Watch strap interchangeability mechanism

Abstract

The present invention relates to a fastening mechanism for fastening an interchangeable strap (1) to a case (2), characterised in that it comprises a fastening device (3) respectively comprising a fixed assembly (30) defining insertion housings (314) arranged on either side of a central recess (36), the insertion housings (314) being suitable for receiving the lateral ends of a transverse pin (11) for fastening the strap (1), and a slidably movable element (33) provided with a covering cap (333) that can be longitudinally actuated in translation between a first, closed position (P1) in which said transverse pin (11) is locked in the insertion housings (314) and a second, open position (P2) in which the transverse fastening pin (11) can be respectively inserted into or released from said insertion housings (314).

Description

[0001] WATCH STRAP INTERCHANGEABILITY MECHANISM

[0002] Technical field of the invention

[0003] The present invention relates to the field of watchmaking and jewelry. More specifically, the invention relates to a fastening mechanism for interchangeable bracelets.

[0004] State of the art

[0005] Usually, watch straps, especially leather ones, are connected to the case of a watch by means of elastic bars inserted transversely at the end of a strand and which engage in holes made inside fixing lugs often fitted directly on the caseband. Thus, when you want to change the strap, it is necessary to use a specific tool to push the ends of the bar inwards and release the strand, which is relatively inconvenient and therefore often requires the use of a professional.

[0006] For this reason, solutions have long been sought to facilitate the assembly and disassembly of the bracelet, so that the user can change it himself whenever he wishes, being able to vary the dimensions, the material, and for example the color of the bracelet.

[0007] Patent FR2766587 describes such a solution for changing a strap without tools, where an actuating finger is provided to counteract the return force holding the bar in place in the fixing housings of the caseband. In addition to the relatively unattractive aesthetic appearance conferred, this solution also has the disadvantage of inadvertently exposing a protruding part to a catch causing the release of the bar and thus the unlocking of the strap, causing the watch to fall and potentially damaging it. Patent FR2738123 describes another solution allowing a user to easily change the strap themselves without having to resort to the use of any tool, according to which a cylindrical pin is inserted transversely into a hollow cylinder closed laterally by a shutter.A disadvantage of this solution is that it requires a sequence of complex and delicate manipulations, on the one hand, and on the other hand the integration of the attachment device is relatively bulky and potentially prominent under the bottom of the case, which can be relatively uncomfortable to use.

[0008] We also know of bracelet attachment systems operating by elastic deformation or clipping of jaws arranged at the ends of a bracelet and which grip around a bar secured to the case; these attachment methods are, however, essentially only suitable for bracelets made of plastic materials which are subject to creep during use and whose durability is therefore particularly limited.

[0009] Document FR2732866 also describes an adjustable link incorporated into the rest of the bracelet, and connected in an articulated manner to the other links conventionally via bars.

[0010] An object of the proposed invention is to provide an exemplary solution to these known drawbacks.

[0011] Summary of the invention

[0012] In particular, an aim of the present invention is to provide a new solution for a bracelet interchangeability mechanism, the actuation of which for both the insertion of a new bracelet and the removal of the bracelet currently worn is more intuitive and more efficient.

[0013] Another object of the present invention is to provide a solution that can be easily integrated into a housing without having any negative impact on wearing comfort.These aims are achieved according to the invention thanks to the characteristics of the main claims, and in particular thanks to a fixing mechanism for an interchangeable bracelet to a case, characterized in that it comprises an attachment device secured to the case respectively comprising a fixed assembly defining insertion housings arranged on either side of a central recess, which are adapted to receive the lateral ends of a transverse pin for integrally fixed fixing of the bracelet, and a sliding movable element provided with a covering cap that can be actuated longitudinally in translation between a first closed position in which the pin is locked in the insertion housings, and a second open position in which the pin can be respectively inserted or released from the insertion housings.

[0014] Thus, a fastening mechanism of simplified construction is proposed, and whose compactness is also improved. Furthermore, the aesthetics of the fastening mechanism is not affected since the parts used for fastening the bracelet are completely hidden in the closed position of the fastening device.

[0015] According to a preferred embodiment, the fixing mechanism for an interchangeable bracelet according to the invention is characterized in that the sliding movable element can be actuated via a ribbed gripping tab.

[0016] An advantage of such an arrangement is to simplify the construction of the attachment device, on the one hand, by simply combining an actuating member with a locking (or respectively unlocking) member. Preferably, this gripping tab is arranged transversely, that is to say parallel to the pin, in order to maximize the available contact surface. Such an arrangement also makes it easier to actuate the sliding movable element which makes it possible to insert and remove the transverse pin for fixing the bracelet, and to improve its reliability, based on the principle that only the gripping tab is supposed to be able to act on the sliding movable element. According to another preferred embodiment, the attachment mechanism for an interchangeable bracelet according to the invention is characterized in that an actuating finger interacting with an elastic return element is also arranged on the sliding movable element.

[0017] In this way, the construction of the attachment device is further simplified.

[0018] According to yet another preferred embodiment, the fixing mechanism for interchangeable bracelet, the gripping tab, the covering cover, as well as the actuating finger are arranged in a single piece on the sliding movable element.

