CH712084B1 - Relaxation for a free escapement mechanism of a clockwork movement. - Google Patents

Abstract

The present application describes an expansion (5, 6) for a free escapement mechanism (1, 2) of a clockwork movement, characterized in that it is made in one piece, monobloc.

Description

Description: [0001] The present invention relates to free escapement mechanisms for clockwork and concerns in particular an expansion for such a mechanism.

Free escapements are now recognized as the best way to maintain the oscillations of a sprung balance system.

[0003] Free exhausts for existing watch movements can be listed in two main categories according to their driving means: - relaxation exhausts; and - anchor escapements.

[0004] 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 lack of impulse during the silent phase, the expansion exhausts are not self-starting.

Anchor escapements exist either with direct impulse of the escapement wheel to the pendulum or indirect impulse through the anchor.

The anchor is a stop that has two rest positions. Anchor escapements advance the gear once in a row. The only exception is the lever escapement, where the escapement 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.

[0008] Most anchor escapements transmit energy indirectly via 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 of 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 need a fall between the release and the pulse and / or between the pulse and the 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.

It would be advantageous to provide a free escapement mechanism for a watch movement whose piloting can be done either by detents or by an anchor that is applicable to portable timepieces and which transmits energy to the oscillator at each alternation of it while reducing energy losses, reduce inertial influences and make the exhaust insensitive to shocks. It would also be beneficial to reduce or eliminate energy-consuming falls.

The present application discloses a free escapement mechanism for equipping watch movements which comprise a frame on which are mounted a cylinder, a cogwheel kinematically connecting the barrel to an escapement mobile and an oscillator provided with a pendulum; 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; characterized by the fact that this escapement mechanism further comprises: - a pulse mobile pivoted on the watch movement frame comprising a pulse fork arranged to cooperate with the pulse pin 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 wheel of escapement during second alternations of the balance being effected in a second direction of rotation opposite to the first direction of rotation.

The present invention aims to achieve detents for a free escape mechanism, including a mechanism as described above, simple and easy to achieve. The invention therefore relates to an expansion, particularly for a free exhaust mechanism, which is distinguished by the fact that it is monobloc, that is to say, made in one piece.

The invention also relates to a free exhaust mechanism comprising such a detent and a timepiece comprising such a free escape mechanism.

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

Fig. 1 schematically illustrates in a plan from above the main elements of the free escape mechanism necessary to illustrate its operation.

Figs. 2 to 8 illustrate the free escape mechanism of FIG. 1, the balance has been removed for clarity, in different positions of the operating cycle.

Fig. 9 illustrates a safety device provided to prevent accidental release of a first de tent in case of shocks.

Fig. 10 illustrates a safety device designed to prevent untimely release of a second trigger in case of shocks.

Figs. 11 and 12 illustrate a safety device avoiding the gallop of the free escapement mechanism when the beam performs its additional arc of the mute phase respectively of the arming phase of the mechanism.

Figs. 13 and 14 illustrate the transmission of energy for two different chronometric behaviors of the free escape mechanism.

Fig. 15 is an isometric view from above of the free exhaust mechanism illustrated in FIG. 1, the swing being removed for a better illustration.

Fig. 16 is an isometric view of the first expansion of the control means.

Fig. 17 is an isometric view of the second detent of the control means.

Fig. 18 is an isometric view of a plate integral with the axis of the balance.

The free escapement mechanism illustrated and comprising the detents according to the invention is an exhaust in which the escapement wheel makes only one step by oscillation of the balance as in the escapement mechanisms lost 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 illustrated in the drawing will be described, this embodiment of the free escape mechanism is controlled by two detents according to the invention. 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 driven 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.

FIG. 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 thus facilitate understanding.

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 free escapement mechanism comprising a first expansion 5 and a second expansion 6 fixed on a fixed part of the clockwork and cooperating with a plate 7 integral with the axis 3.1 of a balance 3 of an oscillator formed of a balance spring. 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 illustrated example, the oscillator has a frequency of 5 Hertz. The plate 7 is constituted in the illustrated example of a large plate 7.1 and a small plate 7.2 (see Fig. 18).

The large plate 7.1 comprises a plate 7.3 comprising fixing means for example a hole to be chased 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 detent 5 (FIG 16) comprises a fixing stud 5.1 for fixing on a fixed part of the watch movement, an elastic portion 5.2 connecting the fixing stud 5.1 to a rigid portion 5.3 having a surface rest stop 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 teeth of the escape wheel 1.2 and whose opposite side face 6.4 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 the 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 the release spring 6.8 form favorably a hook to limit the maximum deflection of the release spring 6.8, this avoiding a plastic deformation or breakage 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 mobile pulse 2 are assembled under prestressing, armed, which allows to have very simple dimension chains for 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 considered during the completion, it is the centering of the mobile pulse 2 with respect to the line connecting the pivot points of the mobile pulse 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.

