EP3374830B1 - Calendar mechanism for a timepiece - Google Patents

Description

Technical area

The present invention relates to the field of watchmaking. More particularly, it relates to a calendar mechanism adapted to indicate information having a period varying according to at least a first cycle and a second cycle, such as a perpetual calendar.

State of the art

The document EP 1 351 104 describes a perpetual calendar mechanism. This schedule has a maximum month length of 31 days, which varies over a first 12-month cycle, and which includes the sequence of 31-28-31-30-31-30-31-31-30-31-30- 31 days a month. A second 4-year cycle of the leap year Julian is superimposed on this first cycle, which adds an extra day in February. A retractable tooth carried by a sliding lever interacts with a 24-hour wheel at the end of February of non-leap years in order to advance the date indication from an indication of 28 directly to an indication of the 1 of the month following. This tooth is retracted in leap years so that the indication can show February 29, before being advanced about 1, 24 hours later. Nevertheless, this mechanism is complex and fragile.

The document EP 1 818 738 also incorporates a third 100-year cycle, to remove February 29 for the divisible years by 100, and a fourth 400-year cycle to restore it for the years divisible by 400. This mechanism thus makes it possible to display the entire cycle of the Gregorian calendar.

The document EP 0 606 576 describes a Muslim calendar mechanism. The Muslim calendar is based on the lunar cycle, and includes a first cycle of 12 months, odd months with 30 days, and even months with 29 days. To compensate for the difference between this cycle and the complete Muslim year, the twelfth month of some years presents 30 days instead of 29, according to a second 30-year cycle. Several variants of this second cycle exist, but a commonly used variant defines the years in which the twelfth month has 30 days instead of 29 as follows: 2 ^nd , 5 ^th , 7 ^th , 10 ^th , 13 ^th , 15 ^th , 18 ^{th th,} 21 ^th, 24 ^th, 26 ^th and 29 ^th.

These calendar mechanisms of the prior art are relatively complex, and require a lot of room in the movement.

The object of the present invention is to provide such a calendar mechanism which is simple, compact and reliable.

Disclosure of the invention

More specifically, the invention relates to a timing mechanism for a timepiece, said timing mechanism being adapted to indicate information having a period varying according to at least a first cycle and a second cycle. By "undergraduate" we mean for example a cycle of months whose number of days of each month is invariable from one year to another, for example from the first to the eleventh month of the Islamic calendar, or the months of January and March to December of the western calendar (Julian or Gregorian). By "second cycle" is meant, for example, a cycle of a length different from the first, for example the 30-year cycle that determines the number of days in the twelfth month of the Islamic calendar, the four-year cycle of the Julian calendar, or the 400-year cycle of the Gregorian calendar which determines the number of days in the month of February. These two cycles are superimposed to give the desired indications on a complete cycle.

This mechanism comprises a month mobile comprising a wheel having a fixed number of teeth, said number being chosen according to the maximum period of the information to be displayed. Normally, this number of teeth is the same as the maximum number of days in a month, or its entire multiple.

The mobile further comprises a rocker arranged to move between an inactive position and an active position and vice versa, this rocker being provided with at least one retractable tooth relative to the periphery of the mobile. This at least one tooth may be a conventional tooth extending in the plane of the rocker, or a tooth extending perpendicularly to this plane in the form of a tooth edge, pin, pin or the like, which are usually all considered as "teeth" when performing the same function.

The mechanism further comprises a drive wheel comprising a first drive member arranged to interact with said fixed teeth and a second drive member angularly offset from the first drive member and arranged to interact with said retractable tooth when said flip-flop is in its active position. In this position, the retractable teeth are positioned in order to cooperate with the drive wheel.

Incorporated in said mechanism are a first cam whose shape represents the variations of said period according to the first cycle, and a second cam whose shape represents the variations of said period according to the second cycle, as well as a kinematic indexing system. with said wheel, with said first cam and with said second cam and adapted to index each of said cams according to said cycles.

