Stepped anchor for an exhaust mechanism

Abstract

The invention relates to an anchor (21) for a watch escapement mechanism (50), the anchor (21) comprising a fork (22) intended to cooperate with an ellipse (23) of a balance wheel (35), an inlet arm (11) and an outlet arm (12) intended to cooperate with an escapement wheel (30), as well as a rod (5) on which the fork (22), the inlet arm (11) and the outlet arm (12) are mounted, the fork (22), the inlet arm (11) and the outlet arm (12) being arranged on the rod (5) in two separate parts, the fork (22) being arranged on a first level and the inlet arms (11) and outlet arms (12) being arranged on a second level of the rod (5), the two levels being separated along the axis of the rod (5) by a predetermined distance (D0).

Description

Technical field of the invention

[0001] The present invention relates to a stepped anchor for a watch escapement mechanism, as well as an escapement mechanism and a watch movement comprising such an anchor. Technological background

[0002] In most mechanical watches, the energy needed to rotate the hands (e.g., minute and hour indicator hands) is stored in a barrel and then released by a balance-spring system, which includes a flywheel called a balance wheel, associated with a spring in the form of a spirally wound ribbon, called a balance spring.

[0003] At one internal end, the spiral is fixed to a shaft that is rotating with the balance wheel; at one external end, the spiral is fixed to a stud mounted on a stud holder which is itself fixed to a bridge (or cock).

[0004] The balance wheel's rotation is maintained—and its oscillations counted—by an escapement mechanism comprising an anchor with a low-amplitude oscillating motion, equipped with two or three pallets that engage the teeth of an escape wheel. Thus engaged, the escape wheel is subjected to a step-by-step rotational movement whose frequency is determined by the anchor's oscillation frequency, itself synchronized with the balance wheel's oscillation frequency.

[0005] With a traditional escapement mechanism, the oscillation frequency is approximately 4 Hz, or about 28,800 vibrations per hour (A / h). One objective of skilled watchmakers is to ensure the isochronism and regularity of the oscillations (or constant rate) of the balance wheel and hairspring.

[0006] The escapement mechanism's anchor is positioned to provide the mechanical link between the balance wheel and the escapement wheel. Therefore, the anchor's placement is crucial for its proper interaction with the other two components.

[0007] Generally, the anchor consists of a single-piece body comprising a fork that engages with an ellipse of the balance wheel and at least two arms, often each fitted with a pallet, that engage with the escapement mechanism. The anchor body is mounted on a stem with a pivot at each end. During assembly, the pivots are inserted into bearings arranged in bridges or the mainplate.

[0008] Today, the balance spring can be replaced by a flexible guide as the spring element to form a virtual pivot. Flexible guides with a virtual pivot significantly improve watch resonators. The simplest are crossed-leaf pivots, composed of two straight-leaf guide devices that intersect. These two leaves can be either three-dimensional in two different planes or two-dimensional in the same plane, in which case they are essentially welded at their point of intersection. However, there are also uncrossed-leaf guides of the RCC (Remote Center Compliance) type, which have straight leaves that do not intersect. Such a resonator is described in documents EP14199039 and EP16155039.

[0009] However, with such flexible guidance, the balance wheel has a much lower amplitude, the angle of rotation being about twenty degrees, whereas with a balance spring the angle of rotation is 330°, and the balance wheel oscillates with a frequency much higher than that of a balance wheel mounted on a balance spring.

[0010] Thus, new configurations of escapement mechanisms have been invented to be able to work with a flexible-guided regulating organ.

[0011] In most mechanical movements, the escape wheel stem, the pallet fork stem, and the balance staff are in the same plane. Viewed from above, the position of these three axes forms a straight line. This is called in-line alignment. However, this arrangement is rather bulky.

[0012] In certain watch movement configurations, the positions of the three axes form a bend. In other words, the escapement wheel, the pallet fork, and the balance wheel are not aligned, but are arranged in a triangular fashion, each at the apex of the same triangle. Such an arrangement reduces the overall size of the watch movement.

[0013] Generally, the pallet fork and the pallets are positioned at the same level within the movement. Furthermore, because the pallet fork interacts with the balance wheel's ellipse and the pallets with the escape wheel teeth, the pallet fork and pallets must be spaced far apart to prevent collisions between the ellipse and the escape wheel teeth. This explains why an in-line "pointing" is typically used.

