CH719915A2 - CLOCK REGULATOR WITH FLEXIBLE GUIDE PROVIDED WITH MEANS OF PRESSURE COMPENSATION - Google Patents

Abstract

The invention relates to a regulating member for a watch movement comprising an oscillating mass (19), for example a balance wheel, a flexible guide (2) comprising at least two flexible blades (9) connecting a rigid support (3) to the mass oscillating (19) to allow the oscillating mass (19) to perform a rotary movement around a virtual pivot, the regulating member (1) comprising an elastic device for compensating (50) for the external pressure, the elastic device compensation (50) being arranged in series with the rigid support (3), so as to connect the rigid support (3) to fixing means (7) of the regulating member (1) on the watch movement, the elastic compensation device (50) being configured to adapt its stiffness as a function of the external pressure in order to compensate for the effect of the external pressure on the regulating member. The invention also relates to a watch movement comprising such a regulating member (1).

Description

Technical field of the invention

[0001] The invention relates to a watchmaking regulating member with flexible guidance provided with pressure compensation means.

Technology background

[0002] Most current mechanical watches are equipped with a sprung balance and a Swiss anchor escapement mechanism. The sprung balance constitutes the time base of the watch. It is also called a resonator or regulating organ.

[0003] The exhaust, for its part, fulfills two main functions: – maintain the comings and goings of the resonator; – count these comings and goings.

[0004] To constitute a regulating organ, you need an inertial element, guidance and an elastic return element. Traditionally, a spiral spring plays the role of an elastic return element for the inertial element that constitutes a balance wheel. This balance wheel is guided in rotation by pivots, which generally rotate in plain ruby bearings.

[0005] Flexible guides are now used as spring parts to form a virtual pivot. Flexible virtual pivot guides make it possible to significantly improve watch resonators. The simplest are cross-blade pivots, consisting of two straight-blade guide devices that cross each other, usually perpendicularly. These two blades can be either three-dimensional in two different planes, or two-dimensional in the same plane and are then welded at their crossing point. But there are also guides with uncrossed blades of the RCC type (for “Remote Center Compliance” in English), which have straight blades that do not cross. Such a resonator is described in document EP 2911912, or in documents EP14199039, and EP16155039.

However, during its operation, such a mechanical resonator may be subject to disturbances caused by changes in external parameters, which generate variations in frequency of the resonator. These parameters are for example temperature, pressure, humidity, or the direction of gravity. The variation in frequency of the resonator results in an error in the measurement of time.

[0007] For example, document CH 704687 describes a regulating member comprising a spiral spring and a member for correcting the position of the eyebolt to correct deformations of the spiral spring due to temperature.

[0008] Today, there is no regulating organ provided with compensation means configured to compensate for variations in ambient pressure. Thus, when the pressure changes, for example because of altitude, the regulating member loses precision, because the pressure difference modifies the aerodynamic friction of the regulating member. For example, an increase in pressure causes a reduction in the oscillation frequency of the regulating organ.

Summary of the invention

[0009] The aim of the present invention is to overcome all or part of the drawbacks cited above by proposing a watchmaking regulating member with flexible guidance provided with pressure compensation means, which are precise and adaptable to flexible guidance.

[0010] For this purpose, the invention relates to a regulating member for a watch movement, the regulating member comprising an oscillating mass, for example a balance wheel, a flexible guide comprising at least two flexible blades connecting a rigid support to the oscillating mass to allow the oscillating mass to perform a rotary movement around a virtual pivot.

[0011] The invention is remarkable in that the regulating member comprises an elastic device for compensating the external pressure, the elastic compensation device being arranged in series with the rigid support, so as to connect the rigid support to means of fixing the regulating member to the clockwork movement, the elastic compensation device being configured to adapt its stiffness as a function of the external pressure in order to compensate for the effect of the external pressure on the regulating member.

[0012] Thanks to the invention, the prestressing means exert a variable force or torque on the elastic element of the elastic compensation device as a function of the pressure, so that the regulating member substantially maintains a precise course despite significant changes in pressure. Indeed, when the pressure changes, the prestressing means modify the force or the torque exerted on the elastic element, so that the stiffness of the flexible guide is modified. By modifying the stiffness of the flexible guide, the action of the regulating member is adjusted. Consequently, when the pressure changes, the elastic device is mechanically impacted to adjust the course of the flexible guide to this change.

