EP2869139B1 - Tourbillon mechanism - Google Patents

Description

Technical area

The present invention relates to the field of watchmaking. It relates, more particularly, to a tourbillon mechanism.

State of the art

The document CH 33 816 discloses a tourbillon mechanism in which the tourbillon cage is pivoted between a first pivot, on the bridge side, and a second pivot, on the plate side, which comprises the movable carrier of the cage. The cage is linked to a plate secured to the mobile carrier of the cage by means of several screws. However, such a connection is bulky and requires a relatively large diameter in order to allow the watchmaker to access the screws during the assembly of the tourbillon. In addition, thanks to this construction, the movable carrier of the cage must have a smaller diameter than the inside diameter of the serge of the fixed wheel, because of the fact that the fixed wheel must be mounted on the plate before the cage and the driving mobile can be placed in the movement.

The documents EP 2246752 A1 and CH 150047 describe whirlpool mechanisms in which the cage pinion is secured directly by screwing or shoring on the pivot shaft of the cage.

The object of the invention is therefore to propose a tourbillon mechanism for a timepiece in which the above-mentioned defects are at least partially overcome.

Disclosure of invention

More specifically, the invention relates to a tourbillon mechanism for a timepiece, comprising a tourbillon cage housing a regulating member comprising a balance, a spiral spring and an escapement pivotally mounted on the cage. The tourbillon cage is arranged so to rotate about an axis of rotation and comprises a first pivot. The tourbillon mechanism also comprises a fixed wheel intended to be mounted integral with a frame element of said timepiece and arranged to mesh with an escapement pinion that includes said escapement. The tourbillon mechanism further comprises a movable cage driver, coaxial with said cage, and preferably arranged to make one revolution per minute. The mobile cage driver is rotationally integral with the tourbillon cage and comprises a toothed wheel, a hub or shaft, and a second pivot. The tourbillon cage is intended to be pivoted on frame elements of the timepiece between said first pivot and said second pivot.

According to the invention, the tourbillon cage and said hub or shaft of the cage driving mobile are rotationally integral by means of a first non-circular part formed by two pins driven into an upper end of said shaft in a direction parallel to the axis of rotation of said shaft and adapted to interact with a second part of complementary non-circular shape located on the cage and adapted to receive said upper end of said shaft. Consequently, it is no longer necessary or useful to have screws joining the cage to the mobile cage driver, which thus makes it possible to mount the fixed wheel after the mobile cage driver is already pivoted in the movement. It is thus possible to use a mobile cage driver having a diameter larger than the inside diameter of the serge of the fixed wheel, for example a diameter identical to the second wheel of the gear train.

In one embodiment, the tourbillon mechanism includes a support member adapted to support the hub during assembly of the tourbillon mechanism. Advantageously, the support member comprises a ring surrounding the hub and, preferably, a ruby-type ring located between the ring and the hub. This simplifies the assembly of the tourbillon mechanism, because the mobile cage drive is held in place during assembly.

Preferably, the support element is integral with said fixed wheel, and the support member is intended to be mounted on a frame element of the timepiece. Therefore, the fixed wheel and the support member can be mounted in the movement in one step.

The invention further relates to a timepiece movement comprising a tourbillon mechanism as defined above. Preferably, the first pivot is pivoted on a bridge that includes the watch movement, and in which the second pivot is pivoted on a plate that includes the watch movement.

• assembler ladite cage de tourbillon, y compris ledit organe régulateur comprenant ledit balancier, ledit ressort spiral et ledit échappement montés pivotants sur la cage ;
• pivoter ledit mobile entraîneur de cage dans une platine du mouvement d'horlogerie ;
• solidariser ledit organe de support sur ledit élément de bâti, supportant ainsi ledit moyeu ou arbre du mobile entraîneur de cage ;
• solidariser ladite roue fixe à la platine ;
• placer ladite cage de tourbillon sur le moyeu ou arbre, en engageant la première partie non circulaire formée de deux goupilles chassées dans l'extrémité supérieure du moyeu ou arbre suivant une direction parallèle à l'axe de rotation de celui-ci avec la seconde partie non circulaire ;
• placer un pont au-dessus de la cage, ledit premier pivot étant pivoté dans ledit pont, le pont étant subséquemment solidarisé avec un élément de bâti.

