Adjustable bracelet clasp

Abstract

The invention relates to a clasp (1) for a bracelet with a folding clasp (20), the clasp comprising: - a cap (2) to which are fixed at least a first blade and a second blade articulated together and to which a first bracelet strand is fixed; - first locking means for holding the blades in the closed position on the cap; - actuating means comprising a first and a second pusher (4, 5); - means for adjusting the length of the bracelet to which a second bracelet strand is fixed. According to the invention, the length adjustment means comprise a sliding end piece (10) in the cap (2), the sliding end piece (10) having a toothed sector (15) arranged to cooperate with second locking means controlled by a pusher (4, 5).

Description

Technical field of the invention

[0001] The present invention relates to a clasp for a bracelet, of the folding clasp type, which allows adjustment of the useful length of the bracelet.

[0002] The present invention also relates to a wristwatch provided with such a clasp. Prior art

[0003] The problem of the need to provide a device for adjusting the useful length of a bracelet is well known.

[0004] On the one hand, in the case of bracelets composed of links, it is possible that the wearer's wrist has a circumference whose value is located between two configurations of the bracelet differing from each other by a single link. Also, it is useful to provide a device for adjusting the useful length of the bracelet allowing a finer adjustment of the length of the bracelet than the removal or addition of a link.

[0005] On the other hand, it is also known that the value of the wrist circumference varies according to the seasons, a maximum value generally being reached in summer and a minimum value being reached in winter. The circumference of the wrist can also be caused to vary depending on the day. It is again preferable to provide a device for fine adjustment of the useful length of the bracelet allowing the wearer of the bracelet to adjust this length to improve the comfort of the bracelet when wearing it.

[0006] For example, patent EP 0 350 785 B1 describes a clasp comprising a device for adjusting the useful length of the bracelet that can be manipulated without tools. The clasp described in this patent is of the folding clasp type comprising two blades hinged together by means of a rod passing through both of them, each of the blades carrying at its free end a member for fixing to a bracelet. A first blade carries a hook intended to engage in a hole made in the second blade to cooperate with a trigger making it possible to lock the hook and therefore the clasp in a closed state. The second blade comprises two parts capable of sliding relative to each other within a certain predefined range, defining a step for adjusting the useful length of the bracelet. A first of its two parts carries the hinge connecting it to the first blade while the second part carries the locking trigger.The hole in which the hook engages to lock the clasp has a length, along the longitudinal direction of the bracelet, corresponding to the sliding range between the two parts of the second blade. The trigger has a central part defining two locations for the hook, along the longitudinal direction of the bracelet, corresponding to two different useful lengths of the bracelet. A control member comprising in particular a pusher makes it possible to actuate the trigger to release the hook and open the clasp.

[0007] It should be noted that a disadvantage resulting from this structure is the loss of adjustment of the length of the bracelet each time the clasp is opened. Therefore, the wearer of the bracelet must ensure each time the clasp is closed that the hook is inserted on the side of the central portion of the trigger corresponding to the desired length for the bracelet.

[0008] Adjustment devices with a specific locking member have also been proposed as an alternative to avoid this type of inconvenience. Summary of the invention

[0009] The present invention aims to overcome the above-mentioned drawbacks and others by providing a clasp for finely adjusting the length of a watch strap, which on the one hand allows the strap length to be adjusted without the risk of inadvertently losing it, and on the other hand provides particularly simple and rapid handling and adjustment.

[0010] To this end, the present invention relates to a clasp for a bracelet with a folding clasp, the clasp comprising: a cap to which is fixed at least a first blade and a second blade articulated together and to which is fixed a first bracelet strand; first locking means for holding the blades in the closed position on the cap; actuating means comprising a first and a second pusher; means for adjusting the length of the bracelet to which is fixed a second bracelet strand.

[0011] According to the invention, the length adjustment means comprise a sliding end piece in the cap, the sliding end piece having a toothed sector arranged to cooperate with second locking means controlled by a pusher, the end piece being arranged to move from a locked position to an unlocked position in which the end piece is completely disengaged from the cap.

