EP1269879A1 - 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 of a watch box. The invention relates more particularly to such a device in which the fixing means leave a portion of the middle part between anchoring zones of the strands of bracelet, while making it possible to easily interchange said bracelet, without having to use special tools.

A watch strap is generally attached to the case by means of bars which cross the ends of the bracelet strands while being attached to horns integral with the middle part or with extensions thereof.

These bars are most often so-called "spring bars", comprising a tube housing a helical spring pressing at each end on two pivots which can therefore be compressed and retracted to become blocked in blind blind housing. With such a fastening system, the replacement of a bracelet can only be carried out by a professional using a special tool, for example tweezers. This system is therefore ill-suited to current trends of the market (mass distribution, mail order), asking less and less less the intervention of a professional for mundane operations, and to the requirements of the consumer who may wish to replace his bracelet himself at any time of the day by another bracelet, for example to match her outfit clothing.

The fastening devices described in US patents 4,561,077 and US 4,624,581 provide a solution in that the fixing is ensured by a hinge, comprising on extensions of the middle and on the ends of the bracelet strands two series of overlapping teeth, the whole being made integral by a metal rod crossing 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 back into place, for example by means of another rod or the point of a needle.

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

In document CH 350610, the bar is also a metal rod, but with a thinning in its central part allowing it to bend and forcefully engage its ends in blind holes in the horns. The document CH 682875 plans to have only one blind hole, the other hole being open on the middle to allow the rod to be engaged and then held in place by means screwing from the bottom. In document CH 503311 a metal handle, of generally open rectangular shape, embedded in each end of the strand bracelet to snap into blind holes in the middle. The model DE 8 509 275 U describes a fixing device in which the underside of the end of each bracelet strand has studs which engage in housing of an extension of the middle being blocked by jumpers crossing said studs and housing in a direction parallel to the bottom of the housing.

In all these fixing devices it can be seen that part of the element of fixing, bar, rod or metal handle always passes in front of the middle 6 o'clock and 12 o'clock positions, which can have drawbacks in certain applications, for example for positioning on the middle of a lens a microcamera integrated in a watch box. We will also observe 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 aim of the invention is therefore to remedy the drawbacks of the art above mentioned by providing a device for fixing the bracelet strands to a box that allows an ordinary user to easily change the bracelet, which does not not detract from the aesthetic appearance of the watch and which can preferably leave it free any fastening element for the middle portions located at 12 o'clock and / or at 6 hours.

To this end the invention relates to a device for fixing bracelet strands on each side of the middle of a watch case without horn, closed by a bottom and by a glass delimiting a space in which is housed at least one movement clockwork for digital or analog time display. The interior surface of each end of the bracelet strand comprises at least two studs extending perpendicular to said surface being drilled in their middle part each a hole in a direction parallel to the length of the strand. Each side of the middle includes at least as many complementary recesses of the studs, in volume interior and positioning, each obviously having in its middle part perpendicular to the bottom of the box a passage passing through the bottom side and a hole blind on the ice side. After fitting the studs in the recesses, each strand is secured to the middle by engaging a rider from the bottom, comprising as many branches than studs, through the through passages, the stud holes and the blind holes.

Before fitting the fixing jumper, each strand of bracelet is positioned perpendicular to the bottom. By pressing with the fingers according to the direction 6 hours - 12 hours, it is easy to carry out the nesting of studs in the recesses, an operation that would be more difficult to perform if the studs were located at the very end of the strand.

The pads are preferably made of a plastic material and the holes which cross them have a diameter slightly smaller than that of the branches of the rider, which allows to block said jumper after its installation. Conversely the through passage and the blind hole of the middle part have a diameter slightly higher than that of the rider's branches, which reduces the effort required to extract it when the user wants to replace the bracelet.

According to a preferred embodiment, the jumper has only two U-shaped branches and the bracelet strand two studs, so that the portion of middle between the two attachment zones is completely free of any means of fixation. The fixing device according to the invention therefore has the advantage of making accessible to fittings, the middle portions located substantially at 12 hours and 6 hours. In the case of a calculator watch or diary having a keyboard on a bracelet strand, the device makes it easier to perform electrical connections through a hole in the middle. In the case of a watch camera it is possible to set the lens to the 12 o'clock position by planning a U-shaped notch 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 boíte 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 characteristics of the invention will appear more clearly on reading the following description of embodiments of the invention, given purely by way of non-limiting illustration, with reference to the appended drawings in which:

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

Figure 1 shows in perspective a wristwatch 1 comprising a middle 2 of generally rectangular shape, closed by a bottom 4 and by a crystal 6 arranged above a dial for an analog display of the time by means of needles 3,5 driven by a clockwork movement (not shown). The dial may also include a digital display window 7 for providing additional time information or non-time information from mechanisms or sensors contained in the box 1 with the movement, these elements which are neither shown nor described further as being well known to skilled in the art and not directly part of the invention. The window digital display 7 is for example the viewfinder of a microcamera integrated in the shows. The wristwatch can be put around the wrist by means of two strands bracelet 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 to man art.

