Oscillating winding mass provided with a decorative element for automatic movement of a timepiece

Abstract

The invention relates to an oscillating winding weight (1) for a timepiece movement, said oscillating winding weight (1) being intended to be mounted for rotation on an axis of the movement, said weight (1) comprising a main element (2) giving the oscillating winding weight (1) its general shape, and a weighting portion enabling the oscillation of the weight (1) in response to the movement of the timepiece and the force of gravity. The weight (1) includes a decorative element (3), for example a logo or emblem, the decorative element (3) being attached to the main element (2), the main element (2) comprising two superimposed parts (4, 5) assembled together, the decorative element (3) being held by at least one end (11) embedded in the material of the main element (2).

Description

Field of invention

[0001] The present invention relates to an oscillating winding mass provided with a decorative element for a movement of a timepiece with an automatic movement. More particularly, the invention relates to such a winding mass intended to equip a wristwatch comprising a transparent back. Background of the invention

[0002] We already know of wristwatches with transparent backs to allow observation of their movement. However, when these watches have a self-winding movement, the oscillating winding weight hides part of the movement.

[0003] Furthermore, the aesthetics of such oscillating weights are not always pleasing, even if it is possible to engrave the material forming the oscillating weight to make it more attractive. For example, a decorative element can be engraved, such as a logo representing the watch brand. But this logo is generally not visible enough to make the result aesthetically convincing. Furthermore, simply coloring the logo is not enough to make the weight more aesthetically pleasing, not to mention that the color can deteriorate over time. In addition, observation of the movement is always truncated by the presence of the oscillating winding weight, which prevents comfortable observation of the movement.

[0004] Document EP1918789A1 discloses, in Figure 6, an oscillating mass comprising a primary oscillating mass secured to a motor shaft and at least one secondary oscillating mass movable relative to the primary mass to cause the initial impulse. The secondary mass is constituted by a part assembled from the outside to the primary mass, being capable of having a clearance between two stops of a guide means located at the periphery of the primary mass.

[0005] Document EP2551731A1 discloses an oscillating weight intended to be pivoted on the outside of a watch movement and comprising an annular or annular sector-shaped frame and a decorative central part, constituting an unbalance of the oscillating weight. Summary of the invention

[0006] The present invention aims to overcome the drawbacks of the prior art by proposing an oscillating winding mass for a timepiece comprising a particular decorative element. The decorative element makes it possible in particular to discern the movement.

[0007] To this end, the invention relates to an oscillating winding mass of a timepiece movement, said mass being defined in independent claim 1.

[0008] Thanks to this new winding mass structure, a decorative element is held by the main element of the winding mass partly in the mass of the main element. Thus, the winding mass has a more attractive aesthetic appearance than a conventional winding mass known from the state of the art. Indeed, the decorative element, which can represent a logo or a brand acronym, gives more cachet to the winding mass and therefore to the timepiece.

[0009] According to a particular embodiment of the invention, the main element comprising two superimposed parts assembled to each other, the decorative element is held by the end between the superimposed parts of the main element.

[0010] According to a particular embodiment of the invention, the main element is a single piece.

[0011] According to a particular embodiment of the invention, the main element comprises amorphous or at least partially amorphous metal, preferably in its entirety.

[0012] According to a particular embodiment of the invention, the decorative element comprises amorphous or at least partially amorphous metal, preferably in its entirety.

[0013] According to a particular embodiment of the invention, the decorative element comprises metallic foam.

[0014] According to a particular embodiment of the invention, the heavy part comprises amorphous or at least partially amorphous metal of high density, preferably in its entirety.

[0015] According to a particular embodiment of the invention, the heavy part is an insert overmolded in the main element.

[0016] According to a particular embodiment of the invention, the main element has a ring shape.

[0017] According to a particular embodiment of the invention, the decorative element comprises a second end held between the two parts.

[0018] According to a particular embodiment of the invention, the decorative element passes at least partially through the ring.

[0019] The invention also relates to a timepiece comprising a case formed from a middle part closed by a glass and an at least partially transparent back and in which is housed a self-winding timepiece movement, said movement being equipped with an oscillating winding mass according to the invention.

[0020] The invention also relates to a manufacturing method as defined in claim 14.

[0021] According to a particular embodiment of the invention, the method comprises a step in which a metal foam is formed to obtain the decorative element, the decorative element being made of amorphous or at least partially amorphous metal.

[0022] According to a particular embodiment of the invention, the method comprises a forming step in which a metal plate provided with an open pattern is formed to obtain the decorative element, the decorative element being made of amorphous or at least partially amorphous metal.

