Chronograph mechanism with vertical clutch

Abstract

The invention relates to a chronograph mechanism for a watch movement, comprising a chronograph wheel (10) of the vertical clutch type, including a chronograph shaft (12), a clutch wheel (24) mounted for free rotation on the chronograph shaft (12), a flange (18) mounted on the chronograph shaft (41), and a constraint member (22) acting on said flange (18). The chronograph mechanism (10) further includes an actuation device comprising an actuation piece (26) having a body (28) arranged at least partially around the clutch wheel (24) and an actuation means (32) for actuating the body (28) in rotation about the chronograph shaft (12).The device further comprises a profiled surface (29) and at least one actuating element (62) arranged to cooperate with the profiled surface so that rotation of the actuating element (26) in one direction and opposite directions induces, respectively, an elevation and a lowering of the body (28) to bring the chronograph wheel (10) into a disengaged and engaged configuration, respectively. The chronograph mechanism (10) further comprises a decoupling element (34) arranged partially between the flange (18) and the body (28) so that the rotation of the latter is not transmitted to the flange.

Description

technical field

[0001] The present invention relates to a chronograph mechanism comprising a chronograph wheel with a vertical clutch and a compact and reliable clutch control. The invention also relates to a chronograph movement comprising the chronograph mechanism and a timepiece incorporating such a movement. State of the art

[0002] In a vertical clutch chronograph, a clutch disc, typically a flange, is arranged to occupy a disengaged position, corresponding to the chronograph's stop position, and an engaged position. The latter corresponds to the chronograph's running position, where the flange is driven by friction from a clutch wheel kinematically connected to the finishing gear train of the watch movement in order to transmit the movement to the chronograph arbor that carries the seconds hand for measuring elapsed time.

[0003] The clutch is operated by a clamp designed to cooperate with a cone attached to the clutch disc, axially moving the disc from the disengaged to the engaged position and vice versa. EP2015145 discloses an example of a chronograph mechanism operated by a clamp.

[0004] Chronographs with a vertical clamp clutch have several drawbacks. The movement of the two clamp arms is not linear but angular, which can lead to a loss of state and, consequently, a loss of elapsed time information during clutch disc disengagement. Furthermore, the clutch disc cone is lifted by the clamp using only two points of support. This can cause axial imbalance of the cone, generating friction during engagement and disengagement. Finally, the clamp arms have a significant range of motion and operate within the plane of the movement. This requires a substantial amount of space within the movement, increasing its overall size. Brief summary of the invention

[0005] One aim of the present invention is therefore to provide a chronograph mechanism free from the aforementioned limitations.

[0006] More specifically, one aim of the present invention is to provide a chronograph mechanism with a vertical clutch chronograph wheel offering better stability during the clutch engagement and disengagement phases of the chronograph.

[0007] Another objective of the present invention is to provide a more compact vertical clutch chronograph mechanism.

[0008] According to the invention, these objectives are achieved, at least in part, by a chronograph mechanism for a watch movement, comprising a chronograph wheel of the vertical gear type, including a chronograph shaft, a clutch wheel mounted for free rotation on the chronograph shaft, a flange fixed for rotation to the chronograph shaft, and a constraint member acting on said flange. The chronograph mechanism further includes an actuation device for moving the flange relative to the chronograph shaft in order to bring the chronograph wheel, on the one hand, into an engaged configuration in which the flange is pressed against the clutch wheel to drive the chronograph shaft in rotation by friction and, on the other hand, into a disengaged configuration in which the flange is located at a distance from the clutch wheel.

[0009] According to the invention, the actuation device comprises an actuating piece including a body arranged at least partially around the clutch wheel and an actuating means for rotating the body around the chronograph axis. The actuation device further includes a profiled surface and at least one actuating element arranged to cooperate with the profiled surface so that rotation of the actuating piece in one direction and opposite directions induces, respectively, an elevation and a lowering of the body to bring the chronograph wheel into the disengaged and engaged positions, respectively. For this purpose, the profiled surface is arranged on one side of the watch movement frame and the body, while the actuating element is arranged on the other side of said frame and body.The chronograph mechanism also includes a decoupling device arranged partially between the flange and the body so that the rotational movement of the latter is not transmitted to the flange.

[0010] In one embodiment, the profiled surface is located on the underside of the body while the actuation element is integral with the plate or a bridge of the frame.

[0011] In one embodiment, the profiled surface of the lower face of the body includes at least one housing having a base for receiving said at least one actuating element and an inclined face extending from the base to said lower face so that the rotation of the body induces its raising or lowering by the action of the actuating element on the inclined face of said at least one housing.

