EP2746872B1 - Clock piece with universal time display - Google Patents

Description

Technical area

The present invention relates to the field of watchmaking. It concerns, more particularly, a watch called universal time. A universal watch makes it possible to simultaneously display the current time in the different time zones of the world. As can be seen on the figure 1 , such a timepiece comprises, in addition to needles 10 to indicate the local time, a disc twenty-four hours 12 and a record of cities 14 representing different time zones of the world.

The hands indicate the time in the time zone of the selected city, generally at noon and which may be advantageously indicated by a particular fixed mark 16 located on the dial. The twenty-four hour disk 12 is driven by the motion and is kinematically connected to the hour hand so as to display the time in the different time zones of the world.

State of the art

In this kind of timepieces, the correction of the different indicators has long been problematic. Indeed, these parts generally include two correcting organs, one for the local time and one for the universal time. The correction mechanisms of the universal time system involved only the mobiles of the cities and twenty-four hours and the latter was again driven during the setting of the needles. Such a setting was not at all intuitive.

We then proposed correction mechanisms to desynchronize the rotation of the disc twenty-four hours of the city disc 14 to be able to either correct all mobile or only change the position of the hands and disc twenty-four hours .

These mechanisms are very complex. In the document CH690205 , the hour hand is carried by a star of hours which, in normal operation, is secured to the wheel hours of movement by a jumper. A corrector actuated by a pusher causes a star of the cities that cooperates with a jumper of the cities and its return spring and which, by a hook is likely to cause the star hours via an hour correction wheel. However, when the correction mechanism is actuated, it is necessary to overcome the pair of jumper connecting the hour star and the hour wheel, which creates a parasitic torque on the movement. In addition, the use of a pusher can induce too great a force on the disk of cities 14 which, because of its great inertia, is likely to be driven too far.

In addition, the document CH703258 in which is disclosed a universal watch in which the time zones are indicated by means for indicating the world time zones. This last includes a disc of the cities which is integral with a city cam, and is concentric to a disc of the hours. During the normal operation of the watch, the disc of the cities remains motionless, the disc of the hours turning with respect to the disc of the cities. During a correction of the time zone, the means for indicating the world time zones and the means for indicating the local time turn together in the same direction. Nevertheless, this mechanism is complicated, and generates a congestion of the movement.

The object of the present invention is to propose a universal time display timepiece with an advantageous correction mechanism and free from the above disadvantages.

Disclosure of the invention

• un mouvement d'horlogerie,
• un premier indicateur pour afficher l'heure locale et destiné à être entraîné par le mouvement à raison d'un tour en douze heures,
• un disque vingt-quatre heures relié cinématiquement au premier indicateur et entraîné en synchronisme avec lui, et destiné à être entraîné par le mouvement à raison d'un tour en vingt-quatre heures,
• un disque des villes portant des indications permettant d'identifier au moins certains fuseaux horaires du monde et mobile en rotation en référence au disque vingt-quatre heures, et
• un organe de réglage de l'heure universelle.

More specifically, the invention relates to a timepiece with a universal time display, comprising:

• a watch movement,
• a first indicator to display the local time and intended to be driven by the movement at the rate of one turn in twelve hours,
• a twenty-four hour disk kinematically connected to the first indicator and driven in synchronism with it, and destined to be driven by the movement at the rate of one revolution in twenty-four hours,
• a disk of the cities bearing indications making it possible to identify at least certain time zones of the world and mobile in rotation with reference to the disk twenty-four hours, and
• a universal time setting device.

The timepiece according to the invention further comprises a kinematic connection between the disc twenty-four hours and the disc cities. This kinematic connection comprises a kinematic transmission ring interposed between the disc twenty-four hours and the city disc, the universal time setting member being adapted to drive said transmission ring. The timepiece according to the invention also comprises a first and a second unidirectional drive system, respectively upstream and downstream of the kinematic transmission ring: the kinematic transmission ring is kinematically connected to the disk twenty-four hours by a linkage train which integrates the first unidirectional drive system, and the kinematic transmission ring and the city disc are kinematically connected by the second unidirectional drive system. Thus, the first indicator and the twenty-four hour disc remain synchronized, the disc of the cities being driven only during a setting of universal time, always in synchronism with the first indicator and the disc twenty-four hours.

