EP1192872B1 - A closing device for wristwatch straps - Google Patents

Abstract

Fastener (4) for connecting first and second supple straps. Fastener comprises a buckle attached to the first of the two straps, while the second strap is inserted into the buckle. The buckle has a fixed hook (14) that attaches to the second strap and a locking mechanism (22), manually operated, that allows the second strap to be lifted up to disengage the hook and to allow it to be fed out of the buckle.

Description

The present invention relates to a clasp for assembling two flexible strands, for example leather or a synthetic material. Such a clasp can be used by example, for a watch strap or a belt.

In the known devices of clasps for assembling flexible strands, the strands have holes for receiving a barb during assembly. This conventional construction, however, has the disadvantage that said strands break easily, usually at the location of the hole receiving the barb, due to fatigue which these strands are subjected.

Now bracelets, especially those that are suitable for watches, ask to be closed on the wrist with ease and without running the risk that the watch may escape when trying to form the loop of closing. For this reason, the bracelet can be continuous so that it arises sure on the wrist.

A first known solution relates to bracelets made of segments contiguous metal that contains small springs that extend the bracelet when you pull on it. Such a solution, to be feasible, however requires very small springs subject to fatigue and that have a life time limited.

To remedy this drawback, hinged clasps have been proposed. multiple articulated, these clasps being essentially mounted on bracelets two-segment metal hinged but not extensible. This solution more advantage has been obtained with continuous devices with rigid segments, articulated, foldable, stackable and hooked to each other. There is a big one number of models.

An example is a model with three rigid segments whose first comes to close under the second, while the third, serving as cover, engages on the second and hangs on the first.

These classic clasps with folding buckle have the advantage of allowing to prevent, to a certain extent, the bracelet from surreptitiously passing through above the hand if a pulling force is exerted on the bracelet. However, this kind of clasp is relatively complicated, implements many pieces, which gives it a fairly high cost.

A significant improvement has been made by the device described in the document CH 530,189 where a construction was proposed which, at the same time that it offers a better aesthetic, improves the ease of closing.

This device consists of a clasp attached to one of the strands of a bracelet and provided with means ensuring the tightening of the other strand of the bracelet. This second strand is clamped between the base of the clasp and an eccentric end of a lever pivoting on the base of this clasp. The base plate of this clasp carries a rib that comes engage in one of the furrows practiced on the invisible face of the bracelet intended for to be in contact with the wrist of the wearer of the watch. Said base plate carries in addition a lug which engages in one of said grooves on the face invisible bracelet.

An advantage of this clasp lies in the fact that, in the embodiment described above, the second strand is engaged under the first strand, which gives a very aesthetic appearance to the bracelet.

Another advantage is the great simplicity of construction of the clasp that significantly reduces its manufacturing costs. This clasp also has for advantage of being able to be adapted to all types of flexible bracelets, for example Milanese or woven, or made of plastic.

The clasp described in document CH 530.189, however, has a certain number of disadvantages, foremost among which are the fact that the lever swivel which closes by its eccentric end the second strand of the bracelet against the base of the clasp does not ensure a secure subjection of the bracelet to the wrist that door. Indeed, an external tearing force can very easily rotate the lever in the open position and pass the bracelet on the hand without this action be desired by the wearer. This way of doing so diminishes the confidence that we can have in this kind of clasp.

On the other hand, as described above, the base plate of the clasp carries both a rib and a lug that each engage in one of the furrows practiced on the underside of the bracelet. Since nothing is planned to lift the bracelet in order to free the furrows from their grip with the rib and the spur, the wearer goes encounter significant difficulties to scroll the second strand off the clasp when he wants to leave his watch. This operation is made all the more delicate that the bracelet is engaged with the base plate, not at a point, but in two distinct points materialized by the rib and the ergot.

Finally, by tightening the bracelet against the base plate of the clasp, the lever to Eccentric has the effect of marking the surface of this bracelet.

