Method for adjusting the operation of a timepiece setting organ by laser

Abstract

The invention relates to a method for adjusting the rate of a regulating organ (10) of a watch movement, the regulating organ (10) comprising an inertial mass (5), for example a balance wheel, elastic return means (2) of the inertial mass (5), for example a balance spring, the elastic return means (2) being configured to allow the inertial mass (5) to perform an oscillatory movement, the method comprising a step of adding and / or removing material from the inertial mass (5), by projection of material (9) by a laser (7).

Description

Technical field of the invention

[0001] The invention relates to the field of watchmaking, and more particularly to the field of mechanical watchmaking, where the regulation of motive energy is carried out by a regulating organ.

[0002] The invention relates more specifically to a method of adjusting the operation of the regulating organ by laser. Technological background

[0003] In most mechanical watches, the energy needed to rotate the hands (e.g., minute and hour indicator hands) is stored in a barrel and then released by a balance-spring system, which includes a flywheel called a balance wheel, associated with a spring in the form of a spirally wound ribbon, called a balance spring.

[0004] At one internal end, the spiral is fixed to a shaft that is rotating with the balance wheel; at one external end, the spiral is fixed to a stud mounted on a stud holder which is itself fixed to a bridge (or cock).

[0005] The balance wheel's rotation is maintained—and its oscillations counted—by an escapement mechanism comprising an anchor with a low-amplitude oscillating motion, equipped with two pallets that engage the teeth of an escape wheel. Thus engaged, the escape wheel is imparted a step-by-step rotational motion whose frequency is determined by the anchor's oscillation frequency, itself synchronized with the balance wheel's oscillation frequency.

[0006] In a traditional escapement mechanism, the oscillation frequency is approximately 4 Hz, or about 28,800 vibrations per hour (A / h). One objective of skilled watchmakers is to ensure the isochronism and regularity of the oscillations (or constant rate) of the balance wheel.

[0007] It is known to regulate the course of the balance wheel by adjusting the active length of the balance spring, defined as the curvilinear length between its inner end and a counting point, located in the vicinity of the outer end of the balance spring and generally defined by a pair of stops carried by a key mounted on a rack system.

[0008] The assembly comprising the bridge, the regulator system, the key, the stud holder, the stud, the arbor, the spring, and the balance wheel is commonly referred to as the "regulating organ." Examples of regulating organs are provided by international application WO 2016 / 192957 and by European patent EP 2 876 504, both in the name of the watch manufacturer ETA.

[0009] Another way to adjust the balance wheel's rate is to change its inertia. This inertia can be changed using radial screws or eccentric weights. By tightening or loosening one or more screws or eccentric weights, the balance wheel's inertia is altered.

[0010] Other adjustment methods involve adding or removing material from the balance wheel to modify its inertia. This allows the rate of the regulating organ to be adjusted.

[0011] However, in most cases, it is necessary to integrate an adjustment device into the movement, and therefore to significantly modify the configuration of the regulating components. These modifications generate substantial manufacturing and development costs.

[0012] Furthermore, these adjustment devices require opening the watch case. Opening the case causes pressure changes, which negatively impact the measurement and adjustment of the timekeeping. Summary of the invention

[0013] The aim of the present invention is to overcome all or part of the aforementioned drawbacks by proposing a method for adjusting the rate of a regulating organ, which does not require significant modifications to the configuration of the regulating organ, and which is capable of allowing this adjustment to be made from outside a closed watch case.

[0014] To this end, the invention relates to a method for adjusting a clockwork movement regulating organ comprising an inertial mass, for example an annular balance wheel, elastic return means for the inertial mass, for example a balance spring, the elastic return means being configured to allow the inertial mass to perform an oscillatory movement.

[0015] The invention is remarkable in that the process includes a step of adding and / or removing material from the inertial mass, by projecting material with a laser.

[0016] Thanks to the invention, a method is available that allows the regulating organ's operation to be adjusted with a very high degree of precision, previously unattainable. Furthermore, the movement does not require significant modifications, as the components do not occupy much space within the movement.

