EP3470934A1 - Shock absorbing system with angular locking - Google Patents

Abstract

The present invention relates to a shock absorbing device (100) for an axis of a component of a timepiece comprising a support (200) comprising a bottom cup (201) surmounted by a defined peripheral rim (203), opposite said cup, by an upper surface (213) and comprising an outer wall (214), said cup (201) and the flange (203) together defining a housing (206), the device further comprising at least a pivot module (400) extending along an axis (C), said at least one pivot module being arranged in said housing and adapted to cooperate with said axis, said device comprising fixing means comprising a peripheral bearing extending from the rim towards the axial center of the cup, elastic means being arranged between the pivot module and the scope to exert a stress on the pivot module.

Description

The present invention relates to a shock absorbing device also called shockproof system for a mobile axis of a micromechanical device, in particular but not exclusively a clockwork movement. The shock absorbing device comprises a support in which there is provided a housing for receiving a pivot system to maintain with a preset clearance a skewer of the axis. The shock absorbing device further comprises elastic means arranged to exert on the pivot system at least one axial elastic return force.

The technical field of the invention is the technical field of fine mechanics.

Technological background of the invention

The present invention relates to a shock absorber device for an axis arranged in a micromechanical mechanism, in particular in a mechanical or electromechanical clockwork movement. Such shock-absorbing devices, also known as "shock-absorbing bearings" or "shock-proofing systems", have long been known by manufacturers of mechanical watches. These shock absorbing devices are intended to allow an axis to absorb the energy resulting from an impact, in particular a side impact, allowing it to momentarily move away from its rest position, then to return to this rest position under the effect of an elastic return force. It will be understood that in the mechanisms of micromechanics in general, and in In particular, most axes extend vertically with respect to the plane in which such micromechanical mechanisms or watch movements extend. A watch movement can therefore undergo essentially two different types of shock: either an axial impact, if the watch falls substantially flat on a surface; a side impact, if the watch falls on the side of the caseband. Of the two types of impact, the side impact is the most troublesome. Indeed, in the case of an axial impact, the force resulting from this shock is substantially perpendicular to the bottom of the watch, and therefore approximately parallel to the direction in which the axes of the watch movement extend. The risks that these axes break up or break are therefore quite limited. On the other hand, in the event of a side impact, the force resulting from the shock is exerted in a direction approximately perpendicular to the axes, so that the risk that the axes leave their housing and / or break is high.

To solve this problem, manufacturers of mechanical watches and other micromechanical mechanisms have therefore proposed shock-absorbing devices, also known as shock-proof systems. Briefly summarized, such shock absorbing devices comprise a support whose base has no bottom to allow passage to an axis terminated by a tigeron. The support receives a kitten which is a generally annular piece and which supports staggered a pierced stone traversed by the axis of the spindle and a counter-pivot stone. The assembly formed by the kitten, the pierced stone and the counter-pivot stone is resiliently held in the support by means of a spring element mounted on the support removably and which exerts on the counter-pivot stone an elastic force of plating. Such shock-absorbing devices are in particular marketed under the Incabloc® trademark. As for the spring element, it can in particular be made of brass or with a spring steel such as commercialized cobalt-chromium austenitic grade under the trademark Phynox © KL, and is conventionally obtained by cutting techniques.

In the case of axial impact, the pierced stone, the counter-pivot stone and the axis move substantially perpendicularly to the bottom of the watch, against the elastic force of return of the spring element which brings all this crew rest position.

In case of side impact, the axis will be misaligned and will abut against the base of the support, which causes the decentering of the pierced stone and, consequently, the kitten and the stone against pivot. In this case too, the spring element brings all the elements back to their equilibrium position.

The figures 1 and 2 attached to this patent application schematically illustrate a shock absorbing device which is currently used in timepieces on the market. This shock absorbing device is described in detail in the European patent application registered under the number EP 16160124.0 in the name of the Claimant.

Designated as a whole by the general numerical reference 1, the shock absorbing device, also called shockproof system, can in particular be mounted in an element of a timepiece movement such as a platinum or a bridge. This shock absorbing device 1 comprises in particular a support 2 which is in the form of a cup 4 whose base 6 is devoid of bottom and which is delimited at its periphery by a first flange 8. It will be noted that the cup 4 and the first rim 8 can be made in one piece, or be separate parts assembled to one another.

