EP2784603B1 - Device for displaying time information - Google Patents

Description

The invention relates to a device for displaying a temporal information with the aid of an indicator member for a timepiece.

In some display devices, called "retrograde", the display is non-circular. Instead of performing a complete revolution, the indicator organ travels from a starting point A to an arrival point B in front of a graduation representing a quantity related to time. Once the path from A to B is achieved, the indicator organ returns back to point A instantaneously. This type of display can be used for any type of size related to time, such as seconds, minutes, hours, days, weekdays or moon phases.

A retrograde display device generally comprises a cam in the form of spiral or spiral, whose profile has an abrupt flank. A lever is supported against the cam via a probe. A return spring ensures the support of the lever against the cam. The lever is provided with a rake, or toothed portion, adapted to mesh and drive a drive gear of the indicator member.

In normal operation (that is to say in the display phase of the magnitude related to time), the rotation of the cam in a first direction corresponding to the chronological direction, or hourly, causes the driving of the indicator member from its starting position A, in which the probe is in a low position down the side of the cam, to its arrival position B, in which the probe is in the up position at the top of the side of the cam. Once the high position is reached, the cam continues to rotate. The probe then moves from its high position to its low position instantaneously, causing the indicator member to return to the starting position A.

The presence of this abrupt flank poses a problem when it is desired to correct the temporal information "in reverse" (that is to say in the anti-chronological or anti-clockwise direction). Indeed, when the probe arrives at the bottom of the abrupt flank, it induces a blockage or even breakage of the elements. This type of correction must be prohibited.

The document EP1918792 discloses a timepiece provided with a conventional retrograde display device having a spiral-shaped cam and a retrograde display lever in contact with the cam profile via a feeler. The display lever controls an indicator hand of a time size. A disengagement device is added to the display device. In the correction phase including rear, the disengagement device allows to move the probe from the retrograde display lever of the path of the cam. Thus, in the rearward correction phase, the indicator needle is in a predetermined position and indicates no value of the time value. The disengagement device thus makes it possible at any time to perform a bidirectional correction of the display of the time value. However, during adjustment, the correction made is not visible to the user, which may lead to adjustment errors of the timepiece. In addition, the disengaging device requires a large number of components that are added to the conventional mechanism.

The document CH331410 discloses the preamble of claim 1.

The object of the invention is to provide a device that overcomes the drawbacks mentioned above and improves the devices known from the prior art. In particular, the invention proposes a simple, reliable and robust device allowing a rearward correction of a retrograde system.

For this purpose, the invention relates to a display device according to claim 1.

The invention thus originates from a problem of retrograde display device. However, the applicant intends not to limit the scope of his application to this particular example of application, but to extend it to any type of display device comprising a cam with at least one sidewall and a control probe intended to raise this sidewall. .

When raising the flank by the probe, the cam flank exerts on the probe a force of action. This action force has the effect of acting on the probe so as to move relative to the lever, against the return action of the second elastic means, and thus to avoid damaging the mechanism. In other words, the invention provides for interposing second elastic means between the feeler and the lever so as to allow a displacement relative of the probe relative to the lever during the ascent of the sidewall. These second elastic means are of course distinct from the first elastic means which are arranged to bias the lever so as to bear against the cam via the probe. During the relative movement of the probe relative to the lever, the probe approaches the lever and thus retracts against the return action of the second elastic means.

Advantageously, the action force exerted by the sidewall of the cam on the probe during the passage of the sidewall in the second direction of movement of the cam acts to cause immobilization of the lever.

Thus, when the flank is raised by the probe, the action force exerted by the cam flank on the probe produces a second effect: this force acts on the lever to cause immobilization thereof.

Advantageously, the action force acts on the lever to cause a pivoting effect thereof against a stop.

Thus, the action force of the sidewall on the probe produces a pivoting effect of the lever. This pivoting takes place against a stop, which causes a stable immobilization of the lever.

In a particular embodiment, the lever being adapted to pivot about a pivot point, the action force passes substantially through said pivot point of the lever. In this case, and advantageously, the drive lever comprising a drive arm of the indicator member, an angle of action, formed by the action force of the cam on the probe and the segment connecting the point of contact of the probe and the cam flank and the pivot point of the lever is located in the half-plane defined by the line containing said segment and not containing the drive arm of the lever.

The line containing the point of contact between the probe and the cam and the pivot point of the lever defines two half-planes, one containing the lever drive arm, the other not containing said arm. The positioning of the angle of action in the half-plane not containing the lever arm has the effect of ensuring a force tending to pivot the lever arm in the correct direction to immobilize it against the stop.

In a particular embodiment, said angle of action is between 0 and 180 °.

• d'une part, elle immobilise le levier en bas du flanc de came, en fin de descente du flanc par le palpeur, lors du déplacement de la came dans le premier sens ;
• d'autre part, elle immobilise le levier, lors de la remontée du flanc par le palpeur, lors du déplacement de la came dans le deuxième sens.

