Chronograph mechanism and method for mounting a chronograph mechanism

Abstract

The invention relates to a chronograph mechanism (10) for a watch movement (1) comprising a reset mechanism (100) including: a first hammer (110) and a second hammer (120) configured on two levels to cooperate respectively with non-coplanar reset members (51, 52); the first hammer (110) and the second hammer (120) being coupled in rotation by an elastic coupling member (116) provided between the first hammer (110) and the second hammer (120) characterized in that the reset mechanism (100) includes: a pre-holding member (115) of the elastic coupling member (116) provided on the second hammer (120) ensuring a pre-mounting of the elastic coupling member (116) on the second hammer (120);a clipping member (118), integral with the first hammer (110), configured to cooperate with the elastic coupling member and bring said elastic coupling member (116) into its operating position in which the first leg (116.1) is in contact with the clipping member (118), in order to ensure an elastic coupling in rotation of the first hammer (110) and the second hammer (120), during a relative axial displacement between the first hammer (110) and the second hammer (120) in a direction parallel to the axis of rotation (105) of the hammers (110, 120), during the assembly of the hammers (110, 120).;

Description

Technical field of the invention

[0001] The present invention relates to a chronograph mechanism for a watch movement.

[0002] More specifically, the invention relates to a chronograph mechanism comprising a mechanism for resetting the chronograph counters.

[0003] The invention also relates to a method for assembling a chronograph mechanism. Technological background

[0004] Chronograph mechanisms allow time to be measured on demand via several chronograph counters, for example minutes and seconds.

[0005] Chronograph mechanisms typically include a reset mechanism for resetting the chronograph counters, i.e., repositioning them in a reference position, so that time can be measured again on demand.

[0006] Typically, such a reset mechanism consists of a reset control that can be operated by the user, for example via a pusher or an actuation pin accessible from outside the case in which the watch movement is mounted.

[0007] The reset control cooperates directly or indirectly via rocker arms with reset hammers which strike the reset cams carried by the various chronograph counters.

[0008] The return to zero of the chronograph counters, and associated hands, is achieved by the pressure of the hammers on the periphery of the reset cams generating a driving torque modifying the position of the chronograph counters in question until they return to a reference position determined by the geometry of the hammers and the reset cam.

[0009] In existing chronograph mechanisms, the hammers are either manufactured as a single piece or formed from separate parts joined together by means of fastening. In this latter case, they share a common activation control. An example of such an implementation is described in EP 2241945.

[0010] Adjusting the reset mechanisms is a complex and time-consuming process requiring skilled craftsmanship. To adjust such a mechanism, the seconds hammer must be brought into contact with the seconds reset cam in its reference position. Then, the tip of the minutes hammer must be filed so that the minutes reset cam is also in its reference position. This operation is lengthy and delicate and can only be performed by a specialized watchmaker.

[0011] One solution to overcome this restrictive adjustment is to use two superimposed hammers whose angular movement is synchronized, while allowing limited relative angular movement of one hammer compared to the other during reset. Such a solution is described in patent CH 220536. This approach allows both hammers to act simultaneously on their respective hearts and prevents the chronograph counter hands from shifting in the reference position.

[0012] However, with this solution, the overlapping hammers make contact with the reset cams with low energy because much of the actuation energy is absorbed by the return and damping spring, which exerts increasing force against the hammers' movements. Therefore, there is a risk that the chronograph counters will not be correctly reset with such a mechanism.

[0013] Therefore, there is a need to improve chronograph mechanisms and in particular the mechanisms for resetting the counters of such chronograph mechanisms. Summary of the invention

[0014] In this context, one of the objectives of the invention is to propose a chronograph mechanism that solves at least one of the problems raised previously.

[0015] One of the objectives of the invention is to provide a reset mechanism that offers a precise reset of the various chronograph counters.

[0016] One of the objectives of the invention is to provide a reliable and secure reset mechanism.

[0017] In this context, the invention relates to a chronograph mechanism for a watch movement comprising a reset mechanism including: a first hammer and a second hammer configured on two levels to cooperate respectively with a first reset organ of a first chronograph counter and a second reset organ of a second chronograph counter which are not coplanar; the first hammer and the second hammer being pivotable about at least one axis of rotation, independently of each other; an elastic coupling organ, provided between the first hammer and the second hammer, having an operating position in which a first leg rests on the first hammer and a second leg rests on the second hammer.

