CH716864B1 - Tourbillon for watch movement. - Google Patents

Abstract

The invention relates to a tourbillon (1) for a watch movement, comprising a balance mechanism (10), an escapement mechanism (40) and a tourbillon support (30). The tourbillon support (30) comprises a fixed support (32) and a movable support (34) arranged to rotate around the fixed support (32). The balance mechanism (10) comprises a flywheel (12) and at least one elastic member (18, 20) connected, on the one hand, to one or more portions (12a, 12b) of the flywheel ( 12) and, on the other hand, to the mobile support (34) of the tourbillon support (30). The escapement mechanism (40) comprises an escapement mobile (42, 44) integral with said mobile support (34) and a stopping device (45) arranged to cooperate with the escapement mobile (42, 44). The flywheel (12) comprises an actuating member (14) arranged to disengage the stopping device (45) so as to release the escape wheel (42, 44) at each oscillation of the flywheel (12) in order to allow the exhaust mobile (42, 44), on the one hand, to be rotated according to the oscillations of the flywheel (12) and, on the other hand, to maintain oscillations of the flywheel.

Description

Technical area

[0001] The present invention relates to a tourbillon for a watch movement as well as a watch movement and a timepiece comprising such a tourbillon.

State of the art

[0002] Traditionally, a tourbillon comprises a conventional sprung balance and an escapement which are mounted in a rotating cage. The cage functions like the seconds mobile. It is attached to the second pinion and driven by the middle wheel. Inside the cage, the role of the exhaust is conventional. The force is transmitted from the escapement pinion which meshes, like a satellite, with the fixed seconds wheel attached to the plate. The tourbillon causes the balance spring to take all vertical positions to compensate for differences in rate in order to improve rate precision.

[0003] An aim of the present invention is to propose a tourbillon for a watch movement, having an original visual appearance.

[0004] Another aim of the present invention is to propose a tourbillon for a watch movement, with a high operating frequency capable of regulating variations in the rate of a watch in all vertical positions of the watch within a very short period of time. course.

Brief summary of the invention

[0005] These goals are achieved thanks to a tourbillon for a watch movement, comprising a balance mechanism, an escapement mechanism and a tourbillon support. The tourbillon support comprises a fixed support and a movable support arranged to rotate around the fixed support. The balance mechanism includes a flywheel and one or more elastic members. The or each elastic member is connected, on the one hand, to a portion of the flywheel and, on the other hand, to the mobile support of the tourbillon support. The balance mechanism is arranged so that the flywheel is connected to the mobile support only by the or each elastic member. The escapement mechanism comprises an escapement mobile secured to said mobile support and a stopping device arranged to cooperate with the escapement mobile. The flywheel comprises an actuating member arranged to disengage the stopping device so as to release the escape wheel at each oscillation of the flywheel in order to allow the escape wheel, on the one hand, to be driven in rotation according to the oscillations of the flywheel and, on the other hand, to maintain the oscillations of the flywheel.

[0006] According to one embodiment, the actuating member is connected to a portion of the flywheel on one side of said at least one elastic member which is adjacent to the exhaust wheel.

[0007] According to one embodiment, the fixed support is in the form of a tenon arranged to be mounted integrally on a plate of a watch movement, said mobile support being arranged to rotate around the tenon.

[0008] According to one embodiment, the mobile support is in the form of a mobile tube whose central axis is coaxial with the longitudinal axis of the tenon.

[0009] According to one embodiment, the tourbillon support further comprises two bearings mounted inside the movable tube. Each bearing has an internal surface surrounding a cylindrical surface of the tenon and an external surface fixed to the movable tube.

[0010] According to one embodiment, the tourbillon support further comprises a stop placed at one end of the tenon in order to prevent axial movement of the movable tube along the tenon.

According to one embodiment, the flywheel is connected to the movable tube only by said at least one elastic member.

[0012] According to one embodiment, the stopping device comprises an exhaust lever and a lever spring arranged to keep the exhaust lever engaged with the escape wheel.

