EP2062102B1 - Timepiece movement for driving a display element along a complex path and timepiece comprising such a movement - Google Patents

Description

Technical area

The present invention relates to a watch movement comprising a frame carrying a driving member, a time base and driving mobiles, pivotally mounted on the frame, arranged to drive at least one display mobile intended to carry a display member of an information.

More particularly, the present invention relates to such a movement, and a timepiece incorporating this movement, arranged to allow the driving of a display member along an original trajectory, differing significantly from the conventional rotation around the clock. a fixed axis relative to the frame of the movement.

State of the art

Many movements have been developed by which an original drive of a display member can be realized. In particular, many watch manufacturers have marketed retrograde movements whose interest lies in the particular kinematics of the associated display member.

For example, the patent application CH 666 591 A3 , filed in the name of J.-M. Wiederrecht and R. Dubuis and published August 15, 1988, describes a movement of this type, comprising a snail cam, having a substantially radial flank, and a rake comprising a finger cooperating with the periphery of the cam and a toothed sector cooperating with a pinion rotatably mounted on the frame of the movement. The pinion carries an indicator needle cooperating with a sector-shaped indicator and is subjected to a return torque exerted by a spiral spring. When the needle reaches one end of the sector, the finger of the rake falls along the radial flank of the cam under the effect of the torque of the spiral spring, bringing the needle to the beginning of the sector.

The document US 5,103,434 proposes a movement in which a fixed toothing is engaged with a toothed member belonging to the display member being arranged in engagement with the fixed toothing. In addition, the movement comprises a drive member having first and second kinematic links, respectively, with one of the driving mobiles and with the display mobile for rolling the latter in translation, in a first sense. along the fixed teeth.

Disclosure of the invention

The main object of the present invention is to propose an alternative to existing movements, in particular by allowing an original drive of an indicator organ.

For this purpose, the invention more particularly relates to a movement for a timepiece of the type mentioned above. When a display member is assembled to the mobile display, it has a rotational movement which is combined with a displacement in translation along the fixed toothing, giving rise to a non-circular path of the body d display.

According to the invention, the fixed toothing has a first and a second end, spaced from each other, the movement being arranged to also allow a drive of the display mobile in the opposite direction to the first direction. Advantageously, the movement comprises in this case a retrograde type mechanism.

It can also provide at least one guide surface extending substantially constant distance from the fixed toothing and against which the display mobile is intended to be arranged at least indirectly in support.

The drive member is preferably made in the form of a deformable loop, in particular by a belt or a chain.

As an indication, the movement according to the present invention may advantageously be implemented in a timepiece to allow the display of different quantities, including the second, the minute, the hour, a second time zone, the day of the week, the calendar, the phases of the moon, a power reserve, an equation of time or the times of sunrise or sunset.

Brief description of the drawings

Other features and advantages of the present invention will appear more clearly on reading the detailed description of preferred embodiments which follows, made with reference to the accompanying drawings given as non-limiting examples and in which:

- the figure 1a represents a simplified top view of a part of a timepiece movement according to a first embodiment of the present invention, in a first operating position;

- the figure 1b represents a simplified top view of the movement of the figure 1a in a second operating position;

- the figure 1c represents a simplified top view of the movement of the figure 1a in a third operating position;

- the figure 2a represents a simplified top view of a part of a timepiece movement according to a second embodiment of the present invention, in a first operating position;

- the figure 2b represents a simplified top view of the movement of the figure 2a in a second operating position, and

- the Figure 2c represents a simplified top view of the movement of the figure 2a in a third operating position.

Mode (s) of realization of the invention

All the figures represent a movement in which the present invention is implemented to control a time display needle, by way of non-limiting example.

The figures 1a , 1b and 1 C are simplified top views of a timepiece movement portion having the features of the present invention according to a first preferred embodiment, in first, second and third operating positions.

The movement represented on the figure 1a comprises a frame 1 carrying a motor member, which is not visible in the figures and, which may be a mainspring or a motor powered from a source of electrical energy without affecting the implementation of the present invention. Source energy transmits its energy to a time base to maintain oscillations of the latter. Similarly, the time base may be a balance spring associated with an escapement or a quartz, without changing the nature of the present invention.

