EP1304054B1 - Closure - Google Patents

Abstract

The clasp consists of two articulated arms (10, 12) connected to the ends of the bracelet, the first having two lengthwise members (18, 20) and the second in the form of a plate (12a) between them, with a lock to hold them in the closed position. The lock is in the form of pushers (28) with studs (30) able to slide transversely relative to the ends of the lengthwise members. The studs are located between the lengthwise members and are equipped with fasteners (30b) engaging with projections (12d) on the plate.

Description

The present invention relates to clasps, of the type intended to connect, removably, the two ends of a bracelet, for example a wristwatch. It is more particularly a folding clasp, comprising two rigid arms, connected to one another in an articulated manner at one of their ends. The arms can occupy an open position, allowing the wearer of the bracelet to remove or slide the wrist strap, and a closed position in which the two arms are removably attached to one another by means of a locking member.

A clasp of this type is, for example, described in the document EP 0 115 740 . It comprises more precisely a first arm forming a rigid support beams and two other arms, each fixed pivotally, by one of its ends, at one end of the rigid support, and the bracelet by its other end. The two pivoting arms comprise two blades each adjacent to one of the longitudinal members of the support arm, arranged side by side and elastically connected to one another. The blades and spars are provided with side faces having complementary profiles, so that in the closed position of the clasp, the engagement of the profiles in each other ensures the locking of the articulated arms on the support arm.

The articulated arms are provided with pushpieces arranged in such a way that by applying a force, the blades approach one another and the profiles of the blades emerge from the profiles of the longitudinal members which allows the pivoting of the arms on their support.

The elastic connection between the two blades can be achieved either by means of coil springs interposed between them, or by a tuning fork structure. It appeared that with the tuning fork structure, the subject matter was aging, so that the gripping force decreased. The coil springs, on the other hand, have greater stability, but, as the pushers do not are not aligned with the spring, the blades are subjected to bending, which gives the whole a greater fragility.

The document EP 0383 039 discloses a clasp having articulated arms. The arms are fixed to each other by notched engagement of portions of the arms cooperating with each other, their release being effected by elastic deformation of a portion of one of the arms. This solution poses the same problems as that described in the document mentioned above.

The clasp described in the document US 4,928,359 has articulated arms formed of metal sheets arranged one above the other. These arms are fixed to each other by means of a locking member comprising a hook, attached to the end of one of the arms, and a latch provided with a transversely oriented tube and fixed on the other arm, next to the hook. A pusher is housed in the tube. The position of the pusher is defined by a coil spring, bearing against the bottom of the tube. The tube is attached to the arm by welding. This can result in a risk of tearing making the bracelet unusable.

Another clasp is described in the document CH 670 941 . It has three articulated arms. One comprises two longitudinal members, while the other two are formed of blades each pivoted at one end of the longitudinal members and extending towards one another. A locking member maintains the arms in the closed position. This member comprises a tube of rectangular section disposed astride the longitudinal members. Two pushers are arranged in the tube. They came in one piece with a biased resilient member when pressure is exerted on the pusher and two latching members and intended to cooperate with the blades to make them integral with the spars They have a tuning fork shape. This solution is simple technically, but the risk of deformation of the elastic members is important, thus affecting the quality of the closure.

The "Patent abstract of Japan vol. 1995, No. 09, October 31, 1995 & the document JP 07 163409 A ) discloses a clasp having two arms formed respectively of a blade and two longitudinal members. It comprises a locking device formed of two parts each releasably attached to one of the arms. Such a solution increases the volume of the clasp and makes it uncomfortable.

The patent application GB 2,340,168 relates to a clasp having three arms joined to one another in an articulated manner by one of their ends. The first arm comprises two longitudinal members and the other two are each formed of a blade inserted between the longitudinal members. This clasp further comprises a locking member for releasably attaching the arms when the clasp is in the closed position. The locking member comprises two pushers, arranged in a recess formed in the middle part of the arm formed of two longitudinal members, between which is interposed a coil spring. The housing is closed by a screwed plate, which holds in place the spring and the pushers. The latter are provided with hooks cooperating with the arm formed by a blade. This solution also requires a large volume making the clasp heavy and not very elegant.

The object of the present invention is to provide a safe, reliable and simple manufacturing operation clasp. This clasp comprises two arms joined to one another, in an articulated manner, by one of their ends, each intended to be connected at least mediately with one end of the bracelet, the first arm comprising two longitudinal members and the second a blade interposed between the longitudinal members and defining together a longitudinal axis, and a locking member for removably attaching the arms to one another when the clasp is in the closed position, and comprising a pusher, an elastic member and a crampon.

