CH719916A2 - Clockwork regulating organ with flexible guidance provided with temperature compensation means. - Google Patents

Abstract

The invention relates to a regulating member (1) for a watch movement comprising an oscillating mass, for example a balance wheel, a flexible guide (2) comprising at least two main flexible blades (9) connecting a mobile support (3) to the oscillating mass to allow the oscillating mass to perform a rotary movement around a virtual pivot, characterized in that the regulating member (1) comprises an elastic temperature compensation device (50) arranged so as to connect the mobile support (3) to fixing means (7) of the regulating member (1) on the clock movement, the elastic compensation device (50) being configured to adapt its stiffness as a function of the temperature in order to compensate the effect of temperature on the regulating organ (1). The invention also relates to a watch movement comprising such a regulating member (1).

Description

Technical field of the invention

[0001] The invention relates to a watchmaking regulating member with flexible guidance provided with temperature compensation means.

Technology background

[0002] Most current mechanical watches are equipped with a sprung balance and a Swiss anchor escapement mechanism. The sprung balance constitutes the time base of the watch. It is also called a resonator or regulating organ.

[0003] The exhaust, for its part, fulfills two main functions: – maintain the comings and goings of the resonator; – count these comings and goings.

[0004] To constitute a regulating organ, you need an inertial element, guidance and an elastic return element. Traditionally, a spiral spring plays the role of an elastic return element for the inertial element that constitutes a balance wheel. This balance wheel is guided in rotation by pivots, which generally rotate in plain ruby bearings.

[0005] Flexible guides are now used as an elastic return spring to form a virtual pivot. Flexible virtual pivot guides make it possible to significantly improve watch resonators. The simplest are cross-blade pivots, consisting of two straight-blade guide devices that cross each other, usually perpendicularly. These two blades can be either three-dimensional in two different planes, or two-dimensional in the same plane and are then welded at their crossing point. But there are also guides with uncrossed blades of the RCC type (for “Remote Center Compliance” in English), which have straight blades that do not cross. Such a resonator is described in document EP 2911012, or in documents EP14199039, and EP16155039.

However, during its operation, such a mechanical resonator may be subject to disturbances caused by changes in external parameters, which generate variations in frequency of the resonator. These parameters are for example temperature, pressure, humidity, or gravity. The variation in frequency of the resonator results in an error in the measurement of time.

Document CH 704687 describes a regulating member comprising a spiral spring and a member for correcting the position of the eyebolt to correct deformations of the spiral spring due to certain parameters, such as temperature.

[0008] However, not only is such a correction member not easily adaptable to flexible guides, but it also does not achieve the desired level of precision.

Summary of the invention

[0009] The aim of the present invention is to overcome all or part of the drawbacks cited above by proposing a watchmaking regulating member with flexible guidance provided with precise temperature compensation means, adaptable to flexible guides.

[0010] For this purpose, the invention relates to a timepiece regulating member for a timepiece movement comprising an oscillating mass, for example a balance wheel, a flexible guide comprising at least two main flexible blades connecting a mobile support to the oscillating mass to allow the oscillating mass to perform a rotary movement around a virtual pivot.

[0011] The invention is remarkable in that the regulating member comprises an elastic device for compensating the temperature arranged so as to connect the support to means for fixing the regulating member to the clock movement, the device elastic compensation being configured to adapt its stiffness as a function of the temperature in order to compensate for the effect of the temperature on the regulating member.

[0012] Thanks to the invention, the prestressing means exert a variable force or torque on the elastic element as a function of the temperature, so that the regulating member substantially maintains a precise course despite significant changes in the temperature . Indeed, when the temperature changes, the prestressing means modify the force or the torque exerted on the elastic element, so that the stiffness of the flexible guide is modified. By modifying the stiffness of the flexible guide, the action of the regulating member is adjusted. Consequently, when the temperature changes, the elastic device is mechanically impacted to adjust the operation of the regulating organ to this change.

