Patent Publication Number: US-11385597-B2

Title: Annular rotating bezel system comprising a spring ring

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to European Patent Application No. 18162851.2 filed on Mar. 20, 2018, the entire disclosure of which is hereby incorporated herein by reference. 
     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 concerns a watch including the watch case. The watch is, for example, a diver&#39;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, an annular holding ring, 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 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, elastic arms intended to cooperate with the toothed ring are arranged on an inner edge of the spring ring, by cutting the latter. The toothed ring and the spring ring are held axially by the rotating bezel and the annular holding ring. The spring ring is angularly joined to the rotating bezel, and the toothed ring is angularly joined to the case middle. However, in a rotating bezel system of this type, the spring ring has limited flexibility in the plane that it defines. This means that sufficient width must be provided in the system to ensure enough clear space radially for deformation of the spring ring, and therefore requires a significant amount of space. Further, the manufacture of such a spring ring is relatively complex, because of the cutting operation to form the elastic arms. 
     SUMMARY OF THE INVENTION 
     It is thus an object of the invention to provide an annular rotating bezel system that increases the flexibility of the spring ring in its plane, but which is simple to manufacture, and overcomes the aforementioned drawbacks of the state of the art. 
     To this end, the invention concerns an annular rotating bezel system, which includes the features mentioned in the independent claim  1 . 
     Specific embodiments of the system are defined in the dependent claims  2  to  12 . 
     A first advantage of the present invention is that it increases the flexibility of the spring ring in its plane. Indeed, owing to the thinned portions contained therein, the spring ring flexes in its plane, allowing the teeth 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. 
     Further, such an arrangement is simple to manufacture, compact in diameter, and makes it possible to obtain precisely controlled dimensions for the spring ring and the toothed ring. Moreover, such a configuration of the spring ring does not require tongues or strips to be added to the ring, since the spring ring is formed of a single piece of material. 
     Finally, this arrangement allows a material to be chosen for the toothed ring independently of the material used for the rotating bezel. This makes it possible, for example, to make bezels from precious material with no risk of premature wear since the toothed ring is not integrated in the bezel but is simply secured to said bezel. 
     Advantageously, the rotating bezel includes at least one lug 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 lug 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 lug 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 embodiment of the invention, the teeth of the toothed ring and the or each tooth of the spring ring have an asymmetrical shape in the plane defined by the spring ring. In this first 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 embodiment of the invention thus corresponds to a unidirectional rotating bezel. 
     According to a second embodiment of the invention, the teeth of the toothed ring and the tooth or each tooth of the spring ring have a symmetrical shape in the plane defined by the spring ring. In this second 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 embodiment of the invention thus corresponds to a two-directional rotating bezel. 
     Advantageously, the annular rotating bezel system consists of on 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 easy disassembly. This makes it possible to further 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 claim  13 . 
     A particular embodiment of the watch case is defined in the dependent claim  14 . 
     To this end, the invention also concerns a watch including the watch case described above, and which includes the features mentioned in the dependent claim  15 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects, advantages and features of the annular rotating bezel system according to the invention will appear more clearly in the following description, based on at least one non-limiting embodiment illustrated by the drawings, in which: 
         FIG. 1  is an exploded perspective view of the annular rotating bezel system according to the invention; 
         FIG. 2  is a top view of the annular rotating bezel system of  FIG. 1 , once assembled; 
         FIG. 3  is a sectional view of the system of  FIG. 2 , taken along a sectional plane III-III. 
         FIG. 4  is a bottom view of the annular rotating bezel system of  FIG. 1 , according to a first embodiment of the invention; and 
         FIG. 5  is a bottom view of the annular rotating bezel system of  FIG. 1 , according to a second embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  represents a watch  1  provided with a watch case  2 . Watch case  2  typically includes a case middle  4 . Watch case  2  also includes an annular rotating bezel system  6  and a timepiece movement that extends in a plane, the timepiece movement being omitted from the Figures for reasons of clarity. The annular rotating bezel system  6  is rotatably mounted on case middle  4 . Preferably, as illustrated in  FIGS. 1 to 5 , annular rotating bezel system  6  consists of an independent module. Annular rotating bezel system  6  is, for example, clipped onto case middle  4 , as will be detailed hereinafter. 
