EP1351105A1 - Timepiece with perpetual calender display - Google Patents

Abstract

The display (43) consists of an indicator (46) which sweeps over concentric disks. An outer disk (47) shows days of the week for four weeks and two disks (51,52) show the day of the month for first and second parts of the month. The month is displayed on an inner disk (56). The first and second day of the month disks are successively displaced by amounts to allow for the month length and then restore correct order

Description

The present invention relates to a timepiece equipped with a movement and a calendar display comprising: a dial with a fixed graduation in days of whole weeks that stretches all the way around the dial, indicator means of calendars, driven in rotation by steps and having at least one date scale in correspondence with the graduation of days, and a mobile calendar index rotated by the movement of horology with regard to the graduations of the days and the calendars.

Patent Application EP 285 881 describes an electronic wristwatch to perpetual calendar of this kind, in which central hour hands, minutes and seconds are driven by a first engine to indicate the hour, a fourth central hand is driven from this engine at the rate of 1/35 turn per day to indicate the date, while another off-center hand is driven by a second engine to indicate the month. The date is indicated by the fourth needle on two concentric graduations, namely a fixed graduation days which is divided into thirty-five equal sectors bearing the names of the days of five consecutive weeks, and a date graduation carried by a record pivoting and also divided into thirty-five equal sectors of which thirty-one fields consecutive days are from 1 to 31, the other four sectors being virgins. At the end of each month, the date disc is moved by a third engine to place the next month's calendars in correspondence of the graduation of the days. Thus, the user can see at any time the complete calendar of the current month, while the fourth hand indicates the date and the day on the graduations matched. However a disadvantage of this mode of the date is that, until the evening of the last day of the month, the user does not can not see the schedule of the beginning of the next month. On the other hand, in a watch having a mechanical watch movement, designing a mechanism resulting in such a display of the date would be very difficult.

In the French patent no. 793 442, it was proposed a mechanical calendar in which the seven quantièmes of a whole week are visible in a window beside which are inscribed the names of the days of the week. The mechanism has two concentric date discs each having a semicircular sector which carries the dates of a first part or a second part of the months, the ends of these sectors overlapping over one, two or three days, alternatively to place the date 1 of the next month following the last date of the previous month, then to restore the continuous continuation of the calendars around the middle of the month. The rotation of the two discs of the dates is operated once a week by manual control or movement watchmaking. The relative movements of one of these disks relative to the other are determined by a cam mechanism carried by one of the disks and representing the different lengths of the months.

This mechanical calendar has the disadvantage of not indicating the current date because it can not be combined with a rotary indicator such as a needle driven by a clockwork movement. The observer must therefore know a priori which is the day of the week to be able to read the date or vice versa. In addition, he can only read the calendar for one week at a time. Another disadvantage is only when the week extends to the end of a month and the beginning of the following month, the observer does not know if the name of the month displayed in the window provided for this purpose corresponds to the beginning or the end of the week.

A primary object of the present invention is to overcome the disadvantages mentioned above thanks to a date display mode allowing a global vision of the calendar not only on the current week but also on one or more weeks to come, regardless of the number of days in the current month. Preferably, the calendar will be of the perpetual type, that is, taking into account leap years.

An additional object of the invention is to allow the indication of the date means of a single moving index indicating not only the day and the date, but also the month and possibly the year.

Another object of the invention is to design a calendar mechanism capable of causing such a calendar display from the watch movement.

en ce que les moyens indicateurs de quantièmes comportent deux disques de quantièmes concentriques susceptibles d'être décalés angulairement l'un par rapport à l'autre, à savoir un premier disque dont la graduation comporte les quantièmes d'une première partie d'un mois et un second disque dont la graduation comporte les autres quantièmes jusqu'à 31, correspondant à une seconde partie d'un mois,

en ce que le premier disque de quantièmes est déplacé de N pas dans la seconde partie d'un mois, N étant égal au nombre de jours dudit mois moins le nombre de jours de la graduation des jours, de sorte que le dernier quantième dudit mois sur la graduation du second disque est suivi du premier quantième du mois suivant sur la graduation du premier disque,

et en ce que le second disque de quantièmes est déplacé du même nombre N de pas dans la première partie du mois suivant, ce qui rétablit la suite continue des quantièmes sur l'ensemble formé par les deux graduations de quantièmes.

For this purpose, there is provided a timepiece of the type indicated above in the preamble, characterized:

in that the date indicator means comprise two concentric date discs that can be angularly offset with respect to one another, namely a first disc whose graduation includes the dates of a first part of a month and a second disk whose graduation includes the other calendars up to 31, corresponding to a second part of a month,

in that the first date disc is moved N not in the second part of a month, N being equal to the number of days of the said month minus the number of days of the graduation of the days, so that the last day of said month on the graduation of the second disc is followed by the first calendar of the following month on the graduation of the first disc,

and in that the second date disk is moved by the same number N of steps in the first part of the following month, which restores the continuous sequence of dates on the set formed by the two date scales.

