Spiral spring for a timepiece resonator movement provided with means for adjusting the stiffness

Abstract

The invention relates to a spiral hairspring, in particular for a timepiece resonator mechanism, comprising a flexible strip wound in several turns on itself, the strip having a predefined stiffness, the spiral hairspring comprising means for adjusting its stiffness, characterized in that the adjusting means comprise a first and a second elongated flexible element arranged in series with the strip, each elongated flexible element connecting a same end of the strip to a fixed support, so as to add an additional stiffness to the strip, each elongated flexible element preferably having a higher stiffness than the stiffness of the strip, the adjusting means comprising prestressing means for applying at least two different adjustable forces, the two forces being applied on the first elongated flexible element so as to vary the stiffness of the first elongated flexible element according to the level of prestressing. The invention also relates to a timepiece resonator mechanism comprising such a spiral hairspring.

Description

Technical Field

[0001] This invention relates to a ressort-spiral for a watch resonator mechanism, the ressort-spiral having means for setting the stiffness of the ressort-spiral. The invention also relates to a watch resonator mechanism having such a ressort-spiral. Background Technology

[0002] Most modern mechanical watches feature a balance wheel and a Swiss-style escapement. The balance wheel forms the watch's time base; it is also known as a resonator.

[0003] The escapement mechanism then performs two main functions:

[0004] - Maintain the reciprocating motion of the resonator;

[0005] - Count these reciprocating motions.

[0006] To form a mechanical resonator, an inertial element, a guide element, and a resilient return element are necessary. Traditionally, a spiral hairspring is used as the resilient return element for the inertial element formed by the balance wheel. The balance wheel is rotatably guided by a pivot that rotates in a sliding bearing made of ruby.

[0007] In general, the balance wheel and hairspring should be adjustable to improve the accuracy of the watch. For this purpose, devices are used to adjust the stiffness of the hairspring, such as indexes to modify the effective length of the hairspring. Thus, its stiffness is modified to adjust the watch's running accuracy. However, the effectiveness of conventional indexes for adjusting operation remains limited, and they are not always effective for setting sufficiently precise intervals within a few seconds or tens of seconds per day.

[0008] For more precise adjustment of the operation, there exists a device that includes one or more screws arranged on the rim of the balance wheel. By acting on the screws, the inertia of the balance wheel is modified, which results in a modification of the balance wheel's operation.

[0009] However, this setup method is not easy to implement because it disrupts the balance of the balance wheel and still does not allow for a sufficiently fine setting for the oscillator to operate. Summary of the Invention

[0010] The object of the present invention is to overcome all or part of the aforementioned disadvantages by providing a spiral hairspring with an effective and precise adjustment device, which is particularly configured to set the operation of the timepiece by modifying the effective stiffness of the spiral.

[0011] Therefore, the present invention relates to a spiral hairspring, particularly for use in a watch resonator mechanism, the spiral hairspring comprising a flexible strip wound several times on itself, the strip having a predetermined stiffness, and the spiral hairspring including means for adjusting its stiffness.

[0012] The significant feature of this invention is that the adjustment device includes a first elongated flexible element and a second elongated flexible element, each arranged in series with the strip, each elongated flexible element connecting the same end of the strip to a fixed support to add additional stiffness to the strip. Each elongated flexible element preferably has a stiffness higher than that of the strip. The adjustment device includes a prestressing device for applying at least two different adjustable forces applied to the first elongated flexible element to cause the stiffness of the first elongated flexible element to vary according to the prestress level.

[0013] Because of this invention, the stiffness of at least one of elongated flexible elements (such as flexible blades) can be modified. In fact, the stiffness of the elongated flexible element changes when two forces, such as those mentioned above, are applied. In fact, the stiffness of the elongated flexible element remains the same by a single applied force, whether it is a force or a torque. A total force is obtained by two perpendicular forces (longitudinal and orthogonal) on a blade, which causes the stiffness of the elongated flexible element to change. The combination of the two forces is necessary for this effect.

