CH720121A2 - Bracelet strand with optical effect. - Google Patents

Abstract

The invention relates to a strand of bracelet (1) made of transparent or translucent elastomeric material, comprising a first end (10) capable of connecting with a watch case, characterized in that it comprises a rigid insert (2) having a solid part (20) forming a reinforcement, and a hollow part (21) arranged to receive a fluid (3) and solid elements (4) dispersed in the fluid, said hollow part being located in the center of the solid part, and in what the insert (2) is coated in the transparent elastomer, and is positioned at the first end (10) suitable for connection with a watch case. The invention also relates to a method of manufacturing such a bracelet strand.

Description

Technical field of the invention

[0001] The invention relates to a watch strap with an optical effect.

[0002] The invention also relates to a method of producing a watch strap with an optical effect.

Technology background

[0003] Traditionally, watch straps are made of leather, synthetic material, fabric, rubbery material, or metal. The bracelets also include an insert disposed in a lining or a sheath or between an upper band and a lower band subsequently joined together. This insert has a mainly mechanical and flexible function.

[0004] In the case of a rubber strap, it is common to use an insert made of mechanically resistant rigid material. This insert can in particular be produced via injection using a thermoplastic material of the polyamide type alone or filled (carbon fibers, glass fibers, etc.). Once the insert has been made, it is placed in the mold and the rest of the strand made of rubber is overmolded (by injection or compression) around it.

[0005] Currently, optical or decorative effects can be added to the bracelet, but we note that their integration is difficult to guarantee sufficient protection against different environmental conditions, shocks or even abrasion when wearing the watch.

[0006] We can cite in this respect patent application EP 0 373 806, which describes a watch bracelet. The bracelet includes a transparent plastic pocket filled with a liquid and particles, the pocket receiving between a lower part and an upper part of the bracelet and being visible through an opening in the upper part. However, it does not provide sufficient protection of the pocket against environmental conditions and shock or abrasion, which constitutes a disadvantage. In addition, the general thickness of such a bracelet is often too great and the pocket remains visible, which also harms the aesthetics of the bracelet.

Summary of the invention

[0007] The invention aims in particular to overcome the various disadvantages of bracelets of the prior art.

[0008] More precisely, an objective of the invention is to provide a strand of bracelet with an optical effect having a controlled thickness while guaranteeing good protection of the optical effect.

[0009] For this purpose, the invention relates to a strand of bracelet made of elastomeric material, comprising a first end capable of connecting with a watch case, characterized in that it comprises a rigid insert having a solid part forming a reinforcement , and a hollow part arranged to receive a fluid and solid elements dispersed in the fluid, said hollow part being in the center of the solid part, and in that the insert is coated in a transparent elastomer forming the bracelet strand, said insert being positioned at the first end suitable for connection with a watch case.

[0010] In accordance with other advantageous variants of the invention: – the particles have a density greater than that of the fluid; – the fluid is chosen from: an aqueous solution or a vegetable or mineral oil;

Brief description of the figures

[0011] Other characteristics and advantages of the invention will appear on reading the following detailed description given by way of non-limiting example, with reference to the appended drawings in which: - Figure 1 represents a sectional view according to a median plane in the length direction of a strand of bracelet according to the invention; – Figure 2 shows a sectional view seen in section along a median plane in the direction of the height of a bracelet strand according to the invention; – Figure 3 shows a top view of a bracelet strand according to the invention.

Detailed description of the invention

[0012] With reference to Figure 1, one of the two flexible strands of a watch strap is shown, which together form a watch strap and which each carry an insert 2.

The watch strap strand 1 has a first end 10 able to receive an attachment bar and to be attached to a watch case by means of this attachment bar. The bracelet strand 1 is pierced with holes 11 succeeding one another over part of its length, each of the holes 11 being provided for the passage of a member of a buckle or a pin making it possible to attach the watch strap strand 1 to the other strand of watch strap and thus close the watch strap, for example around a wrist.

The watch strap strand 1 is in the form of a flexible strip of elastomeric material and comprises an insert 2 on which the strip of flexible material is overmolded.

The elastomer forming the bracelet strand is elastically compressible and does not lend itself well to attachment to the watch case, an insert 2 is therefore integrated by overmolding at the first end of the strand 1 which is intended to be connected to the watch box.

[0016] According to the invention, the first end 10 suitable for connection with a watch case comprises a rigid insert 2 forming a reinforcement and increasing the rigidity of the strand near the watch case.

The insert 2 comprises a solid part 20 and a hollow part 21 formed in the center of the solid part and arranged to receive a fluid 3 as well as solid elements 4 dispersed in the fluid.

Advantageously, the solid elements 4 have a density greater than the liquid in which they are located in order to allow them to flow when the bracelet strand is moved or agitated.

[0019] The solid elements 4 are chosen from: 2D or 3D metallic particles, phosphorescent particles, microbeads, flakes, strips, etc.

[0020] Fluid 3 is chosen from: water, oil, etc. and can be colorless or colored. Obviously, the fluid must be transparent or translucent in order to reveal the solid elements.

[0021] According to a preferred embodiment of the invention, the insert 2 is coated in a transparent elastomer forming the bracelet strand 1 to be able to observe the hollow part receiving the fluid and the solid elements dispersed in the fluid. The elastomer is intended to be transparent or translucent, and is made from crosslinked materials of the FKM type or even silicone but also from non-crosslinked materials of the elastomeric thermoplastic type such as TPE-U or TPE-S.

