Calendar mechanism with seasonal display for a watch

Abstract

The calendar mechanism with seasonal indication for a watch comprises a drive wheel (26) whose angular position represents a date, and a seasonal indication member (80) and a seasonal indication drive member (62) configured to be driven by the drive wheel (26) and drive the seasonal indication member (80) only during a predetermined time interval of less than 30 days every three months.

Description

[Technical field]

[0001] The present invention relates to a calendar mechanism with seasonal indication for a watch. [Background technology]

[0002] Calendar mechanisms with seasonal indication have been proposed in US Pat. No. 563268, DE 102008031441 A1 and EP 3327516 A1.

[0003] In US Patent No. 563268, the names of the seasons and months are marked on the dial of the clock, and information about the current month and the current season is given by a moon hand that rotates on the dial. The indication of the seasons is thus dependent on the indication of the moon, making it impossible to indicate the change of seasons with precise dates.

[0004] In DE 102008031441 A1, the dial of a clock comprises four symbols in the form of a sun for summer, a leaf for autumn, a snowflake for winter and a flower for spring, respectively. Each symbol is an aperture made in the dial or in a transparent area of ​​the dial. A first rotating plate, driven by the movement of the clock and arranged below the dial, has a colored portion that makes it possible to change the color of the active season to indicate whether the season is at its beginning, middle or end. A second plate serves to make the symbols corresponding to the three inactive seasons invisible. This patent application only concerns the principle of displaying the seasons. The mechanism for driving the plate is not described.

[0005] Finally, in EP 3327516 A1, a first wheel is arranged to rotate once every 31 days to indicate the date, and a second wheel, coaxial with the first wheel, is provided to indicate the season. The first and second wheels are driven by the same wheel assembly but with different gear ratios, so that the second wheel rotates faster than the first wheel, offsetting it by one revolution for every 12 revolutions of the first wheel. The first wheel carries a hand indicating the date. The second wheel is provided on its upper surface with a symbol representing the season, fully visible through a large opening made in the dial, and the current season is indicated by a symbol or part of a symbol visible through an opening in the hand indicating the date. This mechanism has the advantage of being simple, but it does not allow an accurate indication of the current season or an accurate indication of the change of seasons. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Pat. No. 563,268 [Patent Document 2] DE 102008031441 A1 [Patent Document 3] European Patent Application Publication No. 3327516 [Patent Document 4] Swiss Patent No. 685585 [Patent Document 5] International Publication No. 2019 / 193430 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to propose a calendar mechanism for displaying the seasons, allowing accurate display of the current season and seasonal changes. [Means for solving the problem]

[0008] To this end, a calendar mechanism is provided as set forth in claim 1, particular embodiments being defined in the dependent claims.

[0009] The invention also relates to a timepiece, such as a wristwatch, pocket watch or miniature clock, equipped with a calendar mechanism or the like.

