Spiral spring and rotary resonator mechanism

Abstract

To provide a spiral spring for a timepiece resonator mechanism.SOLUTION: A spiral spring 1 comprises a flexible strip 2 wound around the spiral spring itself multiple times. The strip has prescribed rigidity, and the spiral spring includes means for adjusting the rigidity of the strip. The adjustment means includes a flexible element 5 aligned in series with the strip. The flexible element should impart additive rigidity to the strip by connecting one end 4, 9 of the strip to a rigid support 11. The flexible element has rigidity that is larger than the rigidity of the strip. The adjustment means should change the rigidity of the flexible element by including pre-stress means 6 for adding variable force or torque to the flexible element. The pre-stress means includes a lever 14 capable of operating so that force or torque is transmitted to the flexible element using an actuator 7 by being connected to the flexible element. The lever has one end 15 that is movable in a first direction D1. The spiral spring includes holding means 25 aligned so as to substantially prevent movement of the lever in a second direction D2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a spiral spring for a timepiece resonator mechanism, the spiral spring being provided with improved means for adjusting the stiffness of said spiral spring.

[0002] The invention also relates to a timepiece resonator mechanism comprising such a spiral spring. [Background technology]

[0003] Most mechanical watches today are equipped with a balance spring and a Swiss lever escapement. The balance spring is the time base of the watch. It is also known as the resonator.

[0004] The escapement has two main functions: -The function of continuously moving the resonator back and forth, - This reciprocating motion counting function and has.

[0005] A mechanical resonator requires an inertia element, a guide and an elastic return element. Traditionally, a spiral spring serves as the elastic return element for the inertia element formed by a balance. This balance is rotationally guided by pivots that rotate in ruby ​​plane bearings.

[0006] The balance spring generally needs to be adjustable to improve the accuracy of the watch. To this end, means are used to adjust the stiffness of the spiral spring, such as an index assembly that changes the effective length of the spring. In this way, its stiffness is changed to adjust the speed accuracy of the watch. However, the effectiveness of traditional index assemblies to adjust the speed remains limited and they are not always effective for sufficiently accurate settings within the range of a few seconds or tens of seconds per day.

[0007] Other spiral springs include integrated adjustment means. In these spiral springs, the speed is not adjusted by changing the effective length of the spiral spring, but by applying a force or torque to a flexible element arranged in series with the spiral. This makes it possible to change the stiffness of the flexible element, which in part determines the return force acting on the balance, and thus the stiffness of the entire spiral spring. By adjusting the stiffness of the spiral spring, the speed of the adjustment member can be adjusted. Such spiral springs with flexible elements are described, for example, in US Pat. No. 5,399,433 and US Pat. No. 5,499,433.

[0008] In these cases, normal systems cannot be used as they are not compatible with the spiral spring adjustment device. In addition, because the speed must be adjusted very finely, it is essential that there is no play between the spiral and the area where it interacts with the index assembly mechanism. Otherwise there is a risk that the speed will be altered in the event of an impact if the spiral is not repositioned exactly the same after the impact.

[0009] For the use of such spiral springs, an indexing assembly system is described in US Pat. No. 5,399,433 and US Pat. No. 5,499,666. This racking system comprises a stud holder consisting of two parts movable relative to each other, each part comprising, on the one hand, a stud on which a flexible element is mounted, and, on the other hand, a prestressing means acting on the flexible element. In this way, by moving the two parts relative to each other, the force or torque applied to the flexible element is modified and the stiffness of the spiral spring is adjusted.

[0010] However, in this index assembly system, the moving part moves in a circular motion around the spiral spring, so that the adjustment means is actuated in the tangential direction of the spiral spring, which tangential actuation is provided by the index assembly system, which is complicated to implement.

[0011] To avoid this problem, it has been devised to actuate the lever of the adjustment device by an actuator with a substantially linear motion (e.g. by pulling or pushing the lever, either directly or via an element connecting the actuator to the lever), the actuator comprising, for example, a hook which engages with the lever.

