltage pulse applied during a positive alternation of the induced voltage. In the case shown, it has been planned to apply the correction pulse during the negative half cycle because it occurs following the positive half-cycle which is used to control the triggering of this correction pulse. The person skilled in the art knows how to use the induced voltage signal and, if necessary, a timer to determine, during the passage of the magnet over the coil, the temporal positions of the mechanical resonator and also to determine the corresponding angular positions of the magnet. this mechanical resonator.

[0041] Referring to FIG. 7, we will describe the behavior of the mechanical oscillator in a third case. A driving pulse P3 is provided in an alternation A3. At the initial time tb3 begins this alternation A3, the resonator 40 then being in the configuration of FIG. 4A. Then the driving pulse P3 intervenes at the instant tp3 which is located before the median moment tN3 at which the resonator passes through its neutral position. Figs. 4B and 4C represent the resonator respectively at the two successive instants tP3 and tN3. Finally the alternation A3 ends at the final moment tP3.

In the third case considered, the driving pulse is generated between the beginning of an alternation and the passage of the resonator by its neutral position in this alternation. As expected, the angular velocity in absolute value increases at the moment of the driving pulse P3. However, this induces a positive phase shift TC3 in the oscillation of the resonator, as shown by the two graphs of the angular velocity and the angular position in FIG. 7, an advance relative to the undisturbed theoretical signal (shown in broken lines). Thus, the duration of the alternation A3 is decreased by the time interval TC3 · The oscillation period T3, comprising the alternation A3, is therefore shorter than the oscillation period TO. This therefore generates a point increase in the frequency of the mechanical oscillator and a momentary acceleration of the operation of the associated mechanism.

With reference to FIG. 8, we will describe the behavior of the mechanical oscillator in a fourth case. After a first period TO begins a new period T4, respectively an alternation A4 during which a driving pulse P4 occurs. At the initial time tD4 begins the alternation A4. After a half-wave (TO / 4), the resonator reaches its neutral position at the median time lN4 (configuration shown in Fig. 6A). Then comes the driving pulse P4 at time tP4 which is located after the median moment tN4 to which the resonator passes through its neutral position in the alternation A4. Finally, this alternation ends at the final instant W The angular positions occupied by the resonator at the two successive instants tN4 and tF4 are respectively represented in FIGS. 6B and 6C.

In the fourth case considered, the driving pulse is generated alternately between the median instant at which the resonator passes through its neutral position and the final instant at which this alternation ends and at which the resonator occupies a position. extreme. As expected, the angular velocity in absolute value increases at the moment of the driving pulse P4. Surprisingly, the driving pulse here induces a negative phase shift TC4 in the oscillation of the resonator, as shown by the two graphs of the angular velocity and the angular position in FIG. 8, a delay relative to the undisturbed theoretical signal. Thus, the duration of the alternation A4 is increased by the time interval TC4. The oscillation period T4, comprising the alternation A4, is thus extended relative to the value TO. This therefore generates a specific decrease in the frequency of the mechanical oscillator and a momentary slowing of the operation of the associated mechanism.

[0045] With reference to FIGS. 9, 10A to 10C and 11, there will be described hereinafter a particular regulation mode for a watch assembly similar to that described above with reference to FIGS. 1 and 2. This watch assembly comprises a resonator 6A formed of a balance 18A and a conventional spiral (not shown). The half-axis 26 passes in the middle of the pair of bipolar magnets 22 and 24 already described. When the sprung balance is in its neutral position (rest position), the half-axis 26 occupies an angular position given by the half-axis 27 which defines the reference axis (zero angular position) to measure the angular movement of the resonator over time. The present arrangement is specific in that the coil is arranged with its center aligned with the half-axis 27, so that there is no angular offset between the center of the coil and the neutral position of the half. However, it will be appreciated that each of the two individually considered magnets has a small angular offset relative to the reference half-axis when the resonator is in its neutral position (as shown in Fig. 10B). The induced voltage signal generated by the pair of magnets during the passage opposite the coil has a profile as shown in FIGS. 9 and 11. This voltage profile forms a pulse with a central lobe having a peak defining the maximum amplitude of the voltage induced in the coil and two side lobes (also called wings) on either side of the central lobe.

FIG. 9 shows the effect of a braking pulse P5 applied during the appearance of the first side lobe of an induced voltage pulse, that is to say before the appearance of the central lobe, whose peak defines the passing through the zero position of the half-axis 26, and therefore before the passage of the resonator by its neutral position. Fig. 10A shows the angular position occupied substantially by the balance 18A during the generation of the braking pulse P5 in the Alternance A5 by a short circuit of the coil. In a manner similar to what has been observed previously, the pulse P5 generates a negative phase shift TC5 of the oscillation of the resonator in the alternation A5. Thus, the duration of this alternation is extended by the absolute value of this phase shift Tes relative to the half-period TO / 2 of a free oscillation. The oscillation frequency is momentarily decreased relative to the frequency FO of the free mechanical oscillator (the oscillation frequency in the absence of control pulses).

