CH703461A2 - Method for adjusting oscillation frequency and/or inertia and/or e.g. dynamic balance of time balance motor in clock movement or balance and spring assembly of watch, involves controlling pulse using driving unit to drive movements of beam - Google Patents

Abstract

The method involves removing and/or adding and/or moving a material on a movable micromechanical component by using a laser or picolaser (2) to carry out micromachining and/or micromelting of the material or an added material, for vaporizing and/or moving and/or welding the material, under the effect of a pulse from the laser or picolaser. The pulse is controlled using a driving unit (3) to generate, sequence, and interrupt the pulse, and to drive movements of a beam (20) of the laser or picolaser, where the driving unit is connected to or controlled by a measurement or comparison unit (4). Independent claims are also included for the following: (1) a balance and spring assembly for a timepiece, comprising a counterweight (2) a device for adjusting oscillation frequency and/or inertia and/or balance of a movable component in a clock movement or a balance and spring assembly of a timepiece, comprising a laser source.

Description

Description

Field of the invention

The invention relates to a method of adjusting a pendulum balance-spiral clockwork comprising at least one balance, which comprises a peripheral serge, and at least one spiral spring, attached to one another at a ferrule, said sprung balance assembly being pivotally movable about a balance shaft.

The invention also relates to a device for implementing this method.

The invention relates to the field of watchmaking, and more particularly the adjustments and adjustments ofregulants organs, and in particular balance-spiral sets of watches or timepieces.

Background of the invention

Despite the extreme precision of machining and their high reproducibility, adjustments must almost always be made during an adjustment or adjustment operation, in particular for frequency adjustment, unbalance adjustment and adjustment. of inertia in the case of moving parts.

It is always more difficult, at the assembled stage, to perfect the pairing of some components that, taken independently, are within the tolerances of machining or production, but can not be assembled purely and simply because of the constraints service specific to the mounted assembly.

This is particularly the case of the regulating organs of timepieces, and particularly balance-spiral assemblies. It appears that the unbalance and inertia adjustment settings, both static and dynamic, are already very delicate at the individual component stage, and that these debugging operations prove to be extremely complex when the components are assembled between them. In particular the dynamic settings are difficult to implement, especially the frequency adjustment.

The situation is even more complex when such an assembly is already integrated into an upper assembly, such as a watch movement for example, because of the less accessibility, but also the disruption of the smooth operation of the movement, induced by the performing an adjustment, adjustment or balancing operation.

The difficulty is double because it is about dominating settings and dynamic adjustments on components that are:

- in motion, or

- integrated in a watch movement, or

- in motion and integrated into a clockwork movement.

[0009] There are few solutions to this problem in the prior art. The problem of dynamic balancing has given rise to solutions consisting in locating zones of addition or removal of material, to quantify them, which are carried out after stopping the rotation of the mobile member to be balanced, as in US Patent No. 2538,528 to Kohlhagen. Alternatively, as in the patent document DE 1 142 796 in the name of Hettich, masses are to position or on the contrary to hunt at pre-drilled holes on the entire circumference of a watch balance. The patent CH 367 444 in the name of OMEGA shows the disadvantages of the traditional removal by milling on the pendulums of watches, and proposes a solution of addition or removal of material by electrochemical way, which makes it possible to ensure the correction of the mass and the accuracy of the balancing.

US Pat. No. 3,225,586 in the name of HAMILTON proposes the use of the microphone of a "Watchmaster" type of apparatus, linked to the moving equipment in its rotation, to determine exactly the adjustment of 4 screws in periphery of the pendulum serge.

To improve these two-step processes, measurement and adjustment, a patent CH 390 165 in the name of Zenger proposes a method of equilibration by electro-erosion, continuously with a very slight delay after a stroboscopic measurement, but it requires a rotation in a uniform direction of this pendulum.

[0012] Patent CH 690874 in the name of Witschi further describes a method of removal or addition of material following a prior measurement, with a pendulum stop device to keep it facing means of removal or removal. 'bring.

The patent CH 526097 in the name of the General Electric Company proposes a balancing of a rotating part or oscillating laser beam parallel to the axis of pivoting of the workpiece to be balanced, comprising an optical beam deflection device laser so that it is synchronous with the moving part, and thus vaporize the material in the appropriate place for the duration of the pulse emitted by the laser. This technology represents a significant advance over the prior art, but is not well suited to a component mounted in a set, because of the waste and pollution of the whole.