[0014] By acting on the prestressing device, the intensity level of the load is adjusted, which leads to a modification of the stiffness of the group comprising the flexible element and the strip. In fact, the flexible element, arranged in series with the strip, provides additional stiffness, which, combined with the stiffness of the strip, adds to the overall stiffness. Therefore, when the prestressing device applies a variable force to at least one of the elongated flexible elements, it modifies the stiffness of the flexible element, and thus modifies the stiffness of the group comprising the strip and the flexible element without modifying the stiffness of the strip, even though the variable force is applied to the elongated flexible element.

[0015] In other words, a flexible element is placed in series with the strip between one end of the strip and a fixed support. This flexible element introduces adjustable additional stiffness between the strip and its attachment points, and imparts greater flexibility to the resonator. Therefore, the effective stiffness of the resonator includes the stiffness of the strip and the stiffness of the flexible element. A variable force is applied to prestress the flexible element, but not the strip. By applying prestress to the flexible element, its stiffness changes, while the stiffness of the strip remains essentially constant. By changing the stiffness of the flexible element, the stiffness of the resonator (both the stiffness of the strip and the flexible element) changes, thus modifying the operation of the resonator.

[0016] Therefore, modifying the stiffness of the flexible element modifies the stiffness of the entire resonator, and thus finely sets its operation, allowing for precise adjustment of the frequency of our time base. This results in high accuracy in operating settings, achieved by precisely adjusting the stiffness of the spiral spring through a single, additional element.

[0017] According to a specific embodiment of the invention, the first force is a first tensile / compressive force F substantially oriented in the longitudinal direction of the first elongated flexible element. L Provide (fournir).

[0018] According to a specific embodiment of the invention, the first force further applies a first force F in a direction substantially orthogonal to the longitudinal direction of the second elongated flexible element. T .

[0019] According to a specific embodiment of the invention, the second force is a second force F that is substantially orthogonal to the longitudinal direction of the first elongated flexible element. T supply.

[0020] According to a specific embodiment of the invention, the second force further applies a second tensile / compressive force F, substantially oriented in the longitudinal direction of the second elongated flexible element. L .

[0021] According to a specific embodiment of the invention, each of the first and second elongated flexible elements includes a unique flexible blade.

[0022] According to a specific embodiment of the invention, each of the first and second elongated flexible elements includes a pair of main flexible blades.

[0023] According to a specific embodiment of the invention, the first flexible element is arranged in the radial direction of the spiral hairspring.

[0024] According to a specific embodiment of the invention, the second flexible element is arranged in a direction tangential to the spiral hairspring.

[0025] According to a specific embodiment of the invention, the first and second elongated flexible elements are substantially perpendicular to each other.

[0026] According to a specific embodiment of the invention, the prestressing device includes two secondary flexible blades connected at the ends, each secondary flexible blade being arranged in an extension of one of the elongated flexible elements.

[0027] According to a specific embodiment of the present invention, the prestressing device includes two rigid bodies, each rigid body being disposed at the end of each secondary flexible blade.

[0028] According to a specific embodiment of the invention, the prestressing device includes a variable support device on each rigid body.

[0029] According to a specific embodiment of the present invention, the force is continuously adjustable via a prestressing device.

[0030] According to a specific embodiment of the present invention, a first flexible element and a second flexible element are arranged at the outer end of the strip.

[0031] According to a specific embodiment of the invention, the end of the strip includes an attachment to which a prestressing device and an elongated flexible element are attached.

[0032] According to a specific embodiment of the invention, the ends of the strip are more rigid than elongated flexible elements and strips.

[0033] According to a specific embodiment of the present invention, the elongated flexible element includes a flexible neck.

[0034] According to a specific embodiment of the invention, the prestressing device is configured such that the two forces can be adjusted with different intensities.

[0035] The present invention also relates to a rotating resonator mechanism, particularly for use in watch movements, comprising a balance wheel and a spiral hairspring. Attached Figure Description

[0036] The objects, advantages, and features of the invention will become apparent from the accompanying drawings and from reading several embodiments provided by way of non-limiting example only, wherein:

[0037] - Figure 1 A schematic top view of a spiral hairspring according to a first embodiment of the present invention is shown, and

[0038] - Figure 2 A top view of a spiral hairspring according to a second embodiment of the present invention is shown schematically. Detailed Implementation

[0039] Figure 1 and Figure 2 Each of the figures illustrates a schematic diagram of a different embodiment of the spiral hairspring 1, 10, which is particularly useful in watch resonator mechanisms. In this example, the spiral hairspring extends substantially in the same plane. The spiral hairspring 1, 10 includes a flexible strip 2 wound several times on itself, the strip 2 having a predetermined stiffness. The spiral hairspring 1, 10 includes means for adjusting its stiffness. For example, the adjusting means can be actuated when the spiral hairspring 1, 10 is mounted on a plate of a watch movement (not shown).