FIG. 11 shows the effect of a braking pulse P6 applied during the appearance of the second side lobe of an induced voltage pulse, that is to say after the appearance of the central lobe and therefore after the passage of the resonator by its neutral position. Fig. 10C shows the angular position occupied substantially by the balance 18A during the generation of the braking pulse P6. The pulse P6 generates a positive phase shift Tee of the oscillation of the resonator in the alternation A6. Thus, the duration of this alternation is reduced by the absolute value of this phase shift Tc6 relative to the half-period TO / 2 of a free oscillation. The oscillation frequency is momentarily increased relative to the frequency F0 of the free mechanical oscillator.

It will be noted that an arrangement of the magnetic system with a pair of magnets, as shown in FIG. 2, may advantageously be used in a watch assembly in which it is provided, as in the embodiment described above with reference to FIGS. 4A-4C and 6A-6C, a non-zero angular offset, for example 60 ° to 120 °, between the reference half-axis 27, defined above and shown in FIGS. 10A to 10C, and the half-axis defined by the center of the coil (corresponding to the half-axis 50 shown in Fig. 4A). In this case, one can intervene on the mechanical oscillator before and after a passage through the neutral position of the mechanical resonator in a manner similar to that described with reference to FIGS. 3 to 8, while exploiting the central lobe of the induced voltage pulses which allows magnetic coupling of greater intensity in the magnetic system. It is thus possible to generate, in particular, stronger magnetic braking torques than in the case described above in relation to FIGS. 9 to 11. It will be observed that, in the latter case, the central lobe of the voltage pulses can, however, be used to generate electrical energy stored in a capacitor via a rectifier, this electrical energy can advantageously be used to power the regulating device according to the invention. This is also possible in an embodiment with an aforementioned angular offset for the coil.

By exploiting the physical phenomena described above, the watch assembly according to the invention is characterized by a particular arrangement of the mechanical oscillator control device. Generally, this control device comprises a measurement device arranged to measure, if necessary, a time drift of the mechanical oscillator relative to an auxiliary oscillator, which is implicitly more accurate than the mechanical resonator, and to determine whether this temporal drift at least some advance or at least some delay. Then, the regulating device comprises an electronic control circuit and a device for applying regulation pulses, which are arranged to be able to apply to the mechanical resonator, when the time drift of the mechanical oscillator corresponds to the at least some aforementioned advance, a first braking pulse substantially in a first half-wave before the median time of passage of the mechanical resonator by its neutral position or a first driving pulse substantially in a second half-wave after this median instant and, when the drift time of the mechanical oscillator corresponds to at least a certain delay mentioned above, a second braking pulse substantially in a second half-wave after the median moment of passage of the mechanical resonator by its neutral position or a second driving pulse in a first half -alternance a before this median moment.

In a preferred embodiment which will be described later in more detail, the control device comprises a device for determining the temporal positions of the mechanical resonator, this determination device being arranged to be able to determine, in an alternation of an oscillation, a first moment which occurs before the median moment of passage of the mechanical resonator by its neutral position and after the initial moment at which this alternation begins, and, in the same alternation or another alternation of an oscillation, a second moment which intervenes after the median moment of passage of the mechanical resonator by its neutral position and before the final moment at which this alternation ends. Then, the electronic control circuit is arranged to distinguish the first instant and the second instant and to trigger the aforementioned first braking pulse or the aforementioned second driving pulse substantially at the first instant and the aforementioned second braking pulse or the aforementioned first driving pulse. substantially at the second moment.

It should be noted that the measuring device and the device for applying regulation pulses may have common elements or members, in particular a magnetic assembly, formed of at least one magnet and a coil, of the type previously described. Similarly, the device for determining the temporal positions of the mechanical resonator may have in common elements or members with the measuring device, in particular the above-mentioned magnetic assembly and also electronic components, and with the control circuit, for example a logic circuit and possibly a counter. However, such embodiments are in no way limiting in the context of the present invention. In addition, it will be noted that the magnetic assembly used to couple the sprung balance to the regulation circuit is not limiting.

Embodiments of a regulating device according to the invention are described hereinafter with reference to FIGS. 12 to 19.

A first embodiment, described below with reference to FIGS. 12 to 14, concerns a watch assembly comprising a magnetic system of the type shown in FIGS. 4A-4C. The balance therefore carries a single bipolar magnet with axial magnetization and there is provided a coupling coil 28 angularly offset by a non-zero angle relativement relative to the reference half-axis 48 (see Fig. 4A). The angle Θ is greater than zero and preferably between 30 ° and 180 ° for an amplitude of the mechanical oscillator provided between 200 ° and 300 ° in the operating range of operation, these ranges of values being in no way limiting. The regulator device 52 comprises a regulation circuit 30A and an auxiliary resonator 32A. This auxiliary resonator is for example an electronic quartz resonator. The induced voltage Ui generated at the terminals of the coil, when the mechanical oscillator is activated, forms an analog signal consisting of a succession of pulses lAn and lAm (n, m = 1,2, 3, N, ... ) which correspond to the successive passages of the magnet opposite the coil. This analog signal is firstly compared with a threshold voltage Uth by means of a hysteresis comparator 54 (Schmidttrigger) in order to generate a digital signal "Comp" for the digital electronics of the control circuit. This digital signal "Comp" consists of a succession of digital pulses 74 and 76 respectively corresponding to the succession of analog pulses lAn and lAm.