Thus, the calendar display presents a correspondence at any time between days and days over a period of several weeks that includes the current week and one or more weeks thereafter, which helps the user to choose dates in this period, for example to set appointments. In the first part of the month, this period extends over the entire month in progress. In the second part of the month, which can start at any date chosen by the manufacturer, preferably between the 15th and the 20th, the first date disc is moved while the second disc remains immobile, so that the date 1 of the next month takes place just after the last day of the current month. Through Consequently, the correspondence between the dates and the days is established only for the end of the current month, but also for the first part of the month following.

Of course, the mobile calendar index is driven to advance a day in 24 hours next to the fixed graduation of days. It indicates at the same time day and date on the respective graduations matched one the other.

In a first particular embodiment, the graduation of the days 28 days on the dial, so that N is always positive and the of the date discs are made in the increasing direction of the graduations of days and dates. So the calendar display presents in any time a correspondence between the dates and days over a period of four weeks. The mobile calendar index is driven in this case so as to take a turn in 28 days against the fixed graduation of days.

In a second particular embodiment, the graduation of the days has 35 days around the dial, so that N is always negative and the of the date discs are carried out in the decreasing direction of the graduations of days and dates. So the calendar display presents in any time a correspondence between the dates and days over a period of more than four weeks. The mobile calendar index is driven in this case of way to take a turn in 35 days against the fixed graduation of days.

In the two aforementioned embodiments of the invention, the display calendar can be completed to advantage by a record of months, divided into twelve sectors each bearing the name of a month and arranged concentrically to date discs, next to the calendar mobile index, this disc of the months being driven so as to perform a relative rotation relative to the moving index of a turn in a year. This relative rotation is preferably carried out in the opposite to that of the rotation of the index, so that the ascending order of the months is arranged in the same direction as the increasing order of days and dates.

The perpetual type calendar display may further include a disk years, preferably divided into four sectors corresponding to the four years of a cycle of leap years, this disk being driven in relative rotation continues against the calendar index so as to perform a turn in four years relative to this index.

• la figure 1 représente un premier mode de réalisation des organes d'affichage d'une montre à calendrier perpétuel selon l'invention, comprenant un affichage classique de l'heure et un affichage de calendrier, à la date du 31 janvier 2001,
• la figure 2 représente l'affichage de calendrier à la date du 5 février 2001,
• la figure 3 représente l'affichage de calendrier à la date du 19 février 2001,
• la figure 4 représente l'affichage de calendrier à la date du 5 mars 2001,
• la figure 5 représente l'affichage de calendrier à la date du 19 avril 2001,
• la figure 6 représente l'affichage de calendrier à la date du 5 mai 2001,
• la figure 7 représente l'affichage de calendrier à la date du 19 février 2004,
• la figure 8 représente l'affichage de calendrier à la date du 5 mars 2004,
• la figure 9 représente un deuxième mode de réalisation de l'affichage de calendrier, à la même date que dans la figure 5,
• la figure 10 représente l'affichage de calendrier de la figure 9 à la même date que dans la figure 6,
• la figure 11 représente un troisième mode de réalisation de l'affichage de calendrier, à la même date que dans la figure 3,
• la figure 12 représente schématiquement un mode de réalisation d'un mécanisme de calendrier perpétuel pour commander l'affichage de calendrier selon la figure 11,
• la figure 13 est un schéma en coupe du mécanisme de la figure 12,
• la figure 14 est une vue agrandie d'une roue de programme du mécanisme de la figure 12, dans une position correspondant au mois d'avril d'une année normale,
• la figure 15 est une vue en coupe suivant la ligne XV-XV de la figure 14,
• la figure 16 représente la roue de programme de la figure 14 dans une position correspondant à la fin de février d'une année bissextile,
• la figure 17 représente schématiquement un mode de réalisation d'un mécanisme de calendrier perpétuel pour commander l'affichage de calendrier selon les figures 1 à 8, et
• la figure 18 est un schéma en coupe du mécanisme de la figure 17.

Other features and advantages of the present invention will appear in the following description of various embodiments, presented by way of non-limiting example with reference to the accompanying drawings, in which:

• FIG. 1 represents a first embodiment of the display devices of a perpetual calendar watch according to the invention, comprising a conventional display of the time and a calendar display, as of January 31, 2001,
• Figure 2 shows the calendar display as of February 5, 2001,
• Figure 3 shows the calendar display as of February 19, 2001,
• Figure 4 shows the calendar display as of March 5, 2001,
• Figure 5 shows the calendar display as of April 19, 2001,
• Figure 6 shows the calendar display as of May 5, 2001,
• Figure 7 shows the calendar display as of February 19, 2004,
• Figure 8 shows the calendar display as of March 5, 2004,
• FIG. 9 represents a second embodiment of the calendar display, on the same date as in FIG. 5,
• FIG. 10 represents the calendar display of FIG. 9 at the same date as in FIG. 6,
• FIG. 11 represents a third embodiment of the calendar display, on the same date as in FIG. 3,
• FIG. 12 schematically represents an embodiment of a perpetual calendar mechanism for controlling the calendar display according to FIG. 11,
• FIG. 13 is a sectional diagram of the mechanism of FIG. 12,
• FIG. 14 is an enlarged view of a program wheel of the mechanism of FIG. 12, in a position corresponding to the month of April of a normal year,
• FIG. 15 is a sectional view along the line XV-XV of FIG. 14,
• FIG. 16 represents the program wheel of FIG. 14 in a position corresponding to the end of February of a leap year,
• Fig. 17 schematically shows an embodiment of a perpetual calendar mechanism for controlling the calendar display according to Figs. 1-8, and
• Figure 18 is a sectional diagram of the mechanism of Figure 17.

