Accessory with interchangeable element for a timepiece or a piece of jewellery

Abstract

The present invention relates to a control device (20) for a watch part (10) comprising a control rod (22) which is equipped with a removable crown (24), the control device (20) comprising a locking device (26) which, in the locked position, secures the crown (24) with the control rod (22) and, in the unlocked position, detaches the crown (24) from the control rod (22), characterized in that the crown (24) comprises a cap (28) and a main tubular body (30) which is fixed to the cap (28), in that the locking device (26) comprises an outer ring (36) which, in the locked position, axially locks the crown (24) on the control rod (22) and, in the unlocked position, releases the crown (24) from the control rod (22).

Description

Domaine technique de l'invention

[0001] The present invention relates to an accessory for a timepiece or a piece of jewelry.

[0002] The invention relates more particularly to an accessory comprising an interchangeable or removable element, in particular a control device comprising an interchangeable crown. Arrière-plan technique

[0003] Generally, a timepiece such as a wristwatch contains a watch movement housed in a case. To control the various functions of the movement, and possibly for setting the time or winding the movement, a winding stem is used. This winding stem is connected to an external gripping element called the crown, or winding crown, via a control stem.

[0004] Since the crown is visible on the outside of the case, it has an aesthetic appeal. Therefore, it is useful to be able to easily change the crown without having to change the entire winding or time-setting mechanism.

[0005] The solutions currently available are not always reliable. Moreover, in current designs, there is often significant play between the moving part, such as the crown, and the control stem, which gives the user a negative impression of the assembly quality and the reliability of the winding mechanism.

[0006] Furthermore, it is also useful for jewelry pieces to be able to easily change an element such as a cabochon or any other piece mounted at the end of a stem, as well as a clasp.

[0007] The invention aims to provide a new removable element solution, in particular a removable crown, which does not have the disadvantages of existing solutions.

[0008] A prior art control device for a watch part such as that disclosed in document CH714548A1 is known. A pin extraction tool described and illustrated in document FR935237A is also known. Summary of the invention

[0009] The invention provides an accessory for a watch or jewelry piece as defined by the attached claim 1.

[0010] Thanks to the invention, changing the removable element, for example a crown, is made easier while ensuring reliable mounting on the shaft, for example a control shaft. The locking mechanism is compact and can therefore be easily concealed within the body of the removable element. The locking and unlocking solution prevents accidental disassembly, which is reassuring for the user. According to other features of the invention: at least one elastic return element is mounted between the cap and the outer ring so as to axially stress the outer ring towards its locked position; the outer ring is axially retained towards its locked position by an external stop surface provided on the main tubular body; the locking element is a locking ball, the main tubular body is provided with at least one transverse opening in which the locking ball is received, and, in the locked position, a control surface of the outer ring transversely retains the locking ball in a complementary housing arranged on the stem and, in the unlocked position, the control surface is axially offset relative to the transverse opening to allow the locking ball to be removed from the housing;The removable element comprises an inner ring which is slidably mounted in the main tubular body between an axial retaining position in which it retains the locking ball in the transverse opening on the inner side, and a neutral axial position offset axially with respect to the transverse opening; at least one elastic return element is mounted between the cap and the inner ring so as to force the inner ring axially towards its retaining position; the housing for the locking ball is formed by an annular groove formed on the outer axial wall of the stem; the outer ring has on its inner side a receptacle adapted to receive a portion of the locking ball in the unlocked position; the receptacle is formed by an annular groove formed on the inner axial wall of the outer ring;The removable element comprises several locking balls regularly spaced angularly around the main axis, the main tubular body having a transverse opening for each locking ball; in the locked position, the outer ring occupies an axial position on the side of the rod and, in the unlocked position, the outer ring occupies an axial position on the side opposite the rod; the outer ring forms a push-button in the center of the removable element, on the side opposite the rod; the rod has a male splined section which is received in a female splined section of the main tubular body when the removable element is mounted on the rod, so that the two parts are rotationally linked; the cap has a guide shaft which is provided to be received in a complementary manner inside a bore, or barrel, arranged in the rod when the removable element is mounted on the rod;The accessory is a control device for a watch part; the stem is a control stem, and the removable element is a crown.

