Flexible escapement mechanism having a balance with no roller

Patent metadata

Field	Value
Publication number	US-9304493-B2
Application number	US-201314388641-A
Country	US
Kind code	B2
Filing date	Mar 27, 2013
Priority date	Mar 29, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A timepiece escapement mechanism, including a balance having no roller and an escape wheel, between which impulses are transmitted by a flexible, single-piece mechanism, connected by at least one flexible strip to a fixed structure or to the wheel. Oscillation is maintained by a balance spring ending in a balance spring stud which is mobile during operation, and which is guided by a flexible guide member with flexible strips, and whose center of rotation is coaxial to the balance, the balance spring stud receiving a pin which is mobile in a cam path of the wheel. During the oscillations, the balance spring stud is moved relative to its locking position under action of force exerted by the balance spring, and the pin maintains and regulates the oscillation.

First claim

The invention claimed is:

1. A timepiece escapement mechanism comprising:
a fixed structure;
a balance and an escape wheel;
a flexible, single-piece mechanism configured to transmit impulses between the balance and the escape wheel, the single-piece mechanism including at least one flexible strip which connects the flexible, single-piece mechanism, to the fixed structure or the escape wheel;
a balance spring configured to maintain oscillation and which ends in a balance spring stud arranged to move during operation, and the balance spring stud is guided by a flexible guide member including flexible strips, the balance spring stud receiving a pin configured to cooperate with a cam path of the escape wheel, and
wherein the balance spring stud is subjected to a force exerted by the balance spring, the force tending, during the oscillation, to move the balance spring stud relative to a locking position thereof, and imparting a motion to the pin to maintain and regulate the oscillation without use of a balance roller.

2. The timepiece escapement mechanism according to claim 1 , for a timepiece movement or a timepiece including the balance and the escape wheel,
wherein transmission of the impulses between the balance and the escape wheel is performed by the single-piece, flexible mechanism, comprised in the escapement mechanism and including at least one feeler-spindle cooperating with the escape wheel or respectively the balance, and
wherein the single-piece, flexible mechanism is connected by the at least one flexible strip comprised therein to the fixed structure of the timepiece or respectively to the escape wheel, and
wherein the oscillation is maintained without use of the balance roller via the balance spring stud and the balance spring, which ends in the balance spring stud, which is mobile during operation, and which is guided by the flexible guide member including the flexible strips, the pin being fixed to the balance spring stud,
the escapement mechanism including the escape wheel with the cam path in a shape of a set of teeth where the balance spring stud pin is housed, the escapement mechanism configured such that, during the oscillation, the stud moves relative to the locking position thereof under action of the force exerted thereon by the balance spring, and such that the balance spring stud pin, guided in a profile, fulfils a function of maintaining and regulating the oscillation, so that, during a clockwise motion of the balance:
when the balance is in a first position wherein the balance starts the clockwise motion, the stud pin is arranged to block pivoting of the escape wheel, the pin being retained by the balance spring;
when the balance and the pin are in the locking position, during clockwise rotation of the balance, just after the balance spring passes through the locking position, the balance spring stud is configured to be driven by the balance, and the pin is configured to be released from a locking point comprised in the escape wheel, and the balance spring configured to be reloaded by an anticlockwise impulse;
when the balance is at an end of clockwise travel, the stud pin is configured, once the pin reaches a next locking point on the escape wheel to remain there, retained by the balance in an opposite direction.

3. The timepiece escapement mechanism according to claim 1 , wherein the escapement mechanism is excited, via the balance spring stud, at a frequency half a base frequency of the oscillation, by supplying energy to the balance spring stud every second vibration.

4. The timepiece escapement mechanism according to claim 3 , wherein the escapement mechanism is excited, via the balance spring stud, at an integer sub-multiple or integer multiple frequency of the base frequency of the oscillation.

5. The timepiece escapement mechanism according to claim 1 , wherein the flexible guide member including the flexible strips is a rotational guide member about a center of rotation.

6. The timepiece escapement mechanism according to claim 5 , wherein the center of rotation is coaxial to the balance.

7. The timepiece escapement mechanism according to claim 1 , wherein the flexible guide member includes strips in a bistable position, which change from a first bistable position to a second bistable position during maintenance, to ensure performance of a function in less than a millisecond.

8. The timepiece escapement mechanism according to claim 1 , wherein, for each function to be performed with a duration of less than fifteen milliseconds, the escapement mechanism is configured so that each function is performed during a rotation of the balance that is sprung of less than 10% of an amplitude thereof.

9. The timepiece escapement mechanism according to claim 1 , wherein the balance spring stud is made of magnetic material, and micro-magnets are arranged along a profile of the cam path, in association with each locking point comprised in the escape wheel, to better stabilize a position of the balance spring stud.

10. The timepiece escapement mechanism according to claim 1 , wherein electrets are arranged along a profile of the cam path, in association with each locking point comprised in the escape wheel, to better stabilize a position of the balance spring stud.

11. A timepiece movement comprising the fixed structure and at least one of the timepiece escapement mechanism according to claim 1 .

12. A timepiece including the fixed structure and at least one of the timepiece escapement mechanism according to claim 1 .

13. A timepiece including the fixed structure and at least one of the timepiece movement according to claim 11 .

Assignees

• Nivarox Sa

Inventors

• Stranczl Marc
• Hessler Thierry
• Cabezas Jurin Andres
• Sarchi Davide

Classifications

• G04B15/08

  Lever escapements · CPC title

• G04B15/02

  permanently in contact with the regulating mechanism · CPC title

• G04B15/12

  Adjusting (tools therefor G04D1/02); Restricting the amplitude of the lever or the like {(adjusting the gear train G04B35/00)} · CPC title

• G04B15/00 Primary

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

• G04B15/14 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