[0014] Thus, on the one hand, the relative position, particularly the center-to-center distance, between the anchor and the escape wheel must be precisely defined. On the other hand, the relative position, particularly the center-to-center distance, between the anchor and the balance wheel must also be precisely defined.

[0015] Since, generally, the pallets and the fork belong to the same part (the anchor) and cooperate substantially at the same level, it is difficult to satisfy both requirements simultaneously. Summary of the invention

[0016] One object of the present invention is to provide an anchor for a new type of escapement mechanism, which avoids the aforementioned defects, in particular which facilitates its assembly and its cooperation with the escapement wheel and the balance wheel.

[0017] To this end, the invention relates to an anchor for a watch escapement mechanism, the anchor comprising a fork intended to cooperate with a balance wheel ellipse, an inlet arm and an outlet arm intended to cooperate with an escapement wheel, and a rod on which the anchor is mounted, characterized in that the anchor is arranged on the rod in two separate parts, such that the fork is arranged on a first level and the inlet and outlet arms are arranged on a second level, the two levels being separated along the axis of the rod by a predetermined distance.

[0018] The invention is remarkable in that the fork, the input arm and the output arm are arranged on the rod in two separate parts, so that the fork is arranged on a first level and the arms are arranged on a second level, the two levels being separated along the axis of the rod by a predetermined distance.

[0019] Thus, such an anchor allows the balance wheel and escapement wheel to be positioned at different levels within the watch movement. For example, the escapement wheel can be placed above the mainplate at the bottom of the movement, and the balance wheel at the top. The stepped anchor allows the balance wheel and escapement wheel to work together in such an arrangement, particularly when the anchor, balance wheel, and escape wheel are in a compact configuration.

[0020] According to a particular embodiment of the invention, the first level is arranged at a lower end of the rod.

[0021] According to a particular embodiment of the invention, the predetermined distance is between one quarter and three quarters of the length of the stem, preferably between one third and three thirds of the length of the stem, or even substantially half the length of the stem.

[0022] According to a particular embodiment of the invention, the second level is arranged substantially in the middle of the stem.

[0023] According to a particular embodiment of the invention, the anchor comprises a fork intended to cooperate with an ellipse of the balance wheel, an entry arm and an exit arm intended to cooperate with the escapement wheel.

[0024] The invention also relates to an escapement mechanism comprising an escape wheel and such an anchor.

[0025] The invention further relates to a clock movement comprising a mainplate, a balance wheel, a balance bridge, a flexible guide, the balance wheel being suspended by the flexible guide, and such an escapement mechanism, the anchor cooperating with an ellipse of the balance wheel on one side and with the escape wheel on the other.

[0026] According to a particular embodiment of the invention, the anchor stem is pivotally mounted in the clock movement, the stem comprising a first pivot arranged at a first end of the stem, and a second pivot arranged at a second end of the stem.

[0027] According to a particular embodiment of the invention, the first pivot is mounted pivotally in the plate.

[0028] According to a particular embodiment of the invention, the second pivot is mounted pivotally in the balance bridge.

[0029] According to a particular embodiment of the invention, the balance wheel, the escape wheel and the anchor are arranged so that a line passing through the center of the escape wheel, the center of the balance wheel and the anchor rod forms a bend having an angle of less than 90°, preferably less than 70°, or even less than 60°. Brief description of the figures

[0030] Other features and advantages of the invention will become more apparent upon reading the following description of a particular embodiment of the invention, given by way of simple illustrative and non-limiting example, and the accompanying figures, among which: there figure 1 schematically represents a top view of a clockwork module comprising a regulating organ and an escapement mechanism, the figure 2 schematically represents a profile view of the clockwork module of the figure 1 , there figure 3 schematically represents a cross-sectional view of a clockwork movement comprising the clockwork module of figures 1 and 2 , and the figure 4 schematically represents a perspective view of the anchor according to the invention. Detailed description of the invention

[0031] On the figures 1 and 2 , the clock module 10 includes an escapement mechanism 50 associated with a regulating organ 60.

[0032] The regulating organ 60 includes a balance wheel 35, and a flexible rotating guide 32 for the balance wheel 35, while the escapement mechanism 50 includes an escapement mobile 30, as well as an anchor 21.

[0033] The balance wheel 35 has a bone-like shape with a longitudinal portion 36 and a lateral portion 37 in the form of an arc of a circle at each end of the longitudinal portion 36. The balance wheel 35 further includes stops concentric to the virtual axis of rotation mounted in the middle of the longitudinal portion 36 and adjustment screws 39 for the inertia of the balance wheel arranged in the lateral portions 37.