An actuation system of said latch is also incorporated in said mechanism. This actuation system comprises a first cam follower intended to come into contact with the first cam and a second cam follower intended to come into contact with the second cam, said cam follower probes being in kinematic connection with each other and the actuating system being arranged to change said latch from its inactive position to its active position under the control of each of said cams.

Consequently, these two kinematically connected probes allow the flip-flop to be actuated either according to the information carried by the first cam, or according to the information carried by the second cam, so that it is controlled as a function of superimposing the two cycles in order to display the desired complete cycle, and therefore the moving month is advanced by the appropriate number of steps at the end of each month.

Advantageously, said first cam and said second cam are each coaxial with said wheel and carried by the latter. This results in a particularly compact construction. Alternatively, these two cams could also not be coaxial with said wheel.

Each of said cams may be located on the same side of said wheel, or one on a first side of said wheel, and the other on the opposite side.

In this second case, the second probe advantageously extends through an opening in said wheel so as to feel the cam which is located on the opposite side to the first probe.

Advantageously, the actuation system comprises a first lever provided with said first probe and also provided with a stop intended for contacting said latch to make it evolve to its active position under the control of said first cam.

In a variant, not only the first probe but also the second probe is carried by the first lever, which represents a particularly compact arrangement. Alternatively, the actuating system may comprise a second lever in kinematic connection with said first lever, said second lever carrying said second probe.

In a variant, the actuation system comprises an additional actuation mobile in direct or indirect kinematic connection with said first lever. This additional operating wheel is arranged to change said flip-flop to its active position under the control of said second cam.

Advantageously, the additional operating wheel is pivoted with respect to said wheel and comprises an additional actuating cam intended to rest against said latch under the control of said second cam.

In a variant, said first cam has a shape representative of the number of days in a month varying according to a first cycle, and said second cam has a shape representative of the number of days in at least one particular month which varies according to a second cycle, and wherein said first cam has a notch representative of at least one month whose number of days is determined according to said second cycle. In a particular variant in which the first cycle comprises twelve months and the second cycle comprises thirty years, the form of said first cam represents the number of days from the first to the eleventh month varying according to the first cycle of twelve months, the notch corresponding to the twelfth month, and the shape of said second cam representing the number of days of the twelfth month varying on the second thirty-year cycle. The notch allows the first cam not to influence the position of the first lever for the month where the number of days is determined by the second cam.

Alternatively, the first cycle has four years, the form of the first cam representing the number of days in February varying according to the first cycle of four years (ie, 28 - 28 - 28 and 28 or 29 (according to the second cycle)) , the notch corresponding to the month of February which could be leap or not according to for example the Julian or Gregorian calendar. In this alternative, the second cycle comprises 100 years or 400 years, the shape of the said at least one second cam representing the number of February days of years divisible by four, which can be leap or not according to the Gregorian or Julian cycle.

Advantageously, the mechanism comprises a second additional cam superimposed on said second cam, the combination of the second cam and the second additional cam defining a cycle of 400 years, particularly according to the Gregorian calendar. This avoids using a single cam at 400 sectors, and using two cams simpler in superposition. In order to read these cams, said second probe may be arranged to feel the second cam and the second additional cam in parallel, that is to say simultaneously.

Advantageously, said rocker carries at least two retractable teeth having the same separation as two fixed teeth of the wheel. The mechanism is reversible, and maintains its indexing regardless of the direction of rotation of the drive wheel. Therefore, even when a correction in the opposite direction to the normal operating direction, a correct indexing is ensured.

Advantageously, a day of the week display device may be provided, which is preferably associated with the training wheel to indicate in a simple manner the day of the week.

Brief description of the drawings

• Fig. 1-3 sont des vues de dessus d'un premier mode de réalisation d'un mécanisme de calendrier selon l'invention dans différentes positions ;
• Fig. 4 est un diagramme schématique illustrant le principe de fonctionnement du mécanisme de calendrier selon l'invention ;
• Fig. 5-8 sont des vues en perspective et en plan d'un deuxième mode de réalisation, vu des deux côtés du mécanisme ; et
• Fig. 9-11 sont des vues en perspective d'un troisième mode de réalisation, vu des deux côtés du mécanisme.

