Tourbillon and watch with tourbillon

Abstract

A tourbillon (1) with a rotation cage which is rotatably arranged about a tourbillon axis is provided. The rotation cage mounts a balance wheel (3) and an escapement with an escape wheel (8) and a lever. The tourbillon is characterised in that the rotation cage comprises a bearing wheel (22) which is mounted by bearing elements (13) which engage peripherally on a running surface (11) of the bearing wheel (22).

Claims

1. A tourbillon for a watch, the tourbillon comprising a rotation cage rotatably arranged about a tourbillon axis, the rotation cage mounting a balance wheel and an escapement with an escape wheel and a lever, the rotation cage further comprising a bearing wheel, and the tourbillon further comprising a plurality of bearing elements, wherein the bearing wheel is mounted by the bearing elements, wherein the bearing elements engage peripherally on a running surface of the bearing wheel, and wherein at least one of the bearing elements is mounted on a rocker subject to a spring force of a spring.

2. The tourbillon according to claim 1, wherein the running surface forms an outer surface portion and the bearing elements engage on the bearing wheel radially from the outside.

3. The tourbillon according to claim 1, wherein the bearing elements have a fixed position in the peripheral direction but are rotatable each about a rotation axis, whereby the bearing wheel rolls on the bearing elements give a rotation of the rotation cage.

4. The tourbillon according to claim 3, wherein the bearing elements each comprise a ball bearing.

5. The tourbillon according to claim 3, wherein the bearing elements each comprise a slidingly mounted roller.

6. The tourbillon according to claim 1, wherein the bearing elements form a plain bearing.

7. The tourbillon according to claim 1, wherein precisely three of the bearing elements are present.

8. The tourbillon according to claim 1, wherein the running surface forms a tongue and wherein the bearing elements comprise a groove, into which the tongue engages, in order to form an axial and radial guide.

9. The tourbillon according to claim 1, wherein the running surface forms a groove, and wherein the bearing elements engage into the groove, in order to form an axial and radial guide.

10. The tourbillon according to claim 1, comprising a rotation cage cog, on which a power wheel of a remaining movement engages and via which this power wheel takes up the rotation movement of the rotation cage and, with this, time information, wherein the rotation cage cog is connected to the bearing wheel in a rotationally fixed manner and is arranged axial above or below this.

11. The tourbillon according to claim 1, comprising a base equipped to be assembled in a fixed manner relative to a housing of the watch in which the tourbillon is mounted, the base comprising a toothing into which toothing a pinion coupled to the escape wheel engages, in order to drive this escape wheel given a rotation movement of the rotation cage.

12. The tourbillon according to claim 1, comprising a base equipped to be assembled in a fixed manner relative to a housing of the watch in which the tourbillon is mounted, wherein at least one of the bearing elements is assembled on the base.

13. The tourbillon according to claim 1, wherein the bearing elements are designed in a movable and rolling manner in the peripheral direction.

14. The tourbillon according to claim 13, wherein the bearing elements are balls.

15. A watch, comprising a tourbillon according to claim 1, as well as an energy store and a train for transmitting drive force from the energy store onto the tourbillon and for stepping down the rotation movement of the rotation cage, as well as display elements for displaying the time.

16. The watch according to claim 15, wherein the watch is a wrist watch or a pocket watch.

Description

(1) The subsequent drawings represent exemplary embodiments of the invention, by way of which the invention is described in detail. The same reference numerals in the drawings indicate the same or analogous elements. The drawings show in:

(2) FIG. 1 a view of the tourbillon according to the invention;

(3) FIGS. 2 and 3 in each case schematically, a detail of the guidance of the bearing wheel by one of the bearing elements;

(4) FIG. 4 a detail from a view of a watch provided with the tourbillon.

(5) The functioning manner and the implementation of the invention are hereinafter shown by way of different exemplary embodiments. It is to be understood that the invention is not restricted to these embodiments, but also includes other embodiments which are in concordance with the claims.

(6) FIG. 1 shows a tourbillon 1 which is assembled on a base 12 which is fixed with regard to the housing. The tourbillon 1 comprises a rotation cage which rotates relative to the housing about a tourbillon axis 20, for example with one revolution per minute. The rotation cage can thereby serve as a second hand in a manner known per se, or such a second hand can be coupled to the rotation cage. The details concerning the time display are not essential to the invention and are not discussed further in this text.

