Timepiece regulator provided with an index-assembly system

Abstract

The invention relates to a regulating organ (1) for a clockwork movement comprising an inertial mass, for example an annular balance wheel (23), a balance spring (25), and a regulator system (20) for adjusting the rate of the balance spring (25). The balance spring (25) comprises a wound ribbon (2) and means for adjusting the stiffness of the balance spring having an elastic element (5) arranged in series with the wound ribbon (2). The regulator system (20) comprises a stud holder (31) having a first stud (34) and a second stud (35). The elastic element (5) is arranged between the first stud (34) and the second stud (35), the first stud (34) being movable relative to the second stud (35), the movement of the first stud (34) modifying the stiffness of the balance spring (25).

Description

Technical field of the invention

[0001] The invention relates to the field of watchmaking, and more particularly to the field of mechanical watchmaking, where the regulation of driving energy is provided by a regulating organ. More specifically, the invention relates to a regulating organ equipped with a regulator system, a watch movement comprising such a regulating organ, and a timepiece comprising such a watch movement. Technological background

[0002] In most mechanical watches, the energy needed to rotate the hands (e.g., minute and hour indicator hands) is stored in a barrel and then released by a balance-spring system, which includes a flywheel called a balance wheel, associated with a spring in the form of a spirally wound ribbon, called a balance spring.

[0003] At one internal end, the spiral is fixed to a shaft that is rotating with the balance wheel; at one external end, the spiral is fixed to a stud mounted on a stud holder which is itself fixed to a bridge (or cock).

[0004] The balance wheel's rotation is maintained—and its oscillations counted—by an escapement mechanism comprising an anchor with a low-amplitude oscillating motion, equipped with two pallets that engage the teeth of an escape wheel. Thus engaged, the escape wheel is imparted a step-by-step rotational movement whose frequency is determined by the anchor's oscillation frequency, itself synchronized with the balance wheel's oscillation frequency.

[0005] In a traditional escapement mechanism, the oscillation frequency is approximately 4 Hz, or about 28,800 vibrations per hour (A / h). One objective of skilled watchmakers is to ensure the isochronism and regularity of the oscillations (or constant rate) of the balance wheel.

[0006] It is known to regulate the course of the balance wheel by adjusting the active length of the balance spring, defined as the curvilinear length between its inner end and a counting point, located in the vicinity of the outer end of the balance spring and generally defined by a pair of stops carried by a key mounted on a rack system.

[0007] In operation, this regulator system is fixed in rotation relative to the axis of the balance spring. However, it is possible, by manual intervention, to finely adjust its angular position, e.g. by pivoting, using a screwdriver, an eccentric that acts on the regulator system in the manner of a cam.

[0008] The assembly comprising the bridge, the regulator system, the key, the stud holder, the stud, the arbor, the spring, and the balance wheel is commonly referred to as the "regulating organ." Examples of regulating organs are provided by international application WO 2016 / 192957 and by European patent EP 2 876 504, both filed in the name of the watch manufacturer ETA.

[0009] Some racket systems feature a stud holder to which one end of the balance spring is attached, and the racket system key allows for some play to permit the spring to move between two stops. However, the chronometric properties, particularly anisochronism as a function of amplitude, are highly sensitive to the play in the racket key, which is difficult to control precisely.

[0010] In some mechanisms, the stops are adjustable to tighten the balance spring and eliminate play, particularly during its operation. In this case, the rate is first set by moving the regulator key, then the balance spring is tightened with the key. However, tightening the balance spring with the regulator key risks putting stress on it and creating chronometric errors, notably by misaligning the coils. Furthermore, eliminating the play also alters the rate, and once the balance spring is tightened, the regulator key cannot be moved along the spring to fine-tune the rate.

[0011] Other balance springs incorporate an integrated adjustment mechanism. In these balance springs, the rate is not adjusted by changing the effective length of the balance spring, but by applying a force or torque to an elastic element arranged in series with the balance spring. This allows the stiffness of the elastic element, and consequently of the balance spring as a whole, to be modified. Adjusting the stiffness of the balance spring allows the rate of the regulating organ to be regulated. Such a balance spring with an elastic element is described, for example, in patent application EP21202213.1 and in patent CH704687B1.

[0012] However, in these cases, standard regulator systems cannot be used because they are incompatible with the balance spring adjustment mechanism. Furthermore, since the rate must be adjusted very precisely, it is essential that there be no play between the balance spring and its points of interaction with the regulator. Otherwise, the rate could be altered in the event of a shock if the balance spring does not return to its original position afterward. Summary of the invention

[0013] The aim of the present invention is to overcome all or part of the aforementioned disadvantages by proposing a racket system compatible with this type of adjustment device.