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

• Fig. 1-3 are top views of a first embodiment of a calendar mechanism according to the invention in different positions;
• Fig. 4 is a schematic diagram illustrating the operating principle of the calendar mechanism according to the invention;
• Fig. 5-8 are perspective and plan views of a second embodiment, viewed from both sides of the mechanism; and
• Fig. 9-11 are perspective views of a third embodiment, viewed from both sides of the mechanism.

Embodiments of the invention

The figures 1-3 schematically illustrate an embodiment of a calendar mechanism 1 according to the invention, in the form of a Muslim calendar. In order to more clearly illustrate the interaction between the various components and to give a better appreciation of the depth in the figures, various hatches were used. Moreover, the figure 4 illustrates the operating principle in the form of a diagram.

The mechanism 1 comprises a mobile of month 3, which comprises a wheel 4 carrying fixed teeth 5 with respect to the wheel 4. The number of fixed teeth 5 is chosen according to the number of days maximum to be displayed, in particular thirty in the case illustrated. An integer multiple of this number is also possible. The positioning of the mobile of month 3 can be provided in a conventional manner by means of a jumper (not shown). Wheel 4 is conventionally associated with one (or more) display member (s) (not shown) which indicates (s) the date.

The mobile of month 3 is driven by a driving wheel 7, which comprises a first driving member 7a provided with four teeth or driving fingers separated by gaps, the latter being shaped to cooperate with the fixed teeth 5. The driving wheel 7 is arranged to be driven itself by a base movement (not shown) at a rate of Quarter turn in 24 hours, typically around midnight. The number of teeth or driving fingers can be chosen according to the needs of the watchmaker, and considered generically, if n is the number of teeth or driving fingers, the driving wheel 7 performs 1 / n turns per day.

The mobile of month 3 also comprises a rocker 9, pivoted on the wheel 4 at a pivot point 9a, which carries retractable teeth 11 located in a plane different from that of the fixed teeth 5 and integral with the rocker 9. In the view of the figure 1 , the rocker 9 and the retractable teeth 11 are in their retracted - inactive - position while they are in their deployed - active - position in the figures 2 and 3 . A return spring (not shown) tends to keep the rocker 9 in its inactive position ( figure 1 ). In the active position of the rocker 9, the retractable teeth 11 can cooperate with a second drive member 7b that includes the drive wheel 7. The retractable teeth 11 are retractable relative to the periphery of the mobile of month 3.

This second drive member 7b has a shape substantially similar to the first drive member 7a, but is offset angularly by 1/8 of a turn relative to the latter and is located in a plane allowing it to cooperate with the retractable teeth 11.

Therefore, if the retractable teeth 11 are in their retracted position ( figure 1 ), the second drive member 7b has no effect, and for each quarter turn of the driving wheel 7, the moving month 3 is rotated by one step, namely a tooth in the illustrated case .

If the retractable teeth 11 are in their active position ( figures 2 and 3 ), a quarter turn of the driving wheel 7 rotates the wheel of month 3 one step by means of the interaction between the first drive member 7a and the fixed teeth 5, and a further step to means of the interaction between the second drive member 7b and the retractable teeth 11.

If the retractable teeth 11 comprise only one tooth 11, the calendar mechanism 1 operates only in one direction of rotation. By cons, in the illustrated case where two retractable teeth 11 are present and are each superimposed on a pair of fixed teeth of the wheel 4 (or are shifted by a pair of fixed teeth of the wheel 4), with a similar separation or identical to the separation between two stationary teeth 5 of the wheel 4, the calendar mechanism 1 operates in a reversible manner, that is to say that the number of steps made by the mobile of month 3 following a drive in one way or the other (for example following a manual correction of the date in the opposite direction to the direction of rotation usual of the mobile of month 3) remains correct, and the mechanism remains always correctly indexed compared to the date displayed by means of the indicating bodies associated therewith (not illustrated). In the case where the wheel 4 has a fixed number of teeth 5 which is a multiple of the maximum number of days in a month, the number of retractable teeth can be multiplied by this multiple.