[0040] According to the present invention, the adjusting device includes a first elongated flexible element 5 and a second elongated flexible element 15 extending longitudinally. Each flexible element 5, 15 is arranged in series with the strip 2, and the first flexible element 5 and the second flexible element 15 connect the same end 4 of the strip 2 to the fixed supports 11, 14. In other words, the strip 2 is connected to the fixed supports 11, 14 only by these flexible elements 5, 15.

[0041] Flexible elements 5 and 15 are fixed to one of the ends 4 of the strip 2. Preferably, the two flexible elements 5 and 15 are arranged perpendicular to each other.

[0042] The embodiments described below include flexible elements 5 and 15 fixed to the outer end 4 of the strip 2. The inner end 19 of the strip 2 is intended to be assembled to the support 3 of the pendulum hammer of the resonator 1.

[0043] The flexible elements 5 and 15 add additional stiffness to the strip 2. Preferably, the flexible elements 5 and 15 have a greater stiffness than the strip 2. The first flexible element 5 is arranged in the extension of the strip 2, while the second flexible element 15 is arranged perpendicular to the first flexible element 5. Preferably, the adjusting device and the strip 2 are made as one piece and can be formed from the same material.

[0044] Furthermore, the outer end 4 of the strip 2 is bent vertically to form the attachment 9. The attachment 9 serves as an attachment point and allows for the reception of forces. Preferably, the attachment 9 is substantially rigid, i.e., at least more rigid than the strip 2 and / or the elongated flexible elements 5, 15, in order to minimize its influence on the stiffness of the strip 2.

[0045] In the first embodiment, each elongated flexible element 5, 15 is a unique flexible blade 13, 15 that connects the appendix 9 to the fixed support 11. A unique first flexible blade 13 is arranged in the extension of the appendix 9, while a unique second flexible blade 13 is arranged in a direction substantially perpendicular to the appendix 9.

[0046] Therefore, in the resting position of the spiral hairspring 1, the unique first flexible blade 13 is arranged in a radial direction, preferably through the center of the spiral hairspring 1, while the second flexible blade is arranged in a direction tangential to the strip 2.

[0047] exist Figure 2 In the second embodiment, each elongated flexible element 5, 15 includes a pair of main blades 23, 25 extending from the appendix 9 to the fixed support 11. The main blades 23, 25 in each pair are offset from each other from the appendix 9 to the fixed support 11 and form an angle between each other, for example, between 10° and 40°.

[0048] The spiral hairspring 1 also includes a prestressing device 6 for applying at least two different forces to at least one of the flexible elements 5 and 15 (preferably both flexible elements 5 and 15). For example, the two forces are provided on the first flexible element 5.

[0049] Preferably, the two forces are a tensile-compressive longitudinal force F. L and normal force F T These forces are variable. Longitudinal force F L Oriented according to the longitudinal direction of the first flexible element 5, and the orthogonal force F T Oriented perpendicular to the longitudinal direction of the first flexible element 5, the two forces preferably belong to the plane of the spiral hairsprings 1 and 10. Therefore, the stiffness of the first flexible element 5 can be modified, and thus the operation of the spiral hairsprings 1 and 10 can be adjusted, especially to improve the operating accuracy of the movement.

[0050] The action modifies the stiffness of the first flexible element 5, rather than acting directly on the strip 2. However, the end 4 of the strip 2 may be movable during oscillation.

[0051] In addition, longitudinal force F L and normal force F T It can be continuously adjusted via the prestressing device 6. In other words, the force F L and F T It is not limited to discrete values. Therefore, the stiffness of the flexible element 5 can be precisely adjusted with high accuracy.

