Device with retractable finger for actuating a timepiece mechanism

Abstract

The present invention relates to a retractable finger device (10) for a watch movement, comprising an actuation module (20) for a watch mechanism, in particular a multi-time display mechanism, and a drive module (40) arranged to drive the actuation module (20) so that it can perform a succession of 360° rotation cycles. The actuation module (20) comprises a finger (22), a finger support (30) on which the finger (22) is mounted, a finger cam (28) arranged to cooperate with the finger (22), a first drive member (32) integral with the finger support (30) and a second drive member (34) integral with the finger cam (22).The drive module (40) comprises a first transmission member (50) arranged to drive the first drive member (32) and a second transmission member (62, 66a, 66b) arranged to drive the second drive member (34) so ​​as to induce a relative movement between the finger support (30) and the finger cam (28). This relative movement allows the finger (22) to move from a deployed to a retracted configuration and vice versa. The finger (22) is arranged to actuate the watch mechanism when the finger passes through the deployed configuration. The finger (22) is also arranged to disengage from the watch mechanism when the finger passes through the retracted configuration so as not to actuate said mechanism with each rotation cycle of the drive module (20).

Description

technical field

[0001] The present invention relates generally to a retractable finger device for actuating a clockwork mechanism. The retractable finger device is particularly suitable for reducing the time jump between two successive time indications on a display mechanism. The display mechanism may, in particular, include indications relating to the 31 days of the month, the seven days of the week, or the months of the year. State of the art

[0002] The mechanisms used to advance a display, such as the day, month, and week, conventionally consist of a finger fixed to a 24-hour wheel that completes one revolution every 24 hours. This finger is positioned to rotate a star attached to a disc bearing the displays to be shown sequentially. The star works in conjunction with a positioning jumper, which ensures the star's precise angular position after each advance.

[0003] This solution is simple but has the drawback of resulting in a slow transition time, since the movement from one display to the next depends on the rotation speed of the 24-hour wheel. Although the date, for example, changes at night, reading it late at night is not optimal.

[0004] To address this problem, there are "dragging" jump mechanisms where the jump time between displaying one indication and the next is minimized by reducing the time the finger takes to engage with the star wheel and by adapting the shape of the positioning jumper to make the jump as quickly as possible. However, these mechanisms do not significantly reduce the jump time, especially if the leading finger is fixed to a 24-hour wheel.

[0005] We also know of systems for triggering instantaneous jumps that use a cam arranged to cock a lever for 24 hours, in order to smooth out the torque reaction. When the cam jumps, the lever falls and engages the function, for example a star wheel, which is generally held in position by a jumper, which has the disadvantage of consuming additional energy to perform the jump.

[0006] DE102018106373 discloses a date mechanism comprising a date ring and a device for driving the ring. The device includes a pawl mounted on a carrier wheel. This pawl has a U-shaped locking section and an actuating finger. The locking section is arranged to cooperate with a triangular cam to retract the actuating finger so as not to actuate the ring with each rotation of the carrier wheel. The carrier wheel is driven at a speed suitable for minimizing the ring's jump time. Brief summary of the invention

[0007] One aim of the present invention is to propose an actuation device for a clockwork mechanism comprising a retractable finger according to an alternative solution.

[0008] Another objective of the present invention is to provide a clockwork mechanism actuation device in which the energy required to actuation the mechanism is significantly reduced compared to known instantaneous jump mechanisms.

[0009] These goals are achieved in particular by means of a retractable finger device for watch movements, comprising an actuating module for a watch mechanism, in particular a multi-time display mechanism, and a drive module arranged to drive the actuating module so that it can perform a succession of 360° rotation cycles. The actuating module comprises a finger, a finger support on which the finger is mounted, a finger cam arranged to cooperate with the finger, a first drive member fixed to the finger support, and a second drive member fixed to the finger cam.The drive module has a first transmission element arranged to drive the first drive element and a second transmission element arranged to drive the second drive element so as to induce a relative movement between the finger support and the finger cam in order to bring the finger from a deployed configuration to a retracted configuration and vice versa.

