EP2660661B1 - Free escapement mechanism for timepiece movement, movement and/or timepiece comprising said escapement mechanism - Google Patents

Description

The present invention relates to free escapement mechanisms for clockwork.

Free exhausts are nowadays recognized as the best means for the maintenance of the oscillations of a system balance-spiral.

• les échappements à détente ; et
• les échappements à ancre.

Free escapements for existing clock movements can be classified into two main categories according to their means of control:

• escapements with relaxation; and
• anchor escapements.

Expansion exhausts are direct impulse exhausts. The trigger is a stop with only one rest position.

The escape wheel gives a pulse per period to the oscillator without the need for an intermediate element. As a result, the wheel goes forward only once per period. A period of an oscillator consists of two alternations. Due to the lack of impulse during the silent phase, the expansion exhausts are not self-starting.

For example, documents EP 1 770 452 A1 and EP 1 538 490 A1 each discloses a timepiece movement comprising a frame, a barrel, a mechanical oscillator and an exhaust mechanism connected to the barrel by a drive train for its drive.

Anchor escapements exist either with a direct impulse from the escapement wheel to the pendulum or indirectly by means of the anchor.

The anchor is a stopping piece that has two resting positions. Anchor escapements advance the gear once in a row. The only exception is the lever escapement, or the escape wheel falls during the so-called "dumb" phase on a second resting surface. During this silent phase, the known bleed escapements can not transmit energy to the oscillator. The silent phase, even as it moves the wheel very little, aims to blow the seconds hand once per period of the oscillator.

Most anchor escapements transmit energy indirectly through the anchor.

All known free exhausts have in common, that the escape wheel, once released, accelerates and transmits energy to the oscillator before damping its movement on the pallet rest. This energy damping is a considerable loss of energy and is well audible being one of the origins of ticking a watch.

Most anchor or expansion escapements require a fall between clearance and impulse and / or pulse and rest. This fall is essential as a security to overcome manufacturing tolerances. It aims to avoid the attachment of functional surfaces due to dimensional variations of the components. At least the fall after the impulse is a pure loss of energy. It only serves to produce the strong ticking mentioned above.

The object of the present invention is to provide a free escapement mechanism for a clockwork movement that can be controlled either by detents or by an anchor that is applicable to portable timepieces and transmits energy. oscillator at each alternation of it while reducing energy losses, reduce inertial influences and make the exhaust insensitive to shocks. Another goal is to reduce or eliminate energy-consuming falls.

The present invention relates to a timepiece movement according to claim 1.

• un mobile d'impulsion pivoté sur le bâti du mouvement d'horlogerie comportant une fourchette d'impulsion agencée pour coopérer avec la cheville d'impulsion du plateau; un ressort d'impulsion; et un bras terminé par un crochet adapté à coopérer avec la denture de la roue d'échappement; et
• des moyens de pilotage agencés pour libérer la roue d'échappement d'un pas pendant des premières alternances du balancier s'effectuant dans un premier sens de rotation, et dégageant le crochet du mobile d'impulsion de la denture de la roue d'échappement pendant des secondes alternances du balancier s'effectuant dans un second sens de rotation opposé au premier sens de rotation.

In a preferred embodiment, the movement according to the invention comprises a frame on which are mounted a barrel, a gear train kinematically connecting the barrel to an escapement wheel and an oscillator provided with a balance wheel; this escapement mechanism comprising an escape wheel forming part of the escapement mobile and a plate, secured to an axis on which is mounted the rocker comprising a pulse pin. The escape mechanism further comprises:

• a pulse mobile rotated on the clockwork frame having a pulse fork arranged to cooperate with the pin pulse of the plate; a pulse spring; and an arm terminated by a hook adapted to cooperate with the toothing of the escape wheel; and
• control means arranged to release the escape wheel by one step during the first half-waves of the balance being effected in a first direction of rotation, and releasing the hook of the impulse mobile from the toothing of the escape wheel during second alternations of the balance being effected in a second direction of rotation opposite to the first direction of rotation.

• La figure 1 illustre schématiquement en plan de dessus les éléments principaux du mécanisme d'échappement libre nécessaire pour illustrer son fonctionnement.
• Les figures 2 à 8 illustrent le mécanisme d'échappement libre de la figure 1, le balancier ayant été enlevé pour plus de clarté, dans différentes positions du cycle de fonctionnement.
• La figure 9 illustre un dispositif de sécurité prévu pour éviter les dégagements intempestifs d'une première détente en cas de chocs.
• La figure 10 illustre un dispositif de sécurité prévu pour éviter des dégagements intempestifs d'une seconde détente en cas de chocs.
• Les figures 11 et 12 illustrent un dispositif de sécurité évitant le galop du mécanisme d'échappement lorsque le balancier effectue son arc supplémentaire de la phase muette respectivement de la phase d'armage du mécanisme.
• Les figures 13 et 14 illustrent la transmission d'énergie pour deux comportements chronométriques différents du mécanisme d'échappement.
• La figure 15 est une vue isométrique de dessus du mécanisme d'échappement illustré à la figure 1, le balancier étant retiré pour une meilleure illustration.
• La figure 16 est une vue isométrique de la première détente des moyens de pilotage.
• La figure 17 est une vue isométrique de la seconde détente des moyens de pilotage.
• La figure 18 est une vue isométrique d'un plateau solidaire de l'axe du balancier.

