CLASP FOR WRISTWATCH STRAP

Description

Domaine technique de l'invention

[0001] The present invention relates to the field of watchmaking, and in particular to a clasp for a wristwatch. It relates even more particularly to a clasp for a diving watch. État de la technique

[0002] For leather or plastic watch straps, clasps are known that use a buckle and a pin, in which one of the strands of the clasp is pierced with several holes regularly spaced from each other. To define the length of the strap, the pin is inserted into one of the holes to define the desired length and the locking is then obtained by inserting the remaining length of the pierced strand into a hoop formed above the other strand.

[0003] For watches using bracelets preferably made of metal, clasps of the folding buckle type are known, with two branches folded over each other in the closed position, and which allow the user to insert his wrist into the bracelet in the open position without having to separate the two strands thanks to the increased diameter provided. Such an arrangement makes it possible to improve safety and comfort of use, by allowing, on the one hand, the wristwatch to be simply put on the wrist, and to remove it just as quickly and efficiently, without having to separate the strands of the bracelet; on the other hand, such combined bracelet attachment and locking devices make it possible to prevent the watch from falling if the two strands were to become detached from each other in the event of a malfunction of the locking system.

[0004] In addition to two-prong clasps, three-prong devices are also known, also called "butterflies", where two small lateral branches arranged symmetrically and articulated around the ends of a central branch fold into the center of the latter.

[0005] The disadvantage of folding clasps, especially when used with bracelets made of metal links, is that they do not allow for any automatic adjustment of the length depending on the conditions of use, i.e., for example, heat and pressure having a significant influence on the circumference of the wrist. This is the reason why mechanisms for fine adjustment of the useful length of such bracelets have been proposed in addition to these types of bracelets to compensate for this lack of comfort.

[0006] One of the most basic solutions that has been proposed for folding clasps is to provide a plurality of pairs of holes on a cover in which it is possible to accommodate bars for securing one of the ends of a strand. In this way, the spacing between two adjacent pairs of holes defines an adjustment pitch for the useful length of the bracelet. Such a solution, described for example in patent application EP0913106A1, however has the disadvantage of having to use a small pointed tool to carry out the adjustment, which cannot therefore be easily carried out by the wearer of the watch himself.

[0007] To avoid such a disadvantage and improve the convenience of the adjustment operation, patent EP0350785B1 describes an alternative solution having a length adjustment device allowing the adjustment to be carried out more simply using a trigger actuated by the user himself using a push button. According to this solution, a hook arranged at the end of one of the blades can engage in several holes made in a second blade formed in two parts sliding relative to each other. The trigger allows the hook to be released and locked, and the length adjustment is then carried out by sliding the blade until it faces the next hole opposite the hook. However, the disadvantage of such a system is that it requires the clasp to be completely opened in order to be able to carry out the adjustment, which is impossible as long as the hook is positioned in one of the holes.

[0008] Most of the time, the control members intended for actuating the adjustment device and the unlocking are separated in order to avoid any handling error. However, document CH707483 presents for example an original solution according to which a control member in the form of a lever can take two distinct activation positions to respectively actuate the unlocking and allow the adjustment of the length by pivoting the lever in opposite directions. Such a solution certainly has the advantage of a certain compactness due to the dispensation of redundancy of activation members and dedicated actuating kinematic chains, but it is however not very ergonomic or intuitive for the user who must himself associate a direction of tilting of the lever from a rest position with a predetermined function.However, since there is no explicit association between a pivoting direction and the function to which the corresponding activation position relates, repeated operating errors are still possible.

[0009] There is therefore a need for a solution free from these known limitations. Résumé de l'invention

[0010] An aim of the present invention is to provide an alternative solution for a folding clasp, which is provided with a locking and adjustment device that can be operated more intuitively by a common control member.

[0011] Another object of the present invention is to provide a clasp of simple and elegant construction.

[0012] According to the invention, these aims are achieved by means of a clasp for a timepiece in accordance with the characteristics of the main claim; the characteristics of the dependent claims relate to advantageous embodiments.

[0013] In particular, these aims are achieved by means of a folding clasp for a wristwatch comprising at least a first branch and a second branch articulated relative to each other around an axis, the clasp comprising on the one hand a locking device for holding the first branch and second branch in the folded position on each other in the closed position of the clasp, and on the other hand a device for adjusting the useful length of said bracelet comprising a connecting element mounted to slide under a cover of the clasp, and a stop element cooperating with this sliding connecting element, as well as a control member which can be actuated from a rest position to an active position.The clasp is characterized in that the end of the second branch opposite the axis comprises means for attachment to a first strand of the bracelet and that the end of the first branch opposite the axis is connected in an articulated manner to the sliding connecting element, and that the control member is arranged so as to be able, when it is in the active position, both to cause the unlocking of the clasp by acting on a locking element, and to release the sliding connecting element from the stopping element, the sliding connecting element then being able to be moved, when the control member is in the active position, independently of the open or closed position of said clasp.

[0014] Thus, thanks to the fact that only one active position is defined for the control member, which is the same for activating the unlocking of the clasp and allowing the adjustment of the useful length of the bracelet, the convenience of use is greatly improved since the user no longer has to ask himself the question of the type of activation to activate the desired function. Furthermore, the adjustment no longer requires opening the clasp as is the case for most solutions of the prior art.

[0015] Another advantage of the proposed solution is that it is particularly compact and discreet. In fact, not only the locking mechanism, but also the adjustment mechanism are mounted under a cover.

