EP2132604B1 - Tourbillon movement for timepiece - Google Patents

Abstract

A movement for a timepiece, that includes: a housing (10, 12); an energy source; a gear driven by the energy source (14); a frame (26) for a tourbillon (18) rotatingly mounted on the housing (10, 12) about a first axis (AA) and driven by the gear (14); a balance (32) mounted so as to oscillate in bearings on the frame (26); and an escapement (16, 34) including a fixed wheel (16) and a control member (34) interacting with the balance (32), the fixed wheel (16) sustaining the balance (32). In this movement, the bearings are arranged so that the balance (32) oscillates about a second axis (BB) inclined relative to the first axis (AA).

Description

Technical area

The present invention relates to the movements of tourbillon timepieces. Such movements are well known to those skilled in the art. The tourbillon is a device for improving the accuracy of the timepiece. It comprises a cage rotatably mounted on the frame of the timepiece and a rocker mounted oscillating in the cage. The swinging movement of the balance is generally maintained by an escapement also mounted on the cage. The cage is rotated by a train whose last mobile meshes with a pinion secured to the cage. The escape wheel, mounted on the cage, meshes with a fixed wheel.

State of the art

Some watchmakers have developed so-called fast vortices, in which only the anchor is embedded on the cage, the escape wheel being fixedly mounted on the frame of the movement. Such solutions are described in the book entitled "The Whirlpool", by R. Meis, ISBN No2-58917-097-8 .

Such devices have been the subject of only a few unique pieces. Although the total inertia of the vortex is substantially reduced, it is however important since, for construction reasons, it is difficult to envisage having more than a dozen teeth on the fixed escape wheel. This is equivalent to saying that if the pendulum oscillates at a frequency of 3 Hz, the cage must make a turn in four seconds.

Furthermore, there are also known devices of the tourbillon type described, for example, in the documents WO 2007/033513 , WO 2005/043257 , WO 03/017009 and EP 1 564 608 . But in these devices, the escape wheel associated with the anchor is pivotally mounted on the tourbillon cage. These documents can not be taken into account to solve problems that concern devices comprising a fixed escape wheel.

The present invention is intended in particular to produce a tourbillon timepiece comprising a fixed escape wheel, in which the speed of rotation of the cage is reduced.

Disclosure of the invention

• un bâti,
• une source d'énergie,
• un rouage entraîné par la source d'énergie,
• une cage de tourbillon montée en rotation sur le bâti autour d'un premier axe et entraîné par ledit rouage,
• un balancier monté oscillant sur la cage dans des paliers, et
• un échappement comprenant une roue d'échappement fixe montée sur le bâti et un organe de commande coopérant avec le balancier et la roue d'échappement fixe pour permettre l'entretien du balancier.

The timepiece movement according to the invention, as defined by claim 1, comprises:

• a frame,
• a source of energy,
• a train driven by the energy source,
• a tourbillon cage rotatably mounted on the frame about a first axis and driven by said wheel,
• a rocker mounted oscillating on the cage in bearings, and
• an exhaust comprising a fixed escape wheel mounted on the frame and a control member cooperating with the balance and the fixed escape wheel to allow maintenance of the balance.

The bearings of the balance are arranged so that it oscillates about a second axis inclined relative to the first axis. In a second embodiment, the movement is defined by the independent claim 6. In this way, it is possible to have a lever arm of the exhaust control member relatively long, without increasing the l total inertia of the cage. This makes it possible to increase the number of teeth of the fixed wheel and thus reduce the speed of rotation of the cage.

• L'angle d'inclinaison est compris entre 15° et 50°;
• L'échappement est de type à ancre ;
• La roue d'échappement est de type à denture extérieure.

Advantageously:

• The angle of inclination is between 15 ° and 50 °;
• The escapement is anchor type;
• The escape wheel is of type with external teeth.

Brief description of the drawings

Other features of the present invention will appear more clearly on reading the description which follows, made with reference to the accompanying drawing, in which the single figure shows, in section and in a schematic manner, a part movement part. watchmaking according to the invention.

Embodiment of the invention

• un bâti comprenant une platine 10 et un pont 12 de tourbillon,
• un rouage de finissage dont une roue 14 seulement est visible,
• une roue d'échappement fixe 16 montée rigidement sur la platine 10, et
• un tourbillon 18, monté rotatif entre deux paliers 20 et 22, solidaires l'un de la platine 10, l'autre du pont 12, autour d'un axe AA perpendiculaire au plan de la platine 10.

The timepiece portion shown in the drawing comprises in particular:

• a frame comprising a plate 10 and a vortex bridge 12,
• a finishing gear of which only one wheel 14 is visible,
• a fixed exhaust wheel 16 mounted rigidly on the plate 10, and
• a vortex 18, rotatably mounted between two bearings 20 and 22, integral with one of the plate 10, the other of the bridge 12, about an axis AA perpendicular to the plane of the plate 10.

The vortex 12 comprises a cage 24, formed of two parts 26 and 28 interconnected by pillars 30, only one being visible in the drawing, a rocker 32 and an anchor 34, both pivotally mounted on the cage 24.

The two parts 26 and 28 each comprise a shaft portion respectively referenced 36 and 38, and a board respectively referenced 40 and 42. The shafts 36 and 38 are each provided with a tigeron 36a and 38a. In addition, the shaft 38 forms a pinion 38b engaged with the wheel 14.

The shaft 36 and the board 40 are integral with each other. The latter is inclined relative to the shaft by an angle of the order of 60 °. It is pierced with a hole in which is conventionally driven, a balance bearing not shown in the drawing. The latter receives, in a conventional manner, one of the pivots of the pendulum 32.