[0013] This elastic element modifies the rigidity of the attachment point and provides additional flexibility to the resonator. Thus, the effective rigidity of the resonator includes the rigidity of the flexible guide and the rigidity of the elastic element. The variable force or torque makes it possible to pre-stress the elastic element, preferably without pre-stressing the flexible guide and without moving the end of the flexible guide. By pre-stressing the elastic element, its rigidity changes, while the rigidity of the flexible guide remains unchanged, since it is not pre-stressed and its end does not move.

By changing the rigidity of the elastic element, the rigidity of the resonator (rigidity of the flexible guide and rigidity of the elastic element) changes, which consequently modifies the operation of the resonator. The elastic element being preferably more rigid than the flexible guide, the share of the flexibility of the elastic element in the overall rigidity is less than that of the flexible guide. Consequently, a modification of the rigidity of the elastic element modifies the rigidity of the entire resonator, and consequently fine-tunes its operation, which makes it possible to precisely adjust the frequency of our time base. We thus obtain great precision in maintaining operation as a function of temperature.

[0015] According to a particular embodiment of the invention, the elastic compensation device comprises an elastic element arranged between the support and the fixing means, as well as prestressing means for applying a variable force or torque on the elastic element as a function of temperature.

[0016] According to a particular embodiment of the invention, the prestressing means comprise a spring part connected to the movable support, the spring part transmitting the force or the torque to the elastic element via the movable support, the spring part, the mobile support and the elastic element being arranged on the same axis.

[0017] According to a particular embodiment of the invention, the prestressing means comprise a body which is deformable as a function of the temperature, the deformable body being at least partly in contact with the spring part.

[0018] According to a particular embodiment of the invention, the deformable body is an elongated bimetallic strip.

According to a particular embodiment of the invention, the spring part comprises a first flexible blade connected to the mobile support.

According to a particular embodiment of the invention, the spring part comprises a first translation table connected to the first flexible blade.

[0021] According to a particular embodiment of the invention, the deformable body is in contact with the first translation table.

[0022] According to a particular embodiment of the invention, the spring part comprises a spring arranged between the deformable body and the first translation table.

According to a particular embodiment of the invention, the first translation table comprises a first movable element connected to the first flexible blade.

[0024] According to a particular embodiment of the invention, the elastic part comprises a first movable element connected to the first flexible blade, a second movable element, and a second flexible blade connected to the thermally deformable body, the first movable element and the second movable element being connected by a pair of parallel flexible blades.

According to a particular embodiment of the invention, the elastic part comprises a second flexible blade connected to the thermally deformable body and to the second movable element.

According to a particular embodiment of the invention, the regulating member comprises means for adjusting the prestressing means to apply a variable force on the prestressing means, for example on the first elongated movable element.

According to a particular embodiment of the invention, the adjustment means comprise a second translation table arranged at one end of the deformable body, the variable force being applied to the second translation table.

[0028] According to a particular embodiment of the invention, the two main blades of the flexible guide are crossed.

[0029] According to a particular embodiment of the invention, the regulating member extends substantially in the same plane, except for the oscillating mass.

According to a particular embodiment of the invention, the elastic element comprises a pair of uncrossed blades connecting the support to the fixing means.

[0031] The invention also relates to a watch movement comprising such a regulating member.

Brief description of the figures

[0032] The aims, advantages and characteristics of the present invention will appear on reading several embodiments given solely by way of non-limiting examples, with reference to the appended drawings in which: – Figure 1 schematically represents a top view of a regulating member provided with temperature compensation means according to a first embodiment of the invention, – Figure 2 schematically represents a top view of a regulating member provided with temperature compensation means according to a second embodiment of the invention, and – Figure 3 schematically represents a top view of a regulating member provided with temperature compensation means according to a third embodiment of the invention.

Detailed description of the invention

[0033] Figures 1 to 3 represent three embodiments of a regulating member 1, 10, 20 according to the invention, the regulating member 1, 10, 20 comprising an elastic device 50 configured to compensate for a thermal variation exerted on the regulating member 1, 10, 20. Such regulating members 1, 10, 20 are intended to be arranged in a clockwork movement to regulate it.