[0011] The invention also proposes a timepiece characterized in that it includes an accessory according to one of the preceding characteristics.

[0012] The invention further provides a tool for dismantling a removable element for an accessory according to one of the preceding characteristics, as defined by the attached claim 16. Brève description des figures

[0013] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for an understanding of which reference should be made to the attached drawings in which: [ Fig.1 ] - there figure 1 is an axial cross-sectional view that schematically represents a timepiece equipped with a control device comprising a control stem, a crown, and a device for locking the crown onto the control stem, according to a first embodiment; [ Fig.2 ] - there figure 2 is an exploded perspective view that represents the control device of the figure 1 ; Fig.3 ] - there figure 3 is an axial cross-sectional view that schematically represents the control device of the figure 1 when the locking device is in the locked position and the crown is mounted on the control rod; [ Fig.4 ] - there figure 4 is a view similar to that of the figure 3 which schematically represents the control device during crown disassembly, when its outer ring is in an unlocked position before the locking balls are retracted; [ Fig.5 ] - there figure 5 is a view similar to that of the figure 3 which schematically represents the control device during the dismantling of the crown, after the step shown on the figure 4 , when the inner ring begins to lock the locking balls in their unlocked position; [ Fig.6 ] - there figure 6 is a view similar to that of the figure 3 which schematically represents the control device in the unlocked position and which corresponds either to the end of disassembly or to the beginning of mounting the crown on the control rod; [ Fig.7 ] - there figure 7 is a view similar to that of the figure 3 which schematically represents the control device during crown assembly, in an intermediate position where the control rod begins to push back the inner ring of the locking device, before the locking balls are released; [ Fig.8 ] - there figure 8 is a view similar to that of the figure 3 which schematically represents the control device during crown mounting, in the final axial mounting position of the crown on the control rod, just before the locking balls move to their locking positions, just before complete locking; [ Fig.9 ] - there figure 9 is a view similar to that of the figure 1 which schematically represents a tool for dismantling the crown of the control device of the figure 1 in a position ready for unlocking; [ Fig.10 ] - there figure 10 is a view similar to that of the figure 9 which schematically represents the dismantling tool in the unlocked position allowing the crown to be removed; [ Fig.11 ] - there figure 11 is a view similar to that of the figure 3 which schematically represents a second embodiment of the control device according to the invention in the locked position; [ Fig.12 ] - there figure 12 is a view similar to that of the figure 11 which schematically represents the control device of the figure 11 when the outer ring is in the unlocked position, which corresponds to the position of the figure 4 for the first embodiment; [ Fig.13 ] - there figure 13 is a view similar to that of the figure 11 which schematically represents the control device of the figure 11 in the unlocked position, which corresponds to the position of the figure 5 for the first embodiment; [ Fig.14 ] - there figure 14 is a view similar to that of the figure 3 which schematically represents a third embodiment of the control device according to the invention in the locked position; [ Fig.15 ] - there figure 15 is a view similar to that of the figure 14 which schematically represents the control device of the figure 14 when the outer ring is in the unlocked position, which corresponds to the position of the figure 4 for the first embodiment; [ Fig.16 ] - there figure 16 is a view similar to that of the figure 14 which schematically represents the control device of the figure 14 in the unlocked position, which corresponds to the position of the figure 5 for the first embodiment; [ Fig.17 ] - there figure 17 is a schematic view which represents a piece of jewelry comprising an accessory equipped with a removable element according to a fourth embodiment of the invention. Description détaillée de l'invention

[0014] In the description that follows, identical, similar or analogous elements will be designated by the same reference numbers. Premier mode de réalisation

[0015] There figure 1 illustrates a timepiece 10 such as a wristwatch comprising a case 12 in which a timekeeping movement 14 is arranged. The timekeeping movement 14 is here provided with a winding stem 16, or time-setting stem, which extends along a principal axis A1, from left to right considering the figure 1 .

