year, duration or jahrhundertsdatumschaltwerk

摘要

The invention concerns a perpetual calendar mechanism actuated by a power wheel (23) of a clockwork movement and displaying at least the calendar date of the day. It exclusively consists of rotary mobile elements formed by gears and the power wheel (23) completes one revolution per day instantaneously at midnight. One of the gears is a date wheel (31) driving a mobile element displaying (18) the date. Said date wheel (31) comprises thirty one teeth and is driven at the rate of one pitch per day by a driving tooth (24) integral with the power wheel (23). At least another of said gears is a mobile element for the duration of the months (42, 43) capable of being driven in the four last days of the month by a control wheel (30) integral with the date wheel, said mobile element for the duration of months (42, 43) comprising a set of teeth consisting of a set of 0 to 3 tooth groups, each of the groups corresponding to a month of the year. The date wheel (31) is driven at the end of the months of thirty one days by a number of pitches corresponding to the difference between thirty one and the number of days of the month concerned by an adjusting clock train comprising at least a drive pinion (25) integral with the power wheel (23), the mobile element for the duration of the month (42, 43), the date driving pinion (36) and the control wheel (30).