HK1256649B - Timepiece assembly comprising a mechanical oscillator associated with a regulating device - Google Patents

Description

Timepiece assembly including a mechanical oscillator associated with an adjustment device

Technical Field

The invention relates to a timepiece assembly, in particular a precision timepiece, comprising:

-a mechanism, in particular partially forming a mechanical movement,

a mechanical resonator adapted to oscillate along an oscillation axis around a neutral position (neutral position) corresponding to its lowest mechanical potential energy state,

-holding means for holding the mechanical resonator, which forms with the mechanical resonator a mechanical oscillator suitable for defining the operating state of said mechanism, each oscillation of the mechanical resonator exhibiting two successive half-cycles between two end positions defining the amplitude of the mechanical oscillator on the oscillation axis,

-adjustment means suitable for adjusting the frequency of the mechanical oscillator, comprising an auxiliary oscillator, generally more precise than said mechanical oscillator, and means arranged for applying an adjustment pulse to the mechanical resonator on demand to immediately brake it.

In particular, the mechanical resonator is a balance spring and the holding device comprises a conventional escapement device, for example with a swiss pallet assembly. The auxiliary oscillator is formed in particular by a quartz resonator or a resonator integrated in the electronic circuit.

Background

Movements forming a timepiece assembly as defined in the technical field of the invention have been proposed in some prior art documents. Patent CH597636, published in 1977, proposes such a movement, to which reference is made to fig. 3. The movement is equipped with a balance spring and a conventional holding device comprising a pallet assembly and an escape wheel kinematically connected to a barrel equipped with a spring. The timepiece movement includes means for adjusting the frequency of the mechanical oscillator. The regulating device comprises an electronic circuit and a magnetic assembly formed by a flat coil arranged on a support arranged below the felloe of the balance and two magnets mounted on the balance and arranged close to each other so as to pass both above the coil when the oscillator is started.

The electronic circuit comprises a time base comprising a quartz generator and for generating a reference frequency signal FR, which is compared with the frequency FG of the mechanical oscillator. The frequency FG of the oscillator is detected via an electric signal generated in the coil by a pair of magnets. The regulating circuit is adapted to instantaneously induce a braking torque via the magnetic magnet-coil coupling and the switchable load connected to the coil. Document CH597636 provides the following teachings: "the resonator formed should have a variable oscillation frequency (isochronous error) that coincides with the amplitude on either side of the frequency FR". It therefore teaches to vary the variation of the oscillation frequency of the non-isochronous resonator by varying its amplitude. An analogy is made between the amplitude of the resonator and the angular speed of the generator comprising a rotor equipped with magnets and arranged in the gear train of the timepiece movement in order to regulate its operation. Since the braking torque reduces the rotational speed and therefore the rotational frequency of such a generator, it is only envisaged here that the oscillation frequency of the forced non-isochronous resonator can be reduced by applying a braking torque that reduces its amplitude.

In order to perform electronic regulation of the frequency of the generator or mechanical oscillator, it is envisaged in one particular embodiment that the load is formed by a switchable rectifier via a transistor which loads the storage capacity during the braking pulse to take up power to supply the electronic circuit. The consistent teaching given in document CH597636 is as follows: when FG > FR, the transistor is conductive; power Pa is then drawn from the generator/oscillator. When FG < FR, the transistor is non-conductive; thus, power is no longer drawn from the generator/oscillator. In other words, the adjustment is only made when the frequency of the generator/oscillator is greater than the reference frequency FR. The regulation consists in braking the generator/oscillator in order to reduce its frequency FG. As such, in the case of a mechanical oscillator, those skilled in the art understand that due to the spontaneous isochronism error of the mechanical oscillator chosen, adjustment is only possible when the balance spring is securely installed and the free oscillation frequency (natural frequency) is greater than the reference frequency FR. Thus, there is a double problem in that the mechanical oscillator is selected for the errors that are common in mechanical movements and the electronic regulation works only when the natural frequency of the oscillator is greater than the nominal frequency.

In summary, the teaching generally provided to those skilled in the art is as follows: if it is sought to mechanically adjust the frequency of the balance spring of a conventional timepiece movement, it is necessary to replace the balance spring in order firstly to arrange at least one magnet on top and secondly to modify its natural frequency so that it is greater than the frequency sought. The results of this teaching are evident: it is necessary to mis-tune the mechanical resonator so that it oscillates at too high a frequency in order to enable the tuning device to constantly return its frequency to a lower frequency consistent with the theoretical frequency sought by a train of brake pulses. The resulting timepiece movement is therefore automatically set in such a way that the precise operation depends on the electronic regulation, which would have a very significant time drift if the electronic regulation were not possible. As such, if the regulating device fails for various reasons, in particular due to damage, the watch equipped with such a movement will no longer be accurate and, to some extent, it will no longer be in fact operating. This situation is problematic.

The use of an electromagnetic system of the magnet-coil type for coupling the balance spring with the electronic regulating circuit causes various problems. Firstly, the arrangement of the permanent magnet on the balance causes a magnetic flux to always be present in the timepiece movement and to vary spatially periodically. Such magnetic flux can have a detrimental effect on various parts or elements of the timepiece movement, in particular on elements made of magnetic material, such as parts made of ferromagnetic material. This reflects on the correct operation of the timepiece movement and also increases the wear of the pivoting elements. In practice it is conceivable to shield the magnetic system in question to some extent, but shielding requires specific elements carried by the balance. Such shielding tends to increase the size of the mechanical resonator and its weight. Furthermore, it limits the possibilities of a clean, visually attractive configuration. Furthermore, high external magnetic fields can damage the magnetized elements of the electromagnetic system.

The person skilled in the art realizes that an embodiment of the proposed mechanical timepiece movement, which comprises a device for adjusting the frequency of the balance spring, wherein it is envisaged that an electromechanical system acts on the oscillating balance, said electromechanical system being formed on the one hand by a stop arranged on the balance and on the other hand by an actuator equipped with a movable finger which is braked in the abutment direction with a defined braking frequency. This concept aims to synchronize the frequency of the oscillator with that of the quartz oscillator by means of the required interaction between the fingers and the stop when the mechanical oscillator exhibits a time drift with respect to the quartz oscillator, the fingers either locking the balance immediately, the balance then stopping its movement for a certain time interval (the stop abutting against the finger moving in the direction in which the balance returns towards its neutral position), or limiting the amplitude when the fingers start to abut against the stop while the balance is rotating in the direction of its maximum amplitude position.

Such a regulation system has a number of disadvantages and can be seriously doubted whether it can form a functioning system. The "blind" action of the movement of the finger relative to the stop and the oscillation of the stop with respect to any potential initial phase shift of the oscillation of the finger presents a number of problems. This action is limited to the angular position given by the position of the actuator with respect to the balance spring. As such, the effect of the interaction between the finger and the stop depends on the amplitude of the balance spring and the position of the actuator. In summary, these embodiments appear to be quite unlikely to those skilled in the art, and those skilled in the art would be prohibitive to such use. Moreover, the person skilled in the art of the present invention is not aware of watches equipped with such electromechanical systems that have been introduced into the market.

Disclosure of Invention

It is an object of the present invention to find a solution to the above mentioned technical problems and drawbacks mentioned in the background of the invention.

A first object within the scope of the development leading to the present invention is to propose a timepiece assembly comprising a mechanical movement having a conventional mechanical resonator of the balance-hairspring type, and an adjustment device which does not use a magnet-coil system to couple the mechanical resonator with the adjustment device, in particular without the need to arrange at least one permanent magnet on the balance. It should be noted that within the scope of the description of the invention, such a magnet-coil system causes a magnetic braking pulse, the magnetic flux generated by at least one coil being coupled with the magnetic flux of said at least one permanent magnet carried on the mechanical resonator itself.

