Adjusting member for timepiece movement, timepiece movement and timepiece

Abstract

The utility model relates to an adjusting member (1) for a clock movement, a clock movement and a clock. The adjusting member of the timepiece movement comprises an inertial mass such as a balance (23), a balance spring (25) comprising a winding band (2) and an adjusting device (30) for adjusting the stiffness of the balance spring, a balance clip (22) and an actuation system (20) for adjusting the rate of the balance spring (25), the device being provided with a flexible element (5) arranged in series with the winding band (2), the adjustment device (30) comprises prestressing means (6) for applying a variable force or torque to the flexible element (5), and the actuation system (20) comprises eccentric means for actuating the prestressing means (6) of the adjustment device (30).

Description

TECHNICAL FIELD

[0001] The present utility model relates to the field of watchmaking, and more particularly to the field of mechanical watchmaking in which the driving energy is regulated by a regulating member. More particularly, the present utility model relates to a regulating member provided with a precision actuation system for adjusting the rate of a balance spring, a timepiece movement comprising such a regulating member, and a timepiece comprising such a timepiece movement. BACKGROUND

[0002] In most mechanical watches, the energy required to rotate the hands (for example the minute and hour hands) is stored in a barrel and then transmitted by a balance system with a spring, comprising a flywheel called the balance, combined with a spring in the form of a spiral winding called the balance spring.

[0003] The inner end of the balance spring is attached to a stem that rotates integrally with the balance; the outer end of the balance spring is attached to a collet mounted on a collet holder, which is itself rigidly connected to a fixed bridge.

[0004] The rotation of the balance is maintained and its oscillations are counted by an escapement comprising an escapement lever excited by low-amplitude oscillatory motion, provided with two escapement forks that engage the teeth of an escapement wheel. When the escapement wheel is engaged in this way, it is caused to rotate in steps, the frequency of said rotation being determined by the frequency of oscillation of the escapement lever, which is itself set to the frequency of oscillation of the balance with spring.

[0005] In a conventional escapement, the frequency of oscillation is approximately 4 Hz, or about 28,800 vibrations per hour (V / h). One of the objectives of the skilled watchmaker is to ensure the isochronism and regularity of the oscillations of the balance (or constancy of the rate).

[0006] The rate of the balance spring can be adjusted in a known manner by adjusting the effective length of the balance spring, defined as the length of the curve between its inner end and a counting point located near its outer end and generally defined by a pair of flanks carried by a key mounted on the index system.

[0007] In operation, this index system cannot rotate around the axis of the balance spring. However, its angular position can be fine-tuned by manual intervention, for example by pivoting the index system using a screwdriver on an eccentric device acting as a cam.

[0008] The assembly comprising the clamping plate, the pointer system, the key, the collet holder, the collet, the arbor, the hairspring and the balance wheel is generally called "regulating member". Examples of regulating members are given in European patent EP 3304215 and European patent EP 2 876 504, both of which are filed by the watch manufacturer ETA.

[0009] There exist pointer systems having a collet holder to which the outer end of the balance spring is attached, and in which the pointer system key is left with a play to allow the balance spring to move between two lugs. However, the timing properties, in particular the anisochronism, are very sensitive to the play at the pointer key, and it is difficult to accurately control this play.

[0010] In some devices, the lugs can be adjusted to clamp the balance spring in order to eliminate the play, in particular when the balance spring is in operation. In this case, the rate is first adjusted by moving the pointer key, and then the balance spring is clamped to this key. However, clamping the balance spring to the pointer key runs the risk of stressing it and creating timing errors, in particular due to the off-centering of the upper bridge. Moreover, removing the play also changes the rate, and once the balance spring has been clamped, it is not possible to move the pointer key along the balance spring to fine-tune the rate.

[0011] Other balance springs have an integrated regulating device. In these balance springs, the rate is not adjusted by changing the effective length of the balance spring, but by applying a force or a torque to an elastic element arranged in series with the balance spring. In this way, it is possible to modify the elastic element, and thus the stiffness of the entire balance spring. Adjusting the stiffness of the balance spring allows the rate of the regulating member to be adjusted. Such a balance spring provided with an elastic element is described, for example, in patent application EP 4009115.

