Annular oscillating mass and timepiece having the same

Abstract

To provide an annular oscillating mass which offers improved shock resistance and does not generate stress that could impair the geometry of a toothed bow.SOLUTION: An oscillating mass (1) for a self-winding timepiece is provided, including: a carrier bow (2) comprising a first transmission part (20) provided with coaxial toothing (21) to drive winding of the timepiece and a second annular supporting part (22); a heavy sector (3) attached to the second annular supporting part (22) of the carrier bow (2). The heavy sector (3) is attached to the carrier bow (2) at several points via blom studs (4) with uneven surfaces to form a reservoir for holding glue.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an annular oscillating mass comprising a carrier bow with an annular transmission part provided with coaxial teeth on the bow and a weight sector attached to the carrier bow. The present invention also relates to a timepiece movement and a self-winding timepiece comprising the annular oscillating mass of the present invention. [Background technology]

[0002] Automatic watches with an annular oscillating mass are common. This oscillating mass is housed in a circular recess located around the movement inside the watch case. Rolling runners are located on the edges of the recess to support and guide the oscillating mass, allowing it to rotate freely within the recess. The carrier bow may, for example, have internal teeth, which mechanically transmit the oscillating mass's rotational motion to the movement's barrel. In this way, the oscillating mass ensures automatic winding of the barrel spring.

[0003] One problem encountered with such seismic masses is that they are easily deformed during assembly, especially when the elements that make up the annular seismic mass are attached using drive pins or bromstuds, which can impair the smooth functioning of the seismic mass and the perceived quality of the part.

[0004] Another problem with such oscillating masses is that the pins or brome studs can become dislodged by impact and cause damage to other parts of the movement. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention particularly aims to remedy various drawbacks of the prior art. [Means for solving the problem]

[0006] The present invention aims to provide an annular seismic mass that offers improved shock resistance while not generating stresses that could compromise the geometry of the toothed bow.

[0007] To this end, the invention relates to a seismic mass for a self-winding watch, comprising a carrier bow with a first transmission part provided with coaxial teeth for driving the winding of the watch, and a second support part, and comprising a weight sector attached to the second annular support part of the carrier bow.

[0008] According to the invention, the weight sectors are secured to the carrier bow at several points using bromstads having uneven surfaces to form reservoirs for holding adhesive.

[0009] According to another advantageous variant of the invention, The carrier bow has a shoulder between the first annular portion and the second annular portion of the carrier bow, the first annular portion and the second annular portion extending in different parallel planes. The weight sector has a shoulder that is complementary to the shoulder of the carrier bow. The second annular portion and the weight sector each have an opening and a hole to accommodate the Bromstad. The Bromstad has a head and a body, and an uneven surface extends from the foot to the head over a portion of the length of the Bromstad. The body of each bromstad (4) has a chamfer. The hole has a diameter smaller than that of the Bromstad foot. The head of the Bromstad is flush with the surface of the second annular support.

[0010] The invention also relates to a clock movement and a clock comprising a seismic mass according to the invention.

[0011] The present invention also provides a method for assembling a seismic mass according to the present invention, comprising the steps of: Providing a carrier bow and a weight sector; machining the carrier bow and weight sector to form openings and holes; depositing a drop of adhesive into each of the holes in the weight sector; inserting a bromstud into the opening of the carrier bow and driving the bromstud into the hole to form a seismic mass; Baking the seismic mass in an oven to polymerize the adhesive; The present invention relates to a method comprising: [Brief explanation of the drawings]

[0012] Other characteristics 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: [Figure 1] 1 is a view from below of a seismic mass according to the invention; FIG. [Figure 2] FIG. 1 is a perspective top view of a seismic mass according to the present invention. [Figure 3a] FIG. 1 is an exploded view of a seismic mass according to the present invention. [Figure 3b] 1 shows a detailed view of the Bromstad seismic mass according to the invention. [Figure 4] FIG. 2 is a cross-sectional view taken along line VV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] FIG. 2 is a perspective view of an annular seismic mass 1 according to the invention.

[0014] Although the invention has been described in the context of an annular seismic mass, it is also suitable for conventional semi-circular disk shaped seismic masses.

[0015] The illustrated oscillating mass 1 comprises a carrier bow 2 and a weight sector 3. According to the invention, the carrier bow comprises a first annular transmission part 20 provided with teeth 21 that drive the winding of the watch, and a second annular support part 22. As shown in Figure 2, the weight sector 3 is supported by and integrated with the second annular part 22, while the first annular transmission part 20 has concentric internal teeth 21.

[0016] The weight sector is made of a material with a higher density than materials typically used for seismic masses, such as gold or tungsten.

[0017] The carrier bow 2 has a shoulder 23 between the first and second annular parts 20 and 22 of the carrier bow, which are in different parallel planes. The weight sector 3 also has a shoulder 30 having a shape complementary to the shoulder 23 of the annular part, and therefore has a first cylindrical part 31 in contact with the second annular part 22 and a second cylindrical part 32 located on the tooth 21. Advantageously, there is a space between the tooth 21 and the second cylindrical part 32 to compensate for assembly clearance when the weight sector is fixed to the carrier bow.

