EP4016195B1 - Tourbillon for a clockwork - Google Patents

Description

Technical area

The present invention relates to a tourbillon for a watch movement comprising a cage intended to be rotatably mounted on said watch movement, said cage carrying a regulating member comprising a balance wheel comprising a balance wheel pivot mounted in balance wheel bearings around a balance wheel axis as well as an anchor comprising an anchor pivot mounted pivoting in anchor bearings around an anchor axis and arranged to cooperate, on the one hand, with said regulating member and, on the other hand, with an escape wheel comprising an escapement pivot pivotally mounted in escapement bearings about an escapement axis.

The present invention also relates to a timepiece movement comprising such a tourbillon as well as a timepiece comprising such a movement.

State of the art

Such tourbillons are mechanisms widely used in watches to cause the regulating organ to assume all vertical positions, which allows deviations in rate due to the attraction of the earth to compensate each other mutually. This improves the accuracy of the watch.

An example of a traditional tourbillon is described in the book " Théorie d'horlogerie", by CA. Reymondin et al., published by the Federation of Technical Schools (Switzerland), ISBN 2-940025-1 0-X, on page 167 .

The tourbillon works like a seconds mobile, ie it meshes with the middle wheel via a central pinion fixed under the carriage. Inside the carriage, the oscillating movement of the regulating organ is maintained by the escapement also mounted on the carriage, the escapement pinion meshing with the outer peripheral toothing of a fixed seconds wheel placed under the carriage and integral with the movement frame.

Traditionally, the anchor and escape wheel pivots are located under the balance, so as not to interfere with its oscillating movement. For this, the lever and the escape wheel are pivotally mounted in bearings arranged respectively in the lower bridge of the carriage and in bridges integral with the lower bridge extending under the balance wheel. But, as a result, the standard tourbillon has a certain thickness due to the two levels or floors occupied respectively by the balance wheel and by the lever and the escapement wheel.

A watch comprising such a tourbillon must therefore have a sufficient thickness in order to be able to accommodate it, so that the standard tourbillon is hardly compatible with an extra-thin watch.

In order to make the use of a tourbillon compatible with an extra-thin watch, various solutions have been proposed. One solution consists of reducing the safety features of the balance, anchor and escapement. However, this undermines the effectiveness of the regulatory body. Another solution consists in removing certain parts, such as for example the upper cage. However, in this case, the disturbances caused by the lack of freedom in the balance are not negligible.

The document CH 713 529 discloses a tourbillon as a theoretical case that embeds an escapement where the axes of the escapement wheel and the levers are positioned outside the balance seen in plan.

In the whirlwind of the document EP 3 663 868 A1 the anchor pivot is arranged outside the space of the balance wheel but the escapement wheel is absent and replaced by a fixed wheel which is on the same axis as the balance wheel.

In the document CN 204 576 069 U the anchor is external but the wheel pivot is not.

In the document EP 3 650 954 , it is the escape wheel which is external.

The present invention aims to remedy these drawbacks by proposing a tourbillon having a reduced thickness compared to a standard tourbillon, compatible with use in an extra-thin movement, while retaining the traditional arrangement of the regulating organ in the cage of the tourbillon, without damaging the securities of said regulating organ.

Disclosure of Invention

To this end, the invention relates to a tourbillon for a watch movement comprising a cage intended to be rotatably mounted on said watch movement, said cage carrying a regulating member comprising a balance comprising a balance pivot pivotally mounted in balance bearings around a balance shaft as well as an anchor comprising an anchor pivot mounted pivoting in anchor bearings around an anchor shaft and arranged to cooperate, on the one hand, with said regulating member and, on the other hand, with an escape wheel comprising a pivot exhaust pivotally mounted in exhaust bearings about an exhaust axis.

According to the invention, the anchor and the escape wheel are positioned relative to the balance wheel in such a way that the distance between the anchor axis and the balance wheel axis and the distance between the escapement axis and the balance wheel axis are greater than the outer radius of the balance wheel.

Thus, the pivots of the lever and of the escape wheel can be positioned so as to come out of the diameter of the balance wheel.

In a particularly advantageous manner, the anchor pivot and the escapement pivot are at least partially located at the same level as the balance, in the direction of the thickness of said anchor and escapement pivots, the anchor bearings and the escapement bearings being arranged between two parallel planes defined by the balance bearings.

