EP3629101B1 - Timepiece display mechanism - Google Patents

Description

The present invention relates to a watchmaking display mechanism, typically for date display.

Traditionally, a date display consists of a disc carried by a date star, this disc bearing a scale comprising thirty-one indications uniformly distributed over a circumference and moving opposite an aperture made in the dial. Similar mechanisms are also known in which the disc and date star assembly is replaced by an annular disc with internal teeth bearing the date indications directly. In order to be able to produce indications of relatively large size, the disc is generally made as large as possible and carries its indications on the largest possible circumference, which leaves little freedom as to the position of the aperture which must be positioned in such a way offset around the circumference of the dial. In this type of mechanism, the disc or the date star is typically driven by a pinion or by a finger and possibly positioned by a jumper depending on whether it is a dragging, semi-instantaneous or instantaneous mechanism.

Other date display mechanisms have been developed to allow a display close to the center of the dial while maintaining relatively large indications. We know, for example, the mechanism described in the patent EP 0 999 482 B1 in which two discs are used, a first bearing the tens digit of the date and a second bearing the units digit, each of these discs being carried by a pinion and driven by a date gear train. Such a mechanism comprises many cogs and is relatively complex to implement. In addition, the date displayed through the window is on two different discs, which is not very aesthetic.

We also know the document WO 92/10794 A1 , in which a disc bearing two series of concentric indications is used, the disc being mounted in rotation on a rocker which makes it possible to display in an aperture the indications of one series (1 to 12), then of the other ( 13 to 31). In this mechanism, the disc and rocker are rotated by motors.

An object of the present invention is to propose a display mechanism, typically for a date display, simple to produce and allowing a display of relatively large size while offering great freedom as to the position of the window on the dial, allowing for example its positioning towards the center of the dial.

The invention proposes for this purpose a watchmaking display mechanism comprising a frame, a rocker, at least one toothed wheel carried by said rocker and movable in rotation with respect to the latter, the or each of said toothed wheels carrying a disk of display comprising indications intended to be read through an aperture whose position is fixed relative to the frame, and stops which are also fixed relative to the frame, said rocker being intended to perform alternating movements in rotation between two predetermined positions around an axis of rotation fixed relative to the frame, the whole being arranged so that, between two consecutive changes in the direction of rotation of the rocker, the or each of the toothed wheels that it carries is rotated through a predetermined angle relative to the rocker under the effect of the cooperation of at least one of its teeth with at least one of said stops, this or these rotations making it possible to position the or each of the discs s display relative to the latch so that an indication of the or one of the discs is fully readable through the window when the latch is in at least one of said predetermined positions.

Typically, the rotation of the or each of the toothed wheels of the mechanism according to the invention by a predetermined angle with respect to the rocker corresponds to a rotation around an axis of rotation, movable with respect to the frame and fixed with respect to the rocker, this axis corresponding to the center of the toothed wheel considered in top view. It is therefore an axis distinct from the axis of rotation of the rocker.

Advantageously, the teeth of the or each of said wheels are asymmetrical, preferably sawtooth. Preferably again, each of the teeth of a given toothed wheel comprises a first flank extending substantially radially with respect to the center of this wheel and a second flank forming an acute angle with the first flank.

Preferably, said first flank constitutes a front flank of the tooth and said second flank constitutes a rear flank of the tooth. The expressions “front flank” and “rear flank” are given in relation to the direction of rotation of the wheel considered in normal operation, the front flank being the one exposed first during rotation of the wheel in normal operation.

“Display disc” is understood to mean a display means including both a complete display disc and an annular display disc. The disk in question is of course not necessarily circular.

• la figure 1 représente en vue de dessus et par transparence un mécanisme d'affichage selon un premier mode de réalisation de l'invention ;
• la figure 2 est une vue de dessus d'un disque d'affichage appartenant au mécanisme d'affichage représenté à la figure 1 ;
• la figure 3 illustre une partie du mécanisme d'affichage représenté à la figure 1 ;
• les figures 4a à 4h illustrent le mécanisme d'affichage représenté à la figure 1 dans des configurations successives atteintes lors de son fonctionnement ; par souci de simplification certaines indications ne sont pas représentées ;
• les figures 5a à 5h illustrent en vue de dessus et par transparence un mécanisme d'affichage selon un second mode de réalisation de l'invention dans des configurations successives atteintes lors de son fonctionnement.

Other characteristics and advantages of the present invention will appear on reading the following detailed description given with reference to the appended drawings in which:

• the figure 1 shows in top view and by transparency a display mechanism according to a first embodiment of the invention;
• the figure 2 is a top view of a display disk belonging to the display mechanism shown in figure 1 ;
• the picture 3 illustrates part of the display mechanism shown in figure 1 ;
• the figures 4a to 4h illustrate the display mechanism shown in figure 1 in successive configurations reached during its operation; for the sake of simplification, certain indications are not represented;
• the figures 5a at 5h illustrate in top view and by transparency a display mechanism according to a second embodiment of the invention in successive configurations reached during its operation.

With reference to the figure 1 , a watchmaking display mechanism 1 according to a first embodiment of the invention comprises a frame 100 such as a plate or a bridge, a rocker 101, a toothed wheel 102 carried by said rocker 101 and frictionally mounted on this last, a display disc 105, a first 103a and a second 103b upper stops and a first 104a and a second 104b lower stops fixed relative to the frame 100.