In addition, the invention relates to a method of assembling a timepiece movement comprising a tourbillon mechanism as defined above and comprising said support member. This process includes the following steps:

• assembling said tourbillon cage, including said regulating member comprising said balance, said spiral spring and said escapement pivotally mounted on the cage;
• pivot said cage driving mobile in a plate of the clockwork movement;
• securing said support member on said frame element, thereby supporting said hub or shaft of the mobile cage driver;
• securing said fixed wheel to the plate;
• place said tourbillon cage on the hub or shaft, engaging the first non-circular part formed by two pins driven into the upper end of the hub or shaft in a direction parallel to the axis of rotation of the latter with the second part not circular;
• placing a bridge over the cage, said first pivot being pivoted in said bridge, the bridge being subsequently secured to a frame element.

Preferably, said fixed wheel is mounted on the support element before the support member is secured to the plate.

Consequently, thanks to the fact that the mounting of the fixed wheel is posterior to that of the mobile cage driver, a mobile cage driver having a diameter larger than the inside diameter of the fixed wheel can be used in the tourbillon mechanism, as stated above.

Brief description of the drawings

• Fig. 1 est une vue en coupe transversale d'un mécanisme de tourbillon selon l'invention ;
• Fig. 2 est une vue en perspective d'une coupe transversale d'un mécanisme de tourbillon selon l'invention, selon une coupe passant au travers des goupilles et vue du côté platine.

Other details of the invention will appear more clearly on reading the description which follows, made with reference to the appended drawing in which:

• Fig. 1 is a cross-sectional view of a tourbillon mechanism according to the invention;
• Fig. 2 is a perspective view of a cross section of a tourbillon mechanism according to the invention, in a section passing through the pins and seen from the plate side.

Mode of carrying out the invention

The figure 1 presents a sectional view of a tourbillon mechanism 1 according to the invention, which illustrates the general construction of the tourbillon mechanism 1. The tourbillon mechanism 1 generally comprises a cage 3 formed by two bridges 5, 6, connected by pillars 9. The cage 3 houses, as it is generally known, a regulating member 11 comprising a spiral spring 13, a balance 15 and an escapement (not illustrated). The details of the regulating member 11 are not part of the current invention and will not be described in more detail. The cage 3 is pivoted on its upper side (with reference to the figure 1 ) in a frame element such as a bridge (not shown) by a first pivot 7.

The tourbillon mechanism 1 further comprises a fixed wheel 17, fixed via a support member 19 to a frame element of a clockwork movement (not shown), such as a plate. In known manner, an exhaust pinion 18 which the exhaust comprises, meshes with the teeth of the fixed wheel 17.

The cage 3 is rotated by means of a mobile cage driver 21, which is preferably arranged to make a revolution in one minute, but other speeds of rotation are possible. The mobile coach of cage 21 includes a toothed wheel 22, which can mesh with a seconds wheel (not shown), located in the center of the clockwork movement or not, and having the same number of teeth as the toothed wheel 22. In the case where said seconds wheel is located in the center of the movement and meshes directly with the mobile cage driver 21, a direct second display is advantageously obtained by using the tourbillon mechanism 1 of the invention. In addition, such an arrangement makes it possible to prevent the overlapping of a center seconds hand. It is also possible that the mobile cage driver 21 is used as a single seconds wheel in the gear train of the clockwork movement.

The mobile cage drive 21 further comprises a hub or shaft 23, which is pivoted on the side of its lower end (with reference to the figures) in a frame element such as a plate (not illustrated) by means of a second pivot 25, which also serves as the second pivot of the cage 3.

The support member 19 serves to support the hub 23 of the mobile cage drive 21 via a support ring 27 formed of a ruby-type ring during the mounting of the tourbillon, as will be explained more clearly hereinafter. It should be noted that the support member supports the second mobile 21, holding it in place exclusively during assembly, and has no function after the tourbillon is assembled.

The hub or shaft 23 of the movable cage drive 21 has at its upper end, that is to say its end opposite to the second pivot 25, a first non-circular shape 37, which is rotationally integral with a second non-circular shape 39 corresponding that includes the lower bridge 6 of the cage 3 at its hub 31. In principle, the non-circular shape can be of any shape allowing the drive of the cage 3 by the hub 23 of the seconds mobile 21, for example square, grooved, with an oval cylinder, or the like, by blocking the shape, without driving, or screwing. In addition, it is not important if the mobile cage drive 21 carries a male form or a female form.