With reference to FIG. 1, the display members of the watch comprise conventional analog time indication bodies, including a hand hours 41 and a minute hand 42 which turn in front of a dial 43 carrying for example twelve fixed hour markers 44. The needles 41 and 42 are driven conventionally by a clockwork movement to turn around the axis central 45 of the watch. Of course, one could still add a needle of seconds in the center.

A calendar index 46 is driven by the watch movement of the shows in order to perform a complete turn around the axis 45 in 28 days, from preferably clockwise, next to a graduation of days 47 which is fixed on the dial 43. The graduation 47, which extends all round the dial, is divided in twenty-eight equal sectors bearing the names of the four-week days consecutive. The index 46 is carried by an annular disc 48 which can be driven either continuously, or in steps of 1/28 turn to place the index 46 always in front from the middle of a sector of the fixed graduation 47. One could also provide a needle to fulfill the function of index 46, as will be discussed below third embodiment.

The calendars 1 to 31 are distributed on respective sectors of two date discs 51 and 52, next to the graduation of days 47. Each sector carrying a date extends over 1/28 turn, so that it can be placed in exact match of a sector of the day graduation 47. The first record of date 51 carries a graduation 53 having the dates of a first part of the month, for example in the present case the dates from 1 to 15 out of consecutive sectors. The second date disk 52 has a scale 54 date of the second part of the month, that is to say in the case present from 16 to 31 out of sixteen consecutive sectors. The second disc 52 is behind the first disk 51 and it has a larger diameter so its graduation 54, arranged on a circular arc of greater radius than the graduation 53, is still visible along the periphery of the first disk 51 and that three sectors respective ends of the two graduations 53 and 54 can be juxtaposed, as seen in Figure 1 for the dates 13 to 18.

We naturally notice that the index 46 being in front of one of the areas of graduation 47, bearing the name of this present day, indicates at the same time the date being in correspondence of this sector. If the index was in an area where the two graduations 53 and 54 overlap (circumstance which does not produced in the examples described here), the observer should by convention read the nearest date of the index, that is to say on the first graduation 53.

Inside the disk 48 carrying the index 46, the perpetual calendar display has an annular disc of months 56, bearing a graduation of the months 57 composed of twelve sectors whose respective angles are proportional to the length of the months they represent. The disc 56 is driven by the movement in order to follow the disk 48 and its index 46, but with a rotation relative retrograde to delay one turn per year. Inside the disc 56 is finds a 58 year-old annular disc carrying a graduation 59 consisting of four equal sectors, corresponding to the four-year Julian cycle of which the the last is leap and indicated by the Roman numeral IV. As a result, the disc years 58 is driven by the watch movement to follow the record 48 carrying the index finger 46, but with relative retrograde rotation to delay a lap in four years compared to the disk 48. Thus, the index 46 indicates in an analog way the current month on graduation 57 and the number of the year in the quadrennial cycle on graduation 59, besides the day of the week and the date.

The relative rotations of the disks 56 and 58 with respect to the disk 48 of the index are retrograde because their graduations are increasing clockwise, which is that of the rotation of the index. Otherwise, if these relative rotations were same meaning as the rotation of the disc 48, said graduations should be increasing in the opposite direction to that of the rotation of the disk 48. The result would be other ratios between the rotational speeds of these disks.

In Figure 1, the date displayed is Wednesday, January 31, 2001, which is the first year of a quadrennial cycle. We can read the correspondence between dates and days of the week throughout the period from 16 January to 15 February this year, that is to say on the second half of January and the first part of February. The limits of this period are highlighted by the recovery of two date scales between the 13th and the 18th.

At a predetermined date during the first part of the following month, namely in February, the second date disc 52 is advanced once in three steps 1/28 turn (N = 3) in the increasing direction of its graduation 53, that is to say here in clockwise, to the position shown in FIG. 2. Its date 16 is then finds after the date of 15 of the first disc 51. Thus, the display shows the correspondence between the days and the calendars over the whole month now underway (February). The user notices this because both Date graduations follow one another correctly in the middle of the month. In this example, said predetermined date is the 5th of each month, but the manufacturer may choose another date if he deems it appropriate.

Note also in Figure 2 that the disc of the months 56 followed the rotation of the index finger 46, but with a small retrograde shift, making the index now finds in front of the beginning of the sector "FEV" of the graduation of the months. Of same, the record of the 58s followed the rotation of the index 46, but with a small retrograde shift making the index now a bit further down the sector "I" of graduation years.

