EP1596261B1 - Annual calendar for a watch movement - Google Patents

Description

The present invention relates to an annual calendar mechanism for a watch movement comprising a calendar mobile with 31 teeth, a jumper engaged with its toothing, a satellite of the months, whose axis of rotation is integral with this mobile of dates and which has five teeth for driving a pitch of twelve steps for months of less than 31 days, a fixed planetary toothing, coaxial with the mobile dates, in desmodromic connection with the satellite months and a drive member the mobile dates in driving connection with the hour wheel of the watch movement and having two drive fingers, the first cutting the trajectory of the tooth of the mobile dates, the second cutting the trajectory of the toothing of the satellite months when its axis of revolution is aligned with those of the planetary toothing, the drive member and the mobile dates.

Such an annual calendar mechanism, associated with a perpetual calendar mechanism, is described in the EP 1 351 104 . This mechanism comprises a month satellite whose pivot axis is integral with a date wheel which makes a turn per month. This month satellite has twelve teeth, seven of which are truncated and five are not truncated. The twelve teeth of this satellite meshes with fixed planetary toothing of seven teeth, coaxial with the date wheel.

During the year, at each turn of the date wheel, the teeth of the satellite of the months occupy a different position when its pivot axis is aligned with the axis of the planetary toothing and the pivot axis of a wheel which take a turn in twenty-four hours to train the date wheel. For this purpose, this twenty-four hour wheel has twenty-four teeth, twenty of which are truncated and among the other four, one is a normal drive tooth that engages with the date wheel once a day and another is an annual correction tooth, shifted parallel to its axis of rotation, to engage with one of the five uncut teeth of the satellite for months whenever the month is less than thirty-one days old.

When the month is less than 31 days old, one of the five uncut teeth of the month satellite covers one of the teeth of the date wheel and is located in the trajectory of a correction tooth of the wheel which makes a turn in twenty- four hours, so that by turning, the correction tooth of this wheel, shifted parallel to its axis of rotation, rotates the satellite months, which is in engagement with the fixed planetary toothing, rotates the wheel of the days before that the normal drive finger of this twenty-four hour wheel rotates the date wheel one step, as it does with each rotation, so that the date wheel is moved two steps for a turn of the twenty-four hour wheel.

This mechanism has the advantage of avoiding cam and lever devices such as those described in FIG. CH 685 585 or in the EP 987609 , which use energy, are difficult to develop and are therefore unreliable.

Although of attractive design, this mechanism has a major disadvantage arising from the fact that the month satellite works on a first pitch circle with the fixed planetary toothing, while it works on a second pitch circle, larger than the first, with the drive teeth of the twenty-four hour wheel. This larger pitch diameter is needed to prevent the drive teeth of the 24-hour wheel from coming into contact with the truncated teeth of the satellite of the months. Therefore, the penetration between the teeth of the twenty-four hour wheel in the satellite toothing of months is low, as well as the angular value of the led. Such a mechanism is therefore not very reliable and is at least extremely difficult to develop, leading to retouches piece by piece.

A further disadvantage of this solution comes from the fact that when the axis of revolution of the satellite months is aligned with the respective axes of revolution of the planetary toothing and the wheel of twenty-four hours, the satellite is between them, in so that the training of this satellite is done on a portion of its toothing located furthest from the center of the date wheel by the twenty-four hour wheel located outside this date wheel, which reduces the at least a lead angle, the penetration and the lead angle being already reduced because the pitch diameter between this twenty-four hour wheel and the month satellite is enlarged relative to the pitch diameter between this satellite and the planetary gear. . The realization and development of such a mechanism is therefore problematic and its reliability is low.

It can therefore be concluded that, despite the existence of the solution covered by EP 1 351 104 no credible alternative to annual calendar mechanisms using cams and levers has yet been proposed.

The object of the present invention is to overcome, at least in part, the aforementioned drawbacks.

For this purpose, the present invention relates to a date mechanism according to claim 1.

The essential advantage of this invention stems from the fact that the presence of two coaxial satellites each of which fulfills a distinct function allows each of them to work. with normal toothings, each toothing working only on a single primitive circle, the respective primitive circles of the two mobiles meshing with each other being tangent. These gear conditions allow the teeth to have optimal penetrations, so the angles of operations capable of producing a reliable drive, which is not the case when working near the ends of the teeth.

