Timepiece mechanism comprising a device for selecting the position of a functional member

Abstract

The present invention relates to a clockwork mechanism comprising a functional member arranged to be mobile between a first and a second position defined by its function, and a position selection device for said functional member, said position selection device comprising a position selection member for the functional member, at least one connecting element (10) provided between said position selection member and the functional member and arranged to be able to pivot about a first axis of rotation alternately from a minimum angular position to a maximum angular position and to be able to interact with the functional member to cause at least one change in position of said functional member following at least one actuation of the position selection member, and an elastic return device (24) arranged to return the connecting element (10) alternately to one and the other of its minimum and maximum angular positions,said elastic return device (24) comprising a spring (26) including two elastic blades (26a, 26b) extending on either side of the connecting element (10) and an attachment element including a base arranged to join the two elastic blades (26a, 26b) by their respective first ends opposite each other, said attachment element being arranged to be mounted pivotally about a second axis of rotation, coaxial with and distinct from the first axis of rotation, on a tenon (22) integral with the connecting element (10). The base of said attachment element is split by a slot (32).

Description

technical field

[0001] The present invention relates to a clockwork mechanism comprising a functional organ arranged to be mobile between a first and a second position defined by its function, and a position selection device for said functional organ, said selection device comprising a position selection member for the functional organ, at least one connecting element provided between said position selection member and the functional organ and arranged to be able to pivot about a first axis of rotation alternately from a minimum angular position to a maximum angular position and to be able to interact with the functional organ to cause at least one change in position of said functional organ following at least one actuation of the position selection member, and an elastic return device arranged to return the connecting element alternately to one or the other of its minimum and maximum angular positions.said elastic return device comprising a spring including two elastic blades extending on either side of the connecting element and an attachment element comprising a base arranged to join the two elastic blades by their respective first ends opposite each other, said attachment element being arranged to be mounted pivoting about a second axis of rotation, coaxial and distinct from the first axis of rotation, on a tenon integral with the connecting element.

[0002] The invention also relates to a watch movement comprising such a watch mechanism as well as a timepiece comprising such a watch mechanism or such a watch movement. State of the art

[0003] Such a horological mechanism, comprising a device for selecting the position of a functional component, is described, for example, in European patent application EP 23170463, the content of which is incorporated by reference into this application. This application, EP 23170463, describes in particular such a selection device, which may include a rotating bezel or a selector whose movement in one direction or the other allows the opening or closing of a shutter flap of at least one aperture provided on the dial of a timepiece to be selected, by means of a connecting element.To guide the movement of the rotating bezel between its first and second stable positions and to ensure its retention in either of these stable positions, corresponding to the stable opening and closing positions of the shutter, the applicant proposed a simple elastic guide or return device. This device comprises, for example, a spring formed of two elastic leaves joined by a central eyelet pivotally mounted around a tenon attached to the connecting element. The other end of the leaves is mounted freely within a frame of the timepiece. The central eyelet positioned around the tenon ensures the spring's attachment to the connecting element and its secure retention on the tenon. The spring leaves, through their flexing, exert a resistive torque on the connecting element.To exert the torque required by the construction specifications, the spring leaves must have a certain thickness. However, this generates very high stresses along the length of the leaves, particularly at their attachment to the central eyelet, especially when the connecting element is in a mid-position between the two stable positions. These very high stresses can lead to damage to the leaves.

[0004] The present invention aims to remedy these drawbacks by proposing a position selection device for a functional element which uses, as an elastic return device, the simple construction of a return spring formed of two elastic blades and driven by a rotating linkage element controlled by a position selection element to move said return spring between two return positions in order to exert a torque sufficient to allow the associated functional element to perform its function while ensuring reduced stress on the blades. Disclosure of the invention

[0005] To this end, the present invention relates to a clockwork mechanism comprising a functional organ arranged to be mobile between a first and a second position defined by its function, and a position selection device for said functional organ, said selection device comprising a position selection member for the functional organ, at least one connecting element provided between said position selection member and the functional organ and arranged to be able to pivot about a first axis of rotation alternately from a minimum angular position to a maximum angular position and to be able to interact with the functional organ to cause at least one change in position of said functional organ following at least one actuation of the position selection member, and an elastic return device arranged to return the connecting element alternately to one or the other of its minimum and maximum angular positions.said elastic return device comprising a spring including two elastic blades extending on either side of the connecting element and an attachment element comprising a base arranged to join the two elastic blades by their respective first ends opposite each other, said attachment element being arranged to be mounted pivoting about a second axis of rotation, coaxial and distinct from the first axis of rotation, on a tenon integral with the connecting element.

