Contactless cylinder escapement

Patent metadata

Field	Value
Publication number	US-9915922-B2
Application number	US-201615286022-A
Country	US
Kind code	B2
Filing date	Oct 5, 2016
Priority date	Dec 10, 2015
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

Magnetic cylinder escapement, comprising a regulating wheel set cooperating with an escape wheel comprising actuators ( 6 ) at the periphery of a first disc, each comprising a first impulse part and a second stop part, generating or guiding magnetic fields parallel to the pivot axes, and arranged to work in attraction, via the first disc, with a second non-magnetically charged, soft ferromagnetic disc integral with the regulating wheel set, the mechanism comprising a conductive ferromagnetic plate, underneath but not in contact with the first disc, comprising a cutout surrounding, in a contactless manner, the periphery of the second disc, with a variable air-gap, and closing a magnetic circuit comprising an actuator, the first disc, the second disc, and a structure in which the escape wheel pivots and which carries the plate.

First claim

What is claimed is:

1. A timepiece escapement mechanism, arranged to cooperate with means for providing torque and comprising at least one escape wheel, which is subjected to a rotational torque, whose moment is lower than or equal to a nominal moment, about a first pivot axis, under the action of said means for providing torque, and comprising a regulating member integral with a regulating wheel set mounted to pivot about a second pivot axis, wherein said escapement mechanism constitutes a magnetic cylinder escapement, and in that said escape wheel comprises a plurality of actuators, regularly spaced around the periphery of a first disc, pivoting integrally with said escape wheel, said actuators each comprising magnetically charged or ferromagnetic magnetic field conductor parts, and each being arranged to work in attraction, via said first disc, with at least a second disc comprised in said regulating wheel set and pivoting integrally therewith, said second disc being soft ferromagnetic and not magnetically charged, each said actuator including at least: a first magnetic impulse part, and a second magnetic stop part, which generate or guide magnetic fields of substantially the same direction and the same sense, substantially parallel to said first pivot axis of said escape wheel, and in that said escape mechanism comprises, substantially in the same plane as said second disc, a conductive ferromagnetic plate, disposed underneath said first disc and not in contact therewith, said plate comprising a cutout which surrounds, in a contactless manner, the periphery of said second disc, so as to provide a variable air-gap between said plate and said second disc, and said plate being arranged to ensure the closing of the magnetic circuit formed by at least one said actuator, said first disc, said second disc, and a structure in which said escape wheel pivots and which carries said plate, and wherein said second disc comprises a first peripheral area defining with said plate a first air-gap greater than a second air-gap that exists between said plate and a second peripheral area adjacent to said first area, and in that said actuators and said first air-gap and said second air-gap are dimensioned such that a said first magnetic part can only cross said second air-gap and is blocked by said first air-gap.

2. The escapement mechanism according to claim 1 , wherein said first area is a cylindrical sector having a first radius about said second pivot axis coaxial with said second area, which is a cylindrical sector having a second radius.

3. The escapement mechanism according to claim 1 , wherein, following said first magnetic impulse part and said second magnetic stop part, each said actuator comprises a mechanical stop, arranged to cooperate, in the event of an excessively high torque, with a non-ferromagnetic truncated crown, comprised in said regulating wheel set, and which forms a complementary mechanical stop.

4. The escapement mechanism according to claim 3 , wherein said truncated crown is superposed on said first area, and in that the opening thereof corresponds to said second area.

5. The escapement mechanism according to claim 3 , wherein said first magnetic impulse part, said second magnetic stop part and said mechanical stop are arranged one after the other, on a substantially equal radius with respect to the first pivot axis.

6. The escapement mechanism according to claim 1 , wherein said regulating member is devoid of magnets.

7. The escapement mechanism according to claim 1 , wherein said disc is made of soft ferromagnetic material.

8. A timepiece movement including an escapement mechanism according to claim 1 .

9. A watch including at least one movement according to claim 8 .

Assignees

• Nivarox Sa

Inventors

• Stranczl Marc

Classifications

• G04C3/10 Primary

  driven by electromagnetic means · CPC title

• G04C5/00

  Electric or magnetic means for converting oscillatory to rotary motion in time-pieces, i.e. electric or magnetic escapements (regulators G04C3/00) · CPC title

• G04C3/105

  pawl and ratchet wheel being magnetically coupled · CPC title

• G04C5/005

  Magnetic or electromagnetic means · CPC title

• G04B15/14 Primary

  Component parts or constructional details, e.g. construction of the lever or the escape wheel {(assembly and manufacture of the spring G04B1/145; assembly and manufacture of components, e.g. pinions, spindles G04B13/02; lubrication of clockwork bearings G04B31/008; oils for clockwork bearings in general G04B31/08)} · CPC title