[0016] According to a preferred embodiment, the folding clasp for a wristwatch according to the invention is characterized in that the locking element consists of hooking means engaging against lower bearing surfaces of the second branch.

[0017] In this way the locking device is achieved without adding any additional level of complexity, and in a relatively simple implementation. Furthermore, this solution has the advantage of minimizing the total height of the system compared, for example, to usual solutions using fixing studs arranged on one of the blades collaborating with clamping jaws.

[0018] According to another preferred embodiment for the present invention, the folding clasp for a wristwatch is characterized in that the attachment means are retractable hooks bearing against shoulders arranged inside a first leg and a second leg of a stretcher forming the second branch.

[0019] In this way the locking device is realized in a particularly simple and intuitive manner in combination for example of retractable hooks with lateral pushers; moreover, the arrangement of the locking device entirely inside the cover towards the stretcher makes it possible to avoid any protruding shape outside the frame of the cover, while minimizing the total volume of the system by occupying the gap between the two legs of the stretcher. In addition, the internal shoulders provided inside the legs of the stretcher make it possible on the one hand to prevent any flushing of the hooks against the skin, and thus to avoid any pinching and consequently to improve the comfort when wearing a wristwatch equipped with such a clasp; these shoulders also make it possible to further minimize the total thickness of the combined system provided for locking and adjustment.

[0020] According to yet another preferred embodiment for the present invention, the folding clasp for a wristwatch is characterized in that the stop element of the adjustment device is formed by at least one tooth engaging with notches of a rack arranged inside said sliding connecting element.

[0021] An advantage of such an arrangement of the adjustment device is that it is particularly simple to implement, while once again minimizing volume requirements.

[0022] According to an even more preferred variant of the previous embodiment, the teeth and notches of the rack have a surface perpendicular to the longitudinal direction of the clasp and an oblique direction oriented in the direction of the narrowing of the useful length of the bracelet.

[0023] In this way, it is possible to require a narrowing of the bracelet by acting directly on the strands of the bracelet and without having to operate the control member, which therefore significantly improves the convenience of use, while an operation of the control member remains necessary to enlarge the size. Beyond the practical nature of such a version, it proves particularly suitable for a diving watch where the impossibility of being able to enlarge the size of the bracelet by a false manipulation is almost vital, while the adjustment by simple mutual tightening of the strands can be desirable to adjust the size of the bracelet to the wrist as quickly and efficiently as possible.

[0024] According to a preferred embodiment, the folding clasp for a wristwatch according to the invention is characterized in that the adjustment device is housed in a first compartment arranged entirely under the cover of the clasp.

[0025] In this way, the proposed solution presents a modular construction that can leave room for the integration of other devices under the cover, and also presents a particularly advantageous aesthetic appearance by concealing the locking and adjustment devices from the outside of the cover.

[0026] According to an even more preferred variant of the preceding embodiment, the folding clasp for a wristwatch according to the invention is characterized in that the sliding connecting element can move between a first shortened adjustment position and a second adjustment position, the sliding connecting element being completely concealed on the one hand under the cover and on the other hand under a cover removably attached to the cover in the first shortened adjustment position, and always concealed under the cover even in the second extended position.

[0027] This further improves the aesthetics by concealing the adjustment device not only from above but also from below. Furthermore, concealing it under a removable cover makes after-sales service easier by changing only the adjustment device in a modular way without having to change the cover or the entire clasp at the same time.

[0028] According to a preferred embodiment, the folding clasp for a wristwatch according to the invention is characterized in that the control member consists of at least one push button housed in a lateral opening of said cover.

[0029] Even more preferably, two pushers will be used, arranged symmetrically on either side of the cover so as to facilitate their grip and make handling particularly intuitive, as on known folding clasps without an adjustment mechanism, the notable advantage of such pushers in the context of the present invention being that they allow the adjustment to be operated simultaneously without having to open the clasp at the same time.

[0030] According to an even more preferred variant relative to the previous embodiment, the folding clasp for a wristwatch is characterized in that the push button is actuated from the rest position to said active position by acting against elastic return means arranged perpendicular to the longitudinal direction of said bracelet towards the inside of the cover, the locking element being formed by a retractable hook and the stop element being formed by a tooth, and the retractable hook and the tooth being integral with said push button.

[0031] In this way, the actuation of the pusher acts directly and immediately on the hooks and on the tooth, so that the unlocking and the actuation of the adjustment are reliable and immediate.

[0032] According to an even more preferential variant for the previous embodiment relating to the folding clasp for wristwatch according to the invention, the retractable hook and the tooth are formed in a single piece with said push button.

[0033] This variant thus has the advantage of a particularly simple and compact construction for integrating and merging three functional elements that are generally distinct from one another, namely a control member, a locking element formed by the retractable hook and the tooth as a stopping element of the adjustment device. In this way, the actuation of the pusher generates the unlocking and adjustment in the most efficient way possible, without any loss of energy in the transmission.

[0034] According to an even more preferred variant of the folding clasp for a wristwatch according to the preceding embodiment, the control member, and respectively the tooth and the retractable hook are movable in planes superimposed on each other in the direction of the thickness of the cover.

[0035] In this way, the gear planes of each of the actuating, locking and adjusting mechanisms are completely separated under the cover, as if each of the functions were triggered by stages of a column wheel. Thus, this solution is on the one hand particularly reliable and on the other hand particularly elegant from a technical point of view.

[0036] According to a particularly preferred variant for the folding clasp for wristwatch according to the previous embodiment also using the cover, the retractable hook is precisely mounted through a window of the cover.