The operation of this escapement mechanism comprises two main phases: - firstly the arming phase during the first alternation of the pendulum during which the escape wheel and all the gear of the watch movement advances one step secondly, the mute phase during the second alternation of the pendulum during which the escape wheel and all the gear 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 via the impulse mobile which receives the energy to be transmitted either directly by the escape wheel during the arming phase either by its pulse spring during the silent phase.

With reference to FIGS. 2 to 4 the first alternation or phase of arming will now be described: Suppose that the balance 3 returns clockwise its point of return. The escape wheel 1.2 is stationary and rests with one of its teeth on the rest surface 5.4 of the first detent 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 released from the resting surface 5.4 of the first detent 5 (FIG 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 in engagement with a tooth of the escape wheel 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 the rest position under the effect of its own elasticity in contact with the escape wheel. The escape wheel 1.2 is again locked (Fig. 4).

FIG. 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 torque at the pulse wheel 2 provided 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 so we always have at least C1 available to transmit energy to the balance 3.

During this arming phase the pulse wheel 2 receives from the escape wheel 1.2 by its hook 2.6 a torque at least equal to C1. This couple switches the impulse wheel 2 from its position a0 (range 2.3 on the left) to position a-ι (range 2.3 on the right). Part (Evar + Ei) 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 energy available 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 FIGS. 13 and 14. Indeed, the slope of the characteristic curve of the spring 2.4, represented by the equation C = ka, modifies the energy distribution in time between the impulse given to the balance 3 and the armature of the spring 2.4. mobile 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 = C2, Fig. 13 or Fig. 2). 14). The surfaces (Evar + Ei) and E2 quantifying the energies are identical.

Between figs. 13 and 14, only the 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 pre-shaping vary at the same time.

For a better understanding of this fact, Figs. 13 and 14 show the line "O" 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 cx0 and α-ι of the impulse mobile, also corresponds at the theoretical neutral position of the oscillator.

It is clearly seen that the stiffer spring 2.4 (FIG 13) transmits more energy before the dead point than the configuration in FIG. 14. Although the total energy transmitted during a pulse 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 portion of energy in FIG. 13 before neutral will advance the oscillator more 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 trigger against the second stop 9. In doing so the release spring 6.8 is deformed to let the 7.10 release pin pass and then return 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 performs its additional arc ascending with a clockwise movement to the point of return of the balance 3. With reference to figs . 5-8 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 (Fig. 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 pulse wheel 2 (Fig. 6). Pulse wheel 2 pivots clockwise under the action of its pulse spring 2.4 which 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 impulse mobile 2, released from the second trigger 6, falls on the next tooth of the escape wheel 1.2 and blocks the impulse mobile 2.

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

During the mute 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 pendulum carries its additional arc ascending with a counterclockwise movement to the point of return. The mechanism is found in the position illustrated in FIG. 2 and a new cycle can begin.

As has been seen from the description of the example of the free escape mechanism, this exhaust 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 free escapement mechanism thus achieves a blowaway escape in which there is necessarily a transmission of energy to the pendulum during each alternation thereof.

The peculiarity of this exhaust mechanism is that it gives a pulse even during the silent phase without the escape wheel turns. 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 mobile 2 can be made in different ways, for example by a spiral spring or as in the example described by a leaf spring which allows to obtain a more complete assembly. possible flat as well as 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 valid for the losses due to the release of the second trigger, because the transmitted energy 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 escape wheel coming in 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 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.

This escapement mechanism having no fall, the entire pitch between two teeth of the escape wheel 1.2 is usable 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 mobile, 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 known relaxation exhausts is the gallop of the exhaust which consists of a second release during the same alternation at very large amplitudes of the oscillator. 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 impeller 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 mute phase, this movement causes the escape wheel to retreat and thus absorbs the superfluous energy of the oscillator (FIG 11). If this rebound occurs during the arming phase (Fig. 12) then the pulse spring 2.4 of the pulse cell 2 will absorb this superfluous energy.

Such elastic rebound disrupts the watch less than the violent rectifications of existing anchor escapements.

This free escape mechanism can 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 free escape mechanism with a high frequency oscillator, 5 Hertz or more, without needing to provide an additional mobile between the second wheel and the exhaust pinion and without the need for 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 free escape mechanism is self starting because the oscillator receives energy during each of its alternations.

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

The present free escapement mechanism can influence at will the timing behavior of the exhaust and eliminate the running errors due to the exhaust or to balance other isochronism defects, for example from the hairspring by an adjustment of the exhaust mechanism. Indeed in this free 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 silent phase relative to the neutral point of the oscillator while 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 free escape mechanism, the gear of the watch movement that is equipped advancing only once per period, or during alternating on two of the oscillator. During the silent alternation the gear does not turn, 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, during the running of a free exhaust mechanism according to the invention, the tick-produced is much less strong than in the known exhausts clearly indicating a reduction of the energy dissipated by shocks.