The accompanying drawing illustrates schematically and by way of example a particular embodiment of a free escapement mechanism for a watch movement according to the invention.

• The figure 1 schematically illustrates in plan from above the main elements of the free escape mechanism necessary to illustrate its operation.
• The Figures 2 to 8 illustrate the free escape mechanism of the figure 1 , the balance having been removed for greater clarity, in different positions of the operating cycle.
• The figure 9 illustrates a safety device designed to prevent untimely releases a first trigger in case of shocks.
• The figure 10 illustrates a safety device provided to prevent untimely release of a second trigger in case of shocks.
• The figures 11 and 12 illustrate a safety device avoiding the gallop of the escapement mechanism when the pendulum performs its additional arc of the mute phase respectively of the arming phase of the mechanism.
• The Figures 13 and 14 illustrate the transmission of energy for two different chronometric behaviors of the escape mechanism.
• The figure 15 is an isometric view from above of the escape mechanism illustrated in figure 1 , the balance being removed for a better illustration.
• The figure 16 is an isometric view of the first detent of the control means.
• The figure 17 is an isometric view of the second detent of the control means.
• The figure 18 is an isometric view of a plate integral with the axis of the balance.

The free escapement mechanism equipping the timepiece movement according to the invention is an escapement in which the escapement wheel makes only one step by oscillating the balance wheel as in the escapement mechanisms with a blow to the difference that in the present mechanism the pendulum receives two pulses per oscillation, one alternately, which is not the case in a classic stroke escapement.

In what follows the embodiment shown in the drawing will be described, this embodiment of the free escape mechanism of the movement according to the invention is controlled by two detents. This is a preferred embodiment because it gives the best results in terms of energy and efficiency of the mechanism but it is obvious that in other embodiments this exhaust mechanism could be controlled. by other control means for example by an anchor. It should be noted, however, that in this case the anchor serves only to control the exhaust, that is to say that the anchor does not participate in the energy transmission of the escape wheel to the axis of the pendulum.

The figure 1 illustrates in plan from above a general view of the free escape mechanism without being represented the other elements of the watch movement such as platinum and bridges, wheel etc. to avoid overloading the drawings and to facilitate understanding of the exhaust mechanism that equips the movement constituting the present invention.

• d'un mobile d'échappement 1 formé du pignon d'échappement 1.1 de neuf dents et de la roue d'échappement 1.2 comportant trente dents dans l'exemple illustré. Ce mobile d'échappement 1 est pivoté sur des parties fixes d'un mouvement d'horlogerie.
• d'un mobile d'impulsion 2 composé d'un axe d'impulsion 2.1 et d'un corps d'impulsion 2.2 chassé sur l'axe d'impulsion 2.1. Ce mobile d'impulsion 2 est également pivoté sur les parties fixes d'un mouvement d'horlogerie. Ce mobile d'impulsion 2 comporte à son extrémité une fourchette 2.3. Le mobile d'impulsion 2 comporte encore un ressort d'impulsion 2.4 dont l'extrémité libre prend appui sur une première butée 4 solidaire d'une partie fixe du mouvement d'horlogerie. Ce mobile d'impulsion est enfin muni d'un bras élastique 2.5 se terminant par un crochet 2.6 présentant une face de repos. L'élasticité du bras élastique 2.5 tend à appliquer le crochet 2.6 contre la denture de la roue d'échappement 1.2 et cette face de repos du crochet 2.6 positionne le mobile d'impulsion 2 par rapport à ladite roue d'échappement 1.2 qui est entraînée par son pignon d'échappement 1.1 relié par le rouage du mouvement (non illustré) au barillet du mouvement (non illustré).
• de moyens de pilotage du mécanisme d'échappement comportant une première détente 5 et une seconde détente 6 fixées sur une partie fixe du mouvement d'horlogerie et coopérant avec un plateau 7 solidaire de l'axe 3.1 d'un balancier 3 d'un oscillateur formé d'un balancier-spiral. La serge 3.2 du balancier 3 est rivée sur l'axe de balancier 3.1 et le plateau 7 est chassé sur ledit axe de balancier 3.1. Le spiral de cet oscillateur n'est pas représenté. L'oscillateur, soit le balancier-spiral, est bien connu dans l'état de l'art et pivote également entre des parties fixes du mouvement d'horlogerie. Dans l'exemple illustré, l'oscillateur possède une fréquence de 5 hertz (Hz).

This free escape mechanism consists of:

• an exhaust mobile 1 formed of the exhaust pinion 1.1 of nine teeth and the escape wheel 1.2 having thirty teeth in the illustrated example. This escapement mobile 1 is pivoted on fixed parts of a clockwork movement.
• a pulse mobile 2 composed of a pulse axis 2.1 and a pulse body 2.2 driven on the pulse axis 2.1. This impulse mobile 2 is also rotated on the fixed parts of a clockwork movement. This mobile pulse 2 has at its end a range 2.3. The impulse mobile 2 further comprises a pulse spring 2.4 whose free end is supported on a first abutment 4 integral with a fixed part of the watch movement. This mobile pulse is finally provided with an elastic arm 2.5 ending in a hook 2.6 having a rest face. The elasticity of the elastic arm 2.5 tends to apply the hook 2.6 against the toothing of the escape wheel 1.2 and this rest face of the hook 2.6 positions the moving pulse 2 relative to said escape wheel 1.2 which is driven by its escape pinion 1.1 connected by the gear of the movement (not shown) to the barrel of the movement (not shown).
• control means of the exhaust mechanism comprising a first detent 5 and a second detent 6 fixed on a fixed part of the watch movement and cooperating with a plate 7 integral with the axis 3.1 of a balance 3 of an oscillator formed of a sprung balance. The serge 3.2 of the balance 3 is riveted on the balance shaft 3.1 and the plate 7 is driven on said balance shaft 3.1. The spiral of this oscillator is not represented. The oscillator, the balance spring, is well known in the state of the art and also pivots between fixed parts of the watch movement. In the example illustrated, the oscillator has a frequency of 5 hertz (Hz).