[0017] In addition, such a process can be used from outside a watch case, notably by directing the laser through the case.

[0018] According to a particular embodiment of the invention, the removal of material by the laser is carried out by removing material arranged in a layer under the inertial mass.

[0019] According to a particular embodiment of the invention, the inertial mass is transparent to the wavelength of the laser, so that the laser can pass through the inertial mass to the fusible material layer.

[0020] According to a particular embodiment of the invention, the addition of material by the laser is carried out from a support comprising the material arranged in a layer, the support being arranged above the inertial mass with respect to the laser source.

[0021] According to a particular embodiment of the invention, the support is transparent to the wavelength of the laser.

[0022] According to a particular embodiment of the invention, the material is to be chosen from gold, platinum, tungsten, rhenium, rhodium, or iridium.

[0023] According to a particular embodiment of the invention, the deposition or removal step is carried out during the oscillation of the inertial mass, the laser being synchronized with the oscillation of the inertial mass.

[0024] According to a particular embodiment of the invention, the method includes a preliminary step of measuring the frequency and / or amplitude of oscillation of the inertial mass, and of determining the deviation from a predetermined value.

[0025] According to a particular embodiment of the invention, the measurement of the oscillation frequency is carried out optically by a camera, or by acoustic measurement by a microphone.

[0026] According to a particular embodiment of the invention, the step of adding and / or removing material from the inertial mass is carried out through the bottom of a watch case, the regulating organ being arranged in said case closed by said bottom, the bottom being transparent to the wavelength of the laser.

[0027] According to a particular embodiment of the invention, the step of adding and / or removing material from the inertial mass is carried out through the glass of the timepiece, the glass being transparent to the wavelength of the laser.

[0028] The invention also relates to a clockwork movement regulating organ, comprising an inertial mass, for example a balance wheel, elastic return means for the inertial mass, configured to allow the inertial mass to perform an oscillatory movement.

[0029] The regulating organ is remarkable in that it comprises a first and a second component, the first component being provided, at least in part, with a layer of fusible material, the first component being transparent to the wavelength of a laser capable of transferring the material onto a second component.

[0030] According to a particular embodiment of the invention, the first component is the inertial mass of the regulating organ, and the second component is a support arranged under the inertial mass.

[0031] According to a particular embodiment of the invention, the first component is a support arranged above the inertial mass, and the second component is the inertial mass.

[0032] The invention also relates to a clockwork mechanism comprising such a regulating organ.

[0033] The invention further relates to a timepiece, for example a watch, comprising a case and such a timepiece movement arranged in the case.

[0034] According to a particular embodiment of the invention, the box is provided with a bottom that is transparent at the wavelength of the laser. Brief description of the figures

[0035] The aims, advantages and features of the present invention will become apparent from the reading of several embodiments given solely by way of non-limiting examples, with reference to the accompanying drawings in which: there figure 1schematically represents a top view of a regulating organ of the prior art, the figure 2 schematically represents a side view of the regulating organ of the figure 1 arranged in a clockwork pattern, the figure 3 schematically represents a side view of part of a first embodiment of a regulating organ during the adjustment process according to the invention, the figure 4 schematically represents a side view of part of a second embodiment of a regulating organ during the adjustment process according to the invention, the figure 5 schematically represents a side view of part of a third embodiment of a regulating organ during the adjustment process according to the invention, and the figure 6 schematically represents a side view of a timepiece comprising a regulating organ during the adjustment process according to the invention. Detailed description of the invention

[0036] The invention relates to a method for adjusting the rate of a regulating organ 1 of a clockwork movement.

[0037] On the figures 1 and 2 Such a regulating organ 1 comprises an inertial mass 5, for example a balance wheel, and elastic means 2 for returning the inertial mass 5, for example a balance spring. The elastic return means 2 are configured to allow the inertial mass 5 to oscillate. Such a regulating organ 1 must be adjustable to change the course of the movement in which it is arranged.