[0016] A control device 20 according to a first embodiment of the invention is mounted on the free end of the winding stem 16. This control device 20 comprises a control stem 22, which is for example screwed and glued onto the winding stem 16, and a crown 24 which is removably mounted on the free end of the control stem 22 by means of a locking device 26. The crown 24 is in this case in the form of a wheel with peripheral axial grooves.

[0017] The locking device 26 is configured here to allow, in the locked position, the crown 24 to be joined with the control rod 22 in translation and rotation and, in the unlocked position, to be separated from the control rod 22.

[0018] The control device 20 is now described in more detail in relation to the figures 2 And 3 where it was shown separated from the clockwork movement 14, in a locked position, with the main axis A1 vertical.

[0019] We will use, as a non-limiting example, an internal / external orientation along the principal axis A1, which corresponds to a bottom-to-top orientation, considering the figures 2 And 3 A part will be described as internal when it is arranged on the side of the clockwork movement 14 and will be described as external when it is arranged on the opposite side of the clockwork movement 14.

[0020] The crown 24 here comprises a cap 28, which forms the outer casing of the crown 24 visible to the user, and a main tubular body 30 which is fixed inside the cap 28 and is coaxial with the control rod 22. In the example shown, the cap 28 has an internal bore 32, and the main tubular body 30 is press-fitted into this internal bore 32. Alternatively, the main tubular body 30 could be screwed into the internal bore 32. The main tubular body 30 extends axially from the bottom of the internal bore 32 to the lower axial end of the cap 28.

[0021] The cap 28 also has an outer bore 34 with a diameter greater than the inner bore 32, thus defining an annular space in which an outer ring 36 belonging to the locking device 26 is slidably mounted. The outer ring 36 is here stressed in axial sliding downwards, i.e. towards the locked position, by a first elastic return element 38 which is interposed axially between the bottom of the outer bore 34 and an external bearing surface 40 provided on the outer ring 36.

[0022] In the locked position, the outer ring 36 is here in axial contact against an external stop surface 42 provided on the main tubular body 30.

[0023] According to the first embodiment, the locking device 26 comprises three identical locking balls 44 which form locking elements, each of which is received in a transverse opening 46 provided in the main tubular body 30 and which, in the locked position, axially lock the crown 24 on the control rod 22. The movement of each locking ball 44 from its locked position to its unlocked position is controlled by the axial movement of the outer ring 36, as will be seen later.

[0024] Advantageously, each transverse opening 46 has a round cross-section and a diameter substantially equal to the diameter of a locking ball 44. Indeed, each transverse opening 46 guides the corresponding locking ball 44 in transverse, or radial, movement with respect to the main axis A1, between a locked transverse position, on the side of the main axis A1, and an unlocked transverse position, on the side opposite the main axis A1.

[0025] Advantageously, the locking balls 44 and the corresponding transverse openings 46 are distributed circumferentially in a regular manner around the main axis A1, i.e. here every 120 degrees.

[0026] In the locked transverse position, each locking ball 44 is partially received in a complementary housing 48 formed on the control rod 22. Each housing 48 has a substantially semi-circular transverse profile so as to conform to the shape of the corresponding locking ball 44. According to the embodiment shown, the housing 48 is formed by a continuous peripheral annular groove, with a semi-circular cross-section, which is formed on the periphery of the outer axial wall of the control rod 22. Alternatively, there could be as many housings 44 as there are locking balls 44; each housing 48 would then consist of a hemispherical recess intended to be positioned opposite the corresponding transverse opening 46.

[0027] According to the embodiment shown, the outer ring 36 has a control surface 50 which, in the locked position, transversely retains each locking ball 44 in its housing 48. The control surface 50 is here constituted by an annular axial surface which is arranged at the external axial end 52 of the outer ring 36.

[0028] The outer ring 36 also includes, in its inner axial wall, a receptacle 54 adapted to receive a portion of each locking ball 44 in the unlocked position. The receptacle 54 is here formed by a continuous annular groove with a rectangular cross-section. Alternatively, there could be as many receptacles 54 as there are locking balls 44.

