EP3818417A2

EP3818417A2 - Timepiece escapement mechanism

Info

Publication number: EP3818417A2
Application number: EP19730836.4A
Authority: EP
Inventors: Stephen Forsey; Robert Greubel; Fabrice Deschanel; Christophe Zwahlen; Florian Corneille
Original assignee: GFPI SA; Complitime SA
Current assignee: GFPI SA; Complitime SA
Priority date: 2018-07-02
Filing date: 2019-06-20
Publication date: 2021-05-12
Also published as: US11988993B2; WO2020007619A3; WO2020007619A2; US20210141340A1

Abstract

Disclosed is an escapement mechanism (1) for a timepiece, designed to cooperate with an oscillator arranged to carry out oscillations, said mechanism (1) comprising: - a count wheel (7) arranged for step-wise forward rotation depending on the oscillations of the oscillator; - an impulse wheel (11) designed to be kinematically linked to a power source, said impulse wheel (11) being arranged to be periodically blocked and released under the control of the count wheel (7) and to supply impulses to the oscillator, characterized in that: - when said escapement mechanism (1) is operating, the count wheel (7) is continuously subjected to a torque; - and the count wheel (7) is arranged to rotate forward by one half-step of its toothing for every vibration of the oscillator.

Description

WATCHMAKING EXHAUST MECHANISM

Technical area

The present invention relates to the field of watchmaking. It relates more particularly to an escape mechanism.

State of the art

The Swiss anchor escapement associated with a balance-spring oscillator has become the regulating system most often used nowadays. It is simple, reliable, impact resistant and is well mastered by watchmakers. However, it is not without its faults, particularly in terms of energy efficiency and its isochronism. Indeed, the interaction at each alternation of the balance between the escapement wheel and the anchor as well as the shocks generated waste a lot of energy. In addition, the pulling of the anchor during disengagement also generates a significant disturbance of the pendulum oscillations. Indeed, the use of an anchor to both trigger an impulse and transmit it to the pendulum is not optimal.

The detent escapement represents an improvement in terms of efficiency and isochronism, the detent lever being actuated once by oscillation and the impulse being supplied directly by the escape wheel to a impulse palette. integral in rotation with the pendulum. The balance is thus disturbed by the pulse once per oscillation instead of each half-wave, and this disturbance is less significant than in the case of the Swiss anchor. Indeed, the resistance provided by the trigger is lower than that of the anchor because the impulse is given directly by the escape wheel instead of being transmitted by an anchor or the like, which generates lower consumption in energy. The exhaust efficiency and the power reserve of the movement are thus improved.

Document CH712052 describes a particular escapement with misses.

The pendulum carries a unidirectional drive system which drives once per oscillation a counting wheel at the rate of one step per drive. This counting wheel is positioned by a jumper, and comprises a cam which, once per n of the counting wheel, raises a locking lever which retains a impulse wheel. The latter is thus free to pivot to give an impulse directly to the balance and is locked by the locking lever until the next actuation.

However, the presence of a unidirectional drive system mounted integral in rotation with the balance presents difficulties in terms of its development and as regards the balance of the balance. Indeed, this arrangement is little, if not even, compatible with conventional pendulums. Furthermore, the use of a jumper to position the counting wheel has low impact resistance and is likely to be improved in terms of the resistance presented to the balance during the training of said wheel.

The object of the invention is therefore to provide an escapement for a timepiece in which the above-mentioned defects are at least partially overcome.

Disclosure of invention

More specifically, the invention relates to an escapement mechanism for a timepiece, as defined by claim 1.

This escape mechanism is, of course, intended to cooperate with an oscillator arranged to perform oscillations, such as for example a balance-spring oscillator, comprising an inertial mass (typically called a "balance"), arranged to perform oscillations in rotation about its axis of rotation under the effect of a restoring force provided by an elastic element such as a spiral spring.

Said mechanism includes:

- a counting wheel arranged to advance in rotation in discrete steps as a function of the oscillations of said oscillator;

- a pulse wheel intended to be in kinematic connection with a driving source such as a barrel storing a driving spring, said wheel pulse being arranged to be blocked and released periodically under the direct or indirect control of said counting wheel, that is to say according to its rotation and thus its angular position and also to provide pulses to said oscillator. In other words, it is the rotational movements of the counting wheel which generate the release of the impulse wheel, and which thus trigger its periodic rotations.

According to the invention, during the operation of said system, the counting wheel is permanently subjected to a torque, for example under the effect of an elastic element which directly or indirectly exerts a force in the direction of the direction of rotation of the counting wheel at any time, and said counting wheel is arranged to advance in rotation at the rate of half a step of its teeth by alternating said oscillator.

By these means, the disturbance of the oscillations of the oscillator is minimized for two reasons. Firstly, no jumper or pawl is necessary for the retention of the counting wheel since the latter is permanently subjected to a torque and can therefore be blocked by one or more pallets or the like. This torque ensures the rotation of the counting wheel, which therefore does not take place by a unidirectional drive system integral in rotation with the oscillator - the only effect of the oscillator being to release the counting wheel instead of training it. It almost goes without saying that a release of the wheel requires less force than a direct drive, which disturbs the oscillator less. In addition, this reduced disturbance is shared between the two opposite half-waves of the oscillator instead of being concentrated in one of the two. The disturbance is therefore rather symmetrically divided between the two half-waves instead of representing a large disturbance due to the driving of one alternating wheel in two. The disturbance of the oscillator is thus minimized, its isochronism is improved, while keeping the excellent power reserve that allows an escapement with blow (s) lost (s).