Thus, the stop has a dual role:

• on the one hand, it immobilizes the lever at the bottom of the cam flank at the end of the descent of the sidewall by the feeler, during the displacement of the cam in the first direction;
• on the other hand, it immobilizes the lever, during the ascent of the flank by the probe, during the displacement of the cam in the second direction.

The invention thus uses, in a clever way, the stop immobilizing the lever at the end of descent of the sidewall to also immobilize the lever during the ascent of the sidewall.

In a particular embodiment, said stop is arranged to immobilize the lever, during the displacement of the cam in the first direction, when the probe reaches the bottom of the sidewall.

The probe head is thus shaped to ensure continuous contact between the probe and the cam flank, during the entire movement of the probe along the cam flank, during the ascent of the cam flank.

The geometry of the probe is advantageously adapted so that there is no contact between the probe tip and the sidewall when the probe passes from the top of the cam flank to the bottom of the cam flank.

In another embodiment, the probe includes a head flange shaped to provide continuous contact between the probe flank and the upper end of the cam flank (i.e., the end at the cam portion of larger radius), during the ascent of the cam flank by the probe.

• par ladite pointe de tête de palpeur avec le flanc de la came, et
• par le flanc de la tête de palpeur avec au moins une portion de profil de came en colimaçon.

Advantageously, the cam having a spiral profile, the probe comprises a head having a contact tip and a contact flank and is adapted to be in contact:

• by said tip of probe head with the side of the cam, and
• by the side of the probe head with at least a portion of a spiral cam profile.

Advantageously, the probe is pivotally mounted on the lever.

With this, the probe can rotate relative to the lever without bending.

Advantageously, an angle formed by the normal to the cam in contact between the feeler and the cam flank and the half-line originating from said contact and passing through the point of pivoting of the probe is greater than the angle formed by the normal to the contact between the probe and the cam flank and the reaction force exerted by the probe on the sidewall. When moving the cam in the first direction, which corresponds to the normal operation of the display device, the second elastic means are slightly deformed due to the action of the cam on the probe. This deformation induces an offset in the display of the temporal information with respect to a display that would be produced by an assembly comprising a probe mounted rigidly on a lever. This offset is compensated by an adaptation of the cam profile. The modified cam profile, adapted, allows to simulate a perfectly rigid set and produces a perfectly exact display.

In a particular embodiment, the displacement of the cam in the first direction causes a prestressing of the second resilient means, which is compensated by a shaped cam profile to ensure an accurate display of the time information.

In a first exemplary embodiment, the second resilient means comprise a flexible blade. With this, the number of components is minimized and the size of the mechanism is reduced. In addition, this avoids any balancing faults that may appear in an assembled lever.

Advantageously, the lever, the second elastic means and the probe are made in one piece. Advantageously, the lever is secured to a toothed portion adapted to cooperate with the toothing of a drive pinion of the indicator member.

The toothed part may comprise teeth to catch play.

The teeth clearance play allows to minimize display errors. It still helps to limit shocks and mitigate the effects of inertia when the time indication element suddenly returns to its initial position.

The lever can be manufactured with one of the materials of the group comprising Ni, NiP and Si.

The invention also relates to a watch movement comprising a display device defined above.

The invention also relates to a timepiece integrating the display device defined above or the watch movement defined above.

The timepiece may comprise a basic movement and a display device defined above, the cam of the display device being driven by the base movement.

• la figure 1 représente le dispositif d'affichage de l'invention, selon un premier exemple de réalisation, pour un affichage rétrograde de l'heure entre 0h et 24h (minuit) ;
• la figure 2A représente le dispositif d'affichage de la figure 1 à 22h ;
• la figure 2B représente une vue de détail d'un ensemble palpeur et came de la figure 2A ;
• la figure 3A représente le dispositif d'affichage de la figure 1 juste avant minuit ;
• la figure 3B représente une vue de détail de l'ensemble palpeur et came de la figure 3A ;
• la figure 4A représente le dispositif d'affichage de la figure 1 à minuit ;
• la figure 4B représente une vue de détail de l'ensemble palpeur et came de la figure 4A ;
• la figure 5 représente le dispositif d'affichage de la figure 1 lors de la remontée d'un flanc de came par le palpeur ;
• les figures 6A et 6B représentent le dispositif d'affichage de la figure 1 juste après la remontée du flanc de came ;
• la figure 7A représente le dispositif d'affichage de la figure 1 lors de la remontée d'un flanc de came par le palpeur, avec la force de réaction du palpeur sur la came ;
• la figure 7B représente le dispositif d'affichage de la figure 1 à la fin de la remontée d'un flanc de came par le palpeur, lorsque celui-ci atteint le sommet de came, avec la force de réaction du palpeur sur la came ;
• la figure 7C représente le dispositif d'affichage de la figure 1 lors de la remontée d'un flanc de came par le palpeur, avec la force d'action de la came sur le palpeur ;
• les figures 8A et 8B représentent les zones fonctionnelles du palpeur en contact avec la came, lors du fonctionnement conventionnel du dispositif d'affichage de la figure 1 ;
• la figure 9 représente un profil de came adapté du dispositif de la figure 1 et un profil de came initiale ;
• la figure 10 représente un deuxième exemple de réalisation d'une partie du dispositif d'affichage de l'invention ;
• la figure 11 représente un troisième exemple de réalisation d'une partie du dispositif d'affichage de l'invention.

