EP1269879B1 - Device for fixing bracelet strap to wrist watch - Google Patents

Abstract

Each bracelet end (10,20) has two or more short cylindrical mechanical contacts (12,14) with their axis in the plane of the watch case. The contacts fit into blind drillings in the watch case (15,17) at the 12 hr and 6 hr positions and the design allows for the installation (13,16) of a microcamera. The bracelet is secured by staples (18,28) which pass through holes in the watch case and contacts

Description

The present invention relates to a device for fixing the strands of a bracelet to a box, and in particular to the middle part of a watch case. The invention relates more particularly to such a device wherein the fastening means leave a portion of the middle part free between anchoring zones of the bracelet strands, while allowing easy interchange of said bracelet, without having to use special tools.

A watchband is generally fixed to the box by means of bars which cross the ends of the bracelet strands being fixed to horns integral with the middle part or extensions thereof.

These bars are most often called "spring" bars, comprising a tube housing a helical spring pressing at each end on two pivots which can be compressed and retract to come to lock in blind housings horns. With such a fastening system, the replacement of a bracelet can only be performed by a professional by means of a special tool, for example tweezers. This system is therefore poorly adapted to current market trends (large distribution, mail order), requiring less and less the intervention of a professional for mundane operations, and the requirements of the consumer who may wish to replace his own bracelet at any time of the day by another bracelet, for example to match it to his dress.

The fastening devices described in US Pat. Nos. 4,561,577 and 4,624,581 provide a solution in that the fastening is provided by a hinge comprising, on extensions of the middle part and on the ends of the bracelet strands, two series of interlocking teeth. together being secured by a metal rod passing through the two rows of teeth being driven into the teeth of the bracelet and free to rotate in the teeth of the middle part.

To replace the bracelet, simply push the rod in place, for example by means of another rod or the tip of a needle.

Other devices for fixing a bracelet on a box have been proposed or used, among which may be mentioned in a non-limiting manner those described in the documents below.

In the document CH 350610 the bar is also a metal rod, but with a thinning in its central part to bend it and forcibly engage its ends in blind holes of the horns. Document CH 682875 provides for having only one blind hole, the other hole being open on the middle to allow to engage the rod and then maintain it in place by means of screwing from the bottom. In the document CH 503311 a metal handle, of generally rectangular open shape, is embedded in each end of bracelet strand to snap into blind holes in the middle part. The utility model DE 8 509 275 U describes a fixing device in which the lower face of the end of each bracelet strand comprises studs which engage in housings of an extension of the middle part being blocked by jumpers passing through said pads and housing in a direction parallel to the bottom of the housing.

In all these fasteners it is seen that a part of the fastening element, bar, rod or metal handle always passes in front of the middle at the 6 o'clock and 12 o'clock positions, which may have disadvantages in certain applications, for example for positioning on the middle of a lens of a microcamera integrated into a watch case. It will also be observed that these fixing devices, which allow the replacement of a bracelet without the intervention of a professional, are generally unsightly, or at least visible when the watch is worn on the wrist.

The main purpose of the invention is thus to overcome the drawbacks of the aforementioned prior art by providing a device for attaching the bracelet strands to a box that allows an ordinary user to easily change the bracelet, which does not interfere with the aesthetic appearance of the watch and which can preferably leave free of any fastener portions of the middle part at 12 o'clock and / or 6 o'clock.

To this end, the subject of the invention is a device for attaching bracelet strands to each side of the middle part of a hornless watch case, closed by a bottom and by an ice defining a space in which at least one housing is housed. watch movement for digital or analog time display. The inner surface of each end of the bracelet strand comprises at least two studs extending perpendicular to said surface being pierced in their middle part each of a hole in a direction parallel to the length of the strand. Each side of the middle part comprises at least as many complementary recesses of the studs, in internal volume and in positioning, each obviously having in its middle part perpendicularly to the bottom of the box a passage through the bottom side and a blind hole on the ice side. After fitting the studs in the recesses, each strand is secured to the middle part by engaging from the bottom a rider, having as many branches as pads, through the through passages, the stud holes and the blind holes.

Before setting up the fixing rider, each strand of bracelet is positioned perpendicular to the bottom. By exerting a simple pressure with the fingers in the direction 6 o'clock - 12 o'clock, it is easy to perform the casing of the studs in the recesses, operation which would be more difficult to perform if the studs were located at the end of the strand.

The studs are preferably made of a plastic material and the holes which pass through them have a diameter slightly smaller than that of the rider's legs, which makes it possible to block said rider after it has been put in place. Conversely, the through passage and the blind hole of the middle part have a diameter slightly greater than that of the branches of the rider, which reduces the effort to provide to extract it when the user wants to replace the bracelet.

