Actuating mechanism for a flexible display hand moved by a clockwork movement

Abstract

The invention relates to an actuating mechanism (1) for a flexible display hand (20), intended to be moved by a clockwork movement of a watch, the flexible display hand (20) a first and second drive pipe (16, 18) arranged coaxially about an axis of rotation D1, the actuating mechanism (1) comprising: - a first differential mechanism (2) comprising a first input intended to receive an angular rotation through an angle (θ1) about the axis of rotation D1, transmitted by the clockwork movement and determining the rotation of the flexible display hand (20) on itself, and an output of the first differential mechanism (2) which is configured to drive the rotation of the flexible display hand (20); - a second differential mechanism (4) comprising a first input kinematically connected to the first input of the first differential mechanism (2) via a gear ratio, a second input intended to receive an angular rotation through an angle (θ2) determining a change in length of the flexible display hand (20), and an output configured to command the change in length of the flexible display hand (20), said output being kinematically linked to a second input of the first differential mechanism (2).

Description

ACTUATING MECHANISM FOR A FLEXIBLE DISPLAY HAND DRIVEN BY A CLOCKWORK MOVEMENT Technical field of the invention

[0001] The present invention relates to an actuating mechanism for a flexible display hand driven by a clockwork movement of a watch. Technological background

[0002] In the recent past, the Applicant has already disclosed a number of actuating mechanisms for flexible display hands. Such actuating mechanisms are arranged to rotate a flexible display hand on itself while controlling its change of shape and length in order to display time or other information in a novel manner.

[0003] However, developing such actuation mechanisms requires fairly complex calculations in order to achieve the desired result in terms of rotation speed and shape change of the flexible display needle. On the other hand, these actuation mechanisms also have the disadvantage of freezing the trajectory of the flexible needle: in other words, the length of the needle is linked to its position. Summary of the invention

[0004] The present invention aims to address the above-mentioned and other needs by providing a flexible display hand actuating mechanism that allows the movement of a flexible display hand and its changes in shape and length to be defined independently of each other.

[0005] To this end, the present invention relates to a mechanism for actuating a flexible display hand driven by a clockwork movement, the flexible display hand comprising a first drive barrel connected to a first end of a first flexible arm, and a second drive barrel connected to a first end of a second flexible arm, the first and second flexible arms being connected to each other at their second end by a tip, the first and second drive barrels being spaced apart from each other in a free, unconstrained state of the flexible display hand.

[0006] The flexible display needle is arranged in a service position in which it has a defined shape and length and is in a stressed state, the first drive barrel and the second drive barrel being arranged coaxially about an axis of rotation. The first drive barrel is mounted with a first defined preload angle, and the second drive barrel is mounted with a second defined preload angle opposite the direction of the first drive barrel.

[0007] The actuating mechanism is arranged to drive the flexible display hand in rotation and control its change in length, the first differential mechanism comprising a first input to which the clockwork movement applies an angular rotation which determines the rotation of the flexible display hand on itself, this angular rotation also being applied with a gear ratio to a first input of the second differential mechanism, a phase shift angular rotation which determines a change in length of the flexible display hand being applied to a second input of the second differential mechanism, an output of the second differential mechanism which controls the change in length of the flexible display hand being applied to a second input of the first differential mechanism, an output of the first differential mechanism driving the flexible display hand into rotation and controlling its change in length.

[0008] Thanks to these features, the present invention provides an actuating mechanism for a flexible display needle whose mechanisms for rotational drive on the one hand, and for controlling its change in length on the other hand. These mechanisms being of the differential type, they can be dissociated, which allows much greater freedom in defining the trajectory of the flexible display needle and in choosing its shape and length.