A second object within the scope of the development leading to the present invention is to make a timepiece assembly comprising a mechanical movement with a mechanical oscillator and means for adjusting the mechanical oscillator, but without having to initially make a faulty adjustment of the mechanical oscillator in order to obtain a timepiece with the precision of the auxiliary electronic oscillator (in particular equipped with a quartz resonator) when the adjustment means is in operation and the precision of the mechanical oscillator when the adjustment means is disabled or not in operation, but in the latter case with a precision that is apt to comply with optimal standards. In other words, it is sought to combine in addition the electronic adjustment with a mechanical movement adjusted with the highest possible precision, so that it remains running with the best possible operation when the electronic adjustment is not used.

The invention also aims to propose a timepiece assembly that at least meets the first objective and is durable, i.e. maintains a high degree of precision even after external disturbances such as shocks.

To this end, the invention relates to a timepiece assembly and to an adjustment module for adjusting a mechanical oscillator assembled in a mechanical timepiece movement. A number of different embodiments and variants are the subject of the dependent claims. The timepiece assembly according to the invention therefore comprises an electronic control circuit adapted to generate a control signal supplied to the adjustment pulse application means for its activation, and a sensor adapted to detect the passage of the mechanical resonator from a specific position on the oscillation axis. The adjusting device of the timepiece assembly includes a measuring device adapted to measure a time drift of the mechanical oscillator relative to the auxiliary oscillator based on the position signal provided by the sensor. Advantageously, the adjustment pulse applying means of the timepiece assembly is an electromechanical device adapted to generate mechanical braking pulses applied to the mechanical resonator in response to the above-mentioned control signal dependent on the measured time drift upon detection of at least a certain time drift of the mechanical oscillator, each mechanical braking pulse applying a certain couple to the mechanical resonator to adjust the intermediate frequency of the mechanical oscillator. Finally, the mechanical resonator defines a braking surface having a specific range along the oscillation axis of the mechanical resonator and arranged to be able to apply a mechanical braking pulse with its triggering at least at a specific moment during one of the two half-cycles of oscillation of the mechanical oscillator, irrespective of the amplitude of the mechanical oscillator in an amplitude range having the specific range and corresponding to the usable operating range of the mechanical oscillator, said specific moment being selected such that no passage from the neutral position of the mechanical resonator occurs during the mechanical braking pulse.

The term "mechanical brake pulse" denotes a brake of mechanical nature and not merely a mechanical effect caused by the brake. As such, this expression excludes, in the first meaning assigned thereto, contactless braking via electromagnetic coupling between the stationary coil and at least one magnet mounted on the mechanical resonator, since in the latter case braking is magnetic and takes place via an electromagnetic system in which an element, i.e. the at least one magnet, is attached to the oscillating part of the mechanical resonator, thereby changing the conventional arrangement of the oscillating part, for example a balance. However, magnetic braking has the end result of reducing the mechanical energy of the oscillating part, but such braking is not mechanical in nature. The above expression also excludes braking caused by an electrical coupling between the oscillating member and the stationary unit of the adjustment device. On the other hand, it is clear that this expression does not exclude electrical and/or magnetic elements incorporated in the electromagnetic device guiding the mechanical braking pulses applied to the mechanical resonator. On the other hand, the term "electromechanical" means that at least one electrical element forms the conditioning pulse applying means.

In a preferred embodiment, the adjustment pulse applying means are formed by an actuator comprising at least one braking member adapted to be actuated in response to the above-mentioned control signal during a mechanical braking pulse in order to apply a certain mechanical couple of forces to the oscillating member of the mechanical resonator. Braking is thus obtained by physical contact between the braking member and the oscillating member.

In an advantageous alternative embodiment of the above-described preferred embodiment, the adjustment pulse applying means is arranged such that the braking energy of each mechanical braking pulse is smaller than the locking energy, so that the mechanical resonator is not stopped immediately during the braking pulse. Subsequently, the oscillating member and the braking member are arranged such that the mechanical braking pulse can be applied substantially by dynamic dry friction between the braking member and the braking surface of the oscillating member.

By virtue of the features of the invention, it is possible to incorporate a module for adjusting its mechanical oscillator (including a balance spring) into the basic mechanical movement without having to modify it. This is a great advantage. In particular, the timepiece component according to the invention can be manufactured without having to change the dynamic characteristics of the mechanical oscillator. It is envisaged that the balance could be surface treated (typically in part) for operation of the sensor if required. In the case of an optical sensor, this processing may be limited to the attachment of black dots on the balance or under the rim of said balance. In this way, the design of the basic mechanical movement does not need to be changed to produce a timepiece assembly according to the invention. In the first case, in which the timepiece component is completely manufactured as new, it is therefore possible to use an existing template that has proven its value in production and to associate this template with another adjustment module according to the invention by arranging the adjustment module at the periphery of the timepiece movement corresponding to this template so as to enable the application of a mechanical braking pulse to the mechanical resonator. Outside the timepiece assembly, it will optionally be necessary to envisage adaptations to enable the incorporation of further regulating modules. In the second case, the timepiece assembly according to the invention is formed by a basic timepiece movement which is firstly set in a watch on the market and secondly to which an adjustment module according to the invention is added in order to improve its precision. An adaptation outside the watch may prove necessary, but not necessarily mandatory. For example, machining at the casing ring may prove sufficient to enable the incorporation of a timepiece assembly in a case already owned by the user, i.e. the addition of an adjustment module according to the invention, which is the subject of the appended claims.

According to a main embodiment, the measuring means are adapted to determine whether the time drift of the mechanical oscillator corresponds to at least one advance or to at least one delay. Subsequently, the control circuit and the adjustment pulse application means are adapted to selectively apply a first mechanical braking pulse to the mechanical resonator when the measured time drift corresponds to a certain advance, at least a major portion of said first mechanical actuation pulse occurring between the start time and the middle time of a half cycle (first quarter cycle), and to selectively apply a second mechanical braking pulse to the mechanical resonator when the measured time drift corresponds to a certain delay, at least a major portion of said second mechanical braking pulse occurring between the middle time and the end time of a half cycle (second quarter cycle). It should be noted that each oscillation cycle of the mechanical resonator defines a first half-cycle and a subsequent second half-cycle, and each half-cycle comprises the passage of the mechanical resonator from a neutral position at said intermediate moment.

As such, the control circuit and the adjustment pulse applying means are adapted to selectively apply a mechanical braking pulse to the mechanical resonator in a first quarter of a cycle of oscillation of the mechanical resonator when the measured time drift corresponds to a certain advance, and to apply a mechanical braking pulse to the mechanical resonator in a second quarter of a cycle when the measured time drift corresponds to a certain delay.

In a main alternative embodiment, the adjusting means comprise means for determining the temporal position of the mechanical resonator, which are adapted to determine, in a half-cycle of the oscillation of the mechanical resonator, a first instant occurring before the middle instant and after the start instant of the half-cycle and to determine, also in a half-cycle of the oscillation of the mechanical resonator, a second instant occurring after the middle instant and before the end instant of the half-cycle. Subsequently, the control circuit is adapted to selectively trigger a first mechanical brake pulse substantially at a first time and to selectively trigger a second mechanical brake pulse substantially at a second time. Finally, the braking surface of the mechanical resonator comprises a first section along its oscillation axis for starting the application of the first mechanical braking pulse substantially at a first instant and a second section along the oscillation axis for starting the application of the second mechanical braking pulse substantially at a second instant, irrespective of the amplitude of the mechanical oscillator in its usable operating range.

