Adjusting element of a timepiece with hairspring provided with gravity compensation means

Abstract

The invention relates to a regulating organ (10) for a clockwork movement comprising an oscillating mass, for example a balance wheel, a balance spring comprising a flexible ribbon (2) wound on itself in several turns, the ribbon (2) having a predefined rigidity to allow the oscillating mass to perform a rotary oscillatory movement, the ribbon (2) comprising an external end (9), characterized in that the regulating organ (10) comprises an elastic device for compensating the direction of gravity with respect to the regulating organ (10), the elastic device being configured to adapt its stiffness according to gravity in order to compensate for the effect of gravity on the regulating organ (10), the elastic device comprising an elastic element (5) connecting the external end (9) to a first support fixed (7) with respect to the clockwork movement,as well as preload means (6) for applying a variable force or torque to the elastic element (5) depending on the direction of gravity relative to the regulating member (10). The invention also relates to a clockwork movement comprising such a regulating member (1).

Description

Technical field of the invention

[0001] The invention relates to a clockwork regulating organ with a spiral spring equipped with gravity compensation means. Technological background

[0002] Most modern mechanical watches feature 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: to maintain the back-and-forth movement of the resonator: to count these back-and-forth movements.

[0004] To construct a mechanical resonator, 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] In watchmaking, several state-of-the-art documents describe regulating organs that take into account the effect of the direction of gravity on the regulating organ. Thus, by choosing a predetermined frequency and adjusting the balance wheel's imbalance, the effect of the direction of gravity on the regulating organ can be minimized.

[0008] However, these adjustments do not sufficiently reduce the effect of gravity on the regulating organ. Therefore, very high precision of the regulating organ cannot be achieved due to gravity.

[0009] On the other hand, there are known complications involving regulating organs such as tourbillons or carousels, which rotate the regulating organ around a central axis at one or two revolutions per minute to compensate for the effects of gravity. However, such complications are only effective when the timepiece remains in a stable position. When the direction of gravity relative to the regulating organ changes rapidly, the rotation of the regulating organ is not fast enough to compensate.

[0010] Document CH 718 191 A2 discloses means for adjusting the stiffness of a spiral spring comprising a flexible element arranged in series with the ribbon. This flexible element connects one end of the ribbon to a fixed support, so as to add additional stiffness to the ribbon. The adjustment means include preload means for applying a variable force or torque to the flexible element without changing the position of the ribbon end, so as to vary only the stiffness of the flexible element. Summary of the invention

[0011] 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 efficient and rapid gravity compensation means.

[0012] 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.

[0013] The invention is remarkable in that the regulating member comprises an elastic device for compensating the direction of gravity relative to the regulating member, the elastic device being configured to adapt its stiffness according to gravity in order to compensate for the effect of gravity on the regulating member, the elastic device comprising an elastic element connecting the external end to a first support fixed relative to the clockwork movement, as well as pre-stressing means for applying a variable force or torque on the elastic element according to the direction of gravity relative to the regulating member.

[0014] Thanks to the invention, the preload means exert a variable force or torque on the elastic element depending on gravity, so that the regulating device maintains a precise movement despite changes in position relative to gravity. Indeed, when the direction of gravity relative to the regulating device changes, the preload means modify the force or torque exerted on the elastic element, thus changing the stiffness of the assembly comprising the spiral spring and the elastic element. By modifying the stiffness of this assembly, the movement of the regulating device is adjusted. Consequently, when the direction of gravity relative to the regulating device changes, the elastic device is mechanically impacted to adjust the movement of the spiral spring to this change. The reaction time of the elastic device is very fast, as it adapts instantaneously to the change in the direction of gravity.

[0015] 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 varying 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. By changing the stiffness of the elastic element, the stiffness of the resonator (i.e., the stiffness of the ribbon and the stiffness of the elastic element) changes, which consequently alters the resonator's behavior. Since the elastic element is preferably stiffer than the ribbon, the proportion of flexibility attributable to the elastic element in the overall stiffness is less than that attributable to the ribbon.Therefore, a change in the stiffness of the elastic element alters the stiffness of the entire resonator, and consequently fine-tunes its operation, allowing for precise adjustment of the timebase frequency. This results in high accuracy in maintaining the resonator's operation in response to gravity.

[0016] 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.

[0017] According to a particular embodiment of the invention, the prestressing means comprise a stress mass exerting a variable force or torque on the spring part depending on the direction of gravity.

[0018] According to a particular embodiment of the invention, the stress mass comprises an oblique wall in contact with the spring part, the oblique wall being movable with the stress mass, so that the variable position of the stress mass causes a change in the force exerted on the spring part.

