CLOSURE FOR BRACELET

Description

[0001] The present invention relates to a clasp for a flexible bracelet, typically made of leather, in particular for a watch strap.

[0002] Patent application CH 712 039 A2 discloses a folding clasp with blades for a flexible bracelet, the first blade of which is provided with first means for attaching to a first strand, referred to as the "fixed strand," of the bracelet. These attachment means comprise a bar held by a connecting rod articulated at the free end of the blade. The second blade is provided with second means for attaching a stud designed to engage in one of a series of holes in the second strand, referred to as the "adjustable strand," of the bracelet, in order to secure the strand and adjust its length. This stud typically has a ridge at its end, which is designed to be forced into a hole in the bracelet to prevent it from being unintentionally dislodged. This type of attachment has the disadvantage of deforming the hole in the bracelet and enlarging it to the point where the bracelet could be lost.

[0003] Patent application EP 0466656 A1 describes the preamble of claim 1.

[0004] There are also clasps where the attachment to the adjustable strap of the bracelet is made using a screw rather than a stud. This type of attachment doesn't require forcing it into a hole in the bracelet; however, this solution isn't ideal because a screw can break and / or get lost, and the threads in the clasp's blade that holds the screw can also wear down over time, potentially requiring the blade to be replaced.

[0005] One aim of the present invention is to provide a clasp that at least partially remedies the aforementioned drawbacks.

[0006] The invention provides for this purpose a clasp for a bracelet according to claim 1.

[0007] The invention also relates to a wristwatch comprising a flexible strap equipped with such a clasp.

[0008] The clasp according to the invention allows the usable length of the bracelet to be adjusted without damaging it, in particular without enlarging its holes. It does not include screws that deteriorate over time or any parts that could detach with wear and be lost. Furthermore, the clasp according to the invention is simple to use and requires no tools for either disassembly or adjustment.

[0009] Other features and advantages of the present invention will become apparent from the following detailed description, made with reference to the accompanying drawings, in which: there figure 1 is a perspective view, from above, of a portion of a watch bracelet comprising a clasp according to a particular embodiment of the invention, said clasp being in the closed position; the figure 2 is a perspective view, from below, of the clasp shown in the figure 1 , in the open position; the figure 3 is a perspective view, from below, of part of the clasp shown in the figure 2 ; there figure 4 is an exploded view of the part of the clasp shown in the figure 3 ; there figure 5 is a cross-sectional view of part of the watch bracelet shown in the figure 1 ; there figure 6 is a longitudinal cross-sectional view of a portion of the watch bracelet shown in the figure 1 ; there figure 7 illustrates a wristwatch comprising a clasp according to a variant of the invention.

[0010] There figure 1 represents a part of a watch bracelet comprising a clasp 100 according to a particular embodiment of the invention.

[0011] With reference to figures 1 à 6 , the clasp 100 includes a cover 1 carrying a stud 2, said stud 2 being intended to pass through a hole chosen from a series of holes carried by a first strand 3 of a flexible bracelet and a support 4, movable relative to said cover 1, to which said stud 2 is coupled to fix said first strand 3 of bracelet between said cover 1 and support 4.

[0012] In the illustrated example, the clasp 100 is a folding clasp comprising a base blade 5 at the ends of which are articulated a first 6 and a second 7 pivoting blades that fold down onto the base blade 5.

[0013] The free end of the first pivoting blade 6 is articulated via a hinge to the cover 1 and support 4. This hinge comprises a rod 8 pivoted in holes 9 formed in protrusions or lugs 10 integral with the cover 1, these holes 9 forming pivot bearings for the rod 8. The support 4 is itself pivotally mounted on the rod 8, for example by means of rings free to rotate around this rod 8, but it could also be fixed to the rod 8. The free end of the first pivoting blade 6 is typically fixed to the rod 8; alternatively, it could be pivotally mounted around this rod 8. Other hinge designs are conceivable to make the support 4 and the cover 1 rotationally mobile relative to each other.

[0014] The assembly comprising the hinge, the cover 1 and the stud 2 it carries, as well as the support 4, forms a system for attaching the clasp 100 to the first strand 3 of the bracelet. This attachment system allows for the adjustment of the bracelet's usable length. In the following description, the first strand 3 is referred to as the "adjustable strand" of the bracelet. figures 3 et 4 illustrate said fastening system.

[0015] As illustrated in figures 1 et 2 The free end of the second pivoting blade 7 is provided with means for attaching it to a second strand 11, called the "fixed strand" of the bracelet. In the illustrated example, these attachment means comprise a bar 12 held by a connecting rod 13 articulated to said free end.

[0016] In the illustrated example, the support 4 comprises two elastic arms 14 defining between them a housing intended to accommodate at least part of the nipple 2.

[0017] To adjust the length of the bracelet, the user places the adjustable strap 3 of the bracelet so that the hole corresponding to the desired length of the adjustable strap of his bracelet is opposite the nipple 2 and then exerts pressure to bring the cover 1 closer to the support 4 by pivoting until the nipple 2 fits elastically into said housing, between said two arms 14.

[0018] Elastic interlocking is a method of assembly where the elements are deformed during assembly. After assembly, there are no (or almost no) stresses and the elements cannot be separated without deforming one or both of the interlocked elements again.