Advantageously, the mechanism comprises a first locking lever arranged to move between a first angular position and a second angular position during a first alternation of said oscillator, and to move between said second angular position and said first angular position during a second alternation of said oscillator, said locking lever being arranged to block the rotation of said counting wheel and for release the latter at the rate of half a step of its teeth during each of said changes in said first locking lever.

Advantageously, the mechanism further comprises a second locking lever arranged to lock and to release said impulse wheel as a function of the rotation of said counting wheel. To this end, said second locking lever can be arranged to release said impulse wheel at the rate of one step of its toothing at each n alternations of said oscillator, n being a number greater than two and preferably even, and even more preferably equal to four or six.

Advantageously, the second locking lever comprises a cam follower arranged to cooperate with at least one cam or at least one cam path integral in rotation with said counting wheel. The follower can be, for example, a lug, a pin, a fork or the like which can come in one piece with said counting wheel or can be attached to the latter or can be composed of an element integral in rotation with the wheel of counting. One can provide, for example, several separate cams, a continuous cam or a continuous cam path which cooperates with a cam follower of a suitable shape for the shape chosen for the cam. It should be noted that the term “cam” is to be taken in the broad sense, a cam thus being able not only to have a conventional shape but also to be able to have a particular form of toothing, pins or lugs, successions of pins or lugs forming a path, a spline etc. or any other element exerting a cam action.

Advantageously, said second locking lever comprises at least one pallet arranged to block and to release (when the time comes) said impulse wheel. This pallet may be of stone or the like or may have come in one piece with said lever. Advantageously, said second locking lever comprises a single pallet arranged to block and to release said impulse wheel, said second locking lever being arranged to be lifted by an actuating lever to release said impulse wheel . This actuation lever is arranged to move in translation between a retracted position in which said actuation lever is outside the range of an actuating pallet integral in rotation with said oscillator and an active position in which said actuation lever is capable of cooperating with said actuating pallet to lift said second locking lever. The state of said actuating lever, that is to say whether it is in an active position or a retracted position, is determined as a function of the angular position of said counting wheel. In this embodiment, the release of the pulse wheel is thus controlled by the counting wheel and triggered by the actuating paddle.

Advantageously, said actuating lever is arranged to move between said active position and said retracted position under the effect of a control lever carrying a cam follower arranged to cooperate with a cam track or integral cams ( s) in rotation of said counting wheel.

Advantageously, said torque, to which said counting wheel is subjected, is supplied by means of an elastic element wound directly or indirectly by the impulse wheel. Said torque thus remains substantially constant during the operation of the mechanism, the elastic element being recharged each time the impulse wheel moves angularly.

Advantageously, said elastic element is part of a refill assembly comprising a wheel in kinematic connection with said counting wheel. A first end of said elastic element can thus be fixed to said wheel and a second end of said elastic element being integral in rotation with a recharging wheel arranged to be driven in rotation by a toothing which comprises said impulse wheel. Advantageously, said charging wheel is arranged to be retained by a retention lever arranged to block a rotation of said charging wheel in a first direction and to be lifted by a tooth of said charging wheel when the latter pivots in a second sense, opposite to said first sense.

Advantageously, said retention lever is arranged to cooperate with a plurality of stops provided on said impulse wheel, said stops being arranged to prevent said retention lever from being released, except when said charging wheel is in the process of 'be driven by said impulse wheel. The retention lever is thus protected from shocks and no accidental triggering of the impulse wheel is possible.

Advantageously, said impulse wheel as well as said recharging wheel each comprise a plurality of teeth distributed between at least two different planes, each tooth of a first plane being located angularly between two teeth angularly adjacent to the other plane (s).

Advantageously, a first end of said elastic element is integral in rotation with said impulse wheel and a second end of said elastic element being integral in rotation with a wheel in kinematic connection with said counting wheel. This construction is notably very compact and does not require any separate charging wheel.

Advantageously, said second blocking lever comprises a single blocking pallet arranged to block the impulse wheel and a cam follower arranged to cooperate with at least one cam which comprises said counting wheel, said counting wheel. having a plurality of stops arranged to prevent said second locking lever from releasing said impulse wheel except when said cam follower is being actuated by said at least one cam. This arrangement of stops protects the second shock blocking lever, preventing it from lifting except when it is actuated by said at least one cam.

Advantageously, the pulse wheel and the counting wheel are each pivoted about their own axis of rotation, each of these axes being distinct from the other, which makes the exhaust compact in height.

Said mechanism can be integrated into a timepiece movement comprising a mechanism according to one of the preceding claims as well as an oscillator arranged to cooperate with said mechanism, this movement being able to be integrated into a timepiece.

Brief description of the drawings

Other details of the invention will appear more clearly on reading the description which follows, made with reference to the appended drawings in which:

Figures 1 to 10 are isometric representations of a first embodiment of an exhaust according to the invention, during several of its operating phases;

Figures 11 to 13 are isometric representations from different angles of a second embodiment of an exhaust according to the invention, just before the release of the counting wheel;

Figures 14 to 21 are isometric representations according to different angles of a third embodiment of an exhaust according to the invention, in several operating states; and

FIG. 22 is an isometric representation of the actuating lever of the third embodiment.

Modes of Carrying Out the Invention

Figure 1 illustrates a first embodiment of an exhaust mechanism 1 according to the invention.

