EP2765883B1 - Watch strap clasp - Google Patents

Description

The present invention relates to a clasp for a watch strap or belt. More specifically, the present invention relates to a clasp for a watch strap or belt comprising means that allow a fine adjustment of the length of the bracelet or the belt.

Clasps comprising means for a fine adjustment of the length of the wristband of a watch are already known from the state of the art. Clasp for fine adjustment of the length of a bracelet, means clasps that allow to adjust the length of a bracelet to a shorter length to allow to fit the fairest length for optimal comfort to wear the shows. Such clasps usually include a terminal link through which one of the strands of the bracelet is connected to the lid of the clasp. This terminal link is slidable in a longitudinal direction of the clasp between a first retracted position in which it is housed in the lid of the clasp and a second extended position in which it is disengaged from the clasp. Therefore, the length available for the fine adjustment is determined by the travel of the end link between its first and second positions. For indexing the position of the end link, the end link cooperates via a toothed element with a toothed rack. For example, the rack can be secured to the lid of the clasp and the toothed element be carried by the terminal link. The permutation of the rack teeth and the toothed element is also possible. an example of clasp according to the preamble of claim 1 is known from document EP 2 361 523 .

When the toothed element is engaged with the rack teeth, the end link is immobilized. To disengage the toothed element from its engagement with the rack teeth, resilient means of uncoupling are provided. These elastic means usually offer a low uncoupling race. Due to the short stroke of the elastic disengagement means, the teeth of the rack teeth can not be very high. Consequently, the force of the notching between the toothed element and the rack tooth is relatively small, so that the position of the end link can be easily deindexed, for example by pulling or pushing the end link, which is not not acceptable. In addition, it is easily understood that, the teeth of the rack teeth are small, the higher the manufacturing tolerances, which increases the cost of such a clasp.

The present invention aims to overcome the drawbacks mentioned above as well as others by providing a clasp for the fine adjustment of the length of a watch strap or a belt allowing in particular to keep the setting the length of the bracelet or belt without the risk of losing it inadvertently.

For this purpose, the present invention relates to a clasp for a watch strap or belt comprising a cover connected from one side to a first strand of bracelet or belt and from a second side to a second strand of bracelet or belt, connecting means being interposed between the second strap or belt strand and the cover of the clasp, these connecting means comprising a terminal link sliding in a longitudinal direction of the clasp between a first position in which the terminal link is at least partially engaged in the lid of the clasp, and a second position in which the end link is disengaged from the lid of the clasp, the end element comprising a push-button by pressure on which it is possible to pass a toothed element of a first position in the toothed element is engaged with a toothed rack integral with the lid of the clasp, at a second position wherein the toothed element is released from its engagement with the rack teeth, the clasp being characterized in that the terminal link comprises a housing in which is disposed at least one spring, the spring being capped by the push button.

Thanks to these features, the present invention provides a watchband clasp or belt in which the disengagement between the toothed element and the rack teeth is controlled by at least one spring. Such a spring provides the push button a substantial stroke, this stroke being determined only by the length of the spring. As the push button directly controls the passage of the toothed element from its first position in which it is engaged with the rack teeth to its second position in which it is released from its engagement with the rack teeth, the race of the toothed element between its two extreme positions is also larger. As a result, the teeth of the rack teeth can be made higher than was the case in the state of the art and therefore the spaces between the deeper teeth. The force of the notching between the toothed element and the rack tooth is therefore higher, so that the position of the end link can not be deindexed, except to destroy the clasp. In addition, as the teeth of the rack teeth are higher, the manufacturing tolerances are less stringent, which allows for gains in terms of cost.

According to a complementary feature of the invention, the push button is equipped with a stop means preventing extraction of the terminal link from the clasp cover.

With this other characteristic, the connecting means between the clasp cover and the second strap or belt strand are captive, except to destroy the clasp. Additionally, according to a preferred embodiment of the invention, the stop means is removable, which allows, if necessary, to replace the end link or the push button when returning the wristwatch or the belt in after-sales service.

• la figure 1 est une vue en perspective et à l'état dissocié du fermoir selon l'invention;
• la figure 2 est une vue en perspective du fermoir de la figure 1 à l'état assemblé, le maillon terminal de réglage fin étant en position rentrée;
• la figure 3 est une vue analogue à celle de la figure 2, le maillon de réglage fin étant en position sortie;
• la figure 4 est une vue en coupe transversale du maillon terminal de réglage fin selon l'invention;
• la figure 5 est une vue analogue à celle de la figure 4 dans laquelle les ressorts hélicoïdaux ont été remplacés par une lame-ressort, et
• la figure 6 est une vue partielle en perspective d'une ceinture équipée du fermoir selon l'invention.