The toothed wheel 102 of the mechanism 1 is mounted by friction on the rocker 101 so as to be able to pivot with respect to the latter around a (virtual) axis of rotation A3, movable with respect to the frame 100 and fixed with respect to the rocker. 101, when subjected to sufficient torque. This axis A3 corresponds to the center of the toothed wheel 102 considered in top view. It is therefore a separate axis from the axis of rotation A1 of the flip-flop 101.

The display disc 105 is carried by the toothed wheel 102. It is typically made integral in rotation with the latter, for example by gluing, driving in, soldering or screwing or by any other suitable assembly technique, so that the movements of rotation of the toothed wheel 102 are transmitted to the display disc 105. The display disc 105 comprises a scale 106 comprising indications corresponding to the dates of the month distributed over two concentric rings of the disc 105, these being intended to be read through a window 107 whose position is fixed relative to the frame 100. The window 107 is typically made in a dial positioned above the display disc 105. In the figures, although such a dial is not represented for reasons of readability, the position of the aperture 107 is materialized.

Rocker 101 is driven in alternating rotational movements around an axis of rotation A1 (virtual), fixed with respect to frame 100, by means of a drive mechanism 109 kinematically connected to the going train of a movement watchmaker (not shown).

There are two predetermined positions of rocker 101 relative to frame 100 in which a date indication can be fully readable through window 107, we will speak of reading positions. These two positions correspond to the two extreme positions taken by rocker 101 during operation of the mechanism. They define the angular movement of rocker 101. In this example, it is approximately 12°. These extreme positions are reached at each alternation of the direction of rotation of the flip-flop 101. The figure 1 , 4a and 4h illustrate a first of these positions, the 4d figure illustrates a second of these positions.

In a first of said reading positions, the reading is done on the outer ring of the display disc 105 and in the second of said reading positions, the reading is on the inner ring.

The rotation of the display disc 105 relative to the rocker 101 occurs under the effect of the cooperation of some of the stops with the teeth of the toothed wheel 102 during the rotational movements of the rocker 101.

As indicated above and as illustrated in picture 2 , the display disk 105 is divided into two concentric rings. It also includes thirty-two identical angular sectors 110 of angle α=11.25°. It typically comprises thirty-two divisions distributed over these concentric rings, sixteen on the outer ring and sixteen on the inner ring, each of these sixteen divisions corresponding to a ring portion defined by two sectors adjacent angular divisions, the interior divisions 111a being offset by an angular sector with respect to the exterior divisions 111b, as illustrated in figure 2 . In the example illustrated, thirty-one of these divisions include an indication of the date scale 106 corresponding to a distinct whole number, these numbers ranging from 1 to 31, and one of these divisions includes an indication "set ". The indications of the numbers on the display disc 105 are arranged in ascending order in the opposite direction to the direction of rotation of the toothed wheel 102, that is to say in the counterclockwise direction on the display disc 105, alternating between the divisions of the inner ring and those of the outer ring. Thus, the number "1" is located on a division of the inner ring and the number "2" is on the division of the outer ring comprising an angular sector in common with the division bearing the number "1" and offset relative to it by an angle α counterclockwise.

As indicated previously, rocker 101 is driven in alternating rotational movements around an axis of rotation A1 fixed with respect to frame 100 by means of a drive mechanism 109 kinematically connected to a gear train for finishing a movement watchmaker (not shown). The drive mechanism 109 shown in picture 3 typically comprises a drive wheel 109a kinematically connected to the going train of a watch movement, said drive wheel 109a carrying an eccentric stud 109b. The pin 109b passes through an oblong opening 101a that includes the rocker 101, said opening 101a being arranged so that, when the drive wheel 109a rotates, the pin 109b drives the rocker 101 alternately upwards then downwards. . As the latter is mounted to move in rotation around an axis of rotation coinciding with the axis of A1, the aforementioned to-and-fro movements (from top to bottom) cause alternating rotational movements of the rocker 101 around of the axis of rotation A1. The amplitude of the alternating rotational movements is constant and identical in the direction clockwise and counterclockwise. It depends in particular on the radius separating the eccentric pin 109b from the center of rotation of the drive wheel 109a as well as the position of the oblong opening 101a in the rocker 101.

Typically, 24 hours elapse between two consecutive changes in the direction of rotation of flip-flop 101.

In the following part of the description, we will describe in detail the operation of the display mechanism for a period of approximately 48 hours with reference to the figures 4a to 4h .

For ease of understanding, we will call tooth #X the tooth of the gear wheel 102 pointing in the direction of the indication bearing the #X in each of the configurations illustrated.

The horizontal line "X" appearing in the central opening of the display disk 105 at the figures 4a to 4h is a purely illustrative reference, fixed with respect to the frame 100, making it possible to highlight the relative movements of the rocker 101 with respect to the frame 100 during the operation of the display mechanism 1.

To the figure 4a , the display mechanism 1 displays, through the window 107, the date of the month "24" located on the outer ring of the display disc 105, the indication "24" is fully readable through the window 107. Latch 101 is in a first of two read positions. It has just completed its clockwise rotation and is about to begin its counter-clockwise rotation. Tooth no. 4 of wheel 102 has its rear flank in contact with a first 104a of the lower stops of the mechanism and tooth no. 10 has its front flank in abutment against the second 104b of the lower stops of mechanism 1.

