Annular rotating bezel system comprising at least one elastic arm

Abstract

An annular rotating bezel system intended to be rotatably mounted on a middle part of a watch case inside which is housed a timepiece movement which extends in a plane, including a rotating bezel, an annular holding ring, a toothed ring, and at least one elastic arm of which a free end is elastically and radially meshed with the toothed ring, said toothed ring and said at least one elastic arm being held in an axial direction perpendicular to the plane of the movement in the bezel by the annular holding ring, either the toothed ring or the elastic arm being arranged to be angularly joined to the rotating bezel, and other being arranged to be angularly joined to the case middle; wherein the elastic arm is formed of a flat strip-spring mounted in a cantilever arrangement in the system.

Claims

1. An annular rotating bezel system intended to be rotatably mounted on a middle part of a watch case inside which is housed a timepiece movement which extends in a plane, comprising: a rotating bezel; an annular holding ring; a toothed ring; and at least one elastic arm of which a free end is elastically and radially meshed with the toothed ring, wherein said toothed ring and said at least one elastic arm are held in an axial direction perpendicular to the plane of the movement in the bezel by the annular holding ring, wherein either the toothed ring or the elastic arm being arranged to be angularly joined to the rotating bezel, and other being arranged to be angularly joined to the case middle, wherein the elastic arm is formed of a flat strip-spring mounted in a cantilever arrangement in the system, and wherein the elastic arm has, on a face located on an opposite side to the toothed ring, a boss, said boss resting against an inner lateral face of the bezel.

2. The annular rotating bezel system according to claim 1, wherein the rotating bezel comprises at least one lug extending over an inner lateral surface of the bezel, and wherein the elastic arm has, on the side of its other end on a surface located on the opposite side to the toothed ring, a hollow wherein the lug of the bezel is engaged, to allow a rotating connection between the elastic arm and the rotating bezel.

3. The annular rotating bezel system according to claim 1, wherein the elastic arm has an arched shape whose centre of curvature is located inside the bezel.

4. The annular rotating bezel system according to claim 3, wherein the free end of the elastic arm has a curved shape towards the centre of the bezel.

5. The annular rotating bezel system according to claim 1, wherein the flat strip-spring is formed of a single piece of material comprising a crystalline or amorphous metal alloy.

6. The annular rotating bezel system according to claim 1, wherein the flat strip-spring is fabricated by a LIGA process.

7. The annular rotating bezel system according to claim 1, wherein the system comprises three elastic arms distributed over 360°, the three elastic arms being spaced apart from each other by 120°.

8. The annular rotating bezel system according to claim 1, wherein the toothed ring has, on an inner edge, at least one lug intended to be received in a hollow provided in an external cylindrical surface of the case middle, to allow angular joining of the toothed ring to the case middle.

9. The annular rotating bezel system according to claim 1, wherein said system is formed of an independent module, said module being configured to be clipped onto the case middle.

10. A watch case comprising: a case middle; and a system provided with an annular rotating bezel rotatably mounted on the case middle, wherein the annular rotating bezel system includes a rotating bezel, an annular holding ring, a toothed ring, and at least one elastic arm of which a free end is elastically and radially meshed with the toothed ring, wherein said toothed ring and said at least one elastic arm are held in an axial direction perpendicular to the plane of the movement in the bezel by the annular holding ring, either the toothed ring or the elastic arm being arranged to be angularly joined to the rotating bezel, and other being arranged to be angularly joined to the case middle, wherein the elastic arm is formed of a flat strip-spring mounted in a cantilever arrangement in the system, and wherein the elastic arm has, on a face located on an opposite side to the toothed ring, a boss, said boss resting against an inner lateral face of the bezel.

11. The watch case according to claim 10, wherein the rotating bezel system includes an independent module configured to be clipped onto the case middle, wherein the case middle includes an external cylindrical surface provided with a peripheral shoulder, the peripheral shoulder including, on a lateral face, an annular protrusion, and wherein the rotating bezel is provided on an inner edge with an annular rim, said annular rim cooperating with said annular protrusion in a clip mount and forming a free hooking system.