[0029] The receptacle 54 is axially offset relative to the control surface 50 so that, in the locked position, the control surface 50 is opposite the transverse openings 46 and, in the unlocked position, the receptacle is opposite the transverse openings 46.

[0030] According to the first embodiment, the crown 24 comprises an inner ring 56 which is slidably mounted in the external axial section 58 of the main tubular body 30. The inner ring 56 is configured to slide between a neutral position, which is shown on the figure 3 , where the inner ring 56 is axially offset upwards, relative to the transverse openings 46, and a retaining position, which is shown on the figure 6 , in which an external axial surface 60 of the inner ring 56 is located opposite the transverse openings 46 so as to retain the locking balls 44 on the inner side.

[0031] The inner ring 56 is stressed in axial sliding downwards, i.e. towards its retention position, by a second elastic return element 62 which is interposed axially between the bottom of the inner bore 32 and a bearing surface on the inner ring 56.

[0032] Advantageously, the inner ring 56 is axially retained in its retention position by a shoulder 66 arranged on the inner axial surface of the main tubular body 30.

[0033] Advantageously, the cap 28 includes a generally cylindrical guide shaft 68 with a circular cross-section which is provided to be received in a complementary manner inside a bore, or barrel 70, arranged in the outer end section of the control rod 22 when the crown 24 is mounted on the control rod 22. The guide shaft 68 extends here from the bottom of the inner bore 32 to an axial insertion end 72 which is axially offset downwards relative to the lower axial end of the cap 28 so as to prevent any transverse pivoting of the crown 24 relative to the control rod 22 during the mounting and dismounting of the crown 24 relative to the control rod 22.

[0034] Advantageously, the control rod 22 has a male grooved section 74 which cooperates with a female grooved section 76 of the main tubular body 30, when the crown 24 is locked onto the control rod 22, to link the crown 24 and the control rod 22 in rotation.

[0035] According to the embodiment shown, the housing 48 and the male grooved section 74 are arranged on an external end section 78 of the control rod 22 whose overall diameter is greater than the diameter of the main section 80 of the control rod 22.

[0036] Advantageously, sealing elements such as O-rings 82 are arranged on the main section 80 of the control rod 22 to ensure dust and water tightness with respect to the housing 12.

[0037] We now describe an operation for dismantling the crown 24 relative to the control rod 22 using the locking device 26 according to the first embodiment, based on the figures 3 à 6 .

[0038] From the locked position which is represented on the figure 3 , the user exerts an upward axial pressure against the outer ring 36, and more specifically against its internal axial end surface 84 which is flush with the internal axial end of the main tubular body 30 and the cap 28.

[0039] By sliding upwards, the outer ring 36 reaches its unlocked position, illustrated by the figure 4 , in which the locking balls 44 are no longer held in their housing 48 by the control surface 50 since the latter is offset upwards.

[0040] From the unlocked position of the figure 4 The user can pull the cap 28 upwards, which causes the locking balls 44 to move towards their receptacle 54 and the crown 24 to detach from the control rod 22, as illustrated by the figures 5 And 6 .

[0041] Throughout the removal of the crown 24, it remains axially guided by the sliding of the guide shaft 68 in the barrel 70, until the guide shaft 68 is completely out of the barrel 70.

[0042] During the removal of the crown 24, the inner ring 56 slides simultaneously downwards, pushed by the second elastic return element 62, remaining in contact with the external axial end surface 64 of the control rod 22. This allows the inner ring 56 to replace the housing 48 as a transverse retaining element, on the inner side, for the locking balls 44.

[0043] We now describe an operation for mounting the crown 24 onto the control rod 22 using the locking device 26 according to the first embodiment, based on the figures 6 à 8 and on the figure 3 .