The comparator is an element of a measurement circuit described hereinafter. Since there are two pulses Un and Um per oscillation period of the mechanical resonator and the succession of digital pulses 74 and 76 alternately define between them two different time intervals T7 and T8 (this resulting from the angular displacement of the coil relative to the reference axis), the digital signal "Comp" is set either on the pulses 74 or on the pulses 76 by means of a rocker 56, which thus periodically provides a pulse per oscillation period. . The flip-flop increments, at the instantaneous frequency of the mechanical oscillator, a bidirectional counter C2, which is decremented at a nominal frequency / setpoint frequency by a clock signal Shor derived from the auxiliary oscillator which generates a digital signal at a minimum. reference frequency. This auxiliary oscillator is formed of the auxiliary resonator 32A and a clock circuit 60. For this purpose, the signal The relatively high frequency reference generated by the clock circuit is divided beforehand by the dividers DIV1 and DIV2 (these two dividers being able to form two stages of the same divider). Thus, the state of the counter C2 determines the advance or the delay accumulated by the mechanical oscillator relative to the auxiliary oscillator with a resolution corresponding substantially to a set period, the state of the counter being supplied to a logic circuit of command 62A.

The control logic circuit 62A, for example a microcontroller, is arranged to determine a succession of time positions tn and tm of the mechanical resonator respectively corresponding to the succession of digital pulses 74 and 76 (detected in particular on their rising flanks). It determines this information directly from the signal "Comp" provided by the comparator 54. In addition, the regulation circuit 30A is arranged to allow the logic circuit 62A to distinguish the pulses 74 which correspond to events occurring in corresponding half-waves before the passage of the resonator by its neutral position of the pulses 76 which correspond to events occurring, in corresponding alternations, after the passage of the resonator by its neutral position. For this purpose, the presence of the fixed angular offset of the coil 28 relative to the reference half-axis is used, which defines the neutral position of the resonator in the center of the magnet fixed on the balance.

The fixed angular offset of the coil has the consequence that two induced voltage pulses UAn and UAm generated in the same oscillation period occur on the same side of the reference half-axis, so that the corresponding digital pulses 74 and 76 have between them a time interval T7 less than the time interval T8 which separate them from the two adjacent pulses occurring respectively in the preceding oscillation period and the next oscillation period. The induced voltage pulses lAm define, in the alternations during which they are generated, events which occur at least in the major part after the passage through the neutral position, while the induced voltage pulses lAn define events which occur at least mostly before passing through the neutral position. Among two digital pulses 74 and 76 which are generated by the comparator in the same period, and which are separated by a time interval T7, the first pulse 76 therefore intervenes after the passage of the resonator by its neutral position and before the instant end of the alternation during which this first pulse 76 intervenes, while the second pulse 74 occurs before the passage of the resonator by its neutral position and after the initial moment of the alternation during which this second pulse 74 intervenes.

In order to differentiate magnet-coil couplings occurring before the neutral position and magnet-coil couplings occurring after this neutral position in the alternations, it is intended to measure the time intervals T7 and T8 by means of a counter C1 which receives a clock signal derived between the two divisors DIV1 and DIV2, and then compare these time measurements T7 and T8 to a differentiation value TDif which is selected between the values T7 and T8 (ie T7 <T dif <T8). Thus, this comparison made in the logic circuit 62A enables it to distinguish between the pulses 74 and the pulses 76, respectively between the instants tn and tm of their rising flanks and thus to determine the instants tn located in the corresponding half-waves before the passage of the resonator by its neutral position and the instants tm located in the corresponding alternations after the passage of the resonator by its neutral position, and to distinguish them from each other. Thanks to this distinction made between the instants t "and the instants tm by the control device, the logic circuit 62A can selectively generate control pulses 74B and 76B to produce pulses, respectively before and after the neutral position of the mechanical resonator. braking and / or driving pulses. Thus, in the variant of the first embodiment described here, the electronic control circuit is arranged so that the regulation pulses are applied, as a function of the measured time drift and according to whether it is braking pulses. or of driving pulses, respectively during the appearance of induced voltage pulses either in first alternations, or in second alternations, each oscillation of the mechanical resonator defining a first alternation followed by a second alternation.

In the case of braking pulses provided for the regulation of a mechanical oscillator which may have either a delay or an advance (a situation which may also evolve over time so that the watch movement may alternatively present periods of delay and periods of advance), the logic circuit 62A controls a transistor 68, via a timer 66 (Timer TR), or by a control signal Sca triggering one or more control pulses 74B to substantially one or more times tn respective in case of advance in the march of the watch movement, either a control signal SCr triggering one or more control pulses 76B to substantially one or more times tm respective in case of delay. The timer 66 determines the duration TR of the braking pulses.

To regulate electronically the frequency of the mechanical oscillator using braking pulses, it is therefore expected to provide in at least one alternation of this mechanical oscillator, when its time drift corresponds to a certain advance, a braking pulse, corresponding here to a control pulse 74B, at a first instant tn which occurs before the median time of passage of the mechanical resonator by its neutral position and, when the time drift of the mechanical oscillator corresponds to a certain delay a braking pulse, corresponding to a control pulse 76B, at a second instant tm which occurs after the aforementioned median instant.