[0018] The reset mechanism further includes a pre-holding element for the elastic coupling element provided on the second hammer and configured to receive said first leg of the elastic coupling element in a pre-assembly position and a clipping element, integral with the first hammer, configured to cooperate with the first leg of the elastic coupling element and bring said elastic coupling element into its operating position in which the first leg is in contact with the clipping element, in order to ensure elastic coupling in rotation of the first hammer and the second hammer, during a relative axial displacement between the first hammer and the second hammer in a direction parallel to said at least one axis of rotation, during the assembly of the hammers.

[0019] In addition to the characteristics mentioned in the preceding paragraph, the chronograph mechanism according to the invention may have one or more additional characteristics from among the following, considered individually or in all technically possible combinations: the elastic coupling member ensures a rotational coupling between the first hammer and the second hammer in the absence of a force greater than a predetermined value by the stiffness of the elastic coupling member applied on one of the hammers; the clipping member is configured to ensure a bending of the elastic coupling member, during the assembly of the two hammers, so that the elastic coupling member in the position of use has a second compressed state more compressed than a first compressed state of the elastic coupling member in the pre-assembly position on the second hammer; The clipping member extends in a direction parallel to at least one axis of rotation of the hammers; the clipping member comprises a body, a portion of which forms a first support member receiving the first leg of the elastic coupling member in the operating position of the elastic coupling member, and an end cone forming the free end of the clipping member; the first support member of the first hammer has a recessed portion to axially secure the first leg of the elastic coupling member, in an axial direction parallel to at least one axis of rotation of the hammers; said recessed portion is provided near the base of the end cone;The second hammer includes a second support member configured to receive the second leg of the elastic coupling member, the second support member having a recessed portion to axially secure the second leg of the elastic coupling member, along an axial direction parallel to at least one axis of rotation of the hammers; the chronograph mechanism includes a user-operable reset control configured to set the first hammer in rotation; the elastic coupling member is shaped to constrain, by elastic effect, the second hammer against a stop surface of the first hammer; the second hammer includes a stop member cooperating with the support surface of the first hammer; the first and second hammers have a common axis of rotation or have dedicated axes of rotation parallel to each other.

[0020] The invention also relates to a watch movement comprising a chronograph mechanism according to the invention.

[0021] The invention also relates to a timepiece comprising a clockwork movement according to the invention.

[0022] The invention also relates to a method of assembling a chronograph mechanism and more particularly the set of hammers of the reset mechanism.

[0023] More specifically, the assembly process includes a step of positioning the elastic coupling member on the second hammer, the elastic coupling member being held in a pre-assembly position in a first compressed state between a pre-holding member carried by the second hammer and a second support member of the second hammer, and a step of assembling the first hammer and the second hammer by relative axial displacement of the two hammers along a direction parallel to said at least one axis of rotation, the relative axial displacement between the two hammers ensuring the elastic coupling between the two hammers, by elastic deformation of the elastic coupling member.

[0024] Preferably, the elastic coupling between the two hammers during the assembly stage is achieved by means of a clipping member attached to the first hammer configured to cooperate with the elastic coupling member in the pre-assembly position and bring said elastic coupling member into a use position, presenting a second compressed state, in which the elastic coupling member is compressed between the clipping member and the second support member of the second hammer. Brief description of the figures

[0025] The aims, advantages and features of the present invention will become apparent from the detailed description below, which refers to the following figures: there figure 1is a partial schematic representation of an example of an embodiment of a chronograph mechanism for a watch movement, comprising a mechanism for resetting the chronograph counters according to the invention; the figure 2 is an exploded view illustrating more precisely the two-hammer system of the reset mechanism shown in the figure 1 elastically coupled by an elastic coupling element; the figure 3 illustrates in particular the elastic coupling element pre-mounted on the second hammer before assembly and rotational coupling of the two hammers; the figure 4 illustrates more specifically the elastic coupling element in its operating position, in which it rests on the first and second hammers to couple the two hammers in rotation; the figure 5 schematically illustrates the main steps of a method for assembling a chronograph mechanism according to the invention.

[0026] In all figures, common elements bear the same reference numbers unless otherwise specified. Detailed description of the invention

[0027] There figure 1 is a partial schematic representation, in top view, of a chronograph mechanism 10 integrated into a watch movement 1 according to the invention.

