Patent ID: 7859950

Claim:
A large date calendar day mechanism for a timepiece comprising indicators superposed one on top of the other, to which a portion of the numerals of the days of the month is affixed, said numerals appearing in turn through a large aperture drilled into the dial forming part of the timepiece, wherein the indicators comprise an upper disc, an intermediate disc and a lower disc, wherein the upper disc is divided into eleven sectors, of which ten are occupied by numerals from 1 to 10 and one is occupied by a window, through which the numerals of the intermediate disc can be seen, the intermediate disc is divided into eleven sectors, of which ten are occupied by numerals from 11 to 20 and one is occupied by a window, through which the numerals of the lower disc can be seen, and the lower disc is divided into eleven sectors, all of which are occupied by numerals from 21 to 31, in that each of the discs is driven by a cannon pinion integral to a star wheel, wherein these cannon pinions are freely pressed one into the other, and wherein a control movement fitted with a calendar day wheel advancing one step per day is arranged to selectively mesh with the star wheels provided for the discs in order to drive the upper disc while the other two discs remain stationary, to drive the intermediate disc when the upper disc has run through all its numerals while the upper and lower discs remain stationary, and to drive the lower disc when the intermediate disc has run through all its numerals while the upper and intermediate discs remain stationary.