The invention will be better understood with the aid of the following description of several particular embodiments of the display device of the invention, with reference to the appended drawings in which:

• the figure 1 represents the display device of the invention, according to a first exemplary embodiment, for a retrograde display of the time between 0h and 24h (midnight);
• the Figure 2A represents the display device of the figure 1 at 22h;
• the Figure 2B represents a detailed view of a probe and cam assembly of the Figure 2A ;
• the figure 3A represents the display device of the figure 1 just before midnight;
• the figure 3B represents a detailed view of the probe and cam assembly of the figure 3A ;
• the Figure 4A represents the display device of the figure 1 at midnight ;
• the Figure 4B represents a detailed view of the probe and cam assembly of the Figure 4A ;
• the figure 5 represents the display device of the figure 1 during the ascent of a cam flank by the probe;
• the Figures 6A and 6B represent the display device of the figure 1 just after raising the cam flank;
• the Figure 7A represents the display device of the figure 1 during the raising of a cam flank by the probe, with the reaction force of the probe on the cam;
• the Figure 7B represents the display device of the figure 1 at the end of the raising of a cam flank by the probe, when it reaches the cam, with the reaction force of the probe on the cam;
• the Figure 7C represents the display device of the figure 1 during the raising of a cam flank by the probe, with the force of action of the cam on the probe;
• the Figures 8A and 8B represent the functional areas of the probe in contact with the cam, during the conventional operation of the display device of the figure 1 ;
• the figure 9 represents a cam profile adapted from the device of the figure 1 and an initial cam profile;
• the figure 10 represents a second embodiment of a part of the display device of the invention;
• the figure 11 represents a third embodiment of a part of the display device of the invention.

For the sake of clarity, it will be noted that the corresponding elements shown in different figures bear the same references, unless otherwise indicated.

A first embodiment of the display device according to the invention is represented on the figure 1 showing an embodiment of a timepiece 300 according to the invention. The timepiece comprises a watch movement 200. The watch movement comprises the display device 100. This display device is intended to be integrated into a watch movement of a timepiece.

The display device 100 of the figure 1 is intended to drive an indicator member 1, here an indicator pointer, of a magnitude related to time (or time information). Needle 1 appears in particular on Figures 2A , 3A and 4A . In the particular example shown in these figures, the magnitude related to time is the time shown on a 24-hour scale placed on an angular arc of 180 °. The forward path of the needle 1, in the time display phase, goes from a "0h" position to a "24h" position. The needle 1 is intended to make an instant return trip from the "24h" position to the "0h" position at midnight.

The invention could of course be applied to any type of magnitude related to time (seconds, minutes, calendars, days of weeks, moon phases, etc.), to a retrograde display represented on any angular arc and to a non-retrograde display, as will be explained in more detail at the end of the description.

With reference to the figure 1 , the display device comprises a cam 2, a probe 3 and a lever 4.

The cam 2 is in the form of a spiral, with a spiral profile and mounted on an axis 20 rotating about a point of rotation 21. The spiral profile of the cam 2 is referenced 24. The cam 2 is kinematically linked to a basic movement of the timepiece through a wheel 22 meshing with a drive wheel 8, for example driving a needle 80 for circular hour indication, as shown in the Figures 2A , 3A and 4A . The profile 24 of the cam 2, in a plane perpendicular to its axis of rotation 21, corresponds, at least substantially, to a spiral portion of Archimedes. The cam 2 has a flank 23 connecting the cam portion of smaller radius and the cam portion of larger radius. In normal operation (that is to say during a time display phase), the flank 23 has the role of ensuring the return to the initial position "0h" of the indicator hand 1, once the final position "24h" reached.

The lever 4 comprises an arm 40, a toothed portion 41 and a counterweight portion 42. The lever 4 is pivotally mounted on an axis 43, about a pivot point 44. The pivot axis 43 of the lever 4 and the axis of rotation 20 of the cam 2 are fixed relative to each other.