[0013] This elastic element modifies the rigidity of the attachment point and provides additional flexibility to the resonator. Thus, the effective rigidity of the resonator includes the rigidity of the flexible guide and the rigidity of the elastic element. The variable force or torque makes it possible to pre-stress the elastic element, preferably without pre-stressing the flexible guide and without moving the end of the flexible guide. By pre-stressing the elastic element, its rigidity changes, while the rigidity of the flexible guide remains unchanged, since it is not pre-stressed and its end does not move.

[0014] By modifying the rigidity of the elastic element, the rigidity of the resonator (rigidity of the flexible guide and rigidity of the elastic element) changes, which consequently modifies the operation of the resonator. The elastic element being preferably more rigid than the flexible guide, the share of the rigidity of the elastic element in the overall rigidity is less than that of the flexible guide. Consequently, a modification of the rigidity of the elastic element modifies the rigidity of the entire resonator, and consequently fine-tunes its operation, which makes it possible to precisely adjust the frequency of our time base. We thus obtain great precision in maintaining walking depending on the pressure.

[0015] According to a particular embodiment of the invention, the elastic compensation device comprises an elastic element arranged between the support and the fixing means, as well as prestressing means for applying a variable force or torque on the elastic element depending on external pressure.

[0016] According to a particular embodiment of the invention, the prestressing means comprise an aneroid capsule whose volume varies as a function of the external pressure, so as to transmit a variable force or torque as a function of the external pressure.

[0017] According to a particular embodiment of the invention, the prestressing means comprise a spring part connected to the mobile support and to the aneroid capsule, the spring part transmitting the force or the torque to the elastic element via mobile support.

[0018] According to a particular embodiment of the invention, the aneroid capsule comprises a movable wall and a stationary wall connected by at least one spring.

According to a particular embodiment of the invention, the spring part comprises a single flexible blade and a translation table arranged in series between the aneroid capsule and the mobile support.

According to a particular embodiment of the invention, the movable wall is connected to the translation table of the flexible part.

[0021] According to a particular embodiment of the invention, the elastic element comprises a pair of uncrossed blades connecting the mobile support to the fixing means.

[0022] According to a particular embodiment of the invention, the prestressing means are arranged between the uncrossed blades of the elastic element.

[0023] According to a particular embodiment of the invention, the two main blades of the flexible guide are crossed.

[0024] According to a particular embodiment of the invention, the regulating member extends substantially in the same plane, except for the oscillating mass.

According to a particular embodiment of the invention, the elastic element has a rigidity greater than the rigidity of the flexible guide, preferably at least five times greater, or even at least ten times greater.

The invention also relates to a watch movement comprising such a regulating member.

Brief description of the figures

[0027] The aims, advantages and characteristics of the present invention will appear on reading several embodiments given solely by way of non-limiting examples, with reference to the appended drawings in which: – Figure 1 schematically represents a top view of an embodiment of a regulating member provided with pressure compensation means, and – Figure 2 schematically represents an enlarged top view of the compensation means of the embodiment of the invention of Figure 1.

Detailed description of the invention

[0028] Figures 1 and 2 represent an embodiment of a regulating member 1 according to the invention, the regulating member 1, comprising an elastic device 50 configured to compensate for a variation in pressure exerted on the regulating member 1 Such regulating organs 1 are intended to be arranged in a clockwork movement to regulate it.

[0029] In this embodiment, the regulating member 1 comprises a flexible guide 2 and an oscillating mass 19. An oscillating mass can for example be of annular shape or a bone-shaped arm.

The oscillating mass 19 is here of annular shape, and comprises a branch 8 passing through the ring, the branch 8 being arranged to divide the ring into two parts, a first part comprising a third of the ring, and a second part comprising two thirds of the ring. In addition, the oscillating mass 19 includes unbalance adjustment screws 20, here three screws. The adjustment screws 20 are distributed angularly around the ring, and they pass through the ring towards the center of the ring.

Preferably, the regulating member 1 extends substantially in the same plane, except the oscillating mass 19, which oscillates in a parallel plane, in a rotary movement around a virtual pivot, for example above the flexible guidance 2.

The flexible guide 2 comprises two main flexible blades 9, and a rigid support 3. The flexible guide 2 extends along a main axis of symmetry. The main flexible blades 9 are joined on the one hand to the rigid support 3 of the flexible guide 2, and on the other hand to the branch 8 of the oscillating mass 19.

