EP3457221B1 - Timepiece oscillator with flexible pivot - Google Patents

Description

The present invention relates to a horological oscillator with a flexible pivot fulfilling the function of a balance-spring.

Flexible pivot watch components have been proposed in documents EP 2645189 , EP 2037335 , WO 2011/120180 and WO 2012/010408 . The components proposed in these documents are essentially escape levers and oscillators. They pivot around a virtual axis defined by an elastic member. The advantage of such a flexible pivot is that it eliminates friction and pivoting play.

The watchmaking components with a flexible pivot known to date most often use flexible pivots with fairly high stiffness, which require a large amount of energy to pivot the component. However, in certain parts of a watch movement, little energy is available to set the various components in motion.

Flexible pivots with separate crossed blades, known for their low stiffness, are described in the documents GB 422862 and EP 2645189 , but the proposed realizations are either difficult to implement or lack compactness.

The document EN 1574359 describes a horological oscillator with a flexible pivot with separate crossed blades comprising a support, a rotary member and elastic blades embedded in the rotary member and fixed to the support by plates and screws. The elastic blades extend in different planes and intersect without contact to define a virtual axis of rotation.

The present invention aims to provide a watch oscillator with a flexible pivot of the type with separated crossed blades which is relatively easy to manufacture and which can have a small footprint.

• une première pièce monolithique définissant une première partie rigide et une deuxième partie rigide reliées par au moins une première lame élastique, et
• une deuxième pièce monolithique définissant une troisième partie rigide et une quatrième partie rigide reliées par au moins une deuxième lame élastique,

les première et deuxième pièces monolithiques étant assemblées l'une à l'autre de telle sorte que :

• les première et troisième parties rigides soient solidaires l'une de l'autre,
• les deuxième et quatrième parties rigides soient solidaires l'une de l'autre, et
• ladite au moins une première lame élastique et ladite au moins une deuxième lame élastique se croisent sans contact et définissent un axe de rotation virtuel pour les deuxième et quatrième parties rigides par rapport aux première et troisième parties rigides.

To this end, the subject of the present invention is a horological oscillator with a flexible pivot fulfilling the function of a balance-spring and comprising:

• a first monolithic part defining a first rigid part and a second rigid part connected by at least one first elastic blade, and
• a second monolithic part defining a third rigid part and a fourth rigid part connected by at least one second elastic blade,

the first and second monolithic parts being assembled together such that:

• the first and third rigid parts are integral with each other,
• the second and fourth rigid parts are integral with each other, and
• said at least one first elastic blade and said at least one second elastic blade intersect without contact and define a virtual axis of rotation for the second and fourth rigid parts with respect to the first and third rigid parts.

• les figures 1 à 3 montrent respectivement en vue de dessus, en perspective de dessus et en perspective de dessous un composant horloger non couvert par les revendications mais utile à la compréhension de l'invention ;
• les figures 4 à 6 montrent respectivement en vue de dessus, en perspective de dessus et en perspective de dessous une première pièce faisant partie du composant horloger illustré aux figures 1 à 3 ;
• les figures 7 à 9 montrent respectivement en vue de dessus, en perspective de dessus et en perspective de dessous une deuxième pièce faisant partie du composant horloger illustré aux figures 1 à 3 ;
• la figure 10 montre en perspective un oscillateur horloger selon l'invention ;
• les figures 11 et 12 montrent des variantes de l'oscillateur horloger illustré à la figure 10 ;
• les figures 13 à 17 montrent en perspective différentes variantes de composants horlogers ou de parties de composants horlogers.