The plate 7 is constituted in the illustrated example of a large plate 7.1 and a small plate 7.2 (see figure 18 ).

The large plate 7.1 comprises a plate 7.3 comprising fixing means for example a hole to be driven on the balance shaft 3.1 and a peripheral skirt 7.4. This skirt 7.4 has an opening 7.5 and a release nose 7.6 projecting radially on the outer peripheral face of this skirt 7.4. This release nose 7.6 is intended to cooperate with the first detent 5. The plate 7.3 of the large plate 7.1 comprises on its periphery a pulse pin 7.7 intended to cooperate with the fork 2.3 of the pulse wheel 2.

The lower face of the small plate 7.2 carries a release pin 7.10 intended to cooperate with the second trigger 6. This small plate also has on its periphery a clearance 7.11 intended to cooperate with the second trigger 6.

The first relaxation 5 ( figure 16 ) has a fixing stud 5.1 for fixing on a fixed part of the clockwork movement, an elastic portion 5.2 connecting the attachment stud 5.1 to a rigid portion 5.3 having a rest surface 5.4 intended to cooperate with the teeth of the escape wheel 1.2. This rigid portion 5.3 extends favorably towards the plate 7 and has at its end a finger 5.5 disposed at rest, the trigger 5 blocking the escape wheel, between the skirt 7.4 of the large plate and the periphery of the small plate 7.2. A leaf spring 5.6 is fixed at one end to the rigid portion 5.3 of the first trigger 5 and extends towards the plate 7 to end in a free end having a pallet 5.7 of greater width than the first trigger 5 and intended to cooperate with the release nose 7.6 of the plate 7.

The second detent 6 comprises a fixing stud 6.1 and a flexible portion 6.2 connecting this fixing stud 6.1 to a rigid portion 6.3 extending partially under the toothing of the escape wheel 1.2 and whose side face 6.4 opposite to the axis of the escapement mobile 1, cooperates with the hook 2.6 of the mobile pulse 2. The rest position of the second trigger 6 is determined by a second stop 9 against which this second trigger is supported by its own elasticity. The free end of this second trigger 6 comprises two branches 6.5, 6.6 going away from one another. The end of the first branch 6.5 comprises a lug 6.7 extending inside the skirt 7.4 of the plate 7 and cooperating with the outer peripheral face of the small plate 7.2 and its clearance 7.11.

The end of the second branch 6.6 of the second trigger 6 carries a release spring 6.8 extending substantially tangentially to the path of the release pin 7.10 of the plate 7. The end of this release spring 6.8 advantageously forms a hook for to limit the maximum deflection of the release spring 6.8, this avoiding a plastic deformation or the breaking of said spring 6.8. In the rest position this second trigger 6 is in abutment against a second stop 9 secured to a fixed part of the watch movement. In this rest position, the lateral face 6.4 of this second trigger 6 is not in contact with the hook 2.6 of the impulse wheel and the hook 2.6 rests on one of the teeth of the escape wheel 1.2.

The detents 5 and 6 and the impulse mobile 2 are assembled under prestressing, armed, which allows to have very simple dimension chains for the tolerance calculations because most of the fluctuations are offset by the elasticity of these elements. . The escape wheel 1.2 is indexed by the first trigger 5 and this escape wheel itself indexes the pulse wheel 2.

If necessary, a single correction can be envisaged during the completion, it is the centering of the pulse wheel 2 with respect to the straight line connecting the pivot points of the pulse wheel 2 and the balance 3 so that the fork 2.3 of the pulse wheel 2 is positioned symmetrically with respect to said straight line. This adjustment of the positioning of the pulse mobile can be done by an eccentric head screw. To do this, the first trigger 5 can slide linearly along its longitudinal axis. Linear guidance is favorably performed by a flexible guide with parallel springs prestressed against the eccentric screw.

• premièrement la phase d'armage pendant la première alternance du balancier pendant laquelle la roue d'échappement et tout le rouage du mouvement d'horlogerie avance d'un pas,
• deuxièmement la phase muette pendant la seconde alternance du balancier pendant laquelle la roue d'échappement et tout le rouage du mouvement d'horlogerie ne bouge pas.

The operation of this escape mechanism has two main phases:

• firstly the arming phase during the first alternation of the balance during which the escape wheel and all the gear of the watch movement advances one step,
• secondly, the silent phase during the second alternation of the pendulum during which the escape wheel and all the wheels of the watch movement do not move.

Nevertheless, during each of these two phases, the arming phase and the silent phase, a determined quantity of energy is transmitted to the balance by means of the impulse wheel which receives the energy to be transmitted directly by the impeller. exhaust during the arming phase either by its pulse spring during the silent phase.

