EP1192872A1 - 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, for example, for a watch strap or a belt.

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

However, bracelets, particularly those that are suitable for watches, ask to be able to be closed on the wrist with ease and without running the risk that the watch may escape when trying to form the buckle closing. For this reason, the bracelet can be continuous so that it can be placed secure on the wrist.

A first known solution relates to bracelets made of segments contiguous metals that contain small springs that allow to lengthen the bracelet when pulling on it. To be practical, such a solution however requires very small springs which are subject to fatigue and which have a lifespan limited.

To overcome this drawback, hinged clasps have been proposed multiple articulated, these clasps being essentially mounted on bracelets metallic with two articulated but non-extendable segments. This solution more advantageous has been obtained with continuous devices with rigid segments, articulated, foldable, stackable and attached to each other. There is a large one number of models.

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

These classic clasps with folding buckle have the advantage of allowing to avoid, to a certain extent, that the bracelet surreptitiously passes through above the hand if a pulling force is exerted on the bracelet. However, this kind of clasp is relatively complicated, implements many parts, 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 has been proposed which, at the same time that it offers better aesthetics, improves the ease of closing.

This device consists of a clasp secured 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 pivoting lever on the base of this clasp. The base plate of this clasp carries a rib which comes engage in one of the grooves on the invisible side of the bracelet intended for be in contact with the wrist of the watch wearer. Said door base plate furthermore a lug which engages in one of said grooves made on the face invisible bracelet.

An advantage of this clasp is that, in the form of execution described above, the second strand engages under the first strand, which gives a very aesthetic appearance to the bracelet.

Another advantage is the great simplicity of construction of the clasp which allows to significantly reduce 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 even made of plastic.

The clasp described in document CH 530,189 has however a certain number of disadvantages, foremost among which we can cite the fact that the lever pivoting which clamps by its eccentric end the second strand of the bracelet against the base of the clasp does not ensure a secure securing of the bracelet on the wrist which door. Indeed, an external breakout force can very easily rotate the lever in the open position and pass the bracelet over the hand without this action is wanted by the wearer. This way of doing things diminishes the confidence that you can have in this kind of clasp.

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

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

Patent CH 454,513 describes a watch strap comprising a clasp secured to one of the strands of the bracelet and provided with means ensuring the tightening of the other side of the bracelet. The clamping means are formed by a slightly curved plate, with a bottom provided on each side, in the direction parallel to the length of the bracelet, with 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 cover presents each side, in the longitudinal direction to the length of the bracelet, a rim. These ledges are slightly inclined inwards, like the edges of the plate, so that when you close the cover, you have to overcome a certain resistance, which prevents inadvertent opening of the cover. The plate has a projection directed towards the top that you engage in one of the grooves in the invisible underside the second strand of the bracelet. With the cover open, the end of the second strand in an opening presented by the clasp. Then we adjust the second strand to the desired length, then the projection is engaged in one of the grooves. Finally, we flap the cover.

This embodiment has the major drawback of wearing out quickly and to no longer ensure a good notching of the cover on the edges of the plate of the clasp. This is mainly due to a high notching force and therefore to a rapid system wear. However, if the clasp cover is not properly closed, an external breakout force can very easily rotate it, so that the user risks losing his watch.

On the other hand, nothing is provided to lift the second strand of the bracelet under the underside of which the grooves are formed in which the projection presented by the plate comes to engage. The user is therefore likely to experience great difficulties in slide the two strands of the bracelet relative to each other, because one of the strands risk of being retained by the projection engaged with the corresponding groove.

The object of the present invention is to remedy the above drawbacks as well as others by proposing a clasp to join two strands flexible, usable for example for a watch strap or a belt, this clasp being inexpensive to produce and having great ease and safety of use.