[0010] Other features and advantages of the invention will become apparent from the following detailed description, given with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0011] [Figure 1] 1 shows a plan view of a calendar mechanism according to one particular embodiment of the present invention. [Diagram 2] FIG. 2 shows a perspective view of the calendar mechanism shown in FIG. [Diagram 3] FIG. 2 shows a unidirectional gear formed by the hour cam and pinion of the date drive wheel assembly of the calendar mechanism shown in FIG. 1. [Figure 4] FIG. 2 shows a plan view of a portion of the calendar mechanism shown in FIG. 1 with some elements removed to show what is located underneath. [Diagram 5] FIG. 5 is a view similar to FIG. 4, but showing hidden parts using dashed lines. [Figure 6] FIG. 2 illustrates a bottom view of a portion of the calendar mechanism shown in FIG. 1 , showing the season indication drive wheel, the safety member, and the season indication star wheel in an inoperative state. [Figure 7] FIG. 7 illustrates a bottom view of the portion shown in FIG. 6 showing the seasonal indication drive wheel, the safety member, and the seasonal indication star wheel during driving of the seasonal indication star wheel. [Figure 8] FIG. 13 shows a plan view of a calendar mechanism according to another embodiment of the present invention showing the quarter drive wheel and the quarter intermediate wheel before the passage of the seasons. [Figure 9] FIG. 13 shows a perspective view of a calendar mechanism according to another embodiment of the present invention, showing the quarter drive wheel and the quarter intermediate wheel before the passage of the seasons. [Figure 10] FIG. 9 illustrates a plan view of the portion shown in FIG. 8 showing the quarter drive wheel and the quarter intermediate wheel before the passage of the month. [Figure 11] FIG. 10 illustrates a perspective view of the portion shown in FIG. 9 showing the quarter drive wheel and the quarter intermediate wheel before the passage of the month. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] With reference to Figures 1 to 3, a calendar mechanism 1 according to the invention, incorporated in a clock movement, comprises an hour cam coaxially and fixedly mounted on the hour wheel of the clock movement, thus rotating at a rate of one revolution every 12 hours. This hour cam 2 is a disk having, over one quarter of its circumference, a toothed portion 6 with four teeth arranged to cooperate with a pinion 8 of a date drive wheel assembly 10. The pinion 8 is driven by the toothed portion 6 when the toothed portion is arranged against the pinion, i.e. for three hours of every 12-hour period, and rotates 180° during these three hours of drive. The pinion 8 remains stationary when it is opposed to a non-toothed portion of the hour cam 2, i.e. for the remaining nine hours. The pinion 8 thus rotates once every 24 hours, but this operation during the 24 hours lasts only six hours in total. The hour cam 2 thus constitutes an acceleration cam making it possible to accelerate the rotation of the pinion 8. The hour hand cam 2 also has the function of preventing any backward time setting of the movement around midnight, as will be explained below with reference to FIG.

[0013] Besides the pinion 8, the date drive wheel assembly 10 comprises a lower finger 12 or first finger and an upper finger 14 or second finger, which are rigidly coupled to the pinion 8 at angularly and height-offset positions (see FIG. 4). With each revolution of the date drive wheel assembly 10, around midnight, the lower finger 12 advances by one pitch a date wheel 16 which has 31 teeth and is acted upon by a date jumper 18. This date wheel 16 thus rotates once per month and is coaxial with a month cam 20 which pivots freely relative to the date wheel 16. The outer edge of the month cam 20 comprises an alternating arrangement of valleys and ridges, the valleys corresponding to months with 31 days and the ridges corresponding to months with less than 31 days.

[0014] A month lever 22 is pivotally mounted on the plate of the date wheel 16 and is provided with a projection 22a capable of cooperating with the outer edge of the month cam 20. The month lever 22 rotates freely, but its movement is limited in one direction by the month cam 20 and in the other direction by a pin 22b driven into the plate of the date wheel 16. When the month lever 22 bears against the protuberance of the month cam 20, the tooth 24 of the month lever 22 overlaps on the tooth of the date wheel 16 and thus lies on the track of the upper finger 14 when the date wheel 16 is in an angular position corresponding to the 30th day. When the projection 22a rests in the valley of the month cam 20, the tooth 24 is retracted relative to the tooth of the date wheel 16 and cannot co-operate with the upper finger 14.

[0015] Thus, during months of 31 days, the upper finger 14 cannot act on the date wheel 16, and the passage from 30 to 31 is carried out, as on the other days, by the action of the lower finger 12. Even if the tooth 24 were arranged superimposed on the toothing of the date wheel 16, the tooth 24 would in fact recede when meeting the upper finger 14, preventing the upper finger 14 from driving the date wheel 16. In contrast, on the 30th day of a 30-day month, around midnight, the upper finger 14 cooperates with the tooth 24 of the month lever 22, which tooth 24 supports a projection 22a on a ridge of the month cam 20 to then move the date wheel 16 by a first pitch for the passage from 30 to 31, and then the lower finger 12 cooperates with the toothing of the date wheel 16 to advance the date wheel 16 by one more pitch to ensure the passage from 31 to 1.

[0016] The movement of each of the date wheels 16 is transmitted via a gear train (not shown) to a date indicating member (not shown), such as a crown, a disc or a hand.

[0017] The date drive wheel assembly 10, the date wheel 16 and the month lever 22 form part of an annual date mechanism based on the principles described in CH 685585 and WO 2019 / 193430. Nevertheless, the date mechanism can be simple or permanent.

