Protective ring for timepiece movement and timepiece movement comprising said protective ring

Abstract

The invention relates to an anti-magnetic and anti-shock protective ring (10) for a watch movement (20), intended to be fixed to a watch movement (20), said ring (10) comprising a tubular body extending between a first and a second axial end (11, 12) and being characterized in that it is made of a material having ferromagnetic properties and in that it is adapted to constitute, by the first axial end (11), a stop limiting the angular displacement around a radial axis of an oscillating mass (23) connected to the watch movement (20).

Description

Technical field of the invention

[0001] The invention relates to the field of watchmaking and more particularly concerns a watch movement comprising a circle for protecting a watch movement against magnetic fields and against possible impacts from an oscillating weight.

[0002] The present invention applies to any mechanical or electronic watch movement comprising an oscillating mass intended to provide mechanical power in order to supply energy to a driving member of a watch, more particularly to wind a mechanical watch movement or to supply electricity to an electronic circuit via a generator. Technological background

[0003] In order to protect the watch movement from disturbances caused by exposure to magnetic fields, there are a large number of solutions.

[0004] The most effective of these solutions consist in particular of inserting a watch movement into a box made of a ferromagnetic material.

[0005] However, this solution has the disadvantage of being relatively bulky and having a considerable impact on the mass of the watch, in addition to complicating its manufacture.

[0006] Furthermore, in order to protect watch movements against mechanical shocks, supports with a certain elasticity allowing the absorption of mechanical stresses have been developed. These supports are interposed between the watch movement and the case of the watches, so they have the same disadvantages as those mentioned above.

[0007] Furthermore, these solutions do not protect watch movements from possible impacts of the oscillating weight due to angular displacement generated during an impact on the watch.

[0008] It is clear here that there is no suitable solution to protect a watch movement from the effects of magnetic fields and mechanical shocks. Summary of the invention

[0009] The present invention aims to provide a solution for protecting the watch movement of a watch both from the effects of magnetic fields and from possible impacts of the oscillating weight caused by shocks on the watch by resolving the aforementioned drawbacks.

[0010] To this end, the invention relates to a watch movement comprising an antimagnetic and shockproof protection circle for a watch movement, intended to be fixed to a watch movement. The circle comprises a tubular-shaped body extending between a first and a second axial end and is made of a material having ferromagnetic properties. It is adapted to constitute, by the first axial end, a stop limiting the angular displacement around a radial axis of an oscillating weight connected to the watch movement. The terms "radial axis" designate an axis perpendicular to the axis of rotation of the oscillating weight.

[0011] Thanks to these characteristics, the circle protects the watch movement, both against possible impacts of the oscillating weight when it is subjected, following a shock to the watch, to an angular displacement around an axis perpendicular to its axis of rotation, and against the effects of magnetic fields.

[0012] The circle also has the effect of supporting the oscillating weight, in the event of an impact on the watch, in order to protect the elements allowing it to be fixed to the watch movement from possible deformation or breakage.

[0013] Furthermore, since the solution of the invention is constituted by a tubular-shaped circle, it has a very small footprint within the watch movement. Another advantage resulting from the use of a tubular-shaped circle lies in the fact that any impacts of the oscillating mass on the field of the circle are not or are barely visible to the naked eye due to the small transverse dimension of said field. The transverse dimension of said field constitutes the thickness of the body of the circle.

[0014] Furthermore, the circle is a single piece, so it can be easily and inexpensively manufactured. For example, the circle can be made by stamping operations followed by bending operations.

[0015] In particular embodiments, the invention may further comprise one or more of the following features, taken individually or in any technically possible combination.

[0016] In particular embodiments, the circle comprises an axial groove extending between the first and second axial ends of said circle, said axial groove separating two longitudinal ends of said circle.

[0017] In particular embodiments, the axial kerf extends from the first or second axial end to the other.

[0018] In particular embodiments, the axial kerf extends from the first or second axial end toward the other.

[0019] In particular embodiments, the axial groove extends from the second axial end to the first axial end, a bridge of material connecting the two longitudinal ends of the circle to each other at the first axial end.