The design of an annual calendar mechanism, without lever or lever, with optimal penetrations and angles of operation according to the present invention, makes any adjustment of this mechanism superfluous. This is an important factor of reliability insofar as, on the one hand, any adjustment has a margin of tolerance and, on the other hand, any adjustment is likely to be unregulated. The instantaneous jump scale, used with the preferred instantaneous change form of the calendars, does not take into account, because it does not participate in the correction of the number of days of the months of the annual calendar mechanism according to the invention, but only serves to deliver accumulated energy for the instantaneous training of the mobile dates.

Advantageously, the axis of revolution of the drive member of the mobile dates, when aligned with the respective axes of revolution of the satellites and the planetary toothing, is located between their axes of revolution.

With this feature, the led can be further improved.

Preferably, the second satellite has a diameter substantially greater than that of the satellite of the months. As a result, the training of the satellite of the months by the correction finger is carried out on a smaller pitch radius than that of the second satellite. Thanks to this particularity, the meaning of rotation of the satellites during their drive by the second drive finger is the same as that of the drive member carrying said second finger.

By this training mode that can be described as pseudo-paradoxical, we further increase the lead angle and therefore the security of the mechanism.

Preferably, the mobile month of the month bearing the satellite of the month is a ring or disc coaxial date in the center of the watch movement, thus allowing to have organs of larger dimensions with a remote mechanism. In addition, the arrangement of the satellites on the date mobile reduces the number of parts, no referral being necessary between the annual calendar mechanism and the date mobile.

The reliability of this mechanism, which uses exclusively gears, with good penetrations of their teeth and angles of operation able to ensure the smooth operation of the mobile dates, lends itself particularly well to be driven by a jump drive mechanism instantaneous. Advantageously, in this case, the date mobile has the shape of a ring.

• La figure 1 est une vue en plan de cette forme d'exécution montrant l'ensemble de ses composants;
• la figure 2 est une vue partielle et simplifiée de la figure 1, montrant la position des différents composants le 30 novembre;
• la figure 2A est une vue partielle agrandie d'une portion indiquée par un cercle A en traits mixtes, de la figure 2;
• la figure 3 est une vue semblable à la figure 2 montrant la position des composants du mécanisme le 30 novembre, après la correction du 30 au 31, mais avant le passage au 1^er décembre;
• la figure 3A est une vue partielle agrandie d'une portion indiquée par un cercle A en traits mixtes, de la figure 3;
• la figure 4 est une vue semblable aux précédentes, montrant la position des composants du mécanisme le 30 mars.

The accompanying drawings illustrate, schematically and by way of example, an embodiment of the date mechanism object of the present invention.

• Figure 1 is a plan view of this embodiment showing all of its components;
• Figure 2 is a partial and simplified view of Figure 1, showing the position of the various components on November 30;
• Fig. 2A is an enlarged partial view of a portion indicated by a phantom circle A in Fig. 2;
• Figure 3 is a view similar to Figure 2 showing the mechanism components of the position November 30, after the correction of 30 to 31, but prior to passage to ¹ December;
• FIG. 3A is an enlarged partial view of a portion indicated by a circle in phantom, of FIG. 3;
• Figure 4 is a view similar to the previous ones showing the position of the mechanism components on March 30th.

The date mechanism object of the invention comprises a mobile dates which is preferably in the form of a date ring 1 also called date disc. The inner edge of this date ring 1 comprises 31 teeth positioned by a jumper spring 2. The daily drive of this date ring is performed by a drive finger 3a integral with a drive member 3 secured to an instantaneous jump cam 4 connected to a wheel 5 by means of a pin 4a engaged with an opening in an arc of circle 5a formed in the wheel 5. This wheel 5 is driven at the rate of one turn in twenty- four hours by the hour wheel 6 of the watch movement and via a mobile 6a.

A rocker 7 is applied against the periphery of the instantaneous jump cam 4 by a spring 8 intended to rotate the cam 4 sharply in the clockwise direction as soon as it reaches the end of the winding ramp. 4b of the spring 8 to drive the drive member 3 of the date ring 1.

What has just been described corresponds to a simple instantaneous date mechanism in which the date ring 1 is driven one step every twenty-four hours, which requires a correction five times a year. at the end of the months of less than thirty-one days.

