EP3761122B1 - Timepiece escapement component, associated escapement mechanism and timepiece - Google Patents

Description

Technical area

The present invention relates to the field of watchmaking. It relates, more particularly, to a horological escapement wheel set such as an anchor, in particular for Swiss lever escapement mechanisms, provided with a pivot of the knife pivot type.

The invention also relates to an escapement mechanism equipped with such a bladed pivot wheel and a timepiece comprising such an escapement wheel and/or escapement mechanism.

State of the art

Lever escapements certainly constitute the most common category of escapements in mechanical clockwork mechanisms, at least in the class of so-called free escapements. Associated with a regulating organ, typically of the pendulum or balance-spring assembly type, a lever escapement makes it possible to maintain the oscillations of said regulating organ by transmitting to it by regular pulses, at a determined frequency, a fraction of the mechanical energy of the source of mechanical energy for a said watch mechanism, usually comprising at least one barrel spring. At the same time, the escapement also makes it possible to count the oscillations of the regulator member and, therefore, to count the time.

Very many variations of lever escapements have been proposed in the state of the art and are well known to those skilled in the art in the field of watchmaking. Their limitations, just as well known, are mainly a propensity to disturb the isochronism of the oscillations of the regulating organ due to the successive shocks and frictions between the anchor and the regulating organ on the one hand as well as between the lever and the escapement wheel on the other hand, These shocks and friction particularly affect the mechanical performance of the escapement; We consider Usually, a Swiss lever escapement, for example, only transmits to the regulating organ 30-40% of the driving force that it receives from the driving source.

Various technological solutions have been explored to improve the performance of lever escapements, based in particular on the use of new materials such as silicon in particular, in order to reduce the friction of the lever, both at the level of its pivot and of the paddles and fork.

However, these techniques are much more expensive due to the high technicality and specificity of production technologies by deep etching of silicon. In addition, the parts thus produced are extremely fragile and their implementation requires even greater know-how and precision on the part of the watchmaker, which limits their mass production (several thousand to tens of thousands of annual pieces), on an industrial scale to date.

Document D1 EP 2 887 151 A2 discloses an escapement with lever pivoted on a virtual pivot.

The object of the present invention is to propose a new geometry of an escapement mechanism which can be manufactured according to conventional industrial techniques and in materials usual in the field of watchmaking and which nevertheless makes it possible to singularly reduce mechanical disturbances such as friction, for example, thus improving the performance of a lever escapement.

Another object of the invention is to provide a timepiece comprising such an escapement comprising an anchor or any other escapement part whose displacement is less than 45 degrees, such as for example a trigger.

Disclosure of Invention

According to a first object, the present invention thus proposes an escapement mechanism according to claim 1.

According to one embodiment, the pivot of the escape wheel set is arranged to allow rotation of said wheel set around said axis of rotation at an angle of at most 45°.

In a preferred embodiment, the mobile is an anchor and the body is a rod extending substantially in a longitudinal direction contained in said plane and carrying at a first end a first and a second arm and at a second end a fork.

According to the invention, the pivot of the escapement wheel set comprises a blade and a counter-blade, the blade or the counter-blade being fixed to the body of the wheel set when it is able to be fixed to a frame element of a watch movement.

Preferably, the blade comprises a blade edge and the counter-blade a groove of a shape complementary to the edge of the blade.

According to one embodiment, the groove has the shape of a dihedral in a plane perpendicular to the virtual pivot axis of the escapement wheel set.

The escapement mechanism comprises a member for returning the second wheel set to the rest position.

Also, the return member is secured to the second escapement mobile at a first end, in particular to the pivot, and adapted to be secured to a frame element of a watch movement at a second end.

The invention finally relates to a timepiece comprising said escapement mechanism.

Brief description of the drawings

• La figure 1 représente un mécanisme d'échappement selon un mode de réalisation préféré de la présente invention dans une première position de repos sur une palette d'entrée de l'ancre,
• la figure 1a représente un agrandissement de la figure 1 au niveau du pivot à lame de l'ancre du mécanisme de la figure 1,
• La figure 2 représente le mécanisme d'échappement de la figure 1 au cours d'une phase d'impulsion à la palette d'entrée,
• la figure 2a représente un agrandissement de la figure 2 au niveau du pivot à lame de l'ancre du mécanisme de la figure 1,
• La figure 3 représente le mécanisme d'échappement de la figure 1 et 2 en dans une deuxième position de repos sur une palette de sortie,
• la figure 3a représente un agrandissement de la figure 3 au niveau du pivot à lame de l'ancre du mécanisme de la figure 3.