At a predetermined date during the second half of the current month (February), the first date disc 51 is advanced from zero steps, that is to say does not move not, because for February of a normal year N = 28 days - 28 = 0. Figure 3 for example, the status of the calendar view on February 19, 2001. The date of 19 is chosen here for moving the first disc because this is the first which avoids the presence of the index 46 in front of the overlap zone of the two date scales, for example in their position represented in figure 1.

At a predetermined date during the first part of the following month, namely on March 5, 2001, the second date disc 52 is advanced by the same number of not N = 0 than in the previous operation, that is to say that it does not move and that the state of the display at this date is shown in Figure 4.

On March 19, the first date disc 51 is advanced N = 31 - 28 = 3 steps to bring its date 1 after the 31st of March. This state is not represented. The correspondence between days and dates is then established for the second part of March and the first part of April.

On April 5th, the second date disc 52 is advanced by the same number of not N = 3 than in the previous operation, in order to put his date 16 back to the following the date of the fifteenth of the first disc 51 and thus display the correspondence between days and calendars throughout the month of April. This state is not represented.

On April 19, the first date disc 51 is advanced N = 30 - 28 = 2 steps to bring its date 1 after the April 30th date, in the position shown in Figure 5. The correspondence between days and dates are then established for the second part of April and the first part of May.

On May 5th, the second date disc 52 is advanced by the same number of not N = 2 than in the previous operation, in order to put his date 16 back to the following the date of the fifteenth of the first disc 51 and thus display the correspondence between days and calendars throughout the month of May. This state is represented in figure 6. The same pair of operations is carried out during successive months, with the values appropriate from N.

Figures 7 and 8 show the transition from February to March in a year leap. As of February 19, 2004 corresponding to Figure 7, the first disk of dates 51 was advanced of N = 29 - 28 = 1 step to bring its date 1 following the last 29th of February. The correspondence between days and calendars is then established for the second part of February and the first part of March.

As of March 5, 2004 corresponding to Figure 8, the second disk of dates 52 was advanced by the same number of steps N = 1 as in the operation previous year, in order to put back its date 16 following the 15 th of the first disk 51 and thus display the correspondence between days and calendars on the whole of March.

In a variant not shown, the part of the first disk 51 which is not not covered by graduation 53 could be removed and the part bearing this graduation could cover the edge of the second disk 52, so that both graduations 53 and 54 could be arranged on radius arcs equal and that the ends of the first graduation 53 could be superimposed on those of the second graduation 54 instead of being juxtaposed. This would have the advantage to reduce the radial clutter of the display, but would prevent reading the calendar over a period of more than 28 days.

Figures 9 and 10 show a second embodiment that avoids this last disadvantage. We will describe here only what differs from the first mode of production. Of course, the watch also includes the time display members 41 at 44 shown in Figure 1, but these are omitted in Figures 9 and 10 for clarify the drawing. The fixed graduation 47 days is divided in this case into thirty-five sectors and therefore covers five weeks. Calendar index 46 is driven in the increasing direction of the graduation 47, in this case clockwise, so as to take a ride in 35 days. On the first date disc 51, the area board carrying the graduation 53 covers the second date disc 52 and she is indented on the rest of the circumference to show the graduation 54 of the second disc, except that it will hide dates 29, 30 and / or 31 at the end months of less than thirty-one days thanks to the relative movements of the discs 51 and 52.

Figure 9 shows the status of the calendar display on Thursday, April 19, 2001, therefore the same date as in Figure 5. Previously the position of the first disc 51 was such that his date 15 was next to the date 16, the two ticks 53 and 54 are thus connected to display the complete calendar of the February. To reach the position of FIG. 9, the first disc 51 retreated of N = 5 steps relative to the fixed graduation 47 and the second disc 52, so in the anti-clockwise, to place its date 1 now representing May 1 to following the 30th date representing 30 April, the sector of the date 1 the display of 31. The display thus shows the correspondence between days and dates for the second part of April and the first part of May. In this mode of realization, the absolute value of the number N is equal to 35 minus the number of days of the current month.

In the first part of the following month, here on May 5, 2001, the display of calendar is put in the position shown in Figure 10 by a decline of the same number of five steps of the second disc 52 in order to bring the date 16 back to 15 and then show the correspondence between days and calendars throughout the month from May. We also see in this figure that in the second part of May, the first disc 51 will have to go back four steps to place its date 1 after 31, the June 1, 2001 being a Friday.

Note also that the fixed graduation of days 47 could be arranged to the outside compared to the date gradations 53 and 54, without the readability of the display is affected.

While the two embodiments described above are based on a graduation of days covering respectively four weeks and five weeks on the circumference of the dial, we can predict a number of different weeks and generalize the concept of the display by both date discs 51 and 52 moved alternately by N steps, defining an algebraic value (positive or negative) of N by the following formula: N = M - 7 · S where S is the number of weeks of the graduation of the days and M is the number of days of the month concerned. A positive value of N characterizes a rotation of the disc in the increasing direction of the graduations of the days and the calendars. For example, in the second embodiment described above, S is 5 and the formula becomes N = M-35, so that N is always negative and therefore the disks must move backward relative to the graduation of the days.

