Thermally actuated micromechanical device, in particular for timepiece

Abstract

The invention relates to a thermally actuated micromechanical device, in particular for a timepiece. The invention relates to a thermally actuated micromechanical device (1), in particular for a timepiece movement, said micromechanical device (1) comprising a mechanically actuatable first moving part (3) and a mechanically actuatable second moving part (4) which can be moved in translation relative to the first moving part (3) between a coupled position, in which the second moving part (4) can be moved in translation relative to the first moving part (3), and a locked position, in which the second moving part (4) can be moved in translation relative to the first moving part (3), in which the second moving part (4) can be moved in translation relative to the first moving part (3). The invention relates to a micromechanical device (1) comprising a first mobile part (3), a second mobile part (4), a locking position in which the first mobile part (3) is in mechanical engagement with the second mobile part (4) so as to actuate the second mobile part (4), and a locking position in which the second mobile part (4) is not in mechanical engagement with the first mobile part (3), the micromechanical device (1) comprising a support part (5) on which the second mobile part (4) is mounted, characterized in that the support part (5) is thermally deformable, the second movable member (4) is moved from the locking position to the coupling position and / or vice versa.

Description

Technical Field

[0001] This invention relates to the field of point-actuable micromechanical devices, and more particularly, to the field of thermally actuated micromechanical devices, especially for watches. Background Technology

[0002] In gear mechanisms, micromechanical devices that can be actuated may be required. More specifically, in the field of watchmaking, there are mechanisms used to keep time for specific watch modules, such as for setting the time or date, or to set the rate of the movement.

[0003] These mechanisms are point-actuated and mechanically engage gears.

[0004] To actuate them, these mechanisms either require access from outside the timer, such as a winding crown and stem for setting the time, or they require opening the timer's case to access the timer module, for example, when setting the rate.

[0005] Actuation from outside the case makes the movement more complex, as components must be added to allow access to the watch modules to be actuated. The case must also be waterproof.

[0006] Opening the watch case changes the pressure inside, which negatively affects the speed of the regulating mechanism.

[0007] Micromechanical actuators exist that can be actuated from the outside of the watch case without opening it. For example, document DE1720495 proposes a magnetic actuator, document CH504030 proposes a thermal actuator, and document EP3118693 proposes an optical actuator.

[0008] However, these micromechanical actuators cannot achieve sufficient setting accuracy. Summary of the Invention

[0009] The present invention aims to overcome all or some of the above-mentioned disadvantages by providing a micromechanical device that can be actuated from outside the watch case for accurate setting.

[0010] Therefore, the present invention relates to a thermally actuated micromechanical device, particularly for use in watch movements, comprising a first mechanically actuable movable member and a second mechanically actuable movable member, the second movable member being translatable relative to the first movable member between a coupled position and a locked-out position, wherein in the coupled position the first movable member is mechanically engaged with the second movable member to actuate the second movable member, and in the locked-out position the second movable member is not mechanically engaged with the first movable member, the micromechanical device comprising a support on which the second movable member is mounted.

[0011] The significant feature of this invention is that the support member is thermally deformable to move the second movable member from the locked position to the coupled position and / or vice versa.

[0012] This invention provides a micromechanical device for mechanically connecting two moving parts by means of thermal actuation. As a result, no additional mechanical mechanism is required to connect the two moving parts.

[0013] The device is simple to manufacture and can be remotely actuated by heating the support components.

[0014] Furthermore, such a device can be actuated from outside the watch case, for example, in the case of a timer for which it is desirable to adjust the setting without opening the watch case. In practice, the micromechanical device can be actuated by heating, thereby closing the watch case.

[0015] According to a particular embodiment of the invention, the support member comprises at least partially, preferably entirely, a memory material that is thermally deformable when it exceeds a threshold temperature.

[0016] According to a particular embodiment of the invention, the threshold temperature is included between 60°C and 80°C, preferably between 65°C and 75°C, or even substantially equal to 70°C.

