Timepiece movement comprising a module fitted with a wheel set meshing with another wheel set pivoting in a base on which the module is mounted

摘要

Timepiece movement including a module fitted with a first wheel set meshing with a second wheel set, which pivots on a base on which the module is mounted. The movement includes a means of positioning the module formed by a cam, at least most of the periphery of which forms an Archimedes' spiral. The cam is arranged so as to allow the distance of centers between the first and second wheel sets to be adjusted, when the cam is rotated on itself about the center of the Archimedes' spiral. The cam is preferably calibrated. The invention also concerns a method of adjusting the distance of centers between the two wheel sets using said cam to optimise the gearing efficiency of the two wheel sets.