Escapement mechanism of a timepiece

Abstract

An escapement mechanism of a timepiece, including: a first escapement wheel, a second escapement wheel called an impulse pinion and a drive pinion; the impulse pinion, the drive pinion and the first escapement wheel being mounted on the same axis; an intermediate wheel meshing with the drive pinion; a balance plate carrying a plate peg and a direct impulse pallet stone arranged to cooperate with the first escapement wheel; pallets including a pallet entry cooperating with the plate peg, an impulse pallet stone arranged to cooperate with the impulse pinion, and first and second support pallet stones arranged to cooperate with the first escapement wheel. The first escapement wheel, the drive pinion and the impulse pinion are mounted in this order.

Claims

1. An escapement mechanism of a timepiece, comprising: a first escapement wheel, a second escapement wheel called an impulse pinion and a drive pinion; the impulse pinion, the drive pinion and the first escapement wheel being mounted on the same axis; an intermediate wheel meshing with the drive pinion; a balance plate carrying a plate peg and a direct impulse pallet stone arranged to cooperate with the first escapement wheel; pallets including a pallet entry cooperating with the plate peg, an impulse pallet stone arranged to cooperate with the impulse pinion, and first and second support pallet stones arranged to cooperate with the first escapement wheel; wherein the first escapement wheel, the drive pinion and the impulse pinion are mounted in this order.

2. The escapement mechanism according to claim 1, wherein the pallets are coplanar with the drive pinion.

3. The escapement mechanism according to claim 1, wherein the impulse pallet stone of the pallets has a height (h1) such that said impulse pallet stone extends level with the teeth of the impulse pinion.

4. The escapement mechanism according to claim 1, wherein at least one from among the direct impulse pallet stone of the balance plate, the impulse pallet stone of the pallets and the support pallet stones of the pallets consists of a ruby lift.

5. The escapement mechanism according to claim 1, wherein the plate peg is made from ruby.

6. The escapement mechanism according to claim 1, wherein the escapement mechanism is a coaxial escapement.

7. A horological movement comprising the escapement mechanism of claim 1 and a balance spring, wherein the balance plate of the escapement mechanism is secured to the balance spring.

8. A timepiece comprising the horological movement of claim 7.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The aims, advantages and features of the coaxial escapement mechanism for a timepiece according to the invention will appear more clearly in the following description on the basis of at least one non-limitative embodiment illustrated by the drawings, on which:

(2) FIG. 1 is a perspective view from below of a part of a horological movement of a watch comprising an escapement mechanism according to the invention;

(3) FIG. 2 is a perspective view from below of a part of the coaxial escapement mechanism of FIG. 1, the coaxial escapement mechanism comprising a triple coaxial wheel and pallets;

(4) FIG. 3a is a perspective view from below of the triple coaxial wheel of FIG. 2;

(5) FIG. 3b is a perspective view from below of the pallets of FIG. 2;

(6) FIG. 4a is a plan view of the escapement mechanism of FIG. 1;

(7) FIG. 4b is a view from below of the escapement mechanism of FIG. 1;

(8) FIG. 5 illustrates a perspective view from below of the escapement mechanism according to another embodiment.

DETAILED DESCRIPTION OF THE INVENTION

(9) In the following description, reference is made to a horological movement provided with an escapement mechanism, preferably coaxial, for an oscillator of the balance spring type. The usual components of the horological movement, which are well known to a person skilled in this technical field, are described only in a simplified manner or not described at all. A person skilled in the art will in fact be able to adapt these various components and to make them cooperate for the functioning of the horological movement. In particular, everything that relates to the oscillator of the balance spring type will not be described hereinafter, although such a balance spring can advantageously cooperate with the coaxial escapement mechanism according to the invention.

(10) FIGS. 1, 4a, 4b and 5 show a part of a timepiece 1, which comprises a horological movement 2. The timepiece 1 is typically a watch or a clock.

(11) The horological movement 2 includes an oscillator provided with a balance and a balance spring (not shown), an energy source (not shown) and an escapement mechanism 4 placed between the energy source and the oscillator.