[0012] According to other advantageous variants of the invention: the locking means comprise a lever pivoting between a locked position and an unlocked position, the lever having a first end arranged to cooperate with one of the pushers and a second end having a toothed element arranged to cooperate with the toothed sector of the sliding end piece; the locking means comprise elastic return means for holding the lever in the locked position; the cap has a general U-shaped section and is provided with two wings facing each other, these wings each carrying an opening for receiving the first and second pushers; the pushers have a body and a head, the head of each pusher resting in one of the openings and one of the heads being arranged to cooperate with the first end of the lever;the body of the pushers carries the first locking means of the clasp, the length of the body of each pusher being predefined in such a way that when the pushers are actuated simultaneously the body of the pushers comes into contact and does not disengage the lever; the clasp comprises a plate secured to the cap to form a housing between the plate and the cap, the plate having two openings through which the first locking means pass; the cap comprises a cavity arranged to receive a spring, the spring cooperating with the sliding end piece; the sliding end piece has a machining of a shape complementary to the shape of the cavity; the clasp comprises stop means preventing the sliding end piece from being dislodged from the cap; the toothed sector has a plurality of teeth, each tooth defining an indexed position of the sliding end piece;the toothed sector comprises teeth of asymmetrical shape such that a first portion of the tooth is perpendicular to the direction of movement of the sliding tip, and the second portion of the tooth has a slope; the toothed element of the lever has a shape complementary to the asymmetrical shape of the teeth of the toothed sector. ; Brief description of the figures

[0013] Other characteristics and advantages of the present invention will emerge more clearly from the following detailed description of an embodiment of the clasp for a watch bracelet or for a belt according to the invention, this example being given purely for illustrative and non-limiting purposes only in connection with the appended drawing in which: THE Figures 1a and 1b are exploded perspective views of the clasp according to the invention; the figure 2 is a perspective view of the clasp of the figure 1 in the assembled state; the figure 3is a perspective view from below of the clasp according to the invention, the adjustment link being in the engaged position; the figure 4 is a cross-sectional view of the clasp according to the invention, with the fine adjustment link in the released position. Detailed description of the invention

[0014] The invention will now be described in connection with a watch strap. It goes without saying, however, that this example is given purely for illustrative purposes and is not limiting and that the clasp according to the invention can also be used for a belt buckle, for example.

[0015] THE Figures 1a and 1b are exploded perspective views of the clasp according to the invention while the figure 2is a perspective view of this same clasp in the assembled state. The clasp 1 according to the invention comprises a cap 2 connected on a first side to a first bracelet strand (not shown) with the interposition of a folding clasp closure system 20 and first locking means 30, 31 of the clasp, the structures of which are known and which will therefore not be described further here, the folding clasp closure system being able to comprise two or three blades. The cap 2 is connected on a second side to a second bracelet strand (not shown) via a sliding end piece 10 to carry out a fine adjustment of the length of the watch bracelet. The bracelet strands can be formed by a succession of links or by a strand made of leather, textile or even elastomer material.

[0016] As can be observed in the figure 1, the cover 2 has a general U-shaped section and is provided with two wings 12 facing each other, these wings 12 carrying on each of their faces an opening 14 for receiving a pusher 4, 5. Furthermore, a cavity 16 is provided in the bottom of the cover 2 and defines a receptacle for a spring 18 whose role will be described in detail later.

[0017] The sliding end piece 10 comprises guide means in order to be guided in sliding in the cap 2, these guide means being formed by a groove 11 machined in the bottom of the cap 2 and cooperating with the cavity 16 to guide the end piece 10 in the cap 2, the groove and the cavity being coaxial.

[0018] The sliding end piece 10 comprises a lug 13 arranged to slide in the groove 11 of the cap 2 and guide the end piece 10 during its translational movement. The length of the groove 11 makes it possible both to define the stroke length of the end piece 10 relative to the cap 2 and to form a stop for the end of stroke of the end piece 10 when the lug 13 reaches the end of the groove 11. It will also be noted in the figures that the end piece 10 has a machining 17 of a shape complementary to the cavity 16 to provide an additional guiding means, which makes it possible to limit the play of the end piece 10 once it is mounted in the cap 2.

[0019] Thus, the sliding end piece 10 is capable of sliding in a longitudinal direction of the clasp 1 between a first position in which the sliding end piece 10 is engaged in the cap 2 of the clasp 1, and at least one second position in which the sliding end piece 10 is completely disengaged from the cap 2 of the clasp 1. The length available for adjusting the bracelet is determined by the travel of the sliding end piece 10.

