Timepiece resonator mechanism with flexible rotation guide and provided with holding means

Abstract

The invention relates to a timepiece resonator mechanism comprising a structure and an anchoring unit to which at least one inertial element is suspended, said at least one inertial element being arranged to oscillate with a first rotational degree of freedom RZ about a pivot axis extending in a first direction Z, the inertial element is subjected to a restoring force exerted by a flexible guide forming a virtual pivot, the anchoring unit being suspended to the structure by a flexible suspension system arranged to allow the anchoring unit to move in a second direction X and in a third direction Y orthogonal to the second direction X in a plurality of degrees of freedom, at least two of the plurality of degrees of freedom lie in a plane XY, the timepiece resonator mechanism comprising retaining means for the flexible suspension system, these retaining means being configured to damp rotation of the inertial element and the flexible suspension system about the second direction X and / or about the third direction Y.

Description

Technical Field

[0001] The invention relates to a timepiece resonator mechanism with a flexible rotation guide and provided with retaining means.

[0002] The invention further relates to a timepiece movement comprising at least one such resonator mechanism.

[0003] The present invention relates to the field of timepiece resonators and more particularly to those resonators comprising elastic strips acting as reset means for the operation of the oscillator. Background Art

[0004] For most timepiece oscillators, which include at least one balance spring or elastic band forming a flexible guide, and particularly for resonators with crossed bands, the torsional rigidity of the suspension system is a delicate issue. Furthermore, shock resistance also depends on this torsional rigidity; more specifically, during an impact, the stresses experienced by the bands rapidly reach very high values, correspondingly reducing the distance the components can travel before breaking. Numerous variations of shock absorbers are available for timepieces. However, their purpose is essentially to protect the fragile pivot of the resonator's shaft, rather than elastic elements such as the balance spring in conventional examples.

[0005] According to Swiss Patent Application No. CH15442016 filed by ETA Manufacture Horlogère Suisse and its derivative patents (the teachings of which are directly applicable to the present invention and allow for further improvements in the sensitivity of the resonator to shocks in certain specific directions), a new mechanical architecture makes it possible to maximize the quality factor of the resonator by using flexible guides and a lever escapement with a very small lift angle. The goal is therefore to protect the strap from breakage in the event of an impact. It is evident that the shock protection systems proposed to date for resonators with flexible guides only protect the strap from shocks in certain directions, not all, or they have the drawback of allowing the setting of the virtual pivot to shift slightly according to its oscillating rotation, which should be avoided as much as possible.

[0006] Swiss patent application number CH5182018 or European patent application number EP18168765 filed by ETA Manufacture Horlogère Suisse describes a timepiece resonator mechanism comprising a structure carrying an anchoring unit via a flexible suspension system, to which an inertial element is suspended, the inertial element oscillating in a first rotational degree of freedom RZ under the action of a restoring force exerted by a virtual pivot, the virtual pivot comprising first elastic strips, each of which is fixed to the inertial element and to the anchoring unit, the flexible suspension system being arranged so as to allow a certain level of mobility to the anchoring unit in each degree of freedom except the first rotational degree of freedom RZ, only the inertial element being able to move in the first rotational degree of freedom RZ so as to avoid any interference with its oscillation, and the stiffness of the suspension system in the first rotational degree of freedom RZ being very significantly higher than the stiffness of the virtual pivot in this same first rotational degree of freedom RZ.

[0007] Swiss patent application number CH715526 or European patent application number EP3561607 filed by ETA Manufacture Horlogère Suisse describe a timepiece resonator mechanism comprising a structure and an anchoring unit from which at least one inertial element is suspended, said inertial element being arranged to oscillate with a first rotational degree of freedom RZ about a pivot axis extending in a first direction Z, said inertial element being subject to a restoring force exerted by a virtual pivot comprising a plurality of substantially longitudinal elastic strips, each of which is fixed at a first end to the anchoring unit and at a second end to the inertial element, each of said elastic strips being deformable substantially in a plane XY perpendicular to said first direction Z.

[0008] However, there are other spurious movements of the inertial element and the translation stage, in particular additional rotational movements about the second direction X or about the third direction Y. These spurious movements are caused by sudden movements of the timepiece or even by the escapement driven by the inertial element. Current devices cannot avoid these spurious movements. Summary of the Invention

[0009] The present invention proposes to improve the resonator mechanism of Swiss patent application number CH715526 or European application number EP3561607 filed by ETA Manufacture Horlogère Suisse in order to protect the flexible suspension system from the above-mentioned drawbacks.

