CH719120A2 - Clockwork mechanism comprising a jumper and a toothed component pivotally mounted. - Google Patents

Abstract

The present invention relates to a watch mechanism (1) comprising a toothed component (2) pivotally mounted and subjected to the action of a jumper (6), said jumper (6) comprising an engagement element (8) and a elastic (10) comprising at least one elastic blade (12) arranged to work in buckling, said elastic blade (12) comprising two ends (12a, 12b) linked to a support and being interrupted in its central part by the element of engagement (8), said engagement element (8) being arranged to occupy an engagement position in which it is kept engaged between two consecutive teeth (3) of the toothed component (2) by the elastic member (10) to to hold it in a rest position and to move in a generally linear manner through a predetermined range of positions relative to the engagement position when the toothed component (2) moves one step to occupy a next rest position, the engagement element (8) being lifted by the toothed component (2) against the action of the elastic member (10) then being brought back by the elastic member (10) in its engagement position to maintain the toothed component (2) in the next rest position, the elastic member (10) having zero or negative stiffness in at least part of the predetermined range. The ends (12a, 12b) of said at least one elastic blade (12) are pivotally mounted on said support by means of pivots.

Description

Technical area

The present invention relates to a watch mechanism comprising a toothed component pivotally mounted and subjected to the action of a jumper, said jumper comprising an engagement element and an elastic member comprising at least one elastic blade arranged to work in buckling , said elastic blade comprising two ends linked to a support provided in the watch mechanism and being interrupted in its central part by the engagement element, the engagement element being arranged to occupy an engagement position in which it is held engaged between two consecutive teeth of the toothed component by the resilient member to hold it in a rest position and to move in a generally linear manner through a predetermined range of positions relative to the engagement position as the toothed component moves one step to occupy a next rest position, the engagement element being lifted by the toothed component against the action of the elastic member and then being returned by the elastic member to its engagement position to hold the toothed component in the next rest position, the elastic member having zero or negative stiffness in at least part of the predetermined range.

The present invention also relates to a timepiece comprising such a mechanism.

State of the art

[0003] Such a mechanism is for example described in publication WO 2018/203187 by the applicant. In this document, a jumper is described in which the elastic blade or blades have their two ends fixed integrally to a support fixed to the frame of the mechanism, so that the two ends of the blades are embedded.

[0004] This assembly makes it possible to obtain an elastic member having a negative stiffness in the predetermined range of positions that the engagement element can take when it moves in a generally linear manner with respect to its engagement position during the operation of the mechanism. This makes it possible to reduce the overall energy consumption during a rotation of one step of the toothed component compared to a traditional jumper which conventionally has a positive stiffness signifying an increase in the torque generated by the jumper with the movement of the element of commitment.

[0005] Such a mechanism also has the advantage of being less sensitive to linear shocks than traditional jumpers. It also allows the use of low height blades so that the height of the mechanism can be reduced.

[0006] However, the proposed mechanism takes up surface space. Furthermore, the thin blades necessary for its operation can prove to be complex to manufacture.

[0007] In addition, the elastic member can behave like a bistable and become blocked. It is therefore necessary to provide a stop in order to prevent a movement of the elastic member which would cause a bistability effect.

[0008] The present invention aims to propose a new watchmaking mechanism making it possible to overcome, at least in part, the aforementioned drawbacks.

Disclosure of Invention

[0009] To this end, the invention relates to a watch mechanism comprising a toothed component pivotally mounted and subjected to the action of a jumper, said jumper comprising an engagement element and an elastic member comprising at least one elastic blade arranged to work in buckling, said elastic blade comprising two ends linked to a support provided in the watch mechanism and being interrupted in its central part by the engagement element, the engagement element being arranged to occupy an engagement position in which it is held engaged between two consecutive teeth of the toothed component by the resilient member to hold it in a rest position and to move in a generally linear manner through a predetermined range of positions relative to the engagement position when the toothed component moves one step to occupy a next rest position, the engagement element being lifted by the toothed component against the action of the elastic member and then being returned by the elastic member to its position of engagement to maintain the toothed component in the next rest position, the elastic member having zero or negative stiffness in at least part of the predetermined range.

According to the invention, the ends of said at least one elastic strip are pivotally mounted on said support by means of pivots.

This configuration according to the invention makes it possible to use thicker elastic blades than the elastic blades of systems of the prior art with recessed blades, the thicker blades being easier to manufacture, while obtaining the same stiffness.