In the embodiment of the figure 2 , the first non-circular shape 37 is formed by two pins 29 driven into the upper end of the hub or shaft 23 of the cage driving mobile 21 and projecting from the hub 23. They are arranged parallel to the axis of rotation of the latter, next to a generally cylindrical part 35 which comprises the upper end of said hub hub 23. The hub 31 of the lower bridge 6 of the cage 3 has a second non-circular shape comprising an opening complementary to the first non-circular shape and adapted to receive the upper end of the hub 23 of the mobile cage drive 21, including including the pins 29. The cage 3 is thus secured in rotation to the second mobile 21, and can be driven by the latter. It should be noted that the number of pins 29 can be chosen according to the needs of the watchmaker.

The steps for mounting the tourbillon mechanism are as follows.

The tourbillon cage 3, including the regulating member 11, is assembled, as well as the movable cage driver 21 with its toothed wheel 22. In addition, the fixed wheel 17 is secured to the support member 19, which comprises the support ring 27.

The mobile cage drive 21 and its toothed wheel 22 are pivoted on a frame element, such as a plate, of a clockwork movement. Then, the fixed wheel 17 - support member 19 - support ring 27 assembly is fitted around the hub or shaft 23 of the movable cage drive 21, and is secured to the frame element, for example by means of screws 33 The mobile cage drive 21 is thus supported in position by the support ring 27.

Subsequently, the cage 3 is placed on the upper end of the hub or shaft 23 of the mobile cage drive 21, the first non-circular part and the second non-circular part interacting with each other.

Finally, an upper bridge is placed around the first pivot 7 of the cage 3, and is secured to an element of the frame of the watch movement.

Claims (8)

1. A tourbillon mechanism (1) for a timepiece comprising:

   - a tourbillon cage (3) housing a regulating member (11) comprising a balance (15), a spiral spring (13) and an escapement, pivotally mounted on said cage (3), said cage (3) being arranged to rotate about an axis of rotation and comprising a first pivot (7);

   - a fixed wheel (17) intended to be mounted integrally with a frame element of said timepiece and arranged to mesh with an escapement pinion (18) which comprises said escapement;

   - a cage driving mobile (21) coaxial with said cage (3), said cage driving mobile (21) comprising a toothed wheel (22) and a hub or shaft (23), and a second pivot (25);

   wherein said cage (3) is intended to be pivoted on frame elements of the timepiece between said first pivot (7) and said second pivot (25),
   characterized in that said cage (3) and said hub or shaft (23) of the cage driving mobile (21) rotate integrally by means of a first non-circular portion formed by two pins (29) countersunk in an upper end of said shaft (23) in a direction parallel to the axis of rotation of said shaft (23) and adapted to interact with a second non-circular complementary portion located on the cage (3) and adapted to receive said upper end of said shaft (23).
2. A tourbillon mechanism (1) according to the preceding claim, wherein the tourbillon mechanism (1) comprises a support element (19) adapted to support said shaft (23) of the cage driving mobile (21) during the assembling of the tourbillon mechanism (1).
3. A tourbillon mechanism (1) according to the preceding claim, wherein the support element (19) comprises a ring surrounding said shaft (23) of the cage driving mobile (21) and, preferably, a ruby type ring (27) located between the ring and said shaft (23).
4. A tourbillon mechanism (1) according to one of the preceding claims, wherein the support element (19) is integral with said fixed wheel (17), the support element (19) being intended to be mounted on a frame element of the timepiece.
5. A clockwork comprising a tourbillon mechanism according to one of the preceding claims.
6. A clockwork according to the preceding claim, wherein the first pivot (7) is pivoted on a bridge included in the clockwork, and wherein the second pivot (25) is pivoted on a plate included in the clockwork.
7. A method for assembling a clockwork comprising a tourbillon mechanism (1) according to one of claims 3 to 5, comprising the steps of:

   - assembling the tourbillon cage (3), including said regulating member (11) including said balance (15), said spiral spring (13) and said escapement mounted pivotally on said cage (3);

   - pivoting said cage driving mobile (21) in a frame element of the clockwork;

   - securing said support element (19) to said frame element, thereby supporting said hub or shaft (23) of the cage driving mobile (21);

   - securing the fixed wheel (17) to said frame element;

   - placing said tourbillon cage (3) on said hub or shaft (23) of the cage driving mobile (21), engaging the first non-circular portion formed of two pins (29) countersunk in the upper end of the hub or shaft (23) in a direction parallel to the axis of rotation thereof with the second non-circular portion ;

   - placing a bridge over said cage (3), said first pivot (7) being pivoted in said bridge, the bridge being subsequently secured to a frame element.
8. A method according to the preceding claim, wherein said fixed wheel (17) is mounted on the support element (19) before said support element (19) is secured to the plate, said fixed wheel (17) and the support element (19) thus being simultaneously secured to said frame element.

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