It is the same for a patent FR 2 159 367 in the name of Les Fabriques Assortiments Réunies, which proposes a method by machining with minimization of the number of operations, but where the position of the machining head depends on the fault to be corrected, which is not possible in a mounted assembly.

In sum, the known methods capable of performing a correction of inertia, or balancing, on a moving part are rare and poorly adapted to perform this correction on the same piece mounted in a set. In addition, few are suitable for reciprocating movement, which is that of a pendulum or a pendulum-spiral mounted assembly.

Only US Patent 6,534,742 in the name of ETA SA Fabrique d'Ebauches proposes a method for adjusting the oscillation frequency of a balance spring, by the implementation of a laser acting on the spiral spring to reduce its elastic torque, reducing its thickness or height. While representing a clear progress over the prior art, this teaching does not solve all cases, because it can only create delay by weakening the spring. On the other hand, it can only be used outside the watch movement, because of the pollution and the waste generated by the action of the laser.

Summary of the invention

The invention proposes to provide a solution to this problem, by developing a method suitable for dynamic adjustments and adjustments of balance-spiral assemblies movable pivotally, and in particular in mounted assemblies.

In particular the invention is to provide an effective method, fast and accurate frequency adjustment settings, also used for inertia adjustments, and dynamic balancing settings.

For this purpose, the invention relates to a method of adjusting a pendulum balance-spiral clockwork comprising at least one balance, which comprises a peripheral serge, and at least one spiral spring, attached one at the other at the level of a shell, said sprung-balance assembly being pivotally movable about a balance shaft, characterized in that a removal of material is carried out by transforming at least a part of the material of said assembly sublimation spiral balance, by the implementation of a suitable micro-machining means, for performing the adjustment of inertia, and / or balancing, and / or oscillation frequency, of said balance-arm assembly; spiral.

According to a feature of the invention, at least a portion of the material of said sprung-balance assembly, or components carried by said sprung-balance assembly, is converted by sublimation and is chosen as said micro-machining means. at least one picolaser for effecting said micro-etching removal by the action of at least one pulse of said picolaser so as to directly transform the solid material into a sublimation gas stream, and said pulse is controlled by means of control arranged to generate, sequence, interrupt any pulse of said picolaser, said control means being further arranged to control the movements of at least one beam from said picolaser, said control means being connected to measuring or comparison means or enslaved to said measuring or comparison means.

According to one characteristic of the invention, said measurement or comparison means are chosen for making at least inertia and oscillation frequency measurements or comparisons, and they are arranged to perform measurements or / and comparisons on said sprung-balance assembly during a movement of said sprung-balance assembly.

According to a characteristic of the invention, this method is used to effect the oscillation frequency adjustment of said balance spring-balance assembly, and it comprises a first process according to which:

the advance or the delay of said balance-spring assembly with respect to said reference oscillation frequency is evaluated;

said control means are programmed so as to generate, as the case may be, an advance by a reduction of inertia by removal of material on said balance, or a delay by modifying the stiffness of said spiral spring by removal of material from said coil spring;

said driving means are programmed to carry out said removal of material, as the case may be on said balance or on said spring-spring, by generating at least one sequential series with a medium high frequency of pulses of said picolaser to create, on said zone, at least one line of successive impacts of the beam of said picolaser in order to perform a micro-etching by localized removal of sublimation material.

According to a feature of the invention, said control means is programmed so as to define at least one particular area on which the material must be removed, as the case may be, in a first alternative in case of need for creation of advancing said zone being defined at the level of said serge of said balance or components or flyweights or studs or screws that carries said balance, or in a second alternative in case of need for creation of delay said zone being defined at the level of at least a turn of said spiral spring, and said control means is programmed so as to generate at least one sequential series with a medium high frequency of pulses of said picolaser so as to generate, on said zone, at least one line of successive impacts of the beam of said picolaser to perform a micro-etching by localized removal of sublimation material.

The invention also relates to a device for implementing this method, characterized in that it comprises at least one picolaser source, control means of said source arranged to generate, sequence, interrupt at least one sequential series pulses of said picolaser, said control means being further arranged to control the movements of at least one beam from said picolaser or the movement of said source itself, means for measuring and comparing interfaces with said control means, and means for gripping and supporting said pendulum-spiral assembly micro-machining.