[0012] However, in these cases, it is not possible to use a usual pointer system, because it is not compatible with the balance spring regulating device. Moreover, since the rate must be adjusted to a very fine degree, there must be no play between the balance spring and the area where the balance spring interacts with the pointer mechanism. More specifically, if this is not the case, there is a risk of changing the rate when an impact occurs, if the balance spring does not reposition itself in exactly the same way after being subjected to an impact. Invention content

[0013] The object of the present invention is to overcome some or all of the above-mentioned drawbacks by providing an actuation system that is compatible in particular with regulating devices of this type.

[0014] To this end, the utility model relates to an adjusting member for a timepiece movement, comprising an inertial mass, such as a balance, a balance spring, a balance clamping plate and an actuation system for adjusting the rate of the adjusting member, the balance spring comprising a coiled strip and a device for adjusting the stiffness of the balance spring, the device being provided with an elastic element arranged in series with the coiled strip, the adjusting device comprising a prestressing device for applying a variable force or torque to the flexible element.

[0015] The utility model features that the actuation system comprises an eccentric device actuating the prestressing device of the adjusting device.

[0016] Thanks to the utility model, it is possible to adjust the rate of the adjusting member by changing the position of the eccentric device only, the eccentric device acting on the prestressing device to adjust the rate of the adjusting member.

[0017] In a particular embodiment of the utility model, the eccentric device is arranged to pass through the balance clamping plate, whereby the eccentric device is rotatably mounted.

[0018] In a particular embodiment of the utility model, the eccentric device comprises a head and a body extending from the head.

[0019] In a particular embodiment of the utility model, the body comprises a finger extending from the body, the finger being off-center with respect to the main axis of the body of the eccentric device.

[0020] In a particular embodiment of the utility model, the head comprises a recess intended to receive the tip of a tool for actuating the eccentric device.

[0021] In a particular embodiment of the utility model, the prestressing device comprises a first movable lever connected to the flexible element, wherein the eccentric device is in direct or indirect contact with the first lever so as to be able to actuate the first lever.

[0022] In a particular embodiment of the utility model, the prestressing device comprises a second movable lever connected to the flexible element, wherein the eccentric device is in direct or indirect contact with the second lever so as to be able to actuate the second lever.

[0023] In a particular embodiment of the utility model, the prestressing device comprises a movable body connected to the first lever and / or to the second lever, wherein the finger is in contact with the movable body so as to be able to move the movable body.

[0024] In a particular embodiment of the utility model, the finger comprises a peripheral groove cooperating with the movable body.

[0025] In a particular embodiment of the present invention, the actuation system includes a pin retainer, the pin retainer including a pin on which the balance wheel hairspring is mounted, the pin being mechanically connected to an elastic element of the balance wheel hairspring.

[0026] In a particular embodiment of this invention, the pin is mechanically connected to the elastic element.

[0027] In a particular embodiment of this utility model, the pin retainer is arranged on the balance wheel clamp plate around the bearing on the balance wheel shaft.

[0028] This utility model also relates to a watch movement that includes such an adjusting component.

[0029] This utility model also relates to a timepiece, such as a wristwatch, that includes such a timepiece movement. Attached Figure Description

[0030] The objects, advantages, and features of this invention will become apparent after reading the several embodiments given with reference to the accompanying drawings. These embodiments are provided for illustrative purposes only and are not intended to limit the scope of this invention, wherein:

[0031] Figure 1 A top view of the adjusting member according to a first embodiment of the present invention is shown in an illustrative manner.

[0032] Figure 2 Diagrammatically Figure 1 The bottom view of the first embodiment of the adjusting member shown.

[0033] Figure 3 Diagrammatically Figure 1 A side view of a cross-section taken along section line III of the first embodiment of the adjusting member shown.