[0020] In particular embodiments, the circle comprises fixing members extending from its second axial end, intended to be engaged in housings made in the watch movement, so as to fix the circle with said watch movement.

[0021] In particular embodiments, the circle has elastic properties and is configured so as to be in a mechanically constrained state when the fixing members are engaged in the housings, so that said fixing members respectively exert clamping forces against said housings.

[0022] In particular embodiments, each fixing member has a tongue shape, a first portion of which, called the "proximal portion", is oriented in an axial direction in a direction opposite to the first end of the circle and a second portion of which, called the "distal portion", connected to the proximal portion, extends in a radial plane of the circle and towards the outside of the latter.

[0023] In particular embodiments, a fixing member is arranged diametrically opposite the axial groove.

[0024] In particular embodiments, a fixing member is arranged at each of the longitudinal ends of the circle.

[0025] In particular embodiments, the circle comprises a chamfer at the junction between its first axial end and each of its longitudinal ends.

[0026] In particular embodiments, the circle comprises a fixing member in the form of a radial collar extending from the second end, intended to be arranged to bear against the watch movement.

[0027] The watch movement comprises a cage formed by a plate on which a set of bridges is fixed, and an oscillating mass which can rotate relative to said cage and extends radially beyond the set of bridges.

[0028] The watch movement further comprises a circle as previously described, configured to encircle the set of bridges and to extend axially towards the oscillating weight.

[0029] The present invention advantageously makes it possible to assemble the entire watch movement before introducing said watch movement into a caseband of a watch, thanks to the design of the circle which allows for contained dimensions of the latter.

[0030] The plate forms, by a surface called the “lower face”, a radial shoulder relative to the set of bridges, housings receiving the fixing members being made on said lower face.

[0031] In particular embodiments, the fixing members are welded to the housings, for example by laser.

[0032] In particular embodiments, the fixing members are glued to the housings.

[0033] In particular embodiments, the fixing members cooperate with the housings by elastic fitting. Brief description of the figures

[0034] Other characteristics and advantages of the invention will appear on reading the following detailed description given by way of non-limiting example, with reference to the appended drawings in which: there figure 1represents a perspective view of a preferred embodiment of a circle according to the present invention; figure 2 represents a perspective view of a watch movement comprising the circle of the figure 1 ; there figure 3 represents a side view of the clock movement of the figure 2 . Detailed description of the invention

[0035] There figure 1 represents an antimagnetic and antishock protection circle 10 for watch movement 20, according to a first aspect of the present invention.

[0036] The circle 10 is intended to be fixed against a watch movement 20, as shown in the Figures 2 and 3 , itself intended to be housed in an internal volume of a watch case middle (not shown).

[0037] The watch movement 20 comprises an oscillating mass 23 which can rotate and is adapted to supply energy to an organ of the watch movement 20, such as a barrel or a generator depending on whether the watch movement is of the mechanical type or the electronic type, in a manner known to those skilled in the art.

[0038] The circle 10 comprises a tubular-shaped body, extending axially between two ends, respectively called “first and second axial ends” 11 and 12 in the remainder of the text. The body of the circle 10 has an internal face 13 intended to be arranged opposite a cage of the watch movement 20. In the preferred embodiment of the invention shown in the figures, the body of the circle 10 has a substantially circular cross section.

[0039] More precisely, the cage of the watch movement 20 comprises, in a manner known per se to those skilled in the art, a plate 21 on which a set of bridges 22 is fixed. The circle 10 is, as shown in particular by the Figures 2 and 3 , configured so as to encircle the set of bridges 22 of the watch movement 20. In other words, the circle 10 is configured so that the internal face 13 of the body of the circle 10 is arranged opposite the periphery of the set of bridges 22.

[0040] It should be noted that the components of the watch movement 20 other than the cage and the oscillating weight 23 are not described in the present text insofar as they are well known to those skilled in the art and do not as such relate to the present invention.

[0041] The circle 10 is advantageously made of a material having ferromagnetic properties, so as to have high permeability to magnetic fields. Such a material may be made of soft iron. Thus, the circle 10 makes it possible to channel the magnetic field lines surrounding the watch movement 20, and therefore to provide it with protection against the effects of said magnetic fields.