FIG. 14 gives the flowchart corresponding to the control algorithm implemented in the control logic circuit 62A to implement the control method implemented by the control device 52. In an initialization phase, following the activation of the device 52 in the POR step, the bidirectional counter C2 is reset ("Reset"). Then, on detecting a rising edge of a first digital pulse 74 or 76, the counter C1 is reset ("Reset"). When the next rising edge of a digital pulse is detected, the state of the counter C1 is compared with the differentiation value TDif. If the value of the counter C1 is smaller than the value TDif, this indicates that the pulse corresponding to the new rising rising edge occurs before the passage of the mechanical resonator by its neutral position. The position of this resonator during magnet-coil coupling can reduce its instantaneous frequency by a braking pulse. On the other hand, if the value of the counter C1 is greater than the value TD | F, this indicates that the pulse corresponding to the new detected rising edge comes after the passage of the mechanical resonator by its neutral position. The position of this resonator during magnet-coil coupling can increase its instantaneous frequency by a braking pulse.

Thus, if C1 <TDif, the logic circuit checks the state of the counter C2 to see if it indicates a certain advance of the mechanical oscillator relative to the auxiliary oscillator. For this purpose, this logic circuit compares the value of the counter C2 with a positive integer N1 greater than zero. If C2> N1, then the logic circuit instantaneously triggers a control pulse 74B and the control device directly generates a braking pulse. In the opposite case, no braking pulse is generated and the sequence is terminated. The counter C1 is reinitialized directly after each detection of a rising edge to determine the time period between the detected pulse and the next one, and thus allow the sequence represented on the flow chart to be looped for continuous regulation of the gait. of the watch movement. On the other hand, if C1> TD | F, then the logic circuit compares the value of the counter C2 with a negative integer -N2, less than zero, to see if it indicates a certain delay of the mechanical oscillator relative to the auxiliary oscillator. If C2 <-N2, the logic circuit then instantly triggers a control pulse 76B and the control device directly generates a braking pulse. In the opposite case, no braking pulse is generated and the sequence is terminated. Note that N1 and N2 are natural numbers (positive integers not equal to zero).

Note that, in the case where C2> N1 or C2 <-N2, it is possible in a variant to provide a plurality of successive control pulses 74B, respectively 76B at a plurality of instants tn, respectively tm according to the method described here. This amounts to inhibiting the interrogation of the state of the counter C2 during a certain number of sequences. It will be noted that the values N1 and N2 may be identical in a particular variant. It will also be noted that a braking pulse can already be generated when C2 = N1 or C2 = -N2.

In a variant where it is intended to apply driving pulses, the circuit of FIG. 12 can easily be modified for this purpose by connecting the lower terminal of the transistor 68 not to the "earth" (Gnd) but to a power source capable of generating driving pulses when the transistor is made conductive by the timer 66. The control method is reversed relative to that described above for braking pulses. Thus, on the one hand, if C1> TDif and C2> N1, the logic circuit triggers a control pulse 76B and the control device directly generates a driving pulse. If C2 <= N1, no driving pulse is generated and the sequence is complete. On the other hand, if C1 <TD | F and C2 <-N2, the logic circuit then triggers a control pulse 74B and the control device directly generates a driving pulse. If C2> = -N2, no driving pulse is generated and the sequence is complete.

[0064] Referring to FIGS. 15 to 17, a variant of the first embodiment will be described below. The elements already described and the operation of the control device already amply described will not be described again in detail. This variant differs from that which has just been described essentially in that the counter C1 and the comparisons made by the logic circuit in relation to this counter C1 are replaced by a subcircuit which performs a similar function. This sub-circuit receives the signal "Comp" from the comparator 54, this signal being supplied to a timer 84 (Timer TDif) and to two "AND" gates 86 and 87. The second input of the gate 86 receives a signal from the timer 84 and the second input of the gate 87 receives the signal from the timer 84 inverted by the "NOT" gate 88. As shown by the signals "TD | F", "AV" and "AP" in FIG. 16, the timer 84 is reset to each falling edge of the digital pulses 74 and 76. Its output signal indicates whether since the last reset the measured time interval is smaller (value "1") or higher (value "0") to the TD | F differentiation value. The signal AV at the output of the logic gate 86 has pulses 74A (value "1") which reproduce the pulses 74 of the comparator 54. The signal AP at the output of the logic gate 87 has pulses 76A (value "1" ) which reproduces the pulses 76 of the comparator 54. The signal AV therefore indicates to the control logic circuit 62B when a magnet-coil coupling occurs before the neutral position of the mechanical resonator and the signal AP indicates to this circuit when a coupling magnet-coil intervenes after the neutral position. It then suffices for the logic circuit 62B to interrogate the state of the counter C2 to generate, if necessary, a signal SCa or a signal SCr described previously.

FIG. 17 gives the flowchart corresponding to the control algorithm implemented in the control logic circuit 62B to implement the control method carried out by the control circuit 30B of the control device 82. In an initialization phase, following activation of the device 82 in the POR step, the bidirectional counter C2 is reset ("Reset"). Then, the control circuit follows the evolution of the state of the bidirectional counter C2 to see if a certain advance, C2> N1, or if a certain delay, C2 <-N2, in the movement of the watch movement is detected. . In case of a detected advance, the control circuit waits for the AV signal to have a logic state "1", indicating substantially the beginning of a magnet-coil coupling before the neutral position of the resonator, to generate a control pulse 74B which directly produces a braking pulse before the neutral position. In case of a detected delay, the control circuit waits for the signal AP to have a logic state "1", indicating substantially the beginning of a magnet-coil coupling after the neutral position of the resonator, to generate a control pulse 76B which directly produces a braking pulse after the neutral position. In this variant embodiment, the braking time TR is advantageously selected so as to be greater than the time required for the induced voltage "Ui" in the coil 28 to drop below a voltage threshold "Uth" in the case non-braked, this so as to avoid in the event of braking the generation of a second rising edge of the signal "Comp" in the positive half of Ui.

