Timepiece resonator mechanism

Patent metadata

Field	Value
Publication number	US-9958831-B2
Application number	US-201715410294-A
Country	US
Kind code	B2
Filing date	Jan 19, 2017
Priority date	Feb 10, 2016
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

A watch or movement including a timepiece resonator movement including two RCC flexural pivots mounted in series about an intermediate rotary support and having the same virtual pivot axis, each including two straight flexible strips of the same length, whose clamping points opposite to this pivot axis are at the same distance with respect to this axis, and which define linear directions, forming angles, in pairs, with this virtual pivot axis, whose value expressed in degrees is comprised between:

109.5+5/[( D/L )−(2/3)] and 114.5+5/[( D/L )−(2/3)],

or more particularly between 107+5/((D/L)−(2/3)) and 112+5/((D/L)−(2/3)).

First claim

What is claimed is:

1. A timepiece resonator mechanism comprising a first support with a first anchor and a second anchor, wherein a flexural pivot mechanism is attached to said first support, wherein said flexural pivot mechanism defines a virtual pivot axis about which rotatably pivots a pivoting weight, and wherein said flexural pivot mechanism includes at least one front RCC flexural pivot and one back RCC flexural pivot, mounted in series and head-to-tail relative to each other about said virtual pivot axis,
said front RCC flexural pivot including, between said first support and an intermediate rotary support, two straight flexible front strips of the same front length LA between the clamping points thereof, defining two linear front directions which intersect at said virtual pivot axis and which define, with said virtual pivot axis, a front angle, and wherein the respective anchors of said two straight flexible front strips farthest from said virtual pivot axis are both at the same front distance DA from said virtual pivot axis,
and said back RCC flexural pivot including, between said intermediate rotary support, which includes a third anchor and a fourth anchor, and said pivoting weight, two straight flexible back strips of the same back length LP between the clamping points thereof, defining two linear back directions which intersect at said virtual pivot axis and which define, with said virtual pivot axis, a back angle, and wherein the respective anchors of said two straight flexible back strips farthest from said virtual pivot axis are both at the same back distance DP from said virtual pivot axis,
wherein said flexural pivot mechanism is planar, wherein the center of inertia of the assembly formed by said pivoting weight and any added inertial weight carried by said pivoting weight is on said virtual pivot axis or in immediate proximity thereto,
wherein said front angle expressed in degrees is comprised between:
107+5/[( DA/LA )−(2/3)] and 114.5+5/[( DA/LA )−(2/3)],

wherein said back angle expressed in degrees is comprised between:
107+5/[( DP/LP )−(2/3)] and 114.5+5/[( DP/LP )−(2/3)].

2. The timepiece resonator mechanism according to claim 1 , wherein said front angle and said back angle are equal.

3. The timepiece resonator mechanism according to claim 2 , wherein said front length and said back length are equal to a common length, and wherein said front distance and said back distance are equal to a common distance.

4. The timepiece resonator mechanism according to claim 3 , wherein said front angle and said back angle are equal to a common angle, expressed in degrees, and wherein said common angle and the ratio between said common length L and said common distance D satisfy the relation: 107+5/((D/L)−(2/3))<α<112+5/((D/L)−(2/3)).

5. The timepiece resonator mechanism according to claim 3 , wherein said front angle and said back angle are equal to a common angle (α), expressed in degrees, which is expressed as a function of the ratio between said common length L and said common distance D and which is equal to 109.5°+5/[(D/L)−(2/3)].

6. The timepiece resonator mechanism according to claim 1 , wherein said intermediate rotary support is made thinner by recesses to minimize the mass thereof and to prevent undesirable fundamental modes of vibration.

7. The timepiece resonator mechanism according to claim 1 , wherein said first support, said pivoting weight, and said flexural pivot mechanism are arranged very close to each other about said virtual pivot axis and include surfaces forming anti-shock banking members to prevent breakage of said flexible strips.

8. The timepiece resonator mechanism according to claim 7 , wherein said intermediate rotary support comprises banking arms arranged to cooperate in abutment in case of shock with complementary surfaces comprised in said first support.

9. The timepiece resonator mechanism according to claim 1 , wherein said first support, said pivoting weight, and said flexural pivot mechanism form a one-piece assembly.

10. A timepiece resonator movement according to claim 9 , wherein said one-piece assembly is a temperature-compensated silicon assembly.

11. The timepiece resonator movement according to claim 9 , wherein said pivoting weight carries an added inertia weight, and wherein said flexural pivot mechanism is made of silicon, oxidized such that said complete resonator mechanism with said added inertia weight is temperature-compensated.

12. The timepiece resonator mechanism according to claim 1 , wherein said resonator mechanism comprises a plurality of said flexural pivot mechanisms mounted in series, to increase the total angular travel, disposed in parallel planes, and about the same said virtual pivot axis.

13. A timepiece movement including at least one timepiece resonator mechanism according to claim 1 .

14. A watch including at least one movement according to claim 13 .

Assignees

• Swatch Group Res & Dev Ltd

Inventors

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

Classifications

• G04B31/02

  Shock-damping bearings {(shock damping in the case G04B37/052, G04B37/055, G04B37/0418)} · CPC title

• G04B17/04 Primary

  Oscillators acting by spring tension · CPC title

• G04B17/045 Primary

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

• G04B17/26

  for the effect of variations of the impulses · CPC title

• G04B17/28

  for the effect of imbalance of the weights, e.g. tourbillon · CPC title