Tension ring for a clock oscillator mechanism with a lateral inertia adjustment weight

Abstract

To provide an oscillator mechanism capable of avoiding out-of-plane secondary vibration.SOLUTION: A balance wheel 15 for an oscillator mechanism 1 for a timepiece includes a main arm 6 arranged along a longitudinal axis. The balance wheel 15 comprises at least a first lateral direction weight 11 for adjusting inertia of the balance wheel 15. The first lateral direction weight 11 is mounted in a movable manner to the main arm 6 of the balance wheel 15 so as to be able to take a plurality of positions closer to or further away from the main arm 6 in order to adjust inertia of the balance wheel 15.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an adjustable inertial balance for a timepiece oscillator mechanism.

[0002] The present invention also relates to an oscillator mechanism for a timepiece movement including at least one such balance wheel.

[0003] The present invention also relates to a method of setting up an oscillator mechanism.

Background Art

[0004] According to Patent Document 1 in the name of ETA Manufacture Horlogere Suisse and its derivatives (the teachings of which can be directly used in the present invention), by using a flexible guide using a lever escapement with a very small lift angle with a new mechanism architecture, it is possible to maximize the quality factor of the oscillator.

[0005] Patent Document 2 or Patent Document 3 in the name of ETA Manufacture Horlogere Suisse describes a timepiece oscillator mechanism including a structure that supports an anchor block by a flexible suspension, an inertial element is suspended from the anchor block, and the inertial element vibrates according to a first rotational degree of freedom RZ under the action of a restoring force applied by a virtual pivot including a first elastic blade fixed to the inertial element and the anchor block respectively, and the flexible suspension is configured to allow some mobility of the anchor block in all degrees of freedom other than the first rotational degree of freedom RZ in which only the inertial element is movable in order to avoid disturbance of its vibration, and the rigidity of the degrees of freedom of the balance other than the first rotational degree of freedom RZ is much greater than the rigidity of the virtual pivot in the same first rotational degree of freedom RZ.

[0006] Patent Document 4 or Patent Document 5 in the name of ETA Manufacture Horlogere Suisse describes a watch oscillator mechanism that includes a structure and an anchor block with at least one inertial element suspended so as to oscillate with a first rotational degree of freedom RZ about a pivot axis extending in a first direction Z. Each inertial element is subject to a restoring force applied by a virtual pivot including a plurality of substantially vertical elastic blades each fixed to the anchor block at a first end and fixed to the inertial element at a second end, and each of said elastic blades is basically deformable in a plane XY perpendicular to said first direction Z.

[0007] When the oscillator mechanism is operating, the inertial element performs an oscillatory motion centered on the Z direction in the XY plane at a reference oscillation frequency. Further, the inertial element can also perform rotational secondary oscillations centered on the X direction on the one hand and the Y direction on the other hand. These secondary oscillations are in a vibration mode known as "out-of-plane" oscillations, i.e., oscillations outside the main oscillation XY plane of the inertial element.

[0008] These "out-of-plane" secondary oscillations have a more or less limited influence on the movement of the speed regulating mechanism. However, when the frequencies of these secondary oscillations are multiples of the reference frequency of the inertial element in the XY plane, the secondary oscillations become large and interfere with the operation of the oscillator. Therefore, it is important to make the frequencies of the secondary oscillations different by multiples of the reference frequency.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

[0010] In order to avoid the above-mentioned drawbacks, the present invention proposes to improve the oscillator mechanism of Patent Document 4 or Patent Document 5 in the name of ETA Manufacture Horlogere Suisse. [Means for Solving the Problems]

[0011] For this purpose, the present invention relates to a template for a watch oscillator mechanism including a main arm arranged along the vertical axis.

[0012] It is worth noting that the balance wheel includes at least a first lateral weight for adjusting the inertia of the balance wheel, and the first lateral weight is movably attached to the main arm of the balance wheel so that it can take a plurality of positions closer to or farther from the main arm for adjusting the inertia of the balance wheel.

[0013] According to the present invention, the balance wheel can be adjusted to control and avoid large secondary vibrations around at least one axis, particularly in the X direction passing through the center of mass of the balance wheel, and secondary vibrations occurring in the YZ plane perpendicular to the XY plane of the vibration.

[0014] This lateral adjustment weight makes it possible to change and select the secondary vibration frequency so as to avoid multiples of the reference vibration frequency of the template in the XY plane. In this way, the oscillator mechanism to which such a template is attached is more accurate.

[0015] Furthermore, the lateral adjustment weight does not have a significant impact on the reference vibration around the Z direction.

[0016] According to a particular embodiment of the present invention, the first side feeder is arranged perpendicular to the longitudinal axis of the main arm so as to be able to change the frequency of the vibration of the main arm around the longitudinal axis of the main arm.