[0009] Thus, thanks to the dissociation of the functions of driving rotation and changing the shape and length of the flexible display hand, the actuating mechanism according to the invention makes it possible, remarkably, to display two separate pieces of information using a single flexible display hand. Indeed, like any differential type mechanism, the first differential mechanism of the actuating mechanism according to the invention comprises two inputs and one output, a first input receiving an angular rotation applied by the clockwork movement which ensures the rotation of the flexible display hand on itself, the second input receiving the command for controlling the change in length of the flexible display hand, and the output ensuring the driving of the latter.

[0010] As for the second differential mechanism of the actuating mechanism according to the invention, one of its inputs receives, through a gear ratio, the angular rotation applied to the first differential mechanism by the clockwork movement, its second input receives a phase shift angular rotation applied by the clockwork movement which determines the change in length of the flexible display hand, and its output applies to the hand and to the second input of the first differential mechanism the command to change the length of the flexible display hand.

[0011] The actuating mechanism thus comprises two independent inputs, one controlling the rotation of the flexible display hand, while the other controls the length of the latter. Thus, by way of non-limiting example only, the rotation of the flexible display hand can be used to display the current time, while the change in length can be programmed to occur at the time of triggering an alarm bell.

[0012] This result can be achieved by connecting the second input of the actuating mechanism which controls the length of the flexible display hand to an alarm mobile, for example the regulator.

[0013] In particular embodiments, the invention may further comprise one or more of the following features, taken individually or in any technically possible combination.

[0014] In particular embodiments, the first differential mechanism is centered on a first axis of rotation D1 and is carried by a first planet wheel to which the clockwork movement is intended to apply the angular rotation of angle.

[0015] This first planetary wheel forms the first input of the first differential mechanism.

[0016] In particular embodiments, the first differential mechanism comprises a first sun gear forming a first cannon pinion intended to carry the first drive barrel, and a first sun wheel mounted freely rotatable coaxially with the first sun gear. The first sun wheel comprises a second sun gear and a first sun wheel, the second sun gear forming a second cannon pinion intended to carry the second drive barrel.

[0017] The first sun gear and the second sun gear constitute the output of the first differential mechanism.

[0018] In particular embodiments, the first pinion sun gear is arranged in meshing relationship with a first return gear, the latter meshing with a second return gear, itself being in meshing relationship with the second sun gear, the first and second returns being arranged eccentrically on the first planet carrier wheel.

[0019] In particular embodiments, the second differential mechanism is centered on a second axis of rotation D2, and is carried by a second planetary wheel which is rotated by the first planetary wheel in a gear ratio.

[0020] The second planetary wheel constitutes the first input of the second differential mechanism.

[0021] In particular embodiments, the second differential mechanism comprises a second sun wheel formed by a third sun pinion and by a second sun wheel, the latter being engaged with the first sun wheel of the first differential mechanism.

[0022] Said second sun gear forms the output of the second differential mechanism and said first sun gear forms the second input of the first differential mechanism.

[0023] In particular embodiments, the second differential mechanism comprises a differential ring gear centered on the third sun gear, this differential ring gear being provided with internal teeth and cooperating with a profile of a cam, the second differential mechanism further comprising at least one satellite pinion rolling on the internal teeth and meshing with the third sun gear.

[0024] The cam constitutes the second input of the second differential mechanism.

[0025] In particular embodiments, the second differential mechanism comprises a rake provided with a toothed sector by which it is engaged with an external toothing of the differential crown, at its other end opposite the toothed sector, the rake carrying a cam follower finger by which it bears against the profile of the cam.

[0026] In particular embodiments, the rotating cam is capable of being driven in an angular rotation of angle 62 determining the length of the flexible display needle, the rotation of the rotating cam causing, by means of the rack, a pivoting of the differential crown, and by means of a kinematic chain formed by the satellite pinion, the second sun wheel, the first sun wheel and the first and second return gears, an antagonistic rotational movement of the first and second sun wheel relative to each other.

[0027] In particular embodiments, the actuating mechanism comprises a control member actuable by a user and capable of changing the angular position of the cam following its activation, in order to modify the length of the flexible display needle.