[0034] In the three embodiments of Figures 1 to 3, the regulating member 1, 10, 20 comprises a flexible guide 2 and an oscillating mass, for example an annular balance or a bone-shaped member comprising an arm main and two ends extending on each side of the central arm, the oscillating mass not being shown in the figures.

Preferably, the regulating member 1, 10, 20 extends substantially in the same plane, except for the oscillating mass, which oscillates in a parallel plane, preferably above the flexible guide 2.

The flexible guide 2 comprises two main flexible blades 9, and a rigid support 3. The flexible guide extends along an axis of symmetry substantially perpendicular to the main axis of the regulating member 1, 10, 20. flexible blades 9 are joined on the one hand to the rigid support 3 of the flexible guide 2 and on the other hand to a fastener 8 intended to associate the oscillating mass. The two main blades 9 of the flexible guide 2 are crossed, preferably straight and of the same length.

The rigid support 3 has a U shape, the main flexible blades 2 being connected inside the base of the U, and extending outside the U up to the attachment 8.

[0038] According to the invention, the regulating member 1, 10, 20 comprises an elastic device 50 for compensating the temperature, the elastic device being arranged on either side of the rigid support 3 so as to connect the rigid support 3 to fixing means 7 of the regulating member 1, 10, 20 on the clock movement. The fixing means 7 are for example an elongated body intended to be assembled to the plate.

The elastic compensation device 50 is configured to adapt its stiffness as a function of the temperature in order to compensate for the effect of temperature on the regulating member 1, 10, 20. The elastic compensation device 50 preferably has a stiffness superior to the main flexible blades 9 crossed.

The elastic compensation device 50 comprises an elastic element 5 arranged between the rigid support 3 and the fixing means 7, as well as prestressing means 6 for applying a variable force or torque on the elastic element 5 and the rigid support 3 depending on the temperature.

The elastic element 5 comprises a pair of uncrossed blades 4 connecting the rigid support 3 to the fixing means 7. The elastic element 5 is connected to a first external side of the U, and extends perpendicular to the flexible guide 2 The uncrossed blades 4 extend from the rigid support 3 to the fixing means 7, moving away from each other.

The prestressing means 6 comprise a spring part provided with a flexible blade 11 connected to the second external side of the U. The first flexible blade 11 extends perpendicular to the flexible guide 2.

[0043] In the first embodiment of Figure 1, the spring part of the prestressing means 6 comprises a first translation table 33 provided with a first mobile element 12 in the shape of an L and a second immobile support 13 by in relation to the movement plate. The first movable element 12 is connected to the flexible blade 11 by one end of a first arm of the L. The second arm of the L includes a rounded projection 53 on the external side. In addition, the first translation table 33 comprises a pair of parallel blades 14, connecting the interior of the first arm of the L to the second stationary support 13. Thus, the first movable element 12 is guided by the parallel blades 14, when it moves.

The prestressing means 6 further comprise a thermally deformable body 15 as a function of the temperature, the deformable body 15 exerting the variable force or torque on the movable element 12.

[0045] In this example, the thermally deformable body 15 is a bimetal whose deformation is caused by the temperature. The bimetallic strip has a body extending longitudinally, and comprises two elongated parts 51, 52 associated longitudinally. The two elongated parts 51, 52 are each formed of a different material, with thermal deformation properties different from each other. Thus, under the effect of heat, the bimetallic strip deforms laterally, one end 55 of the bimetallic strip being retained, the other end being able to move and deform the bimetallic strip to bend it to one side.

The bimetallic strip is arranged perpendicular to the movable element 12, so that a first free part 54 is in contact with the protrusion 53 of the second arm of the L. The retained end 55 is held by a second table of translation 34 comprising a second movable element 18 and a second pair 17 of parallel flexible blades connecting the second movable element 18 to a third immobile support 19 relative to the movement plate. The second movable element 18 has an L shape, one arm of the L supporting the retained end 55 of the bimetallic strip, while the blades of the second pair 17 of blades connect the internal face 56 of the second arm to the third immobile support 19. The blades of the second pair 17 of blades are arranged perpendicular to the bimetallic strip in the rest position of the prestressing means 6.

