EP1272906B1 - Escapement device for timepiece component - Google Patents

Abstract

The invention concerns an escapement device comprising a power source capable of delivering a variable torque based on the angle of rotation of a pinion fixed to said power source, said variable torque having at least a stable position and an unstable position. The device further comprises locking means capable of locking power transmission to an oscillator in a stable point of equilibrium and unlocking means capable of unlocking power transmission to said oscillator between a stable point of equilibrium and an unstable point of equilibrium.

Description

The present invention relates to an exhaust device for a timepiece.

For a timepiece, in particular a mechanical timepiece, the exhaust device constitutes a master piece, being charged on the one hand to deliver the energy necessary for the maintenance of oscillator oscillation movement. mechanical, balance and hairspring, and secondly to transmit the oscillation frequency of the oscillator to the gear train causing the time display.

The prior art concerning this type of device is therefore considerable, the manuals entitled "Exhausts and Stepper Motors" and "Clockwork Theory", ISBN 2-940025-10-X, both published by the Federation of Schools Techniques of Switzerland, describe many exhaust systems, including the "anchor", "trigger" and "Graham" exhausts.

• un faible rendement ; le meilleur rendement qu'il est possible d'obtenir avec ces dispositifs connus est de l'ordre de 30 % à 40 %, ce qui limite l'autonomie de la montre,
• une fréquence de travail limitée ; le rendement des échappements connus diminue considérablement lorsqu'on augmente de manière sensible la fréquence de l'oscillateur, de plus pour les échappements à ancre il apparaît un problème d'usure de la roue d'échappement lorsque la fréquence est élevée.
• des difficultés de fabrication ; Pour obtenir des rendements de l'ordre de 30 % à 40 %, les échappements à ancre nécessitent plusieurs retouches finales de grande précision.

The major disadvantages of these known devices are:

• low efficiency; the best efficiency that can be obtained with these known devices is of the order of 30% to 40%, which limits the autonomy of the watch,
• a limited working frequency; the efficiency of the known escapements decreases considerably when the frequency of the oscillator is significantly increased, moreover for anchor escapements there is a problem of wear of the escape wheel when the frequency is high.
• manufacturing difficulties; To obtain efficiencies of the order of 30% to 40%, anchor escapements require several final touches of great precision.

FR-A-1522609 describes an exhaust device that avoids these drawbacks, but is intended for an electric timepiece.

An object of the present invention is therefore to provide an exhaust device for an improved timepiece relative to known devices, that is to say whose known disadvantages have been at least partially reduced.

Another object of the invention is to provide an exhaust device that is insensitive to external shocks and does not exhibit a galloping phenomenon.

Yet another object of the invention is to propose a timepiece provided with such an exhaust device.

These aims are obtained by a timepiece escapement device as described in claim 1 as well as by a timepiece as described in claim 19. Particular embodiments or variants are described in FIGS. dependent claims.

• la figure 1 représente un schéma de principe d'une montre mécanique,
• la figure 2 représente une première forme d'exécution d'un dispositif d'échappement selon l'invention,
• la figure 3 représente un détail d'un dispositif de blocage du dispositif d'échappement de la figure précédente,
• la figure 4 représente un diagramme du couple mécanique transmis,
• la figure 5 représente une première forme d'exécution des moyens de production d'un couple variable,
• la figure 6 représente un diagramme du couple magnétique transmis,
• la figure 7 représente les moyens intermédiaires de transmission,
• la figure 8 représente les moyens de dégagement,
• la figure 9 représente les moyens de transmission d'énergie,
• la figure 10 représente un diagramme du couple résultant,
• la figure 11 représente une deuxième forme d'exécution des moyens de production d'un couple variable,
• la figure 12 représente une deuxième forme d'exécution d'un dispositif d'échappement selon l'invention,
• la figure 13 représente un détail du dispositif de blocage du dispositif d'échappement de la figure 12,
• la figure 14 représente les moyens de dégagement du dispositif d'échappement de la figure 12,
• la figure 15 représente les moyens de transmission d'énergie du dispositif d'échappement de la figure 12,
• la figure 16 représente un autre diagramme du couple mécanique transmis, et
• la figure 17 représente un autre diagramme du couple magnétique transmis.