The rocker 101 begins its rotation in the counterclockwise direction, around the axis A1. The position of the second 104b of the lower stops as well as the shape of the teeth of the toothed wheel 102 and in particular the shape of their front flank, are such that the rotation of the lever 101 counterclockwise, from this position, can be done with very little or even no rotation of the toothed wheel 102 relative to the rocker 101. Indeed, the toothed wheel 102 is substantially immobile relative to the rocker 101 throughout its rotation between the state shown in figure 4a and the state shown in figure 4b .

The toothed wheel 102 is asymmetrical, it comprises sixteen identical teeth. Each of the teeth of sprocket 102 includes a front flank extending radially from the center of wheel 102 and a rear flank forming an acute angle with the front flank. Such a shape for the front flank can cause the toothed wheel to rotate slightly relative to the rocker as it rotates. These are just parasitic movements. For example, an arched front flank could limit or even completely eliminate these parasitic movements.

To the figure 4b , it can be seen that, due to the rotation of the rocker 101 counterclockwise, the indication "24" is no longer fully readable through the aperture 107. This figure illustrates the moment when the rear flank of the tooth No. 20 of the toothed wheel 102 comes into contact with a first 103a of the upper stops.

As the rocker continues its rotation in the counterclockwise direction after this contact, the rear flank of tooth no. 20 in contact with said first 103a of the upper stops rubs against this stop 103a which causes the rotation of the wheel 102 in the clockwise direction. relative to the swing. The figure 4c corresponds to a freeze frame during this rotation. This stop 103a which participates in the rotation of the toothed wheel 102 with respect to the rocker 101 will be called "upper drive stop".

At approximately the same time that this upper drive stop 103a comes into contact with the bottom of the toothing of the toothed wheel 102, the front flank of tooth No. 26 of the toothed wheel 102 comes into contact with a second 103b of the upper stops. This prevents the continuation of the rotation of the toothed wheel 102 relative to the rocker 101. This stop 103b will be called "upper locking stop" which participates in the blocking of the rotation of the toothed wheel 102 relative to the rocker 101. A At this stage, the display mechanism 1 displays the date of the month "25" located on the inner ring of the display disc 105, the indication "25" is entirely readable through the aperture 107. The rocker 101 is located in the second of the two reading positions. It has just completed its counter-clockwise rotation and is about to begin its clockwise rotation. This configuration, shown in 4d figure is similar to that shown in figure 4a .

Then the rocker begins its rotation in the clockwise direction. As during the start of the rotation of the rocker 101 in the counterclockwise direction, the start of the rotation of the rocker 101 in the clockwise direction can be done, from this position, with very little or even no rotation of the toothed wheel 102 with respect to rocker 101, the front flank of tooth no. 26 moving along the upper locking abutment 103b, as illustrated in figure 4e . By analogy to what has been described above, by modifying the shape of the front sides of the toothed wheel 102, for example by making them arcuate, it is possible to limit or even completely cancel the rotational movements of the toothed wheel. 102 with respect to the rocker 101, when the latter begins its rotation. The toothed wheel 102 is substantially stationary relative to the flip-flop 101 throughout its rotation between the state shown in 4d figure and the state shown in figure 4f . To the figure 4e , it can be seen that, due to the rotation of the rocker 101, the indication "25" is no longer fully readable through the window 107.

The figure 4f illustrates when the rear flank of tooth #6 of sprocket 102 comes into contact with the first 104a of the lower stops.

As rocker 101 continues to rotate clockwise, the rear flank of tooth no. 6 in contact with said first of the lower stops rubs against this stop 104a which causes the rotation of the toothed wheel 102 in the clockwise direction relative to the rocker 101. By analogy to the upper drive stop 103a, this first lower stop 104a is called lower drive stop. The figure 4g corresponds to a freeze frame during this rotation.

At approximately the same time that this lower drive stop 104a comes into contact with the bottom of the toothing of the toothed wheel 102, the front flank of tooth No. 12 of the toothed wheel 102 comes into contact with the second 104b of the lower stops. This prevents further rotation of the toothed wheel 102 with respect to the rocker 101. By analogy to the upper locking stop 103b, this second lower stop 104b is called lower locking stop.

At this stage, the display mechanism 1 displays the date of the month "26" located on the outer ring of indications of the display disc 105, the indication "26" is fully readable through the aperture 107. The Rocker 101 has just completed its rotation in the clockwise direction and is about to begin a rotation in the counterclockwise direction again. This configuration, shown in figure 4 o'clock is almost identical to that illustrated in figure 4a and corresponds to the same reading position of flip-flop 101 that has been defined as the first reading position. The steps described above are then repeated to pass from the display of the date 26 to the date "27" then to the date "28" and so on by shifting the numbers of the teeth by two units on each return trip of the rocker 101.

After the date “30” of the month, the display mechanism 1 is arranged to indicate “set” in the window 107. This makes it possible to alert the user to the fact that an action on his part is required. Indeed, if the month is a month of thirty-one days, the user can manually rotate the display disc 105 by means of an actuating rod driving the rocker 101 in movement until the indication bearing the number “31” is entirely legible through the aperture. If the month is a month of thirty days, the user can manually rotate the display disc 105 further so that the indication "1" is fully readable through the window 107.

The arrangement of display mechanism 1 according to the invention is such that each time rocker 101 passes from one reading position to another, toothed wheel 102 moves by an angle α, corresponding to an angular sector 110 of the display disc 105, relative to the rocker 101. It therefore performs on each return trip a displacement of an angle equal to 2α corresponding to two angular sectors 110 of the display disc 105.

