Rotating resonator with flexure bearing maintained by a detached lever escapement

Patent metadata

Field	Value
Publication number	US-11619909-B2
Application number	US-201716344567-A
Country	US
Kind code	B2
Filing date	Jul 27, 2017
Priority date	Nov 23, 2016
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

Timepiece regulator ( 300 ) comprising a detached lever ( 7 ) escapement mechanism ( 200 ), and a resonator ( 100 ) including an inertia element ( 2 ), which includes an impulse pin ( 6 ) cooperating with a fork ( 8 ) of the lever ( 7 ), and which is subjected to the action of elastic return means ( 3 ) fixed to the plate ( 1 ) and is arranged to cooperate indirectly with an escape wheel set ( 4 ), this resonator ( 100 ) is a resonator with a virtual pivot rotating about a main direction (DP), with a flexure bearing returned by flexible strips ( 5 ) attached to the plate ( 1 ), defining a virtual pivot having a main axis (DP), the resonator ( 100 ) is attached to an elastic suspension strip ( 9 ) attached to the plate ( 1 ), allowing displacement in the main direction (DP), the plate ( 1 ) comprising shock absorber stops ( 11, 12 ), in the main direction (DP), cooperating with at least one stiff element of the inertial element ( 2 ).

First claim

The invention claimed is:

1. A timepiece regulating mechanism, comprising:
a resonator mechanism arranged on a main plate, the resonator mechanism having an energy loss quality factor Q; and
an escapement mechanism arranged on the main plate, the escapement mechanism being subjected to the torque of drive means comprised in a movement,
wherein said resonator mechanism includes an inertia element arranged to oscillate with respect to said plate, said inertia element being subjected to the action of elastic return means directly or indirectly attached to said plate, and said inertia element being arranged to cooperate indirectly with an escape wheel set comprised in said escapement mechanism,
wherein said resonator mechanism is a resonator with a virtual pivot rotating about a main axis, with a flexure bearing including at least two flexible strips, and including an impulse pin integral with said inertia element,
wherein said escapement mechanism includes a lever pivoting about a secondary axis and including a lever fork arranged to cooperate with said impulse pin, and is a detached escapement mechanism, wherein, during an operating cycle, said resonator mechanism has at least one phase of freedom in which said impulse pin is at a distance from said lever fork,
wherein at least said resonator mechanism is attached to an intermediate, elastic suspension strip attached to said plate and arranged to allow a displacement of said resonator mechanism in a direction of said main axis, and in that said plate includes at least one shock absorber stop at least in the direction of said main axis, arranged to cooperate with at least one stiff element of said inertia element,
wherein a lift angle β of the resonator, during which said impulse pin is in contact with said lever fork, is less than 10°, and
wherein said main axis, said secondary axis and the axis of pivoting of said escape wheel set, are arranged to be centered at a right angle whose apex is on said secondary axis within a plane defined perpendicular to the main axis, secondary axis, and axis of pivoting.

2. The timepiece regulating mechanism according to claim 1 , wherein the inertia IB of said inertia element with respect to said main axis on the one hand, and the inertia IA of said lever with respect to said secondary axis on the other hand, are such that the ratio IB/IA is greater than 2Q·α 2 /(0.1·π·β 2 ), where α is a lift angle of the lever which corresponds to the maximum angular travel of said lever fork.

3. The timepiece regulating mechanism according to claim 1 , wherein an overall lift angle of the resonator is less than twice the angle of amplitude by which said inertia element deviates furthest, in only one direction of motion, from a rest position.

4. The timepiece regulating mechanism according to claim 1 , wherein the angle of amplitude, by which said inertia element deviates furthest from a rest position, is comprised between 5° and 40°.

5. The timepiece regulating mechanism according to claim 1 , wherein, during each vibration, in a contact phase, said impulse pin penetrates said lever fork with a depth of travel greater than 100 micrometers, and in an unlocking phase, said impulse pin remains at a distance from said lever fork with a safety distance greater than 25 micrometers, and in that said impulse pin and said lever fork are dimensioned such that the width of said lever fork is greater than (P+S)/sin(α/2+β/2), said depth of travel and said safety distance being measured radially with respect to said main axis
where α is a lift angle of the lever which corresponds to the maximum angular travel of said lever fork, P is a depth of travel of the impulse pin with respect to the lever fork, and S is a distance between the impulse pin and the lever fork during the unlocking phase.