[0006] According to the invention, the base of said fastening element is split.

[0007] Advantageously, such a split base, which has a slot at the base of the spring attachment point and extending through the entire thickness of the base, allows for continuous stress distribution across the springs. This reduces the maximum stress while maintaining sufficient torque on the connecting element to allow the functional component to operate. Furthermore, the stresses are no longer concentrated at the first end of the springs but around the perimeter of the attachment point.

[0008] Preferably, the spring is arranged to move in a plane perpendicular to the first axis of rotation between a first and a second return position corresponding respectively to the minimum and maximum angular positions of the linking element.

[0009] Preferably, the second free end of each leaf of the spring is mounted to slide against a guide wall of a housing of a frame of said clock mechanism.

[0010] Depending on the embodiment, the two leaves of the spring may have a constant thickness or a thickness that decreases from their first end to their second end.

[0011] Advantageously, the attachment element has an inner contour whose shape is arranged to guide the spring in rotation around the tenon of the connecting element.

[0012] Preferably, the attachment element can have an omega Ω shape, an open square at its base, an inverted U, or an inverted V shape.

[0013] Preferably, the linking element may include a transmission axis whose axis coincides with the first axis of rotation and a transmission lever fixed to the transmission axis and comprising at least one element perpendicular to the transmission axis carrying the tenon and one element parallel to the transmission axis arranged to be able to interact with the functional member.

[0014] Advantageously, the selection device includes a fork or lever mounted pivoting about an axis coaxial with or coinciding with the first axis of rotation, said fork or lever being integral with the linking element and arranged to be pivotable by the position selection member.

[0015] Depending on the embodiment and the function of the functional part, the spring may be bistable or not.

[0016] According to one embodiment, the selection member can be a ring rotating about an axis coaxial with the first axis of rotation or a selector intended to be mounted sliding in rotation or translation on a watch case, the spring is bistable and the functional member can be a shutter flap arranged to be movable in rotation about an axis coaxial with the first axis of rotation between a first stable closed position and a second stable open position.

[0017] According to another embodiment, the selection element can be a corrector, the spring is not bistable and the functional element can be a correction element movable between a first inactive position and a second correction position.

[0018] The present invention also relates to a watch movement comprising a watch mechanism as defined above.

[0019] The present invention also relates to a timepiece comprising a clock mechanism or clock movement as defined above. Brief description of the drawings

[0020] Other features and advantages of the present invention will become apparent from the following detailed description of various embodiments of the invention, given by way of non-limiting examples, and made with reference to the accompanying drawings in which: there figure 1 is a partial perspective view of a first embodiment of a timepiece according to the invention, viewed from above and shown without the case, in which the functional element is a shutter intended to close at least one aperture provided on the dial of said timepiece, the connecting element being in its minimum angular position; the figure 2 is a perspective view of the clockwork mechanism and the case of the timepiece figure 1 , seen from above; the figure 3 is a view similar to the figure 2 and in which the transmission lever has been removed except for the tenon; the figure 4 is a perspective view of the clockwork mechanism according to the invention, the connecting element being in its minimum angular position and the spring being in its first return position; figures 5a, 5b, 5c are top views of the clockwork mechanism of the figure 1 the connecting element being respectively in its minimum angular position, in its intermediate angular position, and in its maximum angular position; figures 6a, 6b, 6c are views similar to figures 5a, 5b, 5c with the transmission lever removed, and the spring in its first return position, intermediate return position, and second return position, respectively; figure 7shows curves representing the torque resulting from the spring on the attachment element as a function of the angular displacement of the tenon of the connecting element for a spring whose attachment element has a slot according to the invention (curve A in solid line) and without a slot as described in application EP 23170463 (curve B in dashed line); the figure 8 shows curves representing the stress in the spring as a function of the angular displacement of the tenon of the connecting element, for a spring whose attachment element has a slot according to the invention (solid line curve C) and without a slot as described in application EP 23170463 (dashed line curve D); the figure 9shows curves representing the torque resulting from the spring on the attachment element as a function of the angular displacement of the tenon of the connecting element for a spring whose attachment element has a slot according to the invention (curve A in solid line) and without a slot and of reduced thickness (curve E in dashed line); the Figure 10 shows curves representing the stress in the spring as a function of the angular displacement of the tenon of the connecting element, for a spring whose attachment element has a slot according to the invention (solid line curve C) and without a slot and of reduced thickness (dashed line curve F); the figure 11 is a partial perspective view of a second embodiment of a timepiece according to the invention, viewed from above, in which the functional member is a correcting member intended to perform at least one correction of an associated member, the connecting element being in its minimum angular position; the figure 12 is a perspective view of the clockwork mechanism of the timepiece figure 11 ; there figure 13 is a top view of the clockwork mechanism of the figure 12 , in which the connecting element is in its minimum angular position, ready to interact with the correction mechanism; and the figure 14 is a top view of the spring used in the present invention, with the blades at rest. Embodiments of the invention

