EP3850980A1 - Clasp for a timepiece - Google Patents

Abstract

Clasp (1) with folding clasp for a wristwatch comprising at least a first branch (2) and a second branch (3) articulated with respect to one another around an axis (23), comprising a on the one hand means for connecting the free ends of each of the branches (2,3) to respective strands of a bracelet, and on the other hand a locking device for holding the branches (2,3) in the folded position one on the other in the closed position of the bracelet, the locking device comprising at least one retractable hook (4A, 4B) arranged on the second branch (3), which cooperates with at least fixed hooking means (62A, 62B) arranged on a cover (6) integral with the first branch (2) in the locking position, the retractable hook (4A, 4B) being held in the locking position by an elastic element (5A, 5B), and further comprising an element sliding (7), arranged in the cover (6) and held in a rest position by at least one other elastic element (710,720), the sliding element (7) being arranged to release the retractable hook (4A, 4B) when acting against the restoring force exerted by the other elastic element (710,720).

Description

Technical field of the invention

The present invention relates to the field of watchmaking, and in particular to a clasp for a wristwatch.

State of the art

There are known clasps of the folding clasp type with two branches folded over one another 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 increase in diameter conferred. Such an arrangement makes it possible to improve safety and comfort of use, by making it possible, on the one hand, to simply put the wristwatch on his 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 devices for fastening and locking the bracelet make it possible to prevent the watch from falling if the two strands were to become detached from one another in the event of a malfunction of the locking system.

Besides the clasps with two branches, there are also known devices with three branches, also called "butterfly", where two small side branches arranged symmetrically and articulated around the ends of a central branch come to be folded in the center thereof. Whatever the number of branches of the clasp, the most usual solution consists in arranging two pushers in the walls of a cover which is clamped on either side of the cover to open the clasp and release hooks arranged perpendicular to the cover. the longitudinal axis of the branches. The disadvantage of this type of clasp where the hooks are arranged at the end of flexible blades is the reliability of the locking device over time.

In addition, there are a large number of hooking or locking systems using the elastic properties of the folding branches of the clasp; a drawback of this type of clasps is, however, that it depends on the material and the dimensions of the folding branches themselves.

There is therefore a need for a solution free from these known limitations.

Summary of the invention

An aim of the present invention is to provide an alternative locking solution for a clasp, which can be easily actuated by the wearer of the wristwatch and whose reliability is guaranteed over time.

Another object of the present invention is to allow a more secure unlocking of the clasp.

According to the invention, these objects 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.

In particular, these goals are achieved by virtue of a folding clasp for a wristwatch comprising at least a first branch and a second branch articulated with respect to one another around an axis, comprising on the one hand means for connecting the free ends of each of the first branch and second branch to respective strands of a bracelet, and on the other hand a locking device for holding the first branch and second branch in the folded position one over the other in the closed position of the bracelet, characterized in that the locking device comprises at least one retractable hook arranged on the second branch, which cooperates with at least fixed hooking means arranged on a cover integral with the first branch in the locking position , the retractable hook being held in the locking position by an elastic element, and further comprises a sliding element, arranged in the cover and held in a e position at rest by at least one other elastic element, the sliding element being arranged to release the retractable hook when acting against the restoring force exerted by the other elastic element.

An advantage of the proposed solution is to provide a new clasp provided with an alternative locking system, the reliability and durability of which are increased thanks to the sliding movement of the locking hooks.

According to a preferred embodiment of the folding clasp according to the invention, the sliding element moves along the longitudinal axis of the first branch and second branch.

An advantage of the solution proposed according to this embodiment is to provide a new clasp provided with a more intuitive locking system, due to the greater space available in the direction of the length of the branches.

According to another preferred embodiment of the folding clasp according to the invention, at least one retractable hook also moves along the longitudinal axis of the first branch and second branch.

An advantage of the solution proposed according to this preferred embodiment is to provide an even more secure locking and unlocking device, owing to the return forces applied to the sliding element and to the retractable hook which can be added.

According to a preferred embodiment of the folding clasp according to the invention, the retractable hook has an inclined upper surface.

An advantage of the solution proposed according to this preferred embodiment is to facilitate the mechanism for re-engaging the hooks in their locking position, which consequently minimizes their wear and preserves their lifetime.

According to a preferred embodiment of the folding clasp according to the invention, the first branch is a central branch, while the second branch is formed by two legs, namely a first leg and a second leg, a first longitudinal housing being provided to house a first retractable hook as well as a first elastic element, and a second longitudinal housing being provided to house a second retractable hook as well as a second elastic element.

An advantage of the solution proposed according to this preferred embodiment is to allow easy integration into a conventional folding clasp structure, and also increasing the restoring force through the use of several hooks whose symmetrical arrangement on each of the legs also makes it possible to optimize the guiding properties.