The position of the rocker 9 is controlled by means of an actuating system 13 as a function of the position of a first cam 15 and a second cam 17. The first cam 15 is located between the pivot point 9a of the rocker 9 and the axis of rotation of the mobile 3, and is arranged to pivot relative to the wheel 4. The shape of the first cam represents the first cycle of 12 months, and therefore has portions of greater radius 15a representing the odd months of 29 days, and portions of lower radius 15b representing even months of 30 days. Since the number of days of the twelfth month depends on the year, this month is represented by a notch 15c whose operation will appear more clearly later.

The second cam 17 is located between the pivot point 9a of the rocker 9 and the periphery of the wheel 4, and is also arranged to pivot with respect to the wheel 4. The shape of the second cam 17 represents the second cycle 30 years, which determines the number of days of the twelfth month. The shape of this cam 17 extends inwards, and comprises parts of upper radius 17a, which represent the twelfth months to 29 days, and portions of lower radius 17b, which represent the twelfth months to 30 days.

Such cams are often called "programming cams" because their shape determines the number of days indicated in a month, and thus serves to "program" the sequence indicated by mechanism 1.

The cams 15, 17 are supported and driven in rotation with respect to the wheel 4 by means of an indexing system 19, which is shown diagrammatically on the Figures 1 to 3 , and ensures that the angular position of each cam 15, 17 relative to the wheel 4 is correctly indexed for the date indicated. As represented by the arrows, the indexing system 19 is driven by the wheel 4, and drives the two cams 15, 17 by means of a suitable transmission system, such as a gear, Maltese cross, star or all other appropriate system. It goes without saying that this transmission system can control the two cams 15, 17 individually, or can control the second cam 17 relative to the first cam (@MB: for information, it is this second type of transmission which is currently planned in our construction: the transmission makes the following path: 4-15-17). The details of the indexing system are not part of the invention per se, and will not be described in more detail.

The actuating system 13 comprises a first lever 21 carrying a feeler 21a, the first lever being pivoted on the wheel 4 at a point of pivoting 21b under the effect of a spring (not shown). The first lever 21 also carries a stop in the form of a stud 21c arranged to rest against a flank of the rocker 9 to bring it into its active position ( figure 2 ). However, said first lever 21 could also work directly with said flip-flop 9 without the use of a stud. Similarly, the flip-flop 9 could comprise a stud and the first lever 21 might not have one. It is also possible that the rocker 9 and the first lever 21 each have a stud.

The first probe 21a follows the first cam 15 so that when the first probe 21a is in contact with a portion of lower radius 15b of the latter ( figure 1 ), the pad 21c does not bring the rocker 9 into its active position, and the retractable teeth 11 are in their retracted position, the second drive member 7b can not interact with the retractable teeth 11, and a cycle of 30 days will be displayed.

On the other hand, when the first probe 21a is in contact with a portion of greater radius 15a of the first cam ( figure 2 ), the pad 21c brings the flip-flop 9 and the retractable teeth 11 into their active positions. Therefore, the second drive member 7b can interact with the retractable teeth 11, and a cycle of 29 days will be displayed because the wheel 4 will advance two steps at the end of the month.

During the twelfth month, the first probe 21a is in the notch 15c, and therefore the pad 21c is moved away from the rocker 9. The length the twelfth month is determined not by the first cam 15, but by the second cam 17.

In order to feel the second cam 17, a second lever 23 is also pivoted on the wheel 4 at a pivot point 23b, and is in kinematic connection with the first lever 21 by means of complementary toothed segments 21d, 23d carried by each lever 21 23. The second lever 23 includes a second probe 23a, which is intended to come into contact with the second cam 17, at least during the twelfth month. If the twelfth month is 30 days, the second probe 23a is in contact with a lower radius portion of the second cam 17, and the actuating device 13 adopts the configuration illustrated in FIG. figure 1 , except that the first probe 21a is opposite the notch 15c.