The present free escapement mechanism is particularly well suited to be integrated in the cages of a vortex at high oscillator frequency, because it allows despite the use of a high frequency oscillator the conservation of 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 wheel including vortex cages.

In general, the free escapement mechanism illustrated is intended to equip watch movements which comprise a frame on which are mounted a barrel, a cogwheel kinematically connecting the barrel to an escape wheel and an oscillator. equipped with a pendulum. This free escapement 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.

This free escape mechanism is distinguished in that it further comprises: - a pulse wheel, pivoted on the frame of the movement, comprising a pulse fork arranged to cooperate with the spindle of the plateau impulse ; 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 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 wheel of escapement during second alternations of the balance 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 illustrated free escapement mechanism further includes security carried by the plate 7, in the illustrated example the skirt 7.4 of the large plate and the periphery of the small plate 7.2, prohibiting any inadvertent movement, for example under the effect of shocks, control means of 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, the mobile pulse can be an elastic arm as in the example described or realized by a rod articulated on the body of the impulse mobile and constrained against the escape wheel by a spring or 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 the impulse we want to transmit to the balance during the second alternations thereof as has been explained in relation to FIGS. 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 example shown as far as the functions necessary for the operation of the exhaust mechanism are performed.

Note that in the example described and illustrated the axes of the escape wheel 1.2, the pulse wheel 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 may be different from 5 Hertz, for example 3 or 4 Hertz. In other variants the frequency can be higher than 5 Hertz.

It is found in fact that this free escape mechanism for a timepiece 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 (a ·) to a second position (a2); 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 (α-ι) 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 pulse mobile is connected to the frame of the movement of the timepiece by a prestressed elastic element, in the example shown the pulse spring 2.4.

Finally, it is noted that the invention also relates to monobloc detents for themselves as described and illustrated in FIGS. 16 and 17 but can of course be used in other types of exhaust than that described in the foregoing.

In fact generally the existing detents for escapements of watch movements are complex and formed of several assembled parts. 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 detent of the type illustrated in FIG. 16, it is noted that it allows free passage of the release nose 7.6 during the silent phase even if the expansion is made in one piece, monobloc, in a plastically 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 trigger 6, also monobloc, the flexible blade forming the release spring 6.8 being tangential to the trajectory of the release pin 7.10, there is no play catch-up effect as

Claims (10)

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 relaxation can also be secured by a skirt that would replace the cam 7.2 or small tray tray 7 described above. These monobloc detents are advantageous and are easy to manufacture, have a high accuracy, 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 free exhaust as described above, but can also be used in conventional expansion exhausts (direct impulse). This is why the present invention relates to a detent for free escapement mechanism of a watch movement which is distinguished by the fact that it is made in one piece, monobloc. claims 1. Relaxation (5, 6) for a free escape mechanism (1, 2) of a clockwork movement, characterized in that it is made in one piece, monobloc. 2. Relaxation (5, 6) according to claim 1, characterized in that it comprises at its free end a control member (5.7, 6.7) for cooperating with a control member (7, 7.1, 7.2) solidaire the axis (3.1) of a balance (3) of the watch movement, its other end (5.1, 6.1) being adapted to be fixed on a fixed part of the watch movement. 3. Relaxation (5, 6) according to claim 1 or 2, characterized in that it comprises at least one elastic portion (5.2, 6.2) and at least one rigid portion (5.3, 6.3). 4. Relaxation (5) according to claim 3, characterized in that it comprises a resting surface (5.4) carried by the rigid part (5.3) and intended to cooperate with the toothing of an escape wheel (1.2 ) of the free exhaust mechanism (1,2). 5. Relaxation (5) according to claim 4, characterized in that the resting surface (5.4) carried by the rigid portion (5.3) is intended to serve as a stop for a tooth of the escape wheel (1.2) for prevent it from turning. 6. Relaxation (5) according to claim 5, characterized in that it comprises a spring blade (5.6) fixed at one of its ends to the rigid portion (5.3) and in that the free end of this blade spring (5.6) comprises a pallet (5.7) intended to be located on the path of a clearance nose (7.6) of a plate (7) integral with the axis (3.1) of a balance (3) of the movement watchmaking. 7. Relaxation (6) according to claim 3, characterized in that the rigid portion (6.3) terminates in two branches (6.5; 6.6) one of which (6.5) has a lug (6.7) intended to cooperate with the peripheral surface of a plate (7.2) provided with a clearance (7.11) and integral with the axis (3.1) of a balance (3) of the clockwork movement. 8. Relaxation (6) according to claim 7, characterized in that the other leg (6.6) of the rigid portion (6.3) carries a release spring (6.8) ending in a drive stop (6.9), this release spring (6.8) and this driving abutment (6.9) being designed to cooperate in turn with a release pin (7.10) of the plate (7.2) integral with the axis (3.1) of the balance (3) of the watch movement. 9. Free exhaust mechanism comprising a detent according to one of claims 1 to 8. Timepiece comprising a free escapement mechanism according to claim 9.