Mobiles are driven in a conventional manner, from the finishing train, to control the movements of one or more display members.

In the embodiments shown in the figures, a wheel, not visible, which may be the hour wheel is driven from the work train and carries a snail cam 2, integral with the barrel of the hour wheel. Such structures are commonly used in retrograde type movements. The cam, as illustrated in the figures, is thus rotated in the clockwise direction.

A rake 3 is pivotally mounted on the frame by its base 4, from which extends an arm 5 carrying a toothing 6 in the form of a circular arc. One end of the toothing is extended by a finger 7 disposed in abutment against the periphery of the snail cam 2, so that the radius variations of the periphery of the cam, related to its rotation, cause the rake to pivot. reference to the frame.

The toothing 6 of the rake is arranged in engagement with a pinion 8 of a mobile gear 9 pivotally mounted on the frame. The reduction gear comprises a wheel 10, integral in rotation with the pinion 8 and arranged in engagement with a drive member 11, elongate and deformable.

The drive member 11 may be made in various ways adapted to the implementation of the present invention, particularly in the form of a simple elastic, a belt, notched or not, or a chain. The use of a belt is schematized here. This is arranged on the frame 1 so as to be stretched between four pulleys 12 rotatably mounted on the frame.

The belt 11 is arranged simultaneously in engagement with a mobile display 13, more precisely with the toothing of a display wheel 14 of this mobile.

A tensioning mechanism 15 is also provided to maintain a minimum tension level of the belt 11, which has characteristics adapted to allow an efficient transmission of the movements of the belt 11 to the display wheel 14. This tensioning mechanism will not be described here in detail to the extent that the skilled person will not encounter any particular difficulty for its implementation. artwork.

The mobile display 13 further comprises a carriage 16, mounted free in translation on the frame of the movement and including a shaft 17 free to rotate with reference to the carriage and on which the display wheel 14 is integrally mounted . A spiral spring 18 is fixed to the carriage by a first end 19 and the shaft 17 by its second end (not visible). The spiral spring exerts a force on the shaft 17 tending to maintain the display wheel 14 in the position shown on the figure 1a .

Furthermore, the movement according to the present invention also comprises a rail 22 having a toothing and fixedly mounted on the frame 1. The display wheel 14 is arranged to mesh permanently with the toothing of the rail 22.

FIGS also show an hour hand 23 driven on the shaft 17 of the mobile display and intended to indicate the hours opposite indications 24, shown schematically in the figures and, carried by a dial ( non visible).

The operation of the mechanism which has just been described will be exposed now, in relation with the figures 1a , 1b and 1 C .

Consider, by way of nonlimiting illustration, that the hour hand 23 indicates midday or midnight in its position represented on the figure 1a the indications 24 extending over twelve hours.

The figure 1b represents the motion pattern six hours after that of the figure 1 at. The snail cam 2 performs a half-turn during these six hours, according to the mode illustrated and described, which causes a rotation of the rake 3 in the counter-clockwise direction.

The pivoting of the rake induces the rotation of the reduction gear 9 in the clockwise direction, causing a translational movement of the belt 11 towards the bottom of the figures in the region of the reduction gear 9. Consequently, the portion of the belt 11 engaged with the display wheel 14 moves simultaneously in translation, direction of the top of the figures, causing a rotation of the display wheel clockwise.

The rotation of the display wheel rolls it without sliding on the toothing of the fixed rail 22, as a direct consequence of the meshing provided between these two elements, this movement being made possible by the ability of the carriage to move in translation. compared to the frame. Thus, the shaft 17 of the display mobile has combined movements of translation and rotation which causes the free end of the needle 23 to follow a path corresponding to the curve schematically the indications 24 of the time.

During the six hours between the configuration of the figure 1 a of that of the figure 1b , the display wheel makes a quarter turn, while it performs an extra quarter turn to reach the configuration of the figure 1c reached six hours after the figure 1 b.

Moreover, in the twelve hours separating the respective configurations of figures 1a and 1 C , the cam 2 performs a complete revolution so that in the configuration of the figure 1c , the finger 7 of the rake is located near the radial flank 200 of the periphery of the cam.