Brief description of the drawings

• la figure 1, déjà évoquée ci-dessus, illustre de manière générale une montre à affichage de l'heure universelle,
• les figures 2, 3 et 4 représentent un mécanisme d'une pièce d'horlogerie selon l'invention, dans différentes configuration de fonctionnement, et
• la figure 5 propose une vue agrandie d'un système d'entraînement unidirectionnel susceptible d'être utilisé dans une pièce d'horlogerie selon l'invention.

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

• the figure 1 , already mentioned above, generally illustrates a watch with a display of the universal time,
• the Figures 2, 3 and 4 represent a mechanism of a timepiece according to the invention, in different operating configurations, and
• the figure 5 proposes an enlarged view of a unidirectional drive system that can be used in a timepiece according to the invention.

Embodiment of the invention

We have shown on the figure 2 a timepiece with universal time display according to the invention. Such a piece includes a watch movement capable of indicating the current time. This information typically relates to the local time, that is to say at the time of the location of the wearer of the timepiece. In the case of the present invention, the local time is provided by a first indicator, typically by a set of hands 10, one of which indicates the time and is driven by the movement at a rate of one turn, typically in twelve hours. Local time could also be displayed in a 24-hour cycle. More particularly, the hour hand is mounted on an additional wheel hours 18. The latter is integral in rotation with the wheel hours of movement but it can be disconnected by means of a frictional connection or snap-fitting for example, a ratchet and a star. Such an arrangement makes it possible, as will be understood hereafter, to adjust the display of the local time by means of a regulator 20 of the universal time, limiting the disturbances on the course of the movement.

The first indicator is kinematically connected by a gear train 22 to a second indicator, taking the form of a disc twenty-four hours 12, bearing the numerical indications of the twenty-four hours of the day. The gear train 22 decreases the rotational speed of the first indicator, so that the second indicator is intended to be driven by the movement at the rate of one revolution in twenty-four hours. For his training, the disc twenty-four hours 12 includes a toothing 12a with which intermesh gear train 22. Due to the fact that the gear train 22 permanently engages the first and second indicators, they remain synchronized. The twenty-four hour disc 12 can also be divided into two equal color equal parts to provide an indication of day and night. We can also choose another means of representation of day and night.

The timepiece according to the invention also comprises a third indicator, taking the form of a city disc 14. The latter comprises twenty-four indications of places, each corresponding to a time zone. The disk of the cities 14 may also indicate half-spindles or quarter-spindle.

The disc of the cities 14 is rotatably mounted in reference to the disc twenty-four hours 12. It is rotated by means of the adjustment member 20 universal time as will be detailed below. The disk of the cities 14 is integral with a set of teeth 23, whose number of teeth corresponds to the number of indicated spindles, in order to index the position of the disk of the cities 14 by the support of a jumper spring 25.

The timepiece further comprises a kinematic link between the twenty-four hour disk 12 and the city disk 14. This kinematic link is formed by a kinematic transmission ring 24 interposed between the twenty-four hour disk 12 and the disk of the two wheels. cities 14. In the proposed example, the kinematic transmission ring 24 comprises a double set of teeth, one inside 24a and the other outside 24b. The internal toothing 24a makes it possible to kinematically connect the transmission ring 24 to that 12a of the twenty-four hour disc 12 by a linkage gear 26 which incorporates a first unidirectional drive system 28.

For the purposes of this application, a unidirectional drive system is a system that transmits a rotational movement that it receives to a driven mobile, when it is driven in a first direction. On the other hand, when it is driven in a second direction, the unidirectional drive system does not transmit the rotational movement to the mobile led. However, it should be noted that the unidirectional drive system remains in engagement with the driven mobile and must therefore be distinguished from a clutch system. Such a unidirectional drive system may be a one-way bearing, as provided by MPS Micro Precision Systems AG, or a unidirectional gear as described by the Applicant in the patent CH700806 .

Thus, in the proposed embodiment, the first unidirectional drive system 28 is of unidirectional rolling type. It is arranged so that a rotation of the disc twenty-four hours 12 in the normal operating direction, that is to say in the direction of movement drive (in the example, in the opposite direction clockwise), does not drive the transmission ring 24 and therefore does not drive the disk of the cities 14.

To kinematically connect the transmission ring 24 and the disk of the cities 14, the timepiece comprises at least one second unidirectional drive system 30. There is therefore a first and a second unidirectional drive system 30, respectively upstream and downstream of the kinematic transmission ring 24. The upstream and downstream are defined with respect to the direction of transmission of the energy in the kinematic chain.

