Timepiece setting organ comprising an improved indexing system

Abstract

The invention relates to a regulating organ (1) for a clock movement comprising an inertial mass, for example a balance wheel (23), a balance spring (25), a balance bridge (22) and a regulator system (20) for adjusting the rate of the balance spring (25), the regulator system (20) comprising a stud holder (31) having a first stud (34) on which the balance spring (25) is mounted, characterized in that the balance bridge (33) has a second stud on which the balance spring (25) is also mounted, the stud holder (31) being movable in rotation relative to the balance bridge (33) to regulate the rate of the regulating organ (1).

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 the driving energy is provided by a regulating organ. The invention relates, more specifically, to a regulating organ provided with a precision index system, a watch movement comprising such a regulating organ, as well as a timepiece comprising such a watch movement. Technological background

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

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

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

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

[0006] It is known to regulate the rate of the balance wheel by adjusting the active length of the balance spring, defined as the curvilinear length between its internal end and a counting point, located near the external 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 index system is fixed in rotation relative to the balance spring axis. However, it is possible, by manual intervention, to adjust its angular position, e.g. by pivoting, using a screwdriver, an eccentric acting on the index system in the manner of a cam.

[0008] The assembly comprising the bridge, the index 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 European patent EP3304215 and by European patent EP2876504, both in the name of the watch manufacturer ETA.

[0009] There are indexing systems that have a stud holder to which one outer end of the hairspring is attached, and whose indexing system key leaves a clearance to allow the hairspring to move between the two stops. However, the chronometric properties, particularly anisochronism, are very sensitive to the play in the index key, while this play is difficult to control precisely.

[0010] In some devices, the stops are adjustable to tighten the hairspring to eliminate play, especially during operation of the hairspring. In this case, the rate is first adjusted by moving the index key, then the hairspring is tightened with the key. But tightening the hairspring with the index key risks constraining it, and creating timekeeping defects, particularly by off-centering of the coils. In addition, removing play also modifies the rate, and once the hairspring is tightened, the index key can no longer be moved along the hairspring to finish fine-tuning the rate.

[0011] Other hairsprings have an integrated adjustment device. In these hairsprings, the rate is not adjusted by changing the effective length of the hairspring, but by applying a force or torque to an elastic element arranged in series with the hairspring. This allows the stiffness of the elastic element and therefore of the hairspring as a whole to be changed. Adjusting the stiffness of the hairspring makes it possible to adjust the rate of the regulating member. Such a hairspring equipped with an elastic element is, for example, described in patent application EP4009115.

[0012] However, in these cases, the usual adjustment systems cannot be used, as they are not compatible with the balance spring adjustment device. In addition, since the rate must be adjusted very finely, it is essential that there is no play between the balance spring and its interaction zones with the adjustment system. Indeed, otherwise, there is a risk of changing the rate in the event of an impact, if the balance spring does not reposition itself in exactly the same way after the impact. Summary of the invention

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

[0014] To this end, the invention relates to a regulating organ for a watch movement comprising an inertial mass, for example a balance, a balance spring, a balance bridge, and a counter-balance system for adjusting the rate of the regulating organ, the counter-balance system comprising a stud holder comprising a first stud on which the balance spring is mounted.

[0015] The invention is remarkable in that the balance bridge comprises a second stud on which the balance spring is also mounted, the stud holder being movable in rotation relative to the balance bridge to regulate the rate of the regulating organ.

[0016] Thanks to the invention, the rate of the regulating organ can be adjusted simply by modifying the position of the stud holder, because this changes the position of the first stud relative to the second stud, which remains fixed relative to the plate. As the balance spring is carried by both studs, the stiffness of the balance spring is modified. Since the position of the second stud is not modified, the reference mark remains unchanged.

[0017] According to a particular embodiment of the invention, the index system comprises a return spring exerting a separation force between the stud holder and the balance bridge.

[0018] According to a particular embodiment of the invention, the stud holder and the spring are in one piece, preferably formed from the same material.

[0019] According to a particular embodiment of the invention, the racket system comprises a rotating movable cam, the cam cooperating with the piton holder to rotate it.

[0020] According to a particular embodiment of the invention, the piton holder comprises an arm in contact with the cam to be able to rotate the piton holder.

[0021] 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 provided with an elastic element arranged in series with the wound ribbon, the second stud being mechanically linked to the elastic element.