[0013] According to one embodiment, the escape wheel comprises an escape wheel arranged to cooperate with the actuating member of the flywheel and a drive wheel arranged to engage with the gear train of a watch movement.

[0014] According to one embodiment, the escape wheel and the drive wheel are superimposed.

[0015] According to one embodiment, the escape wheel and the drive wheel are in one piece.

Another aspect of the invention relates to a watch movement comprising the tourbillon described above. The drive wheel engages with the cog of the watch movement.

Another aspect of the invention relates to a timepiece comprising the aforementioned watch movement.

Brief description of the figures

[0018] Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which: - Figure 1 represents a schematic sectional view of the tourbillon according to an embodiment with an integral tourbillon support the plate of a watch movement; – Figure 2 represents a schematic view of the device for stopping the escape wheel according to one embodiment, and – Figure 3 represents a schematic view of the device for stopping the escape wheel according to another form of execution. execution.

Examples of embodiments of the invention

[0019] According to an embodiment illustrated in Figure 1, the tourbillon 1 comprises a balance mechanism 10 arranged to cooperate with an escapement mechanism 40.

The balance mechanism 10 comprises a flywheel 12 of annular shape and at least one elastic member 18, 20 connected, on the one hand, to one or more portions 12a, 12b of the flywheel 12 and, on the other hand, to a tourbillon support 30. The elastic member can comprise for example a first and a second spiral 18, 20 superimposed and arranged to connect the flywheel 12 to the tourbillon support 30. According to this example, the first and second hairsprings 18, 20 are wound in the opposite direction relative to each other and can be connected to the tourbillon support 30 and to the flywheel 12 of the balance mechanism 10 according to different fixing means.

[0021] It will be noted that the flywheel 12 has no arms and that it is only connected to the tourbillon support 30 by one or more elastic members, for example by the first and second hairspring 18, 20 mentioned above. . Care will therefore be taken to reduce the diameter and weight of the flywheel 12 so that the elastic member(s) have sufficient rigidity in Z in order to guarantee oscillation of the flywheel 12 in a plane perpendicular to the axis of the tourbillon 1 without axial movement in Z. We thus obtain a balance whose oscillation frequency is much higher than traditional balances whose frequency generally oscillates between 2.5 and 5 Hertz. The oscillation frequency of flywheel 12 of tourbillon 1 is preferably greater than 10 Hertz, or even greater than 20 or 30 Hertz. This has the advantage of regulating variations in the rate of a watch in all vertical positions of the watch in a very short period of time.

The tourbillon support 30 comprises a tenon 32 arranged to be mounted integrally on a plate 50 of a watch movement and a mobile support 34. The mobile support 34 is preferably in the form of a tube mounted in rotation around the tenon 32 whose longitudinal axis is coaxial with the central axis of the movable tube 34. One end of the first and the second spiral 18, 20 are integral with a portion of an external surface of the movable tube 34. The mobile support 34 can however take different shapes according to several execution variants. For example, the cross section of the mobile support can resemble a square-shaped frame instead of a ring in the case of a mobile tube.

The escape mechanism 40 comprises an escape wheel 42, 44 and a stopping device 45 arranged to cooperate with the escape wheel 42, 44. The escape wheel comprises an escape wheel 42 and a drive wheel 44 mounted coaxially and in contact with each other. The escape wheel 42 is superimposed on the drive wheel 44, which is arranged to engage with the gear train of the watch movement. The escape wheel 42 and the drive wheel 44 can for example be in one piece to together form a one-piece escape wheel.

The escape wheel 42, 44 may include in its center a through hole, preferably cylindrical, the diameter of which is slightly greater than the external diameter of the mobile tube 34 of the balance support 40 so that the escape wheel 42 , 44 can be fixed on the mobile tube 34 below the balance mechanism 10. According to a variant, the mobile tube 34 and the exhaust mobile 42, 44 are in one piece, obtained for example by a process of additive manufacturing.

