EP3306417B1 - Tourbillon and watch with tourbillon - Google Patents

Description

The invention relates to the field of clocks with mechanical clockwork. It particularly concerns tourbillons.

Tourbillons essentially consist of a bogie on which the balance wheel, escape wheel and anchor are arranged and which rotates relative to the watch case, for example once a minute. If the bogie rotates around a single axis, it is called a single-axis tourbillon. So-called flying tourbillons, in which the bogie is only held from the underside, are particularly popular, making the sophisticated mechanics of the clockwork clearly visible from the top. This is generally used by providing the dial with a corresponding viewing window.

Flying tourbillons according to the prior art, however, have the disadvantage that, due to unfavorable leverage effects on the shaft over which the bearings are mounted, they place very high demands on the bearing and this bearing also forms a potential weak point. In addition, this type of mounting results in a certain minimum axial expansion, generally perpendicular to the face of the dial, which means that the corresponding watches must be relatively thick.

From the EP 1 903 408 a tourbillon for a watch is known which has a bearing wheel forming a tourbillon bogie. This is mounted peripherally by rollers. Two of the rollers are fixed to the watch case, and the third of the rollers is attached to an arm through which it can be pivoted between two positions by turning an eccentric.

The object of the present invention is to create a tourbillon and a watch with a tourbillon which overcome the disadvantages of the prior art and which in particular have at least some of the advantages of a flying tourbillon without having to accept its disadvantages.

These objects are achieved by the invention as defined in the patent claims.

According to one aspect of the invention, a tourbillon is provided with a bogie which is arranged rotatably about a tourbillon axis and which supports a balance wheel and an escapement with an escape wheel and an armature. The bogie has a bearing wheel which is supported by bearing elements which act peripherally on the bearing wheel.

The bearing elements can attack the bearing wheel in particular from the radial outside. Alternatively, the bearing wheel can also define an inner running surface, as a result of which the bearing elements can attack from the inside.

In contrast to the prior art, the bogie is not supported by a shaft which is attached concentrically to the tourbillon axis and in turn is supported by two bearings below the bogie or by one bearing above and below the bogie, but along the periphery of the bearing wheel, which, for example, can have a similarly large scope as the bogie as a whole. As a result, unfavorable leverage forces are to be expected to a far lesser extent, and it is particularly sufficient if the bearing is only in a single axial position, so there is no need for several bearings arranged at an axial distance from one another. Therefore, the axial Dimension of the tourbillon - that is, its depth - can be reduced compared to the prior art. Overall, flatter constructions are therefore possible.

The bearing elements are, for example, not movable relative to the housing in the circumferential direction, but can each be rotated about an axis of rotation, as a result of which the bearing wheel rolls on the bearing elements when the bogie rotates. The bearing elements can, for example, be ball bearing elements (i.e. have a ball bearing, for example by forming a ball bearing). Such have, for example, an inner ring fixed to the housing, an outer roller and a plurality of balls between the ring and the roller, whereby the roller can rotate with little resistance relative to the ring.

In particular, there can be exactly three bearing elements which are arranged approximately evenly distributed in the circumferential direction.

At least one of the bearing elements is resiliently arranged, i. E. it is pressed against the peripheral running surface of the bearing wheel due to a spring force. For example, one of the bearing elements can be mounted on a rocker which is pivotable about a rocker axis and on which a spring acts so that the bearing element is pressed against the running surface. The resilient arrangement of a bearing element can absorb the energy generated in the event of impacts and also has a compensating effect.

If there are three bearing elements, in particular two of them can be fixed to the housing and one can be arranged resiliently in radial directions.

The presence of more than three bearing elements is also not excluded. Four, five or even more bearing elements can also be used, in which case, for example, several of the bearing elements can be arranged in a resilient manner.

In addition to ball bearings, other bearing elements can also be used, for example rollers, which in turn are supported by slide bearings, or the bearing elements can themselves be designed as slide bearings, for example as ruby bearings. As a further alternative, the bearing elements can also be designed as balls or rollers that are guided in a corresponding groove in the housing or a base, so that the bogie as a whole part can be understood as a roller (inner or possibly outer ring) of a ball bearing. It is only important that storage from the periphery is possible and that the friction losses are not too great.

The bearing wheel forms a peripheral, radially outer or possibly inner running surface on which the bearing elements act. For a smooth rolling of the bearing elements, the running surface can be designed in such a way that it has no structure in the circumferential direction, but is smooth, i.e. that it is constant as a function of the azimuth angle and in particular has no teeth or the like.

The running surface can, however, form a circumferential groove or circumferential tongue which cooperates with a complementary structure of the bearing elements in order to fix the bogie in the axial direction. The design and dimensioning of the complementary structure of the bearing elements can differ from the structure of the running surface in such a way that, in general, only two contact points are formed per bearing element. This can be brought about, for example, in that the respective groove in the area of contact with the element (roller; spring) engaging in it has no curvature or a lesser curvature than the corresponding surface of the engaging element.

