TORQUE LIMITING MECHANISM OF A CLOCK MOVEMENT

Description

Field of invention

[0001] The invention relates to an internal torque limiting mechanism for a watch movement, said torque limiting mechanism comprising a first mobile comprising a first felloe and arranged to pivot about a first axis of rotation relative to a structure or a plate or a bridge, said first mobile comprising at least one first elastic arm which, in the free state of said first mobile, projects in the direction of said first axis of rotation relative to said first felloe, and at least one second mobile comprising a second felloe and arranged to pivot relative to said structure about a second axis of rotation parallel to or coincident with said first axis of rotation in at least partial overlap with said first mobile.

[0002] The invention also relates to a barrel winding device comprising a control member arranged to be operated by a user and to drive an input pinion meshing with said first mobile or said second mobile of such a torque limiting mechanism, which said device comprises.

[0003] The invention also relates to a clockwork movement comprising, between an input mechanism and an output mechanism, such a torque limiting mechanism.

[0004] The invention also relates to a timepiece, in particular a watch, comprising at least one such torque limiting mechanism, and / or at least one such movement.

[0005] The invention relates to the field of watch mechanisms, and more particularly to the protection of certain mechanisms against excessive torque input, in particular energy recharging mechanisms such as winding mechanisms, or correction and / or display mechanisms, in particular calendar mechanisms or the like. Background of the invention

[0006] Some watch mechanisms are designed to store and restore significant amounts of energy, however their size is limited by that of the case of the timepiece concerned, and it is not possible to apply high safety coefficients to them to protect them against excessive torque being applied to them. The large size of known torque limiting mechanisms restricts the integration of complications into the timepiece. In addition, the user does not have the possibility of knowing whether he has correctly and safely carried out a complete manipulation, in particular when winding a mechanism.

[0007] Document CH703483A2 in the name of SEIKO discloses a wheel with a torque limiting mechanism comprising an engagement arm portion extending from a proximal end portion to a distal end portion equipped with an engagement projection, which is elastically engaged in a pressure-engaged portion. The projection is detached from the engaged portion to rotate the crown wheels when a torque exceeding a threshold value is exerted. A force directed from the proximal end portion to the distal end portion is applied to the projection when a manual winding torque is applied to the mechanism and adapted to separate the projection from the engaged portion. Summary of the invention

[0008] The invention proposes to produce a torque limiting device, which is very compact, economical, and whose use allows the user to easily determine whether a maneuver has been correctly performed.

[0009] For this purpose, the invention relates to an internal torque limiting mechanism for a clockwork movement, according to claim 1

[0010] The invention also relates to a barrel winding device comprising such a torque limiting mechanism.

[0011] The invention also relates to a clockwork movement comprising, between an input mechanism and an output mechanism, such a torque limiting mechanism.

[0012] The invention also relates to a timepiece, in particular a watch, comprising at least one such torque limiting mechanism, and / or at least one such movement. Summary description of the drawings