With reference to Figures 2 to 4 the first alternation or phase of arming will now be described:
Suppose the balance 3 returns clockwise from its point of return. The escape wheel 1.2 is stationary and rests by one of its teeth on the rest surface 5.4 of the first trigger 5 ( figures 2 and 16 ). The pendulum 3 crosses its additional arc descending to the point of elongation of 25 °. The impulse pin 7.7 of the plate 7 enters the range 2.3 of the impulse mobile 2 without touching it. The release nose 7.6 of the plate 7 comes into contact with the leaf spring 5.6 of the first trigger 5 and pushes this leaf spring 5.6 and all the first trigger whose flexible portion 5.2 flexes to move the resting surface 5.4 away from the tooth of the escape wheel 1.2 with which it is in contact. The rest surface 5.4 slides substantially radially on the tooth of the escape wheel 1.2. During this sliding escape wheel 1.2 does not move yet. The first trigger 5 travels the rest distance, safety necessary to ensure the locking of the escape wheel despite imperfections of the components due to manufacturing tolerances.

Once cleared from the resting surface 5.4 of the first trigger 5 ( figure 3 ), the escape wheel accelerates driven that it is by the barrel and the gear of the watch movement. The rotation of the escape wheel 1.2 drives the impulse wheel 2 by its hook 2.6 which is always engaged with a tooth of the wheel Exhaust 1.2. The fork 2.3 of the impulse mobile 2 catches the impulse pin 7.7 of the plate 7 and transmits a pulse to the balance until the next tooth of the escape wheel 1.2 comes to rest on the rest surface 5.4 of the first trigger which once it has escaped the release nose 7.6 of the plate 7 has returned to rest position under the effect of its own elasticity in contact with the escape wheel. The escape wheel 1.2 is again blocked ( figure 4 ).

The figure 13 illustrates the torque C transmitted to the balance 3 by the pulse wheel 2 during the arming phase as a function of the angle α of the angular displacement of the pulse wheel 2. C2 represents the pulse torque 2 set available by the escape wheel when the barrel of the watch movement is fully armed. C1 represents the torque available at the end of the barrel power reserve. Whatever the winding of the barrel, we therefore always have at least the torque C 1 available to transmit energy to the balance 3.

During this arming phase the impulse wheel 2 receives from the escape wheel 1.2 by its hook 2.6 a torque at least equal to C1. This torque causes the impulse wheel 2 to swing counterclockwise from its position α ₀ (range 2.3 on the right) to position α ₁ (range 2.3 on the left). A part (E _var + E ₁ ) of the energy transmitted to the impulse mobile is transmitted by the range 2.3 thereof to the impulse pin 7.7 and therefore to the balance 3 while another part E2 of the available energy is used to arm the impulse spring 2.4 of the impulse mobile. The distribution between the energy E1 transmitted to the beam and the E2 used to arm the spring 2.4 of the pulse wheel 2 depends on the characteristic or constant K of this spring 2.4 as can be seen by comparing the Figures 13 and 14 . Indeed, the slope of the characteristic curve of the spring 2.4, represented by the equation C '= k · α, modifies the distribution of energy over time between the pulse given to the balance 3 and the armature of the mobile spring 2.4. pulse 2 during the arming phase.

The energy distribution between the impulse given to the balance and the energy stored in the spring 2.4 is equivalent (ratio 1: 1) for the barrel fully armed (maximum torque = C ₂ , Fig. 13 or fig. 14 ). The surfaces (E _var + E ₁ ) and E ₂ quantifying the energies are identical.

Between the Figures 13 and 14 , only temporal distributions vary, the energy value (size of surfaces) being identical, because between Fig. 13 and fig. 14 the stiffness k of the spring 2.4 and its preaming vary at the same time.

For a better understanding of this fact, Figures 13 and 14 show the line "0" linking the center of rotation of the balance 3 to the center of rotation of the impulse mobile 2. This line, perfectly centered between the extreme positions α ₀ and α ₁ of the impulse mobile, also corresponds to the position the theoretical dead point of the oscillator.

It is clear that the 2.4 stiffer spring ( Fig. 13 ) transmits more energy before the dead point than the configuration in Fig. 14 . Although the total energy transmitted during an impulse is substantially identical, the two cases Fig. 13 and fig. 14 are distinguished by the chronometric influence of the escapement on the oscillator, because the transmission of a larger part of energy in Fig. 13 before the dead point will make the oscillator advance further than the configuration in Fig. 14 .

During the impulse, the release pin 7.10 of the plate 7 slides on the release spring 6.8 of the second trigger 6 and forces this second detent against the second stop 9. In doing so the release spring 6.8 is deformed to let the release pin 7.10 then returns to the rest position.

The impulse pin 7.7 of the plate 7 leaves the fork 2.3 of the impulse mobile 2 and the pendulum carries out its additional ascending arc with a clockwise movement to the point of return of the pendulum 3. With reference to FIG. Figures 5 to 8 the second alternation or mute phase will be described below.