[0018] A quarter drive wheel 26 is mounted coaxially on the date wheel 16. The quarter drive wheel 26 can only rotate relative to the date wheel 16 through a certain angle defined by two openings 28 made in the date wheel 16 through which pass two pins 30, respectively, which are driven on the quarter drive wheel 26 on the one hand and on the seasonal part 32 on the other hand. The seasonal part 32 comprises a toothed portion 34 with four teeth which are superimposed on the teeth of the date wheel 16. A return spring 36 mounted on the plate of the date wheel 16 acts on the seasonal part 32 in such a way that at least one of the pins 30 is kept in a supporting position against the wall of the corresponding opening 28. This supporting position allows the date wheel 16 to drive the quarter drive wheel 26.

[0019] The seasonal part 32 is positioned such that, at about midnight on the 19th of each month, the upper finger 14 engages a first tooth of the seasonal part 32 and cooperates with a first tooth to move the quarter drive wheel 26 relative to the date wheel 16 against the action of the return spring 36 by an angle corresponding to one pitch of the date wheel 16. Then, still at about midnight on the 19th, the lower finger 12 acts on a tooth of the date wheel 16 to advance the date wheel 16 by one pitch to catch up with the quarter drive wheel 26. At about midnight on the 20th, the upper finger 14 engages a second tooth of the seasonal part 32 and cooperates with a second tooth to move the quarter drive wheel 26 relative to the date wheel 16 against the action of the return spring 36 by an angle corresponding to one pitch of the date wheel 16. The lower finger 12 then acts on a tooth of the date wheel 16 in order to advance it by one pitch to catch up with the quarter drive wheel 26. The same action takes place on the 21st between the upper finger 14 and the third tooth of the season part 32 and between the lower finger 12 and the tooth of the date wheel 16, and on the 22nd between the upper finger 14 and the fourth tooth of the season part 32 and between the lower finger 12 and the tooth of the date wheel 16. On the other days, it is the date wheel 16 that drives the quarter drive wheel 26 by means of at least one of the pins 30 supported in the wall of the corresponding opening 28.

[0020] Thus, the quarter drive wheel 26 is driven by 1 / 31 of a revolution each day, like the date wheel 16, but between the 19th and 23rd, this operation is performed in a time offset manner with respect to the date wheel 16. This allows a distribution of energy consumption. As will be seen below, the operation of the quarter drive wheel 26 between the 19th and 23rd actually causes the operation of the seasonal display every quarter. In order to avoid large peaks in energy consumption, it is advantageous for the date jumps and the seasonal jumps to take place at different times. However, in one variant, the seasonal part 32 can be omitted and the quarter drive wheel 26 can be fixedly attached to the date wheel 16.

[0021] The quarter drive wheel 26 comprises a seasonal drive toothed portion formed by two large teeth 38. The quarter drive wheel 26 further comprises small teeth 40 for driving the months. The two large teeth 38 are dimensioned to advance the quarter intermediate wheel 42 by four pitches - the first from the 19th to the 20th, the second from the 20th to the 21st, the third from the 21st to the 22nd, and the fourth from the 22nd to the 23rd. The small teeth 40 advance the quarter intermediate wheel 42 by one pitch at the end of each month. The quarter intermediate wheel 42 comprises six toothed portions 44, each having four teeth, the toothed portions 44 being separated by six gaps 46, each taking the place of a tooth. The gaps 46 have the function of allowing the small teeth 40 to catch the correct tooth of the quarter intermediate wheel 42 every time. The gaps 46 do not prevent the two large teeth 38 from driving the quarter intermediate wheel 42.

[0022] The quarter intermediate wheel 42 completes one revolution every six months. A lunar drive wheel 48 (see FIG. 1) is fixedly and coaxially mounted to the quarter intermediate wheel 42 and drives, via an intermediate wheel 50, a lunar wheel 52 which is fixedly and coaxially mounted to the lunar cam 20, one revolution every twelve months.

[0023] The quarter intermediate wheel 42 is acted upon by a quarter jumper 56 and meshes with a 15-tooth pinion 54 which forms part of a quarter wheel assembly 58 (see FIG. 5). The quarter wheel assembly 58 comprises a month indicator drive wheel 60 and a season indicator drive wheel 62, both of which are fixedly mounted on the pinion 54 (see FIG. 1). The quarter wheel assembly 58 moves once per quarter, but with respect to the quarter intermediate wheel 42, its movement is irregular, with one jump each day around midnight between the 19th and 23rd and one jump around midnight at the end of each month, i.e. five jumps per month and fifteen jumps per quarter.