To improve the stability of the disk of the cities, one could have several unidirectional drive systems, of unidirectional gear type, regularly distributed on the disk of the cities 14 and which connect the latter to the transmission ring 24. In the proposed example and illustrated in detail on the figure 5 this second unidirectional drive system 30 comprises pivotally mounted on the disc of the cities 14, a driven pinion 32 secured to a locking wheel 34 meshing with the external toothing 24b of the transmission ring 24. The locking wheel 34 is engaged with two locking pinions 36. The shape of the teeth of the locking wheel 34 is arranged so that, when it rotates in a first direction, it drives the locking pinions 36 and when it rotates in a second direction. direction, she hangs against locking pinions 32. Reference may be made to the aforementioned Swiss patent for details on the geometry of the teeth which makes it possible to obtain these effects.

Finally, the timepiece according to the invention also comprises a mechanism for adjusting the universal time capable of driving the transmission ring 24 in a direction that makes it possible to obtain the locking of the locking wheel 34 against the pinions of locking 36. This adjustment mechanism comprises the adjusting member 20 which typically takes the form of a secondary ring, dissociated from the main control rod which conventionally allows the local time to be adjusted and, if necessary, to arm a source of energy or to perform another function, such as a correction of the date for example. The secondary ring is mounted on a secondary rod 38 which, preferably, must be drawn axially to activate the adjustment mechanism and connect the adjusting member 20 and the transmission ring 24. The adjustment member could also be realized under the shape of a pusher may cause the transmission ring.

In operation, the elements described above behave as follows. In normal operation ( Fig. 2 ), the additional hour wheel 18 is driven in the direction of clockwise and the disc twenty-four hours 12 is driven in the opposite direction. The mobiles of the linkage 26 which are located between the transmission ring 24 and the first unidirectional drive system 28 are driven. In contrast, the mobiles of the linkage 26 located between the first unidirectional drive system 28 and the transmission ring 24 are not driven. The disk of the cities 14 remains motionless. Advantageously, it will be noted that the first unidirectional drive system 28 is placed relatively early in the various kinematic chains, which allows to have few elements driven by the movement in its normal operation.

The same operation is obtained during a correction of the local time by the control rod in the clockwise direction.

When correcting the local time by the control rod, but counterclockwise ( Fig. 3 ), the additional hour wheel 18 is driven in a counterclockwise direction and the disc twenty-four hours 12 is driven in the direction of clockwise, that is to say in the opposite direction to the normal operating direction produced by the movement drive. In this configuration, the first unidirectional drive system 28 transmits the rotational movement that it receives, so that all the mobiles of the linkage 26 are driven, as well as the transmission ring 24. The locking wheel 34 drives locking gears 36 which rotate "in the vacuum". The disk of the cities 14 is not driven and is held in position by the jumper spring 25 which cooperates with the positioning gear 23. In this case, more elements are driven than previously, but this is not detrimental because the training is here manual.

Finally, in case of setting the universal time by the adjusting member 20 ( Fig. 4 ), it is arranged to drive the transmission ring 24 by its internal teeth 24a, in the opposite direction of clockwise. In this case, the twenty-four hour disk 12 is driven by the linkage 26 and by the first unidirectional drive system 28. It is driven in the normal direction of operation, that is to say in the direction counterclockwise, as when driven by movement. Indeed, compared to a normal drive where the first unidirectional drive system does not transmit rotation, even if the directions of rotation are the same, the driving force here comes from the transmission ring 24 and not from the disc twenty- four hours 12. Relatively, the effect is similar to a reversal of the directions of rotation and thus a transmission of the rotation by the first unidirectional drive system 28 is obtained. Similarly, the disc of the cities 14 is driven in rotation by the transmission ring 24, under the action of the second unidirectional drive system 30.

Thus, the setting of the universal time makes it possible to drive in a single operation all the indicator organs, the disc twenty-four hours 12 and the disc of the cities 14 turning counterclockwise while the hour hand turns clockwise. As mentioned above, the fact that the hour hand is mounted on an additional hour wheel 18 makes it possible to limit the disturbances induced on the movement when setting the universal time. Due to the fact that the disk of the cities 14 performs its rotation in steps of 1 / 24th of a turn (because of the spring-jumper 25 and the teeth of the positioning 23), the hour hand will also make jumps in steps of 1 / 12th of a turn synchronously with the disc twenty-four hours 12 and in conjunction with it.

