Abstract:
The invention relates to a timepiece comprising a time train, a 31-toothed wheel, a wheel of units of 30 teeth plus a space corresponding to a tooth which is used to drive a star-wheel of units and a four-toothed wheel for driving a star-wheel of tens, a year cam which is solidly connected to a wheel, and drive means for driving said 31-toothed wheel by one revolution per month and the year cam by one revolution per year. The aforementioned 31-toothed wheel is solidly connected to a corrector element. The drive means comprise a cam which is solidly connected to a wheel, a driving yoke, elastic means which are used to press said yoke against the cam, a corrector yoke, a feeler which is arranged to detect the position of the year cam and elastic means in order to connect said yokes to one another.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of PCT/CH03/00164 filed Mar. 12, 2003, claiming priority of European Application No. 02405246.6 filed Mar. 28, 2002, which is included in its entirety by reference made hereto. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a timepiece with a large-format calendar display and instantaneous jump comprising a time train, a day-of-the-month runner comprising a 31-toothed wheel, a unit wheel of 30 teeth plus one space corresponding to a tooth for driving a 10-toothed unit pinion and a 4-toothed wheel for driving a 4-toothed tens star, an annual cam secured to a 12-toothed wheel, and drive means connected to said time train for driving said day-of-the-month runner by one revolution per month and the annual cam by one revolution per year. 
     2. Description of Related Art 
     Numerous watches exist that have various indications derived from time, such as the date(the day, the day of the month and the month), the phases of the moon, and indication of several time zones in particular. The proliferation of these indications usually makes them difficult to read. This difficulty of reading may be the result as much as of the layout as of the magnitude of the indications. In many cases, the change of indication is not instantaneous but trailing, especially in the case of an annual or even perpetual calendar. The days of the month are often displayed by a needle moving past a day-of-the-month dial rather than using numerals appearing in a window formed in the dial, making them less easy to read. Furthermore, displaying the day of the month using a disk bearing the days of the month from 1 to 31 limits the possible magnitude of these numerals, which means that proposals have already been made for the tens and the units to be displayed on two separate disks so that their size can be increased, thus making the mechanism more complicated. 
     It is obvious that the more indications there are, and the smaller the timepiece, particularly in the case of a wristwatch, rather than a pocket watch, the more difficult these problems are to solve. Even though numerous solutions exist, it is, however found, that none of them meet all the increasingly broad requirements in terms of complex horology aimed first and foremost at demanding collectors who insist that the boundaries of the possible be pushed back further and further. It is necessary not only to be able to meet new technical challenges, but also for the dimensions of such mechanisms to remain acceptable for a watch that has to be worn on the arm, both in terms of the area and in terms of the thickness and to do so without detracting from the reliability which remains the essential criterion. 
     BRIEF SUMMARY OF THE INVENTION 
     The object of the present invention is specifically to contrive for the calendar mechanism of the timepiece to allow large-format display in a calendar with instantaneous jump. 
     To this end, the subject of the present invention is a timepiece with a large-format display calendar and instantaneous jump as defined by claim  1 . 
     Advantageously, the calendar of this timepiece is a perpetual calendar and includes a display of the days and of the months. 
     As a preference, this calendar also includes an indication of the phases of the moon, which is coaxial with an additional train for indicating a second time zone, driven by the main indicator train situated at the center of the watch. 
     The design of this timepiece with calendar is intended to offer a clear display that is easy to read both in terms of the layout of the information displayed and in terms of legibility, by virtue of its having sufficiently large characters. All the information displayed changes instantaneously and preferably requires no correction, the corrections being made by the annual cam. 
     Other particulars and advantages of the present invention will become apparent in the course of the description which will follow and which will make reference to the attached drawings which, schematically and by way of example, illustrate one embodiment of the timepiece with calendar that is the subject of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a plan view of this embodiment, in which the various indicator disks have been shown as transparent in order to reveal the mechanism; 
         FIG. 2  is a plan view of the mechanism of  FIG. 1  without the indicator disks, showing the position of the various components on February 28 of a year that is not a leap year at around midday; 
         FIG. 3  is a view similar to  FIG. 2 , showing the position of the various components just before midnight, and therefore just before the date change; 
         FIG. 4  is view similar to the previous figure, showing the position of the various components on March 1 after the date change; 
         FIG. 5  is a view in section on the line V—V of FIG.  3 . 
     
    
    
       FIGS. 1 and 2  essentially show the calendar mechanism of the timepiece according to the present invention, which comprises a drive wheel  1  secured to the hour wheel RC, illustrated in section in  FIG. 5 , engaging with a wheel  2  and which makes one revolution in 12 hours. The ratio between this pinion  2  and the drive wheel  1  is 2:1 which means that the wheel  2  makes one revolution per day. 
     DETAILED DESCRIPTION OF THE INVENTION 
     This wheel  2  is secured to a cam  3  which operates with a pin  4   a  secured to a yoke  4  mounted to pivot about a spindle  4   b.  This yoke  4  is split into two arms each of which ends in a pawl  5   a,    5   b  for the step-by-step drive of a 31-toothed day-of-the-month runner  7  and the step-by-step drive of a day-of-the-week star  8  (FIG.  1 ), respectively. This yoke  4  has an opening  4   c  in the shape of an arc of a circle centered on its pivot spindle  4   b,  in which opening a stop  4   d  is engaged. This yoke  4  is pressed against one end of this opening  4   c  by a return spring  6  engaged with a pin  4   e  of the yoke  4 . 