[0021] With reference to figures 1 to 10 , a first embodiment of a watch movement of a timepiece 1 according to the invention is described, in which the functional organ is a shutter flap 2 intended to close at least one aperture provided on the dial (not shown) of said timepiece 1.

[0022] The timepiece 1, and here also the shutter 2, define a principal plane XY, corresponding to a "horizontal" plane parallel to the dial or the plane formed by the user's wrist, and a Z-axis perpendicular to the principal plane XY. The shutter 2 is capable of rotation around the Z-axis of the timepiece 1 in a plane parallel to the principal plane XY, parallel to the dial, and arranged to be in a first closed position as shown in the diagram. figure 1 and in a second opening position.

[0023] In order to select the position of the cover 2, the watch mechanism includes a position selection device 4 comprising a position selection member, preferably accessible to a user. This position selection member is advantageously arranged so that, when actuated by the user, it can be moved along an outer edge of the case 6 between at least a first stable position in which the cover 2 is in its first position and a second stable position in which the cover 2 is in its second position. When the case is curved, the position selection member rotates in a plane parallel to the principal XY plane around the Z axis, which then constitutes a central axis of rotation of the case. Advantageously, the selection member may be in the form of a rotating ring 8 mounted between the case back and the case 6, as shown in the figure. figure 1, or between the case 6 and the case bezel, parallel to the principal XY plane, or in the form of a selector mounted to slide rotationally around the case band 2a. When the case is polygonal in shape, the position selector moves in translation in a plane perpendicular to the principal XY plane and perpendicular to the Z-axis. Advantageously, this selector can be in the form of a selector mounted to slide translationally along the case band. Thus, the position selector is arranged to be able to be moved perpendicular to the Z-axis, following the peripheral contours of the case in either a translational or rotational movement.

[0024] In the first embodiment shown on the figures 1 to 8The watch case is round, and the selector mechanism is arranged to be rotated along a curved outer edge of the case 6, said outer edge of the case 6 being parallel to the principal XY plane opposite the case back. However, it is quite clear that this first embodiment can be transposed by those skilled in the art to a polygonal case, the selector mechanism then being arranged to be translated along the contours of a straight outer edge of the case perpendicular to the Z-axis.

[0025] The selection element is the rotating ring 8, freely mounted between the base and the curved outer edge of the case 6, parallel to the principal plane XY, concentrically with them. The rotating ring 8 is arranged so that it can be rotated around the central axis Z of the case or the case 6 in a plane parallel to the principal plane XY with respect to the center of said case, when actuated by a user, by sliding between the case 6 and the base, in order to select the closed or open position of the flap 2. This means that the rotating ring 8 is free to rotate in a plane parallel to the principal plane XY by a certain angle (for example, less than 45°), with each actuation by the user, between a first stable angular position in which the flap 2 is in its first closed position, as shown in the diagram. figure 1and a second stable angular position in which the flap 2 is in its second open position. The rotating ring 8 is a ring without peripheral teeth. The ring 8 is dimensioned to have a diameter greater than that of the base so that its outer face appears around the base when viewed from below the assembled box, thus being accessible to the user. The ring 8 may have grooves 8a on its outer face to facilitate its gripping for movement from the outside by the user.

[0026] The position selection device 4 also includes at least one linking element 10 provided between the rotating ring 8 and the flap 2. The linking element 10 is arranged to be able to pivot about a first axis of rotation Z' coaxial with the central axis Z, alternately from a minimum angular position to a maximum angular position and to be able to interact with the flap 2 to cause at least one change of position of said flap 2 following at least one actuation of the rotating ring 8.

