CH717516A2 - Motor module for a watch movement. - Google Patents

Abstract

The invention relates to a motor module (4) for a watch movement (2), the motor module (4) comprising a plate (6) carrying one or more gear trains (12), and a gear train bridge (8) mounted on the (6), characterized in that the gear train bridge (6) comprises means (18) for clipping the train train bridge (8) onto the plate (6). The invention relates to the field of mechanical and electromechanical watchmaking.

Description

Technical area

The invention relates to a motor module for a watch movement. Such a motor module is in particular intended for driving the hands of a timepiece comprising the timepiece movement.

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

The invention also relates to a method of assembling such a motor module.

Technology background

[0004] Modular timepieces are known. Very widespread in electronic watchmaking, they are less frequent in mechanical watchmaking, where construction by modules, generally designed to decline the same basic mechanical movement in several calibers with different functionalities or presentation, rarely proves to be less expensive than a traditional production. Only certain additional mechanisms, made on additional boards, are relatively widespread. One of the main modules of such a modular timepiece is the motor module. Such a motor module for a watch movement conventionally comprises a plate bearing one or more gear trains, and a gear train bridge mounted on the plate. The gear train bridge delimits with the plate a space inside which, in addition to the gear trains, electromechanical elements are housed, such as for example rotors, stators, or even coils. The engine module can be mechanical, and therefore self-winding. It can also be a quartz motor module.

[0005] When assembling the motor module, once the cogs have been placed on the plate, it is known practice to use a spacing spacer between the gear bridge and the plate. A bridging screw then fixes the plate to the spacer. Such a spacer-based solution is for example described in patent document CH 588 108 B5. However, such fixing by screw and spacer has the drawback of being inflexible and does not make it possible to easily dismantle the parts of the engine module in a short time. Such an operation of dismantling the parts may in fact prove necessary in the event of maintenance to be carried out on the motor module.

[0006] Another known assembly solution consists of engaging the gear bridge on pivots mounted in the plate, with the help of tenons which project from an outer face of the plate and which allow alignment and centering of the gear-train bridge opposite the plate. The gear-train bridge is then slightly driven on the plate, so as to obtain a first hold of the bridge. A thermo-riveting operation is then applied to the tenons, which makes it possible, by heating the tenons, to obtain a deformation of the latter and thus to ensure the attachment of the gear train bridge to the plate. However, a problem posed by this type of assembly of the motor module is that once the gear train bridge is heat-riveted on the plate, it is no longer possible to disassemble the parts of the motor module without causing the parts to be torn out and therefore mechanical damage to the module. In addition, another drawback of such an assembly is that the tenons are insufficient to guarantee that the gear train bridge is securely held in place on the plate. Consequently, the gear-train bridge is poorly pressed against the plate and may come out of the guide of the tenons, and certain pivots may also be disengaged during thermo-riveting. The frolics between the cogs are then no longer guaranteed.

Summary of the invention

[0007] The object of the invention is therefore to provide a motor for a watch movement, making it possible to disassemble and reassemble the parts of the motor module without causing the parts to be pulled out, while guaranteeing sufficient pressing force of the gear train bridge on the plate. guaranteeing movement between the cogs.

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

[0009] Particular forms of the motor module are defined in dependent claims 2 to 11.

[0010] Thanks to the presence, on the gear train bridge, of means for clipping the gear train bridge onto the plate, it is possible for a user to be able to easily disassemble and reassemble the parts of the motor module, without causing tearing or mechanical damage. of these. In addition, such clipping means exert sufficient pressing force to allow the mechanical retention of the gear bridge on the plate, and thus guarantee the movement between the gears.

[0011] Advantageously, the gear bridge is made of a non-magnetic material. Such a non-magnetic material preferably has a high modulus of elasticity. This makes it possible to ensure optimum clipping of the gear train bridge on the plate, and to guarantee an optimized pressing force between these two parts.

[0012] To this end, the invention also relates to a watch movement comprising the motor module described above, and which comprises the characteristics mentioned in dependent claim 12.

[0013] To this end, the invention also relates to a timepiece comprising the timepiece movement described above, and which comprises the characteristics mentioned in dependent claim 13.

[0014] To this end, the invention also relates to a method for assembling the engine module described above, and which comprises the characteristics mentioned in independent claim 14. The assembly method according to the invention makes it possible to eliminate the heat-riveting operation, and thus save at least one assembly operation in the process. This thus enables the operator performing the fitting of the gear trains to also be able to clip the gear train bridge onto the plate, at the same workstation. Thus, the method according to the invention makes it possible to avoid displacement of the motor module under another welding or thermo-riveting station, and thus to eliminate the risk of disengagement of certain pivots. The method according to the invention also makes it possible to save assembly time for the motor module.