In the case where the twelfth month has 29 days, the second probe 23a is opposite an upper radius portion 17a of the second cam 17, as shown in FIG. figure 3 . The first probe 21a being in front of the notch 15c, it can therefore pivot further towards the axis of rotation of the first cam 15 than in the other positions of the first cam 15. The second probe 23a is therefore free to contacting, and seating against, the upper spoke portion 17a of the second cam 17, which pivots the second latch 23 in a clockwise direction (relative to the view of the Figures 1 to 3 . This rotation is transmitted to an actuating mobile additional 25 pivoted on the wheel 4 and consisting of an additional actuating cam 25a arranged to control the latch 9, and a toothed gear 25b which is kinematically connected to the second sensor 23a via a transmission lever 24. In the illustrated case, the transmission lever 24 also comprises two toothed sectors, or even racks, meshing on either side with said toothed gear 25b and with a complementary tooth sector that the second lever 23 comprises.

It goes without saying that any type of kinematic link between the levers 21, 23, 24 and the additional operating wheel 25 are possible, for example pads cooperating with grooves, a belt or the like.

Indeed, the mechanism represents a globally binary logic system, which presents the following transfer table: Cam 1 Cam 2 Rocker 9 0 (lower radius) 0 (lower radius) 0 (retracted, 30 days) 0 1 (upper radius) 0 1 (upper radius) 0 1 (active, 29 days) 1 1 1 (active, 29 days) X (notch) 0 0 X 1 1 (active, 29 days)

It is clear that the cam 1 has the "priority" in this logic, and that it is only when the first probe 21a is in front of the notch 15c that the cam 2 can influence the position of the rocker 9.

In order to avoid conflicts between the various components of the mechanism 1, they are located in appropriate planes so that they can pass one above the other when needed. For example, in the figure 1 the transmission lever 24 is overlapped by the first cam 15 which is therefore located in another plane. The same situation also exists between the second cam 17 which is overlapped by the transmission lever 24 in the figure 3 .

The figure 4 schematically illustrates the operating principle of the mechanism 1 according to the invention. The driving wheel 7 drives around the midnight wheel 4 and, where appropriate, the retractable teeth 11. If the retractable teeth 11 are in their active position and are therefore driven by the second drive member 7b, the force exerted on the rocker drives the wheel 4 by an additional step.

The wheel 4 being kinematically connected to the indexing system 19, each modification of the angular position of the mobile of month 3 modifies the state of the indexing system, which modifies the position of the first cam 15 and the second cam 17 so that they are correctly indexed with respect to wheel 4 for the displayed date. These cams 15, 17 are palpated by the first and second feelers 21a, 23a respectively, which thus determine the position of the rocker 9.

The Figures 5 to 8 illustrate a second embodiment of a Muslim calendar mechanism 1 which applies the same principle as that of Figures 1 to 3 . These figures illustrate the mechanism 1, seen from both sides, in particular from the upper side ( Fig. 5 and 6 ) and lower ( Fig. 7 and 8 ), and according to perspective views ( Fig. 5 and 7 ) and in plan ( Fig. 6 and 8 ), within a month of 30 days. In these figures, the driving wheel 7 has not been shown, but may be identical to that illustrated in FIGS. Figures 1 to 3 or any other appropriate form.

This embodiment differs mainly from the first in the positioning of the second cam 17 and the components of the actuating system 13.

As visible on Figures 5 and 6 , the arrangement of the rocker 9, the first cam 15, the first probe 21a and the pad 21c is substantially unchanged.

However, the first lever 21 extends in a curve so that its rack 21d meshes directly with the toothed sector 25b of the additional operating wheel 25. Consequently, the intermediate levers 23 and 24 of the first embodiment have been removed. Nevertheless, it goes without saying that a different kinematic link between the first lever 21 and the additional operating wheel is also possible.

The second cam 17 is on the opposite side of the wheel 4, so on the other side than that of the first cam 15, and is located centrally, extending outwardly. The second probe 23a is a pin integral with the first lever 21, which extends through an opening 4a made in the wheel 4 so as to feel the second cam 17.

