Patent Application
20250076814
This application claims priority of European patent application No. EP23194760.7 filed Sep. 1, 2023, the content of which is hereby incorporated by reference herein in its entirety.
The invention concerns a timepiece driving device. The invention also concerns a timepiece calendar including such a timepiece driving device. The invention further concerns a timepiece movement including a timepiece driving device of this kind or a timepiece calendar of this kind. The invention also concerns a timepiece including a timepiece movement of this kind or a timepiece driving device of this kind or a timepiece calendar of this kind. The invention also concerns a method of operating a timepiece movement of this kind or a timepiece of this kind or a timepiece driving device of this kind or a timepiece calendar of this kind.
There are known from the prior art instantaneous timepiece calendar systems that employ a driving mobile provided with a cam that cooperates with an energy accumulation device such as a cam lever associated with a spring.
Driven by a driving wheel, the cam enables cocking of the energy accumulation device in a cocking phase and returning the energy during a successive phase of instantaneous driving of the calendar. The cam is then in driving mode and turns relative to the driving wheel. The energy returned serves to drive the cam and a mechanism downstream of the cam.
In a compensation phase following the instantaneous driving phase the cam is immobilized until it has been caught up with and is driven again by the driving wheel so as to cock the energy accumulation device.
The compensation phase can last about 4 to 11 hours depending on the design of the calendar. During this compensation phase the driving wheel turns with no load and consumes very little power compared to the cocking phase. This results in variations of the amplitude of the oscillator of the timepiece movement because of the difference in the load on the driving wheel between the compensation and cocking phases.
The patent EP2407833B1 discloses a solution employing an instantaneously driven date mobile including an auxiliary energy accumulation means intended to compensate the backlash in the gears of a time display train.
The instantaneous driving mobile functions in a conventional manner and successively in:
The specifics of the solution disclosed reside in the fact that the auxiliary energy accumulation means is between the calendar cam and the driving wheel. The auxiliary energy accumulation means is cocked during the compensation phase and is intended to generate a resisting torque on the driving wheel. The time display train is therefore also under tension during the compensation phase, limiting the backlash in the gears of said train.
However, it is necessary for the cocking torque of the auxiliary energy accumulation means to be lower than the torque necessary to arm the spring of the cam lever. Consequently the auxiliary energy accumulation means cannot enable significant accumulation of energy that is equivalent to that achieved by cocking the spring of the cam lever.
The object of the invention is to provide a timepiece driving device enabling improvement of the devices known from the prior art. In particular the invention proposes a timepiece driving device enabling the best possible temporal distribution of energy consumption, in particular over a period of rotation of a driving wheel.
A driving device in accordance with the invention is defined by point 1 below.
Embodiments of the driving device are defined by claims 2 to 9.
A timepiece calendar in accordance with the invention is defined by claim 10.
A timepiece movement in accordance with the invention is defined by claim 11.
A timepiece in accordance with the invention is defined by claim 12.
An operating method in accordance with the invention is defined by claim 13.
Ways of executing the operating method are defined by points 14 and 15 below.
The appended drawings represent by way of example two embodiments of a timepiece in accordance with the invention.
One first embodiment of a timepiece 500 is described in detail hereinafter with reference to
The timepiece 500 is for example a watch, in particular a wristwatch. The timepiece 500 includes a timepiece movement 400 intended to be mounted in a timepiece case in order to protect it from the external environment.
The timepiece movement 400 is a mechanical movement, in particular an automatic movement, or a hybrid movement or an electronic movement.
The timepiece movement 400 includes a timepiece calendar 300.
The timepiece calendar 300 includes:
The calendar system 300 enables display via the at least one display member 200 of at least one calendar indication such as a day indication, a date indication, a month indication, a year indication, a bissextile year indication, a phase of the Moon indication.
The at least one calendar indication may be carried by the at least one display member 200 such as a hand or a disc.
The timepiece driving device 100 includes:
The timepiece driving device 100, in particular the main cam and the auxiliary cam, are arranged so that the cam follower 21 comes into contact or substantially into contact with the auxiliary cam profile immediately at the end of the driving of the main cam 11 by the action of the energy accumulator 22 on said main cam 11 via the cam follower 21. Thus it is possible to cock the energy accumulator immediately at the end of the driving of the main cam 11, which is effected by action of the energy accumulator 22 on said main cam 11 via the cam follower 21.