Brief description of figures

The aims, advantages and characteristics of the motor module for a watch movement according to the invention will appear better in the following description on the basis of at least one non-limiting embodiment illustrated by the drawings in which: FIG. 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 provided with three clipping lugs; FIG. 2 is a perspective view of the engine module of FIG. 1, in the assembled configuration; FIG. 3 is a perspective view of one of the clipping lugs of the motor module of FIG. 1, in the exploded configuration of the motor module; Figure 4 is a view similar to that of Figure 3, in the assembled configuration of the motor module shown in Figure 2; and FIG. 5 is a perspective view of a motor module for a watch movement according to a second embodiment of the invention, in the assembled configuration.

Detailed description of the invention

[0016] In the following description, reference is made to a watch movement equipped with a motor module. The usual components of the watch movement, which are well known to a person skilled in the art in this technical field, are only described in a simplified manner or not described at all. A person skilled in the art will know how to adapt these various components and make them cooperate for the operation of the watch movement.

Figures 1 and 2 show 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 comprises a motor module 4, which is represented in FIGS. 1 to 4 according to a first embodiment of the invention. The motor module 4 is configured to be fixed, for example by screwing, gluing or even thermo-riveting, on 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 plate 6. 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 FIGS. 1 and 2, the electromechanical components 10A, 10B are arranged in housings 11 provided for this purpose, under the gear-train bridge 8, such housings 11 being for example formed within the plate 6. The electromechanical components 10A, 10B are thus mounted on the printed circuit board. Corresponding access openings 13 are for example made in the gear bridge 8. Such openings 13 are arranged opposite the electromechanical components 10A, 10B in the vertical direction. The openings 13 allow access to these components 10A, 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 comprises 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 2, plate 6 includes two pre-positioning pins 14. Such pins 14 serve as a reference for mounting gear-train bridge 8 on plate 6.

The plate 6 carries several cogs 12. The plate 6 comprises, for example, several support lugs 15 raising a plate support 17 on which the cogs 12 are mounted.

[0019] The gear bridge 8 has a substantially planar shape which defines a main extension plane P1. The gear-train bridge 8 comprises means 18 for clipping the gear-train bridge 8 onto the plate 6. Preferably, as can be seen in FIGS. 1 and 2, the gear-train bridge 8 also comprises at least one through hole 20 for receiving a tenon. In the particular embodiment illustrated in FIGS. 1 and 2, the gear bridge 8 comprises two through holes 20 for receiving the pin. Each through hole 20 receives one of the pins 14. The gear train bridge 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 bridge 8 consists of a material chosen from the group consisting of: a hardenable austenitic alloy based on cobalt-chrome-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 alloy based on copper-nickel-zinc, in particular a non-magnetic alloy known under the trade name ARCAP©; and brass. The gear-train bridge 8 and the clipping means 18 preferably form a single piece of material, and are for example manufactured using a stamping process (without this being limiting in the context of the present invention).

[0020] Preferably, the plate 6 comprises complementary means 22 for cooperating with the clipping means 18. The complementary means 22 are configured to cooperate with the clipping means 18 to allow locking in translation, in particular vertical, of the gear bridge 8 on the plate 6. Preferably, the clipping means 18 comprise at least one clipping lug 24 which protrudes from an underside 26 of the gear bridge 8. In the particular embodiment illustrated in FIGS. 1 and 2, the clipping means 18 comprise three clipping lugs 24. According to this particular embodiment, the complementary means 22 comprise three locking lugs 28. Each locking lug 28 projects from a side face 30 of the plate support 17 and is configured to cooperate elastically with one of the clipping lugs 24.

[0021] Figures 3 and 4 illustrate the cooperation between one of the clipping lugs 24 of the gear bridge 8 and one of the locking lugs 28 of the plate 6. More specifically, in the particular embodiment illustrated in these figures, each clipping lug 24 is made in one of the recessed portions 13 of the gear bridge 8, and comprises a first part 32 and a second part 34. As can be seen in Figures 1 and 2, the first part 32 extends in the main plane of extension P1 defined by the gear bridge 8 and forms a holding part of the lug 24. The second part 34 is made in one piece with the first part 32 and is folded in an inclined direction with respect to the main extension plane P1. More precisely, the second part 34 extends in a direction substantially perpendicular to the direction of extension of the first part 32, and is oriented downwards from the lower face 26 of the gear bridge 8.