• le poussoir est solidaire d'un plot, fixés l'un à l'autre au moyen d'une tige, disposés de part et d'autre et montés coulissant sur un longeron, selon un axe transversal perpendiculaire à l'axe longitudinal, le plot étant disposé entre les deux longerons et muni d'un organe d'accrochage compris dans l'épaisseur desdits longerons,
• l'organe élastique est interposé entre le poussoir et le longeron sur lequel il est monté, pour les écarter l'un de l'autre,
• le crampon est solidaire de la lame, compris dans son épaisseur, et placé de manière à ce qu'en position fermée du fermoir, il est verrouillé par l'organe d'accrochage lorsque le poussoir se trouve en position de repos, éloignée du longeron, et dégagé de cet organe lorsque le poussoir se trouve en position poussée, voisine du longeron.

The goal defined above is achieved by virtue of the fact that the locking member has the following characteristics:

• the pusher is secured to a stud, fixed to each other by means of a rod, arranged on either side and mounted sliding on a spar, along a transverse axis perpendicular to the longitudinal axis, the stud being disposed between the two longitudinal members and provided with a fastening member included in the thickness of said longitudinal members,
• the elastic member is interposed between the pusher and the spar on which it is mounted, to separate them from one another,
• the crampon is integral with the blade, included in its thickness, and placed so that in the closed position of the clasp, it is locked by the fastening member when the pusher is in the rest position, away from the spar , and released from this body when the pusher is in the pushed position, adjacent to the spar.

An important feature of clasps is the conditions under which they can be closed. It is necessary that the pressure to be exerted is regular, even after a large number of manipulations. Particularly good results have been obtained with a clasp in which the fastening member and the crampon comprise first working surfaces, in contact with each other when pressure is applied on the arms to close the clasp. , tangent to each other. The tangent to the contact point forms an acute angle with the transverse axis, so that the pressure exerted by the crampon on the hooking member tends to move the stud of the spar to which it is adjacent, until the attachment member to pass beyond the crampon.

In order to ensure a locking of the attachment member by the crampon, they each comprise a second working surface parallel to the axes longitudinal and transverse and cooperating with each other when the clasp is in the closed position.

The connection of the pusher with the stud which is associated with it is important to ensure the rigidity of the assembly. That is why they are connected to each other by two rigid rods parallel to each other and through the spar adjacent thereto.

It is possible to guarantee particularly good guiding of the stud, and thus avoid any distortion, when the beams are connected to one another by a bar on which the stud is slidably mounted.

The manipulation of the pushers strongly depends on the constancy of the elastic member. Good results have been obtained with an elastic member comprising a coil spring, interposed between the pusher and the spar, and a tube surrounding the spring and engaged in holes that comprise the pusher and the spar, this tube being fixed in the one and can slide freely in the other. The coil springs allow to work with a large amplitude without risk of exceeding the elastic limit. They are protected by the tubes and therefore do not risk being damaged when wearing. For such a clasp, a symmetrical structure, with reference to the longitudinal axis, makes it possible to reinforce the locking, by the presence of two studs and two fastening members. If the clasp is also symmetrical along the transverse axis, it is then possible to turn it in one direction or the other without the manipulation is changed, which simplifies the manufacture of the bracelet. This is why, in a particularly advantageous embodiment, the clasp comprises two sets formed of a pusher and a stud, each set being mounted on one of the longitudinal members.

In another mode, which can be combined with that mentioned above, the clasp has a third arm, also including a blade. Each blade occupies half the length of the spars and is provided with a crampon. The stud or pads are each provided with two latching members cooperating respectively with a crampon of the one and the other blade. Each of the blades is pivotally mounted on the longitudinal members at one end and is secured to the bracelet by the other.

When these two embodiments are combined, the two studs slide on the bar which connects the side members. The latter is in their middle part with reference to the longitudinal axis.

• les figures 1 et 2 montrent, vu respectivement de côté et de dessous, un fermoir selon l'invention,
• les figures 3 à 5 représentent, vu de dessus, en perspective et coupé, ce même fermoir, respectivement en position ouverte, en cours de fermeture et fermé, et
• la figure 6 se rapporte au fermoir également vu en perspective et coupé, en position fermée, mais vu de dessous.

Other advantages and features of the invention will emerge from the description which follows, given with reference to the appended drawing, in which:

• FIGS. 1 and 2 show, viewed from the side and from below respectively, a clasp according to the invention,
• Figures 3 to 5 show, seen from above, in perspective and cut, the same clasp, respectively in the open position, during closing and closed, and
• Figure 6 relates to the clasp also seen in perspective and cut, in the closed position, but seen from below.

The clasp shown in the drawing comprises three arms 10, 12 and 14, and a locking member 16.

The arm 10 has two longitudinal members 18 and 20, connected to one another by two cylindrical pins 22 and 24 at their ends, and a bar 26 in their middle part. The pins 22 and 24 and the bar 26 are engaged and fixed in holes formed in the longitudinal members 18 and 20, advantageously by welding.