[0044] There figure 6 Figure 24 represents the crown 24 above the control rod 22, in an initial position ready for assembly, with the guide shaft 68 partially inserted into the barrel 70. Note that, after the crown 24 is removed, the elements of the locking device 26 remain in the configuration shown in Figure 26. figure 6 , the inner ring 56 being supported against the shoulder 66 of the main tubular body and the locking balls 44 being held transversely, on one side by the outer axial surface 60 of the inner ring 56 and on the other side by the outer ring 36. It is also noted that, the blocking of the locking balls 44 here causes the axial blocking of the outer ring 36 in its axial unlocking position.

[0045] Starting from the initial position of the figure 6 The user fits the crown 24 into the control rod 22 by inserting the guide shaft 68 into the barrel 70 until the intermediate position illustrated by the figure 7 , which is identical to the figure 5 in which the inner ring 56 bears axially against the control rod 22.

[0046] By maintaining downward pressure on the crown 24, the user causes the inner ring 56 to move axially towards the bottom of the inner bore 32, against the restoring force of the second elastic return element 62, until the locking balls 44 are released, as illustrated by the figure 8 , in which the housing 48 is aligned transversely with the transverse openings 46.

[0047] In this position of release of the locking balls 44, the restoring force of the first elastic return element 38 axially forces the outer ring 36 downwards, i.e., towards the locked position. By moving downwards, the control surface 50 pushes the locking balls 44 back into their housing 48, which allows the outer ring 36 to reach its locked position, which corresponds to the position of the figure 3 To facilitate the removal of the crown 24, a removal tool 86 is provided. According to the embodiment shown in the figures 9 et 10 , the dismantling tool 86 comprises an axial body 88 equipped at a free end with a radial plate 90 having an axial return 92 oriented to the right, considering the figures, i.e. towards the dismantling tool 86.

[0048] The axial return 92 has a bearing surface which allows the required axial pressure to be exerted against the outer ring 36, from the locked position shown in the figure 3 to reach the unlocking position shown on the figure 4 .

[0049] Advantageously, in order to facilitate the handling of the dismantling tool 86 and limit the risks of misuse, the dismantling tool 86 is equipped with a control element 94 which allows the axial movement of a support finger 96 to be controlled against the external axial end of the ring 24 in order to allow support on the ring 24 and to exert the required pressure on the outer ring 36 without having to pull axially on the ring 24.

[0050] The control member 94 allows the support finger 96 to slide relative to the axial body 88, against a third elastic return element 98.

[0051] To perform the disassembly, the user begins by positioning the crown 24 in its extreme axial position of retraction, towards the right, considering the figure 9 This generally corresponds to the axial position of the winding stem 16 for setting the time. This then allows the radial plate 90 to be placed between the case 12 and the crown 24, until the axial return 92 is axially aligned with the outer ring 36. From this position, which is illustrated by the figure 9 The user presses the control element 94 so that the support finger 96 comes into axial contact with the crown 24. By continuing to press the control element 94, since the support finger 96 is axially blocked by the crown 24, the user causes a relative displacement of the axial return 92 to the right, i.e., to the side opposite the housing 12, which allows the axial return 92 to push the outer ring 36 to its unlocked position, as illustrated by the figure 10 .

[0052] From the figure 10 Therefore, the user simply needs to maintain pressure on the control element 94 and move the dismantling tool 86 to the right to remove the crown 24 from the control rod 22.

[0053] Note that the disassembly tool 86 allows the crown 24 to be retained in the axial body 88 after disassembly. Furthermore, it allows for the gentle extraction of the crown 24, limiting the risk of excessive traction on the crown 24 and the control stem 22, which could damage components of the timepiece 10, such as the winding stem 16.

[0054] Of course, the dismantling tool 86 could take other suitable forms, for example, be without the control element 94. The following description describes other embodiments of the control device 20 according to the invention. To this end, we will focus primarily on describing the technical elements that distinguish these embodiments from the first embodiment, without describing all the common parts again. Elements identical or similar to those of the first embodiment will be designated by the same reference numerals. Deuxième mode de réalisation

[0055] In the second embodiment, which is illustrated by the figures 11 à 13 The outer ring 36 is mounted in a reversed manner compared to the first embodiment. Indeed, instead of being mounted to slide in the lower face, or inner face, of the cap 28, it is mounted to slide in the upper face, or outer face, of the cap 28.