Other characteristics and advantages of the present invention will appear on reading the following detailed description given with reference to the appended drawings in which:

• them figures 1 to 3 show respectively in top view, in top perspective and in bottom perspective a watch component not covered by the claims but useful for understanding the invention;
• them figures 4 to 6 show respectively in top view, in top perspective and in bottom perspective a first part forming part of the timepiece component illustrated in figures 1 to 3 ;
• them figures 7 to 9 show respectively in top view, in top perspective and in bottom perspective a second part forming part of the timepiece component illustrated in figures 1 to 3 ;
• the figure 10 shows in perspective a horological oscillator according to the invention;
• them figures 11 and 12 show variants of the horological oscillator illustrated in figure 10 ;
• them figures 13 to 17 show in perspective different variants of watch components or parts of watch components.

With reference to figures 1 to 3 , a watch component with a flexible pivot 1 comprises a central fixing part 2 and a mobile peripheral part 3, both of which are rigid. The mobile peripheral part 3 surrounds the central fixing part 2. The central fixing part 2 is used to mount the timepiece component 1 on a support 4 (shown schematically), which support can be fixed (for example the plate of a movement) or mobile. The mobile peripheral part 3 is pivotable with respect to the central fixing part 2 and to the support 4 around a virtual axis of rotation 5 defined by an elastic member.

In the example illustrated, the watch component 1 is a rocker, more precisely a clutch rocker carrying a clutch wheel (not shown). The clutch wheel pivots around an axis 6 which is parallel to the virtual axis of rotation 5 but distinct from the latter. This clutch rocker is intended to be used, for example, in a chronograph mechanism.

The elastic member defining the virtual axis of rotation 5 comprises two elastic blades 7, 8 called “separate crosses”. These two blades 7, 8 intersect in two different planes parallel to the plane of component 1 (that is to say to the plane of the figure 1 ). Unlike so-called “non-separate crossed blade” systems, the two blades 7, 8 therefore do not physically intersect. This arrangement of the blades 7, 8 reduces the stiffness of the elastic member by a factor of 4 compared to systems with non-separate crossed blades. The virtual axis of rotation 5 corresponds substantially to the straight line which is perpendicular to the plane of the component 1 and which crosses the two blades 7, 8. This virtual axis of rotation 5 is not completely fixed during the movements of the mobile peripheral part 3. He is known in the theory that there is a parasitic translation of the axis of rotation which increases with the angle of rotation. This parasitic translation can be canceled by an arrangement of blades or known elastic parts, for example that described in the patent application WO 2011/120180 .

Thus, the mobile peripheral part 3 can pivot around the virtual axis of rotation 5 without friction and without play. The height of the blades 7, 8 is large enough for the stiffness of the elastic member to be very high perpendicular to the plane of the component 1. In this way, in the case of the clutch lever illustrated in figures 1 to 3 , component 1 does not tilt under the effect of the weight of the clutch wheel. This is an advantage over conventional clutch rockers mounted around a physical axis. Due to play in the bearings of the physical shaft, these classic clutch levers have a tendency to tilt with respect to the horizontal, which can prevent the clutch wheel from performing its function correctly. meshing.

As is visible at figures 2 and 3 , the watch component 1 comprises two monolithic parts 9, 10 assembled to one another. The parts 9, 10 are flat and superimposed in the direction of the virtual axis of rotation 5. The lower part 9 (cf. figures 4 to 6 ) comprises a central part 11 and a peripheral part 12 connected to each other by the elastic blade 7. The central part 11 is lower than the peripheral part 12, or comprises a part which extends below the plane of the peripheral part 12, in order to be able to lean on the support 4 while leaving the peripheral part 12 without contact with this support 4. Alternatively, the support 4 can comprise a raised part on which the central part 11 can lean of the lower part 9 to avoid contact between the peripheral part 12 and said support 4. The upper part 10 (cf. figures 7 to 9 ) comprises a central part 13 and a peripheral part 14 connected to each other by the elastic blade 8. The central part 13 has a greater thickness than the peripheral part 14, or comprises a part which extends beyond below the plane of the peripheral part 14, in order to be able to engage in the central opening of the peripheral part 12 and against the central part 11 of the lower part 9. The central part 11 and the peripheral part 12 of the lower part 9 have the same shape as the central part 13 and the peripheral part 14 of the upper part 10, respectively . The lower and upper parts 9, 10 can thus be pressed against each other to form the component 1. The lower part 9 however includes an extension 15 which forms a bearing receiving a stone 16 in which pivots a first pivot of the clutch wheel shaft. Alternatively, this extension 15 which receives the stone 16 could be part of the upper part 10.

