EP1241540B1 - Device for fastening a bracelet to a watch-case - Google Patents

Description

The present invention relates to a device for fixing a bracelet on a watch case. More and more the user of a watch desire to be able to modify the appearance of his watch by changing the bracelet for certain occasions.

The object of the present invention is to satisfy this trend by providing a strap attachment device on the watch case that allows interchangeability of the bracelet that can be done by the user easily and quickly. The purpose of the present invention also lies in making it possible for the user himself to fix on his watch bracelets of different materials, metal, leather, synthetic or other.

We know from the document CH 662 028 a fastening arrangement between a member that can belong to a watch band and another member that can belong to a watch case, this other member comprising a hinge in which two pins pivoted by the action of a return spring tending to move them apart so that the outer ends of the pivots emerge out of the lateral faces of said hinge.

The present invention relates to a fastening element for a device for attaching a bracelet to a watch case which is distinguished by the features set forth in claim 1, a fixing device comprising it, as well as a watch case. being equipped.

• La figure 1 illustre une boîte de montre équipée du dispositif de fixation selon l'invention, accouplée à des pièces de liaisons que comportent les extrémités du bracelet.
• La figure 2 est une coupe partielle passant par la ligne A-A de la figure 1 suivant un plan parallèle au fond de la boîte de montre.
• La figure 3 est une coupe passant par la même ligne A-A de la figure 1 mais suivant un plan perpendiculaire au fond de la boîte de montre.
• La figure 4 est une vue de dessus de l'élément de fixation.

The accompanying drawing illustrates schematically and by way of example an embodiment of the device for attaching a bracelet to a watch case according to the invention.

• The figure 1 illustrates a watch case equipped with the fastening device according to the invention, coupled to connection pieces that comprise the ends of the bracelet.
• The figure 2 is a partial section through the AA line of the figure 1 following a plane parallel to the bottom of the watch case.
• The figure 3 is a cut passing through the same AA line of the figure 1 but in a plane perpendicular to the bottom of the watch case.
• The figure 4 is a top view of the fastener.

The device for attaching a bracelet to an illustrated watch case comprises a hinge 1 integral with the watch case 2, replacing in a way the usual horns, and a fastening element 3 intended to be fixed on the end of the case. a bracelet to be coupled to the watch case 2.

Each hinge 1 has a transverse through passage having three parts, a small diameter portion 4 opening on one of its side edges, a median portion 5 of larger diameter and a large diameter portion 6, provided with a thread 7 , opening on the other side edge of the hinge 1.

In this transverse passage 4, 5, 6 are housed two pivots 8, 9 having a central portion of a diameter corresponding to the diameter of the middle portion 5 of the through passage of the hinge 1. Each pivot has an inner end of smaller diameter introduced in a coil spring 10 also housed in the transverse passage 4, 5, 6 and tending to separate the pivots 8, 9 from each other.

A threaded bush 11 is screwed into the thread 7 and has a terminal bore 12 of the same diameter as the small diameter portion 4 of the transverse passage 4, 5, 6 of the hinge 1 opening into a housing 13 having a diameter corresponding to that of the medial portion of the transverse passage 4, 5, 6. In this housing 13 slides the middle part of the pivot 9.

Thus, in the service position the pins 8, 9 slide transversely in the hinge 1 and are subjected to the action of the spring 10 which tends to separate them from one another. The outer end portions of the pivot 8, 9 emerge in lateral faces of the hinge 1 and the pivots 8, 9 are retained by their shoulder 30 abutting against the hinge 1 respectively the sleeve 11 screwed into the hinge 1 as illustrated in FIG. figure 3 .

The fastening element 3 can be constituted by the last link of a metal bracelet or by a piece integrated into the end of a leather strap. In the illustrated example, this element 3 comprises a stud provided with a piercing 14. This stud is intended to be fixed to the end of a metal bracelet by means of a pin passing through the piercing 14. This element 3 further comprises two lugs 15 separated by a recess 16 for receiving the hinge 1 of the watch case. These lugs 15 each comprise a recess 17 opening on their external lateral faces, recess 17 extended by a coaxial passage 18 opening on the inner edge of these lugs 15.

