CH718804B1 - Perpetual or annual calendar mechanism. - Google Patents

Abstract

The invention relates to a perpetual or annual calendar mechanism (1) comprising a date wheel (71), a day wheel (52), a month cam (82) and a date rocker (6) arranged to read the duration of the months on the month cam (82) and to drive the date wheel (71), the day wheel (52) of this mechanism being arranged to drive the date rocker (6). The invention also relates to a timepiece such as a wristwatch or a calendar pocket watch comprising such a mechanism (1). The invention makes it possible to avoid desynchronization between a display of the day of the week and a display of the date.

Description

[0001] The present invention relates to a perpetual or annual calendar mechanism for a timepiece allowing the display of the date as well as the display of the day of the week.

[0002] US patent 4,674,889 describes a watch movement comprising a perpetual calendar display mechanism. This mechanism comprises a date rocker pivoted once a day, from a rest position to an actuation position in which it rotates a date mobile by at least one step (more than one step at the end of the month less than 31 days). At the same time, the date rocker acts on a seven-pointed star displaying the days of the week to rotate it by one step each day. This movement allows the user to correct the calendar data (days of the week, date, month and year) by acting on the date rocker. Although the day of the week and date indications are initially synchronized, certain situations can lead to their desynchronization. Indeed, the actions of the date wheel drive pawl and the day star drive lever are not completely simultaneous, it is possible that, during a rapid correction or adjustment operation, setting the time in clockwise direction followed by anti-clockwise direction before the end of the complete passage of the date, the user stops driving the date rocker immediately after having activated one of the displays but before having activated the other, which could lead to loss of synchronization. A desynchronization could also occur in the event of a correction near midnight, typically between 9 p.m. and 3 a.m.

[0003] Such desynchronizations are never appropriate and are particularly problematic in the context of this specific movement because it does not allow them to be resynchronized without dismantling the movement.

[0004] One aim of the invention is to propose a perpetual or annual calendar mechanism making it possible to avoid desynchronization between the display of the days of the week and that of the date.

[0005] To this end, the invention proposes a perpetual or annual calendar mechanism comprising a date wheel, a day wheel, a month cam as well as a date rocker arranged to read the duration of the months on the month cam. month and to drive the date wheel, in which the day wheel is arranged to drive the date rocker.

Advantageously, the drive of the day wheel is of the instantaneous type.

[0007] Preferably, and in particular when the drive of the day wheel is not of the instantaneous type, the mechanism according to the invention comprises a first jumper ensuring the positioning of the day wheel and a second jumper ensuring the positioning of the date wheel, the whole being arranged so that the first jumper lets a tooth of the day wheel pass before the second jumper lets a tooth of the date wheel pass.

[0008] In the context of the present invention, the date rocker advantageously comprises a first lever pivoting around a first axis of rotation A1 and a second lever pivoting around a second axis of rotation A2, said levers being articulated between them. Preferably, the first and second levers are articulated together via a pin carried by one of said levers and received in a fork of the other of said levers.

[0009] Advantageously, the date mechanism according to the invention comprises a day wheel comprising said day wheel and a second day wheel which is coaxial with it and integral in rotation, said second day wheel being driven in rotation by a not per day by a peripheral toothed crown. Advantageously, said peripheral toothed crown is rotated by a pivoting finger at a rate of one revolution per day.

[0010] Preferably, said peripheral toothed ring comprises a first and a second annular toothed discs movable in rotation around a common axis of rotation O and integral in rotation with one another. They can be assembled or in one piece. A first of said annular discs typically has the same shape and the same toothing profile as an annular date disc of a simple date; it includes for example internal teeth with thirty-one teeth. Thus it is easily possible to transform a simple date mechanism comprising a toothed annular disc carrying a date graduation, into a perpetual or annual calendar by replacing said annular disc with the toothed peripheral crown of the date mechanism according to the invention. The mechanism according to the invention is typically a modular date mechanism.

