The present invention relates to an oscillating weight with variable geometry for a timepiece mechanism, and a timepiece mechanism comprising such a weight and a timepiece comprising such a weight and/or such a mechanism.
Oscillating weights for automatic watches are well known and widely used. Typically, an oscillating weight is used to ensure the winding of a movement through its oscillations created by the movements of the wearer of the watch. The weight is mounted to pivot for example by means of a bearing. As a general rule, a reverser ensures the conversion of the reciprocating movement of the weight into a one-way rotary movement. The geartrains of the winding system ensure the link between the various elements. The rotational driving of the winding geartrain is used to arm an energy source of the watch, for example the spring of a barrel.
Watches are known in which the oscillating weight is arranged at the bottom of the case, for example mounted on the side of the bridges of the watch. Also known are watches in which the oscillating weight is arranged matched to the dial of the watch.
Oscillating weights are known which are not visible to the wearer of the watch. Also known however are automatic watches provided with an oscillating weight that is visible to the wearer on the back or front face of the watch.
An ideal oscillating weight has both a great weight and a great moment of inertia, which allows an effective winding of the watch. It can concentrate most of its weight on its outer periphery. Such a weight generally comprises a solid peripheral portion, generally in the form of a circular arc. This portion will hereinafter be called “inertia sector”. In this context, a “plate” links the inertia sector to the bearing, which defines the axis of rotation of the weight.
Generally, such a weight also comprises link elements, for example arms, linking the inertia sector to the bearing. These arms can define cutouts, allowing the elements behind and/or in front of the oscillating weight to be seen, at least partially, while lightening its weight.
Other oscillating weights have no cutouts.
As a general rule, the known oscillating weights are composed of a single part, having a fixed geometry, that is to say a geometry which does not vary over time. Nor does the winding torque of these weights vary over time.
In other known examples, the oscillating weight comprises two or more portions whose relative position does not substantially change over time. In other words, during the movement of the oscillating weight, these portions are synchronous.
For example, the document CH707942 relates to a weight comprising two portions linked by a rigid synchronizing mechanical link, for example a connecting rod, each end of which is secured to one of the portions by a screw. The two portions are always synchronous.
The document EP1136891 relates to two oscillating weights in the same plane, linked by a geartrain so that the two weights still have a synchronous movement, in order to avoid collisions.
The document EP1918789 describes an oscillating weight comprising two portions, of which one portion is displaced on a guiding means on the periphery of the other portion. The portion which is displaced makes it possible to give the initial impulse to the oscillating weight. Then, the two portions have a position that is fixed with respect to one another.
In the case of a one-piece weight or a piece in several portions as presented, in normal conditions of use of the watch, the displacements of the arm of the wearer of the watch bring the weight into imbalance and it is this and the Earth's gravitational force g which define the torque.
If the wearer is a very active person, the accelerations encountered can be substantially higher. For example, the arm and/or the hand which wears (wear) the watch comprising such an oscillating weight can undergo high accelerations. That occurs, for example, when the user practices a sport such as tennis, golf, etc.
Currently, the winding mechanisms are chosen in such a way that they ensure spring arming conditions for a normally active person. The result thereof is that, for a highly active wearer, the barrel spring is greatly stressed and risks wear which cannot be excluded. If, on the other hand, the wearer is not very active, it is possible that the barrel spring will not be sufficiently armed.
In such cases, it would be desirable for the movement of the weight not to cause the winding of the watch in certain conditions. However, that would mean that, in the case of “normal” use of the watch, that is to say, for example when the user does not practice a sport, the winding of the watch would no longer be performed.
The document EP1445668 relates to an oscillating weight comprising two portions that are removable with respect to one another, and arranged so that their relative displacement generates a radial displacement of the center of gravity of the oscillating weight. Thus, it is possible to vary the working conditions of the mechanism and adapt it to the lifestyle of the wearer.
However, the oscillating weight described in the document EP1445668 has certain disadvantages. In fact, to displace the center of gravity of the oscillating weight, the watch has to be brought to a horologist trained for that purpose, because this displacement is done by unscrewing screws and nuts which set the position of the first part with respect to the second. Then the second part has to be moved into a new position and the screws and nuts have to be screwed back.