The running surface of the bearing wheel is in particular arranged peripherally with respect to the whole bogie, i. E. the running surface can essentially form an outermost surface of the entire bogie. The diameter of the bearing wheel or the diameter of the running surface can, for example, correspond to the diameter of the bogie or at least 70% or at least 80% of this diameter. As a result, any torques acting on the bogie can be transmitted to the housing with little effort.

The tourbillon will generally also have a bogie gear on which a drive wheel of the rest of the clockwork engages and via which the latter decreases the rotary movement of the tourbillon and thus the time information. This can - as known per se - also form a peripheral surface of the bogie. Alternatively, the bogie gear can also have internal teeth. The bearing wheel and the bogie gear are generally designed to be non-rotatable relative to one another. Bearing wheel and bogie gear wheel - and possibly other elements of the bogie - can also be integral with one another, i.e. be formed by one and the same element.

The tourbillon can furthermore have a base on which the bearing elements or at least the non-resilient bearing elements are mounted. Such a base can be built into the case of the watch, for example by screwing. The tourbillon as a whole can thus form a module that is manufactured as a whole and built into the case.

Such a base can also have a toothing fixed to the housing, in which a pinion coupled to the escape wheel engages in order to drive it due to the rotary movement of the tourbillon.

A watch according to the invention, in particular a wrist or pocket watch, which, in addition to a tourbillon of the type described, has further movement parts, in particular a spring housing or the like as an energy store, and a gear train for transmitting the drive force from the energy store to the tourbillon and for reducing the rotary movement of the tourbillon, and display means (pointer, dial) for displaying the time, for which a pointer mechanism can also be present in a manner known per se. One or more complications for displaying further information, in particular the date, etc., can also be present.

The gear train can in particular have a drive wheel that meshes with the bogie gear.

The dial can have a viewing window through which the tourbillon is at least partially visible. Because of the flying arrangement according to the invention, the user sees a great deal of the mechanics, and yet the entire clockwork can be very flat and therefore the clock can be correspondingly elegant.

Figur 1

eine Ansicht eines erfindungsgemässen Tourbillons;

Figuren 2 und 3

je schematisch ein Detail der Führung des Lagerrads durch eines der Lagerelemente;

Figur 4

einen Ausschnitt aus einer Ansicht einer mit dem Tourbillon versehenen Uhr.

The following drawings illustrate exemplary embodiments of the invention, on the basis of which the invention is described in detail. In the drawings, the same reference symbols denote the same or analogous elements. The drawings show:

Figure 1

a view of a tourbillon according to the invention;

Figures 2 and 3

each schematically a detail of the guidance of the bearing wheel through one of the bearing elements;

Figure 4

a detail from a view of a clock provided with the tourbillon.

The mode of operation and implementation of the invention is shown below using various exemplary embodiments. It goes without saying that the invention is not restricted to these embodiments, but also includes other embodiments that are consistent with the claims.

Figure 1 shows a tourbillon 1 mounted on a base 12 fixed to the housing. The tourbillon 1 has a bogie which rotates relative to the housing about a tourbillon axis 20, for example at one revolution per minute. In a manner known per se, the bogie can serve as a second hand, or such a hand can be coupled to the bogie. The details of the time display are not essential to the invention and are not described further in this text.

In addition to a bogie platform 2, the bogie has a balance bridge 5 fastened to it with two fastening pins 6. Between the bogie platform 2 and the balance bridge 5, a balance shaft of the balance 3 is mounted, in the embodiment shown coaxially with the tourbillon axis 20. The balance 3, together with a spiral spring 4, forms a vibration system in a manner known per se cooperates in a manner also known per se with an escapement present in the bogie, of which in Figure 1 the anchor is largely covered and the escape wheel 8 is only partially visible. The escape wheel 8 drives the vibration system via the armature and rotates in the process per oscillation by an angle of rotation given by the distance between the escape wheel teeth.

The escape wheel 8 is driven in that an in Fig. 1 The escape wheel pinion, which is not visible and is coupled to the escape wheel, engages in a toothing 9 fixed to the housing and thus rolls on this toothing 9 due to the rotation of the bogie on which the escape wheel is mounted. In the illustrated embodiment, the toothing 9 fixed to the housing is formed on that disk which also forms the base. The base and / or the toothing fixed to the housing could, however, also be formed by the watch housing itself.

The bogie in turn is driven by a drive wheel, which can be understood as a second fourth wheel, which is shown in Fig. 1 is not visible and which, for example, in an in Figure 1 clearly visible external toothing 15 of the bogie platform 2 engages.

The bogie platform 2 forms an outer, peripheral running surface 11. In the exemplary embodiment shown, the bogie platform also has a bogie bearing wheel 22 with the peripheral running surface 11 below a bogie gear 21, which has the external toothing 15, for this purpose . Ball bearing elements 13, which are fastened to the base 12, are arranged radially outside this. The ball bearing elements have an outer roller on which the running surface 11 rolls when the bogie rotates. In total there are exactly three of the ball bearing elements 13 and they are distributed at least approximately evenly in the circumferential direction.

