EP1238599B1 - Foldable fastener for a bracelet - Google Patents

Abstract

The clasp for a watch bracelet comprises two arms (2, 3) attached by pivots at their upper ends to the ends (B1, B2) of the bracelet. Rollers (6, 7, 8, 9) are mounted under these pivots. The lower ends of the arms are mounted on pivots inside parallel rails (1a, 1b) with a space (1c) between. When the clasp is closed the rollers move down over curved surfaces (1d1, 1d2, 1e1, 1e2) into a central space where they are held by transverse, rotating bars (12, 13).

Description

The invention relates to the technical sector of devices suitable for ensuring the coupling of the free ends of a bracelet, in particular but not exclusively a watch strap.

There are essentially two main types of means capable of allow the bracelets to be closed. In a first form of simplified production, one end of the bracelet has a buckle in which is engaged the end of the other strand of the bracelet pierced with several holes capable of cooperating with the articulated hook of the loop. This type of closure is generally reserved for the leather strap, plastic material, textile material, and more generally any material relatively flexible.

However, this solution is not applicable for bracelets rigid or semi-rigid, such as those composed of a plurality of links articulated for example. In this case, a clasp coupled with articulated at the free ends of the bracelet strands. This clasp presents different types of arrangement allowing the strands to be brought together of the bracelet and keep them in the joined position corresponding to the closure as such. The invention relates to this second type of closing.

More particularly, the invention relates to a clasp of the type leaflet, as can be seen for example from Swiss patent teaching CH 633 698 and French FR 2 619 292.

In patent CH 633 698, the clasp comprises two arms coupled at one of their ends, with free articulation, to each of the strands of the bracelet. The two arms are interconnected by a connecting element in being pivotally mounted at each end of said element. The element of connection presents two notches with shapes and dimensions corresponding to those of the arms so that they can fully fit into the thickness of said element in the closed position of the bracelet. A notching system is formed at the free ends of the arms and cooperates with complementary arrangements formed at the level of connecting part of the two notches.

This solution is not entirely satisfactory, since it is difficult to ensure adjustment of the bracelet closure. In addition, the notching system, both at the closure and at the the opening of the bracelet is very practical to handle.

Patent FR 2,619,292 describes a folding clasp having a central element delimiting two parallel branches. These two branches, each of their ends, receive, with free articulation, two arms on which are fitted the strands of the bracelet. In the closed position, the arms are partially included in the thickness of the central element. To ensure the locking in closed position, each arm has, at its end free, a beak likely to hang on two rods arranged transversely, between the branches of the central element.

It is therefore necessary to provide a specific shape at the ends arms. Again, difficulties appear at the level of mating and uncoupling. The arms work by elasticity and by sliding.

The object of the invention is to remedy these drawbacks, simple, safe, efficient and rational way.

The problem that the invention proposes to solve is to achieve a clasp of simplified design and a reduced cost price, being shaped to ensure, in a precise and adjustable way, the closing of the bracelet, having the possibility of making it in different materials.

To solve this problem, it was designed and put a folding clasp of the type of those comprising a profiled plate having two branches spaced parallel lines delimiting a space for free joint mounting at least one blade having, opposite its articulation part, arrangements for the articulated mounting of part of the bracelet.

According to a characteristic underlying the invention, the blade or blades of the bracelet are equipped, close to the part receiving the bracelet, with two rotating rollers arranged coaxially and overlapping on each side side of the blade to cooperate with a profiled rim which has a through recess formed laterally in the thickness of each branch in order to create, after folding the blade, an effect locking by rolling friction resulting from tensioning of the blade, said recess being equipped with means capable of ensuring the stop of a part of the blade (s) in the latching position, corresponding to the closed position of the bracelet.

Advantageously, the invention relates to a double folding clasp. For this purpose, the clasp has two opposite symmetrical blades articulated, at each end of said branches, the recess being formed substantially in the middle part of said branches.

Given these technical characteristics, it follows that exerting support at the end of the blades corresponding to a pressure force, and when we exceed the neutral position of the latching, corresponding to the passage of the rotating rollers at the level of the profiled edge of the recess, concomitantly obtains the automatic latching of the clasp. The blade radius increases.

According to another characteristic, the stop means of the blades in click position, consist of transverse rollers mounted between the side edges of the recess acting as a spacer.

Advantageously, the clasp has two parallel rollers between them and to the axis of the rotating rollers of the blades.

Similarly, the whole of the profiled plate can be made of a monobloc, so that the stop means of the blades in position latching consist of at least one transverse branch formed directly during the manufacture of said plate by being positioned substantially in the middle part of the recess.