[0019] According to a particular embodiment of the invention, the spring part comprises a flexible blade connected to the elastic element.

[0020] According to a particular embodiment of the invention, the spring part comprises several secondary flexible blades connecting a first and a second rigid body.

[0021] According to a particular embodiment of the invention, the first rigid movable body is connected to the flexible blade.

[0022] According to a particular embodiment of the invention, the spring part comprises a translation table, the stress mass being in contact with the translation table.

[0023] According to a particular embodiment of the invention, the translation table comprises tertiary blades and the second rigid body.

[0024] According to a particular embodiment of the invention, the regulating organ extends substantially in the same plane.

[0025] According to a particular embodiment of the invention, the elastic element comprises a suspended body and a pair of uncrossed blades connecting the suspended body to the first stationary support.

[0026] According to a particular embodiment of the invention, the prestressing means are mechanically connected to the suspended body to exert force or torque on the suspended body.

[0027] The invention also relates to a clock movement comprising such a regulating organ. Brief description of the figures

[0028] 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 view of a regulating device according to an embodiment of the invention, and the figure 2 schematically represents a side view of the regulating organ according to the embodiment of the invention of the figure 1 . Detailed description of the invention

[0029] THE figures 1 and 2 represent an embodiment of a regulating organ 10 according to the invention.

[0030] The regulating organ 10 includes a spiral spring equipped with a flexible ribbon 2 wound on itself in several turns. The flexible ribbon 2 includes an external end 9 and an internal end 8.

[0031] The regulating organ 10 includes 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 includes an axial rotation shaft, the inner end 8 of the ribbon 2 being connected to said shaft.

[0032] Preferably, the regulating organ 10 extends substantially in the same plane (x, y), except for the oscillating mass, which oscillates in a parallel plane, preferably above the spiral spring.

[0033] According to the invention, the regulating member 10 includes an elastic device 15 for compensating the effects of gravity on the regulating member 10 in order to adapt the stiffness of the elastic element 5 according to the direction of gravity relative to the regulating member 10.

[0034] The elastic device 15 includes an elastic element 5 connecting the outer end 9 to a fixed support 7 relative to the clockwork mechanism, for example, a plate. The elastic device 15 further includes preload means 6 for applying a variable force or torque to the elastic element 5 depending on the direction of gravity relative to the regulating organ 10.

[0035] The elastic element 5 here comprises a suspended body 13 and a pair of uncrossed blades 4 connecting the suspended body 13 to the stationary support 7. The suspended body 13 is, for example, a parallelepiped-shaped body, with the uncrossed blades 4 spreading out from the suspended body 13 to the stationary support 7.

[0036] 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 between them during the oscillation of the oscillating mass.

[0037] The prestressing means 6 are configured to exert the force or torque on the suspended body 13. The prestressing means 6 comprise a spring part provided with a flexible blade 11 connected to the suspended body 13. The flexible blade 11 extends along the axis of the elastic element and is slightly offset from the outer end 9.

[0038] The outer end 9 of the ribbon 2 and the flexible blade 11 are connected on the same side of the suspended body 13.

[0039] The flexible blade 11 connects the rigid part of the elastic element 5 to a first rigid movable body 14 in the shape of an elbow of the prestressing means 6.

[0040] The prestressing means 6 comprise a second movable rigid body 19 in the shape of an elbow, as well as secondary parallel flexible blades 16 connecting the two rigid bodies 14, 19. The two rigid bodies 14, 19 have segments that are substantially parallel in pairs in the rest position of the prestressing means 6. The four secondary blades 16 are substantially perpendicular to the flexible blade 11 in the rest position of the prestressing means 6, and produce a spring effect between the two rigid bodies 14, 19. The spring portion of the prestressing means 6 comprises the secondary parallel flexible blades 16.

[0041] The spring portion of the prestressing means 6 further comprises two tertiary blades 18 connecting the second body 19 to a second stationary support 17 relative to the clockwork movement. The tertiary blades 18 form a translation table to guide the first rigid movable body 14. The tertiary blades 18 are substantially parallel to the secondary blades and are arranged on the same side of the second rigid body 19. By moving the second rigid movable body 19, the first rigid movable body 14 is in turn moved via the secondary flexible blades 16, so that a variable force or torque is applied to the suspended body 13. Thus, the stiffness of the elastic element 5 is varied, and consequently that of the assembly comprising the elastic element 5 and the spiral spring.

[0042] The prestressing means 6 also include a stress mass 20 whose position in the regulating member 10 is sensitive to gravity.

[0043] The constraint mass 20 is connected to a third fixed support 22 relative to the movement, like a plate, by means of a third pair of flexible blades 21. Thus, the constraint mass 20 is mobile in a direction substantially perpendicular to the plane of the spiral spring, that is to say along the z-axis.