[0028] With reference to the figure 1 , the clock movement 1 includes a plate 2 which serves as a support for the various elements of the clock movement 1, in particular a timekeeping gear (not shown) dedicated to the division of time which is driven by a source of energy (not shown).

[0029] The chronograph mechanism 10 includes a chronograph gear train 20 which can be kinematically linked, on demand, with the time train, via a clutch (not shown) controlled by a chronograph start / stop control.

[0030] For example, the clutch is a rocker clutch that allows a clutch wheel to pivot. Other clutch designs known to those skilled in the art are also applicable.

[0031] The chronograph gear train 20 includes in particular a first chronograph counter comprising a first chronograph counter wheel 21, for example a wheel of a seconds counter, and a second chronograph counter comprising a second chronograph counter wheel 22, for example a wheel of a minutes counter.

[0032] The first seconds counter wheel 21 is coupled to a first shaft, called the seconds counter shaft, which drives a chronograph seconds hand (not shown). The first shaft also carries a first reset mechanism 51, which is fixed to the shaft for rotation.

[0033] The second minute counter wheel 22 is coupled to a second shaft, called the minute counter shaft, which drives a chronograph minute hand (not shown). The second shaft also carries a second reset mechanism 52, which is fixed to the shaft for rotation.

[0034] The first tree and the second tree are coaxial.

[0035] The first seconds counter wheel 21 and the second minutes counter wheel 22 are superimposed and arranged in two separate, superimposed, and parallel planes. The respective reset mechanisms 51 and 52 are also superimposed with respect to each other.

[0036] The reset devices 51, 52 are for example snail-shaped, heart-shaped, or other reset cams, the shape of which allows the needles to be repositioned in a reference position under the action of reset hammers.

[0037] In the example shown, the reset devices 51, 52 are reset cores.

[0038] As depicted on the figure 1 , the chronograph gear train 20 may also include a third additional counter, for example an hour counter, comprising a third chronograph counter wheel 23 associated with a third reset organ 53.

[0039] The chronograph gear train 20 may include intermediate chronograph wheels (not shown) to obtain the desired ratios between the different counter wheels 21, 22, 23 of the chronograph mechanism 10.

[0040] The chronograph mechanism 10 also includes a reset mechanism 100 for resetting the various chronograph counters, and a repositioning to the reference position of the reset organs 51, 52, 53 and associated hands.

[0041] The reset mechanism 100 comprises a first hammer 110 and a second hammer 120, superimposed one on top of the other, and shaped to cooperate respectively with the first reset element 51 of the first chronograph counter and the second reset element 52 of the second chronograph counter. The hammers 110 and 120 are rotated by a reset control 60 that can be operated by the user, for example, via a pusher or an actuating pin 61.

[0042] The reset control 60 is movable in rotation around a rotation axis 66 and cooperates directly or indirectly with one of the hammers 110, 120.

[0043] In the illustrated embodiment, the reset control 60 cooperates directly with the first hammer 110, located in the lower position (i.e., the proximal hammer of the stage 2). However, the reset control 60 can also cooperate directly with the second hammer 120, located in the upper position (i.e., the distal hammer of the stage 2).

[0044] For this purpose, the first hammer 110 includes an activation element 113, for example a pin, a gauge, mounted projecting securely on the body of the first hammer 110, configured to cooperate in direct contact with a portion of the reset control 60.

[0045] There figure 2 illustrates more particularly an exploded view of the set of hammers 110, 120 superimposed according to the invention.

[0046] The first hammer 110 and the second hammer 120 are mounted pivoting about a common axis of rotation 105, extending perpendicularly to the general plane formed by the plate 2. The two hammers 110, 120 are mounted pivoting independently of each other.

[0047] According to one embodiment, the first hammer 110 and the second hammer 120 can have different axes of rotation parallel to each other.

[0048] The second hammer 120 has limited angular freedom relative to the first hammer 110. For this purpose, an angular movement limiting device can be provided between the first hammer 110 and the second hammer 120 to limit the angular stroke of the second hammer 120 relative to the first hammer 110, around the axis of rotation 105.

[0049] An elastic coupling member 116 is provided between the first hammer 110 and the second hammer 120 to achieve a rotational elastic coupling between the two hammers 110, 120.