[0019] The advantage of such an embodiment is that it simplifies to the extreme the machining of the sliding movable element used as a locking and respectively unlocking member combined with an actuating member. In this way, several parts intended to have different functionalities can be produced simultaneously.

[0020] According to an even more preferred embodiment, the sliding movable element furthermore has a peripheral collar, and the fixed assembly is formed from a first part and a second part provided with an internal shoulder arranged to cover the peripheral collar of the sliding movable element when the first part and the second part are assembled together to form the fixed assembly.

[0021] In this way, not only the machining of the parts, but also the assembly of such a conferred fastening device is simplified to the extreme.

[0022] According to a particularly advantageous embodiment for the fixing mechanism for an interchangeable bracelet according to the invention, the covering cap has an inclined or curved end part.

[0023] Such a configuration makes it easier to insert the bracelet pin, for example by using one hand and without having to open the cover at the same time with the other. In fact, the downwardly inclined surface allows the pin to come to bear against the cover, then to push the latter backwards by pulling the pin downwards towards its housing. In this way, the bracelet can be attached simply and particularly intuitively.

[0024] According to a particularly preferred embodiment for the fixing mechanism for an interchangeable bracelet according to the invention, an elastic return element is arranged transversely in an insertion channel of a first part of the fixed assembly, and the elastic return element is arranged to exert a return force in the longitudinal direction when the covering cap is moved from the first closed position to said second open position under the impulse of the actuating finger.

[0025] Such a configuration of the return element allows for greater compactness in the thickness and longitudinal direction compared to conventional springs.

[0026] According to an even more preferred embodiment for the fixing mechanism for interchangeable bracelet according to the invention, the elastic return element is made of Nitinol.

[0027] Such a highly unusual choice of material for the return element - Nitinol is known for its shape memory properties, not its elastic properties and is used for this type of properties in the field of watchmaking - allows for increased reliability in relation to the return forces exerted, as well as durability.

[0028] According to an even more preferred embodiment for implementing the fixing mechanism for an interchangeable bracelet according to the invention, a clearance zone is provided at the rear of the insertion channel to allow deformation of the elastic return element.

[0029] This configuration allows a particularly simple integration of the elastic return element, for example in the base of the first part of the fixed element, without requiring an additional guide element when it is deformed; the clearance zone thus consists simply of a sort of slight bulge at the level of the central part of the insertion gutter for the elastic return element.

[0030] According to an even more preferred embodiment for implementing the invention according to this variant of the fixing mechanism for an interchangeable bracelet according to the invention, the depth of the clearance zone determines a maximum movement stroke for the covering cap.

[0031] In this way, the displacement level of the hood, as well as the exerted restoring force which depends on the deformation level of the restoring element, can be configured in a particularly simple manner, without having to act on the hood directly.

[0032] According to another preferred embodiment for the fixing mechanism for an interchangeable bracelet according to the invention, the sliding mobile element has a “U” shape defining a recess arranged to accommodate a central projection of one end of a strand of a bracelet.

[0033] In this way, both a gain in compactness is conferred by guaranteeing an assembly without gap between the central protruding part of the end of the bracelet when it is inserted into the central recess of the attachment device, but the aesthetics are also improved thanks to the correspondence of the shapes which makes it possible to produce a hinge in a particularly harmonious manner in the center of the attachment device.

[0034] The present invention also relates to a watch case comprising a fixing mechanism for an interchangeable strap according to one of the preceding claims, characterized in that the attachment device is provided with a notch matching the external shape of the case and a projection covered by an upper peripheral edge of a bottom of the case.

[0035] According to this preferred embodiment for the integration of the attachment device into the caseband, a first advantage is aesthetic because the attachment device appears to be fully integrated into the caseband. A second advantage is to allow a gain in terms of thickness since the proximal part of the attachment device at the level of its attachment to the caseband is covered by an edge of the bottom, thus generating no additional thickness below the latter.

[0036] According to another preferred embodiment for implementing the present invention, the watch case comprising a fastening mechanism for an interchangeable strap is characterized in that a gripping tab is provided for actuating said sliding element of the fastening device, the gripping tab being arranged on the bottom side of the case and comprising a first part inclined or curved towards the outside of the case, and a second part inclined or curved towards the inside of said case.

[0037] This configuration has several advantages, the first being aesthetic due to the fact that the tongue is hidden under the case and therefore the mechanism for locking and unlocking the bracelet to the case is hidden from the outside when the wristwatch is worn. Then, the fact that the tongue is arranged under the case more easily avoids any involuntary actuation of the tongue by catching on a projecting external element, the tongue remaining pressed inwards towards the user's wrist. Finally, the particular shape of the tongue with two distinct functional parts makes it possible on the one hand to optimize the quality of the grip when the user acts against the restoring force, thanks to the presence of an at least partially inclined stop surface, and on the other hand to follow the curvature of the wrist and minimize the risk of pinching by following the curvature on the wrist on its terminal part.This improves both ergonomics and transmission efficiency in terms of actuation.