The day wheel typically defines seven successive angular positions, each associated with one of the days of the week. It is preferably a star with seven teeth. It is typically integral in rotation with a display member or indicator allowing the display of the day of the week such as a disc, a needle or an index. The positioning of the day wheel is typically ensured by a positioning member such as a jumper or a ratchet.

[0012] In a preferred embodiment, the date mechanism according to the invention comprises a date mobile comprising said date wheel and a date cam which is coaxial with it and integral in rotation, the date rocker being arranged to drive the date mobile by acting on the date cam at the end of months of less than thirty-one days.

The date wheel typically defines thirty-one successive angular positions, each associated with one of the 31 dates. It is preferably a star of 31. It typically comprises a long tooth intended to cooperate with a coaxial month wheel and integral in rotation with the month cam. The date wheel is advantageously integral in rotation with a display member or indicator allowing the display of the date such as a disc, a hand or an index. The positioning of the date wheel is typically ensured by a positioning member such as a jumper or a ratchet.

The month cam is typically a cam of 48 in the case of a so-called perpetual calendar. The month cam is typically a cam of 12 in the case of a so-called annual calendar. It is also possible to use a 12 cam as well as an additional leap year cam in a perpetual calendar.

The date mechanism according to the invention also typically comprises display members for the current month and/or the current year. It could further also include an indication whether or not the current year is a leap year.

[0016] The invention also relates to a timepiece such as a wristwatch or a pocket watch comprising such a mechanism.

[0017] Other characteristics and advantages of the present invention will appear on reading the following detailed description made with reference to the appended drawings in which Figures 1 to 4 illustrate, in top view, a perpetual calendar mechanism in one mode particular embodiment of the invention in successive configurations during its operation.

[0018] In the following part of the description, any reference to a clockwise or counterclockwise direction of rotation is made with reference to the figures.

[0019] With reference to Figures 1 to 4, a perpetual calendar mechanism 1 according to a particular embodiment of the invention comprises: – a plate or board 100; – a date finger 2; – a first 3 and a second 4 annular disks with internal teeth movable in rotation around a common axis of rotation O and integral in rotation with one another; – a mobile of days 5 comprising a wheel with seven wide teeth 51 and a star of seven 52 coaxial and integral in rotation with one another, said mobile typically being integral in rotation with a display or indicator member ( not illustrated) allowing the display of the day of the week such as a disc, a hand or an index; – a date rocker 6 comprising first and second levers 61, 62 pivotally mounted around axes of rotation respectively A1 and A2 and articulated together via a pin 63 carried by the first lever 61 and received in a fork 65 of the second lever 62; – a date mobile 7 comprising a date star 71 and a date cam 72 pivotally mounted around a common axis of rotation A3 and rotationally secured to one another, said date mobile 7 being advantageously also integral in rotation of a display member or indicator (not illustrated) allowing the display of the date such as a disc, a hand or an index; – a first wheel of months 8 comprising a first wheel of months 81 and a cam of months 82 pivotally mounted around a common axis of rotation A4 and integral in rotation with one another; – a second mobile of months 9 comprising a second wheel of months 91 and a finger 92 pivotally mounted around a common axis of rotation A5 and integral in rotation with one another, said second mobile of months 9 also being integral in rotation of a display member or indicator (not illustrated) allowing the display of the current month; and – a display device from the 10s.

Advantageously, at least one of the first annular disk 3, the second annular disk 4 or the mobile of the days of the week 5 is positioned by a first positioning member such as a jumper or a ratchet. In the example illustrated in the figures, it is the seven star 52 of the mobile of the days of week 5 which is positioned by a jumper 53.

The date star 71 is also advantageously positioned by a second positioning member such as a jumper or ratchet (not illustrated). It is the same for at least one of the first 81 or the second 91 wheel of the months.

[0022] The part of the mechanism 1 comprising the second lever 62, the date mobile 7, the first month mobile 8, the second month mobile 9 and the display device for the years 10 operates in a manner similar to the part of the device described in US patent 4,674,889 going from lever 5 to display discs of years 27 and 30.