According to a preferred embodiment of the folding clasp according to the invention, the first longitudinal housing is arranged in a first bulge at the level of the free end of the first leg, and the second longitudinal recess being arranged in a second bulge at the level of the free end of the first leg. level of the free end of the second leg to accommodate said respective retractable hooks therein.

An advantage of the solution proposed according to this preferred embodiment is to be able to increase the size of the hooks and of the elastic return elements, in order to maximize the reliability of the locking.

According to a preferred embodiment of the folding clasp according to the invention, the retractable hook has an oblong hole in which is inserted a fixing axis perpendicular to the longitudinal axis of the first branch and second branch.

An advantage of the solution proposed according to this preferred embodiment is that it allows simple assembly of the hook or hooks, while maximizing their guiding properties by sliding along the longitudinal axis of the branches.

According to a preferred embodiment of the folding clasp according to the invention, the fixed hooking elements are formed by orifices formed in a vertical wall of the cover.

An advantage of the solution proposed according to this preferred embodiment is to make the arrangement of the fastening elements as simple and as inexpensive as possible, by integrating them into an existing part such as the cover, and this without requiring any addition. of material nor having to generate a complex geometric shape. Moreover, these fastening elements remain hidden under the cover, which guarantees that the aesthetic properties of the clasp are maintained.

According to a preferred embodiment of the folding clasp according to the invention, the sliding element comprises a first protuberance and a second protuberance extending along the longitudinal axis of the first branch and second branch, the first protuberance being arranged to be able to to be introduced into said first orifice and the second protuberance being arranged so as to be able to be introduced into the second orifice.

An advantage of the solution proposed according to this preferred embodiment is to guarantee, by such a symmetrical arrangement via the arrangement of protuberances cooperating respectively with the catching elements of the cover, excellent guiding properties of the sliding element according to the longitudinal axis of the branches.

According to a preferred embodiment of the folding clasp according to the invention, the sliding element is a pusher accessible from the front of the cover.

One advantage of the solution proposed according to this preferred embodiment is that it maximizes the ergonomic properties of the clasp, the unlocking of which can now be actuated via a single finger. The ease of actuation is thus considerably improved compared to the usual clasps requiring the gripping either of a lever, or the simultaneous actuation of lateral pushers.

According to a preferred embodiment of the folding clasp according to the invention, the sliding element is actuated by a lever mounted to pivot relative to the cover along an axis of rotation perpendicular to the longitudinal axis of the first branch and second branch.

One advantage of the solution proposed according to this preferred embodiment is that it maximizes the security of the clasp, the unlocking of which is thus almost impossible via poor handling by the user or even a shock to an external element.

According to a preferred embodiment of the folding clasp according to the invention, the axis of the lever being integral with cams acting on the sliding element.

An advantage of the solution proposed according to this preferred embodiment is to very simply transmit the pivoting movement of the lever to the sliding element hidden under the cover. Thus, the integration of the unlocking force transmission mechanism is simplified.

According to a preferred embodiment of the folding clasp according to the invention, a first cam is arranged in a first axial recess of the sliding element, and a second cam is arranged in a second axial recess of the sliding element.

An advantage of the solution proposed according to this preferred embodiment is to optimize the reliability of actuation via the arrangement of symmetrical cams arranged on either side of the longitudinal axis of the branches, while at the same time preserving the aesthetics. of the clasp.

According to a preferred embodiment of the folding clasp according to the invention, the sliding element is provided with a first longitudinal housing for accommodating a third elastic element and with a second longitudinal housing for accommodating a fourth elastic element.

An advantage of the solution proposed according to this preferred embodiment is to facilitate the integration of elements intended to exert a restoring force against the sliding element directly therein. Thus, it is easy to easily generate a return force along the longitudinal axis which can preferably be added to that exerted by the hooks.

Other preferred embodiments will moreover be detailed in the following description.

It will be understood from the rest of this detailed description that the advantageous characteristics drawn from the preferred embodiments can be taken individually or in combination, except when these will be presented as mutually exclusive, such as for example for the actuation of the unlocking via a push-button or a lever mentioned in the above.