According to a preferred embodiment, the jumper comprises only two U-shaped branches and the bracelet strand two pads, so that the middle portion located between the two attachment areas is completely free of any fastening means. The fastening device according to the invention therefore has the advantage of making accessible to facilities portions of middle part located substantially at 12 o'clock and 6 o'clock. In the case of a calculator or calendar watch having a keyboard on a bracelet strand, the device makes it easier to make the electrical connections through a hole in the caseband. In the case of a camera watch it is possible to put the lens at the 12 o'clock position by providing a U-shaped indentation in the end of the bracelet strand.

• la figure 1 est une vue en perspective d'une montre ayant les deux brins fixés à la carrure;
• la figure 2 est une vue en perspective éclatée du dispositif de fixation selon l'invention pour la montre représentée à la figure 1;
• la figure 3 représente en vue de dessus un mode de réalisation d'attache d'un brin de bracelet à la carrure d'une boîte de montre;
• la figure 4 est une vue en coupe selon la ligne IV - IV de la figure 3, et
• la figure 5 est une vue en coupe selon la ligne V-V de la figure 3.

Other advantages and features of the invention will appear more clearly on reading the following description of embodiments of the invention, given for purely illustrative and non-limiting purposes, with reference to the appended drawings in which:

• Figure 1 is a perspective view of a watch having both strands attached to the middle part;
• Figure 2 is an exploded perspective view of the fastening device according to the invention for the watch shown in Figure 1;
• Figure 3 shows a top view of an embodiment of attaching a bracelet strand to the middle of a watch case;
• FIG. 4 is a sectional view along the line IV - IV of FIG. 3, and
• Figure 5 is a sectional view along the line VV of Figure 3.

FIG. 1 is a perspective view of a wristwatch 1 comprising a middle part 2 of generally rectangular shape, closed by a bottom 4 and by a window 6 arranged above a dial for an analogue display of the hour by means of 3.5 hands driven by a watch movement (not shown). The dial may also include a digital display window 7 to provide additional time information or non-hourly information mechanisms or sensors contained in the box 1 with the movement, these elements being neither represented nor described further as being well known to those skilled in the art and not part of the invention. The digital display window 7 is for example the viewfinder of a microcamera integrated into the watch. The wristwatch can be placed around the wrist by means of two bracelet strands 10, 20 attached to the middle part 2 by the fixing device according to the invention, these strands being joined by any clasp, (not shown), known of the man of the art.

The fastening device is described in more detail below with reference to FIGS. 2 to 5. FIG. 2 is an exploded perspective view of the same wristwatch as that shown in FIG. 1 with a fastening variant for each bracelet strand. It can be seen that the strand 10 to be fastened to the middle part 2 at the 12 o'clock position has in the inner surface of the reinforced end 11 and near each edge a cylindrical stud 12, 14, each stud being pierced in its central part. a hole 12a, 14a in a direction parallel to the length of the bracelet. It is obvious that the outline of the studs 12, 14 could be different, for example of oval or quadrangular shape.

Referring also to FIGS. 3 to 5, it can be seen that the middle part 2 comprises complementary recesses 15, 17, in shape and in positioning, of the studs 12, 14. The recesses 15, 17 can pass entirely through the middle part 2, but according to a preferred embodiment, said recesses 15, 17 are blind. In the median portions of the recesses 15, 17 of the through passages 15a, 17a of the bottom side 4, and the blind holes 15b, 17b on the ice side 6 are formed in the middle part 2 to allow, after fitting of the studs 12, 14 in the recesses 15, 17 to engage a jumper 18 with two branches 19a, 19c through successively the through passages 15a, 17a, the holes 12a, 14a of the pads and the terminal holes 15b, 17b. So that the jumper 18 remains in place, the studs 12, 14 are preferably made of a flexible plastic material having holes 12a, 14a of diameter slightly less than the diameter of the branches 19a, 19c of the jumper 18. Conversely the diameter of the passages through 15a, 17a and terminal holes 15b, 17b may be slightly greater than the diameter of the branches 19a, 19c so as to facilitate the introduction of the jumper 18 and its extraction, for example simply with the end of a pointed object, such as a knife.

Equivalently, it is possible to reverse the blocking of the jumper 18, that is to say to perform it at the through passages 15a, 17a, and / or blind holes 15b, 17b. In the case of a middle part made of a hard material, such as a metal or a ceramic, the interior of the passages or holes will advantageously be filled with a small length of plastic sheath.

In a preferred embodiment, the studs 12, 14 are made of material with a plastic material forming the bracelet strand 10, so that after its fixation it can easily be folded around the wrist. It is of course possible to integrate these pads 12, 14 in the last link of an articulated bracelet, whether metal, ceramic or a rigid synthetic material.

In FIGS. 1 to 3 and 5, it can also be seen that the portion of middle section 8 between the stud / recess fixing zones is not traversed by any part of the jumper 18, which makes it possible to use it for arrangements through the middle 2. In the example shown, this portion of middle 8 comprises an orifice 16 communicating the inside and outside of the box 1, said orifice 16 can be closed by the lens of a microcamera (not shown). To clear the field of this lens, the end 11 of the bracelet strand 10 has a notch 13, which is possible since there is no means of attachment at this point. It is obvious that an arrangement of this type could be provided at the level of the middle portion at 6 o'clock, with or without notch in the strand 20, for example for the passage of electrical connections to a keyboard that would be provided on the strand of bracelet, for example in the case of a watch-calculator.