[0023] Like lever 5 of US patent 4,674,889, the second lever 62 of the date rocker 6 performs a daily back-and-forth tilting or pivoting, the amplitude of which is defined by the cooperation between its feeler 64 and the periphery of the cam of months 82.

The month cam 82 is a cam of 48. It traditionally has solid parts and more or less deep notches representing forty-eight successive months and allowing the date rocker 6 and in particular its second lever 62 to read the duration of the months via its probe 64. This month cam 82 defines the amplitude of tilting of the lever 62 around the axis A2.

The second lever 62 is movable in rotation around an axis A2. It is intended to tilt around the axis A2 in a clockwise direction between a rest position, such as that illustrated in Figure 1, in which its feeler 64 is resting against the cam of the months 82, towards a position of activation illustrated in Figure 3. Such a switch occurs automatically once a day around midnight under the influence of the finishing gear of the timepiece in which mechanism 1 is integrated.

[0026] During the daily tilting of the second lever 62 in the clockwise direction, a pawl 621 which it carries engages in the teeth of the date star 71 and rotates it by one step, corresponding to an angle d 'one thirty-first turn, clockwise. The date display member (not illustrated) associated with it thus increments the date display by at least one unit each day.

[0027] The position of the month cam 82 determines the depth at which the probe 64 is located. This determines the lever arm allowing a large pawl 622, also carried by the second lever 62, to act on the month cam. date 72 integral with the date star 71. Thus, when the current month has less than thirty-one days, the large pawl 622 drives the date star 71 by one, two or three steps. We say that he makes up for the days. Then, the pawl 621 advances the date star 71 an additional step. When a month has thirty-one days, there are no days to make up. The feeler 64 of the second lever 62 is then located on a solid part of the month cam 82. In this case, only the pawl 621 acts on the date star 71 to advance it by one step.

Whatever the length of the current month, the date star 71 makes one revolution per month. It includes a special tooth 711, longer than the others, which drives a tooth of the first wheel of the months 81 by one step each month, imposing on the latter as well as on the cam of the months 82 which is attached to it a frequency of rotation of one revolution in four years in the counterclockwise direction.

The first month wheel 81 meshes with the second month wheel 91 of the second month wheel 9 so as to rotate it one revolution per year, at the rate of one twelfth of a revolution per month, in the direction hourly. The month display member (not illustrated) associated with the second month mobile 9 thus changes the month displayed on the first date of each month.

The finger 92 of the second wheel of the months 9 is integral in rotation with the second wheel of the months 91 and arranged to rotate by one step each year a first wheel 101 of the year display device so as to increment the display of the years of one unit each year.

[0031] Figures 1 to 3 illustrate the transition from February 28 of a non-leap year to the following March 1. Between Figure 2 and Figure 3 the large pawl 622 caused the rotation of 3/31<ths> of a turn of the date wheel 71 by cooperating with the date cam 72 and the pawl 621 caused the advancement of the date star 71 of 1/31 of an additional turn. At the same time, the special tooth 711 of the date star 71 caused the pivoting of one step of the forty-eight month wheel 81 and of the month cam 82 which is attached to it.

[0032] A notable difference between the mechanism according to the invention and that described in the aforementioned US patent 4,674,889 comes from the way in which the lever 62 is rotated, and in particular from the positioning of the day mobile 5.

[0033] The mobile for the days of week 5 is activated every day around midnight via a cog. As illustrated in the figures, in the date mechanism 1 according to the invention, the date finger 2 is pivotally mounted on the plate or board 100 and is rotated one revolution per 24 hours, preferably in a jumping manner, by through “instantaneous” training.

[0034] When it is "jumping", the finger 2 typically cooperates with a spring which is gradually armed during the day and with a triggering system releasing this spring once a day. A jumping display mechanism is for example described in patent application CH 712 012.

