Bracelet clasp

Abstract

The invention relates to a bracelet clasp comprising a first rigid blade (1) whose first end (10) is hinged to a first end (20) of a second folding blade (2) configured to receive a first strand of the bracelet at its second end (21), and whose second end (11) of the first blade is hinged to a first end (30) of a third folding blade (3) from which first and second prongs (32, 34) extend, and a clasp (4) hinged to one of the blades. The clasp is provided with first and second pushers (320, 330). According to the invention, the clasp includes a stop (23) which is positioned between the first and second prongs of the third blade in the closed position of the clasp, so as to ensure symmetrical opening of the prongs when simultaneous pressure is applied to the pushers.

Description

Technical field of the invention

[0001] The invention relates to a bracelet clasp, and in particular to watch bracelets. Technological background

[0002] Document CH 700 356 discloses a clasp comprising two pushers which are integral with two arms articulated on flexible axes. Such a clasp has the disadvantage that the flexible arms, due to machining tolerances, do not open symmetrically and the opening function is therefore not always carried out correctly.

[0003] Also known from document EP 0 913 106, which discloses the preamble of claim 1, is a folding clasp comprising a rigid base provided with two side members, a yoke arranged to be attached to a strand of the bracelet, and at least one folding arm having a rear end attached to one end of the base by a first articulation and having a front end attached to the yoke by a second articulation. The folding arm comprises two juxtaposed branches provided with pushers, and the front ends of which are separated by an elastic element. Such a clasp has the same drawback mentioned above, the yoke having too much play and not allowing symmetrical opening of the flexible arms. Summary of the invention

[0004] An aim of the present invention is to overcome all or part of the drawbacks mentioned above by providing a clasp which meets the security constraints while allowing symmetrical opening of the latter.

[0005] The invention also aims to provide a clasp of simple design and economical to manufacture.

[0006] For this purpose, the invention relates to a bracelet clasp comprising: a first rigid blade, a first end of which is articulated on a first end of a second folding blade configured to receive a first strand of the bracelet at its second end, and the second end of the first blade of which is articulated on a first end of a third folding blade from which extend first and second branches, the free ends of which are crossed by an axis around which is articulated a yoke provided with first and second flaps extending perpendicularly to the yoke, and means for holding a second strand of the bracelet, the third blade partially covering the second end of the second blade when the clasp is in the closed position, first and second pushers forming a body with the first and second branches of the third blade,a locking mechanism arranged to keep the third blade locked on the first blade when no pressure is exerted simultaneously on the pushers.

[0007] According to the invention, the clasp comprises a stop which is housed between the first and second branches of the third blade when the clasp is in the closed position, so as to guarantee symmetrical opening of the branches when pressure is exerted on the pushers.

[0008] Thanks to these characteristics, such a bracelet clasp makes it possible to limit the travel of each flexible branch and therefore to guarantee the function of the clasp by a symmetrical opening of the branches.

[0009] According to other advantageous variants of the invention: the stop is secured to the second end of the second blade; the stop is secured to the first blade; the stop is secured to the yoke; the stop has a width which defines the stroke length of the pushers; the clasp comprises locking means for keeping the second blade locked against the first blade when the clasp is in the closed position, said means comprising hooks; the locking mechanism comprises on the one hand a first pair of hooks secured to the first blade, and on the other hand, a second pair of hooks secured to the third blade; the second pair of hooks is secured to the branches; the branches are laterally flexible over all or part of their length.

[0010] The invention also relates to a wristwatch comprising a bracelet provided with a clasp according to the invention. Brief description of the figures

[0011] Other characteristics and advantages of the invention will appear more clearly on reading the following description of a particular embodiment of the invention, given as a simple illustrative and non-limiting example, and the appended figures, among which: there figure 1 is a perspective view of a clasp according to the invention, the clasp being in the open position; the figure 2 is a top view of a clasp according to the invention, the clasp being in the closed position; the figure 3 is a perspective view from below of a clasp according to the invention, the clasp being in the open position; the figure 4 is a perspective view of the clasp according to the invention; Figure 5 is an exploded view of a clasp according to the invention. Detailed description of the invention

[0012] A bracelet clasp will now be described in the following with joint reference to the figures 1, 2 , 3, 4 And5 .

[0013] THE figures 1 And 4 are perspective views of the bracelet clasp which comprises a first rigid blade 1 having two longitudinal members 1a and 1b connected to each other by a bridge 1c. A first end 10 of this blade is articulated to a first end 20 of a second folding blade 2 by means of a shaft 12. This second blade 2 is configured to receive a first strand of the bracelet at its second end 21 by means of a shaft 23.

[0014] The other end 11 of the first blade 1 is hinged to a first end 30 of a third folding blade 3, the third blade 3 partially covering the second end 21 of the second blade 2 when the clasp is in the closed position.

[0015] From the first end 30 of the third blade 3 emerge first and second branches 32 and 33 movable in translations. According to a variant of the invention, not shown in the figures, the first blade 1 can be provided solid and have a receptacle comprising locking means configured to receive the branches 32 and 33.

[0016] The clasp also comprises a yoke 4, articulated to the branches 32 and 33, provided with first and second flaps 40 and 41 extending perpendicularly to the yoke 4. The flaps 40 and 41 have holes 42 and 43 configured to receive the ends of pushers 320, 330 to provide the articulation between the branches 32, 33 and the yoke 4.