Changing the geometry and therefore the position of the center of mass (or at the center of gravity) of the watch is therefore neither simple nor immediate. It cannot be done by the wearer of the watch.
The user of known watches cannot directly vary the geometry of the oscillating weight, and therefore the position of its center of gravity and thus adapt it to his or her lifestyle (for example, sporty, normal, . . . ).
In other words, a user has no known solutions for acting himself or herself on the watch so that the movement of the weight does not cause the winding of the watch in certain conditions (for example, and in a nonlimiting manner, when practicing a sport), and also so that the movement of the weight on the other hand causes the winding of the watch in other conditions (for example, and in a nonlimiting manner, when he or she has finished practicing his or her sport).
The document EP2544055 describes an oscillating part such as an oscillating weight, in which a front-facing surface of the oscillating part is used as an additional display surface. In one example, the oscillating weight bears a dial and three output displays, notably three hands. The three hands are linked, via geartrains, to three output mobiles revolving about the main pivoting axis of the mechanism. The dial is borne by a dial wheel, which is linked via an intermediate geartrain to a toothing which gives the angular position of the oscillating weight. In this mechanism, the dial remains permanently in the same angular orientation with respect to the plate of the movement, and to the case which contains the latter. This document does not describe a mechanism that makes it possible to vary the center of gravity of the oscillating weight, or the winding torque.
The document U.S. Pat. No. 2,593,685 relates to a mechanism intended to be mounted on the steering wheel of a car and which exploits the movements of the steering wheel and/or the vibrations of the car to wind a watch. To this end, the mechanism comprises a case linked to the steering wheel and comprising two spherical or hemispherical weights, arranged so that the larger one contains the smaller one. The two weights are linked to a “differential” mechanism comprising two parallel tapered gears, both linked to a third tapered gear mounted on a shaft. The mechanism is arranged in such a way that the movements of the weights are converted into a one-way rotational movement of the shaft about the axis, independently of the direction of oscillations of the two weights. In the solution described, the weights are used to rotate the differential mechanism by their movement.
There is therefore a need for an oscillating weight with variable geometry that is free of the limitations of the known oscillating weights.
There is therefore a need for an oscillating weight with variable geometry in which the geometry and therefore the position of the center of gravity of the weight can be varied by the user of the watch without needing to bring the watch to a horologist trained for that purpose.
There is therefore a need for a timepiece mechanism and/or a timepiece such as an automatic watch in which the movement of the weight does not cause the winding of the watch in certain conditions, depending on the wishes of the user.
One aim of the present invention is to propose an oscillating weight with variable geometry that is free of the limitations of the known oscillating weights.
One aim of the present invention is also to propose an oscillating weight with variable geometry in which the position of the center of mass can be modified by the user of the watch without having to bring the watch to a horologist trained for that purpose.
One aim of the present invention is also to propose a timepiece mechanism and/or a timepiece such as an automatic watch for which the user can directly vary the geometry of the oscillating weight, and therefore the position of its center of gravity, and thus adapt it to his or her lifestyle (for example, sporty, normal, . . . ).
According to the invention, these aims are achieved notably by means of the timepiece as claimed in claim 1.
The oscillating weight with variable geometry for a timepiece mechanism according to the invention comprises:
In this context, a “differential mechanism” is a timepiece mechanism which comprises at least one sun gear and at least one planetary wheel comprising an axis of rotation, arranged both to revolve about this axis of rotation and to revolve around the sun gear.
In a preferential variant, the differential mechanism is a differential mechanism with dual planetary wheel and dual sun gear, that is to say that it comprises two sun gears and two planetary wheels.
By virtue of the presence of the differential mechanism, this solution notably has the advantage over the prior art of being able to vary the geometry of the oscillating weight, and therefore the position of its center of gravity, directly by the use of the watch, without having to bring the watch to a horologist trained for that purpose.
The user can thus ensure that the movement of the weight does not cause the winding of the watch in certain conditions (for example, and in a nonlimiting manner, when practicing a sport), and ensure that the movement of the weight causes the winding of the watch in other conditions (for example, and in a nonlimiting manner, when he or she has finished practicing his or her sport).