[0050] More specifically, the elastic coupling member 116 allows the first hammer 110 and the second hammer 120 to be coupled in rotation, while allowing the relative angular freedom of the second hammer 120, by elastic deformation of the elastic coupling member 116, when a force, greater than a predetermined value, and defined by the stiffness of the elastic coupling member 116, is applied on one of the hammers 110, 120, more specifically the second hammer 120 in the illustrated embodiment example since in the example shown the reset control 60 is engaged with the first hammer 110 to drive it in rotation.

[0051] More specifically, the elastic coupling member 116 comprises a first elastic leg 116.1 and a second elastic leg 116.2. The two elastic legs 116.1 and 116.2 meet at a central, elbow-shaped body 116.3. The elastic coupling member 116 is, for example, a spring, a leaf spring, a string spring, etc.

[0052] In a position of use of the elastic coupling element 116, visible more particularly at the figure 4 , the first leg 116.1 is supported on the first hammer 110, and more particularly on a first support member 111 of the first hammer 110, and the second leg 116.2 is supported on the second hammer 120, and more particularly on a second support member 112 of the second hammer 120.

[0053] The first support member 111 and / or the second support member 112 may be elements added and secured to the bodies of the hammers 110, 120, or may be made of material with the bodies of the hammers 110, 120.

[0054] In this operating position, the elastic coupling member 116 is configured to constrain the second hammer 120 bearing against the first hammer 110 in the absence of a force applied to the second hammer 120 greater than a value predetermined by the stiffness of the elastic coupling member 116.

[0055] More specifically, the second hammer 120 includes a stop member 122, directed towards the first hammer 110, and configured to cooperate with a complementary stop surface 128 provided on the first hammer 110. Under the elastic stress of the elastic coupling member 116 bearing on the two hammers 110, 120, the stop member 122 of the second hammer 120 is held in contact with the stop surface 128 of the first hammer 110.

[0056] The first hammer 110 has a first peen 107 configured to strike the first reset mechanism 51 of the first counter. The second hammer 120 has a second peen 126 configured to strike the second reset mechanism 52 of the second counter.

[0057] In a stable position, i.e. without exerting force on the second hammer 120 greater than a predetermined value related to the stiffness of the elastic coupling member 116, the second purlin 126 of the second hammer 120 is not aligned with the first purlin 107 of the first hammer 110. Indeed, the second purlin 126 of the second hammer 120 has a slight offset forward (i.e. in the direction of the reset members 51, 52) relative to the first purlin 107 of the first hammer 110.

[0058] The advance of the second purlin 126 of the second hammer 120 ensures that the two reset members 51, 52 will be in their reference position at the end of the movement of the hammers 110, 120 and the reset control 60. Indeed, during the actuation of the hammers 110, 120, once the second reset member 52 of the second counter is in the reset position, an additional angular displacement of the hammers 110, 120 will generate on the second purlin 126 of the second hammer 120 a force greater than the stiffness of the elastic coupling member 116, which will allow the first reset member 51 of the first counter to continue to be reset if it is not yet in the reference position. A retrograde movement of the second hammer 120 relative to the first hammer 110 is therefore initiated by going against the elastic force of the elastic coupling member 116.

[0059] The chronograph mechanism described below works as follows:

[0060] When the user applies pressure to the reset control 60, via the actuation pin 61, the reset control 60 pivots around its axis of rotation 66, which has the effect of engaging the first hammer 110 via the activation element 113 and pivoting the first hammer 110 around the axis of rotation 105.

[0061] In the absence of force applied to the second purlin 126 of the second hammer 120, the second hammer 120 is coupled in rotation to the first hammer 110, it is therefore also set in motion by the reset control 60 and pivots around the axis of rotation 105.

[0062] The two hammers 110, 120 continue their angular movement under the action of the reset control 60 until the pegs 107, 126 strike the respective reset devices 51, 52.

[0063] Because of the advance of the second breakdown 126 of the second hammer 120, the second reset device 52 will be returned to the reference position before reaching the full angular stroke of the reset control 60.

[0064] By continuing, the angular displacement of the reset control 60, the second reset member 52 of the second counter, being in the reference position which is a stable position, induces a force on the second purlin 126 greater than the stiffness of the elastic coupling member 116, which has the effect of elastically deforming the elastic coupling member 116 and modifying the relative position of the two hammers 110, 120. This decoupling of the two hammers 110, 120 allows the first hammer 110 to continue its angular displacement, driven by the reset control 60, to ensure a complete reset of the first reset member 51 of the first counter.

