US-12625466-B2 - Constant-energy escapement for timepiece

US12625466B2US 12625466 B2US12625466 B2US 12625466B2US-12625466-B2

Abstract

An escapement device for a mechanical timepiece having an escapement wheel cooperating with a rocker and a mobile element, the rocker cooperates with the escapement wheel by blocking arms and with the balance plate by a release fork, the mobile element having a spring cooperating with the teeth of the escapement wheel by a winding arm and with the balance wheel plate by an impulse arm. This space-saving escapement device is able to supply the balance wheel with an almost constant quantity of energy within a variable barrel torque range.

Inventors

Xuan Mai Tu

Assignees

ROLEX SA

Dates

Publication Date: 20260512
Application Date: 20220512
Priority Date: 20210512

Claims (10)

1 . An escapement device for a mechanical timepiece including: an escapement wheel comprising teeth, a rocker, a mobile element, at least one piece forming part of an oscillator of the timepiece, the escapement wheel cooperating with the rocker and the mobile element, the rocker cooperating with the escapement wheel by blocking means and with the piece forming part of the oscillator by release means, the mobile element comprising elastic means arranged to store elastic energy, and cooperating with the escapement wheel by winding means and with the piece forming part of the oscillator by impulse means, characterized in that: the winding means are arranged to carry out a phase of winding the elastic means along a first direction of rotation of the piece forming part of an oscillator and the impulse means are arranged to carry out an impulse phase given by the mobile element to the piece forming part of the oscillator during the rotation of the piece forming part of an oscillator along at least a second direction of rotation of the piece forming part of an oscillator, and in that: the impulse is given directly from the mobile element to the piece forming part of the oscillator, the piece forming part of the oscillator comprises two fingers or levers forming a double lift able to receive energy coming from the mobile element in both directions of rotation of the piece forming part of an oscillator.
2 . The escapement device according to claim 1 characterized in that a first blocking position of the rocker after the phase of winding the elastic means is different from a second blocking position of the rocker after the impulse phase given by the mobile element to the piece forming part of the oscillator.
3 . The escapement device according to claim 1 characterized in that the mobile element is blocked by a tooth of the escapement wheel after the phase of winding the elastic means.
4 . The escapement device according to claim 1 , characterized in that the impulse means comprise: at least one finger or lever protruding from the piece forming part of the oscillator, and/or—at least one impulse arm protruding from the mobile element.
5 . The escapement device according to claim 1 , characterized in that the winding means comprise: at least one tooth of the escapement wheel, and/or—at least one winding arm of the mobile element.
6 . The escapement device according to claim 1 , characterized in that the elastic means of the mobile element are formed by a spiral type spring.
7 . The escapement device according to claim 1 , characterized in that the elastic means of the mobile element are formed by a leaf spring.
8 . The escapement device according to claim 1 , characterized in that the elastic means of the mobile element are formed by leaf springs, so as to form a flexible guiding system without any physical axis of rotation.
9 . The escapement device according to claim 1 , characterized in that the piece forming part of the oscillator is a balance plate.
10 . A timepiece provided with an escapement device according to claim 1 .

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a filing under 35 U.S.C. 371 as the National Stage of International Application No. PCT/EP2022/062883, filed May 12, 2022, entitled “CONSTANT-ENERGY ESCAPEMENT FOR TIMEPIECE,” which claims priority to Swiss Application No. 00542/21 filed with the Intellectual Property Office of Switzerland on May 12, 2021, both of which are incorporated herein by reference in their entirety for all purposes. The present invention relates to a constant energy escapement device for a mechanical timepiece. This escapement device is able to provide the balance with a practically constant amount of energy in a variable torque range of the barrel. It is known that for the frequency of the mechanical oscillator to be as stable as possible, the amplitude of oscillation of the balance must be as constant as possible. A constant energy escapement device makes it possible to obtain this result in the absence of external disturbances. Constant energy escapement devices are known. In the book “clock and watch escapements” by Charles Gros, Watchmakers editions January 2013, pages 349 to 359, several types of constant energy escapements for watches are represented. These escapements have the following disadvantages: a large number of components used, which implies a high manufacturing cost,the surface and/or the height of the escapement are large, which complicates the integration of the escapement into a small volume watch. Patent FR 1 009 853 A describes a constant energy escapement composed of 2 superimposed anchor escapements; the escapement wheels rotate independently around the same axis of rotation and are connected together by a spiral spring (FIG. 3). Patent CH 704 764 A2 also describes a constant energy escapement composed of several superimposed wheels rotating around the same axis of rotation (FIG. 1). The 2 aforementioned patents present the same disadvantages already listed above for the escapements described in Charles Gros' book. The aim of the present invention is to propose a new type of escapement which makes it possible to deliver to the balance a practically constant energy in a variable torque range of the barrel, this with a limited number of components and in a reduced space requirement. Another aim of the invention is to propose a mechanical timepiece equipped with such an escapement. To this end, a first aspect of the invention relates to an escapement device for a mechanical timepiece including: an escapement wheel comprising teeth, that is to say a toothed escapement wheel,a rocker,a mobile element,at least one piece forming part of an oscillator of the timepiece, such as a balance plate, the escapement wheel cooperating with the rocker and the mobile element, the rocker cooperating with the escapement wheel by blocking means and with the piece forming part of the oscillator by release means, the mobile element comprising elastic means arranged to store elastic energy, and cooperating with the escapement wheel by winding means and with the piece forming part of the oscillator by impulse means, characterized in that: the winding means are arranged to carry out a phase of winding the elastic means along a first direction of rotation of the balance and the impulse means are arranged to carry out an impulse phase given by the mobile element to the piece forming part of the oscillator during the rotation of the balance along at least a second direction of rotation of the balance, and in that: the impulse is given directly from the mobile element to the piece forming part of the oscillator, particularly without passing through an intermediate element. According to the embodiment above, the winding means are arranged to wind the elastic means of the mobile element, that is to say transmit energy from the escapement wheel (meshed with the reserve of energy of the timepiece, the barrel and its spring) to the mobile element and its elastic means. The impulse means are for their part designed to distribute or restore the energy (stored by the elastic means) from the mobile element to the piece forming part of the oscillator (the balance plate). Consequently, the rocker does not directly participate in maintaining the oscillations of the oscillating system (the balance). Also, it can be noted that the energy transmitted to the balance is the one stored by the elastic means of the mobile element, and this energy only depends on the winding of the elastic means of the mobile element, it is therefore constant and does not depend on the winding of the barrel spring. Particularly, a phase of winding the elastic means can correspond to a first direction of rotation of the balance and an impulse phase given by the mobile element to the piece forming part of the oscillator can correspond to a second direction of rotation of the balance. In addition, it can be considered that the winding phase is carried out under the effect of the rotation of the balance. Acco