[0017] In a particular embodiment of the present invention, the first lateral weight is movable within the main plane of the tension ring.

[0018] According to a particular embodiment of the present invention, it comprises a second lateral inertia adjustment weight arranged symmetrically on the main arm with respect to the first lateral weight with respect to the longitudinal axis of the main arm.

[0019] According to a particular embodiment of the present invention, one or more lateral feeders are screws.

[0020] In a particular embodiment of the present invention, one or more lateral weights are offset from the center of the arms of the tension ring.

[0021] According to a particular embodiment of the present invention, the tension ring also comprises at least one peripheral inertia adjustment weight attached to both ends of the main arm.

[0022] In a particular embodiment of the present invention, the tension ring comprises a hub.

[0023] In a particular embodiment of the present invention, the main arm includes an enlarged portion on which one or more lateral adjustment weights are arranged.

[0024] The present invention further relates to a pendulum mechanism comprising a structure and an anchor block from which at least one inertial element is suspended so as to oscillate with a first rotational degree of freedom RZ about a pivot axis extending in a first direction Z, said inertial element being configured to receive a restoring force applied by restoring means configured to oscillate the inertial element, the inertial element comprising such a pendulum.

[0025] In certain embodiments of the present invention, the tuning ring is mounted such that its longitudinal axis is substantially perpendicular to the first Z direction.

[0026] In certain embodiments of the present invention, the tuning ring is mounted such that its main plane is substantially perpendicular to the first Z direction.

[0027] The present invention also relates to a method of developing such a clock oscillator mechanism, · a first step of measuring a reference oscillation frequency of an inertia element around the Z direction in the XY plane, · a second step of measuring at least one secondary oscillation frequency of the inertia element in the YZ plane around the X direction, · a third step of comparing the secondary oscillation frequency with the reference oscillation frequency to confirm that the secondary oscillation frequency has a value substantially different from a multiple of the reference oscillation frequency, · a fourth step of changing the position of the control weight with respect to the main arm such that the secondary oscillation frequency is substantially different from a multiple of the reference oscillation frequency when the secondary oscillation frequency has a value close to or substantially equal to a multiple of the reference oscillation frequency and relates to a method including the above steps.

[0028] According to certain embodiments of the present invention, the method includes a fifth confirmation step of measuring the secondary oscillation frequency and confirming that a value other than a multiple of the reference oscillation frequency can be obtained by the new position of the lateral adjustment weight.

Brief Description of the Drawings

[0029] Further features and advantages of the present invention will become apparent from the following detailed description with reference to the accompanying drawings.

Figure 1

Figure 2

Figure 3

Figure 4

DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention mainly relates to a balance wheel and an oscillator mechanism for a timepiece including such a balance wheel.

[0031] In FIGS. 1 and 2, this timepiece oscillator mechanism 1 includes a structure 10 and an anchor block 30 from which at least one inertial element 2 configured to oscillate with a first rotational degree of freedom RZ about a pivot axis extending in a first direction Z is suspended. The anchor block 30 is suspended from the structure 10 by a flexible suspension 300 having a flexible blade, and the flexible suspension 300 is configured to allow the anchor block 30 to move with five flexible degrees of freedom of the suspension. The five flexible degrees of freedom are · A first translational degree of freedom in 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 in the second direction X, and · A third rotational degree of freedom RY about an axis extending in the third direction Y are.

[0032] The structure 10 includes an upper platform 34 and a lower platform 35, and the inertial element 2 is suspended between the upper platform 34 and the lower platform 35.

[0033] This inertial element 2 is subject to a restoring force applied by a restoring means. In an embodiment, the restoring means is a flexible pivot 200 including a plurality of substantially vertical elastic blades 3, each elastic blade 3 having a first end fixed to an anchor block 30 and a second end fixed to the inertial element 2. In the figure, the oscillator mechanism 1 includes two intersecting elastic blades 3. One elastic strip 3 is basically deformable in a plane XY perpendicular to a first direction Z.

[0034] Thanks to the restoring means, the inertial element 2 can oscillate in the XY plane, and the first Z direction is perpendicular to the XY plane.

[0035] The inertial element 2 comprises a clamp 20 to which the elastic blade 3 is attached.

[0036] The inertial element 2 also comprises a template 15 connected to the attachment 20. The template 15 is elongated in a substantially symmetrical bone shape. The rocker arm 15 comprises a main arm 6 arranged along the longitudinal axis of the rocker arm 15 corresponding to the direction X when the mechanism 1 is stationary and the rocker arm is is not oscillating.

[0037] Also, the template 15 comprises two ends 7, 8 of the main arm 6 that are wider than the main arm 6. For example, the ends 7, 8 and the main arm 6 are made of the same material. Alternatively, the ends 7, 8 are attached to the main arm 6.