[0065] At the end of the reset control stroke 60, the two breakdowns 116 and 126 are aligned with each other and the two reset devices 51, 52 are positioned in their reference position.

[0066] The second hammer 120 also includes a third peen 127 configured to return the third reset device 53 to the reference position.

[0067] Advantageously, the reset mechanism 100 includes a pre-holding member 115 to ensure pre-holding in position of the elastic coupling member 116 and facilitate the assembly of the two hammers 110, 120 in the clock movement 1. The pre-holding member 115 also facilitates the assembly of the elastic coupling member 116 between the two hammers 110, 120.

[0068] In the example shown in the figures, the pre-holding member 115 is provided on the second hammer 120 so that the elastic coupling member 116 can be pre-mounted on the second hammer 120 before assembly of the two hammers 110, 120.

[0069] Of course, the pre-holding member 115 can also be provided on the first hammer 110, which is the hammer driven by the reset control 60, so that the elastic coupling member 116 can be pre-mounted on the first hammer 110.

[0070] The pre-holding member 115 allows the elastic coupling member 116 to be elastically constrained on the second hammer 120 in a so-called pre-assembly position. This position is particularly illustrated in the figures 2 And 3 .

[0071] The pre-holding member 115 is configured to receive the first leg 116.1 of the elastic coupling member 116 as support, so that the elastic coupling member 116 can be elastically constrained in its pre-assembly position between the pre-holding member 115 and the second support member 112 of the second hammer 120.

[0072] To tilt the elastic coupling member 116 into its operating position during the assembly of the two hammers 110, 120 by a relative axial displacement in a direction parallel to the axis of rotation 105, the reset mechanism 100 includes a clipping member 118 integral with the hammer which does not include the pre-holding member 115. In the embodiment shown, the clipping member 118 is provided on the first hammer 110.

[0073] The clipping member 118 extends in projection relative to the body of the first hammer 110 in the direction of the second hammer 120. The clipping member 118 extends in a direction parallel to the axis of rotation 105 of the hammers 110, 120.

[0074] The clipping member 118 comprises a body 118a, a portion of which forms the first support member 111 of the first hammer 110, and an end cone 118b, distal to the body of the first hammer, forming the free end of the clipping member 118.

[0075] The clip 118 is configured to come into contact with the first leg 116.1 of the elastic coupling member 116, via the end cone 118b, when the elastic coupling member 116 is in the pre-assembly position on the second hammer 120. The end cone 118b allows the first leg 116.1 to be engaged and its bearing surface to be modified by bringing it onto the support member 111 of the first hammer, by sliding the first leg 116.1 on the conical surface of the end cone 118b. During this sliding on the conical surface of the end cone 118b, the elastic coupling member is slightly compressed.

[0076] Preferably, the first support member 111 has a recessed portion 117, for example a notch, a cavity, a recess, a flat configured to receive the first leg 116.1 of the elastic coupling member 116 and to axially secure the elastic coupling member 116, and more particularly the first leg 116.1 of the elastic coupling member 116, along an axial direction parallel to the axis of rotation 105 of the hammers 110, 120. Thus, axial slippage of the first leg 116.1 of the elastic coupling member 116 and loss of support of the first leg 116.1 on the first support member 111 of the first hammer 110 are avoided during the assembly of the two hammers 110, 120.

[0077] The recessed portion 117 is provided near the base of the end cone 118b. In addition to axially securing the elastic coupling member 116, the recessed portion 117 gives an audible and sensory indication to the watchmaker indicating the correct positioning of the elastic coupling member 116 between the two hammers 110, 120 and therefore the elastic coupling of the two hammers 110, 120.

[0078] According to an alternative embodiment, a recessed portion, for example in the form of a notch, a cavity, a recess, a flat can be provided on the second support member 112 of the second hammer 120 to receive the second leg 116.2 of the elastic coupling member 116 in support and to axially secure the elastic coupling member 116.

[0079] Typically, the reset control 60 cooperates with an elastic reset element (not shown) configured to reposition the reset control 60 to the neutral rest position between each user activation.