12. The watch case according to claim 10, wherein the toothed ring is angularly joined to the case middle, and the other end of the elastic arm is angularly joined to the rotating bezel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) 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:

(2) FIG. 1 is an exploded perspective view of an annular rotating bezel system according to a first embodiment of the invention, comprising three elastic arms;

(3) FIG. 2 is a perspective view of one of the elastic arms of the annular rotating bezel system of FIG. 1;

(4) FIG. 3 is a bottom view of the annular rotating bezel system of FIG. 1; and

(5) FIG. 4 is a bottom view of an annular rotating bezel system according to a second embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(6) 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, 3 and 4, 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.

(7) 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. 1, external cylindrical surface 8 is provided with a peripheral shoulder defined by a lateral wall 12a and a base 12b. This peripheral shoulder serves as a housing for rotating bezel system 6. Lateral wall 12a includes an annular protrusion or bulge 13 extending over the entire perimeter of lateral wall 12a and allowing rotating bezel system 6 to be hooked onto case middle 4 in a clip mount. Annular rotating bezel system 6 rests on base 12b. 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, 3 and 4, 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.

(8) Annular rotating bezel system 6 includes a rotating bezel 14, an annular holding ring 16, a toothed ring 18 and at least one elastic arm 20. A first embodiment of the invention is represented in FIGS. 1 to 3. In this first embodiment, annular rotating bezel system 6 includes three elastic arms 20 distributed over 360°, the three elastic arms 20 being spaced apart from each other by 120°.

(9) 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's watch 1. Decorative ring 22 is for example made of ceramic.

(10) Rotating bezel 14 is of annular shape and includes an upper surface 23a visible to the user and a lower surface 23b. As illustrated in FIG. 1, rotating bezel 14 is, for example, provided with an annular rim 24 on an inner edge. Annular rim 24 engages in a clip fit 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.

(11) Annular ring 16 holds toothed ring 18 and elastic arms 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, 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.

(12) Annular ring 16 rests on base 12b 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.

(13) 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 rectangular cross-section.

(14) Preferably, as represented in FIG. 1, annular ring 16 includes, on an inner edge, an alternation of tongues 30a of a first group of tongues, and tongues 30b of a second group of tongues. Tongues 30a of the first group and tongues 30b of the second group are in contact with external cylindrical surface 8 of case middle 4. Such tongues 30a, 30b limit the passage 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 30a of the first group and tongues 30b 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.

(15) In the example embodiment of FIG. 1, the first and second groups of tongues each include six tongues 30a, 30b, distributed over the inner edge of ring 16 over 360°. The tongues of the same group of tongues are thus spaced apart by 60° two-by-two, tongues 30a, 30b of the first and second groups of tongues being alternated.

(16) Tongues 30a of the first group and tongues 30b of the second group have different dimensions in the radial direction. In the example embodiment of FIG. 1, tongues 30a of the first group of tongues have smaller dimensions in the radial direction than those of tongues 30b of the second group of tongues, and form rotational guiding means 26.

(17) Tongues 30b of the second group of tongues form braking and sound dampening means 28. More precisely, tongues 30b of the second group of tongues are formed of more flexible segments than tongues 30a 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 30a of the first group and tongues 30b 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 30b of the second group have a smaller thickness than that of tongues 30a of the first group, thereby giving them greater flexibility. Due to the axial flexibility of tongues 30b 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.

(18) 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.

(19) Preferably, tongues 30a, 30b of the first and second groups are separated from each other by hollows 32. This improves, in particular, the flexibility of tongues 30b of the second group of tongues.

(20) Preferably too, as seen in FIG. 1, tongues 30a, 30b of the first and second groups of tongues extend angularly over a substantially equal angular sector.

(21) 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.

(22) 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, 3 and 4, toothed ring 18 includes three lugs 34 distributed over 360° and spaced apart 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 felicitating 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.

(23) 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 heat-stable, semi-crystalline thermoplastic material, such as, for example polyarylamide (Ixef®), polyetheretherketone (PEEK) or made of a ceramic material such as zirconia or alumina.