Brief description of the drawings

• la figure 1 est une vue éclatée selon un mode de réalisation préférentiel pour l'invention, selon lequel le déverrouillage du fermoir est actionné par un poussoir;
• la séquence des figures 2A,2B,2C,2D et 2E montre des vues en coupe du mode de réalisation préférentiel pour l'invention illustré par la figure 1 précédente, respectivement selon les plans de coupe A-A, B-B et C-C illustrés sur cette figure, selon différentes positions P1-P5 illustrant le passage d'une position verrouillée à une position déverrouillée, et vice-versa, via le mécanisme de verrouillage et respectivement déverrouillage proposé selon l'invention;
• la figure 3 est une vue éclatée selon un mode de réalisation préférentiel pour l'invention, selon lequel le déverrouillage du fermoir est actionné par un levier;
• la séquence des figures 4A,4B,4C,4D et 4E montre des vues en coupe du mode de réalisation préférentiel pour l'invention illustré par la figure 3 qui précède, respectivement selon les plans de coupe B-B, A-A et D-D illustrés sur cette même figure, selon les mêmes différentes positions P1-P5 que celles de la séquence de figures relative au mode de réalisation précédent, illustrant le passage d'une position verrouillée à une position déverrouillée, et vice-versa, via le mécanisme de verrouillage et respectivement déverrouillage proposé selon l'invention.

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

• the figure 1 is an exploded view according to a preferred embodiment for the invention, according to which the unlocking of the clasp is actuated by a pusher;
• the sequence of figures 2A, 2B, 2C , 2D and 2E shows sectional views of the preferred embodiment for the invention illustrated by figure 1 previous, respectively according to the section planes AA, BB and CC illustrated in this figure, according to different positions P1-P5 illustrating the passage from a locked position to an unlocked position, and vice versa, via the locking and unlocking mechanism respectively proposed according to the invention;
• the figure 3 is an exploded view according to a preferred embodiment for the invention, according to which the unlocking of the clasp is actuated by a lever;
• the sequence of figures 4A, 4B , 4C, 4D and 4E shows sectional views of the preferred embodiment for the invention illustrated by figure 3 which precedes, respectively according to the section planes BB, AA and DD illustrated in this same figure, according to the same different positions P1-P5 as those of the sequence of figures relating to the previous embodiment, illustrating the passage from a locked position to an unlocked position, and vice versa, via the locking and unlocking mechanism respectively proposed according to the invention.

detailed description

The figure 1 illustrates a folding clasp for a timepiece 1 according to a preferred embodiment for the present invention, in which the actuation is particularly ergonomic, since it is carried out via a simple pusher 70.

The folding clasp 1 conventionally comprises two branches, that is to say here a first central branch 2, and a second branch 3 formed of two distinct legs, the first leg 31 and the second leg 32. The first branch 2 and the second branch 3 are articulated around a hinge pin 23, inserted into a first fixing hole 310 of the first leg 31 and another corresponding fixing hole provided in the second leg 32, not shown in the figure. figure 1 . The first branch 2 is folded between the first leg 31 and the second leg 32 of the second branch 3 in the closed position of the clasp 1.

The first central branch 2 is integral with a first bracelet strand B1, not visible in this figure but shown in the sequence of figures 2A-2E which is described below. The bracelet B1 is attached to the cover 6 via an attachment pin 60, while the cover 6 is itself attached to the first branch 2, preferably via one or more fixing screws 24 - here two according to the preferred embodiment illustrated - inserted into the corresponding second fixing holes 240 provided in the first branch 2.

The second branch 3 is integral with a second strand of bracelet B2, not shown in this figure but the insertion of which into the passage 36 provided for this purpose is also shown schematically in the sequence of figures 2A-2E described in the following. We can however distinguish this passage 36 on the figure 1 , formed under the terminal ends of the legs of the second branch 3, that is to say under the first bulge 311 at the level of the free end of the first leg 31 and the second bulge 321 at the level of the free end of the second leg 32 and between the lower gateway 34 connecting side edges 35. This second strap strand B2 is preferably provided with holes in order to allow adjustment in length, and a fixing stud 25, itself integral with the second branch 3 via an insertion in a fixing hole 330 provided in an upper gateway 33 connecting the first leg 31 and the second leg 32, is provided to fix the second strand B2 in a position corresponding to a predefined length, this length being able to take a set of discrete values corresponding to the number of holes made in this second strand B2. In this way, the latter can be held in position under the second branch 3, in the locked or unlocked position of the clasp 1.

At the top of the figure 1 , we can distinguish the detail of the arrangement of the cover 6 on which is therefore mounted the retaining pin 60 for the first strand B1 of a bracelet, but also a pusher 70 constituting a preferred embodiment as an element sliding 7 for actuating the unlocking of the clasp 1, as explained below. The pusher 70 comprises two protuberances arranged symmetrically in the longitudinal direction L of the branches, namely a first protuberance 7A and a second protuberance 7B. These protuberances are arranged to fit respectively into a first retaining orifice 62A and a second retaining orifice 62B, arranged in a vertical wall 61 of the cover 6. This first retaining orifice 62A and this second retaining orifice 62B act in parallel. as holding or respectively hooking elements fixed for the retractable hooks 4A & 4B arranged on the second branch 3, as explained below.

