Escapement mechanism for a timepiece movement and associated timepiece

Abstract

The present invention relates to an escapement mechanism (1) for a timepiece movement comprising an escape wheel (6) and an escapement pallet (2) comprising a pivot (4) defining a virtual axis of rotation (Y) and a body (8) extending in a plane perpendicular to the axis of rotation. The pivot (4) of the escapement pallet (2) comprises at least three blades (24, 26, 28) and three corresponding bearing zones on which the blades (24, 26, 28) bear, the points of contact of the blades (24, 26, 28) with the bearing zones being substantially located on the axis of the pivot (4), the three blades (24, 26, 28) being rigidly connected to the body (8) of the escapement pallet (2), and each of the three bearing zones being intended to be rigidly connected to a respective frame of the timepiece movement. Two of the blades (24, 26) are oriented in the direction of a force that the escape wheel (6) is intended to exert during the operation of the movement, the third blade (28) being oriented in the opposite direction. The invention also relates to a timepiece comprising such an escapement mechanism (1).

Description

[0001] Description

[0002] ESCAPE MECHANISM OF A WATCH MOVEMENT AND ASSOCIATED WATCHPIECE

[0003] Technical field

[0004] The present invention relates to the field of watchmaking. It relates more particularly to an escapement mechanism of a watch movement, in particular with a Swiss anchor, comprising an escapement wheel and an escapement anchor comprising a pivot defining a virtual axis of rotation, of the knife pivot type, and a body extending in a plane perpendicular to said axis of rotation.

[0005] The invention also relates to a timepiece comprising such an escapement mechanism.

[0006] State of the art

[0007] Anchor escapements are certainly the most common category of escapements in mechanical watch mechanisms, at least in the class of so-called free escapements. Associated with a regulating organ, typically of the pendulum type or balance-spring assembly, an anchor escapement makes it possible to maintain the oscillations of said regulating organ by transmitting to it, by regular impulses, at a determined frequency, a fraction of mechanical energy from the mechanical energy source of a said watch mechanism, usually comprising at least one barrel spring. Simultaneously, the escapement also makes it possible to count the oscillations of the regulating organ and, therefore, to count the time.

[0008] Many variations of anchor 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, which are also well known, are mainly a propensity to disturb the isochronism of the oscillations of the regulating organ due to successive shocks and friction between the anchor and the regulating organ on the one hand and between the anchor and the escapement wheel on the other hand. These shocks and friction significantly affect the mechanical efficiency of the escapement; it is usually considered that a Swiss anchor escapement, for example, only transmits to the regulating organ 30-40% of the driving force it receives from the driving source.Various technological solutions have been explored to improve the efficiency of anchor escapements, based in particular on the use of new materials such as silicon in particular, in order to reduce friction of the anchor, both at its pivot and at the pallets and fork.

[0009] However, these techniques are much more expensive due to the high technicality and specificity of deep silicon etching production technologies. In addition, the parts produced in this way are extremely fragile and their implementation requires even greater know-how and precision from the watchmaker, which limits their exploitation in large series (several thousand to tens of thousands of pieces per year), on an industrial scale to date.

[0010] The present invention aims to propose a Swiss anchor type escapement mechanism, in which the anchor has a new geometry, which can be manufactured using conventional industrial techniques and in materials commonly used in the field of watchmaking and which nevertheless makes it possible to significantly reduce mechanical disturbances such as friction, thus improving the efficiency of an anchor escapement.

[0011] Disclosure of the invention

[0012] To this end, the invention relates to an escapement mechanism of a watch movement comprising an escape wheel and an escape anchor comprising a pivot defining a virtual axis of rotation and a body extending in a plane perpendicular to said axis of rotation.

[0013] According to the invention, the pivot of the escapement anchor comprises at least three blades and three corresponding bearing zones on which the blades bear, the contact points of the blades and the bearing zones being substantially located on the axis of the pivot, the three blades being secured to the body of the escapement anchor, and each of the three bearing zones being intended to be secured to a respective frame element of the watch movement. In addition, two of the blades are oriented in the direction of a force that the escape wheel is intended to exert during operation of the movement, the third blade being oriented in the opposite direction.Preferably, the blades oriented in the direction of a force that the escape wheel is intended to exert during operation of the movement are positioned symmetrically on either side of the extension plane of the body of the escapement anchor, extending from said body in the same plane perpendicular to the extension plane of said body.

[0014] Advantageously, the support zone of each of the blades oriented in the direction of a force that the escape wheel is intended to exert during operation of the movement is carried by an arm intended to be made integral with a frame element, said arm extending in a plane perpendicular to the axis of the pivot.