[0034] The balance wheel 35 is mounted on the flexible guide 32 to enable it to perform a rotary oscillatory motion around a virtual axis of rotation. The flexible guide 32 is directly connected to the balance wheel 35.

[0035] The flexible guide 32 comprises at least two flexible blades 37, here two pairs of crossed flexible blades 37, arranged in series, and forming a double pivot to increase the angle of rotation of the rocker 35.

[0036] The anchor 21 is equipped with two arms 11, 12, the ends of which form two pallets cooperating with the teeth 18 of the first escapement wheel 30.

[0037] The arms 11, 12 of the anchor 21 cooperate with the escapement wheel 30, and interact alternately with the teeth 18 of the escapement wheel 30 to regulate the rate.

[0038] The anchor 21 also includes a longitudinal part 14 extending laterally, and is provided with a fork 22 at its end to cooperate with an ellipse 23 of a balance 35.

[0039] The anchor 21 includes a rod 5 substantially perpendicular to the longitudinal part 14 and to the fork 22, and which allows it to be mounted in rotation in the movement.

[0040] The anchor 21 comprises an elongated body 31 extending radially, this body 31 being arranged to cooperate with stops, not shown in the figures. The stops function to restrain the anchor 21 in order to prevent excessive rotation.

[0041] The elongated body 31 is arranged substantially at the level of the entry arms 11 and exit arms 12 of the anchor 21.

[0042] According to the invention, the fork 22 and the inlet arms 11 and outlet arms 12 are arranged in two parts on the rod 5. The fork 22 is arranged on a first level of the rod 5, while the inlet arms 11 and outlet arms 12 are arranged on a second level of the rod 5.

[0043] Thus, the two levels are separated along the axis of the rod 5 by a predetermined distance D0. Preferably, the predetermined distance D0 is between one quarter and three quarters of the length of the rod, preferably between one third and three thirds of the length of the rod, or even substantially half the length of the rod.

[0044] For example, the first level is arranged approximately at a lower end of the stem, while the second level is arranged approximately in the middle of the stem.

[0045] The stem 5 preferably has a length corresponding approximately to the height of the clock movement, from the plate 2.

[0046] The escapement mechanism 50 further includes a second clockwork mechanism, the second clockwork mechanism 20 meshing with the first escapement mechanism 30. The second clockwork mechanism 20 is, for example, a seconds mechanism. The teeth 14 of the second clockwork mechanism 20 mesh with a pinion 3 of the first escapement mechanism 30.

[0047] The balance wheel 35 includes an ellipse 23 extending below the balance wheel 35 to cooperate with the fork 22 of the anchor 21. The ellipse 23 is mounted integrally with the balance wheel 35.

[0048] The center of the balance wheel 35, the escapement wheel 30, and the anchor 21 are arranged on a line forming a bend. This contrasts with conventional escapement mechanisms, where this line is essentially straight, and where the anchor is positioned on this line between the balance wheel and the escapement wheel.

[0049] Thus, the balance wheel 35, the escapement mobile 30, and the anchor 21 are each arranged at the apex of a triangle.

[0050] The elbow has an angle of less than 90°, preferably less than 70°, or even less than 60°. Thus, the balance wheel 35, the escapement mobile 30 and the anchor 21 are arranged in a compact manner.

[0051] On the figure 3 , the clockwork module of figures 1 and 2 is arranged in a clockwork movement 1, specifically for a watch.

[0052] In addition to the clock module 10, the clock movement 1 includes a plate 2 and bridges to support the components of the clock module 10.

[0053] In particular, the clock movement 1 includes a balance bridge 4 arranged above the balance wheel 4. Thus, the balance wheel 4 oscillates between the plate 2 and the balance bridge 4. The balance bridge 4 includes, for example, an upper stop to retain the balance wheel 35 vertically.

[0054] The clockwork movement 1 also includes an escapement bridge 6 to maintain the axis of the escapement mobile 30 in pivoting position.

[0055] The escapement mobile 30 is mounted in pivot between the plate 2 and the escapement bridge 6.

[0056] The rod 5 includes a first pivot 7 arranged at a first end of the rod 5, and a second pivot 8 arranged at a second end of the rod 5.

[0057] The first pivot 7 is mounted pivotally on the plate 2, and the second pivot 8 is mounted pivotally in the balance bridge 4. Thus, the anchor 21 is mounted pivotally between the balance bridge 4 and the plate 2. And the stem 5 extends beyond the balance 35.