[0027] For this purpose, the linking element 10 between the rotating ring 8 and the flap 2 comprises a transmission shaft 12, whose axis of rotation coincides with the first axis of rotation Z', and mounted articulated on the inner face of the ring 8, a transmission lever 14 fixed to the transmission shaft 12 by one of its ends and arranged to interact, by its other end, with a control member 16, such as a groove, arranged to control the movement of the flap 2 between its first and second positions when the rotating ring 8 is moved in rotation.

[0028] More specifically, the transmission shaft 12 is hinged to the ring 8, parallel to the central axis Z of the gearbox, that is, perpendicular to the plane of rotation of the ring 8, which is parallel to the principal plane XY, by means of a fork 18 extending perpendicularly to the transmission shaft 12 from the base of the transmission shaft 12 towards the ring 8. This fork 18 is integral with the connecting element 10, and more specifically with the transmission shaft 12. The fork 18 is arranged to be pivoted by the position selector, here the ring 8. To this end, the fork 18 is pivotally mounted around a finger 20 integral with the inner face of the ring 8, said finger 20 projecting perpendicularly from the ring 8 and being engaged between the teeth of the fork 18, so that the fork 18 can pivot around a coaxial axis to the first axis of rotation Z' of the transmission axis 12.

[0029] Thus, when the selection member, here the ring 8, is moved in rotation between its first stable angular position in which the flap 2 is in its first closed position, and its second stable angular position in which the flap 2 is in its second open position, the fork 18 and the linking element 10 between the rotating ring 8 and the flap 2, comprising the transmission shaft 12 and the transmission lever 14, are driven by said ring 8 to move the control member 16 of the flap 2 and control the movement of said flap 2 between its first closed position and its second open position.

[0030] A through-hole 21 is provided in the housing 6 to communicate with the inside of the gearbox. The transmission shaft 12 is mounted in the hole 21 such that the portion of the transmission shaft 12 attached to the shift fork 18 protrudes from the hole 21 on the side of the ring 8 and the shift fork 18, and the portion of the transmission shaft 12 attached to the shift lever 14 protrudes from the hole 21 on the side of the inside of the gearbox. Thus, the shift lever 14 is entirely housed inside the gearbox. Advantageously, a sealing gasket (not shown) is positioned around the transmission shaft 12, between the shift fork 18 and the shift lever 14, thereby ensuring a seal between the selector mechanism, here the ring 8, and the inside of the gearbox.

[0031] The transmission lever 14 may be fixed, at least rotationally, to the transmission shaft 12 or may be integral with said transmission shaft 12. The transmission lever 14 may comprise several elements perpendicular to each other, depending on the distance between the transmission shaft 12 and the control member 16 of the flap 2. The transmission lever 14 comprises at least one element 14a, which is perpendicular to the transmission shaft 12 and therefore parallel to the fork 18, and which is directly fixed to the transmission shaft 12, and an element 14b, which is parallel to the transmission shaft 12 and arranged to interact with the flap 2 when the ring 8 is moved. Element 14b is kinematically linked to the control member 16 of the flap 2 and comprises a finger engaged in the groove forming said control member 16.

[0032] The element 14a of the transmission lever 14 which is perpendicular to the transmission axis 12 has, projecting on its bottom face, a tenon 22 extending parallel to the transmission axis 12 and to the first axis of rotation Z', the role of which will be described below.

[0033] In order to ensure at least the return to position of the connecting element 10 and the flap 2 during changes of position, but also in this embodiment, the maintenance of the rotating ring 8 in its stable angular positions, the selection device includes an elastic return device 24 arranged to return the connecting element 10 alternately to one and the other of its minimum and maximum angular positions.

[0034] The said elastic return device 24, shown more particularly on the figures 2 , 3 and 4, includes a prestressed spring 26 arranged to move in an XY plane perpendicular to the first axis of rotation Z' between a first and a second return position corresponding respectively to the minimum and maximum angular positions of the connecting element 10.

[0035] In the first embodiment shown, the spring 26 is configured to be bistable in order to ensure that the rotating ring 8 is held in its two stable angular positions.

[0036] The spring 26 comprises two elastic leaves 26a, 26b extending on either side of the linking element 10 of the position selection device 4, and more particularly here on either side of the first element 14a of the transmission lever 14.