Other features and advantages of the present invention will become more apparent from the following detailed description of an embodiment of the wristband or belt clasp according to the present invention. the invention, this example being given for purely illustrative and nonlimiting purposes only in connection with the appended drawing in which:

• the figure 1 is a perspective view and in the dissociated state of the clasp according to the invention;
• the figure 2 is a perspective view of the clasp of the figure 1 in the assembled state, the fine adjustment end link being in the retracted position;
• the figure 3 is a view similar to that of the figure 2 the fine adjustment link being in the extended position;
• the figure 4 is a cross-sectional view of the fine-tuning end link according to the invention;
• the figure 5 is a view similar to that of the figure 4 in which the coil springs have been replaced by a leaf spring, and
• the figure 6 is a partial perspective view of a belt equipped with the clasp according to the invention.

The present invention proceeds from the general inventive idea of using a spring as an elastic means controlling the uncoupling between a toothed element and a toothed rack of a fine tuning link of a clasp for a watch strap or belt. Such a spring provides a greater stroke to the pushbutton associated therewith, so that the displacement of the toothed element controlled by the push button from its first position in which it is engaged with the rack teeth at its second position in which it is released from engagement with the rack teeth is also more important. The teeth of the rack teeth can therefore be provided higher with deeper teeth recesses, which ensures a better notch of the toothed element and reduces the manufacturing tolerances of the teeth of the rack teeth.

The present invention will be described in connection with a watch strap. It goes without saying, however, that this example is given for purely illustrative and non-limiting purposes only and that the clasp according to the invention can also be used for a belt.

The figure 1 is a perspective view in the dissociated state of the clasp according to the invention while the figure 2 is a perspective view of this same clasp in the assembled state. Designated as a whole by the general numerical reference 1, the clasp according to the invention comprises a lid 2 connected on one side to a first strand of bracelet 4, of which only one link is visible in the drawing with the interposition of a closure system. with folding clasp 6 whose structure is known per se and therefore will not be described further here. Note that the clasp closure system 6 can be omitted and the cover 2 can be connected to the first strand of bracelet 4 directly. The lid 2 is connected on the second side to a second strand of bracelet 8, three links of which are visible in the drawing with the interposition of a terminal link 10 for fine adjustment of the length of the wristband of the watch.

As can be seen from the examination of the figure 1 , the lid 2 has a U-shaped general section and is provided with two flanges 12 facing each other, these flanges 12 each carrying on their inwardly directed face a rack toothing 14. Furthermore, a groove 16 is provided in the bottom of the cover 2 and defines two end stops 18 whose role will be described in detail later. Finally, the terminal link 10 comprises lateral guide surfaces 19 to be slidably guided in the cover 2 between the bottom of the cover 2 and the wings 12. It will be appreciated by comparative examination of figures 2 and 3 the end link 10 is capable of sliding in a longitudinal direction of the clasp 1 between a first position ( figure 2 ) in which the end link 10 is engaged in the cover 2 of the clasp 1, and a second position ( figure 3 ) in which the end link 10 is disengaged from the cover 2 of the clasp 1. The length available for adjustment the bracelet is determined by the race of the terminal link 10 between its first and second positions.

The end link 10 comprises two end knuckles 20 between which the middle knuckle 22 of the adjoining link of the second strand of bracelet 8 is interlocked. The assembly between the links is ensured by a bar 24 freely traversing the knuckles 20 and 22 and which is held by two end screws 26.

The terminal link 10 comprises at least one and, preferably, two cylindrical blind housings 28 in each of which is disposed a helical spring 30, these springs 30 being capped by a push-button 32. This push-button 32 is substantially in the form of a rectilinear actuating bar which extends transversely to the longitudinal axis of symmetry of the clasp 1 and which has at each of its ends a toothed element 34 for example in the form of a half-cylinder. These toothed elements 34 are intended to come into engagement with the toothing of the racks 14. It will be understood that when the end link 10 and its pushbutton 32 are slid between the two wings 12 inside the cover 2 of the clasp 1 as illustrated. to the figure 2 , the coil springs 30 which are mounted force the push button 32 towards the racks 14, so that the toothed elements 34 are engaged with the teeth of the racks 14. Conversely, when the push button 32 is depressed following the arrow A against the elastic return force of the springs 30, the toothed elements 34 are released from their engagement with the toothed racks 14. It will also be understood that the coil springs 30 give the push button 32 and therefore To the toothed elements 34 a large stroke, so that the teeth of the rack teeth 14 can be high and the spaces between these deep teeth. As a result, the toothed elements 34 are perfectly notched in the teeth of the racks 14, so that it is impossible to accidentally lose the setting of the end link 10. In addition, the requirements on the tolerances rack toothings 14 are lower, which allows for gains in terms of production costs.