[0024] The lunar indicator drive wheel 60 is provided with three teeth 64 arranged at 120° to each other (only two of which are visible in FIG. 1). On the last day of each month, one of these teeth 64 advances by one pitch a pinion 66 of a lunar indicator intermediate wheel assembly 68 (see FIG. 2) whose wheel 70 meshes with a lunar indicator wheel 72 which is fixedly attached to the pinion 66 and which carries a lunar indicator member such as a hand or a disk which, in combination with the dial, indicates the current month. A square portion 74 with a concave surface, fixedly attached to the pinion 66 and to the wheel 70, fits closely against a toothless upper portion of the periphery of the lunar indicator drive wheel 60 in order to prevent, in the event of an impact, an inadvertent rotation of the lunar indicator wheel 72 and the lunar indicator member under the effect of inertia, or even the driving of the quarter wheel assembly by the lunar indicator wheel 72. Three notches 76 created in the toothless upper portion vertically aligned with the teeth 64 allow the square portion 74 and thus the month indicator intermediate wheel assembly 68 to rotate when one of the teeth 64 cooperates with the pinion 66 to drive it.

[0025] The seasonal indicator drive wheel 62 comprises a toothed portion 78 having three teeth, the remainder of the seasonal indicator drive wheel 62 being toothless. The toothed portion 78 meshes with a seasonal indicator star wheel 80 having 16 teeth to move the toothed portion 78 by four teeth between the 19th and 23rd of every three months. The seasonal indicator star wheel 80 carries a seasonal indicating member, such as a disk carrying the seasonal symbol that is acted upon by a seasonal jumper 82 and is successively visible through an opening in the dial or hour hand. In the example shown, the valleys between the teeth of the seasonal indicator star wheel 80 that are not used to mesh with the seasonal indicator drive wheel 62 are partially filled with material to receive a screw 84 that secures the seasonal indicating disk to the seasonal indicator star wheel 80.

[0026] When the season indication star wheel 80 faces the toothless portion of the season indication drive wheel 62, designated 86, the teeth of the season indication star wheel 80 immediately contact this toothless portion 86 upon impact, preventing it from rotating in an unintended manner. In contrast, during the day when engaged with the toothed portion 78, the season indication star wheel 80, under the influence of impact and its inertia, may exert a driving effect and drive the quarter wheel assembly 58. To avoid this, a safety member 88 complements the quarter wheel assembly 58.

[0027] The safety member 88 comprises a safety surface 90 substantially concentric with the toothless portion 86 and the shaft 92 of the quarter wheel assembly 58 (see FIG. 6 ), the safety surface 90 extending around the periphery of the toothless portion 86 at different heights in the region of the toothed portion 78. The safety member 88 is mounted so as to rotate freely about the shaft 92 of the quarter wheel assembly 58, but its rotation relative to the seasonal display drive wheel 62 is limited by cooperation between a pin 94 fitted in the seasonal display drive wheel 62 and an oblong hole 96 created in the safety member 88. A return spring 98 acting between the seasonal display drive wheel 62 and the safety member 88 keeps the safety member 88 supported against the pin 94 in an angular position relative to the seasonal display drive wheel 62 in which three notches 100 provided in the safety surface 90 are vertically aligned with the three teeth of the toothed portion 78, respectively.

[0028] The toothed portion of the seasonal indicator star wheel 80 has a sufficient height to be able to cooperate with both the seasonal indicator drive wheel 62 and the safety member 88. When the toothed portion 78 and the seasonal indicator star wheel 80 are engaged and immobile, as in the configuration shown in Fig. 6, one tooth 80a of the seasonal indicator star wheel 80 faces a part of the safety surface 90, and one tooth 80b of the seasonal indicator star wheel 80 adjacent to the tooth 80a faces another part of the safety surface 90 or a toothless portion 86 of the seasonal indicator drive wheel 62, depending on the relative angular positions of the wheel 62 and the star wheel 80. Thus, when an impact is received by the calendar mechanism 1 attempting to rotate the seasonal indicator star wheel 80, one of the two teeth 80a, 80b immediately contacts the safety surface 90 or the toothless portion 86, depending on the direction of the impact. In this way, rotation of the seasonal indicator star wheel 80 in an untimely manner and driving of the quarter wheel assembly 58 is prevented.