Thus, the pivots of the lever and of the escape wheel can be positioned outside the balance wheel, substantially at one and the same level as that of the balance wheel, so that the thickness of the tourbillon can be reduced, without having to modify the arrangement of said balance wheel.

The present invention also relates to a movement comprising a tourbillon as defined above as well as a timepiece comprising such a movement. This movement and this timepiece according to the invention have the advantage of being able to be ultra-flat.

Brief description of the drawings

• la figure 1 est une vue de dessus du tourbillon l'invention;
• la figure 2 représente une vue de dessus du pont inférieur portant l'ancre et la roue d'échappement en position de rebat;
• la figure 3 est une en coupe de la figure 1 ;
• la figure 4 est une vue de dessus du tourbillon et de la roue de seconde fixe;
  et
• la figure 5 est une vue en coupe de la figure 4.

Other characteristics and advantages of the present invention will appear on reading the following detailed description of an embodiment of the invention, given by way of non-limiting example, and made with reference to the appended drawings in which:

• there figure 1 is a top view of the inventive tourbillon;
• there picture 2 shows a top view of the lower bridge carrying the anchor and the escape wheel in the rebate position;
• there picture 3 is a cross section of the figure 1 ;
• there figure 4 is a top view of the tourbillon and the fixed seconds wheel;
  And
• there figure 5 is a sectional view of the figure 4 .

Embodiments of the Invention

With reference to the figures, the present invention relates to a tourbillon 1 for a watch movement comprising a cage intended to be rotatably mounted around an axis A on a frame element of said watch movement (not shown) and comprising a lower bridge 2 and an upper bridge 4 which are parallel, interconnected by pillars 6.

In a standard manner, the cage carries a regulating member comprising a balance wheel 8 and a hairspring 10. The balance wheel 8 comprises a circular rim 8a integral with a balance wheel pivot 12 pivotally mounted around a balance wheel axis A in balance wheel bearings 14, 15, such as shockproof bearings, carried respectively by the lower 2 and upper bridge 4. The balance wheel 8 is located inside the cage, the balance wheel ancier A corresponding to the axis of rotation of the cage. The rim 8a has a maximum radius, called the outer radius R of the balance wheel 8. The hairspring 10 is arranged above the balance wheel 8. The hairspring 10 is secured by one end to the balance wheel pivot 12 and by its other end to a stud holder 16 mounted on the upper bridge 4.

The cage also carries an anchor 18 and an escape wheel comprising an escape wheel 20 and an escape pinion 22 (cf. fig. 5 ) integral with said escape wheel 20.

With particular reference to the picture 3 , the anchor 18 comprises an anchor pivot 24 pivotally mounted in anchor bearings 25, 26, such as stones, around an anchor axis B. The anchor 18 is arranged to cooperate, on the one hand, with said regulating member and, on the other hand, with the escape wheel 20, via its two pallets 27a, 27b. A detailed description of the anchor 18 will be given below.

With particular reference to the figure 5 , the escapement wheel 20 comprises an escapement pivot 28 pivotally mounted in escapement bearings 29, 30, such as stones, around an escapement axis C. Said escapement pivot 28 also carries the escapement pinion 22.

In the example represented here, the cage is driven in rotation by the gear train of the movement via an external peripheral toothing 32 provided around a circular crown forming the lower bridge 2. The cage is intended to be assembled with the frame element of the watch movement via a ball bearing 34, so that the tourbillon illustrated here is of the flying tourbillon type. With reference to the figure 5 , the ball bearing 34 comprises a hub 36 secured to the cage by means of a pin 38 providing rotational resistance between the lower bridge 2 and the hub 36, and an outer ring 40, intended to be secured to a frame element of the watch movement. Such a ball bearing is known to those skilled in the art and does not require a detailed description.

In accordance with the invention, the anchor 18 and the escape wheel 20 are positioned with respect to the balance wheel 8 such that the distance d1 between the anchor axis B and the balance wheel axis A (cf. Figure 3 ) and the distance d2 between the escapement axis C and the balance wheel axis A (cf. Figure 5 ) are greater than the outer radius R of the balance 8.

In a particularly preferred manner, the anchor pivot 24 and the escapement pivot 28 are at least partially, and preferably entirely, located at the same level as the balance 8, in the direction of the thickness of said anchor 24 and escapement 28 pivots, the anchor bearings 25, 26 and the escapement bearings 29, 30 being arranged between two parallel planes P, P' defined by the bottoms of the balance bearings 14, 15 respectively.

