Annular oscillating weight and timepiece comprising such an oscillating weight

Abstract

The invention relates to an oscillating weight (1) for a self-winding timepiece, comprising a drive ring (2) including a first transmission portion (20) provided with coaxial teeth (21) for winding the timepiece and a second support portion (22), and including a heavy sector (3) attached to the second support portion of the drive ring (2). According to the invention, the heavy sector (3) is attached to the drive ring at several points via studs (4) having a flat surface to form a reservoir arranged to receive glue.

Description

Technical field of the invention

[0001] The invention relates to an annular oscillating weight comprising a drive ring including an annular transmission portion with teeth coaxial to the ring, and a heavy sector fixed to the drive ring. The present invention also relates to a watch movement and a self-winding timepiece, which respectively comprise the annular oscillating weight of the invention. Technological background

[0002] We are familiar with automatic watches equipped with an annular oscillating weight. This oscillating weight is housed in a circular passage formed around the movement inside the watch case. Rollers are also arranged around the edge of the passage to support and guide the oscillating weight, allowing it to rotate freely within the passage. The drive ring may, for example, have internal teeth, through which the rotational movements of the oscillating weight are mechanically transmitted to the mainspring barrel. The oscillating weight thus ensures the automatic winding of the mainspring.

[0003] One problem encountered with such oscillating weights is that they are easily deformed during assembly, particularly when the components of the annular oscillating weight are joined using driven pins or studs. Such deformations can impair the proper functioning of the oscillating weight and the perceived quality of the part.

[0004] Another problem associated with such oscillating masses is that the pins or studs can become dislodged under the effect of shocks and end up damaging other parts of the movement. Summary of the invention

[0005] The invention aims in particular to overcome the various drawbacks of the prior art.

[0006] The invention aims to provide an annular oscillating mass without generating stresses that could deteriorate the geometry of the toothed ring, while providing improved shock resistance.

[0007] For this purpose, the present invention relates to an oscillating weight for a self-winding timepiece comprising a drive ring including a first transmission part provided with coaxial teeth to drive the winding of the timepiece and a second support part, and including a heavy sector fixed to the second annular support part of the drive ring.

[0008] According to the invention, the heavy sector is fixed to the drive ring at several points via studs having a flat to form a reservoir arranged to receive glue.

[0009] In accordance with other advantageous variants of the invention: the drive ring has a shoulder between the first annular part and the second annular part of the drive ring, the first annular part and the second annular part extending in different parallel planes; the heavy sector has a shoulder complementary to the shoulder of the drive ring; the second annular part and the heavy sector include respectively openings and holes for receiving the studs; the studs have a head and a body, the flat extending from the foot to the head over part of the length of the stud body; the body of each stud (4) has a chamfer; the holes have a diameter less than the diameter of the stud foot; the heads of the studs are flush with the surface of the second annular support part.

[0010] The invention also relates to a watch movement and a timepiece comprising an oscillating weight according to the invention.

[0011] The invention also relates to a method for assembling an oscillating mass according to the invention, the method comprising the following steps: Provide a drive ring and a heavy sector; machine the drive ring and the heavy sector to form openings and holes; place a drop of glue in each of the holes in the heavy sector; place studs in the openings of the drive ring and then drive them into the holes to form the oscillating mass; place the oscillating mass in the oven to polymerize the glue. Brief description of the figures

[0012] Other features and advantages of the invention will become apparent from the following detailed description, given by way of non-limiting example, with reference to the accompanying drawings in which: there figure 1 represents a bottom view of an oscillating mass according to the invention; the figure 2represents a top perspective view of an oscillating mass according to the invention; the figure 3a represents an exploded view of an oscillating mass according to the invention; the figure 3b illustrates a detailed view of a block of the oscillating mass according to the invention; the figure 4 represents a cross-sectional view along line VV of the figure 1 . Detailed description of the invention

[0013] There figure 2 is a perspective view of an annular oscillating mass 1 according to the invention.

[0014] The invention is described in the case of an annular oscillating mass, and is also suitable for a conventional oscillating mass in the shape of a half-disk.

[0015] The oscillating weight 1 shown comprises a drive ring 2 and a heavy sector 3. According to the invention, the drive ring includes a first annular transmission portion 20 provided with teeth 21 for winding the timepiece and a second annular support portion 22. As shown in the figure 2 , the heavy sector 3 is supported by and integral with the second annular part 22, while the first annular transmission part 20 has a concentric internal toothing 21.

[0016] The heavy sector is made of a material with a high density, higher than the materials generally used for an oscillating mass, such as gold or tungsten.

[0017] The drive ring 2 has a shoulder 23 between the first annular portion 20 and the second annular portion 22 of the drive ring, the first and second annular portions being in different parallel planes. The heavy sector 3 also has a shoulder 30 with a shape complementary to the shoulder 23 of the annular portion, the heavy sector 3 thus having a first cylindrical portion 31 in contact with the second annular portion 22 and a second cylindrical portion 32 resting on teeth 21. Advantageously, a space is present between the teeth 21 and the second cylindrical portion 32 to compensate for assembly clearances when the heavy sector is fixed to the drive ring.