[0028] In particular embodiments, the differential crown is provided with a cam follower finger by which it bears against the profile of the cam. Brief description of the figures

[0029] Other characteristics and advantages of the present invention will emerge more clearly from the following detailed description of an embodiment of a mechanism for actuating a flexible display needle according to the invention, this example being given purely for illustrative and non-limiting purposes only in connection with the appended drawing in which: Figure 1 schematically represents a sectional view of an embodiment of a mechanism for actuating a flexible display needle according to the present invention; - figure 2 schematically represents a perspective view and in the dissociated state of the actuating mechanism according to the invention illustrated in figure 1; - figure 3 schematically represents a top view in the unassembled state of a flexible display needle intended to be driven by the actuating mechanism according to the invention; - figure 4 schematically represents, in a particular embodiment of the invention, the actuating mechanism of figure 2, in which the differential crown is provided with a cam follower finger by which it bears against the profile of the cam. Detailed description of the invention

[0030] The present invention proceeds from the general inventive idea of ​​providing an actuating mechanism for a flexible display hand of a watch, comprising a first and a second differential mechanism designated respectively by the reference numerals 2 and 4.

[0031] An embodiment of the actuating mechanism according to the invention is illustrated in Figures 1 and 2.

[0032] Designated as a whole by the general reference numeral 20, the flexible display needle capable of being driven by an actuating mechanism 1 according to the invention is illustrated in its entirety in FIG. 3 and partially in FIG. 1. This flexible display needle 20 comprises a first drive barrel 16 arranged at a first end of a first flexible arm 46, and a second drive barrel 18 arranged at a first end of a second flexible arm 48. At their second end, the first and second flexible arms 46 and 48 are connected to each other by a tip 50.

[0033] In Figure 3, the flexible display needle 20 is shown in a free, unconstrained state with the first and second drive barrels 16, 18 spaced apart from each other.

[0034] However, when in the service position, the flexible display needle 20 is in a stressed state in which it is elastically deformed and in which the first drive barrel 16 and the second drive barrel 18 are arranged coaxially as shown schematically in FIG. 1. In this stressed position, the first drive barrel 16 is mounted with a first defined preload angle, and the second drive barrel 18 is mounted with a second defined preload angle opposite that of the first drive barrel 16.

[0035] The first differential mechanism 2 is intended to receive an angular rotation applied by a watch movement of the watch, so as to ensure the rotation of the flexible display hand on itself. The second differential mechanism 4 is kinematically connected to the first differential mechanism 2 with a gear ratio and is intended to receive a phase-shift angular rotation applied by the watch movement or by the user, for example by actuation of a push button. The phase-shift angular rotation determines a change in length of the flexible display hand 20.

[0036] Thus, the actuating mechanism of the flexible display needle 20 according to the invention comprises two inputs independent of each other, one being intended to drive the rotation of the flexible display needle 20 and the other being intended to drive the change of its length. Thanks to this characteristic, the function of rotation of the needle is dissociated from the function of changing the shape and length of the latter, which in particular makes it possible to offer manufacturers great freedom in determining the trajectory of the needle.

[0037] The first differential mechanism 2, centered on a first axis of rotation D1, is carried by a first planet carrier wheel 6 to which a clockwork movement applies an angular rotation of angle 61. This first differential mechanism 2 comprises a first sun gear 8 arranged centered on the planet carrier 6 and free to rotate relative to the latter. The first differential mechanism 2 also comprises a first sun wheel 10 mounted free to rotate coaxially with the first sun wheel 8. This first sun wheel 10 comprises a second sun wheel 12 and a first sun wheel 14 fixedly mounted on the second sun wheel 12.