3 Brief description of the drawings

Other features and advantages of the invention will appear on reading the description which follows, with reference to the accompanying drawings in which:

[0026]

- fig. 1 represents a graph with, on the ordinate, the algebraic value of the position of the center of mass of the material removed during an operation of micromachining by ablation under a picolaser beam, as a function of the amplitude of the angular position a watch clock;

- fig. 2 represents, schematically, a device for implementing the invention;

- fig. 3 represents, schematically and partially, the simultaneous intervention of two picolasers in microusinage on a pendulum-balance assembly reduced in the figure to its single balance;

- fig. 4 represents, in a similar manner to FIG. 3, delayed intervention of two such picolasers;

- fig. 5 shows, similarly to FIG. 3, the intervention of a single such picolaser.

Detailed Description of the Preferred Embodiments

The invention relates to the field of watchmaking, and more particularly the adjustments and adjustments ofregulants organs, and in particular balance-spiral sets of watches or timepieces.

The invention defines a method of adjusting a pendulum balance-spiral clockwork comprising at least one balance, which comprises a peripheral serge, and at least one spiral spring, attached to one another at a ferrule, said sprung balance assembly being pivotally movable about a balance shaft.

In a particular and advantageous manner, this method is implemented for the oscillation frequency adjustment of a pendulum-spiral clockwork assembly.

According to the invention, a material removal is carried out by transforming at least a portion of the material of this balance-spiral assembly by ablation, in particular by sublimation, by the implementation of a suitable micro-machining means. , for effecting inertia adjustment, and / or balancing, and / or oscillation frequency, of said sprung balance assembly.

Advantageously, it transforms at least a portion of the material of this sprung-balance assembly, or components that carries this sprung-balance assembly, by sublimation, that is to say a direct passage of the solid state in the gaseous state, without redeposition of solid or liquid waste on the component, and at least one picolaser is chosen as a micro-machining means. It is thus possible to carry out this removal of material by micro-etching under the effect of at least one pulse of this picolaser so as to directly transform the solid material into a gaseous flow by sublimation. This pulse, or preferably these pulses, is controlled by control means which are arranged to generate, sequence, interrupt any pulse of the picolaser. These control means are still arranged to control the movements of at least one beam from the picolaser. These control means are interfaces or connected to measurement or comparison means. In a particular variant, the control means are slaved to the measuring or comparison means.

These measurement or comparison means are chosen to perform measurements or comparisons, at least inertia and oscillation frequency, and are arranged to perform measurements and / or comparisons on this pendulum assembly- spiral during a movement of this pendulum-balance assembly.

According to the invention, this method is implemented to effect the oscillation frequency adjustment of said sprung-balance assembly, and it comprises a first process according to which:

the progress or the delay of the sprung-balance assembly with respect to this reference oscillation frequency is evaluated;

the control means are programmed so as to generate, as the case may be, an advance by a reduction of inertia by removal of material on the balance, or a delay by modification of the stiffness of the spiral spring by removal of material from the spiral spring;

the control means are programmed to effect the removal of material, as the case may be on the balance or on the spring-spring, by generating at least one sequential series with a medium high frequency of pulses of the picolaser to create, on the this zone, at least one line of successive impacts of the picolaser beam in order to perform a microgravure by localized removal of sublimation material.

It is understood that we speak here of high average frequency of pulses picolaser, because it is not essential that the frequency of the pulses is constant, especially the generation of pulses can be of random type, or follow a special rule of variation.

This first process may, but not necessarily, be a first iterative process until a target oscillation frequency is reached within a given tolerance.

The piloting means is programmed so as to define at least one particular area on which material is to be removed, as the case may be:

- In a first alternative in case of need for creation in advance this area is defined at the level of the balance rod or components or flyweights or studs or screws that carries this pendulum,

or in a second alternative in the case of the need for delay creation, this zone is defined at the level of at least one turn of the spiral spring.

In a preferred embodiment, these control means are programmed so as to generate at least one sequential series with a high average frequency of pulses of the picolaser, in order to generate, on this zone, at least one line of successive impacts. of the picolaser beam in order to perform micro-etching by localized removal of sublimation material.

It is understood that the method can be implemented in different ways:

in deferred processing between phases of measurement and / or comparison on the one hand, and micromachining phases on the other, or

in simultaneous or semi-simultaneous processing, with the execution of certain measurement and / or comparison operations during the execution of certain micromachining operations.

In an example of a preferred embodiment, the average firing frequency is between 50 Hz and 500 Hz, and preferably of the order of 300 kHz.