We also observe the examination of figures 1 and 4 that between the two blind cylindrical housings 28 formed in the end link 10 is provided a first threaded through hole 36 in which is screwed a screw 38 whose tip projects into the groove 16 formed in the bottom of the lid 2. As this groove 16 is bounded at each of its ends by a stop 18 which marks the bottom of the groove 16, the end link 10 of fine adjustment is completely captive once the screw 38 screwed. Finally, a second through hole 40 aligned with the first threaded through hole 36 is machined in the pushbutton 32. According to a first embodiment of the invention, a plug (not shown) is driven or glued into the second through hole 40 to hide the screw 38 and not to reveal a hole in front of the user. In this case, however, the pushbutton 32 is permanently unmountable. According to a second variant embodiment of the invention, a screw 42 is screwed into the second through hole 40. This screw 42 masks the screw 38 with respect to the user. However, the assembly remains removable to the extent that it is sufficient to remove the screw 42 to then be able to remove the screw 38. These two variants are preferred to the variant in which only one screw is provided that is long enough for the head of this screw is flush with the surface of the pushbutton 32. Indeed, in this embodiment, the head of the screw protrudes from the pushbutton 32 when it is pressed against the return force spring elastic 30, which is not aesthetic.

It will be noted that at the bottom of the cylindrical blind housings 28 are provided two pins 44 for centering the springs 30. Furthermore, the push-button 32 is provided on its surface facing the end link 10 of fine adjustment of two cylindrical housings 46 coaxial with cylindrical blind housings 28 for guiding and holding springs 30.

It goes without saying that the present invention is not limited to the embodiment which has just been described and that various modifications and simple variants may be envisaged by those skilled in the art without departing from the scope of the invention as defined by the appended claims.

In particular, as illustrated in figure 5 , it may be envisaged to replace the two coil springs 30 by a leaf spring 48. In the example shown in the drawing, this leaf spring 48 has a V-shaped profile. It is fixed at its center by means of a screw 50 in the bottom 52 of the terminal link 10 and the push-button 32 bears elastically on the two arms 54 of the leaf spring 48. The degree of deflection of these arms 54 determines the stroke of the push-button 32 and 34. The greater the degree of deflection, the greater the stroke of the push button and the more the teeth of the rack teeth 14 can be high and the spaces between these deep teeth. As a result, the toothed elements 34 are perfectly notched in the teeth of the racks 14, so that it is impossible to accidentally lose the setting of the end link 10. In addition, the requirements on the tolerances of the toothed racks 14 are smaller, which allows to realize gains in terms of production costs. As before, the tip of the screw 50 protrudes into the groove 16 formed in the bottom of the cover 4, so that the end link 10 of fine adjustment is completely captive once the screw 50 screwed. Similarly, as already described above, a screw 58 screwed into the push button 32 is aligned with the screw 50 to hide the screw 50 and not to reveal a hole in front of the user.

Similarly, as illustrated in figure 6 it goes without saying that the clasp according to the invention can also be used for a clothing belt. In this case, a first end 60 of the belt 62 is connected directly to the lid 2 of the clasp, while the second end 64 of the belt 62 is connected to the lid 2 of the clasp with the interposition of the connecting means according to the invention which comprise the terminal link 10.

Claims (10)

1. Clasp for a watch bracelet or for a belt comprising a cover (2) connected on a first side to a first strand (4) of a bracelet or belt and on a second side to a second strand (8) of a bracelet or belt, a connecting means being inserted between the second bracelet or belt strand (8) and the cover (2) of the clasp (1), said connecting means comprising an end link (10) sliding along a longitudinal direction of the clasp (1) between a first position in which the end link (10) is at least partially engaged in the cover (2) of the clasp (1), and a second position in which the end link (10) is disengaged from the cover (2) of the clasp (1), the end link (10) comprising a push-button (32) which, when pressed, causes a toothed element (34) to change from a first position, in which the toothed element (34) is in mesh with a rack toothing (14) integral with the cover (2) of the clasp (1), to a second position, in which the toothed element (34) is released from the engagement thereof with the rack toothing (14); the clasp being characterized in that the end link (10) includes a housing (28) in which there is arranged at least one spring (30), said spring (30) being covered by the push-button (32) acting along a direction perpendicular to the plane of the clasp.
2. Clasp according to claim 1, characterized in that the toothed element (34) is carried by the push-button (32).
3. Clasp according to any of claims 1 or 2, characterized in that the push-button (32) is provided with an arresting means preventing the removal of the end link (10) from the cover (2) of the clasp (1).
4. Clasp according to claim 3, characterized in that the arresting means is removable.
5. Clasp according to claim 4, characterized in that the arresting means is formed by a screw (38) which projects into a groove (16) arranged in the bottom of the cover (2) and which defines two end stop members (18).
6. Clasp according to any of claims 3 to 5, characterized in that the arresting means is concealed from the user's view.
7. Clasp according to claim 6 dependent on claim 3, characterized in that the arresting means is concealed by means of a cap that is driven or bonded thereon.
8. Clasp according to claim 6, characterized in that the arresting means is concealed by means of a second screw (42).
9. Clasp according to any of claims 1 to 8, characterized in that the cover (2) has a generally U-shaped section and is provided with two wings (12) facing each other, said wings (12) each carrying a rack toothing (14) on the inward facing surface thereof.
10. Clasp according to claim 9, characterized in that the end link (10) includes lateral guide surfaces (19) for slidably guiding said link inside the cover (2) between the bottom of the cover (2) and the wings (12).

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