Other details of the invention will appear more clearly on reading the following description, made with reference to the appended drawings in which:

• There figure 1 shows an escapement mechanism according to a preferred embodiment of the present invention in a first rest position on an entry pallet of the anchor,
• there picture 1a represents an enlargement of the figure 1 at the blade pivot of the anchor of the mechanism of the figure 1 ,
• There figure 2 represents the escapement mechanism of the figure 1 during an impulse phase at the input pallet,
• there figure 2a represents an enlargement of the figure 2 at the blade pivot of the anchor of the mechanism of the figure 1 ,
• There picture 3 represents the escapement mechanism of the figure 1 And 2 in a second rest position on an output pallet,
• there picture 3a represents an enlargement of the picture 3 at the blade pivot of the anchor of the mechanism of the picture 3 .

Embodiments of the Invention

THE figures 1 to 3 represent an improved lever watch escapement mechanism 1 according to a preferred embodiment. This escapement mechanism 1 is equipped with an anchor 2 constituting an escape wheel set.

However, the invention applies appropriately to any escapement part, such as a trigger, rotatable over an angle of at most 45° in function in an escapement mechanism.

The anchor 2 conventionally comprises a rod 21 forming a body extending longitudinally along an axis X and carrying at a first end two arms 22 at the free ends of which are arranged integrally with pallets 25e, 25s. At a second end of the rod 21, the anchor 2 comprises a fork 23, partially visible in the figures, and of conventional form in itself, comprising two horns separated by a notch in which extends along the longitudinal axis X of the rod 21 a stinger.

The anchor 2 comprises an anchor pivot 24 by which it is adapted to be mounted so as to be able to rotate around a virtual axis Y defined by said pivot 24 on a frame element of a watch movement such as a plate between an escapement wheel set 3 and a regulating member 4 themselves rotatably mounted on a frame element of the watch movement around their own axes of rotation which are preferably parallel to that Y defined by the anchor pivot 24. The longitudinal axis X of extension of the rod 21 is contained in a median plane of the anchor 2 perpendicular to the virtual Y axis of rotation defined by the pivot 24.

In a known manner and not shown in the figures, the escapement wheel 3 is preferably coupled in use by an escapement pinion coaxial with its axis of rotation to the cog of a watch movement and a source of driving energy of the watch movement such as one or more barrels. Similarly, the regulator member 4 can be a balance-spring assembly, of which only the large plate 41 and the pin 42 are shown in the figures for brevity.

The anchor 2 thus forms a member for transmitting an engine torque from the escapement wheel set 3 to the regulating member 4. The pallets 25e, 25s are configured to interact alternately with the teeth 31 of the escapement wheel set 3 during rest phases ( Fig. 1 And 3 ) during which the pallets hold the escapement mobile 3 stationary during the free path of the additional arc of the regulating member 4 as well as during pulse phases ( fig. 2 ) intermediate to the phases of rest during which the escapement wheel set 3 transmits, after release of the anchor 2 by action of the pin 42 of the regulating member 4 on a horn of the fork 23 of the anchor near the point death of the escapement, a driving impulse to a pallet 25e, 25s which pivots the anchor 2 on its pivot 24 transmitting the driving fraction to the regulating member 4 so as to maintain its oscillations. The angular displacements of lever 2 are, here again conventionally, limited by pins 5 driven into the plate of the watch movement on either side of fork 23 of lever 2.

The escapement mechanism 1 of the invention is thus similar and as shown in the figures to a classic Swiss lever escapement.

However, specifically and advantageously, the anchor pivot 24 does not consist of a rod, shaft, pin driven into a suitable orifice of a plate as in a conventional lever escapement, but of a blade pivot.

In addition, in a particular way to the escapement mechanism 1 of the invention, the anchor 2 is advantageously elastically returned by an elastic return means 6 in each rest position in order to provide a constant draw of the escapement mobile on the anchor 2, as will be described later.