The peripheral parts 12, 14 each define two lugs 17, 18 each pierced with a hole. The hole of each ear 17 of the lower part 9 is aligned with the hole of the corresponding ear 18 of the upper part 10 but has a smaller diameter. Tubes 19 are driven into the holes of the ears 17 of the lower part 9 and are received in the holes of the ears 18 of the upper part 10 so as to position and secure in rotation the two parts 9, 10 with respect to each other. the other. Tubes 19 are tapped to allow a bridge to be screwed onto component 1, which bridge includes the bearing for the second pivot of the clutch wheel shaft. The central part 11 of the lower part 9 is pierced with holes 20 which are aligned with corresponding holes 21 of the central part 13 of the upper part 10. These holes 20, 21 allow pins fixed to the support 4 to pass through the parts lower and upper 9, 10 to position the component 1 on the support 4. Another hole 22 of the lower part 9 aligned with a hole 23 of the upper part 10 allows a screw to pass through the lower and upper parts 9, 10. This screw is screwed into support 4 and presses component 1 against said support 4.

It can thus be seen that the lower and upper parts 9, 10 are fixed to each other axially by being together fixed to the support 4. Alternatively, the parts 9, 10 could be directly fixed to each other. , for example by gluing or welding, before being mounted on the support 4.

Thus assembled, the lower and upper parts 9, 10 have their respective central parts 11, 13 which are integral to together form the central fixing part 2 of the component 1 and their peripheral parts 12, 14 which are integral to form together the peripheral part mobile 3 of component 1.

As seen at figure 1 , the empty space 24 between the central fixing part 2 and the mobile peripheral part 3 which surrounds it has a width l which allows a rotation of the mobile peripheral part 3 with respect to the central fixing part 2 within a certain range . From a certain amplitude of rotation, in one direction or the other, the mobile peripheral part 3 abuts against the central fixing part 2 to limit the deformation of the elastic blades 7, 8. The width l is chosen to be sufficiently small so that the elastic limit of the blades 7, 8 cannot be exceeded. Thus, the blades 7, 8 cannot deform plastically or break. As a variant, to limit the deformation of the elastic blades 7, 8, a stop could be provided fixed to the support 4 and against which the mobile peripheral part 3 could come to rest.

The lower and upper parts 9, 10 are typically made of metal, for example steel or titanium, or of a metal alloy such as a nickel-based alloy, and can be obtained by wire machining, for example. They can also be produced by electroforming, for example according to the LIGA technique, in suitable materials such as gold, nickel or a nickel-based alloy such as nickel-phosphorus. The lower and upper parts 9, 10 can also be made of a fragile material such as silicon and obtained by an etching technique, for example of the DRIE type. In the case of parts 9, 10 made of silicon, they can be associated with metallic elements electroformed in the silicon or at its periphery, as described in the patent application EP 2145237 , or silicon bonded, as described in the patent application EP 2579104 . Thus, for example, the watch component may comprise two monolithic silicon parts each defining two rigid parts connected by an elastic blade, and the rigid parts or one of them can be linked to complementary rigid metal parts serving for example as fastening parts.

Thanks to its two assembled parts 9, 10, each comprising one of the elastic blades 7, 9, the timepiece component 1 is relatively easy to manufacture and can take up little space.

The above description could apply to watch components other than a clutch lever. The present invention is an application of the above description to a horological oscillator serving as a time base (that is to say fulfilling the function of a balance-spring).