Other advantages of the invention appear in the detailed description which follows, which is to be read with reference to the appended drawing comprising the figures in which:

• the figure 1 represents a schematic diagram of a mechanical watch,
• the figure 2 represents a first embodiment of an exhaust device according to the invention,
• the figure 3 represents a detail of a device for blocking the exhaust device of the preceding figure,
• the figure 4 represents a diagram of the mechanical torque transmitted,
• the figure 5 represents a first embodiment of the means for producing a variable torque,
• the figure 6 represents a diagram of the transmitted magnetic torque,
• the figure 7 represents the intermediate means of transmission,
• the figure 8 represents the means of disengagement,
• the figure 9 represents the means of transmission of energy,
• the figure 10 represents a diagram of the resulting couple,
• the figure 11 represents a second embodiment of the means for producing a variable torque,
• the figure 12 represents a second embodiment of an exhaust device according to the invention,
• the figure 13 represents a detail of the exhaust device locking device of the figure 12 ,
• the figure 14 represents the means of disengagement of the exhaust system of the figure 12 ,
• the figure 15 represents the energy transmission means of the exhaust system of the figure 12 ,
• the figure 16 represents another diagram of the mechanical torque transmitted, and
• the figure 17 represents another diagram of the transmitted magnetic torque.

In some of the figures mentioned above and described in detail below, some superimposed parts are represented as if they were transparent, in order to better understand the interactions.

The figure 1 represents a schematic diagram of a mechanical watch in which the mechanical energy coming from a winding device, manual or automatic, is stored in a mainspring 1 to be distributed through a set of gear wheels 2 to a mechanical mechanism Exhaust 3 and a display 4.

The purpose of the exhaust device 3 is, on the one hand, to deliver the energy necessary to maintain the oscillations of the oscillator 5, generally comprising a spiral spring and a mass of inertia, and other part of transmitting the frequency delivered by this oscillator to the gear 2 to synchronize the time display with this frequency.

A good exhaust system must not only have a good transmission efficiency between the power source and the oscillator, but it must also preserve the isochronism of the oscillator. For this, the inertias related to the exhaust device must be reduced to a minimum and the energy transfer between the exhaust device and the oscillator must be done over a very short time, while the speed of the oscillator is Max.

The figure 2 shows a first embodiment of an exhaust device 3 according to the invention comprising: a transmission wheel 30, driven by the gear assembly 2 seen above, locking means 31, means for producing a magnetic torque 32, intermediate transmission means 33, unlocking means 34 and energy transmission means 35. These various means are described in more detail below.

The figure 3 shows the transmission wheel 30 and the locking means 31. The transmission wheel 30 is rotated from the barrel spring 1 via the gear 2, being driven by a mechanical torque substantially constant value. The shaft 300 supporting the transmission wheel 30 transmits the advance movement to the device 4. The locking means 31 are constituted here by a piece of shape or cam 310, mounted on the same shaft 333 as a pinion 330 forming part of the intermediate transmission means shown in more detail in FIG. figure 7 , as well as pins 311 mounted projecting on the transmission wheel 30, perpendicular to the plane of said transmission wheel. The pins 311 are regularly distributed over a perimeter of said transmission wheel. In the exemplary embodiment shown, the transmission wheel 30 comprises 10 pins 311, but could include a different number as required.

The shape and the dimensions of the cam 310, as well as the diameter of the pins 311 as well as the diameter of the perimeter on which they have been implanted, are determined so that when the cam 310, in simultaneous rotation with the pinion 330 driven by the transmission wheel 30, has one or the other of its lateral faces 312 to the transmission wheel 30, the torque transmission can be done directly from the wheel 30 to the pinion 330. On the other hand, when it is a end face 313 which arrives in front of a pin 311, there is a blocking of this end face 313 of the cam 310 on the pin 311, with interruption of the transmitted torque.

The figure 4 shows the shape of the mechanical torque transmitted to the shaft 333 carrying the pinion 330 as a function of the angle of rotation of said pinion. The curve first has a constant value torque, until the cam 310 reaches the locking position, marked at A ₁ in the figure, where the transmitted torque is canceled. Deblocking means which will be described below then enable the device to be unlocked, thereby allowing the torque of constant value to be transmitted again until the next blocking, marked at A ₂ , and so on.

The locking means 31 described here cause two locking positions A ₁ and A ₂ per turn of the pinion 330, but they could equally well be designed to cause a different number.