The pusher 70 is here fixed to the cover by means of a fixing screw 73 inserted in the central hole 610 of the vertical wall 61. In the pusher 70 are also arranged longitudinal housings, visible in the sequence of figures 2A-2E described below, in which are inserted elastic means exerting a first return force F1 against the pusher 70. These elastic elements are respectively qualified as third elastic means 710 and fourth elastic means 720, in order to distinguish them from the first elastic element 5A acting on the first retractable hook 4A and second elastic element 5B acting on the second retractable hook 4B arranged on the second branch 3, as illustrated at the bottom of the figure 1 . The first elastic element 5A and the second elastic element 5B also exert a restoring force, referred to as the second restoring force F2 in order to differentiate it from the first restoring force F1, but which is here also arranged so as to orient itself according to the longitudinal direction L of the two branches of the clasp. In this way, these two return forces F1 and F2 oriented in the same direction and in the same direction, accumulate to improve the security of the clasp, the force required F for unlocking can easily be made to lie above a predetermined threshold excluding any inadvertent handling error by the user.

According to the preferred embodiment illustrated in figure 1 , the first retractable hook 4A is inserted, like the first elastic element 5A, in a first housing 31A provided in the first leg 31 of the second branch 3, while, similarly, the second retractable hook 4B is inserted, likewise that the first elastic element 5B, in a second housing 32A arranged in the second leg 32 of the second branch 3. The first retractable hook 4A comprises a first oblong hole 40A and similarly the second retractable hook 4B comprises a second oblong hole 40B, allowing sliding of each of these hooks in the longitudinal direction L of the branches.

Each of the hooks is moreover fixed to its respective leg of the second branch 3 by means of a fixing pin; thus the first retractable hook 4A is fixed to the first leg 31 via a first fixing pin 41A inserted in a lateral fixing hole 410A provided in the first bulge 311, and the second retractable hook 4B is similarly fixed in the second bulge of the second leg 32 via a second fixing pin 41B inserted into a corresponding lateral fixing hole (not visible on the figure 1 ) arranged in the 2 ^nd bulge 321. Each of the fixing pins, that is to say the first fixing pin 41A and the second fixing pin 41B are intended to be inserted in parallel respectively into the first oblong hole 40A of the first retractable hook 4A and the second oblong hole 40B of the second retractable hook 4B.

As can also be seen at the bottom right of the figure 1 , each of the two retractable hooks is furthermore provided with an inclined upper surface, namely a first inclined upper surface 42A on the first retractable hook 4A and a second inclined upper surface 42B on the second retractable hook 4B. These inclined surfaces are intended to facilitate the process of re-engaging the clasp, as explained in view of the sequence of figures 2A-2E described below. On the contrary, the two studs visible below the cover 6 consist of pawls-springs 63 exerting a repulsive force between the branches and thus making it possible to facilitate the opening of the clasp 1.

The sequence of figures 2A-2E illustrates the clasp 1 in a first locked position P1, then in a second unlocking actuation position P2 where the two branches are still superimposed on each other but where the pusher 70 has been pressed to release the retractable hooks, then in a third unlocked position P3, where the branches are no longer superimposed on one another and the clasp is open, and then in a fourth position P4 of re-engagement of the locking mechanism, where the two branches are at again almost superimposed one on the other, and finally a fifth position P5 where the clasp is again in the locked position. In other words, the positions P1 and P5 are completely identical.

Each of these five positions are described with the aid of three sectional views, corresponding to sagittal section planes of the clasp 1 crossing the axes AA, BB, and CC of the clasp 1 illustrated on the figure. figure 1 .

The sagittal section plane via A-A passes through the first retractable hook 4A, and thus illustrates the movement of the latter during the locking and unlocking process. It may be noted that a view along a sagittal section plane crossing the second retractable hook 4B arranged symmetrically with respect to the first retractable hook 4A would be identical in all points.

The sagittal section plane B-B passes through the third elastic element 710 exerting a restoring force against the pusher 70 and illustrating the movement of the latter during the locking and unlocking process. As for the previous sectional view, it will be noted that a view along a sagittal section plane crossing the fourth elastic element 720 would also be identical in all points.

Finally, the sagittal section plane C-C is a median sagittal plane passing through the cover 6 and the first central branch 2 at their center.

In what follows, the various positions P1, P2, P3, P4 (and P5 corresponding again to P1) will be described with indifference to the various cutting axes A-A, B-B and C-C.