The functions of the central 2 and peripheral 3 parts could be reversed. Thus, the peripheral part 3 could be a fixing part used to mount the timepiece component on a support, while the central part 2 could be an active part, mobile relative to the support.

The number of separate crossed elastic strips 7, 8 can be greater than two. In other words, the timepiece component 1 could comprise three, four or more superimposed monolithic parts of the type of parts 7, 11, 12 and 8, 13, 14, in particular to increase the stiffness, perpendicular to the plane of the component, of the elastic member defining the virtual axis of rotation 5. By way of example, the figure 10 shows an oscillator 25 intended to fulfill the function of a balance-spring, comprising four assembled monolithic parts 26, 27, 28, 29 together forming an inner fixing part 30, a mobile peripheral part 31 and two elastic members 32, 33 connecting the inner fixing part 30 and the mobile peripheral part 31. In the example illustrated, the mobile peripheral part 31 has an annular shape and the inner fixing part 30 has the shape of an annular arc concentric with the mobile peripheral part 31. The mobile peripheral part 31 plays the role of an oscillating inertial part (balance wheel) while the elastic members 32, 33 play the role of the hairspring. The elastic members 32, 33 are superimposed and define an axis of rotation Z for the balance. Each elastic member 32, 33 comprises two separate cross blades 32a, 32b, 33a, 33b which connect the fixing part 30 and the mobile peripheral part 31. Spacers 34, 35 can separate the monolithic parts 26, 27 from the monolithic parts 28, 29.

Thanks to its superimposed elastic members 32, 33, this horological oscillator 25 has low rigidity in the direction of rotation Rz around the axis Z, but very high rigidity in the directions of rotation Rx, Ry around axes X, Y perpendicular to the Z axis, as well as very high rigidity in translation along the X, Y and Z axes.

Many modifications of oscillator 25 are possible. For example, the figure 11 shows an oscillator 25' which differs from oscillator 25 in that the monolithic pieces 28, 29 have been interchanged to change the relative vertical position of the blades 33a, 33b. The figure 12 shows a 25" oscillator which differs from oscillator 25 in that the monolithic parts 28, 29 have been turned by 180° with respect to the monolithic parts 26, 27, the 25" oscillator thus comprising two internal fixing parts 30a, 30b diametrically opposed and defined respectively by the monolithic parts 26, 27 and by the monolithic parts 28, 29. The monolithic parts 28, 29 can also be turned relative to the monolithic parts 26, 27 by an angle different from 180° so that , at rest, the elastic blades 32a and 33a, respectively 32b and 33b, are not in the same vertical plane, unlike the examples of figures 10 to 12 where they are aligned.

Other modifications of the oscillator 25 can consist in changing the shape of the internal fixing part 30 and of the mobile peripheral part 31. For example, the internal fixing part 30 could be a central part like the central part 2 of the figures 1 to 3 , and the mobile peripheral part 31 could be an interrupted ring.

The present invention is not limited to monolithic parts each comprising a single elastic blade. The figure 13 shows a watch component (oscillator) or part of a watch component, each part of which monolithic comprises two elastic blades 36, 37, respectively 38, 39, which are parallel (as shown) or non-parallel. The figure 14 shows another timepiece component or part of a timepiece component, each monolithic part of which comprises two elastic blades 40, 41, 42, 43 respectively, which are parallel (as shown) or non-parallel.

Finally, the elastic blades of the different monolithic parts are not necessarily located in different planes, the main thing being that they intersect in a non-physical way, that is to say without contact. The figures 15 to 17 show elastic blades of two respective monolithic parts crossing without contact while they are globally in the same plane. To the figure 15 , the elastic blades 44, 45 are in the same plane but have notches 46, 47 to allow their crossing. To the figure 16 , each elastic blade 48, 49 leaves its plane before the crossing of the blades 48, 49 then returns to its plane after the crossing. To the figure 17 , each elastic blade 50, 51 changes plane before the blades cross. Of course, many other configurations are possible in which at least part of each elastic strip is in the same plane as at least part of the other strip. This type of configuration has the advantage of making the component more compact.