The figure 5 shows a preferred embodiment of means making it possible to obtain a variable torque as a function of the angle of rotation of the pinion 330. In this embodiment, these means 32 are of the magnetic type, comprising a stator 320 and a rotor 321 disposed within said stator. The stator 320 consists of a ring of soft ferromagnetic material, having on its inner periphery two cells 322 diametrically opposed. The rotor 321 consists of a permanent magnet of cylindrical shape, having a diametrical magnetization, represented by the arrow in the drawing. The rotor 321 is fixed on the same shaft 333 as the pinion 330 and the cam 310 described above.

The presence of the cells 322 creates, during the rotation of the rotor 321, a magnetic torque acting on said rotor, having a substantially sinusoidal appearance as seen in FIG. figure 6 . When the rotor 321 is oriented so that its axis of magnetization is parallel to the axis CC of the figure 5 , respectively perpendicular to the axis BB carrying the two cavities 322, the rotor 321 is in stable equilibrium position, a slight angular offset tending to bring the rotor towards this stable position, whereas when the same rotor is oriented from so that its axis of magnetization is parallel to the axis BB, it is in unstable equilibrium position, that is to say that a slight angular offset tends to move the rotor even further from this position unstable. Stable angular positions are marked S on the curve of the figure 6 they correspond to a zero crossing of the curve with a negative slope of the torque curve while the unstable angular positions are marked I on the same curve and correspond to a zero crossing with a positive slope of the torque curve.

It should be noted here that the frequency of the curve representing the torque is twice that of the rotation of the magnet, respectively of the pinion 330, this being due to the stator / rotor configuration described. Another configuration would have a multiple different from two between these two frequencies.

The intermediate transmission means 33 represented in the figure 7 essentially comprise the pinion 330 already seen above and a second transmission wheel 331 mounted on a shaft 339. Recall that the shaft 333 carrying the pinion 330 also carries the cam 310 and the rotor 321. The intermediate transmission means 33 allow the combination of different couples involved in the device.

The means of clearance 34 of the figure 8 are of known construction. The clearance pallet 340 is integral with the oscillator (not shown in the figure) and oscillates on the shaft 341. During its oscillation movement in the counter-clockwise direction, the tooth of the pallet 340 encounters a tooth of the escape wheel 342, giving it a torque pulse in the clockwise direction. The escape wheel 342 being mounted on the same shaft 339 as the second transmission wheel 331 seen above, this torque pulse is transmitted from this transmission wheel 331 to the pinion 330. By properly stalling the escape wheel 342 on the transmission wheel 331, so that the torque pulse is transmitted just after the locking device described above has blocked the pinion 330, the anti-clockwise torque pulse transmitted to the pinion 330 unblocks the cam 310 of its locking position on the pin 311, allowing the wheel of transmission 30 to perform a portion of a turn until the next block. The time display 4 has thus advanced a time portion corresponding to a movement of the pallet 340.

The figure 9 shows means 35 for transmitting energy to the oscillator of conventional construction, consisting of a transmission wheel 350 fixed on the same shaft 339 as the wheel 331 and the escape wheel 342, and a piece of form 351, mounted on the shaft 341 seen above and attached to the balance of the spiral (not shown). When the wheel 350 rotates clockwise as indicated and one of its teeth encounters the end 352 of the shaped piece 351 moving counter-clockwise at a lower speed, the wheel 350 supplies the kinetic energy to the workpiece 351, respectively spiral, thereby maintaining the oscillation movement of the oscillator.

As indicated, the release means 34 and the energy transmission means 35 are of known construction and described here as exemplary embodiments; other devices fulfilling the same functions can be provided instead.

The resulting torque on pinion 330, consisting of the substantially constant torque transmitted by wheel 30 and shown in FIG. figure 4 and the variable torque transmitted by the stator / magnetic rotor assembly and shown in FIG. figure 6 , is represented at figure 10 .

In the example shown for this first embodiment of an exhaust device, this pair comprises two stable positions for a turn of the pinion 330, marked S ₁ and S ₂ in the figure, these two stable positions corresponding to both blocking positions of the figure 4 . These two stable positions S ₁ and S ₂ are defined as previously by a zero crossing of the torque curve with a negative slope. The pair also comprises two unstable positions for a turn of the pinion 330, these positions being marked I ₁ and I ₂ , corresponding to the two unlocking positions of the figure 4 . These two unstable positions I ₁ and I ₂ are defined as previously by a zero crossing of the torque curve with a positive slope.