[0022] According to a particular embodiment of the invention, the flexible element is connected to a rigid support, the second stud being integral with the rigid support.

[0023] According to a particular embodiment of the invention, the adjustment means comprise prestressing means for applying a variable force or torque to the flexible element, the first stud being mechanically linked to the prestressing means.

[0024] According to a particular embodiment of the invention, the elastic element and the prestressing means are arranged between the first stud and the second stud, the first stud being movable relative to the second stud to actuate the prestressing means, the movement of the first stud relative to the second stud modifying the stiffness of the spiral spring.

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

[0026] According to a particular embodiment of the invention, the prestressing means comprise a rigid structure arranged in parallel with the flexible element, the lever being connected to the rigid structure.

[0027] According to a particular embodiment of the invention, the flexible element is connected to a rigid support, the second stud being integral with the rigid support.

[0028] According to a particular embodiment of the invention, the stud holder is arranged on the balance bridge around a bearing of the balance shaft.

[0029] The invention also relates to a clockwork movement comprising such a regulating organ.

[0030] The invention also relates to a timepiece, for example a watch, comprising such a timepiece movement. Brief description of the figures

[0031] The aims, advantages and characteristics of the present invention will appear on reading several embodiments given solely as non-limiting examples, with reference to the appended drawings in which: there figure 1 schematically represents a perspective view from above of a regulating member according to a first embodiment of the invention, the figure 2 schematically represents a perspective view from above, partly disassembled, of the first embodiment of the regulating member of the figure 1 , there figure 3 schematically represents a top view of a spiral spring of the regulating member according to the invention, the figure 4 schematically represents a perspective view from below, partly disassembled, of the first embodiment of the regulating member of the figure 1 , there Figure 5 schematically represents a view from below of the first embodiment of the regulating organ of the figure 1 , there figure 6 schematically represents a partial perspective view from above of a regulating member according to a second embodiment of the invention, the figure 7 schematically represents an enlarged partial view of a part of the second embodiment of the regulating member of the figure 6 , and the figure 8 schematically represents a perspective view from above of the piton holder of the second embodiment of the regulating member of the figure 6 . Detailed description of the invention

[0032] THE figures 1 to 5 show a schematic representation of a first embodiment of a regulating member 1, intended to be arranged in a watch movement, not shown in the figures. Such a watch movement comprises for example a plate provided with a housing for receiving the regulating member 1, the regulating member 1 being provided with an inertial mass, and an elastic return element of the inertial mass configured to make it oscillate.

[0033] The regulating organ 1 further comprises a counter-balance system 20, an annular balance 23 as inertial mass, a balance shaft 24, a balance spring 25 as elastic return element, and a balance bridge 22.

[0034] On the figures 1 to 3 , are superimposed, here from bottom to top, the balance wheel 23, the balance spring 25, the balance bridge 22 and the index system 20.

[0035] The balance shaft 24 is centered and passes through the center of the balance 23, the balance spring 25 and the balance bridge 22. The balance shaft 24 is held by two shock-absorbing bearings 28 arranged at both ends of the balance shaft 24. A first bearing, not shown in the figures, is arranged under the balance 23 and the balance bridge 22, and the second bearing 28 is held by the balance bridge 22. The balance bridge 22 is provided with a hole, here through, in which the second bearing 28 is held. The index system 20 is mounted on the balance bridge 22 and is arranged, in this embodiment, on the central axis of the balance shaft 24.

[0036] Represented on the figures 3, an example of a spiral spring 25 preferably extends substantially in one plane. The spiral spring 25 comprises a flexible ribbon 2 wound on itself in several turns, the ribbon 2 having a predefined stiffness. The internal end 9 of the ribbon 2 comes from the same material or is assembled to a support 3, generally called a collet. The support 3 has a substantially triangular shape, and is threaded around the balance shaft 24.

[0037] The spiral spring 25 further comprises means for adjusting its stiffness. For example, the adjustment means can be actuated by an operator when the regulating member is mounted on the plate of the watch movement.

[0038] The adjustment means comprise a flexible element 5 arranged in series with the ribbon 2, the flexible element 5 connecting one end 4 of said ribbon 2 to a rigid support 17, and secured to one of the ends 4 of the ribbon 2. The flexible element 5 is secured to the external end 4 of the ribbon 2. The elastic element 5 is a different element from the ribbon 2.