[0038] The first and second sun gears 8 and 12 are kinematically connected to each other by first and second return gears 42 and 44 mounted freely rotatable and eccentrically on the first planet-carrying wheel 6. In particular, as shown in FIGS. 1 and 2, the first sun gear 8 meshes with the first return gear 42, the latter meshing with the second return gear 44, itself being in meshing relationship with the second sun gear 12.

[0039] As described in detail below and as visible in FIG. 1, the first sun gear 8 acts as the first cannon pinion and the second sun gear 12 acts as the second cannon pinion, respectively for the first and second drive pipes 16 and 18 of a flexible display hand 20.

[0040] The flexible display hand 20 is therefore arranged to change its angular position when the first and second sun gears 8 and 12 are rotated by the watch movement.

[0041] It is also understood that the flexible display needle 20 is able to change shape and length when the angular position of the second sun gear 12, corresponding to that of the second drive barrel 18, varies relative to the angular position of the first gear solar 8, corresponding to that of the first training gun 16, by pivoting around the axis of rotation D1.

[0042] The second differential mechanism 4, centered on a second axis of rotation D2, is carried by a second planet wheel 22 which is driven by the first planet wheel 6. This second differential mechanism 4 comprises a second sun wheel 23 formed of a third sun pinion 24 and a second sun wheel 25 which is engaged with the first sun wheel 14 of the first differential mechanism 2. This second differential mechanism 4 also comprises a differential ring gear 26 centered on the third sun pinion 24. This differential ring gear 26 is provided with an internal toothing 28A and an external toothing 28B.

[0043] At least one satellite pinion 30 (three satellite pinions spaced 120° apart from each other in the example shown) rolls on the internal toothing 28A of the differential crown 26 and meshes with the third sun pinion 24. The second differential mechanism 4 further comprises a rack 32 provided with a toothed sector 34 by which it is engaged with the external toothing 28B of the differential crown 26. At its other end opposite the toothed sector 34, the rack 32 carries a cam follower finger 36 by which it follows a profile 38 of a rotating cam 40.

[0044] As already mentioned above, the energy necessary for the operation of the actuating mechanism 1 according to the invention is supplied to it by a clockwork movement which applies an angular rotation 61 to the first planet wheel 6 of the first differential mechanism 2. Thus driven by the clockwork movement, the first planet wheel 6 in turn drives the first differential mechanism 2 in rotation on itself around the axis of rotation D1. More precisely, the first planet wheel 6 drives the first and second sun gears 8 and 12 in rotation around the axis of rotation DI. via the rotation of the first and second intermediate wheels 42 and 44 around said axis of rotation D1.

[0045] It is therefore understood that the rotation of the first satellite wheel 6 ensures the angular displacement of the flexible display needle 20.

[0046] Furthermore, the rotation of the first planet wheel 6 causes that of the second planet wheel 22 around the axis of rotation D2. By rotating, the second planet wheel 22 drives the planet pinion(s) 30 in rotation. These planet pinions 30 roll on the internal toothing 28A of the differential ring gear 26 and in turn drive in rotation, via the third sun pinion 24, the second sun wheel 25 which is engaged with the first sun wheel 14 of the first differential mechanism 2. The rotation of the second sun pinion 12 around the axis of rotation D1 is therefore also caused by that of the second sun wheel 25 around the axis of rotation D2.

[0047] Simultaneously, the clockwork movement can apply to the rotating cam 40 an angular rotation of angle 62 so as to cause the modification of the length of the flexible display hand 20. Indeed, by rotating, the rotating cam 40 causes the pivoting of the rack 32 which, by pivoting the differential crown 26, transmits, through the kinematic chain formed by the satellite pinions 30, the second sun wheel 23, the first sun wheel 10, the first and second intermediate wheels 42 and 44, and the first sun pinion 8, an antagonistic rotational movement of the first and second sun pinion 8 and 12 relative to each other. This opposing rotational movement corresponds to the angular phase shift rotation and makes it possible to modify the relative angular position of the drive barrels 16 and 18 of the flexible display needle 20 with respect to each other, and therefore to adjust the length of the flexible display needle 20.