Preferably, the balance pivot 12, the anchor pivot 24 and the escapement pivot 28 are substantially of the same thickness and are located substantially at the same level, in the direction of the thickness of said pivots 12, 24, 28.

For this, the tourbillon 1 also comprises an escapement bridge 42 extending outside the balance wheel 8, and integral with the lower bridge 2. The escapement bridge 42 is arranged to carry one of the lever bearings, namely the bearing upper escapement bearing 26, and one of the escapement bearings, namely the upper escapement bearing 30, the other of the escapement bearings, namely the lower pallet bearing 25, and the other of the escapement bearings, namely the lower escapement bearing 29, being carried by the circular crown forming the lower bridge 2. The diameter of the circular crown forming the lower bridge 2 is chosen so that the lower bridge extends sufficiently outside the balance 8 in order to be able to position the anchor 24 and escapement 28 pivots outside the diameter of said balance wheel 8.

It is of course possible to provide other embodiments, depending on the configuration of the lower and upper bridges, and the thickness that one wishes to give to the tourbillon. For example, when the upper deck is in the form of a plank, the upper anchor and escapement bearings can be mounted on the upper deck, the lower anchor and escapement bearings being mounted either on the lower deck or on an escapement deck integral with the upper deck, at the height required for the anchor to cooperate with the regulating organ. It is also possible to provide specific bridges for the anchor and the escapement wheel, integral with the lower and upper bridges, the main thing being that the anchor and escapement bridges, carried by the cage, extend outside of the balance 8 so that the anchor 24 and escapement 28 pivots come out of the diameter of the balance 8, and are at the height required for the anchor 18 to be able to cooperate with the regulating organ.

The escapement bridge 42 preferably has the shape of an arc of a circle coaxial with the axis A, so that the pallet 18 and the escapement wheel 20 are positioned so that the distance d1 between the pallet axis B and the balance staff A is equal to the distance d2 between the escapement shaft C and the balance staff A.

Advantageously, the escapement pinion 22 is positioned around the escapement pivot 28 above the escapement wheel 20, facing the escapement bridge 42, unlike a standard tourbillon construction. With reference to figures 4 and 5 , a fixed second wheel 44 is provided, centered on the axis of the balance wheel A or of the tourbillon, integral with an element of the movement frame, and arranged to cooperate with the escapement pinion 22. Unlike a standard tourbillon construction, the fixed second wheel 44 has a diameter greater than that of the cage, and in particular the diameter of the lower bridge 2, so that the fixed second wheel 44 surrounds the tourbillon 1. In addition, the fixed second wheel 44 has internal peripheral toothing 46 arranged to mesh with the escapement pinion 22. As a result, the escapement pinion 22 being positioned substantially at the same level as the balance wheel 8, the fixed second wheel 44 is also positioned substantially at the same level as the balance wheel 8, instead of being placed under the cage of a standard tourbillon. This makes it possible to further reduce the size of the assembly.

The positioning of the anchor pivot 24 outside the diameter of the balance wheel 8 is made possible due to the design by the applicant of a new assembly for an anchor escapement, making it possible to develop a new pointing escapement (distance escapement axis / anchor axis and distance anchor axis / balance wheel axis). Such an exhaust assembly is described in patent application no. EP 20180912 filed by the applicant, incorporated by reference into the present application.

Advantageously, and with particular reference to the figure 2 , pallet 18 has no stinger to gain thickness, and comprises, on the one hand, an input pallet 27a and an output pallet 27b, intended to cooperate alternately with escape wheel 20 and, on the other hand, a fork intended to cooperate with a pin 48 carried by balance wheel 8 and comprising first 52 and second 54 horns delimiting a fork input. A plate 50 secured to the balance 8 is at least partially located at the same level as the pin 48, in the direction of the thickness of the plate 50 (cf. Figure 3 ). The plate 50 has an anti-rollover wall of generally cylindrical shape in which a notch 56 is provided, in a region adjacent to the peg 48. The anchor 18, the plate 50 and the peg 48 are shaped and dimensioned such that, in a service position, said anti-rollover wall is capable of defining an abutment for the first and second lugs 52, 54, said anchor 18, said plate 50 and said peg 48 being further shaped and dimensioned such that, in the service position, each of said horns 52, 54 is capable of penetrating inside the notch 56 exclusively when the pin 48 is at least partially located in the entrance of the fork.