The exhaust 1 cooperates with a balance-spring oscillator, of which only the plate 3 has been shown so as not to overload the drawings and whose axis of rotation has been represented by a vertical chain line. This plate 3, as well as the balance spring to which it is integral in rotation, can be of conventional shape but other known variants (for example pendants without serges, at high frequency or the like) are also possible. The plate comprises a pin 3a as well as a pulse pallet 3b, which can alternatively be mounted directly on the balance. These components each have a conventional shape, the pin 3a serving to pivot a first locking lever 5 via a fork 5a which the latter comprises. It is noted that it is also possible that the plate 3 is composed of several parts, for example in order to be able to adjust the angular position of one or the other of the pin 3a and of the impulse pallet 3b by compared to the plate 3, and this without influencing the position of the other.

Said fork 5a is well known in the context of the Swiss lever escapement. It cooperates with the pin 3a once alternately in order to move the first locking lever 5 from a first stable angular position (illustrated in FIG. 1), to a second stable angular position (illustrated in FIG. 2) during alternation of the balance in a first direction (clockwise according to the orientation shown in Figure 1) and in the other direction when the balance alternates in the other direction (counterclockwise according to the orientation of Figure 1). The extreme angular positions of the first locking lever are defined by conventional stops 17a, arranged on either side of an arm of said lever 5.

The first locking lever 5 comprises a pair of paddles 5b, 5c, which cooperate with a counting wheel 7, which is pivoted around a corresponding axis of rotation 7z and which is subjected to a torque tending to drive clockwise (according to the orientation in Figure 1) when the exhaust is working. When the first locking lever 5 is in its first angular position (see FIG. 1), the output pallet 5c blocks a tooth of the counting wheel 7, and, when said lever 5 is in its second angular position, the input pallet 5b in turn blocks another tooth of the counting wheel 7. By doing this, during each alternation of the balance wheel, the counting wheel 7 advances at the rate of half a step of its toothing, a whole step being carried out during a complete oscillation, which by definition consists of two successive alternations. Although the pallets 5a, 5b have been represented here as stone pallets fixed to the first locking lever 5, they can alternatively have come integrally with the latter. Indeed, the term "pallet" rather means a functional element integral with the lever 5 instead of a separate element attached to the latter, which also applies to any pallet mentioned in the present text.

To provide torque to ensure the advancement of the counting wheel 7, the exhaust mechanism 1 further comprises a charging assembly 9, which includes a wheel 9a in kinematic connection with the counting wheel 7 by means of a pinion 7a integral in rotation with the latter. Coaxial with said wheel 9a are a charging wheel 9c as well as an elastic element 9b, one of its ends of which is fixed to said wheel 9a and the other end of which is fixed to the charging wheel 9c. The wheel 9a can pivot relative to the recharging wheel 9c, and, when the mechanism 1 is at rest, the elastic element is subjected to a prestress. The counting wheel 7 is thus subjected to a torque at all times, this torque being supplied by the elastic element 9b and tending to drive the counting wheel 7 in its direction of rotation. Note that the elastic element 9b as shown is a spiral spring, but other shapes are also possible, such as, for example, a leaf spring or any other elastic element known to those skilled in the art.

In this embodiment, the recharging wheel 9c is driven by the impulse wheel 11, as explained below, and is prevented from pivoting in the wrong direction by a retention lever 13, whose angular positions extremes are defined by ad hoc stops 17b. This retention lever 13 comprises a blocking pallet 13a which, at rest, cooperates with a straight flank of a tooth which comprises the recharging wheel 9c. When the recharging wheel 9a is pivoted counterclockwise (relative to FIG. 1) by a tooth of the impulse wheel 11, the blocking pallet 13a is lifted by the curved side of the next tooth, as described below - below.

The impulse wheel 11 is pivoted about its own axis of rotation 11 z, and is driven by a driving source such as a barrel, the force arriving on its pinion 11a which is integral with it in rotation. This pinion 11a thus serves as a torque input for the mechanism 1.

The impulse wheel 11 comprises a plurality of impulse teeth 11b, arranged in two rows on two different levels of the impulse wheel 11, the teeth of one row being interposed angularly between those of the other with constant angular separations. These teeth cooperate with the impulse pallet 3b, which has a sufficient height to cooperate with the two rows. It should also be noted that an arrangement of the teeth 11b in a single plane is also possible, but the configuration chosen makes it possible to prevent angularly adjacent teeth inadvertently coming into contact with other elements, for example, during training. of the charging wheel 9c. For the surplus, the teeth can also be arranged in more than two rows on more than two different levels, the teeth of the refill wheel 9c being of course arranged to cooperate correctly with the rows of teeth of the impulse wheel.

The impulse wheel 11 is blocked by a second locking lever 15, which comprises a pair of paddles 15a and 15b arranged to block the teeth 11b of the impulse wheel 11 and to release them one by one when the locking lever 15 is moved from one of its stable angular positions to the other, in a conventional manner. In this embodiment, the second locking lever 15 therefore takes the form of an anchor, and the same comments, as above, in the context of pallets 5b and 5c, apply to pallets 15a and 15b.