6. The timepiece regulating mechanism according to claim 1 , wherein said lever is in a single layer of silicon, placed on an arbor pivoted with respect to said plate.

7. The timepiece regulating mechanism according to claim 1 , wherein said escape wheel set is a silicon escape wheel.

8. The timepiece regulating mechanism according to claim 1 , wherein said escape wheel set is an escape wheel which is perforated to minimize its inertia with respect to its axis of pivoting.

9. The timepiece regulating mechanism according to claim 1 , wherein said lever is perforated to minimize its said inertia with respect to said secondary axis.

10. The timepiece regulating mechanism according to claim 1 , wherein said lever is symmetrical with respect to said secondary axis.

11. The timepiece regulating mechanism according to claim 1 , wherein the largest dimension of said inertia element is greater than half the largest dimension of said plate.

12. The timepiece regulating mechanism according to claim 1 , wherein said flexure bearing includes two flexible strips which are crossed in projection onto a plane perpendicular to said main axis, at said virtual pivot defining said main axis, and located in two parallel and distinct levels.

13. The timepiece regulating mechanism according to claim 12 , wherein said two flexible strips, in projection onto a plane perpendicular to said main axis, form therebetween an angle comprised between 59.5° and 69.5°, and intersect at between 10.75% and 14.75% of their length, such that said resonator mechanism has a deliberate isochronism error which is the additive inverse of the loss error at the escapement of said escapement mechanism.

14. The timepiece regulating mechanism according to claim 12 , wherein said two flexible strips are identical and are positioned in symmetry.

15. The timepiece regulating mechanism according to claim 12 , wherein each said flexible strip forms part of a one-piece assembly in one piece with means thereof for alignment and attachment to said plate or to said intermediate elastic suspension strip.

16. The timepiece regulating mechanism according to claim 1 , wherein said inertia element includes inertia blocks for adjusting rate and unbalance.

17. The timepiece regulating mechanism according to claim 1 , wherein said impulse pin is in one-piece with a said flexible strip.

18. The timepiece regulating mechanism according to claim 1 , wherein said lever includes bearing surfaces arranged to cooperate in abutment with teeth comprised in said escape wheel set and to limit the angular travel of said lever.

19. The timepiece regulating mechanism according to claim 1 , wherein said flexure bearing is made of oxidized silicon to compensate for the effects of temperature on the rate of said regulating mechanism.

20. A timepiece movement including drive means and a regulating mechanism according to claim 1 , wherein said escapement mechanism is subjected to the torque of said drive means.

21. A watch including a timepiece movement according to claim 20 .

22. A watch including a regulating mechanism according to claim 1 .

Assignees

• Eta Sa Mft Horlogere Suisse

Inventors

• Winkler Pascal
• Helfer Jean-Luc
• Di Domenico Gianni

Classifications

• G04B17/26

  for the effect of variations of the impulses · CPC title

• G04B31/00

  Bearings; Point suspensions or counter-point suspensions; Pivot bearings; Single parts therefor (bearings in general F16C {; manufacture and composition of springs G04B1/145; suspension of oscillating weights G04B5/18; suspension of a pendulum G04B17/02; bearings for electrical measurement apparatus G01R1/10, G01R1/12, G01R11/12, G01R11/14; inserting jewels A44C17/04; inserting cutting diamonds B23P5/00; devices for fixation of bearing jewels, bearing sleeves, or the like G04D3/04}) · CPC title

• G04B17/045 Primary

  with oscillating blade springs (mechanical oscillations maintained by electro-magnetic means, e.g. tuning forks G04C3/10) · CPC title

• G04B15/08 Primary

  Lever escapements · CPC title

• G04B18/02

  Regulator {or adjustment} devices; Indexing devices {, e.g. raquettes} · CPC title