EP2238519B1 - Timepiece comprising a chronograph mechanism - Google Patents

Description

Technical area

• une source d'énergie,
• de moyens d'affichage du temps courant, et
• un mécanisme de chronographe comprenant un mobile de commande comportant au moins un organe de commande pour activer les fonctions de départ, d'arrêt et de remise à zéro du chronographe.

The present invention relates to the field of mechanical watchmaking. It concerns, more particularly, a timepiece comprising a movement provided with:

• a source of energy,
• display means of the current time, and
• a chronograph mechanism comprising a control wheel having at least one control member for activating the starting, stopping and resetting functions of the chronograph.

State of the art

The mechanisms of chronographs are varied and are well known to those skilled in the art. There are two main types, depending on whether the control wheel is a column wheel or a cam. We can notably refer to the book " Theory of Watchmaking "by Reymondin et al, Federation of Technical Schools, 1998, ISBN 2-940025-10-X, pages 225 to 252 , to find details about these mechanisms.

Conventionally, the functions of the chronograph mechanism are activated by means of two pushers, acting on the control wheel, at a drive member. In column wheel chronographs, the driving member is a toothed board. In a cam chronograph, we have two shuttles that make up the cam. The shuttles form both the control member and the drive member. Indeed, one of the pushers acts on one of the shuttles so that its movement activates the starting and stopping functions, and the other of the pushers acts on the other of the shuttles so that its movement activates the function of reset.

The document US 3, 890, 779 discloses a chronograph in which the control member is constituted by a three-level piece.

There are also known monopusher chronographs, in which all functions are provided, as the name suggests, by a single pusher. The latter acts in translation on a column wheel, whose control member is adapted to control all of the functions. In an elegant manner, this pusher is generally housed in a control rod and protrudes from the crown located at the end of the rod. The latter provides, in a conventional manner, the functions of setting the time and reassembly of the movement, independently of the chronograph. The winding is done in the position 0 of the control rod, that is to say when it is in its position proximal to the movement, and the time setting is in the position 1 of the control rod, that is to say in a position further from the rod relative to the movement.

It can be noted that in both types of chronograph bulky levers and sometimes complex shapes, are interposed between the or pushers and the drive member of the control member.

The present invention aims to provide a particularly original alternative to activate the functions of a chronograph mechanism and avoiding the aforementioned drawbacks.

Disclosure of the invention

More specifically, the invention relates to a timepiece as defined in the first paragraph above; characterized in that the control mobile further comprises a drive member having a toothed sector kinematically connected to the control member. The timepiece further comprises a button capable of being rotated, this button being integral with a toothing capable of being kinematically connected to the toothed sector, so that the pivoting of said button activates the starting functions, stopping and resetting the chronograph.

It may be noted that, advantageously, the proposed construction makes it possible to eliminate the levers between the control rod and the drive member. In fact, it can be easily adapted to an existing chronograph mechanism.

Other advantageous features are defined in the claims.

Brief description of the drawings

• la figure 1 est une vue de dessus d'un mode de réalisation préféré de l'invention,
• les figures 2, 3, 4 sont des vues de dessus et la figure 5 est une vue en coupe de détails du mécanisme de la figure 1,
• les figures 6, 7, et 8 représentent le mécanisme dans les positions correspondant aux fonctions de départ, d'arrêt et de remise à zéro du chronographe, et
• les figures 9 et 10 montrent deux autres modes de réalisation selon l'invention.

The present invention is described below with reference to the accompanying drawing, in which:

• the figure 1 is a view from above of a preferred embodiment of the invention,
• the Figures 2, 3, 4 are top views and the figure 5 is a sectional view of details of the mechanism of the figure 1 ,
• the figures 6 , 7 , and 8 represent the mechanism in the positions corresponding to the functions of starting, stopping and resetting the chronograph, and
• the figures 9 and 10 show two other embodiments according to the invention.

Mode (s) of realization of the invention

We have shown on the figure 1 , the main elements of a chronograph mechanism according to a preferred embodiment of the invention, the elements being mounted on a frame. This mechanism can be integrated in or modularly mounted on a basic movement which, for the sake of clarity, has not been shown. Naturally, this movement comprises an energy source for driving a finishing gear train and for displaying the current time by means of display members. A control rod 8, visible on the figure 2 , also called winding stem, is provided in a conventional manner to be able to occupy a first position in which it is arranged to arm the energy source, and a second position in which it is arranged to act on the display means. These two functions are well known to those skilled in the art and can be achieved by a system comprising a winding pinion, a sliding pinion and a zipper.