In another variant of the first embodiment, the magnetic assembly comprises a pair of bipolar magnets mounted on the balance and having axial magnetization axes of opposite respective polarities, the coil being integral with the support of the mechanical resonator. , the median half-axis starting from the axis of rotation of the balance and passing through the middle of this pair of magnets defining a reference half-axis when the resonator is at rest and therefore in its neutral position, the pair of magnets and the coil being arranged so that an induced voltage signal generated in the coil at the passage of the pair of magnets facing this coil has a lobe of maximum amplitude resulting from a simultaneous coupling of the two magnets of the pair of magnets with the coil. Then, the coil has at its center an angular offset relative to the reference half-axis such that a lobe of maximum amplitude is located before the passage of the central half-axis by the reference half-axis during a first alternation. of any oscillation and after the passage of this medial half-axis by the reference half-axis during a second alternation of any oscillation. Finally, the electronic control circuit is arranged so that the regulation pulses are applied, as a function of the measured time drift and according to whether they are braking pulses or motor pulses, respectively during apparitions. of lobes of maximal amplitude either in first alternations, or in second alternations.

A second embodiment, described below with reference to FIGS. 18 to 20 relates to a watch assembly comprising a magnetic system of the type shown in FIGS. 10A-10C. The balance therefore carries a pair of bipolar magnets with axial magnetization and there is provided a coupling coil 28 whose center is aligned in superposition with the reference half-axis 27 (see Fig. 10A) corresponding to the rest position of the half -axis 26 passing in the middle of the pair of magnets. The regulating device 92 comprises a regulation circuit 30C. The induced voltage Ui generated across the coil (Fig. 19) forms an analog signal consisting of a succession of pulses lPm and lNm (m = 1, 2, 3, N, ...) generated at the successive passes of the pair of magnets facing the coil.

In each oscillation period, the resonator passes twice by its neutral position respectively in the two opposite directions of its oscillation movement. Thus, two pulses lPm and lNm shown in FIG. 19 occur in each oscillation period and respectively in two successive alternations, one lPm having a central lobe LCm positive voltage and the other lNm having a central lobe negative voltage. Conversely, the pulse lPm has two side lobes of negative voltage and the pulse lNm has two side lobes LAm and LRm of positive voltage.

The regulation circuit 30C comprises various elements already described. The divisor DIV corresponds to the set of two divisors DIV1 and DIV2 described in FIG. 12. In this embodiment, as an additional function, there is provided a rectifier 94 associated with a storage capacitor 95, this rectifier being arranged to charge the storage capacity only when the negative central lobes of the pulses LNM appear. The circuit 30C comprises a circuit for measuring a time drift of the mechanical oscillator relative to the auxiliary oscillator, which is arranged similarly to the measurement circuit 58 described above. The circuit 30C comprises two hysteresis comparators 96 and 98. The first comparator serves to detect the succession of the central lobes LCm having a positive voltage, these central lobes of the pulses lPm occurring at the instantaneous frequency of the mechanical oscillator, ie once per second. oscillation period. To do this, the voltage of the coil 28 is compared with a voltage threshold Th1 whose value is greater than the maximum voltage of the side lobes. The "Compì" signal of the comparator 96 is supplied on the one hand to the counter C2 (already described above) and on the other hand to the control logic circuit 62C. The comparator 98 is used to detect the succession of side lobes LAm and LRm having a positive voltage by a comparison of the coil voltage at a voltage threshold Th2, this to allow the application of braking pulses either during the appearance first side lobes LAm in case of advance in the march of the watch movement, or when the appearance of second side lobes LRm in case of delay in the running of this watch movement, so as to regulate this step. Reference is made to the description of FIGS. 9 to 11 about it. The signal "Comp2" of the comparator 98 is supplied to the control circuit. In summary, the first side lobes LAm appear before the passage of the mechanical resonator by its neutral position while the second side lobes LRm appear after the passage of the mechanical resonator by its neutral position. The application of braking pulses during the appearance of first side lobes LAm generates a correction which tends to reduce the oscillation frequency of the mechanical oscillator. On the contrary, the application of braking pulses during the appearance of second side lobes LRm generates a correction which tends to increase this oscillation frequency.

As shown in FIG. 19, the "Compì" signal presents digital pulses 100 periodically at the instantaneous frequency of the mechanical oscillator. The signal "Comp2" also detects the central lobes of positive voltage by a pulse 102 substantially centered on the corresponding pulse 100 and of greater duration than the latter. Then, the signal "Comp2" generates two digital pulses 103 and 104 corresponding to the two side lobes of the pulses lNm. These two digital pulses determine two respective instants tAm and tRm respectively corresponding to their rising flanks. These two instants are distinguished by the control circuit so as to selectively generate either a braking pulse at a time tAm to increase a period of the mechanical oscillator and thus momentarily decrease its instantaneous frequency, a braking pulse at a given instant. tRm to decrease a period of the mechanical oscillator and thus momentarily increase its instantaneous frequency.