     As illustrated in  FIG. 1 , case middle  4  is of annular shape. Case middle  4  includes an external cylindrical surface  8 . As seen in  FIG. 3 , external cylindrical surface  8  is provided with a peripheral shoulder defined by a lateral wall  12   a  and a base  12   b . This peripheral shoulder serves as a housing for rotating bezel system  6 . Lateral wall  12   a  includes an annular protrusion or bulge  13  extending over the entire perimeter of lateral wall  12   a  and allowing rotating bezel system  6  to be secured by clipping onto case middle  4 . Annular rotating bezel system  6  rests on base  12   b . Rotating bezel system  6  is thus mounted on case middle  4 , from the top of the latter, thereby blocking system  6  in an axial direction perpendicular to the plane of the timepiece movement, while allowing rotation of the bezel around case middle  4 . In the watch case  2  taken as an example in  FIGS. 1 to 5 , the configuration of the watch case is substantially circular. However, the invention is not limited to this watch case configuration, or to the other arrangements described above for case middle  4 . The case middle may be made of metal, typically steel, titanium, gold, platinum or ceramic, typically made from alumina, zirconia or silicon nitride. 
     Annular rotating bezel system  6  includes a rotating bezel  14 , an annular holding ring  16 , a toothed ring  18  and a spring ring  20 . Preferably, system  6  further includes a decorative ring  22  press fitted onto rotating bezel  14 . Decorative ring  22  bears, for example, graduations, typically diving graduations in the case of a diver&#39;s watch  1 . Decorative ring  22  is for example made of ceramic. 
     Rotating bezel  14  is of annular shape and includes an upper surface  23   a  visible to the user and a lower surface  23   b . As illustrated in  FIGS. 1  and  3 , rotating bezel  14  is, for example, provided with an annular rim  24  on an inner edge. Annular rim  24  engages by clipping together with protrusion  13  of case middle  4 , and forms therewith a free hooking system. Rotating bezel  14  is, for example, made of metal but could be made of any other material, for example, of ceramic. 
     Annular ring  16  holds toothed ring  18  and spring ring  20  in bezel  14 , in an axial direction perpendicular to the plane of the timepiece movement. This facilitates the mounting of rotating bezel  14  on case middle  4 . Preferably, and as seen in  FIG. 3 , annular ring  16  is pressed into rotating bezel  14 , securing it thereto. In a variant not represented in the Figures, annular ring  16  is secured to case middle  4 . 
     Annular ring  16  rests on base  12   b  of case middle  4 , and thus surrounds external cylindrical surface  8  of case middle  4 . Annular ring  16  is configured to cooperate with external cylindrical surface  8  to allow rotation of rotating bezel  14  on case middle  4 . Annular holding ring  16  is, for example, a flat ring. 
     According to a particular variant illustrated in  FIG. 1 , annular ring  16  includes means  26  for guiding rotating bezel  14  in rotation around case middle  4  and means  28  configured to brake the rotation of rotating bezel  14  around case middle  4  and to dampen sound. In this variant illustrated in  FIG. 1 , annular ring  16  is, for example, formed of a single piece of material consisting of a plastic material, especially PTFE, ethylene tetrafluoroethylene (Tefzel®), and polyoxymethylene (Delrin®), where necessary coated with a layer intended to improve the friction coefficient. Annular ring  16  is, for example, of generally rectangular cross-section. 
     Preferably, as represented in  FIG. 1 , annular ring  16  includes, on an inner edge, an alternation of tongues  30   a  of a first group of tongues, and tongues  30   b  of a second group of tongues. Tongues  30   a  of the first group and tongues  30   b  of the second group are in contact with external cylindrical surface  8  of case middle  4 . Such tongues  30   a ,  30   b  limit the passage of dirt into rotating bezel system  6 . In the variant not represented in the Figures, wherein annular ring  16  is integral with case middle  4 , tongues  30   a  of the first group and tongues  30   b  of the second group are arranged on an external edge of annular ring  16  and are in contact with an inner surface of rotating bezel  14 . 
     In the example embodiment of  FIG. 1 , the first and second groups of tongues each include six tongues  30   a ,  30   b , distributed over the inner edge of ring  16  over 360°. The tongues of the same group of tongues are thus spaced apart from each other by 60°, tongues  30   a ,  30   b  of the first and second groups of tongues being alternated. 