Notwithstanding these structural changes, the operating principle of the mechanism remains unchanged.

The Figures 9 to 11 illustrate the same principle of operation as described above, but applied to the February treatment of the Gregorian calendar. As this system is more complicated than those described above, some mounting elements (pins, pins, etc.) have not been illustrated. Moreover, the representation is strongly schematic in order to make its operation appear more clearly, and the elements dealing with the jumps of the days 31 and 30 of the month have been represented separately from those dealing with the jump of the day 29 of the month, in different figures.

The figure 9 illustrates the elements ensuring the jump from 31 ^th day of the month during the months of 30 days each and February, and jumping the 30 ^th day of the month at the end of every February. These jumps follow a single cycle of 12 month, and therefore do not apply the principle of superposition cycles of the invention, but are illustrated here in an interest of completeness.

In this embodiment, the wheel 4 of the mobile of month 1 comprises 31 teeth (or alternatively an integer multiple of 31 teeth) which cooperates with a first drive member 7a of the drive wheel 7, and during its standard operation , turn clockwise in the view of the figure 9 at a rate of one round per month. A first additional rocker 27 is pivoted on the wheel 4 (its axis having been removed from the figure), and has two teeth arranged similarly to those of the rocker 9 mentioned above and which are positioned in order to be able to interact with a body. additional drive 7c of the drive wheel 7, located in a plane other than the first drive member. A second additional latch 29 is also pivoted on the wheel 4 (its axis has also been removed from the figure), and also has two teeth shifted by a step in the direction -amont relative to those of the first additional latch 27, and which are positioned to be able to interact with yet another additional drive member 7d located in yet another plane on the drive wheel. These additional flip-flops 27, 29 operate in a manner similar to flip-flop 9, except that they are each controlled by a single cam. Furthermore, in the illustrated embodiment, the drive members are provided in pairs, offset by 180 °. The training mobile is a half-turn per day. Other arrangements are also possible, for example 1, 3 or 4 drive members per level.

The actuation of these flip-flops arising in a single cycle of 12 months, the mobile 3 comprises a first additional cam 31, which is followed by a probe 27a of the first additional flip-flop 27 to bring this flip-flop into its active position at the end of the month of 28, 29 or 30 days. This additional cam 31 thus has five projections corresponding to the months of less than 31 days. A second additional cam 33, integral in rotation with the first additional cam 31, is also followed by a probe 29a of the second additional rocker 28 to bring this rocker into its active position at each February, and for this purpose this cam additional 31 has a corresponding projection in the month of February.

The indexing system 19 ensures the angular relationship between the additional cams 31, 33 and the wheel 4, ensuring a rotational speed ratio of 11/12 or 13/12 of the additional cams 31, 33 with respect to the wheel 4 , depending on the direction of relative rotation desired between these components. However, any other speed ratio between the wheel 4 and the cam 31 and between the wheel 4 and the cam 33 is conceivable, provided that the teeth of the latches 27 and 29 are positioned adequately when they pass in front of the mobile Training 7.

The Figures 10 and 11 illustrate the elements that concern the month of February. The illustrated arrangement represents a modification of the system of Figures 5 to 8 and, therefore, only the differences with the embodiment of these latter figures will be described in detail here, the elements having the same reference signs having the same functions, mutatis mutandis.

The first cam 15, the rocker 9 (whose axis of rotation 9a has not been illustrated), and the components of the actuating system 13 visible on the figure 10 are superimposed on the additional rockers 27, 29 and the additional cams 31, 33 so that the teeth 11 of the rocker 9 can interact with the second drive member 7b of the driving wheel 7.

The first cam 15 has 48 sectors representing the first cycle of 4 years / 48 months, most of these sectors have the same radius, lower, 15b (months other than February). The three parts of larger radius 15a are bumps representing the month of February which are always non-leap and which cause the flip-flop 9 to its operative position in order to skip the ^29th of the month, and a notch 15c is that of a year could possibly be leap (and therefore have 29 days) according to the Gregorian calendar (that is to say every year divisible by 4). The indexing system ensures that the first cam 15 makes a quarter turn per year relative to the wheel 4.