Like a conventional cam chronograph mechanism, there is shown an oscillating pinion, driven permanently by a second wheel of the movement. This pinion 10 is mounted on a rocker 12 terminated by a first feeler 14. A spring member 16 exerts a force on the rocker 12 tending to bring the pinion 10 in contact with a chronograph wheel 18, intended to rotate at the rate of one revolution per minute, when the pinion 10 is engaged.

Typically, the wheel 18 is provided with 60 teeth, so as to provide a precise clutch to the nearest second. The chronograph wheel 18 is intended to carry a display member of the second of the timed time. A core 20 is mounted integral with the axis of the wheel 18. In addition, an elastic finger 22 is also disposed on the wheel 18, to drive once per revolution, an intermediate gear 24, in engagement with a counter wheel 26 minutes. The counter wheel 26 is intended to carry a display member of the minute of the timed time. A core 28 is mounted integral with the axis of the wheel 26. A jumper spring 30 ensures the positioning of the wheel 26.

A blocker 32 is pivotally mounted on the frame. It comprises a brake 34 intended to cooperate with the chronograph wheel 18 to block its rotation, and a second probe 36 for controlling the positioning of the blocker 32, as will be understood later. A spring 35 is arranged to exert a force tending to press the brake 34 against the chronograph wheel 18.

A double-hammer 38 is provided to cooperate with the cores 20 and 28 to cause the display members of the second and the minute to zero. The double-hammer 38 is provided with a lever 40 comprising a third probe 42, intended to control the position of the double-hammer 38. On the lever is pivotally mounted a rocker 44. On either side of the pivot point, the latch 44 is respectively provided with a first 48 and a second 50 bearing surfaces, to cooperate with the hearts. Two pins 52 arranged on the lever 40, are provided to limit the pivoting of the latch 44. A spring 54 exerts on the rocker a force tending to bring the bearing surfaces 48 and 50 against their respective heart.

A control wheel 60 is arranged to cooperate with the different feelers and thus position the above elements so as to activate the functions of starting, stopping and resetting the chronograph mechanism. According to the embodiment chosen as an illustration, the control wheel comprises a control member composed of a cam pivoting about an axis AA. For the sake of clarity, we can refer to Figures 2, 3 and 4 which particularly show the elements of the cam.

The cam has a first shuttle 62 ( figure 2 ), called superior. It has an active zone 64 intended to cooperate with the third probe 42 of the double-hammer 38. Depending on the position of the cam, the active zone 64 is arranged so as to oppose or not to the force exerted by the spring 54. Respectively, the bearing surfaces do not cooperate or cooperate with the hearts of wheels 18 and 26.

The cam has a second shuttle 66 ( figure 3 ), said intermediate, integral in rotation with the first. It has an active zone 78 intended to cooperate with the first probe 14 of the rocker 12. According to the position of the cam, the active zone 78 is arranged to oppose or not to the force exerted by the spring member 16 Respectively, the pinion 10 is not engaged or is engaged with the chronograph wheel 18. The shuttle 66 further comprises a projecting element, such as a pin 80 whose role will appear below.

The cam still has a third shuttle 76 ( figure 4 ), called lower. The shuttle 76 has two indentations 70a, separated by a tooth 70b, with which a jumper 72 cooperates, so as to define the two stable positions of the cam corresponding to the start and stop functions of the chronograph. In addition, one of the notches, the one defining the stop function, extends beyond the level defined by the tooth 70b, by an inclined plane 70c with which the jumper 72 cooperates to position the cam for the return function. zero of the chronograph. Finally, the shuttle 76 has a housing 74 positioned and dimensioned so that the pin 80 takes place, without play in the direction of rotation of the cam. The shuttle 76 also has an active zone 68 intended to cooperate with the second probe 36 of the blocker 32. Depending on the position of the cam, the active zone 68 is arranged so as to oppose or not to the force exerted by the spring 35. Respectively, the brake 34 does not cooperate or co-operate with the chronograph wheel 18.