[0044] The stress mass 20 is here a parallelepiped with an oblique face 23. The stress mass 20 is arranged so that the oblique face 23 is in contact with the rear of the second body 19. The spring effect produced by the four secondary blades 16 presses the second body 19 against the oblique face 23.

[0045] The oblique face 23 forms an angle with the x, y plane other than 90°.

[0046] The constraint mass 20 is configured to move according to gravity along the z-axis.

[0047] When the direction of gravity is perpendicular to the plane of the regulating member 10 in a first direction opposite to the z-axis, the stress mass 20 is pushed downwards, and the oblique face 23 presents a part further away from the second rigid body 19, which moves back relative to the first rigid mobile body 14. Thus, the stiffness of the elastic element 5 is increased, and therefore that of the regulating member 10 in general.

[0048] When the direction of gravity is perpendicular to the plane of the regulating member 10 in a second direction along the z-axis, which is the opposite of the first direction, the stress mass 20 is pushed upwards, and the oblique face presents a part closer to the second rigid body 19, which moves towards the first rigid mobile body 14. Thus, the stiffness of the elastic element 5 is reduced, and therefore that of the regulating member 10 in general.

[0049] When the direction of gravity is in the x, y plane of the regulating organ 10, the stress mass 20 remains in an average position.

[0050] All intermediate directions of gravity are possible, so that the stress mass 20 pushes the second rigid body 19 more or less depending on this direction, according to the portion of the oblique face 23 in contact with the second rigid body 19.

[0051] Depending on the direction of gravity, the stress mass 20, and therefore the oblique face 23, rises or falls, so that it pushes the second rigid body 19 more or less towards the first rigid body 14. Thus, depending on the direction of gravity with respect to the stress mass 20, the stiffness of the elastic element 5 is modified, and therefore the movement of the regulating organ 10.

[0052] The invention also relates to a clockwork movement, not shown in the figures, the movement comprising a regulating organ 10 as described above.

[0053] 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.

Claims

1. A regulating member (10) for a horological movement comprising an oscillating mass, for example a balance, a balance spring comprising a flexible strip (2) coiled on itself in several turns, the strip (2) having a predefined rigidity to enable the oscillating mass to perform a rotary oscillatory movement, the strip (2) comprising an outer end (9), characterised in that the regulating member (10) comprises a resilient device for compensating the direction of the gravity with respect to the regulating member (10), the resilient device being configured to adapt its stiffness according to gravity in order to compensate for the effect of gravity on the regulating member (10), the resilient device comprising a resilient element (5) connecting the outer end (9) to a first non-movable support (7) with respect to the horological movement, as well as prestressing means (6) for applying a variable force or torque on the resilient element (5) according to the direction of gravity with respect to the regulating member (10).

2. The regulating member according to claim 1, characterised in that the prestressing means (6) comprise a stressing mass (20) exerting a variable force or torque on a spring portion according to the direction of gravity.

3. The regulating member according to claim 2, characterised in that the prestressing means (6) comprise the spring portion connected to the resilient element (5), the spring portion transmitting the force or the torque to the resilient element (5).

4. The regulating member according to claim 3, characterised in that the stressing mass (20) comprises an oblique wall (23) in contact with the spring portion, the oblique wall (23) being movable with the stressing mass (20), so that the variable position of the stressing mass (20) causes a modification of the force exerted on the spring portion.

5. The regulating member according to any one of the preceding claims, characterised in that the spring portion comprises a flexible blade (11) connected to the resilient element (5).

6. The regulating member according to claim 5 and any one of claims 3 and 4, characterised in that the spring portion comprises several secondary flexible blades (16) connecting first and second rigid bodies (14, 19).

7. The regulating member according to claim 6, characterised in that the first movable rigid body (14) is connected to the flexible blade (11).

8. The regulating member according to claim 7 characterised in that the spring portion comprises a translation table, the prestressing mass (20) being in contact with the translation table.

9. The regulating member according to claim 8, characterised in that the translation table comprises two tertiary blades (18) and the second rigid body (19).

10. The regulating member according to any one of the preceding claims, characterised in that the regulating member (10) extends substantially in the same plane.

11. The regulating member according to any one of the preceding claims, characterised in that the resilient element (5) comprises a suspended body (13) and a pair of uncrossing blades (4) connecting the suspended body (13) to the first non-movable support (7).

12. The regulating member according to claim 11, characterised in that the prestressing means (6) are mechanically connected to the suspended body (13) to exert the force or the torque on the suspended body (13).

13. A horological movement comprising a regulating member (10), according to any one of the preceding claims.

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