On the figure 2A , in particular on the view along the sagittal plane along the axis AA, one can distinguish the first bracelet strand B1 fixed to the cover 6 integral with the first branch 2 via the attachment axis 60, as well as a spring pawl 63 inserted into its respective housing 630 on the underside of the cover 6. The first retractable hook 4A is in its locking position, where it is compressed to the right under the action of the second return force F2 of the first elastic element 5A arranged behind it in the first longitudinal housing 31A of the first leg 31. Thus, the first fixing pin 41A is on the left of the first oblong hole 40A, while the first retractable hook 4A is engaged in the first hole maintenance 62A - not referenced in this figure for reasons of readability but visible further on the figure 2C - Arranged in the vertical wall 61 of the cover, as well as the first protruding part 7A of the sliding element 7 formed here by the pusher 70. Under this locking device of the clasp, one can also distinguish the lower gateway 34 defining the passage 36 for the second strand B2 of the bracelet under the legs of the second branch 3.

The sagittal sectional view along the axis B-B shows the longitudinal housings for the elastic elements intended to exert the return force against the pusher, which is here in its rest position. Thus, the first longitudinal housing 71 arranged directly in the pusher 70 houses the third elastic element 710 exerting the second return force F2 against the pusher, in the longitudinal direction of the branches. In this sectional view, one can also distinguish an inclined lower surface 61A at the bottom of the vertical wall 61 of the clasp, which will make it possible to cooperate with the upper inclined surface of the first retractable hook (see in particular the figure in sagittal section AA of the fourth reset position P4, described below).

Finally, the view in sagittal section along the axis CC shows the attachment of the pusher 70 to the cover via the fixing screw 73, the head of which is, in this first locking position P1, in contact with the vertical wall 61 of the cover 6.

The difference between the first locking position P1 and the second unlocking actuation position P2 illustrated on figure 2B consists of the position of the pusher 70, on which a force F is exerted in the opposite direction to both the second return force F2 exerted on the first retractable hook and the first return force F1 exerted on the pusher 70. Thus, the pusher is pushed slightly to the left, so that the first protuberance 7A sinks even further into the retaining hole 62A, pushing the first retractable hook 4A in parallel to release it progressively until it is released. . In this position where the first retractable hook is released, the first fixing pin 41A is then located completely in abutment on the right of the first oblong hole 40A, that is to say its other end.

On the view in sagittal section along the axis CC, it can also be clearly seen that the base of the head of the fixing screw 73 of the pusher 70 is no longer resting on the vertical wall 61 of the cover, but s 'is slightly shifted to the left.

In the third unlocked position P3, illustrated on figure 2C , the branches are no longer superimposed on one another and it is thus possible to clearly separate the first branch 2 from the second branch 3; on the view in sagittal section along the AA axis, we can now clearly see the lower end of the pawl-spring 63, which has made it possible to exert a repulsive force R downwards and to facilitate the process of mutual dissociation of the branches . However, it can be seen that the return forces exerted respectively on pusher 70 and the first retractable hook 4A, that is to say respectively the first return force F1 and the second return force F2 exerted via the first elastic element 5A and the third elastic element 71, have precisely enabled both the first retractable hook 4A and the pusher 70 to be in the same “at rest” position, that is to say at the end of travel to the right. All these elements are therefore found in the same position as in the first locking position P1.

In the fourth position P4, shown on 2D figure , where one seeks to re-lock the clasp, only an action is exerted against the second return force F2 to allow the first retractable hook 4A to be first pushed to the left before be reinserted into the first retaining hole 62A made in the vertical wall 61 of the cover 6. No action is necessary on the pusher 70, which is in the same position as on the figures 2A and 2C previous ones, that is to say in the first locking position P1 and the third unlocking position P3. In order to facilitate the release and then snap-in mechanism of the first retractable hook 4A, the first inclined surface 42A of the first retractable hook 4A cooperates with the lower inclined surface 61A of the vertical wall 61 of the cover 6, so that the compression of the elastic element is as progressive as possible and the wear of the clasp is reduced to a minimum. Thus, the inclination of each of these surfaces is preferably identical, and equal to 45 °. Once the nose of the first retractable hook 4A is brought to bear against the vertical wall 61 of the cover, the restoring force F2 is maximum and as the cover 6 is folded over the second branch 3 (of which only the first leg 31 and the first bulge at the end thereof is shown on this 2D figure ), it will be possible to release the hook as soon as it is brought opposite the first retaining hole 62A.

The figure 2E thus corresponds to the moment when the re-engagement of the clasp 1 is complete, so that it is again in the locked position. In other words, the fifth position P5 corresponds to the first locking position P1, but the latter being illustrated only at the end of an unlocking plus re-locking sequence.

In the preferred embodiment which follows, corresponding to a mode of actuation of the unlocking via a lever and which is illustrated by figure 3 , the elements common to those of the preferred embodiment described above illustrated in particular by the figure 1 will not be repeated in detail. Indeed, only the actuation mode for unlocking the clasp changes.

By comparing the figures 1 and 3 , it can be seen that the bottom of each of the figures, relating to the arrangement of the branches and of the retractable hooks in particular, is completely identical; it is thus possible to refer to the explanations which have been previously provided for each of the constituent elements of the clasp.