On the opposite side to the base 6 of the cup 4, the first flange 8 comprises an extended upper surface 10, on the inside of the cup 4, by an inner wall 12, and on the outer side of the cup by an outer wall 14.

The first rim 8 defines with the cup 4 a housing 16 in which a pivot module 18 is inserted. This pivot module 18 comprises a kitten 20, that is to say a part comprising a circular central orifice 22 and a second flange 24 delimited by an external lateral wall 26 and an internal lateral wall 28. In the central circular orifice 22 is inserted a pierced stone 30 whose diameter corresponds to that of the central circular orifice 22. As for the inner side wall 28 of the kitten 20, it is provided with a shoulder 32 on which is placed a stone against pivot 34.

The pivot module 18 thus arranged is placed in the housing 16 of the support 2, then the assembly thus obtained is inserted, for example into a hole of a watch plate or in one of the bridges of a watch movement. The pivot module 18 is arranged to cooperate with a shank 36 of an axis 38.

The shock absorbing device 1 further comprises elastic means 40 provided to cooperate with the pivot module 18 in order to dampen shocks and bring the pivot module 18 back to its rest position when the stresses induced by the shocks fade. These elastic means 40 are fixed on the support 2 and are preferably also in contact with the pivot module 18.

In an embodiment given by way of example only, the elastic means 40 are in the form of a spring ring 42 of flat type, that is to say cut into a band or ribbon whose width is substantially greater than the thickness. This spring ring 42 is metallic and circular in shape, centered on a point Ç.

As can be seen from the examination of figures 1 and 2 , the spring ring 42 comprises for example three regularly spaced arms 44 which extend radially towards the center C of this spring ring 42. These three arms 44 allow the spring ring 42 to press the pivot module 18 into the housing 16 of support 2.

For the mounting of the spring ring 42 on the support 2, a bayonet system 46 is used. This bayonet system 46 comprises a peripheral surface 48 which extends from the first edge 8 of the support 2 towards the center of this support. 2. Furthermore, a circular groove 50 is formed in the inner wall 12 of the first flange 8, under the peripheral surface 48, to define a holding zone.

To cooperate with the bayonet system 46, the spring ring 42 is provided on its outer periphery with three regularly spaced lugs 52 which extend radially away from the center C of this spring ring 42. As can be seen in FIG. design, each of these three lugs 52 is disposed between two consecutive arms 44 of the spring ring 42. Voluntarily, the three lugs 52 give the spring ring 42 an outer diameter which exceeds the inside diameter of the peripheral surface 48. Therefore, to allow the mounting of the spring ring 42 on the support 2, there is provided in the peripheral surface 48 of the first notches 54 to the number of three which open into the circular groove 50. Therefore, to mount the spring ring 42 on the support 2, it is sufficient to present it so that the three lugs 52 engage in the first three notches 54 corresponding, then to rotate to allow the pins 52 of slide inside the circular groove 50, under the peripheral bearing 48.

The notches 54 are typically made by a stamping operation of the peripheral surface 48 which reveals arcuate portions 55. At each end of the arcuate portions 55, the material is locally repulsed during the operation. for forming cavities 57a on the top of these arcuate portions 55, and bosses 57b below the arcuate portions 55. These bosses 57b contribute to the retention of the spring ring 52 when the it is introduced into the circular groove 50, under the arcuate portions 55 of the peripheral surface 48.

Note that the mounting of the spring ring 42 occurs after the step of placing the pivot module 18 in its housing 16. When the spring ring 42 is installed, the pivot module 18 exerts on the spring ring 42 a force which tends to push this spring ring 42. Under the effect of this constraint, the spring ring 42 tends to deform elastically, but is not driven out of its housing 16 thanks to the presence of the pins 52 inserted into the circular groove 50 which absorb the mechanical stresses and oppose the displacement of the spring ring 42. In addition, as the lugs 52 define passive zones of the spring ring 42, the presence of these lugs 52 and the mechanical stresses they absorb have no effect on the behavior of the spring ring 42. Therefore, the behavior of the spring ring 42 is not modified when it is mounted on the support 2.