An additional spring 82 is positioned to act on one of the shuttles, preferably on the third shuttle 76, when the return to zero function is activated, so that it is harder to activate for the user.

According to an important aspect of the invention, the shuttle 76 extends into a toothed sector 84, concentric with the axis AA. So we understand that acting on the toothed sector 84, it will cause the pivoting of the lower cam and, with it, via the cooperation between the pin 80 and the walls of the housing 74, the pivoting of the shuttles 66 and 62. Note that the pin 80 and the housing 74 could be inverted, the pin 80 being on the shuttle 76 and the housing being on the shuttle 66.

To act on the toothed sector, the timepiece according to the invention proposes to use the control rod 8 of the movement. In addition to the winding pinion and the sliding pinion, the rod 8 carries an additional pinion 86, integral in rotation and intended to mesh with the toothed sector 84, in a predetermined position of the rod 8. As shown in FIG. figure 5 the pinion 86 and the toothed sector 84 mesh at 90 °. It can thus be seen that this construction makes it possible to avoid any arm and intermediate lever between the crown of the winding stem, which serves as an actuating member of the chronograph, and the control wheel. There is indeed a direct transmission of energy, by gearing between the pinion 86 and the sector 84. The operation is particularly flexible and precise compared to a mechanism comprising arms and levers between the pushers and the control wheel.

To allow a comfortable operation of the activation of the functions of the chronograph, the displacement of the toothed sector must be rather fast, with respect to the rotation of the crown. Indeed, for example, the start of the chronograph must be done after a limited rotation of the crown and not after a complete turn. For this purpose, the diameter of the pinion 86 is relatively large, typically of the order of 5 mm. In addition, according to the construction illustrated in the drawing, the toothed sector 84 may be located on the periphery of the movement. The pinion 86 is then relatively close to the crown, which can make it difficult to mount in the box. To overcome this problem, the rod is preferably broken, substantially at the pinion, between the latter and the crown. The portion of the rod carrying the pinion 86 can thus be easily assembled in the movement, while the other portion, intended to carry the crown, can be mounted after casing, from the outside.

The position of the sliding pinion and the winding pinion can be advantageously adapted so that, in its proximal position, the rod enables the functions of the chronograph to be activated. There is therefore no need to exert any prior pull on the rod to start the chronograph. When the control rod is pulled into a second position, the energy source can be reassembled and, in a third distal position, the time can be set.

We will now describe the activation of the various functions of the chronograph, with reference to figures 6 , 7 and 8 .

Resting ( figure 6 ), the toothed sector 84 is substantially symmetrical with respect to the axis of the control rod. The cam is held in this position by the jumper 72 which cooperates with a first notch 70a. The first probe 14 of the rocker 12 bears on the active zone 78 of the shuttle 66. The pinion 10 is disengaged from the chronograph wheel 18. At the second probe 36 of the blocker 32, the active zone 68 of the third shuttle 76 does not oppose the spring 35 and the brake 34 cooperates with the wheel 18 to block it. The third probe 42 of the double-hammer cooperates with the active zone 64 of the first shuttle 62 to oppose the spring 54. The hammer is lifted and the bearing surfaces do not cooperate with the cores 20 and 28.

To activate the chronograph start function, the crown is pivoted by the wearer counterclockwise, so as to cause rotation of the shuttle 76 in the clockwise direction, with reference to the figure 7 . The rotation of the shuttle 76 causes the simultaneous pivoting of the shuttles 66 and 62. The jumper 72 passes into the other notch 70a and thus keeps the cam in this position. The first probe 14 of the rocker 12 is no longer supported on the active zone 78 of the shuttle 66, which no longer opposes the spring 16. The pinion 10 is engaged on the chronograph wheel 18. The second probe 36 of the blocker 32 is supported on the active zone 68 of the third shuttle 76, which opposes the spring 35. The brake 34 no longer cooperates with the wheel 18. The hammer is still raised and the bearing surfaces do not cooperate not with hearts 20 and 28.

Rotation of the crown by the wearer in a clockwise direction causes rotation of the shuttle 76 counterclockwise, with reference to the figure 6 . The shuttles 66 and 62 also pivot and the jumper 72 returns to the first notch 70a. We are then in the rest position described above, the chronograph is stopped. The wearer can restart restart and stop the chronograph, without resetting.