[0019] In the illustrated example, the pin 2 is shaped like a straight cylinder with a diameter slightly smaller than that of the holes in the adjustable strap 3 of the bracelet. The free end of the pin 2, designed to pass through one of the holes in the adjustable strap 3 of the bracelet and then to snap into the recess defined between the two arms 14 of the support 4, has inclined planes such that its span widens and then narrows from its free end to its end connected to the cover 1. This allows the arms 14 of the support 4 to expand elastically when the expanded portion of the pin 2 is forced into the recess, and then to return to their initial position (without constraint) once this expanded portion has passed through. More generally, the pin 2 has a shape such that its span includes a local maximum between its free end and its end attached to the cover 1.

[0020] The shape of the nipple 2 could be different, but it is designed so that the part passing through one of the holes in the adjustable strap 3 when adjusting the length of the adjustable strap 3 does not deform the hole it passes through. The local maximum defined previously is therefore smaller than the diameter of the holes in the adjustable strap 3. The base of the nipple 2, on the side of its end connected to the cover, could have a larger cross-section since it is not intended to pass through one of the holes in the strap.

[0021] The shape of the free end of the nipple 2, in particular the inclination of said inclined planes, is such that the elastic fit is reversible, that is to say that the nipple 2 can come out of the housing by elastic spreading of the arms 14 when the user spreads the support 4 away from the cover 1 by rotating it.

[0022] As illustrated in the figure 4 , the nipple 2 is manufactured, for example molded or machined, separately from the cover 1 and then assembled to the latter by interlocking but it could be manufactured as one piece with the cover 1.

[0023] The strands 3, 11 of the bracelet can be made of soft materials such as leather, fabric, canvas, or any other material known to a person skilled in the art for making soft bracelets.

[0024] The preceding description focuses on describing a particular embodiment by way of non-limiting illustration and the invention is not limited to the implementation of certain particular features which have just been described, such as for example the shape of the support 4 and its arms 14 nor that of the cover and its nipple 2.

[0025] As previously mentioned, in the illustrated example, only the arms 14 of the support 4 deform elastically to allow the pin 2 to pass through when the fastening system is locked. Alternatively, both the pin 2 and the arm 14 could have elastic properties.

[0026] In variations, the clasp according to the invention could be a clasp other than a folding clasp with leaves, for example, a simple clasp comprising only the fastening system as described above. A wristwatch 20 comprising such a clasp typically includes a first adjustable strap 3 and a second fixed strap 11, the fastening system described above being directly attached to the fixed strap 11. The fixed strap 11 typically includes a loop into which the stem 8 is inserted. figure 7 illustrates a wristwatch 20 including such a clasp.

[0027] The support 4 could also be pivotally mounted on the cover 1 by means other than by means of a pivoted rod 8.

[0028] Furthermore, it is evident that the shape of the clasp components according to the invention can vary infinitely as long as their functions are ensured.

Claims

1. Clasp (100) for a bracelet comprising at least one cover (1) and a support (4), which can move with respect to each other, the cover (1) bearing a stud (2) intended to pass through a selected hole of a series of holes in a first strap (3) of a flexible bracelet and to be coupled to the support (4) in order to fix said first bracelet strap (3) between said cover (1) and support (4), the support (4) comprising at least one housing defined by a first and a second elastic arm (14) able to move away from one another elastically, said stud (2) being able to be inserted at least partially into said housing in order to be coupled to the support (4), said elastic arms being elastically deformed during this insertion, the clasp (100) being characterised in that said stud (2) is able to pass through said hole while extending in the direction of the wearer's wrist.

2. Clasp (100) for a bracelet as claimed in claim 1, characterised in that once the stud (2) is inserted in said housing, said elastic arms which have been elastically deformed during said insertion resume their initial shape, the stud (2) and the support (4) thus not being able to be decoupled without deforming said elastic arms (14) again.

3. Clasp (100) for a bracelet as claimed in claim 1 or 2, characterised in that the diameter of the stud (2) is smaller than that of the holes of the series of holes of the first bracelet strap (3) so that the stud (2) can be inserted into one of said holes without deforming it.

4. Clasp (100) for a bracelet as claimed in any one of claims 1 to 3, characterised in that it comprises a rod (8) pivoted on the cover (1) and serving as a pivot spindle for the support (4), said support (4) being movable with respect to the cover (1).

5. Clasp (100) for a bracelet as claimed in claim 4, characterised in that the cover (1) comprises two pierced lugs (10) serving as a pivot bearing for the rod (8).

6. Clasp (100) for a bracelet as claimed in any one of the preceding claims, characterised in that it is a folding clasp with wings.

7. Clasp (100) for a bracelet as claimed in claim 6, characterised in that it comprises a first wing and a second wing which is articulated at one of its ends on said first wing and articulated by its other end to the cover (1) and to the support (4).

8. Clasp as claimed in claims 4 or 5 and 7, characterised in that said other end of the second wing is fixedly attached to the rod (8).

9. Timepiece such as a wristwatch comprising a flexible bracelet fitted with a clasp as claimed in any one of claims 1 to 8.