The toothed portion 41 is integral with the end of the arm 40, opposite the axis 43. It meshes with the toothing of a pinion 10 driving the needle 1. In other words, the lever 4 carries the toothed portion 41 intended to cooperate with the driving pinion of the indicator organ. In the particular example described here, the toothed portion 41 and / or the pinion 10 may have a clearance toothing 45 in order to minimize the display errors of the indication provided by the display device. An example of teeth with catch-up play, usable in the invention, is disclosed in particular in the document EP2112567 . The Figures 10 and 11 are examples of embodiments of teeth 45 to play clearance. The teeth are arranged so that teeth mesh in the "0h" and "24h" positions.

The counterweight portion 42 has a generally semicircular shape and is located on the side of the pivot axis 43 opposite the arm 40. The counterweight 42 is adapted to coincide, at least substantially, the center of mass of the lever 4 and its point of contact. pivoting 44.

The probe 3 comprises an arm 30 and a head 31.

The arm 30 extends along a longitudinal axis AX1, shown in FIG. figure 1 , in the vicinity and generally along the arm 40. It comprises two ends 33, 34 respectively close to the counterweight portion 42 of the lever 4 and the toothed portion 41. The end 34 and the end 33 are respectively integral with the arm 40 and a flexible blade 5. The arm 30 is pivoted on the lever 4 at a pivot point 32, located near the connection between the arm 30 and the lever 4. Note γ the angle, represented on the figure 1 formed by the longitudinal axis AX1 of the arm 30 and the segment connecting the pivot point 32 of the probe 3 and the pivot point 44 of the lever 4.

The flexible blade 5 is curved and has, with the arm 30, an S shape. The end of the blade 5 opposite to that integral with the arm 30 is integral with the counterweight portion 42. The flexible blade acts as a spring recall 5, interposed between the probe 5 and the lever 4, against the action of which the probe 3 is arranged to rotate under the action of the cam 2, as will be explained in the description of operation.

• l'angle θ₂ est de l'ordre de 90° ;
• l'angle θ₁ est de l'ordre de 130°.

The head 31 has a triangular profile (perpendicular to the axes of rotation 20 and 43) forming a contact tip 312. It comprises a first flank 310, located on the side of the end 33, and a second flank 311, located on the the end 34. Note θ ₁ the angle formed by the flank 310 and the axis AX1 and θ ₂ the angle formed by the flank 311 and the axis AX1, as represented on the figure 1 . The angle θ ₁ is here obtuse and the angle θ ₂ is preferably orthogonal or acute. In the particular example shown on the figure 1 :

• the angle θ ₂ is of the order of 90 °;
• the angle θ ₁ is of the order of 130 °.

It is emphasized here that the shape of the probe head, as represented on the figure 1 in particular, is only an illustrative embodiment, non-limiting. In any case, the probe head has a shape adapted to ensure proper operation.

The probe head 31 is adapted to be in contact with the cam 2 either by the flank 310 or by the tip 312, as shown in FIGS. Figures 8A and 8B . The contact flank 310 is intended to come into contact with a cam portion, close to the cam top (that is to say from the top of the flank 3, having a maximum cam radius), after the ascent or before the descent of the cam flank 23 by the probe 3, as will be explained later. The contact tip 312 is intended to be in contact with the rest of the cam profile 24, in particular the sidewall 23.

In the particular embodiment shown on the Figures 8A and 8B , the tangent T ₁ to the cam flank 23 passing through the upper end of this flank 23 (that is to say the end of the flank 23 located near the cam portion of greater radius) and the tangent T ₂ to the cam profile 24 at the low end point of this profile 24 (i.e. at the point of the smaller radius cam profile 24, at the bottom of the cam flank 23) form a space delimited by an angle δ and within which the probe head 31 can romp. The angle δ is preferentially obtuse. In the particular example shown on the Figures 8A and 8B this angle δ is at least of the order of 100 °.

• par photolithographie et électroformage avec l'un des matériaux du groupe comprenant du Ni (Nickel), NiP (Nickel Phosphore) et Si (Silicium) ;
• par photolithographie et gravure profonde avec du silicium (Si)

In the particular embodiment shown on the figure 1 , the lever 4 and the probe 3 are made in one piece. They can be manufactured by any of the following techniques:

• by photolithography and electroforming with one of the materials of the group consisting of Ni (Nickel), NiP (Nickel Phosphorus) and Si (Silicon);
• by photolithography and deep etching with silicon (Si)

A return spring 6, distinct from the spring 5 interposed between the lever 4 and the probe 3, acts on the lever 4, here at the toothed portion 41, to ensure the support of the probe 3 against the cam 2. The spring 6 is arranged to urge the lever 4 so as to support the lever 4 against the cam 2 by means of the feeler 3 and thus provide a support of the probe 3 against the cam 2.

• elle est agencée pour immobiliser le levier 4, quand le palpeur 3 est en bas du flanc 23, lorsque la came 2 est entraînée dans un premier sens, correspondant au sens horaire ;
• elle est agencée pour immobiliser le levier 4, pendant la remontée du flanc 23 par le palpeur 3, lorsque la came 2 est entraînée en rotation dans un deuxième sens, correspondant au sens anti-horaire, et agit de manière à faire pivoter le levier 4 à l'encontre de la butée 7.