[0029] The rotational mobility of the safety member 88 relative to the seasonal display drive wheel 62 allows the safety member 88 not to hinder the drive of the seasonal display star wheel 80 by the seasonal display drive wheel 62. In fact, each jump of the seasonal display star wheel 80 comprises a first jump part, during which the star wheel 80 is driven by the toothed portion 78 against the action of the seasonal jumper 82, and a second jump part, caused by the seasonal jumper 82 after it has passed the tip of the tooth of the seasonal wheel 80. During the first jump part, the safety member 88 is fixed relative to the seasonal display drive wheel 62 by means of a pin 94 bearing against the wall of an oblong hole 96. During the second jump part, the safety member 88 makes use of its mobility relative to the seasonal display drive wheel 62 against the action of a return spring 98 to allow the passage of a tooth of the seasonal display star wheel 80 (see FIG. 7) that is located in one of the notches 100, which then continues to move until the jump of the seasonal display drive wheel 62 is over.

[0030] It will have been understood that the different moving members of the calendar mechanism 1 are indexed to one another such that actuation of the quarter drive wheel 26 by the upper finger 14 between the 19th and 23rd of each month does not cause actuation of the seasonal indicator star wheel 80 by the quarter wheel assembly 58 between two successive months (the toothed portion 78 does not face the seasonal indicator star wheel 80) and does cause actuation of the seasonal indicator star wheel 80 by the quarter wheel assembly 58 in the third month between the 19th and 23rd. The seasonal indicator star wheel 80 and the season indicating member on which it is mounted thus rotate a quarter revolution every three months between the 19th and 23rd and remain motionless the rest of the time.

[0031] It goes without saying that it is possible to modify the calendar mechanism 1 so that the seasonal indicator star wheel 80 moves a quarter rotation, for example, four jumps between the 18th and 22nd, two jumps between the 20th and 22nd, one jump between the 20th and 21st, or one jump between the 21st or 22nd, rather than four jumps between the 19th and 23rd.

[0032] All the above dates are based on the European dates for the change of seasons, which vary from season to season and from year to year, but always lie between the 19th and 23rd of the last month of each calendar quarter, i.e. between the 19th and 23rd of the months March, June, September and December, and this applies at least until the year 2100.

[0033] However, the invention is applicable to dates relating to seasonal changes other than European dates, for example Russian or Oriental dates, in particular dates relating to seasonal changes at the beginning or middle of a month. Generally speaking, in the present invention, the season indication star wheel 80 is driven only for a predetermined time interval of less than 30 days every three months, this time interval being preferably a maximum of 10 days, preferably a maximum of 7 days, preferably a maximum of 5 days.

[0034] For European dates, the predetermined time interval is part of the last month of each calendar quarter, and preferably the time interval ends before the last day of the last month. The time interval preferably includes, at least in part, the 21st day of the last month of each calendar quarter. The time interval preferably begins at the earliest on the 18th and ends at the latest on the 23rd.

[0035] In any case, it is advantageous to move the seasonal indication star wheel 80 in several jumps distributed over several days, preferably over at least three days and more preferably over at least four days, for two reasons: to ensure that the time intervals between the movements of the seasonal indication star wheel 80 cover the correct dates for the change of seasons, and to smooth out the torque required to drive the seasonal indication star wheel 80, which has to move in quarter rotations to indicate the change of seasons, thus avoiding peaks in energy consumption.

[0036] It will likewise be understood that the various moving members of the calendar mechanism 1 are indexed relative to one another so that action of the quarter drive wheel 26 by the lower finger 12 produces an effect on the month-indicating wheel 72 only at the transition from the last day of each month to the first day of the next month.

[0037] Thus, the invention makes it possible to change the information displayed to the current season at the exact date relative to the change of seasons or to a preselected date, in particular a date different from the last date of the month. Moreover, due to the nature of the safety members 74 and 88, the indication of the season is permanently synchronized with the indication of the month, so that no desynchronization between the season and the month can occur during the correction or continued operation of one or the other.