[0012] In addition, the Von Mises stresses are lower than those of the prior art systems with recessed blades, so that fatigue is reduced.

[0013] In a particularly preferred manner, said at least one elastic strip has been preformed and buckled.

[0014] In this configuration, the elastic member cannot behave like a bistable. The jumper can therefore not be blocked. Nor is it necessary to provide a stop to limit its movement.

[0015] Preferably, the stiffness of the elastic member is zero or negative over substantially the entire predetermined range. More particularly, the stiffness of the elastic member is negative in substantially all of the predetermined range.

[0016] Advantageously, said engagement element is movable only along a straight line (d).

[0017] Preferably, the assembly comprising said at least one elastic blade and the engagement element is symmetrical with respect to said straight line (d).

[0018] Preferably, the elastic member comprises at least one pair of parallel elastic blades.

[0019] Advantageously, each of the ends of said at least one elastic blade has a rotating element pivotally mounted on the support by means of pins.

The present invention also relates to a timepiece comprising a timepiece mechanism as defined above.

Brief description of the drawings

Other characteristics and advantages of the present invention will appear on reading the following detailed description of various embodiments of the invention, given by way of non-limiting examples, and made with reference to the accompanying drawings in which : FIG. 1 is a diagrammatic view from above of a timepiece mechanism according to the invention, the elastic member comprising two preformed buckled elastic blades; Figure 2 is a schematic top view of the jumper alone of Figure 1 in the engagement position and in the position moved along a straight line (d); FIG. 3 is a graphic representation of the force exerted on the engagement element corresponding to the elastic return force exerted on said engagement element as a function of the displacement of the engagement element for a jumper of FIG. 2, with preformed buckled blades with a blade thickness of 25 µm; FIG. 4 is a graphic representation of the absolute Von Mises stress on a jumper of FIG. 2 with buckled preformed blades with a blade thickness of 25 μm as a function of the displacement of the engagement element; FIG. 5 is a graphic representation of the force exerted on the engagement element corresponding to the elastic return force exerted on said engagement element as a function of the displacement of the engagement element for the jumper of FIG. 2, with preformed buckled blades with a blade thickness of 60 µm (curve E1'), for an equivalent jumper but with straight embedded blades with a blade thickness of 25 µm (curve E2), and for an equivalent jumper but with blades recessed preformed buckled with a blade thickness of 25 µm (curve E3); And Figure 6 is a graphical representation of the absolute Von Mises stress on a jumper of Figure 2 with buckled preformed blades with a blade thickness of 60 μm as a function of the displacement of the engagement element (curve Ct1'), on an equivalent jumper but with straight embedded blades with a blade thickness of 25 µm (curve Ct2), and on an equivalent jumper but with preformed embedded buckled blades with a blade thickness of 25 µm (curve Ct3).

Embodiments of the Invention

In the context of the present invention, the term "stiffness" means the tangential stiffness.

[0023] Referring to Figure 1, the present invention relates to a watch mechanism 1 comprising a toothed component, constituted in this example by a toothed wheel 2, comprising teeth 3 and pivotally mounted on a frame 4. The wheel 2 is subjected is operated by a jumper 6 which holds wheel 2 in position and allows it to rotate in both directions. Wheel 2 is for example a toothed wheel kinematically linked to a display member. More specifically, wheel 2 can carry, drive or form a display member such as a disc, a needle or a display crown. Wheel 2 is for example a date wheel. As a variant, it can also be, for example, a column wheel or any type of toothed wheel traditionally positioned by a jumper. It is other than an escape wheel.

As illustrated in Figure 1, the jumper 6 comprises a rigid engagement element 8 movable and an elastic member 10 prearmed and connecting the latter to a support. The support can be fixed on a frame 4 of the watch mechanism on which the wheel 2 is also mounted. The support can be the frame 4 itself. The rigid engagement element 8 is movable relative to this support. The frame 4 can be fixed or mobile and conventionally comprises the plate bearing the watch movement of which the mechanism 1 forms part.

In the example illustrated, the engagement element 8 has at one end the form of a projection 14 configured to be able to engage between two consecutive teeth 3 of the toothed wheel 2 when said engagement element 8 is in its committed position. For example, the shape of the projection can be defined by two inclined planes forming between them an angle comprised preferably for example between 120° and 170°, and pointing in the direction of the teeth 3 of the toothed wheel 2, preferably towards the center of the toothed wheel 2. The angle represented here is 120°.