The display device also comprises a stop 7, schematically represented in the figures, having a dual role:

• it is arranged to immobilize the lever 4, when the probe 3 is at the bottom of the flank 23, when the cam 2 is driven in a first direction, corresponding to the clockwise direction;
• it is arranged to immobilize the lever 4, during the ascent of the flank 23 by the feeler 3, when the cam 2 is rotated in a second direction, corresponding to the anti-clockwise direction, and acts to rotate the lever 4 against the stop 7.

We will now describe with reference to FIGS. 2A to 7C the operation of the display device, during normal operation, on the one hand, and in the correction phase in reverse or "anti-clockwise", on the other hand.

Normal running :

The normal operation corresponds to the conventional display in the clockwise or chronological direction, of a temporal information, here the hour on a scale of 24h arranged on an angular arc of 180 °. It will be described with reference to Figures 2A-2B , 3A-3B , 4A-4B .

It is recalled that this is a particular illustrative example and that the invention applies to the display of any other size related to time (day-night indication, minutes, seconds, dates, weekdays, etc ...).

• remonte le profil de came 24 en spirale, depuis sa position basse, en bas du flanc 23, à sa position haute, en haut du flanc 23 (c'est-à-dire au sommet de la came 2);
• puis passe du sommet de la came 2, en haut du flanc de came 23, au bas du flanc de came 23.

In normal operation, the cam 2 is rotated in a first direction, called "forward" or "normal operation", here the trigonometric or counterclockwise direction. The probe head 31, bearing against the cam 2 under the spring return action 6, controls a pivoting of the lever 4 in the antitrigonometric direction, which itself drives the needle 1 moving in the trigonometric direction here. During the rotation of the cam 2 in the trigonometrical direction, the probe head 31:

• raises the cam profile 24 in a spiral, from its low position, down the flank 23, to its upper position, at the top of the flank 23 (that is to say at the top of the cam 2);
• then passes from the top of the cam 2, at the top of the cam flank 23, to the bottom of the cam flank 23.

The shape of the probe head 31 is adapted to avoid any contact between the tip 312 of the probe head 31 and the cam flank 23 during the passage of the probe head 31 from the top of the cam 2 to the bottom of the flank of FIG. cam 23.

The raising of the cam profile 24 by the probe head 31 causes a displacement of the needle 1 from the "0h" position to the "24h" position in a rotational movement of 180 ° in the trigonometrical direction. The passage from the top of the cam 2, at the top of the cam flank 23, to the bottom of the cam flank 23 causes instantaneous return of the needle 1 to the "0h" position.

The Figures 2A , 3A and 4A represent the display device respectively at different times, namely 22h, just before midnight and just after midnight, during normal operation. A circular dial with hands 80, 81 for indicating the hours and minutes of the basic movement of the timepiece is also shown.

The Figure 2A represents the display device at 22h. The lever 4 is pivoted so as to position the needle 1 in front of the indication "22h" of the graduation. The Figure 2B represents an enlargement of the cam 2 and the probe head 31 in this position "22h". It will be noted that the head 31 is in contact with the upper part of the cam 2 by its side 310.

The figure 3A represents the display device at midnight (24h), when the probe head 31 reaches the high position of the cam 2, at the top of the flank 23, just before the passage from the top of the cam flank 23 to the bottom of the cam flank 23 by the head 31 of the probe 3. The figure 3B represents an enlargement of the cam 2 and probe head 31 in the "midnight" position. In this position, the needle 1 indicates "24h". The head 31 of the probe 3 bears against the top of the cam 2 by the contact tip 312.

The Figure 4A represents the display device just after midnight, the needle 1 indicating "0h". This position is reached just after the passage from the top of the cam flank 23 to the bottom of the cam flank 23 by the feeler head 31. Figure 4B represents an enlargement of the cam 2 and the probe head 31 in the "0h" position. During the descent of the cam flank 23, under the control of the probe 3, the lever 4 pivots in the trigonometric direction until it bears and stops against the stop 7. The pivoting of the lever 4 causes a return back snapshot of the needle 1 from the "24h" position to the "0h" position, by rotation in the antitrigonometric direction.