[0023] According to a particular embodiment of the invention, the two parts of the main element and the decorative element are assembled by a hot-forming thermoforming process, or by overmolding. Summary description of the drawings

[0024] Other details of the invention will appear more clearly on reading the following description, given with reference to the appended drawings in which: there figure 1 is a perspective view of an embodiment of an oscillating winding mass according to the invention; and the figure 2is a perspective view of a portion of the main element and the decorative element of an oscillating winding mass according to the invention. Detailed Description of a Preferred Embodiment

[0025] It has been represented on the figure 1 a first embodiment of an oscillating winding mass according to the invention, designated by the general reference 1. This mass 1 is intended to conventionally equip the self-winding movement of a timepiece, the piece comprising in particular a case formed of a middle part closed by a glass and a back at least partially transparent to make the movement visible from the back, and which are not shown in the figures.

[0026] The winding mass 1 comprises a main element 2 conferring the general shape of the oscillating winding mass 1. The main element 2 is formed of a ring. The main element 2 comprises a through opening 9 formed by the ring.

[0027] The main element 2 comprises a first material, preferably entirely. The first material is amorphous metal or at least partially amorphous metal, since it allows the use of a hot-forming thermoforming process.

[0028] The main element 2 is connected to the movement mechanism 5 by an axis around which it can rotate. For this purpose, it comprises a fastening clip 6 on the movement, which is for example formed by a small ring arranged in the opening 9 of the ring of the main element 2. The clip 6 is thus made of the same material as the main element and is arranged in the same plane. Thanks to the clip 6, the winding mass can perform a circular movement around the axis, when it oscillates.

[0029] A portion of the winding mass forms a weighted portion allowing the mass to oscillate in response to the movement of the timepiece and the force of gravity. The weighted portion comprises a second material with a density greater than 10, preferably greater than or equal to 20. For example, the third material comprises tungsten or a tungsten alloy with a density substantially equal to 20, preferably entirely. The weighted portion is, for example, an insert overmolded into the main element.

[0030] According to the invention, the main element 2 comprises two superimposed parts 4, 5 assembled together. The upper part 4 and the lower part 5 here have identical shapes. In the separated position, the ring is cut in the plane. In other words, each part 4, 5 has a substantially identical flat ring shape, the thickness of which is less than the total thickness of the ring, preferably substantially equal to half.

[0031] Furthermore, the winding mass 1 comprises a decorative element 3, for example a logo or an acronym, the decorative element 3 being fixed to the main element 2 of the mass 1. The decorative element 3 is here an anchor-shaped logo having a substantially straight segment 7 and a curved segment 8, the straight segment 7 being connected to the curved segment 8 in its middle, on the internal side of the curvature.

[0032] The decorative element 3 is held by at least one end 11, 12 between the superimposed parts of the main element. Thus, the ends 11, 12 are nested in the material of the main element 2. In the example of Figures 1 and 2, the decorative element is held by the end 11 of the straight segment 7 and by the external side 12 of the curved segment 8. When the two parts 4, 5 are assembled, they come to bear on the ends 11, 12 of the decorative element. The assembly is carried out for example by an overmolding process, or by a hot-forming type thermoforming process. Preferably, the ends 11, 12 of the decorative element 3 are embedded in the material of the main element 2. Advantageously, the decorative element 3 is flat to allow the two parts 4, 5 to assemble more easily.

[0033] The decorative element 3 here has a length greater than the diameter of the opening 9 in order to be able to be fixed to the main element by its two ends 11, 12. Thus, the decorative element 3 passes at least partially through the ring. The decorative element 3 preferably has a width less than that of the opening 9 to facilitate vision through the winding mass.

[0034] The decorative element 3 is formed of a third material, preferably entirely. The third material is, for example, amorphous metal or partially amorphous metal.

[0035] To produce the winding mass 1, the production method comprises a first step of manufacturing a main element 2 of the mass 1 in two superimposable parts 4, 5.

[0036] The process includes a second step of manufacturing a decorative element, for example a logo or an acronym.

[0037] Preferably, the material of the decorative element 3 is structured to allow the mechanism to be seen through the decorative element 3. For this, the decorative element 3 is openwork according to a predefined pattern.

[0038] In a first embodiment, the decorative element 3 is formed in a sheet metal by laser cutting. The openwork pattern is drawn on the sheet metal by the laser. The sheet metal is then cut to obtain the overall shape of the decorative element 3.

[0039] Alternatively, stamping or machining can be used to form the decorative element.