Drawings

The invention will be described in more detail hereinafter using the accompanying drawings given by way of non-limiting example, in which:

figure 1 is a top view of a timepiece assembly according to the invention,

figure 2 shows a first embodiment of a regulating device for regulating the oscillation frequency of a balance spring of a timepiece assembly according to the invention,

figure 3 shows the position signal provided by the sensor detecting the passage of the balance spring from its neutral position and the application of the first braking pulse in a certain half-cycle before the balance spring from its neutral position, as well as its angular speed and angular position in the time interval in which the first braking pulse occurs,

fig. 4 is a diagram similar to fig. 3, in which a second braking pulse is applied some half-cycle after the balance spring has passed its neutral position,

figure 5 shows an electronic circuit diagram of a second embodiment of the device for adjusting a mechanical oscillator according to the invention,

FIG. 6 is a flow chart of the operating mode of the regulating device in FIG. 5,

figure 7 shows an electronic circuit diagram of an alternative embodiment of the second embodiment of the adjustment device of the mechanical oscillator,

figure 8 shows two digital signals occurring in the electronic circuit in figure 7,

figure 9 is a flow chart of the operating mode of the regulating device in figure 7,

FIG. 10 is a third embodiment of an adjusting device according to the invention, and

fig. 11 shows a particular embodiment of the braking device of the adjustment device according to the invention.

Detailed Description

In fig. 1, a timepiece assembly 2 according to the invention is shown. This timepiece assembly comprises a mechanical timepiece movement 4 formed at least by a mechanism comprising a gear train 10 actuated by a mainspring arranged in a barrel 8 (this mechanism being partially shown in fig. 1). This timepiece movement comprises a mechanical resonator 14 formed by a balance 16 and a balance spring 18, and a holding device for holding the mechanical resonator, which together with the mechanical resonator forms a mechanical oscillator that controls the operation of the mechanism. The holding device comprises an escapement device 12, here constituted by a pallet fork assembly and an escape wheel kinematically connected to the barrel via a gear train 10. The mechanical resonator is adapted to oscillate along an oscillation axis, in particular a circular axis, around a neutral position corresponding to the lowest mechanical potential energy state. Each oscillation of the mechanical resonator defines an oscillation period.

The timepiece assembly 2 also comprises means 6 for electronically adjusting the frequency of the mechanical oscillator, which adjusting means comprise an electronic adjusting circuit 22 associated with an auxiliary oscillator formed by a quartz resonator 23. It should be noted that it is conceivable to use other types of auxiliary oscillators, in particular oscillators that are fully integrated in the regulating circuit. Of course, the auxiliary oscillator is more accurate than the mechanical oscillator. The device 6 also comprises a sensor 24 for detecting at least one angular position of the balance as it oscillates and a regulating pulse application device 26 for applying a regulating pulse to the mechanical resonator 14. Finally, the timepiece assembly comprises a power supply 28 associated with the means 26 for storing the electric power generated by the power supply. The power source is formed, for example, by a photovoltaic cell or a thermoelectric element, these examples being in no way limiting. In the case of a battery, the power source and the storage device together form the same component.

In general, the adjusting means 6 comprise, in their adjusting circuit, an electronic control circuit adapted to generate a control signal supplied to adjusting pulse applying means adapted to generate, in response to the control signal, successive adjusting pulses each applying a couple of forces to the mechanical resonator. According to the invention, sensor 24 is adapted to detect the passage of at least one reference point of balance 16 through a certain position with respect to the support of the mechanical resonator. Preferably, the sensor is adapted to detect at least the passage of the mechanical resonator from its neutral position. It should be noted that in this preferred alternative embodiment, a sensor may be associated with the pallet assembly to detect the switching of this pallet assembly substantially during the oscillation hold pulse envisaged when the resonator is from its neutral position.

The detection of the neutral point of the resonator makes it possible to generate a usable and stable time reference within the oscillation range. In fact, in the absence of disturbances (in particular those caused by the braking pulses envisaged for the regulation), independently of the amplitude, passing from the neutral point always occurs exactly at the midpoint of the half-cycle. On the other hand, the detection of another angular position of the balance does not provide a stable and clearly defined time reference, in particular with respect to the case in which the balance spring passes from its neutral position and the start or end of a half-cycle, i.e. the moment in which the balance is at maximum amplitude and at zero angular velocity (corresponding to the reversal of the oscillation direction). Furthermore, since the angular velocity of the balance spring is greatest when the balance spring passes from its neutral position, the accuracy of this detection and therefore of the corresponding moment is high. The benefit of detecting the passage of the balance spring from its neutral position will be more clearly understood below during the disclosure of the preferred regulation method given with reference to fig. 3 and 4 and of the following embodiments.

In general, the adjustment means 6 also comprise measuring means adapted to measure the time drift of the mechanical oscillator relative to the auxiliary oscillator on the basis of the position signal provided by the sensor. It will be appreciated that such measurements are readily made once a sensor is provided which is capable of detecting the passage of the mechanical resonator from its midpoint. This occurs every half oscillation cycle of the mechanical oscillator. The measurement circuit will be described in more detail below.

The regulating pulse applying means 26 are adapted to apply to the balance 16 a mechanical braking pulse for regulating the frequency of the mechanical oscillator when a certain time drift of said mechanical oscillator is observed. In a particular alternative embodiment, it is contemplated that the braking energy drawn from the mechanical resonator by any mechanical braking pulse is less than the locking energy of the mechanical resonator, so that the oscillatory motion of the mechanical resonator is not stopped immediately during the conditioning pulse. The locking energy is generally defined as the kinetic energy of the mechanical resonator at the beginning of the brake pulse minus the potential energy difference of the mechanical resonator between the end and the beginning of the brake pulse in question, unless the mechanical oscillator receives no holding energy during the brake pulse. This particular alternative embodiment therefore consists in reducing the angular speed of the balance spring during the braking pulse instead of stopping it more or less long. It should be noted that, in order to ensure the correct operation of the swiss pallet assembly of a standard timepiece oscillator, it is preferable not to generate a braking pulse during the switching of the pallet assembly, during which the holding energy is supplied from the oscillator. Since the switching of the pallet assembly normally takes place around the neutral position of the mechanical resonator, the oscillating movement of the balance spring will therefore be prevented from being destroyed by the braking pulse as it passes from this neutral position.

According to a first embodiment shown in fig. 2, the regulating pulse applying means comprise an actuator 36, which actuator 36 has a movable braking part 38 that is actuated in response to a control signal in order to apply a certain mechanical force to the oscillating part of the mechanical resonator, here the balance, during the mechanical braking pulse. The actuator 36 comprises a piezoelectric element powered by a circuit 39, which circuit 39 generates a voltage according to a control signal supplied by the regulating circuit 22. When the piezoelectric element is immediately energized, the braking member comes into contact with the braking surface of the balance wheel so as to brake it. In the example shown in fig. 2, the bar 38 forming the braking member is curved and its end portion is pressed against the circular side 40 of the felloe 17 of the balance 16. As such, the rim 17 defines a substantially circular braking surface at least on a certain angular section. Subsequently, the braking means comprise a movable portion, here an end portion of the strip, which defines a brake pad arranged to apply pressure against the substantially circular braking surface during application of the mechanical braking pulse. Preferably, it is contemplated within the scope of the invention that the oscillating member and the braking member are arranged such that the mechanical braking pulse is applied by dynamic dry or viscous friction between the braking member and the braking surface of the oscillating member.

In an advantageous alternative embodiment (not shown), the balance comprises a central axle defining or supporting a portion of the balance other than the felloe, defining a circular braking surface at least on a certain angular section. In this case, the brake component pads are arranged to apply pressure against the circular braking surface during application of the mechanical brake pulse.