[0010] To this end, the invention relates to a timepiece resonator mechanism comprising a structure and an anchoring unit to which is suspended at least one inertial element, said inertial element being arranged to oscillate with a first rotational degree of freedom RZ about a pivot axis extending in a first direction Z, said inertial element being subject to a restoring force exerted by a flexible guide forming a virtual pivot, said anchoring unit being suspended from said structure by a flexible suspension system arranged to allow said anchoring unit to move with a plurality of degrees of freedom in a second direction X and in a third direction Y orthogonal to said second direction X, at least two of said plurality of degrees of freedom being situated in a plane XY.

[0011] The invention is characterized in that the mechanism comprises means for maintaining the flexible suspension system, these means being configured to damp a rotation of the inertial element and of the flexible suspension system about the X direction and / or about the Y direction.

[0012] Thus, the spurious rotational movements of the suspension system are damped by its elastic retaining means at least in one direction, for example in direction X or direction Y. Thanks to this damping, the disturbances caused to the operation of the adjustment member are reduced.

[0013] According to a particular embodiment of the invention, the flexible guide comprises a plurality of substantially longitudinal elastic strips, each of which is fastened at a first end to said anchoring unit and at a second end to said inertial element, each of said elastic strips being deformable substantially in a plane XY perpendicular to said first direction Z.

[0014] According to a particular embodiment of the invention, the retaining means comprises a connecting body rigidly connected to the flexible suspension system, movable in a direction substantially perpendicular to direction X or substantially perpendicular to direction Y, ie direction Z.

[0015] In a particular embodiment of the invention, the connecting body comprises an arm extending from a flexible suspension system.

[0016] According to a particular embodiment of the invention, said retaining means comprises an elastically deformable damping element arranged to dampen a displacement of the connecting body.

[0017] According to a particular embodiment of the invention, the damping element is arranged on a first intermediate plate of the flexible suspension system.

[0018] According to a particular embodiment of the invention, the connecting body extends substantially in a plane XY.

[0019] According to a particular embodiment of the invention, the damping element comprises a movable comb and an immovable comb, and a dissipative liquid arranged between the movable comb and the immovable comb.

[0020] According to a particular embodiment of the invention, the damping element comprises a spring in contact with the connection body.

[0021] According to a particular embodiment of the invention, the spring is provided with a curved flexible strip.

[0022] According to a particular embodiment of the invention, the damping element comprises a stopper, and preferably comprises a viscous liquid.

[0023] According to a particular embodiment of the invention, the damping element comprises an elastic body, for example made of a polymer material.

[0024] According to a particular embodiment of the invention, said flexible suspension system comprises a transverse translation stage between said anchoring unit and the first intermediate plate, said transverse translation stage comprising transverse strips extending along said second direction X.

[0025] According to a specific embodiment of the present invention, the flexible suspension system includes a second intermediate mass member and a longitudinal translation platform, wherein the longitudinal translation platform is arranged between the anchoring unit and the second intermediate mass member, and the longitudinal translation platform includes a longitudinal strip extending along the third direction Y; and includes the transverse translation platform located between the second intermediate mass member and the first intermediate plate.

[0026] According to a specific embodiment of the present invention, the mobility of the anchoring unit is possible through five degrees of freedom of the flexible suspension system, which are a first translational degree of freedom along the first direction Z, a second translational degree of freedom along a second direction X orthogonal to the first direction Z, a third translational degree of freedom along a third direction Y orthogonal to the second direction X and the first direction Z, a second rotational degree of freedom RX around an axis extending along the second direction X, and a third rotational degree of freedom RY around an axis extending along the third direction Y.

[0027] The invention further relates to a timepiece movement comprising a resonant mechanism according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Other features and advantages of the present invention will become better understood on reading the following detailed description given with reference to the accompanying drawings, in which:

[0029] - Figure 1 diagrammatically shows a perspective view of a first embodiment of a resonator mechanism with an elastic strip, the resonator mechanism comprising an inertial mass suspended to an anchoring unit by a flexible guide;

[0030] - Figure 2 It diagrammatically shows Figure 1 A first embodiment of a resonator mechanism in FIG. 1 showing a holding device according to the invention;

[0031] - Figure 3 It diagrammatically shows Figure 2 a top view of a portion of a first embodiment of a resonator mechanism in FIG.

[0032] - Figure 4 diagrammatically shows a top view of a portion of a second embodiment of a resonator mechanism according to the present invention;

[0033] - Figure 5 diagrammatically shows a top view of a portion of a third embodiment of a resonator mechanism according to the present invention; and

[0034] - Figure 6 A diagrammatic top view of a portion of a fourth embodiment of a resonator mechanism according to the invention is shown. DETAILED DESCRIPTION

[0035] The present invention relates to a timepiece resonator mechanism that constitutes an alternative to the resonator described in Swiss patent application No. CH5182018 or in European patent application No. EP18168765 filed by ETA Manufacture Horlogère Suisse (incorporated herein by reference), the person skilled in the art knowing how to combine the features of these applications with those specific to the present invention.