The escape wheel 1.2 remains at rest throughout this phase supported by one of its teeth on the rest surface 5.4 of the first trigger 5. As a result the wheel does not move either. The balance returns counterclockwise from its additional arc ( figure 5 ). The release peg 7.10 of the plate 7 comes into contact with the driving abutment 6.9 of the second detent 6 and displaces this second detent 6 by bending its elastic portion 6.2 in the direction of the pulse wheel 2 driving through its lateral face 6.4 the hook 2.6 of the impulse mobile 2. This making the hook 2.6 of the impulse mobile slides on the tooth of the escape wheel 1.2 and after having traveled the rest distance this hook 2.6 escapes the escape wheel 1.2 and releases the impulse mobile 2 ( figure 6 ). Impulse wheel 2 pivots clockwise under the action of its impulse spring 2.4 who was armed during the arming phase. The range 2.3 of the impulse mobile 2 catches the impulse pin 7.7 of the plate 7 and transmits a pulse to the pendulum 3.

The release pin 7.10 of the plate 7 escapes the driving abutment 6.9 of the second trigger 6 and the latter returns to the rest position against the second stop 9 by its own elasticity ( figure 7 ).

The hook 2.6 of the pulse wheel 2, released from the second trigger 6, falls on the next tooth of the escape wheel 1.2 and blocks the pulse wheel 2.

The energy E2 transmitted to the balance 3 by the pulse wheel 2 during this silent phase is the one that the spring 2.4 of the mobile pulse 2 had stored during the winding phase.

During the silent phase, the release nose 7.6 of the plate 7 passes the first detent 5 by deformation of its leaf spring 5.6 ( figure 8 ).

The impulse pin 7.7 of the plate 7 leaves the fork 2.3 of the impulse mobile 2 and the rocker makes its additional arc ascending with a counterclockwise movement to the point of return. The mechanism is found in the position illustrated in figure 2 and a new cycle can begin.

As has been seen from the description of the example of the escape mechanism, this escape mechanism comprises an escape wheel, a pulse mobile and control means. The escape wheel transmits, during an alternation of the pendulum, the energy of the barrel impulse mobile that arms his spring and transmits a portion of the energy received pendulum. During the other alternation of the pendulum the impulse mobile transmits to said balance of the energy supplied by its pulse spring previously armed during the previous alternation.

This exhaust mechanism thus achieves a blowout escape in which there is necessarily a power transmission to the balance during each alternation thereof.

The peculiarity of this escape mechanism is that it gives a pulse even during the silent phase without the escape wheel turning. This is achieved by the winding of the pulse spring 2.4 of the pulse wheel 2 alternately out of two, this energy stored in said spring being restored to the balance during the silent alternation.

The impulse spring 2.4 of the impulse wheel 2 can be produced in different ways, for example by a spiral spring or as in the example described by a leaf spring, which makes it possible to obtain as flat a possible assembly as possible that a characteristic or high slope of the elasticity curve of this spring. Unlike the known escapements that transmit the most energy at the end of the pulse, the high stiffness of the impulse spring 2 pulse pulse 2 causes a strong pulse before the dead point that it delivers immediately to the pulse. oscillator here the balance-spiral. The energy losses due to the clearance are thus immediately compensated.

This is also true for the losses due to the release of the second expansion, because the transmitted energies and their dynamic distribution are identical or similar during the arming phase and the silent phase.

The torque of the impulse spring 2.4 of the mobile pulse 2 armed is only slightly lower than the torque transmitted by the wheel, there is almost a balance of strength. The driving force must necessarily be greater than the maximum torque of the impulse spring 2.4 pulse 2 to ensure the complete arming of the pulse spring and the impulse mobile and the proper positioning of the moving parts of the mechanism. In practice it is preferable that the maximum torque on the pulse wheel 2 does not exceed 95% of the minimum torque, at the end of the power reserve, provided by the escape wheel 1.2.

Thus, the exhaust uses a portion of the energy available to arm the spring 2.4 which gradually decreases the kinetic energy of the escape wheel by the increasing resistance of the spring 2.4 instead of damping said kinetic energy entirely by the shock of the exhaust wheel entering full speed in abutment with the pallet of the steering element (anchor or trigger) and causing the ticking of the movement.

This quasi-balance causes a slowing down of the escape wheel 1.2 at the end of the arming phase. This results in maximum efficiency because only a very low energy will be available at the end of the pulses to be damped by the collision of the moving components with their stops. This reduces the energy losses due to the stopping of the escape wheel on the rest face 5.4 of the first detent 5 in the arming phase and the losses due to the stopping of the pulse wheel 2 by the contact of its hook 2.6 with a tooth of the escape wheel 1.2 at the end of the pulse during the silent phase.

As this escapement mechanism has no drop, the entire pitch between two teeth of the escape wheel 1.2 is exploitable for the transmission of energy. The size of the tooth no longer has a negative effect on the yield, which guarantees rigid teeth. An increase in the number of teeth of the escape wheel 1.2 no longer weakens the rigidity of the teeth nor causes a fall in yield due to falls, as is inevitable for routine constructions.

The escape wheel 1.2 does not recoil. The control elements that are the two detents 5 and 6 are prestressed and find their rest position after shock thanks to their own elasticity.

There is no slippage between the escape wheel 1.2 and the impulse wheel, which reduces losses and wear and eliminates lubrication. The safety in case of impact is ensured because the first 5 and second 6 detents can not flex and therefore move only when the finger 5.5 of the first trigger 5 is opposite the opening 7.5 of the skirt 7.4 of the plate 7, respectively that the lug 6.7 of the second trigger 6 is opposite the clearance 7.11 of the plate 7. This exhaust mechanism is therefore insensitive to shocks.