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

Thanks to these characteristics, the present invention provides an easy clasp to use. Indeed, to assemble the flexible strands of the bracelet or belt and close the clasp, just engage the end of the second strand in the clasp, so that this end is placed above the hooking means. We then adjust the strap strand to the desired length, then the attachment means come to hang in this strand. The bracelet is thus securely held in place and therefore does not risk opening unexpectedly. To open the bracelet, it is just necessary to manually activate the release device. In doing so, the unlocking device lifts the second strand of the bracelet to release it hooking means, so that the wearer only has to pull on this strand for the slide in relation to 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 hooking come to hang in the second strand, it is impossible to pull the second strand back. The confidence you can have in the clasp according to the invention is further enhanced by the fact that this clasp does not require any part for tighten or pinch the second strand of the bracelet to immobilize it. Therefore, there is no risk of the user losing their watch as is the case with the clasps of the prior art provided with clamping or nipping parts which can be opened inadvertently at any time.

According to an additional characteristic of the invention, the means hooking device includes a tooth, and the unlocking device comprises a lever movably mounted on the buckle and capable of lifting the second strand.

The clasp according to the invention therefore comprises only two parts, namely the proper loop which carries a tooth which comes to hang in the second strand and which, as desired, can be made in one piece with the buckle or constitute a piece separate which will be attached to the buckle, and the unlocking device which allows the user to lift the strand to release it from the tooth. Besides the fact that the clasp according to the invention is very simple to use, it also has the advantage of not using only 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 characteristics 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 given purely by way of non-limiting illustration, in conjunction with the appended 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 lifts 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;
• FIG. 7 is a sectional view in the clasp illustrated in FIG. 5, the unlocking device being in a raised position in which it lifts 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 which consists in provide a clasp to join the two strands of a bracelet or belt that either simple to use and reliable, and also inexpensive to manufacture. To this end, the clasp according to the invention comprises on the one hand means hooking which hang in the free strand of the bracelet or belt to assemble with the strand attached to the clasp, so that the two strands are securely held in place, without risk of one of the strands moving by compared to each other. On the other hand, the clasp according to the invention comprises a device for unlocking which advantageously makes it possible to lift the free strand in order to release it hooking means. The wearer of the bracelet or belt can thus easily scroll the second strand out of the loop when it wants to leave, by example, his watch. Finally, it should be noted that the present clasp consists only of two pieces and is therefore inexpensive to manufacture. In addition, it does not has no pinching or blocking device to hold the strands assembled, which constitutes a decisive advantage with regard to the clasps of art previous, to the extent that this type of blocking device is susceptible, under the effect from an external breakout force, to open without the user wanting it.

A first embodiment of the invention is shown in Figures 1 to 4 and a second embodiment in Figures 4 to 8. In both cases, the figures illustrate a bracelet shown partially, around the opposite location from the watch, if this bracelet is intended for a watch. In these two 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, it is obvious that the present invention applies identically to a belt, to a bracelet carrying a jewel, or to any other type of bracelet whose ends can be joined by a clasp according to the invention.

As shown in Figures 1 to 4, a clasp according to this invention, designated as a whole by the general reference numeral 4, is essentially consists of a loop 6 attached to the first flexible strand 1, while the second flexible strand 2 enters the loop 6 to be assembled with the first strand 1.

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

We also see in Figure 1 that we gave the upper edges 12 of the two plates 8 a curved shape which follows the curvature of the wearer's wrist.

According to the present invention, the loop 6 has means fixed hooking 14 which are hooked into the second flexible strand 2. These hooking means 14 prevent the removal of said second strand 2 when the latter is engaged in the buckle 6, this to firmly secure the bracelet to the wrist which The door.

In the embodiment shown in Figures 1 to 4, the means attachment 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 thereto. 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 metallic 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, by for example by gluing, ultrasonic welding or even by screwing.

Note that the invention is not limited to the use of a tooth. The hooking means could consist, for example, of 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 with regard to the wearer at least one milling forming a transverse groove 20 extending over part of the total width of the bracelet. This groove 20 has, for example, the form shown in Figures 2 and 3, i.e. the shape of a section groove substantially triangular.

