EP0957414B1 - Swinging weight for timepieces with self-winding movement and timepiece including the same - Google Patents

Description

The present invention relates to a winding weight oscillating movement timepiece automatic. More particularly, the invention relates such a winding mass intended to equip a wristwatch with a transparent background, said mass being arranged on the side of the bottom of the box and allowing the observation of the entire movement in permanently.

We already know wristwatches with transparent bottom boxes to allow observation of their movement (EP-A-0 360 140). However, when these watches include an automatic movement, observation of the movement is always truncated by the presence of the oscillating winding weight which, even if perforated, as this is the case in so-called "skeleton" watches, prevents comfortable observation of movement.

The main object of the present invention is therefore to remedy the drawbacks of the prior art mentioned above, by providing a winding mass oscillating allowing observation of the movement it team without any visible obstacle.

To this end, the invention relates to a mass of oscillating winding for a timepiece including a heavy part fixed to a connecting member connecting said heavy part having an axis integral with a movement, said mass being intended to be rotatably mounted on said axis, characterized in that said connecting member is made of a transparent or translucent material.

Thanks to this new mass structure of reassembly, it is possible to make it permanently visible the entire movement of the timepiece it team, which gives it an aesthetic aspect improved.

According to a preferred embodiment of the invention, the connecting member is formed by a solid sapphire disc.

It should be noted in this connection in particular that the use of sapphire in a winding mass as connecting member between the heavy part and the movement goes against the prejudices of the skilled person who, when it has to design a winding weight, tends always use materials with great tenacity, i.e. good ability to absorb shocks to which the mass is subjected during its rotation.

According to another aspect, the invention also has for object a timepiece comprising a formed case of a middle closed by a glass and a bottom at least partially transparent and in which is housed a automatic watch movement, characterized in that said movement is equipped with a oscillating winding weight as defined above.

• la figure 1 est une vue en plan d'un premier mode de réalisation d'une masse de remontage oscillante selon l'invention;
• la figure 2 est une coupe selon la ligne II-II de la figure 1;
• la figure 3 est une vue en plan d'un deuxième mode de réalisation d'une masse de remontage oscillante selon l'invention;
• la figure 4 est une coupe, similaire à celle représentée à la figure 2, d'un troisième mode de réalisation selon l'invention;
• la figure 5 est une vue en plan d'un quatrième mode de réalisation d'une masse de remontage oscillante selon l'invention;
• la figure 6 est une coupe partielle selon la ligne VI-VI de la figure 5; et
• la figure 7 est une coupe d'un cinquième mode de réalisation selon l'invention.

Other characteristics and advantages of the present invention will appear in the following description of a preferred embodiment, presented by way of nonlimiting example with reference to the accompanying drawings, in which:

• Figure 1 is a plan view of a first embodiment of an oscillating winding weight according to the invention;
• Figure 2 is a section along the line II-II of Figure 1;
• Figure 3 is a plan view of a second embodiment of an oscillating winding weight according to the invention;
• Figure 4 is a section, similar to that shown in Figure 2, of a third embodiment according to the invention;
• Figure 5 is a plan view of a fourth embodiment of an oscillating winding weight according to the invention;
• Figure 6 is a partial section along the line VI-VI of Figure 5; and
• Figure 7 is a section of a fifth embodiment according to the invention.

FIGS. 1 and 2 show a first mode of realization of an oscillating winding weight according to the invention, designated by the general reference 1. This mass is intended to classically equip the movement to automatic winding of a timepiece (not shown) and including in particular a box formed of a middle closed by a glass and a bottom at least partially transparent to make the movement visible from the bottom.

The winding weight 1 includes a heavy part 2 attached to a connecting member 4 connecting the heavy part to an axis (not shown) integral with a movement of watchmaking, mass 1 being intended to be mounted at rotation on this axis. To this end, the liaison body has in its center an opening 6 in which is driven out a ring 8 forming the hub of the mass 1.

According to the invention, the connecting member 4 is formed a solid disc made of a transparent material such as the sapphire which allows to observe the movement at through mass 1. It goes without saying that any other transparent or translucent material, synthetic or natural can be used. In all cases, the material must at least allow the passage of light to ability to distinguish forms from elements behind.