The pulse duration is of the order of one picosecond, ie 10 <12> second in the case of a picolaser, whose average power is between 1 and 10 W, and, in the context of the invention uses pulse durations of the order of a few picoseconds to a few tens or hundreds of picoseconds.

In the first alternative, the control means are programmed so as to create an advance on the balance by repetition of the micro-etching operations on these zones, so as to reach a target frequency value which can be controlled by the measuring or comparison means, and so as to generate the microgravure operations on the zones in respect of the balancing of the sprung-balance assembly with respect to its main axis of inertia, relative to a value setpoint which can be controlled by the measuring or comparison means.

In the second alternative, the control means are programmed so as to create a delay by modifying the stiffness of the spiral spring, without modifying its crystalline structure or its thermal coefficient, by a microgravure carried out under the action of at least one pulse sequence of at least one picolaser, for the thinning of at least one coil of the spiral spring and / or the twisted portion of an end portion when this spiral spring has one, always in respect of the balancing of the sprung-balance assembly relative to its main axis of inertia, relative to a set value that can be controlled by the measuring or comparison means.

[0043] It is thus possible to create a delay:

by modifying the stiffness of the spiral spring by thinning at least one turn of the spiral portion of the spring.

- By modifying the stiffness of the spiral spring by thinning at least the twisted part of an end portion when the spiral spring has one.

In a first embodiment, simultaneously directs at least two beams of the same characteristics in two such areas distant from each other, and radially distant from the same value of the balance axis, or by beam division of a single picolaser, or by synchronization of two picolasers receiving the same instructions from the control means. Preferably, one generates on each of these zones such a sequential series of pulses identical to that of the other zone. If this is not possible, because of slightly different characteristics of two lasers, for example, one makes sure to swap the micro-machining after half of their realization, so as to balance the material actually removed from both sides.

Of course, if the example is given here with two picolasers, it is possible to use more laser sources. However, clutter and access to the work area often makes it inconvenient to use more than two beams on the same set.

In a particular embodiment, simultaneously directs at least two beams of the same characteristics in at least two such areas of the serge or components that carries the beam, or by beam splitting of a single picolaser, or well by synchronization of several picolasers receiving the same instructions from the control means. These zones are distant from each other and radially distant from the same value of the balance shaft. And one generates on each of these zones a sequential series of pulses identical to that of the other zone. More generally, it is possible to perform scans with symmetry of any order n.

The division of the beam may be made by an optical element such as mirror, semi-reflective prism, or the like.

It is still possible to vary the power distribution between the different beams, to act on the unbalance balancing under the control of the control means.

In a preferred embodiment of the invention, in order to minimize the treatment time, the ablation point of the picolaser remains fixed, or possibly moves in a restricted area. As a result, it is possible to perform the ablation uninterruptedly, which minimizes the treatment time.

However, in the general case, a significant unbalance is created. However, it is shown below that it is possible to cancel this imbalance provided that the sprung balance assembly has a well chosen amplitude. This strategy is therefore characterized by two elements:

- (a) continuous ablation in an area of a size of the order of the annular width of the balance serge, or, as the case may be, in a zone of a turn or a terminal curve of the spring -spiral, and

- (b) sprung balance assembly having a well chosen amplitude to minimize the unbalance.

In a second embodiment, the beam of a single picolaser is moved from one such area to another such symmetry area on either side of a plane passing through the axis of balance. This plane is preferably chosen at equal distance from the extreme amplitudes of the pivoting travel of the balance-spring assembly. Preferably, one generates alternately on each of these zones, to which this beam is then focused, such a sequential series of pulses identical to that of another zone preceding it or following it directly in the working sequence of the picolaser. In a particular embodiment, these zones can be chosen in axial symmetry with respect to the axis of pivoting of the balance-spring assembly.

It is understood that, in one mode as in the other, the displacement of the beam relative to the area is a relative displacement: we can just as easily move the beam, or even the source, the entire sprung balance-spiral , or, preferably, both the beam and the sprung-balance assembly.

In this second mode, where a single picolaser is used, advantageously one can use amplitude stabilization means to maintain the pivoting movement of the balance-balance assembly in a constant amplitude oscillation during the course of each sequential series of pulses. This amplitude is stabilized at an angle of 137 ° or 316.5 °. It is also possible to use synchronization means to synchronize the movement of the picolaser beam with the pivoting movement of the balance-spring assembly during the course of each sequential series of pulses. Again, the amplitude is stabilized at an angle of 137 ° or 316.5 °.