[0012] In one embodiment, the profiled surface of the underside of the body has three housings intended to cooperate each with one of three actuation elements.

[0013] In one embodiment, the body is substantially annular in shape.

[0014] In one embodiment, the decoupling member comprises a fixed part arranged to be fixed to the frame of the watch movement, in particular to the mainplate or to a bridge, an annular element arranged inside the fixed part to bear against an upper face of the annular body and to act on an annular edge of the flange in order to raise it relative to the disengaging mechanism, and at least one elastic member connecting the fixed part to the annular element.

[0015] In one embodiment, said at least one elastic organ is in the form of several flexible blades extending along the periphery of the annular element.

[0016] In one embodiment, the constraint element comprises a central part mounted on the chronograph axis and several lugs bearing against a frustoconical surface of the flange.

[0017] In one embodiment, the chronograph wheel further comprises a seconds pinion attached to the clutch wheel and arranged to engage with a gear train of the watch movement.

[0018] In one embodiment, the clutch mechanism is in the form of a seconds wheel of a finishing gear of the watch movement.

[0019] In one embodiment, the chronograph mechanism further comprises a column wheel with a ratchet, a push-button control arranged to pivot upon pressure on a pusher, a ratchet actuated by the push-button control and arranged to cooperate with the column wheel, and a rocker arm cooperating with the column wheel via a beak. The rocker arm is configured to act directly or indirectly on the actuating means of the flange's actuating piece, such that pivoting the rocker arm moves the chronograph wheel from a disengaged to an engaged position and vice versa.

[0020] Another aspect of the invention relates to a watch movement comprising the chronograph mechanism according to one of the aforementioned embodiments, as well as to a timepiece comprising such a movement. Brief description of the figures

[0021] Examples of implementation of the invention are shown in the description illustrated by the accompanying figures, in which: there figure 1 illustrates a top view of a chronograph mechanism, according to one embodiment, comprising a chronograph wheel in an engaged configuration; the figure 2 illustrates an axial cross-section of the chronograph movement of the figure 1 , there figure 3 illustrates a view similar to the figure 1 when the chronograph mechanism is in a disengaged configuration; the figure 4 illustrates an axial cross-section of the chronograph movement of the figure 3 , there figure 5 illustrates a top perspective view of the chronograph movement in an engaged configuration; the figure 6 illustrates a top perspective view of the chronograph mobile in a disengaged configuration; the figure 7 illustrates a perspective view from below of the chronograph mobile of the figure 5 ; there figure 8illustrates a perspective view from below of the chronograph mobile of the figure 6 ; there figure 9 illustrates a top view of the decoupling mechanism of the chronograph movement, and the Figure 10 illustrates a perspective view from below of the actuation piece for engaging / disengaging the chronograph movement. Examples of embodiments of the invention

[0022] According to a preferred form of execution illustrated in particular by the figures 1 and 2The chronograph wheel 10, of the vertical clutch type, is integrated into a chronograph mechanism of a watch movement, comprising a conventional start / stop mechanism for starting and stopping the chronograph. This mechanism includes a column wheel 45 with a ratchet 46, cooperating with a jumper 52, and columns (concealed by the ratchet). A pusher control 42, in the form of a rocker, is arranged to pivot under pressure from a pusher (not shown) and to return to its rest position under the action of the spring 54. In the illustrated example, a pawl 44 is connected to one end of the rocker 42 and is arranged to cooperate with the toothed teeth of the ratchet 46 of the column wheel 45.

[0023] The chronograph start / stop mechanism further comprises a rocker 48 cooperating with the column wheel via a beak 49 under the action of a leaf spring 56. The rocker 48 is connected to an actuating arm 32 of an actuating piece 26 ( Figure 10 ) of the chronograph mechanism 10 for starting and stopping the chronograph, as described later. In one embodiment, the rocker 48 is connected to the actuating arm 32 via a rocker 50. However, the chronograph start / stop mechanism can be adapted so that the rocker 48 is directly connected to the actuating arm 32 of the actuating piece, according to an unillustrated variant.

[0024] Thus, two successive presses of a pusher allow the ratchet 46 to be pulled counterclockwise via the pawl 44 by means of the pivoting of the pusher control 42, in order to position the beak 49 successively between two columns and on the outer flank of one of the columns of the column wheel 45. This allows the actuating arm 32 of the actuating piece to be moved clockwise and counterclockwise respectively, bringing the chronograph wheel 10 into a configuration respectively engaged according to the figures 1 and 2 and disengaged according to the figures 3 and 4 and vice versa.