[0034] Figure 4 Diagrammatically Figure 1 An exploded perspective view of the first embodiment of the adjustment member shown, and

[0035] Figure 5 Diagrammatically Figure 1 A top view of the balance wheel and hairspring of the first embodiment of the regulating member shown. Detailed Implementation

[0036] Figures 1 to 5 A first embodiment of an adjusting member 1 intended for arrangement in a watch movement (not shown in the accompanying drawings) is illustrated in an illustrative manner. Such a watch movement includes, for example, a plate provided with a recess for receiving the adjusting member 1, the adjusting member 1 being provided with an inertial mass, and an elastic return element for the inertial mass, the elastic return element being configured to cause the inertial mass to oscillate.

[0037] The regulating member 1 further comprises an actuation system 20, a ring balance 23 as inertial mass, a balance staff 24, a balance spring 25 as elastic return element and a balance clamping plate 22.

[0038] In the Figures 1 to 3 , the balance 23, the balance spring 25, the balance clamping plate 22 and the actuation system 20 are stacked together, in this case from bottom to top.

[0039] The balance staff 24 is centered and passes through the center of the balance 23, the center of the balance spring 25 and the balance clamping plate 22. The balance staff 24 is held by two anti-shock bearings 28 arranged at both ends of the balance staff 24. A first bearing (not shown in the figures) is arranged below the balance 23 and the balance clamping plate 22, while a second bearing 28 is held by the balance clamping plate 22. The balance clamping plate 22 has a hole, in this case a through hole, inside which the second bearing 28 is held. The actuation system 20 is mounted on the balance clamping plate 22 and, in this embodiment, is arranged along the central axis of the balance staff 24.

[0040] Figure 5 An example of a balance spring 25 extending preferably substantially in one plane is shown. The balance spring 25 comprises a flexible band 2 wound several turns around itself, the band 2 having a predefined stiffness. The inner end 9 of the band 2 is integral or assembled with a support 3, commonly called a collet. The support 3 is roughly triangular in shape and fits around the shaft of the balance 24.

[0041] The balance spring 25 further comprises an adjustment device 30 for adjusting its stiffness. The adjustment device 30 can in particular be actuated by a user, for example when the regulating member is mounted on a plate of a watch movement.

[0042] The adjustment device 30 comprises a flexible element 5 arranged in series with the band 2, with the flexible element 5 connecting one end 4 of said band 2 to a fixed support 53 and being integral with one end 4 of the band 2. The flexible element 5 is integral with the outer end 4 of the band 2. The flexible element 5 is a distinct element from the band 2.

[0043] The flexible element 5 adds an additional stiffness to the stiffness of the band 2. The flexible element 5 is preferably stiffer than the band 2. In this case, the flexible element 5 is arranged as an extension of the band 2. Preferably, the adjustment device and the band 2 are integral or even made of the same material, for example silicon.

[0044] In this embodiment of the balance spring, the flexible element 5 comprises two flexible parts 15, 16 each connecting the band 2 to a fixed support 53.

[0045] The two flexible parts 15, 16 are arranged axisymmetrically relative to each other along the axis A of the balance spring 25. In other words, the two flexible parts 15, 16 are positioned symmetrically relative to said axis A.

[0046] On the one hand, the axis A passes substantially through the center O of the balance spring; while on the other hand, the axis A preferably passes through the outer end 4 of the strip 2.

[0047] The two flexible parts 15, 16 are thus arranged on the periphery of the balance spring such that the two flexible parts 15, 16 are arranged at the same distance from the center O of the balance spring 25.

[0048] The two flexible parts 15, 16 are preferably arranged in "mirror image" positions relative to each other relative to the axis A. To this end, the two flexible parts 15, 16 are preferably substantially identical.

[0049] The flexible parts 15, 16 each comprise a curved flexible strip 55, which preferably forms a semicircle, and which extends from the end of a fixed support 53. Each curved flexible strip 55 is also connected to the outer end 4 of the strip 2 by means of the main flexible strip 7. In this case, the main flexible strips 7 are arranged continuously with each other.

