Timepiece regulating organ with hairspring-spring provided with pressure compensation means

Abstract

The invention relates to a regulating organ (1) for a clockwork movement comprising an oscillating mass (19), for example a balance wheel, a balance spring comprising a flexible ribbon (2) wound upon itself in several turns, the ribbon (2) having a predefined stiffness to allow the oscillating mass to perform a rotary oscillatory motion, the ribbon (2) comprising an external end (9) of the ribbon (2), the regulating organ (1) comprising an elastic compensating device (50) for external pressure, connecting the external end (9) to a first support fixed (7) relative to the clockwork movement, the elastic compensating device (50) being configured to adapt its stiffness according to the external pressure in order to compensate for the effect of the external pressure on the regulating organ (1). The invention also relates to a clockwork movement comprising such a regulating organ (1).

Description

Technical field of the invention

[0001] The invention relates to a regulating organ with a spiral spring equipped with pressure compensation means. The invention also relates to a clockwork movement comprising such a regulating organ. Technological background

[0002] Most modern mechanical watches are equipped with a balance wheel and hairspring, and a Swiss lever escapement mechanism. The balance wheel and hairspring form the watch's timekeeping base. It is also called the resonator or regulating organ.

[0003] The exhaust system, for its part, fulfills two main functions: maintain the back-and-forth movement of the resonator, count these back-and-forth movements.

[0004] To create a regulating organ, one needs an inertial element, a guide, and an elastic return element. Traditionally, a balance spring acts as the elastic return element for the inertial element, which is a balance wheel. This balance wheel is guided in rotation by pivots, which generally rotate in ruby ​​plain bearings.

[0005] A frequency is chosen for the mechanical resonator, which is determined to obtain a predefined rate for the clockwork movement.

[0006] However, during its operation, such a mechanical resonator can be subject to disturbances caused by changes in external parameters, which generate variations in the resonator's frequency. These parameters include, for example, temperature, pressure, humidity, and gravity. The resulting frequency variation in the resonator leads to an error in time measurement and therefore in the accuracy of the clockwork mechanism.

[0007] For example, document CH 704687 describes a regulating element comprising a spiral spring and a pin position correction element to correct spiral spring deformations due to temperature.

[0008] Document EP4009115 A1 describes a balance spring for a resonator clock mechanism, the balance spring being provided with means for adjusting the stiffness of said balance spring.

[0009] Currently, there are no regulating devices equipped with compensation mechanisms designed to offset variations in ambient pressure. Therefore, when pressure changes, for example due to altitude, the regulating device loses precision because the pressure difference alters its aerodynamic friction. For instance, an increase in pressure leads to a decrease in the regulating device's oscillation frequency. Summary of the invention

[0010] The aim of the present invention is to overcome all or part of the aforementioned disadvantages by proposing a spring-spring clock regulating organ equipped with pressure compensation means, which are precise and adapted to a spring-spring.

[0011] For this purpose, the invention relates to a regulating organ for a clock movement comprising an oscillating mass, for example a balance wheel, a balance spring comprising a flexible ribbon wound on itself in several turns, the ribbon having a predefined rigidity to allow the oscillating mass to perform a rotary oscillatory movement, the ribbon comprising an external end.

[0012] The invention is remarkable in that the regulating member includes an elastic device for compensating for external pressure, connecting the outer end of the ribbon to a first support that is stationary relative to the clockwork movement, the elastic compensating device being configured to adapt its stiffness according to the external pressure in order to compensate for the effect of the external pressure on the regulating member.

[0013] Thanks to the invention, the preload means exert a variable force or torque on the elastic element of the elastic compensation device as a function of pressure, so that the regulating member maintains substantially precise operation despite significant pressure changes. Indeed, when the pressure changes, the preload means modify the force or torque exerted on the elastic element, thereby changing the stiffness of the assembly comprising the elastic element and the spiral spring. By modifying the stiffness of this assembly, the operation of the regulating member is adjusted. Consequently, when the pressure changes, the elastic device is mechanically impacted to adjust the operation of the spiral spring to this change.

[0014] This elastic element modifies the stiffness of the attachment point and provides additional flexibility to the resonator. Thus, the effective stiffness of the resonator comprises the stiffness of the ribbon and the stiffness of the elastic element. The variable force or torque allows the elastic element to be pre-stressed, preferably without pre-stressing the ribbon and without moving the ribbon end. By pre-stressing the elastic element, its stiffness changes, while the stiffness of the ribbon remains unchanged, since it is not pre-stressed and its end does not move.