The tourbillon support 30 comprises two bearings 36 mounted inside the movable tube 34 at the respective ends of the tenon 32. Each bearing 36 comprises an internal surface surrounding a cylindrical surface of the tenon 32 and an external surface fixed to a portion of the internal wall of the movable tube 34. The tourbillon support 30 further comprises a stop 38 disposed at one end of tenon 32. The respective bearings 36 also bear against respectively the plate 50 of the watch movement and a surface bottom of the stop 38 in order to prevent axial movement of the movable tube 34 along the tenon 32. The shape of the bearings is determined in order to minimize the contact zones with respectively the plate 50 and the lower surface of the stop 38 so as to to limit friction.

The drive wheel 44 has standard teeth to mesh with the gear train of the watch movement. The escape wheel 42, for its part, can have different types of profiled teeth in order to allow rotation of the escape wheel 42 in only one direction. For example, the escape wheel 42 may include wolf-tooth teeth as illustrated in Figures 2 and 3.

[0027] According to an embodiment illustrated in Figure 2, the stopping device 45 comprises an escape rocker 46 engaged with the escape wheel 42 under the action of a rocker spring 48. The exhaust rocker 46 cooperates with a leaf spring 49 arranged to be actuated by an actuating member 14 which is integral with the flywheel. The actuation of the exhaust rocker 46 by the actuating member 14 of the flywheel 12 takes place at each oscillation of the flywheel 12, in other words once every two alternations of the flywheel.

The actuating member 14 can for example be in the form of a projection extending from a portion of the lower side of the flywheel 12 along an axis parallel to the axis of the tourbillon 1 in order to be able to cooperate with the stopping device 45. The actuating member 14 can, however, take on different shapes integral with the flywheel 12 in order to adapt in particular to the diameter of the escape wheel 42. The actuation of the flywheel can for example have a bent shape extending from the internal edge of the flywheel in a radial direction then along an axis substantially parallel to the axis of the tourbillon 1 in the direction of the escape wheel 42.

[0029] According to Figure 2, when the actuating member 14 of the flywheel moves clockwise and strikes the blade spring 49, the latter bends as it passes in a first direction and activates the rocker exhaust 46 in the clockwise direction, which remains engaged with the escape wheel 42. When the actuating member 14 of the flywheel moves in the counterclockwise direction and strikes again the leaf spring 49, this bends in its passage in a second direction opposite to the first direction and actuates the escape rocker 46 in the counterclockwise direction, which disengages from the escape wheel 42. This is actuated in rotation by the train of the watch movement until the rocker spring 48 returns the escapement rocker 46 to the engaged position with the escapement wheel. At each oscillation of the flywheel 12, the escape wheel pivots through an angle of 360°/N where N is the number of teeth of the escape wheel 42.

[0030] The stopping device 45 can have different configuration, such as that illustrated in Figure 3. According to this example, when the actuating member 14 of the flywheel moves in the clockwise direction, it slides on a portion of the exhaust rocker 46 while when the actuating member 14 of the flywheel moves in the counterclockwise direction it abuts against a portion of the exhaust rocker 46 in order to disengage the rocker from the escape wheel. This is rotated by the gear train of the watch movement until the rocker spring 48 returns the escapement rocker 46 to the engaged position with the escape wheel.

[0031] Unlike a Swiss anchor type escapement where the energy of the escape wheel is transmitted to the plate pin of the balance shaft via the anchor fork so as to maintain the oscillations of the balance, depending on the configuration of the tourbillon 1, the energy is transmitted to the point of attachment of the chosen elastic member, for example to the points of attachment of the first and second hairspring 18, 20 on the movable tube 34 which “pulls” these attachment points according to the oscillations of the balance mechanism 10 in order to maintain the oscillations of the flywheel 12.

[0032] Although the balance mechanism 10, according to the embodiment which has just been described, comprises two superposed hairsprings, the balance mechanism 10 can only comprise one hairspring according to a variant of execution. In this case, the dimensions of the hairspring must be calculated to provide the hairspring with the necessary rigidity to allow the flywheel 12 to oscillate in a plane perpendicular to the axis of the tourbillon 1. Furthermore, the or each hairspring can be replaced by any other elastic member whose shape is adapted to provide the necessary rigidity in Z to the elastic member so that the flywheel can oscillate in the plane perpendicular to the axis of the tourbillon 1.