[0037] In this way, the adjustment mechanism is completely hidden under the cover and the locking device simply appears from below as a solution using retractable hooks. The adjustment device is thus completely separate and invisible from the locking device.

[0038] According to an even more preferred embodiment, the folding clasp for a wristwatch according to the invention is characterized in that the elastic return means are formed by a first elastic return element and a second elastic return element arranged parallel to each other in a direction perpendicular to the longitudinal direction of the bracelet.

[0039] Such a doubling of the elastic return means according to the direction of actuation of the push buttons, i.e. radially towards the inside of the cover, makes it possible to avoid any discomfort in use by eliminating any degree of freedom in rotation of each of the push buttons, which are then confined to an inward sliding movement in a direction perpendicular to the longitudinal direction of the bracelet.

[0040] According to a preferred embodiment linked to a diving watch, the folding clasp for a wristwatch according to the invention is characterized in that it further comprises a device for extending the useful length of the bracelet housed in a second compartment arranged entirely under the cover of the clasp.

[0041] An advantage of such a solution is that it allows on the one hand a modular construction for the integration of both the device for fine adjustment of the strap length and the usual extension device of diving watches to pass the watch over a neoprene suit, but also particularly refined and aesthetic because each of the two adjustment and extension devices offered are perfectly hidden under the clasp cover.

[0042] According to an even more preferred variant of the previous embodiment linked to a diving watch, the folding clasp for a wristwatch according to the invention is characterized in that the extension device comprises a piece for attachment to a second bracelet strand forming a hinge with an intermediate link pivotally fixed relative to the cover, a cylindrical locking pin of the intermediate link being able to fit into a transverse groove for fixing the attachment piece in the retracted position of the extension device.

[0043] In this way, it is particularly easy to switch from normal carrying mode to diving mode, i.e. from retracted mode to extended mode of the bracelet by simply pressing on the attachment part which causes it to detach from the underside of the cover thanks to a release of the pin cylindrically from its fixing housing formed by the transverse groove, and the return to position being just as easy by folding the intermediate link under the cover and clipping the cylindrical pin into the transverse groove via a slight elastic deformation.

[0044] Other preferred embodiments will also be detailed in the following description.

[0045] It will be understood from the remainder of this detailed description that the advantageous characteristics drawn from the preferred embodiments may be taken in isolation or in combination, except when the latter have been presented as mutually exclusive. Brève description des dessins

[0046] Other advantageous characteristics will emerge more clearly from the following description of particular embodiments of the invention given as non-limiting examples and represented by the appended drawings, in which: there figure 1 is a three-dimensional view of a clasp according to a preferred embodiment of the invention, in the closed position of the clasp, with the pushers in their corresponding rest position; the figures 2A And 2B shows two exploded views of two particularly advantageous variants for implementing the preferred embodiment for the invention illustrated by the figure 1 previous, allowing adjustment to 2 or 3 positions respectively; the figures 3A And 3B are three-dimensional views from below of a clasp according to the preferred embodiment for the invention illustrated in the figure 1 previous, showing the clasp in the closed and open position respectively; the figure 4A shows a three-dimensional view from below of a cover of a clasp according to the preferred embodiment of the preceding figures, seen from below, highlighting the two compartments for housing the adjustment device and the extension device. The figure 4B shows a three-dimensional view, still from below, of the cover of the figure 4A , but now with pushers with integrated retractable teeth and hooks inserted into the side openings of this cover; The figure 4C shows a three-dimensional view, still from below, of the cover and the pushers of the figure 4B , now with the integral actuating mechanism with the elastic elements positioned between each of the pushers constituting the control members; The figures 5A et 5B respectively show an embodiment with 3 adjustment positions and 2 adjustment positions, with the sliding connecting element respectively in the free adjustment position, i.e. when the pusher is in the active position, and in the indexed position, corresponding on the contrary to the rest position of the pusher. The figure 5A further shows the sliding element in a shortened position of the bracelet and the figure 5B the sliding element in a respectively elongated position under the clasp cover. Description détaillée

[0047] In the following description, the constituent elements of a clasp of several preferred embodiments for the present invention, corresponding to a diving watch, will be described in detail; those skilled in the art will understand, however, that these embodiments are given for information purposes only and are not intended to describe all of the possible variants for implementing the invention.

[0048] The clasp 100 will also be described in various positions to highlight the operation of the opening of the clasp 100 and its adjustment.

[0049] There figure 1 shows the clasp 100 in the closed position, and thus highlights the particularly refined aesthetic conferred by the fact that the entire opening and adjustment mechanism is hidden under the cover 7.

[0050] In this figure, the two blades of the clasp, i.e. the first branch 2 and the second branch 3, which are shown in detail in particular in the exploded figures 2A and 2B which follow, are folded over each other and concealed under the upper surface 73 and the side walls 74 of the cover 7, which extends in the longitudinal direction L. At one end of the second branch 3 are provided first attachment means 33 for a first strand B1 of the bracelet, which here preferably consist of a first fixing bar 35 arranged between a first pair of attachment horns 34. In the closed position of the clasp 100, the other end of the second branch 3 is positioned under a second pair of attachment horns 812 forming, with the second fixing bar 83, second attachment means 81 for the second strand B2 of the bracelet.