The angular displacement of the second locking lever 15 to effect the release of the impulse wheel 11 is controlled by the counting wheel 7, which has a cam path 7b. The latter comprises sections with a smaller radius 7c and sections with a larger radius 7d, regularly distributed angularly. A cam follower 15c, in the form of a pin, is carried by an arm 15d of the second locking lever 15 and takes place in this cam path 7b. The latter is shaped to control the second locking lever 15 in order to release the impulse wheel once per n pendulum oscillations during the transition from a section with a smaller radius 7c to a section with a larger radius 7d, and vice versa. In the illustrated embodiment, n is three and, therefore, the radius of the cam track changes each three teeth of the counting wheel, but it can in principle change more or less frequently. Therefore, after the passage of three teeth (that is to say following 6 alternations of the balance), the second locking lever 15 changes angular position from one of its extreme positions to the other and l one of the teeth 11b of the pulse wheel 11 cooperates with the pulse paddle 3b in order to transmit a pulse to the oscillator. Alternatively, the counting wheel 7 may include a conventional cam, a cam follower carried by the second locking lever 15 being held in contact with said cam by an ad hoc elastic element. Again alternatively, the counting wheel 7 may include a cam with a constant radius, the second locking lever 15 having a fork, the two arms of which follow said cam.

Before being blocked again by one of the pallets 15a, 15b of the second locking lever 15, one of the teeth 11b of the impulse wheel cooperates with a tooth of the recharging wheel 9c in order to drive it at the rate of one step of its toothing, the latter also comprising two rows of teeth arranged in two different planes in order to be able to cooperate with the toothing in two rows of the impulse wheel. As a result, the retention lever 13 is lifted by the curved flank of a tooth, then falls back into the path of the next tooth under the effect of a return spring 13b in order to re-lock the charging wheel 9c.

In order to protect the retention lever 13 from shocks, it further comprises a safety pallet 13c, which takes place inside the impulse wheel 11. The latter has a plurality of stops 11c s extending from its serge in a direction parallel to the axis of rotation of the wheel 11. These stops 11c serve to prevent lifting of the retention lever 13 except when driving the charging wheel 9c. To this end, the stops 11c are arranged to block the safety pallet 13c, and interstices 11 d separating said stops 11c are positioned to allow the passage of the safety pallet 13c exclusively at the time of driving the charging wheel 9c. As a result, the retention lever 13 is prevented from inadvertently moving angularly, for example following an impact. Even if the stops 11c and the interstices 11 d have been illustrated as having come in one piece with the impulse wheel 11, they can also be defined by one (or even several) element (s) attached to it.

The construction and the general principle of operation of the exhaust of Figure 1 having been described, the phases of its operation will now be explained in more detail. Thereafter, only the reference signs mentioned in the text in the context of a particular figure will be reproduced on the figure in question.

FIG. 1 illustrates the positions of the components during a first alternation of the oscillator in the direction indicated. The counting wheel 7 is locked by the output pallet 5c of the first locking lever 5, which is in its first angular position. The plate 3 is pivoting clockwise (relative to FIG. 1) and the pin 3a has just entered the fork 5a of the first locking lever 5. The pin 15c of the second locking lever 15 is located at the start of a lower radius section of the cam track 7b and the impulse wheel 11 is blocked by the output pallet 15b of the second locking lever 15.

In Figure 2, the plate 3 has pivoted to the point where the first locking lever 5 has arrived in its second angular position after having rotated counterclockwise (relative to Figure 2). This change in angular position freed the counting wheel, which pivoted at the rate of half a pitch of its toothing under the effect of the elastic element 9b, and was again blocked by the entry pallet 5b of the first locking lever 5. The pin 15c of the second locking lever remains in the same lower radius section of the cam track 7b, and the rest of the mechanism thus remains in the same state. Figure 3 illustrates the situation during the next alternation, counterclockwise (relative to Figure 3), after actuation of the first locking lever 5 by the pin 3a. Again, the change in angular position of the first locking lever 5 from its second angular position to its first angular position releases the counting wheel 7 at the rate of another half a step under the effect of the elastic element 9b, the counting wheel 7 being locked again by the output pallet 5c of the first locking lever 5. In doing so, the pin 15c of the second locking lever remains in the same section with a lower radius of the cam path 7b, and the rest of the mechanism remains in the same state.

This cycle continues until the pin 15c reaches the end of the lower radius section of the cam path 7b, which takes place at the sixth alternation counted from the state illustrated in FIG. 1.

The moment when the counting wheel 7 is released during the sixth half-cycle is illustrated in FIG. 4.

The counting wheel 7 has pivoted and the pin 15c of the second locking lever 15 has just risen towards the next section of the cam path 7b, with an upper radius 7d.

This section transition rotated the second release lever 15, which raised its output pallet and released the impulse wheel.

In Figure 5, the pin 15c has completed its rise in the upper radius section 7d and the output pallet 5c of the first locking lever 5 has blocked the next tooth of the counting wheel 7, which has had the effect of arresting him.

Simultaneously, a tooth of the impulse wheel 11 catches up with the impulse paddle 3b and begins to give an impulse to the latter.

FIG. 6 illustrates the state of the components at the end of the pulse, just before the contact between the pulse paddle 3b and the corresponding tooth of the pulse wheel 11 is broken. At the same time, another tooth of the impulse wheel comes into contact with the right face of a tooth of the recharging wheel 9c, as indicated by the corresponding oval. FIG. 7 illustrates the state of the components when recharging the recharging wheel 9c. The tooth of the impulse wheel 11, which interacts at this time with the recharging wheel 9c, rotates the latter in a counterclockwise direction (relative to FIG. 7), which raises the elastic element 9b. During this training, the curved face of another tooth of the recharging wheel 9c comes into contact with the blocking pallet 13a. At this precise moment, the safety pallet 13c is opposite a gap 11 d between two stops 11c of the impulse wheel 11. The oscillator continues its course and no longer concerns us until the next half-wave.

FIG. 8 illustrates the state of the components a few moments after that described in FIG. 7. The blocking pallet 13a has reached the top of the tooth of the recharging wheel 9c and the safety pallet 13c has returned to the interstice 11 d, which allows sufficient angular displacement on the part of the retention lever 13 to perform this operation.