[0026] The engagement element 8 is arranged to occupy an engagement position, as shown in Figure 1, in which it is kept engaged, resting between two consecutive teeth 3 of the toothed wheel 2 by the member elastic 10, which is then in a stable state, to maintain said toothed wheel 2 in a rest position and to move in a generally linear manner in a predetermined range of positions with respect to the engagement position when the toothed wheel 2 moves one step to occupy a next rest position, the engagement element 8 being raised by the toothed wheel 2 against the action of the elastic member 10 and then being brought back by the elastic member 10, then in a unstable state, in its engagement position to maintain the toothed wheel 2 in the next rest position.

The elastic member 10 has zero or negative stiffness in at least part of the predetermined range, and preferably in substantially the entire predetermined range.

[0028] Preferably, the stiffness of the elastic member is negative over substantially the entire predetermined range, as will be described in detail below.

Thus, the mechanism 1 comprising a wheel 2 and a jumper 6 allows a reduction in energy consumption during the rotation of a step of the toothed wheel 2 compared to a traditional jumper using a spring with positive stiffness allowing an equivalent maintenance in position. In particular, the jumper 6 consumes less energy when it goes up on a tooth 3.

The elastic member 10 comprises at least one elastic blade 12 arranged to work in buckling. The elastic blade 12 comprises two ends 12a, 12b linked to the support provided in the watch mechanism, here the frame 4, and being interrupted in its central part by the engagement element 8.

In the example shown in Figures 1 and 2, the elastic member 10 advantageously comprises at least one pair of parallel elastic blades 12, here a pair, arranged to work in buckling. Each of these blades 12 is interrupted in its central part by the engagement element 8 and has its two ends 12a, 12b linked to the support, here the frame 4.

The engagement element 8 is guided in translation by the elastic blades 12 and moves in translation along the y axis in both directions along a straight line (d) preferably passing through the center of the toothed wheel 2. In the example shown in Figure 2, the engagement element 8 moves in vertical translation upwards along the arrow A when the engagement element 8 is lifted by the wheel 2 to position itself at 8', the blades 12 deforming at 12', and the engagement element 8 moves in vertical downward translation along the arrow B, when the engagement element 8 is brought back towards the wheel 2. Preferably , the engagement element 8 is arranged to be free only on the translation in y, so that said engagement element 8 is movable only along the line (d), without risk of rotation.

In the example shown in Figures 1 and 2, the line (d) passes through the center of the toothed wheel 2 and the assembly comprising the elastic blades 12 and the rigid engagement element 8 is symmetrical by relative to this line (d). Within the mechanism 1, the pair of elastic blades 12 is pre-armed and exerts a force tending to push the engagement element 8 against the wheel 2, when it is in the engagement position, as represented by the arrow E in figure 1.

According to the invention, each end 12a, 12b of said at least one elastic blade 12 is pivotally mounted on the support, here the frame 4, by means of pivots16 provided on said support.

Preferably, each of the ends 12a, 12b of the elastic blades 12 has a rotary element 18 pivotally mounted on the support, here the frame 4, by means of pins 20 integral with said support, in order to constitute the pivot 16. Any other suitable pivot mounting means can be used.

In a particularly preferred way, the elastic blades 12 have been preformed buckled, that is to say they have been machined with a buckled shape. The elastic blades 12 are therefore in a buckled form before their use.

Preferably, the ratio between the apex h (measurement between the bottom of the engagement element 8, the elastic blades being at rest, and the horizontal 22 formed by the upper pivots 16) and the thickness elastic blades e is less than 1.886 so as not to have a bistability effect, and without possible rotation.

[0038] Each of the elastic blades 12 could also have been preformed in the form of two half-straight lines mounted inclined in the shape of a V extending on either side of the engagement element 8, and only buckling under the effect of its pre-armage.

In this case, the ratio between the apex h (measurement between the bottom of the engagement element 8 when the blades are at rest and the horizontal of the upper pivots 16) and the thickness of the elastic blades e is preferably less than 1.57 so as not to have a bistability effect.

[0040] The preformed elastic blades buckled at the factory and straight make it possible not to have any bistability effect by choosing the appropriate h/e ratio, nor possible rotation. This makes it possible to avoid the use of a safety stop to limit the displacement of the engagement element 8 and not to block the jumper 6.