Each of the horns 52, 54 of the fork has an inner wall delimiting the entrance to said fork and an outer wall shaped and dimensioned such that in a rebate situation, the distance between the point of contact of the peg 48 on the outer wall of the horn 52, 54 concerned and the end of said outer wall closest to the inner wall is greater than the distance between the peg 48 and that of the junctions between the anti-rollover wall and the notch 56 closest to the horn 52, 54 concerned.

Thus, the horns 52, 54, in addition to their conventional function, are intended to ensure safety against overturning. The horns 52, 54 replace the stinger in its anti-rollover function and have a width greater than the typical width of the stinger. Thus, the notch 48 must be enlarged with reference to conventional escapements and the plate 50 itself must also be enlarged as a result. These modifications imply an elongation of the anchor rod 18a.

The rod 18a connects the entry and exit pallets 27a, 27b to the fork and capable of pivoting between two extreme positions, in the service position, by defining a maximum angle of movement of the anchor 18, the external wall of each of the lugs 52, 54 having, from its end closest to the internal wall, a first portion defining a safety surface and presenting an average angle, with reference to the rod 18a, such that the said safety surface is substantially tangent to the anti-rollover wall when it is located opposite the latter, then a second portion having an angle of the order of 0 to 45° with reference to the strip 18a, and extending at least to the point of contact of the pin 48 on the said external wall in the rebate situation.

With this escapement assembly, the amplitude of oscillation of anchor 18 is unchanged. The rebate angle of the balance 8 (position represented on the figure 2 ) is superior to a standard configuration, which is favorable for isochrony.

The anchor 18 and the escapement wheel 20 are intended to be arranged, in the service position, in such a way that the distance between the anchor axis B and the balance axis A is at least equal to twice the distance between the anchor axis B and the escapement axis C, which defines a new escapement score.

The operation of the tourbillon according to the invention is similar to that of a standard tourbillon.

Thanks to a specific pallet geometry, a new escapement pointing has been defined to allow the anchor pivot and the escapement pivot to be released from the balance wheel. It is thus possible, by positioning the escapement pivots substantially at the same level as the balance pivot, to eliminate the floor or the level usually occupied by the escapement in a standard tourbillon. Thus, the thickness of the tourbillon cage according to the invention is reduced.

In addition, the solution of the invention makes it possible to reduce the thickness of the cage without sacrificing either the securities between the balance, lever and escapement wheel, or the quality factor of the regulating member. It also makes it possible not to disturb the functioning of the balance, the standard balance pivots and the traditional anti-shock bearings being retained.

Furthermore, according to the preferred embodiment, the removal of the conventional central seconds pinion and the positioning of the fixed seconds wheel at cage height make it possible to further gain in thickness.

The invention therefore makes it possible to obtain an extra-flat tourbillon enabling it to be used in an extra-flat movement or to save space in order to optimize watch mechanisms.

Claims (14)

