EP3084529B1 - Hairspring with device to prevent coils from moving close together - Google Patents

Description

Field of the invention

The invention relates to a hairspring intended to reduce the risk of bonding between its turns in order to improve the operation of a resonator in which said hairspring is used.

Background of the invention

It is usual in watchmaking to form spirals whose winding of the blade substantially follows the trajectory of an Archimedean spiral. However, it has been noticed that coil gluing could be generated since the use in watchmaking of new materials such as crystalline silicon.

The document US3696687 discloses a hairspring for a measuring instrument comprising material bridges on each turn.

Summary of the invention

The object of the present invention is to overcome all or part of the disadvantages mentioned above by proposing an alternative to the usual spiral which avoids the gluing of the turns together.

For this purpose, the invention relates to a spiral comprising a polygonal section blade wound on itself in several turns characterized in that at least one coil of the spiral comprises an anti-approach device of turns comprising at least four stops mounted on the same face and projecting from the thickness of said at least one turn of the blade, each of said at least four stops being arranged to come into contact with the face facing another turn of the blade. blade preventing the other turn to touch said at least one turn during a shock.

Advantageously according to the invention, the spiral with anti-approximation device of turns makes it possible to prevent geometrically the risk of bonding between turns by limiting the contact surface to said at least four stops.

• lesdites au moins quatre butées sont distribuées sur ladite face selon un angle identique entre elles ;
• ladite au moins une spire comporte un dispositif anti-rapprochement de spires comprenant quatre butées distribuées selon un angle de 90° ou huit butées distribuées selon un angle de 45° ;
• lesdites au moins quatre butées font saillies de l'épaisseur sur au moins une partie ou toute de la hauteur de la lame ;
• lesdites au moins deux butées sont chacune en forme de prisme triangulaire ou pentagonal afin qu'une arête fasse vis-à-vis avec la face de ladite autre spire ;
• l'arête desdites au moins quatre butées faisant vis-à-vis avec la face de ladite autre spire est arrondie pour offrir une pression de contact moins élevée lors d'un choc ;
• lesdites au moins quatre butées sont chacune en forme de prisme semi-discoïdal pour offrir une pression de contact moins élevée lors d'un choc ;
• la surépaisseur desdites au moins quatre butées représente entre 20% et 50% de l'épaisseur nominale de la lame ;
• lesdites au moins quatre butées sont au moins partiellement évidées afin d'ajuster l'effet de leur masse sur le balourd du spiral ;
• lesdites au moins quatre butées sont montées sur ladite face du spiral à l'aide d'une base intermédiaire pour limiter l'augmentation de rigidité locale ;
• lesdites au moins quatre butées sont distribuées sur chaque spire du spiral ;
• la spire interne est solidaire d'une virole agencée pour être fixée à un axe ;
• le spiral est formé à base d'un matériau comportant du silicium ;
• le spiral est monobloc.

According to other advantageous variants of the invention:

• said at least four stops are distributed on said face at an identical angle to each other;
• said at least one turn comprises a turn anti-approach device comprising four stops distributed at an angle of 90 ° or eight stops distributed at an angle of 45 °;
• said at least four abutments protrude from the thickness over at least a portion or all of the height of the blade;
• said at least two abutments are each in the form of a triangular or pentagonal prism so that one edge faces the face of said other turn;
• the edge of said at least four abutments facing the face of said other turn is rounded to provide a lower contact pressure upon impact;
• said at least four stops are each in the form of a semi-discoidal prism to provide a lower contact pressure during an impact;
• the thickness of said at least four stops represents between 20% and 50% of the nominal thickness of the blade;
• said at least four stops are at least partially recessed in order to adjust the effect of their mass on the unbalance of the hairspring;
• said at least four stops are mounted on said face of the hairspring by means of an intermediate base to limit the increase in local rigidity;
• said at least four stops are distributed on each turn of the hairspring;
• the inner coil is integral with a ferrule arranged to be fixed to an axis;
• the hairspring is formed from a material comprising silicon;
• the spiral is monobloc.

Finally, the invention also relates to a timepiece characterized in that it comprises at least one hairspring according to one of the preceding variants.