[0038] According to the invention, the process includes a step of adding or removing material from the inertial mass, by projecting material with a laser.

[0039] The material is projected, for example, using a LIFT (Laser Induced Forward Transfer) type device.

[0040] This type of device uses a principle of targeting the material with a laser through a substrate on which the material is deposited in layers, in order to detach at least some of this material from the substrate and project it onto another object. Such a process is described in the following documents: Printing Method for Long Flight Distance by Laser-Induced Forward Transfer, H. Suhara, J. Aoto, M. Iwata, Journal of Laser Micro / nanoengineering Vol 15, No 2, 2020, Laser-Induced Forward Transfer: A high-resolution additive manufacturing technology, P. Delaporte, AP. Alloncle, Optics & Laser Technology 78 (2016) 33-41, Laser-Induced Forward Transfer: A method for Printing Functional Inks, JM Fernandez-Pradas, P. Serra, and Selective metallization of surfaces by laser, A. Bahouka, Engineering Techniques, Dec 10, 2017, M 1 643 V2.

[0041] Thanks to this process, material can be added or removed from the inertial mass 5 in order to modify its inertial properties, and thus correct the operation of the regulating organ 1.

[0042] Indeed, by adding or removing material from the inertial mass 5, its inertia, and therefore its oscillation frequency, is modified. This induces a correction in the operation of the regulating organ.

[0043] On the figure 3 , is represented in part a first embodiment of a regulating organ 10 enabling the process according to the invention to be implemented, in particular in the case of an addition of material to the inertial mass 5.

[0044] In the case of adding material to the inertial mass 5, this is done from a support 6 containing the fusible material. In addition to the inertial mass 5, the regulating member 10 includes a support 6 for the fusible material.

[0045] The support 6 comprises a body transparent at the laser wavelength, beneath which a layer 8 of material has been deposited. The transparent body is, for example, a synthetic sapphire of the Al2O3 type, a silicon glass, quartz, or monocrystalline silicon. The support 6 is arranged between the laser source and the inertial mass 5. Thus, the laser beam passes through the support 6 to the layer of material 8, so that pieces of material 8 leave the support 6 and are deposited on the inertial mass 5.

[0046] Preferably, the distance between the support 6 and the inertial mass 5 is less than 10mm, preferably less than 5mm, or even less than 2mm.

[0047] The support 6 is for example a plate, having a shape corresponding at least in part to that of the inertial mass 5.

[0048] Alternatively, the support 6 is a bridge, for example a balance wheel bridge, on which the regulating organ 1 is mounted.

[0049] The support 6 is for example driven into a balance bridge, on which the regulating organ 1 is mounted.

[0050] Preferably, material 9 should be chosen from gold, platinum, tungsten, rhenium, rhodium, or iridium.

[0051] A laser, for example, emits a frequency ranging from the infrared spectrum to the UV spectrum, passing through the visible spectrum. Thus, the body of support 6 is transparent to the infrared spectrum, and / or the visible spectrum, and / or the UV spectrum. The laser's wavelength is between 350 and 1100 nm, preferably between 500 and 1000 nm, or even between 1000 and 1100 nm.

[0052] For example, the upper surface of the support 6 is targeted with the laser 7, which passes through the transparent body to reach the layer 8 of material. Under the action of the laser 7, the material melts or evaporates, or it detaches into pieces depending on the laser and the material used.

[0053] This results in a projection of matter 9, which detaches from the support 6 and is deposited onto the inertial mass 5. The laser 7 is moved along the layer 8 to transfer the desired amount of matter onto the inertial mass 5. The matter is deposited, for example, onto the circular part of the pendulum. Consequently, the pendulum is made heavier by the deposited material, and therefore its oscillation frequency is changed.

[0054] Support 6 can comprise several layers of different densities to facilitate selecting the amount of material to be transferred. Alternatively, support 6 can be replaced by several supports, each with a layer of material of varying densities.

[0055] The support 6 may comprise a simple layer 8 or a stack of layers to improve the adhesion of the transferred material to the inertial mass 5. For example, a layer of Au or Pt is used on a layer of Ti or Cr as an adhesion layer.