[0017] According to a specific embodiment of the invention, the support is a lever.

[0018] According to a particular embodiment of the invention, the lever includes a bent portion that straightens to move the second moving member from a locked position to a coupled position.

[0019] According to a particular embodiment of the invention, the second movable member is arranged in the curved portion of the lever or in the immediate vicinity of the curved portion.

[0020] According to a particular embodiment of the invention, the micromechanical device includes a mandrel arranged perpendicular to a first end of the lever to form a pivot about which the lever can rotate.

[0021] According to a particular embodiment of the invention, the support includes a pinion that meshes with the second moving member.

[0022] According to a specific embodiment of the present invention, the first moving element is a gear.

[0023] According to a particular embodiment of the present invention, the second moving element is a gear.

[0024] According to a particular embodiment of the invention, the micromechanical device includes a return spring for pushing the second moving member back to the locked position.

[0025] The present invention also relates to a watch movement comprising such a micromechanical device.

[0026] According to a particular embodiment of the invention, the watch movement includes a plate or rod with a base for the support member.

[0027] According to a particular embodiment of the invention, the base includes a flange that forms a support for a second end of the lever.

[0028] The present invention also relates to a timepiece comprising such a watch movement. Attached Figure Description

[0029] Referring to the accompanying drawings, the objects, advantages, and features of the invention will become apparent from the several embodiments provided by way of non-limiting example only, in which: - Figure 1 This is a schematic perspective view of a part of a watch movement, which includes thermally actuated micromechanical devices in a first configuration. - Figure 2 yes Figure 1 A schematic perspective view of this part of the watch movement, in which the thermally actuated micromechanical device is in a second configuration. - Figure 3 This is a schematic perspective view of a part of a thermally actuated micromechanical device. - Figure 4 This is a schematic top view of this part of the thermally actuated micromechanical device, and - Figure 5 This is a schematic perspective view of a portion of a setting mechanism driven by a micromechanical device according to the present invention. Detailed Implementation

[0030] Figure 1 and Figure 2 A schematic diagram of an embodiment of a thermal actuator 1 designed to be mounted in a watch movement 10 is shown. The watch movement 10 includes a plate 11 and a base 12 disposed in the plate 11 to accommodate the thermal actuator 1.

[0031] The watch movement 10 also includes a main setting moving part 2, which drives the watch module mechanism.

[0032] For example, the main moving part 2 is a date drive wheel. Such a wheel has a high gear ratio with the shank, which enables precise setting resolution.

[0033] For example, the watch module includes a mechanism for setting the rate of the watch movement, which is actuated by cam 14, such as... Figure 5 As seen in the diagram. This means that the setting mechanism functions when the main moving part 2 is actuated.

[0034] The thermally actuated device 1 further includes: a first mechanical moving part 3, which is a first gear in this case; and a second mechanical moving part 4, which is a second mechanical moving part in this case.

[0035] The first mechanical moving part 3 engages with the main moving part 2, making it actuable. Therefore, rotating the main moving part 2 will rotate the first mechanical moving part 3, thereby actuating the setting mechanism on the clock module associated with the first mechanical moving part 3.

[0036] The second mechanical moving part 4 can move relative to the first mechanical moving part 3 between a coupled position and a locked position. In the coupled position, the first mechanical moving part 3 is engaged with the second mechanical moving part 4, and in the locked position, the first mechanical moving part 3 is not engaged with the second mechanical moving part 4.

[0037] For this purpose, a second mechanical moving part 4 is mounted on a support 5, which is configured to move the second mechanical moving part 4 from a locked position to a coupled position, and vice versa.

[0038] In this embodiment, the support 5 is a substantially longitudinal lever. The lever includes a curved portion 7 connecting two substantially straight portions. The lever includes two ends 9 and 15.

[0039] Preferably, the second mechanical moving part 4 is arranged in the curved portion 7 of the lever, which moves over a longer distance compared to the straight portion.

