HK1077719B - Articulated bracelet including decorative links threaded onto a chain - Google Patents

Description

Hinged watch chain comprising decorative links threaded on the chain

Technical Field

The invention relates to a chain link, in particular for a wristwatch, comprising a chain link and a plurality of tubular decorative links. The chain is composed of metal links connected in pairs by hinges, the tubular decorative links being threaded on the chain and able to abut each other longitudinally on their respective faces, each decorative link having at least one longitudinal channel in which a metal link and a hinge connected to the metal link are housed and which, when in the folded position, can abut against the inner surface of the lower wall of the decorative link in the region in which the hinge is located. The invention also relates to a decorative link that can be used in such a bracelet.

Background

Watch chains of this type are disclosed in particular in patent publications CH684988, EP 549979 and EP1136011, and their decorative links are preferably made of hard ceramic material, thus preventing scratches and their surface remains shiny for many years. However, these materials have the disadvantage of being somewhat brittle and less resistant to tensile and bending stresses than metallic materials. In some cases, a chain link passing through the tubular decorative link may exert such stress on some of the decorative links that one of the walls of the decorative link is damaged, requiring replacement of the broken link. If it is a good item, it is very annoying to do so. Since the appearance of the bracelet is important, these links cannot always be reinforced mainly by increasing their wall thickness. Therefore, there is a need to remedy this situation by at least partially using other methods.

Disclosure of Invention

The invention is based on the idea that the above-mentioned features of the ceramic links are due to the additional bending stresses in the transverse direction caused by the hinges resting against the base of the links when the lateral distance between the abutment areas of the front faces of two consecutive links and the abutment areas of the hinges is large, as will be explained in more detail below with reference to the drawings. The principle of the solution proposed by the invention is therefore to arrange the mutually opposite faces of the decorative chain links in such a way that their abutment areas are as close as possible to each area in which the hinge abuts against the base of the chain link.

More specifically, according to a first aspect of the invention, there is provided a watch chain of the type mentioned in the introduction, characterized in that each decorative link has, in a lower portion of its front face, at least one raised portion in the same region of the width of the decorative link as said inner face against which the hinge or metal link bears, the raised portion being arranged to abut against the opposite front face of an adjacent decorative link when the hinge is in said folded position. Thus, even if the opposite faces are perfectly flat or slightly curved, the abutment stresses between two consecutive links still occur in a zone or in several well-defined zones that are not laterally offset with respect to the zones of the ornamental links. This will substantially eliminate or reduce bending stresses in the transverse direction of the decorative link.

According to another aspect of the invention, a tubular decorative link made of ceramic material is provided, comprising at least one longitudinal channel in which a flexible or chain-link connector is housed and can abut against the inner surface of the lower wall of the decorative link, characterized in that, in the lower part of at least one front face of the decorative link, which is in the same region of the width of the decorative link as the inner surface against which the connector abuts, the lower part of the front face is inclined towards the inside of the link with respect to a plane perpendicular to the direction of the longitudinal channel.

Further characteristics and advantages of the invention will appear from the following description of a preferred embodiment, given by way of non-limiting example with reference to the accompanying drawings.

Drawings

Figure 1 is a schematic side view of a bracelet to which the invention is applied.

Fig. 2 is an exploded perspective view of the watch chain of fig. 1, showing in particular two sets of tubular decorative links and two link-type metal chains on which the decorative links pass.

Fig. 3 is an enlarged schematic view in longitudinal section showing two of the adjacent decorative links and the portion of chain they contain, with the hinge contained in one of the links in a folded position.

Figure 4 is a front view of one of the decorative links of the bracelet.

Fig. 5 is a longitudinal sectional view taken along line V-V in fig. 4.

Fig. 6 is an enlarged view of detail VI in fig. 5.