[0015] By changing the flexibility of the elastic element, the rigidity of the resonator (ribbon rigidity and elastic element rigidity) changes, which in turn alters the resonator's behavior. Since the elastic element is preferably more rigid than the ribbon, its contribution to the overall flexibility is less than that of the ribbon. Therefore, changing the elastic element's rigidity modifies the rigidity of the entire resonator, thus fine-tuning its behavior and allowing for precise adjustment of our timebase frequency. This results in high accuracy in maintaining the resonator's behavior as a function of pressure.

[0016] According to the invention, the elastic compensation device comprises an elastic element arranged between the outer end of the ribbon and the stationary support, as well as pre-stressing means to apply a variable force or torque to the elastic element as a function of the external pressure.

[0017] According to a particular embodiment of the invention, the prestressing means comprise a spring part connected to the elastic element, the spring part transmitting the force or torque to the elastic element.

[0018] According to the invention, the prestressing means comprise an aneroid capsule whose volume varies according to the external pressure, so as to transmit a force or torque that varies according to the external pressure.

[0019] According to a particular embodiment of the invention, the aneroid capsule comprises a movable wall and a fixed wall connected by at least one spring.

[0020] According to a particular embodiment of the invention, the spring part comprises a first flexible blade connected to the elastic element.

[0021] According to a particular embodiment of the invention, the spring part comprises a translation table connected to the first flexible blade, the aneroid capsule being in contact with the translation table.

[0022] According to a particular embodiment of the invention, the elastic part comprises a first movable element connected to the first flexible blade, and a second movable element, the first movable element and the second movable element being connected by a pair of parallel flexible blades.

[0023] According to a particular embodiment of the invention, the spring part comprises a second flexible blade connecting the second moving element to the aneroid capsule.

[0024] According to a particular embodiment of the invention, the elastic element comprises a suspended point body and a pair of uncrossed blades connecting the suspended point body to the first stationary support.

[0025] According to a particular embodiment of the invention, the prestressing means are connected to the suspended point body to exert the force or torque on the suspended point body.

[0026] According to a particular embodiment of the invention, the regulating member includes means for adjusting the prestressing means to apply a variable force on the prestressing means, for example on the first elongated moving element.

[0027] According to a particular embodiment of the invention, the regulating organ extends substantially in the same plane, except for the oscillating mass.

[0028] The invention also relates to a clock movement comprising such a regulating organ. Brief description of the figures

[0029] 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 1 schematically represents a top cross-sectional view of a first embodiment of a regulating device equipped with pressure compensation means, and the figure 2 schematically represents a top cross-sectional view of a second embodiment of a regulating organ equipped with pressure compensation means. Detailed description of the invention

[0030] THE figures 1 and 2each represent an embodiment of a regulating organ 1, 10 according to the invention, the regulating organ 1, 10 comprising an elastic device 50 configured to compensate for a variation of pressure exerted on the regulating organ 1, 10. Such regulating organs 1, 10 are intended to be arranged in a clockwork movement to regulate it.

[0031] In these embodiments, the regulating member 1, 10 comprises a spiral spring equipped with a flexible ribbon 2 wound upon itself in several turns. The flexible ribbon 2 comprises an outer end 9 and an inner end 8.

[0032] The regulating organ 1, 10 comprises an oscillating mass, for example an annular balance wheel (not shown in the figures), which is connected to the inner end 8 of the ribbon 2. The ribbon 2 has a predefined rigidity to allow the oscillating mass to perform a rotary oscillatory motion. For example, the oscillating mass comprises an axial rotation shaft, the inner end 8 of the ribbon 2 being connected to said shaft.

[0033] Preferably, the regulating organ 1, 10 extends substantially in the same plane, except for the oscillating mass, which oscillates in a parallel plane, above the spiral spring.

[0034] According to the invention, the regulating member 1, 10 comprises an elastic device 50 for compensating an external parameter configured to adapt the stiffness of the elastic element 5 according to the pressure in order to compensate for the effect of the pressure on the regulating member 1, 10.

[0035] The elastic compensation device 50 is configured to adapt its stiffness according to variations in ambient pressure in order to compensate for the effect of these variations on the spiral spring. The elastic compensation device 50 preferably has a stiffness greater than that of ribbon 2.

[0036] The elastic device 50 includes an elastic element 5 connecting the outer end 9 of the ribbon 2 to a stationary support 7 relative to the clockwork mechanism, for example, to a fixed plate. The elastic device 50 further includes preload means 6 for applying a variable force or torque to the elastic element 5 depending on the external parameter.

[0037] The elastic element 5 here comprises a suspended point body 3 and a pair of uncrossed blades 4 connecting the suspended point body 3 to the stationary support 7. The suspended point body 3 is for example a cylindrical body of height substantially equal to the diameter, the uncrossed blades 4 spreading apart from the suspended point body 3 to the stationary support 7.