The blade pivot 24 of the anchor 2 advantageously consists firstly of a blade 241, defined by a first part or substantially laminar portion forming a projection on the surface of the rod of the anchor 2 along a median plane P perpendicular to the plane of the rod 21 of the anchor containing the longitudinal axis X thereof and one edge of which defines a edge of the blade 241f, that is to say a thinnest and most acute edge of the blade 241 of infinitesimal width compared to the other dimensions of the blade 241. In practice the width of the blade wire 241f is of the order of a few micrometers to tens of micrometers, located in the plane P and passing through the center of gravity of the anchor 2 Secondly, the lever pivot 24 comprises a counter-blade 242 capable of being fixed to a watch movement frame element such as a plate or a bridge. This counter-blade 242 comprising a groove or notch 243 in the shape of a dihedral, at the bottom of which the blade edge bears. The bottom of the groove 243 and the edge of the blade 241 are advantageously aligned along the longitudinal axis X of the rod 21 and thus define the virtual axis of the anchor pivot 24. Such an anchor pivot configuration 24 is thus akin to the leaf pivot described in the application WO 2016012281 A1 of the Applicant.

It is possible to provide means for limiting movement in translation by sliding of the blade 241 in the groove 243, for example by a flange, a tailstock or counter-pivot (not shown) closing the dihedral of the counter-blade 242 and maintaining the blade 241 fixed along the axis of anchor pivot 24.

The anchor 2 can thus pivot, according to a limited angular amplitude, relative to the counter-blade 242 around the virtual axis of pivot formed in contact with the edge of the blade and the bottom of the groove 243, whatever the orientation. of the pivot axis.

The groove 243 of the counter-blade 242 is shown in the figures as a dihedral; however, it could also have other shapes, provided that the radii of curvature of the edge of the blade 241 and of the bottom of the groove 243 are preferably substantially equal so that the edge of the blade rolls in the groove more than slips in it. the latter, said rolling then being able to be assimilated to a rotation due to the very small radius of the edge of the blade. One then obtains minimal friction of the anchor pivot 24, and therefore a loss of driving energy transmitted and minimal disturbance of the regulating member 4.

Of course, the respective positions of the blade 241 and of the counter-blade 242 with respect to the anchor 2 could be reversed; the blade 241 could thus be integral with an element of the frame of a watch movement and the counter-blade integral with the rod 21 of the lever 2.

Advantageously again, the blade 241 of the anchor pivot 24 is advantageously held in abutment in the groove 243 by a return member. This return member may for example consist of a circlip or a ring fitted together around the counter-blade 242 and of an edge of the blade opposite to the edge of the latter. The two elements 241, 242 of the anchor pivot 24 are thus secured in translation in any direction orthogonal to the virtual axis Y of the pivot. Preferably, the return force passes through the axis of the pivot so as not to disturb the pivoting.

According to the invention, the blade return member 241 is none other than the elastic return member 6, advantageously of the anchor 2. Advantageously, the elastic return member 6 of the anchor is arranged to offer a constant pulling force between the anchor 2 and the escape wheel set 3 in each rest position. According to the invention, the return member 6 is formed of a leaf spring, one end of which is hooked onto the rear edge of the blade 241 opposite to the edge of the latter, as visible on the figure 1A , 2A , And 3A especially. The other end of leaf spring 6 is able to be secured by any appropriate means (in particular pin, lug, screw or the like) to a fixed point on a frame element of a watch movement. At this title the representation of the leaf spring 6 in the figures is completely arbitrary and has no limiting value of the shape or arrangement of said leaf spring 6 with respect to the other elements of the escapement mechanism 1 shown. In addition, other forms of return members 6 can be envisaged by those skilled in the art in the field of watchmaking, in particular a spiral spring for example.

As seen on the Fig. 1 , the spring 6 is shaped so as to exert a force in the plane P on the blade 241 in order to give it two so-called “bistable” positions; the first position being the blade 241 constrained on the left side of the counter-blade 242 and the second position being that opposite, that is to say the right side of the counter-blade 242. The spring 6 is fixed by n in any way whatsoever on a fixed support such as the plate of a watch movement.

The anchor 2, its pivot 24 (the blade 241 and the counter-blade 242) as well as the escapement wheel set 3 can be made of several elements, preferably but not exclusively of metallic material, assembled together, or also monolithically by stamping or molding and machining or by LIGA type processes (acronym for "Röntgenlithography, Galvanoformung, Abformung" in German) or deep silicon etching, or by additive manufacturing processes, in particular by 3D printing .