[0035] When it is not of the instantaneous type, the drive of finger 2 can be dragging or semi-trailing. The finger 2 is typically integral in rotation with a 24-hour wheel meshing via a return with the hour wheel of the finishing gear of the timepiece hosting the mechanism 1. It cooperates with the internal teeth of the first annular disk 3. The two annular disks 3, 4, integral in rotation with one another, comprise the same number of teeth, namely thirty-one teeth. Thus, every 24 hours, finger 2 rotates annular discs 3 and 4 one step clockwise. The internal teeth of the second annular disk 4 engage with the teeth of the wheel 51 with seven wide teeth so that, every 24 hours, the day mobile 5 pivots by one step, that is to say by a seventh turn, clockwise. Note that the annular disc 4 has “wide” teeth of a shape corresponding to that of the wheel 51, the aim of which is to minimize the play between these gears.

The seven star 52 of the day mobile 5 is arranged to cooperate with the first lever 61 of the date rocker 6. Indeed, as can be seen in Figures 1 to 3, the pivoting of a step of the seven star 52 causes the first lever 61 to pivot counterclockwise around the axis of rotation A1. The arrangement of the first and second levers 61, 62 around the pin 63 is such that the pivoting of the first lever 61 in the counterclockwise direction around the axis A1 causes the clockwise pivoting of the second lever 62. Thus, the The advancement of one daily step of the seven star 52 causes the daily tilting of the second lever 62 as described previously and therefore the pivoting of the date mobile 7. The mobile of the days of the week 5 and the date mobile 7 are arranged in series.

[0037] In order to avoid any desynchronization of the different elements of the date mechanism 1, and in particular between the day mobile 5 and the date mobile 7, it is important that the day mobile 5, the date flip-flop 6 and the date mobile 7 are arranged so that the pivoting of the day mobile 5, more precisely of its seven star 52, cannot cause a tilting of the date rocker 6, more precisely of its lever 62, sufficient to rotate the date wheel 7 and in particular the date wheel 71, only when it can no longer go back.

This is always the case when the pivoting of the drive finger 2 every 24 hours is of the instantaneous type because this also makes the pivoting of the mobile on days 5 instantaneous.

[0039] In the case of a trailing or semi-trailing drive of the finger 2, desynchronization can be avoided by fine adjustment of the positioning members respectively of the day mobile 5 and the date mobile 7.

[0040] In the example illustrated, the jumper 53 which determines the relative position of the day mobile 5 relative to the plate or board 100 must have passed the tooth 531 of the teeth of the seven star 52 which lifts it under the impulse of finger 2 before the jumper (not illustrated) positioning the date star 71 and therefore the date mobile 7 has passed the tooth of the date star 71 which raises it at that moment.

[0041] Figure 1 illustrates the jumper 53 in a rest position between two teeth of the star of seven 52. As explained, under the influence of the rotation of the finger 2 in the clockwise direction, the day mobile 5 pivots clockwise. In Figure 2, the top of the jumper 53 has just passed the tooth 531 which lifted it. At this stage neither the pawl 621 nor the pawl 622 have yet pushed the date star sufficiently to move it forward one step. In this configuration, if the finger 2 stopped or went back, the jumper 53 would maintain the day mobile 5 in its angular position illustrated in Figure 2 and would prevent it from going back. Then, when finger 2 resumes its rotation, the seven star 52 would finish its rotation and the date mobile 7 would be rotated in a conventional manner, as illustrated in Figures 3 and 4. Finally, each of the day mobile 5 and of the date mobile 7 would have advanced normally desynchronization. Advantageously, the perpetual calendar mechanism 1 according to the invention comprises a date correction device capable of causing a back and forth tilting of the second lever 62 identical to that caused by the daily pivoting of the seven star 52 but by acting directly on the second lever 62 and without impacting the day mobile 5. This is made possible by the articulation of the rocker 62 as well as by the arrangement of the first lever 61 of the date rocker 6 in relation to the mobile of the days days of the week 5. The aforementioned date correction device typically drives the previously described back and forth movement of the second lever 62 via a pin (not shown) cooperating with a hole 623 of the second lever 62 .