[0025] With reference in particular to figures 2 And 4, the chronograph mechanism 10 comprises for this purpose a chronograph shaft 12 on which the seconds hand 14 is mounted, a clutch disc 24 integral with a seconds pinion 16 mounted for free rotation on a lower portion 12c of the chronograph shaft 12, a flange 18 integral for rotation with the chronograph shaft, and a constraint member 22 ( figure 5 ) acting on the flange 18 to maintain a ring surface 19 against the clutch disc 24. This constraint element also allows the chronograph shaft 12 to be connected to the clutch disc by friction in order to be able to reset the chronograph.

[0026] Pinion 16 is arranged to mesh with a gear train of the watch movement. According to an unillustrated variant, the clutch wheel is in the form of a seconds wheel from a finishing gear train of the watch movement. In this case, the chronograph wheel 10 lacks a seconds pinion.

[0027] In the example illustrated in particular by the figures 5 and 6 The flange 18 has an annular edge 19 and a frustoconical surface 20 defining a circular recess. The constraint member 22 is preferably in the form of an elastic member comprising, on the one hand, a central part 22a fixed on a washer 23 arranged against a collar 12a of the chronograph axis 12 as illustrated by the figure 2 and, on the other hand, flexible blades 22b acting on the frustoconical surface 20 of the flange.

[0028] These blades are, for example, three in number, spaced angularly 120° apart from each other and extending radially from the central part 22a to the distal part of each blade 22b. These allow an annular surface 21 of the flask 18 to be constrained ( figure 2) against the clutch disc 24 with sufficient force so that the flange can be driven by friction by the clutch disc 24 as soon as the chronograph mechanism is triggered.

[0029] The actuating part 26 of the chronograph movement 10 illustrated in the Figure 10 is intended to move the flange 18 relative to the chronograph axis 12 in order to bring the chronograph wheel 10, on the one hand, into a engaged configuration in which the flange 18 is supported against the clutch wheel 24, according to the figure 2 , in order to drive it by friction and, on the other hand, in a disengaged configuration in which the flange 18 is located at a distance from the clutch wheel 24 according to the figure 4 .

[0030] The actuating piece 26 is preferably a single unit and preferably comprises an annular body 28 arranged around the clutch wheel 24 and an actuating arm 32 extending radially from the annular body to actuate it in rotation about the chronograph axis 12. According to an alternative embodiment, the chronograph start / stop mechanism is adapted to act on a lug located on the outer periphery of the annular body in order to rotate it. In this case, the actuating piece is without an actuating arm.

[0031] A lower face 29 of the annular body 28 is profiled to cooperate with at least one actuating element 62 fixed to the movement frame. This actuating element is, for example, attached to the mainplate 60 or to a bridge of the watch movement. This actuating piece has the advantage of being compact and fitting perfectly into the clutch mechanism, thus allowing for a significant space saving compared to known clip-on chronograph mechanisms.

[0032] The rotation of the annular body 28 in one direction and opposite directions, achieved by the engagement / disengagement mechanism, induces an upward and downward movement of the annular body 28 along the chronograph axis 12, thus bringing the chronograph wheel 10 into its respectively disengaged and engaged positions. More specifically, the upward and downward movement of the annular body is induced by the action of the actuating element 62 on the profile of its lower face 29 during this rotation.

[0033] According to the embodiment illustrated in the Figure 10 , the lower face 29 of the annular body 28 has a profiled surface with three housings 30 spaced about 120° apart and each having a bottom 30a intended to accommodate one of three actuation elements 62 ( figure 7) and an inclined face 30b extending from the bottom to this lower face 29. The rotation of the actuating piece 26 thus makes it possible to induce the raising and lowering of the annular body 28 by the action of each actuating element 62 on the inclined face 30b of each housing 30. The stroke of the actuating piece 26 is thus limited in height to a few millimeters which allows better stability of the flange during the engagement / disengagement phase of the chronograph compared to known clip-on chronograph mechanisms.

[0034] The actuation elements are, for example, in the form of pins 62 pressed onto the plate 60 or a bridge. Depending on the embodiment, the annular body may have only two housings, or even a single housing designed to cooperate with two or a single actuation element attached to the movement frame. In this case, guiding means may be provided to ensure the stability of the annular body when it is raised or lowered relative to the watch movement frame.

