CH706462A2 - free escapement mechanism for watch movement, movement and / or a timepiece including this escape mechanism. - Google Patents

Abstract

Exhaust mechanism for the oscillation maintenance of a pendulum (3) of a watch part comprising a frame; this escapement mechanism comprising an escapement wheel (1.2) and a plate (7), integral with a balance shaft (3) comprising an impulse pin (7.7); characterized by the fact that this escapement mechanism further comprises: an impeller (2) pivoted on the frame of the watch movement having an impulse fork (2.3) cooperating with the impulse pin (7.7); a pulse spring (2.4); and an arm (2.5) terminated by a hook (2.6) cooperating with the escape wheel (1.2); and control means (5, 6, 7.6, 7.10) releasing the escape wheel (1.2) from a pitch during first half-waves (3), and releasing the hook (2.6) from the impulse mobile ( 2) of the escapement wheel (1.2) during second alternations of the balance (3).

Description

The present invention relates to free escapement mechanisms for watch movement.

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: escapements with relaxation; 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 the 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.

The object of the present invention is to provide a free escapement mechanism for a watch movement which can be controlled either by detents or an anchor that is applicable to portable timepieces and transmits the oscillator energy 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 free escapement mechanism for clockwork movements of a portable timepiece including a wristwatch or pocket watch that is distinguished by an exhaust mechanism for equipping clockwork movements which comprise a frame on which are mounted a barrel, a gear train kinematically connecting this barrel to an escapement wheel and an oscillator equipped 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; characterized by the fact that this 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.

The invention also relates to a movement and / or timepiece incorporating such an exhaust mechanism.

In addition the present invention also aims to achieve simple relaxation and easy to achieve. The invention therefore also relates to an expansion, particularly for an exhaust mechanism which is distinguished by the fact that it is monobloc that is to say made in one piece.

The accompanying drawing illustrates schematically and by way of example a particular embodiment of the free escapement mechanism for a watch movement. <tb> Fig. <sep> 1 schematically illustrates in a plan from above the main elements of the free escape mechanism necessary to illustrate its operation. <tb> Figs. 2 to 8 <sep> illustrate the free escape mechanism of FIG. 1, the balance has been removed for clarity, in different positions of the operating cycle. <tb> Fig. 9 <sep> illustrates a safety device provided to prevent untimely releases of a first trigger in case of shocks. <tb> Fig. 10 <sep> illustrates a safety device designed to prevent untimely release of a second trigger in the event of shocks. <tb> Figs. 11 and 12 <sep> illustrate a safety device avoiding the gallop of the exhaust mechanism when the rocker performs its additional arc of the mute phase respectively of the arming phase of the mechanism. <tb> Figs. 13 and 14 <sep> illustrate the transmission of energy for two different chronometric behaviors of the escape mechanism. <tb> Fig. <Sep> is an isometric view from above of the exhaust mechanism illustrated in FIG. 1, the rocker being removed for a better illustration. <tb> Fig. 16 <sep> is an isometric view of the first detent of the control means. <tb> Fig. 17 <sep> is an isometric view of the second detent of the control means. <tb> Fig. 18 <sep> is an isometric view of a plate integral with the axis of the balance.

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

In what follows the embodiment illustrated in the drawing will be described, this embodiment of the free escape mechanism 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.

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 to facilitate understanding of the exhaust mechanism that constitutes the present invention.

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 equipped with a 2.5 elastic arm se ending with 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.

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 board 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 escape mechanism comprises 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.

However, during each of these two phases, the arming phase and the silent phase, a determined quantity of energy is transmitted to the balance beam via the impulse wheel which receives the energy to be transmitted 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:

Assume that 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 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 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, 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 switches the impulse mobile 2 from its position α0 (range 2.3 on the left) to position α1 (range 2.3 on the right). Part (Evar + E1) 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 = k · α, modifies the distribution of energy in time between the impulse given to the balance 3 and the arming of the spring 2.4 of the pulse wheel 2 during the arming phase.

The energy distribution between the impulse given to the pendulum 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. 14 ). The surfaces (Evar + E1) and E2quantizing 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. 14the stiffness k of the spring 2.4 as well as its pre-arming vary at the same time.

For a better understanding of this fact, Figs. 13 and 14 show the line "0" linking the center of rotation of the balance 3 to the center of rotation of the pulse wheel 2. This line, perfectly centered between the extreme positions α0 and α1 of the pulse wheel, also corresponds to the position the theoretical dead point of the oscillator.