The elastic blades 12 could also have been preformed straight and work in buckling under the effect of a compression of their ends. To do this, the pivots 16 are brought together to be able to compress the blades 12 and make them take the appropriate shape. This allows adjustment of the displacement and the intensity of the compression force. It is also possible to adjust the apex by compressing the blades.

In order not to have a bistability effect when the configuration of the blades makes it possible despite everything, it is also possible to limit the displacement of the engagement element 8 in the direction of the arrow A by using a safety stop (not shown) forming part of the support, here the frame 4.

Figure 2 shows, for understanding the invention, the jumper 6 positioned on the pivots 16 isolated. The jumper 6 is therefore here considered outside the mechanism 1, that is to say free of any interaction with the toothed wheel 2.

[0044] With reference to FIG. 3, the displacement of the engagement element 8 isolated along the straight line (d) is called Δ, Δ being equal to 0 when the engagement element 8 is moved away to the maximum. from the horizontal 22 formed by the upper pivots 16 (in this position the preformed buckled blades 12 are at rest) and increasing when the engagement element 8 approaches the horizontal 22 as represented by the engagement element 8'. Δ corresponds to the distance between the projection 14 of the engagement element 8 and the projection 14' of the engagement element 8'.

The curve E1 of FIG. 3 is a graph E(Δ) which represents the evolution of the force E resulting from the elastic return forces exerted by the pair of elastic strips 12 on the engagement element 8 of the jumper 6 used in accordance with the invention, and which corresponds to the force exerted by said engagement element 8 in the direction of the arrow E, as a function of the displacement Δ. This force was measured, for each position Δ, by measuring the opposing force necessary to maintain the engagement element 8 in a given position. In general, when the engagement element 8 is in the position in which Δ=x mm, it is said that the jumper 6 is armed with x mm. As can be seen on curve E1 in figure 3, this force follows an evolution in several phases: the starting point Δ=0, corresponds to a stable state of jumper 6. Indeed, in this position, the force E is zero, that is to say that the engagement element 8 does not exert any strength; for a position Δ between 0 and a first value the force E increases linearly and rapidly with the position Δ; when Δ reaches the first value Δ1, the force E reaches a maximum then remains substantially constant until the position Δ2. “Substantially constant” force means a force that does not vary by more than 10%, preferably 5%, more preferably 3%, it being understood that this percentage can be further reduced; beyond position Δ2, the force begins to decrease substantially linearly while remaining positive until reaching position Δmax=1 mm, without reaching a second stable state of jumper 6, so that jumper 6 does not present any bistability over the range [Δ2, Δmax]. No safety stop limiting the movement of the engagement element to prevent it from tilting into another stable state is therefore not to be provided, unlike the jumper with embedded blades of the mechanism described in publication WO 2018/203187.

The isolated jumper 6 having an evolution of the force E of the type shown in Figure 3 differs from conventional elastic structures. Its properties are based on the ability of its elastic blades 12 to work in buckling. Obtaining elastic blades having these properties is within the reach of those skilled in the art. The applicant has designed a particular jumper 6 comprising a pair of parallel elastic blades 12. With reference to FIG. 2, the dimensions of this jumper 6 are those indicated in table 1 below:

Table 1

[0047] Length L of a blade element (projected onto the horizontal) [mm] 3.5 Apex h of the blades at rest [mm] 0.8 Height of the blades [mm] 0.15 Thickness e of the blades [µm] 25 Maximum displacement Δ of the engagement element [mm] 1 Coefficient of friction of the pins 0.15

[0048] L is the length of a blade element or of a "half-blade", that is to say the length projected onto the horizontal between the pivotally mounted end 12a or 12b of the element blade and the other end of the blade element integral with the engagement element 8.

The height or depth of a blade is the dimension of the blade along the z axis.

[0050] The elastic blades 12 have been preformed flamed in the factory.

FIG. 3 shows an FEM model representing the evolution of the force E(Δ) of the particular jumper 6 thus produced as a function of the position of its engagement element 8 along the straight line (d).

This model considers a non-monolithic jumper 6 made by assembling several elements or parts, these elements can moreover be made of identical or different materials from each other. For example, at least the blades 12 are made of an alloy based on cobalt, nickel and chromium, more precisely Nivaflex<®>45/18, but any suitable material can be used. For example, materials such as silicon typically coated with silicon oxide, metallic glasses, mineral glasses, ceramic glasses, plastics or CK101 (unalloyed structural steel) are also suitable.

