EP4121822B1 - Mechanical stop and start system for a function, and watch comprising such a system - Google Patents

Description

Technical area

The present invention relates to the field of watchmaking and concerns a system for mechanically starting and stopping a function. By starting the function, we define the passage of the function, from an initial state, of rest, to a second state, active, and by stopping the function, we define the reverse passage from the active state to the state of rest.

State of the art

In the field of mechanical watchmaking, we know functions which have rest or stop states and operating states. For example, this is the case with a chronograph, or with a minute repeater, which are operated by pushers or by a bolt. Certain functions are also controlled automatically, by complex trigger systems, such as ringtones or alarm clocks.

We know the document US3541781 , a mechanism for detecting whether a wearer is standing or sitting and counting the time spent in these positions. A lever is mounted free to rotate, and comes under the sole action of its weight, and depending on the position of the device, to block or leave free, an anchor wheel of a counting cog. However, this mechanism is not very precise and the positions of the device in which the measurement starts or stops are not defined.

The present invention aims to propose a mechanism for controlling a function, which can be used in a mechanical watch, that is to say which does not use electronic or electrical elements, and which is remedied at least partially to the disadvantages of the prior art.

Disclosure of the invention

More precisely, the invention relates to a system for mechanically starting and stopping a function of a timepiece, comprising a mass, movably mounted on a frame, between a first and a second extreme positions, defined respectively by a first and a second stop, said mass moving, under the effect of gravity, by constraining a spring between the first and second extreme positions, and by relaxing said spring between the second and first extreme positions, said mass being connected kinematically or directly to a control member of said function.

The mass and the force of the spring are determined as a function of the force necessary to control said function and move the control member, and the predetermined spatial orientations of the frame, in which the mass is moved in a bistable manner from one to the other. other of its extreme positions, depending on the result of the forces exerted by the spring and by gravity, the movement of the mass from the first extreme position to the second extreme position being capable of causing the starting or stopping of said function by via the control member, and the movement of the mass from the second extreme position to the first extreme position being capable of causing the stopping or starting respectively of said function via the control member. piloting.

This definition of the invention extends to a system for controlling a function of a timepiece, capable of occupying a first state and a second state, in particular an animation.

According to another aspect, the invention also relates to a watch comprising such a starting and stopping system.

Brief description of the drawings

• la figure 1 représente une définition choisie pour les axes de rotation qu'une montre peut subir au porté,
• la figure 2 et la figure 4 sont des vues du système de démarrage et d'arrêt selon un mode de réalisation particulier, respectivement dans une première et une deuxième positions extrêmes, et
• la figure 3 représente une montre comprenant un système selon l'invention, pour positionner des axes et angles de référence.

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

• there figure 1 represents a definition chosen for the axes of rotation that a watch can undergo when worn,
• there figure 2 and the Figure 4 are views of the starting and stopping system according to a particular embodiment, respectively in a first and a second extreme positions, and
• there Figure 3 represents a watch comprising a system according to the invention, for positioning reference axes and angles.

Mode of carrying out the invention

The aim of the present invention is to provide a mechanical switch, making it possible to start and stop a function, on command, but without pressure or direct mechanical action on the switch. More precisely, the starting and stopping system according to the invention makes it possible to start and stop the function, according to the spatial orientation of the system and therefore of the watch in which it is integrated. As will be understood later, different dimensions are possible, but a preferred embodiment is to dimension and arrange the system according to the invention in such a way that the function starts when the wearer makes the usual gesture to read the time when the watch is on his wrist and the function stops when he rotates his wrist, for example to return his arm to a more vertical position.

More particularly, the system for starting and stopping a function according to the invention comprises a mass, of the oscillating mass type, movably mounted on a watch frame, between a first and a second extreme positions. The latter are defined respectively by a first and a second stops, which can be elastic in order to absorb shocks.

A spring is connected to the mass. The connection between the spring and the mass is preferably direct, so that the movements of the mass have a direct impact on the winding of the spring. More particularly, when the mass moves under the effect of gravity, following a gesture by the wearer which sets it in motion, the spring is arranged so as to be constrained by the mass when it moves between the first and the second extreme position. Conversely, when the mass moves between the second and first extreme positions, the spring relaxes and, if necessary, returns the energy stored in the mass, against gravity.