In the event of a change in temperature, the deformable body 15, here the bimetallic strip, bends or straightens, so that the first free part 54 exerts a force on the protrusion, and therefore on the first movable element 12. , which moves while being guided by the first translation table 33. Thus, via the first flexible blade 11, the elastic element 5 receives a force or a torque modifying its stiffness and therefore the operation of the member regulating 1.

[0048] Adjustment means, such as a screw, can be added to exert a force 57 on the second movable element 18, in particular at the end of the second arm 58, parallel to the longitudinal axis of the bimetallic strip. Thus, we can adjust the effective length d of the bimetallic strip, to adjust the effect of the prestressing means 6 on the elastic element 5, in particular as a function of the external parameter, here the temperature. By moving the second movable element 18, guided by the second translation table 34, the free part 54 in contact with the protrusion 53 is modified, and thus the effective length d of the bimetallic strip is increased or reduced.

The second embodiment of regulating member 10 of Figure 2 is similar to the first embodiment. The difference lies in the first translation table 33, which is not directly in contact with the mobile body 15, and does not carry any protrusion.

The prestressing means 6 further comprise a spring 21 connecting the first movable element 12 to a movable body 22 comprising a projection 53 similar to the first embodiment. Spring 21 provides additional flexibility. Preferably, the mobile body 22 is held between two walls 23 which guide the movement of the mobile body 22.

[0051] Thus, the protrusion 53 is not on the first movable element 12, but on the movable body 22, the first movable element not being in direct contact with the deformable body 15.

[0052] Thus, when the bimetallic strip bends or straightens, it exerts a more or less significant force on the mobile body 22, which moves between the guide walls 23, and transmits a more or less significant force to the first movable element 12 via spring 21. For the rest, the operation is the same as for the first embodiment. Thus, the elastic element 5 experiences a variable force or torque, which modifies its stiffness, and therefore that of the flexible guide 2.

[0053] In the third embodiment of Figure 3, to exert the force or torque on the elastic element 5, the spring portion of the prestressing means 6 comprises a first elongated movable element 29, connected to the flexible blade 11 by one end and arranged in its extension.

[0054] A first pair of parallel flexible blades 25 connects the first movable element 29 to a second movable element 28.

The second movable element 28 is connected to the thermally deformable body 15 by a second flexible blade 31, which is substantially parallel to the first movable element 29.

[0056] In this embodiment, the thermally deformable body 15 is preferably also a bimetallic strip arranged perpendicularly to the second flexible blade 31 and to the first elongated movable element 29. The second flexible blade 31 is connected to the top of the free part of the bimetallic strip , the latter being held by a fixed support 32 at its base.

[0057] Thus, when the bimetallic strip curves or straightens, the second flexible blade 31 transmits a movement to the second movable element 28, which transmits a force to the first elongated movable element 29 by the second pair of parallel flexible blades 25.

[0058] Similar to the first embodiment, the variation in temperature will cause a modification in the stiffness of the elastic element 5, and therefore in the operation of the regulating member.

[0059] A third pair of parallel flexible blades 26 connects the second movable element 28 to a third stationary element 27 relative to the movement plate. The third pair of parallel flexible blades 26 and the third movable element 27 are superimposed on the second pair of parallel flexible blades 25 and the second movable element 28. The second movable element 28 and the two parallel flexible blades 26 form a translation table, the second movable element 28 being guided in translation relative to the third stationary element 27 to transmit a movement to the first elongated movable element 29 via the second pair of parallel flexible blades 25. Thus, the first elongated movable element 29 transmits a force or torque to the elastic element 5 through the first flexible blade 11.

[0060] Adjustment means, such as a screw, can be added to exert a force 49 on the first elongated movable element 29. By increasing the force 49, the movement of the bimetallic strip is transmitted more weakly to the first movable element 29, while By reducing the force, the movement of the bimetallic strip is transmitted more strongly to the first movable element 29. The adjustment means make it possible to adjust the sensitivity of the prestressing means 6 as a function of the temperature.