1. Tourbillon (1) for a horology movement comprising a cage intended to be rotatably mounted on said horology movement, said cage bearing a regulating organ comprising a balance (8) comprising a balance pivot (12) pivotally mounted in balance bearings (14, 15) about a balance axis (A) together with an anchor (18) comprising an anchor pivot (24) pivotally mounted in anchor bearings (25, 26) about an anchor axis (B) and arranged to cooperate, on the one hand, with said regulating organ and, on the other hand, with an escapement wheel (20) comprising an escapement pivot (28) pivotally mounted in escapement bearings (29, 30) about an escapement axis (C), wherein the anchor (18) and the escapement wheel (20) are positioned relative to the balance (8) in such a manner that the distance (d1) between the anchor axis (B) and the balance axis (A) and the distance (d2) between the escapement axis (C) and the balance axis (A) are greater than the outer radius (R) of the balance (8).
2. Tourbillon according to Claim 1, characterised in that the anchor pivot (24) and the escapement pivot (28) are at least partly located at the same level as the balance (8), along the thickness direction of said anchor pivot (24) and escapement pivot (28), the anchor bearings (25, 26) and the escapement bearings (29, 30) being arranged between two parallel planes (P, P') defined by the balance bearings (14, 15).
3. Tourbillon according to one of Claims 1 and 2, characterised in that the cage comprises a lower bridge (2) and an upper bridge (4) bearing the balance bearings (14, 15), and in that the tourbillon also comprises an escapement bridge (42) integral with the lower bridge (2) and arranged to bear one of the anchor bearings (25, 26) and one of the escapement bearings (29, 30), the other of the anchor bearings (25, 26) and the other of the escapement bearings (29, 30) being borne by said lower bridge (2).
4. Tourbillon according to one of the preceding claims, characterised in that the anchor (18) and the escapement wheel (20) are positioned in such a manner that the distance (d1) between the anchor axis (B) and the balance axis (A) is equal to the distance (d2) between the escapement axis (C) and the balance axis (A).
5. Tourbillon according to one of the preceding claims, characterised in that the balance pivot (12), the anchor pivot (24) and the escapement pivot (28) are of substantially identical thickness and are located substantially at the same level, along the thickness direction of said balance pivot (12), anchor pivot (24) and escapement pivot (28).
6. Tourbillon according to one of the preceding claims, characterised in that the anchor (18) has no guard pin and comprises, on the one hand, an entry pallet (27a) and an exit pallet (27b), intended to cooperate alternately with the escapement wheel (20) and, on the other hand, a fork intended to cooperate with a pin (48) integral with the balance (8), itself integral with a roller (50), and comprising first and second horns (52, 54) defining a fork entry, said roller (50) being at least partly located at the same level as said pin (48), along the thickness direction of the roller (50), said roller (50) having a generally cylindrical anti-overbanking wall in which a notch (56) is provided in a region adjacent to said pin (48), said anchor (18), said roller (50) and said pin (48) being shaped and dimensioned such that, in a service position, said anti-overbanking wall is capable of defining a stop for said first and second horns (52, 54), said anchor (18), said roller (50) and said pin (48) being furthermore shaped and dimensioned such that, in the service position, each of said first and second horns (52, 54) is able to penetrate into the interior of said notch (56) exclusively when said pin (48) is at least partly located in said fork entry.
7. Tourbillon according to Claim 6, characterised in that each of the first and second horns (52, 54) of said fork has an inner wall defining the entry of said fork and an outer wall shaped and dimensioned such that, in a knocking situation, the distance between the point of contact of said pin (48) on the outer wall of the horn (52, 54) in question and the end of said outer wall closest to the inner wall is greater than the distance between the pin (48) and that of the junctions between the anti-overbanking wall and the notch (56) which is closest to the horn (52, 54) in question.
8. Tourbillon according to the preceding claim, characterised in that the anchor (18) comprises a lever (18a) connecting said entry (27a) and exit (27b) pallets to said fork and capable of pivoting between two extreme positions, in the service position, so defining a maximum angle of travel of the anchor (18), said outer wall of each of said first and second horns (52, 54) having, starting from the end thereof closest to said inner wall, a first portion defining a safety surface and having a mean angle relative to said lever (18a), such that said safety surface is substantially tangential to said anti-overbanking wall when it is located facing the latter, followed by a second portion having an angle of the order of 0 to 45° relative to said lever (18a), and extending at least up to the point of contact of said pin (48) on said outer wall in a knocking situation.
9. Tourbillon according to one of the preceding claims, characterised in that the anchor (18) and the escapement wheel (20) are intended to be arranged, in the service position, such that the distance (d1) between the anchor axis (B) and balance axis (A) is at least equal to twice the distance between the anchor axis (B) and the escapement axis (C).
10. Tourbillon according to one of Claims 3 to 9, characterised in that the lower bridge (2) of the cage comprises external peripheral teeth (32) arranged to drive said cage in rotation.
11. Tourbillon according to one of Claims 3 to 10, characterised in that the escapement wheel (20) is integral with an escapement pinion (22), said escapement pinion (22) being positioned above said escapement wheel (20), facing the escapement bridge (42).
12. Horology movement comprising a tourbillon according to one of Claims 1 to 11.
13. Movement according to Claim 12, the tourbillon comprising an escapement pinion (22) integral with the escapement wheel (20), characterised in that it comprises a fixed seconds wheel (44), the escapement pinion (22) and said fixed seconds wheel (44) being positioned substantially at the same level as the balance (8).
14. Timepiece comprising a movement according to one of Claims 12 to 13.

Images