[0014] For this purpose, the invention relates to a regulating organ for clockwork movement according to the terms of the attached claim 1.

[0015] The invention is remarkable in that the racket system includes a peg holder mechanically linked to the elastic element, the peg holder having a first peg and a second peg, characterized in that the elastic element is arranged between the first peg and the second peg, the first peg being movable relative to the second peg, the displacement of the first peg modifying the stiffness of the spiral spring.

[0016] Thanks to the invention, we have a racket system compatible with an adjustment device for a spiral spring applying a force or torque on an elastic element of the spiral spring.

[0017] Indeed, by moving the first eyelet relative to the second eyelet, we modify the stiffness of the elastic element between the two eyelets, because a variable force or torque is applied to the elastic element by the two eyelets.

[0018] In addition, such a racket system is easy to use, and mounting on the watch movement does not require significant modification because the mounting is little different from a racket system usually used for a classic balance spring.

[0019] According to a particular embodiment of the invention, the eyelet holder comprises a first part equipped with the first eyelet, and a second part equipped with the second eyelet, the first part being movable relative to the second part to move the first eyelet. According to a particular embodiment of the invention, the first part and the second part are superimposed.

[0020] According to a particular embodiment of the invention, the racket system includes an adjustment means, such as an eccentric screw, cooperating with the first part so as to be able to move it when it rotates.

[0021] According to a particular embodiment of the invention, the racket system comprises an arm arranged on the first part and a cam cooperating with the arm, such that actuation of the cam moves the first part relative to the second part According to a particular embodiment of the invention, the racket system includes a return means, such as a spring, exerting a force between the first part and the second part to hold the arm of the first part against the cam. According to a particular embodiment of the invention, the second part is stationary relative to the plate. According to a particular embodiment of the invention, the first part is mobile in rotation relative to the second part.

[0022] According to a particular embodiment of the invention, the first eyelet is rotationally movable.

[0023] According to a particular embodiment of the invention, the spiral spring comprises a wound ribbon and means for adjusting the stiffness of the spiral spring, the adjustment means comprising an elastic element, the elastic element being arranged between the first pin and the second pin, the displacement of the first pin modifying the stiffness of the elastic element.

[0024] According to a particular embodiment of the invention, the adjustment means include prestressing means for applying a variable force or torque to the flexible element, the prestressing means being arranged between the first and second eyelet, the displacement of the first eyelet relative to the second eyelet actuating the prestressing means.

[0025] According to a particular embodiment of the invention, the prestressing means comprise a lever connected to the flexible element, the first pin being integral with a free end of the lever.

[0026] According to a particular embodiment of the invention, the flexible element is linked to a fixed support, the second eyelet being integral with the fixed support.

[0027] According to a particular embodiment of the invention, the prestressing means comprise a semi-rigid structure arranged in parallel with the flexible element, the lever being connected to the semi-rigid structure.

[0028] The invention also relates to a clockwork mechanism comprising such a regulating organ.

[0029] The invention also relates to a timepiece, for example a watch, comprising such a timepiece movement. Brief description of the figures

[0030] The aims, advantages and features of the present invention will become apparent from the reading of several embodiments given solely by way of non-limiting examples, with reference to the accompanying drawings in which: there figure 1 schematically represents a perspective view of a regulating organ according to a first embodiment of the invention, the regulating organ being arranged in a clockwork movement, the figure 2 schematically represents a perspective view of part of the first embodiment of the regulating organ of the figure 1 , without a balancing bridge and without a racket system, the figure 3 schematically represents a top view of a spiral spring of the regulating organ, the figure 4 schematically represents a perspective view of part of a regulating organ according to a second embodiment of the invention, the regulating organ being arranged in a clockwork movement, and the figure 5schematically represents a perspective view of the second embodiment of the regulating organ of the figure 4 . Detailed description of the invention

[0031] THE figures 1 and 2 show a schematic representation of a first embodiment of a regulating organ 1 arranged in a clockwork movement 10. The clockwork movement 10 includes a plate 21, an inertial mass, an elastic return element for the inertial mass configured to make it oscillate, and a balance bridge 22.

[0032] The regulating organ 1 further includes a racket system 20, an annular balance wheel 23 as an inertial mass, a balance shaft 24 and a balance spring 25 as an elastic return element.