The component parts of this clasp are advantageously made of stainless steel. As can be seen in Figure 1, the arms 10, 12 and 14 are curved to fit the shape of the wearer's wrist.

For ease of description, reference will be made to an axis AA, longitudinal, parallel to the rails 18 and 20 and which is placed halfway between them, and a transverse axis BB, coinciding with the axis of the bar 26. On will call "lower" the parts of the clasp intended to be oriented towards the wearer's wrist, "superior" the opposite parts, and "lateral" the outer faces oriented along the axis AA and perpendicular to the axis BB.

The rails 18 and 20 of the arm 10 are provided with blind holes whose function will be specified later, identified by the letter a , axes parallel to the axis BB and opening on their side faces.

The arms 12 and 14 are arranged symmetrically with respect to the axis BB, between the longitudinal members 18 and 20 and thus each extend from one end of the arm 10 to its middle portion. They comprise a central blade identified by the letter a , two charnnerons identified by the letters b and c and each disposed at one end of the blade a , and two studs identified by the letter d .

More specifically, Charnons 12b and 14b are arranged in the extension of their respective blade 12a and 14a and cooperate respectively with the pins 22 and 24 to form pivot axis hinges parallel to the axis B-B. Charnons 12c and 14c are integral with the other end of their respective blade 12a and 14a and protrude from the upper face of the clasp. They are intended to ensure the attachment of the clasp to the bracelet.

Cleats 12d and 14d, whose function will be specified later, are formed of pins respectively extending the blades 12a and 14a towards the bar 26 and having two functional surfaces, a curved surface 12e, embracing about a quarter circle turned towards the lower face and towards the axis AA, and a flat surface 12f turned towards the upper face (FIG. 3).

The locking member 16 is in the middle part of the arm 10. It comprises two identical sets arranged symmetrically with respect to the axis AA and each having a pusher 28 and a stud 30, placed on either side of the longitudinal members. 18 or 20. The stud 30 is disposed between the longitudinal members 18 and 20. Two pins 32 rigidly connecting the pusher 28 and the stud 30 to each other are engaged in sliding holes in the longitudinal members 18 or 20. .

Each of the pushers 28 is provided with two cylindrical holes in each of which is fixed a tube 34. The latter extends from the pusher 28 and enters one of the holes 18a or 20a. The tubes 34 serve as a housing for a coil spring 36 (Figure 2), one end bears against the pusher 28 and the other against the spar 18 or 20, thus tending to move the pusher away from the spar with which it is associated.

The studs 30, of generally parallelepipedal shape, are provided with a hole 30a of axis coinciding with the axis BB, in which the bar 26 is engaged and with a locking member formed of two hooks 30b each disposed at the one of the ends of the neighboring stud of the crampons 12d and 14d. Each hook comprises an inclined plane 30c forming an angle of about 40 ° with the axis BB, the inclined planes 30c of the two studs 30 intersecting beyond the upper face of the clasp, and a parallel bearing surface 30d to the AA and BB axes and facing the underside (Figure 6). In this way, the inclined plane 30c of a hook 30b and the curved surface 12e or 14e of a crampon 12d or 14d are tangent to each other, the tangent forming an acute angle with the transverse axis BB. As a result, a pressure exerted on one of the arms 12 or 14 and thus on the crampons 12d and 14d, tends to press on the hooks 30b and thus separate each of the studs 30 of the spar to which it is adjacent, up to allow the hooks 30b to pass beyond the crampon 12d or 14d associated with it.

In the rest position, the assemblies forming the locking member 16 are subjected to the force generated by the coil springs 36, so that the pushers 28 are kept away from the longitudinal members 18 or 20, while the studs 30 are in contact with each other. support against these. In this position the hooks 30b, by their bearing surface 30d, cooperate with the cleats 12d or 14d by their flat surface 12f or 14f, so that the arms 12 and 14 are attached to the arm 10.

Each of the two sets is arranged so that it is possible to move it along the axis BB, the pads 30 and with them the hooks 30b, away from the side members 18 and 20 when pressure is applied to the pushers 28. The amplitude of the movement is sufficient so that, in the depressed position of the pushers 28, the hooks 30b no longer cover the crampons 12d and 14d, so that the arms 12 and 14 can then pivot freely on the pins 22 and 24 , the clasp opening thus.

To close the clasp, simply fold the arms 12 and 14 and apply a force substantially perpendicular to the axes A-A and B-B. The crampons 12d and 14d are then supported by their curved surface 12e or 14e against the inclined planes 30c of the hooks 30b. The applied force moves the pads to bring them closer to each other and frees the space allowing the crampons 12d and 14d to pass beyond the hooks 30b and thus come to lock the arms 12 and 14.