[0037] The spring 26 also includes an attachment element 28 arranged to be mounted pivoting about a second axis of rotation Z" (cf. figure 1), coaxial and distinct from the first axis of rotation Z', on the tenon 22 integral with the connecting element 10, and more particularly with the first element 14a of the transmission lever 14. Said attachment element 28 comprises a base 28a and a guide portion 28b arranged to surround the tenon 22, said base 28a being arranged to connect the two elastic blades 26a, 26b by their respective first ends 30a, 30b facing each other via the guide portion 28b. More particularly, the base 28a is defined as the portion of the spring 26 that extends the guide portion 28b in the direction of the blades 26a, 26b to connect the first ends 30a, 30b of said blades 26a, 26b to said guide portion 28b. Base 28a extends over a length d (cf. figures 3 And 14) substantially equal to the outside dimension, here the outside diameter, of the guide portion 28b and has a thickness e, which may for example be slightly greater than that of the blades 26a, 26b at the level of their first ends 30a, 30b (cf. Figure 14 The thickness e is the measurement taken perpendicular to the longitudinal axis of the blades 26a, 26b, in the XY plane. Thus, the base 28a is the additional portion of material between the first ends 30a, 30b of the blades 26a, 26b and the guide portion 28b. The guide portion 28b has an inner contour whose shape is arranged to guide the rotation of the spring 26 around the tenon 22 of the connecting element 10.

[0038] According to the invention, the base 28a of the fastener 28 is slotted. This means that the fastener 28 is not completely closed around the tenon 22. More specifically, the base 28a of the fastener 28 has a slot 32 that extends across the entire thickness e of the base 28a, as shown in the figure. figure 14 The slot 32 is open at both ends so that it extends through the entire thickness of the spring 26 at the level of the attachment element 28. Preferably, the width of the slot 32 corresponds to an opening in the guide portion 28b at an angle of a few tens of degrees, and in particular less than 45°, for example an angle of 30°, with respect to its center. Preferably, the slot 32 extends radially with respect to the tenon 22 and perpendicularly to the longitudinal axis of the blades 26a, 26b at rest.

[0039] Thus, preferably, the inner contour of the attachment element 28 has an omega (Ω) shape as shown in the figure 3 , the slot 32 corresponds to the interior space between the outer edges of the Ω. In other variants not shown, the attachment element 28 may have a shape in the form of a square open at its base, in an inverted U, or in an inverted V.

[0040] The second end 34a, 34b of the blades 26a, 26b respectively, is free and is mounted to slide, generally along the longitudinal direction of the blade 26a, 26b respectively, bearing against a guide wall of a housing in the frame of the clock mechanism. More particularly, said housing can advantageously be formed by means of two lugs 36a, 36b fixed rigidly to the case 6 symmetrically with respect to an axis passing through the first axis of rotation Z' and perpendicular to said first axis of rotation Z' of the connecting element 10. As shown in the figure 4 , each ear 36a, 36b is arranged to form a housing 38a, 38b of which a guide wall, here the inner wall 40a, 40b respectively, parallel to the longitudinal axis of the blade 26a, 26b respectively, and perpendicular to the XY plane, forms a slide for the second free end 34a, 34b of the blades 26a, 26b when the spring 26 moves between its two return positions.

[0041] The two blades 26a, 26b of the spring 26 may have a constant thickness. But preferably, the two blades 26a, 26b of the spring have a thickness that decreases from their first end 30a, 30b respectively, to their second end 34a, 34b respectively.

[0042] The second axis of rotation Z" is as far away as possible from the first axis of rotation Z' so that the spring 26 is mounted eccentrically with respect to the first axis of rotation Z' of the transmission lever 14. This allows the spring 26 to exert a resistive torque on the transmission lever 14 through the bending of its blades 26a, 26b, by a lever arm effect.

[0043] The operation of the position selection device according to the first embodiment is as follows: When the flap 2 is closed in its first position as shown in the figure 1 The rotating ring 8 is positioned in its first stable angular position and the connecting element 10 is in its minimum angular position, the assembly being held by the elastic return device 24, the spring 26 being in its first return position, as shown in the figures 5a and 6aIn this configuration, viewed from above, the transmission lever element 14a, which carries the tenon 22, is oriented downwards. The elastic blades 26a, 26b are positioned in their housings 38a, 38b of the lugs 36a, 36b, their ends 34a, 34b being offset downwards, viewed from above. The elastic blades 26a, 26b are configured to act on the ring 8 indirectly, via the transmission lever 14, the transmission shaft 12, and the fork 18, in order to maintain said ring 8 in its initial stable position.