The pivoting of the rake 3 during these twelve hours opposes the force exerted by the spiral spring 18 on the shaft 17 of the display unit. Thus, when the finger 7 of the rake crosses the radial flank of the cam 2, because of the continuous rotation of the latter, the kinematic chain connecting the rake to the display wheel 14, comprising the mobile gear 9 and the belt 11, is able to undergo the force exerted by the spiral spring on the shaft 17 to produce a rapid retrograde movement of the display unit 13, this kinematic chain and the rake 3.

As has been described above, the torque experienced by the display wheel induces combined movements of rotation and translation of the latter due to its meshing with the toothing of the fixed rail 22. The display wheel then rolls rapidly on the toothing of the fixed rail, driving the carriage 16 in a translation with reference to the frame, as it returns to its initial position, namely that represented on the figure 1 at.

At the same time, the hour hand 23, integral in rotation with the shaft 17, describes a reverse trajectory of that traveled during the twelve previous hours. A new cycle of twelve hours starts again at this moment, as it has just been described.

Note that the location of the spiral spring as shown and described is preferred, but not limiting, because it avoids the appearance of games in the kinematic connection between the rake 3 and the display wheel 14 , without having to resort to gears of a particular type which constitute an effective alternative but more expensive.

Moreover, a time-setting rod 30, which can also fulfill the winding function, has been shown schematically in the figures. The skilled person will not encounter any particular difficulty for its implementation, according to its own needs.

It is also schematized the presence of a dial, which could be transparent for aesthetic reasons, arranged above the movement, when it is mounted in a timepiece box, this dial comprising a rectilinear slot 31 defining lateral bearing or guiding surfaces for the display unit 13 during its translation movement with reference to the frame. For example, the carriage 16 may carry a barrel coaxial with the shaft 17 and whose periphery is disposed in permanent contact with the edges of the slot 31.

The Figures 2a , 2b and 2c illustrate a second preferred embodiment of the movement according to the present invention, in particular the fact that the latter is of course not limited to the shape of the fixed rail bearing the toothing with which the display wheel meshes, or to the gear reduction implemented between the toothing of the rake and the display wheel. In addition, the second embodiment illustrates the fact that the trajectory of the display member depends mainly on the shape of the fixed toothing as well as this reduction factor, considered in relation to the length of the race of the wheel. display on the fixed teeth.

The elements already described in relation to the first embodiment bear the same numerical references for the sake of simplification and will not be repeated in detail.

Two main changes have been made by moving from the first embodiment to the second, namely the dimensioning of the wheel display, the wheel 114 being of smaller dimensions than the display wheel 14, and the shape of the fixed rail 122 bearing the toothing on which rolls the display wheel. The fixed rail has been schematized as being reduced to a toothing in order to simplify the figures, in a nonlimiting manner.

The fact that the display wheel 114 has a small diameter significantly increases the angle traveled by the hour hand 23, the curvature of the fixed rail influencing the shape of the trajectory followed by the display wheel 114 when it rolls. on the fixed toothing, and therefore the trajectory followed by the free end of the needle 23. As on the figures 1a , 1b and 1 C , indications of time 124 have been schematized, by a double line, on the Figures 2a , 2b and 2c , these having substantially the shape of a heart.

Furthermore, it is also schematized the presence of a dial, possibly transparent for aesthetic reasons, in which is formed a slot 131, curved, defining guide surfaces for the carriage 16. The slot 131 preferably extends at a distance rail constant 122 to ensure the maintenance of the meshing between the display wheel 114 and the toothing of the fixed rail 122 during translation movements of the carriage 16.

The figures 2b and 2c illustrate the respective configurations of the movement of the figure 2a six hours later and ten hours later. As the operation of the mechanism is identical to what has been described above, it will not be discussed in more detail.

In particular, when the cam 2 completes a complete revolution, the finger 7 of the rake 3 crosses the radial flank 200 of the cam, which causes a rapid return of the elements of the kinematic chain between the rake and the display wheel, up to their respective initial positions, namely those visible on the figure 2a . As in the first embodiment, the retrograde movement is induced by the force exerted by the spiral spring 18 on the shaft 17 of the display unit 113.

The above description corresponds to preferred embodiments of the invention described in a non-limiting manner. In particular, the shapes shown and described for the various constituent elements of the movement for a timepiece are not limiting.