The toothed wheel 102 is designed so that the angle α defined by an angular sector 110 corresponds to a half step of the toothed wheel. To do this, the toothed wheel 102 of the mechanism 1 typically comprises sixteen teeth separated by a bottom whose length is the same as that of the tooth at the level of the foot circle. The toothed wheel 102 corresponds to a wheel with thirty-two identical teeth in the form of saw teeth, one tooth out of two of which has been removed.

Thus, between two consecutive changes in the direction of rotation of the rocker, the cooperation between one of the drive stops 103a, 104a and the front flank of the tooth which faces it causes a rotation of an angle α corresponding to the passage of a tooth therefore half a pitch. The particular positioning of the indications of the scale 106 on the display disc 105 described in figure 2 fact that a rotation of an angle α suffices to pass from one indication to the next on the display disk 105.

The display mechanism 1 according to the first embodiment of the invention has the advantage of allowing a display of relatively large size by reducing the space used to achieve this compared to a mechanism according to the prior art. Due to this smaller size, such a mechanism makes it possible to have a display of equivalent size to that which can be obtained with a display mechanism with an eccentric aperture of the dial according to the prior art while arranging the aperture as desired on the dial, for example in the center of the dial. In addition, in each reading position, the date displayed through the window can be read on a single disc at a time.

With reference to figures 5a at 5h , a watchmaking display mechanism 2 according to a second embodiment of the invention comprises a frame 200 such as a plate or a bridge, a rocker 201, two toothed wheels 2021, 2022 frictionally mounted on said rocker 201 so to be able to pivot relative to the latter when they are subjected to sufficient torques, and two display discs 2051, 2052. It also comprises an upper locking stop 2031b, 2032b and an upper drive stop 2031a, 2032a as well a lower locking stop 2041b, 2042b and a lower drive stop 2041a, 2042a for each of said two toothed wheels 2021, 2022, i.e. eight stops, all fixed relative to the frame 200.

A first 2021 of the toothed wheels, called “odd wheel”, carries a first display disc 2051 which will be called “odd display disc”. This disk 2051 is typically an annular disk. It has a 2061 scale with indications corresponding to the odd dates of the month, ranging from 1 to 29 inclusive, as well as a “set” indication. These indications are uniformly distributed over a circumference of said display disc 2051 and are intended to be read through an aperture 207 whose position is fixed relative to the frame 200. The aperture 207 is typically made in a dial positioned by- above the display discs 2051, 2052. In the figures, although such a dial is not shown for reasons of readability, the position of the counter 207 is materialized.

A second 2022 of the toothed wheels, called the “peer wheel”, carries a second display disc 2052 which will be called the “peer display disc”. peers ". This disk 2052 is typically an annular disk. It features a 2062 graduation with indications corresponding to even-numbered dates of the month ranging from 2 to 30 inclusive. It can also, when the latter is not carried by the odd number display disc 2051, also carry the date “31”. These indications 2062 are uniformly distributed over a circumference of said disc 2052 and are intended to be read through window 207.

The cogwheels 2021, 2022 respectively of odd and even are identical. They are typically identical to that of the display mechanism 1 according to the first embodiment of the invention.

The toothed wheels of the odd 2021 and the even 2022 of the mechanism 2 are capable of pivoting with respect to the rocker 201 around axes of rotation (virtual) respectively of the odd A4 and the even A5. These odd A4 and even A5 axes are movable with respect to the frame 200 and fixed with respect to the rocker 201, and correspond respectively to the centers of the toothed wheels 2021, 2022 considered in top view. They are distinct from the (virtual) axis of rotation A2 of the rocker 201.

Typically, each of the display discs 2051, 2052 is made integral in rotation with the toothed wheel 2021, 2022 which carries it, for example by gluing, driving in, brazing, screwing or by any other suitable assembly technique, so that the rotational movements of each of the toothed wheels 2021, 2022 are transmitted to the display disk 2051, 2052 which it carries.

Each of the toothed wheels 2021, 2022 comprises sixteen identical teeth. Each of the teeth of a given toothed wheel 2021, 2022 comprises a front flank extending radially with respect to the center of said toothed wheel 2021, 2022 and a rear flank forming an acute angle with the front flank.

In the remainder of the description, an abutment may be qualified as an even abutment or an odd abutment depending on the toothed wheel 2021, 2022 with which it is associated.

Rocker 201 is here in one piece. As a variant, it could be a rocker in several parts integral with each other. This rocker 201 is driven in alternating rotational movements around an axis of rotation A2 fixed relative to the frame 200 by means of a drive mechanism (not shown) kinematically connected to the going train of a watch movement ( also not shown). This may typically be the same drive mechanism (109) used in the first embodiment of the invention.

There are two predetermined positions or reading positions of the flip-flop 201 relative to the frame 200 in which a date indication can be fully readable through the window 207. These two positions correspond to the two extreme positions that the flip-flop 201 takes during operation. of the display mechanism 2. They define the angular movement of the rocker 201. In this example, it is approximately 30°. These extreme positions are reached at each alternation of the direction of rotation of the flip-flop 201. The figure 5a and 5am illustrate a first of these positions, the figure 5d illustrates a second of these positions.

In a first of said read positions, the read is on the even display disc 2052 and in the second of said read positions, the read is on the odd display disc 2051.