The timepiece driving device 100, in particular the main cam and the auxiliary cam, is advantageously arranged so as to cock the energy accumulator 22 via the cam follower 21 over all or substantially all of the rotation period of the input mobile 13, in particular a period of 24 hours, with the exception of a driving phase in which the main cam is in driving mode. This makes it possible to minimize and to smooth the mechanical power necessary for cocking the energy accumulator. To this end the driving device, in particular the profiles of the main cam and of the auxiliary cam, are such that the mechanical power supplied to the energy accumulator 22 is constant or substantially constant throughout the time for which the main cam 11 is not in driving mode or more particularly throughout the time during which the main cam 11 is not driven by the energy accumulator 22 via the cam follower 21.
The input mobile 13 and the auxiliary cam 12 are part of a first mobile.
The main cam 11 is part of a second mobile.
The first and second mobiles are pivoted in a frame of the timepiece movement 400.
The second mobile includes a driving element 14 kinematically connected to the main cam 11 or secured to the main cam 11. The driving element 14 may be fixed onto the main cam 11. The driving element 14 is intended to drive the display member 200 directly and periodically.
The main cam 11 is intended to cooperate with an energy accumulation device 20 so as periodically to accumulate and periodically to return instantaneously the energy necessary for driving the display member 200.
The accumulation device 20 includes:
The input mobile 13 includes a driving wheel 13 secured to the auxiliary cam 12. The input mobile is driven continuously by a train of the timepiece movement 400. It is intended to drive the second mobile or more specifically the main cam 11 via a decoupling device.
The decoupling device in particular enables:
The instantaneous driving phase is the phase in which the energy accumulated by the energy accumulation device 20 is returned and the display member 200 is driven instantaneously by the driving element 14.
The decoupling device includes a portion 15 on one of the first or second mobiles intended to cooperate with an angular abutment 16a on the other of the first or second mobiles so that the rotation of the input mobile 13 can drive rotation of the cam 11, in particular during the cocking phase.
During the instantaneous driving phase the decoupling device allows a degree of freedom in rotation of the second mobile relative to the first mobile or more specifically a degree of freedom in rotation of the main cam 11 relative to the input mobile 13.
This degree of freedom may in particular be achieved by shaping the portion 15, which is adapted to move in a groove 16 in a direction that is orthoradial relative to the rotation axis of the first and/or second mobile. In the first embodiment depicted in the figures the groove 16 includes the angular abutment 16a. In particular the groove 16 extends between two angular abutments 16a, 16b. Alternatively, this degree of freedom could be achieved by a freewheel.
The input mobile 13 preferably turns at a constant speed. Consequently, the decoupling device must enable the main cam 11 to travel instantaneously and substantially completely the angular travel necessary for the driving phase. Consequently, during the driving phase the portion 15 is decoupled and moved relative to the angular abutment 16a in the groove 16.
At the end of the instantaneous driving phase the driving element 14 and the main cam 11 are stationary for the time taken for the input mobile 13 to catch up with the latter in a compensation phase. More particularly, the angle of travel that the main cam 11 has performed during the instantaneous driving phase must be compensated so that the portion 15 is again in contact with the angular abutment 16a and again drives the main cam 11. The compensation phase therefore succeeds the driving phase and precedes the cocking phase.
One particular feature of the solution resides in the fact that immediately after the phase of instantaneous driving of the display 200 the lever 21 is in contact with the auxiliary cam 12 and is out of reach of the main cam 11 so as to commence a first cocking of the energy accumulation device 20 immediately at the end of the instantaneous driving phase. This first cocking continues for at least the whole of the compensation phase and until the cam lever 21 is again in contact with the main cam 11.
The lever 21 is preferably in contact with the auxiliary cam 12 exclusively during the compensation phase.
From one phase to the other the transitions of contact of the lever 21 of the main cam 11 with the auxiliary cam 12 and vice versa are sized so as to be as continuous as possible with no sudden interruption and no significant disturbance in respect of the power consumption of the timepiece movement 400 and thus to prevent variations of amplitude.
In the embodiments depicted the instantaneous driving device 100 is designed to allow instantaneous driving of a calendar date system 300 including a date disc 200 indexed by a jumper.
The first and second mobiles are coaxial and pivot about an axis A1. Thus the main cam 11 and the auxiliary cam 12 pivot about the same axis A1.
The driving element 14 is a date finger 14 intended to cooperate with teeth 201 of the date disc 200 during the instantaneous driving phase. Here the date finger 14 is welded to a hub 17 driven into and/or riveted onto the main cam 11.
The hub 17 pivots on the frame about the axis A1.