[0038] According to yet another preferred embodiment, the watch case comprising a fastening mechanism for an interchangeable bracelet according to the invention is characterized in that the bracelet attachment device forms attachment horns for the end of the bracelet. Thanks to such a configuration, the attachment device gives the illusion of being totally integrated into the case like horns generally formed in one piece with the caseband, and therefore the proposed solution is similar to a conventional solution for fastening a bracelet using elastic bars inserted into lateral through holes of the horns, whereas the pins according to the invention are here fixed and thus prevent any method of fastening via a telescopic extension in the transverse direction.

[0039] Other preferred embodiments will also be detailed in the following description.

[0040] It will be understood from the remainder of this detailed description that the advantageous characteristics derived from the preferred embodiments may be taken in isolation or in combination, except when these are presented as mutually exclusive.

[0041] Brief description of the drawings

[0042] Other advantageous characteristics will emerge more clearly from the following description of particular embodiments of the invention given by way of non-limiting example and represented by the appended drawings, in which:

[0043] - Figure 1 is a three-dimensional view of the end of an interchangeable bracelet used in the context of the present invention;

[0044] - Figures 2A and 2B show two perspective views of a fastening device according to a preferred embodiment for the present invention, shown respectively in the closed position and in the open position;

[0045] - Figures 3A and 3B show two exploded perspective views of the attachment device according to the preferred embodiment of Figures 2A and 2B, respectively from above and below in order to highlight the different parts which compose it and the way in which they are assembled to each other; - Figure 4 shows a bottom view of a wristwatch provided with an attachment mechanism for an interchangeable bracelet according to another preferred embodiment for the invention;

[0046] - Figure 5 shows a sagittal sectional view along axis AA of Figure 4, corresponding to the longitudinal axis of the middle of the wristwatch, illustrating a gripping tab which is particularly advantageous for implementing the present invention, as well as a preferred method of assembling a back with respect to the attachment device.

[0047] Detailed description

[0048] Figure 1 illustrates an example of an interchangeable bracelet 1 used in the context of the present invention, or more precisely the attachment end of such an interchangeable bracelet 1 for a steel bracelet.

[0049] The last link 12 of the bracelet has an “H” shape bearing the image of the applicant, and it is connected in an articulated manner to a central projection 10 forming a prominent part between its two lateral edges. In order to connect this central projection 10 also in an articulated manner to the case 2 (not shown in this figure but visible in particular in figures 4 and 5), a transverse pin 11 is inserted at the front end of the central projection 10, in order to be connected to a fixing element of the case. The lateral ends of the transverse pin 11 are referenced respectively 11A and 11B, corresponding to a first end and a second lateral fixing end.

[0050] According to the invention, and unlike the usual solutions for fixing an interchangeable bracelet 1 , the proposed fixing mechanism is essentially integrated into a fastening device 3 secured to the case 2, illustrated in the following figures, and not at the end of the interchangeable bracelet strand 1 , as is usually the case. Here, the fixing end of the interchangeable bracelet 1 is simplified as much as possible because it does not contain a movable locking element such as a bar or any sliding shutter which could be actuated by the user. Such a refined structure is advantageous for minimizing the thickness of the bracelet and thus improving wearing comfort; moreover, it makes it possible to reduce the manufacturing costs of wear parts, thanks to the reduction in the quantity of material required.This consideration is particularly valid for the production of interchangeable leather bracelets 1 according to a variant not illustrated, for which the production of large telescopic bars for fixing requires a substantial thickness of leather around the bar, which is necessarily larger than a simple fixed transverse pin since it involves the arrangement of a cylindrical part fitted into another cylinder.

[0051] In Figures 2A and 2B which follow, a fastening device 3 will be described according to a preferred embodiment for the present invention, shown respectively in a first closed position P1 in which the transverse pin 11 is held captive in housings, and a second open position P2 in which it can be extracted therefrom. As explained previously, the transverse fixing pin 11 is here entirely fixed, and movable elements are only arranged on this fastening device 3.Figures 2A and 2B will be described substantially jointly because they show substantially the same fixing elements, illustrated simply in the locking and respectively unlocking position for the transverse pin 11 corresponding respectively to the first position P1 and the second position P2; for reasons of readability, all the elements referenced in Figure 2A will not be repeated in Figure 2B, and vice versa.

[0052] In Figure 2A, it can be seen that the attachment device 3 has a central recess 36 which is intended to house the central projection 10 of the interchangeable bracelet 1 when they are mutually assembled to each other. On the sides of this central recess 36 are arranged lateral insertion housings 314 for the transverse pin 11, and more precisely a first lateral insertion housing 314A for housing the first end 11A of the transverse pin 11 and a second lateral insertion housing 314B for housing the second end 11B of the transverse fixing pin 11. These lateral insertion housings 314 have a rectangular cross-section shape for reasons of simplifying machining, but could have other shapes adapted to leave only one degree of freedom in rotation with respect to the transverse pin 11 when the latter is held in the insertion housings 314 by the covering cap 333.