[0044] To move the flap 2 into its open position, the user turns the ring 8 counterclockwise when viewed from above, dial side, so that the finger 20 rotates with the ring 8. The fork 18, fixed to the transmission shaft 12, cannot move with the ring 8, but pivots around the finger 20 counterclockwise when viewed from above. This causes the transmission shaft 12 to pivot about its own axis of rotation Z' counterclockwise when viewed from above, resulting in the transmission lever 14 pivoting counterclockwise when viewed from above, as shown in the diagrams. figures 5b and 6b , for which the ring 8 has been rotated into an intermediate median position. The element 14b of the transmission lever 14 then drives the control member 16 of the flap 2 to control the rotation of said flap 2.

[0045] During the pivoting of the transmission lever 14, the attachment element 28 of the spring 26, carried by the element 14a of the transmission lever 14, is also driven counterclockwise, viewed from above, which moves the blades 26a, 26b and their ends 34a, 34b upwards, viewed from above, into their housing 38a, 38b of the lugs 36a, 36b, the attachment element 28 pivoting on the tenon 22. In the intermediate position of the figure 6b , blades 26a, 26b are centered in their housing 38a, 38b.

[0046] When the user has completed the rotation of the ring 8, the fork 18 and the transmission lever 14 have completed their counterclockwise pivoting as viewed from above, so that the element 14b of the transmission lever 14 has moved the control member 16 of the flap 2 into the position corresponding to the movement of said flap 2 in its open position. The blades 26a, 26b, driven by the tenon 22 carried by the transmission lever 14, have moved in their housings 38a, 38b, their ends 34a, 34b moving along the wall 40a, 40b of said housings 38a, 38b, to reach the final upward-offset position, as viewed from above, as shown in the diagrams. figures 5c and 6cThe elastic blades 26a, 26b act on the ring 8 via the transmission lever 14, the transmission shaft 12, and the fork 18 to return and hold the rotating ring 8 in its second stable position. The connecting element 10 is then in its maximum angular position, the spring 26 being in its second return position.

[0047] The return to the first stable position is carried out in a similar manner, with the direction of rotation reversed.

[0048] There figure 7shows a solid curve A representing the torque resulting from the spring 26 on the fastener 28 having a slot 32 according to the invention, as a function of the angular displacement of the tenon 22 of the connecting element 10. For comparison, the dashed curve B represents the torque resulting from a similar spring but on a fastener without a slot, as described in EP 23170463, as a function of the angular displacement of the tenon of the connecting element. For comparison, the dashed curve E on the figure 9 represents the resulting torque of a similar spring but on a fastener element without a slot and of lesser thickness, as a function of the angular displacement of the tenon of the connecting element.

[0049] There figure 8shows a solid curve C representing the stress in the spring 26, whose attachment element 28 has a slot 32 according to the invention, as a function of the angular displacement of the tenon 22 of the connecting element 10. For comparison, the dashed curve D represents the stress in a similar spring but whose attachment element is without a slot, as described in EP 2317046332, as a function of the angular displacement of the tenon of the connecting element. For comparison, the dashed curve F on the Figure 10 represents the stress in a similar spring but whose attachment element is without a slot and of lesser thickness, as a function of the angular displacement of the tenon of the connecting element

[0050] There figure 8shows that opening the guide portion 28b of the attachment element 28 by providing a slot 32 at its base 28a, according to the invention, allows for continuity of stress in the leaves 26a, 26b of the spring 26. This advantageously reduces by more than 30% the maximum stress that appears when the transmission lever 14 is in an intermediate position, between the two stable positions. figure 7This shows that the resulting torque exerted by the blades 26a, 26b on the guide portion 28b of the attachment element 28 is reduced by between 20% and 50% depending on the direction of rotation of the transmission lever 14. However, the resulting torque exerted on the transmission lever 14 is sufficient to allow the rotating ring 8 to perform its function. In a particularly advantageous manner, the stresses are no longer concentrated at the first end 30a, 30b of the blades 26a, 26b but around the periphery of the guide portion 28b of the attachment element 28. Surprisingly and unexpectedly, the opening of the attachment element 28 does not impair the strength of the spring 26, nor does it compromise the proper retention of said spring 26 on the tenon 22 of the transmission lever 14.

[0051] There Figure 10shows that reducing the spring thickness, which is generally the recommended solution for reducing stress, does indeed allow for a stress similar to that obtained with the open attachment element according to the invention, lower than that of the spring without a slot and of unreduced thickness. However, the figure 9 shows that, in this case, the resulting torque exerted by the blades on the attachment element is reduced by more than 70% and is therefore no longer sufficient to allow the rotating ring 8 to perform its function.