[0013] Other characteristics and advantages of the invention will appear on reading the detailed description which follows, with reference to the appended drawings, where: there figure 1represents, schematically and in perspective, a torque limiting mechanism according to the invention, comprising a first upper mobile and a second lower mobile, which are held in frictional cooperation, at the level of elastic arms which each of them comprises, by an upper stroke limiter here constituted by a screw within reach, and by a lower structure here constituted by a bridge or similar; the figure 2 represents, in a schematic and cross-sectional manner, the cooperation of the elastic arms of the two mobiles of the figure 1 ; there figure 3 represents, schematically and in plan view, the first mobile of the figure 1 ; there figure 4 represents, schematically and in diametrical section, the mobile of the figure 3 ; there Figure 5 represents, schematically and in side view, in the free state, the mobile of the figure 3 ; there figure 6represents, schematically and in perspective, a barrel winding device, comprising the torque limiting mechanism of the figure 1 , and comprising a control member, here constituted by a rod driving a winding pinion arranged to be operated by a user and drive an input pinion meshing with the second mobile, and where the first mobile meshes with a barrel ratchet; the figure 7 represents, in a schematic and perspective way, the barrel arming device of the figure 6 assembled on a barrel bridge on which the mobiles and the ratchet pivot, and which supports the screw within reach acting as a travel limiter; the figure 8 represents, schematically and in side view, the wolf tooth winding pinion of the figure 6 ; THE figures 9 and 10 represent, in a similar way to Figures 1 and 2 respectively, the cooperation of the first mobile and the second mobile in normal support; the figures 11 and 12represent, in a similar way to Figures 1 and 2 respectively, the cooperation of the first mobile and the second mobile just before the disengagement; the figures 13 and 14 represent, in a similar way to Figures 1 and 2 respectively, the cooperation of the first mobile and the second mobile just after the disengagement; the figure 15 represents, in a schematic and cross-sectional manner, the mechanism of the figure 7 ; there figure 16 represents, schematically and in perspective, a variant where the first mobile and the second mobile are not coaxial; the figure 17 represents, schematically and in perspective, a variant where the torque limiting mechanism comprises three stacked and coaxial mobiles; the figure 18 represents, in a schematic and exploded section, the mechanism of the figure 17 ; there figure 19represents, schematically and in exploded perspective, a variant where the torque limiting mechanism comprises two different mobiles, one comprising elastic arms in a circular arc, the other with radial elastic arms; the figure 20 is a block diagram representing a watch comprising a movement which comprises a barrel winding device, comprising such a torque limiting mechanism; the figure 21 is a block diagram representing a watch comprising a movement which includes such a torque limiting mechanism, between an input mechanism and an output mechanism. Detailed Description of Preferred Embodiments

[0014] The invention relates to a clockwork torque limiter mechanism 100. This mechanism 100 comprises a first mobile 1, which comprises a first rim 10 and is arranged to pivot around a first axis of rotation D1 relative to a structure 4 or a plate or a bridge.

[0015] This first mobile 1 comprises at least one first elastic arm 31, which, in the free state of the first mobile 1, projects in the direction of the first axis of rotation D1 relative to the first felloe 10. More particularly and non-limitingly, this first elastic arm 31 is movable in a first cutout 41 of the first mobile 1.

[0016] The mechanism 100 comprises at least one second mobile 2, which comprises a second felloe 20 and arranged to pivot relative to the structure 4 around a second axis of rotation D2, parallel or coincident with the first axis of rotation D1, at least partially overlapping the first.

[0017] The mechanism 100 comprises a travel limiter 5, which is fixed to the structure 4, and which is arranged to hold the second mobile 2 on the first mobile 1 for their cooperation in friction support in certain relative angular positions.

[0018] The invention is here more particularly described in the simplified case where the mechanism 100 only comprises the first mobile 1 and the second mobile 2, the person skilled in the art will be able to extrapolate it to a greater number of mobiles, for a mechanism comprising more than one input and one output.

[0019] The invention proposes to vary the friction force between the first mobile 1 and the second mobile 2.

[0020] For this purpose, the second mobile 2 and / or the travel limiter 5 and / or the structure 4 comprises at least one relief forming a ramp, and which projects in a direction parallel to or coincident with that of the first axis of rotation D1. This relief is arranged to, in certain relative angular positions of the component carrying this relief relative to the first mobile 1, cooperate in frictional support with at least one first elastic arm 31 of said first mobile 1, and, in other relative angular positions, allow a relative travel without friction between the first mobile 1 and the component carrying this relief.

[0021] When the structure 4 or the travel limiter 5 comprises such a relief, the mechanism constitutes a simple ratchet, arranged to vary the axial position of the first elastic arm of the first mobile 1, or to vary the axial position of the entire first mobile 1 and thus vary the friction force applied to the second mobile 2.

[0022] The invention relates more particularly to the case where the second mobile 2 comprises at least one second arm 32 forming a ramp and which, in the free state of the second mobile 2, projects in the direction of the second axis of rotation D2 relative to the second felloe 20.

[0023] More particularly, this second arm 32 is a second elastic arm 32. Even more particularly, this second arm 32 is a second elastic arm 32 movable in a second cutout 42.

[0024] When only the first mobile 1 and the second mobile 2 have reliefs projecting relative to their respective rim, they are mounted head to tail, with each first elastic arm 31 projecting towards the second mobile 2, and with each second arm 32 projecting towards the first mobile 1.