Detailed Description

In a known manner, a watch chain 1 as shown in figures 1 and 2 has two chain bands (strands) 2 and 3, each comprising a plurality of tubular decorative links 4 and a metal chain 5, the decorative links 4 being threaded on the metal chain 5, the decorative links preferably being made of a hard ceramic material. One end of each chain 5 is connected to the connecting elements 6 and 7 of a folding clasp 8, itself provided with a decorative element 9, while the other end is intended to be connected to the watch case. Each chain 5 is made up of a plurality of metal links 11, each connected to the next by a hinge 12 having a transverse axis, which has a pin 13 inserted in respective rings 14 and 15 of the adjacent metal links 11. Each decorative link 4 houses one of the metal links 11 and one of the hinges 12 of the metal chain 5. The general structure of the bracelet 1 may be identical to that described in patent application EP1136011, except for the specific features of the present invention. This document is incorporated herein by reference, to which the reader is referred for additional details.

As can be seen in greater detail in fig. 3, each decorative link 4 has a longitudinal channel 20 in which the central flat portion 21 of one of the metal links 11 of the chain and the hinge 12 connecting it to the next are located. In the example shown here, each metal link 11 has two flat portions 21 placed side by side and spaced apart by a certain distance, as in the constructions described in patent publications CH684988 and EP 1136011. It should be understood that the invention can be used with watch chains using different chains, provided that they have at least one hinge housed inside the decorative link. So that the hinge is not visible from the outside, the hinge 12 is housed in a space 22 at the entrance of the channel 20, which space leads to a first face 23 of the decorative link 4. In other words, it can be seen from fig. 3 that the ring 15 of the metal link 11 located in the decorative link 4 on the right also extends into the entry space 22 of the decorative link on the left.

The bracelet may have a curved configuration due to the angular clearance of the hinges 12 of the chain. This angular clearance is limited by the folded position shown in fig. 3, in which the lower portion of the face 23 of the left decorative link abuts against the lower portion of the opposing face 24 of the right decorative link. The link on the right thus exerts a force indicated by the arrow a on the lower part of the front face 23 of the other decorative link 4. This force is balanced by an equal tension in the chain. With the hinge 12 in the folded position, the tension forces the hinge 12 against the inner surface 26 of the channel 20 with a force F that is substantially perpendicular to the abutment surface 26.

In decorative links formed according to the prior art, it can be seen that, although these forces are not very great, these stresses can sometimes cause the base 27 of one of the decorative links 4 to break. In fact, some ceramic links are able to withstand these stresses well, while others break. A thorough study of this phenomenon has revealed that this is caused by the irregular shape of the faces 23 and 24 of the decorative links 4 due to the deformations associated with sintering. For example, if a longitudinal abutment force a is applied close to the side of the link 4, i.e. close to the side of the bracelet, the vertical abutment force acting on the central portion of the base 27 will exert a transverse bending stress F at the centre, which stress will cause the ceramic to break. This conclusion has been confirmed by the fact that: if the relevant parts of the front faces 23 and 24 are polished so that they can abut against each other over their entire width, the number of cracks of this type is greatly reduced. However, such machining of each decorative link can result in significant cost increases.

Fig. 4 to 6 show an example of the arrangement of decorative links 4 that makes it possible to avoid the drawbacks described above. The chain link is a monolithic element made of ceramic material, which is produced in a known manner by moulding and sintering, possibly followed by polishing. In order to allow the double chain 5 to pass, the tubular chain link has two longitudinal channels 20 separated by a central partition 28, the central partition 28 connecting the link base 27 to its upper wall 30 and having an end 29 at the bottom of the inlet space 22 to make the necessary space for the hinge. On either side of each channel 20, the bottom of the (entrance) space also has side shoulders 31 and a lower shoulder 32, against which the hinge can rest in the longitudinal direction.