     A second yoke  9 , which constitutes a correction yoke, is mounted to pivot about the same spindle  4   b  as the yoke  4 . It is connected to the latter by an elastic arm  9   a  which rests against the pin  4   a  of the yoke  4 , which projects from both sides of this yoke  4 . The yoke  9  ends in a pawl  10  intended to engage selectively with a notch  11   a  in a correction cam  11  secured to the day-of-the-month runner  7 . 
     The day-of-the-month runner  7  is also secured to two wheels, a unit drive wheel  12 , comprising 30 teeth and an empty space corresponding to the 31 st  tooth engaged with a 10-toothed star  13  for displaying the units of the day of the month. The second wheel secured to the day-of-the-month runner  7  is a 4-toothed tens-drive wheel  14  engaged with a star  15  for displaying the tens of the days of the month. Each of these stars  13 ,  15  is respectively secured to an annular disk  13   a  concentric with a disk  15   a  (FIGS.  1  and  5 ), the annular disk  13   a  bearing the numerals of the units from 0 to 9 and the disk  15   a  bearing the numerals of the tens from 0 to 3, it being possible for 0 to be replaced with an empty space. These numerals appear through an aperture G formed through the dial C of the timepiece (FIG.  5 ). 
     The day-of-the-month runner  7  engages, in a 1:1 ratio, with a wheel  16  secured to an instantaneous jump cam  17 . A yoke  18  pivoting about a spindle  18   a  is pressed against the instantaneous jump cam  17  by a spring  19 . This yoke  18  bears a drive pawl  20  which engages with a 12-toothed annual runner  21  secured to an annual cam  22  which has sectors of varying radii representative of the number of days in the months of the year. A portion  22   a  of this annual cam  22  is secured to a planet pinion  23  ( FIG. 1 ) engaging with a months sun wheel  24  secured to the frame of the calendar mechanism. The gear ratio between the planet pinion  23  and the months sun wheel  24  is chosen so that this planet pinion  23  makes one revolution per four revolutions of the months sun wheel  24 . The cam portion  22   a  has four sides, three of which are the same distance away from the axis of the pinion  23 , while the fourth is a further distance away than the other three. 
     The second yoke  9  comprises a feeler arm  9   b  intended to come into contact with the periphery of the annular cam each time the yokes  4  and  9  move, that is to say once per day. Given that the various portions of the annual cam  22  have different radii according to the length of the month, the amplitudes of the movements of the yoke  9  and of its pawl  10  vary and the differences between the various amplitudes are absorbed by the elastic arm  9   a  of the yoke  9 . 
     As illustrated by  FIG. 1 , the annual runner  21  is secured to a disk  21   a  bearing the indications of the 12 months of the year. 
     The day-of-the-month runner  7  and the annual runner  21  together with the units star  13  and the tens star  15  are positioned angularly by respective jumpers  25 ,  26 ,  27 ,  28 . 
     One of the teeth of the annual runner  21  is markedly thicker than the other 11 teeth. Thanks to this thicker tooth, the annual runner  21  drives a four-branched star  29  by one step per year. This star is secured to an intermediate wheel  30  which drives a set of intermediate wheels,  31 ,  32 ,  33  the last of which is secured to a four-branched star  34  engaged with a jumper  35 . This star  34  is also secured to a disk  34   a  ( FIG. 1 ) bearing the numerals  1 ,  2 ,  3  and the letter B to indicate a 4-year cycle in which one year is a bissextile year (leap year) B. 
     The day-of-the-week star  8  ( FIG. 1 ) is positioned by a jumper  41  and bears a disk  36  on which the days of the week are displayed. This 7-branched star  8  is engaged with a second star  37 , also having 7 branches, positioned by a jumper  38 . This second star  37  is secured to a pinion  39  ( FIG. 1 ) which engages with an intermediate wheel  40  which engages with a wheel  42  secured to and coaxial with a wheel  43  which engages with a wheel  44  to indicate the phases of the moon. The gear ratios of this gear set between the day-of-the-week star  8  and the wheel  44  for indicating the phases of the moon are chosen so that the wheel  44  makes one revolution in three lunar months, so that this wheel  44  bears three circles  45  representing the moon, distributed 120° apart on the wheel  44  so that each of them can be used to indicate a lunar cycle in conjunction with an aperture (not depicted) of appropriate shape, formed through the dial C, to simulate the phases of waxing and waning of the moon visible in the aperture. 