FIG. 20 gives the flowchart corresponding to the control algorithm implemented in the control logic circuit 62C to implement the control method performed by the control device 92. In an initialization phase, following the activation of the device 92 in the POR, the bidirectional counter C2 is reset ("Reset"). Then, the control circuit 62C firstly expects the detection of a falling edge of a pulse 100 and then the detection of a rising edge of a pulse 103. If the value of the counter C2 is greater than a positive value N1, it then triggers a braking pulse substantially at time Um and ends the sequence. In the opposite case, the control circuit waits for the detection of the rising edge of the pulse 104 which follows. If the value of the counter C2 is smaller than a negative value -N2, it then triggers a braking pulse substantially at the instant tRm and ends the sequence. It will be noted that between the instants tAm and tRm, the mechanical resonator passes through its neutral position. It will be understood that it is alternatively possible to obtain a similar regulation by using the appearance of the negative voltages in the coil 28 and then selecting negative voltage thresholds applied to the respective positive inputs of the two comparators 96 and 98.

Claims (13)

Thus, in the second embodiment, the electronic control circuit is arranged so that the regulation pulses are applied, depending on the measured time drift and whether it is braking pulses or motor impulses, respectively at the occurrence of one of the two side lobes or during appearances of the other of these two side lobes. In addition, preferably, the watch assembly further comprises a rectifier connected to an electrical energy storage capacitor and arranged to charge this storage capacitor, when the pendulum oscillates, during apparitions of said central lobe. This storage capacity can advantageously be used for the power supply of the regulating device. Note that in both embodiments, chopped braking pulses can be generated. The hashing can in particular be used to monitor the evolution of the induced voltage while giving short braking pulses. The hash rate can also be modulated to vary the intensity of the braking pulse. In figs. 21 and 22 is shown an advantageous embodiment of a mechanical oscillator 106 incorporated in a movement according to the invention. The resonator 106 is formed by a balance 18A which comprises two plates of ferromagnetic material 112 and 114. The upper plate 112 bears on the side of its lower face the two bipolar magnets 22 and 24. This upper plate is also used to close the lines of fields of the two magnets. The lower plate 114 serves to close lower the field lines of the two magnets. The two plates of the balance thus axially form a magnetic shielding for the two magnets so that their respective magnetic fields remain substantially confined in a volume located between the respective outer surfaces of these two plates. The coil 28 is arranged partially between the two plates which are fixedly mounted on a cylindrical piece 116 of non-magnetic material, this piece being fixedly mounted on a shaft 118 of the balance. In a variant, the piece 116 may be made of steel and thus conduct a magnetic field, which may be an advantage in a variant provided with a single bipolar magnet, having its magnetic axis oriented axially, on one of the two trays or on each two trays. In the latter case, if the cylindrical connecting piece is non-magnetic, then at least one plate may have a ferromagnetic portion that approaches the other or the key to close the field lines of each magnet through the two trays and thus allow the coil or coils to be traversed axially by substantially the entire magnetic field produced by each magnet when the pendulum oscillates. It will also be noted that the trays can be made only partially by a high magnetic permeability material which forms two parts located respectively above and below the magnet or, where appropriate, magnets, these two parts being arranged in so as to let the coil or, if necessary, the coils of the regulating device between them when the balance oscillates. The resonator 106 further comprises a spiral spring 110, one end of which is conventionally fixed to the shaft 118. It should be noted that the spiral spring is preferably made of non-magnetic material, for example silicon, or paramagnetic material. In fig. 22 is also shown an escape mechanism formed of a pin arranged on a small plate integral with the balance shaft, an anchor 120 and an escape wheel 122 (shown partially). Under the upper plate, opposite the magnets 22 and 24, there is provided a balancing mass 124 of the balance. Other means to perform a fine adjustment of the inertia and balance of the balance can also be provided. Note that in a variant, magnets are also carried by the lower plate. Such magnets are preferably arranged facing the magnets carried by the upper plate, the coil or coils provided (s) being arranged (s) so as to pass between the magnets respectively fixed to the first and second trays. Thus, in the context of the advantageous variant described above, the balance generally comprises a magnetic structure which is arranged so as to define a magnetic shield for the magnet or magnets carried (s) by the pendulum while facilitating the magnetic coupling of this magnet or magnets with the coil or the coils provided (s). claims 1. watch assembly (2), comprising: - a mechanism, - a mechanical resonator (6, 40, 6A, 106) capable of oscillating around a neutral position corresponding to its minimum mechanical potential energy state, each oscillation mechanical resonator defining an oscillation period and having two successive alternations between two extreme positions which define the oscillation amplitude of the mechanical resonator, each alternation having a passage of the mechanical resonator by its neutral position at a median instant and a duration between an initial instant and a final instant respectively defined by the two extreme positions occupied by the mechanical resonator at the beginning and the end of this alternation, - a maintenance device (10) of the mechanical resonator forming with this mechanical resonator a mechanical oscillator which is arranged to control the operation of said mechanism, - a regulating device (8, 52 , 82, 92) arranged to regulate the average frequency of the mechanical oscillator, this regulator comprising an auxiliary oscillator, a device for applying regulation pulses to the mechanical resonator, a measuring device arranged to be able to measure the drift time of the mechanical oscillator relative to the auxiliary oscillator and an electronic control circuit connected to the measuring device and arranged to control the regulation pulse application device, the measuring device and the electronic control circuit