[0038] Peripheral inertial weights 9 are attached to each of the ends 7, 8. The first end 7 comprises one peripheral inertial weight 9, and the second end 8 comprises two axial inertial weights 9. These peripheral adjustment weights 9 make it possible to adjust the speed of the oscillator mechanism by changing the inertia of the template 15, particularly with respect to the Z direction.

[0039] These peripheral weights 9 also make it possible to adjust the position of the center of mass of the inertial element 2 in the X and Y directions. The peripheral weights 9 are adjusted using procedures well known to those skilled in the art. By measuring the movement at four vertical positions, the displacements required for each of the three peripheral weights 9 can be estimated using equations well known to those skilled in the art.

[0040] Preferably, these peripheral weights 9 are screws whose positions can be changed relative to the ends 7, 8.

[0041] The inertial element 2 is configured to oscillate at least partially about a first pivot stud 5 extending from the upper platform 34 of the structure 10, and the pivot stud 5 is configured such that the inertial element 2 can pivot about it.

[0042] For this purpose, the main arm includes a hub 16 for inserting the first pivot stud 5. The hub 16 has a diameter larger than that of the first stud 5 so that the pendulum 15 can rotate around it. The hub 16 is preferably arranged at the center of the arm.

[0043] According to the present invention, the pendulum 15 includes at least one lateral weight 11 for adjusting the inertia of the pendulum 15, and the weight 11 is attached to the main arm 6. In this embodiment, the pendulum 15 includes two lateral weights 11 attached to the main arm 6. The two lateral weights 11 are attached to the main arm 6 symmetrically with respect to the longitudinal axis of the template 15.

[0044] These lateral weights 11 are arranged perpendicular to the longitudinal axis of the main arm 6 so as to be able to change the oscillation frequency of the main arm 6 around its longitudinal axis. The lateral weights 11 can also move within the main plane XY of the pendulum 16.

[0045] Each transverse weight 11 is movable so as to be able to take a plurality of positions closer to or farther from the main arm 6. In this way, the inertia of the template can be adjusted around the direction X. When the weight moves away from the main arm, the inertia of the tent ring around the X direction increases, while when the weight approaches the main arm, the inertia of the tent ring 15 around the X direction decreases.

[0046] The transverse weight 11 is a screw having a polygonal head and a threaded shank extending from the polygonal head. In order to expand the adjustment range of the inertia around the X direction, several variations of the transverse weight 11 having different sizes of heads can be manufactured.

[0047] The transverse weight 11 also deviates from the center of the main arm 6 towards the first end 7. The main arm 6 has an enlarged portion 12 where the transverse adjustment weight 11 is disposed. The enlarged portion 12 extends from the first end 7 and includes a central cavity 13 bounded by two side walls 14, and a screw is screwed into the central cavity 13.

[0048] Thanks to these transverse weights 11, it is possible to change the secondary vibration frequency of the tent ring 15 around the X direction, in particular, to avoid multiple values of the reference vibration frequency of the tent ring 15 around the Z direction in the XY plane.

[0049] The inertia element 2 also includes an anchor 25 assembled under the attachment 20, and the anchor 25 is disposed at the center of the tent ring 15 and the hub 16. The anchor 25 includes two main arms 17, 18 in the form of circular arcs, and the ends of the two main arms 17, 18 are configured to cooperate with a derailleur wheel (not shown). The derailleur can be mechanical or magnetic, or a combination of the two magnetic-mechanical.

[0050] The second pivot stud 19 extending from the lower platform 35 of the structure 10 is inserted into the anchor 25 along the axis of rotation of the inertial element 2. The anchor 25 has a second hole 21 into which the second stud 19 is inserted, and the second hole 21 is wider than the second stud 19 to avoid contact between the anchor 25 and the second hole 21. The second stud 19 is arranged in line with the first stud 5. In this way, the inertial element 2 surrounds the first stud 5 and the second stud 19, one inserted into the tension ring 15 and the other into the anchor 25, enabling the inertial element 2 to vibrate along the axis of rotation passing through the two studs 5, 19. The amplitude of the vibration in the vibration plane of the inertial element 2 is, for example, in the range of 20° to 40°. The frequency of the vibration is, for example, greater than 10 Hz.

[0051] The present invention also relates to a method 40 of adjusting a clock oscillator mechanism as described above in order to avoid large secondary vibrations in a plane perpendicular to the XY plane, particularly secondary rotational vibrations about the X direction.

[0052] As shown in FIG. 4, the method 40 includes a first step 41 of measuring the reference vibration frequency of the inertial element 2 about the Z direction in the XY plane. For this purpose, the number of vibrations per second of the inertial element 2 is measured. For example, a measurement method using a laser measurement system well-known to those skilled in the art is used.

[0053] In a second step 42, the secondary vibration frequency of the inertial element 2 in the YZ plane about the X direction is measured.