[0012] However, the contact area between the actuator and the lever creates friction problems when the lever is moved relative to the actuator, especially when the reference mark of the limiting member is adjusted. Indeed, when the spiral spring is moved, the lever experiences friction from the actuator and moves the hook, thus modifying the speed setting. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] European Patent Application Publication No. 4009115 [Patent Document 2] Swiss Patent Application No. 0700385 / 2021 [Patent Document 3] European Patent Application No. 22177059.7 [Patent Document 4] Swiss Patent Application No. 000678 / 2022 Summary of the Invention

[0014] The object of the present invention is to alleviate some or all of the aforementioned drawbacks by providing a spiral spring with effective and precise adjustment means, in particular designed so as not to interfere with the movement of the regulating member.

[0015] To this end, the invention relates to a spiral spring, in particular for a timepiece resonator mechanism, comprising a flexible strip wound on itself several times, said strip having a given stiffness, said spiral spring comprising means for adjusting its stiffness, said adjusting means comprising a flexible element arranged in series with said strip, said flexible element connecting one end of said strip to a rigid support so as to add an additional stiffness to said strip sequence, said flexible element preferably having a stiffness greater than that of said strip, said adjusting means comprising prestressing means for applying a variable force or torque to said flexible element so as to vary the stiffness of said flexible element, said prestressing means comprising a lever connected to said flexible element and operable by an actuator to transmit said force or torque to said flexible element, said lever comprising one end movable in a first direction.

[0016] The invention is notable in that the spiral spring includes retaining means arranged to prevent movement of the lever substantially in the second direction.

[0017] The invention avoids parasitic movements caused by friction between the actuator and the lever, which may cause the lever to move in a second direction and distort the adjustment, in particular by choosing a second direction of movement of the lever that is substantially perpendicular to the first direction, so that the actuator moves the lever in the first direction even if the orientation of the spiral spring changes.

[0018] In a particular embodiment of the invention, a retaining means connects the rigid support to the lever.

[0019] In certain embodiments of the invention, the retaining means comprises a flexible guide.

[0020] In a particular embodiment of the invention, the flexible guide includes a first translation table including two first flexible blades and a first rigid portion.

[0021] In a particular embodiment of the invention, the flexible guide includes a second translation table arranged in series with the first translation table, the second translation table including two second flexible blades and a second rigid portion.

[0022] In certain embodiments of the invention, the flexible guide includes a single flexible blade.

[0023] In certain embodiments of the invention, the flexible guide includes a pair of non-intersecting flexible blades.

[0024] In a particular embodiment of the invention, the retaining means comprises a second flexible lever.

[0025] According to a particular embodiment of the invention, the second direction is substantially perpendicular to the first direction of movement of the lever.

[0026] In certain embodiments of the invention, the flexible element comprises a flexible blade.

[0027] In a particular embodiment of the invention, the torque or force is continuously adjustable by means of a prestressing means.

[0028] The invention also relates to a rotary resonator mechanism including a limiting member and such a spiral spring, in particular for a timepiece movement. [Brief description of the drawings]

[0029] The objects, advantages and features of the present invention will become apparent from a number of embodiments, given by way of non-limiting example only and with reference to the accompanying drawings, in which:

[0030] [Figure 1] 1 shows a schematic top view of a spiral spring according to a first embodiment of the present invention; FIG. [Diagram 2] FIG. 4 shows a schematic top view of a spiral spring according to a second embodiment of the present invention; [Diagram 3] FIG. 13 shows a top view of a spiral spring according to a third embodiment of the present invention; [Figure 4] FIG. 10 shows a top view of a spiral spring according to a fourth embodiment of the present invention; [Diagram 5] FIG. 13 shows a top view of a spiral spring according to a fifth embodiment of the present invention; [Figure 6] FIG. 13 shows a top view of a spiral spring according to a sixth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] 1 to 6 respectively show schematic representations of different embodiments of spiral springs 1, 10, 20, 30, 40, 50, in particular for limiting members of a time resonator mechanism.