The mass is connected kinematically or directly to a control member of said function. Advantageously, the connection between the mass and the control member is desmodromic. This connection can be of the meshing type with a pinion or a rack carried by the mass and meshing with the control member. The mass can also directly carry a magnet, which can magnetically control, for example, visual animation type functions as will be detailed below.

The mass (of the mass) as well as the force of the spring are determined according to the force necessary to control said function and move the control member. We also dimension the system according to the predetermined angular orientations of the watch, in which the mass is moved from one to the other of its extreme positions, according to the result of the forces exerted by the spring and by gravity, the movement of the mass from one to the other of said extreme positions causing the starting or stopping of said function via the control member.

In other words, we first determine the force or torque necessary to start or stop the function (to rotate shuttles or a chronograph column wheel, activate a trigger lever, move a magnet, etc.). .).

We also determine the orientations of the watch in which we want the function to be started or stopped. In a preferred embodiment, it is determined that the function is started when the wearer brings the watch to his or her gaze in a reading position. As can be seen on the figure 1 , we define the alpha angle as being the angle of rotation around the axis 9H-3H, the beta angle as being the angle of rotation around the axis 12H-6H and the gamma axis as being l angle of rotation around the orthogonal axis passing through the center of the dial. These three angles are zero when the watch is placed horizontally, in front of the wearer, with the 9H-3H axis schematically parallel to the shoulder line. In the usual time reading position, in which we want to start the function, we have Alpha between 30-35°, Beta =0°, Gamma=0°.

Preferably, but without it being obligatory, we also want to stop the function in a wrist rotation position which is different from the previous position. This limits the risk of untimely alternation between stops and starts, around a single orientation. Preferably, the stop orientation is defined for Alpha between 15-18°, Beta =0°, Gamma=0°. It will be noted that the stopping orientation is preferably different from the neutral orientation of the starting point taken into consideration for starting (in which Alpha = 0°, Beta = 0°, Gamma = 0°). We can play on this hysteresis in the calculation of the spring, to differentiate the orientations of the watch used respectively for starting and stopping the function. This differentiation makes it possible to avoid unwanted alternations of start and stop, which could occur if the watch oscillated around a single start and stop position.

From these factors, we determine the travel of the mass, the mass (of the mass) to generate the necessary torque.

However, the spring must also be dimensioned both in terms of its stiffness and its preload. Its function is to keep the mass abutting in its first extreme position, against gravity, until the watch has been placed in the corresponding orientation. Beyond this orientation, the force exerted by gravity is greater than the force exerted by the spring, and the mass moves starting the function. The spring also has the function, when the mass is abutted in its second extreme position, of returning the mass to its first extreme position when the force exerted by gravity becomes smaller than the force exerted by the spring. The mass then stops the function.

The sizing and calculations of the mass and characteristics of the spring are within the reach of those skilled in the art, without having to describe them in detail. To obtain the expected result, several parameter solutions exist, for example with a heavier mass, and a stronger spring, the system can be triggered and stopped according to the requested specifications.

We could use an unbalanced mass mounted to move in rotation, like an automatic winding oscillating mass, some of which operate with a limited angular stroke. In this case, we will take into account the unbalance, which includes the eccentricity of the mass, which has an effect on the torque supplied. However, the mass can also have a linear or complex trajectory.

Thus, a starting orientation and a stopping orientation are predetermined. The mass is of the bistable type and is maintained in its first extreme position as long as the watch has not crossed the starting orientation, and is maintained in its second extreme position as long as the watch has not crossed the starting orientation. 'stop.

Unlike the present invention, an oscillating mass of an automatic winder does not make it possible to stop the winding function. In any case, even if we were to consider that in certain positions of the mass, notably when it is stationary, there is no winding of the barrel, the winding and non-winding positions are not not predefined and do not correspond to specific spatial orientations of the watch.

In order to reduce shocks linked to mass movements and interactions with the stops, the ground can be connected to a speed regulator. The latter can be an escapement, for example with a rubbing rest as used in certain bells, or a brake with centrifugal weights, also of the type used in bells. It is also possible to use a magnetic or oil bath brake device.