To solve the problem posed of the blade stop while allowing their handling, the ends of the blades, opposite their articulation, have a profiled shape angularly oriented above rotary rollers, being able to bear on the rollers spacer, said shapes, in the latching position of the blades, being arranged in a substantially contiguous manner.

In this closed position, the blades are perfectly integrated into the thickness of the space resulting from the bracing of the two branches.

To solve the problem of ensuring the coupling of the two strands of the bracelet, the free ends of the profiled shapes are pierced transversely right through for assembly, with capacity of articulation, of the corresponding parts of the bracelet.

To solve the problem of reducing costs and facilitating mounting the entire clasp, the spacer rollers are constituted by a tube arranged between the lateral edges opposite the recess, by being mounted on a hollow axis engaged in the thickness of the branches, said axis receiving, at each of its ends, means removable locking in translation.

To solve the problem of power, at will, to increase or decrease the snap force, the coaxial snap rollers are rotatably mounted on a common axis with dismantling capacity for adapt their diameter to the desired latching force.

• la figure 1 est une vue en perspective, avant montage des principaux éléments constitutifs, du fermoir selon l'invention ;
• la figure 2 est une vue correspondant à la figure 1 après montage des éléments constitutifs du fermoir ;
• la figure 2A est une vue semblable à la figure 2 montrant une variante de réalisation au niveau de la plaque profilée recevant les lames ;
• la figure 3 est une vue en coupe longitudinale du fermoir, en position d'ouverture ;
• la figure 4 est une vue semblable à la figure 3 montant le début de l'encliquetage ;
• la figure 5 est une vue semblable à la figure 4 en position d'encliquetage des branches ;
• la figure 6 est une vue en plan avec coupe partielle correspondant à la figure 5 ;
• la figure 7 est une vue en coupe transversale considérée selon la ligne A-A de la figure 3 ;
• la figure 8 est une vue en coupe transversale considérée selon la ligne B-B de la figure 4 ;
• la figure 9 est une vue en coupe transversale considérée selon la ligne C-C de la figure 5 ;
• la figure 10 est une vue en perspective d'une forme de réalisation préférée du fermoir dépliant selon l'invention ; les différents éléments constitutifs sont montrés avant montage, de même que les maillons du bracelet ;
• la figure 11 est une vue en perspective correspondant à la figure 10, après montage des éléments constitutifs du fermoir et avant montage des maillons du bracelet ;
• la figure 12 est une vue semblable à la figure 11 après montage des maillons du bracelet ;
• la figure 13 est une vue de face du fermoir en position ouverte ;
• la figure 14 est une vue en plan correspondant à la figure 13.

The invention is set out below in more detail with the aid of the figures of the appended drawings in which:

• Figure 1 is a perspective view, before mounting of the main components, the clasp according to the invention;
• Figure 2 is a view corresponding to Figure 1 after mounting of the components of the clasp;
• FIG. 2A is a view similar to FIG. 2 showing an alternative embodiment at the level of the profiled plate receiving the blades;
• Figure 3 is a longitudinal sectional view of the clasp, in the open position;
• Figure 4 is a view similar to Figure 3 showing the start of the latching;
• Figure 5 is a view similar to Figure 4 in the latching position of the branches;
• Figure 6 is a plan view with partial section corresponding to Figure 5;
• Figure 7 is a cross-sectional view taken along line AA of Figure 3;
• Figure 8 is a cross-sectional view taken along line BB of Figure 4;
• Figure 9 is a cross-sectional view taken along the line CC of Figure 5;
• Figure 10 is a perspective view of a preferred embodiment of the folding clasp according to the invention; the various constituent elements are shown before assembly, as are the links of the bracelet;
• Figure 11 is a perspective view corresponding to Figure 10, after assembly of the components of the clasp and before assembly of the bracelet links;
• Figure 12 is a view similar to Figure 11 after mounting of the bracelet links;
• Figure 13 is a front view of the clasp in the open position;
• FIG. 14 is a plan view corresponding to FIG. 13.

As shown in particular in Figures 1 and 2, the folding clasp comprises a profiled plate (1) having two parallel branches (1a) and (1b). The two branches (1a) and (1b) define a space (1c) for the free-mounting of at least one, but preferably two symmetrical and identical blades (2) and (3). The two blades (2) and (3) are articulated between the two branches (1a) and (1b), at each of their ends, by means of a transverse axis (4) and (5).

For example, each of the axes (4) and (5) is constituted by a tube hollow engaged transversely in the thickness of the branches (1a) and (1b) in being held in translation by rivets (4a) and (5a). In a known way, the plate (1) and the branches (2) and (3) are bent longitudinally. Of even, still in a known manner, the free ends of the blades (2) and (3), opposite their articulation (4) and (5) have any type of arrangement for the free articulation mounting of the strands (B1) and (B2) of the bracelet (B).

