DRIVE MODULE FOR A CLOCK MOVEMENT

Description

technical field

[0001] The invention relates to a motor module for a watch movement. Such a motor module is particularly intended for driving the hands of a timepiece comprising the watch movement.

[0002] The invention also relates to a watch movement comprising such a motor module, as well as a timepiece comprising such a watch movement. The timepiece is, for example, a watch.

[0003] The invention also relates to a method for assembling such a motor module. Technological background

[0004] Modular watch components are well-known. Widespread in electronic watchmaking, they are less common in mechanical watchmaking, where modular construction—generally designed to create several calibers of the same basic mechanical movement with different functionalities or presentations—is rarely less expensive than traditional manufacturing. Only certain additional mechanisms, built on separate boards, are relatively widespread. One of the main modules of such a modular watch component is the movement module. A typical movement module for a watch typically consists of a mainplate carrying one or more gears, and a gear bridge mounted on the mainplate. The gear bridge, along with the mainplate, defines a space within which, in addition to the gears, electromechanical components are housed, such as rotors, stators, or coils.The motor module can be mechanical, and therefore self-winding. It can also be a quartz motor module.

[0005] During the assembly of the motor module, once the gears are placed on the mainplate, it is known to use a spacer between the gear bridge and the mainplate. A bridging screw then secures the mainplate to the spacer. Such a spacer-based solution is described, for example, in patent document CH 588 108 B5. However, this screw and spacer fastening method has the disadvantage of being inflexible and does not allow for easy and quick disassembly of the motor module components. Such disassembly may indeed be necessary for maintenance of the motor module. CH 700 987 A2 discloses the mounting of a bridge to a mainplate using elastic fastening devices comprising a protruding element and an elastic member. CH 713 547 A2 relates to a shock-resistant watch movement with carbon rods that jointly secure the components.

[0006] Another known assembly method involves engaging the gear train on pivots mounted in the plate. This is achieved using tenons that protrude from an outer face of the plate, allowing for alignment and centering of the gear train relative to the plate. The gear train is then slightly pressed onto the plate to provide initial support. A heat-riveting process is then applied to the tenons. Heating the tenons deforms them, thus securing the gear train to the plate. However, a problem with this type of motor module assembly is that once the gear train is heat-riveted to the plate, it is no longer possible to disassemble the motor module components without causing them to break off and resulting in mechanical damage to the module.Furthermore, another drawback of such an assembly is that the tenons are insufficient to ensure the gear train bridge is properly secured to the mainplate. Consequently, the gear train bridge is poorly pressed against the mainplate and can slip out of the tenon guides, and some pivots may even become disengaged during the heat-riveting process. The play between the gears is then no longer guaranteed. Summary of the invention

[0007] The invention therefore aims to provide a motor for a watch movement, allowing the parts of the motor module to be disassembled and reassembled without causing the parts to be torn off, while ensuring sufficient clamping force of the gear bridge on the plate to guarantee the play between the gears.

[0008] To this end, the invention relates to a motor module for a watch movement, and which includes the characteristics mentioned in independent claim 1.

[0009] Specific shapes of the motor module are defined in dependent claims 2 to 5.

[0010] Thanks to the presence of clipping mechanisms on the gear train bridge, the user can easily disassemble and reassemble the motor module components without causing any damage or tearing. Furthermore, these clipping mechanisms exert sufficient clamping force to ensure the gear train bridge remains mechanically attached to the plate, thus guaranteeing proper movement between the gears.

[0011] Advantageously, the gear train bridge is made of a non-magnetic material. Such a non-magnetic material preferably has a high modulus of elasticity. This ensures optimal clipping of the gear train bridge onto the mainplate and guarantees an optimized clamping force between these two parts.

[0012] For this purpose, the invention also relates to a watch movement comprising the motor module described above, and which includes the features mentioned in dependent claim 6.

[0013] For this purpose, the invention also relates to a timepiece comprising the clock movement described above, and which includes the features mentioned in dependent claim 7.

[0014] To this end, the invention also relates to a method for assembling the motor module according to claim 8. The assembly method according to the invention eliminates the need for heat-riveting, thus saving at least one assembly step in the process. This allows the operator installing the gears to also clip the gear bridge onto the mounting plate at the same workstation. Therefore, the method according to the invention avoids moving the motor module to another welding or heat-riveting station, thereby eliminating the risk of disengaging certain pivots. The method according to the invention also saves time during the assembly of the motor module. Brief description of the figures

[0015] The aims, advantages and characteristics of the motor module for watch movement according to the invention will become clearer in the following description based on at least one non-limiting embodiment illustrated by the drawings in which: there figure 1 is an exploded perspective view of a motor module for a watch movement according to a first embodiment of the invention, the motor module comprising a gear train bridge equipped with three clipping lugs; the figure 2 is a perspective view of the engine module of the figure 1 , in assembled configuration; there figure 3 is a perspective view of one of the clipping tabs of the motor module of the figure 1 , in the exploded view of the engine module; the figure 4 is a view analogous to that of the figure 3 , in the assembled configuration of the motor module shown on the figure 2 ; and the figure 5is a perspective view of a motor module for a watch movement according to a second embodiment of the invention, in assembled configuration. Detailed description of the invention

[0016] The following description refers to a watch movement equipped with a motor module. The usual components of a watch movement, which are well known to anyone skilled in this technical field, are described only in simplified form or not at all. A person skilled in the art will know how to adapt these various components and make them work together for the proper functioning of the watch movement.