[0015] Advantageously, the arms carrying the support zones of the blades oriented in the direction of a force that the escape wheel is intended to exert during operation of the movement are superimposed and connected to the same base intended to be made integral with a frame element.

[0016] Advantageously, said base is mounted movably on a slide secured to a frame element.

[0017] Preferably, the blade oriented in the direction opposite to that of a force that the escape wheel is intended to exert during operation of the movement extends from the body of the escapement anchor in the same plane as the extension plane of said body.

[0018] Preferably, the support zone of the blade oriented in the direction opposite to that of a force that the escape wheel is intended to exert during operation of the movement is carried by a cylindrical part with an axis coincident with the axis of the pivot.

[0019] Advantageously, the escapement mechanism comprises two jewels for holding the escapement anchor, said jewels being arranged on either side of the cylindrical part carrying the support zone of the blade oriented in the opposite direction to that of a force that the escape wheel is intended to exert during operation of the movement. Preferably, each blade is provided with a blade wire, and the corresponding support zone is a groove extending in a direction parallel to the axis of the pivot and against which the blade wire bears.

[0020] Preferably, the groove is complementary in shape to the edge of the blade.

[0021] Advantageously, said groove has a dihedral shape in a plane perpendicular to the axis of the pivot.

[0022] Advantageously, the escapement mechanism is arranged to allow rotation of the escapement anchor around its virtual axis of rotation through an angle of at most 45°, and preferably between 15° and 45°.

[0023] The invention also relates to a timepiece comprising an escapement mechanism as defined above.

[0024] Brief description of the drawings

[0025] Other characteristics and advantages of the present invention will appear on reading the following detailed description of an embodiment of the invention, given by way of non-limiting example, and made with reference to the appended drawings in which:

[0026] - figure 1 is an isometric view of an escapement mechanism according to the invention;

[0027] - figures 2 and 3 are isometric views representing the escape anchor of figure 1 and the elements of the frame secured to the support zones;

[0028] - Figure 4 is an isometric view of the escape anchor of Figure 1; and Figure 5 is a top view of the escape anchor of Figure 1 and the frame elements secured to the support zones.

[0029] Embodiments of the invention With reference to Figures 1 to 5, there is shown an improved anchor clock escapement mechanism 1 according to a preferred embodiment of the invention. This escapement mechanism 1 is provided with an escapement anchor 2, comprising a pivot 4 defining a virtual axis of rotation Y, and an escape wheel 6.

[0030] The anchor 2 comprises a body 8 of overall annular segment shape extending in an extension plane perpendicular to the Y axis. The body 8 carries at its free ends two arms 10 at the ends of which pallets 12 are arranged integrally intended to cooperate with the teeth of the escape wheel 6 in the manner of a conventional Swiss anchor escapement. On the other side of the arms 10, the body 8 extends into a third arm 14 terminated by a fork 16. Said fork 16 is of conventional shape, comprising two separate horns intended to cooperate with a roller pin 18 driven onto a roller 20 of a balance wheel (not shown). The fork 16 also carries a pin 22.

[0031] The anchor 2 is mounted to be mobile in rotation around the virtual axis Y defined by the pivot 4 on a frame element of a watch movement such as a plate between the escape wheel 6 and a regulating organ, such as a balance, themselves mounted to be mobile in rotation on a frame element of the watch movement around specific axes of rotation and preferably parallel to that Y defined by the pivot 4.

[0032] The escapement mechanism 1 of the invention is similar to a classic Swiss anchor escapement, so that the details concerning the escape wheel and the balance wheel are known to those skilled in the art.

[0033] However, specifically and advantageously, the pivot 4 of the anchor 2 is not made up of a rod, shaft, or pin driven into a suitable orifice of a plate as in a conventional anchor escapement but of a blade pivot defining a virtual axis of rotation Y. According to the invention, said pivot 4 comprises at least three blades 24, 26, 28 and three respective bearing zones 30, 32, 34 on which the blades 24, 26, 28 come to bear, the points of contact of the blades 24, 26, 28 and the bearing zones being substantially located on the axis of the pivot 4. The three blades 24, 26, 28 are integral with the body 8 of the escapement anchor 2, positioned inside the space between the arms 10. The three blades 24, 26, 28, can be in one piece on the anchor 2 or be reported separately.

[0034] Each of the three support zones 30, 32, 34 is intended to be made integral with a respective frame element of the watch movement, such as a plate or a bridge.