[0040] A second embodiment consists of making the decorative element 3 from a metal foam. To make it, a mold is formed, for example from salt, the mold being a negative of the foam that one wishes to make. Amorphous metal is used, which is infiltrated or injected into the mold. The resulting foam is then sectioned into plates, which are cut to the dimensions of the decorative element.

[0041] In a third step, the two parts 4, 5 of the main element 2 and the decorative element 3 are assembled by a hot-forming thermoforming process. The decorative element 3 is placed between the two parts 4, 5 of the main element 2, then the assembly is heated to mold the two parts onto the decorative element 3. This type of production can be done using the amorphous metal material of the main element 2 and / or the decorative element 3. Thus, the decorative element is held between the two parts by at least one end, here two.

[0042] In an alternative embodiment, the decorative element can be overmolded onto the main element, or the main element can be overmolded onto the decorative element. This results in a main element made of the same material, i.e. a single piece.

[0043] The invention also relates to a second embodiment of an automatic winding mass, not shown in the figures. The winding mass comprises a main element formed from the same material, and a decorative element identical to that of the first embodiment. In this case, the winding mass is similar to that of the first embodiment, except that the main element is a single piece and not in two parts.

Claims

1. An oscillating weight assembly (1) for a timepiece movement, said oscillating weight assembly (1) being designed to be rotatably mounted on a movement axis, said assembly (1) comprising a main element (2) conferring the overall form of the oscillating weight assembly (1) the main element (2) comprising an attachment lug (6) on the movement and a weighted part enabling the assembly to oscillate (1) in response to the movement of the timepiece and to the force of gravity, the oscillating weight assembly (1) also comprising a decorative element (3), for example a logo or an acronym, the decorative element (3) being attached to the main element (2) by at least one end (11) embedded in the material of the main element (2), the main element (2) comprising a through opening (9), the decorative element (3) being arranged at least partly in said opening (9).

2. The weight assembly (1) according to claim 1, characterised in that the main element (2) comprises two superimposed parts (4, 5) connected to each other, the decorative element (3) is held by the end (11) between the superimposed parts (4, 5) of the main element (2).

3. The weight assembly according to claim 1, characterised in that the main element is made in one piece.

4. The weight assembly (1) according to any of the preceding claims, characterised in that the main element (2) comprises amorphous or at least partially amorphous metal, preferably in its entirety.

5. The weight assembly (1) according to any of the preceding claims, characterised in that the decorative element (3) comprises amorphous or at least partially amorphous metal, preferably in its entirety.

6. The weight assembly (1) according to any of the preceding claims, characterised in that the decorative element (3) comprises a metallic foam.

7. The weight assembly (1) according to any of the preceding claims, characterised in that the decorative element (3) comprises a pierced pattern.

8. The weight assembly (1) according to any of the preceding claims, characterised in that the weighted part comprises amorphous or at least partially amorphous high-density metal, preferably in its entirety.

9. The weight assembly (1) according to any of the preceding claims, characterised in that the weighted part is an insert moulded in the main element (2).

10. The weight assembly (1) according to any of the preceding claims, characterised in that the main element (2) is in the form of a bow.

11. The weight assembly (1) according to any of the preceding claims, characterised in that the decorative element (3) comprises a second end (12) held between the two parts (4, 5).

12. The weight assembly (1) according to claim 10 and any of the preceding claims, characterised in that the decorative element (3) runs at least partially through the bow.

13. A timepiece comprising a case formed by a middle closed by a glass and an at least partially transparent back in which a self-winding horology movement is fitted, characterised in that said movement is equipped with an oscillating weight assembly (1) according to any one of the preceding claims.

14. A method for manufacturing an oscillating weight assembly according to any of claims 1, 2 or 4 to 12, the method comprising a first step in which said main element (2) of the weight assembly (1) is manufactured in two superimposable parts (4, 5), a second step in which said decorative element (3), for example a logo or an acronym, is manufactured, and a third step in which the main element (2) and the decorative element (3) are assembled, the decorative element (2) being held between the two parts (4, 5) by at least one end (11).

15. The method according to claim 14, characterised in that the method comprises a step in which a metallic foam is formed in order to obtain the decorative element (3), the decorative element (3) being made of amorphous or at least partially amorphous metal.

16. The method according to claim 14, characterised in that the method comprises a forming step in which a metal plate with an open pattern is formed in order to obtain the decorative element (3), the decorative element (3) made of amorphous or at least partially amorphous metal.

17. The method according to claim 14, characterised in that the two parts (4, 5) of the main element (2) and the decorative element (3) are assembled by a hot-forming method or by overmoulding.

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