[0020] The clasp 1 comprises length adjustment means formed by the sliding end piece 10 which moves in the cap 2. According to one embodiment of the invention, the clasp comprises a closing element in the form of a plate 3 secured to the cap 2 to form a housing between the plate 3 and the cap 2, the end piece sliding within this housing. Advantageously, the plate 3 has two openings 32, 33 through which the first locking means 30, 31 pass. Such a configuration thus makes it possible to prevent foreign bodies from becoming lodged in the cap and disrupting the proper functioning of the clasp.

[0021] The end piece 10 has a toothed sector 15 arranged to cooperate with second locking means controlled by one of the pushers 4, 5, so as to lock or unlock it for adjusting the length of the clasp.

[0022] As can be observed in the Figures 1a, 1b And 3, the second locking means are in the form of a lever 6 pivoting between a locked position and an unlocked position. The lever 6 is pivotally mounted on a stud 63, the lever 6 having a first end 60 arranged to cooperate with one of the pushers 4, 5 and a second end 61 having a toothed element 62 arranged to cooperate with the toothed sector 15 of the sliding end piece 10.

[0023] The toothed element 62 is arranged to cooperate with the toothed sector 15 so as to lock the sliding end piece 10 in the adjustment position chosen by the wearer, the toothed sector 15 having at least two teeth 150, 151 to form at least two positions. Those skilled in the art will obviously not encounter any particular difficulty in adding several teeth to form several length adjustment positions.

[0024] The toothed element 62 is formed in the first portion of the lever 6 by machining for example, and has dimensions close to those of the teeth of the toothed sector.

[0025] The lever 6 is arranged to move from a first position, called the rest position, in which the toothed element 62 is engaged with a tooth of the toothed sector 15, to a second position in which the toothed element 62 is released from its engagement with the toothed sector 15.

[0026] The locking means also comprise elastic return means for holding the lever 6 in the locked position. These elastic return means are in the form of a torsion spring 7 articulated around the axis of rotation of the lever, a first portion 71 of the spring being fixed to the cap and a second portion 72 constraining the lever 6 in its rest position.

[0027] According to the invention, the toothed sector 15 comprises teeth 150, 151, 152, 153 of asymmetrical shape such that a first portion of each tooth is perpendicular to the direction of movement of the sliding end piece 10, and the second portion of each tooth has a slope.

[0028] The toothed element 62 of the lever 6 has a shape complementary to the asymmetrical shape of the teeth of the toothed sector in such a way that the sliding end piece 10 is blocked by the lever when the wearer pulls on the bracelet strand attached to the end piece without having previously unlocked the lever. On the other hand, the wearer can shorten the length of the bracelet without having to unlock the sliding end piece 10 thanks to the geometry of the teeth.

[0029] As can be observed in the figure 3, the cap 2 comprises a cavity 16 of substantially parallelepipedal shape, in which the spring 18 is arranged, this spring being compressed between the bottom of the cavity 16 and the bottom of the machining 17 of the end piece 10. It will be understood that when the sliding end piece 10 is assembled in the cap 2, the spring 18 is compressed between the cavity and the sliding end piece 10, which forces the end piece to disengage from the cap 2 when the lever 6 is unlocked by the wearer.

[0030] Thus, when the end piece is 10 unlocked when the wearer presses the pusher, the lever 6 disengages from the toothed sector 15 and releases the end piece 10 which slides in the housing and is completely released from the cap 2 under the action of the spring. Once the end piece is completely released from the cap, the wearer can adjust the length of the clasp while keeping it on the wrist. By completely released from the cap 2, it is meant that the end piece 10 reaches the furthest position permitted by the stroke length while remaining integral with the cap.

[0031] On each side of the cap 2 near the end through which the end piece 10 slides, retaining means 19 are machined, limiting the travel of the end piece 10 and preventing it from being completely extracted from the cap 2 once the clasp 1 is assembled.

[0032] The pushers 4, 5 have a body 40, 50 and a head 41, 51, the head of each pusher resting in one of the openings of the cap 2 and one of the heads 41, 51 being arranged to cooperate with the first end 60 of the lever 6 to unlock the end piece 10. The pushers are held in their rest position by means of a pair of springs 8, each of the ends of the springs being housed in a blind hole formed in the head of the pushers.

[0033] The body 40, 50 of the pushers carries the first locking means 30, 31, here hooks arranged to cooperate with the blades of the folding clasp. Advantageously, the body of each pusher 4, 5 has a predefined length such that when the pushers 4, 5 are actuated simultaneously by the wearer, the bodies of the pushers come into contact (or stop) and do not disengage the lever 6. The length of the body of the pushers thus makes it possible to define the stroke length of the latter to avoid involuntary adjustment by the wearer when opening the clasp.