As its name suggests, a shock absorber device is intended to allow a micromechanical axis, for example housed in a watch movement, to absorb without breaking the energy resulting from an impact, in particular a side impact. , allowing this axis to move momentarily under the effect of a shock before returning it elastically in its rest position. Depending on the intensity of the shock and the direction in which it is applied, the spring ring 42 is nevertheless likely to pivot on itself and it is quite possible that it finds itself in a situation in which the three lugs 52 are in the first three notches 54 corresponding. In such a situation, the spring ring 42 can decouple from the support 2. The axis 38 is then no longer maintained by the shock absorber device 1, which inevitably leads to the breakdown of the mechanical device, for example watchmaker, in which is installed this shock absorber device 1. Such a risk is all the less acceptable that, in the field of watchmaking in particular, shock-absorbing devices are mainly installed in watches that belong to the upper segment of the market.

To remedy this problem, it has already been proposed in the patent application EP 16160124.0 mentioned above to check the peripheral scope 48 in the areas between two successive notches 54. By countersinking is meant the action of raising the lower surface of the peripheral surface 48 by removing material by means of a rotating blade. Thanks to this countering action, it is possible to partially reduce the thickness of a third flange 56 of the peripheral surface 48 and to create, between two successive notches 54, clearances 58 in which the lugs 52 are housed.

The above solution has not been fully satisfactory. First of all, the clearances 58 in which the lugs 52 are housed have proved insufficiently deep and their peripheral rims insufficiently high in order to guarantee a good immobilization in angular pivoting of the spring ring 42 in the event of shocks, in particular in case of side impacts. On the other hand, machining the clearances 58 by means of a milling cutter, usually a T-type milling cutter, has proved extremely long, tedious and with random results. During machining operations, care was especially taken not to bite on the inside diameter of the peripheral bearing 48. The feed rates of the milling cutter T were low and vibrations appeared in the milling tool. Finally, despite all the care taken in milling operations, it was not uncommon for burrs to remain in the clearances.

Summary of the invention

The present invention aims to solve the problems mentioned above as well as others by providing a shock absorbing device whose risks that its various components disengage in the event of axial or lateral impact are considerably reduced, or even eliminated.

For this purpose, the present invention relates to a shock-absorbing device for an axis of a mobile of a micromechanical device, in particular a clockwork movement, this shock-absorbing device comprising a support which comprises a cup whose base is without a bottom and which is bounded at its periphery by a rim, the rim comprising an upper surface extended, on an inner side of the cup, by an inner wall, and, on an outer side of the cup, by a wall external, the rim of the cup defining a housing in which a pivot module is inserted, the pivot module comprising a kitten having a central orifice into which is inserted a pierced stone which corresponds in shape and dimensions to those of the central orifice, a counter-pivoting stone being placed on the kitten, above the pierced stone, the shock-absorbing device also comprising a spring ring arranged between the port and the pivot module to exert elastic stress on the pivot module, the shock absorbing device being provided with a bayonet system for mounting the spring ring between the support and the pivot module, this bayonet system comprising a peripheral bearing which extends from the inner wall of the flange towards the inside of the support, and under which is formed a circular groove which defines a holding zone, the spring ring being provided on an outer periphery with at least one lug which gives this ring spring an outer diameter which exceeds an inner diameter of the peripheral surface, at least one first notch which opens into the circular groove being provided in the peripheral surface, this first notch defining a first diameter at least equal to the outer diameter of the ring spring, so that it suffices to present the spring ring so that the lug engages in the first corresponding notch, then to rotate the spring ring to allow the pin to slide inside the circular groove, under the peripheral bearing, the shock absorbing device being characterized in that at least one second notch is machined in the peripheral scope, this second notch defining a second diameter less than the outer diameter of the spring ring, so that the lug is embedded in the second notch, ensuring the angular immobilization in pivoting of the spring ring.