[0038] In the calendar mechanism 1 as described above, the season indication star wheel 80 cannot move backwards without risk of damage due to the presence of the safety member 88. Other parts of the calendar mechanism 1 may be affected by this problem, for example the month indication if it were retrograde. To protect the calendar mechanism 1, the invention prevents the correction of the time backwards around midnight. To do this, as shown in FIG. 3, the tooth 102 of the pinion 8 of the date drive wheel assembly 10 corresponding to the time range including around midnight has a flat tip 104 oriented tangentially to the axis of the pinion 8 and is truncated on the surface of the front flank 106 of the flat tip 104. When the hour cam 2 is driven by the reverse rotation of the winding stem 108 and starts to rotate counterclockwise, the tooth 6 of the hour cam 2 comes into contact with the tip 104 of one of the teeth 102 and blocks the gear by abutment. The tooth 102 and the toothed portion 6 thus form a unidirectional gear.

[0039] The rotation of the winding stem 108, when the winding stem is located in the axial time setting position, is continuously transmitted to the hour wheel 4 via the timing wheel 110, the first intermediate wheel 112, the second intermediate wheel 114, the third intermediate wheel 116, the motion work wheel 118 and the motion work pinion 120 (see Figures 1 and 2). The second and third intermediate wheels 114, 116 are fixedly mounted coaxially. However, one of the second and third intermediate wheels 114, 116 is frictionally mounted on the common shaft of the intermediate wheels 114, 116 so that the winding stem 108 can be disconnected from the motion work if an excessive torque is applied in the opposite direction by the user to the winding stem 108 while the hour cam 2 is blocked by the pinion 8 of the date drive wheel assembly 10.

[0040] In one exemplary embodiment, the month and season indications may be corrected by means of a corrector acting on a ratchet wheel fixedly mounted coaxially on the quarter intermediate wheel 42. In another exemplary embodiment, the month and season indications may be corrected by the winding stem 108 of the timepiece movement, which has a dedicated axial position, the rotation of which causes the date wheel 16 to rotate independently from the hour wheel 4. In this other exemplary embodiment, it is beneficial to prevent any desynchronization between the quarter intermediate wheel 42 and the date wheel 16. To achieve this purpose, the safety systems shown in figures 8 to 11 may be used.

[0041] The safety system comprises a first safety surface 122 and a third safety surface 124 at the periphery of the quarter drive wheel 26. The first safety surface 122 extends angularly over the entire height of the quarter drive wheel 26 in the toothless portion of the quarter drive wheel 26 preceding the two large teeth 38 for driving the season. Furthermore, the first safety surface 122 is concentric with the axis of the wheel 26 and has a radius R1. The second safety surface 124 extends angularly over the toothless portion of the quarter drive wheel 26 following the two large teeth 38 that protrude slightly beyond the toothless portion, but in the height direction only extends over the lower portion of the quarter drive wheel 26. Furthermore, the second safety surface 124 is concentric with the axis of the wheel 26 and has a radius R2 that is greater than the radius R1 and equal to the radius of the tip circle of the two large teeth 38. The upper part 126 of the toothless part of the quarter drive wheel 26, which follows the two large teeth 38, is concentric with the axis of the wheel 26 and has a radius R3 smaller than the radius R1. This upper part 126 extends from the seasonal drive toothed part formed by the two large teeth 38 to the small tooth 40 for driving the moon, which in this case is no longer in the form of a tooth but in the form of a transition surface between the first safety surface 122 and the upper part 126.

[0042] As can be seen in Fig. 8, the first safety surface 122 serves as an abutment for the last tooth 44a and the first tooth 44b, respectively, of two adjacent toothed portions 44 of the quarter intermediate wheel 42 separated by a gap 46, thus preventing the wheel 42 from releasing its support in one direction or the other to the quarter drive wheel 26 before the passage of the seasons, in the event of an impact. In its face, the second safety surface 124 serves as an abutment for the second tooth 44c and the first tooth 44d, respectively, of two adjacent toothed portions 44 of the quarter intermediate wheel 42 (see Fig. 10), thus preventing the wheel 42 from releasing its support in one direction or the other to the quarter drive wheel 26 before the passage of the months, in the event of an impact.

[0043] In order to enable cooperation between the teeth of the quarter intermediate wheel 42 and the safety faces 122, 124, as well as between the teeth of the quarter intermediate wheel 42 and the teeth of the quarter drive wheel 26, the last two teeth of each toothed portion 44 have a height lower than the height of the first two teeth and are arranged at a height different from the height of the second safety face 124, i.e., on the height of the upper portion 126 and the transition face 40, as shown in Figures 9 and 11.