[0039] The flexible element 5 adds additional stiffness to that of the strip 2. The flexible element 5 preferably has a stiffness greater than that of the strip 2. The flexible element 5 is here arranged in the extension of the strip 2. Preferably, the adjustment means and the strip 2 are in one piece, or even formed from the same material, for example silicon.

[0040] The flexible element 5 of the spiral spring 25 comprises a pivot with uncrossed flexible blades. The pivot comprises two uncrossed flexible blades 11, 12 and a rigid part 18. The flexible blades 11, 12 are joined, on the one hand laterally to a rigid support 17, and on the other hand to the rigid part 18 by approaching each other. Thus, preferably, the flexible blades 11, 12 move away from the rigid part 18 to the rigid support 17. The external end 4 of the ribbon 2 is joined to the rigid part 18. The rigid support 17 is stationary relative to the plate. The rigid support 17 has an L shape, a first branch 46 of the L serving as a connection with the flexible blades 11, 12, the second branch 47 of the L being oriented on the side opposite the pivot with uncrossed blades so that it can be assembled to the clockwork movement.

[0041] The spiral spring adjustment means 25 further comprise pre-stressing means 6 for applying a variable force or torque to the flexible element 5. Thus, the stiffness of the spiral spring can be adjusted. The torque or force is continuously adjustable by the pre-stressing means 6. In other words, the torque or force is not restricted to point values. Thus, the stiffness of the flexible element 5 can be adjusted with great precision.

[0042] The prestressing means 6 comprise a secondary flexible blade 19, arranged on an opposite side of the rigid part 18 in the extension of the pivot with uncrossed blades. The secondary flexible blade 19 is arranged tangentially to the strip 2, at the external end 4.

[0043] The secondary flexible blade 19 is connected by the other end to a curved lever 14 going around the strip 2. The lever 14 is connected, in addition to the secondary flexible blade 19, to a rigid structure 27 linked to the rigid support 17. The rigid structure 27 deforms in part when the lever 14 is actuated by force or torque.

[0044] The force or torque is exerted on the free end 15 of the lever 14. Thus, the lever 14 of the prestressing means 6 transmits the force or torque to the flexible element 5 via the secondary flexible blade 19 and the rigid structure 27, so as to modify the stiffness of the spiral spring 25.

[0045] On the Figures 1 and 2 , the spiral spring 25 has another configuration. The uncrossed blades 11, 12, the rigid part 18 and the secondary flexible blade 19 are replaced by a single blade, the external end 4 of the lever 14 being attached to the single blade.

[0046] In order to be able to apply the variable force or torque to the spiral spring 25, the regulating organ comprises a counter-rotation system 20.

[0047] In this first embodiment of the figures 1, 2 , 4 And 5 , the racket system 20 is provided with a piton holder 31 provided with a first piton 34.

[0048] According to the invention, the balance bridge 22 is provided with a second stud 35. The stud holder 31 is mechanically linked to the lever 14 of the prestressing means 6, but it does not block the ribbon 2.

[0049] The stud holder 31 is in contact with the balance bridge 22, and is held and positioned by the shock absorber 28.

[0050] The stud holder 31 is rotatable around the balance shaft relative to the balance bridge 22, in order to be able to move the first stud 34 and act on the lever 14.

[0051] The piton holder 31 comprises a central ring 38 arranged around the second bearing 28.

[0052] The stud holder 31 comprises two protrusions 41, 42, extending radially from the central ring 38, a first protrusion 41 holding the first stud 34 downwards using a first screw 74. The second protrusion 42 holding the second stud 35 downwards using a second screw.

[0053] In a reference arrangement, the first stud 34 and the second stud 35 are for example arranged in a substantially symmetrical manner relative to the balance shaft 24.

[0054] The first stud 34 cooperates with the free end 15 of the lever 14, and the second stud 35 cooperates with the second branch 47 of the rigid support 17. Thus, the prestressing means 6 are supported by the racket system 20, and the elastic element 5 by the balance bridge 22 from which they are suspended.

[0055] The two studs 34, 35 are arranged on either side of the prestressing means 6 and the elastic element 5. Furthermore, the two studs 34, 35 are rigidly connected to the lever 14 and to the rigid support 17. In other words, the first 34 and the second stud 35 are respectively secured to the lever 14 by the free end 15 and to the rigid support 17 by the second branch 47. The assembly of the studs and the spiral spring 25 is for example carried out by gluing, brazing, welding, by deformation of metallic glass, or by mechanical fixing.