It is important to take into account the ratio between the elastic limit and the Young's modulus of the material to choose the material constituting the elastic blades 12.

It emerges from the FEM model presented in FIG. 3 that a locally maximum elastic restoring force is obtained for a displacement Δ1=0.15 mm of the engagement element 8 of the particular isolated jumper 6 studied, then that a decreasing linear elastic return force is obtained for a displacement of the engagement element 8 of the particular insulated jumper 6 studied greater than Δ2=0.25 mm.

The stiffness of the elastic member 10 is the derivative of the function E(Δ) defined above.

Over the range of positions [Δ1, Δ2] over which the effort or the force is substantially constant, the stiffness of the elastic member 10 in the isolated jumper 6 is substantially zero. Then from Δ=Δ2, and over the range [Δ2, Δmax], the effort or the force is decreasing, so that the stiffness of the elastic member 10 in the jumper 6 isolated is negative. In the present invention, it is advantageous to place oneself in this range [Δ2, Δmax] or at least partly in this range. Within the mechanism 1, the jumper 6 is therefore arranged to force the engagement element 8 to remain in a predetermined range of positions for which the stiffness is negative, said range being included in the range of positions [Δ2, Δmax] associated with the jumper 6 during the rotation of a step of the wheel 2 against the return action of the elastic member 10.

To obtain such an arrangement, the jumper 6 is mounted by pivotally mounting the ends 12a, 12b of the blades 12 on the pins 20 integral with the support, here the frame 4 of the mechanism 1 so that the projection 14 of the engagement element 8 is engaged in a centered manner between two consecutive teeth 3 of the wheel 2 already placed on the frame 4, which keeps the latter in position under the effect of the return force exerted by the pair of elastic strips 12, jumper 6 being armed with a value Δarm>Δ2 in this position.

The choice of the value Δarm defines the lower limit of the predetermined range of positions in which the engagement element 8 moves when the wheel 2 rotates one step. The shape and dimensions of the teeth 3 of the wheel 2 and the angle between the inclined planes defining the projection 14 of the engagement element 8 are chosen so that the maximum value Δ reached during the rotation of a pitch of wheel 31 is less than or equal to Δmax.

The curve Ct1 of Figure 4 is a graphical representation of the absolute Von Mises stress on the jumper 6 of Figure 2 with a blade thickness of 25 μm as a function of the displacement of the engagement element 8.

Advantageously, it is possible to increase the force exerted by the elastic member 10 by increasing the thickness e of the elastic blades 12. It is for example possible to envisage blades with thickness variations to change the negative stiffness , these variations being able to be linear variations or by providing different blade sections of different thicknesses.

[0061] Figure 5 is a graphical representation of the force E (Δ) exerted on the engagement element corresponding to the elastic return force exerted on said engagement element as a function of the displacement of the element of engagement for the jumper of FIG. 2, with preformed buckled blades with a blade thickness of 60 μm (curve E1'), for an equivalent jumper but with straight embedded blades with a blade thickness of 25 μm (curve E2), and for an equivalent jumper but with embedded preformed buckled blades with a blade thickness of 25 μm (curve E3), as described in publication WO 2018/203187.

The various curves E1', E2 and E3 show that the linear jumper 6 with negative stiffness mounted with the ends of its blades pivoted and with preformed blades buckled in accordance with the present invention makes it possible to obtain, with a blade thickness of 60 μm , a stiffness similar to that obtained with a jumper with straight embedded blades or buckled preformed blades, with a blade thickness of 25 µm. Preformed buckled pivoted slats exhibit similar behavior to recessed straight or preformed buckled slats.

[0063] Figure 6 is a graphical representation of the absolute Von Mises stress on a jumper of Figure 2 with buckled preformed blades with a blade thickness of 60 μm as a function of the displacement of the engagement element (curve Ct1 '), on an equivalent jumper but with straight embedded blades with a blade thickness of 25 µm (curve Ct2), and on an equivalent jumper but with preformed embedded buckled blades with a blade thickness of 25 µm (curve Ct3).

Figure 6 shows that the Von Mises stresses in the case of pivoted preformed blades buckled by 60 μm are always lower than the stresses in the case of straight embedded blades or preformed buckled 25 μm blades.