Preferably, for a better efficiency, this at least one zone consists solely of surfaces which are constituted by metal surfaces, on the one hand at the balance or components or flyweights or studs or adjusting screws that carries this balance, or secondly at a spiral portion or an end curve of the spiral spring. In the absence of such metal surfaces to correct the advance or the delay if necessary, it implements a second process by which the balancing balancing adjustment is modified so as to recreate a correction capacity, as appropriate , on the balance and / or on the spiral spring. This second process may be a second iterative process, whereby the first iterative process is repeated until the target oscillation frequency within its tolerance is reached.

In a particular embodiment of the method, the control means are slaved to the measuring or comparison means.

Preferably, before the start of the process, a static and dynamic balancing prior to the sprung-balance assembly, to make its main axis of inertia coincide with the balance axis, and to reach a value of inertia reference within a given tolerance.

The ablation strategy on a pendulum-spiral assembly in motion, that is to say in its pivoting movement about the axis of the balance, is specified by the calculation that follows.

The invention proposes, thanks to the implementation of a new method, to perform the frequency adjustment of this balance-hairspring assembly, but also to allow its adjustment inertia and balancing, in order to to make this pivot pivot axis coincide with its main axis of inertia.

The present invention is developed to be implemented both at the level of a single beam, an assembled sprung balance, a built-in sprung balance and mounted in a movement of a piece of watchmaking.

This strategy has the effect of optimizing the processing time and the unbalance created.

As will be detailed below, this amplitude is then stabilized at an angle of a value of 137 ° or 316.5 °. To stabilize the amplitude, different methods can be used, alone or in combination: choice of a particular state of winding of the barrel, amplitude control in closed loop by setting an external torque source on the rod or on one of the mobiles movement such as a second or minute needle or other, use of an external source of stabilization such as a breath of air in free oscillation anchor removed, or other.

In the case where a single picolaser is used, it is also possible to use synchronization means to synchronize the movement of at least one beam coming from the picolaser to the pivoting movement of the balance-spring assembly during the course of each said sequential series of pulses.

To synchronize, it is a question of estimating the phase of the oscillation of the balance, or of the balance-balance-spring as the case, which is possible by different methods, alone or in combination: acoustic method by capture by

6 microphone noise generated by the escapement, optical method by arm arm detection or arm roughness, to determine position, speed and acceleration of the serge, or any other method.

We now detail how are determined the amplitudes that minimize or even cancel the unbalance.

As the ablation point does not change while the sprung-balance assembly is moving, the removal of material is distributed along the serge, not necessarily on the entire perimeter, depending on the amplitude of the pendulum assembly. -spiral, or is distributed along a turn. For simplicity we here assimilate to the serge the elements that it is likely to wear, such as weights, pads, balancing screws and / or adjustment. Similarly, it is likened to a coil spiral spring elements reported that may include this spiral spring, as a terminal curve, ferrule, or other. In addition, since the ablation is preferably done at a constant firing rate, but the speed of the sprung-balance assembly varies, the amount of material removed at an angular position of the balance also varies. Our objective is to find an amplitude of oscillation of the sprung-balance assembly which cancels out the unbalance, or, in an equivalent way, leads to a center of mass of the removed material situated in the center of the pendulum-balance spring assembly.

The position Xcm of the center of mass of the removed material is given by: j S dm j integration being along the serge. Let f denote the function of 6 which gives the linear distribution (along the serge or turn, as the case may be) of material removed. In order for the unbalance created by the material removed to be zero, it is necessary that

I xed.

I Æ /

U.

The fact of considering only linear magnitudes comes from the fact that we can neglect the width of the picolaser working area compared to the size of the balance-spiral assembly, as well as the component of the unbalance according to the invention. Pivot axis, although the fact that f varies as a function of # results in a non-constant ablation depth.

Consider for the moment only the first quarter of a single period. The quantity dm of material removed over an interval d # around #, has been for a certain time dt, and we also have dm = k dt, where k is the removal rate of the material. Since the firing frequency of the picolaser is preferably constant and very high relative to the oscillation frequency of the balance, it can be considered that k is constant. We have k dt = f (#) d #.

But # = A (t), where A is the function that gives the angular position of the pendulum at time t, and therefore d # = Â (t) dt, which implies that

 (t)  {a <~ l> {Ô)}

In other words, the material distribution removed at the position 6 of the serge is inversely proportional to the speed of the sprung-balance assembly when its angular extension is #.