[0018] By referring to Figures 1 And 3, it can be observed that the heavy sector 3 is secured to the second annular support part 22 by means of studs 4. These studs 4 have a head 40 and a body 41 comprising a flat 42 to form a reservoir 5 arranged to receive glue when the batches are assembled.

[0019] These studs 4 are arranged to be fitted into openings 220 and holes 222 machined respectively in the second annular part 22 and in the heavy sector 3. As can be seen in the figure 4 The opening 220 has a first section with a diameter corresponding to the diameter of the head 40 of the stud 4, and a second section with a diameter corresponding to the diameter of the body 41 of the stud 4, the second section having a diameter smaller than the diameter of the first section. This arrangement allows the head 40 of the stud 4 to be flush with the surface of the second annular part 22.

[0020] The heavy sector 3 features holes 222, preferably blind holes, whose diameter is smaller than the diameter of the body of the studs 4 for press-fitting or recessing. This can be observed in figures 3b And 4 The body 41 of the stud 4 has a flat 42 extending from the bottom of the body 41 towards the head 40 over part of the body's height. This arrangement allows for the formation of a reservoir 5 for adhesive during the assembly of the three elements, namely the drive ring 2, the heavy sector 3, and the stud 4. The adhesive thus provides a more reliable assembly while reducing stress during assembly.

[0021] Another advantage of such a flat surface is that it facilitates the insertion of the studs, as the flat surface creates a void and prevents the stud from acting like a piston during insertion. This piston effect causes deformation of the heavy sector 3 due to air trapped in hole 222 by stud 4, preventing stud 4 from being driven to the bottom of the hole.

[0022] It will also be noted that figure 4 that the studs 4 have a chamfer 43 on the free end of the body 42 to facilitate the insertion of the studs 4 into the holes 222.

[0023] The invention also relates to a method of assembling an oscillating mass as described above.

[0024] The assembly process for the oscillating mass includes the following steps: provide a drive ring 2 and a heavy sector 3; machine the drive ring and the heavy sector to form openings 220 and holes 222; place a drop of glue in each of the holes 222 of the heavy sector; place studs 4 in the openings 220 of the drive ring 2 and then drive them into the holes 222, to form the oscillating mass 1; once the mass is assembled, place it in the oven to polymerize the glue.

[0025] The oscillating weight according to the invention is designed to be mounted in a watch movement for an automatic timepiece and to wind the movement. Such a watch typically includes an energy accumulator, often a mainspring barrel, designed to work with the oscillating weight to perform this function. The oscillating weight thus supplies energy to the accumulator by winding its mainspring. The energy accumulator powers a time base in the movement, which in turn drives the gear train.

Claims

1. Oscillating weight (1) for a self-winding timepiece comprising a drive ring (2) including a first transmission part (20) provided with coaxial teeth (21) for driving the winding of the timepiece and a second support part (22), and including a heavy sector (3) fixed to the second support part (22) of the drive ring (2), characterized in that the heavy sector (3) is fixed to the drive ring (2) at several points via studs (4) having a flat (42) to form a reservoir (5) arranged to receive glue.

2. Oscillating mass (1) according to claim 1, characterized in that the drive ring (2) has a shoulder (23) between the first annular part (20) and the second annular part (22) of the drive ring (2), the first annular part and the second annular part extending in different parallel planes.

3. Oscillating mass (1) according to claim 1 or 2, characterized in that the heavy sector has a shoulder (30) complementary to the shoulder (23) of the training ring (2).

4. Oscillating mass (1) according to claim 1 or 2, characterized in that the second part (22) and the heavy sector (3) respectively include openings (220) and holes (222) to receive the studs (4).

5. Oscillating mass (1) according to any one of claims 1 to 4, characterized in that the studs (4) have a head (40) and a body (41), the flat (42) extending from the body (41) towards the head (40) over part of the length of the body of the stud.

6. Oscillating mass (1) according to claim 5, characterized in that the body (41) of each stud (4) has a chamfer (43).

7. Oscillating mass (1) one of claims 1 to 6, characterized in that the holes (222) have a diameter smaller than the diameter of the base of the block.

8. Oscillating mass (100) according to any one of claims 1 to 7, characterized in that the head (40) of the studs is flush with the surface of the second annular support part (22).

9. Clock movement comprising an oscillating weight (1) according to any one of claims 1 to 8.

10. Timepiece comprising a timepiece movement according to claim 9.

11. Method for assembling an oscillating mass (1) according to any one of claims 1 to 8, characterized in that It includes the following steps: - provide a drive ring (2) and a heavy sector (3); - machine the drive ring and the heavy sector to form openings (220) and holes (222); - deposit a drop of glue in each of the holes (222) of the heavy sector; - place studs (4) in the openings (220) of the drive ring (2) and then drive them into the holes (222), to form the oscillating mass (1); - place the oscillating mass (1) in the oven to polymerize the glue.

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