[0036] like Figures 1 to 3 As shown in FIG, this timepiece resonator mechanism 100 comprises a structure 1 and an anchoring unit 30, to which is suspended at least one inertial element 2 arranged to oscillate with a first rotational degree of freedom RZ about a pivot axis D extending in a first direction Z. The inertial element 2 comprises a balance wheel 20. The balance wheel 20 is bone-shaped and comprises a straight section 11 provided with a bulbous portion 12 at each end. Each bulbous portion 12 may include a small inertial mass 29 to adjust the inertia of the inertial element 2. The inertial element 2 is subjected to a restoring force exerted by a flexible guide 200 forming a virtual pivot.

[0037] The flexible guide 200 comprises a plurality of substantially longitudinal elastic strips 3 (in this case two elastic strips 3), each of which is fastened at a first end to an anchoring unit 30 and at a second end to the inertial element 2. Each elastic strip 3 is deformable substantially in a plane XY perpendicular to the first direction Z.

[0038] The anchoring unit 30 is suspended to the structure 1 by a flexible suspension system 300 arranged to allow the anchoring unit 30 to move in five flexible degrees of freedom of the suspension system, which are:

[0039] a first degree of freedom of translation along a first direction Z,

[0040] a second degree of freedom of translation along a second direction X orthogonal to the first direction Z,

[0041] a third degree of freedom of translation along a third direction Y orthogonal to the second direction X and the first direction Z,

[0042] a second rotational degree of freedom RX about an axis extending in a second direction X, and

[0043] a third degree of rotational freedom RY about an axis extending in a third direction Y.

[0044] The anchoring unit 30 is installed inside the first U-shaped intermediate mass member 304 .

[0045] The principle is to use the torsional flexibility of the translation stage to better manage the torsional stiffness of the suspension system. This is achieved by orienting the strips of the XY stage so that the direction of maximum torsional flexibility is towards the axis of rotation of the resonator.

[0046] Thus, the flexible suspension system 300 comprises a transverse translation stage 32 between the anchoring unit 30 and a first intermediate plate 303 attached to the structure 1 in the first direction Z, the transverse translation stage comprising transverse strips 320 which are preferably rectilinear and extend in the second direction X.

[0047] As illustrated by the figures, the flexible suspension system 300 further includes a longitudinal translation stage 31 located between the anchoring unit 30 and the second intermediate mass 305, the longitudinal translation stage including two longitudinal strips 310, which are preferably straight and extend along the third direction Y. The longitudinal strips 310 connect the ends of the U-shaped member to the second intermediate mass 305 by extending along the sides of the U-shaped member.

[0048] The second intermediate mass 305 is in the shape of an elbow, preferably substantially vertical, with two longitudinal strips 310 mounted on the same inner side of a first arm of the elbow.

[0049] Furthermore, between the second intermediate mass 305 and the first intermediate plate 303 , the transverse translation stage 32 comprises two transverse strips 320 , preferably rectilinear and extending in the second direction X. The transverse strips 320 are thus substantially perpendicular to the longitudinal strips 310 .

[0050] Two transverse strips 320 connect the same outer side of the second arm of the elbow to the first intermediate plate 303 .

[0051] The first intermediate panel 303 is intended to be mounted on the structure 1 .

[0052] The first intermediate plate 303 further comprises an opening 33 through which a Bloom's stud 28 for a screw can pass.

[0053] According to the invention, the resonator mechanism 100 comprises holding means 10 for the flexible suspension system 300 , which are configured to damp a rotation of the inertial element 2 and of the flexible suspension system 300 about the second direction X and / or about the third direction Y.

[0054] In the figures, the retaining device 10 of the flexible suspension system 300 is configured to dampen a rotation of the flexible suspension system 300 about the second direction Y.

[0055] Alternatively, the retaining device 10 of the flexible suspension system 300 may be configured to dampen a rotation of the flexible suspension system 300 about the second direction X by modifying the movement direction of the retaining device 10 .

[0056] The holding device 10 comprises a connecting body 13 for connecting the flexible suspension system 300 to the first intermediate plate 303. The connecting body 13 is rigidly connected to the flexible suspension system 300 and is movable in a direction substantially perpendicular to the third direction Y or the second direction X. Thus, in the embodiment shown in the figures, the connecting body 13 moves in the first direction Z.