[0061] The invention also relates to a clock movement, not shown in the figures, the movement comprising a regulating member 1, 10, 20 as described above.

Naturally, the invention is not limited to the embodiments described with reference to the figures and variants could be considered without departing from the scope of the invention.

[0063] In the embodiments described, the flexible blades are preferably straight. In addition, flexible blades of the same type are preferably of the same length. Flexible blades can be continuously flexible or have flexible portions only, such as necks.

Claims (18)

1. Regulating member (1, 10, 20) for a watch movement comprising an oscillating mass, for example a balance wheel, a flexible guide (2) comprising at least two main flexible blades (9) connecting a mobile support (3) to the oscillating mass to allow the oscillating mass to perform a rotary movement around a virtual pivot, characterized in that the regulating member (1, 10, 20) comprises an elastic temperature compensation device (50) arranged so as to connect the mobile support (3) to fixing means (7) of the regulating member (1, 10, 20) on the clock movement, the elastic compensation device (50) being configured to adapt its stiffness as a function of temperature in order to compensate for the effect of the temperature on the regulating member (1, 10, 20). 2. Regulating member according to claim 1, characterized in that the elastic compensation device (50) comprises an elastic element (5) arranged between the movable support (3) and the fixing means (7), as well as means for prestressing (6) to apply a variable force or torque on the elastic element (5) depending on the temperature. 3. Regulating member according to claim 2, characterized in that the prestressing means (6) comprise a spring part connected to the movable support (3), the spring part transmitting the force or the torque to the elastic element (5) by via the movable support (3), the spring part, the movable support (3) and the elastic element (5) being arranged on the same axis. 4. Regulating member according to claim 3, characterized in that the prestressing means (6) comprise a deformable body (15) as a function of the temperature, the deformable body (15) being at least partly in contact with the spring part . 5. Regulating member according to claim 4, characterized in that the deformable body (15) is an elongated bimetallic strip. 6. Regulating member according to any one of the preceding claims, characterized in that the spring part comprises a first flexible blade (11) connected to the movable support (3). 7. Regulating member according to claim 6 and any one of claims 3 to 5, characterized in that the spring part comprises a first translation table (33) connected to the first flexible blade (11). 8. Regulating member according to claim 7, characterized in that the deformable body (15) is in contact with the first translation table (33). 9. Regulating member according to claim 8, characterized in that the spring part comprises a spring (21) arranged between the deformable body (15) and the first translation table (33). 10. Regulating member according to any one of claims 7 to 9, characterized in that the first translation table comprises a first movable element (12) connected to the first flexible blade (11). 11. Regulating member according to claim 6, characterized in that the elastic part comprises a first movable element (29) connected to the first flexible blade (11), a second movable element (28), and a second flexible blade (31) connected to the thermally deformable body (15), the first movable element (29) and the second movable element (28) being connected by a pair of parallel flexible blades (25). 12. Regulating member according to claim 11, characterized in that the elastic part comprises a second flexible blade (31) connected to the thermally deformable body (15) and to the second movable element (28). 13. Regulating member according to any one of the preceding claims, characterized in that it comprises means for adjusting the prestressing means (6) to apply a variable force (49, 57) on the prestressing means (6). ), for example on the first elongated movable element (29). 14. Regulating member according to claim 4 and claim 13, characterized in that the adjustment means comprise a second translation table (34) arranged at one end of the deformable body (15), the variable force (57) being applied to the second translation table (34). 15. Regulating member according to any one of the preceding claims, characterized in that the two main blades (4) of the flexible guide (2) are crossed. 16. Regulating member according to any one of the preceding claims, characterized in that the regulating member (1, 10, 20) extends substantially in the same plane, except for the oscillating mass (2). 17. Regulating member according to any one of the preceding claims, characterized in that the elastic element (5) comprises a pair of uncrossed blades (4) connecting the movable support (3) to the fixing means (7). 18. Clock movement comprising a regulating member (1, 10, 20), according to any one of the preceding claims.