The return spring 5 is dimensioned so as to be as rigid as possible during the rotation of the cam 2 in the forward direction (trigonometric direction in the particular example described). However, this rigidity is limited by the stresses within the material and the allowable torque to the cam 2 during a correction of the time in reverse. Indeed, it is not necessary that the rigidity of the spring 5 is too important, because it would result in significant efforts to allow the passage of the flank 23. As a result, during the rotation of the cam 2 in the direction of travel before, in normal operation, the return spring 5 undergoes a prestressing and is slightly deformed under the action of the cam 2 on the probe 3. This preload and this deformation depend on the action exerted by the spring 6 recalling the lever to the stop 7. In addition, this action itself depends on the position of the lever relative to the stop. This deformation induces a time shift in the display of the needle 1 relative to the display of a needle connected to a mechanism comprising a probe mounted rigidly on a lever. This time difference is quantifiable and corresponds to a given duration, for example 1h. It is compensated by an adaptation of the cam profile 24. In other words, the cam profile 24 is adapted, modified with respect to a cam profile, said "initial", 25 operating with a similar mechanism (feeler, spring and lever) that would be perfectly rigid. The figure 9 represents the initial cam profile 25 and the cam profile 24 of the display device of the figure 1 . The two cam profiles 24, 25 substantially correspond to an Archimedean spiral.

Operation during correction phase in reverse :

A correction in reverse is to correct the display counterclockwise or anti-chronologically. Operation in the reverse correction phase will be described with reference to Figures 5 to 7C .

To correct the display in reverse, the cam 2 is rotated in a second direction, called "reverse", anti-trigonometric.

Under the control of the probe 3 bearing against the cam 2, the lever 4 drives the needle 1 in rotation in the anti-trigonometric direction.

During the path of the probe 3 along the cam profile 24 from the top of the cam 2 to the bottom of the cam flank 23, the needle 1 moves from the "24h" position to the "0h" position. When the needle 1 is in the "0h" position, the cam follower 31 is positioned at the bottom of the cam flank 23 and the lever 4 bears against the stop 7.

• elle agit, d'une part, pour faire pivoter le palpeur 3 autour du point 32 par rapport au levier 40, ce qui provoque une rétractation du palpeur 3, c'est-à-dire un rapprochement du palpeur 3 vers le bras de levier 40, contre l'action de rappel du ressort 5 qui se comprime ;
• elle agit, d'autre part, pour entraîner en pivotement le levier 4, à l'encontre de la butée 7, ce qui provoque une immobilisation du levier 4.

Once the bottom position of the cam flank 23 is reached, the probe head 31 moves up the cam flank 23, the head 31 being in contact with the flank 23 by its point 312. figure 5 represents the display device during the ascent of the flank 23. During the ascent of the cam flank 23, it exerts an action force noted F on the probe head 31, as represented on the Figure 7C . We notice F 'The reaction force exerted by the head of probe 31 on the side of cam 23. This action force F , or reaction F ', produces two effects:

• it acts, on the one hand, to rotate the probe 3 around the point 32 relative to the lever 40, which causes a retraction of the probe 3, that is to say a closer of the probe 3 to the lever arm 40, against the return action of the spring 5 which is compressed;
• it acts, on the other hand, to pivot the lever 4, against the stop 7, which causes a immobilization of the lever 4.

So the force of action F acts to bring the probe 3 of the arm 40 of the drive lever 4, and thus retract the probe 3, against the return action of the spring 5 interposed between the probe 3 and the lever 4. The retraction of the probe 3, here by pivoting about the point of pivoting 32, allows a rise of the sidewall 23 without damaging the mechanism.

The immobilization of the lever 4 during the ascent of the flank 23 allows immobilization of the needle 1 and prevents any erroneous indication of the needle 1 during the ascent of the flank 23.

Once the top of the flank 23 has been reached, the needle 1 is instantaneously in a synchronized display position with the position of the main hands 30 and 40 of the hours and minutes, as shown in FIGS. Figures 6A and 6B .

The stop 7 serves, during normal operation, to immobilize the lever 4 at the end of descent of the sidewall 23 and thus to immobilize the needle in position "0h" just after midnight, after its return "retrograde" from the position "24h" . In addition, during the ascent of the sidewall 23 during correction phase in reverse, the stop 7 also serves to stably immobilize the lever 4 and thus immobilize the needle 1 in the "0h" position. Thanks to this, the needle 1 is perfectly stable during the ascent of the flank 23.

The Figures 7A to 7C represent the force vector F action of the cam flank 23 on the probe head 31 and the force vector F of the probe tip 312 on the flank 23 during the raising of the flank 23 by the probe head 31. The point C represents the point of contact between the probe head 31 and the flank 23. The vector not represents the normal to flank 23 at point of contact C.

• la force de réaction F ',
• le vecteur n ,
• le segment [C32] reliant le point de contact C et le point de pivotement 32 du palpeur 3,
• l'angle, noté α, formé par la normale n et le segment [C32] reliant le point de contact C et le point de pivotement 32
• l'angle, noté Atan(µ), formé par la normale n et la force de réaction F ', correspondant à l'arc-tangente du coefficient de frottement µ entre la pointe 312 de tête de palpeur 31 et le flanc de came 23.