Brief description of the drawings

• la figure 1 est une vue partielle de dessus d'un dispositif anti-rapprochement de spires selon l'invention ;
• les figures 2 et 3 sont des vues partielles en perspective de deux exemples de dispositif anti-rapprochement de spires selon l'invention ;
• les figures 4 à 10 sont des vues partielles de dessus de modes de réalisation de dispositif anti-rapprochement de spires selon l'invention ;
• la figure 11 est une vue en perspective partielle d'une virole et du début de spire interne d'un spiral selon l'invention ;
• les figures 12 et 13 sont des vues de dessus de autres modes de réalisation de dispositif anti-rapprochement de spires selon l'invention.

Other particularities and advantages will emerge clearly from the description which is given hereinafter, by way of indication and in no way limiting, with reference to the appended drawings, in which:

• the figure 1 is a partial view from above of an anti-approach device of turns according to the invention;
• the Figures 2 and 3 are partial views in perspective of two examples of anti-approach device of turns according to the invention;
• the Figures 4 to 10 are partial top views of coil anti-closures embodiments of the invention;
• the figure 11 is a partial perspective view of a ferrule and the beginning of inner coil of a spiral according to the invention;
• the Figures 12 and 13 are views from above of other embodiments of anti-approach device of turns according to the invention.

Detailed Description of the Preferred Embodiments

The present invention relates to a spiral for the field of watchmaking. More specifically, the hairspring is intended to be mounted in a timepiece such as, for example, in cooperation with a beam to form a pendulum resonator - spiral forming the regulating member of the timepiece.

As explained above, it has been noticed that coil splices could be generated with the use of silicon spirals. lens. Indeed, the heights H , that is to say the vertical parts, turns facing each other are so smooth that an adhesion can be generated by simply bringing two turns together, for example, from an impact suffered by the timepiece. This adhesion can be further increased by contaminating the hairspring with impurities or lubricant during manufacture or wearing.

The hairspring 1, 11, 21, 31, 41, 51, 61, 71, 81, 91 according to the invention comprises a blade 3, 13, 23, 33, 43, 53, 63, 73, 83, 93 of length L , of height H and thickness E forming a polygonal section, preferably rectangular, formed by the height H and the thickness E. The blade 3 is wound on itself in several turns. It is therefore understood that the face formed according to the height of the blade 3, 13, 23, 33, 43, 53, 63, 73, 83, 93 of a first turn vis-a-vis the opposite face of the blade on the turn immediately consecutively.

Advantageously according to the invention, to solve the adhesion problems explained above, at least one turn 8, 10 of the spiral 1, 11, 21, 31, 41, 51, 61, 71, 81, 91 comprises a device 5 , 15, 25, 35, 45, 55, 65, 75, 85, 95 turns approximation comprising at least four stops 7, 7 ', 17, 27, 37, 47, 57, 67, 77, 87, 97 mounted on the same face and projecting from the thickness E of said at least one turn of the blade, each of said at least four stops 7, 7 ', 17, 27, 37, 47, 57, 67, 77, 87, 97 being arranged to come into contact with the face facing another turn of the blade 3, 13, 23, 33, 43, 53, 63, 73, 83, 93 preventing the other turn touches said at least one turn during a shock.

As illustrated in figure 1 we can see an example of spiral 1 according to the invention which is fully contracted. The figure 1 is a partial top view of an example of a device 5 anti-approximation of turns. A first turn 8 formed by the blade 3 extends along a first radius R ₁ relative to the center of the hairspring 1. A second turn 10 formed by the blade 3 extends along a second radius R ₂ relative to the center of the hairspring 1. The hairspring 1 being contracted to the maximum at figure 1 it is understood that the difference between the second radius R ₂ and the first radius R ₁ corresponds to the minimum distance D between turns 8, 10 during normal operation ( R ₂ - R ₁ = D ).

To the figure 1 it can be seen that the said at least four abutments 7, 7 'protrude from the thickness E of the blade to a depth P which leaves an interstice I with respect to the minimum distance D between turns ( I = D - P ) in normal operation. In addition, said at least four stops 7, 7 'are distributed on the same face of the first turn 8 at an angle α .

In the event of an impact, the anti-approach device 8, 10 prevents the second turn 10 from touching the first turn 8. In the diagram of FIG. figure 1 the second turn 10 is represented by the turn 10 'in broken lines. It can be seen that the second turn 10 'abnormally deformed by a shock comes into contact with said at least four stops 7, 7' so that the second turn 10 'abnormally deformed remains at a safety distance S with respect to the first turn 8.