[0033] The plate 21 has a housing 26 for receiving the regulating organ 1, in which, from bottom to top, are superimposed the balance wheel 23, the balance spring 25, the balance bridge 22, and the regulator system 20. The balance staff 24 is centered in the housing 26 and passes through the center of the balance wheel 23, the balance spring 25, and the balance bridge 22. The balance staff 24 is held by two shock-absorbing bearings 28 arranged at its two ends. The first bearing is located at the bottom of the housing 26, and the second bearing 28 is located above the housing 26 and is held by the balance bridge 22. The balance bridge 22 passes through the top of the housing 26 via the central axis of the housing 26. The balance bridge 22 has a through hole in which the second bearing 28 is held. The racket system 20 is mounted on the balance bridge 22 and is arranged on the central axis of the housing 26.

[0034] Represented on the figures 2 And 3 The balance spring 25 preferably extends substantially in a plane. The balance spring 25 comprises a flexible ribbon 2 wound upon itself in several turns, the ribbon 2 having a predetermined rigidity. The inner end 9 of the ribbon 2 is formed from or assembled to a support 3. The support 3 has a substantially triangular shape and is threaded around the balance staff 24.

[0035] The balance spring 25 also includes means for adjusting its rigidity. For example, these adjustment means can be operated by a user when the regulating organ is mounted on the movement's mainplate.

[0036] The adjustment means comprise a flexible element 5 arranged in series with the ribbon 2, the flexible element 5 connecting one end 4, 9 of said ribbon 2 to a fixed support 17, and integral with one of the ends 4, 9 of the ribbon 2. The flexible element 5 is integral with the outer end 4 of the ribbon 2. The elastic element 5 is a separate element from the ribbon 2. The fixed support 17 is fixed relative to the plate 21.

[0037] The flexible element 5 adds additional rigidity to that of the ribbon 2. The flexible element 5 preferably has a greater rigidity than that of the ribbon 2. The flexible element 5 is arranged here in the extension of the ribbon 2. Preferably, the adjustment means and the ribbon 2 are monobloc, or even formed from the same material, for example silicon.

[0038] The flexible element 5 of the spiral spring 25 includes a pivot with uncrossed flexible leaves. The pivot comprises two uncrossed flexible leaves 11, 12 and a rigid part 18. The flexible leaves 11, 12 are joined, on one side laterally to a fixed support 17, and on the other side to the rigid part 18 by bringing them closer together. Thus, preferably, the flexible blades 11, 12 move away from the rigid part 18 to the fixed support 17. The outer end 4 of the ribbon 2 is joined to the rigid part 18. The fixed support 17 is stationary relative to the plate 21. The fixed support 17 has an L shape, a first arm 46 of the L serving as a link with the flexible blades 11, 12, the second arm 47 of the L being oriented on the opposite side of the pivot with uncrossed blades so as to be able to be assembled to the clock movement 10.

[0039] The means for adjusting the spiral spring 25 further include preload means 6 for applying a variable force or torque to the flexible element 5. This allows the stiffness of the spiral spring to be adjusted. The torque or force is continuously adjustable by the preload means 6. In other words, the torque or force is not restricted to specific values. Therefore, the stiffness of the flexible element 5 can be adjusted with high precision.

[0040] The prestressing means 6 comprise a secondary flexible blade 19, arranged on an opposite side of the rigid part 18 in line with the pivot with crossed blades. The secondary flexible blade 19 is positioned tangentially to the band 2, at the outer end 4.

[0041] The secondary flexible blade 19 is connected at the other end to a curved lever 14 which bypasses the ribbon 2. The lever 14 is connected, in addition to the secondary flexible blade 19, to a semi-rigid structure 27 linked to the fixed support 17. The semi-rigid structure 27 deforms in part when the lever 14 is actuated by force or torque.

[0042] The force or torque is exerted on the free end 15 of the lever 14. Thus, the lever 14 of the preload means 6 transmits the force or torque to the flexible element 5 via the secondary flexible blade 19 and the semi-rigid structure 27, so as to modify the stiffness of the spiral spring 25.

[0043] In order to be able to apply the variable force or torque on the spiral spring 25, the regulating member includes a particular racket system 20 according to the invention.

[0044] In the first embodiment of figures 1 and 2The snowshoe system 20 is equipped with a two-part piton holder 31, a first part 32 and a second part 33. The first part 32 of the piton holder 31 suspends the first piton 34, while a second part 33 of the piton holder 31 is equipped with the second piton 35. The piton holder 31 is mechanically linked to the elastic element 5, but it does not block the tape 2.