[0056] The outer ring 36 is here generally in the form of a substantially cylindrical push button, which is mounted to slide in an axial opening 100 made in the outer face of the cap 28. The outer ring 36 terminates at its external axial end with a cabochon 102 which closes the crown 24 at the axial opening 100.

[0057] The outer ring 36 has an external annular portion 104 designed to bear axially upwards against a shoulder surface of the cap 28 in the locked position. The outer ring 36 is subjected to an upward axial load by the first elastic return element 38, which is interposed axially between the external annular portion 104 and an internal transverse portion 106 belonging to the main tubular body 30.

[0058] In this second embodiment, the main tubular body 30 is fixed to the cap 28 by fitting the internal transverse portion 106 into the external bore 34 of the cap 28. In addition, the guide shaft 68 is fixed to the main tubular body 30 by means of a tubular portion 108, here made in one piece with the guide shaft 68, which is press-fitted onto the external axial end section of the main tubular body 30. Thus, the internal bore 32 is arranged in said tubular portion 108.

[0059] The general operation of the locking device 26 according to the second embodiment remains similar to that of the first embodiment.

[0060] Starting from the locked position illustrated by the figure 11 The user applies axial pressure to the cabochon 102 as if it were a button until the outer ring 36 is placed in the unlocked position shown on the figure 12 This allows the locking balls 44 to be released and retract into the receptacle 54, as illustrated by the figure 13 , thus allowing the crown 24 to be removed from the control rod 22.

[0061] Note that this locking device 26 makes it possible to do without a dismantling tool.

[0062] The crown 24 is then mounted in the reverse order, by placing the crown 24 onto the control rod 22 by axial translation from top to bottom, considering the figure 13 . Troisième mode de réalisation

[0063] The third embodiment, which is illustrated by the figures 14 à 16 This embodiment is very similar to the first one. Indeed, the outer ring 36 must be moved axially upwards, as in the first embodiment, to unlock it. However, instead of being accessible only from below the cap 28 as in the first embodiment, the outer ring 36 is accessible here directly through the diameter of the crown 24.

[0064] In this third embodiment, the outer ring 36 is arranged on the periphery of the cap 28 and effectively forms the outer part of the cap 28. Thus, the outer ring 36 is no longer arranged in an external bore. The outer ring 36 is still mounted to slide on the main tubular body 30. It also includes a first additional splined section 110 at its external axial end, which cooperates with a second additional splined section 112 arranged on the peripheral edge of the cap 28 to ensure the rotational connection of the two parts.

[0065] In the third embodiment, the main tubular body 30 is still press-fitted into the inner bore 32 formed in the cap 28. The external abutment surface 42 of the main tubular body 30 has a larger diameter than in the first embodiment, since it has the same outer diameter as the outer ring 36. This external abutment surface 42 is arranged on a portion that forms a plate 114 designed to support the entire internal axial end of the outer ring 36 in the locked position, as illustrated by the figure 14 This plate 114 here forms the internal axial end of the ring 24.

[0066] The outer axial wall 116 of the outer ring 36 forms the gripping portion of the crown 24, allowing the user to rotate the crown 24 to wind the watch movement or set the time. This outer axial wall 116 can therefore be fluted or knurled like the cap 28 of the first embodiment. This outer axial wall 116 of the outer ring 36 has a peripheral groove 118 that facilitates the user's grip in the direction of an upward pull for unlocking.

[0067] The general operating principle of the third embodiment remains substantially the same as that of the first and second embodiments.

[0068] Starting from the locked position illustrated by the figure 14 The user pulls the outer ring 36 upwards, causing it to move axially relative to the main tubular body 36 and the cap 28, which remain fixed. When the outer ring 36 reaches its axial unlocking position, illustrated by the figure 15 The locking balls 44 are no longer held in their housing 48. Simply pulling the crown 24 upwards causes the locking balls 44 to move laterally outwards, allowing the crown 24 to be removed from the control rod 22, as illustrated by the figure 16 .