[0032] The regulating member generally includes an inertial mass, such as an annular balance, a balance shaft, and a balance bridge, not shown, and a spiral spring 1, 10, 20, 30, 40, 50 configured to oscillate the inertial mass as an elastic return element for the inertial mass.

[0033] In these examples, each spiral spring 1, 10, 20, 30, 40, 50 extends in substantially the same plane.

[0034] The spiral spring 1, 10, 20, 30, 40, 50 comprises a flexible strip 2 which is wound several times on itself and has a given stiffness. The inner end 9 of the strip 2 is integral with or assembled to a support 3, commonly called a collet, which is substantially triangular in shape and can be slid around a shaft of balance.

[0035] The spiral spring 1, 10, 20, 30, 40, 50 also comprises means for adjusting its stiffness, which can for example be actuated by a user, in particular when the adjustment member is mounted on a plate of a clock movement.

[0036] The adjustment means comprises a flexible element 5 arranged in series with the strip 2, which connects the outer end 4 of said strip 2 to a rigid support 11 intended to be fixed relative to the flexible element 5. The flexible element 5 is fixed to the outer end 4 of the strip 2. The flexible element 5 is a distinct element from the rolled strip 2.

[0037] The flexible element 5 adds additional stiffness to that of the strip 2. The flexible element 5 is preferably stiffer than 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 integral or made from the same material, for example silicone.

[0038] The flexible element 5 of the spiral spring 1, 10, 20, 30, 40, 50 comprises a first flexible blade 19 and a movable rigid part 18. The movable rigid part 18 extends from the outer end of the strip 2 and is connected to the first flexible blade 19, preferably on the same side of said rigid part 18. The first flexible blade 19 is also connected to the rigid support 11.

[0039] The adjustment means of the spiral spring 1, 10, 20, 30, 40, 50 also comprise prestressing means 6 for applying a variable force or torque to the flexible element 5. In this way the stiffness of the spiral spring can be adjusted. The torque or force is continuously adjustable by the prestressing means 6. In other words the torque or force is not limited to a point value. In this way the stiffness of the flexible element 5 can be adjusted with great precision.

[0040] The prestressing means 6 comprises a second flexible blade and a curved semi-rigid portion 21 arranged opposite the rigid portion 18 in the extension of the first flexible blade 19 .

[0041] The second flexible blade and curved semi-rigid element 21 is connected at its other end to a curved lever 14 which extends around the strip 2. The second flexible blade and curved semi-rigid element are connected to rigid structures 17, 27, 37 which are connected to the rigid support 11.

[0042] The force or torque acts on the free end 15 of the lever 14. The lever 14 of the prestressing means 6 thus transmits the force or torque via the second flexible leaf 19 to the flexible element 5 so as to modify the stiffness of the spiral spring 1,10,20,30,40,50.

[0043] To actuate the lever 14 to adjust the speed, the adjustment member further comprises an actuation system including an actuator 7 in contact with the lever 14. The actuator is configured to push and / or pull the lever 14.

[0044] In the drawings, the actuator 7 is represented by a circular body contacting the lever 14 on the inside towards the strip 2. Preferably, the actuator 7 comprises a hook at least partially surrounding the lever 14, preferably in a rigid portion 23 arranged at the end 15 of the lever 14.

[0045] According to the invention, the spiral spring 1, 10, 20, 30, 40, 50 comprises a retaining means 25 for retaining the lever 14 in a second direction D2, which is substantially perpendicular to the end 15 of the lever 14 and to the movement of the actuator 7 in the first direction D1. In this way, the lever is prevented from moving in this second direction D2, so that the adjustment of the speed, when it is attempted to be adjusted by the actuator, is not distorted by such a movement.