[0051] According to this preferred embodiment corresponding to a diving watch, the second strand B2 of the bracelet is not directly connected to the cover 7, but connected to the latter via an extension device 8 which is also at least partially hidden under the cover 7 during normal use of the watch, that is to say when it is not necessary to resort to an extension of the bracelet of at least 10 millimeters, and preferably of approximately 15 to 20 millimeters to pass the bracelet over a neoprene suit. This extension device 8 is fixed to the cover 7 via third attachment means 741, inserted into fixing holes provided in the side walls 74 of the cover.It will be understood, however, that the constituent elements of the extension device 8 only constitute intermediate connecting means between the cover 7 and the second strand B2 of the bracelet, and that this second strand B2 could, according to a variant not illustrated, also be attached directly to the cover 7 and not only indirectly to it.

[0052] On either side of the cover 7, inserted into lateral openings provided for this purpose in the side walls 74 of the bracelet 7, push buttons are provided, namely a first push button 5A and a second push button 5B, which together form a control member 5 for preferably actuating both the unlocking of the clasp 100 and the adjustment of the length of the bracelet.

[0053] In the following, we will refer indifferently to figures 2A And 2B, which have exactly the same references, but the only difference is the number of adjustment positions available via the sliding connecting element 4, which has a rack 42 defining two or three positions respectively (two for the rack of the figure 2B And 3 for the rack of the figure 2A ). In both cases, and as described later using the figures 5A et 5B , it may however be noted that the orientation of the first toothing 42A and second toothing 42B of the rack 42 are arranged in such a way that it is possible to shorten the useful length of the bracelet without having to resort to actuating the adjustment device, which is only essential to require an increase in length.

[0054] At the top of the figures 2A And 2B, we thus find the cover 7 taken separately with its upper surface 73, its side walls 74, one of which is provided with a first lateral insertion opening 740A provided for the first push button 5A shown just below. At the rear end of the clasp 7, that is to say towards the right in the figures, is materialized the first connecting orifice 741A into which is introduced the visible end of the fixing bar 821 of the intermediate link 82 of the extension device 8, which is connected in an articulated manner to a central link 811 preferably made in one piece with the second pair of attachment horns 812 of the second strand B2 to form the second attachment means 81 of the second strand.

[0055] The detail of the extension device 8 is illustrated at the top right of Figures 8A and 8B, with the intermediate link 82 formed by a first lateral link 82A and a second lateral link 82B connected to the cover 7 via the fourth fixing bar 821, and the connecting pin 882 inserted into the central through hole 8110 of the central link 811 of the second attachment means 81 of which the third attachment horn 812A of the second pair of attachment horns 812 can be seen, as well as the associated third attachment hole 8210A, the fourth attachment horn 812B as well as the fourth attachment hole 8120B being hidden in this figure, but visible for example in the figure 3B described further.

[0056] In the intermediate part of the second attachment means 81 is arranged a transverse fixing groove 813 intended to receive the transverse fixing pin 812 when the intermediate link 82 is folded back 180 degrees relative to the configuration illustrated in this figure, corresponding to that for example of the figure 3B . In order to keep the central link 811 fitted onto the intermediate link 82, a slight elastic deformation is necessary, which can be applied to one or other of these elements generally preferably made of metal. The shape of the transverse fixing groove 813 is preferably provided in such a way that insertion is facilitated at the edge, and that retention is ensured at the bottom of the groove, for example using a slight inward curvature requiring greater deformation to pass behind but at the same time providing an upward retention stop holding the pin at the bottom of the groove.We generally refer to this type of attachment requiring the exceeding of a certain threshold of elastic deformation to reach a rest position where this deformation is again less by "clipping" and it is this type of attachment method which is favored in the context of the present invention in order to ensure maximum compactness of the system; however, it will be understood here again that the person skilled in the art could envisage other modes of actuation and locking to switch from a normal mode of use of a diving watch according to the invention and the diving mode requiring the extension of the bracelet.

[0057] Just below the extension device 8 but more to the left of the figures 2A And 2B, the adjustment device 45 according to the invention is detailed, which connects the cover 7 to the front end (first end 21) of the first branch 2 via the sliding connecting element 4. This sliding connecting element 4 is arranged, for aesthetic and ergonomic reasons - in particular to avoid any pinching - under a cover 70 fixed here by screwing to the internal face of the cover 7. The first fixing screw 712A is inserted into a first through fixing hole 701A, tapped or not, corresponding and the second fixing screw 712B into a second through fixing hole 710B, tapped or not, arranged in a front bulge 701 making it possible to create sufficient space in height to house the sliding connecting element 4. At the rear of the cover 70 is provided a spoiler 702 which delimits a first compartment under the cover, illustrated further on in particular on the figures 4A à 4C .

[0058] The cover 70 is also provided with a first window 70A and a second window 70B constituting orifices intended to allow the locking hooks to pass - that is to say the first locking hook 53A secured to the first push button 5A and the second locking hook 53B secured to the second push button 5B - which are inserted, in the closed position of the clasp 100, under the second branch 3, and here more precisely under a first shoulder 36A of the first leg 3A and a second shoulder 36B of the second leg 3B.

[0059] In the adjustment device 45 according to the preferred embodiment described, the connecting element 4 is slidably mounted under the cover 7, but is fixed relative to the first end 21 of the first branch 2, to which it is connected via the fixing axis 24, and therefore relative to the first strand B1. The sliding connecting element 4 is thus mounted between the underside of the cover 7 and the cover 70 so as to be able to move only according to one degree of freedom in translation, and in an indexed manner according to different adjustment positions, depending on the number of notches of the rack 42.The fixing axis 24 preferably consists of an elastic bar introduced on the one hand into a first fixing through-hole 210 of the first end 21 of the first branch 2, and on the other hand into the second fixing through-hole 41A and the third fixing through-hole 41B provided at the front end 41 of the sliding connecting element 4, which is closed behind the first lateral toothing 42A and the second lateral toothing 42B by a crosspiece forming the rear end 43.