     Tongues  30   a  of the first group and tongues  30   b  of the second group have different dimensions in the radial direction. In the example embodiment of  FIG. 1 , tongues  30   a  of the first group of tongues have smaller dimensions in the radial direction than those of tongues  30   b  of the second group of tongues, and form rotational guiding means  26 . 
     Tongues  30   b  of the second group of tongues form braking and sound dampening means  28 . More precisely, tongues  30   b  of the second group of tongues are formed of more flexible segments than tongues  30   a  of the first group. These segments are able to bend in an axial direction perpendicular to the plane of the timepiece movement. To achieve this, a specific example embodiment represented in  FIG. 1  consists in that tongues  30   a  of the first group and tongues  30   b  of the second group have different thicknesses, the thickness being measured in the axial direction perpendicular to the plane of the timepiece movement. Typically, tongues  30   b  of the second group have a smaller thickness than that of tongues  30   a  of the first group, thereby giving them greater flexibility. Due to the axial flexibility of tongues  30   b  of the second group, said tongues can brake the rotation of rotating bezel  14  about case middle  4  by friction against external cylindrical surface  8 , and also dampen the sound produced. 
     Braking the rotation of bezel  14  via means  28  has the advantage of smoothing the different plays inside the system so that the user of the bezel does not feel them, and of controlling the rotational torque of the bezel by softening it. Further, braking and sound dampening means  28  reduce the noise produced by rotation of the bezel and thus improve user experience. 
     Preferably, tongues  30   a ,  30   b  of the first and second groups are separated from each other by hollows  32 . This improves, in particular, the flexibility of tongues  30   b  of the second group of tongues. 
     Preferably too, as seen in  FIG. 1 , tongues  30   a ,  30   b  of the first and second groups of tongues extend angularly over a substantially equal angular sector. 
     Evidently, in other variants of the invention, the annular holding ring may comprise a single annular ring of rectangular cross-section over its entire circumference pressed into bezel  14 . 
     Toothed ring  18  includes several teeth, for example 120 teeth, also distributed over 360° on its external edge. Preferably, toothed ring  18  also has, on its inner edge, at least one lug  34  received in a hollow  36  provided in external cylindrical surface  8  of case middle  4 . In the example embodiments illustrated in  FIGS. 1 to 5 , toothed ring  18  includes three lugs  34  distributed over 360° and spaced apart from each other by 120°. External cylindrical surface  8  of case middle  4  has three corresponding hollows  36 . This system of lugs  34 /hollows  36  allows easy angular joining of toothed ring  18  to case middle  4 , while facilitating the positioning of toothed ring  18  on case middle  4 . This system also allows rotating bezel system  6  to be guided for mounting on case middle  4 . Thus, pressing from the top of system  6  causes lugs  34  to engage in hollows  36 , locking the elements inside system  6  and clipping system  6  onto case middle  4 . 
     Toothed ring  18  is formed of a single piece of material. Toothed ring  18  is formed, for example, of a metal alloy, especially a cobalt based alloy (40% Co, 20% Cr, 16% Ni and 7% Mo) commercially known as phynox or steel, typically a stainless steel such as 316L steel. In a variant, toothed ring  18  may be formed of a thermoplastic material, particularly a thermostable, semi-crystalline thermoplastic material, such as, for example polyarylamide (Ixef®), polyetheretherketone (PEEK) or made of a ceramic material such as zirconia or alumina. 
     As visible in  FIGS. 4 and 5 , toothed ring  18  is arranged to be inserted into spring ring  20 , i.e. toothed ring  18  is sized to be able to be placed inside spring ring  20 . Toothed ring  18  and spring ring  20  are concentric and coplanar and are held between lower face  23   b  of bezel  14  and an upper face of holding ring  16 . 