The rotation of each of the display discs 2051, 2052 relative to the rocker 201 occurs under the effect of the cooperation of the drive stops 2031a, 2041a, 2032a, 2042a with the teeth of the corresponding toothed wheel 2021, 2022 , during the rotational movements of the rocker 201.

The odd number display disc 2051 comprises sixteen angular sectors 2101 with an angle β=22.5° (360 divided by 16), as illustrated in figure 5a . It comprises sixteen divisions, each of these sixteen divisions corresponding to a portion of the disc defined by an angular sector. In the example shown, fifteen of these sixteen divisions comprise an indication 2061 corresponding to a distinct odd whole number, these numbers ranging from 1 to 29 and one of the divisions comprises an indication “set”. The indications of the odd numbers 2061 on the odd number display disc 2051 are arranged in ascending order in the opposite direction to the direction of rotation of the odd number wheel 2021 i.e. counterclockwise on the disc. odd number display 2051, the indication “set” being interposed between the indications “1” and “29”.

The peer display disk 2052 also comprises sixteen angular sectors 2102 with an angle β=22.5°, as illustrated in figure 5a . It comprises sixteen divisions, each of these sixteen divisions corresponding to a portion of the disc 2052 defined by an angular sector. In the example illustrated, fifteen of these sixteen divisions include an indication 2062 corresponding to a distinct even whole number, these numbers ranging from 2 to 30 and one of the divisions includes the indication corresponding to the date “31”. The indications of even numbers 2062 on the evens display disc 2052 are arranged in ascending order in the opposite direction to the direction of rotation of the evens wheel 2021 i.e. clockwise on the disc. peer display 2052.

As indicated previously, rocker 201 is driven in alternating rotational movements around axis of rotation A2 by means of a drive mechanism kinematically connected to the going train of a watch movement (not shown).

Typically, 24 hours elapse between two consecutive changes in the direction of rotation of flip-flop 201.

The display mechanism 2 according to the second embodiment operates according to the same principle as the display mechanism 1 according to the first embodiment of the invention. Indeed, the toothed wheels which are the even wheel 2022 and the odd wheel 2021 cooperate with the drive stops 2032a, 2042a, 2031a, 2041a and blocking 2032b, 2042b, 2031b, 2041b of the even and odd during back and forth movements of the rocker 201. This causes the rotation of said toothed wheels 2021, 2022 as well as the discs display 2051, 2052 that they carry, clockwise for the odd wheel 2021 and counterclockwise for the even wheel 2022. the odd disc 2051 and on the even disc 2052.

In the following part of the description, we will describe in detail the operation of the display mechanism 2 for a period of 48 hours with reference to the figures 5a at 5h .

To facilitate understanding, we will call tooth n°X the tooth of the toothed wheel concerned (odd 2021 or even 2022) pointing in the direction of the indication bearing the n°X in each of the configurations illustrated.

To the figure 5a , the display mechanism 2 displays, through the window 207, the date of the month "2" located on the peer display disc 2052, the indication "2" is entirely readable through the window 207. The rocker 201 is in a first of two read positions. It has just completed its counter-clockwise rotation and is about to begin its clockwise rotation. Tooth No. 21 of the odd wheel 2021 has its rear flank in contact with the lower odd drive stop 2041a and its front flank tooth No. 27 abuts against the lower odd blocking stop 2041b. Similarly, tooth No. 31 of the peer wheel 2022 has its rear flank in contact with the upper peer drive stop 2032a and its front flank tooth No. 6 has its front flank in abutment against the upper peer locking stop. 2032b.

Rocker 201 begins its rotation clockwise around axis A2. As for the display mechanism 1 according to the first embodiment of the invention, the position of the lower odd blocking stop 2041b as well that the shape of the teeth of the odd wheel 2021 and in particular the shape of their front flank, are such that the rotation of the rocker 201 clockwise, from this position, can be done with very little or even no rotation of the toothed wheel 2021 carrying the disc 2051 of the odds with respect to the rocker 201. The toothed wheel of the odds 2021 is substantially immobile with respect to the rocker 201 throughout its rotation between the state represented in figure 5a and the state shown in figure 5b .

Similarly, the position of the upper peer locking stop 2032b as well as the shape of the teeth of the peer wheel 2022 and in particular the shape of their front flank, are such that the rotation of the rocker 201 clockwise, from the position shown in figure 5a , can be done with very little or even no rotation of the toothed wheel 2022 carrying the disk of the peers 2052 relative to the rocker 201. The toothed wheel of the peers 2022 is substantially immobile relative to the rocker 201 throughout its rotation between the state shown in figure 5a and the state shown in figure 5c .

By analogy to what has been described in the first embodiment of the invention, by modifying the shape of the front sides of the toothed wheels 2021, 2022, for example by making them arcuate, it is possible to limit or even completely cancel the rotational movements of the toothed wheels 2021, 2022 relative to the rocker 201 at the start of a phase of rotation of the rocker 201.

To the figure 5b , it can be seen that, due to the rotation of the flip-flop 201 clockwise, the indication "2" is no longer entirely readable through the window 207. This figure 5b illustrates when the trailing flank of tooth #1 of odd wheel 2021 comes into contact with upper odd drive stopper 2031a.

As rocker 201 continues its rotation in the clockwise direction after this contact, the rear flank of tooth no. 1 in contact with said drive stop upper odd number 2031a rubs against this stop which causes the rotation of the odd wheel 2021 clockwise relative to the rocker 201. figure 5c corresponds to a freeze frame during this rotation.