The shaft 38 and the board 42 are also integral with each other. The latter comprises a first portion 42a inclined relative to the shaft 38 and parallel to the board 40, and a second portion 42b disposed perpendicularly to the axis of the shaft 38. A hole is formed in the first portion 42a, aligned relative to the hole of the board 40, to form the second bearing of the rocker 32, together defining a pivot axis BB of the rocker 32. Another hole is made in the portion 42b, in which is driven a stone 44 forming a bearing for the Anchor 34. The latter pivots, in addition, in a second stone 46 carried by a bridge 48, which is fixed on the portion 42b, by means of a screw represented by a dashed line.

The anchor 34 comprises a rod 50 pivotally mounted in the bearings 44 and 46, of axis parallel to the axis AA. The rod 50 carries, rigidly fixed, a part 52 formed of pallets 52a and their support 52b, and a fork 54. The part 52 is substantially oriented in a plane perpendicular to the axis AA. Its pallets 52a cooperate with the fixed escape wheel 16.

The fork 54 has a portion 54a engaged on the rod 50 and a tail 54b inclined in a direction substantially parallel to the board 40 and the portion 42b of the board 42. It extends to the vicinity of the balance 32, allowing the transmission of energy to the latter by means of a plate 56 secured to the balance shaft 32.

Due to the fact that the fork is inclined, its length can be increased, so that for the same angle of impulse on the balance, the anchor travels at a lower angle. It is thus possible to increase the number of steps per revolution and, in this way, reduce the speed of rotation of the vortex. With such a configuration, it appears as possible to make a wheel of thirty teeth, which, with a balance oscillating at a frequency of 3 HZ, causes the vortex to make a turn in ten seconds.

In the embodiment that has just been described, the anchor pivots on an axis parallel to the axis of the cage. It is also possible to use a pivoting anchor on an axis parallel to the axis of the balance. In this case, the escape wheel, fixed, advantageously present a set of teeth in a truncated cone.

In either of the embodiments mentioned above, it would also be possible to use a fixed wheel with an internal toothing, the pallets then being turned outwards.

Other types of exhausts are also usable. Thus, the inclination of the balance relative to the axis of rotation of the cage allows, in addition, other perspectives. It is thus quite possible to produce a structure in which the balance plate is substantially off-center with respect to the axis of rotation of the cage, even though the center of gravity of the balance is substantially on this axis.

With such a configuration it is possible to use an exhaust in which at least one pulse out of two is given directly to the pendulum, without passing through the anchor which is then replaced by a control member subject to the pendulum and which releases the vortex when the pendulum can receive a pulse.

It is even possible to use a rubbing rest exhaust, such as a cylinder exhaust. In this case, the control member will be formed by the cylinder, which is associated with the balance.

The tourbillon described rotates on two bearings arranged at its axial ends. It is quite clear that the same principle can equally well apply to a whirlwind flying type.

In another variant that has not been shown, the movement could include two vortex cages, the first being pivotally mounted on the second. The fixed escape wheel 16 would then be fixed on the second cage. In this case, the axis of the first cage, in which the balance oscillates, would be inclined relative to the balance shaft.

Thus, thanks to the fact that the balance is inclined with reference to the axis of the cage in which it is mounted oscillating, it is possible to make a vortex in which the escape wheel is fixed and whose cage rotates at a speed reasonable, while improving the accuracy of the watch.

Claims (10)

1. A timepiece movement comprising:

   • a frame (10, 12),

   • an energy source,

   • a train driven by the energy source (14),

   • a tourbillon (18) cage (26) mounted rotatingly on the frame (10, 12) around a first axis (AA) and driven by said train (14),

   • a balance (32) mounted oscillating on the cage (26) in bearings, said bearings being arranged such that said balance (32) oscillates around a second axis (BB) which is inclined in relation to the first axis (AA),

   and characterized by an escapement (16, 34) comprising a fixed escape-wheel (16) mounted on the frame and a control organ (34) cooperating with the balance (32) and the fixed escape-wheel (16) in order to sustain the balance (32).
2. The movement according to claim 1, characterized in that the incline angle between the two axes is between 15° and 50°.
3. The movement according to one of claims 1 and 2, characterized in that the escapement is of the lever type.
4. The movement according to one of claims 1 to 3, characterized in that the fixed escape-wheel (16) is of the exterior toothing type.
5. The movement according to one of claims 1 to 4, characterized in that the cage (26) of said tourbillon (18) turns on two bearings (20, 22) arranged at its ends.
6. A timepiece movement comprising:

   • a frame,

   • an energy source,

   • a train driven by the energy source,

   • a first tourbillon cage mounted rotatingly on the frame and driven by said train,

   • a second tourbillon cage mounted pivoting on said first tourbillon cage around a first axis,

   • a balance mounted oscillating on the second tourbillon cage in bearings, said bearings being arranged such that said balance oscillates around a second axis which is inclined in relation to the first axis,

   and characterized by an escapement comprising a escape-wheel fixed on the first tourbillon cage and a control organ cooperating with the balance and the escape-wheel in order to sustain the balance.
7. The movement according to claim 6, characterized in that the incline angle between the two axes is between 15° and 50°.
8. The movement according to one of claims 6 and 7, characterized in that the escapement is of the lever type.
9. The movement according to one of claims 6 to 8, characterized in that the fixed escape-wheel is of the exterior toothing type.
10. The movement according to one of claims 6 to 9, characterized in that said first tourbillon cage turns on two bearings arranged at its ends.

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