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

The method of assembling the engine module 4 according to the invention will now be described. The cogs 12 and the electromechanical components 10 are initially placed in their respective slots and housings 11 within the plate 6. The method comprises a phase of assembly of the gear bridge 8 on the plate 6. This assembly phase comprises for example a step initial pre-positioning of the gear train bridge 8 on the plate 6. To do this, the gear train bridge 8 is guided on the pre-positioning pins 14, by inserting the latter into the receiving holes 20 of the train train bridge 8. The phase assembly comprises a following step of clipping the gear bridge 8 onto the plate 6. To do this, in the particular embodiment represented in FIGS. 1 to 4, the free end 36 of each clipping lug 24 is brought up to in the position illustrated in FIG. 4, so that the elastic biasing part 42 cooperates elastically with one of the lugs 28 of the plate 6 for locking in translation, in particular vertical, of the gear bridge 8 on r plate 6.

[0024] The motor module 4 according to a second embodiment of the invention will now be described with reference to FIG. 5. In this second embodiment of the invention, the elements described with the same reference numerals as those of 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 comprises means 46 for vertical fixing of the gear bridge 8 on the plate 6. The vertical fixing means 46 consist for example of one or more fixing, typically three fixing screws as in the example illustrated in figure 5.

Claims (14)

1. Motor module (4) for a watch movement (2), the motor module (4) comprising a plate (6) carrying one or more gear trains (12), and a gear train bridge (8) mounted on the plate (6) , characterized in that the gear train bridge (6) comprises means (18) for clipping the train train bridge (8) onto the plate (6). 2. Motor module (4) according to claim 1, characterized in that the clipping means (18) comprise at least one clipping lug (24), preferably three clipping lugs (24), projecting from a lower face (26) of the gear bridge (8). 3. Motor module (4) according to claim 2, characterized in that the or each clipping lug (24) is formed in a recessed portion (13) of the gear bridge (8), and comprises a first part (32) of holding the lug extending in a main extension plane (P1) defined by the gear bridge (8), and a second part (34) integral with the first part (32) and extending in one direction substantially perpendicular to the direction of extension of the first part (32). 4. Engine module (4) according to claim 3, characterized in that the second part (34) has a free end (36), said free end (36) forming an elastic clipping member having a hollow central portion (38) and a continuous closed rim (40) bounding said recessed central portion (38). 5. Motor module (4) according to any one of the preceding claims, characterized in that the plate (6) is provided with complementary means (22) for cooperating with the clipping means (18) of the gear train (8), for locking in translation, in particular vertical, of the gear train bridge (8) on the plate (6). 6. Motor module (4) according to claim 5 when it depends on claim 2, characterized in that the complementary means (22) of cooperation with the clipping means (18) comprise at least one locking lug (28) projecting from a side face (30) of the plate (6), said lug (28) being configured to cooperate elastically with the or one of the clipping lug(s) (24). 7. Engine module (4) according to claim 6 when it depends on claim 4, characterized in that the continuous closed periphery (40) of the elastic clipping member (36) has an elastic biasing part (42) configured to cooperate elastically with the blocking lug (28) when the lug (28) extends inside the hollow central portion (38), for blocking in translation, in particular vertical, of the gear bridge (8 ) on the plate (6). 8. Motor module (4) according to any one of the preceding claims, characterized in that it further comprises at least one pin (14) for pre-positioning the gear bridge (8) on the plate (6); and in that the gear train bridge (8) is provided with at least one, preferably two, through hole(s) (20) for receiving pin. 9. Motor module (4) according to any one of the preceding claims, characterized in that the gear train bridge (8) consists of a non-magnetic material. 10. Engine module (4) according to any one of the preceding claims, characterized in that the gear train bridge (8) consists of a material chosen from the group consisting of: a hardenable austenitic alloy based on cobalt-chrome- 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 alloy based on copper-nickel-zinc, in particular a non-magnetic alloy known under the trade name ARCAP©; and brass. 11. Engine module (4) according to any one of the preceding claims, characterized in that it further comprises means (46) for vertical fixing of the gear train bridge (8) on the plate (6), in particular one or more screw. 12. Watch movement (2) comprising a motor module (4), characterized in that the motor module (4) conforms to any one of the preceding claims. 13. Timepiece (1) comprising a timepiece movement (2), characterized in that the timepiece movement (2) conforms to claim 12. 14. Method of assembling a motor module (4) for a watch movement (2), the motor module (4) comprising a plate (6) carrying one or more cogs (12), and a cog bridge (8) , the method comprising a phase of mounting the gear train bridge (8) on the plate (6), characterized in that the gear train bridge (8) comprises clipping means (18) and in that the assembly phase of the gear train bridge (8) on the plate (6) comprises a step of clipping the gear train bridge (8) onto the plate (6).