It should be noted, however, that a value of S less than 4 makes it difficult to month, because of the magnitude of the recoveries of their two graduations, and that a value of S greater than 5 requires very small and has no advantage. This is why the embodiments where S worth 4 or 5 are preferable.

Figures 11 to 13 illustrate a third embodiment, which is close of the first and whose differences will be described essentially in relation to the latter.

A first difference is that the index 46 and the disk 48 carrying it in the first embodiment are replaced by a central hand which constitutes the calendar index 46. It also makes a turn in 28 days in the increasing direction of the graduation of the days 47. To be well distinguished from the hands of the hours 41 and minutes 42, the hand of the calendar index 46 may have for example a particular color.

A second difference is that the fixed graduation of days 47 is arranged around the annular date disks 51 and 52, that is to say directly on the watch face. This avoids interposing a fixed element between the different disks of the calendar mechanism.

Finally, a third difference lies in the display of years. In this embodiment, the annular disk of the 58 years makes a turn in ten years compared to the index 46, its graduation 59 bearing the numbers from 0 to 9. In addition, a central disc of the decades 60 is concentrically arranged at the center of the calendar display and carries a decades index 61 next to the graduation of the years 59. The disc of decades is driven to perform a turn in a hundred years compared to the record of the 58's. As a result, his index 61 indicates on the graduation 59 the digit of the tens of the current year. This can be reminded to the user by means of an inscription such as "x 10" on the index of decades 61.

The calendar display devices of the examples described above may be actuated by any appropriate means, at times determined by the mechanical, electromechanical or electronic movement of a timepiece whatever, be it a watch or a clock. They can be powered by one or more electric motors dedicated to them.

Figures 12 and 13 show a calendar mechanism capable to operate the display shown in Figure 11 from the watch movement of the analog watch, more precisely from a central wheel of the hours 99 which is integral with the hour hand 42 and which obviously makes a turn in twelve hours. In Figure 13, the numbers written in italics represent the numbers of mobile teeth that will be described below.

The hour wheel 99 meshes with a wheel 101 having a pinion 102 which meshes with a wheel 103 having a pinion 104, which meshes with a wheel 105 integral with two other wheels 106 and 107. The wheel 105 s meshes with a wheel 108 fixed on a barrel 109 which surrounds the axes of the needles 41, 42 and which carries the calendar index needle 46. With the numbers of teeth indicated in FIG. 13, it is verified that the ratio of transmission between the hour wheel 99 and the index 46 is: R i = 15 · 8 · 18 · 29 · 45 · 64 · 29 · 42 · = 1 56

As the 99 hour wheel rotates twice a day, the index 46 accomplishes a turn clockwise in exactly 28 days.

The wheel 107 meshes with a central wheel 110 secured to the disk of the years 58. In order to follow the index 46 by delaying with respect to it a lap in ten average years of the Julian cycle, the disk 58 is driven by the wheel 99 with the following transmission ratio: R at = 15 · 8 · 18 · 37 45 · 64 · 29 · 54 = 37 2088 = 1 56.432432

As a result, the year 58 disc rotates clockwise a little more slowly than the index 46, with respect to which it undergoes the following shift (expressed in number of revolutions) during an average year of the Julian cycle:

The wheel 106 meshes with a wheel 111 secured to the disc of the 60s. This wheel is driven by the wheel of the hours 99 with the following report: R d = 15 · 8 · 18 · 24 45 · 64 · 29 · 35 = 1 56.388889

Thus, we note that the record of the decades turns clockwise less quickly than the index 46, but slightly faster than the record of the 58 years. In an average year, it undergoes the following shift with respect to the disk 58:

In this way, the index of decades 61 takes a hundred years to go through the entire graduation of the 59s and indicates well the decade on this graduation.

On the barrel 109 is fixed a driving wheel 112 which meshes with a wheel 113 secured to a wheel 114, which meshes with a central wheel 115 secured to the disc of the month 56. This disc is driven by the barrel 109 of index 46 clockwise such that its offset from index 46 in an average year is:

On the other hand, the driving wheel 112 drives the date discs 51 and 52 through a perpetual calendar mechanism 120 shown in the right part of Figures 12 and 13. The wheel 112 meshes with a wheel 121 secured to a wheel 122 which meshes with a wheel 123, itself secured to a wheel 124 to a tooth 125. The wheels 123 and 124 are driven by the barrel 109 at the rate of 12 turns clockwise by average year, which is apparent from the following formula in which R _i is given by formula (1): 2 · R i · 67 · 12 46 · 19 · 365.25 ≅ 12 t / year

Two program wheels 126 and 127 are arranged on either side of the wheel 124, so that the single tooth 125 of the latter drives alternately both program wheels counterclockwise, each once a month with a gap of half a month between one and the other. It will be noted that this offset can be changed by slightly moving the wheel to a tooth in relation to the pair of program wheels. Each program wheel 126 and 127, whose structure will be described later, takes a complete turn by calendar year, regardless of the number of days this year.