According to an important characteristic of the invention, each blade (2) and (3) is equipped, near the free end where the strands are articulated (B1) and (B2) of the bracelet, of two rotary rollers (6-7) and (8-9) arranged coaxially, projecting from each lateral side of said blades (2) and (3). These rollers (6-7) and (8-9) are intended to cooperate with a flange profile (1d1-1d2) and (1e1-1e2) that has a recess (1d) and (1e) formed laterally in the thickness of each branch (1a) and (1b). Ledges (1d1-1d2) and (1e1-1e2) are connected to the top of each of the branches (1a) and (1b), by a cam profile capable of creating, after folding the blades corresponding (2) and (3) in a space (1e), a snap effect by rolling friction when engaging the rotary rollers (6-7) and (8-9). This results, concomitantly, in tensioning the blades (2) and (3) by increasing their radius of curvature, as will be indicated in the following description.

Note that the profiled edges (1d1-1d2) and (1e1-1e2) are determined to allow the blades (2) and (3) to snap under a low force traction, and conversely, the uncoupling of said blades under a force relatively high traction, in order to avoid any uncoupling untimely.

As shown in particular in Figure 1, the rollers (6-7) and (8-9) are arranged coaxially by being mounted rotating on a common axis (10-11) housed transversely in the thickness of each of the branches (2 and 3). Each of the axes (10 and 11) has, at each of its ends, a circular bearing (10a and 11a) for rotary mounting, with capacity for disassembly, rollers or rollers (6-7) and (8-9). Given these provisions, it is thus possible to use a rotating roller of different diameter depending on the desired latching force.

According to another characteristic, transverse rollers (12 and 13) are mounted between the opposite lateral edges of the recesses (1d) and (1e). These rollers (12) and (13) act as a spacer for the branches (1a) and (1b), and ensure the abutment of a part of the blades (2) and (3), in position snap. The two rollers (12) and (13) are mutually parallel and to the axes (10) and (11) of the rotary rollers (6-7) and (8-9). In the example illustrated, the spacer rollers (12) and (13) consist of a tube (12a) and (13a) disposed between the lateral edges opposite the recesses (1d) and (1e). The tubes (12a) and (13a) are mounted on a hollow axis (12b) and (13b) engaged in the thickness of the branches (1a) and (1b) at the level of the recess (1d) and (1e). The axes (12b) and (13b) receive, at each of their ends, removable means for locking in translation constituted by example by a point (14).

In another embodiment and as shown in the figure 2A and Figures 10, 11 and 12, for the purpose of simplification and reduction costs, the whole of the profiled plate (1), with the two branches (1a) and (1b) delimiting the space (1c), is produced in a monobloc manner, that is to say in one piece. The stop means in the latching position of the blades (1) and (2) are constituted by a transverse branch (1f) connected directly to the lateral branches (1a) and (1b) where the blades are articulated (2) and (3). The transverse branch (1f) is positioned substantially in the middle part of the recess (1d-1e).

The ends of the blades (2) and (3), opposite their axis articulation (4) and (5) have a profiled head (2a) and (3a) oriented angularly above the rotating rollers (6-7) and (8-9). Heads profiles (2a) and (3a) are able to bear on the spacer rollers (12) and (13) or the transverse branch (1f). In the snap position of blades (2) and (3), the profiled heads (2a) and (3a) are arranged in a way substantially contiguous.

In the example illustrated, the heads (2a) and (3a) are pierced transversely right through, for the assembly, with free articulation, of ends of the strands (B1) and (B2) of the bracelet in question. For example, heads (2a) and (3a) allow the assembly, with free articulation, of the links a bracelet.

Given these characteristics, we refer more particularly Figures 3, 4 and 5, which show the clasp in the open position (Figure 3) in the snap-in position (Figure 4), that is to say when the rollers (6-7) and (8-9) attack the ramp-shaped profile (1d1-1d2) and (1e1-1e2) of the recesses (1d) and (1e), and in the snap position (figure 5), that is to say when the rollers (6-7) and (8-9) under the pressure force (P) exerted on the profiled heads (2a) and (3a), have exceeded the neutral the snap. The resulting component ensures snap-in automatic clasp. The radius of curvature of the blades (2) and (3) increases.

In this latching position, the blades (2) and (3) are fully integrated into the space (1c) of the two branches (1a) and (1b).