Patent CH 454,513 for its part describes a watchband comprising a clasp secured to one of the strands of the bracelet and provided with means ensuring the tightening the other strand of the bracelet. The clamping means are formed by a slightly curved plate, having a bottom provided on each side, in the direction parallel to the length of the bracelet, a perpendicular edge. A rod fixed in the edges ensures the connection of the clasp with one of the strands of the bracelet. A cover is hinged on the clamping means and pivots around the same rod as that by which the clasp is connected to one of the strands. The lid presents each side, in the longitudinal direction to the length of the bracelet, a flange. These edges are slightly inclined inwards, like the edges of the plate, so that when you fold down the lid, you have to overcome some resistance, which prevents inadvertent opening of the lid. The plate has a projection directed towards the top that is engaged in one of the furrows in the invisible lower face the second strand of the bracelet. With the lid open, the end of the second strand in an opening that presents the clasp. We then adjust the second strand to the desired length, then engage the projection in one of the furrows. Finally, we fold the lid.

This form of execution has the major disadvantage of wearing out quickly and not to ensure a good notch of the cover on the edges of the plate of the clasp. This is mainly due to a high notching force and hence to a rapid wear of the system. But if the lid of the clasp is not properly closed, an external tearing force can very easily rotate it, from so that the user risks losing his watch.

On the other hand, nothing is planned to lift the second strand of the bracelet under the underside of which are formed grooves in which the projection that presents the plate comes to engage. The user may therefore have great difficulty in slide the two strands of the bracelet relative to each other because one of the strands risk of being held by the projection in engagement with the corresponding groove.

The present invention aims to overcome the above drawbacks as well as others by offering a clasp to assemble two strands flexible, usable for example for a watch strap or a belt, this clasp being inexpensive to produce and presenting a great ease and safety of use.

For this purpose, the present invention relates to a clasp for assembling a first and second flexible strands comprising a loop attached to the first of the two strands while the second strand enters the loop, the loop comprising fixed hooking means which hang in the second strand, and comprising an actuatable unlocking device manually, characterized in that the unlocking device allows to lift the second strand to release it from the hooking means and to scroll it out of the loop.

Thanks to these features, the present invention provides an easy clasp to use. Indeed, to assemble the flexible strands of the bracelet or the belt and close the clasp, simply engage the end of the second strand in the clasp, so that this end is placed above the attachment means. We then adjust the strand of the bracelet to the desired length, then the hooking means come hang on in this strand. The bracelet is thus firmly held in place and therefore does not risk opening unexpectedly. To open the bracelet, it's just necessary to manually operate the unlocking device. In doing so, the unlocking device raises the second strand of the wristband to release it from means of attachment, so that the wearer only has to pull on this strand for the drag from the first strand and release it from the loop.

The clasp according to the invention also offers great security of operation. Indeed, as described above, when the means snap hook in the second strand, it is impossible to pull the second strand back. The confidence that we can have in the clasp according to the invention is further increased by the fact that this clasp does not require any parts for tighten or pinch the second strand of the bracelet to immobilize it. Therefore, the user is not likely to lose his watch as is the case with the clasps of the prior art provided with clamping or pinching parts that can open untimely at any time.

According to a complementary characteristic of the invention, the means latching means comprise a tooth, and the unlocking device comprises a lever mounted movably on the buckle and which is able to lift the second strand.

The clasp according to the invention therefore comprises only two parts, namely the buckle itself that carries a tooth that hangs in the second strand and which, at choice, can be made from a piece with the buckle or constitute a piece the buckle, and the unlocking device that allows the user to lift the strand to release it from the tooth. Besides the fact that clasp according to the invention is very simple to use, it also has the advantage of not using as a small number of parts and thus be inexpensive to manufacture.

• la figure 1 est une vue en perspective d'un premier mode de réalisation du fermoir selon l'invention;
• la figure 2 est une vue en coupe dans le fermoir illustré à la figure 1, le dispositif de déverrouillage étant en position de repos;
• la figure 3 est une vue en coupe dans le fermoir illustré à la figure 1, le dispositif de déverrouillage étant dans une position rabattue dans laquelle il soulève le second brin du bracelet;
• la figure 4 est une vue en plan du fermoir de la figure 1;
• la figure 5 est une vue en perspective d'un second mode de réalisation du fermoir selon l'invention;
• la figure 6 est une vue en coupe dans le fermoir illustré à la figure 5, le dispositif de déverrouillage étant en position de repos;
• la figure 7 est une vue en coupe dans le fermoir illustré à la figure 5, le dispositif de déverrouillage étant dans une position soulevée dans laquelle il soulève le second brin du bracelet, et
• la figure 8 est une vue en plan du fermoir de la figure 1.