As mentioned above, the movement according to the present invention can be implemented to display different quantities as an alternative to the time display, among which a second time zone, the minute, the second, the day of the week, the date, the phases of the moon, or even other quantities such as the power reserve, the equation of time, the time of sunrise or sunset. Those skilled in the art will not encounter any particular difficulty in adapting the known mechanisms of the state of the art for displaying these quantities during the implementation of the present invention. Of course, in the case of the display of the power reserve, for example, the movement would include a bidirectional drive mechanism of the belt, or other such drive member, to account for the load and discharge of a mainspring, replacing the retrograde mechanism just described.

It may be noted that in the case where the present invention is implemented in an electromechanical-type timepiece, the gear trains may be arbitrary and the person skilled in the art will not encounter any particular difficulty in adapting them to his own needs.

Similarly, it is possible to provide a jumping display of the desired size. As an illustration, from the described embodiments, it is conceivable to mount a star of twelve integral in rotation with the cam 2 to obtain displacements of the cam in successive jumps.

Moreover, it is possible to provide a correction of the value of the displayed quantity in increments of one unit. Thus, in the case of the hour, one could provide a corrector which, with each pressure, would turn the cam 2 by a twelfth of a turn.

As previously mentioned, the drive member 11 can be made in various forms without departing from the scope of the present invention, especially in the form of a belt, notched or not, a simple elastic, or a chain. Likewise, the person skilled in the art will not encounter any particular difficulty in modifying the number and the locations of the pulleys, or other suitable guiding means, such as described in connection with the two embodiments which have just been exposed. The same applies to the illustrated tensioning member.

It will also be possible to use simultaneously two mechanisms of the type that has just been described in the same movement, or more, such as for example to display the hour and minute following two original trajectories.

Claims (9)

1. A clockwork movement comprising:

   - a frame (1) bearing a motor organ, a time base and driving wheels (9), pivotably mounted on said frame, arranged so as to drive at least one display wheel (13) designed to bear a display organ (23) for displaying information,

   - a fixed toothing (22) secured to said frame, said display wheel having a toothed organ (14) engaged with said fixed toothing, and

   - a driving organ (11) having first and second kinematic connections, with one of said driving wheels (9) and with said toothed wheel (14), respectively, to roll the latter part in translation, in a first direction, along said fixed toothing,

   - characterized in that said fixed toothing (22) has first and second distinct ends, and in that the clockwork movement is arranged so as also to allow said toothed organ to be driven in the direction opposite said first direction.
2. The movement according to claim 1, characterized in that it also comprises a retrograde mechanism (2, 3, 18) designed to allow said toothed organ (14) to be driven at a first speed in said first direction from an initial position to a final position and to allow said toothed organ to be driven at a second, faster speed in said opposite direction from said final position to said initial position.
3. The movement according to claim 2, characterized in that said retrograde mechanism has a balance-spring (18) mounted coaxial to said toothed organ (14) and arranged so as to act on the latter to cause it to roll on said fixed toothing (22), in said opposite direction, from said final position as far as said initial position.
4. The movement according to one of claims 1 to 3, characterized in that it comprises at least one guide surface (31) extending at a substantially constant distance from said fixed toothing (22) and which said display wheel (13) is designed to be positioned at least indirectly bearing against.
5. The movement according to any one of the preceding claims, characterized in that said driving organ (11) is deformable.
6. The movement according to claim 5, characterized in that said driving organ (11) is a rubber band, a belt, preferably notched, or a chain.
7. The movement according to one of claims 5 and 6, characterized in that it has at least one tightening organ (15) acting on said driving organ (11) to keep it live in all positions of said display wheel (13).
8. A timepiece comprising a box closed by a glass and containing a movement according to one of claims 1 to 7, a hand (23), visible through said glass, being borne by said display wheel to display information from the group consisting of the second, the minute, the hour, a second time zone, the day of the wheel, the date, and the phases of the Moon.
9. A timepiece comprising a box closed by a glass and containing a movement according to one of claims 1 to 7, a hand (23), visible through said glass, being borne by said display wheel to display information from the group consisting of the power reserve, the equation of time, and the sunrise or sunset time.

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