We will now describe the components that allow to go from the simple date described above to an annual calendar. For this purpose, a planetary toothing 9 is fixed to the frame of the clockwork movement, concentrically to the date ring 1. A planet gear 10 whose number of teeth is twelve or, preferably, a multiple of twelve is mounted pivoting about an axis integral with the date ring 1. This pinion gear 10 is constantly engaged with the planetary gear 9, forming with it a simple epicyclic gear that makes one turn per month. A second satellite gear of months 11 having only five teeth out of twelve is integral and coaxial with the pinion satellite 10. Preferably, the diameter of the satellite pinion months 11 is less than that of the pinion satellite 10.

Finally, the drive member 3 carries a second finger 3b offset, on the one hand angularly, forwardly relative to the direction of rotation corresponding to that of the watch hands of this drive member 3, on the other hand parallel to its axis of rotation. This second finger 3b of the drive member 3 constitutes a correction finger intended to drive the date ring 1 by one additional step at the end of each month of less than 31 days.

The principle on which the correction mechanism operates is to bring the 30 of each month less than 31 days one of the five teeth of the satellite gear 11 months substantially in alignment with the line joining the respective axes of revolution of the sun gear 9, the drive member 3 of the mobile of dates 1 and satellites 10, 11, as illustrated in FIG. 2.

As soon as the rocker 7 arrives beyond the end of the winding curve 4b of the instantaneous jump cam 4, it suddenly rotates this cam 4 and the driving member 3 which is secured to it in the direction needles from the shows. This sudden rotation of the cam 4 is made possible by the arcuate opening 5a in which the pin 4a of the cam 4 is engaged. During this movement, the correction finger 3b which is in contact with one of the five teeth of the satellite gear 11 is driven. Given, on the one hand, that this satellite 11 is integral with the larger diameter satellite 10 which is in engagement with the sun gear 9 and, on the other hand, that the drive member 3 is situated between the axis of revolution of the sun gear 9 and the axis of revolution of the satellites 10, 11, the displacement of the satellite 11 by the correction finger 3b results in a rotation of this satellite 11 in the direction of the hands of the watch, that is to say say in the same direction as the drive member 3. This gear that can be described as pseudo-paradoxal increases the contact angle between the correction finger 3b and the pinion 11, improving safety displacement and ensuring that the date ring 1 will not be brought back by the jumper 2, but on the contrary, that it will complete the drive of the date ring by moving it in the direction of the needles of the shows.

At the end of this first training phase, the components of the date mechanism are in the position illustrated in FIG. 3, that is to say that the date ring 1 has been advanced by one step at 31. During the second phase, it is the normal training finger 3a that takes over and moves the disc as it does every twenty-four hours, to bring the "1" of the following month into the wicket 13 whose position is indicated in phantom.

It is obvious that the two phases of training of the ring of the dates which have just been described succeed one another without interruption, in the same angular displacement. instantaneous jump cam 4, the total training time being only a few hundredths of a second, so it is not noticeable to the naked eye.

In order for the five teeth of the planet gear 11 to be arranged in the correct position at the end of each month as a function of the number of days of the month, it is obviously necessary that the number of revolutions of the satellite per revolution of the date ring be a non-integer number. However this condition is not enough.

The first condition to fulfill is obviously that the satellite 10 which represents the months, has a number of teeth corresponding to twelve or a multiple of twelve. With regard to the satellite of the five-toothed months distributed over a twelve-step pinion, its five teeth must be either arranged on five consecutive steps or chronologically distributed, as are the months of less than thirty-one days and the months thirty-one days or in reverse chronology.

avec i = 1,2,3,..., et z_l = 5It has been possible to establish, empirically, a formula for calculating the number of teeth of the sun gear 9 capable of bringing one of the five teeth of the satellite gear in alignment with the respective axes of revolution of the satellites 10, 11, 11 3 drive member of the mobile dates 1 and the sun gear 9, the 30 of each month less than thirty-one days. This condition is satisfied for all numbers or multiples thereof obtained by the following formula: $$z_{i+1}=z_i+3+{\left(-1\right)}^i,\mathrm{with}i=1,2,3,...,\mathrm{and}{\mathrm{<figure-callout\; id="1"\; label="z"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">z</figure-callout>}}_1=5$$

with i = 1,2,3, ..., and z _l = 5

In order to guarantee the most precise angular positioning possible of the satellite of months 11 with respect to the correction finger 3b, the respective numbers of teeth of the satellite 10 and the sun gear 9 are chosen as large as possible, which reduces the angular clearance of the planet pinion 10 and therefore that of the satellite pinion months to five teeth 11. In the example described, the sun gear has 123 teeth while the pinion gear 10 has 36.

