Time-keeping transmission system

Abstract

The invention relates to a time-keeping transmission system (90) comprising: a first moving part (10) comprising a first toothing (10a); a second moving part (11) comprising a second toothing (11a), meshing with the first moving part and designed to be driven by the first moving part; and a third moving part (14) comprising a third toothing (14a) designed to mesh with the second moving part and designed to be driven by the second moving part; the meshing of the first toothing with the second toothing being irreversible and the meshing of the third toothing with the second toothing being irreversible.

Description

[0001] The invention relates to a mechanical transmission clockwork system. The invention also relates to a clockwork mechanism comprising such a system. The invention also relates to a timepiece comprising such a system or clockwork mechanism.

[0002] In timepieces, it is important that the elements indicating time or time-derived information are not subject to uncontrolled movements due to movements of the wearer of the timepiece or to shocks suffered by the timepiece or to the orientation of the timepiece. In summary, it is important that the movements of the elements indicating time or time-derived information are not due to accelerations suffered by the timepiece.

[0003] This is particularly important when the element indicating time or time-derived information has significant inertia, for example when the element indicating time or time-derived information is a disc.

[0004] This problem does not arise for elements indicating time or time-derived information which are integral or fixed to a wheel of the finishing train, because these wheels are always kept under tension from the mainspring during operation of the timepiece.

[0005] However, for other elements indicating time or time-derived information which are linked to the finishing gear with a transmission having operating clearances, it is necessary to provide means to prevent their untimely movements, in particular their jittering. Thus, for example, friction can be provided in the transmission or provision can be made to index the position of the elements indicating time or time-derived information using a jumper.

[0006] Such solutions consume energy and are detrimental to chronometry.

[0007] Document CH712477A2 presents a timepiece provided with a display member and comprising a winding stem arranged to occupy a position for correcting the indication, a sliding pinion mounted integral in rotation on the winding stem, a correcting wheel kinematically connected to the sliding pinion when the stem occupies the correction position, and a lever arranged to pivot from a first position, called the slow correction position, to a second position, called the fast correction position.

[0008] The aim of the invention is to provide a transmission system making it possible to overcome the drawbacks mentioned above and to improve the systems known from the prior art. In particular, the invention proposes a transmission system making it possible to avoid untimely movements of an element indicating time information or information derived from the time, without excessive energy consumption and without harming chronometry.

[0009] A system according to the invention is defined by claim 8.

[0010] Various embodiments of the system are defined by dependent claims 9 to 14.

[0011] A mechanism according to the invention is defined by claim 15.

[0012] A timepiece according to the invention is defined by claim 16.

[0013] A method according to the invention is defined by claim 1.

[0014] The attached figures represent, by way of example, an embodiment of a timepiece according to the invention. There figure 1 is a schematic view of an embodiment of a timepiece, dial side. The figure 2 is a schematic view of the embodiment of the timepiece, dial removed. The figures 3 to 9 are views of an embodiment of a mechanical transmission system of the embodiment of the timepiece.

[0015] An embodiment of a timepiece 200 is described below with reference to figures 1 to 9 . The timepiece is, for example, a watch, in particular a wristwatch. The timepiece comprises a watch mechanism, in particular a mechanical watch movement 100. The watch movement is, for example, of the hand-wound type or the self-winding type.

[0016] The movement comprises, for example, a finishing gear train between a barrel and an oscillator. The gear train comprises, for example, a 12-hour wheel 7, in particular a 12-hour wheel in the center of the movement, on which is fixed an hour display element, such as, for example, an hour display disc 1. This disc comprises, for example, a marker, such as a triangle or an arrow, cooperating with a limb 3, in particular a limb comprising hour markers 31, provided on the movement or on an attached dial. This cooperation allows the hours to be indicated.

[0017] In this movement, a cannon pinion 4, part of the finishing gear, makes one revolution in 12 hours. A wheel 5 drives a wheel 6 and the hour wheel is driven onto the cannon pinion.