The circular braking surface of the oscillating member (balance) for pivoting, associated with at least one braking pad carried by the braking device of the regulating device, forms a mechanical braking system with decisive advantages. In fact, with such a system, the braking pulse can be applied to the mechanical resonator at any moment of oscillation, regardless of the amplitude of the balance. The correction caused by the braking pulse can then be managed precisely, in particular by a suitable choice of its duration and the braking couple applied. By means of the position measurement made by the sensor, the moment during a half cycle at which the actuation pulse is applied can also be determined. As such, at least the braking torque, the duration of the pulses and the respective moments at which they are generated may be selected and varied in accordance with the time drift of the mechanical oscillator. In particular, slight corrections for fine and precise adjustment of the oscillation frequency can thereby be brought about.

It should be noted that the amplitude generally varies according to the degree of arming of the barrel (arming) (unless particular means for generating a constant force are envisaged). Thus, at a non-zero given moment before or after the resonator passes from its neutral position in any half cycle of its oscillating movement, the angular position of the balance varies according to the amplitude. If, for example, the braking pulse is chosen to be provided to always adjust the oscillation frequency at a defined fixed time interval before or after the resonator passes from its neutral position (see the preferred adjustment principle disclosed below), the braking surface should then extend over an angular length such that the brake pad can in any case exert a braking force on the balance at a plurality of angular positions along the braking surface. As such, the mechanical resonator has a braking surface that extends at least over a certain angular section having a certain angular length different from zero (i.e. the angular section is considered non-local) to enable a mechanical braking pulse to be applied at least at a certain moment in the oscillation cycle of the mechanical oscillator, irrespective of the amplitude of the mechanical resonator for the available operating range of the mechanical oscillator.

It should be noted that, according to the above-mentioned time interval or to the time gap chosen for applying the braking pulse before or after the instant at which the mechanical resonator passes its neutral position in the various half-cycles of its oscillatory movement, detected by the sensor 34, it is only necessary that the two defined corner segments of the balance respectively have or define two rounded surfaces for the braking member pads, so that the braking pulse can be applied in the usable operating range of the mechanical oscillator, i.e. in a specific usable angular range (for example between 200 ° and 300 °) for the amplitude of its oscillation. In general, it is conceivable for the braking surface of the mechanical resonator to have at least one first corner section for applying a first mechanical braking pulse in a half-cycle at a first time substantially before an intermediate time of passage of the mechanical resonator from its neutral position and at least one second corner section for applying a second mechanical braking pulse in a half-cycle at a second time substantially after said intermediate time, irrespective of the amplitude of the mechanical resonator in the usable operating range of the mechanical oscillator in question. It should be noted that in the particular case in which the first and second instants are at the same time distance from the intermediate instant in the half-cycle and are located on the same side of the neutral position, the first and second corner segments substantially merge and thereby define the same braking corner segment. In other cases, the first and second corner segments have a common portion or are separate. The same considerations apply for the first and second time intervals in which it is conceivable to apply the first and second brake pulses, respectively. In an alternative embodiment shown in fig. 2, the braking surface has a range that enables the application of a mechanical braking pulse at any moment of the oscillation of the mechanical resonator.

It should also be noted that the brake component pad may also have a rounded contact surface with the same radius as the braking surface, but such a configuration is not required. The contact surface may in particular be planar, as shown in the figures. The flat surface has the advantage of allowing a certain margin of positioning of the braking member with respect to the balance, which makes it possible to have greater manufacturing and assembly tolerances of the braking device in or at the periphery of the timepiece movement.

The sensor 34 is an opto-electronic optical sensor. It comprises a light source suitable for emitting a light beam towards the balance and a light detector suitable for receiving a return light signal, the intensity of which varies periodically according to the position of the balance. In the illustrative example shown in fig. 2, a light beam is emitted onto the lateral surface of the rim 17, this surface having a restricted zone with a reflectivity different from that of two adjacent zones, so that the sensor can detect the passage of this restricted zone and provide a position signal to the adjustment means when this occurs. It will be appreciated that the circular surface with variable reflection for the light beam may be located at other positions of the balance. In one particular case, the variation may be produced by an aperture in the reflective surface. The sensor may also detect the passage of a particular part of the balance, for example an arm, the neutral position corresponding for example to the middle point of the signal reflected by this arm, or to the start or end point of such a signal. It will therefore be understood that the modulation of the optical signal, which may consist of a succession of light pulses, which are in turn detected by a light detector, may define the angular position of the balance in various ways by means of a negative or positive variation of the detected light.

In other alternative embodiments, the position sensor may be of the capacitive or inductive type and as such is suitable for detecting a change in capacitance or inductance depending on the position of the balance. Inductive sensors preferably operate without the presence of magnetized material on the resonator, for example by detecting the presence of non-magnetized material or only detecting changes in the distance between such material and the sensor. Those skilled in the art know numerous sensors that can be easily incorporated into a timepiece assembly according to the invention.

Advantageously, the various elements of the regulating device 6 form an independent module of the timepiece movement. As such, the module may be assembled or associated with the mechanical movement 4 only during its assembly, in particular in the watch case. In particular, such a module can be attached to a casing ring around a timepiece movement. It will be understood that the electronic regulation module can therefore be advantageously associated with the timepiece movement once it has been completely assembled and regulated, the assembly and disassembly of this module being possible without having to work on the mechanical movement itself.

In the following, an adjustment method representing a significant improvement of the invention will be described with reference to fig. 3 and 4, followed by a description of an embodiment of the timepiece assembly according to the invention in which this very advantageous adjustment method is implemented.

Fig. 3 shows four graphs. The first graph provides a digital signal provided by sensor 34 over time when resonator 14 oscillates, i.e. when the mechanical oscillator of the timepiece movement starts. It should be noted that in the first alternative embodiment the digital signal is provided directly by the sensor, but in the second alternative embodiment the sensor provides an analog signal and the adjusting circuit converts it into a digital signal, in particular by means of a comparator. As mentioned above, the sensor and the balance are adapted so that the sensor can detect the passage of the balance spring from its neutral position in succession. This is achieved byThis action takes place twice per oscillation cycle, at the instant t when the sensor supplies the pulse 42_ZnOnce in each of the two half cycles.

Each oscillation cycle of the mechanical oscillator defines a first half-cycle and a subsequent second half-cycle between two end positions defining the amplitude of the mechanical oscillator, each half-cycle having a mechanical resonator at an intermediate time t_ZnPassing from its neutral position and at the start time t for the half cycle a1 in fig. 3_An-1Or T_D1And a starting instant T for the half cycle a2 in fig. 4_D2And the end time t for the half cycle a1 in fig. 3_AnOr t_F1And an end time t for the half cycle a2 in fig. 4_F2The duration of time in between. These start and end times are defined by the two end positions that the mechanical resonator occupies at the beginning and end of each half-cycle, respectively. The second graph shows the time t at which a braking pulse is applied to the mechanical resonator 14 to correct the operation of the mechanism timed by the mechanical oscillator_P1. The instant at which the rectangular pulses (i.e. the binary signal) occur is defined in fig. 3 and 4 by the temporal position of the middle point of these pulses. However, according to alternative embodiments and embodiments of the regulating circuit, the start or end of a pulse may be considered as characterizing the instant of the pulse, i.e. the rising or falling edge of said pulse. This is particularly true for brake pulse situations where the start (i.e., trigger) and duration are typically determined.