     A third wheel  46  pivots on the same spindle as the wheels  42 ,  43  of the moon-phase gear set. This third wheel  46  ( FIG. 1 ) bears a disk  46   a  split into two sectors of 180° each, one being black and the other white to indicate night-time hours and daytime hours through an aperture (not depicted) made in the dial C of the timepiece. As can be seen in  FIG. 1 , the wheel  46  engages with an intermediate wheel  47  which engages with a wheel  48 , coaxial with the moon-phase wheel  44  which engages with the wheel  2  of the calendar. These wheels  46 ,  48  and 2 have 1:1 ratios with respect to one another which means that the wheel  46  makes one revolution in 24 hours as does the wheel  2 . Thus, for 12 hours the black shows through the aperture in the dial and the white shows through this aperture for the next 12 hours. 
     The way in which the calendar mechanism described hereinabove works is as follows: 
     Every 24 hours, the cam  3  secured to the wheel  2  of the calendar gradually lifts the yokes  4  and  9  against the pressure exerted by the return spring  6  on the yoke  4 . As they pivot, the pawls  5   a,    5   b  are displaced in the clockwise direction about the pivot spindle  4   b  of the yokes  4 ,  9 , thus disengaging from the teeth  7  and  8  and the finger  9   b  of the yoke  9  to a greater or lesser extent limits the amplitude of pivoting of this yoke  9  according to which part of the annual cam  22  lies in the path of this finger  9   b  and against which this finger  9   b  abuts. During the rest of its pivoting, the yoke  4  pivots with respect to the correction yoke  9 , this relative pivoting of this yoke  4  with respect to the yoke  9  being absorbed by deformation of the elastic arm  9   a  of this yoke  9 . 
     During the period ranging from the 1 st  to the 29 th  of the month, the yoke  9  and its pawl  10  have no function, the pawl  10  sliding against the plain surface of the correction cam  11  with each back and forth movement of the yokes  9  and  10 . In the case of a 30-day month, when the day of the month changes between the 30 th  and the 1 st  of the next month, when the finger  9   b  of the yoke  9  rests against one of the smaller-diameter portions of the annual cam  22 , the pawl  10  engages behind the notch  11   a  in the correction cam  11  so that when the cam  3  frees the yokes  4  and  9  to the return force of the spring  6 , the pawl  10  drives the correction cam  11 , by the magnitude of two steps of the day-of-the-month wheel  7 , secured to this correction cam  11 , causing the day of the month to move from 30 to 01. 
     When there is a change in day of the month during a month, either there is only a change in units and the wheel  12  drives the star  13  by one step or there is a simultaneous change of units and of tens and the wheels  12  and  14  drive the stars  13  and  15  respectively by one step simultaneously. 
     At the end of a 31-day month, as the units of the next day of the month, 01, do not change, only the tens changes. This is why the day-of-the-month wheel  12  has 30 teeth and a space corresponding to a missing tooth. Thus, during the switch from the 31 st  to the 01 st , the missing tooth of the day-of-the-month wheel finds itself facing the units star  13  so that the latter is not driven and so that the numeral  1  is displayed on two consecutive days. Only the tens star  15  is driven by one step by the four-toothed tens wheel  14 , causing the tens disk  15   a  to move on from 3 to 0. 
     For the calendar to be perpetual, the annual cam  22  has a portion  22   a  secured to a planet pinion  23  ( FIG. 1 ) which corresponds to the correction to be made at the end of the month of February which has either 28 days in a normal year or 29 days in a leap year. This cam portion  22   a  makes one quarter of a revolution each year and has four sides, one of which is a greater distance away from the center of the planet pinion  23  than the other three. When the finger  9   b  of the correction yoke  9  faces this cam portion  22   a  during a 28-day month of February, it allows the correction yoke  9  to rock through a greater angle than it does in the other months, so that on February 28, the pawl  10  of the yoke  9  comes behind the notch of the correction cam  11 , as illustrated in  FIG. 3 ; this then is the maximum amplitude of the correction yoke  9 . As soon as the instantaneous jump cam  3  releases the drive yoke  4  to the pressure of the spring  6 , the pawl  10  of the correction yoke  9  drives the day-of-the-month wheel by four steps, causing the display on the disks  13   a  and  15   a  to move on instantaneously from 28 to 01. 
     In a leap year, it is the surface of the portion  22   a  of the cam  22  which is furthest from the center of the planet pinion  23  which faces the finger  9   b  of the correction yoke  9 , the distance from this surface to the center of pivoting of the cam  22  being between the distance of the cam surfaces  22  relating to the 30-day months and the distance of the surfaces of the cam portion  22   a  corresponding to 28-day months of February, which means that the pawl  10  will engage with the notch  11   a  of the correction cam  11  on February 29 and will advance the day-of-the-month wheel  7  simultaneously and instantaneously by three steps. These corrections to the day-of-the-month runner cause a synchronous change in the annual runner  21  and in the months display disk  21   a  secured to this annual runner  21 . 
     By contrast, these corrections have no influence on the pawl  5   b  that drives the star  8  secured to the day-of-the-week disk which days of the week obviously follow on from one another in an immutable manner, this star  8  causing the wheel  44  to advance each day to indicate the phases of the moon by a fraction of a lunar cycle corresponding to a solar day. 
     The continuous movement of the wheel  2  engaged with the drive wheel  1  secured to the hour wheel RC is imparted to the wheel  46  bearing the black/white sectors that indicate daytime hours and night-time hours with a ratio 1:1.