[0069] In the three embodiments shown, each of the two elastic return elements 38, 62 consists of a helical compression spring. Alternatively, each helical compression spring could be replaced by several helical compression springs of smaller diameters, which would be evenly distributed around the periphery of the locking device 26 and received in suitable housings. Fourth mode of implementation

[0070] According to a fourth embodiment, which is illustrated by the figure 17 , the watch part is replaced by a piece of jewelry 210 which is equipped with an accessory 220 having a removable element 224 mounted at the end of a rod 222 equivalent to the control rod 22 of the first embodiments.

[0071] The jewelry item 210 could be, for example, a bracelet, a necklace, a ring, an earring, or a cufflink. The accessory 220 could be, for example, a bracelet link, a clasp, or a decorative element of the jewelry item 210.

[0072] In the description of this fourth embodiment, by convention, the elements of the jewelry piece 210 that are equivalent to elements of the watch piece 10 mentioned in reference to the first three embodiments will be designated by three-digit references beginning with the digit "2".

[0073] The removable element 224 and the stem 222 are arranged here in a similar manner to the first embodiment. The main difference lies in the compactness afforded by the fact that it is not necessary to provide a rotational connection between the stem 222 and the removable element 224, particularly its cap 228. Indeed, the removable element 224 does not constitute a winding crown and is not designed for rotational drive. The removable element 224 can serve as a fastening element on a clasp or cufflink, for example. It can rotate freely relative to the stem 222, insofar as the locking device 226 prevents translational movement on the stem 22.

[0074] The locking device 226 therefore includes here an outer locking ring 236 as in the first embodiment.

[0075] The cap 228 also includes a main tubular body 230 on which the outer ring 236 is slidably mounted to form the locking device 226.

[0076] The operation of the locking device 226 according to the fourth embodiment is identical to the operation described with reference to the first embodiment.

[0077] Of course, the jewelry piece 210 could also be equipped with an arrangement according to the second or third embodiment, with different variations in the shape of the cap 228 and in the shape of the removable element 224, without departing from the scope of the invention.

[0078] List of references: 10: watch part 12: case 14: watch movement 16: winding stem 20: control device 22: control stem 24: crown 26: locking device 28: cap 30: main tubular body 32: inner bore 34: outer bore 36: outer ring 38: first elastic return element 40: external bearing surface 42: external stop surface 44: locking balls 46: transverse openings 48: housing 50: control surface 52: external axial end 54: receptacle 56: inner ring 58: external axial section 60: outer axial surface 62: second elastic return element 64: external axial end surface 66: shoulder 68: guide shaft 70: barrel 72: end Axial insertion 74: Male splined section 76: Female splined section 78: External end section 80: Main section 82: O-rings 84: Internal axial end surface 86: Disassembly tool 88: Axial body 90: Radial insert 92: Axial return 9496: control element; 98: support finger; 100: third elastic return element; 102: axial opening; 104: cabochon; 106: external annular portion; 108: internal transverse portion; 110: tubular portion; 112: first additional grooved section; 114: second additional grooved section; 116: plate; 118: external axial wall; 210: peripheral groove; 220: jewelry piece; 222: accessory; 224: stem; 226: removable element; 228: locking device; 230: cap; 236: main tubular body; 236: outer ring; A1: main axis

Claims

1. Accessory (20, 220) for a timepiece (10) or a piece of jewellery (210) comprising a stem (22, 222) which extends along a main axis (A1) and which is equipped with a removable element (24, 224), the accessory (20, 220) comprising a locking device (26, 226) enabling, in the locked position, the removable element (24, 224) to be secured to the stem (22, 222) at least in translation and, in the unlocked position, the removable element (24, 224) to be released from the stem (22, 222), the removable element (24, 224) comprising a cap (28, 228) and a main tubular body (30, 230) which is fixed to the cap (28, 228), the locking device (26, 226) comprising an outer ring (36, 236) slidable axially relative to the main tubular body (30, 230), between a locked position in which the outer ring (36, 236) controls at least one locking element (44) so as to axially block the removable element (24, 224) on the stem (22, 222) and an unlocked position in which the outer ring (36, 236) controls the locking element (44) so as to release the removable element (24, 224) relative to the stem (22, 222), the accessory being characterised in that at least one elastic return element (38) is mounted between the cap (28) and the outer ring (36) so as to urge the outer ring (36) axially towards its locked position.