[0045] The first part 32 of the stud holder 31 is positioned partially above the second part 33 of the stud holder 31, which is in contact with the balance bridge 22. The regulator system 20 includes two screws 36, 37. The first screw 36 is eccentric to allow angular adjustment between the two parts of the stud holder 31. The first screw 36 passes through the first part 32 and the second part 33. A second screw 37 is used to fix the regulator system 20 to the balance bridge 22.

[0046] The two parts 32, 33 surround the second level 28. For this, each part 32, 33 includes a central ring 38, 39 arranged around the second level 28, the two central rings 38, 39 being superimposed.

[0047] The first part 32 comprises two protrusions 41, 42 extending radially from the central ring 38, a first protrusion 41 holding the first pin 34 downwards in the housing 26, the second protrusion 42 having an arc-shaped form cooperating with the first screw 36.

[0048] The second part 33 comprises three protrusions 43, 44, 45 extending from the central ring 39. A first protrusion 43 holds the second pin 35 downwards in the housing 26, a second protrusion 44 extending around the first screw 36, and the third protrusion 45 having an arc-shaped form cooperating with the second screw 37.

[0049] In a reference arrangement, the first stud 34 and the second stud 35 are, for example, arranged in a substantially symmetrical manner with respect to the rocker arm 24.

[0050] The first pin 34 cooperates with the free end 15 of the lever 14, and the second pin 35 cooperates with the second arm 47 of the fixed support 17. Thus, the prestressing means 6 and the elastic element 5 are supported by the racket system 20 from which they are suspended.

[0051] The two pins 34, 35 are arranged on either side of the prestressing means 6 and the elastic element 5. In addition, the two pins 34, 35 are rigidly connected to the lever 14 and the fixed support 17. In other words, the first 34 and the second pin 35 are respectively fixed to the lever 14 and the fixed support 17. The assembly of the pins and the spiral spring 25 is carried out, for example, by gluing, brazing, welding, by deformation of metallic glass, or by mechanical fastening.

[0052] The first peg 34 is movable relative to the second peg 35. To this end, the first part 32 is movable relative to the second part 33. The first part 32 is movable in rotation around the second bearing 28. Thus, the first peg 34 moves with the first part 32, the first peg 34 being movable in rotation around the second bearing 28. The first peg 34 can, for example, be moved over an angular range of 20°, or even 10°.

[0053] The displacement of the first pin 34 relative to the second pin 35 modifies the stiffness of the elastic element 5, because the displacement exerts a greater or lesser force or torque on the lever 14 of the preload means 6, so that the stiffness of the elastic element 5 varies, and thus the stiffness of the entire spiral spring 25. The ratchet system 20 thus allows adjustment of the operation of the regulating member 1.

[0054] To this end, the regulating member 1 includes adjustment means 30 to modify the position of the first pin 34 relative to the second pin 35. The first pin 34 and the second pin 35 are connected to the adjustment means 30.

[0055] The adjustment means 30 include the second arc-shaped protrusion 42 of the first part 32 and the first eccentric screw 36. The arc has substantially the same diameter as the head of the first screw 36, so that the displacement of the first screw 36 causes the second protrusion 42, and therefore the first part 32 relative to the second part 33, to move circularly around the second bearing 28, while the second part 33 remains in position when the first part 32 is actuated. Thus, by rotating the first screw 36, the second arc-shaped protrusion 42 moves circularly around the second bearing 28. The first part 32 moves relative to the second part 33, and consequently, the first pin 34 moves relative to the second pin 35 to modify the force or torque applied to the preload means 6 of the spiral spring 25.

[0056] Adjustment marks 29 are arranged on the second protrusion 42 in the shape of an arc around the first eccentric screw 36. Thus, to adjust the racket system 20, the first screw 36 is oriented according to a preferred reference mark.

[0057] In the second embodiment of the regulating organ 40 of the Figures 4 and 5 , the characteristics of the regulating organ 40 are substantially identical to the first embodiment, except for the adjustment means 50 of the racket system 60.

[0058] The first part 52 of the racket system 60 comprises an arm 63 extending radially outwards from the first part 52 in the same plane. The second part 53 comprises only two protrusions, and does not include the arc-shaped protrusion cooperating with the second screw 37.

[0059] The adjustment means 50 include a movable cam 55 in place of the first screw. The cam 55 cooperates with the arm 63 of the first part 52 to rotate it around the second bearing 28. The end 56 of the arm 63 is constantly in contact with the cam 55, so that the rotation of the cam 55 causes a displacement on the arm 63 according to the angular position of the cam 55. Thus, the first part 52 of the racket system 60 moves in a manner similar to the first embodiment. Such adjustment means 50 equipped with a cam 55 allow the stiffness of the spiral spring 25 to be varied linearly.