It is clearly seen that the stiffer spring 2.4 (FIG 13) transmits more energy before the neutral 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. Before the neutral point, the oscillator will advance further than the configuration in FIG. 14.

During the pulse, 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 carries 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 it 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 expansion 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. 2and a new cycle can begin.

As seen from the description of the example of the exhaust 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 exhaust 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 escape 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 expansion, 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 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 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 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 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 running of the watch less than the violent rectifications of existing anchor escapements.

This exhaust mechanism allows 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 much 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 exhaust mechanism allows to influence at will the timing behavior of the exhaust and eliminate the run-off due to the exhaust or to balance other isochronism defects, for example from of the hairspring, 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 escape mechanism the cog of the watch movement that is equipped advances only once per period, or during alternation of 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, or the arming phase, the impulse and the escape wheel are almost in balance of strength. 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 running an exhaust mechanism according to the invention, the tick is produced much less strong than in the known exhaust clearly indicating a reduction of the energy dissipated by shocks.

The present escape 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 preservation of a report. gear of ordinary gear 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 general, the escapement mechanism according to the invention is intended to equip watch movements which comprise a frame on which are mounted a cylinder, a cogwheel kinematically connecting the cylinder to an exhaust mobile and an oscillator equipped with a balance. This escapement mechanism comprises an escape wheel forming part of the escape wheel and a plate secured to the axis of the balance comprising a pulse pin.

This exhaust mechanism according to the invention is distinguished in that it further comprises: 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 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.

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 according to the invention 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 mobile pulse can be realized in different ways, a leaf 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 embodiment 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 according to the invention are carried out.

Note that in the example described and illustrated the axes of the escape wheel 1.2, the mobile pulse 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 escapement 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 (α1) to a second position (α2); 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 (α1) 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 parts 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 elastics. 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 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 detent 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 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 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 according to the invention as described above, but can also be used in conventional expansion exhausts (direct impulse). This is why the present invention also relates to a detent for watchmaking exhaust mechanism which is distinguished by the fact that it is made in one piece, monobloc.

Claims (29)