To activate the reset, the carrier must, in reference to the rest position, through which he must necessarily pass, rotate the crown clockwise, causing the rotation of the shuttle 76 counterclockwise, with reference to the figure 8 . The shuttles 66 and 62 also pivot, forcing the additional spring 82, and the jumper 72 mounts on the inclined side 70c. The first probe 14 of the rocker 12 is still resting on the active zone 78 of the shuttle 66. The pinion 10 is disengaged from the chronograph wheel 18. The second probe 36 of the blocker 32 bears on the active zone 68 of FIG. the third shuttle 76, which opposes the spring 35. The brake 34 does not cooperate with the wheel 18. The third probe 42 of the double-hammer no longer cooperates with the active zone 64 of the first shuttle 62. Under the effect the spring 54, the hammer falls and the bearing surfaces are pressing the hearts 20 and 28, to bring the display members to zero. When the user releases the crown, the jumper 72 returns the mechanism to its rest position, by action on the inclined side 70c.

It is therefore the jumper that positions the cam so that the functions can be executed correctly. On the other hand, the user could rotate the crown too much, which could cause the shuttles to force on the feelers. To avoid this, it is possible to have the stop elements on the frame, on both sides of the shuttle 76.

Thus is proposed a chronograph mechanism to activate the various functions in a particularly original way, while removing any lever between the control rod and the drive member of the control member.

The figures 9 and 10 propose two other embodiments, also to operate the various functions of the chronograph according to a principle similar to that proposed above.

On the figure 9 , there is the toothed sector 84 ending the third shuttle 76. A ring 90 dimensioned to substantially surround the movement, is disposed on the-circle casing. More particularly, the inner diameter of the ring 90 is sufficient for the movement to take place there, while its outer diameter allows the ring 90 to be hidden by the clasp circle or inside the box. of the watch. The ring 90 is placed on the hoop and is guided in rotation, possibly by stones. The ring 90 is at least partially toothed and comprises a first 90a and a second 90b toothing, respectively on its inner periphery and on its outer periphery. The teeth can be cut directly in the ring, over the entire periphery or not, or, as in the example shown on the figure 9 , be made by inserts, to arrange the teeth only in the required areas. Such an arrangement can be interesting in terms of size.

To operate the functions of the chronograph, a button 92 is rotatably mounted in the box, so as to be accessible from the outside by the wearer of the watch. In the illustrated example, but without limitation, the button 92 is pivotable along an axis perpendicular to the plane of movement. In other words, the button defines a plane substantially parallel to that of the movement. The button 92 is rotationally fixed to a toothing, typically taking the form of a pinion 94 arranged coaxially with it. This pinion 94 meshes with the ring 90, preferably by the second toothing 90b located at its outer periphery. The toothed sector 84 is engaged with the first toothing 90a located at the inner periphery of the ring.

Thus, by turning the knob 92, the user can operate the various functions of the chronograph. Note that the button 92 can also be pivotally mounted along an axis parallel to that of the movement, the pinion 94 meshing perpendicularly with the ring.

On the figure 10 there is also a toothed sector 84 terminating the third shuttle 76. A rack 96 is mounted movably in translation inside the box or movement, being guided by at least one oblong opening, within which cooperates a fixed element, such as a screw for example fixed on a support of the movement or on the frame of the movement. The skilled person can use any other means within reach to mount the rack. A button 92 is rotatably mounted in the box so as to be accessible from the outside. In an advantageous embodiment, the button is mounted on the upper part of the box, on the dial side, possibly in a corner of this box, in the case of a square box with a round dial. As in the previous embodiment, the button 92 is pivotable along an axis perpendicular to the plane of movement and is integral with a pinion 94, which is coaxial with it. The rack 96 engages on the one hand with the pinion 94 and on the other hand with the toothed sector 84. Those skilled in the art can easily adapt the different levels of these elements so that the rack 96 can transmit a rotation of the button 92 to the drive member of the chronograph mechanism. In particular, the toothed sector 84 is normally located on the bottom side of the movement, if the button 92 is located on the dial side, the pinion 94 can be connected to the button 92 by a shaft which passes through the movement. Thus, by rotating the button, the user can operate the various functions of the chronograph.