The first program wheel 126 drives step by step a pinion 130 secured to a wheel 131 which meshes with an internal toothing 132 of the first date disk 51. The second program wheel 127 drives step by step a pinion 134 integral with a wheel 135 which meshes with an internal toothing 136 of second date disk 52. In FIG. 13, the second program wheel 127 is omitted to clarify the drawing.

Table I shows more precisely the numbers of revolutions made by the main rotary mobiles of the calendar mechanism represented in FIG. 13, in an average year of the Julian cycle. Reference number Designation Number of laps in 365.25 days 99 Hour wheel 730.5 46 Calendar Index 13.04464 56 Disc of the months 12.04467 58 Record of the years 12.94468 60 Record of decades 12.95468 124 One-tooth wheel 11.99988

The value indicated in the last line of Table I has a relative error of -10 ^-6 compared to the ideal value of 12, so that the moment when the one-tooth wheel 124 controls the advance of a date disc will be around 5 minutes a year, which is better than the accuracy of a good mechanical watch.

Note that if the calendar mechanism were to be driven not by the watch movement, but by a clean electric motor, the wheels 101 to 104 could be removed and the motor could be controlled by motion timepiece to drive once a day the mobile formed wheels 105 to 107.

Figures 14 and 16 show the program wheel 126 in two situations which correspond to the month of April of a normal year (to reach the state of the display according to Figure 5) and at the end of February of a year leap (display state according to Figure 7).

The program wheel 126 is a composite mobile which rotates on a fixed axis 139 provided with a fixed wheel 140 with six teeth. It includes a first board 141 provided with an input toothing with twenty-four teeth 142 regularly spaced, a second board 143 provided with an output toothing 144 which will be described later, two eight-tooth planet wheels 145 and 146 meshing with the fixed wheel 140, and a sliding mobile element 147 provided with a single tooth 148 preceded by a hollow 149 itself preceded by a shoulder 150 in an arc. The elements 140, 145, 146 and 147, which are drawn in bolder lines to facilitate the reading of the drawing, are housed between the boards 141 and 143, in a recess 152 of the second Plate 143. The side wall of this recess has two shoulders 153 and 154 forming stops that define the two functional positions of the element 147. The planet wheels 145 and 146 are rotatable around tenons respective 155 and 156 secured to the second board 143. With the fixed wheel 140, they constitute a control mechanism of the sliding element 147, as will describe it further.

The output gear 144 of the program wheel is a thirty-six toothing. modules but has only twenty-four teeth 158 and twenty-nine troughs 159 adjacent to these teeth, the teeth and the depressions being arranged in groups which are separated by five gaps corresponding to months of less than 31 days. These gaps are occupied by respective shoulders 160 to 164 in an arc of a circle, corresponding respectively to the months of February, April, June, September and November. Shoulders 161 to 164 correspond to the removal of two teeth and a hollow between them, for the months of 30 days, while the shoulder 160 corresponds to the removal of three teeth and two gaps between them, for a month from February to 29 days. In the position shown in Figure 14, the shoulder 150 of the sliding element 147 extends the shoulder 160 of a module, so that these two shoulders combined correspond to the removal of four teeth and three between them for a normal February month of 28 days.

The height of the shoulders 150 and 160 to 164, i.e. their radius per report to the center 151 of the program wheel, is enough for two teeth successive sprocket 130 can slide while leaning against the shoulder, thus blocking the position of the pinion 130, the wheel 131 (FIG. 12) and the disc of dates 51 associated with the latter. Thus, the successive positions of the disc of dates are indexed by the output teeth of the program wheel, without need a jumper spring. Indexing of this kind and its benefits are described in Swiss patent no. 688 671 of the same applicant.

It will be understood that the passage of each shoulder 160 to 164 in front of the pinion 130 rotates it one step, so finally has the same effect as the passage of one of the teeth 158.

Each turn of the wheel 124 to a tooth 125 produces at a two-step advance of the input gear 142 of the program wheel, that is to say one twelfth of tower. Between these operations in advance, the program wheel is stopped by the periphery circular 176 of the wheel 124, which is supported by sliding against the head of the teeth 142. The program wheel, trained twelve times a year, takes a complete turn by year. In Figures 14 and 16, the circumference of the program wheel is subdivided into twelve sectors equal to 30 degrees, numbered by Roman numerals I to XII and corresponding to the twelve months of the year. The number of depressions 159 associated with each month determines the number of steps of the advance made this month by the pinion 130, the wheel 131 and the date disc 51. This number is 0, 1, 2 or 3 depending on whether the month corresponding to twenty-eight, twenty-nine, thirty or thirty-one days, as explained above.

The sliding element 147 and its control mechanism are intended for change the number of steps in the advance corresponding to the month of February, depending on whether month to twenty-eight or twenty-nine days. In the position shown in Figure 14, which corresponds to a month of February of 28 days, the element 147 is in position of withdrawal and its additional tooth 148 is superimposed on a tooth 158a of the second Plate 143. The thickness of tooth 158a corresponds to the lower half of the thickness of the other teeth 158 of the toothing 144. The two teeth 148 and 158a having exactly the same shape, the additional tooth 148 is somehow retracted and has no particular effect. The hollow 149 which precedes it is in front of a hollow wider 166 of the board 143, which is otherwise covered by the shoulder 150 of the element 147. Thus, the pinion 130 will remain blocked by sliding on the shoulders 160 and 150 throughout the twelfth of a turn corresponding to the month of February of a normal year, and no step in advance of the date disc will be made, as described with reference to FIG.