[0017] THE figures 1 and 2 represent a part of a timepiece 1, which includes a watch movement 2. The timepiece 1 is, for example, a mechanical watch or a quartz watch. The watch movement 2 includes a motor module 4, which is shown in the figures 1 to 4according to a first embodiment of the invention. The motor module 4 is configured to be fixed, for example by screwing, gluing, or heat-riveting, onto a printed circuit board (not shown) of the watch movement 2. The motor module 4 comprises a plate 6 and a gear train bridge 8 mounted on the plate 6. The motor module 4 also includes several electromechanical components 10, such as, for example, a stator 10A, a rotor (not shown in the figures), and one or more coils 10B. In the particular embodiment illustrated in the figures 1 and 2The electromechanical components 10A and 10B are arranged in housings 11 provided for this purpose under the gear train 8. Such housings 11 are, for example, provided within the circuit board 6. The electromechanical components 10A and 10B are thus mounted on the printed circuit board. Corresponding access openings 13 are, for example, made in the gear train 8. These openings 13 are arranged opposite the electromechanical components 10A and 10B in the vertical direction. The openings 13 allow access to these components 10A and 10B from outside the motor module 4 without having to disassemble the latter. Each opening 13 forms a recessed portion in the gear train bridge 8. Preferably, the motor module 4 also includes at least one pin 14 for pre-positioning the gear train bridge 8 on the plate 6. In the particular embodiment illustrated in the figures 1 and 2The plate 6 includes two pre-positioning pins 14. Such pins 14 serve as a reference for mounting the gear bridge 8 on the plate 6.

[0018] The plate 6 carries several gears 12. The plate 6 includes, for example, several support lugs 15 raising a plate support 17 on which the gears 12 are mounted.

[0019] The gear train bridge 8 has a substantially flat shape that defines a principal extension plane P1. The gear train bridge 8 includes means 18 for clipping the gear train bridge 8 onto the plate 6. Preferably, as visible on the figures 1 and 2 The gear bridge 8 also includes at least one through hole 20 for receiving a tenon. In the particular embodiment illustrated on the figures 1 and 2The gear train 8 includes two through holes 20 for receiving pins. Each through hole 20 receives one of the pins 14. The gear train 8 is, for example, made of a non-magnetic material. The modulus of elasticity of the non-magnetic material typically has a value greater than or equal to 190,000 MPa. Preferably, the gear train 8 is made of a material selected from the group consisting of: a hardenable austenitic alloy based on cobalt-chromium-nickel, in particular an alloy known under the trade name PHYNOXO; a non-magnetic stainless steel, in particular a non-magnetic stainless steel known under the trade name SANDVIK 13RM19 ©<; a non-magnetic copper-nickel-zinc alloy, in particular a non-magnetic alloy known under the trade name ARCAP ©<; and brass.The gear bridge 8 and the clipping means 18 preferably form a single piece of material, and are for example manufactured via a stamping process (without this being limiting within the scope of the present invention).

[0020] Preferably, the plate 6 includes additional means 22 for cooperation with the clipping means 18. The additional means 22 are configured to cooperate with the clipping means 18 to allow the gear bridge 8 to be locked against translation, particularly vertical translation, on the plate 6. Preferably, the clipping means 18 include at least one clipping tab 24 that projects from an underside 26 of the gear bridge 8. In the particular embodiment illustrated in the figures 1 and 2The clipping means 18 include three clipping tabs 24. According to this particular embodiment, the complementary means 22 include three locking lugs 28. Each locking lug 28 projects from a lateral face 30 of the plate support 17 and is configured to cooperate elastically with one of the clipping tabs 24.

[0021] THE figures 3 and 4 illustrate the cooperation between one of the clipping lugs 24 of the gear train bridge 8 and one of the locking lugs 28 of the plate 6. More precisely, in the particular embodiment illustrated in these figures, each clipping lug 24 is formed in one of the hollowed portions 13 of the gear train bridge 8, and comprises a first part 32 and a second part 34. As can be seen in the figures 1 and 2The first part 32 extends in the principal extension plane P1 defined by the gear bridge 8 and forms a retaining part for the lug 24. The second part 34 is formed from the material of the first part 32 and is folded in an inclined direction relative to the principal extension plane P1. More precisely, the second part 34 extends in a direction substantially perpendicular to the extension direction of the first part 32, and is oriented downwards from the lower face 26 of the gear bridge 8.

