Patent ID: 6934221
Filing Date: 2005-08-23
Classification: G04B

Abstract:
1. A date mechanism for a timepiece such as a wristwatch including two superposed respectively lower and upper date rings, whose surface is divided into a plurality of sectors, the upper ring including sixteen sectors, fifteen of which respectively bear fifteen successive markings of a cycle of 31 positions, and the sixteenth of which is an extra sector having an open or transparent aperture, whereas the lower ring includes seventeen sectors, sixteen of which bear respectively the other sixteen markings of the cycle of 31 positions, and the seventeenth of which is an extra sector, each of said rings being provided with a peripheral toothing made of a succession of regularly spaced teeth and cooperating with drive means such that the markings of the lower ring appear successively in a display zone through the aperture, the upper ring remaining immobile, and in that, since the lower ring is immobile, the markings of the upper ring successively appear in the display zone, the upper ring concealing the markings of the lower ring, the date mechanism further including a jumper-effect stopping device able to stop each ring in any desired position, the stopping device being adapted to the pitch of the particular ring concerned, said date mechanism being wherein one location on the upper ring and one location on the lower ring is provided with a thinned tooth and, located between two successive teeth of the toothing of the ring concerned, the position of the drive means with respect to the toothing of the rings being such that when a ring has its extra sector at the location of the display zone, the thinned tooth is located opposite the drive means such that said drive means only drive the other ring, the thinned teeth not disturbing the movement of the drive means and allowing the stopping device to be constantly housed between two successive teeth of each of the rings.