With these features, the present invention provides a shock absorbing device in which second notches are cut in the rim of the peripheral scope. This deviates from the circular profile of the rim of the peripheral bearing, which allows the lugs of the spring ring to adopt a position of least stress under the lower surface of the peripheral rim, and to abut against the edges that define the profile of these second notches. The spring ring is thus locked in angular pivoting, which ensures that in case of impact, in particular lateral, the risk that the axes of mobile disengage completely are limited, or even zero. Another advantage of the invention lies in the fact that the notches are very easy to machine, for example by stamping or cutting. The manufacturing times are therefore considerably reduced and the scrapping rates of the support parts are very low, all of which make it possible to substantially reduce the cost price of the shock-absorbing devices according to the invention. Finally, since the notches are very easy to machine in the peripheral range, it is possible to vary almost infinitely the profile of the second notches, which makes it possible to search the profile which, for a given geometry of the different elements of the damping device of shocks, makes it possible to obtain optimal blocking and response of the spring ring in the event of impact.

Brief description of the figures

• les figures 1 et 2, déjà citées, illustrent de manière schématique un dispositif amortisseur de chocs connu dans lequel des évidements sont usinés dans la surface inférieure de la portée périphérique du support, afin de tenter de bloquer l'anneau ressort en pivotement angulaire en cas de choc ;
• les figures 3A et 3B sont des vues respectivement de dessus et en perspective d'un dispositif amortisseur de chocs selon une première forme d'exécution de l'invention ;
• les figures 4A et 4B sont des vues respectivement de dessus et en perspective d'un dispositif amortisseur de chocs selon une deuxième forme d'exécution de l'invention ;
• les figures 5A et 5B sont des vues respectivement de dessus et en perspective d'un dispositif amortisseur de chocs selon une troisième forme d'exécution de l'invention ;
• la figure 6A est une vue de détail à grande échelle de la région du support selon l'art antérieur dans laquelle la portée périphérique est munie de dégagements qui reçoivent les ergots de l'anneau ressort, et
• la figure 6B est une vue de détail à grande échelle de la région du support selon l'invention dans laquelle la portée périphérique est munie d'encoches qui reçoivent les ergots de l'anneau ressort.

Other features and advantages of the present invention will emerge more clearly from the following detailed description of an embodiment of a shock-absorbing device according to the invention. example being given for purely illustrative and nonlimiting purposes only in connection with the appended drawing in which:

• the figures 1 and 2 , already mentioned, schematically illustrate a known shock absorber device in which recesses are machined in the lower surface of the peripheral bearing surface, in order to try to block the spring ring in angular pivoting in case of impact;
• the Figures 3A and 3B are views respectively from above and in perspective of a shock-absorbing device according to a first embodiment of the invention;
• the Figures 4A and 4B are views respectively from above and in perspective of a shock-absorbing device according to a second embodiment of the invention;
• the Figures 5A and 5B are views respectively from above and in perspective of a shock-absorbing device according to a third embodiment of the invention;
• the Figure 6A is a large-scale detail view of the region of the support according to the prior art in which the peripheral surface is provided with recesses which receive the lugs of the spring ring, and
• the Figure 6B is a large-scale detail view of the region of the support according to the invention wherein the peripheral surface is provided with notches which receive the lugs of the spring ring.

Detailed description of an embodiment of the invention

The present invention proceeds from the general inventive idea of cutting, in the rim of the peripheral bearing surface of a shock absorbing device, notches intended to receive the locking lugs of a spring ring intended to constrain the stone. counter pivot in the direction of the pierced stone which guides the shank of a mobile axis. These notches, for example made by stamping or cutting, are easier to machine, so that the cost of the resulting media is less than in the past. Moreover, since the notches are cut in the entire thickness of the rim, the locking of the lugs against the edges which delimit the contour of these notches is optimal. Finally, because of the ease with which these notches can be made, there is great freedom in terms of the shape that can be given to these notches, which for each spring ring geometry, allows look for the shape of the notches guaranteeing the best locking of this spring ring.

The shock absorbing device according to the invention is in all respects identical to the shock absorbing device of the prior art described above, with the notable difference that the edge of the peripheral bearing surface of the support is partially cut in notches which allow the locking of the lugs of the spring ring, and thus the locking in angular pivoting of the latter. It will therefore be understood that, in what follows, the elements identical to those described in connection with the figures 1 and 2 will be designated by the same numerical references.