[0057] In this case, the connecting body 13 takes the form of an arm extending from the flexible suspension system 300 toward the first intermediate plate 303. The connecting body 13 connects the second intermediate mass 305 to one side of the first intermediate plate 303. The arm is substantially curved to extend from the end of the second intermediate mass 305 along the side of the first intermediate plate 303.

[0058] Preferably, the connection body 13 extends in the same plane as the plane of the flexible suspension system 300 .

[0059] The retaining device 10 further comprises an elastically deformable damping element 15 , which is arranged to dampen and damp movements of the connecting body 13 .

[0060] The damping element 15 is arranged between the connection body 13 and the first intermediate plate 303. For example, the damping element 15 is arranged partly at the ends of the arms of the connection body 13 and partly on the first intermediate plate 303.

[0061] exist Figure 2 and Figure 3 In the first embodiment shown in FIG, the damping element 15 comprises a movable comb 16 arranged on the connecting body 13 and a fixed comb 17 mounted on the structure 1. The movable comb 16 and the fixed comb 17 are arranged facing each other in the same plane, one nested inside the other. Each comb 16, 17 includes a plurality of teeth 18, 19. Each tooth 18 of the movable comb 16 is arranged between two teeth 19 of the fixed comb 17, and vice versa.

[0062] The movable comb 16 extends laterally from the arm towards the first intermediate plate 303. The immovable comb 17 is formed in the first intermediate plate 303. The combs 16, 17 also extend in the plane of the first intermediate plate 303. Thus, the movable comb 16 moves in the first direction Z.

[0063] Preferably, the damping element 15 further comprises a dissipative liquid 14 arranged between the teeth 18 of the movable comb 16 and the teeth 19 of the immovable comb 17. Thus, when the movable comb 16 moves relative to the immovable comb 17, the movement is partially damped by the dissipative liquid 14. For example, the dissipative liquid is glycerol.

[0064] In the second embodiment, the damping element 15 includes a spring 21 mounted on the first intermediate plate 303. When the spring 21 is actuated according to the additional rotation mode, the connecting body 13 bears against the spring. The end 24 of the arm of the connecting body 13 is bent to bear against the spring. This end extends perpendicular to the first intermediate plate 303. The spring 21 is provided with a flexible strip that is bent at its end 22 to form a hook shape and extends from the structure 1. The spring 21 prevents or reduces the rotation of the inertial element 2 by rubbing against the end 24 of the arm of the connecting body 13. More specifically, because the end 24 of the arm contacts the spring 21, its movement in the Z direction is hindered by the end 24.

[0065] Preferably, the eccentric disc 23 is also arranged against the spring to hold it in place and prevent it from moving under the effect of movement of the connecting body 13. Thus, only the bent end 22 of the spring 21 is used to dampen movement of the connecting body 13.

[0066] Figure 5 The third embodiment shown in FIG 1 depicts a connecting body 13 comprising an arm having a protrusion formed at a bent end 24, in this case rounded into the shape of a disk. The end 24 of the connecting body 13 is inserted into a cavity 26 formed through the first intermediate plate 303. A stopper 34 is positioned above the protrusion of the end 24 to prevent displacement of the end 24 in the direction Z and, therefore, rotation of the inertial element 2 in the second direction Y. The end 24 and the stopper 34 are spaced a predetermined distance apart.

[0067] In an alternative embodiment, the stopper may be arranged below the end portion 24. For example, the stopper 34 is also disc-shaped and is rigidly connected to the first intermediate plate 303 by being directly or indirectly assembled to the first intermediate plate 303. The end portion 24 moves in the cavity 26 along the first direction Z.

[0068] Preferably, a viscous liquid is disposed between the end 24 of the connecting body 13 and the stopper 34 by adhesion, partially absorbing the energy resulting from displacement of the connecting body. Therefore, if the connecting body 13 and its end 24 move in the first direction Z within the cavity 26, this movement is damped by the viscous liquid and the stopper 34. For example, glycerin or lubricating grease used in the watchmaking industry can be used as the viscous liquid in this embodiment.

[0069] exist Figure 5 In the example shown in , the viscous liquid is arranged and held between two discs (the disc of the stopper 34 and the disc of the circular end 24 ).

[0070] exist Figure 6 In the fourth embodiment shown in FIG, the damping element 15 includes an elastic body 27, for example made of a polymer material such as elastomer or polyoxymethylene. The elastic body 27 connects the bent ends 24 of the arms of the connecting body 13 to the first intermediate plate 303. In this case, the elastic body 27 is bone-shaped, with each enlarged end embedded in the end 24 and the first intermediate plate 303.

