EP3024351B1 - Method for fastening precious stones - Google Patents

Description

The invention relates to a method for attaching at least one gemstone to a shell made of a fusible material, wherein the shell has at least one recess in which the gemstone is arranged, wherein the gemstone touches the shell at least one point.

The secure attachment of gemstones to objects is a well-known problem to which there are already diverse solution ideas in the art. There are several points to consider. On the one hand, the attachment should be as cost-effective and automated as possible. On the other hand, the most varied forms and types of gemstones must be attachable.

The AT 338 020 describes a method for producing a gemstone composite, wherein the gems are arranged with their effect surface in a sieve and then a melting adhesive film is placed on the surface of the opposite surface of the effect. In an oven and with a device for generating negative pressure, the hot-melt adhesive film is melted to the setting surface of the gemstones. Subsequently, the film to which the gems are attached, glued in a heated to melting temperature of the film oven to a socket that has adapted for this purpose to the shape of the gems recesses.

FR 1 120 802 describes a method for attaching at least one gemstone to a shell of fusible material, wherein the gemstone contacts the shell at at least one location, wherein the gemstone is heated by a heat source until the shell transitions into an at least partially molten state at the point of contact so that a firm connection between gemstone and shell can be produced by cooling.

Another way to connect gemstones, especially with garments, is to place a heat activatable adhesive on a flat side of a gemstone. With their opposite side of the gemstones are arranged on a transfer film. By ironing, heat passes through the transfer film and the gemstone to the adhesive, which activates it and the gemstone is glued to the garment. Subsequently, the transfer film can be removed.

Disadvantages of this process are, on the one hand, the often insufficient stability of the adhesive bond and the problem that only gemstones with a specific shape can be used.

The object of the invention is to provide a method for attaching at least one gemstone to a shell made of fusible material available, which overcomes the said disadvantages and ensures an efficient and secure fastening for gems on or in a shell.

This is achieved by a method having the feature of claim 1.

By the shell, to which the at least one gemstone is attached, having at least one recess into which the gemstone is arranged for attachment to the shell, wherein the gemstone, when placed in the recess, contacts the shell at at least one location created an interface through which heat from the gemstone can be passed to the shell.

The term shell should be understood to mean an object with which at least partially a space is bounded. In particular, these include cases, e.g. for watches, mobile phones, MP3 players or other portable electronic devices, as well as retrofittable protective covers. Likewise, other containers in the broadest sense fall under this term, such as e.g. Cases, bags, cases or packaging containers, e.g. for cosmetics.

By suitable selection of a shell with a fusible material, the shell can thus be locally melted by heating the gem by means of a heat source in the region of contact by a correspondingly long and strong heating and pass in this area in a molten or molten state and thereby partially around the Deform the point of contact depending on the geometric shape of the gemstone. After deactivation or removal of the heat source, after reducing the heating power or after active cooling, the shell cools, whereby a connection with the gemstone is formed.

This type of connection in which the envelope medium is melted locally and deformed and redistributed according to the outer shape of the gemstone to be connected after cooling with the gemstone, ensures a fast and cost-effective method to selectively stones individually into a shell too integrate. The resulting compound is stronger than with an adhesive, whereby a shortened production time is made possible because no adhesive must be mixed and also no transfer sheets must be used as in the prior art. In addition, this process is also environmentally friendly, since no chemicals such as an adhesive must be used.

This type of connection is basically suitable for all types and shapes of gemstones. In particular, natural or synthetically produced jewelery and precious stones, such as e.g. Zirconia or glass-made gemstones (glass blocks) can be attached to a shell using this method.

By the method according to the invention, the brilliance of the gemstone is hardly or not at all influenced. In contrast to many methods of the prior art, the method according to the invention can also be used for gemstones without a mirror layer or without chemical mirroring and for gemstones without protective foils or vapor-deposited layers. However, the method is also suitable to attach gemstones with reflective coating, protective layers or films to a shell.

The heating of the gemstone heat distribution and heat conduction in the stone, whereby the shell is heated in the region of the contact point and thus in a local and defined area, while the shell material in this area above the melting point or depending on the nature of the shell material approximately to the melting point is brought and goes into a molten state. The method is particularly suitable for synthetic gemstones such as zirconia, since they are usually not steamed or provided with a protective film and are not attached by means of an adhesive to a shell.

However, the heating of the gem does not necessarily take place after the arrangement in the recess of the shell. It is also possible to heat the gem in advance, for example in an oven, and then bring it with a transfer device to the shell and then push it into the shell. The temperature of the gemstone during the transfer process and the arrangement in the shell must be above the melting temperature of the shell material.