The top of the figure 3 shows on the other hand a new actuating device for unlocking, including a lever 8 mounted to pivot about an axis of rotation 80 of the cover 6. This lever 8 is provided with fixing insertion holes 84, in which come s 'insert at least one cam intended to be integral in rotation with the lever 8. According to the preferred embodiment illustrated, the actuating device for the unlocking comprises a first cam 81 which has a first rod 810, integral with an insertion orifice (not visible in this figure), and which is inserted into a lateral orifice 83 of the cover 6, as well as a first head 811 in egg-shaped intended to be housed in a first axial recess 74 of the sliding element 7, actuated in translation by the lever 8.

A second cam 82, arranged symmetrically with respect to the first cam 81 vis-à-vis the cover 6, for its part has a second rod 820 fixed to the fixing hole 84 of the lever 8, and which similarly passes through another hole insertion (not visible on the figure 3 ), as well as a second head 821 having the same egg shape as the first head 811, and which is intended to be housed in a second axial recess 75 of the sliding element 7, actuated in translation by the lever 8.

In this way, the actuation of the sliding element 7 in translation takes place via the actuation of the lever 8 in rotation, the rotary movement of which is transformed into an actuation movement in translation in the longitudinal direction via the first cam 81 and second cam 82. Therefore, the sliding element 7, which preferably comprises the same protruding parts as the pusher 70 according to the previous embodiment - that is to say a first protuberance 7A and a second protuberance 7B, respectively being inserted into a first retaining orifice 62A and a second retaining orifice 62B (not shown in the figure 3 , but which will be visible on the sequence of figures 4A-4E following) unlocks the clasp in the same way as according to the embodiment described above, that is to say by acting on the retractable hooks 4A, 4B in the longitudinal direction L of the branches against the second force return F2 exerted by the first elastic element 5A and the second elastic element 5B. The essential difference relates only to the mode of actuation in translation of this sliding element 7, which is merged with a pusher 70 according to the first embodiment of the figure 1 to form one and the same part, while this sliding element 7 cannot be actuated directly by hand, but on the contrary indirectly via the lever 8 which then becomes the actuating part that must be gripped and manipulated by the user. In other words, the solution according to the mode of realization of the figure 1 is more ergonomic, that is to say more user-friendly and easier to handle, for example using the single index finger of the hand opposite to that in which the watch is worn, but conversely, the solution proposed according to the embodiment illustrated on the figure 3 guarantees maximum reliability of use, because it is almost impossible to activate the unlocking of the clasp by mistake.

The sequence of figures 4A-4E illustrates the clasp 1 in the same positions P1-P5 as those of figures 2A-2E , that is to say a first locked position P1, then in a second unlocking actuation position P2 where the two branches are still superimposed on each other but where the sliding element 7 has been pushed by the cams in order to release the retractable hooks, then in a third unlocked position P3, where the branches are no longer superimposed on one another and the clasp is open, and then in a fourth position P4 for re-engaging the mechanism locking, where the two branches are again almost superimposed on one another, and finally a fifth position P5 where the clasp is again in the locked position. In other words, the positions P1 and P5 are completely identical.

Each of these five positions are described with the aid of three sectional views, corresponding to sagittal sectional planes of the clasp 1 crossing the axes AA, BB and DD of the clasp 1 illustrated on the figure. figure 3 . The axes AA and BB are common to the clasp illustrated on the figure 1 , however the central CC axis of the previous embodiment is now replaced by the DD axis passing through the head of the first cam 81. It may however be noted that a figure produced along a cutting axis passing through the second retractable hook 4B would be identical to that of the figure in sagittal section along the axis AA, and that a figure produced along a sagittal section plane passing through the head of the second cam 82 would be identical to that illustrated along the axis DD.

Given the many similarities between figures 4A-4E and the figures 2A-2E , here again we will insist on the distinctive elements of this new embodiment, without repeating the elements common to the preferred embodiment described above.

On the figure 4A , corresponding to the first locking position P1, according to the view along the sagittal plane along the axis AA now disposed in the middle, we can distinguish the first bracelet strand B1 fixed to the cover 6 integral with the first branch 2 via the axis fastener 60, as well as a spring pawl 63 inserted in its respective housing 630 on the underside of the cover 6. The first retractable hook 4A is in its locking position, where it is compressed to the right under the action of the second restoring force F2 of the first elastic element 5A arranged behind it in the first longitudinal housing 31A of the first leg 31. Thus, the first fixing axis 41A is located on the left of the first oblong hole 40A, while the first retractable hook 4A is engaged in the first retaining hole 62A - not referenced in this figure for reasons of readability but visible further on the figure 4C - Arranged in the vertical wall 61 of the cover, as well as the first protruding part 7A of the sliding element 7 hidden under the cover 6. Affixed on the cover 6, one can also distinguish a part of the lever 8. Under this device of locking the clasp, we can also distinguish the lower gateway 34 defining the passage 36 for the second strand B2 of the bracelet under the legs of the second branch 3. In this sectional view, we can also distinguish an inclined lower surface 61A at the bottom of the vertical wall 61 of the clasp, which will make it possible to cooperate with the upper inclined surface of the first retractable hook 42A, not shown in this figure for reasons of visibility, but highlighted later on figures 4C and 4D corresponding to the third and respectively fourth positions P3 and P4.