Other features and advantages of the present invention will appear more clearly on reading the detailed description which follows of an example of a first and a second embodiment of the clasp according to the invention, this example being given purely illustrative and not limiting, in conjunction with the accompanying drawings in which:

• Figure 1 is a perspective view of a first embodiment of the clasp according to the invention;
• Figure 2 is a sectional view in the clasp illustrated in Figure 1, the unlocking device being in the rest position;
• Figure 3 is a sectional view in the clasp illustrated in Figure 1, the unlocking device being in a folded position in which it raises the second strand of the bracelet;
• Figure 4 is a plan view of the clasp of Figure 1;
• Figure 5 is a perspective view of a second embodiment of the clasp according to the invention;
• Figure 6 is a sectional view in the clasp illustrated in Figure 5, the unlocking device being in the rest position;
• Figure 7 is a sectional view in the clasp illustrated in Figure 5, the unlocking device being in a raised position in which it raises the second strand of the bracelet, and
• Figure 8 is a plan view of the clasp of Figure 1.

The present invention proceeds from the general inventive idea of provide a clasp to assemble the two strands of a bracelet or belt that simple to use and reliable operation, and also inexpensive to manufacture. For this purpose, the clasp according to the invention comprises on the one hand means hanging on the free end of the bracelet or belt to be assembled with the strand attached to the clasp, so that both strands are securely held in place, without the risk of one of the strands moving by report to the other. On the other hand, the clasp according to the invention comprises a device for unlocking which advantageously allows to lift the free end to release it hooking means. The wearer of the bracelet or the belt can thus easily scroll the second strand out of the loop when he wants to leave, by example, his watch. Finally, it should be noted that the present clasp is constituted only two pieces and is therefore inexpensive to manufacture. In addition, it does not has no pinch or blocking member to hold the strands assembled, which constitutes a decisive advantage with regard to the clasps of art prior art, insofar as this type of locking device is susceptible, under the effect an external tearing force, to open without the user desires.

A first embodiment of the invention is shown in FIGS. 1 to 4 and a second embodiment in FIGS. 4 to 8. In both cases, the figures illustrate a bracelet partially represented, approximately at the opposite place to the watch, if bracelet is intended for a watch. In both cases, the bracelet is intended to be worn mainly around the wrist and has a first flexible strand 1 and a second flexible strand 2 whose first ends (not shown) are attached to the watch.

The present invention will therefore be described with reference to a watch. he goes however, of course, the present invention applies identically to a belt, a bracelet with a jewel, or any other type of bracelet whose ends can be joined by a clasp according to the invention.

As represented in FIGS. 1 to 4, a clasp according to the present invention, designated as a whole by the general reference numeral 4, essentially consists of a loop 6 attached to the first flexible strand 1, while that the second flexible strand 2 enters the loop 6 to be assembled at the first strand 1.

As can be seen in particular in the perspective view of FIG. loop 6 comprises two plates 8 parallel to each other and extending from other first and second strands 1 and 2, in a longitudinal direction to the length of the strands 1 and 2. To stiffen the loop 6 and give it a good mechanical strength, the two plates 8 are connected at their ends by two transverse crosspieces 10 audits flexible strands 1 and 2.

It is also seen in Figure 1 that the upper edges were given 12 two plates 8 a curved shape that matches the curvature of the wearer's wrist.

According to the present invention, the loop 6 presents means fastening hooks 14 which hang in the second flexible strand 2. These fastening means 14 prevent removal of said second strand 2 when the latter is engaged in the loop 6, this to firmly fasten the wristband to the wrist The door.

In the embodiment shown in FIGS. 1 to 4, the means fastening 14 are in the form of a tooth 16 carried by a rib 18 which extends between the two plates 8 of the loop 6, perpendicular to them. According to a particularly advantageous embodiment, the tooth 16, the rib 18 which the door and the two plates 8 of the loop 16 can be made in one piece, for example by molding or by injection of a plastic or metal material. According to another variant, the tooth 16 and its rib 18 are manufactured so separated and fixed between the plates 8 of the loop 16 by any appropriate means, for example example by gluing, ultrasonic welding or by screwing.

It should be noted that the invention is not limited to the use of a tooth. The means of attachment could be, for example, a small hook or still in a nipple (not shown).

The end portion 19 of the second strand 2 has on its invisible lower face in view of the wearer at least one milling forming transverse groove 20 extending over part of the total width of the bracelet. This groove 20 has, for example, the shape shown in Figures 2 and 3, that is to say the shape of a section groove substantially triangular.

