Device intended to control the angular speed of a train in a timepiece movement and including a magnetic escapement

Patent metadata

Field	Value
Publication number	US-2016357155-A1
Application number	US-201415109066-A
Country	US
Kind code	A1
Filing date	Dec 22, 2014
Priority date	Dec 23, 2013
Publication date	Dec 8, 2016
Grant date	—

Abstract

There is provided a device for regulating the operation of a horological movement, including a magnetic escapement, which includes a resonator and a magnetic escapement mobile turning about an axis. The mobile includes at least one magnetic track with a plurality of magnets having an angular dimension that is greater than their radial dimension. The resonator includes at least one magnetic element for coupling to the magnetic track. The coupling element extends radially relative to the axis of rotation, and has a contour with a portion oriented substantially angularly when the resonator is in the rest position. When the mobile is driven in rotation, each magnet penetrates beneath the coupling element and gradually accumulates some potential magnetic energy. The magnet then exits from beneath the coupling element through the portion and the coupling element receives a pulse located around its rest position.

First claim

1 . A device for regulating the relative angular frequency (co) between a magnetic structure and a resonator magnetically coupled so as to define together an oscillator forming said regulating device, the magnetic structure comprising at least one annular magnetic track centred on an axis of rotation of said magnetic structure or of the resonator, the magnetic structure and the resonator being arranged to rotate in relation to one another about said axis of rotation when a torque is applied to the magnetic structure or to the resonator; the resonator comprising at least one magnetic element for a magnetic coupling to said annular magnetic track, said magnetic coupling element having an active end portion made of a first magnetic material and situated on the same side as said annular magnetic track; said annular magnetic track being made at least in part of a second magnetic material arranged such that the potential magnetic energy of the oscillator varies angularly and periodically along the annular magnetic track, thus defining an angular period (θ P ) of said annular magnetic track, and defining magnetically first zones and second zones angularly alternating with a first zone and an adjacent second zone in each angular period; each second zone producing, relative to an adjacent first zone, a stronger repulsion force or a weaker attraction force for any same zone of said active end portion when said any same zone is superimposed, in orthogonal projection to a general geometric surface in which the annular magnetic track extends, respectively on said second zone or on said adjacent first zone; said magnetic coupling element being magnetically coupled to said annular magnetic track such that an oscillation by a degree of freedom of a resonant mode of the resonator is maintained within a useful range for the torque applied to the magnetic structure or to the resonator and that a such period of said oscillation occurs during said relative rotation in each angular period of said annular magnetic track, the frequency of said oscillation thus determining said relative angular frequency, said degree of freedom defining an axis of oscillation of said active end portion passing through its centre of mass; said resonator being arranged relative to said magnetic structure such that said active end portion is at least for the most part superimposed in orthogonal projection on said annular magnetic track during substantially a first alternation in each period of said oscillation, and such that the course taken by the magnetic coupling element during said first alternation is substantially parallel to said general geometric surface, the annular magnetic track having in said general geometric surface a dimension along the orthogonal projection of said axis of oscillation which is greater than the dimension of said active end portion along said axis of oscillation;
wherein each of said second zones has in orthogonal projection a general contour with a first portion, defining a line of penetration above said second zone for said active end portion of the magnetic coupling element during said oscillation, and with a second portion defining an exit line above said second zone for said active end portion during said oscillation, said exit line being oriented substantially in an angular direction parallel to a zero position circle which is centred on said axis of rotation and which passes through the orthogonal projection of the centre of mass of said active end portion in its rest position; wherein the magnetic structure also defines for the active end portion at least one exit zone which extends in said general geometric surface, said at least one exit zone receiving in orthogonal projection at least the greater part of said active end portion when said active end portion exits, during said oscillation, successively from the annular magnetic track by the respective exit lines of the second zones, said at least one exit zone producing, relative to said second zones, a weaker repulsion force or a stronger attraction force for any same zone of said active end portion when said any same zone is superimposed in orthogonal projection respectively on said at least one exit zone or on said second zones; wherein the active end portion of said coupling element in its rest position has, in orthogonal projection in said general geometric surface, a first dimension, along a first axis perpendicular to said zero position circle and passing through the orthogonal projection of the centre of mass of said active end portion, and a second dimension, along a second axis defined by said zero position circle, which is greater than said first dimension; and wherein said exit line of each of the two zones has a length, along said at least one exit zone and along said second axis, which is greater than the first dimension of the active end portion.

2 . The device according to claim 1 , wherein said exit line of each second zone is substantially merged with said zero position circle.

3 . The device according to claim 2 , wherein said useful torque range, said annular magnetic track, said at least one exit zone and said magnetic coupling element define in each angular period, depending on the relative position of said annular magnetic track and of said active end portion, an accumulation sector in which said oscillator basically accumulates potential magnetic energy and a pulse sector, adjacent to said accumulation sector, in which the magnetic coupling element basically receives a pulse, the pulse sectors being situated in a central pulse zone comprising the relative positions corresponding to said zero position circle.

4 . The device according to claim 2 , wherein said zero position circle and said axis of oscillation are substantially orthogonal at their point of intersection.

5 . The device according to claim 1 , wherein the second dimension of said active end portion is at least twice as great as its first dimension and said length of the exit line is at least twice as great as said first dimension.

6 . The device according to claim 1 , wherein the second dimension of said active end portion is at least four times greater than its first dimension and said length of the exit line is at least four times greater than said first dimension.

7 . The device according to claim 1 , wherein the orthogonal projection in said general geometric surface, said penetration line of each second zone is oriented substantially along said axis of oscillation when this penetration line is aligned with the centre of mass of said active end portion.

8 . The device according to claim 1 , wherein the exit line of said second zones along said at least one exit zone and said active end portion extend angularly relative to said axis of rotation over substantially half an angular period (θ P ).

9 . The device according to claim 1 , wherein the dimension of each of said second zones, along an axis perpendicular to said zero position circle at a mid-point of said exit line, is at least three times as great as the first dimension of said active end portion.

10 . The device according to claim 1 , wherein the dimension of each of said second zones, along an axis perpendicular to said zero position circle at a mid-point of said exit line, is at least six times greater than the first dimension of said active end portion.

11 . A device for regulating the relative angular frequency (ω) between a magnetic structure and a resonator magnetically coupled so as to define together an oscillator forming said regulating device, the magnetic structure comprising at least one annular magnetic track centred on an axis of rotation of said magnetic structure or of the resonator, the magnetic structure and the r

Assignees

• Swatch Group Res & Dev Ltd

Inventors

• Di Domenico Gianni
• Winkler Pascal

Classifications

• G04C5/005 Primary

  Magnetic or electromagnetic means · CPC title

• G04B18/00

  Mechanisms for setting frequency {(for stabilising frequency G04B17/00)} · CPC title

• G04B17/04

  Oscillators acting by spring tension · CPC title

• G04B15/00

  Escapements ({in striking mechanisms G04B21/06;} electric or magnetic means for converting oscillatory to rotary motion in electromechanical time-pieces {G04C5/005}) · CPC title

• G04B15/06

  Free escapements · CPC title