ANNUAL CALENDAR MECHANISM FOR A TIMEPIECE

摘要

The invention concerns an annual calendar mechanism, including: a date ring ( 10 ) including a lug ( 30 ) and 31 teeth ( 32 ), and a date wheel set ( 12 ) arranged for rotating the date ring ( 10 ) through one step per day, an intermediate wheel set ( 16, 56 ) cooperating with said lug ( 30 ) such that the date wheel set ( 12 ) drives the intermediate wheel set ( 16 ) through a first step when the date passes from the 30^th to the 31^st of the month, via the date ring ( 10 ), an annual wheel set ( 14 ) meshed with the intermediate wheel set ( 16 ) and cooperating with the date wheel set ( 12 ), said date ( 12 ), intermediate ( 16 ) and annual ( 14 ) wheel sets being arranged such that said date wheel set ( 12 ) drives the intermediate wheel set ( 16 ) through a second step when the date passes from the 31^st to the 1^st of the month, for the months of 31 days, via the date ring ( 10 ), and such that said date wheel set ( 12 ) drives the intermediate wheel set ( 16 ) through a second step after the date has passed from the 30^th to the 31^st of the month, for the months of less than 31 days, via the annual wheel set ( 14 ), the intermediate wheel set ( 16 ) then driving the date wheel ring ( 10 ). The mechanism further includes a month indicator ring ( 52 ) cooperating with the intermediate wheel set ( 16 ), the intermediate wheel set ( 16 ) being arranged for rotating the month ring ( 52 ) at least to the second step.