[0060] The only difference between the figures 2A And 2B consists simply of the number of notches on the rack 42, which are three in number for the rack of the figure 2A and two for the figure 2B . In other words, the clasp 100 according to the preferred embodiment illustrated by the figure 2A determines a shortened, intermediate and elongated position for the useful length of the bracelet, while that illustrated by the figure 2B has only one shortened position and one extended position, spaced however by the same adjustment step as that corresponding to the other variant. Preferably, the adjustment step between each of the positions of the variant of the figure 2B is between 2.5 and 4 millimeters, so that the difference between the minimum and maximum length of the bracelet is between 5 and 8 millimeters. If the disadvantage of the variant illustrated by the figure 2B is to eliminate an intermediate adjustment position, this variant however has the advantage of allowing easier handling to move from one setting to another due to the lesser slope of the elongated notch of the rack. These aspects will be discussed in more detail when describing the figures 5A et 5B . According to the preferred embodiment illustrated by the figure 2B , the adjustment step is preferably between 6 and 7 millimeters.

[0061] As explained above, since the sliding connecting element 4 is fixed relative to the two branches, and therefore relative to the first strand B1 of the bracelet which is connected via the first attachment means 33, that is to say a bar (not shown in these figures 2A And 2B ) inserted between a first pair of horns 34 each provided respectively with a first fixing orifice 340A and a second fixing orifice 340B. It is nevertheless sliding relative to the cover 7, and therefore of the control member 5 formed by the first push button 5A and the second push button 5B, which are themselves fixed relative to the cover 7 since they are arranged in lateral insertion openings made in the side walls 74 of the cover.

[0062] The two push buttons are connected to each other via elastic return means 6, formed here by a first elastic return element 61 and a second elastic return element 62 which consist of a kind of elastic bars or pawls, the ends of which are inserted, for example but not necessarily via a force fitting, into insertion orifices arranged on the internal face of the push buttons, that is to say opposite their projecting domed part intended to be manipulated by the user.

[0063] On the figures 2A And 2B, it can thus be seen that the first elastic return element 61 has a first insertion pin 61A and a second insertion pin 61B intended to be fitted respectively into a first insertion orifice 51A of the first push button 5A and a third insertion orifice 51B of the second push button 5B, while the second elastic return element 62 has a third insertion pin 62A and a fourth insertion pin 61B intended to be fitted respectively into a second insertion orifice 52A of the first push button 5A and a fourth insertion orifice 52B of the second push button 5B. On the figures 2A And 2B, the entirety of the components of the elastic means formed by the first elastic element 6 and the second elastic element can be discerned; however, the internal face of the first push button 5A in which the first insertion hole 51A and the third insertion hole 51B are arranged is hidden; this is however highlighted on the figure 4B .

[0064] The advantage of such a configuration for the elastic return elements is to guarantee the stability of the movement of the pushers when they are pressed when the user seeks to cause the clasp to unlock and / or actuate the adjustment device 45.

[0065] According to the preferred embodiment described, the push buttons each respectively have both a locking element and an integrated stop element, which act in superimposed planes. Thus, the first push button 5A has a first retractable hook 53A, which is released from its bearing surface constituted by the first shoulder 36A below the first leg 3A of the second branch 3 when a force F is exerted towards the inside of the cover (NB: this force is not illustrated in these figures for reasons of readability but represented on the figure 5B ). Similarly, the second push button 5B has a retractable hook 53B, which comes to bear under the second shoulder 36B of the second leg 3B in the closed position of the clasp, that is to say when the first end 21 of the first branch 2, opposite its second end 22 at the level of the articulation axis 23 with the second branch 3, comes to be interposed between the third ends 31A of the first leg 3A and the fourth end 31B of the second leg 3B of the second branch 3. Nevertheless, the stop elements interacting with the teeth of the rack are masked - the first stop tooth 54A supposed to cooperate with the first lateral toothing 42A of the rack 42 of the sliding connecting element 4 can barely be seen. For this reason, the detail of the configuration of the stop elements will be explained in view of the figures 4A-4C and 5A-5B.

[0066] At the bottom of the figures 2A And 2B, it can be noted that the distal ends of the first and second legs 3A, 3B of the stretcher forming the second branch 3 according to the preferred embodiment described have a notch of length E relative to the thickness of the legs at their proximal end with respect to the articulation axis 23 relative to the first branch 2. To facilitate reading and show the opposition between the proximal and distal ends, the proximal end of the second branch has been referenced 32 and consequently the proximal end of each of the legs of the stretcher referenced 32A and 32B, respectively for the first leg 3A and the second leg 3B. This notch does not, however, correspond to the maximum possible travel for adjustment, which is materialized by the reference C, also illustrated further on the figure 5B . However, it is precisely at the level of this notch that the shoulders are arranged, that is to say the first shoulder 36A and the second shoulder 36B. These shoulders constitute a particular preferred form of lower bearing surfaces of the first branch 3, that is to say bearing surfaces located on the lower side thereof. Given that they make it possible to maintain the hooks above the lower surface of the first leg 3A and the second leg 3B in the closed position of the clasp, in such a configuration, the fact that no prominent shape goes below the lower surface of the legs avoids on the one hand any discomfort to the wearer of the bracelet in use, since no protruding shape perceptible at the wrist risks generating pinching; on the other hand this also makes it possible to avoid prints being left on the skin of the wearer of the wristwatch when it is removed from the wrist.