FIG. 9 illustrates the situation once the blocking pallet 13a has passed the top of the tooth of the recharging wheel 9c. The blocking pallet 13a as well as the retention lever 13, of which it is integral, fall back into their initial position under the effect of their return spring 13b. In doing so, the safety pallet 13c leaves the gap 11 d and the locking pallet 13a blocks the right face of the next tooth of the refill wheel 9c, stopping it again. The impulse wheel 11 remains free for the moment, and therefore continues to rotate clockwise (with respect to FIG. 9).

FIG. 10 illustrates the end of this phase of rotation of the impulse wheel 11, one of its teeth being brought into contact with the entry pallet 15a of the second locking lever 15.

Six oscillations of the oscillator later, the same pulse and recharging cycle is repeated, the second locking lever 15 permuting from its second angular position, as illustrated in FIG. 10, towards its first angular position, as illustrated in FIG. 1, when the cam follower 15c transitions from the section with an upper radius to the section with a lower radius of the cam path 7b. The system is thus returned to its starting position and the entire cycle is repeated. It is thus clear that, by modifying the shape of the cam path 7b, the manufacturer can modify the number of lost strokes of the exhaust. It can even arrange the escapement to give pulses asymmetrically, that is to say that the number of alternations counted can vary, for example according to a sequence of 4 vibrations, then 6 vibrations, then 4 vibrations, then 6 alternations, by acting on the respective angular lengths of the sections with a lower radius 7c and upper 7d.

Figures 11 to 13 illustrate a second embodiment of an escapement mechanism 1 according to the invention, from several angles. The operating principle of this embodiment remains substantially similar to that of the embodiment of Figures 1 to 10 and therefore only the structural and functional differences will be described later.

The second locking lever 15 of this embodiment takes the form of a trigger instead of an anchor and, for this purpose, has only one locking pallet 15a. The latter is held in engagement with the impulse wheel 11 by means of an elastic return element 15f, one end of which is fixed to a frame element (not illustrated), the other exerting a force on the lever 15. The extreme angular positions of the latter are again defined by ad hoc stops 17c. The impulse wheel 11, which has only a single row of teeth arranged in a single plane, is arranged to pivot counterclockwise (with respect to FIG. 11), but modifications to rotate it in the other senses are within the reach of the skilled person.

The second locking lever 15 is actuated by a plurality of cams 7f, integral in rotation with the counting wheel 7, which are arranged to raise the cam follower 15c, which is again carried by an arm 15d of the second locking lever 15, and is formed as an extension of the latter in the direction of the counting wheel 7. Once by n alternations (n being 6 here), one of the cams 7f, which here have the shape of a plurality of individual teeth, raises the second locking lever 15, which lets a tooth escape from the impulse wheel 11. The second locking lever 15 immediately falls under the effect of its elastic element 15f and the rotation of the impulse wheel 11, at the rate of one step, provides an impulse to the impulse paddle 3b clockwise (relative to the figure 11), through another of its teeth. Then, the pallet 15a blocks the impulse wheel 11.

In order to ensure that the second locking lever 15 is not inadvertently raised following an impact, the counting wheel 7 is provided with a plurality of stops 7g extending projecting from the wheel serge counting 7, these stops 7g being separated by interstices 7h. Again, these stops 7g extend parallel to the axis of rotation of the counting wheel 7. When the cam follower 15c is not facing a gap 7h, it is blocked by one of the stops 7g and the impulse wheel 11 cannot thus be released. On the other hand, when the cam follower 15c cooperates with one of the cams 7f of the counting wheel 7 to move the second locking lever 15 in order to release the impulse wheel 11, said follower 15c is opposite a gap 7h between two adjacent stops 7g, as shown more clearly in Figure 12. Therefore, the cam follower 15c is not blocked by the stops 7g and the second locking lever 15 is free to pivot enough to release the impulse wheel 11 and thus trigger a pulse.

In this embodiment, the recharging assembly 9 is simplified and mounted coaxial with the impulse wheel. For this purpose, the inner end of the elastic element 9b is integral in rotation with the impulse wheel 11, and no recharging wheel is present. Consequently, each time the impulse wheel 11 is released by the second locking lever 15, the elastic element 9b is simply raised by the rotation of the axis of the latter.

The operating cycle of this embodiment therefore follows similarly to that of the embodiment of Figures 1 to 10, mutatis mutandis. Figures 14 to 21 further illustrate an embodiment of an exhaust mechanism 1 according to the invention. Again, all of the reference signs do not appear on each figure. This embodiment will be explained with reference to its differences from that of FIGS. 11 to 13, with which it has the greatest similarities, in particular in view of the fact that the impulse wheel 11 is coaxial with the wheel 9a of the 'charging assembly 9 and that the second locking lever 15 again takes the form of a trigger having a single pallet 15a. The return force of the second locking lever 15 is provided by a leaf spring 15f, but other forms are possible.

However, in this embodiment the second locking lever 15 is not directly controlled by the cam path 7b integral in rotation with the counting wheel 7, but indirectly by means of an actuating lever 19, mounted in translation and in pivoting on a frame element not shown. This pivoting will be described below in the context of FIG. 17 and is limited by conventional stops 17a.