[0035] According to an alternative embodiment not shown, the profiled surface described above can be located on the watch movement frame, specifically on the mainplate or a bridge, while the actuation elements designed to interact with this profiled surface are fixed to the underside of the annular body. Thus, the rotation of the annular body also induces an upward and downward movement of the annular body along the chronograph axis, bringing the chronograph wheel into its respectively disengaged and engaged positions.

[0036] With reference in particular to figures 2 , 4 And 9The chronograph wheel 10 further comprises a decoupling member 34 arranged partially between the annular body 28 and the annular edge 19 of the flange 18. Thus, the flange is decoupled from the clutch wheel 24 so that the flange is not driven by the rotation of the annular body. This prevents a loss of the elapsed time when the chronograph is stopped. To this end, the decoupling member 34 comprises a fixed part 36 with eyelets for fixing it to the watch movement frame, in particular to the mainplate 60 or to a bridge, and an annular element 38 arranged inside the fixed part 36 which bears against an upper face of the annular body 28 and acts on a lower side of an annular edge 19 of the flange 18 ( figure 4) to raise it relative to the disengagement mobile 24 and at least one elastic element 40 connecting the fixed part 36 to the annular element 38 so that the shape of the decoupling member 34 can adapt to the raised or lowered position of the annular body.

[0037] In the example illustrated in the figure 9 , the elastic element of the decoupling element 34 is in the form of several flexible blades 40, for example five blades, extending over the entire perimeter of the annular element 38. These flexible blades allow a stable vertical movement of the actuating part 26 during the clutching and disengagement phases of the chronograph wheel 10.

[0038] According to the above description relating to the start / stop mechanism of the chronograph wheel 10, actuating the pusher control 42 with a pusher (not shown) allows the actuating arm 32 to be moved clockwise, according to the figure 1, to bring the chronograph mobile 10 into an engaged configuration according to the figure 2 At this moment, under the action of the constraint element 22, the flange 18 is pressed against the clutch disc 24, which is driven in rotation by the pinion 16 meshing with a gear of a movement connected to the finishing gear train. The chronograph axis 12 is thus driven in rotation by the flange 18 according to the intermittent rotation of the finishing gear train, which is determined by the oscillation frequency of the balance wheel and hairspring.

[0039] In the engaged configuration of the chronograph mobile 10 and with regard to the figure 7 , the three pins 62 of the plate 60 are located in the three housings 30 of the annular body.

[0040] An additional press on the pusher of the chronograph mobile's start / stop mechanism 10 allows the operating arm 32 to be actuated in a counter-clockwise direction according to the figure 3This allows the annular body of the actuating piece to be raised by the action of the studs 62 on the respective inclined faces 30b of the housings until the heads of the studs are in contact with the lower face 29 of the annular body 28 as illustrated by the figure 8 .

[0041] During the transition from the engaged to the disengaged configuration of the chronograph mechanism, the upper face of the annular body 28 is in contact with the lower face of the annular element 38 of the decoupling member and moves angularly relative to the latter. The decoupling member thus transmits only the movement of the annular body along the chronograph axis 12, thereby stopping the chronograph as soon as the lug 18 is no longer in contact with the clutch disc 24.

[0042] It will be understood that various modifications and / or improvements, obvious to a person skilled in the art, can be made to the chronograph mechanism according to the embodiment described herein without departing from the scope of the invention as defined by the attached claims. For example, any type of start / stop mechanism can be used to actuate the actuating arm of the actuating part in both clockwise and counterclockwise directions.

[0043] Furthermore, the body of the actuating element can have a different shape, typically a partially annular shape extending, for example, over 180°, provided that one or more points of contact between the profiled surface and the actuating element(s) arranged to cooperate with it can be created in order to raise the flange. In this case, the decoupling member is adapted to rest on the upper surface of the body, depending on the shape of the latter. List of references

[0044] Chronograph wheel 10 Chronograph axis 12 Collar 12a Upper portion 12b Lower portion 12c Seconds hand 14 Seconds pinion 16 Flange 18 Annular edge 19 Truncated conical surface 20 Annular surface 21 Constraint element 22 Central part 22a Flexible blades 22b Washer 23 Clutch wheel 24 (e.g., disc, seconds wheel) Actuating part 26 Annular body 28 Lower face 29 Housings 30 Case back 30a Inclined face 30b Actuating means 32 Decoupling element 34 Fixed part 36 Fixing eyelets 37 Annular element 38 Elastic element 40 (leaf spring) Push-button control 42 Ratchet 44 Column wheel 45 Ratchet 46 Main rocker 48 Beak 49 Intermediate rocker 50 Jumper 52 Leaf spring 54, 56 Plate 60 Actuating element 62 (e.g. stud)