Returning to FIG. 2, there is shown at the 6 o'clock position a fixing device which differs from that just described in that the reinforced portion 21 of the end of strand strand 20 has in its inner surface three pads 22, 23, 24, pierced as previously each of a hole 22a, 23a, 24a, and the corresponding middle portion comprises three recesses 25, 26, 27 each provided with through passages 25a, 26a, 27a and blind holes 25b , 26b, 27b. The jumper 28 to ensure the connection between the strand 20 and the portion 8 of the middle part 2 then comprises three branches 29a, 29b, 29c. With this variant we no longer have the advantages of the previous construction having only two pads, since the middle branch 29b of the jumper 28 crosses the middle part substantially at the 6 o'clock position. On the other hand, the fastening of the bracelet strand 20 is reinforced, which can be an advantage if the functions of the watch do not require placing the inside and the outside of the box in communication. For aesthetic reasons it is preferable that the two bracelet strands have the same conformation, but they can also be different as shown in FIG.

The above description relates to a box of generally rectangular shape so that the studs and the recesses are aligned in directions substantially parallel to the length of the bracelet. The fastening device is also suitable for watch cases of generally round or oval shape, the studs and the recesses then being aligned in directions, concurrent in the center of the box. In the latter case the jumper 18 or 28 may have the shape shown in Figure 2, but the connecting element of the branches may also have a curvature corresponding to that of the box at the junction.

Claims (10)

1. Device for attaching wristband strands (10, 20) to each side of the middle part (2) of a watchcase without horns, closed by a back cover (4) and by a crystal (6), characterised in that the inner surface of each wristband strand end (11, 21) includes at least two studs (12, 14, 22, 23, 24) extending perpendicularly to said surface and each being pierced in their median part by a hole (12a, 14a, 22a, 23a, 24a) along a direction parallel to the length of the strand (10, 20), in that each side of the middle part (2) includes at least as many recesses (15, 17, 25, 26, 27) as studs, said recesses being complementary to the studs (12, 14, 22, 23, 24) in volume and positioning, each recess (15, 17, 25, 26, 27) having in its median part perpendicular to the back cover (4), a through passage (15a, 17a, 25a, 26a, 27a) on the back cover (4) side and a blind hole (15b, 17b, 25b, 26b, 27b) on the crystal (6) side, and in that a staple (18, 28), including as many branches (19a, 19c, 29a, 29b, 29c) as studs (12, 14,22, 23, 24) at each strand (10, 20) is engaged, on the back cover (4) side, after the studs have been fitted into the recesses, through the through passages, the holes of the studs and the blind hole.
2. Attachment device according to claim 1, characterised in that the diameter of the branches (19a, 19c, 29a, 29b, 29c) of the staples (18,28) is slightly greater than the diameter of the hole (12a, 14a, 22a, 23a, 24a) in the studs (12, 14, 22, 23, 24) and substantially less than the diameter of the through passage (15a, 17a, 25a, 26a, 27a) and of the blind hole (15b, 17b, 25b, 26b, 27b) opening out into the recesses (15, 17, 25, 26, 27) of the middle part (2).
3. Attachment device according to claim 1, characterised in that at least one of the strands (10) has only two studs (12, 14) close to the edges of said strand (10) and includes a U-shaped scalloping (13) in its median part between the studs (12, 14).
4. Attachment device according to claim 3, characterised in that the side of the middle part (2) to which the strand (10) with two studs (12, 14) is attached further includes facing the U-shaped scalloping an orifice (16) through the middle part (2) causing the inside and outside of the case to communicate with each other.
5. Attachment device according to claim 4, characterised in that the orifice (16) in the middle part (2) is sealed by the lens of a micro-camera housed in the case.
6. Attachment device according to claim 1, characterised in that the recesses (15, 17, 25, 26, 27) in the middle part (2) are blind holes.
7. Attachment device according to claim 1 wherein the middle part (2) of the case has a generally rectangular or square shape, characterised in that the studs (12, 14, 22, 23, 24) and the recesses (15, 17, 25, 26, 27) are aligned along a direction substantially parallel to the 12 o'clock-6 o'clock direction.
8. Attachment device according to claim 1, wherein the middle part (2) of the case has a generally round or oval shape, characterised in that the studs (12, 14, 22, 23, 24) and the recesses (15, 17, 25, 26, 27) are aligned along directions substantially concurrent with the centre of the case.
9. Attachment device according to claim 1, characterised in that the studs (12, 14, 22, 23, 24) are made of a plastic material integral with the wristband strand (10, 20).
10. Attachment device according to claim 1, characterised in that the studs (12, 14, 22, 23, 24) are made of a plastic material added to the last link of a wristband strand.

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