[0048] It should be noted that the antagonistic rotational movement of the first and second sun gears 8 and 12 relative to each other is caused in particular by the first and second gears 42 and 44.

[0049] As previously described, the first differential mechanism 2 ensures the rotation of the flexible display needle 20, without changing length. Indeed, by way of illustration, in the hypothesis where the rotating cam 40 would be stationary (in other words, 62=0), the first sun gear 8 and the first sun wheel 10 would rotate at the same speed and in the same direction because the gear ratio is calculated so that, in this case, the speed of the first planet wheel 6, which is equal to that of the first sun gear 8, is equal to the speed of the first sun wheel 10. The first and second sun gears 8 and 12 respectively acting as first and second cannon pins on which the first and second drive pipes 16 and 18 are fixed, in this case, the flexible display hand 20 is therefore driven in rotation around the axis of rotation D1 while retaining its length.

[0050] The second differential mechanism 4 ensures the change in length of the flexible display hand 20, without rotation of the latter. Indeed, by way of illustration, in the hypothesis where the first planet-carrying wheel 6 would be stationary (in other words, 61 = 0), the first sun gear 8 and the first sun mobile 10 would rotate at the same speed but in opposite directions relative to each other, corresponding to an angular phase shift between the first and second sun gears 8 and 12 linked to the antagonistic rotation described above in the text.

[0051] It will be noted that there can be no blocking situation between the first differential mechanism 2 and the second differential mechanism 4 because the actuating mechanism 1 as a whole is arranged so that the first sun gear 14 and the second sun gear 25 rotate at the same tooth frequency when the rotating cam 40 is stationary (in other words, 62=0).

[0052] It goes without saying that the present invention is not limited to the embodiment which has just been described and that various simple modifications and variants can be envisaged by those skilled in the art without departing from the scope of the invention as defined by the appended claims.

[0053] In particular, it will be understood that by “length of the flexible display hand 20” is meant the radius R which passes between the two drive pipes 16, 18 and through the tip 50 of this flexible display hand 20. It will also be noted that, in the case where the rotating cam 40 is not driven by the watch movement, a control member, for example a push button, can be envisaged, actuable by the user from outside the watch case in order to change the angular position of the cam, and thus, modify the length of the flexible display hand 20.

[0054] Indeed, by moving the cam from a first to a second position different from the first, this has the effect of changing the phase shift between the flexible arms 46, 48 of the flexible display needle 20 and therefore the length of the latter.

[0055] Then, as the position of the cam remains unchanged, the flexible display needle 20 will only rotate on itself, without changing its length. By modifying the length of the flexible display needle 20, it is thus for example possible to bring the tip 50 of this flexible display needle 20 opposite one or the other of two distinct graduations, and therefore to display the values ​​of two different parameters.

[0056] Thus, for example, the angle formed by the flexible display hand 20 with its initial position can be used to provide the indication of the current time, while the length and / or the shape of the flexible display hand 20 will provide the user with an indication relating to the power reserve of the watch.

[0057] Figure 4 illustrates a particular embodiment of the invention in which the differential crown 26 is provided, on its outer perimeter which, in this case, is devoid of teeth, with a cam follower finger 52 by which it bears against the profile 38 of the cam 40.