[0080] The reset mechanism 100 may also include a retaining element (not shown) to secure the reset mechanism 100 and ensure full actuation of the reset control 60. The retaining element is configured to momentarily prevent the actuation of the reset control 60, and thus of the hammers 11, 120, until a certain force is applied to the reset control 60. Such a retaining element is a safety device preventing an unwanted reset of the chronograph mechanism hands 10. The retaining element exhibits dynamic behavior similar to a mechanical fuse.

[0081] As shown in the various figures, the chronograph mechanism 10 includes a column wheel 63 to control the various movements of different levers that bear against a column or between two columns. The operation of a chronograph mechanism 10 with such a column wheel 63 is widely known, so further explanation of its function is unnecessary.

[0082] Of course, the chronograph mechanism 10 can also be a cam chronograph mechanism in place of the column wheel 63 without going out of the context of the invention.

[0083] The invention also relates to a timepiece, for example a wristwatch, comprising such a timepiece movement.

[0084] The invention also relates to an assembly method 400 of the chronograph mechanism 10 according to the invention comprising the reset mechanism 100. More particularly, the assembly method according to the invention makes it easier to assemble and elastically couple the two hammers 110, 120.

[0085] With reference to the figure 5 The method includes a pre-assembly step 410 of the elastic coupling member 116, consisting of pre-positioning the elastic coupling member 116 on one of the hammers, for example the second hammer 120, so that the elastic coupling member 116 is held in a pre-assembly position in a first compressed state between the pre-holding member 115 carried by the second hammer 120 and the second support member 112 of the second hammer 120. figure 3 particularly illustrates this first compressed state of the elastic coupling member 116 in position on the second hammer 120.

[0086] Once the elastic coupling member 116 is pre-mounted on the second hammer 120, the process includes a step 420 of assembling the two hammers, 110, 120 by translation along a direction parallel to the axis of rotation 105.

[0087] The axial movement of the two hammers 110, 120 allows the clipping member 118 to come into contact with the first leg 116.1 of the elastic coupling member 116, which is supported by the pre-retaining member 115. With axial displacement, the end cone 118b progressively compresses the elastic coupling member 116 to release the support on the pre-retaining member 115. Once the first leg 116.1 passes the base of the end cone 118b, it clips onto the recessed portion 117 of the clipping member 118 by elastic recoil of the first leg 116.1, as shown in the figure. figure 4The elastic coupling member 116 is then in its operating position, in a second compressed state, more compressed than the first compressed state of the pre-assembly position, and bearing on the first hammer 110 and the second hammer 120 to ensure a rotational elastic coupling between the two hammers 110, 120. In the operating position, the elastic coupling member 116 is axially secured to prevent unwanted loss of contact.

Claims

1. Chronograph mechanism (10) for a watch movement (1) comprising a reset mechanism (100) including: - a first hammer (110) and a second hammer (120) configured on two levels to cooperate respectively with a first reset member (51) of a first chronograph counter and a second reset member (52) of a second chronograph counter which are not coplanar; the first hammer (110) and the second hammer (120) being pivotable about at least one axis of rotation (105) independently of each other; - an elastic coupling member (116), provided between the first hammer (110) and the second hammer (120), having an operating position in which a first lug (116.1) is in contact with the first hammer (110) and a second lug (116.2) is in contact with the second hammer (120); characterized in thatthe reset mechanism (100) includes: - a pre-holding element (115) of the elastic coupling element (116) provided on the second hammer (120) and configured to receive said first leg (116.1) of the elastic coupling element (116) in a pre-assembly position; - a clipping member (118), integral with the first hammer (110), configured to cooperate with the first leg (116.1) of the elastic coupling member and bring said elastic coupling member (116) into its operating position in which the first leg (116.1) is in contact with the clipping member (118), in order to ensure an elastic coupling in rotation of the first hammer (110) and the second hammer (120), during a relative axial displacement between the first hammer (110) and the second hammer (120) in a direction parallel to said at least one axis of rotation (105), during the assembly of the hammers (110, 120).

2. Chronograph mechanism (10) for watch movement (1) according to the preceding claim characterized in that The elastic coupling member (116) ensures a rotational coupling between the first hammer (110) and the second hammer (120) in the absence of a force greater than a predetermined value by the stiffness of the elastic coupling member (116) applied on one of the hammers (110, 120).