For a treatment time of the order of one second or ten seconds, the oscillation of the balance-spring assembly is well described by a harmonic evolution,

A (t) = A0sin (#t).

Thus, by explaining the last expression for f, we find f (0 which is finally written ίίθ) k eQsf <'> arcsmif? / ^ ^) K

.4 i) * / i - {Θ f A o) -

This expression does not make sense when #> A0, but we agree that for the values of # greater than A0, f is zero, which is normal, since the picolaser does not reach these positions.

To achieve this result, we restricted ourselves to a quarter of oscillation of the sprung balance assembly.

The final expression for f corresponding to a complete period is obtained from that valid for the quarter period by symmetry. However, it is not really necessary to include them effectively. In addition, each additional period additionally does not increase the unbalance.

To understand why we can limit ourselves to the first quarter period for our calculation, call Ox the axis that joins the axis of the pendulum to the working point of the picolaser, and Oy the axis perpendicular to Ox. By adding the second half of the period to f, we do not change the coordinate Xcm of the center of mass of the material removed, and we make sure that the coordinate y will be zero, by symmetry. By adding the second quarter period to f, we only multiply f by two, which does not change the condition for Xcm = 0. Therefore, we study Xcm as a function of f defined by the equation (1 ).

We have

I - = toO.

0 AQJJ / / -

Finally, it is necessary to determine the values of determining the values of Ao which cancel Xcm. Since there is no primitive to obtain a closed-form solution of the integral in play, we obtain the zeros of the right-hand side of equation (2) above in an approximate manner, by numerical integration.

A graph of the right-hand side of equation (2) as a function of A0 is given in FIG. 1, where is represented on the ordinate, the algebraic value of the position of the center of mass Xcm of the removed material, as a function of the amplitude A0de the angular position.

It can be seen that for amplitude values between 0 ° and 360 °, there are two amplitudes which give zero unbalance, ie A0 = 137 ° and A0 = 316 °.

Preferably, there is applied to these values a tolerance of plus or minus 2.5 ° per microgram x centimeter of unbalance, for example more or less 5 ° for an unbalance of 2 micrograms x centimeter.

In practice, it is not necessary that the picolaser remains absolutely immobile. It can for example be made to make a radial back and forth movement, while remaining on the serge or on the turn as appropriate. It can also be made to follow different figures, such as a circle, an eight, a polygon. But as long as the area swept by the picolaser has a typical extension of the order of the thickness of the serge or the width of the turn, the theoretical model above remains an excellent approximation, and its conclusions remain valid.

In the above reasoning, we did not consider the effect of a phase shift. Its contribution to the unbalance is negligible, however, because each complete oscillation of the sprung-balance assembly produces a zero unbalance, so the unbalance associated with the phase shift amounts to at most the maximum unbalance created during a single incomplete period.

The concrete calculation presented above was conducted when the evolution of the movement of the sprung balance assembly has an amplitude of less than 360 °. However, there is nothing to limit it to this case. For example, if a sprung-balance assembly should have an amplitude greater than 360 °, the function A <'1> (#) will then have several solutions, even over a quarter of a period, which complicates the writing of expressions, without however, change the reasoning behind them.

The invention also relates to a device 1 for implementing the method, which comprises at least one picolaser source 2 and control means 3 of this source arranged to generate, sequence, interrupt at least one sequential series of pulses. picolaser 2. These control means 3 are further arranged to control the movements of at least one beam 20 from the picolaser or the movement of this source 2 itself. The device 1 further comprises means for measuring and comparing 4 interfaces with these control means 3, and means for gripping and support 5 of a sprung balance-spring assembly 1 1 micro-machining. Figs. 1 and 3 to 5, for simplicity, only represent, of this sprung-balance assembly 1 1, its pendulum and its serge 12.

Preferably, this device 1 further comprises pivoting drive means 6 of a pendulum-balance 1 1 micro-machining, which are interfaces with these control means 3. In another variant, it is also possible to implement the method of the invention with a free-spiral balance-hairspring assembly, the device 1 then comprises pulse means for its initial setting in oscillation.

In a first embodiment, as visible in FIG. 2, the device 1 comprises dividing means 7 of the beam coming from the picolaser 2. The control means 3 are arranged to drive each of the beams 20, 20A, from the division. The device 1 may also comprise, alternatively or in addition, as shown in FIG. 3, several picolaser sources 2, 2A, the control means 3 are then arranged to control each of their beams 20, 20A to micro-machining zones 13, 13A defined by the control means 3.