[0040] exist Figure 3 In this configuration, the support member 5 also includes a pinion 6 and a spindle 8 arranged at the first end 9 of the lever, the pinion 6 being mounted on the spindle 8. The spindle 8 passes through the plate 11 and is assembled through the support member 5. Thus, the first end 9 of the lever is held in the base 12. However, the spindle 8 forms a pivot about which the lever can rotate.

[0041] Regardless of its position, pinion 6 engages with the second mechanical moving part 4. When the second mechanical moving part 4 is driven, pinion 6 actuates the spindle. The spindle 8 is connected to a gear system (not shown) that is actuable, preferably intermittently actuable, for example, by the wearer of a timer including the movement.

[0042] According to the present invention, the support member 5 can be thermally deformable between two configurations: a first configuration in which the second mechanical moving member 4 is in a coupled position; and a second configuration in which the second mechanical moving member 4 is in a locked position, such as... Figure 2 As shown in the image.

[0043] More specifically, the support 5 undergoes thermal deformation when its temperature exceeds a threshold temperature. Preferably, when the threshold temperature is exceeded, the support 5 deforms to the coupling position.

[0044] For this purpose, the support 5 includes a shape memory material. Such a material deforms above a threshold temperature and returns to its initial shape below that threshold temperature.

[0045] Different types of shape memory materials are possible.

[0046] For example, a copper-based alloy having the following components by weight can be used: • Cu is between 64.5% and 85%, Zn is between 9.5% and 25%, and Al is between 4.5% and 10%. • Cu is between 79.5% and 84%, Al is between 12.5% ​​and 14%, and Ni is between 2.5% and 6%. • Cu is between 87% and 88%, Al is between 11% and 12%, and Be is between 0.3% and 0.7%.

[0047] Gold-based alloys also exist, such as 50Au40Ti10Zr, 52Au47Ti1Zr, and 50Au45Ti3Zr2Nb, which have the following composition (e.g., in atomic percentage): • Gold with an atomic percentage of 46 to 55, • Titanium with an atomic percentage of 38 to 47, • Zirconium with an atomic percentage of 0.1 to 15, • Niobium with an atomic percentage of 0 to 5.

[0048] Nickel and titanium alloys (such as nitinol) or even plastics can also be used as shape memory materials for this support.

[0049] Therefore, if the temperature rises above the threshold temperature, the lever straightens and moves the second mechanical moving part 4 from the locked position to the coupled position, making it actuated by the first mechanical moving part 3, and thus by the main moving part 2. When the lever deforms, the ends 9 and 15 remain in substantially the same position. However, the curvature of the bent portion 7 of the lever decreases.

[0050] The curved portion 7 moves toward the first mechanical moving part 4.

[0051] The base 12 on plate 11 includes a flange 13 that forms a support for the second end 15 of the lever. The base 12 is designed to allow deformation of the lever. In this case, the shape of the base expands from the flange 13 for the second end 15. The bent portion 7, and therefore the second mechanical moving member 4, moves within the base 12 under the action of deformation.

[0052] When the temperature returns below the threshold temperature, the lever returns to its original shape with a more pronounced curvature. Thus, the second mechanical moving part 4 separates from the first mechanical moving part 3 again and can no longer be driven by the latter.

[0053] For example, the threshold temperature is included between 60°C and 80°C, preferably between 65°C and 75°C, or even substantially equal to 70°C. This temperature range is high enough to avoid undesirably triggering material deformation, for example, due to high external temperatures, but not so high as to avoid the risk of deterioration of components (e.g., oil) in the movement.

[0054] Alternatively, the threshold temperature can be selected within a negative temperature range, such as below -20°C.

[0055] As a variant, the selected material has two different threshold temperatures: a first threshold temperature for moving from the locked position to the coupled position, and a second threshold temperature for moving from the coupled position to the locked position.