The profile of the main cam 11 adapted to cooperate with the energy accumulation device 20 comprises successively a cocking portion 11a, a return portion 11b and a stop portion 11c. The functionalities of these portions are described in more detail hereinafter.
The period of rotation of the driving wheel 13 is 24 hours so as to enable driving of the calendar system 300 by at least one step each day. In other words, for each period of rotation of the driving wheel 13 the instantaneous driving device 100 is respectively and successively in:
The auxiliary cam 12 is secured to the driving wheel 13 by driving it in and/or riveting it on. Alternatively, the driving wheel 13 and the auxiliary cam 12 could be in one piece, i.e. then forming a monobloc assembly.
The driving wheel 13 and the auxiliary cam 12 are assembled so as to pivot on the hub 17 about the axis A1. Alternatively, they could pivot directly on the frame.
The auxiliary cam 12 includes a portion for pre-cocking the profile 12a adapted to cooperate with the energy accumulation device 20 during the compensation phase.
The decoupling device consists of a stud 15 assembled onto or in one piece with the main cam 11 adapted to cooperate with an angular abutment 16a at the first end of a groove 16 machined into a portion of the perimeter of the auxiliary cam 12.
Alternatively, the groove 16 could be machined into the driving wheel 13.
The length of the groove 16 enables the stud 15 to travel substantially all of the angular travel necessary for the driving phase. In other words, the angle of rotation that the stud 15 is able to travel in the groove 16 must at least correspond to the angle of rotation of the date finger 14 and the main cam 11 during the driving phase.
Alternatively or additionally the angular travel necessary for the driving phase, more specifically the angular travel of the stud 15, may be limited by the second angular abutment 16b at a second end of the groove 16.
The cam lever 21 advantageously includes a bearing or more specifically a jewel or a ruby roller 23. The latter is adapted to cooperate with the respective profiles of the main cam 11 and the auxiliary cam 12.
The roller 23 makes it possible to reduce the friction torque induced by the force with which the lever 21 bears against the main cam 11 and/or the auxiliary cam 12. Consequently, this roller 23 enables reduction of the energy consumption and the amplitude losses of the oscillator of the timepiece movement 400.
One method of executing a method of operating the timepiece or the timepiece movement or the timepiece calendar or the driving device is described hereinafter.
During the cocking phase, depicted in
The energy accumulation device 20, and more specifically the roller 23, is preferably out of reach of the auxiliary cam 12 during this phase.
The cocking portion 11a is preferably shaped so as to generate a constant or substantially constant consumption of power and amplitude loss of the balance. In other words, this portion makes it possible to obtain a constant or substantially constant cocking torque on the input mobile 13.
In other words, during the cocking phase, the follower 21 follows the main cam profile 11a, while energy is accumulated in the spring 22 and the profile of the auxiliary cam 12 is not in contact with the follower 21. It is therefore the input wheel that drives the main cam, the follower 21 follows the profile 11a of this cam and the spring 22 is gradually cocked. The energy is therefore transferred according to the following chain: barrel, geartrain, input wheel 13, main cam 11, follower 21, spring 22.
When the roller 23 reaches the apex of the main cam 11, as depicted in
During this driving phase, depicted in
The auxiliary cam 12 is out of reach of the energy accumulation device 20 and more specifically of the roller 23 at all times during the driving phase.
At the end of the driving phase it is advantageous for the date finger 14 to be stopped and to remain positioned in a position of interference with the teeth 201 of the date disc 200 in order to constitute an obstacle to it and to prevent an untimely additional jump because of its inertia and the considerable energy that is returned during this phase.
To this end, as depicted in
In a complementary or alternative manner, the second abutment 16b may be used for the partial or total dissipation of said residual kinetic energy.
The display member 200 is also stopped instantaneously. In other words, the instantaneous driving phase includes stopping the display member 200.
In other words, during the driving phase, the main cam 11 is driven, the follower 21 travels abruptly along the profile 11b of the main cam 11 and causes its release from the wheel 13 as well as the jump drive of the display member 200. In this phase, it also turns out that the profile of the auxiliary cam 12 is not in contact with the follower 21. The energy is therefore transferred according to the following chain: spring 22, follower 21, main cam 11, display member 200.
As described above the main cam 11 is decoupled from the input mobile 13 at the start of the instantaneous driving phase. The angular abutment 16a must then catch up with the stud 15 to drive the main cam 11 again.
During this compensation phase, as depicted in
As for the cocking portion 11a, the pre-cocking portion of the profile 12a is preferably shaped so as to generate a constant cocking torque at the level of the input mobile 13 and consequently constant consumption of power by and constant amplitude loss of the balance.