[0025] In a variation and as seen on the figure 16 , the second axis of rotation D2 is distant from the first axis of rotation D1.

[0026] In another variant and as visible in most of the other figures, the second axis of rotation D2 is merged with the first axis of rotation D1.

[0027] More particularly, each second arm 32 is arranged to cooperate successively, during a relative rotation of the second mobile 2 with respect to the first mobile 1, cyclically with the first felloe 10, a first elastic arm 31, and a first cutout 41 before returning to cooperate with the first felloe 10.

[0028] It is understood that the first mobile 1 and the second mobile 2 are arranged, if they are coaxial, to rotate in the same direction: either they both rotate in the same direction, or one rotates and the other is blocked. These mobiles can, in other applications where they are not coaxial, rotate in opposite directions to each other.

[0029] Each first elastic arm 31 of the first mobile defines a first ramp, which begins at an articulation 310 with the first felloe 10, and rises to the level of a first vertex. More particularly and as visible in the figures, this first elastic arm 31 is a cantilevered arm, and the vertex coincides with the distal end of this first arm 31, the edge of which defines a first front surface 311. In this particular variant, any relief of an opposing mobile, in particular the second mobile 2, during a rotation always in the same direction of each mobile, climbs this first ramp, then falls after passing the vertex; depending on the configuration this relief falls on the first felloe 10, or in the first cutout 41. This jump corresponds to the disengagement of the mechanism.

[0030] In other variants not illustrated, the first elastic arm 31 comprises an ascending ramp from the first felloe 10 to the first apex, then a descending ramp from the first apex to the first felloe 10. In the same way, the relief of the second mobile 2 can be constituted in different ways, the figures represent this relief in the form of a second elastic arm 32 similar to the first elastic arm 31 of the first mobile 1, this configuration is advantageous because it makes it possible to use, for the first mobile 1 and the second mobile 2, identical components, at least at the level of these reliefs cooperating with each other; of course, depending on the application, the first mobile 1 and the second mobile 2 can comprise different teeth, depending on the components of the movement with which they cooperate.

[0031] More particularly, each first elastic arm 31 is arranged to cooperate successively, during a relative rotation of the second mobile 2 with respect to the first mobile 1, with the second felloe 20, a second arm 32, and a second cutout 42 that the second mobile 2 comprises, before returning to cooperate with the second felloe 20.

[0032] The arrangement with a first front surface 311, and a second similar front surface 312 for the second elastic arm, allows, in a particular direction of rotation, the cooperation in abutment with each other, and the driving in rotation by simple support, without friction, of one mobile by the other, whereas, in the opposite direction of rotation, the elastic arms cooperate progressively until a detent position where one of the mobiles is no longer driven by the other.

[0033] In a particular variant illustrated by the figures, each first elastic arm 31 is a substantially annular sector which extends substantially concentrically with respect to the first axis of rotation D1. Its radial section may be constant, or progressive or degressive, so as to obtain variable friction depending on the relative angle between the opposing mobiles. Preferably, the upper surface of the first elastic arm 31 extends, radially with respect to the first axis of rotation D1, perpendicular to it. In a variant not illustrated, this first elastic arm 31 may also be warped and sloping. Each second elastic arm 32 may be formed in a similar manner. And in particular, more particularly, each second elastic arm 32 extends substantially concentrically with respect to the second axis of rotation D2.

[0034] In another variation and as seen on the figure 19, at least one first elastic arm 31 and / or at least one second arm 32 extends substantially radially relative to the axis of rotation of the mobile which carries it.

[0035] More particularly, and as visible on the figures 17 And 18 , the mechanism 100 comprises, in at least partial superposition in a direction parallel to the axis of rotation of each of them, more than two mobiles arranged to cooperate two by two in friction support, and all mounted captive between the structure 4 and the stroke limiter 5, and at least one intermediate mobile between the end mobiles comprises at least one elastic arm projecting on each side of its rim, in its axial direction: this is the case of the second mobile 2 of the figure 18, which cooperates, on the upper side of the second rim 20, with the first mobile 1, and, on the lower side of the second rim 20, with the relief 39 projecting from the third rim 90 of a third mobile 9 resting on the structure 4.