The tooth 16 carried by the loop 6 penetrates through its upper end into the groove 20 so as to block the second strand 2 securely, since no force tear can not pass the object over the hand without this action either wanted by the wearer.

Note that the safety of the clasp 4 according to the invention is further increased by the fact that tooth 16 is at a higher level than the upper side of the first strand 1. The second strand 2 which is introduced into loop 2 thus has a layout curve which makes it pass over said tooth 16, so that, when released the second strand 2 and the wrist of the wearer relaxes, this causes displacement said second strand 2 in the direction of opening, which results in tightening the second strand 2 and engage tooth 16 more firmly in groove 20 or hole with which said tooth 16 is engaged.

So far, there has been talk of only one groove 20 to receive the tooth 16 of the loop 6, this single groove 20 defining a single length of the bracelet when the second strand 2 is engaged in said loop 6. However, it is possible to desire several choice of lengths to adapt to 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 one part of the total length of said second strand 2. Thus, tooth 16 can it be introduced into the choice in any of the grooves 20 to adapt the length of the bracelet to around the wrist that wears it.

According to a variant, the grooves 20 can be replaced by as many holes (not shown) drilled in the end part 19 of the second strand 2 and in which the tooth 16 can penetrate to block said second strand 2 in the position of closing. However, we prefer to make grooves rather than holes in the strand 20 insofar as the grooves 20, formed in the underside of said strand 20, are invisible to the wearer of the bracelet.

According to the present invention, the loop 6 also includes a unlocking device 22 which can be operated manually, this unlocking 22 allowing the second strand 2 to be lifted to free it from hooking means 14 and scroll 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 tooth 16 capable of remain hooked in one of the grooves 20 or holes made 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 lifting 26 of the second strand 2 connected to an actuation plate 28 by two longitudinal arms 30. As can be seen in FIGS. 2 and 3, the terminal part 19 of the second strand 2 is passed above the lifting bar 26, so it suffices for the user to press lightly on the actuating plate 28 to lift said strand 2. To this end, the lever 24 is pivotally articulated on the loop 6 by means of a bar 32 introduced into hinges 34 formed in one and the other plates 8 of the loop 6.

Advantageously, the first strand 1 is wound at a fixed length around the same bar 32 as that by which the unlocking lever 24 is articulated 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 part 19 in the loop 6 while doing so pass over the lifting bar 26 of the unlocking lever 24. The tooth 16 is engaged in one of the grooves 20 formed in the invisible lower face of the second strand 2. The actuation plate 28 has a transverse part 36 which abuts against a flange 38 which the cross member 10 faces, which limits the travel of the unlocking lever 24.

In FIG. 3, the user pushes the unlocking lever 24, which rotates this lever around its axis 32 and causes the rise of the lifting bar 26 which raises the second flexible strand 2. The grooves 20 or holes practiced in the second strand 2 thus escape the tooth 16 of the loop 6, and the user can pull said second strand 2 relative to the first strand 1 and remove it from the loop 6.

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

As can be seen very clearly, in particular in FIGS. 6 and 7, the second embodiment of the clasp 4 according to the invention essentially differs from the first in that the unlocking lever 24 is mounted in the opposite direction on the bar 32. Thus, as is apparent from FIG. 7, the user must no longer push, but on the contrary, pull the unlocking lever 24 to rotate it around the bar 32 and lift the second flexible strand 2 which rests on the bar uplift 26. This second embodiment is also distinguished from the first in that the actuating plate 28 has under its surface a housing 40 arranged to come over the crosspiece 10 of the loop 6 which is opposite this housing 40. The assembly formed by the housing 40 and the corresponding cross-member 10 is done with limited play, so you have to overcome some resistance when the actuating plate 28 is folded over the crosspiece 10, which prevents the unlocking lever 24 unexpectedly opens.