The Figures 7A and 7B represent, respectively, during the ascent of the flank 23 and at the end of the ascent of the flank 23 (when the probe tip 312 reaches the top of the cam 2):

• the reaction force F '
• the vector not ,
• the segment [C32] connecting the contact point C and the pivot point 32 of the probe 3,
• the angle, denoted α, formed by the normal not and the segment [C32] connecting the point of contact C and the pivot point 32
• the angle, noted Atan (μ), formed by the normal not and the reaction force F ', corresponding to the arc tangent of the coefficient of friction μ between the tip 312 of the probe head 31 and the cam flank 23.

The angle α varies during the ascent of the flank 23 by the probe tip 312. The pivot point 32 is defined in such a way that this angle α is greater than the angle Atan (μ), during the entire ascent of the flank 23 by the probe head 31. The moment when the angle α is the smallest and tends towards the angle Atan (μ) corresponds to the moment when the point 312 reaches the top of cam 2 (in other words the top of the sidewall 23) , as shown on the Figure 7B . The pivot point 32 is thus determined so that at the moment when the tip 312 reaches the top of the cam 2, the angle α is greater than the angle Atan (μ) and thus allows the probe 3 to pivot relative to the lever 4. It will be noted, with reference to the Figure 7B , that when the probe tip 312 reaches the top of the cam 2, the compression of the return spring 5 is maximum.

• le point de contact C,
• la force d'action F ,
• le segment [C44] entre le point de contact C et le point de pivotement 44 du levier 4,
• le segment [44-32] entre le point de pivotement 44 du levier 4 et le point de pivotement 32 du palpeur 3,
• l'angle orienté, noté β, formé entre la force d'action F et le segment [C44], avec $\mathrm{\beta }=\left(\overrightarrow{F},\left[\mathrm{<figure-callout\; id="44"\; label="C"\; filenames="imgf0001.png,imgf0007.png"\; state="\{\{state\}\}">C</figure-callout>}44\right]\right),$
  
  ou la droite contenant ce segment.

The Figure 7C represent :

• the point of contact C,
• the force of action F ,
• the segment [C44] between the point of contact C and the pivot point 44 of the lever 4,
• the segment [44-32] between the pivot point 44 of the lever 4 and the pivot point 32 of the probe 3,
• the oriented angle, denoted β, formed between the action force F and the segment [C44], with $\mathrm{\beta }=\left(\overrightarrow{\mathrm{<figure-callout\; id="44"\; label="F\; \to \; VS"\; filenames="imgf0001.png,imgf0007.png"\; state="\{\{state\}\}">F\; </figure-callout>}},\left[\mathrm{VS}\right],\left[\mathrm{}44\right]\right),$
  
  or the line containing this segment.

The pivot point 44 of the lever 4 is defined in such a way that the action force F immobilizes the lever 4 or causes a pivoting of the lever 4, here in the counterclockwise direction, against the stop 7, which has the effect of to immobilize the lever 4. For this purpose, the angle β, defined by the vectors F and C 44 and as represented on the Figure 7C , is positive and less than the value π: $$0<\mathrm{\beta }<\mathrm{\pi }$$

The strength of action F and the angle β are located in the half-plane defined by the straight line containing the point of contact C and the pivot point 44 of the lever 4 and not containing said lever arm 40. Thus, the force of action F acts to rotate the lever 4 against the stop 7 to immobilize effectively during the ascent of the side 23 by the probe 3. The action force F is thus directed and located on the side of the pivot point 44 of the lever 4, capable of causing a pivoting effect of the lever 4, this pivoting taking place against the stop 7, thus immobilizing the lever 4.

In other words, the oriented angle β can be defined as an action angle formed by the force of action F of the cam on the probe and the segment, noted [C44], connecting the point of contact cam follower C and the pivot point 44 of the lever 4. This angle of action β is located in the half-plane defined by the right containing this segment [C44] and not containing said lever arm 40. It is preferably between 0 ° and 180 °.

In another embodiment, the action force F of the cam 2 on the probe 3 passes substantially through the pivot point 44 of the lever 4, ie the action angle β is 0. In this configuration, the action force F acts to immobilize the lever 4 without inducing its pivoting against a stop.

In the above description, the probe 3, the lever 4 and the spring 5 are monobloc. On the figure 10 another example embodiment is shown which differs from that just described by the shape of the spring blade 5 which forms a U with the probe arm.

As a variant, the display device could comprise an assembly comprising a lever 4 on which a feeler 3 is pivoted. figure 11 represents, by way of illustration, a particular example of such an alternative embodiment. The probe 3 is pivotally mounted on the lever 4 by means of a pivot. The return spring 5, interposed between the lever 4 and the feeler 3, is formed by a flexible blade. This is here secured to the lever 4, at one of its ends, and in abutment against the arm 30 of the probe 3, at its other end. In operation, during the ascent of the cam flank 23, the head 31 and the portion of the arm 30 carrying the head 31 of the probe 3 come closer to the lever arm 40 against the return action of the spring 5, thus causing a retraction of probe 3, under the action of the force F exerted by the cam flank 23.