This exhaust mechanism avoids one of the major drawbacks of known escapement exhausts is the gallop of the exhaust which consists of a second clearance during the same alternation at very large oscillator amplitudes. Indeed, such a second clearance is excluded here because the impulse pin 7.7 of the plate 7 comes into contact with the outer flanks of the horns of the fork 2.3 of the impulse cell 2 ( figures 11 and 12 ). Unlike the anchor escapements, these stops, here said horns of the range 2.3, are not rigid but elastic because the mobile pulse 2 can move. During the silent phase, this movement causes the escape wheel to retreat and thus absorbs the superfluous energy of the oscillator ( figure 11 ). If this rebound occurs during the arming phase ( figure 12 ) then the impulse spring 2.4 of the impulse mobile 2 will absorb this superfluous energy.

Such an elastic rebound disrupts the watch movement less than the violent recoil of existing anchor escapements.

This exhaust mechanism makes it possible to significantly increase the number of teeth of the escape wheel without increasing its diameter. It is possible to double or more the number of teeth of the escape wheel compared to a classic anchor escapement without increasing the diameter. It is then possible to use this escapement mechanism with a high frequency oscillator, 5 hertz or more, without the need to provide an additional mobile between the second wheel and the exhaust pinion and without the need for additional reports. gearing to maintain the angular velocity imposed by the second wheel. In fact, a large reduction is already achieved by the fact that the escape wheel advances only one step for two alternations of the oscillator and the fact of being able to increase the number of teeth in a given diameter of the wheel. exhaust through the use of the impulse mobile 2.

The escape mechanism is self-starting because the oscillator receives energy during each of its alternations.

In this escape mechanism a large part of the energy is transmitted before the dead point of the oscillator, resulting in an advance at small amplitudes of the balance. This characteristic is original and unprecedented, the known escape mechanisms usually cause delay.

The present escapement mechanism makes it possible to influence the chronometric behavior of the escapement at will and to eliminate the run-out errors due to the escapement or to balance other isochronism defects, for example originating from the spiral, by an adjustment of the exhaust mechanism. Indeed in this escape mechanism it is possible to adjust and adjust the temporal distribution of energy supplied to the balance in the arming phase and in the dummy phase relative to the neutral point of the oscillator by playing on the stiffness or elastic characteristic of the impulse spring 2.4 of the impulse mobile. It is thus possible by choosing the characteristic of this impulse spring 2.4 of the impulse mobile to obtain an escapement exhibiting neither advance nor chronometric delay.

With the present escapement mechanism, the cogwheel of the clockwork movement equipped with it advances only once per period, ie during alternating half of the oscillator. When the dumb alternation the gear turns not, although the oscillator receives a pulse. This reduces the energy loss due to the inertia of the gear when it is started.

At the end of the first alternation, that is to say the winding phase, the impulse wheel and the escape wheel are almost in force balance. This feature allows to recover the kinetic energy stored in the wheel. The losses due to the inertia of the gear train, including a possible tourbillon cage, participate in the winding of the impulse spring 2.4 of the impulse mobile 2. In the dumb phase, the impulse spring 2.4 of the mobile of pulse 2 is almost discharged before the hook 2.6 of said mobile pulse 2 does not fall on a tooth of the escape wheel, there will also be less energy dissipated.

Practically, when walking a clockwork according to the invention comprising an exhaust mechanism as described, the ticking product is much less strong than in the known exhausts clearly indicating a reduction of the energy dissipated by shocks.

The present escapement mechanism is particularly well adapted to be integrated in the cages of a vortex with a high oscillator frequency of a clockwork movement, because it allows, despite the use of a high frequency oscillator the conservation a gear ratio ordinary because of the large number of teeth of the escape wheel and moreover, it allows to recover the kinetic energy of the train including vortex cages.

In a general manner the watch movement according to the invention comprises a frame on which are mounted a barrel, a gear train kinematically connecting this barrel to an escapement mobile part of an escapement mechanism and an oscillator provided with a pendulum. The escape mechanism comprises an escape wheel forming part of the escape wheel and a plate integral with the axis of the balance comprising a pulse pin.

• un mobile d'impulsion, pivoté sur le bâti du mouvement, comportant une fourchette d'impulsion agencée pour coopérer avec la cheville d'impulsion du plateau; un ressort d'impulsion; et un bras comportant un crochet adapté à coopérer avec une denture de la roue d'échappement; et
• des moyens de pilotage agencés pour libérer la roue d'échappement d'un pas pendant des premières alternances du balancier s'effectuant dans un premier sens de rotation, et dégageant le crochet du mobile d'impulsion de la denture de la roue d'échappement pendant des secondes alternances du balancier s'effectuant dans un second sens de rotation opposé au premier sens de rotation.

This escape mechanism also includes:

• a pulse wheel, pivoted on the frame of the movement, having a pulse fork arranged to cooperate with the pulse pin of the plate; a pulse spring; and an arm having a hook adapted to cooperate with a toothing of the escape wheel; and
• control means arranged to release the escape wheel by one step during first half-wave oscillations taking place in a first direction of rotation, and releasing the hook of the impulse mobile of the toothing of the escape wheel during the second half-waves of the pendulum being effected in a second direction of rotation opposite to the first direction of rotation.

The control means comprise control members carried by the plate 7 formed in the example illustrated by the release nose 7.6 and the release pin 7.10.