The present invention can be applied to all types of flexible bracelets formed of strands, for example of the Milanese type or braided, or made of leather, rubber or 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 can be envisaged by a person skilled in the art without departing from the scope of the present invention.

Claims (18)

Clasp (4) for assembling first and second flexible strands (1, 2) comprising a loop (6) attached to the first (1) of the two strands, while the second strand (2) enters the loop (6), characterized in that the loop (6) comprises fixed hooking means (14) which are hooked into the second strand (2), and in that it comprises a manually operable unlocking device (22), unlocking device (22) making it possible to lift the second strand (2) to release it from the hooking means (14) and to scroll it out of the loop (6). Clasp according to claim 1, characterized in that the hooking means (14) comprise a tooth (16), and in that the unlocking device (22) comprises a lever (24) mounted movably on the loop ( 6) and who is capable of lifting the second strand (2). Clasp according to claim 2, characterized in that the tooth (16) and a rib (18) which carries it are made in one piece with the buckle (6). Clasp according to claim 2, characterized in that the tooth (16) and a rib (18) which carries it are produced separately and fixed on the buckle (6). Clasp according to any one of claims 2 to 4, characterized in that the unlocking lever (24) is pivotally articulated on the buckle (6). Clasp according to any one of claims 2 to 5, characterized in that the unlocking lever (24) is controlled by pressure to lift the second strand (2). Clasp according to any one of claims 2 to 5, characterized in that the unlocking lever (24) is controlled by traction to lift the second strand (2). Clasp according to any one of Claims 2 to 7, characterized in that at least one transverse groove (20) in which the tooth (16) can be housed is formed in the invisible lower face of the second strand (2). Clasp according to any one of Claims 2 to 7, characterized in that at least one hole in which the tooth (16) can be housed is drilled in the second strand (2). Clasp according to any one of claims 8 or 9, characterized in that the second strand (2) has a plurality of grooves (20) or holes arranged in a row over part of the total length of said second strand (2) , so that the tooth (16) can be optionally introduced into one of the grooves (20) or holes to adapt the length of the first and second strands (1, 2) attached together around the wrist. Clasp according to any one of Claims 2 to 10, characterized in that the unlocking lever (24) comprises a lifting bar (26) above which the free end (19) of the second strand (2) passes, this lifting bar (26) being connected to an actuating plate (28) by two longitudinal arms (30), the unlocking lever (24) being pivotally articulated on the loop (6) by means of a bar ( 32). Clasp according to claim 11, characterized in that the first strand (1) is wound at a fixed length around the bar (32) by which the unlocking lever (24) is pivotally articulated on the loop (6). Clasp according to any one of claims 1 to 12, characterized in that the loop (6) comprises two parallel plates (8) extending on either side of the first and second strands (1, 2) and connected to their ends by two transverse crosspieces (10) audits strands (1, 2). Clasp according to claim 13, characterized in that the upper edges (12) of the two plates (8) of the loop (6) are given a curved shape which conforms to the curvature of the wrist. Clasp according to any one of claims 1 to 14, characterized in that the tooth (16) being at a level substantially higher than the upper face of the first strand (1), the second strand (2) which is introduced in the loop (6) has a curved line which makes it pass over said tooth (16), so that, when the second strand (2) is released and the wearer's wrist relaxes, this causes displacement of said second strand (2) in the direction of opening, which results in tensioning the second strand (2) and more firmly engaging the tooth (16) in the groove (20) or in the hole with which said tooth (16) is engaged. Clasp according to any one of claims 1 to 15, characterized in that the first and second strands (1, 2) are of the Milanese type or woven, or made of rubber, leather or a flexible synthetic material. Clasp according to claims 6, 11 and 13, characterized in that the actuating plate (28) has a transverse part (36) which abuts against a flange (38) that has the crosspiece (10) facing, which limits the travel of the unlocking lever (24). Clasp according to claims 7, 11 and 13, characterized in that the actuating plate (28) has under its surface a housing (40) arranged to come to cover the crosspiece (10) opposite.

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