Calendar mechanism with season display for a timepiece

1 . Calendar mechanism with display of the seasons for a timepiece, comprising:

a drive wheel, the angular position of which is representative of the date,

a season display member, and

a season display drive member arranged to be driven by the drive wheel and to drive the season display member only during a predetermined time interval, of less than thirty days, every three months,

wherein the season display drive member is arranged in order, during the predetermined time interval, to move the season display member by several pitches distributed over several days.

2 . The calendar mechanism as claimed in claim 1 , wherein the predetermined time interval is of at most ten days.

3 . The calendar mechanism as claimed in claim 1 , wherein the predetermined time interval is a part of the last month of each calendar quarter.

4 . The calendar mechanism as claimed in claim 3 , wherein the predetermined time interval ends before the last day of said last month.

5 . The calendar mechanism as claimed in claim 3 , wherein the predetermined time interval includes, at least partially, the twenty-first day of the last month of each calendar quarter.

6 . The calendar mechanism as claimed in claim 3 , wherein the predetermined time interval begins at the earliest on the 18 th , and ends at the latest on the 23 rd .

7 . The calendar mechanism as claimed in claim 1 , wherein the season display drive member forms part of a wheel assembly arranged to be driven by the drive wheel and further comprising a month display drive member.

8 . The calendar mechanism as claimed in claim 7 , wherein said wheel assembly is a quarter year wheel assembly making one turn in three months, wherein the season display drive member is a wheel comprising a toothed sector and wherein the month display drive member is another wheel comprising three teeth located at 120° with respect to each other.

9 . The calendar mechanism as claimed in claim 8 , wherein the quarter year wheel assembly further comprises a safety member to prevent the season display member from driving the quarter year wheel assembly under the effect of its inertia in the event of an impact.

10 . The calendar mechanism as claimed in claim 9 , wherein the safety member comprises a safety surface substantially concentric with the shaft of the quarter year wheel assembly and against which the season display member can abut in the event of an impact when it is in engagement with the toothed sector, and wherein the safety member has limited rotational mobility with respect to the season display drive member as well as notches in its safety surface so as not to impede the normal driving of the season display member.

11 . The calendar mechanism as claimed in claim 1 , wherein the drive wheel is coaxial to a date wheel arranged to drive a date indicator member and to be driven by a date drive wheel assembly, and wherein the drive wheel is arranged to be driven by the date drive wheel assembly in a time-offset manner with respect to the driving of the date wheel during the predetermined time interval.

12 . The calendar mechanism as claimed in claim 11 , wherein the drive wheel is arranged to be driven by the date wheel every day except during the predetermined time interval in which it is driven directly by the date drive wheel assembly in a time-offset manner with respect to the driving of the date wheel.

13 . The calendar mechanism as claimed in claim 12 , wherein the date drive wheel assembly comprises first and second fingers at different heights, the first finger being arranged to cooperate every day with the date wheel, the second finger being arranged to cooperate with at least one tooth fixedly attached to the drive wheel during the predetermined time interval.

14 . The calendar mechanism as claimed in claim 13 , wherein the second finger is also arranged to cooperate with a tooth of a lever carried by the date wheel and arranged to cooperate with a month cam coaxial to the date wheel during passage from the last day of a month of thirty days to the first day of the following month.

15 . The calendar mechanism as claimed in claim 1 , further comprising, between an hour wheel and the drive wheel, a gear, at least a part of which is unidirectional so as to prevent backwards time-setting around midnight.

16 . Timepiece comprising a calendar mechanism as claimed in claim 1 .

17 . Calendar mechanism with display of the seasons for a timepiece, comprising:

a drive wheel, the angular position of which is representative of the date,

a season display member, and

a season display drive member arranged to be driven by the drive wheel and to drive the season display member only during a predetermined time interval, of less than thirty days, every three months,

wherein the season display drive member forms part of a wheel assembly arranged to be driven by the drive wheel and further comprising a month display drive member, and

wherein said wheel assembly is a quarter year wheel assembly making one turn in three months, wherein the season display drive member is a wheel comprising a toothed sector and wherein the month display drive member is another wheel comprising three teeth located at 120° with respect to each other.

18 . Calendar mechanism with display of the seasons for a timepiece, comprising:

a drive wheel, the angular position of which is representative of the date,

a season display member, and

a season display drive member arranged to be driven by the drive wheel and to drive the season display member only during a predetermined time interval, of less than thirty days, every three months,

wherein the drive wheel is coaxial to a date wheel arranged to drive a date indicator member and to be driven by a date drive wheel assembly, and

wherein the drive wheel is arranged to be driven by the date drive wheel assembly in a time-offset manner with respect to the driving of the date wheel during the predetermined time interval.