(7) Apart from a rotation cage platform 2, the rotation cage comprises a balance wheel bridge 5 which is fastened to this platform by two fastening pins 6. A balance staff of the balance wheel 3 is mounted between the rotation frame platform 2 and the balance wheel bridge 5, and specifically coaxially with the tourbillon axis 20 in the shown embodiment. The balance wheel 3 together with a spiral spring 4, in a manner known per se forms an oscillation system which likewise in a manner known per se interacts with an escapement which is present in the rotation cage and of which in FIG. 1 the lever is largely covered and the escape wheel 8 is only partly visible. The escape wheel 8 drives the oscillation system via the lever and thereby per oscillation rotates by a rotation angle which is defined by the distance of the escape wheel teeth.

(8) The drive of the escape wheel 8 is effected by way of an escape wheel pinion which is not visible in FIG. 1 and which is coupled onto the escape wheel engaging into a toothing 9 which is fixed with regard to the housing and thus rolling on this toothing 9 due to the rotation of the rotation cage, on which the escape wheel is assembled. In the represented embodiment example, the toothing 9 which is fixed with regard to the housing is formed on that disc which also forms the base. The base and/or the toothing fixed with regard to the housing can however also be formed by the watch housing itself.

(9) The rotation cage for its part is driven by a power wheel which can be considered as a second fourth wheel which is not visible in FIG. 1 and which for example engages into an outer toothing 15 of the rotation cage platform 2 which is well visible in FIG. 1.

(10) The rotation cage platform 2 forms an outer, peripheral running surface 11. For this purpose, in the represented embodiment example, the rotation cage platform below a rotation cage cog 21 which comprises the outer toothing 15 also comprises a rotation cage bearing wheel 22 with the peripheral running surface 11. Ball bearing elements 13 which are fastened to the base 12 are arranged radially outside this running surface. The ball bearing elements comprise an outer roller, on which the running surface 11 rolls given a rotation of the rotation cage. As a whole, exactly three of the ball bearing elements 13 are present and these are distributed at least approximately uniformly in the peripheral direction.

(11) FIG. 2 shows a schematic cross section through an outer roller of a ball bearing element 13 and through the peripheral region of the rotation cage platform. The ball bearing element 13 mounts the rotation cage platform and secures its axial and radial position due to the fact that the rotation cage platform 2 at its periphery forms a groove, into which the roller engagesthe running surface 11 as a whole is designed approximately V-shaped in cross section. The rotation cage platform 2 is therefore mounted by the three ball bearing elements 13 in a suspended, i.e. cantilevered manner. In the present example there are two contact points per ball bearing element on account of the roughly V-shaped design of the groove which forms the running surface 11 and on account of the convex shape of the roller, by which means the resistance is minimised.

(12) As an alternative to a groove, the running surface can also comprise a projection 25 which engages into a corresponding groove of the ball bearing element 13, which is represented schematically in FIG. 3. The principle of the axial and radial mounting functions analogously.

(13) The running surface can be coated with wear-resistant material which minimises the rolling friction, for example diamond-like carbon (DLC). Otherwise, the applied materials can be metals or composite materials, in particular special plastics, or also ceramics, which per se are valid as being suitable for the described purpose, for example high-grade steels, titanium alloys, etc.

(14) As a further variant, the running surface can also be an inner running surface, i.e. the bearing wheel forms a peripheral, revolving ring, on whose inner side the running surface is formed, and the bearing elements engage on the running surface from the inside.

(15) FIG. 4 in a detailed manner shows an upper view of a watch, whose dial comprises a window 30, through which the movement and in particular the tourbillon is partly visible. Apart from the tourbillon 1, one can recognise the power wheel 41 as well as further cogs of the movement which interact with this power wheel and by way of which on the one hand the drive energy is transmitted from a non-shown spring onto the power wheel and on the other hand the rotation movement of the rotation cage is stepped down, in order to control the forwards drive of the minute hand and hour hand, as well as, if required, one or more further intricacies (date display etc.).

(16) FIG. 4 also shows the possibility, apart from two fixedly assembled ball bearing elements 13.1, of providing a ball bearing element 13.2 which is resiliently mounted relative to the housing. The resiliently mounted ball bearing element 13.2 is pressed against the running surface 11 by a resiliently mounted rocker 44. This type of spring mounting or suspension can absorb energy which occurs with impacts and acts in a compensating manner, for example given different thermal expansions.

(17) A pivot pin 46 as well as a spring 45 which presses the ball bearing element against the running surface 11 is provided for the mounting of the rocker 44.

(18) The tourbillon 1 according to FIG. 1 including the base can be manufactured as a module and be insertable into a housing of the watch, for which screw holes visible in FIG. 1 next to each ball bearing element can serve. Only a single mechanical interface to the remaining components of the movement is necessary, and this is formed at the tourbillon side by the rotation cage cog.

(19) The invention was described by way of a single-axis tourbillon. However, with suitable adaptations it can also be applied to multi-axis tourbillons.