This application claims priority from European Patent Application No. 04006894.2 filed Mar. 23, 2004, the entire disclosure of which is incorporated herein by reference.
The present invention relates to a linked bracelet, in particular for a watch, comprising a linked chain composed of metal links joined in twos by hinges and a series of ornamental tubular links threaded onto said chain and able to rest longitudinally one against the other at their respective front faces, each ornamental link having at least one longitudinal passage, in which a metal link and a hinge associated with it are housed and can rest against an inside surface of a lower wall of the ornamental link in the region of the hinge, when the hinge is in a folded position. The invention also relates to an ornamental link that may be used in such a bracelet.
Watch bracelets of this type are described in particular in patent publications CH 684 988, EP 549 979 and EP 1 136 011, and their ornamental links are preferably made from a hard ceramic material, and are therefore scratch-resistant and can have an attractive shiny appearance for a great number of years. However, a disadvantage of these materials is that they are somewhat fragile and are less resistant than metal materials to tensile and bending stresses. In some circumstances, the linked chain passing through the tubular ornamental links can exert stresses of this type on some of these can cause one of their walls to break, thus requiring the broken link to be replaced. Incidents of this type are very annoying when top of the range articles are concerned. As bracelets are articles, in which appearance plays a significant role, these links cannot always be reinforced by a significant increase in the thickness of their walls. Therefore, there is a need to remedy this situation by at least partially using other means.
The present invention is based upon the idea that the above-mentioned fractures of ceramic links can result from parasitic bending stresses produced in a transverse direction by the hinge resting on the base of the link, when the abutment zones of the front surfaces of two successive links are at a relatively large lateral distance from the abutment zone of the hinge, as shall be explained in detail below with reference to the drawings. Therefore, the principle of the solution provided in this invention is to arrange the mutually opposite front faces of the ornamental links in such a way that their abutment zones are positioned as closely as possible to each zone, where the hinge rests on the base of the link.
More particularly, according to a first aspect of the invention a bracelet of the type mentioned above in the introduction is provided, which is characterised in that in its lower section a front face of each ornamental link has at least one raised section located in the same region of the width of the ornamental link as said inside surface where the hinge or the metal link rests, this raised section being arranged to abut against an opposite front face of the adjacent ornamental link when the hinge is in said folded position. Thus, even if said opposite front face is simply flat or slightly curved, the abutment stress between two successive links still occurs in one zone or some well defined zones which are not shifted laterally in relation to the regions of the ornamental link, on which the chain rests. This results in a substantial suppression or reduction of the bending stresses in the transverse direction of the ornamental link.
According to another aspect of the invention, a tubular ornamental link made of ceramic material is provided for a bracelet comprising at least one longitudinal passage, in which a flexible or linked connection is housed and can rest against an inside surface of a lower wall of the ornamental link, characterised in that in a lower section of at least one of its front faces, it has at least one raised section located in the same region of the width of the ornamental link as said inside surface where the connection abuts, said lower section of the front face being inclined towards the inside of the link in relation to a plane perpendicular to the direction of said longitudinal passage.
Other characteristics and advantages of this invention will be seen in the description of a preferred embodiment provided below by way of non-restrictive example with reference to the attached drawings.
The watch bracelet 1 shown in
As will be seen in more detail in
The bracelet can have a curved configuration as a result of the angular clearance of the hinges 12 of the chain. This angular clearance is limited to the folded position shown in
In the ornamental links formed according to the prior art, it is seen that these stresses sometimes cause the base 27 of one of the ornamental links 4 to break open, even though the forces in question are not very high. In fact, some ceramic links withstand these stresses perfectly, while others break. A thorough study of this phenomenon has shown that this is attributable to irregularities in shape of the front faces 23 and 24 of the ornamental links 4 as a result of deformations associated with sintering. If longitudinal abutment forces A are exerted, for example, close to the side faces of the links 4, i.e. close to the flanks of the bracelet, the vertical abutment force F acting on the central section of the base 27 exerts a transverse bending stress F on this, which can cause the ceramic to fracture. This conclusion has been confirmed by the fact that the number of fractures of this type is greatly reduced if the sections concerned of the front surfaces 23 and 24 are precision-ground so that they can abut against one another over their entire width. However, such machining of each ornamental link greatly increases the cost.
The lower section 23a, 24a of each front face 23, 24 has a profile inclined towards the inside of the link in relation to a plane perpendicular to the direction of the longitudinal passage 20 from a horizontal line 23b, 24b located at the level of the axis of the hinge to allow the hinge to fold as far as an end angle without causing substantial tension in the chain and without the chain becoming visible from above. On its lower section 23a, the front face 23 has two raised sections 34 of low thickness (less than 0.5 mm, e.g. 0.08 mm) each located below the centre of one of the passages 20, i.e. in the same regions of the width of the link 4 as the two inside surfaces 26 described above. In this example, each raised section 34 has a width essentially equal to that of the ring of the chain 5 resting on the surface 26 above it, but it could, of course, be slightly wider or narrower. This ring can be provided with an outside diameter that is slightly larger than that of the rings lying adjacent to it in order to properly position the abutment of the chain in said regions of the width of the link 4. For the abutment of the adjacent ornamental link on a certain width, each raised section 34 preferably has a prism shape, which has an inclined flat surface 35 intended to rest against the essentially flat lower section 24a of the adjacent link. Thus, the abutment force shown by arrow A in
Although the example described here refers to two raised sections on one of the front faces of each ornamental link, a person skilled in the art will understand that the invention also extends to other numbers and/or arrangements of the raised sections, in particular depending on the width and configuration of the links of the chain and the ornamental links. In particular, an out-of-centre raised section can be provided on each front surface 23 and 24 to rest against a flat zone of the front surface of the adjacent link. It should also be noted that the abutment of the chain on the lower surface 26 of the ornamental link does not necessarily occur via the hinge 12, but can also occur via another section of the metal link 11.
It should also be noted that ornamental links according to the invention can be used with a flexible connection instead of the hinged connection formed by the chain mentioned here.
Number | Date | Country | Kind |
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04006894 | Mar 2004 | EP | regional |
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1357139 | Bayardi | Oct 1920 | A |
4840044 | Scholpp | Jun 1989 | A |
4930304 | Meister | Jun 1990 | A |
5347498 | Loth et al. | Sep 1994 | A |
5365753 | Carrola | Nov 1994 | A |
6345492 | Luscher et al. | Feb 2002 | B1 |
6714400 | Guerry et al. | Mar 2004 | B1 |
Number | Date | Country |
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684 988 | Feb 1995 | CH |
549 979 | Jul 1993 | EP |
1 136 011 | Sep 2001 | EP |
Number | Date | Country | |
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20050210857 A1 | Sep 2005 | US |