An escapement mechanism for sustaining the oscillations of a pendulum (3) of a timepiece comprising a frame; this escapement mechanism comprising an escape wheel (1.2) forming part of an escape wheel (1) and a plate (7), integral with an axis on which is mounted the rocker (3) comprising an ankle pulse (7.7); characterized by the fact that this escape mechanism further comprises: - a pulse wheel (2) pivoted on the frame of the clockwork comprising a pulse fork (2.3) arranged to cooperate with the pulse pin (7.7) of the plate (7); a pulse spring (2.4); and an arm (2.5) terminated by a hook (2.6) adapted to cooperate with the toothing of the escape wheel (1.2); and - control means (5, 6, 7.6, 7.10) arranged to release the escape wheel (1.2) of a pitch during the first half-waves of the balance (3) taking place in a first direction of rotation, and disengaging the hook (2.6) of the impulse wheel (2) of the toothing of the escape wheel (1.2) during second alternations of the rocker (3) taking place in a second direction of rotation opposite to the first direction of rotation. 2. Exhaust mechanism according to claim 1, characterized in that the pulse spring (2.4) is a leaf spring. 3. Exhaust mechanism according to claim 1 or claim 2, characterized in that the pulse spring (2.4) has come from a workpiece with the pulse wheel (2). 4. Exhaust mechanism according to claim 1 or claim 2, characterized in that the pulse spring is removably mounted on the body (2.2) of the impulse mobile or come from a workpiece with this body (2.2). 5. Exhaust mechanism according to one of the preceding claims, characterized in that the control means comprise a release nose (7.6) integral with the plate (7) cooperating with a first trigger (5) fixed on the frame of the movement and applied against the teeth of the escape wheel (1.2) by an elastic action. 6. Exhaust mechanism according to claim 5, characterized in that the first detent (5) comprises an elastic portion (5.2) and a rigid portion (5.3) the latter having a rest face (5.4) serving as a stop a tooth of the escape wheel (1) to prevent it from rotating. 7. Exhaust mechanism according to claim 6, characterized in that the first detent comprises a leaf spring (5.6) fixed at one of its ends to the rigid portion (5.3) of the first detent and in that the free end of this leaf spring (5.6) comprises a pallet (5.7) located on the path of the release nose (7.6) of the plate (7). 8. Exhaust mechanism according to claim 7, characterized in that the free end of the first trigger (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). 9. Exhaust mechanism according to one of the preceding claims, characterized in that the control means comprise a release pin (7.10) carried by the plate (7) cooperating with a second trigger (6) fixed on the frame of the watch movement. 10. Exhaust mechanism according to claim 9, characterized in that the second detent (6) comprises an elastic portion (6.2) and a rigid portion (6.3) ending in two branches (6.5, 6.6) one of which (6.5) has a lug (6.7) cooperating with the peripheral surface of a small plate (7.2) provided with a clearance (7.11). 11. Exhaust mechanism according to claim 9 or claim 10, characterized in that the other leg (6.6) of the rigid portion (6.3) of the second trigger carries a release spring (6.8) ending in a driving abutment (6.9), this release spring (6.8) and this driving abutment (6.9) cooperating in turn with a release pin (7.10) of the plate (7). 12. Exhaust mechanism according to one of the preceding claims, characterized in that the second trigger (6) has a side face (6.4) cooperating with the hook (2.6) of the arm (2.5) of the impulse mobile ( 2). 13. Exhaust mechanism according to claim 12, characterized in that the second trigger (6) rests in the rest position on a second stop (9) by its own elasticity. 14. Exhaust mechanism according to one of the preceding claims, characterized in that the escape wheel (1.2) has thirty or more teeth. 15. Exhaust mechanism according to one of the preceding claims, characterized in that the oscillator at a frequency of 3, 4, 5 Hertz or more. 16. Exhaust mechanism according to one of the preceding claims, characterized in that the pivoting axes of the balance (3) of the escapement mobile (1) and the impulse mobile (2) form, seen in plan , an isosceles, equilateral or scalene triangle. 17. Exhaust mechanism according to one of the preceding claims, characterized in that the free end of the pulse spring (2.4) bears on a first stop (4). 18. Exhaust mechanism according to one of claims 1 to 16, characterized in that the impulse mobile (2) is connected to the frame of the timepiece by an elastic member and prestressed. 19. Exhaust mechanism for a timepiece for transmitting to a mechanical oscillator (3) pulses once alternately to maintain its movement, characterized in that an escapement wheel (1) provides while it advances by one step during a first alternation of the oscillator, the total energy necessary to maintain the movement of the oscillator (3) during two successive alternations of the oscillator (3) and that this oscillator (3) ) receives during a first alternation only a part of the energy and that the other part of this total energy is stored by a pulse mobile (2) in order to be transmitted to the oscillator during a second alternation of it. 20. Exhaust mechanism according to claim 19, characterized in that the impeller (2) remains in contact with the escape wheel (1.2) during the first alternation of the balance while rocking a first position (α1) at a second position (α2); control means (6, 7.10) causing loss of contact between the escape wheel (1.2) and the impulse wheel (2) during the second alternation of the oscillator (3), during which the mobile of pulse (2) returns to its first position (α1) under the effect of the energy stored during the first alternation of the oscillator (3) while transmitting a portion of this energy to said oscillator during its second alternation. 21. Movement and / or timepiece incorporating an exhaust mechanism according to one of claims 1 to 20. 22. Detent for watch movement escapement mechanism, characterized in that it is made in one piece, monobloc. 23. Relaxation according to claim 22, characterized in that it comprises at least one elastically deformable portion. 24. Relaxation according to claims 22 or 23, characterized in that it comprises a resting surface for cooperating with the toothing of an escape wheel. 25. Relaxation according to one of claims 22 to 24, characterized in that it comprises at its free end a control member intended to cooperate with a control member secured to the axis of a beam, its other end being adapted to be fixed on a fixed part of a clockwork movement. 26. Relaxation according to one of claims 22 to 25, characterized in that it comprises an elastic portion (5.2) and a rigid portion (5.3) the latter having a rest face (5.4) serving as a stop tooth an escape wheel (1.2) to prevent it from rotating. 27. Relaxation according to claim 26, characterized in that it comprises a leaf spring (5.6) fixed by one of its ends on the rigid portion (5.3) of the first detent and in that the free end of this leaf spring (5.6) comprises a pallet (5.7) located on the path of the release nose (7.6) of the plate (7). 28. Relaxation according to one of claims 22 to 25, characterized in that it comprises an elastic portion (6.2) and a rigid portion (6.3) ending in two branches (6.5, 6.6) one of which (6.5 ) has a lug (6.7) cooperating with the peripheral surface of a small plate (7.2) provided with a clearance (7.11). 29. Relaxation according to claim 28, characterized in that the other leg (6.6) of the rigid portion (6.3) of the trigger carries a release spring (6.8) ending in a drive stop (6.9), this release spring (6.8) and this driving stop (6.9) cooperating in turn with a release pin (7.10) of a plate (7).