The view in sagittal section along the axis BB of the figure 4A highlights the longitudinal housings for the elastic elements intended to exert the return force against the sliding element 7, which is here in its rest position. Thus, the first longitudinal housing 71 arranged directly in the sliding element 7 houses the third elastic element 710 exerting the first return force F1 against the pusher, in the longitudinal direction L of the branches.

Finally, the view in sagittal section along the axis DD shows the relationship between the position of the lever 8 and the position of the first cam 81, of which the head is here oriented downwards (that is to say the first head 811 with its tapered part pointing downwards). In this first locking position P1 where the lever 8 is affixed to the cover 6, it can be seen that the first cam 81 does not act on the sliding element, which is held in position via the first return force F1 exerted by the third elastic member 710 and the fourth elastic member 720 (not shown).

The difference between the first locking position P1 and the second unlocking actuation position P2 illustrated on figure 4B consists of the position of the lever 8, now pulled upwards, and which makes it possible to exert a force F in the opposite direction to both the first return force F1 exerted on the sliding element 7 and the second force of recall F2 exerted on the first retractable hook 4A. Thus, under the impulse of the first head 811 of the first cam 81, the sliding element is depressed slightly to the left, so that the first protuberance 7A sinks even more into the retaining hole 62A, pushing back at the same time, the first retractable hook 4A to gradually release it until it is released. In this position where the first retractable hook 4A is released, the first fixing pin 41A is then completely in abutment on the right of the first oblong hole 40A, that is to say its other end relative to that where it is located. found on the figure 4A previous along the AA axis.

On the view in sagittal section along the D-D axis, it is also possible to clearly visualize the action of the first head 811 of the first cam 81 pushing the sliding element to shift to the left.

In the third unlocked position P3, illustrated on figure 4C , the branches are no longer superimposed on one another and it is thus possible to clearly separate the first branch 2 from the second branch 3; on the view in sagittal section along the AA axis, we can now clearly see the lower end of the pawl-spring 63, which has made it possible to exert a repulsive force R downwards and to facilitate the process of mutual dissociation of the branches . However, it can be seen that the restoring force exerted on the first retractable hook 4A, that is to say the second restoring force F2 exerted via the first elastic element 5A, allowed the first retractable hook 4A to find yourself in the same position "at rest", that is to say at the end of the stroke to the right. Thus, just after releasing the lever 8, again affixed in the closed position on the cover 6, the first return force F1 exerted by the third elastic element 71 on the sliding element 7 will allow all these fastening elements of the clasp. to find oneself therefore in the same position as in the first locking position P1.

In the fourth position P4, shown on figure 4D , where one seeks to re-lock the clasp, only an action is exerted against the second return force F2 to allow the first retractable hook 4A to be first pushed to the left before be reinserted into the first retaining hole 62A provided in the vertical wall 61 of the cover 6. No action is necessary on the sliding element 7 via the lever and the cam mechanism, the latter all being in the same position as on the figures 4A and 4C previous ones, that is to say in the first locking position P1 and respectively the third unlocking position P3. In order to facilitate the release and then snap-in mechanism of the first retractable hook 4A, the first inclined surface 42A of the first retractable hook 4A cooperates with the lower inclined surface 61A of the vertical wall 61 of the cover 6, so that the compression of the elastic element is as progressive as possible and that the wear of the clasp is reduced to a minimum. Thus, the inclination of each of these surfaces is preferably identical, and equal to 45 °. Once the nose of the first retractable hook 4A is brought to bear against the vertical wall 61 of the cover, the restoring force F2 is maximum and as the cover 6 is folded over the second branch 3 (of which only the first leg 31 and the first bulge at the end thereof is shown on this figure 4D ), it will be possible to release the hook as soon as it is brought opposite the first retaining hole 62A.

The figure 4E thus corresponds to the moment when the re-engagement of the clasp 1 is complete, so that it is again in the locked position. In other words, the fifth position P5 corresponds to the first locking position P1, but the latter being illustrated only at the end of an unlocking plus re-locking sequence.

It will be understood from the above description that the embodiments described are given only by way of example, without however being intended to interpret the claims in a limiting manner.