[0042] Such a correction device is particularly advantageous in the case where the date mechanism according to the invention is an annual and not a perpetual calendar mechanism. Indeed, in the case of an annual calendar, the wearer of the watch is obliged to increment the date by several units at the end of each month of February and this without modifying the display of the day of the week in which case it would itself introduce a desynchronization of the displays.

[0043] The invention thus proposes a perpetual or annual calendar mechanism comprising, among other things, a pivoting drive finger, a mobile for the days of the week 5, a calendar rocker 6, a calendar mobile 7, a mobile months associated with a months cam and a years display device arranged in series, in this order, and thus forming a single kinematic chain.

[0044] Such a series arrangement makes it possible to avoid desynchronization of the different members of the date mechanism. Indeed, once the first jump has taken place (finger 2 of 24 hours, discs 3 and 4 or mobile of days 5), all displays then follow.

Such a date mechanism 1 is intended to be mounted in a timepiece such as a pocket watch or a wristwatch.

The preceding description attempts to describe a particular embodiment by way of non-limiting illustration, and the invention is not limited to the implementation of certain particular characteristics which have just been described, such as for example the shape of the different organs (wheels, levers, cams, etc.) which can vary infinitely as long as their respective functions are ensured.

[0047] Furthermore, it goes without saying that those skilled in the art are able to adapt the mechanism 1 illustrated to make it a perpetual calendar mechanism with a twelve cam and a leap year cam or to transform it in one annual calendar.

Claims (10)

1. Perpetual or annual calendar mechanism (1) comprising a date wheel (71), a day wheel (52), a month cam (82) as well as a date rocker (6) arranged to read the duration of the months on the month cam (82) and to drive the date wheel (71), characterized in that the day wheel (52) is arranged to drive the date rocker (6). 2. Mechanism (1) according to claim 1, characterized in that the drive of the day wheel (5) is of the instantaneous type. 3. Mechanism (1) according to claim 1 or 2, characterized in that it comprises a first jumper (53) ensuring the positioning of the day wheel (52) and a second jumper ensuring the positioning of the date wheel ( 71), the whole being arranged so that the first jumper (53) lets a tooth (531) of the day wheel (52) pass before the second jumper lets a tooth of the date wheel (71) pass. 4. Mechanism (1) according to one of claims 1 to 3, characterized in that the date rocker (6) comprises a first lever (61) pivoting around a first axis of rotation (A1) and a second lever (62) pivoting around a second axis of rotation (A2), said levers (61, 62) being articulated together. 5. Mechanism (1) according to claim 4, characterized in that the first (61) and second (62) levers are articulated together via a pin (63) carried by one of said levers and received in a fork (65) of the other of said levers. 6. Mechanism (1) according to one of the preceding claims, characterized in that it comprises a day wheel (5) comprising said day wheel (52) and a second day wheel (51) which is coaxial with it and integral in rotation, said second day wheel (51) being rotated one step per day by a toothed peripheral ring gear (3,4). 7. Mechanism (1) according to claim 6, characterized in that said toothed peripheral ring (3, 4) comprises a first (3) and a second (4) toothed annular discs movable in rotation around an axis of rotation ( O) common and integral in rotation with each other, the first toothed annular disc (3) being intended to cooperate with a finger (2) for driving the peripheral toothed ring (3, 4) and the second toothed annular disc (4) cooperating with the second day wheel (51) to drive it in rotation. 8. Mechanism (1) according to claim 7, characterized in that the teeth of said first toothed annular disc (3) are internal teeth comprising thirty-one teeth. 9. Mechanism (1) according to one of the preceding claims, characterized in that it comprises a date wheel (7) comprising said date wheel (71) and a date cam (72) which is coaxial and integral with it in rotation, the date rocker (6) being arranged to drive the date mobile (7) by acting on the date cam (72) at the end of months of less than thirty-one days. 10. Timepiece such as a wristwatch or a calendar pocket watch characterized in that it comprises a mechanism (1) according to one of claims 1 to 9.