[0053] In the first position P1 illustrated, the lateral insertion housings 314 are closed on top by a covering cover 333, i.e. a first covering cover 333A for the first lateral insertion housing 314A and a second covering cover 333B for the second lateral insertion housing 314B which acts as a vertical shutter.As can be seen by comparing Figure 2A showing the fastening device 3 in the first position P1, i.e. its closed position, with Figure 2B where the fastening device 3 is shown in the second position P2, i.e. its open position, the covering cap 333 slides longitudinally back and forth, being actuated by a gripping tab 332 slightly curved upwards to facilitate gripping and actuation by the user when he wishes to change the strap; when it is in position P2, a restoring force F is exerted by an elastic restoring element described later in the exploded figures 3A and 3B. This restoring force is preferably between 3 Newton and 5 Newton in order to avoid any involuntary handling error and can move over a maximum displacement stroke C of between 0.5 and 1.5 mm, as required, the maximum force then being exerted at the end of the stroke.

[0054] Still in Figure 2B, it can be seen that a curved shape is arranged at the bottom of the central part of the attachment device 3, preferably in the form of a cylindrical guide surface 317 corresponding to the shape of the central projection of the interchangeable bracelet 1. This cylindrical guide surface 317 is arranged on a first part 31 of a fixed assembly 30 also comprising a second part 32 to which the first part 31 is assembled using a series of screws (which will be referred to, by convention, as the second series of screws 352, the first series of screws 351 being that used to fix the attachment device 3 to the case 2, as explained later).In Figures 2A and 2B, it is possible to distinguish the first fixing screw 352A inserted at a first lateral edge 311A ​​of the first part 31 of the fixed assembly 30 of the attachment device 3, referenced further on in Figures 3A and 3B, and a first lateral tab 325A of the second part 32 of the fixed assembly 30, on the left of these figures and the second fixing screw 352B at a second lateral edge 311B of this same first part 31, and a second lateral tab 325B of the second part 32 of the fixed assembly 30, located on the side opposite the central recess 36 on the right of these figures.

[0055] The front of the covering hood 333 is arranged in the form of an inclined or curved end portion 3330, i.e. a first inclined or curved end portion 3330A for the first part of the covering hood 333A and a second inclined or curved end portion 3330B for the second part of the covering hood 330B. Each of these inclined end portions bear against a front face of the first part 31 of the fixed assembly 30 of the attachment device 3, and more precisely the first inclined or curved end portion 3330A of the first part of the covering hood 333A bears against a first front face 312A of the first part 31 and the second inclined or curved end portion 3330B of the second part of the covering hood 333A bears against a first front face 312A of the first part 31. It is thus possible to affix the ends of the transverse pin 11,that is to say more precisely the first end 11A of the transverse pin 11 on the first inclined or domed end surface 3330A of the covering cap 333 and the second end 11B of the transverse pin 11 on the second inclined or domed end surface 3330B of the covering cap 333, and by pulling the pin 11 downwards in order to insert its lateral ends into their corresponding insertion housings 314, the reaction generated by the covering cap 333 thanks to these inclined surfaces contains an orthogonal component without the longitudinal direction going against the restoring force F. In other words, this inclination makes it possible to exert a return tending to open the covering cap 333 at the same time as one seeks to insert the pin 11, which makes the manipulation for inserting and locking the end of a new interchangeable bracelet 1 particularly convenient: in fact,this can be carried out with one hand by acting only on the interchangeable bracelet 1 and without having to actively actuate anything at the attachment device 3, the sliding of the covering cap 333 passively following the movement of the transverse pin 11 as its ends are inserted into the corresponding lateral insertion housings (i.e. the first end 11A in the first lateral insertion housing 314A and the second end 11B in the second lateral insertion housing 314B), then when these ends of the transverse pin 11 pass below the first part 333A and respectively the second part 333B of the covering cap 333, the latter automatically closes the lateral insertion housings from above under the action of the restoring force F which will have been generated as its longitudinal movement progresses.

[0056] Although the attachment device 3 has been illustrated here in modular form without the housing 2, it is possible to distinguish in Figure 2A a first central notch 316 made at the rear of the first part 3, and whose curvature corresponds substantially to that of a housing 2 to which the attachment device is intended to be fixed. Superimposed on this first notch 316, and having according to the preferred embodiment illustrated a shape identical to the first notch 316, there is a second notch 323 formed at the rear of the second part 32. This second notch 323 is bordered by a first lateral projection 324A on the left and a second lateral projection 324B on the right, which advantageously make it possible to form a bearing surface for the peripheral rim of a bottom, as explained later with the aid of Figures 4 and 5 showing an example of another preferred embodiment for the invention.

[0057] Figure 2B also highlights the preferred “U” shape of the sliding movable element 33 formed in a single piece with the gripping tab 332 which constitutes its actuating member. This sliding movable element 33 is also formed in a single piece with the covering cap 33 which constitutes the locking member of the attachment device 3, each of the parts of the covering cap 333 (i.e. the first part 333A and the second part 333B) forming a projection releasing an interior space similar to the central recess 36 with respect to the first part 31 of the fixed assembly of the attachment device 30.The recess 37 materializing this interior space formed between the internal vertical wall 335 and the side walls of the sliding mobile element 333, that is to say the left side wall 336A and the right side wall 336B has however not been referenced in this figure, but in the following figure 3A for the sake of clarity because it only concerns this sliding mobile element 33, and not the entirety of the attachment device 3.

