EP0126382A1 - Extensible fastener for a flexible wrist strap, especially a watch strap - Google Patents

Abstract

The extendable clasp for flexible bracelet, particularly suitable for watches, comprises two segments (5, 6) each articulated to a set of links (1, 2) of a bracelet, said segments being articulated with one another (7). One of the two segments (6) is provided with a locking element (8) and the other of the two segments (5) is formed by two fixed (51) and mobile (52) half-segments sliding relative to one another. to the other. The fixed half-segment (51) is articulated to a set of links (1) and is provided with a plurality of holes (53) while the movable half-segment (52) is articulated to the segment (6) and does not is provided with only one hole (54). The blocking element (8) passes through the holes (53, 54) when they are aligned one on the other thus allowing the blocking of the bracelet.

Description

The present invention relates to a clasp for a flexible bracelet, in particular for a watch bracelet comprising first and second elongated segments and attached to one another by means of a hinge and provided at the end of each of them. them articulation means composed of bars to attach them to the first and second links from which the bracelet is formed, the second segment being formed of two half-segments coupled together and sliding one inside the other, one of the two half-segments being fixed and articulated on the first link and the other of the two half-segments being mobile and articulated on the first segment.

Straps, particularly those that are suitable for watches, require that they can be closed on the wrist with ease and without running the risk that the watch may escape when trying to form the closure loop.

For this, it is preferable that the bracelet is continuous so that it rests securely on the wrist. It is however advisable to reduce the length of that necessary for its passage on the hand to that which is adapted to its suitable adhesion on the wrist.

A first solution is known of bracelets made of contiguous metal segments which contain small springs which make it possible to lengthen the bracelet when a traction is exerted on it. To be feasible, such a solution, however, requires very small springs subject to fatigue and which have a limited lifespan.

For this, we proposed clasps with hinged multiple hinges, essentially mounted on metal bracelets with two articulated segments but not extensible. This more advantageous solution was obtained with continuous devices with rigid segments, articulated, foldable, stackable and attached to each other. There are a large number of models. We can cite as an example a model with three rigid segments, the first of which closes under the second, while the third, serving as a cover, engages on the second and hangs on the first.

A notable improvement has been achieved with the device described in document CH-A-568 035 where a construction has been proposed which, at the same time as offering better aesthetics, improves the ease and security of closure.

This device consists of only two non-deformable and articulated segments and in which the second segment is completely covered by a part of the flexible strap, while the two segments are superimposed on each other in the closed position. When the bracelet is closed, its line appears as continuous, interrupted only by a plate which hides a lateral blocking device.

The bracelet is elegant, the segments are invisible, the closure is secure and inspires confidence. There is, however, between a closed bracelet and an open bracelet, a limited difference in length, particularly if short segments are used as indicated for small female wrists.

Other manufacturers have proposed bracelets in which there are two rigid segments, but where, at the end of one of the segments, there is a spring joint in the thickness of the bracelet. This way of doing things, however, decreases the confidence that one can have, at the same time as the aesthetics of the bracelet.

It is also claimed in the application IT 21 114 A / 81 an extensible bracelet of which one of the two segments is composed of two half-segments sliding one inside the other, recalled by the springs and fixed together in the contracted position. This ensures extensibility and safety in use, but there remain two drawbacks: the fatigue of the small springs and the tendency to close which the two half-segments exhibit already during the operation of inserting the bracelet. On the other hand, the adjustment margin is small.

The object of the present invention is to provide a bracelet clasp which does not have the drawbacks mentioned above.

More particularly, the aim is to produce a neat closure for a flexible bracelet which is extensible, adjustable on the wrist, especially on small wrists, such as female wrists and which can be articulated with simplicity and security.

It has been found that this object can be obtained by means which appear in the claims.

Thus, by bringing the movable half-segment in or out, the hole which it carries can appear in front of one of the holes in the other fixed half-segment making it possible to make several different lengths. The suitable length is chosen with ease and safety thanks to the shape given to the blocking element which blocks the two half-segments between them and closes the bracelet in an easy and simple way.

This form of lock can easily be hidden under a small cover hinged on a bracelet link, said cover having a reduced length. Thus, the bracelet maintains line continuity and good grip on the wrist.

• La figure 1 représente le fermoir vu de côté et dans son extension maximale, de même que les maillons articulés auxquels il est attaché.
• La figure 2 représente le même fermoir que celui montré en figure 1, mais vu en plan.
• La figure 3 représente le fermoir de la figure 1 fermé et bloqué.
• La figure 4 représente une coupe selon la ligne IV-IV de la figure 2.
• La figure 5 représente, à échelle agrandie, le fermoir de la figure 1 à l'instant précédant le blocage.
• La figure 6 représente le même fermoir que celui de la figure 5, mais en position de blocage.

The constructive and functional characteristics of the extensible clasp for bracelet, object of the present invention, will be better understood on reading the description which follows and which refers to the figures of the drawing which illustrate by way of example an embodiment and in which:

• Figure 1 shows the clasp seen from the side and in its maximum extension, as well as the articulated links to which it is attached.
• Figure 2 shows the same clasp as that shown in Figure 1, but seen in plan.
• Figure 3 shows the clasp of Figure 1 closed and blocked.
• FIG. 4 represents a section along the line IV-IV of FIG. 2.
• FIG. 5 represents, on an enlarged scale, the clasp of FIG. 1 at the instant preceding the blocking.
• Figure 6 shows the same clasp as that of Figure 5, but in the locked position.