[0010] The finger is arranged, on the one hand, to be able to activate the watch mechanism when the finger passes through the deployed configuration and, on the other hand, to be released from the watch mechanism when the finger passes through the retracted configuration, so as not to activate the watch mechanism at each rotation cycle of the actuation module.

[0011] In one embodiment, the device further comprises a pivot and a return element that are integral with the finger support. The finger can be pivotally mounted on the pivot. The return element is arranged to constrain the finger against the finger cam so that the finger can move from the retracted to the extended configuration under the action of the finger cam, and from the extended to the retracted configuration under the action of the return element.

[0012] According to one embodiment, the return element is in the form of a spring blade 26 which extends along a curved path around the finger cam 28.

[0013] According to one embodiment, the finger cam is mounted coaxially to the axis of rotation of the finger support.

[0014] In one embodiment, the finger cam profile comprises a first and a second sector. The first and second sectors are distanced from the center of the cam by a first and a second distance, respectively. The second distance is greater than the first distance in order to bring the finger into the deployed and retracted configurations, respectively.

[0015] In one embodiment, the finger cam profile comprises a circular sector, a vertex, a transition sector between the end of the circular sector and the vertex, and a sharp break between the vertex and the beginning of the cam's circular sector. The finger is in its deployed configuration when in contact with the cam's vertex and in its retracted configuration when in contact with the cam's circular sector.

[0016] In one embodiment, the actuation module further comprises a cylindrical element, for example, a tube or a rod. The finger cam and the second drive element are fixed to the cylindrical element and are arranged on either side of the assembly comprising the finger support and the first drive element. The latter is pivotally mounted around the cylindrical element to allow relative movement between the finger support and the finger cam.

[0017] In one embodiment, the actuation module and the drive module are adapted so that the rotational speed of the finger support driving the finger is at least twice the rotational speed of the finger cam. Preferably, the rotational speed of the finger support is at least four times, or even eight times, that of the finger cam to further reduce the jump time.

[0018] According to one embodiment, the first and second drive elements of the actuation module are arranged coaxially.

[0019] According to one embodiment, the first and second drive elements of the actuation module are respectively a driven wheel and a Maltese cross.

[0020] In one embodiment, the first transmission member of the drive module is a driving wheel meshing with the driven wheel of the actuating module. The second transmission member of the drive module comprises a plate that is rotatably fixed to the driving wheel and at least one pin fixed to the plate and arranged to cooperate with the Maltese cross of the actuating module in order to impart a jerky rotation to the finger cam. The second transmission member further comprises a locking device fixed to the plate in order to stabilize the position of the finger cam when the pin is disengaged from the Maltese cross.

[0021] Another aspect of the invention relates to a clockwork mechanism, in particular a mechanism for displaying the date, days of the week, or months of the year, comprising the retractable finger device, as well as to a clockwork component comprising the clockwork mechanism. Brief description of the figures

[0022] Examples of implementation of the invention are given in the description illustrated by the accompanying figures, in which: there figure 1 illustrates a top view of the retractable finger device comprising an actuation module, where the finger support is shown in dashed lines, and a drive module according to one embodiment; the figure 2 illustrates a top view of the device's actuation module figure 1 ; there figure 3 illustrates a cross-sectional view of the actuation module of the figure 2 according to AA; the figure 4 illustrates an exploded view of the device's actuation module figure 1 , there figure 5 illustrates a top view of a date display featuring the retractable finger device arranged to cooperate with a 31 star of the display and engaged with a driving wheel in one embodiment, the figures 6a to 6cillustrate top views of an operational sequence of the retractable finger device of the figure 5 , to bring the finger into a retracted position so that the finger is clear of the star as it passes, and the figures 7a to 7e illustrate top views of an operational sequence of the retractable finger device of the figure 5 , to bring the finger into a deployed configuration so that the finger can activate the jump star as it passes. Example(s) of an embodiment of the invention

[0023] With reference to the figure 1 The retractable finger device 10 comprises an actuating module 20 and a drive module 40 arranged to drive the actuating module 20 so that it can perform a succession of 360° rotation cycles. The actuating module is intended to trigger or actuate a clockwork mechanism, for example a 31-tooth star 70 for displaying the date as illustrated in the figure 5 .