[0036] As seen on the Figure 6 and 7, the invention also relates to a barrel winding device 200, comprising a control member 201 which is arranged to be operated by a user, such as a control rod, a pusher, a bolt, a bezel, or the like, and to drive an input pinion 202 meshing with the first wheel set 1 or the second wheel set 2 of such a torque limiting mechanism 100, which this device 200 comprises. More particularly, the other wheel set of this mechanism 100, the second wheel set 2 or respectively the first wheel set 1, is arranged to drive a ratchet 203 of a motor or striking barrel, the whole being assembled on the structure 4 which is, in this particular case, a barrel bridge. The travel limiter 5 is advantageously a screw fixed on this structure, which facilitates the assembly of the entire mechanism 100 and allows disassembly.

[0037] Thus, in a particular manner specific to the invention, the usual crown wheel is split into two boards, constituting the first wheel set 1 and the second wheel set 2, and advantageously in a very economical embodiment, first 31 and second 32 elastic arms are cut out and folded in each of them. These boards are then mounted head to tail in place of the crown wheel. The first wheel set 1 meshes with a winding pinion 202, and the second wheel set 2 meshes with the barrel ratchet 203. The first wheel set 1 and the second wheel set 2 are secured by means of the elastic arms 31 and 32, which transmit a torque by friction. If the torque applied to the winding pinion 202 is too great, the elastic arms 31 and 32 deform and slide against each other, until the system disengages.When disengaging, the jump made by the elastic arms 31 and 32 during unclipping produces a characteristic noise which informs the user that the barrel is fully reloaded.

[0038] In the variant illustrated by the figures, each mobile 1, 2, has three elastic arms 31 32. After disengagement, the first mobile 1 makes a third of a turn.

[0039] More specifically, the clearance between the rims of the two mobiles is between 0.06 and 0.10 mm, and the axial elastic travel of each arm is half the value of this clearance.

[0040] The invention also relates to a clockwork movement 500 comprising, between an input mechanism 300 and an output mechanism 400, such a torque limiting mechanism 100.

[0041] More particularly, the input mechanism 300 is a calendar or date mechanism, and the output mechanism 400 is a month, day of the week, or date display mechanism. And the torque limiter 100 is arranged to control, during any jump of an arm of a mobile 1 or 2 of the torque limiter 100, the advancement of one step of the display concerned. For example, the control of the correction of the day of the week display is a cyclic control for which the device according to the invention is well suited. In the same way, a clear adjustment of the date correction can be obtained.

[0042] The invention is easily adaptable to any semi-instantaneous or trailing display: months, days, time zones, hours, or others.

[0043] The invention also makes it possible to produce an inverter for mono- or bidirectional winding: the first mobile 1 meshes with an automatic winding oscillating weight, and the second mobile 2 meshes with the winding gear train. When the first mobile 1 rotates clockwise, the system clicks and the second mobile 2 does not rotate. When the first mobile 1 rotates counterclockwise, it drives the second mobile 2 through the distal ends 311, 321, of the elastic arms 31 and 32.Thus, more particularly the movement 500 comprises an automatic winding oscillating weight and an automatic winding train, and such a torque limiter 100 comprising elastic arms 31, 32, constitutes an inverter for mono- or bidirectional winding, the first mobile 1 meshing with the automatic winding oscillating weight, and the second mobile 2 meshing with the winding train, so that, when the first mobile 1 rotates clockwise, or respectively counterclockwise, the system de-clicks and the second mobile 2 does not rotate, and when the first mobile 1 rotates counterclockwise, or respectively clockwise, it drives the second mobile 2 through distal ends 311, 321, which the elastic arms 31, 32 respectively comprise.

[0044] The invention also makes it possible to produce a blocker, for example to prevent a barrel from discharging. The ratchet can be arranged with elastic arms, and the barrel bridge with notches, so that the ends of the arms fall into the notches. Thus, more particularly the movement 500 comprises at least one barrel and one ratchet arranged on a barrel bridge, and such a torque limiter 100 constitutes a blocker, to prevent a barrel from discharging, the ratchet constituting one of the mobiles 1, 2, and comprising elastic arms, and the barrel bridge constituting a structure 4 and comprising notches, so that the ends of the arms fall into the notches.