[0056] The first stud 34 is movable relative to the second stud 35. For this purpose, the stud holder 31 is movable relative to the balance bridge 22. The stud holder 31 is movable in rotation around the second bearing 28. Thus, the first stud 34 moves with the stud holder 31, the first stud 34 being movable in rotation around the second bearing 28. The first stud 34 can for example be moved over an angular range of 20°, or even 10°.

[0057] The movement of the first stud 34 relative to the second stud 35 modifies the stiffness of the elastic element 5, because the movement exerts a more or less significant force or torque on the lever 14 of the prestressing means 6, so that the stiffness of the elastic element 5 varies, and thus the stiffness of the entire spiral spring 25. The index system 20 thus makes it possible to adjust the rate of the regulating member 1.

[0058] To this end, the index system 20 makes it possible to modify the position of the first stud 34 relative to the second stud 35. The stud holder 31 moves relative to the balance bridge 22, and consequently, the first stud 34 moves relative to the second stud 35 to modify the force or torque applied to the prestressing means 6 of the balance spring 25.

[0059] The piton holder 31 of the racket system 20 comprises an arm 63 extending radially outwards in the same plane.

[0060] The index system 20 comprises a rotating cam 55 arranged on the balance bridge 22. The cam 55 cooperates with the arm 63 of the stud holder 31 to rotate it around the second bearing 28. The end 56 of the arm 63 is preferably constantly in contact with the cam 55, so that the rotation of the cam 55 exerts a movement on the arm 63 according to the angular position of the cam 55. Thus, the stud holder 31 of the index system 20 moves in rotation around the second bearing 28. Such an index system 20 provided with a cam 55 makes it possible to vary the stiffness of the balance spring 25 with linearity.

[0061] To keep the arm 63 of the stud holder 31 in contact with the cam 55, the racket system 20 comprises a spring 57 exerting a return force on the stud holder 31.

[0062] On the figure 4, the spring 57 has a substantially horseshoe shape, a first end 58 of the spring being assembled to the balance bridge 22, and a second end 59 of the spring 57 surrounding a retaining stud 60 extending from the stud holder 31. The spring 57 is arranged in a recess 61 hollowed out in the balance bridge 22 below, on the side of the balance 23 and the balance spring 25. The balance bridge 22 comprises a through hole 62 opening into the recess 61, the stud 60 extending into the recess 61 through the through hole 62. The through hole 62 is sized to allow the stud 60 to move when the stud holder 31 rotates relative to the balance bridge 22.

[0063] Thus, the spring 57 exerts a return force on the stud holder 31 of the indexing system 20, the return force having the function of constantly maintaining the arm 63 of the stud holder in contact with the cam 55. When the cam 55 is acted upon, the stud holder 31 rotates to move the first stud 34 relative to the second stud 35, while undergoing a return force exerted by the spring 57, to allow the contact of the arm 63 of the stud holder 31 against the cam 55, in particular when the peripheral wall 64 of the cam 55 moves away from the arm 63.

[0064] The clockwork system 20 is configured to adjust the rate of the regulating organ 1 with a resolution less than or equal to 1 second per day, preferably less than or equal to 0.5 seconds per day, or even less than or equal to 0.1 seconds per day. The configuration of the regulating organ 1 makes it possible to achieve such precision.

[0065] Adjustment marks 49 are further arranged on the cam 55. Thus, to adjust the racket system 20, the cam 55 is moved, for example by means of an adjustment knob (not shown in the figures), arranged on the cam 55, and which can be rotated. Thus, to adjust the racket system 20, the cam 55 is oriented according to a preferred mark.

[0066] Preferably, the adjustment marks 49 correspond to the resolution. In other words, the difference between two consecutive marks makes it possible to modify the rate by one second, 0.5 seconds, or even 0.1 seconds per day. On the figure 6 , the resolution of the adjustment marks 49 is 0.1 seconds.

[0067] THE figures 6 to 8show a schematic representation of a second embodiment of a regulating member 40 according to the invention. In this embodiment, the stud holder 71 and the spring 72 are in one piece, preferably formed from the same material. For the other characteristics, the regulating member 40 is identical to the first embodiment.

[0068] The piton holder 71 comprises only one protrusion 81 carrying the first piton 34. The piton holder 71 comprises the spring 72 in place of the second protrusion.