It is found that the resulting torque is always positive, except at the locking positions where it is negative.

On the figure 11 , there is shown a second way to obtain a variable mechanical torque having two stable points and two unstable points per wheel revolution. A cam 323 is fixed on the same shaft 333 as the pinion 330 seen above; this cam having two concave portions and two convex portions. A spring lever 324, pivoted on one of its ends, is supported by a wheel 325 on the The resulting torque of this device has a variable shape, with two stable points when the wheel 325 is aligned with the axis CC and two unstable points when it is aligned on the axis BB.

It can thus be seen that there are several possibilities of obtaining a variable mechanical torque having at least one stable point and one unstable point.

The figure 10 represents the shape of the mechanical torque acting on the shaft 333 of the pinion 330 in the absence of contact with the oscillator as a function of the angle of rotation of said pinion, we can now describe in parallel the operation of the device in function time.

After a first rotation, the device arrives in the locked position, as described with reference to the figure 3 , and corresponding to point S ₁ of the figure 10 . The device remains in this position for a duration T ₁ .

When the pinion 330 receives the unlocking pulse, as described with reference to FIG. figure 8 it moves from the position S ₁ to the position I ₁ of the figure 10 , this passage taking place during a very short time, called T ₂ , less than a thousandth of a second. This duration should be as short as possible so as to disturb the oscillator only minimally.

From this position, the resulting torque becoming positive provides the oscillator, through the energy transmission means described, the energy required for the oscillator for a duration T ₃ of the order of a few thousandths of seconds until the next lock position S ₂ .

Generally a mechanical oscillator has an oscillation frequency of a few Hz, typically 4 Hz. For this frequency, the period T, corresponding to the sum of T ₁ + T ₂ + T ₃ is 250 ms. Given the low values indicated above for T ₂ and T ₃ , we will have a value T ₁ just a few ms lower than the value of T. As a result, the device is in the blocking position during most of the period T .

Although a timepiece equipped with an exhaust system as described above meets the requirements indicated, such an exhaust device mounted on a wristwatch could be subject to the phenomenon of gallop.

Indeed, in a wristwatch, in the absence of external disturbance, the amplitude of oscillation of the balance in the clockwise direction is of the order of + 240 ° with respect to the axis passing through the centers of rotation and of the order of -240 ° in the opposite direction. In these conditions the wheel Exhaust 30 advance one step clockwise each oscillation of the balance.

During an impact involving a component located in the plane of rotation of the exhaust device, additional energy is transmitted to the oscillator through the inertia of the balance, making the amplitude of oscillation of the balance can increase beyond 360 °. Under these conditions, for an exhaust system as shown in figure 2 , the unlocking means 34 give more than one pulse per oscillation period, which causes a running advance of the watch here called gallop.

The figure 12 represents another embodiment of an exhaust device 3 according to the invention, which avoids the disadvantage mentioned above. This embodiment of the exhaust system comprises, as before, a transmission wheel 30 driven by the set of wheels 2 (cf. fig 1 ), locking means 31, means for producing a magnetic torque 32, intermediate transmission means 33, unlocking means 34 and energy transmission means 35, these various means being described below.

The locking means 31 of the exhaust device of the figure 12 are visible on the figure 13 , being composed of a toothed wheel 354 cooperating with the pinion 330. The toothed wheel 354 here has eight asymmetrically shaped teeth and is mounted on the same axis 300 and pivots with the transmission wheel 30 seen above.

In the position, called rest position, represented on the figure 13 , the end of the tooth 332 of the pinion 330 is rested on the right side of an asymmetrical tooth of the wheel 354.

When a torque is applied on the axis 300 of the wheel 354 in the direction of the arrow, it exerts a force passing through the center of rotation of the shaft 333 of the pinion 330. As a result, no torque is transmitted. to the pinion and this gear-pinion assembly remains blocked, this until unlocking by the unlocking means described below.