The fixing device is described in more detail below with reference to Figures 2 to 5. Figure 2 shows in exploded perspective the same wristwatch than that shown in Figure 1 with a variant of attachment for each strand of bracelet. It can be seen that the strand 10 having to be fixed on 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 middle part with a hole 12a, 14a in a direction parallel to the length of the bracelet. It is well obvious that the outline of the studs 12, 14 could be different, for example in shape oval or quadrangular.

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, studs 12, 14. The recesses 15, 17 can pass entirely through the middle 2, but according to a preferred embodiment, said recesses 15, 17 are blind. In the middle parts of the recesses 15, 17 of the through passages 15a, 17a side bottom 4, and blind holes 15b, 17b on the glass side 6 are provided in the middle part 2 to allow, after fitting studs 12, 14 in the recesses 15, 17 to engage a rider 18 with two branches 19a, 19c successively through the through passages 15a, 17a, the holes 12a, 14a of the studs and the terminal holes 15b, 17b. So that the jumper 18 remains in place, the studs 12, 14 are made of preferably a flexible plastic material having holes 12a, 14a in diameter slightly less than the diameter of the branches 19a, 19c of the rider 18. Conversely the diameter of the through passages 15a, 17a and the terminal holes 15b, 17b can be slightly greater than the diameter of the branches 19a, 19c so as to facilitate placing in place of the jumper 18 and its extraction, for example simply with the end a sharp object, such as a knife.

Equivalently, the blocking of the jumper 18 can be reversed, i.e. perform it at the level of the through passages 15a, 17a, and / or of the blind holes 15b, 17b. In the case of a middle part made of a hard material, such as a metal or a ceramic, the inside of the passages or holes will advantageously be lined with a short length of plastic sheath.

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

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

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

The above description relates to a generally rectangular box so that the studs and the recesses are aligned in directions substantially parallel to the length of the bracelet. The fixing device is suitable also for watch cases of general 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 rider 18 or 28 may have the form shown in the Figure 2, but the branch junction element may also have a curvature corresponding to that of the box at the junction.

Claims (10)

Device for fixing strands (10, 20) of a bracelet on each side of the middle part (2) of a watch case without horns, closed by a base (4) and by a crystal (6), characterized in that the inner surface of each end of strand (11, 21) comprises at least two studs (12, 14, 22, 23, 24) extending perpendicular to said surface by being drilled in their median part each with a hole (12a, 14a, 22a, 23a, 24a) in a direction parallel to the length of the strand (10, 20), in that each side of the middle part (2) has at least as many recesses (15, 17, 25, 26, 27) complementary to the studs (12, 14, 22, 23, 24), in volume and in positioning, each obviously (15, 17, 25, 26, 27) having in its middle part perpendicular to the bottom (4) a through passage (15a, 17a, 25a, 26a, 27a) on the bottom side (4) and a blind hole (15b, 17b, 25b, 26b, 27b) on the glass side (6), and in that a jumper (18, 28), with as many branches (19a, 19c, 29a, 29b, 29c) that studs (12, 14, 22, 23, 24) on each strand (10, 20), is engaged on the bottom side (4), after fitting the studs in the recesses, through the through passages, the stud holes and the blind hole. Fastening device according to claim 1, characterized in that the branches (19a, 19c, 29a, 29b, 29a) of the jumpers (18, 28) have a diameter substantially 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 into the recesses (15, 17, 25, 26, 27) of the middle part (2). Fastening device according to claim 1, characterized in that at least one strands (10) have only two studs (12, 14) near the edges of said strand (10) and comprises a notch (13) in a U in its middle part between the studs (12, 14). Fastening device according to claim 3 characterized in that the side of the middle part (2) to which the strand (10) is fixed with two studs (12, 14) further comprises, at the level of the U-shaped notch, an orifice (16) through the middle part (2) connecting the inside and the outside of the box. Fastening device according to claim 4, characterized in that the orifice (16) in the middle part (2) is closed by the objective of a microcamera housed in the box. Fastening device according to claim 1, characterized in that the recesses (15, 17, 25, 26, 27) in the middle part (2) are blind holes. Fastening device according to claim 1 wherein the middle part (2) of the box has a generally rectangular or square shape, characterized in that the studs (12, 14, 22, 23, 24) and the recesses (15, 17, 25, 26, 27) are aligned in a direction substantially parallel to the 12 o'clock - 6 o'clock direction. Fastening device according to claim 1, in which the middle part (2) of the box has a generally round or oval shape, characterized in that the studs (12, 14, 22, 23, 24) and the recesses (15, 17 , 25, 26, 27) are aligned in substantially concurrent directions in the center of the box. Fastening device according to claim 1, characterized in that the studs (12, 14, 22, 23, 24) are made of a plastic material coming from one material with the strand (10, 20) of the bracelet. Fastening device according to claim 1, characterized in that the studs (12, 14, 22, 23, 24) are made of a plastic material attached to the last link of a bracelet strand.

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