Claims (12)

1. Timepiece oscillator with a flexible pivot fulfilling the function of a balance and hairspring assembly and comprising:

   - a first monolithic piece (26) defining a first rigid part and a second rigid part which are connected to one another by at least one first elastic strip (32a), and

   - a second monolithic piece (27) defining a third rigid part and a fourth rigid part which are connected to one another by at least one second elastic strip (32b),

   the first and second monolithic pieces (26, 27) being assembled together such that:

   - the first and third rigid parts are rigidly connected to one another,

   - the second and fourth rigid parts are rigidly connected to one another, and

   - said at least one first elastic strip (32a) and said at least one second elastic strip (32b) cross each other without contact and define a virtual axis of rotation (Z) for the second and fourth rigid parts with respect to the first and third rigid parts.
2. Timepiece oscillator as claimed in claim 1, characterised in that the first and second monolithic pieces (26, 27) are flat and superimposed.
3. Timepiece oscillator as claimed in claim 1 or 2, characterised in that the first and third rigid parts form a central or internal part (30) of the timepiece oscillator and in that the second and fourth rigid parts form a peripheral part (31) of the timepiece oscillator.
4. Timepiece oscillator as claimed in claim 3, characterised in that the peripheral part (31) completely or almost completely surrounds the central or internal part (30).
5. Timepiece oscillator as claimed in any one of claims 1 to 4, characterised in that the first and third rigid parts form a fixing part (30) of the timepiece oscillator, serving to mount the timepiece oscillator on a support (4).
6. Timepiece oscillator as claimed in any one of claims 1 to 5, characterised in that the first rigid part extends at least partially outside the plane of the second rigid part in order to permit it to be fixed to a support (4) without contact between the support (4) and the second and fourth parts.
7. Timepiece oscillator as claimed in any one of claims 1 to 6, characterised in that the assembly formed by the second and fourth rigid parts is arranged to be able to abut against the assembly formed by the first and third rigid parts upon rotation of the second and fourth rigid parts with respect to the first and third rigid parts, in order to limit the deformation of said at least one first elastic strip and of said at least one second elastic strip and to prevent their elastic limit from being exceeded.
8. Timepiece oscillator as claimed in any one of claims 1 to 7, characterised in that it comprises at least one guiding or fixing element rigidly connected to the second and fourth rigid parts and intended to guide or fix an additional element.
9. Timepiece oscillator as claimed in any one of claims 1 to 8, characterised in that said at least one first elastic strip (32a) and said at least one second elastic strip (32b) are entirely located in different planes substantially perpendicular to the virtual axis of rotation (Z).
10. Timepiece oscillator as claimed in any one of claims 1 to 8, characterised in that at least part of said at least one first elastic strip (44; 48; 50) is in the same plane, substantially perpendicular to the virtual axis of rotation, as at least part of said at least one second elastic strip (45; 49; 51).
11. Timepiece oscillator as claimed in any one of claims 1 to 10, characterised in that it comprises a third monolithic piece (28) defining fifth and sixth rigid parts rigidly connected respectively to the first and second rigid parts and connected to one another by at least one third elastic strip (33a), said at least one third elastic strip (33a) defining, with said at least one first elastic strip (32a) and said at least one second elastic strip (32b), the virtual axis of rotation (Z).
12. Timepiece oscillator as claimed in claim 11, characterised in that it comprises a fourth monolithic piece (29) defining seventh and eighth rigid parts rigidly connected respectively to the first and second rigid parts and connected to one another by at least one fourth elastic strip (33b), said at least one third elastic strip (33a) and said at least one fourth elastic strip (33b) crossing each other without contact and defining, with said at least one first elastic strip (32a) and said at least one second elastic strip (32b), the virtual axis of rotation (Z).

Images