[0056] In the case of material removal by laser 7, material 9 is removed from the inertial mass 5 of the regulating organ 20, as shown in the figure 4 Preferably, the inertial mass 5 comprises a body transparent to laser light, and under which a layer of matter 12 has been deposited.

[0057] In this case, the laser 7 passes through the transparent body to reach the layer 12 of material located beneath the transparent body. A portion of the material 9 from the layer 12 is projected onto a support 11 of the regulating organ 20, which is positioned beneath the inertial mass 5. Thus, the inertial mass 5 is lightened in this variant of the process, so that its oscillation frequency is modified to regulate the operation of the regulating organ 20.

[0058] On the figure 5 This embodiment combines the two previous embodiments, to allow for adding or removing material from the inertial mass 5 as needed.

[0059] In this case, the regulating organ 30 comprises a first support 6 arranged above the inertial mass 5 and a second support 11 arranged below the inertial mass 5. The inertial mass 5 and the first support 6 each have a body transparent to the wavelength of the laser 7. In addition, they each include a layer of material 8, 12 arranged below the transparent body.

[0060] Preferably, the material layers 8, 12 are not superimposed so that the laser 7 can reach them independently.

[0061] Thus, by choosing to point the laser 7 at the first support 6 or at the inertial mass 5, we can either add matter or remove matter from the inertial mass 5.

[0062] Thanks to this configuration, we can modify the inertia of the inertial mass 5, by increasing or decreasing it, to adjust the oscillation frequency of the pendulum.

[0063] In a first example of the process, a nanosecond laser is used. The material is gold deposited on a sapphire support, while the balance wheel is made of brass coated with a CuBe layer.

[0064] Laser 7 is pulsed, with a duration for example between 1fs and 500ns, preferably between 1ns and 400ns.

[0065] The fluence of the laser pulse is between 0.1 and 100 J / cm2, preferably between 0.5 and 50 J / cm2, or even between 1 and 15 J / cm2.

[0066] The laser power is between 5W and 30W, preferably between 10W and 20W.

[0067] The laser frequency is, for example, between 50kHz and 300kHz, preferably between 150kHz and 250kHz.

[0068] Thanks to these parameters, we obtain a material deposit in length between 0.05µg / mm and 1 µg / mm for a width between 20 and 80µm.

[0069] A femtosecond laser can also be used, with a power output between 0.1W and 2W, preferably between 0.2W and 1W, but the resulting layer is more spread out. The laser pulse duration is, for example, 260fs.

[0070] The laser frequency is between 10kHz and 250kHz, preferably between 150kHz and 250kHz.

[0071] The material is, for example, gold placed on a sapphire base. A layer of material is then transferred to the brass balance wheel.

[0072] Preferably, the position of the laser 7 can be modified relative to the support 6 and / or the inertial mass 5. Thus, the laser 7 can select areas of layers 8 and / or 12 that have not yet been impacted.

[0073] Preferably, the deposition or removal step is performed when the inertial mass 5 is stationary. This prevents the inertial mass 5 from oscillating, thus facilitating the deposition or removal of material by the laser 7.

[0074] In one embodiment, the deposition or removal step is carried out during the oscillation of the inertial mass 5. To this end, the laser pulses are synchronized with the oscillation of the inertial mass 5.

[0075] Alternatively, the laser pulses are distributed over a complete period of the oscillation of the inertial mass 5 without any particular synchronization.

[0076] Preferably, the method includes a preliminary step of measuring the frequency and / or amplitude of oscillation of the inertial mass 5. The oscillation frequency is measured, for example, optically using a camera, or audibly using a microphone, for example a Witchi microphone, or by any other measurement method known to those skilled in the art. Preferably, the oscillation frequency is measured in the four standardized positions in order to correct for any potential imbalance in the inertial mass 5.

[0077] The process also includes a step to determine the deviation from a predetermined value. This determines the difference between the actual rate of the movement and the desired rate.