The variation of the oscillation period over which the braking pulses occur and thus the independent variation of the frequency of the mechanical oscillator is observed. In fact, as seen in the last two graphs in fig. 3, which show respectively the angular speed (value in radians per second: [ rad/s ]) and the angular position (value in radians: [ rad ]) of the balance over time, the temporal variation is related to the single half-cycle in which the braking pulse occurs. It should be noted that each oscillation has two consecutive half-cycles, defined herein as the two half-cycles for which the balance is subjected to an oscillating movement in one direction and then in the other direction, respectively. In other words, a half cycle corresponds to one oscillation of the balance in one direction or another between its two end positions defining the amplitude.

The term braking pulse denotes the application of a certain couple to the mechanical resonator, i.e. a couple opposing an oscillating movement of the mechanical resonator, which brakes it, approximately in a limited time interval. Within the scope of the invention, each braking pulse is generated by applying a mechanical brake of the mechanical braking couple to the mechanical resonator, as shown in the third graph representing the angular velocity of the balance.

In fig. 3 and 4, the oscillation period T0 corresponds to the "free" oscillation of the mechanical oscillator of the timepiece component (i.e. without the application of a regulating pulse). The two half-cycles of the oscillation period each have a duration T0/2 without external disturbances or constraints, in particular those generated by the adjustment pulse. The start of the first half-cycle is marked by the time t-0. It should be noted that the "free" frequency F0 of the mechanical oscillator is here approximately equal to 4Hz (F0 ═ 4Hz), so that the period T0 is approximately 250 ms.

First, the behavior of a mechanical oscillator corresponding to that shown in fig. 3 in the case of a first modification of its oscillation frequency will be described. After the first period T0, a brake pulse occurs_P1A new period T1 or a new half period a 1. At a starting time t_D1The half cycle a1 begins, and the resonator 14 occupies a maximum positive angular position corresponding to the end position. Then, at an intermediate time t, situated at the passage of the resonator from its neutral position_N1Previous time t_P1Generating braking pulses_P1. Finally, the half-cycle a1 is at the end time t_F1And (6) ending. The brake pulse is immediately followed by the most recent intermediate time t detected by the sensor before half cycle A1_ZnTime interval T of_A1And then triggered. Duration T_A1Is selected to be greater than one-quarter period T0/4 and less than half period T0/2 minus the brake pulse_P1The duration of (c). In the example provided, the duration of the brake pulse is significantly less than the quarter period T0/4. The term "intermediate time" denotes a time occurring approximately at the midpoint of a half cycle. This is especially the case when the mechanical oscillator is free to oscillate. On the other hand, for the half period of supplying the adjustment pulse, it should be noted that the middleThe instant no longer corresponds exactly to the midpoint of the duration of each of these half-cycles, due to the disturbance of the mechanical oscillator caused by the adjusting means.

In this first case, the braking pulse is generated between the start of a half-cycle and the passage of the resonator from its neutral position in this half-cycle. As envisaged, the absolute value of the angular velocity decreases during the brake pulse P1. This braking impulse causes a negative time phase shift T in the oscillation of the resonator as shown by the two graphs of angular velocity and angular position in fig. 3_C1I.e. the delay relative to the theoretical signal (used with the dashed line) that is not disturbed. As such, the duration of half cycle a1 is increased by time interval T_C1. The oscillation period T1, which includes the half period a1, is thus extended with respect to the value T0. This causes an isolated reduction in the frequency of the mechanical oscillator and a brief slowing of the operation of the associated mechanism.

With reference to fig. 4, the behavior of the mechanical oscillator in a second modified situation of its oscillation frequency will now be described. The graph in this fig. 4 shows the progression over time of the same variables as in fig. 3. After the first period T0, a new oscillation period T2 or half period a2 of the braking pulse P2 is generated begins. Half cycle A2 at initial time t_D2Initially, the mechanical resonator is then in an end position (maximum negative angle position). After a quarter period (T0/4), the resonator is at an intermediate time T_N2To its neutral position. Then, at an intermediate time t, situated at the passage of the resonator from its neutral position in the half-cycle a2_N2After a time t_P2A brake pulse P2 is generated. Finally, after the braking pulse P2, the half cycle a2 is at the end time T when the resonator once again occupies the end position (maximum positive angular position in the cycle T2)_F2And (6) ending. The brake pulse being at an intermediate time t immediately following the half-cycle A2_N2Time interval T of_A2And then triggered. Duration T_A2Is selected to be less than the quarter period T0/4 minus the duration of the brake pulse P2. In the example provided, the duration of the brake pulse is significantly one-quarter cycle.

In the second case in question, the braking pulse is therefore in one and a halfThe cycle occurs between the intermediate moment the resonator passes from its neutral position and the end moment the half cycle ends and the resonator occupies the end position. As envisaged, the absolute value of the angular velocity decreases during the brake pulse P2. It is evident that the braking pulse here causes a positive time phase shift T in the oscillation of the resonator as shown by the two graphs of angular velocity and angular position in fig. 4_C2I.e. advanced with respect to the theoretical signal (shown with dashed line) without interference. As such, the duration of the half cycle a2 is reduced by the time interval T_C2. Therefore, the oscillation period T2, which includes the half period a2, is shorter than the value T0. This therefore causes an isolated increase in the frequency of the mechanical oscillator and a brief acceleration of the operation of the associated mechanism. This phenomenon was unexpected and not obvious, which was why those skilled in the art have overlooked it in the past.

The tuning method is unusual in that it exploits the unexpected physical phenomenon of mechanical oscillators. The inventors conclude the following observations: unlike the general teaching in the field of timepieces, it is possible not only to lower the frequency of the mechanical resonator by means of braking pulses, but also to increase the frequency of such a mechanical oscillator by means of braking pulses. Those skilled in the art will expect that it is possible in practice to only reduce the frequency of a mechanical oscillator with a braking pulse, and by inference to only increase the frequency of such a mechanical oscillator by applying a driving pulse when powering said oscillator. This intuitive idea, which has been established in the horological field and is therefore first thought by the person skilled in the art, proves to be incorrect for a mechanical oscillator. Although this behavior is true for microgenerators in which the rotors rotate continuously in the same direction, it is not true for mechanical oscillators to the contrary.

In fact, a mechanical oscillator, which is furthermore highly accurate, can be adjusted electronically via an auxiliary oscillator comprising, for example, a quartz resonator, so that it immediately assumes a higher or lower frequency. For this purpose, it is envisaged that the moment of application of the mechanical braking pulse is correctly selected according to the operation of the mechanism in question and the frequency of the mechanical oscillator which thus sets the speed of the operation. The inventors have observed that the effect of the conditioning pulse on the mechanical resonator depends on the moment at which it is applied in one half-cycle with respect to the moment at which the mechanical resonator passes from its neutral position. According to this principle, disclosed by the inventors and used in the timepiece component according to the invention, the braking pulse applied in any half-cycle between the two end positions of the mechanical resonator, substantially before the passage of the mechanical resonator via its neutral position (idle position), produces a negative time phase shift in the oscillation of said resonator and therefore a delay in the operation of the mechanism determined by the resonator, whereas the braking pulse applied in this half-cycle, substantially after the passage of the mechanical resonator from its neutral position, produces a positive time phase shift in the oscillation of said resonator and an advance in the operation of the mechanism. This makes it possible to correct excessively high frequencies or excessively low frequencies only by means of brake pulses. In summary, the application of the braking couple during a half-cycle of the oscillation of the balance spring causes a negative or positive phase shift in the oscillation of said balance spring depending on whether said braking torque is before or after the passage of the balance spring from its neutral position.