The described mechanism requires very few components compared to other much more complex universal time systems. The elements involved are almost exclusively rotating mobiles, which makes the mechanism very reliable and simple. All mobiles remain permanently engaged, which makes any deindexing impossible. In addition, the movement works normally even if the user forgets to push the secondary rod. In the case where the secondary rod 38 remains drawn while an adjustment is made on the main control rod, unidirectional drive systems prevent any breakage and maintain indexing of the different indicator organs.

Examples of unidirectional drive systems may be substituted for each other. One could, for example, have a unidirectional gear replacing the unidirectional bearing of the first system, or have the city disc 14 connected to the transmission ring 24 by a unidirectional bearing, the assembly forming a ring surrounding the movement. The transmission ring 24 would then have only an internal toothing to be kinematically connected to the linkage 26 and to the adjustment member 20. Other types of unidirectional drive could also be implemented, such as ratchet inverter systems, of the type used in automatic winding gears.

Those skilled in the art may still consider other variants without departing from the scope of the invention as defined in the claims. In particular, the gear trains and linkages could be adapted or modified.

Claims (10)

1. A timepiece for displaying the global time, comprising:

   - a clockwork movement,

   - a first indicator to display the local time and intended to be driven by the movement at a rate of one revolution in twelve hours,

   - a twenty-four hour disc (12) kinematically connected to the first indicator and driven in synchronism therewith, and intended to be driven by the movement at a rate of one revolution in twenty-four hours,

   - a cities disc (14) bearing indications making it possible to identify at least certain time zones of the world and rotatable in reference to the twenty-four hour disc (12), and

   - an adjusting organ (20) for adjusting the global time,

   said timepiece further comprising a kinematic link between the twenty-four hour disc (12) and the cities disc (14), the kinematic link including a kinematic transmission crown (24) inserted between the twenty-four hour disc (12) and the cities disc (14), the adjusting organ (20) for adjusting the global time being able to drive said kinematic transmission crown (24),
   characterized in that it includes first (28) and second (30) unidirectional drive systems, respectively upstream and downstream from the kinematic transmission crown (24), in that the kinematic transmission crown (24) is kinematically connected to the twenty-four hour disc (12) by a linking train (26) that incorporates the first unidirectional drive system (28), and in that the kinematic transmission crown (24) and the cities disc (14) are kinematically connected by said second unidirectional drive system (30).
2. The timepiece according to claim 1, characterized in that the first unidirectional drive system (28) is arranged such that a rotation of the twenty-four hour disc (12) in the normal operating direction, i.e., in the direction of driving by the movement, does not drive the cities disc (14).
3. The timepiece according to claim 2, characterized in that the first unidirectional drive system (28) is arranged such that a rotation of the twenty-four hour disc (12) in the normal operating direction, i.e., in the direction of driving by the movement, does not drive the transmission crown (24).
4. The timepiece according to claim 3, characterized in that the first unidirectional drive system (28) is arranged such that a rotation of the twenty-four hour disc (12) in the direction opposite the normal operating direction drives the transmission crown (24) in a first direction and in that the second unidirectional drive system (30) is arranged not to drive the cities disc (14) when the transmission crown (24) is driven in the first direction.
5. The timepiece according to claim 4, characterized in that it includes a mechanism for adjusting the global time able to drive the transmission crown (24) in a second direction opposite the first direction.
6. The timepiece according to claim 5, characterized in that the first (28) and second (30) unidirectional drive systems are arranged such that, when the transmission crown (24) is driven in the second direction by the mechanism for adjusting the global time, the twenty-four hour disc (12) is driven in the normal operating direction.
7. The timepiece according to one of the preceding claims, characterized in that at least one of the unidirectional drive systems includes a unidirectional rolling bearing.
8. The timepiece according to one of claims 1 to 6, characterized in that at least one of the unidirectional drive systems includes a unidirectional gear.
9. The timepiece according to claim 8, characterized in that said at least one unidirectional drive system includes a driven pinion (32) secured to a locking wheel (34), said locking wheel being engaged with two locking pinions (36), the shape of the teeth of the locking wheel being arranged such that, when the locking wheel rotates in a first direction, it drives the locking pinions, and when the locking wheel rotates in a second direction, it locks against the locking pinions.
10. The locking system according to one of claims 1 to 6, characterized in that at least one of the unidirectional drive systems includes a reverser system.

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