In the same way as for the embodiment of Figures 5 to 8 this notch delegates the control of the rocker 9 to at least a second cam 17, located on the opposite side of the wheel 4. In this case, the mechanism comprises not only a second cam 17, but also a second additional cam 18 coaxial to the second. These two cams are palpated in parallel by the second probe 23a. In the illustrated embodiment, the second cam 17 has twenty sectors, three of which have notches, and the second additional cam 18 has five sectors, one of which has a notch. Indeed, the combination of these notches provides the information of if the year in question is divisible by 100 and not by 400.

Looking at the figure 11 , we see the second cam 17, which performs for example a turn in 400 years with respect to the wheel 4, and the second additional cam 18 which performs a turn in 20 years, also with respect to the same wheel. Alternatively, the second cam 17 can for example also make a turn in 80 years, and the second additional cam 18 can make a turn in 400 years. A single second cam 17 having 400 sectors is indeed very difficult to achieve given the size of such a mechanism, and it is for this reason that we chose to use the logical combination "AND" of two cams 17, 18. This combined cycle of 400 years is the second cycle within the meaning of the invention.

Therefore, if a notch of the second cam 17 and a notch of the second additional cam 18 are below the second probe 23a (which is the case for each year divisible by 100 but not 400), the latter falls into the combined notch (provided that the feeler 21a, which is on the opposite side of the wheel 4, is above the notch 15c), and the first lever 21 pivots counterclockwise according to the view of the figure 10 . Its rake 21d therefore controls the additional actuating cam 25a to bring the retractable teeth 11 into their active position, and the day of the 29th of the month is thus skipped for the years 1700, 1800, 1900, but not for 1600, 2000 etc. For any other month of February, the year is leap and at least one of the second cam 17 and the second additional cam 18 prevents the first lever 21 to rotate and the retractable teeth 11 remain in their inactive position. Therefore, the 29th of the month is not skipped and is therefore displayed. Such a configuration is illustrated in the figure 11 .

This system is also fully reversible and maintains its indexing during a correction back through the drive mobile.

However, the illustrated embodiment is not limiting, and according to the arrangement, the dimensioning and the nature of the drive means of the cams 17, 18, any other appropriate speed ratio between the latter can be envisaged and is covered by the present invention, provided that the teeth 11 of the flip-flop 9 are positioned adequately during their passage in front of the training mobile 7.The important thing is that, in February, leap years (so when the probe 21a has the possibility of falling into the notch 15c) and when the teeth 11 are close to the mobile 7, the cams 17 and 18 are correctly positioned.

In all the embodiments, it is also possible to provide a display device of any day of the week, which can be associated with the drive wheel 7.

Although the invention has been described with reference to some particular embodiments, modifications are possible without departing from the scope of the invention as defined by the claims. In particular, it should be noted that the same principle can also be applied to a Gregorian calendar, Western annual or Julian, Chinese, Hebrew or similar.

Claims (17)

1. Calendar mechanism (1) for a timepiece, said calendar mechanism (1) being adapted to indicate information having a period varying according to at least a first cycle and a second cycle, said mechanism (1) comprising:

   - a month-wheel (3) comprising a wheel (4) having a number of fixed teeth (5), said number being chosen on the basis of the maximum period of the information to be displayed, characterized in that the wheel (3) further comprises a control-lever (9) arranged to move between an inactive position and an active position and being provided with at least one retractable tooth (11),

   and in that said mechanism (1) comprises:

   - a drive-wheel (7) comprising a first driving organ (7a) arranged to engage with said fixed teeth (5) and a second driving organ (7b) angularly offset relative to the first driving organ (7a) and arranged to interact with said retractable tooth (11) when said lever (9) is in its active position;

   - a first cam (15) representing the variations of said period according to the first cycle;

   - at least one second cam (17) representing the variations of said period according to the second cycle;