FIG. 2 gives an example of steering beams 20 and 20A from the division and whose trajectory in space is defined by the orientation of mirrors or motorized prisms 21, preferably at one or two degrees of freedom in pivoting, which are controlled by the control means 3. Such mirrors or prisms 21 may also be incorporated in a galvanometer, or be made in any case known in the general technique of power lasers.

Advantageously, the device 1 comprises amplitude stabilization means 8 for maintaining the pivoting movement of the sprung-balance assembly 1 1 to micro-machining in a constant amplitude oscillation. Advantageously, the device 1 comprises synchronization means 9, preferably disengageable, for synchronizing the movement of at least one beam 20 from the picolaser 2 to the pivoting movement of the balance-hairspring assembly 1 1 during the course of each sequential series pulse.

8

Claims (10)

[0089] Preferably and advantageously to channel any pollution and to leave the working area perfectly clean, the device 1 comprises means 10 for evacuating the gases and / or waste associated with the sublimation, these evacuation means operating. preferably by pressure difference. These means of evacuation have the dual function of, on the one hand to remove the gases from the sublimation of the field of work, and on the other hand to protect the operators in the case where these gases may have toxicity. claims 1. A method of adjusting a pendulum balance-sprung assembly comprising at least one balance, which comprises a peripheral serge, and at least one spiral spring, attached to one another at a ferrule, said spiral-balance assembly being movable in pivoting about a balance shaft, characterized in that a removal of material is carried out by transforming at least a part of the material of said balance-spiral assembly by sublimation, by the implementation of micro-machining means adapted to perform the adjustment of inertia, and / or balancing, and / or oscillation frequency, said balance-spiral assembly. 2. Method according to claim 1, characterized in that transforms at least a portion of the material of said sprung-balance assembly, or components carried by said sprung-balance assembly, by sublimation, and is chosen as said means of micro machining at least one picolaser to carry out said removal of material by micro-etching under the effect of at least one pulse of said picolaser so as to directly transform the solid material into a gas stream by sublimation, and said pulse is controlled by means of control means arranged to generate, sequence, interrupt any pulse of said picolaser, said control means being further arranged to control the movements of at least one beam from said picolaser, said control means being connected to measurement or comparison means or else slaved to said measuring or comparison means. 3. Method according to claim 2, characterized in that said measuring or comparison means for making measurements or comparisons at least inertia and oscillation frequency, and that they are arranged to perform measurements and / or comparisons on said sprung-balance assembly during a movement of said sprung-balance assembly. 4. Method according to claim 2 or 3, characterized in that it is implemented to effect the oscillation frequency adjustment of said sprung-balance assembly, and that it comprises a first process in which: the advance or the delay of said balance sprung assembly with respect to a reference oscillation frequency is evaluated; said control means are programmed so as to generate, as the case may be, an advance by a reduction of inertia by removal of material on said balance, or a delay by modifying the stiffness of said spiral spring by removal of material from said coil spring; said driving means are programmed to carry out said removal of material, as the case may be on said balance or on said spring-spring, by generating at least one sequential series with a medium high frequency of pulses of said picolaser to create, on said zone, at least one line of successive impacts of the beam of said picolaser in order to perform a micro-etching by localized removal of sublimation material. 5. Method according to claim 4, characterized in that program said control means so as to define at least one particular area on which material is to be removed, as appropriate, in a first alternative in case of need of creation in advance said zone being defined at the level of said serge of said balance or components or flyweights or studs or screws that carries said balance, or in a second alternative in case of need for creation of delay said zone being defined at the level of at least one turn of said spring -spiral, and said control means is programmed so as to generate at least one sequential series with a high average frequency of pulses of said picolaser so as to generate, on said zone, at least one line of impacts successive beams of said picolaser in order to perform a micro-etching by localized removal of sublimation material. 6. Method according to claim 4 or 5, characterized in that said control means is programmed so as to create advance on said balance by the repetition of said micro-etching operations on said zones, so as to achieve a reference frequency value which can be controlled by said measuring or comparison means, and so as to generate said micro-etching operations on said zones in respect of the balancing of said balance-sprung assembly with respect to its main axis of inertia, relative to a set value that can be controlled by said measuring or comparison means. 