In the leap position shown in Figure 16, which corresponds to one month February of 29 days, the sliding element 147 is moved temporarily to the left compared to the previous figure, so that its additional tooth 148 is moved one module relative to the teeth 144, while the adjacent hollow 149 of the sliding element is always in front of the wider hollow 166 of the 144. The shoulder 150 of the element 147 is then superimposed on the shoulder 160 of the plate 143. The tooth 148 and the hollow 149 thus determine the unique pitch of the advance of the first date disc at the end of February of a year leap, as described with reference to Figure 7.

The teeth of the two planet wheels 145 and 146 are arranged to support by sliding against two corresponding edges 168 and 169 of the sliding element 147 in order to position this element, namely to move it between its two positions represented in Figures 14 and 16 and positively position it permanently without using a spring. The gear ratio between the fixed wheel 140 and each of the satellite wheels 145 and 146 being 3/4, each satellite wheel is three quarters of a revolution per year in the direction of the arrow it carries. In other words, a month's worth of February to the next, it is shifted a quarter of a turn in the opposite direction to the arrow. The wheel 145 has a long tooth 171 and seven short teeth 172, so that its tooth long 171 will push the sliding element 147 in February one year out of four only, which will put element 147 in the leap position represented in Figure 16. On the other side, the satellite wheel 146 has five long teeth 173 that support each other. against the edge 169 of the element 147 to hold it in the position of FIG. 14, while the short teeth 172 of the other satellite wheel 145 pass along the opposite edge 168 of this element. The latter is held by abutment against the shoulder 153. In the position of FIG. 16, these are the three short teeth 174 of the wheel 146 which pass freely along the edge 169 of the element 147, which is retained by stop against the shoulder 154. Furthermore, the element 147 has an inner edge curved 170 which can be supported by sliding against the head of the teeth of the fixed wheel 140.

Between two successive leap years, the rotation of the satellite wheels 145 and 146 goes twice temporarily put the slide element 147 in its leap position, but these events will occur in other months than February, if although the additional tooth 148 will be distant from the pinion 130 and will have no effect at all. those moments.

The second program wheel 127 is identical to the first 126 and works exactly the same way, to drive the second disc of date 52 with the same number of steps as the first, but with an offset half a month. If necessary, we can choose another value of this offset in modifying the mutual positions of the axes of the program wheels and the wheel 124 who drives them.

Figures 17 and 18 are similar to Figures 12 and 13 and show a calendar mechanism capable of operating the display shown in FIGS. 1 to 8 from the watch movement of the analog watch, more precisely from a central wheel of hours 99. In figure 18, the figures written in italics represent the numbers of mobile teeth that will be described below.

The hour wheel 99 meshes with a wheel 171 having a pinion 172 which meshes with a central wheel 173 integral with the disc 48 bearing the calendar index 46. With the numbers of teeth indicated in FIG. that the transmission ratio between the hour wheel 99 and the index 46 is: R i = 15 · 6 60 · 84 = 1 56

As the 99 hour wheel rotates twice a day, the index 46 accomplishes a turn clockwise in exactly 28 days.

The wheel 173, which is shown twice in Figure 18 to clarify the diagram, is integral with another central wheel 174 which meshes with a reference formed of two wheels 175 and 176. The wheel 176 meshes with a central wheel 177 integral with the disk of the months 56 and another central wheel 178. The latter drive, via a two-wheeled reference 180 and 181, a central wheel 182 secured to the record of the 58 years.

In addition, the central wheel 174 to sixty-seven teeth plays the same role of wheel driving that the wheel 112 of the example of Figures 12 and 13, to drive the same way the date disks 51 and 52 via the calendar mechanism perpetual 120 comprising in particular the two program wheels 126 and 127, this mechanism being identical to that of the above example.

The foregoing description shows that the program wheels 126 and 127 of the perpetual calendar mechanism can have a relatively build simple and of low thickness. In addition, as the numbers of teeth of the elements which compose it are relatively weak, the modules of the teeth are large enough to help reduce the cost of manufacturing. On the other hand, he note that the entire calendar device described above is devoid of return springs or jumper springs, which would have the disadvantage of creating friction, therefore wear and an adverse influence on the progress of the shows.

In the second embodiment illustrated by FIGS. 9 and 10, where the number of steps N = M - 35 of the monthly movements of each disc of between 4 and 7 in absolute value, a person skilled in the art may build a program wheel similar to the wheel 126 described above, but whose numbers of teeth and troughs in the output teeth 144 will be adapted values of N. This set of teeth shall have up to 7 tooth modules per monthly sector (sectors I to XII shown in Figure 14), so having a circumference divided into 84 modules.