Claims

AMENDED CLAIMS received by the International Bureau on January 15, 2024 (15.01.2024) Actuation mechanism (1) for a flexible display hand (20), intended to be driven by a clockwork movement of a watch, the flexible display hand (20) comprising a first drive pipe (16) connected to a first end of a first flexible arm (46), and a second drive pipe (18) connected to a first end of a second flexible arm (48), the first and second flexible arms (46, 48) being connected to each other at their second end by a tip (50), the flexible display hand (20) being in a service position in which it is in a stressed state and has a defined shape and length, the first and second drive pipes (16, 18) being arranged coaxially around an axis of rotation D1, the actuating mechanism (1) being characterized in that it comprises: - a first differential mechanism (2) comprising a first input intended to receive an angular rotation of angle (61) around the axis of rotation D1, transmitted by the clockwork movement, and an output of the first differential mechanism (2) configured to drive the flexible display hand (20) in rotation; - a second differential mechanism (4) comprising a first input kinematically connected to the first input of the first differential mechanism (2) with a gear ratio, a second input intended to receive an angular rotation (62), and an output configured to cause the change in length of the flexible display needle (20), said output being kinematically connected to a second input of the first differential mechanism (2). Actuating mechanism (1) according to claim 1, characterized in that the first differential mechanism (2) is centered on a first AMENDED SHEET (ARTICLE 19) axis of rotation D1 and is carried by a first planet wheel (6) to which the clockwork movement is intended to apply the angular rotation of angle (91). Actuating mechanism (1) according to claim 2, characterized in that the first differential mechanism (2) comprises a first sun pinion (8) forming a first cannon pinion intended to carry the first drive barrel (16), and a first sun wheel (10) mounted free to rotate coaxially with the first sun pinion (8), the first sun wheel (10) comprising a second sun pinion (12) and a first sun wheel (14), the second sun pinion (12) forming a second cannon pinion intended to carry the second drive barrel (18).Actuating mechanism (1) according to claim 3, wherein the first sun gear (8) is arranged in meshing relationship with a first return gear (42), the latter meshing with a second return gear (44), itself being in meshing relationship with the second sun gear (12), the first and second returns (42, 44) being arranged eccentrically on the first planet wheel (6). Actuating mechanism (1) according to one of claims 2 to 4, characterized in that the second differential mechanism (4) is centered on a second axis of rotation D2, and is carried by a second planet wheel (22) which is rotated by the first planet wheel (6) in a gear ratio.Actuating mechanism (1) according to claim 5, characterized in that the second differential mechanism (4) comprises a second sun wheel (23) formed by a third sun pinion (24) and by a second sun wheel (25), the latter being engaged with the first sun wheel (14) of the first differential mechanism (2). Actuating mechanism (1) according to claim 6, characterized in that the second differential mechanism (4) comprises a crown of. AMENDED SHEET (ARTICLE 19) differential (26) centered on the third sun gear (24), this differential crown (26) being provided with an internal toothing (28A) and cooperating with a profile (38) of a cam (40), the second differential mechanism (4) further comprising at least one satellite pinion (30) rolling on the internal toothing (28A) and meshing with the third sun gear (24). Actuating mechanism (1) according to claim 7, characterized in that the second differential mechanism (4) comprises a rake (32) provided with a toothed sector (34) by which it is engaged with an external toothing (28B) of the differential crown (26), at its other end opposite the toothed sector (34), the rake (32) carrying a cam follower finger (36) by which it bears against the profile (38) of the cam (40).Actuating mechanism (1) according to claims 4 and 8, characterized in that the rotating cam (40) is capable of being driven in an angular rotation of angle (92) determining the length of the flexible display needle (20), the rotation of the rotating cam (40) causing, by means of the rack (32), a pivoting of the differential crown (26), and by means of a kinematic chain formed by the satellite pinion (30), the second sun wheel (23), the first sun wheel (10) and the first and second return gears (42, 44), an antagonistic rotational movement of the first and second sun wheel (8, 12) relative to each other. Actuating mechanism (1) according to claim 9, characterized in that it comprises a control member actuable by a user and capable of changing the angular position of the cam (40) following its activation, in order to modify the length of the flexible display needle (20).Actuating mechanism (1) according to claim 7, characterized in that the differential crown (26) is provided with a follower finger. AMENDED SHEET (ARTICLE 19) cam (52) by which it bears against the profile (38) of the cam (40). AMENDED SHEET (ARTICLE 19)

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