[0060] To maintain the arm 63 of the first part 52 in contact with the cam 55, the adjustment means 50 include a spring 57 exerting a restoring force on the first part 52. The spring 57 is substantially U-shaped surrounding the second screw 37, one end 58 of the U being assembled to the second part 53 of the regulator system 20, and a second end 59 of the U being retained by a retaining hook 61 arranged on the first part 52. The spring 57 is arranged on the balance bridge 22 symmetrically to the cam 55 with respect to the second bearing 28. The spring 57 is covered by a cover 62 assembled on the balance bridge 22, in order to hold it in place.

[0061] Thus, the spring 57 exerts a restoring force on the two parts 52, 53 of the racket system 60, the restoring force having the function of keeping the arm 63 of the first part 52 constantly in contact with the cam 55. When the cam 55 is acted upon, the first part 52 rotates to move the first peg 34 relative to the second peg 35, while undergoing a restoring force exerted by the spring 57, to allow the contact of the arm 63 of the first part 52 against the cam 55, in particular when the peripheral wall 64 of the cam 55 moves away from the arm 63.

[0062] Naturally, the invention is not limited to the embodiments of regulating organs described with reference to the figures, and variants could be envisaged without departing from the scope of the invention.

Claims

1. Regulating member (1, 40) for a horological movement comprising an inertial mass, for example a balance (23), a balance spring (25), and an index-assembly system (20, 60) for adjusting the rate of the balance spring (25), the balance spring (25) comprising a coiled strip (2) and means for adjusting the stiffness of the balance spring, which are provided with a resilient element (5) arranged in series with the coiled strip (2), the index-assembly system (20, 60) comprising a stud-holder (31) mechanically joined to the resilient element (5), the stud-holder (31) including a first stud (34) and a second stud (35), characterised in that the resilient element (5) is arranged between the first stud (34) and the second stud (35), the first stud (34) being capable of moving relative to the second stud (35), the movement of the first stud (34) changing the stiffness of the balance spring (25).

2. Regulating member according to claim 1, characterised in that the stud-holder comprises a first part (32, 52) provided with the first stud (34), and a second part (33, 53) provided with the second stud (35), the first part (32, 52) being capable of moving relative to the second part (33, 53) in order to move the first stud (34).

3. Regulating member according to claim 2, characterised in that the first part (32, 52) and the second part (33, 53) are superimposed.

4. Regulating member according to claim 2 or 3 , characterised in that the index-assembly system (20) comprises a regulator means, such as an eccentric screw (36), which cooperates with the first part (32) so as to move it as it is screwed / unscrewed.

5. Regulating member according to any one of claims 2 to 4, characterised in that the index-assembly system (60) comprises an arm (63) arranged on the first part (52) and a cam (55) cooperating with the arm (63), such that the actuation of the cam (55) moves the first part (52) relative to the second part (53).

6. Regulating member according to claim 5, characterised in that the index-assembly system (60) comprises a return means, such as a spring, exerting a force between the first part (52) and the second part (53) to hold the arm (63) of the first part (52) against the cam (55).

7. Regulating member according to any one of the claims 2 to 6, characterised in that the second part (33, 53) is unmoving relative to the plate (21).

8. Regulating member according to any one of the claims 2 to 7, characterised in that the first part (32, 52) is capable of moving in rotation relative to the second part (33, 53).

9. Regulating member according to any one of the preceding claims, characterised in that the first stud (34) is capable of moving in rotation.

10. Regulating member according to any one of the preceding claims, characterised in that the adjustment means comprise prestressing means (6) for applying a variable force or torque to the flexible element (5), the prestressing means (6) being arranged between the first stud (34) and the second stud (35), the movement of the first stud (34) relative to the second stud (35) actuating the prestressing means.

11. Regulating member according to claim 10, characterised in that the prestressing means (6) include a lever (14) connected to the flexible element (5), the first stud being integral with a free end (15) of the lever (14).

12. Regulating member according to claim 10 or 11, characterised in that the flexible element (5) is joined to a fixed support (17), the second stud (35) being integral with the fixed support (17).

13. Regulating member according to any one of claims 10 to 12, characterised in that the prestressing means (6) include a semi-rigid structure arranged in parallel with the flexible element (5), the lever (14) being connected to the semi-rigid structure.

14. Horological movement, characterised in that it comprises a regulating member (1, 40) according to any one of the preceding claims.

15. Timepiece, for example a watch, characterised in that it comprises a horological movement according to claim 14.

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