Claims

1. Chronograph mechanism for a watch movement, comprising a chronograph wheel (10), of the vertical clutch type, including a chronograph shaft (12), a clutch wheel (24) mounted for free rotation on the chronograph shaft (12), a flange (18) fixed for rotation to the chronograph shaft (12), and a constraint member (22) acting on said flange (18), the chronograph mechanism further comprising an actuating device for moving the flange (18) relative to the chronograph shaft (12) in order to bring the chronograph wheel (10), on the one hand, into an engaged configuration in which the flange (18) is pressed against the clutch wheel (24) in order to drive the chronograph shaft (12) in rotation by friction and, on the other hand, into a disengaged configuration in which the flange (18) is located at a distance from the clutch mechanism (24), characterized in thatThe actuation device comprises an actuation piece (26) having a body (28) arranged at least partially around the clutch wheel (24) and an actuation means (32) for actuating the body (28) in rotation about the chronograph axis (12), a profiled surface (29) arranged on one of the watch movement frame and the body (28), and at least one actuation element (62) arranged on the other of said frame and body to cooperate with the profiled surface (29) so that the rotation of the actuation piece (26) in one direction and in the opposite direction induces respectively an elevation and a lowering of the body (28) to bring the chronograph wheel (10) into the respectively disengaged and engaged configuration and in that the chronograph mechanism further includes a decoupling element (34) arranged partially between the flange (18) and the body (28) so that the rotation of the body (28) is not transmitted to said flange (18).

2. Chronograph mechanism according to claim 1, characterized in that the profiled surface is located on the lower face (29) of the body (28) and in that said at least one element (62) is integral with the plate (60) or a bridge of the frame.

3. Chronograph mechanism according to claim 2, characterized in that the profiled surface of the lower face (29) of the body (28) includes at least one housing (30) having a bottom (30a) intended to accommodate said at least one actuating element (62) and an inclined face (30b) extending from the bottom to said lower face (29) so that the rotation of the body (28) induces its raising or lowering by the action of the actuating element (62) on the inclined face (30b) of said at least one housing (30).

4. Chronograph mechanism according to the preceding claim, characterized in thatthe body (28) has three housings on its lower face (29) each intended to cooperate with one of three actuation elements (62).

5. Chronograph mechanism according to any one of the preceding claims, characterized in that said body (28) is annular in shape.

6. Chronograph mechanism according to the preceding claim, characterized in that The decoupling member (34) comprises a fixed part (36) arranged to be fixed to the plate or to a bridge of the watch movement, an annular element (38) arranged inside the fixed part (36) to bear against an upper face of the annular body (28) and to act on an annular edge (19) of the flange (18) to raise it relative to the disengagement mobile (24) and at least one elastic member (40) connecting the fixed part (36) to the annular element (38).

7. Chronograph mechanism according to the preceding claim, characterized in thatsaid at least one elastic organ is in the form of several flexible blades (40) extending along the annular element (38).

8. Chronograph mechanism according to any one of the preceding claims, characterized in that the constraining member (22) comprises a central part (22a) mounted on the chronograph axis (12) and several lugs (22b) bearing against a frustoconical surface (20) of the flange (18).

9. Chronograph mechanism according to any one of the preceding claims, characterized in that It also includes a seconds pinion (16) attached to the clutch wheel (24) and arranged to engage with a gear train of the watch movement.

10. Chronograph mechanism according to any one of claims 1 to 8, characterized in that the clutch mechanism is in the form of a seconds wheel of a finishing gear of the watch movement.

11. Chronograph mechanism according to any one of the preceding claims, further comprising a column wheel (45) having a ratchet (46), a pusher control (42) arranged to pivot under the action of pressure on a pusher, a ratchet (44) actuable by the pusher control (42) and arranged to cooperate with the column wheel and a rocker (48) cooperating with the column wheel by means of a beak (49), the rocker (48) being configured to act directly or indirectly on the actuation means (32) of the actuation part (26) of the flange (18) so that the pivoting of the rocker (48) brings the chronograph wheel (10) from a disengaged configuration to an engaged configuration and vice versa.

12. Watch movement comprising the chronograph mechanism according to one of the preceding claims.

13. Timepiece comprising the time movement according to claim 12.

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