[0069] The spring 72 is elongated and extends from the ring 737 of the stud holder 71 on the side opposite the arm 81. The spring 72 has a U shape and it rests on the balance bridge 52, when the stud holder 71 is mounted in the regulating member 40. A first end 75 of the U is integral with the ring 77 of the stud holder 71, while a second end 76 is free.

[0070] The second end 76 is inserted into a hole made in the balance bridge 52. The second free end 76 comprises, for example, an elbow 79 for hooking the hole. Thus, the second end 76 of the spring 72 rests in the hole to block the spring 72 on this side.

[0071] Thus, when the stud holder 71 rotates, under the effect of the movement of the cam 55, the spring 72 is more or less constrained, and exerts a return force on the stud holder 71 to hold the arm 63 against the cam 55, whatever its position.

[0072] Alternatively, the second free end 76 could be wedged against a rim 78 of the balance bridge 52.

[0073] Apart from these differences, the regulating member 40 of the second embodiment has characteristics identical to those of the first embodiment, in particular concerning the cam 55, the first 34 and the second stud 35, as well as the spiral spring 25.

[0074] Such a stud holder 71 facilitates its assembly in the regulating organ, since there is only one component to be arranged on the balance bridge. In addition, storage is also simplified, since a single component replaces two components.

[0075] Naturally, the invention is not limited to the embodiments of regulating members 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 clockwork movement comprising an inertial mass, for example a balance (23), a hairspring (25), a balance bridge (22) and a counter-balance system (20) for adjusting the rate of the hairspring (25), the counter-balance system (20) comprising a stud holder (31, 71) comprising a first stud (34) on which the hairspring (25) is mounted, characterized in that the balance bridge (33, 53) comprises a second stud on which the balance spring (25) is also mounted, the stud holder (31, 71) being movable in rotation relative to the balance bridge (22, 52) to adjust the rate of the regulating member (1, 40).

2. Regulating body according to claim 1, characterized in that the spiral spring (25) comprises a wound ribbon (2) and means for adjusting the stiffness of the spiral spring provided with an elastic element (5) arranged in series with the wound ribbon (2), the second stud (35) being mechanically linked to the elastic element (5).

3. Regulating body according to claim 2, characterized in that the adjustment means comprise pre-stressing means (6) for applying a variable force or torque to the flexible element (5), the first stud (34) being mechanically linked to the pre-stressing means (6).

4. Regulating body according to claim 3, characterized in that the elastic element (5) and the prestressing means (6) are arranged between the first stud (34) and the second stud (35), the first stud (34) being movable relative to the second stud (35) to actuate the prestressing means (6), the movement of the first stud (34) relative to the second stud (35) modifying the stiffness of the spiral spring (25).

5. Regulating body according to claim 4, characterized in that the prestressing means (6) comprise a lever (14) connected to the flexible element (5), the first stud being integral with a free end (15) of the lever (14).

6. Regulating body according to any one of claims 3 to 5, characterized in that the prestressing means (6) comprise a rigid structure arranged in parallel with the flexible element (5), the lever (14) being connected to the rigid structure.

7. Regulating body according to any one of claims 2 to 6, characterized in that the flexible element (5) is connected to a rigid support (17), the second stud (35) being integral with the rigid support (17).

8. Regulating body according to any one of the preceding claims, characterized in that the racket system (20, 60) comprises a cam (55) movable in rotation, the cam (55) cooperating with the piton holder (31, 71) to rotate it.

9. Regulating body according to claim 8, characterized in that the piton holder (31, 71) comprises an arm 63 in contact with the cam to be able to rotate the piton holder.

10. Regulating body according to any one of the preceding claims, characterized in thatthe index system (20, 60) comprises a return spring (57, 72) exerting a separation force between the stud holder (31, 71) and the balance bridge (22, 52).

11. Regulating body according to claim 10, characterized in that the stud holder (31, 71) and the spring (57, 72) are in one piece, preferably formed from the same material.

12. Regulating body according to any one of the preceding claims, characterized in that the stud holder (31, 71) is arranged on the balance bridge (22, 52) around a bearing (28) of the balance shaft (24).

13. Clockwork, characterized in that it comprises a regulating member (1, 40) according to any one of the preceding claims.

14. Timepiece, for example a watch, characterized in that it comprises a clockwork movement according to claim 13.

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