[0022] The second part 34 of each clipping tab 24 has a free end 36. Preferably, as seen on the figures 1 to 4The free end 36 of the second part 34 forms an elastic clipping member which has a central hollow portion 38 and a continuous closed periphery 40. The continuous closed periphery 40 delimits the central hollow portion 38. The continuous closed periphery 40 of the elastic clipping member 36 preferentially has a portion subjected to elastic stress 42. As illustrated in the figure 4 The elastic stress portion 42 is configured to cooperate elastically with one of the locking lugs 28 when the lug 28 extends inside the hollowed central portion 38 of the free end 36. This cooperation between each locking lug 28 and each elastic stress portion 42 of a corresponding clipping lug 24 allows the locking in translation, in particular vertical, of the gear bridge 8 on the plate 6.

[0023] The assembly method for the motor module 4 according to the invention will now be described. The gears 12 and the electromechanical components 10 are initially placed in their respective locations and housings 11 within the plate 6. The method includes a mounting phase of the gear bridge 8 onto the plate 6. This mounting phase includes, for example, an initial step of pre-positioning the gear bridge 8 on the plate 6. To do this, the gear bridge 8 is guided onto the pre-positioning pins 14 by inserting these pins into the receiving holes 20 of the gear bridge 8. The mounting phase includes a subsequent step of clipping the gear bridge 8 onto the plate 6. To do this, in the particular embodiment shown in the figures 1 to 4 , the free end 36 of each clipping tab 24 is brought to the position illustrated on the figure 4, so that the elastic stress part 42 cooperates elastically with one of the lugs 28 of the plate 6 for blocking in translation, in particular vertical, of the gear bridge 8 on the plate 6.

[0024] The motor module 4 according to a second embodiment of the invention will now be described with reference to the figure 5 In this second embodiment of the invention, the elements described with the same numerical references as those of the first embodiment are identical to the latter and will therefore not be described in detail again. In this second embodiment of the invention, the motor module 4 further includes means 46 for vertically fixing the gear train 8 to the plate 6. The vertical fixing means 46 are, for example, made up of one or more fixing screws, typically three fixing screws as in the example illustrated in the figure 5 .

Claims

1. Motor module (4) for a horological movement (2), the motor module (4) comprising a plate (6) bearing one or more cogs (12), and a cog bridge (8) mounted on the plate (6), the cog bridge (6) comprising means (18) for clipping the cog bridge (8) onto the plate (6), characterised in that the clipping means (18) comprise at least one clipping tab (24), preferably three clipping tabs (24), projecting from a lower face (26) of the cog bridge (8), the or each clipping tab (24) is provided in a recessed portion (13) of the cog bridge (8), and comprises a first part (32) for holding the tab extending in a main extension plane (P1) defined by the cog bridge (8), and a second part (34) formed integrally with the first part (32) and extending in a direction substantially perpendicular to the direction of extension of the first part (32) and. the second part (34) having a free end (36), said free end (36) forming a resilient clipping member having a central recessed portion (38) and a continuous closed periphery (40) delimiting said central recessed portion (38) and. the plate (6) being provided with complementary means (22) for cooperating with the clipping means (18) of the cog bridge (8), for locking the cog bridge (8) onto the plate (6) in translation, said the complementary means (22) for cooperating with the clipping means (18) comprising at least one locking lug (28) projecting from a lateral face (30) of the plate (6) and, said lug (28) being configured to cooperate resiliently with the clipping lug or one of the clipping lugs (24) and the continuous closed periphery (40) of the resilient clipping member (36) having a resilient stressing part (42) configured to cooperate resiliently with the locking lug (28) when the lug (28) extends inside the central recessed portion (38), for locking the cog bridge (8) onto the plate (6) in translation, in particular vertically.

2. Motor module (4) according to the preceding claim, characterised in that it further comprises at least one pin (14) for prepositioning the cog bridge (8) on the plate (6); and in that the cog bridge (8) is provided with at least one, preferably two, through hole(s) (20) for receiving the pin.

3. Motor module (4) according to any of the preceding claims, characterised in that the cog bridge (8) is made from a non-magnetic material.

4. Motor module (4) according to any of the preceding claims, characterised in that the cog bridge (8) is made from a material selected from the group consisting of: a hardenable austenitic cobalt-chromium-nickel-based alloy, in particular an alloy known by the trade name PHYNOX©; a non-magnetic stainless steel, in particular a non-magnetic stainless steel known by the trade name SANDVIK 13RM19©; a non-magnetic copper-nickel-zinc-based alloy, in particular a non-magnetic alloy known by the trade name ARCAP©; and brass.

5. Motor module (4) according to any of the preceding claims, characterised in that it further comprises means (46) for vertically fixing the cog bridge (8) onto the plate (6), in particular one or more fixing screws.

6. Horological movement (2) comprising a motor module (4), characterised in that the motor module (4) is in accordance with any of the preceding claims.

7. Timepiece (1) comprising a horological movement (2), characterised in that the horological movement (2) is in accordance with claim 6.

8. Method of assembling a motor module (4) for a horological movement (2) according to claim 6, the motor module (4) comprising a plate (6) bearing one or more cogs (12), and a cog bridge (8), the method comprising a phase of mounting the cog bridge (8) on the plate (6), characterised in that the cog bridge (8) comprises clipping means (18) and in that the phase of mounting the cog bridge (8) onto the plate (6) comprises a step of clipping the cog bridge (8) onto the plate (6).