[0024] In view of the figures 2 and 3 The actuation module 20 comprises a finger 22, a finger support 30, for example in the form of a plate, on which the finger 22 is mounted, a finger cam 28 mounted coaxially to the axis of rotation of the finger support 30 and arranged to cooperate with the finger 22, a first drive member 32 fixed to the plate 30 and a second drive member 34 fixed to the finger cam 28. The first drive member is, for example, a wheel 32. The plate 30 and the wheel 32 are fixed together so that the plate 30 can be driven in unison with the wheel 32.

[0025] The finger cam 28 and the second drive member 34 are mounted on either side of the assembly comprising the plate 30 and the wheel 32. For this purpose, the actuation module 20 includes a tube 36. One end of the tube 36 is fixed to the finger cam 28, while the other end of the tube is fixed to the second drive member 34. The wheel 32 is pivotally mounted around the tube 36 in order to induce a relative movement between the finger cam 28 and the plate 30 supporting the finger 22.

[0026] In the example illustrated in the figure 2The finger 22 is pivotally mounted around a pivot 24, for example a pin, fixed to the plate 30. The finger 22 has a distal portion 22a for actuating the clock mechanism, and an actuable portion 22b arranged to cooperate with a return member 26 for holding the finger 22 against the finger cam 28. This return member may, in particular, be in the form of a leaf spring 26 having a fixing portion 27 fixed to the plate 30 by fixing pins 27a, for example, and a distal portion acting on the actuable portion 22b of the finger 22, it being specified that the distal and actuable portions of the finger are arranged on either side of the pivot 24. In this example, the leaf spring 26 extends along a curved path around the finger cam 28 over at least 90°.

[0027] The finger cam 28 comprises a circular sector 28a, a vertex 28c, a transition sector 28b extending from the end of the circular sector 28a to the vertex 28c of the cam, and a clean cut 28b extending, for example, in a radial direction from the vertex 28c of the cam to the beginning of the circular sector 28a. The finger 22 is in a retracted configuration when it moves along and against the circular sector 28a of the cam. The finger 22 is arranged to begin pivoting around the pivot 24 when it cooperates with the beginning of the transition sector 28b and continues to pivot as it progresses along this transition sector in order to reach its deployed configuration when it cooperates with the top 28c of the cam 28. As soon as the finger 22 passes the clean cut 28, the spring blade 26 pivots the finger in the opposite direction in order to return it to its retracted configuration against the circular sector 28a of the cam 28.

[0028] By referring to the figure 1 , the drive module 40 of the retractable finger device 10 includes a first transmission member 50 engaged or arranged to cooperate with the first drive member 32 of the actuation module 20 and a second transmission member engaged or arranged to cooperate with the second drive member 34 of the actuation module 20.

[0029] According to the illustrated example, the finger cam 28 is arranged to be driven by a jerky rotation via a Maltese cross drive. For this purpose, the second drive element of the actuating module 20 is a Maltese cross 34 fixed to the tube 36 and having four grooves. The second transmission element of the drive module 40 comprises a plate 66 and two pins 64a, 64b fixed diametrically opposite to the plate 66 and near its periphery. The drive module 40 also includes a locking device 62 fixed to the plate 66 and having a shape complementary to the Maltese cross 34 in order to stabilize its angular position when one or both of the two pins 64a, 64b are not engaged in a groove of the Maltese cross.

[0030] The first transmission element of the drive module 40 is a wheel 50 meshing with the wheel 32 of the actuation module 20. The wheel 50 is rotationally fixed to the plate 66 of the Maltese cross drive. In the example illustrated in the figure 5 The wheel 50 meshes with a driving wheel 80 of a clockwork movement. This driving wheel has 48 teeth and is arranged to be driven by the movement at a rate of one revolution every 24 hours. The wheel 50 of the drive module 40, which meshes with the driving wheel 80, has 24 teeth and is driven at a rate of two revolutions every 24 hours. The wheel 32 of the actuation module 20 has 12 teeth and is driven at a rate of four revolutions every 24 hours. This speed thus corresponds to the speed of the plate 30 supporting the finger 22 and consequently to the rotational speed of the latter.

