FR2821725A1 - FOLDING CLASP FOR 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

hollow interior spaces of adjacent links.

- - - - - -

FOLDING CLASP FOR BRACELET

  The invention relates to the technical sector of devices capable of coupling the free ends of a bracelet, in particular but not exclusively to a watch bracelet. There are essentially two main types of means capable of enabling the bracelets to be closed. In a first simplified embodiment, one of the ends of the bracelet has a loop 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 leather, plastic, textile material, and more generally any material

relatively flexible.

  On the other hand, this solution is not applicable for rigid or semi-rigid bracelets, such as those composed of a plurality of articulated links for example. In this case, a clasp is used which is hinged to the free ends of the strands of the bracelet. This clasp has different types of arrangement making it possible to bring the strands of the bracelet together and to keep them in the joined position corresponding to the closure as such. The invention relates to this second type of closure. More particularly, the invention relates to a folding-type clasp, as is apparent, for example, from the teaching of Swiss patents

  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 connected together by a connecting element by being pivotally mounted at each end of said element. The connecting element has two indentations with shapes and dimensions corresponding to those of the arms so that the latter can completely 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 the

  connecting part of the two notches.

  This solution is not entirely satisfactory, given that 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, at each of their ends, receive, with free articulation, two arms on which the strands of the bracelet are mounted. In the closed position, the arms are partially included in the thickness of the central element. To ensure locking in the closed position, each arm has, at its free end, a spout capable of coming 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 of the arms. Here again, difficulties appear at the level of coupling and uncoupling. The arms work by elasticity and

by sliding.

  The invention aims to remedy these drawbacks,

  simple, safe, efficient and rational way.

  The problem which the invention proposes to solve is to produce a clasp of simplified design and of a reduced cost price, being shaped to ensure, in a precise and adjustable manner, the closing of the

  bracelet, having the possibility of making it in different materials.

  To solve this problem, it has been designed and fitted with a folding clasp of the type of those comprising a profiled plate having two spaced parallel branches delimiting a space for the free-articulation mounting of at least one blade having, opposite its joint part,

  arrangements for articulated mounting of part of the bracelet.

  According to a characteristic underlying the invention, the blade or blades of the bracelet are equipped, near the part receiving the bracelet, with two rotary rollers arranged coaxially and projecting from each lateral side of the blade to cooperate with a reDord profile which has a through recess formed laterally in the thickness of each branch in order to create, after folding the blade, a snap effect by rolling friction resulting from a tensioning of the blade, said recess being equipped means capable of ensuring the abutment of a part of the blade or blades in the snap-in position, corresponding to

  the closed position of the bracelet.

4 2821725

  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 by exerting a support at the end of the blades corresponding to a pressing force, and when the dead center of the snap is exceeded, corresponding to the passage of the rotary rollers at the level of the profiled edge of the recess, we obtain, from a concomitant matrix, the automatic snap-on of the

  clasp. The radius of the blades increases.

  According to another characteristic, the stop means of the blades in the latching position are constituted by transverse rollers mounted between the lateral edges of the recess acting as a spacer. Advantageously, the clasp has two parallel rollers between

  them and to the axis of the rotary blades rollers.

  Similarly, the whole of the profiled plate can be produced in a single piece, so that the stop means of the blades in the snap-in position consist of at least one transverse branch formed directly during the manufacture of said plate. while being

  positioned substantially in the middle part of the recess.

  To solve the problem posed of the stop of the blades while allowing their manipulation, the ends of the blades, opposite their articulation, have a profiled shape oriented angularly above the rotary rollers, being able to bear on the spacer rollers , 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 posed by ensuring the coupling of the two o -. strands of the bracelet, the free ends of the profiled forms are drilled transversely right through for mounting, with capacity

  of articulation, of the corresponding parts of the bracelet.

  To solve the problem posed to reduce costs and facilitate.

  mounting the entire clasp, the spacer rollers are constituted by a tube disposed between the lateral edges facing the recess, being mounted on a hollow axis engaged in the thickness of the branches, said axis receiving, each of its ends, means

  removable translational locking.