The Figures 3A and 3B illustrate, respectively in plan view and in perspective, a first embodiment of a shock-absorbing device according to the invention. Designated as a whole by the general reference numeral 60, this shock absorbing device comprises in particular a spring ring 42 of flat type provided with at least one and, in the example shown, of three regularly spaced arms 44 which extend radially. towards the center C of this spring ring 42. These three arms 44 allow the spring ring 42 to press the pivot module 18 in the housing 16 of the support 2.

For the mounting of the spring ring 42 on the support 2, a bayonet system 46 is used which comprises a peripheral surface 48 extending from the first rim 8 of the support 2 towards the center of this support 2. Furthermore, a circular groove 50 is formed in the inner wall 12 of the first rim 8, under the peripheral surface 48, to define a holding zone .

To cooperate with the bayonet system 46, the spring ring 42 is provided on its outer periphery with at least one and, in the example shown, with three regularly spaced lugs 52 which extend radially away from the center Ç of this spring ring 42. As can be seen in the drawing, these three lugs 52 are arranged angularly offset relative to the three arms 44 of the spring ring 42, preferably at equal angular distance from two arms 44 consecutive.

Voluntarily, the three lugs 52 give the spring ring 42 an outer diameter which exceeds the inside diameter D of the peripheral surface 48. Therefore, to allow the mounting of the spring ring 42 on the support 2, it is provided in the peripheral surface 48 of the first notches 54 of which three open into the circular groove 50. These first three notches 54 are arranged with the same angular spacing as the pins 52. Therefore, to mount the spring ring 42 on the support 2, it is sufficient to present it so that the three lugs 52 are found opposite the first three notches 54 corresponding, then to rotate to allow the lugs 52 to slide inside the circular groove 50, under the peripheral reach 48.

The notches 54 are typically made by a stamping operation of the peripheral surface 48 which reveals arcuate portions 55. At each end of the arcuate portions 55, the material is locally repulsed during the operation. stamping, which forms depressions 57a on the top of these arcuate portions 55, and bosses 57b below the arcuate portions 55. These bosses 57b contribute to the maintenance of the spring ring 52 when it is introduced into the circular groove 50, under the arcuate portions 55 of the peripheral surface 48.

Note that the mounting of the spring ring 42 occurs after the step of placing the pivot module 18 in its housing 16. When the spring ring 42 is installed, the pivot module 18 exerts on the spring ring 42 a force which tends to push this spring ring 42. Under the effect of this constraint, the spring ring 42 tends to deform elastically, but is not driven out of its housing 16 thanks to the presence of the pins 52 inserted into the circular groove 50 which absorb the mechanical stresses and oppose the displacement of the spring ring 42. In addition, as the lugs 52 define passive zones of the spring ring 42, the presence of these lugs 52 and the mechanical stresses they absorb have no effect on the behavior of the spring ring 42. Therefore, the behavior of the spring ring 42 is not modified when it is mounted on the support 2.

In order to guarantee the immobilization in angular pivoting of the spring ring 42 and thus to ensure that the shock-absorbing device 60 is not likely to dislodge in the event of an impact, second slots 62, numbering three, are machined, for example by cutting or stamping, in the third rim 56 of the peripheral surface 48 of the support 2. Thus, once the spring ring 42 engaged in the circular groove 50 of the bayonet system 46, simply rotate the spring ring 42 until the lugs 52 are embedded in the second notches 62 abutting against the edges 64 which define the profile of these second notches 62.

By examining Figures 6A and 6B it is found that, in the case of the shock absorbing device 1 of the prior art ( Figure 6A ), it is only reduce from below the thickness of the third flange 56 of the peripheral surface 48, without altering the perimeter of the rim 56, to create the clearances 58. Now, it is easy to understand that such an operation machining is long and delicate to achieve. In addition, the clearances 58 have proved insufficiently deep and their peripheral edges insufficiently high to be able to ensure good immobilization in angular pivoting of the spring ring 42 in case of shocks. On the contrary, in the case of the shock-absorbing device 60 according to the invention ( Figure 6B ), the second notches 62 are cut in the third flange 56 of the peripheral surface 48 of the support 2, over the entire thickness of the third flange 56 and biting on the perimeter of the third edge 56. Thus, these second notches 62 are sufficiently deep and their edges 64 high enough to ensure the proper locking of the pins 52 and the immobilization of the spring ring 42 in angular pivoting in case of impact.