End pieces 19 are driven into the recesses 17 of the tabs. These end pieces comprise a housing 20 in which slides a counter-pivot 21, possibly subject to the action of a spring tending to move away from the longitudinal axis of the bracelet. An orifice 22 of smaller size than the housing 20 extends the latter and opens on the free face of the nozzle 19.

In the lower face of the lugs 15 are arranged two guide grooves inclined bottom 23 whose width corresponds to the diameter of the end of the pivots 8, 9 emerging laterally of the hinge 1.

The fixing device also comprises an elastic clip 24 whose branches are provided with lugs 25.

To detach the bracelet from the watch case 2 the user takes the clamp 24 and introduces the lugs 25 of the elastic branches into the orifices 22 of the end pieces 19. By bringing the branches of the clamp closer the user pushes the counter pivots 21 which retracts the pivots 8, 9 into the hinge 1 (see figure 2 ). By pulling on the pliers in the axis of the bracelet, the connecting element 3 is then separated from the hinge 1 and the bracelet is detached from the watch case 2.

To assemble the bracelet to the watch case the user presents the connecting element 3 above the hinge 1, the grooves 23 engaged on the pushers 8, 9 coming out of the hinge 1. The user then forces the fastening element 3 on the hinge, the inclined planes of the grooves 23 retract the pushers 8, 9 to when the passages 18 are opposite these pushers 8, 9 and that they enter these passages 18 under the action of the spring 10. The bracelet is thus again secured to the watch case.

Thanks to this fixing device the user can with the help of a simple clip change his watch strap.

Claims (6)

1. Fastening element (3) to be fastened at one end of a watch bracelet, said fastening element (3) being provided with two tongues (15) between which a space intended to take up a hinge (1) is defined, each of these tongues comprising an axial slot (17) extended by a passage (18) terminating in the space comprised between these tongues (15) and having a diameter corresponding to that of the ends of the pivots (8, 9), characterised in that this slot (17) is connected with the lateral outer faces of the tongues (15) by a hole (22) having a smaller diameter than the slot (17), and in that plungers (21) sliding within this slot (17) have an inner end with a diameter corresponding to that of the passages (18).
2. Fastening element (3) according to claim 1, characterised in that the plungers (21) are slidingly mounted into ferrules (19) driven into the slots (17) of the tongues (15).
3. Fastening element (3) according to claim 1 or 2, characterised in that each plunger (21) is subject to an elastic action tending to push it against the ferrule (19).
4. Device for fastening a watch bracelet to a watch case comprising a hinge (1) integral with the watch case (2) within which slide two pivots (8, 9) subject to the action of a return spring (10) tending to spread them apart so that the outer ends of the pivots (8, 9) emerge from the lateral faces of said hinge (1), characterised in that it comprises a fastening element (3) according to one of claims 1 to 3, said fastening element (3) being provided with two tongues (15) between which a space intended to take up the hinge (1) is defined, each of these tongues comprising an axial slot (17) extended by a passage (18) terminating in the space comprised between these tongues (15) and having a diameter corresponding to that of the ends of the pivots (8, 9), this slot being connected with the lateral outer faces of the tongues (15) by a hole (22) having a smaller diameter than the slot (17); in that plungers (21) sliding within this slot (17) have an inner end with a diameter corresponding to that of the passages (18); said fastening device being intended to cooperate with a U-shaped clamp (24) the elastic arms of which comprise studs (25) able to become engaged into the holes (22) so that they will act upon the plungers (21).
5. Fastening device according to claim 4, characterised in that the inner faces of the tongues (15) when aligned with the longitudinal axis of the bearings (17) comprise guide grooves (23) having a width corresponding to the diameter of the pivots (8, 9).
6. Watch case (2), characterised in that it is fitted with a fastening device according to claim 4 or claim 5.

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