Mechanism for driving an indicator

A mechanism for driving an indicator of information connected to a clockwork movement and varying over several periods, during each of which said information evolves step by step, up to a maximum value varying between n and n−m, said mechanism comprising:

• a first set of first drive pinions supplied with energy by the movement,
• a drive wheel comprising a first toothing arranged to mesh with the first set of first drive pinions to advance by n steps per period,
• a second set of second drive pinions supplied with energy by the movement, the first and second sets of drive pinions being positioned relative to one another such that they do not cooperate at the same time with the drive wheel,
• m retractable teeth carried by the drive wheel, each being arranged to move between at least two positions, namely an active position for meshing with one of the second drive pinions of the second set of second drive pinions and advancing the drive wheel by one additional step, and an inactive position for not cooperating with said second drive pinion,
• coding cams, each associated with at least one retractable tooth, and coding wheels secured with said coding cams, the number of coding cams being comprised between 1 and m and the number of coding wheels being less than or equal to the number of coding cams, each coding cam being associated with at least one minimum value n−x of the information, x comprised between 1 and m, for a period, and arranged both to cause the associated retractable tooth to go from the active position to the inactive position and from the inactive position to the active position upon each period for which the maximum associated value of the information is a value comprised between n−m and n−x, and
• drive means arranged to kinematically connect the drive wheel to each of the coding wheels and arranged to impart a suitable speed of rotation to the coding cams relative to the drive wheel, such that, when the information reaches a maximum value n−x for a period, x retractable teeth enter the active position, then return to the inactive position, the drive wheel advancing by x additional steps for that period, n, m and x being natural integers, m being ≧1, wherein each retractable tooth comprises a stud and the corresponding coding cam associated with a maximal value n−x of the information comprises a track in which the stud can circulate, the track having a suitable configuration such that the retractable tooth remains in its inactive position upon each period for which the associated maximal value of the information is a value comprised between n−x+1 and n, and such that the retractable tooth moves from its inactive position toward its active position upon each period for which the associated maximal value of the information is a value comprised between n−m and n−x, and then returns to its inactive position after having cooperated with the second drive pinion.