After calculation, it has been determined according to a good approximation that said at least four stops 7, 7 ', 17, 27, 37, 47, 57, 67, 77, 87, 97 must be preferentially distributed on the same face of a turn at an angle α between 45 ° and 170 ° depending on the number of stops per turn. By compromise, it seems that an angle of 90 ° can ensure a satisfactory safety distance S in all the constructions of a hairspring 1, 11, 21, 31, 41, 51, 61, 71, 81, 91 watchmaker. Of course, the angle α can be modulated according to the desired applications.

According to a first variant illustrated in figure 2 , the hairspring 1 comprises a blade 3 provided with a device 5 anti-approximation of turns of which said at least four stops 7 protrude the thickness E over the entire height H of the blade 3 of the hairspring 1. Of course, this first variant is in no way limitative as to the relative height and / or position said at least four stops 7 with respect to the height H of the blade 3. As a second variant illustrated in FIG. figure 3 , the spiral 11 comprises a blade 13 provided with a device 15 anti-approximation of turns of which said at least four stops protrude the thickness E on only part of the height H of the blade 13.

Of course, it may be envisaged to combine, in the same device 5, 15, 25, 35, 45, 55, 65, 75, 85, 95 anti-approximation of turns, said at least four stops 7, 7 ', 17 , 27, 37, 47, 57, 67, 77, 87, 97 of different configurations, that is to say for example to alternate stops 7 of the first variant with stops 17 of the second variant.

Examples of Figures 1 to 3 disclose said at least four abutments 7, 7 ', 17 each in the form of a triangular prism so that an edge 9, 19 is vis-à-vis with the opposite face of another turn. It is readily understood that said at least four stops 7, 7 ', 17, 27, 37, 47, 57, 67, 77, 87, 97 can not be limited to such a triangular prismatic shape.

Thus, according to alternatives, said at least four abutments 7, 7 ', 17, 27, 37, 47, 57, 67, 77, 87, 97 may be of different shape, for example in pentagonal or semi-discoidal prismatic form. , with an edge 9, 9 ', 19, 29, 39, 49, 59, 69, 79, or partially recessed, or of different arrangement as, for example, mounted on the same face of the spiral differently.

Examples of embodiments of the device 5, 15, 25, 35, 45, 55, 65, 75, 85, 95 anti-approximation of turns according to the invention will be described in reference to Figures 4 to 10 and 12 to 13 . The first embodiment of the figure 4 is the one already illustrated at Figures 1 to 3 . It comprises a spiral 1 formed by a blade 3 provided with a device 5 anti-approximation of turns comprising said at least four stops 7, 7 'as a solid triangular prism directly protruding from the thickness E of the blade 3 with a pointed ridge 9 facing the turn immediately consecutively.

The second embodiment of the figure 5 is close to that of the figure 4 . Indeed, it comprises a spiral 21 formed by a blade 23 provided with a device 25 anti-approximation of turns comprising said at least four abutments 27 as a solid triangular prism directly protruding from the thickness E of the blade 23. However, in this second embodiment, the edge 29, which faces the turn immediately consecutive, is rounded to provide a lower contact pressure during an impact.

The third embodiment of the figure 6 is close to that of the figure 5 . Indeed, it comprises a spiral 31 formed by a blade 33 provided with a device 35 anti-approximation of turns comprising said at least four stops in the form of a triangular prism directly protruding from the thickness E of the blade 33 with a 39 rounded edge that faces the turn immediately consecutive. However, in this third embodiment, said at least four stops 37 are at least partially recessed in order to adjust the effect of their mass on the unbalance of the hairspring 31.

The fourth embodiment of the figure 7 comprises a spiral 41 formed by a blade 43 provided with a device 45 anti-approximation of turns comprising said at least four stops 47 as a solid pentagonal prism directly protruding from the thickness E of the blade 43 with a sharp edge 49 who faces the turn immediately consecutively.

The fifth embodiment of the figure 8 is close to that of the figure 7 . Indeed, it comprises a hairspring 51 formed by a blade 53 provided with a device 55 anti-approach of turns comprising said at least four stops 57 in the form of a pentagonal prism directly protruding from the thickness E of the blade 53. However in this fifth embodiment, the ridge 59 which faces the turn immediately following is rounded and said at least four stops 57 are at least partially hollowed out.