[0045] More particularly, the input mechanism 300 is a minute repeater trigger mechanism, and the output mechanism 400 is a minute repeater mechanism. The torque limiter 100 is then arranged to control, during any jump of an arm of a wheel set 1 or 2 of the torque limiter 100, the tilting of an isolator, which the minute repeater mechanism comprises, to prevent the control of another repeater during the execution of a repeater strike.

[0046] The invention also relates to a timepiece 1000 comprising at least one such torque limiting mechanism 100, and / or at least one such movement 500. More particularly, this timepiece 1000 is a watch.

[0047] In short, the proposed mechanism is very simple, because it does not require any elastic return means other than those carried by the first mobile 1, and preferably the second mobile 2. In particular, it is not necessary to interpose, in the space delimited by the structure 4 and the travel limiter 5, a spring to press the first mobile 1 and the second mobile 2 against each other.

[0048] The coaxial arrangement of the mobiles is particularly advantageous, because the forces exerted on the mobiles are symmetrical, and the transmissible force is maximum. In the case where the arrangement in the clockwork involves offsetting the first 1 and the second 2 mobiles, it is advantageous to increase the number of elastic arms to avoid blind spots.

[0049] The production of mobiles can come, very economically, from stamping, the mobiles can be identical, and possibly differ only by their teeth.

[0050] The invention allows the user to ensure the proper completion of the function he is performing, winding, display correction, triggering, and ensures the protection of the components of the mechanism concerned against any excessive torque. For example, the user can fully wind a barrel without fear of breaking a component.

Claims

1. Internal torque limiting mechanism (100) for a horological movement (500), said torque limiting mechanism (100) including: a first wheel (1) including a first felloe (10) and arranged to pivot about a first axis of rotation (D1) relative to a structure (4), said first wheel (1) including at least a first elastic arm (31) which, in the free state of said first wheel (1), projects along the direction of said first axis of rotation (D1) relative to said first felloe (10), and at least a second wheel (2) including a second felloe (20) and arranged to pivot relative to said structure (4) about a second axis of rotation (D2) parallel or merged with said first axis of rotation (D1) overlapping at least partially with said first wheel (1), said second wheel (2) including at least a second arm (32) arranged to engage in frictional pressure with said first wheel (1) for the relative actuation of one by the other, said at least one second arm (32) forming a ramp and which, in the free state of said second wheel (2), projects along the direction of said second axis of rotation (D2) relative to said second felloe (20), a travel limiter (5) fastened to said structure (4) and which is arranged to hold said second wheel (2) on said first wheel (1) for the engagement thereof in frictional pressure in certain relative angular positions, the second arm (32) being arranged to, in certain relative angular positions with respect to said first wheel (1), engage in frictional pressure with at least a said first elastic arm (31) of said first wheel (1), and, in further relative angular positions, allow a frictionless relative travel between said first wheel (1) and the second wheel (2).

2. Mechanism (100) according to claim 1, characterised in that at least a said first elastic arm (31) is movable in a first pressed section (41) of said first felloe (10).

3. Mechanism (100) according to one of claims 1 to 2, characterised in that said second arm (32) is a second elastic arm (32).

4. Mechanism (100) according to claim 3, characterised in that at least said second arm (32) is movable in a second pressed section (42) of said second felloe (20).

5. Mechanism (100) according to claim 3 or 4, characterised in that said first wheel (1) and said second wheel (2) are mounted top-to-tail, with each said first elastic arm (31) projecting towards said second wheel (2), and with each said second arm (32) projecting towards said first wheel (1).

6. Mechanism (100) according to one of claims 1 to 5, characterised in that said second axis of rotation (D2) is at a distance from said first axis of rotation (D1).

7. Mechanism (100) according to one of claims 1 to 5, characterised in that said second axis of rotation (D2) is merged with said first axis of rotation (D1).

8. Mechanism (100) according to claim 3 or 4, and according to one of claims 1 to 7, characterised in that each said second arm (32) is arranged to engage successively, upon a relative rotation of said second wheel (2) relative to said first wheel (1), with said first felloe (10), a said first elastic arm (31), and a said first pressed section (41) before returning in engagement with said first felloe (10).