  To solve the problem posed of being able, at will, to increase or decrease the latching force, the coaxial latching rollers are mounted rotating on a common axis with dismantling capacity for

  adapt their diameter to the desired latching force.

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

6 2821725

  - 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; - Figure 2A is a view similar to Figure 2 showing an alternative embodiment at 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 the figure 3 showing the start of the snap 0; - 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 A-A of Figure 3; - Figure 8 is a cross-sectional view taken along line B-B of figure 4; - Figure 9 is a cross-sectional view seen according to the

line C-C in Figure 5.

  Like the monkent in particular Figures 1 and 2, the folding clasp comprises a profiled plate (1) having two parallel branches (la) and (lb). The two branches (la) and (lb) define a space (lc) for mounting, with free articulation, 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 (la) and (lb), 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 hollow tube engaged transversely in the thickness of the branches (la) and (lb) while being held in translation by rivets (4a) (5a). In known manner, the plate (1) and the branches (2) and (3) are bent longitudinally. Similarly, always in a known manner, the free ends of the blades (2) and (3), opposite their articulation (4) and (S) have any type of arrangement for mounting with free articulation strands (B1) and (B2) of

bracelet (B).

  According to an important characteristic of the invention, each blade (2) and (3) is equipped, near the free end where the strands (B1) and (B2) of the bracelet are articulated, with 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 profiled twist (ldl-ld2) and (lel-le2) that has a recess (ld) and (le) formed laterally in the thickness of each branch (la) and (lb). The reDords (ldl-ld2) and (lel-le2) and connected to the top of each of the branches (la) and (lb), by a cam profl able to create, after folding down the corresponding blades (2) and (3) in a space (lc), a snap effect by rolling friction when the rotary rollers (6-7) and (8-9) are engaged. This results, concomitantly, in tensioning the blades (2) and (3) by increasing their radius of curvature, as will be

  indicated in the following description.

  : 4. As shown in particular in FIG. 1, the rollers (6-7) and (8-9) are arranged coaxially by being mounted rotating on a common axis (1011) 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 surface (10a and 11a) for rotary mounting, with dismantling capacity, rollers or rollers (6-7) and (8-9). In view of these provisions, it is thus possible to use a rotary roller of different

  diameter depending on the desired latching force.

  o According to another characteristic, transverse rollers (12 and 13) are mounted between the opposite lateral edges of the recesses (ld) and (le). These rollers (12) and (13) act as a spacer for the branches (la) and (lb), and provide the abutment for part of the blades (2) and (3), in the latching position. 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 (ld) and (le). The tubes (12a) and (13a) are mounted on a hollow axis (12b) and (13b) engaged in the thickness of the branches (la) and (lb) at the level of the recess (ld) and (le). 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 FIG. 2A, with the aim of simplifying and reducing costs, the whole of the profiled plate (1), with the two branches (la) and (lb) delimiting the 'space

  (lc), is made in a single piece, that is to say in one piece.

  The stop means in the latching position of the blades (1) and (2) consist of a transverse branch (lf) directly connected to the lateral branches (la) and (lb) where the blades (2) and (3) are articulated ). The transverse branch (lf) is positioned substantially in the middle part of the recess (1 d- 1 e). The ends of the blades (2) and (3), opposite their axis of articulation (4) and (S) have a profiled head (2a) and (3a) oriented angularly above the rotary rollers (6 -7) and (8 9). The profiled heads (2a) and (3a) are able to bear on the spacer rollers (12) and (13). In the latching position of the blades (2) and (3), the heads

  sections (2a) and (3a) are arranged in a substantially contiguous manner.

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

a bracelet.