The heavy part 2 comprises a ring 10 which has an unbalance 12 on an arc of about 180 ° which is formed by an extra thickness of said ring 10. In the example illustrated, the ring 10 and the unbalance 12 are made in one piece. Preferably, the part weighing 2 is made of a high density metal, by example, a tungsten alloy. However, it goes from so that according to a variant, the unbalance 12 can be attached to the ring 10 by any fixing means conventional such as screwing, gluing, crimping, welding or similar. In this case, the ring 10 can be made in an easily machinable material such as steel, and unbalance 12 in a tungsten alloy. In the example shown, the ring 10 includes a rebate 14 in which the disc 4 is engaged and glued. However, he will of itself that according to a variant, this disc 4 can be fixed in the rebate 14 of the ring 10 by any other means conventional fastening such as screwing, riveting or similar.

In Figure 3 there is shown a second mode of realization of an oscillating winding weight 1 according to the invention. In this figure and the following figures, elements identical to those described in conjunction with Figures 1 and 2 have been designated by the same references digital. It should also be noted that, for reasons of clarity, the ring 8 forming the hub of the mass 1 has been omitted in Figure 3.

Unlike the embodiment shown in Figures 1 and 2, the connecting member 4 of this mode of realization consists of a partially hollowed out disc also in sapphire. More specifically, the liaison body 4 includes a central part 16 provided with the opening 6 and a peripheral ring 18 concentric with the opening 6, the central part 16 being connected to the peripheral ring 18 by three arms 20. The recesses of the disc 4 will be advantageously made using diamond grinding wheels or again using a laser beam.

FIG. 4 shows a third mode of realization of an oscillating winding weight 1 according to the invention in which the connecting member 4 is formed of a circular magnifying optical lens. It goes from so that according to variant embodiments, any other type of optical lens can be considered. We will be able to especially provide Fresnel lenses that have the peculiarity of being flatter than a conventional lens for a given magnification. We could still consider to use 4 lenses for these connecting members producing kaleidoscopic effects.

Figures 5 and 6 show a fourth mode of an oscillating winding weight 1 of the invention in which the connecting member 4 is formed a transparent plate shaped into an angular sector extending over approximately 180 ° and in which the part weighing 2 is formed by a ring portion extending to the periphery of plate 4 on an arc about 180 °. Plate 4 is made of sapphire and further includes a magnifying optical lens 22 which extends radially from ring 8 to the ring of the heavy part 2.

FIG. 7 shows a fifth mode of realization of an oscillating winding weight 1 according to the invention in which the connecting member 4 is formed a transparent plate in the form of an angular sector extending about 180 ° and including at its periphery a flange 24 folded at an angle. In this embodiment the heavy part 2 is also formed by a part ring extending over an arc of approximately 180 ° and fixed by means of screws 26 on the inner face 28 of the ledge 24. Note that this embodiment of the winding weight 1 allows, thanks to its folded rim 24, to adapt as best as possible to the external shape of the movement that it is intended to equip, it being understood that the rim 24 is folded in the direction of movement.

Claims (10)

1. Oscillating winding weight for a timepiece including a heavy portion secured to a_connecting element connecting said heavy portion to an arbour fixed to the movement, said weight being intended to be rotatably mounted on said arbour, characterised in that said connecting element is made of a transparent or translucent material.
2. Winding weight according to claim 1, characterised in that said connecting element is formed of a full disc.
3. Winding weight according to claim 1, characterised in that said connecting element is formed of an at least partially hollowed disc.
4. Winding weight according to claim 1 or 3, characterised in that said connecting element is formed of at least two connecting arms.
5. Winding weight according to any of the preceding claims, characterised in that said connecting element is made of sapphire.
6. Winding weight according to any of the preceding claims, characterised in that said connecting element includes an optical lens.
7. Winding weight according to any of the preceding claims, characterised in that said heavy portion is formed of a ring portion extending over an arc of a circle of approximately 180°.
8. Winding weight according to any of claims 1 to 6, characterised in that said heavy portion is formed of a circular ring including, over an arc of a circle of approximately 180°, an unbalance.
9. Winding weight according to any of the preceding claims, characterised in that said heavy portion is secured to said connecting element by bonding.
10. Timepiece including a case formed of a middle part closed by a crystal and an at least partially transparent back cover and wherein self winding clockwork movement is housed, characterised in that said movement is fitted with an oscillating winding weight according to any of claims 1 to 9.

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