[0046] In fact, when the spiral spring 1, 10, 20, 30, 40, 50 and the actuator 7 move relative to each other, the contact friction between them can cause the lever 14 to move laterally, which can result in errors in the accuracy of the speed adjustment.

[0047] By virtue of the retaining means 25, in the event of movement relative to one another, the retaining means 25 prevents lateral movement of the levers 14 due to friction.

[0048] In addition, when the actuator 7 pulls or pushes the end 15 of the lever 14, the lever 14 moves only in the first direction D1 of movement of the actuator 7, so that the lever 14 substantially maintains its lateral position relative to the strip 2.

[0049] Preferably, these holding means 25 comprise flexible guides arranged between the lever and the rigid support 11 of the flexible element 5, here between the lever and the rigid support 17.

[0050] In the first embodiment of FIG. 1, the flexible guide is a translation table.

[0051] The rigid support 11 is L-shaped, with a first leg 46 of the L serving as a connection to the first flexible blade 19 and a second branch 47 of the L pointing away from the first flexible blade 19 so that it can be assembled to the clock movement 10.

[0052] The rigid support 17 further comprises an arm 8 which extends towards the end 15 of the lever 14 and parallel to the second branch 47 of the L-shape.

[0053] The translation table comprises two substantially parallel flexible blades 22, 24 and a rigid part 23 movable relative to the arm 8, on which the two flexible blades 21, 22 are mounted. The two flexible blades 22, 24 are connected to the arm 8 of the rigid support 17.

[0054] The rigid portion 23 is directly assembled to the end of the lever 14 .

[0055] Thanks to the translation table, the lever can move mainly in a first direction D1 substantially perpendicular to the flexible blades 22, 24 of the translation table, but not in a second direction D2 substantially parallel to said flexible blades in the rest position of the translation table. In fact, the flexible blades 22, 24 hold the lever 14 in this second direction D2, but nevertheless allow it to move in the first direction D1.

[0056] The flexible element 5, the prestressing means 6 and the retaining means 25 form a closed circuit around the wound strip.

[0057] In the second embodiment of FIG. 2, the holding means 25 includes a second translation table arranged in series with the first translation table.

[0058] Here, the rigid support 17 of the flexible element 5 does not include an arm.

[0059] The first translation table is attached to the end 15 of a lever 14, similar to the first embodiment.

[0060] The second translation table extends directly from the rigid support 11 of the flexible element 5. The second translation table includes substantially parallel second flexible blades 25, 26 extending from the rigid support 11 and a second rigid portion 29 moveable relative to the rigid support 17 to which the second flexible strips 25, 26 are connected.

[0061] The first flexible blades 22 , 24 are attached to a second rigid portion 29 .

[0062] The second translation table allows increasing the distance in the first direction D1 covered by the lever 14 while maintaining a substantially linear motion.

[0063] Figure 3 shows a third embodiment of the spiral spring 20 of figure 3. Here, the flexible guide comprises one single flexible blade 32 which connects the elastic element 5 to the rigid part 23 of the end 15 of the lever 14 via a half-moon shaped body 31.

[0064] The half-moon shaped body 31 is connected on the one hand to the flexible element 5 and on the other hand to a single flexible blade 32, which is here straight in the rest position of the single flexible blade 32.

[0065] A single flexible blade 32 allows the lever 14 to be held against movement in a second direction D2 perpendicular to the first direction D1 of movement of the actuator 7.

[0066] Alternatively, as shown in the variant of Fig. 4, the flexible guide comprises a curved flexible blade 33. In this case, the rigid structure is an S-shaped, half-moon shaped body or rear arm without a branch. The curved blade 33 is mounted directly on the S-shaped rigid structure, with the rigid part 23 directly connected to the end 15 of the lever 14.

[0067] In FIG. 5, a fourth embodiment of a flexible guide includes a flexible pivot having two non-intersecting flexible blades 34 , 35 .