7. Method according to claim 4 or 5, characterized in that said control means is programmed so as to create a delay by modifying the stiffness of said spiral spring, without modification of its crystal structure or its thermal coefficient, by a microgravure carried out under the action of at least one sequence of pulses of at least one picolaser, for the thinning of at least one turn of said spiral spring and / or of the twisted portion of an end portion when said spiral spring has one. 8. A method according to claim 7, characterized in that creates a delay by modifying the stiffness of said spiral spring by thinning at least one turn of said spiral portion of said spiral spring. 9. A method according to claim 7, characterized in that creates a delay by modifying the stiffness of said spiral spring by thinning at least the twisted portion of an end portion when said spiral spring has one. 9 10. Method according to claim 5, characterized in that: at least two beams of the same characteristics are simultaneously directed in two said zones distant from each other, and radially distant from the same value of said balance axis, or else by division of the beam of a single picolaser, or else by synchronization of several picolasers receiving the same instructions from said control means; - Generating on each of said zones a so-called sequential series of pulses identical to that of the other zone. 1 1. Process according to claim 5, characterized in that: moving the beam of a single picolaser from one said zone to another said zone in symmetry on either side of a plane passing through said balance axis; alternatively, generating on each of said zones, to which this beam is then focused, a so-called sequential series of pulses identical to that of another zone preceding it or following it directly in the working sequence of said picolaser. 12. Method according to claim 5, characterized in that: a single picolaser is used and amplitude stabilizing means are used to maintain the pivoting movement of said balance spring assembly in a constant amplitude oscillation during the course of each said sequential series of pulses. 13. The method of claim 12, characterized in that stabilizes said amplitude at an angle of a value of 137 ° or 316.5. 14. Process according to claim 5, characterized in that: a single picolaser is used and synchronization means are used to synchronize the movement of its beam with the pivoting movement of said balance-spring assembly during the course of each said sequential series of pulses. 15. The method of claim 4 or 5, characterized in that said at least one zone consists solely of surfaces which are constituted by metal surfaces, on the one hand at said balance or components or flyweights or pads or adjusting screws that carries said balance, or secondly at a spiral portion or an end curve of said spring -spiral, and that, in the absence of such metal surfaces to correct the advance or delay if necessary, implementing a second process by which the balancing balancing adjustment is modified so as to recreate a correction capacity, as the case may be, on said balance or / and on said spring-spiral, and by which one resumes said first process, until the target oscillation frequency is reached within its tolerance. 16. The method of claim 2, characterized in that slave said control means to said measuring means or comparison. 17. The method of claim 4, characterized in that said first process is a first iterative process until a target oscillation frequency is reached within a given tolerance. 18. Method according to one of the preceding claims, characterized in that performs a prior static and dynamic balancing of said sprung-balance assembly, to coincide its main axis of inertia with said balance shaft, and to achieve a value inertia setpoint within a given tolerance. 19. Device (1) for implementing the method according to claim 2, characterized in that it comprises at least one picolaser source (2), control means (3) of said source (2) arranged to generate, sequencing, interrupting at least one sequential series of pulses of said picolaser (2), said control means (3) being further arranged to control the movements of at least one beam (20) issuing from said picolaser (2) or the movement of said source (2) itself, means for measuring and comparing (4) interfaces with said control means (3), and means for gripping and supporting (5) a pendulum-spiral micro-machining assembly . 20. Device (1) according to the preceding claim, characterized in that it further comprises pivoting drive means (6) of a pendulum-spiral assembly micro-machining, which are interfaces with said control means (3). 21. Device (1) according to claim 19 or 20, characterized in that it comprises dividing means (7) of said beam (20) from said picolaser (2), said control means (3) being arranged to drive each of beams (20; 20A) from the division, or / and that it comprises several picolaser sources (2; 2A), said control means (3) being then arranged to drive each of their beams (20; 20A) . 22. Device (1) according to one of claims 19 to 21, characterized in that it comprises amplitude stabilization means (8) for maintaining the pivoting movement of said balance-hairspring assembly in a constant amplitude oscillation. micro-machining. 23. Device (1) according to one of claims 19 to 22, characterized in that it comprises synchronization means (9) for synchronizing the movement of at least one beam (20) from said picolaser (2) to pivoting movement of a sprung-balance assembly to micro-machining during the course of each said series of sequential pulses. 24. Device (1) according to one of claims 19 to 23, characterized in that it comprises means for evacuating (10) gases and / or waste associated with said sublimation, said means of evacuation operating by pressure difference. 11