[0042] As visible on the Figures 1 and 2 , the circle 10 may advantageously comprise, in the preferred embodiment of the invention, an axial groove 14, for example radially traversing, extending between the first and second axial ends 11 and 12 of said circle 10. The axial groove 14 separates two longitudinal ends of said circle 10 arranged opposite each other.

[0043] An advantage of the axial groove 14, when it is a through groove, as shown in the figures, is to allow the passage of an adjustment or winding stem 24, or of a push button or more generally of any other control member connected to the watch movement 20.

[0044] In the preferred example shown in the figures 1 to 3 , the axial groove 14 extends from one of the first and second axial ends 11 and 12 to the other. The axial groove 14 can therefore be axially traversing.

[0045] The axial groove 14, whether through or not, helps to give elastic properties to the circle 10. More particularly, the circle 10 can advantageously be elastically deformed so as to vary the distance separating the two longitudinal ends of the circle 10. Indeed, even if it is not through, the axial groove 14 constitutes a zone of weakness giving the circle 10 a certain mobility.

[0046] Such a characteristic helps in particular to facilitate the fixing of the circle 10 on the watch movement 20 as described in more detail below.

[0047] In an exemplary embodiment not shown in the figures, the axial groove 14 can only extend from the second axial end 12 towards the first axial end 11, a bridge of material connecting the two longitudinal ends of the circle 10 to each other at the level of the first axial end 11.

[0048] In this embodiment also, the axial groove 14 helps to give elastic properties to the circle 10.

[0049] In other embodiments of the invention, the circle 10 may comprise several axial grooves 14 distributed at a distance from one another or at a distance from one another.

[0050] When the circle 10 is fixed to the watch movement 20, its first axial end 11 is intended to rest opposite the oscillating mass 23 and its second axial end 12 is intended to rest opposite the plate 21, as illustrated in the Figures 2 and 3 .

[0051] More particularly, when it is fixed to the watch movement 20, the circle 10 is adapted to constitute, by its first axial end 11, a stop limiting the angular displacement of the oscillating mass 23 around an axis perpendicular to its axis of rotation, so that said oscillating mass 23 cannot come into contact with a bridge of the set of bridges 22 of the watch movement 20 and so as to protect from possible deformation or possible breakage, the elements allowing the fixing of said oscillating mass 23 to the watch movement 20.

[0052] In other words, the oscillating mass 23 is likely to impact the field of the circle 10.

[0053] Such a movement can be generated when the watch movement 20, and more particularly the watch which comprises it, is subjected to a shock, in particular a shock with a component in an axial direction.

[0054] Advantageously, the possible impacts of the oscillating mass 23 being made on the field of the circle, if they generate marks or scratches, these are not or are very little visible to the naked eye, insofar as said field has a relatively small transverse dimension, typically of the order of a few tenths of a millimeter.

[0055] The invention is suitable for watch movements comprising an oscillating mass 23 extending radially beyond the set of bridges 22, as illustrated in the Figures 1 and 2 . Indeed, as shown in the side view of the figure 2 , the oscillating mass 23 is then cantilevered opposite the circle 10, which can therefore act as a stop.

[0056] For this purpose, the circle 10 may be configured to extend axially beyond the bridge assembly 22, towards the oscillating mass 23, as shown in Figures 2 and 3 .

[0057] The circle 10 includes fixing members 15 allowing it to be mechanically linked without any degree of freedom with the watch movement 20.

[0058] As shown in the figure 1 , the fixing members 15 of the circle 10 extend from the second axial end 12. These fixing members 15 are intended to be engaged in housings 25 made in the watch movement 20, and in particular in the plate 21 of the latter, so as to fix the circle 10 and the watch movement 20 together.

[0059] In particular, in the preferred embodiment of the invention shown in the figures 1 to 3, each fixing member 15 has a tongue shape of which a first portion, called “proximal portion” 150, is oriented in an axial direction in a direction opposite to the first end 11 of the circle 10 and of which a second portion called “distal portion” 151, connected to the proximal portion 150, extends in a radial plane of the circle 10 and towards the outside of the latter.