The unlocking means 34 of this embodiment are visible on the figure 14 . The clearance pallet 344 is integral with the oscillator (not shown in the figure) and oscillates on the shaft 341. During its oscillation movement, the tooth 3441 of the pallet 344 alternately encounters the teeth 3451 and 3452 of an intermediate piece 345 according to which the pallet 344 rotates counterclockwise or clockwise. The oscillating movement of the intermediate piece 345 about the axis 3450 is limited by the pins 347 and 348. The pulse of unlocking, from the beam, is transmitted to the pallet 346, mounted on the same axis 333 and pivoted with the pinion 330 seen above, currently blocked. This impulse transmission de facto through the teeth 3454 and 3455 of the intermediate piece 345 on one of the teeth 3461 or 3462 of the pallet 346 and has the effect of dislodging the wheel assembly 300 - pinion 330 of the figure 13 now allowing the free rotation of pinion 330.

The figure 15 represents another embodiment of the energy transmission means 35; these means operating in a manner similar to those described with regard to the figure 9 .

The means for producing a variable magnetic torque 32 as a function of time are similar to those described with respect to the figure 5 .

The advantage of this embodiment of the exhaust system according to the figure 12 , in relation to the form of execution of the figure 2 is that it limits the amplitude of oscillation of the balance in case of shock, thanks to the pins 347 and 348, thus preventing desynchronization between the movement of the balance wheel and that of the wheel 30 and gallop mentioned above.

The figure 16 shows another diagram of the torque transmitted by an exhaust system. As before, this pair is superimposed on that produced by the magnet to obtain the one shown in FIG. figure 17 .

An exhaust device adapted to operate according to these diagrams comprises locking means having two stable positions by alternating oscillation, that is to say four stable positions per period, which represents another way of avoiding the galloping phenomenon mentioned above. .

Other embodiments and variants than those described above can still be envisaged, in particular, the pinion 330 could be replaced by an anchor having an oscillating movement, the rod of the fork of said anchor carrying two magnets in opposition.

• vu que les diamètres des pièces en rotation du dispositif selon l'invention sont plus faibles que ceux des pièces correspondantes des dispositifs connus, l'inertie desdites pièces en rotation est nettement plus faible,
• l'énergie nécessaire pour le déblocage est plus faible ; de plus ce déblocage ne s'accompagne généralement pas d'un mouvement de recul comme dans les échappements à ancre connus,
• grâce à l'allure variable de la courbe de couple, sinusoïdale dans les formes d'exécution décrites, on a un maximum de couple juste après la position de déblocage, faisant que le maximum d'énergie est transmis immédiatement après le déblocage, soit sur un angle d'oscillation limité de l'oscillateur, au moment où celui-ci est à sa vitesse maximum ; de cette manière, l'isochronisme de l'oscillateur est préservé au maximum,
• les roues de transmission possèdent des profils classiques avec des rendements de transmission de l'ordre de 90 %.
• Certaines des transmissions de mouvement se faisant par roues dentées, elle ne nécessitent pas un huilage aussi fréquent que les transmissions conventionnelles.

With regard to the exhaust devices of the prior art, an exhaust device according to the invention and according to one or other of the embodiments described, still has several significant advantages:

• as the diameters of the rotating parts of the device according to the invention are smaller than those of the corresponding parts of known devices, the inertia of said rotating parts is significantly lower,
• the energy required for unlocking is lower; moreover this release is not generally accompanied by a recoil movement as in known anchor escapements,
• thanks to the variable shape of the sinusoidal torque curve in the embodiments described, there is a maximum torque just after the unlocking position, so that the maximum energy is transmitted immediately after the unlocking, either on a limited oscillation angle of the oscillator, at the moment when it is at its maximum speed; in this way, the isochronism of the oscillator is preserved to the maximum,
• the transmission wheels have conventional profiles with transmission efficiencies of the order of 90%.
• Some of the gear transmissions are geared, so they do not require as frequent oiling as conventional transmissions.

An exhaust device as described in one or other of its embodiments can easily be implemented in a timepiece, particularly in a wristwatch given the small diameter of the constituent parts of said device.

Claims (19)