[0067] There figure 3A shows a view of the clasp 100 in the closed position, in accordance with the figure 1 , but this time seen from below. For the sake of brevity, all the references already mentioned in detail in the description of the figures 1 And 2A-2B will not be reintroduced in full within the framework of the description of this figure. In reality the only references to be introduced are those which were hidden in the previous figures, and in particular the fourth fixing orifice 8120B of the fourth attachment horn 821B, as well as the second connecting orifice 741B of the third attachment means 741, all the others having already been introduced.

[0068] There figure 3A shows the clasp 100 in the closed position, but also the push button in its rest position (Pr), i.e. not pressed. In this position, it can be seen that the retractable hooks 53 - i.e. the first retractable hook secured to the first push button 5A and the second retractable hook 53B secured to the second push button 5B are supported on their respective locking surfaces, the first shoulder 36A under the first leg 3A being particularly highlighted here. Such shoulders forming a sort of "intermediate step" make it possible to minimize the total height of the clasp, and thus its overall size. They also and above all make it possible to minimize any risk of pinching or discomfort when wearing at the wearer's wrist by not generating any prominent shape at the internal face of the clasp, i.e. under the first leg 3A and the second leg 3B.

[0069] There figure 3B shows the same clasp 100, that is to say according to the same preferred embodiment as that illustrated by the previous figures, but now in the open position. The comparison between the figures 3A And 3B highlights one of the major advantages of the present invention, that is to say that dissociating the adjustment from the position of the clasp 100. In other words, the adjustment can be carried out both in the open or closed position, and thus does not require unlocking the clasp to carry out the adjustment operation, as is often the case according to the solutions of the prior art and which constitutes a constraint not appreciated by users. In this way, the user-friendliness is greatly improved. Indeed, even in the case where the clasp is closed as illustrated in the figure 3A , the depression of the first and second pushers 5A, 5B causes the release of the first and second retractable locking hooks 53A, 53B and thus allows any adjustment operation, regardless of whether the latter are located near their respective bearing surfaces during locking, i.e. the first shoulder 36A and the second shoulder 36B.

[0070] There figure 3B allows to highlight the dissociated and superimposed gear planes between the adjustment device 45, just below the cover 7, and the locking mechanism, arranged one level below. It also highlights the compactness of a clasp 100 produced for a diving watch with the adjustment device 45 arranged in a first compartment on the left under the clasp 100, and the extension device 8 arranged just next to it in a modular manner. According to the illustrated configuration, the extension device 8 is in the retracted position Pn, that is to say in the context of normal use, not corresponding to the diving mode. In this folded configuration of the intermediate link 82 and the central link 82, one can note the similarity between the two lateral links (first lateral link 82A and second lateral link 82B) of the intermediate link 82 and the stretcher of the folding clasp of the clasp.To activate the dive mode and switch to an unfolded configuration of the extension device 8, and thus provide an extension of the useful length of the bracelet by a predetermined length, it is sufficient to press one of the two attachment horns of the second pair of horns 812 of the bracelet downwards, or respectively pull the cover 7 upwards at this attachment end of the second strand B2.

[0071] There figure 3B also makes it possible to highlight, in addition to the compactness of the combined locking and adjustment device, the effectiveness and aesthetics of the concealment of the proposed adjustment mechanism. Indeed, the adjustment device 45 proposed within the framework of the present invention remains hidden under the cover 7, interposed between the latter and the cover 70, whatever the adjustment position, i.e. in the shortened or extended position. According to the proposed embodiment, the cover 70 is screwed under the cover 7 so that after-sales service is also greatly facilitated due to the removable nature of the attachment of the latter. In this way, constituent parts of the clasp can be replaced in a modular manner without requiring the entire clasp to be changed if any problem should arise.

[0072] THE figures 4A à 4C which follow aim to highlight the particular arrangement of the control mechanism 5 of the clasp 100 proposed, as well as the modular nature of the adjustment device 45 in relation to the extension device 8 which it contains according to the preferred embodiment described. Here again, all the references which have already been introduced in the preceding figures will not necessarily be repeated in their entirety, the emphasis being simply placed on certain particular parts.

[0073] There figure 4A , which illustrates a view from below of the cover 7 taken in isolation, thus highlights the two compartments in which the adjustment device 45 and the extension device 8 illustrated in the figure are intended to be housed respectively. figure 3B previously described. The first internal compartment 71 of the cover 7 is thus intended to receive the adjustment device 45 while the second internal compartment 72 of the cover 7 is provided to receive, in a modular manner, the extension device. Thus, it is possible to additionally adjust the maximum adjustment stroke C - visible on the figure 5B described below - of the adjustment device 45 with respect to the desired length extension in the context of use in diving mode. In particular, it can be seen on the left of the figure 4A that an internal bulge 711 is provided towards the center of the first internal compartment 71 of the cover, which is provided with a first tapped blind hole 710A and a second tapped blind hole 710B, into which the first fixing screw 712A and the second fixing screw 712B are respectively inserted. Such an arrangement makes it possible to carry out the removable fixing of the cover 70 simply, by screwing, without risking damaging the external appearance of the cover 7 or having to modify the thickness of its upper external wall.

[0074] THE figures 4B et 4C show, in addition to the figure 4A , how the push buttons are mounted on the cover 7 and how the locking 53 and stop 54 elements are integrated into the control member 5, i.e. to form only one piece made from a single piece, for example by molding. The figure 4B shows in particular the first fixing orifice 51A and the third fixing orifice 51B intended to receive the ends of the first elastic 61 and of the second elastic element 62 and which were hidden in the previous figures; figures 4B et 4C distinctively show the shape and arrangement of a stop tooth, here in particular the second stop tooth 54B, just below the body of the second push button 5B. It can thus be understood how by actuating the push buttons, and in particular the second push button 5B, inwards, the unlocking and the adjustment operation can be triggered simultaneously in a simple, efficient and intuitive manner.