[0052] The present invention therefore makes it possible to propose a position selection device for a functional element which uses, as an elastic return device 24, the simple construction of a return spring 26 formed of two elastic blades 26a, 26b and driven by a rotating linking element 10 controlled by a position selection element, such as the ring 8, to move said return spring 26 between two return positions in order to exert a torque sufficient to allow the associated functional element, such as the flap 2, to perform its function while ensuring reduced stress on the blades 26a, 26b.

[0053] With reference to figures 11 to 13 A second embodiment of the invention is shown. Identical elements are reproduced with the same references.

[0054] In this second embodiment, the functional element is movable between a first position in which the functional element is inactive and a second position taken by said functional element when performing a function to which said functional element is associated. For example, the functional element is a correction element, in particular for the date or the month. In this case, the position selection element is a corrector 50 and the functional element is a correction element, such as a flip-flop 52, shown in the figure 13 , mobile between a first inactive position and a second correction position in which the correction element, here the rocker 52, cooperates with an element of the mechanism to be corrected (not shown).

[0055] The corrector 50 is a correction pusher accessible from outside the case to a user and here embedded in the case 6. In a known manner, the corrector 50 is arranged so that it can be moved between an initial rest position, in which the correction member is in its first inactive position, and a position pushed into the case 6, in which the correction member is in its second correction position to perform the correction function, when it is operated by the user.

[0056] In addition to the corrector 50, the position selection device 4 also includes the linking element 10 provided between the corrector 50 and the rocker 52. The linking element 10 is identical to that described above for the first embodiment and includes the transmission shaft 12 with axis Z' and the transmission lever 14 which is fixed by its first element 14a to the transmission shaft 12, its last element 14b being arranged to be able to interact with the rocker 52 to cause a change in position of said rocker 52 following the actuation of the corrector 50.More specifically, the last element 14b is arranged so that it can give a push on said rocker 52 when in inactive position and control its movement into its correction position, when the linking element 10 pivots around the first axis of rotation Z' from its minimum angular position to its maximum angular position, following the actuation of the corrector 50 from its initial position to its pressed position.

[0057] For this purpose, the linking element 10, and more particularly its transmission axis 12, is mounted rotatably, with its axis of rotation coinciding with the first axis of rotation Z', on a support element 54 (cf. figure 12 ) attached to the inner face of the case 6, near the corrector 50.

[0058] The position selection device 4 also includes a lever 56 attached to the transmission shaft 12 and arranged to be actuated by the corrector 50 in order to cause its pivoting and that of the transmission shaft 12 around the first axis of rotation Z' relative to the support element 54.

[0059] Thus, when the corrector 50 is pushed in between its initial rest position in which the rocker 52 is in its inactive position, and its pushed-in position in which the rocker 52 is in its correction position, the lever 54 and the linking element 10 between the corrector 50 and the rocker 52 pivot from their minimum angular position to their maximum angular position to move said rocker 52 from its inactive position to its correction position.

[0060] In this second embodiment, the correction is unidirectional and the mechanism to be corrected is configured accordingly. After a correction, the corrector 50 and the rocker 52 return to their initial position by their own return spring (not shown).

[0061] As regards the connecting element, the return of said connecting element 10 from one to the other of the minimum and maximum angular positions is ensured by the elastic return device 24 as described above, with the difference that, in this second embodiment, the spring 26 is not bistable.

[0062] The spring 26 is similar to that described above for the first embodiment. Said spring 26 comprises the two elastic blades 26a, 26b extending on either side of the first element 14a of the transmission lever 14 and the attachment element 28 mounted pivotally about the second axis of rotation Z", on the tenon 22 integral with the first element 14a of the transmission lever 14. The blades 26a, 26b, the lugs 36a, 36b are similar to those in the first embodiment.

[0063] According to the invention, the base 28a of the attachment element 28 comprises the slot 32 as described above.

[0064] The operation of the position selection device according to the second embodiment is similar to that of the first embodiment. The spring 26 moves in the XY plane perpendicular to the first axis of rotation Z from its first to its second return position to ensure the return of the connecting element 10 from its minimum angular position, as shown in the figure 13 The linkage element 10 is at its maximum angular position when it is rotated counterclockwise, viewed from above, in order to interact with the rocker 52 and move it from its inactive position to its correction position when the corrector 50 is pressed. The spring 26 moves in the XY plane perpendicular to the first axis of rotation Z from its second to its first return position to ensure that the linkage element 10 returns from its maximum angular position to its minimum angular position after a correction.