[0068] The rigid structure 27 is S-shaped with a rearwardly extending curled arm 38. The two flexible blades 34, 35 do not cross from the tip of the curled arm 38 to the rigid portion 23 at the end 15 of the lever 14.

[0069] These non-intersecting blades 34, 35 have essentially the same effect as the blades of a translation table.

[0070] In the embodiment of Figure 6, the retaining means 25 comprises a second flexible lever 36 arranged symmetrically to the first lever 14 around the flexible strip 2. The first lever 14 and the second lever 36 are joined together at a rigid joint 37 and form part of a ring around the strip 2.

[0071] The actuator 7 engages in a rigid joint 37 of the two levers 14, 36. The rigid joint 37 is U-shaped, into which the actuator 7 can be inserted.

[0072] The second lever 36 prevents the first lever from moving in the second direction D2 and only allows the first lever to remain movable in the first direction D1.

[0073] The invention also relates to a regulating member and a rotary resonator mechanism, in particular for a clock movement. The regulating member of the resonator mechanism comprises a seismic mass, not shown, and a spiral spring 1, 10, 20, 30, 40, 50 as described above. The seismic mass is, for example, an annular balance. The seismic mass is joined to the spiral spring so as to be fixed to a support 3.

Claims

1. A spiral spring, in particular for a clock resonator mechanism, said spiral spring (1, 10, 20, 30, 40, 50) comprising a flexible strip (2) wound on itself a number of times, said strip (2) having a given stiffness, said spiral spring (1, 10, 20, 30, 40, 50) comprising means for adjusting said stiffness, said adjustment means comprising a flexible element (5) arranged in series with said strip (2), said flexible element (5) connecting one end (4, 9) of said strip (2) to a rigid support (11, 14, 17) in order to give said strip (2) additional stiffness. , 24), said flexible element (5) preferably having a stiffness greater than the stiffness of said strip (2), said adjusting means comprising prestressing means (6) for applying a variable force or torque to said flexible element (5) to vary the stiffness of said flexible element (5), said prestressing means (6) comprising a lever (14) connected to said flexible element (5) and operable by an actuator (7) to transmit said force or torque to said flexible element (5), said lever (14) comprising one end (15) movable in a first direction (D1), A spiral spring, characterized in that said spiral spring (1, 10, 20, 30, 40, 50) includes retaining means (25) arranged to prevent movement of said lever (14) substantially in a second direction (D2).

2. Spiral spring according to claim 1, characterized in that said retaining means (25) connect said rigid support (11, 14, 17, 24) to said lever (14).

3. Spiral spring according to claim 1, characterized in that said retaining means (25) comprise a flexible guide.

4. 4. A spiral spring according to claim 3, characterized in that said flexible guide comprises a first translation table including two first flexible blades (22, 24) and a first rigid portion (23).

5. the flexible guide includes a second translation table arranged in series with the first translation table; the second translation table includes two second flexible blades (26, 28) and a second rigid portion (29); 5. The spiral spring according to claim 4 .

6. 4. A spiral spring according to claim 3, characterized in that said flexible guide comprises one single flexible blade (32, 33).

7. 4. A spiral spring as claimed in claim 3, characterized in that said flexible guide comprises a pair of non-intersecting flexible blades (34, 35).

8. Spiral spring according to claim 2, characterized in that said retaining means (25) comprise a second flexible lever (36).

9. 2. A spiral spring according to claim 1, characterized in that said second direction (D2) is substantially perpendicular to said first direction (D1) of movement of said lever (14).

10. Spiral spring according to claim 1, characterized in that the flexible element (5) comprises a flexible blade (19).

11. Spiral spring according to claim 1, characterized in that the torque or the force is continuously adjustable by the prestressing means (6).

12. A rotary resonator mechanism, in particular for a clock movement, comprising a seismic mass, characterised in that it comprises a spiral spring (1, 10, 20, 30, 40, 50) according to any one of claims 1 to 11.

Images