[0038] The elastic element 5 is arranged in the extension of the flexible ribbon 2, the spiral spring and the elastic element 5 being adjacent, but avoiding contact during the oscillation of the oscillating mass.

[0039] The prestressing means 6 are configured to exert the force or torque on the suspended point body 3. Thus, the stiffness of the elastic element is modified, because the prestressing means 6 modify the stiffness of the uncrossed blades 4.

[0040] The prestressing means 6 include a spring part equipped with a single flexible blade 11 connected to the suspended point body 3. The single flexible blade 11 extends along the axis of the elastic element, tangentially to the spiral spring, and is slightly offset from the outer end 9.

[0041] The spring part is further configured to undergo a variable force or torque, which is transmitted to the elastic element 5.

[0042] In the first embodiment of the figure 1The spring portion of the prestressing means 6 comprises a translation table 33 equipped with a first movable L-shaped element 12 and a second fixed support 18 relative to the movement. The first movable element 12 is connected to the single flexible blade 11 by one end of a first arm of the L. The second arm of the L has a rounded protrusion 53 on its outer side. The translation table 33 comprises two substantially parallel flexible blades 14 connecting the first movable element 12 to the second fixed support 18.

[0043] To transmit a force or torque that varies according to the external pressure to the spring part, the prestressing means 6 include an aneroid capsule.

[0044] Such a capsule is generally used to measure atmospheric pressure. For this purpose, the capsule includes a space that is at least partially evacuated of air, and incorporates a spring-like elastic element within this space to retain a movable wall of the capsule. Thus, when the external pressure increases, the capsule is compressed, and when the external pressure decreases, the capsule expands.

[0045] On the figure 1 The aneroid capsule comprises a variable volume depending on the external pressure.

[0046] For this purpose, the aneroid capsule comprises a movable wall 13 and a fixed wall 15. A sealed enclosure, not shown in the figures, allows at least part of the vacuum to be established inside the movable wall 13 and fixed wall 15.

[0047] The stationary wall 15 is stationary relative to the movement, and is, for example, attached to a fixed plate or plate bridge. The stationary wall 15 is here schematically represented as a parallelepiped.

[0048] The movable wall 13 also has a schematic parallelepiped shape, the movable wall 13 being arranged opposite the fixed wall 15.

[0049] The aneroid capsule further includes a spring 16 connecting the movable wall 13 and the stationary wall 15, which form the elastic restoring element of the aneroid capsule. The spring 16 is arranged between the movable wall 13 and the stationary wall 15.

[0050] Depending on the pressure exerted on the movable wall 13, the spring 16 extends, particularly when the pressure decreases, or contracts, particularly when the pressure increases. Thus, it moves the movable wall 13 closer to or further from the stationary wall 15.

[0051] The spring part of the prestressing means 6 is connected to the aneroid capsule, the spring part transmitting the force or torque from the aneroid capsule to the point body 3 of the elastic element 5.

[0052] The translation table 33 has the function of transforming the distance of the capsule into a constraint force for the point body 3.

[0053] When the pressure changes, the movable wall 13 moves closer to or further from the fixed wall 15. Thus, the movable element 12 of the translation table 33 experiences a more or less significant pushing force towards the elastic element 5, this force being transmitted to the point body 3 via the single flexible blade 11.

[0054] The prestressing means 6 exert a variable thrust force on the elastic element 5. As a result, the stiffness of the elastic element 5 varies, and allows the rocker arm to be adapted to the external pressure conditions to maintain the accuracy of the regulating organ.

[0055] For example, when the pressure increases, the moving wall 13 moves closer to the stationary wall 15. This approach results in a decrease in the thrust force on the point body 3, which is exerted by the prestressing means 6. Thus, the stiffness of the elastic element 5 is increased.

[0056] On the contrary, when the pressure decreases, the movable wall 13 moves away from the fixed wall 15. This separation generates an increase in the thrust force on the point body 3, which is exerted by the prestressing means 6. Thus, the stiffness of the elastic element 5 is reduced.

[0057] In the second embodiment, the regulating member 10 comprises a spiral spring, an oscillating mass (not shown in the figure), an elastic element 5, and a first flexible blade 11 identical to the first embodiment.

[0058] To exert force or torque on the elastic element 5, the spring part of the prestressing means 6 includes a first elongated movable element 22, connected to the flexible blade 11 and arranged in its extension.

[0059] The spring part comprises a first pair of parallel flexible blades 25 arranged on the same side, and connects the first moving element 22 to a second moving element 28.