At approximately the same time as the upper odd drive stopper 2031a comes into contact with the bottom of the tooth of the odd wheel 2021, the front flank of tooth No. 7 of the odd wheel 2021 comes into contact with the upper odd blocking stop 2031b. This prevents further rotation of the odd wheel 2021 with respect to the flip-flop 201. This configuration is illustrated in figure 5d .

While the rear flank of tooth #1 rubs against the upper odd drive stop 2031a, the rear flank of tooth #22 of the even wheel 2022 comes into contact with the lower even drive stop 2042a. This state corresponds to the state shown in figure 5c .

As rocker 201 continues its rotation in the clockwise direction after this contact, the rear flank of tooth no. 22 in contact with said lower peer drive stop 2042a rubs against this stop, which causes rotation of the peer wheel. 2022 counterclockwise relative to flip-flop 201.

At about the same time that the lower peer drive stopper 2042a comes into contact with the bottom of the tooth of the peer wheel 2022, the front flank of tooth No. 28 of the peer wheel 2022 comes into contact with the lower peer blocking stop 2042b. This prevents further rotation of peer wheel 2022 relative to flip-flop 201. This configuration is illustrated in figure 5d .

At this stage ( figure 5d ), the display mechanism displays the date of the month "3" located on the odd number display disc, the indication "3" is entirely readable through the aperture 207. The rocker 201 is located in the second of the two reading positions. It has just completed its clockwise rotation and is about to begin its counter-clockwise rotation.

Then the rocker 201 begins its rotation in the counterclockwise direction. As during the initiation of the rotation of the rocker 201 in the clockwise direction, the initiation of the rotation of the rocker 201 in the counterclockwise direction can be done, from this position, with very little or even no rotation of the wheels. toothed odd 2021 and even 2022 with respect to rocker 201, the front flank of each of teeth No. 7 and No. 28 respectively in contact with the upper odd blocking stop 2031b and the lower even blocking stop 2042b moving along these stops.

By analogy to what has been described above, by modifying the shape of the front sides of the toothed wheels, for example by making them arcuate, it is possible to limit or even completely cancel the rotational movements of the toothed wheels 2021, 2022 relative to flip-flop 201 at the start of a rotation phase of flip-flop 201.

Thus, the peer gear 2022 is substantially immobile with respect to the latch during the rotation of the latch 201 between the state shown in figure 5d and the state shown in figure 5e . To the figure 5e , it can be seen that, due to the rotation of the rocker, the indication "3" is no longer readable through the aperture 207.

The figure 5e illustrates when the trailing flank of tooth #2 of peer wheel 2022 comes into contact with upper peer drive stop 2032a.

As rocker 201 continues to rotate counterclockwise after this contact, the rear flank of tooth no. 2 rubs against said upper peer drive stop 2032a which causes peer wheel 2022 to rotate counterclockwise. relative to the swing. The figures 5f and 5g correspond to successive freeze frames during this rotation.

At about the same time that the upper peer drive stopper 2032a comes into contact with the bottom of the peer wheel tooth 2022, the front flank of the peer wheel tooth No. 8 comes into contact with the upper peer blocking stop 2032b. This prevents further rotation of peer wheel 2022 relative to flip-flop 201. This configuration is illustrated in picture 5h .

While the trailing flank of tooth #2 rubs against the upper even drive stopper 2032a, the trailing flank of tooth #23 of the odd wheel 2021 comes into contact with the lower odd drive stopper 2041a. This state corresponds to the state shown in figure 5f . As rocker 201 continues to rotate counterclockwise after this contact, the rear flank of tooth no. 23 rubs against said lower odd drive stop 2041a causing odd wheel 2021 to rotate clockwise. relative to flip-flop 201. The figure 5g corresponds to a freeze frame during this rotation.

At about the same time that the lower odd drive stopper 2041a comes into contact with the bottom of the tooth of the odd wheel 2021, the front flank of tooth No. 29 of the odd wheel 2021 comes into contact with the lower odd blocking stop 2041b. This prevents further rotation of the odd wheel 2021 with respect to the flip-flop 201. This configuration is illustrated in picture 5h .

At this stage ( picture 5h ), the display mechanism displays the date of the month "4" located on the peer display disc 2052, the indication "4" is entirely readable through the window 207. The flip-flop 201 is again in the first of two reading positions. It has just completed its counter-clockwise rotation and is about to begin its clockwise rotation.

This configuration, shown in picture 5h is almost identical to that illustrated in figure 5a and corresponds to the same reading position of the flip-flop 201 which has been defined as the first reading position. The steps described above are then repeated to pass from the display of the date "4" to the date "5" then to the date "6" and so on by shifting the numbers of the teeth by two units on each round trip of flip-flop 201.

After the date “30” of the month, the display mechanism 2 is arranged to indicate “set” in the window 207. This makes it possible to alert the user to the fact that an action on his part is required. Indeed, if the month is a month of thirty-one days, the user can manually rotate the display discs 2051, 2052 by means of an actuating rod causing the rocker 201 to move until indication bearing the number "31" is entirely readable through window 207. If the month is a month of thirty days, the user can manually rotate display discs 2051, 2052 further to that the indication bearing the number "1" is fully readable through the window 207.