[0050] The fixed support 53 has an open trapezoidal shape on the long side facing the outer end 4 of the strip 2.

[0051] The device for adjusting the balance spring 25 also comprises a prestressing device 6 for applying a variable force or torque to the flexible element 5. In this way, the stiffness of the balance spring can be adjusted. Thanks to the prestressing device 6, this torque or force can be adjusted continuously. In other words, the torque or force is not limited to isolated values. The stiffness of the flexible element 5 can thus be adjusted very precisely.

[0052] Preferably, the prestressing device 6 applies substantially the same force or torque to each flexible part 15, 16. The direction of the force is preferably substantially symmetrical relative to the axis A.

[0053] The prestressing device 6 also comprises two levers 14, 26, which each connect a curved strip 55 to the same movable body 19, which is arranged on the other side of the balance spring 25 relative to the fixed support 53. In this case, the movable body 19 is hook-shaped.

[0054] This variable force or torque is applied to the movable body 19. This variable force or torque is transmitted at least partially to the main flexible strips 7 of the flexible parts 15, 16 of the flexible element 5 via the levers 26.

[0055] In Figures 1 to 4In the embodiment illustrated in the figures, the actuation system 20 is equipped with a stud holder 31 provided with a stud 34.

[0056] The stud holder 31 is in contact with the balance clamping plate 22 and is held and positioned by the shock absorber 28.

[0057] During the operation of the adjustment member 1, the stud holder 31 is preferably fixed with respect to the balance clamping plate 22.

[0058] The stud holder 31 comprises a central ring 38 arranged around the second bearing 28.

[0059] The stud holder 31 comprises a protrusion 41 extending radially from the central ring 38, the protrusion 41 pressing the stud 34 by means of a screw 74.

[0060] The stud 34 cooperates with the fixed support 53 of the flexible element 5. Thus, the flexible element 5 is held by the stud. The balance spring 25 is held by the flexible element 5 on the one hand and by the support 3 on the other hand.

[0061] The prestressing device 6 is also supported by the stud holder 31.

[0062] The stud and the balance spring 25 are assembled together, for example by bonding, brazing, welding, by metallic glass deformation or by mechanical fastening.

[0063] In order to be able to apply this variable force or torque to the balance spring 25, the adjustment member comprises an actuation system 20.

[0064] According to the invention, the actuation system 20 comprises a rotatable eccentric device 10 cooperating with the balance spring 25 to modify its stiffness.

[0065] The eccentric device 10 comprises a head 21 provided with a recess 18 for receiving the tip of a tool for adjusting the eccentric device 10. The eccentric device 10 has a body 11 extending from the head 21, the body 11 being preferably cylindrical.

[0066] The eccentric device 10 also comprises a finger 12 which is off-center with respect to the main axis of the body 11 of the eccentric device 10. The finger 12 extends from the body 11. The finger 12 is mechanically coupled to the prestressing device 6, but does not obstruct the band 2.

[0067] The eccentric device 10 is arranged to pass through the balance clamping plate 22. The balance clamping plate 22 comprises a flared through hole 17 in order to hold the head 21 of the eccentric device 10 and to allow the body 11 and the finger 12 to pass through to the other side of the balance clamping plate 22.

[0068] The eccentric device 10 is held by a clamp 29 clamped around the body 11 of the eccentric device 10 below the balance clamping plate 22.

[0069] Preferentially, the body 11 comprises a recess 32 into which the clamp 29 is inserted to hold the eccentric device 10 in the hole 17.

[0070] The eccentric device 10 is rotatably mounted in the balance clamping plate 22. It can thus rotate in the hole 17 and the clamp 29 around a main axis of the eccentric device 10, preferably substantially perpendicular to the balance clamping plate 22 and / or substantially parallel to the balance axle 24.

[0071] The finger 12 of the eccentric device 10 is in contact with the movable body 19 of the prestressing device 6 so as to be able to more or less forcefully push the levers 14, 26 when the eccentric device 10 rotates.