Examples of implementation of the invention are indicated in the description illustrated by the attached figures in which:
In the example of
In the example of
In the example of
In the example of
In the example of
Although in the example of
In the example of
In particular, the distance between these two planes 261, 262 corresponds substantially to the thickness of the first part 10 so that when the inertia sector 12 of the first part 10 enters into contact with the inertia sector 22 of the matching second part 20 of the contact region C, the plate 16 of the first part 10 and the second portion 262 of the plate 26 of the second part 20 are coplanar.
In other words, in the example of
In other words again, in the example of
Obviously, other variants can be imagined, for example and in a nonlimiting manner, the inertia sector 12 of the first part 10 can be disposed side-by-side with the inertia sector 22 of the second part 20 and all the plate 16 of the first part 10 can be superposed on all the plate 26 of the second part 20.
In yet another variant, each of the two parts 10, 20 is flat and a first portion 161 of the plate 16 of the first part 10 is superposed on a first portion 261 of the plate 26 of the second part 20 (matching the axis of rotation 40). The two parts thus remain on two different planes even when they are placed alongside one another. It is possible in this variant for one end of the inertia sector of a part to be superposed partially on the inertia sector of the other part.
In a variant, when the two parts 10, 20 are placed alongside one another, the oscillating weight 1 can comprise means for maintaining the position of one part with respect to the other. For example, one part can bear a finger or lug which engages in a corresponding opening in the other part. Other variants can easily be imagined.
In a variant, the first part 10 and/or the second part 20 are made of a heavy material, often of heavy metal, of gold or of platinum in the high-end watches.
According to the invention, a differential mechanism 30, partially visible in
In fact, as can be seen in
In the position of
By contrast, in the configuration of
The user can advantageously modify the geometry of the oscillating weight 1 according to the invention, that is to say the winding torque of the watch, at any time, for example between two extreme positions (for example those of
In a variant, an indicator that is not illustrated allows the chosen torque to be displayed.
The result thereof is an interaction with the wearer of the watch who adapts the geometry of the two oscillating parts 10, 20 either to take account of his or her activity or, for example, to remain within the zone of optimal tension of the energy source of the watch (for example power reserve in median zone).
Although in the variant of
For example, it is possible, upon the displacement of the first part 10, for the second part 20 to also be displaced.
It is also possible for only the second part 20 to be displaced with respect to the first part 10, which remains fixed.
Although in the variant of
Possibly, an optional indicator 60 can indicate the chosen configuration of the parts 10, 20 and/or the chosen mode of operation of the watch.
The differential mechanism 30 according to the invention is represented in
In the example of
In this context, the expression “planetary wheel” denotes a wheel, notably a toothed wheel, which is arranged both to revolve about its axis of rotation and which can at the same time revolve also about another wheel.
In the case of
The intermediate wheel 32 in the example of
In the variant illustrated, the first sun gear 31 is linked to the first part 10, notably it is borne by the first part 10. It is arranged to revolve about the axis of rotation 40 of the oscillating weight 1.
In the example of
In the variant illustrated, the second sun gear 34 is fixed for most of the time, except during the changing of geometry of the oscillating weight 1. It is arranged to revolve about the axis of rotation 40 of the oscillating weight 1.
The differential mechanism of
Although in the example of
In the example of
In a standard situation, when no modification is made by the wearer of the watch, the sun gear 34 is kept fixed by means of a fixing mechanism (not illustrated) such as a jumper.
In the case of a modification by the wearer of the watch, the second sun gear 34 revolves about the axis of rotation 40, thus driving the second planetary wheel 33b about its axis of rotation 42 and around the sun gear 34. The second planetary wheel 33b in turn drives the rotation of the first planetary wheel 33a about its axis of rotation 42 and around the first sun gear 31. The first sun gear 31 therefore also revolves about the axis of rotation 40, causing the displacement of the first part 10 with respect to the second part 20.
It should be noted that, during the relative displacement of one part 10, 20 with respect to the other 20, 10, the planetary wheels 33a, 33b revolve both about their axis of rotation 42 and also around the central wheels (or possibly the intermediate wheels). Once the two parts occupy the desired relative position, they are no longer displaced with respect to one another. In this case, during the movement of the oscillating weight 1, the two parts are synchronous and, during their movement, the planetary wheels 33a, 33b revolve only about their axis of rotation 42.