being arranged to be able to determine if the measured time drift corresponds to at least some advance, the regulating pulse application device being arranged so as to be able to generate on command control pulses each exerting a certain force torque on the mechanical resonator ; the watch assembly being characterized in that the measuring device and the electronic control circuit are arranged to be able to further determine if the time drift corresponds to at least a certain delay; and in that the electronic control circuit and the regulation pulse application device are arranged to be able to selectively apply to the mechanical resonator: - following a determination of the said at least some advance, a first braking pulse (P1, P5) at least a major part of which intervenes between said initial instant (tbi) and said median time (tN1, tN5) of an alternation (A1, A5) or / and a first driving pulse (P4) of which at least a major part intervenes between said median instant (tN4) and said final instant (tF4) of an alternation (A4), - following a determination of said at least one delay, a second braking pulse (P2, P6) of which at least one major part intervenes between said median instant (W, tN6) and said final moment (tF2) of an alternation (A2, A6) or / and a second driving pulse (P3) of which at least a major portion intervenes between said initial moment (tD3 ) and said i median nstant (tN3) of alternation (A3). 2. Watchmaking assembly according to claim 1, characterized in that the electronic control circuit and the regulating pulse application device are arranged to be able to selectively apply to the mechanical resonator in a plurality of alternations: - following a determination said at least one advance, respectively a plurality of first braking pulses, each similar to said first braking pulse, or / and respectively a plurality of first driving pulses, each similar to said first driving pulse, - following a determination said at least one delay, respectively a plurality of second braking pulses, each similar to said second braking pulse, and / or respectively a plurality of second driving pulses, each similar to said second driving pulse. 3. Watchmaking assembly according to claim 1 or 2, characterized in that the regulating device comprises a device (54, C1, 62A, 54, 84, 86, 87, 88, 62B, 98, 62C) for determining temporal positions. of the mechanical resonator, this determination device being arranged to be able to determine, in an alternation of an oscillation of the mechanical resonator, a first moment which occurs before said median moment and after said initial moment of this alternation and, also in an alternation of an oscillation of the mechanical resonator, a second instant occurring after said median instant and before said final instant of this alternation; and in that said electronic control circuit is arranged to be able to selectively trigger said first braking pulse or said second driving pulse substantially at said first instant and said second braking pulse or said first driving pulse substantially at said second instant. 4. Watchmaking assembly according to any one of the preceding claims, characterized in that the regulating device comprises a magnetic assembly formed of at least one magnet (22, 24; 44) and at least one coil (28) respectively arranged on the mechanical resonator (6A, 40) and on a support of this mechanical resonator or respectively on the support of the mechanical resonator and on this mechanical resonator, this magnetic assembly forming said regulating pulse application device and partially said measuring device . 5. watch assembly according to claim 4, characterized in that the mechanical resonator comprises a rocker (18A) provided with elastic means, which are arranged to exert on the balance a restoring force when it deviates angularly from said neutral position. ; and in that said maintenance device comprises an escapement kinematically connected to a barrel provided with a mainspring, the escapement being capable of supplying the balance spring with a mechanical torque for maintaining its oscillation. 6. Watchmaking assembly according to claim 5, characterized in that the magnetic assembly comprises a bipolar magnet (44) mounted on the balance with an axis of axial magnetization, the middle half axis (46) starting from the axis of rotation (20) of this balance and passing through the center of the bipolar magnet defining a reference half-axis (48) when the resonator is at rest and therefore in its neutral position; in that the coil is secured to the support of the mechanical resonator and arranged so that said bipolar magnet passes opposite this coil when the balance oscillates, the coil having at its center an angular offset (9) relative to the reference half-axis such that an induced voltage signal generated in the coil at the passage of the bipolar magnet facing said coil is substantially located, during a first oscillation of any oscillation, before the passage of the median half-axis through the reference half-axis and, during a second alternation of any oscillation, after the passage of this medial half-axis by the reference half-axis; and in that the electronic control circuit is arranged in such a way that the control pulses are applied respectively at the occurrence of this induced voltage signal and selectively, as a function of the measured time drift and whether it is braking impulses or motor pulses, in first alternations or in second alternations. 7. Horological assembly according to claim 5, characterized in that the magnetic assembly comprises a pair of bipolar magnets (22, 24) mounted on the balance and having respectively two axial axes of magnetization with opposite polarities, the coil being secured to the support of the mechanical resonator, the median half-axis (26) extending from the axis of rotation of the balance and passing through the middle of the pair of bipolar magnets defining a reference half-axis (27) when the resonator is at rest and therefore in its neutral position, the pair of magnets and coil being arranged so that an induced voltage signal generated in the coil at the passage of the pair of magnets opposite this coil has a central lobe and two lateral lobes, of lesser amplitude than that of the central lobe, which are located respectively on both sides of this central lobe; in that said coil is aligned with the reference half-axis, the electronic control circuit being arranged so that the control pulses are applied, as a function of the measured time drift and according to whether they are pulses braking or driving pulses, respectively when appearing one of the two side lobes or when appearing on the other of these two side lobes; and in that the watch assembly further comprises a rectifier connected to an electrical energy storage capacitor and arranged to