[0018] In this movement, wheel 5 drives a minute display element, such as a minute display disc 2. This disc comprises, for example, a marker, such as a triangle or an arrow, cooperating with a limb, in particular a limb comprising hour markers, provided on the movement or on an attached dial. This cooperation allows the minutes to be indicated. The same limb can be used for the hours and minutes. Disc 2 is, for example, a disc crown.

[0019] The drive of the disc 2 by the wheel 5 is done via a set of wheels 8, 9, 10, 11 and 12. The wheels 5, 8, 9, 10 and 11 are toothed wheels with external teeth. The wheel 12 is a toothed crown with internal teeth. The disc 2 is mounted or fixed on the toothed crown 12.

[0020] The toothed crown 12 is for example guided on a frame 50 of the movement using rollers 51, in particular three rollers 51 mounted on the frame.

[0021] The drive of disc 2 by wheel 5 is therefore done via a transmission system 90 downstream of wheels 5, 8 and 9.

[0022] The 90 transmission watch system includes: a first mobile 10 comprising a first toothing 10a; a second mobile 11 comprising a second toothing 11a, meshing with the first mobile and intended to be driven by the first mobile; and a third mobile 14 comprising a third toothing 14a, intended to mesh with the second mobile and intended to be driven by the second mobile.

[0023] The meshing of the first tooth with the second tooth is irreversible and the meshing of the third tooth with the second tooth is irreversible.

[0024] By "the meshing of the first toothing with the second toothing is irreversible", we mean that the meshing, in particular the teeth, is such that the first mobile can drive the second mobile in both directions and such that the second mobile can only drive the first mobile in one direction.

[0025] By "the meshing of the third toothing with the second toothing is irreversible", we mean that the meshing, in particular the teeth, is such that the third mobile could drive the second mobile in both directions and such that the second mobile can only drive the third mobile in one direction.

[0026] Furthermore, the teeth are such that the direction in which the second mobile can drive the first mobile is opposite to the direction in which the second mobile can drive the third mobile.

[0027] As a result of this construction, when the second and third teeth are meshed, the second mobile cannot drive either the first mobile or the third mobile unless it is driven by one of the first and third mobile.

[0028] As seen previously, the second mobile is a mobile to which is secured, in particular by gearing, the element indicating time information or information derived from the time, in particular the element indicating the minutes.

[0029] To achieve these irreversibilities, the first toothing comprises teeth with asymmetrical profiles and / or the third toothing comprises teeth with asymmetrical profiles. By “asymmetrical” profile, it is meant that each tooth has a first flank and a second flank, the first and second flanks being non-symmetrical relative to a radius of the first mobile, respectively of the third mobile, passing through the top of the tooth.

[0030] Preferably, the second toothing comprises teeth with symmetrical profiles. The second toothing is, for example, a toothing with a standardized profile. This ensures that the first mobile is capable of driving the second mobile in two directions of rotation.

[0031] The first mobile 10 is pivoted around a first axis 10b on the frame 50.

[0032] The second mobile 11 is pivoted around a second axis 11b on the frame 50.

[0033] The third mobile 14 is pivoted about a third axis 14b on a movable element 20 relative to the frame 50. The third mobile is mounted freely. A slight friction resisting the rotation of the third mobile may exist.

[0034] The movable element is for example a rocker pivoted around a fourth axis 20b on the frame 50.

[0035] The movable element is advantageously movable between a first position in which the second and third teeth mesh and a second position in which the second and third teeth do not mesh. The first position is preferably defined by a first stop 21 against which the movable element comes into contact in the first position. The second position is preferably defined by a second stop 22 against which the movable element comes into contact in the second position.

[0036] Advantageously, the system further comprises a selection element and / or a correction element. The movable element is then preferably arranged so as to be moved depending on the actuation of the selection element and / or the correction element. Thus, advantageously, the movable element is moved to the second position when the element for selecting a time correction is activated or when the time correction element is activated. In addition, the movable element can be moved to the first position when the element for selecting a time correction is no longer activated or when the time correction element is no longer activated.

[0037] The selection element and / or the correction element may comprise a rod 99.

[0038] In particular, the movement of the movable element 20 can be controlled via a pull mechanism 98 controlled by a rod 99 (shown schematically in the figure 8).