To offer the user the possibility of shunting the switch and moving the watch without starting the function, a ground blocking device can be provided. This device is advantageously accessible from outside the watch. It may consist of a pusher or a lock cooperating directly or indirectly with the mass to block its movements, preferably in one of its extreme positions.

The system according to the invention could be arranged in the form of an independent module, comprising its own frame and mounted on a base movement. The mechanism or components making it possible to carry out the function to be controlled may also be arranged on the frame or be arranged on the basic movement. In this case, a kinematic or other connection, magnetic for example, will be provided between the module and the basic movement.

The system according to the invention can be used to control, that is to say start and stop, a function whose mechanism which allows it to be carried out is arranged in the watch.

An example of a function that can be controlled by the system according to the invention is a visual animation. The visual animation can be controlled mechanically, for example by releasing or blocking a barrel, respectively when the mass is in its first or second extreme positions. This barrel can drive an automaton, of the Jacquemart type, typically by driving a cam on which a mobile element is held pressed. By mounting a magnet on the mass or by having a magnet driven by the mass, this magnet can cause the movement of a paramagnetic or diamagnetic mobile element, capable of reacting to the movement of the magnet by moving itself. This movement can be guided by the mounting of said movable element, for example in rotation or on a guide rail.

To the figure 2 , an example of a particular embodiment of a starting and stopping system according to the invention has been shown. According to the example, the The function to be controlled is an animation, controlled by the movement of a magnet.

The mass is an oscillating mass 10, mounted to move in rotation. It is provided with teeth 100, meshing with teeth 120 secured to the control member, which takes the form of a lever 12, pivotally mounted on the frame of the module or timepiece. The teeth 100 and 120 are advantageously incomplete, that is to say they are arranged on a toothed sector, less than 360°, given that the oscillating mass 10 is limited in its rotation between its two extreme positions, by two stops not shown. In the exemplary embodiment, the reduction ratio between the teeth is taken equal to -1.

The spring 14 is of the spiral type, acting on the control member, according to the example at the level of the axis of rotation of the lever, by a first of its ends. The other end is fixed to the frame.

The lever 12, at its end opposite its axis of rotation, carries a magnet 16. The latter acts on a magnetic, mobile element, movable for example above the dial, to be visible to a user, while the system of Start and stop is hidden under the dial.

When the watch is in a horizontal position, gravity is parallel to the axis of rotation of the mass. As a result, the unbalance of the mass does not generate any torque at the axis.

In addition, the spring 14 is preloaded, according to the example in a clockwise direction. The spring 14 will therefore apply a torque in the clockwise direction to the lever, transmitting to the oscillating mass 10, via the gear connection, a torque tending to make it pivot in the counterclockwise direction. However, in this position, the oscillating mass 10 is in its first extreme position, against a so-called high stop (not shown in the drawing). The system is therefore in equilibrium in a first stable position. The magnetic element positioned by the magnet is also in a first stable position. In this first position, it can be hidden behind a cover so as not to be visible to the wearer.

Beta étant l'angle (avec un signe selon les normes trigonométriques) du centre de masse par rapport à l'axe 9h-3h (figure 2)When the wearer of the watch rotates it along the axis 9H-3H ( Figure 3 ) from an angle alpha, the torque generated by gravity on the mass at the level of the X axis will gradually increase according to the formula: $$\mathrm{Couple}\mathrm{mass}=\mathrm{d}*\mathrm{m}*\mathrm{gravity}*\mathrm{sinus}\left(\mathrm{alpha}\right)*\mathrm{cosine}\left(\mathrm{beta}\right)$$

Beta being the angle (with a sign according to trigonometric standards) of the center of mass relative to the 9h-3h axis ( figure 2 )

Beta0 étant l'angle Beta lorsque la masse est dans sa première position stable.The torque of the return spring (reduced to the center of rotation of the mass) is constant as long as Beta remains the same and its value is: $$\mathrm{Couple}\mathrm{Spring}=-\mathrm{K}*\left(\mathrm{Theta}0+\mathrm{Beta}0-\mathrm{Beta}\right)$$

Beta0 being the Beta angle when the mass is in its first stable position.