Given the characteristics underlying the invention, the assembly of the clasp can be made of any material. Advantageously but not exclusively, it can be made of carbon fiber, the blades being injected without a demoulding drawer, which makes it possible to reduce significant, costs. Still with the objective of reducing costs, by simplifying manufacturing, the entire plate can be executed, as indicated, in a single piece.

• l'encliquetage par frottement de roulement des deux rouleaux coaxiaux en étirant les lames par augmentation de leur rayon de courbure ;
• facilité de l'encliquetage par le faible frottement de roulement ;
• augmentation et diminution de la force d'encliquetage en adaptant le diamètre des rouleaux rotatifs d'encliquetage ;
• possibilité d'obtenir une grande côte d'encliquetage, ainsi qu'une grande course d'encliquetage ;
• la sécurité de fermeture ;
• la possibilité d'utiliser une lame de faible largeur compte tenu des rouleaux coaxiaux rotatifs ;
• simplicité de réalisation ;
• diminution des coûts ;
• utilisation de pièces simplifiées et standard.

The advantages emerge clearly from the description, in particular it is emphasized and recalled:

• latching by rolling friction of the two coaxial rollers by stretching the blades by increasing their radius of curvature;
• ease of latching due to the low rolling friction;
• increasing and decreasing the latching force by adapting the diameter of the rotary latching rollers;
• possibility of obtaining a large ratcheting rib, as well as a large ratcheting stroke;
• closing security;
• the possibility of using a blade of small width taking into account the rotating coaxial rollers;
• simplicity of implementation;
• lower costs;
• use of simplified and standard parts.

Claims (10)

1. An unfolding clasp for a bracelet having a profiled plate (1) having two spaced-apart parallel branches (1a) and (1b) defining a space (1c) for the assembly, in a freely articulating manner, of at least one blade (2-3) having, on the side away from its articulating part, provisions for the articulated assembly of part of the bracelet,
   wherein the blade or blades (2-3) of the bracelet are equipped, close to the part receiving the bracelet, with two rotating rollers (6-7) and (8-9) placed coaxially with and protruding from each lateral side of the blade (2-3) in order to cooperate with the profiled rim (1d1-1d2) and (1e1-1e2) of an open recess (1d-1e) formed laterally in the thickness of each branch (1a) and (1b) for the purpose of creating, after folding down of the blade. (2-3), a snap-fastening effect by rolling friction resulting from tensioning of the blade, said recess (1d-1e) being equipped with means (12-13) capable of providing the stop for part of the blade or blades (2-3) in the snap-fastened position.
2. The clasp as claimed in claim 1, wherein it has two opposed symmetrical blades (2-3) articulated to each of the ends of the branches (1a) and (1b), the recess (1b-1e) being formed substantially in the central part of said branches.
3. The clasp as claimed in claim 1, wherein the means of stopping the blades (2-3) in the snap-fastened position consist of transverse rollers (12) and (13) assembled between the lateral edges of the recess (1d-1e), thereby acting as a spacer.
4. The clasp as, claimed in claim 3, wherein it has two rollers (12) and (13) which are mutually parallel and parallel to the spindle of the rotating rollers (6-7) and (8-9) of the blades (2) and (3).
5. The clasp as claimed in claim 1, wherein the means for stopping the blades (2-3) in the snap-fastened position consist of at least one transverse branch (1f) positioned substantially in the central part of the recess (1d-1e) and formed directly during the manufacture of the profiled plate (1).
6. The clasp as claimed in claim 2, wherein the ends of the blades (2-3) away from their articulation have a profiled shape (2a-3a) oriented at an angle above the rotating rollers (6-7) and (8-9), thereby being capable of pressing on the spacer rollers (12) and (13), said shapes being arranged in a substantially contiguous manner in the snap-fastened position of the blades (2) and (3).
7. The clasp as claimed in claim 6, wherein the free ends of the profiled shapes (2a) and (3a) are perforated transversely straights through the assembly, with articulation of the corresponding parts of the bracelet.
8. The clasp as claimed in claim 1, wherein the coaxial snap-fastening rollers (6-7) and (8-9) are mounted so as to rotate on a common spindle (10) and (11) with the capacity to be dismantled in order to adjust their diameter to the desired snap-fastening force.
9. The clasp as claimed in claim 3, wherein the spacer rollers (12) and (13) consist of a tube (12a) and (13a) placed between the lateral edges facing the recess (1d-1e), thereby being assembled on a hollow spindle (12b-13b) engaged in the thickness of the branches (1a) and (1b), said spindle accommodating, at each of its ends, detachable means (14) for translational locking.
10. The clasp as claimed in claim 1, wherein the assembly of the plate (1) and of the blades (2) and (3) is bent longitudinally.

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