In the foregoing description, the cam flank 23 is substantially straight. Alternatively, it may have a more or less marked curvature adapted in particular to ensure that the force of action F permanently passes through the pivot point 44 of the lever 4, or substantially by this pivot point 44, to immobilize the lever 4 (without pivoting effect against a stop).

The device which has just been described, according to various exemplary embodiments, can be implemented in order to indicate retrograde any temporal information, or derived from the time (indication of the time of a time zone, indication calendar such as the indication of the dates, days of the week, months, moon phases, etc ...). However, the invention is not limited to a retrograde application but concerns any implementation involving a lever cooperating with a cam (spiral or other) whose profile has at least one sidewall. The invention could for example be applied to a perpetual calendar with a cam, for example such as that disclosed in the document EP0191921 , or within an instant jump chronograph counter, in other words within a chronograph whose counting of instantaneous indications is instantaneous, for example such as that disclosed in the document CH702137 . Furthermore, the invention allows bidirectional driving of the display of the time information, whether or not it is indicated in a retrograde manner.

The display device of the invention is integrated in a watch movement, itself integrated into a timepiece comprising a basic movement, to which the movement of the invention is kinematically related. The invention therefore also relates to the watch movement incorporating the display device which has just been described and the timepiece.

Claims (16)

1. A device (100) for displaying time information with the aid of an indicator member (1), including

   • a cam (2) the profile of which includes a flank (23) ;

   • a lever (4) driving the indicator member (1);

   • a follower (3) controlling the lever (4), pressed against the cam (2) by first spring means (6), adapted, during movement of the flank (23) in a first direction of movement of the cam (2), to control movement of the lever (4) intended to drive movement of the indicator member (1),

   characterized in that the follower (3) controlling the lever (4) is adapted to be moved relative to the lever (4) against the return action of second spring means (5), interposed between the follower (3) and the lever (4), by an action force (F) exerted by the flank (23) of the cam (2) on the follower (3) during movement of the flank (23) in a second direction of movement of the cam (2).
2. A device as claimed in claim 1, characterized in that the action force (F) exerted by the flank (23) of the cam (2) on the follower (3) during movement of the flank (23) in the second direction of movement of the cam (2) acts to bring about immobilization of the lever (4).
3. A device as claimed in claim 1 or 2, characterized in that said action force (F) acts on the lever (4) to bring about an effect of pivoting of the latter against a stop (7).
4. A device as claimed in claim 1 or 2, characterized in that, the lever (4) being adapted to pivot about a pivot point (44), said action force (F) passes substantially through said pivot point (44) of the lever (4).
5. A device as claimed in one of previous claims, characterized in that, the drive lever (4) including an arm (40) driving the indicator member (1), the angle (•), called the action angle, defined by the action force (F) of the cam (2) on the follower (3) and the line segment ([C44]) connecting the point (C) of contact of the follower (3) and the cam flank (23) and the pivot point (44) of the lever (4) is located in the half-plane defined by the line segment containing said segment ([C44]) and not containing the arm (40) driving the lever (4).
6. A device as claimed in one of claims 3 or 4 to 5 when depending from claim 3, characterized in that said stop is adapted to immobilize the lever (4) during movement of the cam (2) in the first direction when the follower (3) reaches the base of the flank (23).
7. A device as claimed in one of previous claims, characterized in that, the cam (2) having a snail-shaped profile, the follower (3) includes a head (31) provided with a contact tip (312) and a contact flank (310) and is adapted to be in contact:

   • via said tip (312) of the follower head (31) with the flank (23) of the cam (2), and

   • via the flank (310) of the follower head (31) with at least a portion of the profile of the snail-shaped cam (2).
8. A device as claimed in one of previous claims, characterized in that the follower (3) is pivotably mounted on the lever (4).
9. A device as claimed in one of previous claims, wherein the movement of the cam (2) in the first direction brings about prestressing of the second spring means (5) that is compensated by a cam profile (24) conformed to ensure accurate display of the time information.
10. A device as claimed in one of previous claims, characterized in that the second spring means (5) comprise a flexible blade.
11. A device as claimed in one of previous claims, characterized in that the lever (4), the second spring means (5) and the follower (3) are made in one piece.
12. A device as claimed in one of previous claims, characterized in that the lever (4) includes a toothed portion (41) adapted to cooperate with the teeth of a pinion (10) driving the indicator member (1).
13. A device as claimed in one of previous claims, characterized in that the first and second spring means are separate.
14. A clock movement (200) including a display device as claimed in claim in one of claims 1 to 13.
15. A timepiece incorporating the display device as claimed in one of claims 1 to 13 or the clock movement as claimed in claim 14.
16. A timepiece (300) as claimed in the preceding claim, characterized in that it comprises a basic movement and the display device as claimed in one of claims 1 to 13, the cam of the display device being driven by the basic movement.

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