There is also resistive torque to move the function from a stopped state to a started state. We will consider this couple as being constant in our example (of Cresistif value) and opposite to the direction of movement.

The balance of torques applied to the mass is therefore: C=d*m*gravity*sine(alpha)*cosine(beta)-K*(Theta0+Beta0-Beta)- Cresistive

As long as this torque is negative, the mass tends to rotate counterclockwise and therefore remains at a stop, in the first stable position.

L'angle pour lequel le couple devient positif est appelé Alpha0This couple becomes positive when sine (Alpha) becomes greater than (beta=beta0): $$\mathrm{sinus}\left(\mathrm{alpha}0\right)>\left(\mathrm{K}*\left(\mathrm{Theta}0\right)+\mathrm{Cresistive}\right)/\left(\mathrm{d}*\mathrm{m}*\mathrm{gravity}*\mathrm{cosine}\left(\mathrm{beta}0\right)\right).$$

The angle for which the torque becomes positive is called Alpha0

Once the result of the torques applied to the oscillating mass 10 has become positive, the torque generated by gravity will be greater than the resistive torque of the function and the return spring. The mass will therefore rotate around its axis, clockwise (Beta will decrease). The oscillating mass 10 will remain in motion until it has reached its second extreme position ( Fig. 4 ), against a so-called low stop (not shown) or that the torque generated by gravity becomes smaller again than the resistive torques.

In practice if the alpha angle of the watch does not vary, only the Beta angle will change, and we will seek to ensure that the evolution of the torque generated by gravity increases faster than that of the spring (by choosing judiciously the different parameters of the mass and the spring). In this way, once the mass is set in motion, the torque only increases with the movement of the oscillating mass 10 and the passage from the first to the second extreme positions is carried out continuously, without passing through a stable intermediate position (without modification of the angle of the watch), and the mass is therefore bistable. The magnetic element is also in a second stable position. In this second position, it can be visible to the wearer.

As long as the angle of the watch remains unchanged, the system remains in balance with the oscillating mass 10 in its second stable position. The torque equation has however changed because the resistive torque of the function has now changed sign (to move the function this time from a started state to a stopped state), the mass having to rotate counterclockwise) .

We have : C=d*m*gravity*sine(alpha)*cosine(beta)-K*(Theta0+Beta0-Beta)+ Cresistive

As long as this torque is positive, the oscillating mass 10 tends to rotate clockwise and therefore remains at a stop, in the second stable position.

This couple becomes negative when sine (Alpha) becomes smaller than (beta =betaF): sine(alphaF)<(K*(Theta0+Beta0-BetaF)-Cresistive)/(d*m*gravity*cosine (betaF)). The angle for which the torque becomes negative is called AlphaF

Once the result of the torques applied to the mass has become negative, the torque generated by gravity will be smaller than the resistive torque of the function and the return spring. The oscillating mass 10 will therefore pivot around its axis, counterclockwise (Beta will increase). The mass will remain in motion until it returns to its first extreme position or until the torque generated by gravity becomes greater than the resistive torques again.

In practice if the angle of the watch does not vary, only e will change, and we will seek to ensure that the evolution of the torque generated by gravity decreases more quickly than that of the spring (by choosing judiciously the different parameters of mass and spring). In this way, once the mass is set in motion, the torque only decreases with the movement of the mass and the passage from the second to the first extreme positions is carried out continuously, without passing through a stable intermediate position (without modification of the angle of the watch), and the mass is therefore bistable.

It should be noted that in the case of a visual animation, the notions of stopping and starting the function must be understood broadly, as corresponding to a first and a second state of the visual animation. For all practical purposes, we can use the term control system, as equivalent to the term start and stop system.

Like the visual animation driven by a barrel, the function can also be a striking mechanism, the triggering of which can be repeated by a ringing in passing. The barrel is released or blocked depending on the positioning of the mass, respectively when it is in its first or second extreme positions.