These control means further comprise either an anchor or, as in the example shown, two detents controlled by said control members.

Finally, the escape mechanism also comprises security devices carried by the plate 7, in the example illustrated the skirt 7.4 of the large plate and the periphery of the small plate 7.2, preventing any inadvertent movement, for example under the effect of shocks, means for controlling the mechanism.

It goes without saying that the pulse spring of the impulse mobile can be realized in different ways, a blade spring as in the example described but also a spiral spring or a coil spring.

The arm, terminated by a hook, of the impulse can be an elastic arm as in the example described or realized by a connecting rod articulated on the body of the impulse mobile and constrained against the escape wheel by a spring or still be realized by a linear guide.

The impulse spring 2.4 of the impulse mobile could be removably attached to the body 2.2 of the impulse mobile to be able to adapt to this impulse mobile a pulse spring corresponding to the energy that we want transmit to the pendulum during the second alternations of it as has been explained in relation to the Figures 13 and 14 .

It goes without saying that the realization of the control means and safety devices may be different from that described in the illustrated example provided that the functions necessary for the operation of the escape mechanism s are realized.

Note that in the example described and illustrated the axes of the escape wheel 1.2, the impulse mobile 2 and the balance 3 form, seen from above, an equilateral triangle. In a variant this triangle could be isosceles or scalene.

It goes without saying that the frequency of the oscillator can be different from 5 Hertz, for example 3 Hz or 4 Hz. In other variants the frequency can be higher than 5 Hertz.

It is found in fact that this escapement mechanism for timepiece movement is intended to transmit to a mechanical oscillator pulses once alternately to maintain its movement. An escape wheel provides as it advances by one step during a first alternation of the oscillator the total energy necessary to maintain the movement of the oscillator during two successive alternations of the oscillator and that this oscillator receives during a first alternation only a part of the energy and that the other part of this total energy is stored by a mobile pulse to be transmitted to the oscillator during a second alternation of it.

In addition, the impulse mobile remains in contact with the escape wheel during the first alternation of the balance while rocking from a first position (α0) to a second position (a1); control means cause the loss of contact between the escape wheel and the impulse wheel during the second alternation of the oscillator during which the impulse wheel returns to a first position (α0) under the effect of the energy stored during the first alternation of the oscillator while transmitting a portion of this energy to said oscillator during its second alternation.

Finally, this impulse mobile is connected to the frame of the movement of the timepiece by a prestressed elastic element, in the example illustrated the pulse spring 2.4.

Finally, it can be seen that the monobloc detents as described and illustrated in FIGS. Figures 16 and 17 can of course be used in other types of exhaust that described in the foregoing.

In fact, generally, the existing detents for escapes of watch movements are complex and formed of several pieces assembled. The one-piece detents described with reference to the present escapement are simple, easy to machine with modern machining methods (DRIE) and can of course be used on all types of escapements watch detents. One of their originalities is to be made in one piece. Another of their originalities is that they each have two portions 5.2, 5.6 or 6.2, 6.8 elastic. Finally, these detents can be manufactured in brittle materials, not plastically deformable, such as silicon for example.

In the case of a relaxation of the type illustrated in figure 16 , it is noted that it allows free passage of the release nose 7.6 during the silent phase even if the expansion is performed in one piece, monobloc, in a plastically non-deformable material such as silicon. This one-piece detent 5 thus comprises a space between the leaf spring 5.6 and the rigid part 5.3 obtained by the machining process DRIE. Upon disengagement, the release nose 7.6 first contacts the second level 5.7 of the leaf spring 5.6 and moves it until it abuts with the rigid portion 5.3 of the trigger. We have here a series spring system composed of the flexible spring blade 5.6 and the flexible portion 5.2 of the trigger 5.

In the case of the second detent 6, also one-piece, the flexible blade forming the release spring 6.8 being tangential to the trajectory of the release pin 7.10, there is no catch-up effect as for the first relaxation 5. The release is immediate. This second relaxation 6 can also be performed by the DRIE method and be monobloc.

It goes without saying that this second trigger can also be secured by a skirt that would replace the cam 7.2 or small plateau tray 7 described above.

These monobloc detents are advantageous and are easy to manufacture, have a high precision, no longer require assembly or subsequent handling to their machining. They have less inertia, are less influenced by gravity. In the case of the first expansion 5 the contact between the flexible blade 5.6 and the release nose 7.6 is flexible and there is therefore no bouncing effect.

These two embodiments of monobloc detents apply to the exhaust described in the foregoing, but can also be used in conventional expansion exhausts (direct impulse).