The two main blades 9 of the flexible guide 2 are crossed, preferably straight and of the same length. The crossing point of the main flexible blades 9 is closer to the rigid support 3 than to the branch 8. The main flexible blades 9 are centered, so that the main axis of symmetry passes through a straight line dividing the ring in two.

The flexible guide 2 is arranged inside the ring in the second larger part.

The rigid support 3 has an elongated, substantially parallelepiped body.

[0036] According to the invention, the regulating member 1 comprises an elastic pressure compensation device 50, the elastic device being arranged in series with the rigid support 3 so as to connect the rigid support 3 to fixing means 7 of the regulating organ 1 on the clock movement.

The elastic compensation device 50 is configured to adapt its stiffness as a function of variations in the surrounding pressure in order to compensate for the effect of these variations on the regulating member 1. The elastic compensation device 50 preferably has a stiffness superior to the pair of main flexible blades 9.

The elastic compensation device 50 comprises an elastic element 5 arranged between the rigid support 3 and the fixing means 7, as well as prestressing means 6 for applying a variable force or torque on the elastic element 5 and the rigid support 3 depending on the pressure.

[0039] In Figure 2, the elastic element 5 comprises a pair of uncrossed blades 4 connecting the rigid support 3 to the fixing means 7. The uncrossed blades 4 extend from the rigid support 3, on the side opposite to the side of the blades main flexibles 9 to the fixing means 7 moving away from each other.

The prestressing means 6 are arranged between the flexible blades of the pair of uncrossed blades 4.

The prestressing means 6 comprise a spring portion exerting the variable force or torque on the rigid support 3. Thus, the stiffness of the elastic device is modified, because the prestressing means 6 modify the stiffness of the uncrossed blades 4. spring part is further configured to experience a variable force or torque, which is transmitted to the elastic element 5.

To transmit a variable force or torque as a function of the external pressure to the spring part, the prestressing means 6 comprise an aneroid capsule 10.

Such a capsule is generally used to measure atmospheric pressure. To this end, the capsule comprises a space at least partly empty of air, and comprises a spring-type elastic return element in the space to retain a movable wall of the capsule. Thus, when the external pressure increases, the capsule is compressed, and when the external pressure decreases, the capsule expands.

[0044] In Figure 2, the aneroid capsule 10 comprises a variable volume depending on the external pressure.

[0045] For this, the aneroid capsule 10 comprises a movable wall 13 and a stationary wall 15 connected by at least one spring 16. A sealed enclosure, not shown in the figures, makes it possible to establish at least a partial vacuum inside the aneroid capsule 10. inside the movable 13 and immobile 15 walls.

The immobile wall 15 is integrally connected to the fixing means 7. The immobile wall 15 has an L shape, the large segment 21 of which is substantially parallel to the fixing means 7 and to the support, and the small segment 22 is connected to the fixing means 7 perpendicular to the large segment 21.

The movable wall 13 has an L shape, the movable wall 13 being arranged head to tail relative to the stationary wall 15, so that the large segments 17, 21 of the L are substantially opposite one of the 'other, and that the small segments 18, 22 of the L are substantially opposite each other.

The prestressing means 6 further comprise at least one spring, here two springs 16 connecting the large segments 17, 21 on the interior side, which form the elastic return element of the aneroid capsule. Depending on the pressure exerted on the movable wall 13, the springs 16 extend, particularly when the pressure drops, or contract, particularly when the pressure increases. Thus, they bring the movable wall 13 closer to or further away from the immobile wall 15.

The spring part of the prestressing means 6 is connected to the mobile support 3 and to the aneroid capsule 10, the spring part transmitting the force or the torque of the aneroid capsule 10 to the elastic element 5 via the support mobile 3.

The spring part comprises a single flexible blade 11 connected perpendicularly to the rigid support 3 on the same side as the uncrossed blades 4. The single flexible blade 11 makes it possible to transmit the prestressing force to the mobile support 3 while leaving the mobile support 3 free to turn.

[0051] The spring part also comprises a translation table 33 arranged in series between the movable wall 13 and the single flexible blade 11. The translation table 33 comprises two substantially parallel flexible blades 14 and a movable element 12. The flexible blades 14 connect the movable element 12 to the interior side of the small segment of the L of the movable wall 13, parallel to the large segments of the L.