[0022] Depending on the needs of those skilled in the art, the hollow part 21 is in the form of a logo, a letter, a number or even a pattern.

[0023] According to another embodiment of the invention, the insert 2 is coated in an opaque elastomer forming the bracelet strand 1, the bracelet strand comprising an opening 23 or a recess of material up to the insert 2 to be able to observe the hollow part receiving the fluid and the solid elements dispersed in the fluid.

[0024] According to yet another embodiment, the insert 2 has a logo, a letter, a number or a pattern formed in positive relief housing in a corresponding opening of the bracelet strand and forming the hollow part of the insert.

This insert 2 is made of a non-compressible material such as a thermoplastic. In this example, the insert 2 is in the form of a parallelepiped element. The insert thus makes it possible to make the end in connection with the watch case extremely rigid.

Advantageously, the insert is made from a transparent, amorphous or very low crystallinity polymer of the type PEF, PET, polycarbonate, polyamide or even polymethyl methacrylate, epoxy or PUR.

[0027] The insert is produced via molding, 3D printing or even machining.

[0028] The insert has mechanical resistance with a Young's modulus greater than 1GPa in order to be able to withstand the tensile/twisting/flexing stresses of the bracelet during its installation and use.

[0029] According to one embodiment of the invention, the insert is reinforced with a metal blade 5 at the first end of the strand 1 which is intended to be connected to the watch case in order to ensure good tensile strength and traction/twisting of the bracelet, the metal blade 5 being arranged to be in contact with the watch case when the bracelet strand is attached to the latter.

[0030] In order to be able to fill the hollow part of the insert 2, the latter comprises a channel 22 opening onto the hollow part to fill the latter, the fluid and solid element mixture being injected into the hollow part by means of a syringe for example.

[0031] The connection between the bracelet strand 1 and the insert 2 can be improved by an adhesion agent or mechanical gripping elements, and thus avoid detachment of the insert during overmolding and repeated bending of the bracelet strand when used. Different adhesion agents can be used depending on the pair of materials used.

[0032] According to a second embodiment of the invention, the insert is in the form of two shells arranged to be assembled by means of a joint, welding or glue, each shell comprising a cavity forming the hollow part.

[0033] The invention also relates to a method of manufacturing a bracelet strand provided with an insert.

[0034] The method of manufacturing a bracelet strand comprises the following steps: a) providing a transparent insert comprising a hollow part; b) obtain a fluid and add solid elements to it to form a solution with suspended particles; c) inject the solution obtained into the insert via a channel opening into the hollow part; d) seal the channel; e) overmolding a transparent or translucent elastomeric material onto the insert to form a bracelet strand, then vulcanizing or “cooking” the overmolded material until a flexible strand of elastomeric material is obtained comprising an insert with a hollow part so as to so that the solution with the particles in suspension is visible from outside the bracelet strand.

[0035] The invention also relates to a watch comprising at least one strand of bracelet according to the invention.

[0036] Thanks to these different aspects of the invention, we have a bracelet strand having an optical effect with good mechanical resistance.

Of course, the present invention is not limited to the example illustrated and is susceptible to various variants and modifications which will appear to those skilled in the art, without departing from the scope of the invention as defined by the claims.

Claims (11)

1. Bracelet strand (1) made of transparent or translucent elastomeric material, comprising a first end (10) suitable for connection with a watch case, characterized in that it comprises a rigid insert (2) having a solid part ( 20) forming a reinforcement, and a hollow part (21) arranged to receive a fluid (3) and solid elements (4) dispersed in the fluid, said hollow part being located in the center of the solid part, and in that the The insert (2) is coated in the transparent elastomer, and is positioned at the first end (10) suitable for connection with a watch case. 2. Bracelet strand (1) according to claim 1, characterized in that the particles have a density greater than that of the fluid. 3. Bracelet strand (1) according to claim 1 or 2, in which the fluid is chosen from: an aqueous solution or a mineral or vegetable oil. 4. Bracelet strand (1) according to one of claims 1 to 3, in which the solid elements are chosen from: metal particles, phosphorescent particles, beads, flakes, strips, etc. 5. Bracelet strand (1) according to one of claims 1 to 4, characterized in that the insert is made from a transparent, amorphous or very low crystallinity polymer. 6. Bracelet strand (1) according to one of claims 1 to 5, characterized in that the insert has a mechanical resistance with a Young's modulus greater than 1 GPa. 7. Bracelet strand (1) according to one of claims 1 to 6, characterized in that it comprises a metal blade arranged to be in contact with the watch case. 8. Bracelet strand (1) according to one of claims 1 to 7, characterized in that the hollow part is in the form of a logo, a letter, a number or a pattern. 9. Bracelet strand (1) according to one of claims 1 to 8, characterized in that the insert comprises two shells, each shell comprising a cavity forming the hollow part. 10. Bracelet strand (1) according to one of claims 1 to 9, characterized in that the insert (2) comprises a channel (22) opening onto the hollow part (21) to fill the latter. 11. Method for manufacturing a bracelet strand according to one of claims 1 to 10, characterized in that it comprises the following steps: a) provide yourself with a transparent insert comprising a hollow part; b) obtain a fluid and add solid elements to it to form a solution with suspended particles; c) inject the solution obtained into the insert via a channel opening into the hollow part; d) seal the channel; e) overmolding a transparent or translucent elastomeric material onto the insert to form a bracelet strand, then vulcanizing or “cooking” the overmolded material until a flexible strand of elastomeric material is obtained comprising an insert with a hollow part so as to so that the solution with the particles in suspension is visible from outside the bracelet strand.