[0058] Figure 2B also shows, in the open position of the fastening device (i.e. the second position P2), a horizontal bearing surface 3101 provided on a base 310 illustrated further on in the following figures 3A and 3B. In the center of the figure, a central through hole can be seen forming part of a series of through holes 315 intended to cooperate with a first series of screws 351, the entirety of which will also be illustrated in the following figures 3A and 3B, which show two exploded perspective views of the fastening device 3 according to the preferred embodiment of the preceding figures 2A and 2B, respectively from above and from below.

[0059] Figures 3A and 3B, which will be described jointly, are intended to highlight the different parts that make up the attachment device 3, and the way in which the three main elements that make it up, namely the first part 31 and the second part 32 forming the fixed assembly 30, and the sliding movable element 33, are assembled to each other. In these figures, not all the elements already described in the context of the previous figures 2A and 2B will necessarily be repeated in detail, the emphasis being placed on the new references to be explained using these specific views.

[0060] In Figures 3A and 3B, it is thus easy to deduce the way in which the first part 31 is fixed to the second part 32 to form the fixed assembly 30 of the attachment device 3, namely using the second series of screws 352 inserted into the lateral fixing orifices 321 of the second part 32 then into a series of blind holes 318. Furthermore, for fixing the attachment device 3 to an external element such as the case middle, i.e. the case 2 of a wristwatch, a first series of screws 351 must be inserted into a series of through holes 315, here three in number.More specifically, it can be seen that the first screw 352A of the second series of screws 352 is inserted into the first lateral fixing hole 321A of the second part 32 of the fixed assembly 30, then into the first threaded blind hole 318A of the first part 31 of the fixed assembly 30, just as the second screw 352A of the second series of screws 352 is inserted into the second lateral fixing hole 321B then into a second blind hole 318B which can be guessed to be hidden behind the left edge (first lateral edge 311) of the first part 31 of the fixed assembly 30.

[0061] Similarly, for fixing this first part 31 to the housing, the first screw 351A of the first series of screws 351 can be assembled in the first through hole 315A of the series of through holes, and the second screw 351B in the second through hole 315B and finally the third screw 315C in the third through hole 315C, the first two being arranged laterally and the third at the central level.

[0062] Figures 3A and 3B also show how the sliding mobile element 33 can be simply interposed between the two parts intended to be mutually assembled to each other. Indeed, as can be seen at the top of Figure 3A and the bottom of Figure 3B, the sliding mobile element 33 has, according to the preferred embodiment illustrated, several functional elements made in one piece, that is to say in a single piece with respect to this mobile vehicle. Indeed, at the top of Figure 3A, it can be seen that the ribbed gripping tab 332, extending over the entire width of the sliding mobile element 33, directly extends the two lateral tabs bordering the recess 37 and which form the covering hood 333 via its two lateral portions, that is to say the first part of the covering hood 333A and the second part of the covering hood 333B.In other words, the locking member formed by the covering cap 333 is integrally secured to the actuating member formed by the gripping tab 332. And these two functional members are also integrally secured and formed in one piece with an actuating finger 34 arranged at the lower face of the movable element 33. It is this element which is intended to urge the deformation of an elastic return element 34, here produced in wire form and not in the form of a usual helical spring. The elastic return element 34 is installed in an insertion gutter 3102 formed here by a transverse groove, of substantially corresponding length, and if possible of corresponding section to avoid any seizure during its insertion and thus allow more easily a correction in particular for a recentering.Nevertheless, the fact of having here a substantially square section while that of the elastic return element 34 is essentially cylindrical facilitates the machining of the base 310 of the first part 31 of the fixed assembly 30.

[0063] According to the preferred embodiment illustrated, the elastic return element 34 is preferably formed by an element made of Nitinol, of cylindrical section and having a diameter of between 0.3 and 0.5 mm for a length of substantially 12 mm, and preferably between 10 mm and 15 mm, in order to obtain the return force whose intensity is within the desired range of values ​​(namely between 3 and 5 Newton) in a substantially uniform manner over the entire displacement travel, the maximum displacement travel C being dependent on the size of the ends of the transverse pin 11 for fixing the interchangeable bracelet 1 and reduced to a minimum, as much as possible, i.e. if possible less than 1 mm. The use of such a material appears surprising in the field of watchmaking, where Nitinol is rather used for its shape memory properties, but not for its elasticity.Alternatively, other materials for elastic return elements could be used, such as Phynox, Nivaflex as metal alloys, or Delerin as a plastic, each of which, however, has different properties in terms of variance in the generated force and durability after a large number of usage cycles.