The arrangement of the display mechanism 2 according to the invention is such that each time the rocker 201 passes from one reading position to another, each of the toothed wheels 2021, 2022 performs a displacement of an angle β/2, corresponding to a half angular sector 2101, 2102 of angle β of the display disc 2051, 2052 that it carries, relative to the flip-flop 201. Each of the toothed wheels 2021, 2022 therefore performs on each return return a displacement of an angle equal to β corresponding to an angular sector 2101, 2102 of the corresponding display disc 2051, 2052.

Each of the toothed wheels 2021, 2022 is designed so that the angle β defined by an angular sector 2101, 2012 corresponds to one pitch of the toothed wheel. To do this, the toothed wheel 2021 of the mechanism 2 typically comprises sixteen teeth separated by a bottom whose length is the same as that of the tooth at the level of the root circle. The 2021 gear wheel corresponds to a wheel with thirty-two identical teeth in the shape of saw teeth, of which every other tooth has been removed.

Thus, between two consecutive changes in the direction of rotation of the rocker 201, the cooperation between one of the drive stops 2031a, 2041a, and the front flank of the tooth which faces it causes a rotation of an angle β/2 corresponding at the passage of a tooth therefore at a half-step. Similarly, between two consecutive changes in the direction of rotation of rocker 201, the cooperation between one of drive stops 2032a, 2042a, and the front flank of the tooth facing it causes rotation through an angle β/2 corresponding to the passage of a tooth therefore to a half-step. As the date is read alternately on one then on the other of the two display discs, a rotation of a half-step of each of the toothed wheels 2021, 2022 between two consecutive changes in the direction of rotation of the rocker 201 is suitable.

The display mechanism 2 according to the second embodiment of the invention has the advantage of allowing a display of relatively large size by reducing the space used to achieve this compared to a mechanism according to the prior art. Because of this less bulk, such a mechanism makes it possible to have a display of equivalent size to that which can be obtained with a display mechanism with an eccentric window of the dial according to the prior art while arranging the window at leisure on the dial, for example in the center of the dial. In addition, in each reading position, the date displayed through the window can be read on a single disc at a time.

Whatever the embodiment considered, the display mechanism according to the invention has the advantage of limiting the number of gears necessary for rotating one or more display discs.

In addition, the display mechanism according to the invention can operate in dragging or jumping fashion. Preferably, it works by jumps. In this way, the rocker of the mechanism remains in a given reading position for a little less than 24 hours, typically for more than 23h59minutes and the transition from one reading position to another of the rocker takes place in a few seconds or even in a few milliseconds. , for example in about 30ms. This has the advantage of allowing correct display of the date for as long as possible and this also limits the risk of the mechanism becoming out of adjustment in the event of an impact at a time when the lever is between two reading positions.

Whatever the embodiment considered, the rocker has an angular movement of less than 360°, preferably less than a value X with X between 300° and 359°, preferably X between 240° and 300°, preferably X between 180° and 240°, preferably X between 120° and 180°, preferably X between 60° and 120°, more preferably X between 1° and 60°.

Mechanisms in which the rocker has a small angular displacement are preferred because they require less surface area than those associated with a large angular displacement. In addition, a small angular movement has the advantage of limiting the duration of the phase during which the rocker is between two reading positions and phase during which there is a risk of the mechanism becoming out of adjustment in the event of an impact.

Furthermore, the flanks of the toothed wheel(s) of the display mechanism according to the invention could also have shapes other than those previously described. For the front flanks, any shape allowing the rotation of the toothed wheel to be blocked when one of the front flanks is in abutment against the locking abutment is possible, and, for the rear flanks, any shape allowing the drive in rotation of the toothed wheel during the interaction of one of the rear flanks with a drive stop is possible.

It will clearly appear to those skilled in the art that the present invention is in no way limited to the embodiments presented above and illustrated in the figures.

In variants, the display of the mechanism according to the invention may be different from a date display. It may, for example, typically be a display indicating the current month, day and night, hours, minutes or seconds, signs of the zodiac or any other indication of a calendar of any culture, power reserve, leap years, or any other display.

It is obvious that the shape of the rocker can vary ad infinitum as long as its functions are ensured.

In addition, the drive mechanism of the rocker in alternating rotational movements around a fixed axis of rotation may itself be different from that represented in the figure 1 , any mechanism allowing this function being conceivable.

The position of the drive and locking stops may vary. A person skilled in the art will be able to move them while ensuring that they perform their respective functions, namely the rotation of the toothed wheel(s) carrying the display means and the blocking of the rotation of these same wheels at the beyond the angle of rotation necessary for the proper functioning of the mechanism.

As previously indicated, at the end of the month, the user will be able to manually rotate the display disc(s) of the mechanism by means of an actuating rod acting on the movements of the rocker to position the indication desired in the counter. However, another possibility for adjusting the date would consist in providing a mechanism allowing the or each of the display discs to be rotated directly with respect to the gear wheel associated with it. In this case, rather than being glued, chased, brazed or screwed onto the toothed wheel which carries it, the or each of the display discs could be friction mounted on said toothed wheel.

The “set” indication provided in the two embodiments of the invention is of course optional.

In the illustrated embodiments, the toothed wheel or wheels are on a single level and the stops are all on this same level. However, it is obvious that the toothed wheel(s) as well as the stops with which they are supposed to interact can be distributed over several levels.