A main embodiment of the timepiece assembly according to the invention, exploiting the above-mentioned physical phenomena, is characterized by a specific arrangement of the adjustment means of the mechanical oscillator and in particular of the electronic adjustment circuit. In general, the adjustment means comprise measuring means adapted to measure, where applicable, the time drift of the mechanical oscillator relative to the auxiliary oscillator, which is implicitly more accurate than the mechanical resonator, and to decide whether the time drift corresponds to at least some advance or at least some delay. The adjusting means then comprise a control circuit connected to the above-mentioned adjusting pulse applying means, which are adapted to apply a first braking pulse to the mechanical resonator substantially before the middle moment of passage of the mechanical resonator from its neutral position in a first half-cycle when the time drift of the mechanical oscillator corresponds to at least a certain advance, and to apply a second braking pulse to the mechanical resonator substantially after the middle moment of passage of the mechanical resonator from its neutral position in a second half-cycle when the time drift of the mechanical oscillator corresponds to at least a certain delay.

In a preferred embodiment, which will be described in detail below, the adjusting means comprise determining means for determining the temporal position of the mechanical resonator, which determining means are adapted to determine, in one half-cycle of the oscillation, a first instant occurring before the intermediate instant in which the mechanical resonator passes from its neutral position and after the starting instant in which this half-cycle starts, and to determine, in the same or another half-cycle of the oscillation, a second instant occurring after the intermediate instant in which the mechanical resonator passes from its neutral position and before the ending instant in which this half-cycle ends. Subsequently, the control circuit is adapted to selectively detect the first brake pulse substantially at a first time instant and the second brake pulse substantially at a second time instant.

It should be noted that the device for determining the temporal position of the mechanical resonator may have elements or components in common with the measuring device (in particular the position measuring sensor) and the control circuit, for example the logic circuit and the counter in terms of operation. However, these examples are in no way intended to limit the scope of the present invention.

With reference to fig. 5 and 6, a second embodiment of the timepiece assembly according to the invention, in particular of the adjusting device thereof, will be described below. The adjusting means 46 comprise an electronic adjusting circuit 48 and the auxiliary resonator 23. The auxiliary resonator is for example an electronic quartz resonator. Sensor 24 here provides an analog signal consisting of a pulse generated as the balance spring passes sequentially from its neutral position. The analog signal is compared with a reference voltage U by means of a hysteresis comparator 50 (schmitt trigger) arranged in the circuit 48_REFA comparison is made in order to generate a digital signal "Comp" for the digital circuit of the regulating circuit. The digital signal "Comp" is composed of a succession of digital pulses 42, the corresponding rising edges of which are each at a time t_ZnThis occurs, N ═ 1, 2, ·, N, · (see fig. 3 and 4).

The comparator is an element of the measurement circuit 52 described below. Assuming there are two pulses 42 per oscillation cycle of the mechanical resonator, the digital signal "Comp" is supplied to the lever 54, which lever 54 supplies one pulse periodically per oscillation cycle. The lever increments an up-down counter C2 at the instantaneous frequency of the mechanical oscillatorThe counter C2 passes a clock signal S derived from an auxiliary oscillator that generates a digital signal at a reference frequency_horDecreasing at the nominal/set point frequency. The auxiliary oscillator is formed by the auxiliary resonator 23 and the clock circuit 56. For this purpose, the relatively high-frequency reference signal generated by the clock circuit is decomposed beforehand by the decomposers DIV1 and DIV2 (these two decomposers optionally form two stages of the same decomposer). As such, the state of the counter C2, which determines the advance or retard relative to the auxiliary oscillator accumulated by the mechanical oscillator over time, with an accuracy substantially corresponding to the setpoint period, is supplied to the logic control circuit 58. The state of calculator C2 corresponds to the time drift of the mechanical oscillator.

As shown in the flow chart of fig. 6, at the start-up of the regulating means and the power-up of its regulating circuit 48, the circuit is initialized at step POR. In particular, a "reset" of the counter C2 is performed. Then, the detection of the first rising edge of the digital signal "Comp" is awaited. At this point, the control circuit 58 resets the counter C1. At the same time, the control circuit verifies whether a certain time drift has been observed. More specifically, it determines whether a possible time drift corresponds to a certain advance (C2 > N1. It should be noted that N1 and N2 are natural numbers (positive integers other than zero). In case no such advance or such delay is observed, the control circuit ends the sequence (implemented in a cycle) and waits for the occurrence of another pulse 42 in the sensor signal.

If the condition C2 > N1 is verified ("YES"), the control circuit waits until the counter C1 has measured the first time interval T_A1(see fig. 3) and then sends a control signal to the timer 60, which timer 60 immediately closes the switch 62 (which is then switched to the "on" state) to energize the mechanical brake, more specifically to cause the mechanical brake to apply during the braking period T_RDuring which the mechanical braking components thereof are activated. In the case of a piezoelectric element for moving the movable end portion of bar 38 towards the felloe or arbour of the balance (see fig. 2), switch 62 then commands the energization of this piezoelectric element. First interval T_A1Is selected to be greater than one-quarter period T0/4 andless than half period T0/2 minus at least the duration of the braking pulse, so that the entire braking pulse is applied in the half period before the mechanical resonator passes from its neutral position, to cause a reduction in the instantaneous frequency of the mechanical oscillator, assuming a time drift indicating that its free frequency is on average greater than the nominal frequency, i.e. greater than the set point frequency determined by the auxiliary oscillator. At the generation of brake pulses (duration T)_R) After that, the sequence ends and a new sequence is started before another pulse 42 appears in the signal supplied by the sensor.

If the condition C2 < -N2 is verified ("YES"), the control circuit waits until the counter C1 has measured the second time interval T_A2(see fig. 4) and then sends a control signal to timer 60, which timer 60 immediately closes switch 62 to cause the mechanical brake to operate for a braking period T_RDuring which the mechanical braking components thereof are activated. At the generation of brake pulses (duration T)_R) After that, the sequence ends and a new sequence is started before another pulse 42 appears in the signal supplied by the sensor. A second interval T_A2Is selected to be less than the quarter period T0/4 minus the duration of the brake pulse so that the entire brake pulse is applied in the half period after the mechanical resonator passes from its neutral position and before the end of the half period to cause an increase in the instantaneous frequency of the mechanical oscillator, assuming that the time drift indicates that its free frequency is on average less than the set point frequency.

It should be noted that in fig. 3 and 4, the time interval T_A1And T_A2Just as the mechanical resonator passes from its neutral position. However, if the pulse 42 is centered on the instant at which the event occurs and exhibits a certain duration different from zero, the detection of its rising edge or its falling edge then displays a certain time shift with respect to the event. As such, it should be understood that the interval T_A1And T_A2The value range of (b) may here differ slightly from the value ranges obtained from fig. 3 and 4 (slight variation of the limit values, approximately half the duration of the position pulse) in order to comply with the two main conditions of the regulation method.

It should be noted that in the case of C2 > N1 or C2 < -N2, at oneIn alternative embodiments, it is conceivable to use the described method at a plurality of times t_Zn+T_A1Or t_Zn+T_A2A plurality of successive control pulses is supplied. This includes disabling the interrogation of the state of counter C2 during a certain number of sequences. This alternative embodiment makes it possible to supply a series of low-energy brake pulses. To limit the possible range of time drift of the oscillator, it is preferable to take low values for N1 and N2. For example, N1 ═ N2 ═ 1 or 2.

The sensor, comparator 50, control circuit 58 and counter C1 incremented by clock circuit 60 via resolver DIV1 together form a means for determining the temporal position of the mechanical resonator that makes it possible to apply the mechanical braking pulses selectively in a plurality of half-cycles before and after the mechanical resonator passes from its neutral position. As such, the preferred tuning method described above may be implemented efficiently and safely to correct for natural frequencies of the mechanical oscillator that are too high or too low relative to the set-point frequency generated by clock circuit 60 via the resolver. The means for determining the time position are therefore adapted to measure, after detecting the passage of the resonator from its neutral position, a first time interval and a second time interval, wherein the respective end points define a first time instant and a second time instant, respectively, in any half-cycle of the oscillation of the mechanical resonator, temporally preceding and succeeding, respectively, the time instant at which said resonator passes from its neutral position.