Reference list

[0033] Tourbillon 1 Balance mechanism 10 Flywheel 12 Portion 12a, 12b Actuating member 14 Elastic member First hairspring 18 Second hairspring 20 Tourbillon support 30 Fixed tenon support 32 Mobile support 34 Mobile tube Bearings 36 Stopper 38 Mechanism d exhaust 40 Exhaust mobile Escape wheel 42 Drive wheel 44 Stop device 45 Exhaust rocker 46 Rocker spring 48 Leaf spring 49 Plate 50

Claims (12)

1. Tourbillon (1) for a watch movement, comprising a balance mechanism (10), an escapement mechanism (40) and a tourbillon support (30), the tourbillon support (30) comprising a fixed support (32) and a movable support (34) arranged to rotate around the fixed support (32), the balance mechanism (10) comprising a flywheel (12) and one or more elastic members (18, 20), the or each member elastic (18, 20) being connected, on the one hand, to a portion (12a, 12b) of the flywheel (12) and, on the other hand, to the movable support (34) of the tourbillon support (30) , the balance mechanism (10) being arranged so that the flywheel (12) is connected to the movable support (34) only by the or each elastic member (18, 20), the escapement mechanism (40) comprising an escape wheel (42, 44) integral with said mobile support (34) and a stopping device (45) arranged to cooperate with the escape wheel (42, 44), the flywheel (12) comprising an actuating member (14) arranged to disengage the stopping device (45) so as to release the escape wheel (42, 44) at each oscillation of the flywheel (12) in order to allow the wheel exhaust (42, 44), on the one hand, to be rotated according to the oscillations of the flywheel (12) and, on the other hand, to maintain the oscillations of the flywheel. 2. Tourbillon (1) according to claim 1, in which the actuating member (14) is connected to a portion of the flywheel (12) on one side of said at least one elastic member (18, 20) which is adjacent to the exhaust mobile (42, 44). 3. Tourbillon (1) according to one of the preceding claims, in which the fixed support is in the form of a tenon (32) arranged to be mounted integrally on a plate (50) of a watch movement, said movable support (34) being arranged to rotate around the tenon (32). 4. Tourbillon (1) according to claim 3, wherein the movable support (34) is in the form of a movable tube whose central axis is coaxial with the axis of the tenon (32). 5. Tourbillon (1) according to claim 4, wherein the tourbillon support (30) further comprises two bearings (36) mounted inside the movable tube (34), each bearing (36) comprising an internal surface surrounding a cylindrical surface of the tenon (32) and an external surface fixed to the movable tube (34). 6. Tourbillon (1) according to claim 4 or 5, in which the tourbillon support (30) further comprises a stop (38) disposed at one end of the tenon (32) in order to prevent axial movement of the movable tube ( 34) along the tenon (32). 7. Tourbillon (1) according to one of the preceding claims, wherein the stopping device (45) comprises an escapement rocker (46) and a rocker spring (48) arranged to maintain the escapement rocker ( 46) engaged with the exhaust mobile (42, 44). 8. Tourbillon (1) according to one of the preceding claims, wherein the escape wheel comprises an escape wheel (42) arranged to cooperate with the actuating member (14) of the flywheel (12). ) and a drive wheel (44) arranged to engage with the cog of a watch movement. 9. Tourbillon (1) according to the preceding claim, in which the escape wheel (42) is superimposed on the drive wheel (44) 10. Tourbillon (1) according to the preceding claim, wherein the escape wheel (42) and the drive wheel (44) are in one piece. 11. Watch movement comprising the tourbillon (1) according to one of claims 8 to 10, the drive wheel (44) being engaged with the cog of the watch movement. 12. Timepiece comprising the watch movement according to claim 11.