9. Mechanism (100) according to claim 3 or 4, and according to one of claims 1 to 8, characterised in that each said first elastic arm (31) is arranged to engage successively, upon a relative rotation of said second wheel (2) relative to said first wheel (1), with said second felloe (20), a said second arm (32), and a said second pressed section (42) included in said second wheel (2), before returning in engagement with said second felloe (20).

10. Mechanism (100) according to one of claims 1 to 9, characterised in that each said first elastic arm (31) is an annular sector which extends substantially concentrically relative to the first axis of rotation (D1).

11. Mechanism (100) according to claim 3 or 4, and according to one of claims 1 to 10, characterised in that each said second arm (32) extends substantially concentrically relative to said second axis of rotation (D2).

12. Mechanism (100) according to claim 3 or 4, and according to one of claims 1 to 8, characterised in that at least a said first elastic arm (31) or / and at least a said second arm (32) extends substantially radially relative to the axis of rotation of the wheel bearing same.

13. Mechanism (100) according to one of claims 1 to 12, characterised in that said mechanism (100) includes, at least partially superimposed along a direction parallel with the axis of rotation of each thereof, more than two wheels arranged to engage pairwise in frictional pressure, and all mounted trapped between said structure (4) and said travel limiter (5), and in that at least one intermediate wheel between the end wheels includes at least one elastic arm projecting from each side of the felloe thereof, along the axial direction thereof.

14. Barrel winding device (200) including a control member (201) arranged to be operated by a user and actuate an input pinion (202) engaging with said first wheel (1) or said second wheel (2) of a torque limiting mechanism (100) according to one of claims 1 to 13, included in said device (200), of which said second wheel (2) or respectively said first wheel (1) is arranged to actuate a ratchet (203) of a driving or striking-mechanism barrel.

15. Horological movement (500) including, between an input mechanism (300) and an output mechanism (400), a torque limiting mechanism (100) according to one of claims 1 to 13.

16. Horological movement (500) according to claim 15, characterised in that said input mechanism (300) is a calendar or date mechanism, and in that said output mechanism (400) is a mechanism for displaying the month, or day of the week, or date, and in that said torque limiting mechanism (100) is arranged to command, upon any jump of an arm of a wheel (1; 2) of said torque limiter (100), the gain by one step of the display in question.

17. Horological movement (500) according to claim 15, characterised in that said input mechanism (300) is a minute repeater release mechanism, and in that said output mechanism (400) is a minute repeater mechanism, and in that said torque limiter (100) is arranged to command, upon any jump of an arm of a wheel (1; 2) of said torque limiting mechanism (100), the control of a lifting-lever, included in said minute repeater mechanism, to inhibit the command of a further repeater during the execution of a repeater striking-mechanism.

18. Horological movement (500) according to claim 15, characterised in that said movement (500) includes an oscillating automatic winding mass, an automatic winding train, and a torque limiting mechanism (100) according to claim 4 or 5, and according to one of claims 1 to 9, said torque limiting mechanism (100) forming a reverser for mono- or bidirectional winding, said first wheel (1) engaging with said oscillating automatic winding mass, and said second wheel (2) engaging with the winding train, such that, when said first wheel (1) turns in the clockwise, or respectively anticlockwise, direction, the system unclicks and said second wheel (2) does not turn, and when said first wheel (1) turns in the anticlockwise, or respectively clockwise, direction, it actuates said second wheel (2) via distal ends (311; 321) included in said elastic arms (31; 32).

19. Horological movement (500) according to claim 15, characterised in that said horological movement (500) includes at least a barrel, a ratchet arranged on a barrel bridge, and a torque limiting mechanism (100) according to claim 3 or 4, and according to one of claims 1 to 8, the torque limiting mechanism forming a brake-lever, to prevent a said barrel from being discharged, said ratchet forming one of said wheels (1; 2) and including elastic arms, and said barrel bridge forming a said structure (4) and including notches, such that the ends of said arms fall into said notches.

20. Timepiece (1000) including at least a torque limiting mechanism (100) according to one of claims 1 to 13, and / or at least a horological movement (500) according to one of claims 15 to 19.

21. Timepiece (1000) according to claim 20, characterised in that it is a watch.