[0039] A mode of execution of a method of operating the timepiece 200 or the movement 100 or the transmission system is described below.

[0040] The transmission system is assumed initially in the configuration shown in the figure 8 . In this configuration, the first mobile 10 rotates counterclockwise and drives the second mobile clockwise. The second mobile drives the third mobile counterclockwise. In this configuration, opposite flanks of the second toothing are in contact on the one hand with the first mobile and on the other hand with the third mobile.

[0041] If the second mobile is subjected to an acceleration tending to make it rotate clockwise, there is an arcing between the first and second teeth and the second mobile is prevented from rotating.

[0042] If the second mobile is subjected to an acceleration tending to make it rotate counterclockwise, there is an arcing between the second and third teeth and the second mobile is prevented from rotating.

[0043] The teeth of the first and third toothings are arranged and / or dimensioned so that at least one tooth of the first toothing is positioned with less clearance between two consecutive or neighboring teeth of the second toothing and so that at least one tooth of the third toothing is positioned with less clearance between two other consecutive or neighboring teeth of the second toothing. For example, the clearance is such that the angular clearance of the second mobile around the second axis 11b between two blockings in opposite directions is less than or equal to 10°, or even less than or equal to 6°, or even less than or equal to 4°. It follows that the angular movement of the toothed crown 12, and therefore the movement of the element 2 indicating time information or information derived from the time, around its axis of rotation between two locks in opposite directions is less than or equal to 3°, or even less than or equal to 1.8°, or even less than or equal to 1.2°.Due to this arrangement of the teeth, when the second mobile is stressed due to acceleration, there is an arcuate action at the contact with the first mobile or with the third mobile which immobilizes the second mobile. This arcuate action follows a compensation of the play mentioned above. Given the amount of play, the movement is imperceptible to the user. In addition, this arcuate action immobilizes the second mobile and prevents movements which could otherwise be transmitted by the wheels 5, 8, 9 and 10 and which could overcome the friction torque at the road surface.

[0044] The movable element is moved from the first position in which the second and third teeth mesh to the second position in which the second and third teeth do not mesh. This movement is achieved by the action of a selection element or a correction element. The transmission system is then in the configuration shown in the figure 9 .

[0045] In this configuration, the first mobile 10 is turned clockwise and counterclockwise to correct the time indication.

[0046] The movable element is then moved from the second position to the first position. This movement is achieved by the action of a selection element or a correction element. The transmission system is then in the configuration shown in figure 8 .

[0047] In the embodiment described, the element for indicating time or time-derived information is a minutes indication wheel. Alternatively, the element for indicating time or time-derived information may in particular be a seconds indication element.

[0048] In the embodiment described, the element for indicating time or time-derived information is a disc. Alternatively, the element for indicating time or time-derived information may in particular be a hand.

[0049] According to the invention as claimed in the appended set of claims, the third wheel is pivoted on the movable element. Alternatively, according to an embodiment close to the invention, the third wheel can be pivoted directly on the frame. In this case, the second and third wheel remain permanently meshed and the correction of the time indication can only be carried out in the clockwise direction.

[0050] Any other type of teeth than those described can be used to produce the first, second and third teeth provided that they allow the irreversibilities described above to be achieved.

[0051] The transmission system has been described in an application for displaying watch information. It can nevertheless be used for any application where it is necessary to ensure irreversibility of the drive provided by the transmission system.

Claims

1. A method for operating a timepiece transmission system comprising: - a frame (50), - a first mobile (10) comprising a first toothset (10a); - a second mobile (11) comprising a second toothset (11a), said second mobile meshing with the first mobile and being intended to be driven by the first mobile; and - a third mobile (14) comprising a third toothset (14a), said third mobile being intended to mesh with the second mobile and intended to be driven by the second mobile; the meshing of the first toothset with the second toothset being irreversible, the first mobile being able to drive the second mobile in both directions and the second mobile being able to drive the first mobile only in one direction, and the meshing of the third toothset with the second toothset being irreversible, the third mobile being able to drive the second mobile in both directions and the second mobile being able to drive the third mobile only in one direction, the first mobile being pivoted about a first staff (10b) on the frame, the second mobile being pivoted about a second staff (11b) on the frame, and the third mobile being pivoted about a third staff (14b) on an element (20) that is movable relative to the frame, or an operating method of timepiece mechanism comprising such a timepiece system or an operating method of timepiece comprising such a timepiece system, the method comprising the following steps: - moving the movable element from a first position, in which the second and third toothsets mesh, to a second position, in which the second and third toothsets do not mesh; - correcting a timepiece indication by rotating the second mobile in a first direction and in a second direction, - moving the movable element from the second position to the first position.