The anchor 2 equipped with an anchor pivot 24 of the blade pivot type and the escapement mechanism 1 integrating the latter and recalled by a drawing spring 6 provide a significant reduction in friction and therefore energy losses. and efficiency of a classic Swiss lever escapement, which makes it possible to reduce the disturbance of the regulating organ of a watch movement comprising them, but also to significantly improve the power reserve by reducing the dissipation of energy driving by friction and maintaining a constant pulling force when the escapement wheel is at rest. It is therefore possible to optimize a lever escapement in a simple, reliable and economical manner without any significant complexification of the structure and the adjustment of the latter, but with increased performance.

The operation of the escapement mechanism 1 of the invention in this embodiment is substantially identical to that of a Swiss lever escapement classic. In a first resting position ( Fig. 1 and 1A ), the escapement wheel set is supported by a tooth 31 on the rest plane of the 25th entry pallet and the fork 23 is held against a first pin 5 by the pulling effect of the escapement wheel set on the anchor 2. In this position, the return spring 6 does not exert any particular action on the anchor 2, apart from the restoring force of the blade 241 in the groove 243 of the counter-blade 242. During this time, the regulating member 4 traverses its additional arc.

When the regulating member 4 returns to its next alternation, it causes via its pin 42 on the fork 23 the release of the anchor 2 from the escapement wheel set 3. Substantially at the neutral point of the escapement shown in Fig. 2 and 2A , a tooth 31 of the escapement wheel set 3 provides an impulse on the corresponding surface of the entry pallet 25e of the lever 2, as in a conventional Swiss lever escapement, thereby transmitting a fraction of driving energy to the anchor 2 which pivots around its virtual axis Y at the bearing zone of the blade 241 in the groove 243 of the counter-blade ( Fig. 2A ) and catches up with the regulating member 4 and transmits to it a corresponding driving impulse.

The regulating member 4, the anchor 2 and the escape wheel set 3 all then continue their respective rotation, in this case clockwise in the figures. The anchor 2 then reaches its second rest position by abutment of its fork 23 against the second pin 5 ( Fig. 3 ) and a tooth 31 of escapement wheel set 3 comes to a halt on output pallet 25s of anchor 2. Regulator member 4 then continues its course on its additional arc until its next alternation.

Claims (6)

1. An escapement mechanism (1), including an escapement wheel and pinion (3) rotationally movable around an axis of rotation and equipped with a series of peripheral teeth (1), a second escapement wheel and pinion (2) including a pivot (24) defining an axis of rotation (Y), and a body (21) extending in a plane perpendicular to said axis of rotation, the pivot (24) defining a virtual axis of rotation (Y) oriented perpendicularly to the extension plane of the body (21), said second wheel and pinion (2) being rotationally movable around the virtual axis of rotation (Y) between two resting positions, and a return member (6) of the second wheel and pinion (2) in the resting position, characterized in that the pivot (24) includes a strip (241) including an edge (241f) defining a strip wire and a rear edge opposite the edge (241f) defining a strip wire, and a support element (242) on which the edge (241f) defining a strip wire of the strip (241) is held by resting on the return member (6) constituting the strip return member (241), one of the strip (241) and of the support element (242) being rigidly connected to the body of the second wheel and pinion (2) and the other of the strip (241) and of the support element (242) being capable of being rigidly connected to a frame element of a watch movement, and in that said return member (6) is formed by a strip spring, one end of which is hooked on the rear edge of the strip (241), the other end of the strip spring being capable of being rigidly connected to a frame element of a watch movement.
2. The escapement mechanism (1) according to Claim 1, in which the second escapement wheel and pinion (2) is a watchmaking anchor, including a bar (21) forming the body of said second wheel and pinion (2) and extending substantially in a longitudinal direction (X) in said extension plane of said body.
3. The escapement mechanism (1) according to any one of Claims 1 and 2, characterized in that the second wheel and pinion (2) is arranged to allow a rotation of said second wheel and pinion (2) around said axis of rotation (Y) at an angle of at most 45°.
4. The escapement mechanism (1) according to any one of Claims 1 to 3, characterized in that the support element (242) includes a groove (243) having a complementary form to the edge (241f) defining a strip wire of the strip (241).
5. The escapement mechanism (1) according to Claim 4, characterized in that the groove (243) has a dihedral form in a plane perpendicular to the virtual pivot axis (Y) of the second wheel and pinion (2).
6. A timepiece including an escapement mechanism (1) according to any one of Claims 1 to 5.

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