(24) Each elastic arm 20 has a fixed end 37 and a radially and elastically free end 38 in mesh with toothed ring 18. Each elastic arm 20 is formed of a flat strip-spring, flat strip springs 20 extending around toothed ring 18, in substantially the same plane as the plane defined by said ring. Flat strip-springs 20 are arranged such that a longitudinal face of each flat strip-spring 20 extends opposite each toothed ring 18. Each flat strip-spring 20 is mounted in a cantilever arrangement in annular rotating bezel system 6. To achieve this, according to a particular example embodiment illustrated in FIGS. 1 to 3, the fixed end 37 of each elastic arm 20 is angularly joined to rotating bezel 14, while the opposite free end 38 takes the form of a beak 38a forming a tooth cooperating with the toothing of toothed ring 18. More precisely, each elastic arm 20 has, on the side of its fixed end 37 on a face located on the side opposite to toothed ring 18, a hollow 40 in which a lug 42 of bezel 14 is engaged. In the example embodiment illustrated in FIG. 3, rotating bezel 14 includes, on an inner lateral face, three lugs 42 distributed over 360° and spaced apart from each other by 120°. This system of lugs 42/hollows 40 allows elastic arms 20 to be easily rotatably connected to rotating bezel 14, while facilitating the positioning of arms 20 in bezel 14.

(25) In this configuration, flat strip-springs 20 are mounted to be flexible in a cantilevered arrangement in annular rotating bezel system 6.

(26) Preferably, and as seen in FIGS. 1 to 3, each elastic arm 20 has, on a face located on the side opposite to toothed ring 18, a boss 44. Each boss 44 rests against an inner lateral face of bezel 14. The spring is arranged to bend between its free end in mesh with the tooth and the boss. The location of this boss thus determines the desired return force of the spring. This boss is arranged on the spring in this example, but could also, according to a variant (not represented), be arranged on the bezel.

(27) Again preferably, each elastic arm 20 has an arched shape whose centre of curvature is located inside bezel 14. Further, the free end 38 of each elastic arm 20 is preferably bent towards the centre of rotating bezel 14 terminating in beak 38a. In other words, the free end 38 of each elastic arm 20 has an accentuated curvature compared to the rest of arm 20, i.e. the radius of curvature of free end 38 is smaller than the radius of curvature of the rest of arm 20.

(28) In this manner, the free ends 38 of elastic arms 20 cooperate elastically via beak 38a with toothed ring 18. In this configuration, each free end 38 of an arm 20 is in contact with the toothed ring so that there is a rest position in which the beak 38a of each free arm 38 is in a hollow between two teeth of toothed ring 18. When the user takes hold of bezel 14 and imparts thereto a rotational torque higher than a certain spring torque determined by elastic arms 20, elastic arms 20 deform and move radially closer to rotating bezel 14, allowing beaks 38a of free ends 38 of arms 20 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. This movement is possible in only one predefined direction: clockwise or anticlockwise, depending on the orientation of elastic arms 20 relative to toothed ring 18. The bezel in this system according to the invention is thus a unidirectional bezel. The direction of rotation of the bezel can, however, be changed by changing the orientation of elastic arms 20 relative to toothed ring 18.

(29) Each flat strip-spring 20 is formed of a single piece of material. Each flat strip-spring 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, each flat strip-spring 20 can also, in a variant, be made from a synthetic material.

(30) According to a particular example embodiment, each flat strip-spring 20 is fabricated by a LIGA-process (from the German Röntgenlithographie, Galvanoformung, Abformung).

(31) A second embodiment of the invention will now be described with reference to FIG. 4. According to this second embodiment, annular rotating bezel system 6 has only one elastic arm 20. The features of elastic arm 20 illustrated in FIG. 4 are identical to the features of the other arms 20 illustrated in FIGS. 1 to 3 and described with reference to the first embodiment of the invention. Of course, variants with more than three elastic arms preferably also arranged at the periphery of the bezel may also be envisaged.

(32) The preceding description of the annular rotating bezel system was given with reference to a toothed ring angularly integral with the case middle, and to elastic arms angularly integral with 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 integral with the rotating bezel, and the or each elastic arm angularly integral with the case middle.