2. The method as claimed in claim 1, wherein the first toothset comprises teeth with asymmetric profiles and / or the third toothset comprises teeth with asymmetric profiles.

3. The method as claimed in either of the preceding claims, wherein the second toothset comprises teeth with symmetric profiles.

4. The method as claimed in one of the preceding claims, wherein the second mobile is a mobile to which an element (2) for indicating an item of time information or an item of information derived from the time is secured, in particular secured by meshing, in particular a minutes mobile to which an element for indicating minutes is secured or a seconds mobile to which an element for indicating seconds is secured.

5. The method as claimed in one of the preceding claims, wherein the movable element is a lever pivoted about a fourth staff (20b) on the frame.

6. The method as claimed in one of the preceding claims, wherein the movable element is movable between a first position, in which the second and third toothsets mesh, and a second position, in which the second and third toothsets do not mesh.

7. The method as claimed in one of the preceding claims, wherein the system comprises a selection element and / or a correction element, the movable element being arranged so as to be moved depending on the actuation of the selection element and / or of the correction element.

8. A timepiece transmission system (90) comprising: - a first mobile (10) comprising a first toothset (10a); - a second mobile (11) comprising a second toothset (11a), said second mobile meshing with the first mobile and being intended to be driven by the first mobile; and - a third mobile (14) comprising a third toothset (14a), said third mobile being intended to mesh with the second mobile and intended to be driven by the second mobile; the meshing of the first toothset with the second toothset being irreversible and the meshing of the third toothset with the second toothset being irreversible the meshing of the first toothset with the second toothset being irreversible, the first mobile being able to drive the second mobile in both directions and the second mobile being able to drive the first mobile only in one direction, and the meshing of the third toothset with the second toothset being irreversible, the third mobile being able to drive the second mobile in both directions and the second mobile being able to drive the third mobile only in one direction, the system comprising a frame (50), the first mobile being pivoted about a first staff (10b) on the frame, the second mobile being pivoted about a second staff (11b) on the frame, and the third mobile being pivoted about a third staff (14b) on an element (20) that is movable relative to the frame.

9. The transmission system as claimed in the preceding claim, wherein the first toothset comprises teeth with asymmetric profiles and / or the third toothset comprises teeth with asymmetric profiles.

10. The transmission system as claimed in either of claims 8 and 9, wherein the second toothset comprises teeth with symmetric profiles.

11. The transmission system as claimed in one of the claims 8 to 10, wherein the second mobile is a mobile to which an element (2) for indicating an item of time information or an item of information derived from the time is secured, in particular secured by meshing, in particular a minutes mobile to which an element for indicating minutes is secured or a seconds mobile to which an element for indicating seconds is secured.

12. The transmission system as claimed in one of claims 8 to 11, wherein the movable element is a lever pivoted about a fourth staff (20b) on the frame.

13. The transmission system as claimed in one of claims 8 to 12, wherein the movable element is movable between a first position, in which the second and third toothsets mesh, and a second position, in which the second and third toothsets do not mesh.

14. The transmission system as claimed in one of claims 8 to 13, wherein the system comprises a selection element and / or a correction element, the movable element being arranged so as to be moved depending on the actuation of the selection element and / or of the correction element.

15. A timepiece mechanism (100), in particular a timepiece movement, in particular a mechanical timepiece movement, comprising a system (90) as claimed in one of claims 8 to 14.

16. A timepiece (200), in particular a wristwatch, comprising a mechanism as claimed in the preceding claim and / or a system as claimed in one of claims 8 to 14.

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