[0018] 1 and 3, it can be seen that the weight sectors 3 are connected to the second annular support 22 by means of bromstuds 4. These bromstuds 4 have a head 40 and a body 41 with an uneven surface 42 to form a reservoir 5 that holds the adhesive when the batch is assembled.

[0019] These Bromstuds 4 are positioned to be driven into openings 220 and holes 222 machined in the second annular portion 22 and the weight sector 3, respectively. As can be seen in Figure 4, the openings 220 have a first portion with a diameter corresponding to the diameter of the heads 40 of the Bromstuds 4 and a second portion with a diameter corresponding to the diameter of the body 41 of the Bromstuds 4, the second portion having a smaller diameter than the first portion. This configuration allows the heads 40 of the Bromstuds 4 to be flush with the surface of the second annular portion 22.

[0020] The weight sector 3 has a hole 222, preferably a blind hole, with a diameter smaller than that of the body of the Bromstud 4 for press-fitting or hammering. It can be seen in Figures 3b and 4 that the body 41 of the Bromstud 4 has an uneven surface 42 extending from the bottom of the body 41 toward the head 40 over part of its height. This configuration allows a reservoir 5 to be formed for adhesive when assembling the three elements: the carrier bow 2, the weight sector 3, and the Bromstud 4. In this way, the adhesive provides a more reliable overall assembly while reducing stress during assembly.

[0021] Another advantage of such an uneven surface is that it makes it easier to drive the Bromstud in, as the uneven surface prevents gaps from forming and causing a piston effect as the Bromstud is driven in. The piston effect occurs when air trapped in the hole 222 by the Bromstud 4 causes deformation of the weight sector 3, preventing the Bromstud 4 from being driven completely into the hole.

[0022] It can also be seen in FIG. 4 that Bromstud 4 has a chamfer 43 at the free end of body 42 to facilitate insertion of Bromstud 4 into hole 222.

[0023] The present invention also relates to a method for assembling a seismic mass as described above.

[0024] The method for assembling the seismic mass is as follows: providing a carrier bow 2 and a weight sector 3; machining the carrier bow and weight sectors to form openings 220 and holes 222; depositing a drop of adhesive in each of the holes 222 of the weight sector; Inserting the brome stud 4 into the opening 220 of the carrier bow 2 and hammering the brome stud 4 into the hole 222 to form the seismic mass 1; After the mass is assembled, baking the mass in an oven to harden the adhesive; Includes.

[0025] The oscillating mass according to the invention is intended to be attached to a watch movement for an automatic watch and to ensure the winding of the movement. Such watches conventionally comprise an energy storage device (often a barrel) designed to cooperate with the oscillating mass to ensure this function. The oscillating mass thus supplies energy to the storage device by winding its mainspring. The energy storage device is used to power the time base of the movement, which in turn drives the train.

Claims

1. A seismic mass (1) for an automatic timepiece, comprising: a carrier bow (2) comprising a first transmission part (20) provided with coaxial teeth (21) for driving the winding of the timepiece, and a second support part (22); a weight sector (3) attached to a second support (22) of the carrier bow (2); The seismic mass (1) is characterized in that the weight sector (3) is attached to the carrier bow (2) at several points using bromstuds (4) having an uneven surface (42) to form a reservoir (5) for holding adhesive.

2. 2. The seismic mass (1) according to claim 1, characterized in that the carrier bow (2) has a shoulder (23) between the first annular portion (20) and the second annular portion (22) of the carrier bow (2), the first annular portion and the second annular portion extending in different parallel planes.

3. 2. The seismic mass (1) according to claim 1, characterized in that the weight sector has a shoulder (30) complementary to the shoulder (23) of the carrier bow (2).

4. 2. The seismic mass (1) according to claim 1, characterized in that the second part (22) and the weight sector (3) respectively have an opening (220) and a hole (222) for accommodating the Blomstad (4).

5. 2. The seismic mass (1) according to claim 1, characterized in that the Bromstad (4) has a head (40) and a body (41), and the uneven surface (42) extends from the body (41) towards the head (40) over a portion of the length of the Bromstad body.

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

7. 2. A seismic mass (1) according to claim 1, characterized in that the holes (222) have a diameter smaller than the diameter of the feet of the Bromstad.

8. 2. The seismic mass (100) of claim 1, wherein the Blomstad head (40) is flush with the surface of the second annular support (22).

9. A clock movement comprising a seismic mass (1) according to claim 1.

10. A timepiece comprising the timepiece movement according to claim 9.

11. A method for assembling a seismic mass (1) according to claim 1, comprising the steps of: Providing a carrier bow (2) and a weight sector (3); - machining the carrier bow and the weight sector to form openings (220) and holes (222); - depositing a drop of adhesive in each of the holes (222) of said weight sector; - inserting brom studs (4) into the openings (220) of the carrier bow (2) and hammering them into the holes (222) to form the seismic mass (1); Baking the seismic mass (1) in an oven to polymerize the adhesive; A method comprising:

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