[0075] Unlike the figures 2A And 2B , there figure 4C shows the interior of the return means 6, and in particular the arrangement of the first elastic element 61 and the second elastic element. This figure, however, clearly highlights the fusion of the various functional parts mentioned above, namely the control member 5, the locking element 53 and the stop element 54, produced by a single structural part, namely a push button, a tooth and a retractable hook. The doubling of each of these structural elements makes it possible to further increase the comfort of use by using a particularly intuitive operation. Furthermore, this figure also shows how the two push buttons are guided in translation in a radial direction, perpendicular to the longitudinal direction L of the clasp 100 (corresponding to that of the cover 7), thanks to the use of two separate elastic return elements.Indeed, the fact that the outer casing of both the first push button 5A and the second push button 5B is in contact with respect to the internal surface of each lateral insertion opening provided in the side walls 74 of the cover combined with this arrangement of a mutual connection via two split elastic return elements makes any rocking movement of the push buttons impossible and confines their movement to a single translation towards the inside of the cover. Furthermore, it may be noted that the shape of the side walls of the internal bulge 711, partially cylindrical, additionally forms at least in part an internal bearing surface for the elastic return means 6, when they are constituted by first and second cylindrical elastic elements 61 and 62 respectively, and consequently further reinforces the slide structure provided.

[0076] Finally, we will describe in the following simultaneously the figures 5A et 5B , corresponding respectively to a position of the clasp in which the length of the bracelet is shortened, conventionally called the first adjustment position P1, and a position of the clasp in which the length of the bracelet is on the contrary lengthened, conventionally called the second adjustment position P2. Apart from this configuration in terms of adjustment position, the figures 5A et 5B differ in that the figure 5A illustrates a case where the control member 5 is at rest (rest position Pr) while the figure 5B illustrates a case where the control member 5 is in the active position Pa, that is to say where the first push button 5A and the second push button 5B are pressed and consequently the stop teeth 54A, 54B integral with each of these push buttons 5A, 5B are released from the toothing of the rack 42A, 42B which is associated with them, here in particular the second tooth 54B of the corresponding notch of the second lateral toothing 42B of the rack 4.

[0077] Each of the figures 5A et 5B illustrates the interior of the cover 7 according to the same view as the figures 4A-4C previous ones, and the only thing that has been added to these new latest figures compared to the previous ones mainly concerns the sliding connecting element 4 as well as the associated rack mechanism. As a reminder, this sliding connecting element 4 is connected in an articulated manner to a first end 21 of the first branch 2, itself connected to the first leg 3A and second leg 3B of the stretcher forming the second branch 3 of the clasp via the articulation axis 23, as illustrated on the left of these figures.

[0078] As can be seen by comparing the figures 5A et 5B , it is possible to move from the second adjustment position P2 corresponding to the extended length of the bracelet to the first adjustment position P1 without having to actuate the control member 5, but on the contrary by simply acting on the strands of the bracelet. Indeed, the oblique surface O of the notches 420 of the rack, which had not been referenced on the figures 2A And 2Bfor reasons of readability, and oriented inwards going from right to left in the figure, which means that it is possible to push the sliding connecting element 4 from its "exit" position of the first internal compartment 71 of the cover 7 towards the bottom of this same compartment to the right, up to the demarcation line materializing the delimitation with respect to the second internal compartment 72. In other words, a shortening of the length of the bracelet is possible without pressing the push buttons 5A, 5B. However, on the contrary and in accordance with the requirements applicable in particular to diving watches, it must always be impossible to generate an enlargement of the size of the bracelet without requiring a specific actuation, and this to avoid any handling error and losing the watch, which could prove very dangerous.To do this, the shape of each of the notches of the lateral teeth of the rack, namely the first notches 420A of the first lateral tooth 42A and the second notches 420B of the second lateral tooth 42B have, in addition to the oblique surface O, a surface S perpendicular to the longitudinal direction of the clasp, making any jump backwards impossible. Such a mechanism is therefore in no way likely to cause any involuntary elongation of the length of the bracelet. The extension of the surfaces S and O of the notches has been shown in dotted lines in each of these figures.

[0079] To achieve such an elongation, it is thus necessary, according to the invention, to move to the active position Pa of the control member 5, illustrated here by the depression of the second push button 5B under the action of a force F exerted radially towards the inside of the cover 7. Such an action thus releases the second stop tooth 54B from the second notch 420B with which it was engaged. In this way, if it is not necessary to resort to the active position Pa of the second push button 5B (and implicitly of the first push button 5A, actuated simultaneously) to move from the second adjustment position P2 illustrated on the figure 5B to the first adjustment position shown on the figure 5A , such an active position Pa is however imperative to move from the first adjustment position P1 as illustrated on the figure 5A to the second adjustment position P2 as shown in the figure 5B .

[0080] The maximum adjustment stroke C, which is preferably between 5 and 8 millimeters, is indicated on the figure 5B as corresponding to the difference in bracelet length between the first adjustment position P1 and the second adjustment position P2.

[0081] Thus, the present invention describes a new folding clasp of simple and refined construction particularly suitable for a diving watch with regard to the additional mechanism for extending the length of the bracelet which can be easily concealed in addition to that of the fine adjustment of the length under the cover of the clasp. Furthermore, the proposed adjustment device can be easily integrated in a modular manner into an existing folding clasp solution, and what is more in a particularly aesthetic manner by concealing it entirely under a removable cover. This variant also has the additional advantage of facilitating after-sales service by allowing spare parts of the clasp to be replaced more easily.