[0052] In addition, the prestressing device 6 is configured to modify the stiffness of the second flexible element 15.

[0053] In fact, the first force also applies a first force that is substantially orthogonal to the longitudinal direction of the second elongated flexible element 15. Since the two flexible elements 5 and 15 are arranged perpendicular to each other, the longitudinal force applied to one of the elongated flexible elements 5 and 15 generates a substantially orthogonal force applied to the other flexible element.

[0054] Similarly, the second force also applies a second tensile / compressive force that is substantially oriented in the longitudinal direction of the second elongated flexible element 15.

[0055] In order to apply these adjustable forces, the prestressing device 6 includes two devices for applying forces to the elongated flexible elements 5, 15.

[0056] Each of the application devices includes two secondary flexible blades 12, 13. Each secondary flexible blade 12, 13 is arranged in the extension of the elongated flexible element 5, 15 and is fastened to the other side of the attachment 9.

[0057] The two secondary flexible blades 12 and 13 are arranged perpendicular to each other.

[0058] Alternatively, secondary blades 12 and 13 can be replaced by conventional springs.

[0059] Each secondary flexible blade 12, 13 has a rigid body 14, 16 at its free end. The rigid body 14, 16 allows for the application of variable forces on the secondary flexible bodies 12, 13 to adjust the forces transmitted to the elongated flexible elements 5, 15.

[0060] By moving rigid bodies 14 and 16, the variable longitudinal force F varies according to each direction of movement of each rigid body 19 and 21. L and variable orthogonal force F T It is applied to the auxiliary part 9. Therefore, the stiffness of the elongated flexible elements 5 and 15 is modified. By moving the rigid bodies 19 and 21, the value of the force applied to the unique flexible blade 15 is modified.

[0061] The prestressing device 6 also includes a variable support device on the rigid bodies 14 and 16. By actuating the support device, the rigid bodies 14 and 16 move, causing the secondary flexible blades 12 and 13 to bend more or less, and thus transmitting substantial forces of varying magnitudes on the elongated flexible elements 5 and 15. Therefore, the rigidity of the elongated flexible elements 5 and 15 is modified, thereby modifying the operation of the spiral spring, and this can be adjusted.

[0062] For example, the variable support device includes screws 24 that contact the rigid bodies 14, 16, and the screws 24 are arranged longitudinally according to the direction of the secondary flexible blades 12, 13. Therefore, by moving the screws 24, the secondary flexible blades 12, 13 apply substantial forces of varying magnitudes to the appendages 9, and thus apply substantial forces of varying magnitudes to the elongated flexible elements 5, 15.

[0063] Alternatively, the variable support device includes a spring fastened to a rigid body on one side and a movable body disposed at the other end of the spring. Thus, by moving the movable body, the spring applies a substantial force, large or small, to the secondary flexible blades.

[0064] In another variation, the prestressing device includes a first magnet disposed on a rigid body and a movable second magnet disposed at a distance from the rigid body. Therefore, by modifying the distance of the second magnet relative to the first magnet, the force applied to the secondary flexible blade is modified.

[0065] Alternatively, a pivot rod can be used, which is assembled to a rigid body at a first end and has a free end that serves as a means for actuating the rod by moving the free end.

[0066] Preferably, the prestressing device is configured to allow adjustment of two forces, in this case, two longitudinal tensile / compressive forces of different intensities. Therefore, the first application device allows for adjustment within a wider setting range, and the second application device allows for adjustment within a finer setting range.

[0067] For this purpose, for example, the secondary flexible blades 12 and 13 have different cross sections or lengths. Alternatively, the variable support devices on the rigid bodies 14 and 16 are configured to achieve different setting ranges, for example, different pitches.

[0068] The present invention also relates to watch movements that include such spiral hairsprings. In particular, the spiral hairspring is used to actuate the movement of the balance wheel.

[0069] Of course, the present invention is not limited to the embodiments described with reference to the accompanying drawings, and variations may be considered without departing from the scope of the invention.

[0070] As for the longitudinal elements, the flexible blades described in different embodiments of the spiral hairspring can be continuous flexible blades, as generally seen in the figures; or blades having a rigid section and a flexible neck connecting that section.