The tooth 16 carried by the loop 6 penetrates by its upper end into the groove 20 so as to block the second strand 2 safely, since no force outside tearing can not pass the object on the hand without this action be desired by the wearer.

It will be noted that the security of the clasp 4 according to the invention is further increased by the fact that the tooth 16 is at a higher level than the upper face of the first strand 1. The second strand 2 which is introduced in the loop 2 and has a path curve which makes it pass above said tooth 16, so that, when released the second strand 2 and the wrist of the wearer relaxes, this causes the displacement said second strand 2 in the opening direction, which has the effect of tending the second strand 2 and to further firmly engage the tooth 16 in the groove 20 or the hole with which said tooth 16 is engaged.

So far, only one groove 20 has been discussed to receive the tooth 16 of the loop 6, this only groove 20 defining a single length of the bracelet when the second strand 2 is engaged in said loop 6. However, several choice of lengths to suit the different edges that a wrist. For this purpose, Figures 2 and 3 show a plurality of grooves 20 (here four) made in the second flexible strand 2 and arranged in a row on a part of the total length of said second strand 2. Thus, the tooth 16 can be introduced at choice in any of the grooves 20 to adapt the length of the bracelet to around the wrist that wears it.

According to one variant, the grooves 20 can be replaced by as many holes (not shown) drilled in the end portion 19 of the second strand 2 and in which tooth 16 can penetrate to block said second strand 2 in the position of closing. However, it is preferable to create furrows rather than holes in the strand 20 insofar as the grooves 20, made in the underside of said strand 20, are invisible to the wearer of the bracelet.

In accordance with the present invention, the loop 6 also includes a unlocking device 22 manually operable, this device unlocking 22 for lifting the second strand 2 to release it from hooking means 14 and scrolling out of the loop 6. Thus, after having actuated the unlocking device 22, the wearer of the bracelet only has to pull on the second strand 2 to slide it relative to the first strand 1 and release it from the loop 6, without this operation being thwarted by the tooth 16 likely to remain hooked in one of the grooves 20 or holes in said second strand 2.

The unlocking device 22 is in the form of a lever 24 movably mounted on the loop 6 and capable of lifting the second strand 2. This lever 24 has a shape resembling that of a stretcher and consists of a bar of lifting 26 of the second strand 2 connected to an actuating plate 28 by two longitudinal arms 30. As can be seen in Figures 2 and 3, the terminal 19 second strand 2 has passed over the lift bar 26, so it is sufficient for the user to lightly press the actuating plate 28 to lift said strand 2. For this purpose, the lever 24 is articulated to pivot on the loop 6 by means of a bar 32 inserted into hinges 34 made in one and the other plates 8 of the loop 6.

Advantageously, the first strand 1 is wound to a fixed length around the same bar 32 as that by which the unlocking lever 24 is articulated to pivoting on the loop 6.

In Figure 2, the clasp 4 according to the invention is shown in the closed state. The second strand 2 is engaged by its end portion 19 in the loop 6 by doing so pass over the lifting bar 26 of the unlocking lever 24. The tooth 16 is engaged in one of the grooves 20 made in the invisible lower face the second strand 2. The actuating plate 28 has a transverse portion 36 which abuts against a flange 38 that crossbar 10 presents opposite, which limits the movement of the unlocking lever 24.

In FIG. 3, the user exerts a push on the unlocking lever 24, which pivots the lever about its axis 32 and causes the rise of the lifting bar 26 which raises the second flexible strand 2. The grooves 20 or holes made in the second strand 2 and escape the tooth 16 of the loop 6, and the user can pull said second strand 2 with respect to the first strand 1 and take it out of the loop 6.

FIGS. 5 to 8 illustrate a second embodiment of clasp 4 according to the invention. In all that follows, the elements identical to those described previously will be designated by the same numerical references.

As can be seen very clearly, especially in Figures 6 and 7, the second embodiment of the clasp 4 according to the invention is essentially different from the first in that the unlocking lever 24 is mounted in opposite directions on the bar 32. Thus, as shown in Figure 7, the user must not push, but instead pull on the unlocking lever 24 to rotate it around the bar 32 and lift the second flexible strand 2 which rests on the bar of 26. This second embodiment is also different from the first in that the actuating plate 28 has a housing 40 below its surface arranged to come to cap the crossbar 10 of the loop 6 which is next to this housing 40. The assembly formed by the housing 40 and the corresponding cross member 10 is made with limited play, so you have to overcome some resistance when the actuating plate 28 is folded over the cross member 10, which prevents the unintentional opening of the unlocking lever 24.

