This application claims priority to European Patent Application No. 18187998.2, filed Aug. 8, 2018, the entire contents of which are incorporated by reference herein.

FIELD OF THE INVENTION

The invention concerns an annular rotating bezel system.

The invention also concerns a watch case comprising a middle part and the annular rotating bezel system rotatably mounted on the case middle.

The invention also concerns a watch including the watch case. The watch is, for example, a diver's watch, although this is not limiting in the context of the present invention.

BACKGROUND OF THE INVENTION

Known annular rotating bezel systems comprise a rotating bezel, a toothed ring and a spring ring. A rotating bezel system of this type is, for example, described in European Patent No 2672333A1. The spring ring is angularly joined to the rotating bezel, and the toothed ring is angularly joined to the case middle. The toothed ring has several teeth regularly distributed over its outer edge, in this case 120 teeth in the example embodiment provided in this document. The spring ring extends in a plane in which it is capable of deforming elastically along a radius and cooperates elastically with the toothed ring. To achieve this, three lugs in the form of elastic arms and intended to cooperate with the toothed ring are made on an inner edge of the spring ring, by cutting the latter. The three lugs are regularly distributed over the inner edge of the spring ring. Consequently, regardless of the position of the bezel, the three lugs are always engaged with the toothing of the toothed ring at the same time, which results in 120 stable positions for the rotating bezel. The number of positions therefore corresponds to the number of teeth. The position indexing resolution of the rotating bezel is thus limited by the total number of possible positions of the bezel, in this case 120 positions. However, the greater the number of teeth for a given diameter, the smaller the dimension of the teeth, which entails a high wear factor for said teeth. It is thus desirable to find a technical solution that can ensure, for a given bezel diameter, a number of stable positions that is higher than the number of teeth in the ring toothing, without thereby increasing the wear of the ring toothing.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide an annular rotating bezel system which, with the same number of teeth in the toothed ring as in systems of the prior art, makes it possible to obtain a greater number of possible stable positions for the rotating bezel, and which overcomes the aforementioned drawbacks of the prior art.

To this end, the invention concerns an annular rotating bezel system, which includes the features mentioned in the independent claim1.

Specific embodiments of the system are defined in the dependent claims2to16.

One advantage of the present invention is that, with the same number of teeth in the toothed ring as in the systems of the prior art, it is possible to obtain a larger number of possible stable positions for the rotating bezel. Indeed, by means of the configuration wherein the or each offset angle between two successive lugs has a value different from an integer sub-multiple of 360 degrees, a single lug is elastically or radially engaged with the toothing of the toothed ring in each position of the bezel. The total number of possible positions for the bezel is in that case provided by the result of multiplying the number of lugs on the spring ring by the number of teeth on the spring ring. This makes it possible to obtain a larger number of possible stable positions for the rotating bezel.

Conversely, it is, for example, possible, by means of the system of the invention, to increase the size of the teeth and to reduce the number of teeth on the toothed ring in order to decrease the wear thereof, while still maintaining the same number of stable positions of the bezel as in prior art systems.

Advantageously, the spring ring includes at least two thinned portions arranged to increase the flexibility of the spring ring in its plane, with each lug extending from one of the thinned portions. This increases the flexibility of the spring ring in its plane. Indeed, via the thinned portions it contains, the spring ring flexes in its plane, allowing the lugs it carries to move in and out of mesh with the toothed ring as the bezel rotates. This makes it possible to reduce the width required for the spring ring to operate in the system and thus to obtain a space saving as regards the width of the assembly.

Advantageously, the rotating bezel includes at least one bead or protrusion extending over an inner lateral face of the bezel, and the spring ring has, on an outer edge, at least one hollow in which the bezel protrusion is engaged. This means the spring ring can easily be rotatably connected to the rotating bezel, while facilitating the positioning of the spring ring in the bezel.

Advantageously, the toothed ring has, on an inner edge, at least one protrusion intended to be received in a hollow arranged in an external cylindrical surface of the case middle. This allows easy angular joining of the toothed ring to the case middle, while facilitating the positioning of the toothed ring on the case middle and allowing the rotating bezel system to be guided for assembly on the case middle.

According to a first example embodiment of the invention, the teeth of the toothed ring and the lugs of the spring ring each have an asymmetrical shape in the plane defined by the spring ring. In this first example embodiment, the spring ring can rotate with respect to the toothed ring in a single predefined direction: clockwise or anticlockwise depending on the shape chosen for the teeth. This first example embodiment of the invention thus corresponds to a unidirectional rotating bezel.

According to a second example embodiment of the invention, the teeth of the toothed ring and the spring ring lugs have a symmetrical shape in the plane defined by the spring ring. In this second example embodiment, the spring ring can rotate with respect to the toothed ring in one or other of the two directions: clockwise or anticlockwise. This second example embodiment of the invention thus corresponds to a two-directional rotating bezel.

Advantageously, the annular rotating bezel system consists of an independent module, said module being configured to be clipped onto the case middle. This provides a simple, practical means of mounting the rotating bezel system on the case middle, and also allows for easy disassembly. This makes it possible to simplify the method for manufacturing the watch case. The clip mounting system used forms a free hooking system.

To this end, the invention also concerns a watch case including the annular rotating bezel system described above, and which includes the features mentioned in the dependent claim17.

A particular embodiment of the watch case is defined in the dependent claim18.

To this end, the invention also concerns a watch including the watch case described above, and which includes the features mentioned in the dependent claim19.