     Spring ring  20  engages elastically with toothed ring  18 . More specifically, spring ring  20  comprises at least one thinned portion  38  having at least one tooth  40  elastically and radially in mesh with toothed ring  18 . In the example embodiments illustrated in  FIGS. 1 to 5 , spring ring  20  comprises three thinned portions  38  distributed over 360°, each thinned portion  38  having one tooth  40  arranged in a median part of thinned portion  38 . The three thinned portions  38  are spaced apart by 120° from each other. Spring ring  20  extends in a plane in which it is capable of deforming elastically along one radius. Thinned portions  38  are arranged to increase the flexibility of spring ring  20  in its plane. This configuration means that, when toothed ring  18  is inserted inside spring ring  20 , teeth  40  cooperate with the teeth of toothed ring  18 . In this configuration, each tooth  40  is in contact with the toothed ring so that there is a rest position in which each tooth  40  is in a hollow between two teeth of toothed ring  18 . When the user takes hold of bezel  14  and rotates it, the flexibility of spring ring  2 ′ provided by thinned portions  38 , causes spring ring  20  to deform elastically in its plane, allowing teeth  40  to be released from the hollows of toothed ring  18  and to re-engage in an adjacent tooth of toothed ring  18 . Bezel  14  then actually rotates by a corresponding angular sector into a new position. 
     Preferably, as illustrated in  FIGS. 1, 4 and 5 , thinned portions  38  are thinned radially. 
     Again preferably, spring ring  20  has on its outer edge at least one hollow  42  in which a lug  44  of bezel  14  is engaged to join these two elements in rotation. In the example embodiments illustrated in  FIGS. 1  to  5 , toothed ring  20  includes three hollows  42  distributed over 360° and spaced apart from each other by 120° and rotating bezel  14  has three corresponding lugs  44  on an inner lateral face. Hollows  42  are arranged in portions  46  of spring ring  20  that are thicker than thinned portions  38  in median parts of these portions  46 . Thus, teeth  40  and hollows  42  are alternated on spring ring  20 , regularly distributed over 360°. This system of lugs  44 /hollows  42  makes it easy to rotatably connect spring ring  20  to rotating bezel  14 , while facilitating the positioning of spring ring  20  in bezel  14 . 
     Spring ring  20  is formed of a single piece of material. Spring ring  20  is, for example, formed of a metal alloy having good spring properties, i.e. which deforms elastically easily while being able to deform significantly without undergoing Plastic deformation, especially Phynox® or amorphous metal alloys. Of course, spring ring  20  can also, in a variant, be made from a synthetic material. 
     A first embodiment of the invention will now be described with reference to  FIG. 4 . According to this first embodiment, the teeth of toothed ring  18  and teeth  40  of spring ring  20  have an asymmetrical shape in the plane defined by spring ring  20 . The asymmetrical shape is, for example, a ‘wolf tooth’ shape, i.e. the teeth are substantially right triangle-shaped. In the meshed position of the teeth, the hypotenuse of the triangle formed by each tooth  40  of the spring ring extends along the hypotenuse of the triangle formed by one of the teeth of toothed ring  18 . 
     Teeth  40 , each arranged in a median part of a thinned portion  38 , are regularly distributed over 360°. Thus, in the example illustrated in  FIG. 4 , in which spring ring  20  has three teeth  40 , teeth  40  are spaced apart by 120° from each other. 
     In this first embodiment, spring ring  20  can rotate relative to toothed ring  18  in a single predefined direction: clockwise or anticlockwise depending on the shape chosen for the teeth. This first embodiment of the invention thus corresponds to a unidirectional rotating bezel  14 . 
     A second embodiment of the invention will now be described with reference to  FIG. 5 . According to this second embodiment, the teeth of toothed ring  18  and teeth  40  of spring ring  20  have a symmetrical shape in the plane defined by spring ring  20 . The symmetrical shape is, for example, an isosceles triangle or equilateral triangle. 
     In this second embodiment, spring ring  20  can rotate relative to toothed ring  18  in one or other of the two directions: clockwise or anticlockwise. This second embodiment of the invention thus corresponds to a two-directional rotating bezel  14 . 
     Preferably, according to this second embodiment, spring ring  20  includes three thinned portions  38  regularly distributed over 360°. Each thinned portion  38  carries one tooth  40 . 
     The preceding description of the annular rotating bezel system was given with reference to a toothed ring angularly joined to the case middle, and a spring ring angularly joined to the rotating bezel. However, those skilled in the art will understand that the reverse configuration is possible without departing from the scope of the present invention, i.e. the toothed ring may be angularly joined to the rotating bezel, and the spring ring angularly joined to the case middle.