The present invention can be applied to all types of flexible bracelets made of strands, for example of the Milanese type or braided, or made of leather, in rubber or a synthetic material.

It goes without saying that the invention is not limited to the embodiments which have just been described, and that modifications and variants may be envisaged by those skilled in the art without departing from the scope of the present invention.

Claims (18)

1. Clasp (4) for assembling first and second flexible strands (1, 2) including a buckle (6) attached to the first (1) of the two strands while the second strand (2) penetrates the buckle (6), the buckle (6) including fixed catching means (14) which are caught in the second strand (2), and including an unlocking device (22) able to be actuated manually, characterised in that this unlocking device (22) allows the second strand (2) to be raised to release it from the catching means (14) and to slip it out of the buckle (6).
2. Clasp according to claim 1, characterised in that the catching means (14) include a tooth (16), and in that the unlocking device (14) includes a lever (24) mounted so as to move on the buckle (6) and which is capable of raising the second strand (2).
3. Clasp according to claim 2, characterised in that the tooth (16) and a rib (18) which carries it are manufactured in a single piece with the buckle (6).
4. Clasp according to claim 2, characterised in that the tooth (16) and a rib (18) which carries it are manufactured separately and fixed to the buckle (6).
5. Clasp according to any one of claims 2 to 4, characterised in that the unlocking fever (24) is articulated so as to pivot on the buckle (6).
6. Clasp according to any one of claims 2 to 5, characterised in that the unlocking lever (24) is controlled by pressure to raise the second strand (2).
7. Clasp according to any one of claims 2 to 5, characterised in that the unlocking lever (24) is controlled by traction to raise the second strand (2).
8. Clasp according to any one of claims 2 to 7, characterised in that at least a transverse groove (20) in which the tooth (16) can be housed is arranged in the invisible lower face of the second strand (2).
9. Clasp according to any one of claims 2 to 7, characterised in that at least a hole in which the tooth (16) can be housed is pierced in the second strand (2).
10. Clasp according to any one of claims 8 or 9, characterised in that the second strand (2) has a plurality of grooves (20) or holes arranged along a row over a part of the total length of said second strand (2), so that the tooth (16) can be introduced as desired into one of the grooves (20) or holes to fit the length of the first and second strands (1, 2) together attached to the contour of the wrist.
11. Clasp according to any one of claims 2 to 10, characterised in that the unlocking lever (24) includes a raising bar (26) above which the free end (19) of the second strand (2) passes, this raising bar (26) being connected to an actuating plate (28) by two longitudinal arms (30), the unlocking lever (24) being articulated so as to pivot on the buckle (6) by means of a small bar (32).
12. Clasp according to claim 11, characterised in that the first strand (1) is wound to a fixed length around the small bar (32) via which the unlocking lever (24) is articulated so as to pivot on the buckle (6).
13. Clasp according to any one of claims 1 to 12, characterised in that the buckle (6) includes two parallel plates (8) extending on either side of the first and second strands (1, 2) and connected to their ends by two crosspieces (10) transversal to said strands (1, 2).
14. Clasp according to claim 13, characterised in that the upper edges (12) of the two plates (8) of the buckle (6) are given a curved shape which matches the curvature of the wrist.
15. Clasp according to any one of claims 1 to 14, characterised in that since the tooth (16) is located at a substantially higher level than the upper face of the first strand (1), the second strand (2) which is introduced into the buckle (6) has a curved profile which causes it to pass over said tooth (16), so that, when the second strand (2) is released and the wearer's wrist relaxes, this causes said second strand (2) to move in the opening direction, as a result of which said second strand (2) is stretched and the tooth (16) is engaged still more firmly in the groove (20) or the hole with which said tooth (16) is engaged.
16. Clasp according to any one of claims 1 to 15, characterised in that the first and second strands (1, 2) are of the Milanese or woven type, or made of rubber, leather or a flexible synthetic material.
17. Clasp according to claims 6, 11 and 13, characterised in that the actuating plate (28) has a transverse part (36) which abuts against an edge (38) of the opposite crosspiece (10), which limits the clearance of the unlocking lever (24).
18. Clasp according to claims 7, 11 and 13, characterised in that the actuating plate (28) has, under its surface, a recess (40) arranged to cap the opposite crosspiece (10).

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