[0072] Preferentially, the finger 12 comprises a peripheral recess 33 that cooperates with the movable body 19 of the balance spring 25, the movable body 19 being inserted into the recess 33.

[0073] Thus, when the eccentric device 10 rotates, the finger 12 more or less presses on the movable body 19, since it is eccentric with respect to the main rotation axis of the eccentric device 10.

[0074] The movement of the finger 12 with respect to this movable body modifies the stiffness of the flexible element 5, since this movement exerts more or less force or torque on the movable body 19 of the prestressing device 6, so that the stiffness of the flexible parts 15, 16 of the flexible element 5 is varied via the lever 26 and thus the overall stiffness of the balance spring 25 is also varied. The actuation system 20 thus allows to adjust the rate of said regulating member 1.

[0075] To this end, the actuation system 20 can be used to modify the position of the finger 12.

[0076] The actuation system 20 is configured to adjust the rate of the regulating member 1 with a resolution less than or equal to 1 s / day, preferentially less than or equal to 0.5 s / day, or even less than or equal to 0.1 s / day. The configuration of the regulating member 1 allows to achieve such a precision.

[0077] It goes without saying that the present invention is not limited to the embodiments of the regulating member described with reference to the drawings and that alternatives can be considered without departing from the scope of the present invention.

Claims

1. Regulating member (1) for a timepiece movement comprising an inertial mass, a balance spring (25), a balance clamping plate (22) and an actuation system (20) for adjusting the rate of the balance spring (25), the balance spring (25) comprising a coiled strip (2) and adjustment means (30) for adjusting the stiffness of the balance spring, the adjustment means being provided with a flexible element (5) arranged in series with the coiled strip (2), the adjustment means (30) comprising prestressing means (6) for applying a variable force or torque to the flexible element (5), characterized in that, The actuation system (20) comprises an eccentric device (10) actuating the prestressing device (6) of the regulating means (30).

2. The adjustment member of claim 1, wherein The eccentric device (10) is rotatably mounted through the balance clamping plate (22).

3. Adjusting member according to claim 1 or 2, characterized in that The eccentric device (10) comprises a head (21) and a main body (11) extending from the head (21).

4. The adjustment member of claim 3, wherein, The eccentric device (10) further comprises a finger (12) extending from the main body (11), the finger (12) being off-center with respect to a main axis of the main body (11) of the eccentric device (10).

5. The adjustment member of claim 3, wherein, The head (21) comprises a recess (18) intended to receive a tip of a tool for actuating the eccentric device (10).

6. The adjustment member of claim 4, wherein, The prestressing device (6) comprises a first movable lever (14) connected to the flexible element (5), wherein the eccentric device (10) is in direct or indirect contact with the first lever (14) so as to be able to actuate the first lever (14).

7. The adjustment member of claim 6, wherein, The prestressing device (6) comprises a second movable lever (26) connected to the flexible element (5), wherein the eccentric device (10) is in direct or indirect contact with the second lever (26) so as to be able to actuate the second lever (26).

8. The adjustment member of claim 7, wherein, The prestressing device (6) comprises a movable body (19) connected to the first lever (14) and / or to the second lever (26), wherein the finger (12) is in contact with the movable body (19).

9. The adjustment member of claim 8, wherein, The finger (12) comprises a peripheral groove (33) cooperating with the movable body (19).

10. The adjustment member according to claim 1 or 2, characterized in that The actuation system (20) comprises a stud holder (31) comprising a stud (34) on which the balance spring (25) is mounted, the stud (34) being mechanically coupled to the flexible element (5) of the balance spring (25).

11. The adjustment member of claim 10, wherein, The stud holder (31) is arranged on the balance clamping plate (22) around a bearing (28) on a balance shaft (24).

12. The adjustment member of claim 1, wherein, The inertial mass is a balance (23).

13. A timepiece movement, characterized in that, The timepiece movement comprises a regulating member (1) according to any one of claims 1 to 12.

14. A timepiece, characterized by The timepiece comprises a timepiece movement according to claim 13.

15. A timepiece according to claim 14, characterised in that, The timepiece is a watch.

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