   - an indexing system (19) kinematically linked to said wheel (4), with said first cam (15) and with said second cam (17) and adapted to index each of said cams (15, 17) relative to said wheel (9) in function of said cycles;

   - an actuating system (13) for said lever (9), the actuating system (13) comprising a first feeler-spindle (21a) intended to come into contact with the first cam (15) and a second feeler-spindle (23a) intended to come into contact with the second cam (17), said feeler-spindles (21a, 23a) being kinematically linked with each other and the actuating system (13) being arranged to move said lever (9) from its inactive position to its active position under the control of each of said cams (15, 17) .
2. Calendar mechanism (1) according to Claim 1, wherein said first cam (15) and said second cam (17) are each coaxial to said wheel (4) and are carried by this latter.
3. Calendar mechanism (1) according to any of Claims 1 and 2, wherein each of said cams (15, 17) is located on the same side of said wheel (4).
4. Calendar mechanism (1) according to any of Claims 1 and 2, wherein one of said cams (15, 17) is located on a first side of said wheel (4), and the other one of said cams (17, 15) is located on a second side of said wheel (4) .
5. Calendar mechanism (1) according to Claim 4, wherein the second feeler-spindle (23a) extends through an opening (4a) in said wheel (4) .
6. Calendar mechanism (1) according to any of the preceding claims, wherein the actuating system (13) comprises a first lever (21) provided with said first feeler-spindle (21a), the first lever (21) also comprising an abutment (21c) intended to come into contact with said lever (9) in order to move said lever to its active position under the control of said first cam (15).
7. Calendar mechanism (1) according to the preceding claim, wherein the second feeler-spindle (23a) is carried by the first lever (21).
8. Calendar mechanism (1) according to Claim 6, wherein the actuating system comprises a second lever (23) kinematically linked with said first lever (21), said second lever (23) carrying said second feeler-spindle (23a) .
9. Calendar mechanism (1) according to any of Claims 6 to 8, wherein the actuating system (13) comprises an additional actuating wheel (25) kinematically linked with at least said first lever (21) and arranged to move said lever (9) to its active position under the control of said second cam (17).
10. Calendar mechanism (1) according to Claim 9, wherein the additional actuating wheel (25) is pivoted relative to said wheel (4) and comprises an additional actuating cam (25a) intended to press against said lever (9) under the control of said second cam (17).
11. Calendar mechanism (1) according to any of the preceding claims, wherein said first cam (15) has a form (15, 15b) representing the number of days in a month varying according to a first cycle, and said second cam (17) has a form (17a, 17b) representing the number of days in at least one particular month that varies according to a second cycle, and wherein said first cam (15) comprises a notch (15c) representing at least one month, the number of days of which is determined according to said second cycle.
12. Calendar mechanism (1) according to Claim 11, wherein the first cycle comprises twelve months, the form of said first cam (15) representing the number of days from the first to the eleventh month varying according to the first twelve month cycle, the notch (15c) corresponding to the twelfth month, and wherein the second cycle comprises thirty years, the form of said second cam (17) representing the number of days of the twelfth month varying on the second thirty year cycle.
13. Calendar mechanism (1) according to Claim 11, wherein the first cycle comprises four years, the form of said first cam (15) representing the number of days in February varying according to the first four year cycle, the notch (15c) corresponding to the optionally leap year month of February, and wherein the second cycle comprises 400 years, the form of said at least one second cam (17) representing the number of days in February of the years divisible by four.
14. Calendar mechanism (1) according to Claim 13, further comprising a second additional cam (18) superposed on said second cam (17), the combination of the second cam (17) and of the second additional cam (18) defining a 400 year cycle.
15. Calendar mechanism (1) according to Claim 14, wherein said second feeler-spindle (23a) is arranged to feel the second cam (17) and the second additional cam (18) in parallel.
16. Calendar mechanism (1) according to any of the preceding claims, wherein said lever (9) carries at least two retractable teeth (11) having the same separation as two adjacent fixed teeth (5).
17. Calendar mechanism (1) according to any of the preceding claims, further comprising display a device for the day of the week, which is preferably associated with the drive wheel (7).

Images