Claims (20)

1. Timepiece movement comprising a frame, a barrel, a mechanical oscillator (3), and an escapement mechanism comprising an escapement mobile (1) connected to the barrel by a drive going train for driving thereof, characterised in that the movement also comprises an impulse mobile (2) arranged to cooperate with the mechanical oscillator (3); in that the escapement mobile (1) is arranged to cooperate with the impulse mobile (2) so that, upon each step of the escapement mobile (1) during a first alternation of the mechanical oscillator (3), energy is transmitted to the impulse mobile (2) by the escapement mobile; and in that the impulse mobile (2) is arranged:

   • to transmit some of this energy to the mechanical oscillator (3) for maintenance of its movements and to store the rest of this energy upon said first alternation of the mechanical oscillator (3); and

   • to transmit some of the stored energy to the mechanical oscillator (3) upon a second alternation thereof.
2. Escapement movement as claimed in claim 1, characterised in that the impulse mobile (2) is arranged to remain in contact with the escapement mobile (1) upon the first alternation of the mechanical oscillator (3) while tipping from a first position (α0) to a second position (α1); and in that the escapement mechanism comprises control means (6, 7.10) controlled by the mechanical oscillator (3) and arranged to cause the loss of contact between the escapement mobile (1) and the impulse mobile (2) upon the second alternation of the mechanical oscillator (3), the impulse mobile (2) being arranged to return to its first position (α0) during the second successive alternation of the mechanical oscillator (3) under the effect of the energy stored by said impulse mobile (2) during the first alternation of the oscillator (3) while transmitting some of this energy to said mechanical oscillator (3) during this second alternation.
3. Movement as claimed in claim 2, characterised in that the mechanical oscillator is a balance-hairspring (3) comprising a plate (7) integral with the staff of the balance-hairspring (3), comprising an impulse pin (7.7); in that the escapement mechanism also comprises an escapement wheel (1.2) forming part of the escapement mobile (1); in that the impulse mobile (2) is pivoted on the frame of the timepiece movement and comprises an impulse fork (2.3) arranged to cooperate with the impulse pin (7.7) of the plate (7), an impulse spring (2.4), and an arm (2.5) terminated by a hook (2.6) adapted to cooperate with the teeth of the escapement wheel (1.2); and in that the control means (5, 6, 7.6, 7.10) are arranged to cooperate with the members of the plate (7), the escapement wheel (1.2) and the arm (2.5) of the impulse mobile (2) and are arranged to release the escapement wheel (1.2) by one step during first alternations of the balance-hairspring (3) taking place in a first rotational direction, and to disengage the hook (2.6) of the impulse mobile (2) from the teeth of the escapement wheel (1.2) during second alternations of the balance (3) taking place in a second rotational direction opposite to the first rotational direction.
4. Movement as claimed in claim 3, characterised in that the impulse spring (2.4) is a strip-spring.
5. Movement as claimed in any one of claims 3 or 4, characterised in that the impulse spring (2.4) is formed as one manufactured piece with the impulse mobile (2).
6. Movement as claimed in any one of claims 3 or 4, characterised in that the impulse spring is detachably mounted on the body (2.2) of the impulse mobile or is formed as one manufactured piece with this body (2.2).
7. Movement as claimed in any one of claims 3 to 6, characterised in that the free end of the impulse spring (2.4) bears against a first stop (4).
8. Movement as claimed in any one of claims 3 to 7, characterised in that the control means comprise a first detent (5) arranged to be applied against the teeth of the escapement wheel (1.2) by an elastic action and to cooperate with a disengaging lug (7.6) integral with the plate (7).
9. Movement as claimed in claim 8, characterised in that the first detent (5) has an elastic portion (5.2) and a rigid portion (5.3), this latter comprising a rest face (5.4) serving as a stop to a tooth of the escapement wheel (1.2) to prevent this wheel from turning.
10. Movement as claimed in claim 9, characterised in that the first detent (5) comprises a leaf-spring (5.6) fixed by one of its ends to the rigid portion (5.3) of this first detent and in that the free end of this leaf-spring (5.6) comprises a pallet (5.7) located on the path from the disengaging lug (7.6) to the plate (7).
11. Movement as claimed in claim 10, characterised in that the free end of the first detent (5) comprises a finger (5.5) cooperating with a skirt (7.4) of the plate (7), skirt (7.4) having a lateral opening (7.5).
12. Movement as claimed in any one of claims 5 to 11, characterised in that the control means comprise a second detent (6) fixed to the frame of the timepiece movement and arranged to cooperate with a disengaging pin (7.10) on the plate (7).
13. Movement as claimed in claim 12, characterised in that the second detent (6) comprises an elastic portion (6.2) and a rigid portion (6.3) terminating in two branches (6.5, 6.6), of which one (6.5) comprises a stub (6.7) cooperating with the peripheral surface of a small plate (7.2) provided with a clearance (7.11).
14. Movement as claimed in claim 13, characterised in that the other branch (6.6) of the rigid portion (6.3) of the second detent (6) has a disengaging spring (6.8) terminating in a drive banking (6.9), this disengaging spring (6.8) and this drive banking (6.9) cooperating in turn with the disengaging pin (7.10) of the plate (7).
15. Movement as claimed in any one of claims 12 to 14, characterised in that the second detent (6) has a lateral face (6.4) cooperating with the hook (2.6) of the arm (2.5) of the impulse mobile (2).
16. Movement as claimed in claim 15, characterised in that the second detent (6) bears, in the rest position, on a second stop (9) by reason of its own elasticity.
17. Movement as claimed in any one of claims 3 to 16, characterised in that the escapement wheel (1.2) has thirty teeth or more.
18. Movement as claimed in any one of the preceding claims, characterised in that the mechanical oscillator has a frequency of 3 hertz, 4 hertz, 5 hertz or more.
19. Movement as claimed in any one of the preceding claims, characterised in that the pivot axes of the mechanical oscillator (3), of the escapement mobile (1) and of the impulse mobile (2) form, when seen in plan view, an isosceles, equilateral or scalene triangle.
20. Timepiece comprising a movement as claimed in any one of the preceding claims.

Images