[0064] As can be seen at the bottom of Figure 3A, above the central through hole (third through hole 315C) a recess 3103 is provided in the base 310 of the first part 31 in order to be able to receive the actuating finger 334 in the depth direction. This actuating finger 334 is, at rest, that is to say in the closed position (first position P1 illustrated above in Figure 2A) of the attachment device 3, both in abutment against this recess 3103, at the front, and at the rear against the elastic return element 34, which can preferably be slightly prestressed in order to better guarantee the maintenance of the covering hood 333 in the closed state without generating operating play which could cause a slight gap in use.As can be seen from the bottom of Figure 3A which shows in detail the interior of the first part 31, it can be seen that the base 310 of this first part 30 has a horizontal bearing surface 3101 on which the lower surface 330 of the sliding movable element 33 can precisely come to bear, while the upper surface 3310 of the peripheral collar 331 still arranged in a single piece with respect to the sliding movable element 33 can be arranged under a shoulder 322 of the second part 32 of the fixed assembly 30. In this way, it is very simple to confine the movement of the sliding movable element 33 according to a single degree of freedom in translation in a longitudinal direction parallel to that in which the restoring force F generated by the elastic restoring element 34 is exerted.

[0065] Still at the bottom of this figure 3A, it can be seen that the maximum displacement stroke C of the sliding movable element 33 is indicated at the level of the clearance zone 3104 designed as a bulge at the central level of the insertion gutter 3012 provided for the elastic return element 34; the maximum displacement stroke C corresponds substantially to the depth of the clearance zone 3104, as will be seen later in view of Figure 4.

[0066] Figures 3A and 3B also highlight how the ends of the transverse fixing pin 11 can be confined to a zero degree of freedom in translation thanks to the stop surfaces defining the depth of the lateral insertion housings 314 in the longitudinal direction. Indeed, inside the first front face 312A, on the right in these figures, is arranged a first front internal stop surface 3120A and a first rear stop surface 313A defining the bottom of the first lateral insertion housing 314A; similarly, inside the second front face 312B, on the left in these figures, is arranged a second front internal stop surface 3120B as well as a corresponding second rear stop surface 313B defining the bottom of the second lateral insertion housing 314B.In this way, once positioned in their housings, the ends of the transverse fixing pin 11 can no longer move in the longitudinal direction; the covering cap 333 then prevents any movement in height in parallel - this is the reason why, in Figure 2A, the first lateral insertion housing 314A closed by the first part 333A of the covering cap 333 appears as a "square hole" - and it thus only has one degree of freedom in rotation.

[0067] It may also be noted, upon reading FIG. 3B, that not only the lower surface 330 of the sliding movable element 33 but also the peripheral lower surface 320 of the second part of the fixed assembly are intended to come to bear on the horizontal bearing surface 3101 of the base of the first part 31 of the fixed assembly 30; a possible sequence of assembly of the sliding movable element 33 relative to the fixed assembly 30 may therefore for example be the following:

[0068] - assembly of the first part 31 to a housing 2 (not shown but visible for example in the following figures 4 and 5 using the first series of screws 351;

[0069] - arrangement of the elastic return element 34 in its insertion gutter 3102, then

[0070] - positioning of the actuating finger 334 of the sliding mobile element 33 in the hollow 3013,

[0071] - covering of the peripheral collar 331 of the sliding movable element 33 by the internal shoulder 322 of the second part 32 of the fixed assembly 30, and finally

[0072] - screwing the second part 32 to the first part 31 via the second series of screws 352 inserted into the lateral fixing holes 321 of the second part and the blind holes 318 of the first part to form the fixed assembly 30.

[0073] According to the preferred embodiment illustrated in these figures, it will be noted that the ribbed gripping tab 332 has a particular shape, and in particular that it comprises a first inclined or respectively curved portion 332A, at the proximal level of its attachment to the sliding movable element 33, aimed at improving the quality of gripping by the user, in addition to the ridges extending over the entire width of the gripping tab 332, and a second portion 332B, in its distal part, having another inclination or another curvature aimed at improving wearing comfort. This optimization of the configuration of the gripping tab 332 will be described in more detail on the basis of FIG. 5 which follows.

[0074] Figures 4 and 5 illustrate another preferred embodiment for the present invention, which differs slightly from that which has been described with the aid of the preceding figures in that the shape of the second notch 323 made on the second part 32 does not correspond to that of the first central notch 316 of the first part 31 of the fixed assembly 30 of the attachment device 3, and now extends in an arc over the entire width of the attachment device 3 and no longer only in the center thereof. This has the effect that the projection 324, which was separated into two parts (left lateral projection 324A and right lateral projection 324B) in the previous embodiment now extends over the entire width of the second part 324; Figure 5 thus highlights the manner in which this projection 324 is covered by a lower peripheral rim 201 of the bottom of the housing 2, this assembly being completely hidden in the top view of Figure 4.

[0075] The purpose of Figure 4 is to illustrate how the attachment device 3 according to the invention, once integrated into a case 2 of a wristwatch, makes it possible to emulate a structure in which attachment horns 38 would be formed, here in a fairly thick manner by the combination of the lateral edges (first lateral edge 311 A and second lateral edge 311 B) of the first part 31 and the lateral tabs 325 (first left lateral tab 325A and second right lateral tab 325B of the first part 31), the whole closed by the front faces 312 (first left front face 312A and second right front face 312B). Consequently, such a configuration makes it possible to achieve a solution of conventional appearance while implementing a fixing solution which is, on the contrary, totally original at the functional level.In Figure 4, the attachment device 3 fixed to the top of the case 2 is not provided with the end of an interchangeable bracelet strand 1, while the bottom one is provided with the end of such a bracelet strand 1. We can therefore clearly distinguish the central recess 36 between the left attachment horn 38A and the right attachment horn 38B in which the central projection 10 of the interchangeable bracelet 1 is inserted, going beyond the last “H”-shaped link 12 of the bracelet 1.