The actuating lever 19 has one end 19a, which is linked to the main body of said lever 19 by means of a blade 19f which has a certain flexibility, said end 19a being arranged to cooperate with a pallet d '3d actuation integral with the plate 3. The latter can take the form of a conventional pallet, a pin, a finger or any equivalent form. It may have come integrally with the plate 3 or may be an element attached to the latter. In the state shown in FIG. 14, just before the first release of the counting wheel 7 at the start of an operating cycle, the actuating lever 19 is in an inactive position and its end 19a is out of reach of the 3d actuation palette and therefore has no effect during oscillations of the oscillator. Note also that said end 19a is in a plane different from that of the impulse wheel 11, and we will return to this point below.

The translation of the actuating lever 19 is controlled by a control lever 21, pivotally mounted on a frame element (not shown). A first end of this lever 21 carries a cam follower 21a which takes place in said cam path 7b, the other end 21b being arranged to move the actuating lever 19 in translation in a direction along substantially the main axis of the latter. To this end, the control lever 21 carries a stud 21c which takes place with play in a slot 19d in the actuating lever, this slot 19d extending substantially perpendicular to said direction and to the main axis 19g of said lever. 19 (see Figure 22). Other configurations are of course possible. A screw 21 d, visible in FIGS. 14 and 20 exclusively, ensures that the control lever 21 and the actuation lever do not separate from each other.

The cam path 7b is shaped so that, during the four alternations of the balance wheel which follow, the follower 21a remains in a section with an upper radius 7d that comprises said cam path 7b. In doing so, the actuating lever 19 remains in its retracted position and its end does not cooperate with the actuating pallet.

FIG. 15 illustrates the situation just before the release of the counting wheel 7 during the fifth half-wave, at which time the cam follower 21a has reached the end of a section with an upper radius 7d of the cam path 7b.

The plate 3 continues to rotate counterclockwise (relative to Figure 15), raises the first locking lever 5 and releases the counting wheel 7, which advances at a rate of half a step under the effect of the elastic element 9b as discussed above in the context of the other embodiments.

Figures 16 and 17 illustrate in two views the state of the mechanism towards the end of said fifth alternation, the cam follower 21a having followed the cam path 7b to the bottom of a section with a smaller radius 7c. In doing so, the control lever 21 has pivoted clockwise (according to the orientation in FIG. 16), which has caused the actuation lever 19 to translate in the direction of the plate 3, as indicated by the arrows. The actuating 3d pallet has just lifted the end 19a of said rocker 19, without effect on the angular position of the body of the latter, thanks to the elasticity of the blade 19f which allows the end 19a to deviate when the 3d actuating pallet moves counterclockwise (also according to the orientation of figure 16). For the rest, it should be noted that this separation of the end 19a can occur in different directions, depending on the configuration and the shape of the components of the system "actuating pallet - actuating rocker - blade", in particular parallel to the 'axis of rotation of the plate, radially or a combination of the two. Modifications to the mechanism to allow spacing in these other directions are within the reach of those skilled in the art and therefore should not be described in detail here.

So that said translation is substantially rectilinear, the actuating lever 19 is guided by its two slots 19b, 19c, which extend substantially parallel to the main axis 19g (see FIG. 20) of the lever actuation 19. The first slot 19b houses a pin 15h which is integral with the second locking lever 15 at a point distant from its axis of rotation. The second slot 19c contains a stud 23 which is integral in translation with a frame element and which serves as a pivot axis for the second locking lever 15. Consequently, when the control lever 21 pivots as described above, the actuating lever 19 is moved in translation so that its end 19a enters the scope of the actuating pallet 3d. The actuating lever 19 is thus in an active position, in which it is capable of cooperating with the actuating paddle 3d to trigger the pulse as will be described later.

The alternation in progress continues, the plate 3 continuing its course counterclockwise (relative to FIG. 16).

During the next alternation, that is to say the sixth from the situation illustrated in FIG. 14, the actuating pallet 3d, moving clockwise (relative to FIG. 16) enters contact with the end 19a of the actuating lever 19, as illustrated in FIG. 18. The interaction between the actuating pallet 3d and the actuating lever 19 takes place before the pin 3a changes the angular position of the first locking lever 5. Since the end 19a is linked to the main body of the actuating lever 19 by means of the flexible blade 19f, the lever 19 also comprises a stop 19h, substantially rigid, against which the end 19a and / or the blade 19f abuts so that the actuating pallet 3d can act on the angular position of the assembly of the actuating lever 19 when it circulates in the clockwise from Figure 16 (but not the other way around as mentioned above).

As illustrated in FIG. 19, the 3d actuating pallet raises the end 19a of the actuating lever 19, which raises the second locking lever 15 thanks to the interaction between the first slot 19b and the 3 o'clock pin (see Figure 17).

The impulse wheel 11 is thus released, the impulse is triggered and one of the teeth of the impulse wheel 11 impulses the impulse paddle 3b counterclockwise (relative to the Figure 19) under the effect of the torque from the power source (not shown) as described above in the context of the other embodiments.

When the 3d actuating pallet exceeds the end 19a and consequently releases the actuating lever 19, the latter as well as the second locking lever 15 fall under the effect of the elastic element 15f, the pallet blocking 15a stopping and blocking the next tooth of the impulse wheel. This situation is illustrated in Figure 20.

Since the control lever 21 is still in the position of Figures 16 to 19, the actuating lever 19 is still in its active position. In order to prevent the impulse pallet 3b from abutting against the end 19a of said rocker 19, which would stop the oscillator, said pallet 3b includes a cutout 3f which avoids any contact between these two elements, the interaction between the impulse wheel 11 and said pallet 3b take place in a plane different from that of said cutout 3f.