[0054] The third step 43 consists of comparing the secondary vibration frequency with the reference vibration frequency. More specifically, it is confirmed whether the secondary vibration frequency has a value substantially different from a multiple of the reference vibration frequency.

[0055] If the secondary vibration frequency has a value substantially different from a multiple of the reference vibration frequency, the position of the lateral adjustment weight 11 with respect to the main arm 6 is not changed.

[0056] When the secondary vibration frequency is close to a multiple of the reference vibration frequency or is substantially equal to the reference vibration frequency, the method includes a fourth step 44. The fourth step 44 consists of changing the position of the lateral adjustment weight 11 with respect to the main arm 6 such that the secondary vibration frequency is substantially different from a multiple of the reference vibration frequency.

[0057] The method can include a fifth verification step 45 of measuring the secondary vibration frequency and verifying that a value other than a multiple of the reference vibration frequency can be obtained by the new position of the lateral adjustment weight 11. Thus, if necessary, the position of the lateral weight 11 can be changed again if the measured secondary vibration frequency is not satisfactory.

[0058] Naturally, the present invention is not limited to the illustrated embodiments, and various modifications and variations will be apparent to those skilled in the art.

Claims

1. A pendulum (15) for a timepiece oscillator mechanism (1) comprising a main arm (6) arranged along a longitudinal axis, said pendulum (15) comprising at least a first transverse weight (11) for adjusting the inertia of said pendulum (15), said first transverse weight (11) being movably attached to said main arm (6) of said pendulum (15) so as to be able to assume a number of positions closer or further from said main arm (6) for adjusting the inertia of said pendulum (15); The pendulum (15) is characterized in that the first lateral weight (11) is arranged perpendicular to the longitudinal axis of the main arm (6) so as to be able to change the frequency of oscillation of the main arm (6) about the longitudinal axis of the main arm (6).

2. 2. Pendulum (15) according to claim 1, characterized in that the first transverse weight (11) is movable in the main plane of the pendulum (15).

3. 2. The pendulum (15) according to claim 1, characterized in that the pendulum (15) comprises a second transverse weight (22) arranged on the main arm (6) symmetrically to the first transverse weight (11) with respect to the longitudinal axis of the main arm (6) for adjusting the inertia of the pendulum (15).

4. 4. Pendulum (15) according to claim 3, characterized in that the first (11) and the second (22) transverse weights are screws.

5. 4. Pendulum (15) according to claim 3, characterized in that the first (11) and the second (22) transverse weights are offset from the centre of the main arm (6) of the pendulum (15).

6. 2. The pendulum (15) according to claim 1, characterized in that the pendulum (15) comprises at least one axial peripheral weight (9) attached to both ends (7, 8) of the main arm (6) for adjusting the inertia of the pendulum (15).

7. The pendulum (15) of claim 1, characterized in that the pendulum (15) includes a hub (16).

8. 4. Pendulum (15) according to claim 3, characterized in that the main arm (6) comprises an enlarged portion (12) in which the first (11) and the second (22) transverse weights are arranged.

9. 1. A timepiece oscillator mechanism (1) comprising a structure (10) and an anchor block (30) on which is suspended at least one inertial element (2) configured to oscillate with a first rotational degree of freedom RZ about a pivot axis (D) extending in a first direction Z, said inertial element (2) being configured to receive a return force exerted by return means configured to oscillate said inertial element (2), characterized in that said inertial element (2) comprises a pendulum (15) according to claim 1.

10. 10. A timepiece oscillator mechanism (1) according to claim 9, characterized in that said pendulum (15) is mounted such that the longitudinal axis of said main arm (6) is substantially perpendicular to said first direction Z.

11. 10. A timepiece oscillator mechanism (1) according to claim 9, characterized in that the pendulum (15) is mounted such that the main plane of the pendulum (15) is substantially perpendicular to the first direction Z.

12. A method (40) for developing a timepiece oscillator mechanism (1) according to claim 9, said method (40) comprising the steps of: a first step (41) of measuring a normal vibration frequency of said inertial element (2) about a Z direction in an XY plane; a second step (42) of measuring at least one secondary vibration frequency of said inertial element (2) in the YZ plane about the X direction; a third step (43) of comparing the secondary vibration frequency with the reference vibration frequency to verify that the secondary vibration frequency has a value different from a multiple of the reference vibration frequency; a fourth step (44) of modifying the position of the first transverse weight (11) relative to the main arm when the secondary vibration frequency has a value close to or equal to a multiple of the reference vibration frequency, so that the secondary vibration frequency is different from the multiple of the reference vibration frequency; A method (40) comprising:

13. 13. The method (40) according to claim 12, characterized in that it comprises a fifth verification step (45) of measuring the secondary vibration frequency to verify that a new position of the first lateral weight (11) allows to obtain a value other than a multiple of the reference vibration frequency.

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