Claims

1. A clasp (100) with a folding buckle for a wristwatch, comprising at least one first arm (2) and a second arm (3) articulated with respect to one another around an axis (23), said clasp (100) having, on the one hand, a locking device for holding said first arm (2) and second arm (3) in the folded position on top of one another in the closed position of the clasp and, on the other hand, a device (45) for adjusting the effective length of said strap comprising a linking element (4) mounted slidingly under a top cover (7) of said clasp (1), and a stop element (54) cooperating with said sliding linking element (4), as well as a control member (5) which can be actuated from a rest position (Pr) towards an active position (Pa), characterised in that the end of said second arm (3) opposite said axis (23) comprises attachment means to a first strand (B1) of the strap, and in that the end of the first arm (2) opposite said axis (23) is connected in an articulated manner to said sliding linking element (4), and in that said control member (5) is arranged so as to be able, when it is located in the active position (Pa), to simultaneously bring about the unlocking of said clasp (100) by acting on a locking element (53), and to release said linking element (4) from said stop element (54), said sliding linking element (4) being able to be moved, when said control member (5) is located in said active position (Pa), independently of the open or closed position of said clasp (100).

2. The clasp (100) with a folding buckle for a wristwatch according to Claim 1, characterised in that the locking element (53) consists of hooking means engaging against lower support surfaces of said second arm (3).

3. The clasp (100) with a folding buckle for a wristwatch according to Claim 2, characterised in that said hooking means are retractable hooks (53A,53B) coming to rest against shoulders (36A,36B) arranged inside a first leg (3A) and respectively a second leg (3B) of a shaft forming said second arm (3).

4. The clasp (100) with a folding buckle for a wristwatch according to any one of the preceding claims, characterised in that said stop element (54) of said adjusting device (45) is formed by at least one tooth (54A, 54B) engaging with notches (420) of a rack (42) arranged inside said sliding linking element (4).

5. The clasp (100) with a folding buckle for a wristwatch according to Claim 4, characterised in that said teeth (54A,54B) and said notches (420) of said rack (42) have a surface (S) perpendicular to the longitudinal direction (L) of the clasp (100) and a surface stretching in an oblique direction (O) oriented in the narrowing direction of the effective length of the strap.

6. The clasp (100) with a folding buckle for a wristwatch according to any one of the preceding claims, characterised in that said adjusting device (45) is housed in a first compartment (71) arranged entirely under said top cover (7) of said clasp (100).

7. The clasp (100) with a folding buckle for a wristwatch according to Claim 6, characterised in that the sliding linking element (4) can move between a first shortened adjustment position (P1) and a second extended adjustment position (P2), said sliding linking element (4) being entirely concealed, on the one hand, under said top cover (7) and, on the other hand, under a bottom cover (70) which is removably fixed to said top cover (7) in said first shortened adjustment position (P1), and always concealed under said top cover (7) even in the second extended position (P2).

8. The clasp (100) with a folding buckle for a wristwatch according to any one of the preceding claims, characterised in that the control member (5) consists of at least one pushbutton (5A,5B) housed in a lateral opening (740A,740B) of said top cover (7).

9. The clasp (100) with a folding buckle for a wristwatch according to Claim 8, characterised in that said pushbutton (5A,5B) is actuated from the rest position (Pr) towards said active position (Pa) by acting against elastic return means (6) arranged perpendicularly with respect to the longitudinal direction (L) of the strap towards the interior of said top cover, said locking element (53) being formed by a retractable hook (53A,53B) and the stop element (54) being formed by a tooth (54A,54B), and said retractable hook (53A,53B) and said tooth (54A,54B) being integral with said pushbutton (5A,5B).

10. The clasp (100) with a folding buckle for a wristwatch according to Claim 9, characterised in that said retractable hook (53A,53B) and said tooth (54A,54B) are formed by a single piece with said pushbutton (5A,5B).

11. The clasp (100) with a folding buckle for a wristwatch according to Claim 9 or 10, characterised in that said control member (5), and respectively said tooth (54A,54B) and said retractable hook (53A,53B) are mobile in planes superposed on top of one another in the thickness direction of said top cover (7) .

12. The clasp (100) with a folding buckle for a wristwatch according to Claim 11, when it is dependent on Claim 7, characterised in that said retractable hook (53A,53B) is mounted through a window (70A,70B) arranged in said bottom cover (70).

13. The clasp (100) with a folding buckle for a wristwatch according to any one of Claims 9 to 12, characterised in that the elastic return means are formed by a first elastic return element (61) and a second elastic return element (62) arranged in parallel with respect to one another according to a direction perpendicular to the longitudinal direction (L) of the strap.

14. The clasp (100) with a folding buckle for a wristwatch according to any one of the preceding claims, characterized in that it furthermore comprises an extension device (8) of the effective length of the strap housed in a second compartment (72) arranged entirely under said top cover (7) of said clasp (100).

15. The clasp (100) with a folding buckle for a wristwatch according to Claim 14, characterised in that said extension device (8) comprises an attachment piece (81) with a second strap strand (B2) forming a hinge with an intermediate link (82) pivotally fixed with respect to the top cover, a cylindrical locking pin (820) of said intermediate link (82) being able to be fitted into a transverse fixing groove (813) of said attachment piece (81) in the retracted position (Pn) of said extension device (8).