Then, the pin 3a drives the first locking lever 5 counterclockwise (relative to FIG. 20), which releases and advances the wheel. counting 7 at the rate of half a step, the cam follower 21 a goes up towards the next section with a higher radius 7d. In doing so, the control lever 21 pivots counterclockwise (relative to FIG. 20), thereby removing the actuating lever 19 so that its end 19a is no longer within the range of the actuating pallet. 3d and the mechanism is thus found in the situation illustrated in FIG. 14. The operating cycle can thus start again.

By these means, again the counting wheel 7 controls the periodic release of the impulse wheel 1 1, even if the latter is triggered by the 3d actuation paddle. In other words, the position of the actuating lever 19 is controlled by the counting wheel 7 via the control lever 21, the active position of the actuating lever 19 authorizing the triggering of the pulse.

In order to prevent the actuating lever 19 from being displaced in the event of an impact and from entering into rotation and / or translation - when it must not be in the passage area of the 3d actuation paddle (between the 6 ^th and the 4 ^th next alternation) - stops 17a are provided in order to avoid untimely rotation of this rocker: indeed, this would have the effect of lifting the 2 ^nd lever lock 15 and release the wheel

momentum 1 1 at an unwanted time.

In addition, to prevent this rocker 19 from moving in translation in said zone, the cam follower 21a, being in the cam path 7b (therefore having an anti-shock effect), is prevented from moving

accidentally.

However, an arrangement of cams similar to that of the mode of

realization of Figures 1 1 to 13 is also possible, with an appropriate shockproof arrangement.

In addition, between the 5 ^th and 6 ^th ^half-waves , so that the pulse wheel 1 1 is not accidentally released in the event of an impact, the second locking lever 15 carries a finger 15 g, designed to abut against the around plate 3 when this second locking lever 15 is not authorized to rise. In order to authorize the release of the impulse wheel 11, exclusively when the plate 3 is in the correct orientation, a notch 3f is provided in the plate 3. When the finger 15g is located opposite said notch 3f (see Figures 18 and 19), the second locking lever 15 is authorized to rise in order to release the impulse wheel 11 in the event that an interaction between the actuating paddle 3d and the actuating lever 19 takes place.

Furthermore, other arrangements for guiding the rocker

of actuation 19 are of course possible, and the refill assembly 9 of the embodiment of Figures 1 to 10 can also be applied in this embodiment.

The technical effects obtained by these constructions are as follows.

Regarding the first locking lever 5, the forces generated during its interaction with the pin 3a are minimal and are generated in a "symmetrical" manner. As a result, the disturbance of the oscillator is minimized and is divided between the half-waves in the two directions of rotation instead of being concentrated in a single more significant disturbance, once per oscillation.

The fact that the counting wheel 7 is subjected to a torque by means of the elastic element 9b has the consequence of avoiding any use of a jumper or the like to retain the counting wheel 7, which is simply blocked by the pallets of the first locking lever 5 in a similar manner to a conventional anchor. For this purpose, a pull angle can be provided for the rest surfaces of the pallets 5b and 5c, in known manner. Therefore, the oscillator does not itself drive the counting wheel 7, as is the case in the document CH712052. The oscillator simply triggers the rotation of the counting wheel 7 under the effect of the elastic element 9b. It goes without saying that such a trigger requires significantly less force than a direct drive overcoming the effect of a jumper, and consequently the disturbances of the oscillator are minimized. Since the counting wheel 7 is driven by the elastic element 9b which is recharged at each step of the impulse wheel 11, said torque remains relatively constant and the resistance to disengagement of the first locking lever 5 also remains substantially constant and does not vary according to the winding state of the barrel spring of the movement in which the exhaust 1 is integrated.

Since the performance of this exhaust 1 is very good, we can increase the number of blows of the exhaust 1, that is to say by providing a pulse only once every two or three (or even more) of oscillations, the power reserve of the movement being thus improved compared to a conventional escapement since the impulse wheel 11 pivots less frequently. In addition, the disturbances of the oscillator due to pulses are also reduced by decreasing the pulse frequency, which increases the isochronism of the oscillator.

We also note that the escapement mechanism 1 according to the invention, in all its variants, is compatible with integration into a whirlpool system with one, two, or three axes of rotation.

As regards the materials which can be used to make the various components of the exhaust mechanism 1, these can be composed of "traditional" materials, such as metals and alloys (steel, brass, nickel, nickel phosphorus, ...), silicon-based materials (Si, SiOx, SiCx, SiNx, ...) in monocrystalline, polycrystalline or amorphous form, diamond, ruby, sapphire, corundum, glasses, ceramics, glass ceramics, polymers, composites etc. The components can be machined in a conventional way, but can also come from additive technologies such as LIGA, sintering, 3D printing etc. in various materials (eg epoxy or other polymeric material), depending on the material. In addition, coatings of different materials can be provided in the places requested to strengthen their resistance, reduce friction or the like (diamond, etc.). Although the invention has been particularly shown and described with reference to particular embodiments, other variants are possible without departing from the scope of the invention as defined in the claims.

For example, considering the embodiment of Figures 11 to 13, the second locking lever 15 may take the form of an anchor, like that of Figures 1 to 10, the cams 7f being replaced by a conventional cam or a cam track like that of FIGS. 1 to 10. The use of a cam track for the actuation of a second locking lever having the shape of an anchor will make it possible to remove the stops 7g on the wheel. counting 7 since such an arrangement is impact resistant.

Alternatively, a person skilled in the art can modify the arrangement of FIGS. 1 to 10 so that the second locking lever 15 only has a single locking pallet and thus acts as a trigger.