[0076] For reasons of readability, the references of the attachment device 3 at the top of the figure and that at the bottom of the figure are not completely identical, each aiming to show different characteristics of the attachment device 3, the top showing the constituent elements of the attachment horns 38 and the covering cap 333, and the bottom the cooperation with the bracelet 1. The references common to the attachment device 3 at the top and bottom are however those relating to the first part 31 and to the second part 32, assembled to each other using the first screw 352A of the second series of fixing screws 352 as well as the second screw 352B of this second series of screws. In the center of the figure, it can be seen that the back 20 is conventionally screwed to the case by a third series of screws 21, here six in number and which are not referenced individually like the other screws of the other series.In this top view of the sliding mobile element 33, only the gripping tab 332 and the covering cap 333 can be seen, the first part 333A and the second part 333B of which are referenced on the top attachment device 3. These two elements, which are made in one piece to form a “U” shape and also allow, given their opposite arrangement relative to the case middle, i.e. on either side of the case 2, to recall an “H” emblematic of the applicant’s trademark.

[0077] The fact that the opening mechanism for releasing the ends of the transverse fixing pin 11, not visible in this figure 4 because they are hidden in their respective insertion housings, is located on the internal face of the case 2, that is to say on the back 2 side thereof, provides not only an aesthetic advantage thanks to the complete concealment of the attachment mechanism when the watch is worn, on the one hand, and on the other hand a functional advantage by avoiding any untimely opening of the attachment device 3 by involuntary catching of the sliding mobile element 3 with an external element. A preferred embodiment for the gripping tab 332 of the sliding mobile element 33 is explained in view of the following figure 5, which constitutes a sagittal sectional view of the attachment device 3 from the bottom along the axis AA.This sagittal sectional view makes it possible, on the one hand, as explained previously, to show how the attachment device 3 is assembled to the housing 2, giving the impression that it consists of a natural extension of the latter to form usual attachment horns 38. At the top of Figure 5, it can thus be seen how a lower peripheral edge 201 (NB: this view is shown with the bottom 20 of the housing 2 oriented towards the top of the figure) covers the projection 324 of the second part 32 of the fixed assembly 30, while at the bottom of the figure, it can be seen how the base 310 of the first part 31 of the fixed assembly 30 is fixed to the housing 2 by means of the third screw 351C of the first series 351 of fixing screws.On the right of the figure, it can be seen how the partially cylindrical guide surface 317 matches the cylindrical shape of the central projection 10 of the interchangeable bracelet, of which the transverse fixing pin 11 can be seen in its center. The protruding part of the base 310 relative to the case 2 also forms a covering beak 319 advantageously making it possible to hide the bulge at the end of the central projection 10 where the pin is arranged, and thus to mask the hinge formed with respect to the case 2 when the latter is seen from above.

[0078] This sagittal sectional figure also highlights the single-piece arrangement of the sliding mobile element 33, which comprises at its base an actuating finger 334 bearing against the elastic return element 34, and at the top a gripping tab 332 composed here of a first part 332A curved towards the outside of the case 2, that is to say tending to rise relative to the bottom as one approaches the center of the case 2. Such an arrangement makes it possible to improve the quality of gripping the tab 332 when the user seeks to change the bracelet 2, and pulls the gripping tab 332 towards the center of the case 2, here towards the left and going against the return force F which will be generated by the elastic return element 34.The second part 332B of the gripping tab 332 has an inclination or a curvature in the opposite direction, aimed at optimizing the ergonomics of the housing 2 to which the attachment device 3 according to this particularly advantageous embodiment would be made. Indeed, this terminal part (second part 332B) of the tab 332 makes it possible to best match the curvature of the user's wrist by descending downwards as one approaches the center of the housing 2.According to the embodiment illustrated in Figure 5, there is in reality no inflection point between the first part 332A and the second part 332B of the gripping tab 332, the latter being produced in an essentially convex shape and the demarcation line between the first part 332A and the second part 332B materialized in dotted lines has the sole purpose of indicating where the highest point of the gripping tab 332 is located, or more precisely the lowest point relative to the bottom 20 of the case 2 when the watch is worn.

[0079] Another aspect detailed in Figure 5 concerns the management of the maximum displacement stroke C of the sliding mobile element 33 in the longitudinal direction when it comes to opening the attachment device 3. Indeed, as can be seen in Figure 5, there is a clearance D between the rear of the peripheral collar 331 of the sliding mobile element 33 and the bottom of the internal shoulder 322 of the second part 32, but which does not necessarily correspond exactly to this maximum displacement stroke C which is defined here as being equal to the difference between the depth P of the clearance zone 3104 in the longitudinal direction and the thickness E of the elastic return element 34, which here corresponds to its diameter in view of its cylindrical shape.However, the case illustrated in Figure 5 corresponds to an extreme case where the elastic return element 34, shown here at rest in its insertion groove 3102, is absolutely not prestressed when the actuating finger 334 has been introduced into the corresponding recess. In practice, even at rest corresponding to the first locked position P1 of the attachment device, the elastic return element 34 is slightly prestressed, that is to say slightly deformed towards the rear, and in which case the space available at the rear thereof in the longitudinal direction and in the direction opposite to the return force F, will not have exactly the entire depth P but a reduced depth, less than P of the amount of deformation of the elastic return element 34 in the longitudinal direction.