The thick blades that can be used with the linear jumper 6 with negative stiffness mounted with the ends of its blades pivoted and with preformed blades buckled in accordance with the present invention are easier to manufacture. In addition, the linear jumper 6 with negative stiffness mounted with the ends of its blades pivoted and with preformed blades buckled in accordance with the present invention has no bistability effect. Such a jumper can therefore not be blocked. Nor is it necessary to provide a safety stop. The stress exerted on the linear jumper 6 with negative stiffness mounted with the ends of its blades pivoted and with preformed blades buckled in accordance with the present invention being lower than that of the embedded blades, the jumper 6 undergoes less fatigue.

It is obvious that the engagement element can be of a different shape from that illustrated in Figures 1 and 2.

The toothed wheel 2 with truncated teeth used in the example described is preferred because it makes it possible to limit the recoil of the engagement element 8 of the jumper 6 when it performs a rotation of one step. However, it can easily be replaced by a conventional toothed wheel such as a star or by a wheel with asymmetrical teeth. In all cases, the two inclined planes of the engagement element advantageously have two respective points of support with the toothing of the wheel when the latter is in the rest position.

[0068] A person skilled in the art can also replace the toothed wheel with any other toothed component such as a rack or such as a crown, for example a display, with internal teeth.

Claims (13)

1. Clockwork mechanism (1) comprising a toothed component (2) pivotally mounted and subjected to the action of a jumper (6), said jumper (6) comprising an engagement element (8) and an elastic member (10 ) comprising at least one elastic blade (12) arranged to work in buckling, said elastic blade (12) comprising two ends (12a, 12b) linked to a support provided in the watch mechanism and being interrupted in its central part by the element engagement element (8), said engagement element (8) being arranged to occupy an engagement position in which it is held engaged between two consecutive teeth (3) of the toothed component (2) by the elastic member (10 ) to hold it in a rest position and to move in a generally linear manner through a predetermined range of positions relative to the engagement position when the toothed component (2) moves one step to occupy a rest position next, the engagement element (8) being lifted by the toothed component (2) against the action of the elastic member (10) and then being brought back by the elastic member (10) into its engagement position to maintaining the toothed component (2) in the next rest position, the elastic member (10) having zero or negative stiffness in at least part of the predetermined range, characterized in that the ends (12a, 12b) of said at least one elastic blade (12) is pivotally mounted on said support by means of pivots. 2. Timepiece mechanism (1) according to claim 1, characterized in that said at least one elastic blade (12) has been preformed buckled. 3. Timepiece mechanism (1) according to one of the preceding claims, characterized in that the stiffness of the elastic member (10) is zero or negative in substantially the entire predetermined range. 4. Clockwork mechanism (1) according to one of the preceding claims, characterized in that the stiffness of the elastic member (10) is negative in substantially the entire predetermined range. 5. Timepiece mechanism (1) according to one of the preceding claims, characterized in that said engagement element (8) is movable only along a straight line (d). 6. Timepiece mechanism (1) according to claim 5, characterized in that the assembly comprising said at least one elastic blade (12) and the engagement element (8) is symmetrical with respect to said straight line (d). 7. Clockwork mechanism (1) according to one of the preceding claims, characterized in that the engagement element (8) comprises two inclined planes forming between them an angle preferably comprised between 120° and 170° and pointing in the direction teeth (3) of the toothed component (2). 8. Timepiece mechanism (1) according to one of the preceding claims, characterized in that the elastic member (10) comprises at least one pair of parallel elastic blades (12). 9. Clockwork mechanism (1) according to the preceding claim, characterized in that the ratio between the apex (h) and the thickness (e) of the elastic blades (12) is less than 1.886. 10. Clockwork mechanism (1) according to one of the preceding claims, characterized in that the toothed component (2) is a wheel kinematically linked to a display member or a column wheel. 11. Clockwork mechanism (1) according to one of the preceding claims, characterized in that the support on which the ends of said at least one elastic blade (12) are pivotally mounted is a frame (4) of said clockwork mechanism (1) . 12. Clockwork mechanism (1) according to one of the preceding claims, characterized in that each of the ends (12a, 12b) of said at least one elastic blade (12) has a rotary element (18) pivotally mounted on the support at the means of pins (16). 13. Timepiece comprising a timepiece mechanism (1) according to any one of claims 1 to 12.