[0071] Furthermore, the unique flexible blades can be oriented in directions other than radial and orthogonal relative to the spiral spring. Therefore, it can be oriented in any direction, including both radial and orthogonal directions.

Claims

1. A spiral hairspring, said spiral hairspring (1, 10) comprising a flexible strip (2) wound several turns thereon, said strip (2) having a predetermined stiffness, said spiral hairspring (1, 10) comprising means for adjusting its stiffness, characterized in that, The adjustment device includes a first elongated flexible element (5) and a second elongated flexible element (15) arranged in series with the strip (2), each elongated flexible element (5, 15) connecting the same end (4, 9) of the strip (2) to a fixed support (11, 14) to add additional stiffness to the strip (2), the adjustment device including a prestressing device for applying at least two different adjustable forces applied to the first elongated flexible element (5) to cause the stiffness of the first elongated flexible element (5) to vary according to the prestress level.

2. The spiral hairspring according to claim 1, characterized in that, The first force is a first tensile / compressive force that is substantially oriented in the longitudinal direction of the first elongated flexible element (5). F L supply.

3. The spiral hairspring according to claim 1, characterized in that, The first force also applies a first force that is substantially orthogonal to the longitudinal direction of the second elongated flexible element (15).

4. The spiral hairspring according to any one of claims 1 to 3, characterized in that, The second force is a second force that is substantially orthogonal to the longitudinal direction of the first elongated flexible element (5). F T supply.

5. The spiral hairspring according to claim 4, characterized in that, The second force also applies a second tensile / compressive force that is substantially oriented in the longitudinal direction of the second elongated flexible element (15).

6. The spiral hairspring according to any one of claims 1 to 3, characterized in that, Each of the first elongated flexible element (5) and the second elongated flexible element (15) includes unique flexible blades (13, 18).

7. The spiral hairspring according to any one of claims 1 to 3, characterized in that, Each of the first elongated flexible element (5) and the second elongated flexible element (15) includes a pair of main flexible blades (23, 25).

8. The spiral hairspring according to any one of claims 1 to 3, characterized in that, The first elongated flexible element (5) and the second elongated flexible element (15) are substantially perpendicular to each other.

9. The spiral hairspring according to any one of claims 1 to 3, characterized in that, The first elongated flexible element (5) is arranged in the radial direction of the spiral hairspring (1, 10).

10. The spiral hairspring according to any one of claims 1 to 3, characterized in that, The second elongated flexible element (15) is arranged in a direction tangential to the spiral hairspring (1, 10).

11. The spiral hairspring according to any one of claims 1 to 3, characterized in that, The prestressing device (6) includes two secondary flexible blades (12, 13) connected at the end (4), each secondary flexible blade (12, 13) being arranged in an extension of one of the elongated flexible elements (5, 15).

12. The spiral hairspring according to claim 11, characterized in that, The prestressed device (6) includes two rigid bodies (14, 16), each of which is arranged at the end of each secondary flexible blade (12, 13).

13. The spiral hairspring according to claim 12, characterized in that, The prestressing device (6) includes a variable support device on each rigid body (14, 16).

14. The spiral hairspring according to any one of claims 1 to 3, characterized in that, The applied force is continuously adjustable via the prestressing device (6).

15. The spiral hairspring according to any one of claims 1 to 3, characterized in that, The first elongated flexible element (5) and the second elongated flexible element (15) are arranged at the outer end (4) of the strip (2).

16. The spiral hairspring according to any one of claims 1 to 3, characterized in that, The prestressing device (6) is configured to adjust the two forces at different intensities.

17. The spiral hairspring according to any one of claims 1 to 3, characterized in that, The spiral hairspring is used in the clock resonator mechanism.

18. The spiral hairspring according to any one of claims 1 to 3, characterized in that, Each elongated flexible element (5) has a higher stiffness than the strip (2).

19. A rotary resonator mechanism, the rotary resonator mechanism comprising a pendulum hammer, wherein, The rotary resonator mechanism includes a spiral hairspring (1, 10) according to any one of the preceding claims.

20. The rotary resonator mechanism according to claim 19, characterized in that, The rotary resonator mechanism is used in watch movements.

Images