It is possible to adjust the force required to open and close the pusher, by varying the stiffness of the coil springs 36 and the angle of the inclined planes 30c that the hooks 30b.

Aging tests were carried out with clasps as described. After 10'000 opening and closing functions, the forces required to open and close the clasp had hardly changed.

Specifically, the force required for closing has remained within a limit of between 10 and 20 N, the opening force between 5 and 10 N

The clasp as described can be subject to many variations, without departing from the scope of the invention. It is more particularly possible to realize the locking member with a single element. In this way, the arms 12 and 14 will include only a spike, disposed substantially in the middle of the space between the two spars 18 and 20. Such a solution allows for a narrower strap, well suited to ladies' watches .

It is also possible to have only two arms, one formed of two longitudinal members, similar to the arm 10, and the other similar to one of the arms 12 or 14, also disposed between the rails 18 and 20, there being pivoted by one of its ends, but extending over most of their length. In this clasp, the locking member is mounted on one and / or the other of the longitudinal members, at the end opposite to that forming a hinge. In this case, the bracelet is attached to the free ends of the two arms.

Claims (9)

1. Clasp for a wristband or bracelet including two arms (10, 12) assembled to each other in an articulated manner via one of the ends thereof, each arm to be connected at least mediately to one of the ends of the wristband or bracelet, the first arm (10) including two branches (18, 20) and the second (12) a plate (12a) inserted between the branches (18, 20) and together defining a longitudinal axis (A-A), and a locking member (16) for attaching the arms (10, 12) to each in a removable manner when the clasp is in a closed position and including a push-button (28), a resilient member (36) and a hook (12d), characterized in that the locking member (16) has the following features:

   ■ the push button (28) is integral with a stud (30), secured to each other by means of a pin (32), arranged on either side of and slidably mounted on a branch (18 or 20) along a transverse axis (B-B) perpendicular to the longitudinal axis (A-A), said stud (30) being arranged between the two branches (18, 20) and fitted with a hooking member (30b) comprised in the thickness of said branches,

   ■ the resilient member (36) is inserted between the push-button (28) and the branch (18 or 20) on which said member is mounted, to move said push-button and said branch apart,

   ■ the hook (12d) is secured to said plate (12a) comprised in the thickness thereof, and placed such that, when the clasp is in the closed position, the hook is locked by the hooking member (30b) when the push-button is in the rest position, at a distance from the branch (18, 20), and released from said member (30b) when the push-button (28) is in the pushed-in position, close to the branch (18 or 20).
2. Clasp according to claim 1, characterized in that said hooking member (30b) and said hook (12d) include first working surfaces (30c, 12e) in contact with each other when pressure is applied to the arms to close the clasp, tangent to each other, said tangent forming an acute angle with the transverse axis (B-B), such that the pressure exerted by the hook (12d) on the hooking member (30b) tends to move the stud (30) away from the branch (18 or 20) to which it is adjacent, until the hooking member (30b) is able to pass beyond said hook (12d).
3. Clasp according to claim 2, characterized in that said hooking member (30b) and said hook (12d) include second working surfaces (12d, 30d) parallel to the longitudinal and transverse axes and cooperating with each other when the clasp is in the closed position, in order to lock the hooking member (30b) via the hook (12d).
4. Clasp according to any of claims 1 to 3, characterized in that said push-button (28) is connected to the stud (30) by two rigid pins (32) parallel to each other and passing through the respectively adjacent branch (18 or 20).
5. Clasp according to claim 4, characterized in that the branches (18, 20) are connected to each other by a bar (26) on which the stud (30) is slidably mounted.
6. Clasp according to claim 5, characterized in that the resilient member includes a helical spring (36), inserted between the push-button (28) and the branch (18 or 20), and a tube (34) surrounding said spring (36) and engaged in holes comprised in the push-button (28) and the branch (18 or 20), said tube (34) being secured in one hole and able to slide freely in the other hole.
7. Clasp according to claim 6, characterized in that it includes two assemblies formed of a push-button (28) and a stud (30), each assembly being mounted on one of the branches (18 or 20).
8. Clasp according to any of claims 6 and 7, characterized in that it includes a third arm (14), also including a plate (14a), said plates (12a, 14a) each occupying half of the length of said branches (18, 20) and each being fitted with a hook (12d, 14d), and in that said stud (30) includes two hooking members (30b) respectively cooperating with a hook (12d) of one plate and a hook (14d) of the other plate, each of the second and third arms (12, 14) being pivotably mounted on the branches (18, 20) via one of the ends thereof (12b, 14b) and being secured to the wristband or bracelet via the other end (12c, 14c).
9. Clasp according to claim 8, characterized in that said bar (26) connects the branches (18, 20) in the median part thereof relative to the longitudinal axis (A-A).

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