[0056] To improve the transition between positions, especially to return to the locked position, the micromechanical device may include a return spring (not shown) to push the lever and thus the second mechanical moving part back to the locked position.

[0057] Figure 5 A portion of a setting mechanism driven by a thermo-actuated micromechanical device is shown. A third gear actuator 16 is mounted at the other end of the spindle 8 and engages with a cam actuator 17 including a cam 14. The cam 14 interacts with another part of the setting mechanism (not shown), which includes a contact rod shaft or a moving ratchet, and, for example, enables the setting of the rate. Thus, when the first actuator 3 is in the coupled position, the cam 4 is driven.

[0058] In a variant embodiment not shown in the figure, the cam movement is replaced by a movement equipped with an eccentric wheel. Such an eccentric wheel can engage with a setting mechanism that cooperates with the eccentric wheel.

[0059] A watch movement equipped with such a micromechanical device 1 can be fitted into a timepiece. For this purpose, the timepiece includes a case enclosed by a back cover.

[0060] For example, the back cover is transparent to allow laser radiation to penetrate and reach the watch movement, particularly the support structure of the micromechanical components. This laser radiation is configured to heat the micromechanical support structure, causing it to deform.

[0061] Of course, the present invention is not limited to the embodiments of the speed regulating mechanism described with reference to the accompanying drawings, and variations are conceivable without departing from the scope of the invention.

Claims

1. A thermally actuated micromechanical device (1) particularly for use in watch movements, the micromechanical device (1) comprising a mechanically actuable first movable member (3) and a mechanically actuable second movable member (4), the second movable member (4) being translatably movable relative to the first movable member (3) between a coupled position and a locked position, wherein in the coupled position the first movable member (3) is mechanically engaged with the second movable member (4) to actuate the second movable member (4), and in the locked position the second movable member (4) is not mechanically engaged with the first movable member (3), the micromechanical device (1) comprising a support member (5) on which the second movable member (4) is mounted, characterized in that, The support member (5) is thermally deformable to move the second movable member (4) from the locked position to the coupled position and / or vice versa.

2. The micromechanical device according to claim 1, characterized in that, The support (5) comprises at least partially, preferably entirely, a memory material that is thermally deformable when it exceeds a threshold temperature.

3. The micromechanical device according to claim 2, characterized in that, The threshold temperature is between 60°C and 80°C, preferably between 65°C and 75°C, or even substantially equal to 70°C.

4. The micromechanical device according to any one of the preceding claims, characterized in that, The support component (5) is a lever.

5. The micromechanical device according to claim 4, characterized in that, The lever includes a bent portion (7) that straightens to move the second movable member (4) from the locked position to the coupled position.

6. The micromechanical device according to claim 5, characterized in that, The second movable element (4) is arranged in the curved portion (7) of the lever or in the adjacent area of ​​the curved portion (7).

7. The micromechanical device according to any one of claims 4 to 6, characterized in that, The micromechanical device (1) includes a spindle (8) arranged perpendicular to the first end (9) of the lever to form a pivot around which the lever can rotate.

8. The micromechanical device according to any one of the preceding claims, characterized in that, The support member (5) includes a pinion (6) that meshes with the second moving member (4).

9. The micromechanical device according to any one of the preceding claims, characterized in that, The first moving part (3) and the second moving part (4) are gears.

10. The micromechanical device according to any one of the preceding claims, characterized in that, The micromechanical device includes a return spring for pushing the second movable element (4) back to the locked position.

11. A watch movement, characterized in that, The watch movement includes a micromechanical device (1) according to any one of the preceding claims.

12. The watch movement according to claim 11, characterized in that, The watch movement includes a plate (11) or rod with a base (12) for supporting the member (5).

13. The watch movement according to claim 12, when subordinate to claim 4, is characterized in that, The base (12) includes a flange (13) that forms a support for the second end (15) of the lever.

14. A timepiece comprising a watch movement according to any one of claims 11 to 13.

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