Claims (16)

Timepiece equipped with a clockwork movement and a calendar display comprising: a dial (43) with a fixed graduation (47) in days of whole weeks which extends over the entire circumference of the dial, date indicator means (51, 52), rotated in steps and having at least one date scale in correspondence with the graduation of the days, and a mobile calendar index (46) driven in rotation by the watch movement opposite the graduations of the days and the calendars, characterized in that the date indicator means comprise two concentric date discs (51, 52) capable of being angularly offset with respect to each other, namely a first disc (51) whose graduation (53) ) comprises the calendars (1 to 15) of a first portion of a month and a second disc (52) whose graduation (54) comprises the other calendars up to 31, corresponding to a second part of a month,
in that the first date disc (51) is moved by N not in the second part of a month, N being equal to the number of days of said month minus the number of days of the graduation of the days, so that the last date of said month on the graduation of the second disc is followed by the first calendar of the following month on the graduation of the first disc,
and in that the second date disc (52) is moved by the same number N of steps in the first part of the following month, which restores the continuous sequence of the dates on the set formed by the two date scales. Timepiece according to claim 1, characterized in that the graduation of the days (47) comprises twenty-eight days on the turn of the dial, so that N is always greater than or equal to zero and the movements of the date discs are carried out in the increasing direction of the graduations of the days and the calendars. Timepiece according to claim 1, characterized in that the graduation of the days (47) comprises thirty-five days on the turn of the dial, so that N is always negative and that the movements of the date discs are performed in the decreasing meaning of the graduations of the days and the calendars. Timepiece according to claim 1, characterized in that the calendar display comprises a disc of the months (56), concentric with the date discs and carrying a circular graduation of the months (57), this disc of months being driven by in a relative rotation of a lathe in one year relative to the moving calendar index (46). Timepiece according to Claim 1, characterized in that the calendar display comprises a disc of the years (58), concentric with the date discs and bearing a circular graduation of the years (59), this disc of the years being driven by to perform a lap in an integer number of years relative to the calendar mobile index (46). Timepiece according to claim 5, characterized in that the disc of the years (58) performs a revolution in ten years with respect to said index, its graduation (59) bearing the numbers from 0 to 9, and in that the The calendar display further includes a disk of decades (60), driven to perform a lap in one hundred years from said index and bearing an index of decades (61) next to the graduation of the years (59). Timepiece according to one of claims 1 to 6, characterized in that the two date scales (53, 54) are arranged on arcs of circles of different radii, so that they can be partially juxtaposed. Timepiece according to one of claims 1 to 6, characterized in that the two date scales (53, 54) are arranged on arcs of circles of equal radius, so that they can be partially superimposed. Timepiece according to one of claims 1 to 6, characterized in that it comprises a calendar mechanism (120) driven by the watch movement and having, to drive the first date disk (51), a first program wheel (126), driven once a month by the watch movement so as to make one turn per year and provided with an output gear (144) having five gaps corresponding to the months of less than thirty and one day, and a gear train (130, 131) connecting the output teeth of this program wheel to a toothing (132) of the first date disk (51). Timepiece according to claim 9, characterized in that the calendar mechanism (120) comprises, for driving the second date disc (52), a second program wheel (127), similar to the first and driven once. per month by the watch movement to make one turn per year, and a train (134, 135) connecting the output gear of the second program wheel to a toothing (136) of the second date disc (52) , and in that the two program wheels (126, 127) are driven by means of a wheel (124) to a tooth (125) which rotates twelve times a year, the two program wheels being arranged on both sides. the other of the one-tooth wheel to be driven by said tooth (125) alternately in the first part and in the second part of each month. Timepiece according to claim 9 or 10, characterized in that the or each program wheel (126, 127) carries a movable element (147) provided with an additional tooth (148) and a control mechanism (140, 145, 146), the moveable member having a leap position, wherein the additional tooth (148) is added to the output toothing (144) in the gap corresponding to February, and a withdrawal position in which the tooth additional (148) is retracted, the control mechanism being arranged to put the movable member (147) temporarily in the leap position every February in positions of the program wheel which are shifted by a quarter of a turn of one year to the next, so that the additional tooth (148) drives the corresponding gear only one year out of four. Timepiece according to claim 11, characterized in that said control mechanism comprises two planet wheels (145, 146), rotatably mounted on the program wheel and meshing with a fixed wheel (140) concentric with the wheel of program so that each satellite wheel shifts a quarter turn per year from the program wheel, said planet wheels having cam surfaces abutting against said movable member (147) to position it. Timepiece according to claim 12, characterized in that the fixed wheel (140) has six teeth and each satellite wheel (145, 146) has eight teeth. Timepiece according to claim 12, characterized in that said movable member (147) is arranged to pivot about the center of the program wheel and in that its additional tooth (148), in its retracted position, is superimposed at one (158a) of the teeth of the exit gear (144) of the program wheel. Timepiece according to claim 10, characterized in that each program wheel (126, 127) is devoid of any spring. Timepiece according to claim 10, characterized in that the calendar mechanism is devoid of any spring.

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