1. An escapement device (3) provided for a mechanical timepiece, comprising a gear train (330) for transmitting energy towards an oscillator (5) capable of receiving said energy and of transmitting an oscillation frequency,
   and first means (32) capable of producing at least one first portion of the energy transmitted by said gear train and intended to power the oscillator (5),
   said escapement device being characterized in that said first means (32) are configured so as to provide an essentially variable mechanical torque depending on the angular displacement angle of said gear train (330), said mechanical torque having at least one stable position (S) and at least one unstable position (I) over an angular displacement period of said gear train.
2. The device according to claim 1, characterized in that it further comprises second means (1, 2, 30) capable of producing a second portion of the energy intended to power the oscillator (5), said second means being configured so as to provide an essentially constant mechanical torque depending on the angular displacement angle of said gear train (330).
3. The device according to claim 2, characterized in that it further comprises blocking means (31) capable of blocking the transmission of energy from said second means (1, 2, 30) able to produce a second portion of the energy intended to power the oscillator (5).
4. The device according to claim 3, characterized in that the energy transmitted to the oscillator by said gear train (330) results from the combination of said first means (32) for producing energy and of said second means (1, 2, 30) for producing energy, said transmission of energy being blocked during the actuation of said blocking means (31).
5. The device according to claim 4, characterized in that the gear train for transmitting energy is a rotating cog (330) which always transmits a positive mechanical torque except for the moments when the torque is located between a stable position and an unstable position.
6. The device according to claim 5, characterized in that the torque transmitted by said cog (330) has two stable positions (S1, S2) and two unstable positions (I1, I2) per rotational turn of said cog.
7. The device according to claim 5, characterized in that the torque transmitted by said cog (330) has four stable positions (S1, S2, S'1, S'2) and four unstable positions (I1, I2, I'1, I'2) per rotational turn of said cog.
8. The device according to claim 5, characterized in that said first means capable of producing at least one first portion of the energy intended to power the oscillator (5), comprise a rotor (321) bearing a magnet and attached to said rotating cog (330), said rotor being positioned in a magnetic circuit (320).
9. The device according to claim 8, characterized in that the magnetic circuit (320) is formed by a stator surrounding said rotor (321), said stator having at least one asymmetry (322).
10. The device according to any of claims 5 to 7, characterized in that said first means capable of producing at least one first portion of the energy intended to power the oscillator (5), comprise a cam (323) having at least one concave portion and one convex portion, attached to said rotating cog (330), a lever (324) being supported on the perimeter of the cam, being pressed against said perimeter by an elastic means.
11. The device according to any of claims 3 to 10, characterized in that the blocking device (31) is configured so as to operate at stable equilibrium points (S1, S2, S'1, S'2) of the transmitted torque curve.
12. The device according to claim 11, characterized in that the blocking device (31) is configured so that its operating point at the stable equilibrium points (S1, S2, S'1, S'2) of the curve of the transmitted torque is closer to the unstable equilibrium position (I) of the mechanical torque provided by said first means (32) capable of producing at least said first portion of the energy intended to power the oscillator (5), than to the stable position (S) of the mechanical torque transmitted by the same first means (32).
13. The device according to claim 12 when the latter comprises the characteristics of claim 5, characterized in that the blocking device (31) comprises a cam (310) having at least one blocking perimeter portion (313), said cam being attached to said cog (330) for transmitting the energy powering said oscillator, and a transmission wheel (30) provided with protruding projections (311) cooperating with said cam for blocking said escapement.
14. The device according to claim 12 when the latter comprises the characteristics of claim 5, characterized in that the blocking device (31) comprises said cog (330) for transmitting the energy powering said oscillator and a toothed wheel (354) having a plurality of asymmetrical teeth, cooperating with said cog (330) for blocking said escapement.
15. The device according to claim 5, characterized in that it further comprises an unblocking device (34) capable of controlling resumption of transmitting the energy intended to power the oscillator, said unblocking device being configured so as to operate between a stable equilibrium point and an unstable equilibrium point of the transmitted torque curve.
16. The device according to claim 15, characterized in that the unblocking device (34) comprises a disengagement pallet (340) mounted on said oscillator, said disengagement pallet being capable of transmitting a torque pulse to an escapement wheel (352) capable of retransmitting this pulse to said cog (330), said pulse being able to unblock said cam (310) blocked by one of said protruding projections (311).
17. The device according to claim 15, characterized in that the unblocking device (34) comprises a disengagement pallet (344) mounted on said oscillator, said disengagement pallet being capable of transmitting a torque pulse to an intermediate part (345) pivotably mounted on an axis (3450), said intermediate part being capable of retransmitting this pulse to another pallet (346) mounted on said cog (330), being capable of unblocking said cog (330) blocked against a tooth of the toothed wheel (354).
18. The device according to claim 17, characterized in that the oscillating amplitude of the pivoting of the intermediate part (345) is limited by two pins (347, 348).
19. A time piece provided with an escapement device according to any of the preceding claims.

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