[0031] Since the plate 66 of the drive module 40 has two grooves 64a, 64b, the Maltese cross 34 has four grooves, and the finger cam 28 is fixed to the Maltese cross 34 via the shaft 38, the finger cam 28 is driven at a rate of one quarter turn every 24 hours. The rotational speed of the finger 22 around the finger cam 28 is therefore four times greater than the rotational speed of the latter in this example. It goes without saying that the gear ratios can be varied to modify the relative speed between the finger 22 and the finger cam 28. The rotational frequency of the driving wheel 80 can also be increased by adapting the gear train of the movement meshing with it. This further reduces the jump time when the clockwork mechanism is actuation by the drive module.

[0032] The operation of the retractable finger device will now be described with reference to figures 6a to 7e .

[0033] According to the figure 6a The finger 22 is constrained by the spring blade 26 against the circular sector 28a of the cam 28 in a retracted configuration. At this instant, the apex 28c of the cam is located approximately at 12 o'clock. The star 70 is held in a stable angular position by a jumper 72 cooperating with a spring 74.

[0034] The finger 22 is progressively driven by the plate 30, which engages with the driving wheel 50, in order to be brought into its deployed configuration where it is in contact with the apex 28c of the cam as illustrated in the figure 6b Compared to the figure 6a and in view of the gear ratios described above, the finger 22 pivoted around the cam 38 by about one third of a turn while the plate 66 supporting the pins 64a, 64b made about one sixth of a turn without one of the pins of the plate actuating the Maltese cross.

[0035] The finger 22 continues to rotate around the cam 28. The spring blade 26 again forces the finger 22 against the circular part 28a of the cam 28 as soon as it is disengaged from the top 28c of the cam so that it is returned to its retracted configuration as shown in the figure 6c The distal part 22a of the finger 22 is thus freed from the teeth 71 of the star 70. The latter is therefore not actuated by the distal part 22a of the finger when it passes in front of the teeth 71 of the star.

[0036] With reference to the figure 7a , finger 22 was driven by plate 30 by approximately two-thirds of an additional turn relative to the figure 6cMeanwhile, the Maltese cross has been rotated a quarter turn counterclockwise by one of the pins 64a, 64b of the plate 66. This allows the cam 68 to be rotated a quarter turn counterclockwise so that its apex 28c now points opposite the axis of rotation of the star 70. The finger 22 continues its movement around the cam to be brought into its deployed configuration according to the figures 7b and 7c , in which it is in contact with the 28c apex of the cam.

[0037] The distal part 22a of finger 22 can thus come into contact with a tooth 71 of the star 50 so that the latter makes a jump caused by the rotation of the finger as illustrated by the figures 7d and 7e .

[0038] The finger 22 will then rotate around the cam 28 in order to perform a succession of three 360° rotation cycles in its retracted configuration since, according to the gear ratios between the actuation module and the drive module, the plate 30 supporting the finger 22 must make four additional turns for the finger 22 to be actuated again by the cam 28 in its deployed configuration since the latter pivots a quarter turn in 24H.

[0039] It goes without saying that the invention is not limited to the embodiment just described but encompasses various variants. For example, the actuation module of the retractable finger device can be adapted so that the finger can be actuated not by rotation but by translation. In this case, the return element is adapted to exert a force in a straight line tending to return the finger to its retracted position. Reference list

[0040] Retractable finger device 10 Actuating module 20 Finger 22 Distal part 22a Actuating part 22b Pivot 24 Return member 26 Fixing part 27 Fixing pin 27a Finger cam 28 Circular sector 28a Transition sector 28b Apex 28c Clean break 28d Finger support 30 First drive member 32 Wheel Second drive member 34 Maltese cross Tube 36 Drive module 40 First transmission member 50 Second transmission member 62, 64a, 64b, 66 Locking mechanism 62 Pins 64a, 64b Support 66 Star 70 Teeth 71 Jumper 72 Spring 74 Driving wheel 80