[0035] Each blade 24, 26, 28 comprises an edge parallel to the Y axis, the thinnest and sharpest of the blade 24, 26, 28 of infinitesimal width compared to the other dimensions of the blade 24, 26, 28 defining a blade wire 25, 27, 29 (see figure 4), and the corresponding support zone 30, 32, 34 is a groove extending in a direction parallel to the axis of the pivot 4 and against which the blade wire 25, 27, 29 bears.

[0036] Advantageously, the groove forming the bearing zone 30, 32, 34 is of a shape complementary to the blade wire 25, 27, 29 of the corresponding blade 24, 26, 28, for example V-shaped. Preferably, the groove of the bearing zone 30, 32, 34 has a dihedral shape in a plane perpendicular to the axis of the pivot 4 at the bottom of which the blade wire 25, 27, 29 bears. The bottom of the grooves or bearing zones 30, 32, 34 and the blade wires 25, 27, 29 are advantageously aligned along the Y axis and thus define the virtual axis of the pivot 4 of the escapement anchor 2.

[0037] The first and second blades 24, 26, and more particularly their end carrying the blade wire 25, 27, are oriented in the direction of a force that the escape wheel 6 is intended to exert during the operation of the movement, and the third blade 28, and more particularly its end carrying the blade wire 29 is oriented in the opposite direction, in order to stabilize the assembly.

[0038] The first and second blades 24, 26 are positioned symmetrically, projecting on either side of the extension plane of the body 8 of the escapement anchor 2, their first arm 24a, 26a extending from said body 8 in the same plane perpendicular to the extension plane of said body 8, and their second arm 24b, 26b carrying at its end the blade wire 25, 27, 29, extending perpendicular to the first arm 24a, 26a in the direction of the force exerted by the escapement wheel 6 (see Figure 3). The third blade 28 oriented in the direction opposite to that of a force exerted by the escapement wheel 6 extends from the body 8 of the escapement anchor 2 in the same plane as the extension plane of said body 8.More particularly, its first arm 28a extends from the body 8 in the same plane as the extension plane of said body 8, and its second arm 28b carrying at its end the blade wire 29, extends in the same plane as the first arm 28a in the direction opposite to that of the force exerted by the escape wheel 6 (see Figure 4).

[0039] The blades 24, 26, 28 are arranged so that the blade wire 29 of the third blade 28 is located along the axis of the pivot 4 between the blade wire 25 of the first blade 24 and the blade wire 27 of the second blade 26.

[0040] The bearing zone 30, 32 of each of the blades 24, 26 oriented in the direction of a force exerted by the escape wheel 6 is carried by a respective arm 36, 38 intended to be made integral with a frame element, said arm 36, 38 extending in a plane perpendicular to the axis of the pivot 4. Preferably, the bearing zone 30, 32 is provided at the end of the arm 36, 38 respectively, the other end of the arm 36, 38 extending in the form of two tabs 36a, 36b, 38a, 38b made integral with a frame element.

[0041] Preferably, said arms 36, 38 are superimposed and connected to the same base 40 by their legs 36a, 36b, 38a, 38b, said base 40 being intended to be made integral with a frame element, such as a plate or a bridge.

[0042] Advantageously, said base 40 is mounted movably on a slide secured to a frame element. This allows the base 40 to be able to fit precisely onto the first and second blades 24, 26 and thus ensure play-free operation.

[0043] The bearing zone 34 of the blade 28 oriented in the opposite direction to that of a force exerted by the escape wheel 6 is carried by a cylindrical part 42 with an axis coincident with the axis of the pivot 4, said part 42 being made integral with a frame element, such as a bridge or a plate. Said part 42 may be made of metal, such as a copper metal, ceramic or any synthetic material. Furthermore, the escapement mechanism 1 comprises two holding stones 44 of the escapement anchor 2 with an axis coincident with the axis of the pivot 4, said stones 44 being arranged on either side of said cylindrical part 42. The holding stones 44 make it possible to keep the anchor 2 in height and to protect it from shocks.

[0044] Thus, along the axis of the pivot 4 we find successively superimposed the wire 27 of the second blade 26 and its support zone 32, a holding stone 44, the wire 29 of the third blade 28 and its support zone 34 carried by the part 42, the other holding stone 44, and the wire 25 of the first blade 24.

[0045] Each of the blades 24, 26, 28 pivots through an angle of between 15° and 45° in their respective support zone 30, 32, 34.