[0065] It is quite clear that the functional correction element which interacts with the transmission lever can be any other functional element of the timepiece capable of evolving between at least two positions corresponding to two different states.

Claims

1. A clockwork mechanism comprising a functional member (2, 52) arranged to be movable between a first and a second position defined by its function, and a position selection device (4) of said functional member (2, 52), said position selection device (4) comprising a position selection member (8, 50) of the functional member (2, 52), at least one connecting element (10) provided between said position selection member (8, 50) and the functional member (2, 52) and arranged to be able to pivot about a first axis of rotation (Z') alternately from a minimum angular position to a maximum angular position and to be able to interact with the functional member (2, 52) to cause at least one change of position of said functional member (2, 52) following at least one actuation of the position selection member (8, 50),and an elastic return device (24) arranged to return the connecting element (10) alternately to one or the other of its minimum and maximum angular positions, said elastic return device (24) comprising a spring (26) comprising two elastic blades (26a, 26b) extending on either side of the connecting element (10) and an attachment element (28) comprising a base (28a) arranged to join the two elastic blades (26a, 26b) by their respective first ends (30a, 30b) opposite each other, said attachment element (28) being arranged to be mounted pivotally about a second axis of rotation (Z"), coaxial and distinct from the first axis of rotation (Z'), on a tenon (22) integral with the connecting element (10), , characterized in that the base (28a) of said attachment element (28) is split.

2. Clockwork mechanism according to claim 1, characterized in thatthe spring (26) is arranged to move in a plane (XY) perpendicular to the first axis of rotation (Z') between a first and a second return position corresponding respectively to the minimum and maximum angular positions of the linking element (10).

3. Clockwork mechanism according to any one of the preceding claims, characterized in that the second free end (34a, 34b) of each blade (26a, 26b) of the spring (26) is mounted sliding in support on a guide wall (40a, 40b) of a housing (38a, 38b) of a frame of said clock mechanism.

4. Clockwork mechanism according to one of the preceding claims, characterized in that the two blades (26a, 26b) of the spring (26) have a constant thickness.

5. Clockwork mechanism according to any one of claims 1 to 3, characterized in that the two blades (26a, 26b) of the spring (26) have a thickness which decreases from their first end (30a, 30b) to their second end (34a, 34b).

6. Clockwork mechanism according to any one of the preceding claims, characterized in that the attachment element (28) has an inner contour whose shape is arranged to guide the spring (26) in rotation around the tenon (22) of the connecting element (10).

7. Clockwork mechanism according to one of the preceding claims, characterized in that the attachment element (28) has an omega shape Ω, a square open at its base, an inverted U, an inverted V.

8. Clockwork mechanism according to one of the preceding claims, characterized in that the linking element (10) includes a transmission axis (12) whose axis coincides with the first axis of rotation (Z) and a transmission lever (14) fixed to the transmission axis (12) and comprising at least one element perpendicular (14a) to the transmission axis (12) carrying the tenon (22) and one element parallel (14b) to the transmission axis (12) arranged to be able to interact with the functional member (2, 52).

9. Clockwork mechanism according to one of the preceding claims, characterized in that the spring (26) is bistable or not.

10. Clockwork mechanism according to any one of the preceding claims, characterized in that the selection element is a rotating ring (8) about an axis coaxial with the first axis of rotation (Z') or a selector intended to be mounted sliding in rotation or translation on a watch case, in that the spring (26) is bistable and the functional member is a shutter flap (2) arranged to be mobile in rotation about an axis coaxial with the first axis of rotation (Z') between a first stable closed position and a second stable open position.

11. Clockwork mechanism according to claim 10, characterized in thatthe position selection device (4) includes a fork (18) mounted pivotally about an axis coaxial with the first axis of rotation (Z'), said fork (18) being integral with the connecting element (10) and arranged to be pivotable by the rotating ring (8).

12. Clockwork mechanism according to any one of claims 1 to 9, characterized in that the selection member is a corrector (50), the spring (26) is not bistable and the functional member is a correction member (52) movable between a first inactive position and a second correction position.

13. Clockwork mechanism according to claim 12, characterized in that the position selection device (4) includes a lever (56) mounted pivoting about the first axis of rotation (Z'), said lever (56) being integral with the connecting element (10) and arranged to be pivotable by the corrector (50).

14. Clock movement comprising a clockwork mechanism according to any one of claims 1 to 13.

15. Timepiece comprising a clockwork mechanism according to any one of claims 1 to 13 or a clockwork movement according to claim 14.

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