[0034] Thus, to adjust the clasp, the user presses the pusher located near the lever 6, so that the head of the pusher presses against the first end 60 of the lever 6 to pivot the latter and disengage the toothed element 62 from the toothed sector 15.

[0035] Once the toothed element 62 is disengaged, the sliding end piece 10 is free and moves in translation until it stops under the action of the spring 18, the end piece is then completely released from the cap and the user can release the pusher.

[0036] Finally, to adjust the desired bracelet length, the user manipulates the bracelet strand attached to the movable end piece 10 to partially retract the latter into the cap 2 in the desired position, the association of the toothed element 62 with the toothed sector 15 forming a disengageable snap-fastening and allowing the user to feel the passage from one tooth to the next during adjustment.

[0037] It goes without saying that the present invention is not limited to the embodiment which has just been described and that various simple modifications and variants may be envisaged by those skilled in the art without departing from the scope of the invention as defined by the appended claims.

Claims

1. Clasp (1) for a bracelet with a folding clasp (20), the clasp comprising: - a cap (2) to which are fixed at least a first blade and a second blade articulated together and to which a first bracelet strand is fixed; - first locking means for holding the blades in the closed position on the cap; - actuating means comprising a first and a second push-piece (4, 5); - means for adjusting the length of the bracelet to which a second bracelet strand is fixed; characterized in that the length adjustment means comprise a sliding end piece (10) in a housing formed in the cover (2), the sliding end piece (10) having a toothed sector (15) arranged to cooperate with second locking means controlled by a pusher (4, 5), the end piece being arranged to move from a locked position to an unlocked position in which the end piece (10) is completely disengaged from the cover (2).

2. Clasp (1) according to claim 1, characterized in that the locking means comprise a lever (6) pivoting between a locked position and an unlocked position, the lever (6) having a first end (60) arranged to cooperate with one of the pushers and a second end (61) having a toothed element (62) arranged to cooperate with the toothed sector (15) of the sliding end piece (10).

3. Clasp (1) according to claim 1 or 2, characterized in that the locking means comprise elastic return means (7) for holding the lever in the locked position.

4. Clasp (1) according to one of the preceding claims, characterized in that the cover (2) has a general U-shaped section and is provided with two wings (12) facing each other, these wings (12) each carrying an opening (14) for receiving the first and second pushers (4, 5).

5. Clasp (1) according to one of the preceding claims, characterized in thatthe pushers (4, 5) have a body (40, 50) and a head (41, 51), the head of each pusher resting in one of the openings (14) and one of the heads (41, 51) being arranged to cooperate with the first end (60) of the lever (6).

6. Clasp (1) according to one of the preceding claims, characterized in that the body (40, 50) of the pushers carries the first means for locking the clasp (30, 31), the length of the body (40, 50) of each pusher being predefined in such a way that when the pushers (4, 5) are actuated simultaneously the body of the pushers comes into contact and does not disengage the lever (6).

7. Clasp according to one of the preceding claims, characterized in that it comprises a plate (3) secured to the cover (2) to form a housing between the plate (3) and the cover, the plate having two openings through which the first locking means (30, 31) pass.

8. Clasp (1) according to one of the preceding claims, characterized in that the cap (2) comprises a cavity (16) arranged to receive a spring (18), the spring cooperating with the sliding end piece (10).

9. Clasp (1) according to claim 4, characterized in that the sliding tip (10) has a machining (17) of a shape complementary to the shape of the cavity (16).

10. Clasp (1) according to one of the preceding claims, characterized in that it comprises stop means (19) preventing the sliding end piece (10) from becoming dislodged from the cap (2).

11. Clasp (1) according to one of the preceding claims, characterized in that the toothed sector (15) has a plurality of teeth, each tooth defining an indexed position of the sliding tip.

12. Clasp (1) according to one of the preceding claims, characterized in thatthe toothed sector (15) comprises teeth of asymmetrical shape such that a first portion of the tooth is perpendicular to the direction of movement of the sliding tip, and the second portion of the tooth has a slope.

13. Clasp (1) according to claim 11, characterized in that the toothed element (62) of the lever (6) has a shape complementary to the asymmetrical shape of the teeth of the toothed sector.

Images