The arrangement shown in the figures comprises two parts 1 and 2 of a bracelet each composed of metal links connected on one side to the object to be worn, in particular a watch, and on the other side at the opposite ends of a extendable metal clasp with bars 3 and 4 to form a continuous loop. The clasp comprises a first elongated rigid segment 5 and a second elongated semi-rigid segment 6, the two segments being attached together by means of a hinge 7. The segment 5 is slightly curved to conform to the shape of the wrist. The same is true, but in a more pronounced manner of the segment 6 which further carries, near the bar 4 and on its concave face, a blocking element 8.

As can be seen in FIGS. 5 and 6, the blocking element has the shape of a beak and carries on one side an edge 81 which is curved in the direction of the hinge 7, and on the other side a transverse notch 82 surmounted by a hook-shaped point 83 also directed towards the hinge 7. The locking element 8 and the hole 54 are shaped so that the point 83 will be pressed against the inner edge of the hole 54 when the segment 6 is applied against the segment 5. The notch 82 has a point-side surface 83 which diverges from the half-segment 52 which is adjacent to the locking element 8.

The second segment 5 is formed by two half-segments 51 and 52 mounted to slide one inside the other longitudinally. The half-segment 51 has raised edges forming a slide in which the half-segment 52 is engaged. The half-segment 51 is fixed because it is articulated to the bracelet by means of the bar 3 and the half-segment 52, articulated to the first segment 6 by the hinge 7, is movable since it can slide in said half-segment 51.

The half-segment 51 carries a plurality of equidistant holes 53 (here three) while the half-segment 52 carries only one hole 54. As can be seen in FIG. 2, the hole 54 coincides with the third of the holes 53. In this position, the clasp can be locked at its maximum extension.

To close and lock the clasp, the segment 6 is folded over the segment 5 and, at the same time, the half-segment 52 is slid along the half-segment 51 using a cover 9 pivotally mounted on the bar 4, until the bracelet adapts to the dimensions of the wrist. Pressure is then exerted on the part 2 of the bracelet to compress the central region of the segment 6. As a result, the segment 6 is deformed and elongated and the locking element 8 with which it is provided can be introduced through the hole 54 and hole 53 which is most suitable for the proper adaptation of the bracelet to the wrist, these two holes being, after a back and forth movement, aligned one on the other.

By releasing the clasp, on the one hand, the wrist relaxes and causes the displacement of the half-segment 51 to the left, which results in engaging the notch 82 in the hole 53 and, on the other hand, the segment 6 resumes its normal curved shape and then causes the shortening of the distance separating the hinge 7 from the locking element 8. The clasp is then blocked. As long as the wrist is slightly compressed, the locking element will not slip out of the hole 53 and the tip 83 will not be able to pass through the hole 54.

In the locked position, we see that the cover 9 covers the space between the parts 1 and 2 of the bracelet and thus hides from view the operational elements of the clasp.

To open the clasp, the strap is tightened to release the tip 83 from the hole 53 and pressure is exerted on the part 2 of the strap to compress the central region of segment 6. As we have already said, segment 6 is extension and the locking element 8 can come out of the holes 53 and 54. The cam effect exerted by the edge 81 on the hole 54 also helps this release.

The opening of the clasp is facilitated by lifting the cover 9 by engaging a nail under the front tongue 10. As the cover 9 also has a rear tongue 11 which is supported, when the clasp is locked, on a link 2 of the bracelet, a significant force torque is obtained which makes it possible to tear off the locking element 8 from the holes in which it is engaged. This rear tongue or overflow 11 also prevents the cover from flapping when the clasp is in the closed position.

Note that the half-segments 51, 52 and the element 8 can be made of precious metals or other metals made hard by alloying or quenching. A hardness of at least 140 Vickers is desirable in order to obtain a perfect gloss and to keep this gloss when the moving parts slide on each other.

Claims (7)

1. Extensible clasp for flexible strap, in particular for watch strap comprising first (6) and second (5) elongated segments and attached to each other by means of a hinge (7) and provided at the end of each of them articulation means composed of bars (3, 4) for attaching them to the first (1) and second (2) links from which the bracelet is formed, the second segment (5) being formed of two half-segments (51, 52) coupled together and sliding one inside the other, one of the two half-segments (51) being fixed and articulated on the first link (1) and the other of the two half -segments (52) being mobile and articulated on the first segment (6), characterized in that the first segment (6) is provided in the vicinity of the bar (4) with a locking element (8) inclined and provided a notch (82), that the movable half-segment (52) is provided with a single hole (54) and that the fixed half-segment (51) is provided with a plurality of holes (53) which can come stand in the c hoix opposite the single hole (54) carried by the movable half-segment (52) to allow the locking of the clasp to the desired extension when the locking element (8) is introduced into the aligned holes (53, 54) . 2. Extensible clasp according to claim 1, characterized in that it further comprises a cover (9) articulated on the bar (4) hinged between the first segment (6) and the second link (2) to cover, once closed, the fixed half-segment (51) and facilitate the opening of the clasp. 3. Extensible clasp according to claim 1 or claim 2, characterized in that the fixed half-segment (51) comprises raised edges in which slides the movable half-segment (52). 4. Extensible clasp according to any one of claims 1 to 3, characterized in that the two half-segments (51, 52) and the locking element (8) are made of materials having a hardness of at least 140 Vickers. 5. Extensible clasp according to any one of claims 1 to 4, characterized in that the locking element (8) has a shape of spout whose edge (81) is curved in the direction of the hinge (7) to form the notch (82) of the locking element. 6. Extensible clasp according to claim 5, characterized in that the surface of the notch (82) which is opposite to the first segment (6) diverges from the part of said first segment which is adjacent to the locking element. 7. Extensible clasp according to claim 2, characterized in that the cover (9) is provided with an overflow (11) adjacent to the link (2) to prevent pivoting of said cover when the clasp is in the closed position.

Images