In addition, these second notches 62 are very easy to machine and we can better adapt their profile to ensure optimal blocking. Thus, Figures 3A and 3B Was bitten on the perimeter 56 of the peripheral bearing surface 48 for making notches 62 which extend along circular arcs which are concentric with the center C of the ring spring 42. In the Figures 4A and 4B , the second notches 62 were obtained by cutting the peripheral surface 48 in a circle of small radius whose center Ç1 is on the bisector of the angle α which extends between two first notches 54 successive. Similarly, Figures 5A and 5B , the second notches 62 have been obtained by cutting the peripheral scope in a circle of greater radius whose center C2 is also on the bisector of the angle which extends between two first notches 54 successive.

It goes without saying that the present invention is not limited to the embodiments which have just been described, and that various modifications and simple variants can be envisaged by those skilled in the art without departing from the scope of the invention such that defined by the appended claims.

Nomenclature

• 1. Shock absorbing device or shockproof system
• 2. Support
• 4. Cup
• 6. Base
• 8. First ledge
• 10. Upper surface
• 12. Internal wall
• 14. External wall
• 16. Housing
• 18. Pivot Module
• 20. Kitten
• 22. Circular central hole
• 24. Second edge
• 26. External sidewall
• 28. Internal side wall
• 30. Pierced stone
• 32. Shoulder
• 34. Counter-pivot stone
• 36. Tigeron
• 38. Axis
• 40. Elastic means
• 42. Spring ring
• C. Center of the spring ring
• 44. Bras
• 46. Bayonet system
• 48. Peripheral reach
• 50. Circular groove
• 52. Ergots
• 54. First notches
• 55. Portions in an arc
• 56. Third edge
• 57a. Hollow
• 57b. bosses
• 58. Clearances
• 60. Shock absorbing device
• 62. Notched second
• 64. Edges

Claims (1)

Shock absorbing device (1) for an axis (38) of a mobile of a micromechanical device, in particular a clockwork movement, this shock absorbing device (1) comprising a support (2) which comprises a cup ( 4) of which a base (6) is devoid of bottom and which is delimited at its periphery by a flange (8), the flange (8) comprising a prolonged upper surface (10), an inner side of the cup (4). ), by an inner wall (12), and, on an outer side of the cup (4), by an outer wall (14), the flange (8) of the cup (4) defining a housing (16) in a pivot module (18) is inserted, said pivot module (18) comprising a kitten (20) having a central orifice (22) into which is inserted a pierced stone (30) which corresponds in shape and dimensions to those of the central orifice (22), a counter-pivoting stone (34) being placed on the kitten (20), above the pierced stone (30), the cushioning device of shocks (1) also comprising a spring ring (42) arranged between the support (2) and the pivot module (18) to exert an elastic stress on this pivot module (18), the shock-absorbing device (1) being provided with a bayonet system (46) for mounting the spring ring (42) between the support (2) and the pivot module (18), the bayonet system (46) comprising a peripheral bearing (48) which extends from the inner wall (12) of the flange (8) to the inside of the support (2), and under which is formed a circular groove (50) which defines a holding zone, the spring ring (42) being provided on an outer periphery of at least one lug (52) which gives this spring ring (42) an outer diameter which exceeds an inside diameter of the peripheral span (48), at least one first notch (54) which opens into the circular groove (50) being provided in the peripheral surface (48), this first notch defining a first diameter at least equal to the outer diameter of the spring ring (42), so that it is sufficient to present the spring ring (42) so that the lug (52) engages in the corresponding first notch (54), then to rotate the spring ring (42) to allow the pin (52) to slide inside the circular groove (50), under the peripheral surface (48), the shock-absorbing device (1) being characterized in that at least a second notch is machined in the peripheral bearing (48), this second notch defining a second diameter smaller than the outer diameter of the spring ring (42), so that the lug (52) is embedded in this second notch, guaranteeing the angular immobilization pivoting the spring ring (42).

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