With reference to fig. 7 to 9, an alternative embodiment of the second embodiment of the invention will be described, which defines an improvement of the regulation device according to the invention with respect to the management of the power consumed by the sensors. The same elements of the regulating circuit 48A as in the alternative embodiment described with reference to fig. 5 and 6 will not be described again here, as will the regulating means corresponding to the regulating method of this alternative embodiment described above. The regulating device 66 differs from the regulating device 46 in that the sensor 24 has a standby mode or it can even be switched off. As such, the term "off state means that the sensor is not working and then finds that it is in a lower power consumption state than its" on "state, where it detects the oscillation of the mechanical resonator.

In bookIn an alternative embodiment, it is envisaged to set the sensor to an "off" state during a substantial portion of each oscillation of the mechanical oscillator. For this purpose, the control circuit 58A is adapted to supply the control signal S to the switch 68_CAPThe control signal controls the power supply of the sensor 24 or the state of said sensor between its "on" state and its "off state. As in fig. 8 by signal S_CAPAnd Comp, imagine that in each oscillation period T0 in a time interval T_OFFThe sensor is set to its "off" state during T0 and during a time interval T_ONDuring which the sensor is set to its "on" state (note T0 ═ T)_OFF+T_ON). Preferably, T is envisaged_ONIs less than one-quarter T0/4 to minimize power consumption of the sensor. In fact, the digital signal "Comp" exhibits pulses of relatively short duration, so that the detection of the pulse 42 in each oscillation cycle requires only a relatively small time window T_ON. In this case, the comparator 50 only transmits a single pulse 42 per oscillation cycle, so that the lever envisaged in the previous alternative embodiment is eliminated. The comparator 50 supplies its output signal directly to the counter C2.

In the flow chart in fig. 9, power management of the sensor is performed by setting the sensor to the "off" state in each sequence of the adjustment method according to the detection of the falling edge of the pulse of the "Comp" signal. It should be noted that in this alternative embodiment, the falling edge of the pulse 42 of the position signal is detected. The sensor can thus detect the interval T_ONThe entire position pulse 42. However, the detection of a rising or falling edge does not play any role for the regulation itself. To detect the position of the balance, the rising edge of the pulse may also be detected to trigger the switch of the sensor from its "on" state to its "off state. In the latter case, the duration of the pulses 42 is significantly shortened, since the sensor is not working immediately after the start of these pulses. This alternative embodiment of the embodiment makes it possible to further reduce the consumption of the sensor.

During the start-up of the regulating device, the sensor is detecting the fall of the first pulse 42The edge is immediately previously set to the "on" state (corresponding to the passage of the mechanical resonator via the neutral position). Once this detection has occurred, the sensor is set to its "off" state (sensor off) and the adjustment sequence continues as in the previous alternative embodiment. On the other hand, whether or not a brake pulse is generated, the control circuit 58A continues to follow the increment of the counter C1 until its value coincides with the envisaged time interval T_OFFAnd (7) corresponding. The sequence then ends with another start of the sensor (sensor on), which also marks the beginning of the next sequence. The algorithm as given in fig. 9 envisages a duration T_OFFGreater than duration T_A1. The condition indicates a section T_OFFSignificantly greater than half cycle T0/2. In a further alternative embodiment, it is envisaged to detect only the passage from the neutral position once in the time interval nT0 corresponding to a plurality of oscillation periods (n > 1). In such an alternative embodiment, the measuring device is adapted accordingly so that the counter C2 receives only a single set point pulse derived from the auxiliary oscillator in consecutive intervals nT 0.

With reference to fig. 10, a third embodiment of a timepiece assembly 72 will be described below, which differs from the previous embodiments in the arrangement of its detent 74. The actuator of the braking device comprises two braking modules 76 and 78 each formed by a strip 38A or 38B actuated by a magnet-coil magnetic system 80A or 80B. The coils of the two magnetic systems are controlled by two power supply circuits 82A and 82B, respectively, which are electrically connected to the regulating circuit 22. Strips 38A and 38B define first and second brake pads. The two brake pads are arranged so that, during the application of the mechanical braking pulse, they apply two diametrically opposite radial forces to the balance, respectively, with respect to the axis of rotation of balance 16 and in opposite directions. Obviously, it is envisaged that the forces exerted by each of the two pads during a braking pulse are occasionally substantially equal to each other. As such, the resultant force in the overall plane of the balance is substantially zero, so that no radial force is applied to the balance staff during the braking pulse. This prevents mechanical stresses from being generated on the pivot shafts of the balance staff and more generally at the bearings associated with these pivot shafts. This arrangement may advantageously be incorporated in alternative embodiments in which braking is performed on the balance staff or on the roller of relatively small diameter produced by the staff.

In an alternative embodiment, it is envisaged that the braking force applied to the balance is axial. In such an alternative embodiment, it is advantageous to envisage a braking device of the type set forth in fig. 10. In this case, the actuator is arranged so that, on application of the braking pulse, the first and second pads apply two substantially axial forces to the balance in opposite directions. It is also contemplated herein that the force couple applied by each of the two pads through the brake pulse is substantially equal to each other.

The actuator forming the particular braking device is shown in figure 11. The actuator comprises a timepiece-type motor 86 and a braking member 90 mounted on the rotor 88 of the motor with permanent magnets so as to exert a certain pressure on the balance 16 of the resonator 14 when the rotor performs a specific rotation induced by the supply of the motor coil during a braking pulse in response to a control signal supplied by a regulating circuit.

Claims (21)

1. A timepiece assembly (2), comprising:

-a mechanism for controlling the movement of the movable part,

-a mechanical resonator (14) adapted to oscillate along an oscillation axis with respect to a neutral position corresponding to its lowest mechanical potential energy state,

-holding means (8, 10, 12) for holding the mechanical resonator, which form with the mechanical resonator a mechanical oscillator for defining the operating rate of the mechanism, each oscillation of the mechanical resonator being present as two consecutive half-cycles between two end positions defining the amplitude of the mechanical oscillator on the oscillation axis,

-adjustment means for adjusting the frequency of said mechanical oscillator, the adjustment means comprising an auxiliary oscillator (23), adjustment pulse application means (26, 60, 62) for applying adjustment pulses to said mechanical resonator, and an electronic control circuit (58, 58A) adapted to generate a control signal supplied to said adjustment pulse application means for activation thereof,

-a sensor (24, 34) adapted to detect the passage of the mechanical resonator from at least one specific position on the oscillation axis;

the timepiece assembly is characterized in that: the adjusting means comprise measuring means (50, C2) adapted to measure the time drift of the mechanical oscillator relative to the auxiliary oscillator based on the position signal provided by the sensor; wherein said modulation pulse applying means is formed by an electromechanical device adapted to generate a mechanical braking pulse applied to said mechanical resonator in response to a control signal dependent on said measured time drift, said mechanical braking pulse being applied by dynamic dry or viscous friction between a braking member of the electromechanical device and a braking surface of said mechanical resonator; and the braking surface has a certain extent along the oscillation axis and is arranged to be able to apply the mechanical braking pulse at least with its trigger at a certain moment during one of the two half-cycles of oscillation of the mechanical oscillator, irrespective of its amplitude in an amplitude range having a certain extent and corresponding to the available operating range of the mechanical oscillator, the certain moment being selected such that passage of the mechanical resonator from the neutral position does not occur during the mechanical braking pulse.