According to the number of teeth of the sun gear 9, chosen by the above formula, the five teeth of the satellite gear 11 months will have to be distributed, not grouped as in the example shown, but separated by gaps equal to one or two not, according as the month of less than thirty-one days is followed by one or two months of thirty-one days, as is the case of June and November. In this case, the number of revolutions of the satellites 10, 11 per revolution of the mobile of the dates 1 will be equal, either to a number of whole revolutions more 1/12 ^th of a turn, or to a whole number of revolutions plus 11/12 ^th turn, according to which the five teeth of the satellite gear follow one another chronologically as the months in the year or as the inverse of the months in the year.

Figure 4 illustrates the angular position of the five teeth of the satellite gear 11 months at the end of a month of 31 days, here the month of March. It can be seen that none of the five teeth of the planet gear 11 is in the trajectory of the correction finger 3b. Therefore, when the instantaneous jump rocker 7 will turn the fingers 3a and 3b through the cam 4, the finger 3b will not encounter a tooth of the planet pinion 11 and only the finger 3a will cause a step date ring 1, bringing the "31" into the window 13.

Claims (5)

1. An annual date mechanism for a timepiece movement comprising a 31-toothed date runner (1), a jumper (2) in mesh with its toothset, a months satellite (11), the rotation pin of which is secured to this date runner (1) and which comprises five driving teeth of a toothset on a pitch designed for twelve for the months comprising less than 31 days, a fixed planetary toothset (9) coaxial with the date runner (1) and in a direct-drive relationship with the months satellite (11) and a drive member (3) for driving the date runner (1) in a driving relationship with the hours wheel of the timepiece movement and comprising two drive fingers (3a, 3b), the first intersecting the path of the toothset of the date runner (1), the second intersecting the path of the toothset of the months satellite (11) when its axis of revolution is aligned with those of the planetary toothset (9), of the drive member (3) and of the date runner (1), characterized in that the months satellite (11) is connected to the planetary toothset (9) by a second satellite (10) which is secured to it and coaxial and the number of teeth of which is equal to a multiple of twelve, and the toothset of each of said satellites is a standard toothset which works on a single pitch circle tangential to the pitch circle of the toothset with which it is in mesh, the number of teeth z_i of the planetary toothset (9) being chosen from numbers or multiples of numbers obtained according to the formula: $${\mathrm{Z}}_{\mathrm{i}\mathrm{+}\mathrm{1}}\mathrm{=}{\mathrm{z}}_{\mathrm{i}}\mathrm{+}\mathrm{3}\mathrm{+}{\left(\mathrm{-}\mathrm{1}\right)}^{\mathrm{i}}\mathrm{,}$$

   

   with i = 1, 2, 3, ..., and z₁ = 5
   so that each revolution of the date runner (1) corresponds to a non-integer number of revolutions of the satellites such that one of the five teeth of the months satellite (11) is more or less aligned with the axes of the satellites (10, 11), of the planetary toothset (9) and of the drive member (3) driving the date runner (1) on the 30th of each month comprising less than 31 days so as to allow said second finger (3b) to drive the date runner (1) by an additional step via said satellites (10,11).
2. The date mechanism as claimed in claim 1, in which the axis of revolution of the drive member (3) driving the date runner (1), when aligned with the respective axes of revolution of the satellites (10,11) and of the planetary toothset (9), lies between their axes of revolution.
3. The date mechanism as claimed in one of the preceding claims, in which the second satellite (10) has a diameter appreciably larger than that of the months satellite (11) so that the direction of rotation of satellites (10,11) when they are being driven by the second drive finger (3b) is the same as that of the drive member (3) bearing said second finger (3b).
4. The date mechanism as claimed in one of the preceding claims, in which the date runner (1) is an annulus with an internal toothset.
5. The date mechanism as claimed in one of the preceding claims, in which said drive member (3) is connected to the hours wheel of the timepiece movement by an instantaneous-drive device (4, 7, 8).

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