[0060] Advantageously, the circle 10 is preferably configured so as to be in a stressed state when it is arranged around the watch movement 20 and each fixing member 15 is engaged in a housing 25. Thus, when it is arranged in this position, said circle 10 exerts clamping forces on the watch movement 20, which makes it possible to ensure that said circle 10 is held in position relative to the watch movement 20, and thus to considerably facilitate the fixing of the circle 10 on the watch movement 20. This technical effect is made possible thanks to the elastic property of the circle 10.

[0061] In particular, in the preferred embodiment of the invention, at least some of the distal portions 151 are adapted to exert clamping forces on the housing 25 in which they are intended to be engaged.

[0062] As shown in the figure 1, in the preferred embodiment of the invention, the circle 10 comprises three fixing members 15, one of which is arranged at each of the longitudinal ends of the circle 10, on either side of the axial groove 14, and one of which is arranged diametrically opposite said axial groove 14.

[0063] Thus, the fixing points of the circle 10 are distributed in a balanced manner around the watch movement 20.

[0064] Advantageously, as shown by the figure 2 in particular, the fixing members 15 are dimensioned so that the second end 12 of the circle 10 is arranged at a distance from the plate 21, so that the distal portions 151 of the fixing members 15 are ensured to be in abutment against the housings 25.

[0065] This arrangement makes it easier to attach the circle 10 to the watch movement 20.

[0066] The plate 21 has a face called the “lower face” 210 oriented towards the set of bridges 22, opposite a face called the “upper face”.

[0067] In the preferred embodiment of the invention, as shown in Figures 2 and 3 , the plate 21 of the watch movement 20 extends radially beyond the set of bridges 22 and forms, by a peripheral portion of its lower face 210, a radial shoulder relative to the set of bridges 22.

[0068] The housings 25 are made on this peripheral portion of the lower face 210 of the plate 21.

[0069] The distal portions 151 of the fixing members 15 are preferably welded, for example with a laser welding method, to the housings 25 in which they are engaged.

[0070] Alternatively, the distal portions 151 may be glued to the housings 25 or are assembled by press fit to said housings 25.

[0071] In other embodiments of the invention, the distal portions 151 may be fixed to the housings 25 by elastic fitting.

[0072] In still other embodiments of the invention, the distal portions 151 may comprise a through hole allowing the engagement of a screw intended to cooperate with a tapped hole that the housings 25 of the plate 21 comprise. In an alternative embodiment in which it does not comprise housings 25, the screws cooperate with tapped holes made directly on the lower face 210 of the plate 21 or at the bottom of counterbores intended to countersink the screw heads.

[0073] Alternatively, it is also conceivable that the distal portions 151 comprise a through hole allowing the engagement of a nail intended to be driven into the plate 21.

[0074] Furthermore, as visible on the figures 1 to 3, the circle 10 comprises a chamfer 16 at the junction between the first axial end 11 and each of its longitudinal ends. In other words, the chamfers 16 are each arranged opposite a fixing member 15.

[0075] This feature makes it possible to avoid any risk of the oscillating mass 23 hitting a sharp angle or an edge of the circle 10, which would be likely to harm the proper functioning of the watch movement 20.

[0076] It should be noted that, although in the embodiment shown in the figures 1 to 3,the circle 10 has a tubular shape of a cylinder of revolution, in other embodiments not shown in the figures, it may have other tubular shapes. For example, it may have a cross section of elliptical shape, polygonal shape or any other suitable shape corresponding to the shape of the circumference of the cross section of a set of bridges 22 of a watch movement 20 to be protected.

[0077] Furthermore, in other embodiments not shown in the figures, the fixing members 15 may conform to those described previously, with the difference that they extend towards the inside of the circle 10 and not towards the outside. Furthermore, in this embodiment, the fixing members 15 may cooperate with housings 25 of corresponding shape made in bridges 22 or in the plate 21.

[0078] In yet another embodiment of the invention, the fixing members 15 may be in the form of a relief, for example constituted by an annular boss oriented towards the inside of the circle 10 and extending between the longitudinal ends of the circle 10. The relief is then provided to cooperate with a groove made on the periphery of the set of bridges 22.