(12) The escapement mechanism illustrated in FIGS. 1 to 4b is a coaxial escapement 4, and comprises a triple coaxial wheel 6, an intermediate wheel 8, a balance plate (not shown) and pallets 12. The escapement mechanism illustrated in FIG. 5 is a conventional escapement including two levels with pallets 12, an escapement wheel and a balance.

(13) The triple coaxial wheel 6 includes a first escapement wheel 14, a drive pinion 16 and a second escapement wheel 18 called an impulse pinion. As can be seen in FIGS. 1 to 3a (on which the escapement mechanism 4 is seen from below with respect to the normal arrangement thereof in the movement 2), the first escapement wheel 14, the drive pinion 16 and the impulse pinion 18 are mounted on the same axis X1. More precisely, the first escapement wheel 14, the drive pinion 16 and the impulse pinion 18 are mounted coaxially, in this order, on the axis X1. In other words, the drive pinion 16 is mounted coaxially on the first escapement wheel 14, and the impulse pinion 18 is mounted coaxially on the drive pinion 16. It will thus be understood that, through this particular arrangement between the first escapement wheel 14, the drive pinion 16 and the impulse pinion 18, the coaxial escapement mechanism 4 according to the invention advantageously makes it possible to lower the disc (not shown) of the intermediate wheel 8 in the horological movement 2, level with the drive pinion 16. This advantageously releases space in the horological movement 2, which makes it possible to increase the volume and therefore the inertia of the balance. The quality of isochronism is consequently improved in the horological movement 2, and the variations in running reduced, while obtaining very compact setting for the escapement mechanism 4.

(14) The intermediate wheel 8 meshes with the drive pinion 16, and transmits the motive force to the latter. The intermediate wheel 8 may be the last wheel in the finishing train driven by the barrel of the horological movement 2, typically the seconds wheel.

(15) The balance plate (which is not shown in the figures) is secured to the oscillator formed by the balance and the balance spring. The balance plate carries a plate peg and a direct impulse pallet stone (neither being shown). Preferably, the plate peg is made from ruby. The direct impulse pallet stone is arranged to cooperate with the teeth of the first escapement wheel 14. Preferably, the direct impulse pallet stone consists of a lift made from ruby.

(16) As illustrated in FIGS. 1, 2 and 3b, the pallets 12 include a support 23, a pallets entry 24, an impulse pallet stone 26, and first and second support pallet stones 28a, 28b. The pallets 12 are mounted pivotably in the horological movement 2. More precisely, the support 23 of the pallets 12 includes a shaft 30 provided with pivots 32, preferentially lubricated. Preferably, as can be seen in FIGS. 1 and 2, the pallets are coplanar with the drive pinion 16. The pallets entry 24 cooperates with the plate peg. To do this, the pallets entry 24 comprises for example a fork 34 configured to cooperate with the plate peg. The impulse pallet stone 26 is arranged to cooperate with the teeth of the impulse pinion 18. Preferably, as illustrated in FIGS. 1 and 2, the impulse pallet stone 26 has a height h1 such that the impulse pallet stone 26 extends level with the teeth of the impulse pinion 18, opposite to the support pallet stones 28a, 28b with respect to the support 23, the height being measured along the axis X1.

(17) The first and second support pallet stones 28a, 28b extend alongside the first escapement wheel 14, and are each arranged to cooperate with the teeth on the first escapement wheel 14. Preferably, the impulse pallet stone 26 and/or the first and second support pallet stones 28a, 28b each consist of a ruby lift. More precisely, as illustrated in FIGS. 1 to 4b, each of the pallet stones 26, 28a, 28b is made from a single-piece ruby stone engaged in a groove 36 formed in the thickness of the pallets 12.

(18) The invention also relates to a horological movement 2 comprising an escapement mechanism 4 as described previously and a balance spring, the balance plate of the coaxial escapement mechanism 4 being secured to the balance spring.

(19) The invention also relates to a timepiece 1 comprising such a horological movement 2.