Furthermore, as depicted in
The return portion 11b of the profile of the main cam 11 extends over a first angular portion corresponding to the travel necessary for the second mobile to drive the calendar system 300. The angular portion 11b is complementary to the sum of the angular portions of the cocking portion 11a and the stop portion 11c.
The pre-cocking portion of the profile 12a of the auxiliary cam 12 enables the first cocking of the energy accumulation device 20 to extend over a second angular portion at least equal to or at least substantially equal to the first angular portion of the return portion 11b.
Consequently, the cocking portion 11a of the profile of the main cam 11 enabling a second cocking of the energy accumulation device 20 extends over a third angular portion complementary to the second angular portion. Alternatively, the third angular portion may be of zero or substantially zero length in the situation where the pre-cocking portion of the profile 12a is adapted to enable complete cocking of the energy accumulation device 20.
The sum of the second and third angular portions is advantageously equal to the angle that the input mobile 13 travels over the whole or substantially the whole of the period of rotation.
In other words, during the compensation phase, the follower 21 leaves the main cam profile 11 and instead starts to follow the auxiliary cam profile 12, thus pre-cocking the spring 22. This has the effect of smoothing the load on the input mobile. During the compensation phase, the main cam is not driven. The main cam does not drive another element.
Accordingly, one method of executing the method of operating the timepiece 500 or the timepiece movement 400 or the timepiece calendar 300 or the timepiece driving the device 100 includes at least one iteration and preferably a plurality of iterations of the following steps:
The operating method as a whole or at least one iteration thereof may include accumulation of energy in the energy accumulator 22 by action of the main cam 11 on the energy accumulator 22 via the cam follower 21.
Accordingly:
The driving of the main cam 11 during the driving phase is preferably instantaneous driving.
Of course, the present solution is not limited to a single calendar date system but is also particularly suitable for calendar systems necessitating for example more energy than an annual date calendar or a perpetual date calendar. Furthermore, a timepiece driving device in accordance with the invention may be used for a system for displaying time information or information derived from the time (thus derived from the oscillator), in particular information distinct from calendar information. The timepiece driving device may in particular be used in a system for displaying the time (with a jumping display) or the phases of the Moon.
The first and second mobiles of the driving device need not be coaxial but could pivot about two preferably separate and parallel axes. They would then be connected by gears, for example. The main cam 11 and the auxiliary cam 12 can therefore pivot about separate axes, in particular about parallel axes.
Thus, a second embodiment of a timepiece 500 is described in detail hereinafter with reference to
The timepiece 500 is for example a watch, in particular a wristwatch. The timepiece 500 includes a timepiece movement 400 intended to be mounted in a timepiece case in order to protect it from the external environment.
The timepiece movement 400 is a mechanical movement, in particular an automatic movement, or a hybrid movement or an electronic movement.
The timepiece movement 400 includes a timepiece calendar 300.
The timepiece calendar 300 includes:
The calendar system 300 enables display via the at least one display member 200 of at least one calendar indication such as a day indication, a date indication, a month indication, a year indication, a bissextile year indication, a phase of the Moon indication.
The at least one calendar indication may be carried by the at least one display member 200 such as a hand or a disc.
The timepiece driving device 100 includes:
The first and second wheels of the drive device are not coaxial, but rotated on two separate axis, preferably parallel. They are then connected, for example, by a gear. This allows the main cam 11 and auxiliary cam 12 to be rotated about separate axis, especially around parallel axes.
The auxiliary cam 12 rotates along an axis A2 parallel to the axis A1 and is attached to a wheel 18 which is cinematically linked or is cinematically attached to the driving wheel 13 by a gear.
The stud 15 of the disconnecting device is capable of cooperating with the angular stops 16a and 16b arranged at the ends of the groove 16 machined on the driving wheel 13
The auxiliary cam 12 has the profile 12a including a pre-cocking portion capable of cooperating with the energy accumulation device 20, during the compensation phase. Of course, the sizing of the angular extent of the pre-cocking portion of the profile 12a must take into account the transmission ratio between the main cam 11 and the auxiliary cam 12, more particularly between the drive wheel 13 and a wheel 18. For example, with a gear ratio of 2, the angular extent of the pre-cocking portion of profile 12a should be twice as high as the angular portion corresponding to the travel required for the second mobile to drive the calendar system 300. In other words, with the second embodiment represented, the pre-cocking portion of the auxiliary cam profile 12a allowing the first cocking of the energy accumulation device 20 can extend along a second angular portion at least 2 times greater or at least substantially 2 times greater than the first angular portion of the return portion 11b.