Figure 2 shows a schematic cross section through an outer roller of a ball bearing element 13 and through the peripheral area of the bogie platform. Because the bogie platform 2 forms a groove on its periphery, in which the roller engages - the running surface 11 is overall approximately V-shaped in cross-section - the ball bearing element 13 supports the bogie platform and secures its axial and radial position. The bogie platform 2 is suspended by the three ball bearing elements 13, that is, suspended. In the present example, due to the approximately V-shaped configuration of the groove which forms the running surface 11 and the convex shape of the roller, there are two contact points per ball bearing element, whereby the resistance is minimized.

As an alternative to a groove, the running surface can also have a projection 25 which engages in a corresponding groove of the ball bearing element 13, which is shown in FIG Figure 3 is shown schematically. The principle of axial and radial bearings works in the same way.

The running surface can be coated with an abrasion-resistant material that minimizes rolling friction, for example Diamond Like Carbon (DLC). In addition, the materials used can be metals or composite materials, in particular special plastics, or ceramics, which per se are considered suitable for the purpose described, e.g. high-quality steels, titanium alloys, etc.

As a further variant, the running surface can be an inner running surface, ie the bearing wheel forms a peripheral circumferential ring, on the inside of which the running surface is formed, and the bearing elements grip the running surface from the inside.

Figure 4 shows a detail of a top view of a clock whose dial has a window 30 through which the clockwork and in particular the tourbillon is partially visible. In addition to the tourbillon 1, one recognizes the drive wheel 41 as well as other gears of the clockwork that interact with it, through which the drive energy is transmitted from a spring (not shown) to the drive wheel and the rotary movement of the bogie is reduced to drive the minute and hour hands forward as well as to check one or more complications (date display etc.) if necessary.

Figure 4 also shows the possibility of providing, in addition to two permanently mounted ball bearing elements 13.1, 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 suspension can absorb energy generated by impacts and has a compensatory effect, for example, in the event of different thermal expansions.

For mounting the rocker 44, a pivot pin 46 and a spring 45 are provided, which press the ball bearing element against the running surface 11.

The tourbillon 1 according to Figure 1 can be manufactured as a module including the base and can be inserted into a case of the watch, for which in addition to the ball bearing elements an in Fig. 1 visible screw hole can serve. All that is required is a single mechanical interface to the other components of the movement, and this is formed on the tourbillon side by the bogie gear.

The invention has been described using a single-axis tourbillon. However, it can also be used for multi-axis tourbillons with appropriate adjustments.

Claims (14)

1. A tourbillon (1) with a rotation cage which is rotatably arranged about a tourbillon axis and which mounts a balance wheel (3) and an escapement with an escape wheel (8) and a lever, wherein 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), characterised in that at least one of the bearing elements is arranged in a radially resilient manner.
2. A tourbillon according to claim 1, wherein the running surface (11) forms an outer surface portion and the bearing elements (13) engage on the bearing wheel radially from the outside.
3. A tourbillon according to claim 1 or 2, wherein the bearing elements (13) have a fixed position in the peripheral direction but are rotatable each about a rotation axis, by which means the bearing wheel (22) rolls on the bearing elements give a rotation of the rotation cage.
4. A tourbillon according to claim 3, wherein the bearing elements (13) each comprise a ball bearing.
5. A tourbillon according to claim 3, wherein the bearing elements each comprise a slidingly mounted roller.
6. A tourbillon according to claim 1 or 2, wherein the bearing elements form a plain bearing.
7. A tourbillon according to claim 1 or 2, wherein the bearing elements are designed in a movable and rolling manner in the peripheral direction, for example as balls.
8. A tourbillon according to one of the preceding claims, wherein precisely three of the bearing elements (13) are present.
9. A tourbillon according to one of the preceding claims, wherein the running surface (11) forms a groove, and wherein the bearing elements (13) engage into the groove, in order to form an axial and radial guide.
10. A tourbillon according to one of the claims 1-8, wherein the running surface (11) forms a spring and wherein the bearing elements (13) comprise a groove, into which a projection (25) engages, in order to form an axial and radial guide.
11. A tourbillon according to one of the preceding claims, comprising a rotation cage cog (21), 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 (22) in a rotationally fixed manner and is arranged axial above or below this.
12. A tourbillon according to one of the preceding claims, comprising a base (12) which can be assembled in a manner fixed with regard to the housing and which comprises a toothing (9) which is fixed with regard to the housing and into which toothing a pinion which is coupled to the escape wheel (8) engages, in order to drive this escape wheel given a rotation movement of the rotation cage.
13. A tourbillon according to one of the preceding claims, comprising a base (12) which can be assembled in a fixed manner with regard to the housing, wherein at least one of the bearing elements (13) is assembled on the base.
14. A watch, in particular a wrist watch or pocket watch, comprising a tourbillon (1) according to one of the preceding claims, 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 means for displaying the time.

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