[0071] Therefore, when the connection body 13 moves relative to the first intermediate plate 303 , the elastic body 27 deforms (in this case, in the first direction Z) to absorb some of the energy and maintain the movement of the connection body 13 .

[0072] The invention further relates to a timepiece movement comprising at least one such resonator mechanism 100 .

Claims

1. A clock resonator mechanism (100) comprising a structure (1) and an anchoring unit (30), at least one inertial element (2) being suspended from the anchoring unit, the inertial element being arranged to oscillate with a first rotational degree of freedom RZ about a pivot axis extending in a first direction Z, the inertial element (2) being subjected to a restoring force exerted by a flexible guide (200) forming a virtual pivot, the anchoring unit (30) being suspended from the structure (1) by a flexible suspension system (300), the flexible suspension system being arranged to allow the anchoring unit (30) to move with a plurality of degrees of freedom in a second direction X and in a third direction Y orthogonal to the second direction X, at least two of the plurality of degrees of freedom being located in a plane XY, characterised in that The clock resonator mechanism (100) comprises a retaining device (10) for the flexible suspension system (300), the retaining device being configured to damp a rotation of the inertial element (2) and the flexible suspension system (300) about the second direction X and / or about the third direction Y.

2. The resonator mechanism (100) according to claim 1, characterized in that The flexible guide comprises a plurality of substantially longitudinal elastic strips (3), each of which is fastened at a first end to the anchoring unit (30) and at a second end to the inertial element (2), each of the elastic strips (3) being deformable substantially in a plane XY perpendicular to the first direction Z.

3. The resonator mechanism (100) according to claim 1 or 2, characterized in that The retaining device (10) comprises a connection body (13) rigidly connected to the flexible suspension system (300), the connection body (13) being movable in the first direction Z.

4. The resonator mechanism (100) according to claim 3, characterized in that The connecting body (13) includes an arm extending from the flexible suspension system (300).

5. The resonator mechanism (100) according to claim 3 or 4, characterized in that The retaining device (10) comprises an elastically deformable damping element (15) arranged to dampen displacements of the connecting body (13).

6. The resonator mechanism (100) according to claim 5, characterized in that The damping element (15) is arranged on a first middle plate (303) of the flexible suspension system (300).

7. The resonator mechanism (100) according to claim 5 or 6, characterized in that The damping element (15) comprises a movable comb (16) and an immovable comb (17).

8. The resonator mechanism (100) according to claim 7, characterized in that The damping element (15) comprises a dissipative liquid (14) arranged between the movable comb (16) and the immovable comb (17).

9. The resonator mechanism (100) according to claim 5, characterized in that The damping element (15) includes a spring (21) in contact with the connecting body (13).

10. The resonator mechanism (100) according to claim 9, characterized in that The spring (21) is provided with a curved flexible strip (22).

11. The resonator mechanism (100) according to claim 5, characterized in that The damping element (15) comprises a stopper (34) and preferably comprises a viscous liquid.

12. The resonator mechanism (100) according to claim 5, characterized in that The damping element (15) comprises an elastic body (27), for example made of a polymer material.

13. The resonator mechanism (100) according to any one of the preceding claims, characterized in that The connecting body (13) extends substantially in the plane XY.

14. The resonator mechanism (100) according to any one of the preceding claims, characterized in that The flexible suspension system (300) comprises a transverse translation platform (32) located between the anchoring unit (30) and the first intermediate plate (303), wherein the transverse translation platform comprises a transverse strip extending along the second direction X.

15. The resonator mechanism (100) according to claim 14, characterized in that The flexible suspension system (300) comprises a second intermediate mass member (305) and a longitudinal translation platform (31), wherein the longitudinal translation platform (31) is arranged between the anchoring unit (30) and the second intermediate mass member (305), and the longitudinal translation platform (31) comprises a longitudinal strip extending along the third direction Y; and comprises the transverse translation platform (32) located between the second intermediate mass member (305) and the first intermediate plate (303).

16. The resonator mechanism (100) according to any one of the preceding claims, characterized in that The mobility of the anchoring unit (30) is possible through five degrees of freedom of the flexible suspension system, which are a first translational degree of freedom along the first direction Z, a second translational degree of freedom along a second direction X orthogonal to the first direction Z, a third translational degree of freedom along a third direction Y orthogonal to the second direction X and the first direction Z, a second rotational degree of freedom RX about an axis extending along the second direction X, and a third rotational degree of freedom RY about an axis extending along the third direction Y.

17. A timepiece movement comprising at least one resonator mechanism (100) according to any one of the preceding claims.

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