3. Chronograph mechanism (10) for a watch movement (1) according to any one of the preceding claims characterized in that the clipping member (118) is configured to ensure a bending of the elastic coupling member (116) during the assembly of the two hammers (110, 120) so that the elastic coupling member (116), in the position of use, has a second compressed state more compressed than a first compressed state of the elastic coupling member (116) in the pre-mounting position on the second hammer (120).

4. Chronograph mechanism (10) for a watch movement (1) according to any one of the preceding claims characterized in that the clipping member (118) extends in a direction parallel to said at least one axis of rotation (105) of the hammers (110, 120).

5. Chronograph mechanism (10) for a watch movement (1) according to any one of the preceding claims characterized in that The clipping member (118) comprises a body (118a) a portion of which forms a first support member (111) receiving the first leg (116.1) of the elastic coupling member (116) in the position of use of the elastic coupling member (116) and an end cone (118b) forming the free end of the clipping member (118).

6. Chronograph mechanism (10) for watch movement (1) according to the preceding claim characterized in thatthe first support member (111) of the first hammer (110) has a recessed portion (117) to axially secure the first leg (116.1) of the elastic coupling member (116), along an axial direction parallel to said at least one axis of rotation (105) of the hammers (110, 120).

7. Chronograph mechanism (10) for watch movement (1) according to the preceding claim characterized in that said recessed portion (117) is provided near the base of the end cone (118b).

8. Chronograph mechanism (10) for a watch movement (1) according to any one of the preceding claims characterized in thatthe second hammer (120) has a second support member (112) configured to receive the second leg (116.2) of the elastic coupling member (116) as support, the second support member (112) having a recessed portion to axially secure the second leg (116.2) of the elastic coupling member (116), along an axial direction parallel to said at least one axis of rotation (105) of the hammers (110, 120).

9. Chronograph mechanism (10) for a watch movement (1) according to any one of the preceding claims characterized in that the chronograph mechanism (10) includes a user-operable reset control (60) configured to set the first hammer (110) into rotational motion.

10. Chronograph mechanism (10) for a watch movement (1) according to any one of the preceding claims characterized in thatthe elastic coupling member (116) is shaped to constrain by elastic effect the second hammer (120) bearing against a stop surface (128) of the first hammer (110).

11. Chronograph mechanism (10) for watch movement (1) according to the preceding claim characterized in that the second hammer (120) has a stop member (122) cooperating in support with the bearing surface (128) of the first hammer (110).

12. Chronograph mechanism (10) for a watch movement (1) according to any one of the preceding claims characterized in that the first hammer (110) and the second hammer (120) have a common axis of rotation (105) or have dedicated axes of rotation parallel to each other.

13. Clock movement (1) comprising a chronograph mechanism (10) according to any one of claims 1 to 12.

14. Timepiece comprising a timepiece movement (1) according to the preceding claim.

15. Method for assembling (400) a chronograph mechanism (10) comprising a reset mechanism (100) including: - a first hammer (110) and a second hammer (120) pivoting about at least one axis of rotation (105) and configured on two levels to cooperate respectively with a first reset member (51) of a first chronograph counter and a second reset member (52) of a second chronograph counter, which are not coplanar; - an elastic coupling member (116) formed between the first hammer (110) and the second hammer (120) and configured to couple the first hammer (110) and the second hammer (120) in rotation; the method being characterized in thatIt comprises the following steps: - a step (410) of positioning the elastic coupling member (116) on the second hammer (120), the elastic coupling member (116) being held in a pre-assembly position in a first compressed state between a pre-holding member (115) carried by the second hammer (120) and a second support member (112) of the second hammer (120); - a step (420) of assembling the first hammer (110) and the second hammer (120) by relative axial displacement of the two hammers (110, 120) along a direction parallel to said at least one axis of rotation (105), the relative axial displacement between the two hammers (110, 120) ensuring the elastic coupling between the two hammers (110, 120).

16. Method for assembling (400) a chronograph mechanism (10) according to the preceding claim characterized in thatthe elastic coupling between the two hammers (110, 120) during the assembly step (420) is achieved by means of a clipping member (118) integral with the first hammer (110) configured to cooperate with the elastic coupling member (116) in the pre-assembly position and bring said elastic coupling member (116) into a use position, presenting a second compressed state, in which the elastic coupling member (116) is compressed between the clipping member (118) and the second support member (112) of the second hammer (120).

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