[0060] The second mobile element 28 is connected laterally to an aneroid capsule 15 by a second flexible blade 21 substantially parallel to the first mobile element 22 in the rest position of the regulating organ 10.

[0061] A second pair of parallel flexible blades 26 connects the second moving element 28 to a third stationary element 27 relative to the clockwork mechanism. The second pair of parallel flexible blades 26 and the third stationary element 27 are arranged in series with the second pair of parallel flexible blades 25 and the second moving element 28. The third stationary element 27 is, for example, attached to a fixed plate.

[0062] Adjustment means, such as a screw, can be added to exert a force 59 on the first moving element 22. By increasing the force 59, the displacement of the aneroid capsule is transmitted less strongly to the first moving element 22, while by decreasing the force, the displacement of the aneroid capsule is transmitted more strongly to the first moving element 22. The adjustment means allow the sensitivity of the preload means 6 to pressure to be adjusted.

[0063] Thus, when the movable wall 13 moves away from or towards the fixed wall 15, the second flexible blade 21 transmits a displacement to the second movable element 28, which transmits it to the first movable element 22 via the second pair of parallel flexible blades 25. The first movable element 22 is guided by the first translation table 33 to transmit the force or torque to the elastic element 5 through the first flexible blade 11.

[0064] Similar to the first embodiment, the pressure variation will cause a variation in the volume of the aneroid capsule 15, and therefore a modification of the stiffness of the elastic element 5 and of the operation of the regulating organ 10.

[0065] The invention also relates to a clockwork movement, not shown in the figures, the movement comprising a rotating regulating organ 1, 10 as described previously.

[0066] Naturally, the invention is not limited to the embodiments described with reference to the figures, and variants could be envisaged without departing from the scope of the invention as defined by the attached claims.

Claims

1. A regulating organ (1, 10) for a horological movement comprising an oscillating mass (19), for example a balance, a balance spring comprising a flexible strip (2) wound upon itself in several coils, the strip (2) having a predetermined stiffness to enable the oscillating mass to make a rotating oscillatory movement, the strip (2) comprising an outer end (9), the regulating organ (1, 10) comprising a resilient device (50) for compensating for the external pressure, connecting the outer end (9) of the strip (2) to a first support (7) that is immobile relative to the horological movement, the resilient compensation device (50) being configured to adapt its stiffness according to the external pressure in order to compensate for the effect of the external pressure on the regulating organ (1, 10), the resilient compensation device (50) comprising a resilient element (5) arranged between the outer end (9) of the strip (2) and the immobile support (7), as well as pre-tensioning means (6) for applying a variable force or couple to the resilient element (5) according to the external pressure, characterised in that the pre-tensioning means (6) comprise an aneroid capsule with a volume that varies according to the external pressure, so as to transmit a force or couple that varies according to the external pressure.

2. A regulating organ according to claim 1, characterised in that the aneroid capsule comprises a mobile wall (13) and an immobile wall (15) connected by at least one spring (16).

3. The regulating organ according to claim 1 or 2, characterised in that the pre-tensioning means (6) comprise a spring part connected to the resilient element (5), the spring part transmitting the force or couple to the resilient element (5).

4. The regulating organ according to claim 3, characterised in that the spring part comprises a first flexible blade (11) connected to the resilient element (5).

5. The regulating organ according to claim 4, characterised in that the spring part comprises a translation table (33) connected to the first flexible blade (11), the aneroid capsule being in contact with the translation table (33).

6. The regulating organ according to claim 4, characterised in that the resilient part comprises a first elongated mobile element (22) connected to the first flexible blade (11), and a second mobile element (28), the first elongated mobile element (22) and the second mobile element (28) being connected by a pair of parallel flexible blades (25).

7. The regulating organ according to claim 6, characterised in that the spring part comprises a second flexible blade (21) connecting the second mobile element (28) to the aneroid capsule.

8. The regulating organ according to any of the preceding claims, characterised in that the resilient element (5) comprises a suspended point mass (3) and a pair of uncrossed blades (4) connecting the suspended point mass (3) to the first immobile support (7).

9. The regulating organ according to claim 8, characterised in that the pre-tensioning means (6) are connected to the suspended point mass (3) to exert the force or couple on the suspended point mass (3).

10. The regulating organ according to claim 6 or 7, characterised in that it comprises means for setting the pre-tensioning means (6) in order to apply a variable force (49, 59) to the pre-tensioning means (6), for example to the first elongated mobile element (22).

11. The regulating organ according to any of the preceding claims, characterised in that the regulating organ (1, 10) extends substantially in the same plane, except for the oscillating mass.

12. A horological movement comprising a regulating organ (1, 10) according to any of the preceding claims.

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