Furthermore, in the case where the escapement mechanism 1 is incorporated in a pendulum and is not subjected to impacts, the stops 11 c resp. 7g can be deleted, the safety pallet 13c of the embodiment of Figures 1 -10 can also be deleted.

Claims

claims

1. Escape mechanism (1) for a timepiece, intended to cooperate with an oscillator arranged to perform oscillations, said mechanism (1) comprising:

- a counting wheel (7) arranged to advance in rotation in steps as a function of the oscillations of said oscillator;

- a pulse wheel (11) intended to be in kinematic connection with a driving source, said pulse wheel (11) being arranged to be blocked and released periodically under the control of said counting wheel (7) and to provide pulses to said oscillator;

characterized in that:

- during operation of said exhaust mechanism (1), said counting wheel (7) is permanently subjected to a torque;

- Said counting wheel (7) is arranged to advance in rotation at the rate of half a step of its toothing by alternating said oscillator.

2. Mechanism (1) according to claim 1, further comprising a first locking lever (5) arranged to move between a first angular position and a second angular position during a first alternation of said oscillator, and to move between said second angular position and said first angular position during a second alternation of said oscillator, said locking lever (5) being arranged to block the rotation of said counting wheel (7) and to release the latter at the rate of half a pitch of its teeth during each of said changes in said first locking lever (5).

3. Mechanism (1) according to one of the preceding claims, further comprising a second locking lever (15) arranged to lock and to release said impulse wheel (11) according to the rotation of said counting wheel ( 7).

4. Mechanism (1) according to claim 3, wherein said second locking lever (15) is arranged to release said impulse wheel (11) at a rate of not at each n half-waves of said oscillator, n being a number greater than two.

5. Mechanism (1) according to one of claims 3 and 4, wherein said second locking lever (15) comprises a cam follower (15c) arranged to cooperate with at least one cam (7f) or at least one path cam (7b) integral in rotation with said counting wheel (7).

6. Mechanism (1) according to one of claims 2-5, wherein said second locking lever (15) comprises at least one pallet (15a, 15b) arranged to block and to release said impulse wheel (11) .

7. Mechanism (1) according to one of claims 3 and 4, wherein said second locking lever (15) comprises a single pallet (15a) arranged to lock and to release said impulse wheel (11), said second locking lever (15) being arranged to be lifted by an actuating lever (19) in order to release said impulse wheel (11), said actuating lever (19) being arranged to move in translation between a retracted position in which said actuating lever (19) is out of range of an actuating pallet (3d) integral in rotation with said oscillator, and an active position in which said actuating lever (19) is capable of cooperating with said actuating pallet (3d) for lifting said second locking lever (15), the state of said actuating lever (19) being determined as a function of the angular position of said counting wheel (7).

8. Mechanism (1) according to the preceding claim, wherein said actuating lever (19) is arranged to move between said active position and said retracted position under the effect of a control lever carrying a cam follower arranged for cooperate with a cam track or cams integral (s) in rotation with said counting wheel (7).

9. Mechanism (1) according to one of the preceding claims, in which said torque, to which said counting wheel (7) is subjected, is supplied by means of an elastic element (9b) arranged to be raised by said impulse wheel (11).

10. Mechanism (1) according to the preceding claim, wherein said elastic element (9b) is part of a refill assembly (9) comprising a wheel (9a) in kinematic connection with said counting wheel (7).

11. Mechanism (1) according to the preceding claim, wherein a first end of said elastic element (9b) is fixed to said wheel (9a) and a second end of said elastic element (9b) is rotationally secured to a charging wheel (9c) arranged to be rotated by a toothing which comprises said impulse wheel (11).

12. Mechanism (1) according to the preceding claim, wherein said charging wheel (9c) is arranged to be retained by a retention lever (13) arranged to block a rotation of said charging wheel (9c) in a first direction and to be lifted by a tooth of said recharging wheel (9c) when the latter pivots in a second direction opposite to said first direction.

13. Mechanism (1) according to the preceding claim, wherein said retention lever (13) is arranged to cooperate with a plurality of stops (11c) provided on said impulse wheel (11), said stops (11c) being arranged to prevent said retention lever (13) from disengaging, except when said charging wheel (9c) is being driven by said impulse wheel (1 1).

14. Mechanism (1) according to the preceding claim, wherein said impulse wheel (11) and said recharging wheel (9c) each have a plurality of teeth distributed between at least two different planes.

15. Mechanism (1) according to claim 9, wherein a first end of said elastic element (9b) is integral in rotation with said impulse wheel (1 1), a second end of said elastic element being integral in rotation with a wheel (9a) in kinematic connection with said counting wheel (7).

16. Mechanism (1) according to claims 6 and 15, wherein said second locking lever (15) comprises a single locking pallet (15a) arranged to block the impulse wheel as well as a cam follower (15c) arranged to cooperate with at least one cam (7f) which comprises said counting wheel (7), said counting wheel (7) comprising a plurality of stops (7g) arranged to prevent said second locking lever (15) from releasing said impulse wheel (1 1), except when said cam follower (15c) is being actuated by said at least one cam (7f).

17. Mechanism (1) according to one of the preceding claims, in which said impulse wheel (1 1) and said counting wheel (7) are each pivoted on a respective axis of rotation (1 1 z, 7z), these said axes (1 1 z, 7z) being distinct from each other.

18. Clock movement comprising a mechanism (1) according to one of the preceding claims as well as an oscillator arranged to cooperate with said mechanism.

19. Timepiece comprising a movement according to the preceding claim.