The sixth embodiment of the figure 9 is close to that of the figure 4 . Indeed, it comprises a spiral 61 formed by a blade 63 provided with a device 65 anti-approximation of turns comprising said at least four stops 67 as a solid triangular prism indirectly projecting the thickness E of the blade 63 with a sharp ridge 69 facing the turn immediately consecutively. Thus, in this sixth embodiment, said at least four stops 67 are mounted on the same face of the hairspring using an intermediate base 68 of smaller thickness than the base of the triangular prism to limit the stiffness increase. localized by the localized increase of the thickness E on the blade 63. The intermediate base 68 is of prismatic shape with a substantially rectangular or square base.

Finally, the seventh embodiment of the figure 10 is close to that of the figure 9 . Indeed, it comprises a spiral 71 formed by a blade 73 provided with a device 75 anti-approximation of turns comprising said at least four stops 77 in the form of triangular prism protruding from the thickness E of the blade 73 to the Using an intermediate base 78. However, in this seventh embodiment, the edge 79 which faces the turn immediately consecutive is rounded and said at least four stops 77 are at least partially hollowed out.

Of course, the present invention is not limited to the illustrated example but is susceptible of various variations and modifications that will occur to those skilled in the art. In particular, the seven embodiments are in no way limiting, that is to say that other forms and / or arrangements can be envisaged.

By way of example, said at least four abutments could be partially of cylindrical shape, that is to say have a prismatic base section in the form of a partial disk, such as, for example, semi-cylindrical. So, in the eighth embodiment of the figure 12 comprises a spiral 81 formed by a blade 83 provided with a device 85 anti-approximation of turns comprising said at least four stops 87 as a semi-discoidal prism full projecting directly from the thickness E of the blade 83 which faces at the turn immediately consecutively. As visible at figure 12 , the blade 83 has four stops 87 distributed every 90 ° on each turn, the four sets of stops 87 forming an alignment every 90 ° when the hairspring 81 is at rest. In addition, it is noted that the spiral 81 has an inner coil 82 whose free end is shaped with a ferrule 84 and whose trajectory follows a Grossmann type curve. The hairspring 81 also comprises an outer turn 86 whose free end has come form with a fastener 89 for poking the hairspring 81 and a portion 88 is thickened to provide localized stiffening.

This eighth embodiment was satisfactory by having a blade 83 with a thickness E of 42.5 μm , a resting distance D of 52 μm , a contraction distance D of 300 ° of 26 μm and a depth P from 10 to 15 μ m. It is therefore understood that a depth P between 20% and 50% of the thickness of the blade 83 is sufficient to ensure an anti-approximation device 85 effective.

In the ninth embodiment of the figure 13 comprises a spring 91 formed by a blade 93 provided with a device 95 anti-approximation of turns comprising said at least eight stops 97 as a semi-discoidal prism full projecting directly from the thickness E of the blade 93 which faces at the turn immediately consecutively. As visible at figure 13 the blade 93 has eight stops 97 distributed every 45 ° on each turn, the eight sets of stops 97 forming an alignment every 45 ° when the hairspring 91 is at rest. In addition, it is noted that the spiral 91 has an inner coil 92 whose free end is shaped with a ferrule 94 and whose trajectory follows a Grossmann curve. The hairspring 91 also comprises an outer turn 96 whose free end has come in shape with a fastener 99 for patting the hairspring 91 and a portion 98 of which is thickened to provide localized stiffening.

Of course, like the eighth and ninth embodiments, the hairspring 1, 11, 21, 31, 41, 51, 61, 71 according to the other embodiments may also comprise an internal turn which is integral with a ferrule arranged to be fixed to an axis as shown in the example of the figure 11 .

At this figure 11 it is possible to partially see a hairspring 1 formed by a single blade 3, the inner turn 2 of which is provided with a device 5 for preventing windings with at least four stops 7, 7 'in the form of a triangular prism protruding from the E thickness of the blade 3, the inner coil 2 being integral with a ferrule 4. The substantially clover-shaped ferrule 4 has a hole 6 for, for example, to receive a balance shaft.

It is therefore understandable that it is conceivable to combine one or more of the embodiments of the Figures 1 to 13 on the same face of turn and / or on at least two consecutive turns without departing from the scope of the invention.