[0044] The invention has been described above by way of example only, and it will be appreciated that modifications can be made without departing from the scope of the claims.

Claims

1. A calendar mechanism having a seasonal display for a timepiece, comprising: a drive wheel (26) whose angular position represents a date; a seasonal display member (80); a seasonal display drive member (62) configured to be driven by the drive wheel (26) and to drive the seasonal display member (80) only during a predetermined time interval of less than 30 days every three months; A calendar mechanism, characterized by comprising the above.

2. The calendar mechanism according to claim 1, wherein the predetermined time interval is at most 10 days, preferably at most 7 days, and more preferably at most 5 days.

3. The calendar mechanism according to claim 1 or 2, wherein the seasonal display drive member (62) is configured to move the seasonal display member (80) by several pitches that are dispersed over several days, preferably at least 3 days, and more preferably at least 4 days, during the predetermined time interval.

4. The calendar mechanism according to claim 1 or 2, wherein the predetermined time interval is part of the last month of each calendar quarter.

5. The calendar mechanism according to claim 4, wherein the predetermined time interval ends before the last day of the last month.

6. The calendar mechanism according to claim 4, wherein the predetermined time interval at least partially includes the 21st day of the last month of each calendar quarter.

7. The calendar mechanism according to claim 4, wherein the predetermined time interval starts at the earliest on the 18th day, preferably at the earliest on the 19th day, and ends at the latest on the 23rd day.

8. The calendar mechanism according to claim 1 or 2, wherein the seasonal display drive member (62) forms part of a wheel assembly (58) configured to be driven by the drive wheel (26) and further includes a monthly display drive member (60).

9. The calendar mechanism according to claim 8, wherein the wheel assembly (58) is a quarterly wheel assembly that rotates once every three months, the seasonal display drive member (62) is a wheel having a toothed portion (78), and the monthly display drive member (60) is another wheel having three teeth (64) arranged at 120° to each other.

10. The calendar mechanism according to claim 9, wherein the quarterly wheel assembly (58) further includes a safety member (88) to prevent the seasonal display member (80) from driving the quarterly wheel assembly (58) under the influence of inertia during impact.

11. The safety member (88) includes a safety member (88) that is substantially concentric with the shaft (92) of the quarterly wheel assembly (58) and can come into contact during a collision when the seasonal display member (80) engages with the toothed portion (78). The safety member (88) has limited rotational mobility with respect to the seasonal display drive member (62) and a notch (100) in the safety outer surface (90) so as not to interfere with the normal driving of the seasonal display member (80). The calendar mechanism according to claim 10.

12. The drive wheel (26) is coaxial with a date wheel (16) configured to drive a date indicating member and be driven by a date drive wheel assembly (10). The drive wheel (26) is configured to be driven by the date drive wheel assembly (10) in a time offset manner with respect to the driving of the date wheel (16) during the predetermined time interval. The calendar mechanism according to claim 1 or 2.

13. The drive wheel (26) is configured to be driven by the date wheel (16) every day except during the predetermined time interval when it is directly driven by the date drive wheel assembly (10) in a time offset manner with respect to the driving of the date wheel (16). The calendar mechanism according to claim 12.

14. The date drive wheel assembly (10) includes first and second fingers (12, 14) at different heights. The first finger (12) is configured to cooperate with the date wheel (16) every day, and the second finger (14) is configured to cooperate with at least one tooth (34) fixedly attached to the drive wheel (26) during the predetermined time interval. The calendar mechanism according to claim 13.

15. The second finger (14) is also configured to cooperate with a tooth (24) of a lever (22) held by the date wheel (16) and is configured to cooperate with a month cam (20) coaxial with the date wheel (16) during the transition from the last day of a 30-day month to the first day of the next month. The calendar mechanism according to claim 14.

16. A calendar mechanism according to claim 1 or 2, comprising gears (6, 8) between the hour hand wheel (4) and the drive wheel (26), at least a part (6, 102) of the gears being in a single direction to prevent reverse time setting around 0:00 am.

17. A clock comprising the calendar mechanism according to claim 1 or 2.

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