Regulating element for wristwatch and mechanical movement comprising one such regulating element

#The present invention concerns a regulating element for wristwatch and a mechanical movement comprising one such regulating element.

#Usual mechanical watches comprise an energy accumulator constituted of a barrel, a cinematic chain, or gear train, driving the hands, a regulating element determining the running of the watch as well as an escapement for transmitting the oscillations of the regulating element to the gear train. The present invention concerns in particular the regulating element.

#Conventional regulating elements usually comprise a balance mounted on a rotating axle and a return member exerting a torque on the balance to return it towards an equilibrium position. The escapement, or driving element, maintains the barrel's oscillations around the equilibrium position. The return member generally includes a spiral spring, often called spiral, mounted coaxially to the balance. The spiral transmits a return torque to the balance through the collet; the resting position of the spiral spring determines the return position of the balance.

#The invention will be better understood by reading examples of embodiments illustrated by the attached figures, which show:

#FIG. 1a, a diagrammatic top view of a first embodiment of a regulating member according to the invention.

#FIG. 1b, a diagrammatic top view of a first embodiment of a regulating member according to the invention, with the balance being in the position of equilibrium defined by the magnets.

#In the following description and in the claims, the adjective “fixed” always refers to the movement. An element is fixed if it does not move relative to the movement, for example relative to the movement's bottom plate.

#The term “balance” designates a part oscillating under the effect of an excitation around a position of equilibrium. The more or significantly isochronous oscillations determine the running of the watch. The balance can be constituted by a wheel with any number of spokes, a disc, a rod, pallets, etc.

#FIG. 1b illustrates diagrammatically a regulating member 1 having a balance 3 oscillating around an axle 300 perpendicular to the movement's bottom plate. In this example, the balance 3 has an annular felloe and has two radial spokes (or arms) 302 around the axle 300. Screws 301 allow the balance's inertia moment to be moved easily. The balance constitutes an inertia mass; its mass, as well as its radius, are preferably considerable within the limits set by the will to miniaturize the movement. The considerable return force afforded by the claimed solution allows particularly considerable inertia masses to be used.