[0078] Through these two steps, we determine the quantity of material to add or remove from the inertial mass 5 to achieve the desired step.

[0079] Furthermore, the step of adding and / or removing material from the inertial mass 5 can be carried out through the bottom 16 of a watch case (not shown in the figure), as shown in the figure 6 The case includes a clockwork movement 15 equipped with a regulating organ according to one of the embodiments of the invention.

[0080] The housing is closed by a base 16, preferably removable. To allow the passage of the laser 7, the base 16 includes at least part of a transparent glass at the wavelength of the laser 7.

[0081] This avoids having to open the case to adjust the regulating organ. The case includes a housing for the watch movement, within which the regulating organ is located.

[0082] Naturally, the invention is not limited to the embodiments of regulating organs described with reference to the figures, and variants could be envisaged without departing from the scope of the invention.

Claims

1. Method for regulating the rate of a regulating organ (10, 20, 30) of a clockwork movement, the regulating organ (10, 20, 30) comprising an inertial mass (5), for example a balance wheel, elastic return means (2) for the inertial mass (5), for example a balance spring, the elastic return means (2) being configured to allow the inertial mass (5) to perform an oscillatory motion, characterized in that the process includes a step of adding and / or removing material to the inertial mass (5), by projecting material (9) by a laser (7).

2. Adjustment method according to claim 1, characterized in that the removal of material by the laser (7) is carried out by removing material (9) arranged in a layer (12) under the inertial mass (5).

3. Adjustment method according to claim 2, characterized in thatthe inertial mass (5) is transparent to the wavelength of the laser (7), so that the laser (7) can pass through the inertial mass (5) to the layer (12) of matter (9).

4. A method for adjusting according to any one of the preceding claims, characterized in that the addition of material by the laser (7) is carried out from a support (6) comprising the material (9) arranged in a layer (8), the support (6) being arranged above the inertial mass (5) with respect to the laser source (7).

5. Adjustment method according to claim 4, characterized in that the support (6) is transparent to the wavelength of the laser (7).

6. A method for adjusting according to any one of the preceding claims, characterized in that the material (9) is to be chosen from gold, platinum, tungsten, rhenium, rhodium, or iridium.

7. A method for adjusting according to any one of the preceding claims, characterized in thatthe deposition or removal step is carried out during the oscillation of the inertial mass (5), the laser (7) being synchronized with the oscillation of the inertial mass (5).

8. A method for adjusting according to any one of the preceding claims, characterized in that It includes a preliminary step of measuring the frequency and / or amplitude of oscillation of the inertial mass (5), and of determining the path deviation from a predetermined value.

9. A method for adjusting according to any one of the preceding claims, characterized in that the step of adding and / or removing material from the inertial mass (5), is carried out through the bottom (16) of a case (15) of a watch part, the regulating organ (1, 10, 20) being arranged in said case (15) closed by said bottom (16), the bottom (16) being transparent to the wavelength of the laser.

10. Regulating organ of a clockwork movement, comprising an inertial mass (5), for example a balance wheel, elastic return means (2) for the inertial mass (5), configured to allow the inertial mass (5) to perform an oscillatory motion, characterized in that it comprises a first component provided at least in part with a layer (8, 12) of matter (9), the first component being transparent to the wavelength of a laser (7) capable of transferring the matter (9) onto a second component.

11. Control element according to claim 10, characterized in that the first component is the inertial mass (5) of the regulating organ (10, 30), and the second component is a support (11) arranged under the inertial mass (5).

12. Control element according to claim 10, characterized in that the first component is a support (6) arranged above the inertial mass (5), and the second component is the inertial mass (5).

13. Clockwork movement, characterized in that it includes a regulating element (10, 20, 30) according to any one of claims 10 to 12.

14. A timepiece, for example a watch, comprising a case, characterized in that it includes a clockwork movement (15) according to claim 13, the clockwork movement (15) being arranged in the case.

15. Timepiece according to claim 14, characterized in that the box is fitted with a base (16) transparent to the wavelength of the laser (7).

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