[0017] The yoke 4 may have means for holding a second strand of the bracelet, such as a pin 44 as illustrated in the figures or even a bar so as to define a starting point for the second strand of the bracelet. figure 4illustrates the first and second pushers 320 and 330 which are connected to the first and second branches 32 and 33.

[0018] A locking mechanism is arranged to hold the third blade 3 on the first blade 1 when no pressure is exerted simultaneously on the pushers 320 and 330. For this purpose, the side members 1a and 1b of the first blade 1 respectively have fixed hooks 14 and 15 configured to cooperate respectively with hooks 34 and 35 arranged on the branches 32 and 33. This attachment can be observed at figures 2 And 4 .

[0019] According to the invention, the clasp comprises a stop 23 arranged to be housed or rest between the first and second branches 32, 33 of the third blade when the clasp is in the closed position, and more precisely between the ends of the first and second branches 32, 33 which receive the pushers 320, 330.

[0020] According to a first embodiment, the stop 23 is arranged at the second end 21 of the second blade 2, the stop 23 being positioned between the first and second branches 32, 33 of the third blade when the clasp is in the closed position.

[0021] According to a second embodiment, the stop 23 is arranged in the middle of the first blade 1 on the bridge 1c connecting the two side members 1a and 1b.

[0022] When the clasp is folded or in the closed position as shown in figures 2 And 4, each end of the branches 32, 33 receiving a pusher 320, 330 comes into contact with the stop 23 when pressure is exerted on the pushers 320, 330. The stop 23 thus makes it possible to limit the travel of the free ends of the branches 32 and 33, the distance between the end of the branches 32, 33 and the stop 23 defining the travel length of the free ends of the branches 32 and 33. In this way, it is possible to predetermine the necessary travel length of the branches 32, 33 to obtain a symmetrical movement of the latter and guarantee the correct opening of the clasp.

[0023] When pressure is exerted on the pushers 320 and 330, the clasp is unlocked by a symmetrical opening of the branches 32, 33, the stop 23 making it possible to limit the travel of each branch 32, 33 and therefore to guarantee the correct opening of the clasp.

[0024] It will be understood that if the stop 23 did not exist, a non-identical or similar pressure exerted on the pushers 320, 330 would not allow correct movement of the branches to allow the clasp to open correctly. For example, when the wearer exerts a higher pressure on the pusher 320 than on the pusher 330, the free end of the flexible branch 32 may come into abutment against the other free end of the flexible branch 33 and prevent the clasp from opening correctly.

[0025] In conclusion, to open the clasp of the present invention, the wearer simply exerts simultaneous pressure on the two pushers 320, 330 until the free end of the flexible branches 32, 33 come into contact with the stop 23. The hooks 34 and 35 of the branches 32 and 33 then disengage from the hooks 14 and 15 of the side members 1a and 1b, thus causing the release of the third blade 3 and the opening of the clasp.

[0026] Of course, the present invention, which is defined by the claims, is not limited to the illustrated example but is susceptible to various variants and modifications which will appear to those skilled in the art.

Claims

1. Bracelet clasp comprising: - a first rigid strip (1) of which a first end (10) is hinged on a first end (20) of a second folding strip (2) configured to receive a first strand of the bracelet at the second end (21) thereof, and of which the second end (11) of the first strip (1) is hinged on a first end (30) of a third folding strip (3) from which first and second arms (32, 33) extend at which a cap (4) is hinged equipped with first and second flaps (40, 41) extending perpendicularly with respect to the cap (4), and means for holding a second strand of the bracelet, the clasp being characterised in that the third strip (3) partially covers the second end (21) of the second strip (2) when the clasp is in the closed position, the clasp comprising : - first and second push-pieces (320, 330) integral with the first and second arms (32, 33), - a locking mechanism configured to keep the third strip (3) locked on the first strip (1) when no pressure is exerted simultaneously on the push-pieces (320, 330), the clasp comprises a banking (23) which is housed between the first and second arms (32, 33) of the third strip in the closed position of the clasp, so as to ensure a symmetrical opening of the arms (32, 33) when simultaneous pressures are exerted on the push-pieces (320, 330).

2. Bracelet clasp according to claim 1, wherein the banking (23) is rigidly connected to the second end (21) of the second strip (2).

3. Bracelet clasp according to claim 1, wherein the banking (23) is rigidly connected to the first strip (2).

4. Bracelet clasp according to claim 1, wherein the banking (23) is rigidly connected to the cap (4).

5. Bracelet clasp according to one of claims 1 to 4, wherein the banking (23) has a width which defines the length of travel of the push-pieces (320, 330).

6. Bracelet clasp according to any one of claims 1 to 5, comprising locking means to keep the second strip (2) locked against the first strip (1) when the clasp is in the closed position, said means comprising hooks.

7. Bracelet clasp according to any one of claims 1 to 6, wherein the locking mechanism comprises, on one hand, a first pair of hooks (14, 15) rigidly connected to the first strip (1), and, on the other, a second pair of hooks (34, 35) rigidly connected to the third strip (3).

8. Bracelet clasp according to claim 7, wherein the second pair of hooks (34, 35) is rigidly connected to the arms (32, 33).

9. Bracelet clasp according to any one of claims 1 to 8, wherein the arms (32, 33) are laterally flexible on all or part of the length thereof10. Wristwatch including a bracelet equipped with a clasp according to any one of the preceding claims.

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