Other variants are also possible without departing from the scope of the present invention, in particular as regards the number of retractable hooks, the corresponding number of elastic elements acting on these hooks, the number of protruding parts acting on them for unlock them as well as the method of fixing the sliding element to the cover as well as the number of elastic elements acting on it. One could also envisage an alternative cam mechanism using only a central cam, as well as other methods of fixing the sliding element to the cover, independently of the mode of actuation of the latter in translation (i.e. i.e. via a pusher or lever mechanism associated with a cam system).

Claims (14)

Clasp (1) with a folding clasp for a wristwatch comprising at least a first branch (2) and a second branch (3) articulated with respect to one another around an axis (23), comprising a on the one hand means for connecting the free ends of each of said first branch (2) and second branch (3) to respective strands of a bracelet, and on the other hand a locking device for holding said first branch (2) and second branch (3) in the folded position one on the other in the closed position of the bracelet, characterized in that the locking device comprises at least one retractable hook (4A, 4B) arranged on said second branch (3), which cooperates with at least fixed hooking means (62A, 62B) arranged on a cover (6) integral with said first branch (2) in the locking position, said retractable hook (4A, 4B) being held in the locking position by a elastic element (5A, 5B), and further comprises a grout element ssant (7), arranged in said cover (6) and held in a rest position by at least one other elastic element (710,720), said sliding element (7) being arranged to release said at least one retractable hook (4A, 4B ) when acting against the restoring force exerted by said at least one other elastic element (710,720). A folding clasp (1) for a wristwatch according to claim 1, wherein the sliding element (7) moves along the longitudinal axis (L) of said first branch (2) and second branch (3). Clasp (1) with a folding clasp for a wristwatch according to one of the preceding claims, wherein said at least one retractable hook (4A, 4B) moves along the longitudinal axis (L) of said first branch (2) and second branch (3). Wristwatch folding clasp (1) according to claim 3, characterized in that said at least one retractable hook (4A, 4B) has an inclined upper surface (42A, 42B). A wristwatch folding clasp (1) according to claim 3 or 4, wherein said first leg (2) is a central leg, while the second leg (3) is formed by two legs, namely a first leg (31) and a second leg (32), a first longitudinal housing (31A) being provided to house a first retractable hook (4A) as well as a first elastic element (5A), and a second longitudinal housing (32B) being provided to accommodate a second retractable hook (4B) as well as a second elastic element (5B). Clasp (1) with a folding clasp for a wristwatch according to claim 5, said first longitudinal housing (31A) formed in a first bulge (311) at the free end of the first leg (31), and the second housing longitudinal (32B) being arranged in a second bulge (321) at the level of the free end of the second leg (32) in order to house said respective retractable hooks (4A, 4B) therein. Clasp (1) with a folding clasp for a wristwatch according to one of the preceding claims 3 to 6, said at least one retractable hook (4A, 4B) respectively having an oblong hole (40A, 40B) in which is respectively inserted an axis fixing (41A, 41B) perpendicular to the longitudinal axis (L) of said first branch (2) and second branch (3). Clasp (1) with a folding clasp for a wristwatch according to one of claims 5 to 7, said fixed hooking elements being formed by a first orifice (62A) and respectively a second orifice (62B) formed in a vertical wall ( 61) of the cover (6). Clasp (1) with a folding clasp for a wristwatch according to claim 8, said sliding element (7) comprising a first protrusion (7A) and a second protrusion (7B) extending along the longitudinal axis (L) of said first branch (2) and second branch (3), said first protuberance (7A) being arranged to be able to be introduced into said first orifice (62A) and said second protuberance (7B) being arranged to be able to be introduced into the second orifice (62B ). Clasp (1) with a folding clasp for a wristwatch according to one of the preceding claims, wherein said sliding element (7) is a pusher (70) accessible from the front of the cover (6). Clasp (1) with a folding clasp for a wristwatch according to one of claims 1 to 9, wherein said sliding element (7) is actuated by a lever (8) mounted to pivot relative to said cover (6) along an axis of rotation (80) perpendicular to the longitudinal axis (L) of said first branch (2) and second branch (3). Clasp (1) with a folding clasp for a wristwatch according to claim 11, the axis of said lever (8) being integral with cams (81, 82) acting on said sliding element (7). A wristwatch folding clasp (1) according to claim 12, a first cam (81) being disposed in a first axial recess (74) of said sliding member (7), and a second cam being arranged in a second axial recess (75) of said sliding element. Clasp (1) with a folding clasp for a wristwatch according to one of the preceding claims, in which the sliding element (7) is provided with a first longitudinal housing (71) for accommodating a third elastic element (710) and a second longitudinal housing (72) for housing a fourth elastic element (720).

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