The function of the translation table 33 is to transform the spacing of the capsule into a prestressing force on the mobile support 3.

The movable element 12 is a parallelepiped connected to the rigid support 3 by the single flexible blade 11, the two flexible blades 14 of the translation table 33 being arranged perpendicular to the single flexible blade 11. The single flexible blade 11 s 'extends from the upper side of the movable element 12 to the middle of the lower side of the rigid support 3.

[0054] When the pressure changes, the movable wall 13 approaches or moves away from the stationary wall 15 and the rigid support 3. Thus, the movable element 12 of the translation table experiences a more or less significant thrust force. towards the rigid support 3, this force being transmitted to the rigid support 3 via the single flexible blade 11.

[0055] Thus, the prestressing means 6 exert a variable spacing force between the rigid support 3 and the fixing means 7. Consequently, the stiffness of the elastic element 5 varies, and makes it possible to adapt the course of the balance to external pressure conditions to maintain the precision of the regulating organ.

[0056] For example, when the pressure increases, the movable wall 13 approaches the stationary wall 15. This rapprochement generates an increase in the spacing force between the rigid support 3 and the fixing means 7, which is exerted by the prestressing means 6. Thus, the stiffness of the elastic element 5, and therefore that of the blades 4 of the pair of uncrossed blades is increased.

On the contrary, when the pressure decreases, the movable wall 13 moves away from the stationary wall 15. This spacing causes a reduction in the spacing force between the rigid support 3 and the fixing means 7, which is exerted by the prestressing means 6. Thus, the stiffness of the elastic element 5, and therefore that of the pair of uncrossed blades 4 is reduced.

[0058] The invention also relates to a clock movement, not shown in the figures, the movement comprising a regulating member 1 as described above.

Naturally, the invention is not limited to the embodiments described with reference to the figures and variants could be considered without departing from the scope of the invention.

Claims (12)

1. Regulating member (1) for a watch movement comprising an oscillating mass (19), for example a balance wheel, a flexible guide (2) comprising at least two flexible blades (9) connecting a rigid support (3) to the mass oscillating (19) to allow the oscillating mass (19) to perform a rotary movement around a virtual pivot, characterized in that the regulating member (1) comprises an elastic compensation device (50) for the external pressure , the elastic compensation device (50) being arranged in series with the rigid support (3), so as to connect the rigid support (3) to fixing means (7) of the regulating member (1) on the movement of watchmaking, the elastic compensation device (50) being configured to adapt its stiffness as a function of the external pressure in order to compensate for the effect of the external pressure on the regulating member (1). 2. Regulating member according to claim 1, characterized in that the elastic compensation device (50) comprises an elastic element (5) arranged between the rigid support (3) and the fixing means (7), as well as means for prestressing (6) to apply a variable force or torque on the elastic element (5) depending on the external pressure. 3. Regulating member according to claim 2, characterized in that the prestressing means (6) comprise an aneroid capsule (10) whose volume varies as a function of the external pressure, so as to transmit a variable force or torque depending on of external pressure. 4. Regulating member according to claim 3, characterized in that the preloading means (6) comprise a spring part connected to the mobile support (3) and to the aneroid capsule (10), the spring part transmitting the force or torque to the elastic element (5) via the movable support (3). 5. Regulating member according to claim 3 or 4, characterized in that the aneroid capsule comprises a movable wall (13) and a stationary wall (15) connected by at least one spring (16). 6. Regulating member according to claim 5, characterized in that the spring part comprises a single flexible blade (11) and a translation table (33) arranged in series between the aneroid capsule (10) and the mobile support (3). 7. Regulating member according to claim 6, characterized in that the movable wall (13) is connected to the translation table (33) of the flexible part. 8. Regulating member according to any one of claims 2 to 7, characterized in that the elastic element (5) comprises a pair of uncrossed blades (4) connecting the mobile support (3) to the fixing means (7 ). 9. Regulating member according to claim 8, characterized in that the prestressing means (6) are arranged between the uncrossed blades (4) of the elastic element (5). 10. Regulating member according to any one of the preceding claims, characterized in that the two main blades (9) of the flexible guide (2) are crossed. 11. Regulating member according to any one of the preceding claims, characterized in that the regulating member (1) extends substantially in the same plane, except for the oscillating mass (19). 12. Clock movement comprising a regulating member (1), according to any one of the preceding claims.