Claims

1. Device with retractable finger (10) for a watch movement, comprising an actuation module (20) of a watch mechanism, in particular of a display mechanism with multiple time indications, and a drive module (40) arranged to drive the actuation module (20) so that the latter can perform a succession of 360° rotation cycles, said actuation module (20) comprising a finger (22), a finger support (30) on which the finger (22) is mounted, a finger cam (28) arranged to cooperate with the finger (22), a first drive member (32) secured to the finger support (30), and a second drive member (34) secured to the finger cam (28), the drive module (40) comprising a first transmission member (50) arranged to drive the first drive member (32), and a second transmission member (64a, 64b, 66) arranged to drive the second drive member (34) so as to induce a relative movement between the finger support (30) and the finger cam (28), in order to bring the finger (22) from a deployed configuration to a retracted configuration and vice versa, the finger (22) being arranged, on the one hand, to actuate the watch mechanism upon passage of the finger in the deployed configuration and, on the other hand, to be disengaged from the watch mechanism upon passage of said finger in the retracted configuration, so as not to actuate said mechanism at each rotation cycle of the actuation module (20), characterized in that the device further comprises a return member (26) secured to the finger support (30) and arranged to bias the finger (22) against the finger cam (28), such that the finger (22) can pass from the retracted configuration to the deployed configuration under the action of the finger cam (28), and from the deployed configuration to the retracted configuration under the action of the return member (26).

2. Device (10) according to claim 1, further comprising a pivot (24) secured to the finger support (30), the finger (22) being pivotally mounted on the pivot (24).

3. Device (10) according to the preceding claim, wherein the return member is in the form of a leaf spring (26) extending along a curved path around the finger cam (28).

4. Device (10) according to any one of the preceding claims, wherein the finger cam (28) is mounted coaxially with the axis of rotation of the finger support (30).

5. Device (10) according to any one of the preceding claims, wherein the profile of the finger cam (28) comprises a first sector (28a) and a second sector (28c) spaced from the center of said cam (28) by a first distance and a second distance, respectively, the second distance being greater than the first distance so as to bring the finger (22) into the deployed and retracted configurations, respectively.

6. Device (10) according to the preceding claim, wherein the profile of the finger cam (28) comprises a circular sector (28a), a peak (28c), a transition sector (28b) between the circular sector and the peak, and an abrupt cutout (28d) between the peak and the circular sector, the finger (22) being in the deployed and retracted configurations when it is in contact with the peak (28c) and with the circular sector (28a) of said cam (28), respectively.

7. Device (10) according to any one of the preceding claims, wherein the actuation module (20) further comprises a cylindrical element (36), the finger cam (28) and the second drive member (34) both being secured to the cylindrical element (36) and arranged on either side of the finger support (30) and of the first drive member (32), the first drive member (32) being pivotally mounted around the cylindrical element (36) so as to allow relative movement between the finger support (30) and the finger cam (28).

8. Device (10) according to any one of the preceding claims, wherein the actuation module (20) and the drive module (40) are configured such that the rotational speed of the finger support (30) driving the finger (22) is at least twice, preferably at least four times, and even eight times greater than the rotational speed of the finger cam (28).

9. Device (10) according to any one of the preceding claims, wherein the first and second drive members (32, 34) of the actuation module (20) are arranged coaxially.

10. Device (10) according to any one of the preceding claims, wherein the first and second drive members of the actuation module (20) are respectively a driven wheel (32) and a Maltese cross (34).

11. Device (10) according to the preceding claim, wherein the first transmission member of the drive module (40) is a drive wheel (50) meshed with the driven wheel (32) of the actuation module (20), and wherein the second transmission member of the drive module (40) comprises a plate (66) rotationally secured to the drive wheel (50), at least one pin (64a, 64b) secured to the plate (66) and arranged to cooperate with the Maltese cross (34) of the actuation module (20) so as to impart a stepped rotation to the finger cam (28), and a locking member (62) secured to the plate (66) so as to stabilize the position of the finger cam (28) when said at least one pin (64a, 64b) is disengaged from the Maltese cross (34).

12. Watch mechanism, in particular a display mechanism for the date, the days of the week, or the months of the year, comprising the device (10) according to any one of the preceding claims.

13. Timepiece comprising the watch mechanism according to the preceding claim

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