In the two aforementioned examples using a barrel, it is wound by a winding mechanism, either specific or via winding of the main barrel of the movement. This winding can be manual or automatic. The animation or ringing mechanism can also be powered by the movement barrel, using a barrel adapted to provide energy via two power take-offs.

By a kinematic connection of gear type (pinion or rack), it is also possible to move wheels or pinions, such as for example a set of shuttles or a chronograph column wheel, as a control member of the chronograph. The reset phase can advantageously be carried out by a pusher acting separately on the control member and on the conventional reset elements (hammers, etc.).

A kinematic connection with the unbalanced mass can also cause the movement of at least one movable flap on or under the main dial, a sub-dial or a part of the dial, to modify the appearance of the watch, or allow specific displays to appear. Polarized lenses can be used and moved via this movable shutter(s).

Such shutters can also be moved by releasing a barrel, as described above.

Thus, the system according to the invention makes it possible to control a function by starting and stopping it, or by controlling its passage from a first state to a second state, and vice versa, when the watch occupies respectively a first and a second spatial orientations. These particular spatial orientations correspond to first and second extreme positions of a mass. These positions are determined and thanks to the bistable nature of the movement of the mass, the transition from one state to another of the function is precise, corresponding to a specific spatial orientation.

Those skilled in the art will be able to adapt the above description, without departing from the scope of the invention defined in the claims. It will be able to define the starting and stopping orientations, the types and forces and spring preloads, the connection between the mass and the control system.

Claims (14)

1. System for mechanically starting and stopping a function of a timepiece, comprising a mass (10) mounted movably on a frame, between a first and a second extreme position, defined respectively by a first and a second stop, said mass moving, under the effect of gravity, while stressing a spring (14) between the first and the second extreme position, and by relaxing said spring between the second and the first extreme position,

   said mass being kinematically or directly connected to a control member (12) of said function,

   the mass (10) and the force of the spring (14) being determined as a function of the force required to control said function and move the control member (12), and also as a function of predetermined spatial orientations of the frame, in which the mass is bistably moved from one to the other of its extreme positions, according to the resultant of the forces exerted by the spring and by gravity, the displacement of the mass from the first extreme position to the second extreme position being adapted for starting said function by means of the control member (12), and the displacement of the mass from the second extreme position to the first extreme position being adapted for stopping said function by means of the control member (12).
2. System according to claim 1, characterized in that the mass is rotatably mounted and is unbalanced.
3. System according to one of the preceding claims, characterized in that the mass is connected to a speed regulator.
4. System according to claim 3, characterized in that the speed regulator is an escapement, a flywheel brake, a viscous friction device in a bath.
5. System according to one of the preceding claims, characterized in that it comprises a device for blocking the mass.
6. System according to one of the preceding claims, characterized in that the control member bears a magnet.
7. System according to one of the preceding claims, characterized in that the spring is calculated in such a way that the orientations of the frame triggering the starting, respectively, the stopping of the function, are different.
8. System according to one of the preceding claims, characterized in that elements for realizing said function are mounted on the frame.
9. Watch comprising a system according to one of the preceding claims and a mechanism for realizing said function, in which said weight passes from its first to its second extreme position, and from its second to its first extreme position, respectively, when the watch is brought into a first or a second spatial orientation.
10. Watch according to claim 9, characterized in that the first and second spatial orientations are similar.
11. Watch according to claim 9, characterized in that the first and second spatial orientations are different.
12. Watch according to claim 11, characterized in that in the first orientation the watch has an angle alpha of between 30 and 35°, Beta =0°, Gamma=0° and in the second orientation the watch has an angle alpha of between 15 and 18°, Beta =0°, Gamma=0°,
    angle alpha being the angle of rotation of the watch about an axis passing through the positions 9H and 3H of the dial, alpha being equal to 0 when the dial is horizontal, angle beta being the angle of rotation about the axis 12H-6H and axis gamma being the angle of rotation about the orthogonal axis passing through the center of the dial.
13. Watch according to one of claims 9 to 12, when dependent on claim 5, characterized in that the weight locking device is accessible from the outside of the watch.
14. Watch according to one of claims 9 to 13, characterized in that the mechanism is selected from a chronograph mechanism, a striking mechanism, a visual animation mechanism.

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