[0079] In yet another embodiment of the invention, the fixing members 15 may take the form of a radial collar extending from the second axial end 12 of the body of the circle 10, towards the outside of the circle 10, said fixing members 15 as well as the body of the circle 10 being intended to be fixed by tight fit between the watch movement 20 and the caseband.

[0080] Alternatively, the collar is fixed by gluing to the plate 21.

[0081] Whatever the embodiments of the fixing members 15, the plate 21 may include threads on its lower face 210 provided to receive fixing screws intended to fix the circle 10 against the watch movement 20. Alternatively, fixing flanges are also possible.

[0082] In other embodiments of the invention, the fixing members 15 of the circle 10 may be formed by lugs extending axially from the second axial end 12 of the circle body 10, said lugs being intended to be engaged in through holes made in the plate 21 so that their free end opens beyond said holes in order to be folded against the upper face of the plate 21.

[0083] In other embodiments of the invention, the body of the circle 10 comprises through holes respectively provided to receive pins or studs extending radially from the set of bridges 22 of the watch movement 20.

Claims

1. Horology movement (20) comprising a cage formed by a plate (21) onto which a bridge assembly (22) is fixed, said plate (21) forming a radial shoulder with respect to the bridge assembly (22) by a so-called "lower face" (210), the horology movement (20) also including an oscillating mass (23) which is rotatable with respect to said cage and extending radially beyond the bridge assembly (22), said horology movement (20) comprising a ring (10) made from a material having ferromagnetic properties and comprising a tubular body extending between a first and a second axial end (11, 12), said ring (10) being configured so as to encircle the bridge assembly (22) and to extend axially towards the oscillating mass (23), and being adapted to form, by the first axial end (11), a stop limiting the angular displacement, about a radial axis, of the oscillating mass (23), said ring (10) including fixing members (15) extending from its second axial end axial (12), engaged in housings (25) formed on the lower face (210) so as to fix the ring (10) with said horology movement (20).

2. Horology movement (20) according to claim 1, wherein the ring (10) includes an axial kerf (14) extending between the first and the second axial end (11, 12) of said ring (10), said axial kerf (14) separating two longitudinal ends of said ring (10).

3. Horology movement (20) according to claim 2, wherein the axial kerf (14) extends from one of the first or second axial ends (11, 12) to the other.

4. Horology movement (20) according to claim 2, wherein the axial kerf (14) extends from the second axial end (12) to the first axial end (11), a bridge of material connecting the two longitudinal ends of the ring (10) to one another at the first axial end (11).

5. Horology movement (20) according to any of claims 2 to 4, wherein the ring (10) has elastic properties and is configured to be in a mechanically constrained state when the fixing members (15) are engaged in the housings (25), so that said fixing members (15) exert clamping forces against said housings (25) respectively.

6. Horology movement (20) according to any of claims 1 to 5, wherein each fixing member (15) has the shape of a tongue, a first portion of which, referred to as the "proximal portion" (150), is oriented in an axial direction in a direction opposite the first end (11) of the ring (10) and a second portion of which, referred to as the "distal portion" (151), connected to the proximal portion (150), extends in a radial plane of the ring (10) and towards the exterior of the latter.

7. Horology movement (20) according to any of claims 2 to 4, wherein a fixing member (15) is arranged diametrically opposite the axial kerf (14).

8. Horology movement (20) according to any of claims 2 to 4, wherein a fixing member (15) is arranged at each of the longitudinal ends of the circle (10).

9. Horology movement (20) according to any of claims 2 to 4, wherein the ring (10) comprises a chamfer (16) at the junction between its first axial end (11) and each of its longitudinal ends.

10. Horology movement (20) according to any of claims 1 to 9, wherein the fixing members (15) are welded to the housings (25).

11. Horology movement (20) according to any of claims 1 to 9, wherein the fixing members (15) are bonded to the housings (25).

12. Horology movement (20) according to any of claims 1 to 9, wherein the fixing members (15) cooperate with the housings (25) by elastic interlocking.

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