In the variant of
In the variant of
In the three cases illustrated, the first part 10 is arranged to be completely superposed on the second part 20 (as illustrated in
In another variant (not illustrated), the oscillating weight 1 comprises several parts (for example three or more) and a differential mechanism arranged to displace the parts so that they are all superposed on one another and to displace them in the manner in which a fan is opened.
In a variant, an indicator (not illustrated) informs the wearer as to the angular difference between the two parts 10, 20 chosen by the wearer of the watch and/or as to the chosen mode of operation and/or as to the geometry of the oscillating weight and/or as to the winding torque of the oscillating weight.
It is for example possible to set, by convention, that this value is zero when the two parts 20, 20 are opposed (as for example in
In the case where this indicator is visible only on the back of the watch, that is to say the part of the watch which is in contact with the wrist of the user, it can be produced as follows: one of the two parts 10, 20, notably the one which is displaced, can comprise an end of the weight configured so as to represent the end of an indicator such as a hand. A graduation, or any other equivalent means, can be positioned on the other part.
In another variant, an indicator such as a hand is secured to a sun gear, for example the gear 34. This indicator can be indexed with a graduation or any other equivalent means which can for example appear on the dial of the watch, taking into account the relative position of the two parts 10, 20. In this variant, a geartrain linked to the gear 34 can make it possible to display the position of the latter at various points of the dial, for example by means of a hand or of an indicator disk, even on a flank of the case, for example by means of a disk visible through a window.
In another variant, the wheels of the differential mechanism can be dimensioned so that the parts 10, 20 are displaced with the same angular speed. In other variants, the wheels of the differential mechanism are dimensioned so that the parts 10, 20 are displaced with a different angular speed.
In another variant, the angular speed of one part is greater, for example two times or N times greater, than the angular speed of the corresponding sun gear. In a variant, this ratio will be taken into account to dimension a possible correction mechanism.
In the example of
The intermediate wheel 32 in the example of
In the variant illustrated, the first sun gear 31 is linked to the first part 10. It is arranged to revolve about the axis of rotation 40 of the oscillating weight 1.
In the example of
The intermediate wheel 35 in the example of
In the variant illustrated, the first intermediate wheel 32 is coaxial to the second intermediate wheel 35. Notably, these wheels share the axis of rotation 43.
In the variant of
In the variant illustrated, the frame 80, notably its central portion 81, comprises an opening 84, to lighten the weight thereof.
The end 83 of the frame 80, which bears the axis of rotation 43 of the first and second intermediate wheels 32, 35, comprises a toothing 89 to be able to mesh with a control wheel 90.
In the variant of
The oscillating weight 1 of
In fact, in the variant of
In the variant of
In the variant of
In the variant of
In another variant, alternative to or in addition to the preceding one, the movement of the control wheel 90 drives the movement of the end 83 of the frame 80, notably its rotation about the axis 43. This rotation, in one embodiment, drives the rotation of the first planetary wheel 33a about its axis 42. Since the first planetary wheel 33a meshes with the first intermediate wheel 32, the latter in turn revolves about the axis of rotation 43, the second intermediate wheel 35 remaining fixed. Since the first intermediate wheel 32 meshes with the first sun gear 31, the latter in turn revolves about the axis of rotation 42, thus making the first part 10 revolve about the same axis of rotation 42.
In the variant of
In the variant illustrated in
As can be seen in
As can be seen in
In a variant, the oscillating weight 1 according to the invention comprises a device that makes it possible to check whether the acceleration of the oscillating weight 1 in the context of a configuration such as that of
In the case where the device is completely mechanical, it could comprise an element linked to one of the two parts 10, 20 in such a way that, with an acceleration of the oscillating weight 1 below a certain threshold, it does not change its position, and with an acceleration of the oscillating weight 1 equal to or above a certain threshold, it changes position, this change of position allowing (directly or through another element) the displacement of one part 10, 20 with respect to the other so that the movement of the weight does not wind the energy source of the watch. In this embodiment, it is thus possible to make the geometry of the oscillating weight vary automatically, without the intervention of the user, thus avoiding damaging the watch if the user has not changed the mode of operation of the watch before the watch undergoes a significant acceleration.
Number | Date | Country | Kind |
---|---|---|---|
CH 01345/18 | Nov 2018 | CH | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2019/059428 | 11/4/2019 | WO | 00 |