[0046] Thus, the escapement mechanism 1 according to the invention allows rotation of the escapement anchor 2 around its virtual axis of rotation Y of pivot formed in contact with the blade wires 25, 27, 29 and the bottom of the grooves forming the support zones 30, 32, 34, according to an angle of at most 45°, and preferably between 15° and 45°.

[0047] The operation of the escapement mechanism 1 of the invention in this embodiment is substantially identical to that of a conventional Swiss anchor escapement.

[0048] The escapement mechanism 1 according to the invention, thanks to its multi-blade pivoting, makes it possible to reduce the contact area between the anchor and its pivot by up to 10 times, which provides a significant increase in efficiency and therefore in the power reserve by reducing the dissipation of driving energy by friction. Wear is also almost non-existent due to the extremely low contact point. The system can operate without lubrication.

Claims

Claims 1. Escapement mechanism (1) of a watch movement comprising an escape wheel (6) and an escape anchor (2) comprising a pivot (4) defining a virtual axis of rotation (Y) and a body (8) extending in a plane perpendicular to said axis of rotation, characterized in that the pivot (4) of the escape anchor (2) comprises at least three blades (24, 26, 28) and three corresponding bearing zones (30, 32, 34) on which the blades (24, 26, 28) bear, the points of contact of the blades (24, 26, 28) and the bearing zones (30, 32, 34) being substantially located on the axis of the pivot (4), the three blades (24, 26, 28) being integral with the body (8) of the escape anchor (2), and each of the three bearing zones (30, 32, 34) being intended to be made integral with a respective frame element of the watch movement, and in that two of the blades (24,26) are oriented in the direction of a force that the escape wheel (6) is intended to exert during operation of the movement, the third blade (28) being oriented in the opposite direction., 2. Escapement mechanism (1) according to claim 1, characterized in that the blades (24, 26) oriented in the direction of a force that the escape wheel (6) is intended to exert during operation of the movement are positioned symmetrically on either side of the extension plane of the body (8) of the escapement anchor (2), extending from said body (8) in the same plane perpendicular to the extension plane of said body (8).

3. Escapement mechanism (1) according to one of the preceding claims, characterized in that the support zone (30, 32) of each of the blades (24, 26) oriented in the direction of a force that the escape wheel (6) is intended to exert during operation of the movement is carried by an arm (36, 38) intended to be made integral with a frame element, said arm (36, 38) extending in a plane perpendicular to the axis of the pivot (4).

4. Escapement mechanism (1) according to claim 3, characterized in that the arms (36, 38) carrying the bearing zones (30, 32) of the blades (24, 26) oriented in the direction of a force that the escape wheel (6) is intended to exert during of the operation of the movement are superimposed and connected to the same base (40) intended to be made integral with a frame element.

5. Escapement mechanism (1) according to claim 4, characterized in that said base (40) is mounted movably on a slide secured to a frame element.

6. Escapement mechanism (1) according to one of the preceding claims, characterized in that the blade (28) oriented in the direction opposite to that of a force that the escape wheel (6) is intended to exert during operation of the movement extends from the body (8) of the escapement anchor (2) in the same plane as the extension plane of said body (8).

7. Escapement mechanism (1) according to one of the preceding claims, characterized in that the support zone (34) of the blade (28) oriented in the direction opposite to that of a force that the escape wheel (6) is intended to exert during operation of the movement is carried by a cylindrical part (42) with an axis coincident with the axis of the pivot (4).

8. Escapement mechanism (1) according to the preceding claim, characterized in that it comprises two stones (44) for holding the escapement anchor (2), said stones (44) being arranged on either side of the cylindrical part (42) carrying the support zone (34) of the blade (28) oriented in the direction opposite to that of a force that the escape wheel (6) is intended to exert during operation of the movement.

9. Escapement mechanism (1) according to one of the preceding claims, characterized in that each blade (24, 26, 28) is provided with a blade wire (25, 27, 29), and in that the corresponding support zone (30, 32, 34) is a groove extending in a direction parallel to the axis of the pivot (4) and against which the blade wire (25, 27, 29) bears.

10. Escapement mechanism (1) according to claim 9, characterized in that the groove is of a shape complementary to the blade wire (25, 27, 29).

11. Escapement mechanism (1) according to one of claims 9 and 10, characterized in that the groove has a dihedral shape in a plane perpendicular to the axis of the pivot (4).

12. Escapement mechanism (1) according to one of the preceding claims, characterized in that it is arranged to allow rotation of the escapement anchor (2) around its virtual axis of rotation at an angle of at most 45°, and preferably between 15° and 45°.

13. Timepiece comprising an escapement mechanism (1) according to one of claims 1 to 12.

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