The cam follower 21 includes a second portion or more particularly a second bearing, such as a second stone or a ruby roller 24, which can cooperate with the auxiliary cam profile 12.
Regardless of the embodiment or the variant the decoupling device could be a unidirectional connecting device such as a freewheel in which the portion 15 would for example be a portion of a ratchet intended to cooperate with the angular abutment 16a.
Regardless of the embodiment or the variant the stud 15 could be on the first mobile, for example on the auxiliary cam 12 or the input mobile 13, and the groove 16 could consequently be on the second mobile, for example on the main cam 11.
In the embodiment described above a roller 23 constitutes a unique bearing element enabling (sequential) cooperation through contact with the main cam 11 and with the auxiliary cam 12. Nevertheless, regardless of the embodiment or the variant the cam follower may include:
Thus the first bearing element may be intended to cooperate exclusively with the main cam 11 and the second bearing element may be intended to cooperate exclusively with the auxiliary cam 12.
In the above description the calendar system 300 is driven by at least one step for each period of rotation of the input mobile 13. Nevertheless, regardless of the embodiment or the variant the instantaneous driving device could be adapted to drive the calendar system on each multiple or each sub-multiple of the period of rotation of the input mobile 13. Of course, the geometries of the main and auxiliary cams could be designed accordingly.
Regardless of the embodiment or the variant the auxiliary cam 12 enables at least partial cocking of the energy accumulator 22. The auxiliary cam 12 may be used to carry out a first cocking of the energy accumulator 22 and the main cam 11 can be used to carry out a second cocking of the energy accumulator 22 complementary to the first cocking. Alternatively, the auxiliary cam 12 may be used to carry out complete cocking of the energy accumulator 22 by adapting the pre-cocking portion of the profile 12a. In this hypothesis the cocking portion 11a is superfluous and the only function of the main cam 11 is to cooperate with the follower 21 to transmit the energy returned by the energy accumulator thanks to the return portion 11b and potentially to dissipate the residual kinetic energy after the display member 200 is driven by the stop portion 11c.
Regardless of the embodiment or the variant the auxiliary cam 12 could actuate the energy accumulation device 20 via a portion of the lever 21 other than that adapted to cooperate with the main cam 11.
Regardless of the embodiment or the variant the term “cam” has a broad meaning and encompasses any geometry cooperating with a cam follower. In particular, a pin cooperating with a cam follower is a cam.
For example, the auxiliary cam 12 could take the form of a portion or of a pin excentric relative to the rotation axis adapted to cooperate with a portion of the lever 21. The shape of the profile of said portion of the lever 21 with said pin would preferably be designed so as to enable cocking with a constant torque at the input mobile 13.
More generally the main and auxiliary cams could have simple geometries, such as pins, cooperating with one or more appropriate profiles on the lever 21 of the energy accumulation device.
The solutions described above exploit two calendar cams, in particular superposed calendar cams, that advantageously enable smooth and limited variations of power consumption over 24 hours. More generally, the proposed solutions advantageously make it possible to smooth the mechanical cocking power throughout the period of rotation of the input mobile 13 with the exception of the instantaneous driving phase. Consequently, the power consumed and therefore the amplitude losses of the balance can be constant, in contrast to the solutions known from the prior art.
Furthermore, given that the energy necessary for the instantaneous driving of the display member can be accumulated over a period of rotation greater than those of the known solutions, it is also possible to minimize the mechanical cocking power for the same total quantity of energy accumulated. By increasing the cocking period from 13 hours to 24 hours it is for example possible to reduce the cocking power by 46%. By increasing the cocking time from 20 hours to 24 hours it is for example possible to reduce the cocking power by 17%.
The instantaneous driving device 100 advantageously enables direct driving of the display member 200 using a single and unique driving element 14. In fact the solution does not necessitate a lever at the interface of said members.
This shaping advantageously enables bidirectional driving of the display member 200. In fact, thanks to the decoupling device in the form of a portion 15 cooperating with a groove 16, the embodiments described also enable driving of the display member 200 by actuation of the input mobile 13 in the opposite operating direction, for example when setting the time on the timepiece movement 400.
Throughout this application by “instantaneous” is preferably meant a duration of the order of one or more fractions of a second.
| Number | Date | Country | Kind |
|---|---|---|---|
| 23194760.7 | Sep 2023 | EP | regional |