The embodiments of the figures 9 and 10 have the same advantages as above, with, moreover, that of releasing the control rod for a third function, including correction of a date or a GMT, for example. In these embodiments, the control rod 98 no longer has a functional link with the chronograph mechanism. In addition, the manufacturer can arrange the chronograph control member in a particularly flexible manner, with reference to the button.

The above description has been given by way of non-limiting example of the invention. Thus, the control member could also be a column wheel, the toothed sector of the drive member then taking the form of a wheel. The activation of the various functions should then be adapted. Thus, the crown should always turn in the same direction to move from one function to another, the chronograph can only work according to the sequence start / stop / reset. Certain details of realization can obviously be adapted by the skilled person, especially at the level of the connection between the shuttles, or in the limitation of the stroke of the cam.

Claims (13)

1. A timepiece comprising a movement provided with

   - a power source,

   - means for displaying the current time,

   - a chronograph mechanism comprising a control mobile (60) including at least one control member to activate the start, stop and reset functions of the chronograph, and

   characterized in that the control mobile (60) also comprises a driving member including a toothed sector (84) kinematically connected to the control member, and characterized in that said timepiece comprises another button (92) capable of being driven in rotation, said button being integral with a toothing capable of being kinematically connected to said toothed sector (84), such that the pivoting of said button activates the start, stop and reset functions of the chronograph.
2. The timepiece according to claim 1, characterized in that the control member includes a first (62), a second (66) and a third (76) shuttle, coaxial and integral in rotation, said third shuttle also being the driving member.
3. The timepiece according to one of claims 1 and 2, comprising a control stem (8) capable of occupying at least a first and a second position in which it is arranged to wind the power source and to act on the display means, respectively, characterized in that said button is mounted integral in rotation with the control stem (8), in that said toothing is a pinion (86) supported by said control stem (8) and in that said control stem is capable of occupying a third position, in which the pinion (86) cooperates with said toothed sector (84) such that the pivoting of said button activates the start, stop and reset functions of the chronograph.
4. The timepiece according to claim 3, characterized in that the control stem (8) is jointed and defines:

   - a first portion designed to be situated at least partially outside the movement and to support a crown, and

   - a second portion designed to be situated in the movement and supporting, at its end situated on the crown side, said pinion (86).
5. The timepiece according to claim 3, characterized in that said third position of the control stem (8) is its proximal position in reference to the movement, in that said second position of the stem is its intermediate position, and in that said first position of the stem is its distal position in reference to the movement.
6. The timepiece according to one of claims 1 and 2, characterized in that said button (92) is connected to the toothed sector via a toothed ring (90), essentially surrounding the movement, and mounted mobile in rotation.
7. The timepiece according to claims 6, characterized in that said toothing (94) meshes with the outer periphery (90b) of the toothed ring, and in that the toothed sector (84) meshes with the inner periphery (90a) of the toothed ring.
8. The timepiece according to one of claims 1 and 2, characterized in that said button (92) is connected to the toothed sector (84) via a rack (96) mounted mobile in translation and meshing, on one hand, with said toothing (94), and on the other hand, with the toothed sector (84).
9. The timepiece according to one of claims 6 to 8, characterized in that said button (92) is capable of pivoting along an axis perpendicular to the plane of the movement.
10. The timepiece according to one of claims 2 and its depending claims, characterized in that said third shuttle (76) is kinematically connected to said second shuttle (66) via a protruding element (80) that one includes, cooperating with a first housing (74) that the other includes.
11. The timepiece according to one of claims 2 and its depending claims, characterized in that the third shuttle (76) has, on its perimeter, a first and a second hollow (70a) separated by a tooth (70b), a jumper (72) being designed to cooperate with the first and the second hollows (70a) so as to stabilize the control mobile in a first position corresponding to the stop function of the chronograph,
    and in a second position corresponding to the start function of the chronograph, respectively, and in that the first hollow is extended by an inclined flank (70c).
12. The timepiece according to one of the preceding claims, characterized in that banking elements are arranged such that said third shuttle evolves between first and second extreme positions.
13. The timepiece according to claim 1, characterized in that the control mobile is a column wheel.

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