[0058] To this end, the balance bridge 6 includes a first bearing 13, which acts as a stop for the balance wheel 37 in case of shock, and is concentric with the virtual axis of rotation defined by the flexible guide 32, and a second bearing 15 for the anchor 21. The distance D1 between the center of the first bearing 13 and the center of the second bearing 15 is predetermined to allow optimal cooperation between the fork 22 of the anchor 21 and the ellipse 23 of the balance wheel 6.

[0059] The plate 2 includes a third bearing 16 for the balance wheel 35, a fourth bearing 17 for the anchor rod 5 21, and a fifth bearing 9 for the escapement wheel 30. The distance D2 between the center of the fourth bearing 17 and the center of the fifth bearing 19 is predetermined to allow optimal cooperation between the arms 11, 12 of the anchor 21 and the escapement wheel 30.

[0060] The escapement bridge 6 includes a sixth bearing 24 for a pivot of the escapement mobile 30.

[0061] Thanks to this arrangement of the anchor 21, the cooperation between the arms 11 and 12 of the anchor 21 and the escape wheel 30 on the one hand, and the cooperation between the fork 22 and the ellipse 23 on the other, is better ensured. Indeed, the stem 5 is not at risk of being too inclined relative to the plate 2.

[0062] Indeed, as the anchor 21 and the balance wheel 35 are positioned between the plate 2 and the balance bridge 4, the distance D1 of the center distance defined between the second pivot 8 of the balance wheel 35 and that of the anchor 21 on the balance bridge 4 is constant, and is not likely to vary during assembly.

[0063] Similarly, the distance D2 of the center distance defined between the first pivot 7 of the anchor and the pivot of the escapement mobile 30 on the plate 2 is constant, and does not vary during assembly.

[0064] Naturally, the invention is not limited to the embodiments described with reference to the figures, and variants could be envisaged without departing from the scope of the invention.

Claims

1. Anchor (21) for a clockwork escapement mechanism (50), the anchor (21) comprising a fork (22) intended to cooperate with an ellipse (23) of a balance wheel (35), an input arm (11) and an output arm (12) intended to cooperate with an escape wheel (30), as well as a rod (5) on which the fork (22), the input arm (11) and the output arm (12) are mounted, characterized in that The fork (22), the input arm (11) and output arm (12) are arranged on the rod (5) in two separate parts, the fork (22) being arranged on a first level, and the arms (11, 12) being arranged on a second level of the rod (5), the two levels being separated along the axis of the rod (5) by a predetermined distance (D0).

2. Anchor according to claim 1, characterized in that the first level is arranged at a lower end of the stem (5).

3. Anchor according to claim 1 or 2, characterized in thatthe predetermined distance (D0) is between one quarter and three quarters of the length of the stem (5), preferably between one third and three thirds of the length of the stem, or even substantially half the length of the stem.

4. Anchor according to any one of the preceding claims, characterized in that the second level is arranged approximately in the middle of the stem (5).

5. Escapement mechanism comprising an escape wheel (30) and an anchor (21) according to any one of the preceding claims.

6. Clock movement comprising a plate (2), a balance wheel (35), a balance bridge (4), a flexible guide (32), the balance wheel (35) being suspended by the flexible guide (32), so as to be able to oscillate about a virtual axis between the plate (2) and the balance bridge (4), characterized in thatIt includes an escapement mechanism according to claim 5, the anchor (21) cooperating with an ellipse (23) of the balance wheel (35) on the one hand, and with the escapement wheel (30) on the other hand.

7. Clockwork movement according to claim 6, characterized in that the stem (5) of the anchor (21) is mounted pivotally in the clock movement (1), the stem (5) comprising a first pivot (7) arranged at a first end of the stem (5), and a second pivot (8) arranged at a second end of the stem (5).

8. Clockwork movement according to claim 7, characterized in that the first pivot (7) is mounted pivotally in the plate (2).

9. Clockwork movement according to claim 7 or 8, characterized in that the second pivot (8) is mounted pivotally in the balance bridge (4).

10. Clockwork movement according to any one of the preceding claims, characterized in thatthe balance wheel (4), the escape wheel (30) and the anchor (21) are arranged so that a line passing through the center of the escape wheel (30), the center of the balance wheel (35) and the stem (5) of the anchor (21) forms a bend having an angle of less than 90°, preferably less than 70°, or even less than 60°.

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