Claims (12)

1. Timepiece display mechanism (1; 2) comprising a frame (100; 200), a lever arm (101; 201), at least one wheel (102; 2021, 2022) borne by said lever arm (101; 201) and rotationally movable with respect to said lever arm, the or each of said wheels (102; 2021, 2022) bearing a display disc (105; 2051, 2052) comprising indications (106; 2061, 2062) intended to be read through an aperture (107; 207), the position of which is fixed with respect to the frame (100; 200), and bankings (103a, 104a; 2031a, 2041a, 2032a, 2042a) which are also fixed with respect to the frame (100; 200), said lever arm (101; 201) being intended to carry out alternating rotational movements between two predetermined positions about an axis of rotation (A1; A2) which is fixed with respect to the frame (100; 200), characterised in that the at least one wheel (102; 2021, 2022) is toothed and in that the whole is arranged so that, between two consecutive changes in the direction of rotation of the lever arm (101; 201), the or each of the toothed wheels (102; 2021, 2022) which it bears is driven in rotation by a predetermined angle with respect to the lever arm (101; 201) under the effect of the cooperation of at least one of its teeth with at least one of said bankings (103a, 104a; 2031a, 2041a, 2032a, 2042a), this or these rotations permitting the or each of the display discs (105; 2051, 2052) to be positioned with respect to the lever arm (101; 201) so that an indication of the or of one of the discs is entirely readable through the aperture (107; 207) when the lever arm (101; 201) is in at least one of said predetermined positions.
2. Timepiece display mechanism (1; 2) as claimed in claim 1, characterised in that a first (103a; 2031a, 2032a) and a second (104a; 2041a, 2042a) driving banking correspond to the or each of the toothed wheels (102; 2021, 2022) and in that, for the or each toothed wheel (102; 2021, 2022), the first of the driving bankings (103a; 2031a, 2032a) which corresponds thereto drives same in rotation by a predetermined angle with respect to the lever arm (101, 201) when said lever arm passes from its first predetermined position to its second predetermined position and the second of said driving bankings (104a; 2041a, 2042a) which corresponds thereto drives same in rotation by a same predetermined angle with respect to the lever arm (101; 201) when said lever arm passes from its second predetermined position to its first predetermined position.
3. Timepiece display mechanism (1; 2) as claimed in claim 2, characterised in that a first (103b; 2031b, 2032b) and a second (104b; 2041b, 2042b) blocking banking correspond to the or each of the toothed wheels (102; 2021, 2022) and in that, for the or each toothed wheel (102; 2021, 2022), the first of the blocking bankings (103b, 2031b, 2032b) which corresponds thereto prevents the rotation thereof with respect to the lever arm (101; 201) beyond the rotation by the predetermined angle caused by the first of the driving bankings (103a; 2031a, 2032a) when the lever arm (101; 201) passes from its first predetermined position to its second predetermined position and the second of the blocking bankings (104b; 2041b, 2042b) which corresponds thereto blocks the rotation thereof with respect to the lever arm (101; 201) beyond the rotation by the predetermined angle caused by the second of the driving bankings (104a; 2041a, 2042a) when the lever arm (101; 201) passes from its second predetermined position to its first predetermined position.
4. Timepiece display mechanism (1) as claimed in any one of claims 1 to 3, characterised in that it comprises a toothed wheel (102) and a display disc (105), said display disc (105) bearing indications (106) arranged in two concentric rings of the disc (105) and in that each of the two predetermined positions of the lever arm (101) permits the reading of an indication of the display disc (105) through the aperture (107), the first of the predetermined positions permitting the reading of an indication on the outer ring and the second of the predetermined positions permitting the reading of an indication on the inner ring.
5. Timepiece display mechanism (2) as claimed in any one of claims 1 to 3, characterised in that it comprises two toothed wheels (2021, 2022) each of them bearing a display disc (2051, 2052) bearing indications (2061, 2062) uniformly distributed over its circumference, and in that each of the two predetermined positions of the lever arm (201) permits the reading of an indication of one of the display discs (2051, 2052) through the aperture (207), the first of the predetermined positions permitting the reading of an indication on one (2052) of the discs and the second of the predetermined positions permitting the reading of an indication on the other (2051) of the discs.
6. Timepiece display mechanism (2) as claimed in claim 5, characterised in that said toothed wheels (2021, 2022) comprise the same number of teeth.
7. Timepiece display mechanism (1; 2) as claimed in any one of the preceding claims, characterised in that the teeth of the toothed wheel (102) or of each of said toothed wheels (2021, 2022) are asymmetrical, preferably saw-tooth-shaped.
8. Timepiece display mechanism (1; 2) as claimed in any one of the preceding claims, characterised in that each of the teeth of the toothed wheel or wheels (102; 2021, 2022) comprises a first flank extending substantially radially with respect to the centre of said toothed wheel (102; 2021, 2022) and a second flank forming an acute angle with the first flank.
9. Timepiece display mechanism (1; 2) as claimed in any one of the preceding claims, characterised in that the or each of the display discs (105; 2051, 2052) is frictionally mounted on the toothed wheel (102; 2021, 2022) which bears it.
10. Timepiece movement comprising a timepiece display mechanism (1; 2) as claimed in any one of claims 1 to 9 and a driving mechanism (109) permitting driving of the lever arm (101; 201) in alternating rotational movements, said driving mechanism (109) being kinematically connected to the finishing going train of said timepiece movement.
11. Timepiece movement as claimed in claim 10, characterised in that it comprises an actuating rod able to drive the lever arm (101; 201) in a movement independently of the finishing going train.
12. Timepiece such as a pocket watch or wristwatch, characterised in that it comprises a timepiece movement as claimed in any one of claims 10 and 11.

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