On reading the above examples, it will be understood that the hairspring 1, 11, 21, 31, 41, 51, 61, 71, 81, 91 may be in one piece, that is to say that the blade 3, 13 , 23, 33, 43, 53, 63, 73, 83, 93 is formed without discontinuity of material. Such a spiral 1, 11, 21, 31, 41, 51, 61, 71, 81, 91 can be formed based on a material comprising silicon, that is to say, for example, monocrystalline silicon, polycrystalline silicon, doped monocrystalline silicon, doped polycrystalline silicon, amorphous silicon, porous silicon, doped or non-doped silicon carbide, doped or non-doped silicon nitride, doped or non-doped silicon oxide such as quartz or silica. Indeed, the Anisotropic etching of such materials can be carried out wet or dry.

Claims (18)

1. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) including a strip (3, 13, 23, 33, 43, 53, 63, 73, 83, 93) of polygonal section wound on itself into several coils (8, 10) and wherein at least one coil (8, 10) includes a device (5, 15, 25, 35, 45, 55, 65, 75, 85, 95) for spacing apart the coils (8, 10) including at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) mounted on the same face and protruding from the thickness (E) of said at least one coil (8) of the strip (3, 13, 23, 33, 43, 53, 63, 73, 83, 93), each of said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) being arranged to enter into contact with the opposite face of another coil (10) of the strip (3, 13, 23, 33, 43, 53, 63, 73, 83, 93) preventing the other coil (10) from touching said at least one coil (8) in the event of a shock.
2. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to the preceding claim, characterised in that said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77) are distributed over said face at an identical angle (α) to each other.
3. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to the preceding claim, characterised in that said at least one coil (8, 10) includes a device (5, 15, 25, 35, 45, 55, 65, 75, 85, 95) for spacing apart the coils (8, 10) including four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) distributed at an angle (α) of 90°.
4. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to claim 2, characterised in that said at least one coil (8, 10) includes a device (5, 15, 25, 35, 45, 55, 65, 75, 85, 95) for spacing apart the coils (8, 10) including eight banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) distributed at an angle (α) of 45°.
5. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of the preceding claims, characterised in that said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) protrude from the thickness (E) over at least part of the height (H) of the strip (3, 13, 23, 33, 43, 53, 63, 73, 83, 93).
6. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to the preceding claim, characterised in that said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) protrude from the thickness (E) over the entire height (H) of the strip (3, 13, 23, 33, 43, 53, 63, 73, 83, 93).
7. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of the preceding claims, characterised in that said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) are each in the shape of a triangular prism so that an edge (9, 9', 19, 29, 39, 49, 59, 69, 79) is opposite the face of said other coil (10).
8. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of claims 1 to 6, characterised in that said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) are each in the shape of a pentagonal prism so that an edge (9, 9', 19, 29, 39, 49, 59, 69, 79) is opposite the face of said other coil (10).
9. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to claim 7 or 8, characterised in that the edge (9, 9', 19, 29, 39, 49, 59, 69, 79) of said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) opposite the face of said other coil (10) is rounded to offer lower contact pressure in the event of a shock.
10. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of claims 1 to 6, characterised in that said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) are each in the form of a semi-discoidal prism to offer lower contact pressure in the event of a shock.
11. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of the preceding claims, characterised in that the overthickness of said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) represents between 20% and 50% of the nominal thickness of the strip (3, 13, 23, 33, 43, 53, 63, 73, 83, 93).
12. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of the preceding claims, characterised in that said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) are at least partially hollowed out to adjust the effect of the mass thereof on the unbalance of the balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91).
13. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of the preceding claims, characterised in that said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) are mounted on the same face of the balance spring with the aid of an intermediate base (68, 78) of smaller thickness than the prismatic base of said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) to limit the increase in local rigidity.
14. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of the preceding claims, characterised in that said at least four banking members (7, 7', 17, 27, 37, 47, 57, 67, 77, 87, 97) are distributed over each coil of the balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91).
15. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of the preceding claims, characterised in that the inner coil is integral with a collet (4, 84, 94) arranged to be secured to an arbor.
16. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of the preceding claims, characterised in that the balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) is in one piece.
17. Balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of the preceding claims, characterised in that the balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) is formed of a material including silicon.
18. Timepiece characterised in that it includes at least one balance-spring (1, 11, 21, 31, 41, 51, 61, 71, 81, 91) according to one of the preceding claims.

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