2. Accessory (20) according to the preceding claim, characterised in that the outer ring (36) is retained axially towards its locked position by an external abutment surface (42) provided on the main tubular body (30).

3. Accessory (20) according to any one of the preceding claims, characterised in that the locking element is a locking ball (44), in that the main tubular body (30) is provided with at least one transverse opening (46) in which the locking ball (44) is received, and in that, in the locked position, a control surface (50) of the outer ring (36) transversely retains the locking ball (44) in a complementary housing (48) provided on the stem (22) and, in the unlocked position, the control surface (50) is axially offset relative to the transverse opening (46) to allow the withdrawal of the locking ball (44) from the housing (48).

4. Accessory (20) according to the preceding claim, characterised in that the removable element (24) comprises an inner ring (56) which is slidably mounted in the main tubular body (30) between an axial retaining position in which it retains the locking ball (44) in the transverse opening (46) on the inner side, and a neutral axial position offset axially relative to the transverse opening (46).

5. Accessory (20) according to the preceding claim, characterised in that at least one elastic return element (62) is mounted between the cap (28) and the inner ring (56) so as to urge the inner ring (56) axially towards its retaining position.

6. Accessory (20) according to any one of claims 3 to 5, characterised in that the housing (48) for the locking ball (44) is constituted by an annular groove provided on the external axial wall of the stem (22).

7. Accessory (20) according to any one of claims 3 to 6, characterised in that the outer ring (36) comprises on the inner side a receptacle (54) suitable for receiving a portion of the locking ball (44) in the unlocked position.

8. Accessory (20) according to the preceding claim, characterised in that the receptacle (54) is constituted by an annular groove provided on the inner axial wall of the outer ring (36).

9. Accessory (20) according to any one of claims 3 to 8, characterised in that the removable element (24) comprises a plurality of locking balls (44) distributed angularly in a regular manner around the main axis (A1), the main tubular body (30) comprising a transverse opening (46) for each locking ball (44).

10. Accessory (20) according to any one of the preceding claims, characterised in that, in the locked position, the outer ring (36) occupies an axial position situated on the side of the stem (22) and, in the unlocked position, the outer ring (36) occupies an axial position situated on the side opposite the stem (22).

11. Accessory (20) according to any one of claims 1 to 9, characterised in that the outer ring (36) forms a push- button at the centre of the removable element (24), on the side opposite the stem (22).

12. Accessory (20) according to any one of the preceding claims, characterised in that the stem (22) comprises a male splined portion (74) which is received in a female splined portion (76) of the main tubular body (30) when the removable element (24) is mounted on the stem (22), so that the two parts are linked in rotation.

13. Accessory (20) according to any one of the preceding claims, characterised in that the cap (28) comprises a guide shaft (68) which is intended to be received in a complementary manner inside a bore, or barrel (70), provided in the stem (22) when the removable element (24) is mounted on the stem (22).

14. Accessory (20) according to any one of the preceding claims, characterised in that the accessory is a control device (20) for a timepiece (10), in that the stem (22) is a control stem (22), and in that the removable element is a crown (24).

15. Timepiece (10) characterised in that it comprises an accessory (20) according to any one of the preceding claims.

16. Removal tool (86) for a removable element (24, 224) for an accessory (20) according to claim 10, comprising an axial body (88) which is provided at one free end with a radial plate (90), the radial plate (90) comprising an axial return (92) suitable for coming into axial abutment against a portion of the outer ring (36) with a view to controlling it from its locked position towards its unlocked position, the tool being characterized in that it comprises a control member (94) movable axially relative to the axial body (88) between a rest position and a removal position in which a support finger (96) integral with the control member (94) comes into abutment against the cap (28).

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