charge this storage capacitor, when the pendulum oscillates, during apparitions of said central lobe. 8. Horological assembly according to claim 5, characterized in that the magnetic assembly comprises a pair of bipolar magnets mounted on the balance and respectively having two axes of axial magnetization of opposite polarities, the coil being secured to the support of the mechanical resonator. , the median half-axis starting from the axis of rotation of the balance and passing through the middle of the pair of bipolar magnets defining a reference half-axis when the resonator is at rest and therefore in its neutral position, the pair of magnets and the coil being arranged so that an induced voltage signal generated in the coil at the passage of the pair of magnets facing this coil has a lobe of maximum amplitude resulting from a simultaneous coupling of the two magnets of the pair of magnets with the coil; in that the coil has at its center an angular offset relative to the reference half-axis such that a lobe of maximum amplitude is situated before the passage of the medial half-axis through the reference half-axis during a first alternation of any oscillation and after the passage of this median half-axis by the reference half-axis during a second alternation of any oscillation; and in that the electronic control circuit is arranged so that the control pulses are applied respectively in the occurrence of maximum amplitude lobes and selectively, as a function of the measured time drift and according to whether it is braking impulses or motor pulses, in first alternations or in second alternations. 9. Horological assembly according to claim 6 or 8, wherein the mechanical oscillator is arranged so that, during a free oscillation in its useful operating range, its amplitude is greater than 200 °, characterized in that said offset angular (Θ) is between 30 ° and 180 °. 10. Watchmaking assembly according to any one of claims 4 to 9, characterized in that the measuring device is arranged to detect the succession of oscillation periods of the mechanical resonator on the basis of an induced voltage signal generated by said magnetic assembly. ; in that the measuring device comprises a bidirectional counter (C2), a first sub-circuit (54, 56; 96) arranged to provide, for each detected oscillation period, a pulse or two pulses at a first input the bidirectional counter, and a second sub-circuit which comprises a clock circuit (60) providing a reference signal clocked at the frequency of said auxiliary oscillator and a divider circuit (DIV1, DIV2, DIV) which receives the signal of reference and generates as output a setpoint signal with periodic pulses defining a setpoint frequency, respectively twice this setpoint frequency, this setpoint signal being supplied to a second input of the bidirectional counter; and in that the bidirectional counter is outputted to said electronic control circuit which is arranged to read the value of this bidirectional counter and to determine whether this value is greater than a certain number or less than a negative number. 11. watch assembly according to claim 9 with claim 3 in its dependence, characterized in that said time position determining circuit is formed by said magnetic assembly and a differentiation circuit arranged to be able to differentiate in said induced voltage signal. generated by said magnetic assembly, first magnet-coil couplings occurring in respective alternations before the neutral position of the mechanical resonator and the second magnet-coil couplings occurring in respective alternations after the neutral position of the mechanical resonator, a first event associated with a first coupling magnet (s) -bobine defining said first instant and a second event associated with a second coupling magnet (s) -bobine defining said second instant. 12. A method for regulating the average frequency of a mechanical oscillator arranged in a watch movement and associated with a device for regulating the running of a mechanism which is clocked by the mechanical oscillator, the latter being formed of a resonator mechanical and a maintenance circuit of the oscillation of the mechanical resonator, the control device comprising an auxiliary oscillator, which is derived a setpoint signal having a set frequency, and being arranged so as to generate, when the mechanical oscillator is activated, on control of the control pulses each exerting a force torque on the mechanical resonator, the control method comprising the following steps: - measuring a possible time drift of the mechanical oscillator relative to the auxiliary oscillator - determine whether the time drift corresponds, for the operation of said mechanism, to a at least some advance or at least some delay, - when the time drift corresponds to said at least some advance, apply to the mechanical resonator at least a first braking pulse, of which at least a major part occurs between a moment initial of a first alternation of the mechanical resonator and a median instant of this first alternation where this mechanical resonator is in its state of minimum potential mechanical energy, and / or at least a first driving pulse of which at least a major part intervenes between the median instant and a final moment of the first alternation, - when the temporal drift corresponds to said at least a certain delay, applying to the mechanical resonator at least a second braking pulse, of which at least a major part intervenes between a median moment a second alternation of the mechanical resonator and a final moment of this two i alternation, or / and at least a second driving pulse of which at least a major part intervenes between an initial moment of the second alternation and the median moment of this second alternation. 13. Control method according to claim 12, characterized in that it further comprises the following steps: A) When said temporal drift corresponds to said at least some advance, - determining in said first half-cycle a first moment which occurs before said median instant and after said initial moment of this first alternation or / and a second moment which occurs after said median moment and before said final moment of this first half cycle, and - triggering said first braking pulse substantially at said first moment and / or said first driving pulse substantially at said second instant; B) When said temporal drift corresponds to a certain delay, - determining in said second alternation a first instant which occurs before said median instant and after said initial moment of this second alternation and / or a second moment which occurs after said median instant and before said final instant of this second alternation, and - triggering said second braking pulse substantially at said second instant and / or said second driving pulse substantially at said first instant.