  In view of these characteristics, reference is made more particularly to FIGS. 3, 4 and S. which show the clasp in the open position (FIG. 3) in the latching position (FIG. 4), that is to say at the time when the rollers (6-7) and (8-9) attack the ramp-shaped profile (ldl) and (ld2) and (lel) and (le2) of the recesses (ld) and (le), and in the latching position (Figure 5), that is to say when the rollers (6-7) and (89) under the pressure force (P) exerted on the profiled heads (2a) and (3a), have passed the point death of the click. The resulting component ensures snap-in

2821725

  automatic clasp. The cutting radius of the blades (2) and (3) increases. In this latching position, the blades (2) and (3) are completely integrated in the space (lc) of the two branches (la) and (lb). Given the basic characteristics of the invention, the entire clasp can be made of any material. Advantageously but not exclusively, it can be made of carbon fiber, the blades being ejected without a demoulding drawer, which makes it possible to reduce costs significantly. Always aiming to reduce costs, by simplifying manufacturing, the whole plate can be

  executed, as indicated, in a single piece.

  The advantages are apparent from the description, in particular one

  underlines and recalls: - the locking 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; - increase and decrease of 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 given the rotary coaxial rollers;

1 1 2821725

  - simplicity of implementation; - reduction of costs;

  - use of simplified and standard parts.

12 2821725

Claims (1)

CLAIMS -1- Folding clasp for bracelet comprising a profiled plate (1) having two spaced parallel branches (la) and (lb) delimiting a space (lc) for mounting with free articulation of at least one blade (23) having the opposite of its articulation part of the arrangements for the articulated mounting of a part of the bracelet, characterized in that the blade (s) (2-3) of the bracelet are equipped, near the part receiving the bracelet, with two rotary rollers (6-7) and (8-9) arranged coaxially and projecting on each lateral side of the blade (2-3) to cooperate with a profiled twist (ldl-ld2) and (lcl-lc2) that presents a stubbing recess (ld-le) formed laterally in the thickness of each branch (la) and (lb) in order to create, after folding down the blade (2-3), a snap effect resulting from rolling friction tensioning the blade, said recess (ld-le) being equipped with means (12- 13) capable of ensuring the abutment of part of the blade (s) (2-3) in the snap position. -2- Clasp according to claim 1, characterized in that it has two opposite symmetrical blades (2-3) articulated, at each of the ends of the branches (la) and (lb), the recess (ld-le) being formed substantially in the middle part of said branches. -3- Clasp according to claim 1, characterized in that the blade stop means (2-3) in the latching position, are constituted by transverse rollers (12) and (13) mounted between the lateral edges of the 'obviously (ld-le) by acting as a spacer. -4- Clasp according to claim 3, characterized in that it has two rollers parallel to each other (12) and (13) and to the axis of the rotary rollers (6 7) and (8-9) of the blades (2) and (3).   -S- Clasp according to claim 1, characterized in that the blade stop means (2-3), in the snap-on position, consist of at least one transverse branch (lf) positioned substantially in the middle part of the '' recess (ld-le) and formed directly during manufacturing of the profiled plate (1).   -6- Clasp according to claim 2, characterized in that the ends of the blades (2-3), opposite their articulation, have a profiled shape (2a-3a) oriented angularly above the rotary rollers (6 -7) and (8-9), being able to bear on the spacer rollers (12) and (13), said shapes, in the latching position of the blades (2) and (3), being   arranged in a substantially contiguous manner.   -7- Clasp according to claim 6, characterized in that the free ends of the profiled shapes (2a) and (3a) are drilled transversely from side to side for mounting, with articulation capacity, of the parts matching bracelet.   -8- Clasp according to claim 1, characterized in that the coaxial snap rollers (6-7) and (8-9) are rotatably mounted on a common axis (10) and (11) with dismantling capacity to adapt their diameter   at the desired snap force.   -9- Clasp according to claim 3, characterized in that the spacer rollers (12) and (13) consist of a tube (12a) and (13a) disposed between the side edges facing the recess (l d- le), while being mounted on a hollow axis (12b-13b) engaged in the thickness of the branches (la) and (lb), said axis receiving, at each of its ends, removable means of translation locking (14).   -10- Clasp according to claim 1, characterized in that all of the