The profile of the lower portion 23a, 24a of each front face 23, 24 is inclined towards the inside of the link from a horizontal line 23b, 24b at the location of the hinge axis, with respect to a plane perpendicular to the direction of the longitudinal channel 20, so that the hinge can be folded to a maximum angle without creating a great tension in the chain and without viewing the chain from above. On its lower portion 23a, the front face 23 has two projecting portions 34 of very thin thickness (less than 0.5mm, for example 0.08mm), each of which is located below the centre of one of the channels 20, i.e. in the same region of the width of the link 4 as the two inner faces 26. In this case, the width of each raised portion 34 is substantially the same as the width of the loop of chain 5 above it that rests on surface 26. But may of course be somewhat wider or narrower. The outer diameter of this ring may be slightly larger than the outer diameter of its adjacent ring in order to properly position the abutment of the chain in said area over the width of the chain link 4. To allow adjacent decorative links to abut across a certain width, each raised portion 34 is preferably rhombus-shaped with an inclined plane 35 for abutting against the substantially planar lower portion 24a of an adjacent link. The abutment force indicated by the arrow a in fig. 3 will thus be distributed in the width direction of each convex part and will have an upward vertical component which exactly balances the downward vertical force F in each region over the width of the link 4 on which the force F acts. Tests have shown that this prevents the cracking problem mentioned in the introduction.

Although the examples described herein indicate two raised portions on one of the faces of each decorative link, it will be appreciated by those skilled in the art that the present invention may also be extended to other numbers and/or arrangements of raised portions, particularly depending on the width and configuration of the chain links and decorative links. In particular, each face 23 and 24 may have an off-center convex portion thereon to abut the planar area of the face of an adjacent link. It should also be noted that the chain does not necessarily have to bear against the lower surface 26 of the ornamental link via the hinge 12, but may also pass through other parts of the metal link 11.

It should also be noted that decorative links according to the present invention may use flexible connectors instead of the hinge connectors formed by chains as mentioned herein.

Claims (11)

1. A chain link watch chain comprising a chain link chain (5) consisting of metal chain links connected in pairs by hinges and a plurality of tubular decorative chain links (4) passing through said chain and able to abut each other longitudinally on their respective faces, each decorative chain link (4) having at least one longitudinal channel (20) in which a metal chain link (11) and a hinge (12) connected to the metal chain link are housed and which, when in a folded position, can abut against the inner surface (26) of the lower wall (27) of the decorative chain link in the region of the hinge, characterized in that in the lower part (23a) of the first face (23) of each decorative chain link (4) there is at least one raised portion (34) in the same region of the width of the decorative chain link as the hinge (12) or the inner surface (26) against which the metal chain link abuts, the raised portion is arranged to abut an opposite second face (24) of an adjacent decorative link when the hinge is in the folded position.

2. Bracelet according to claim 1, characterized in that the lower portion (23a) of said first face (23) is inclined towards the inside of the decorative link with respect to a plane perpendicular to the direction of said longitudinal channel (20).

3. Bracelet according to claim 1, characterized in that the decorative link (4) comprises a space (22) associated with one or more of said channels (20) and arranged to receive the hinge (12).

4. Bracelet according to claim 3, characterized in that said first face (23) of the decorative link (4) is the face closest to said space (22).

5. Bracelet according to one of the preceding claims, characterized in that two similar raised portions (34) are provided on either side of said first front face.

6. Bracelet according to claim 1, characterized in that the lower portion (24a) of said second opposite face is substantially flat.

7. Bracelet according to claim 1, characterized in that it is a bracelet of a wristwatch.

8. A tubular decorative link (4) made of ceramic material and intended for a wristwatch, comprising at least one longitudinal channel (20) inside which a flexible or chain-link type connecting element is fitted resting on an inner surface (26) of a lower wall (27) of the decorative link, characterized in that, in a lower portion (23a) of at least one front face (23) of the decorative link, the decorative link has at least one raised portion (34) located in the same region of the width of the decorative link as said inner surface (26), said lower portion (23a) of the front face being inclined towards the inside of the decorative link with respect to a plane perpendicular to the direction of said longitudinal channel (20).

9. Decorative tubular chain link according to claim 8, characterized in that it has a space (22) associated with one or more of said channels (20) and arranged to receive the hinge (12) of a chain.

10. Decorative tubular chain link according to claim 9, characterized in that the front face (23) is the front face closest to the space (22).

11. Decorative tubular chain link according to claim 8, characterized in that the lower part (24a) of the other face (24) of the decorative tubular chain link is substantially flat.