[0080] In other words, the system defines the constraint:

[0081] C < P - E This constraint, however, makes it possible to define fairly easily the depth of the clearance zone P as a function of the desired maximum displacement stroke C, which also depends on the depth of the insertion housings 314 because it is also desirable for the covering cap 333 to withdraw to a depth at least equal to the latter to allow the release of the ends of the transverse fixing pins 11.

[0082] Although the invention has been described using the preferred embodiments above, those skilled in the art will understand that these embodiments are given for information purposes only and are not intended to describe all of the possible variants for implementing the invention; it will be understood in particular that combinations between several technical characteristics described in the context of different embodiments can be envisaged, provided that they are not mutually exclusive with respect to each other.

Claims

Claims 1. Fixing mechanism for a bracelet (1) interchangeable with a case (2), characterized in that it comprises an attachment device (3) integral with said case (2) respectively comprising a fixed assembly (30) defining insertion housings (314) arranged on either side of a central recess (36), said insertion housings (314) being adapted to receive the lateral ends of a transverse pin (11) for integrally fixed fixing of said bracelet (1), and a sliding movable element (33) provided with a covering cap (333) actuable longitudinally in translation between a first closed position (P1) in which said transverse pin (11) is locked in said insertion housings (314) and a second open position (P2) in which said transverse pin (11) can be respectively inserted or released from said insertion housings (314).

2. Fixing mechanism for interchangeable bracelet (1) according to claim 1, characterized in that said sliding movable element (33) can be actuated via a ribbed gripping tab (332).

3. Fixing mechanism for interchangeable bracelet (1) according to claim 1 or 2, characterized in that an actuating finger (334) interacting with an elastic return element (34) is furthermore arranged on said sliding movable element (33).

4. Fixing mechanism for interchangeable bracelet (1) according to one of the preceding claims, in which said gripping tab (332), said covering cover (333), as well as said actuating finger (334) are arranged in a single piece on said sliding movable element (33).

5. Fixing mechanism for interchangeable bracelet (1) according to one of claims 1 to 4, said sliding movable element (33) also having a peripheral collar (331), and said fixed assembly (30) being formed of a first part (31) and a second part (32) provided of an internal shoulder (322) arranged to cover said peripheral collar (331) of said sliding movable element (33) when said first part (31) and said second part (32) are assembled to each other to form said fixed assembly (30).

6. Fixing mechanism for interchangeable bracelet (1) according to one of the preceding claims, in which said covering cap (333) has an inclined or curved end portion (3330).

7. Fixing mechanism for interchangeable bracelet (1) according to claim 3, characterized in that it has an elastic return element (34) arranged transversely in an insertion gutter (3102) of a first part (31) of the fixed assembly (30), and said elastic return element being arranged to exert a return force (F) in the longitudinal direction when said covering cap (333) is moved from said first closed position (P1) to said second open position (P2) under the impulse of said actuating finger (334).

8. Fixing mechanism for interchangeable bracelet (1) according to claim 7, characterized in that said elastic return element (34) is made of Nitinol.

9. Fixing mechanism for interchangeable bracelet (1) according to claim 8, characterized in that a clearance zone (316) is provided at the rear of said insertion gutter (314) to allow the deformation of said elastic return element (34).

10. Fixing mechanism for interchangeable bracelet (1) according to claim 9, wherein the depth (P) of said clearance zone (3104) determines a maximum displacement stroke (C) for said covering cap (333).

11. Fixing mechanism for interchangeable bracelet (1) according to one of the preceding claims, said sliding mobile element (33) having a “U” shape defining a recess (37) arranged to house a central projection (10) of one end of a strand of an interchangeable bracelet (1).

12. Watch case (2) comprising a fastening mechanism for an interchangeable bracelet (1) according to one of the preceding claims, characterized in that said fastening device (3) is provided with a notch matching the external shape of said case (2) and a projection (324) covered by a lower peripheral edge (201) of a bottom (20) of the case (2).

13. Watch case (2) comprising a fastening mechanism for an interchangeable bracelet (1) according to claim 12, characterized in that a gripping tab (332) is provided for actuating said sliding element (33) of said fastening device (3), said gripping tab (332) being arranged on the bottom side (20) of said case (2), and comprising a first part (332A) inclined or curved towards the outside of said case (2), as well as a second part (332B) inclined or curved towards the inside of said case (2).

14. Watch case (2) comprising a fastening mechanism for an interchangeable bracelet (1) according to one of claims 12 or 13, characterized in that said attachment device (3) of the interchangeable bracelet (1) forms attachment horns (38) for the end of said interchangeable bracelet (1).

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