2. Timepiece assembly according to claim 1, wherein the adjustment pulse applying means are formed by an actuator (36, 76, 78, 86) comprising the braking member (38, 38A, 38B, 90) adapted to be actuated in response to the control signal during the mechanical braking pulse so as to apply a certain mechanical couple to an oscillating member of the mechanical resonator defining the braking surface.

3. The timepiece assembly according to claim 2, wherein the adjustment pulse applying means is arranged such that the braking energy of each mechanical braking pulse is less than the locking energy, so as not to stop the mechanical resonator immediately during the mechanical braking pulse; and the oscillating member and the braking member are arranged such that the mechanical braking impulse energy is applied by dynamic dry friction between the braking member and the braking surface of the oscillating member.

4. Timepiece assembly according to claim 3, wherein the actuator is adapted to actuate the braking member via a piezoelectric element or via an electromagnetic system.

5. Timepiece assembly according to claim 3, wherein the actuator comprises a timepiece-type motor, the braking member being mounted on a rotor of the motor so as to exert a certain pressure on the oscillating member when the rotor performs a certain rotation due to the supply of power to the motor coils in response to the control signal.

6. The timepiece assembly according to claim 3, wherein the oscillating member is formed by a pivoting balance comprising a rim defining the braking surface in a circular shape; and the brake component comprises a movable part defining a brake pad adapted to apply a certain pressure to the circular brake surface during application of the mechanical brake pulse.

7. The timepiece assembly according to claim 3, wherein the oscillating component is formed by a pivoting balance including a central axis defining or supporting a portion of the balance other than a rim defining the braking surface in a circular shape; and the brake component comprises a movable part defining a brake pad adapted to apply a certain pressure to the circular brake surface during application of the mechanical brake pulse.

8. A timepiece assembly according to claim 6 or 7, wherein the movable part is a first part and the brake pad is a first brake pad, the or another brake component also forming the actuator including at least a second movable part defining a second brake pad; and the actuator is arranged such that, during the application of the mechanical braking pulse, the first and second braking pads apply to the balance two radial forces diametrically opposite and in opposite directions with respect to the axis of rotation of the balance.

9. A timepiece assembly according to claim 6 or 7, wherein the movable part is a first part and the brake pad is a first brake pad, the or another brake component also forming the actuator including at least a second movable part defining a second brake pad; and the actuator is arranged such that, during application of the braking pulse, the first and second brake pads apply two axial forces to the balance in opposite directions.

10. The timepiece assembly according to any one of claims 1 to 7, wherein each oscillation cycle of the mechanical oscillator has a first half-cycle and a subsequent second half-cycle, in each first half-cycle and each second half-cycle the mechanical resonator passing from its neutral position at an intermediate moment, and each first half-cycle and each second half-cycle having a duration between a start moment and an end moment defined by two end positions occupied by the mechanical resonator at the start and end of the half-cycle, respectively; the measuring means is adapted to determine whether a time drift of the mechanical oscillator corresponds to at least some advance or at least some delay; and the control circuit and the adjustment pulse applying means are adapted to selectively apply a first mechanical braking pulse (P1) to the mechanical resonator when the measured time drift corresponds to the at least some advance and to apply a second mechanical braking pulse (P2) to the mechanical resonator when the measured time drift corresponds to the at least some delay, wherein at least a major part of the first mechanical braking pulse occurs between the start time (tD1) and the intermediate time (tN1) of one half-cycle (a1) and at least a major part of the second mechanical braking pulse occurs between the intermediate time (tN2) and the end time (tF2) of one half-cycle (a 2).

11. Timepiece assembly according to claim 10, wherein the adjusting means comprise determining means for determining the time position of the mechanical resonator, which determining means are adapted to determine, in one half-cycle of the oscillation of the mechanical resonator, a first time instant occurring before the intermediate time instant and after the start time instant of this half-cycle, and also to determine, in one half-cycle of the oscillation of the mechanical resonator, a second time instant occurring after the intermediate time instant and before the end time instant of this half-cycle; the control circuit is adapted to selectively trigger the first mechanical brake pulse at the first time and the second mechanical brake pulse at the second time; and the braking surface of the mechanical resonator comprises a first section along the oscillation axis for starting the application of the first mechanical braking pulse at the first moment and a second section along the oscillation axis for starting the application of the second mechanical braking pulse at the second moment, irrespective of the amplitude of the mechanical oscillator in its available working range.

12. Timepiece assembly according to any one of claims 1 to 7, wherein the sensor is adapted to detect at least the passage of the mechanical resonator from its neutral position.

13. The timepiece assembly according to claim 11, wherein the sensor is adapted to detect at least the passage of the mechanical resonator from its neutral position; and said determining means for determining the time position are adapted to measure a first time interval (TA1) and a second time interval (TA2) after detecting the passage of the mechanical resonator from its neutral position, wherein the respective endpoints of said first time interval (TA1) and said second time interval (TA2) define said first moment and said second moment, respectively.

14. Timepiece assembly according to any one of claims 1 to 7, wherein the sensor is an optical sensor comprising a light source adapted to send a light beam towards the mechanical resonator and a light detector adapted to receive a return light signal, the intensity of which varies periodically as a function of the position of the mechanical resonator, or a capacitive or inductive sensor adapted to detect a variation in capacitance or inductance as a function of the position of the mechanical resonator.

15. The timepiece assembly according to any one of claims 1 to 7, wherein the detent surface has a range such that the mechanical detent pulse can be applied with its triggering at any time of the respective half cycle of the mechanical oscillator.

16. The timepiece assembly of claim 14, wherein the inductive sensor operates without a magnetized material on the mechanical resonator.

17. An adjustment module for adjusting the intermediate frequency of a mechanical oscillator assembled in a clockwork movement, comprising:

-a conditioning device comprising an auxiliary oscillator (23), conditioning pulse application means (26, 60, 62) adapted to apply conditioning pulses to a mechanical resonator forming said mechanical oscillator, and an electronic control circuit (58, 58A) adapted to generate a control signal supplied to said conditioning pulse application means for activation thereof,

-a sensor (24, 34) adapted to detect the passage of the mechanical resonator from a certain position on its oscillation axis;

characterized in that the adjustment means comprise measuring means (50, C2) adapted to measure the time drift of the mechanical oscillator relative to the auxiliary oscillator based on the position signal provided by the sensor; said modulation pulse applying means is formed by an electromechanical device adapted to generate a mechanical braking pulse susceptible to be applied to said mechanical resonator in response to a control signal dependent on said measured time drift; and the adjusting means are adapted to trigger the mechanical braking pulse at a specific moment during one half cycle of the mechanical oscillator, the specific moment being chosen such that no passage of the mechanical resonator from a neutral position occurs during the mechanical braking pulse.

18. An adjustment module according to claim 17, characterized in that the mechanical resonator defines a braking surface, the adjustment pulse applying means being formed by an actuator (36, 76, 78, 86) comprising a braking member (38, 38A, 38B, 90) adapted to be actuated in response to the control signal during the mechanical braking pulse so as to be able to apply a certain mechanical couple of forces to an oscillating member of the mechanical resonator defining the braking surface.

19. The conditioning module of claim 18, wherein the braking component is arranged such that the mechanical braking impulse can be applied by dynamic dry friction between the braking component and the braking surface of the oscillating component.

20. The conditioning module of claim 19, wherein the braking component comprises a movable portion defining a brake pad adapted to exert a certain pressure on the braking surface during application of the mechanical braking pulse.

21. A conditioning module according to claim 20, wherein the movable part is a first part and the brake pad is a first brake pad, the brake component or another brake component also forming the actuator comprising at least a second movable part defining a second brake pad; and the actuator is arranged such that during application of the mechanical braking pulse, the first and second brake pads apply two aligned forces to the mechanical resonator in opposite directions.