A shell suitable for the method according to the invention consists, at least in the region of the recess, of a material having a lower melting temperature than the melting temperature of the gemstone or of the glass transition temperature in the case of a gemstone made of glass.

Glass stones are often coated with a protective film to protect the gemstone from damage. In this case, the temperature resistance of the protective film is often relevant, which is usually below the glass transition temperature. Thus, in this embodiment of the invention, the sheath material consists of a material having a lower melting temperature than the critical resistance temperature of the protective film, in the case of a gemstone made of glass, coated with such a protective film.

Further advantageous embodiments of the invention are defined in the dependent claims.

In one embodiment of the invention, the sheath, at least in the region of the recess of a fusible, preferably thermoplastic, plastic. These include, among others, all thermoplastics and their compositions such as e.g. Polycarbonates, polyolefins such as polypropylene, amorphous thermoplastics such as acrylonitrile-butadiene-styrene copolymers (ABS) and mixed variants of these substances. Polyurethanes and silicone-like plastics are less suitable as casing material. The shell can also consist of acetate in the region of the recess.

But it is also possible that the shell in the region of the recess consists of a metal and / or a metal alloy with a correspondingly low to medium melting point. A low melting point corresponds to a temperature of up to about 400 ° C. A mean melting point corresponds to a temperature of up to about 1100 ° C. For example, tin, zinc, lithium and their alloys, which have a low melting point, but also aluminum and noble metals such as gold or silver, which have an average melting point for the inventive method used.

Another advantage of the invention is that only small demands are placed on the shape of the recess. In one embodiment, the recess is formed as a through hole. In this case, the through hole over the depth of the shell may have constant dimensions, but it may also be provided to form the through hole as a two- or multi-stage wellbore. In another embodiment, the recess is formed as a cavity, whereby the sheath has higher overall stability.

If a gemstone having a tip is fixed to a shell by the method according to the invention, it may be provided to arrange the gemstone with the tip in the direction of the shell interior in the recess. In another embodiment, the gemstone is placed in the recess such that the tip faces outwardly from the interior of the sheath. In the latter case, the method results in a gemstone composite with an outwardly pointing tip.

In one embodiment of the method according to the invention, a shell is used in which the recess in which the gemstone is arranged has smaller cross-sectional dimensions than the gemstone in the region of its largest cross-sectional dimension. In this case, the gem is placed in the region of its largest cross-sectional dimension on the outer edge of the recess. At the points of contact, the shell material becomes molten during the heating of the gemstone and can be arranged around the area of the largest cross-sectional dimension of the gemstone, so that after solidification of the shell material a firm and permanent fit is formed around the gemstone.

The recess may e.g. have a circular cross-section. If the gem is a so-called chaton, which has a flat board on one side, while the other side converges to a point, there is almost a circular contact area when the gem is placed with the tip in the circular recess.

However, the gem does not necessarily have to be circular in plan view. With the method according to the invention, rectangular, triangular, oval, drop-shaped or similar shape having gems are used, provided that the recess in the shell has a similar cross-sectional shape.

During the heating of the gem stone heat is passed through the gemstone to the shell, making it molten. Due to gravity, the gemstone may continue to move towards the interior of the shell, redistributing the molten shell material. In a further embodiment of the method according to the invention, additional pressure is exerted on the gem, which is pressed in the direction of the interior of the shell in order to achieve the redistribution of the molten shell material. In this case, the recess in the shell must have corresponding dimensions to allow a displacement of the gemstone in the direction of the shell interior. If the gemstone has a region of the greatest cross-sectional extent, the gemstone can be pushed so far towards the interior of the shell until the region of the largest cross-sectional dimension is located inside the shell and, after curing of the shell material by a particularly firm and permanent fit around the area largest cross-section gemstone forms.

If a part of the gemstone protrudes from the shell after arrangement in the recess, the gemstone is located at the beginning of the heating process between the shell and the heat source. The gemstone is therefore heated from above.

In one embodiment of the method according to the invention, the gemstone is heated by contact with the heat source. In this case, the heat source may be formed so small that - in the case of the arrangement of several gems in the shell - is heated by the heat source only a single stone. Areas of the shell, where no gemstone is arranged, are not or only slightly heated. The heat source may also be configured to include a plurality of local heat sources, each heating a single gemstone. The heat emitted by the heat source is forwarded via the gemstone to the contact points of the shell.

As a heat source, for example, pin-shaped heat sources, eg heating pins or soldering iron, come with a suitable attachment, for example, with a flat end for use. Such heat sources are known per se in the prior art.

The method can be used to decorate a casing, in particular a casing, a case or a packaging container with at least one gemstone, which is attached to the casing by a method as described above. Examples of such cases are housings and protective covers for mobile phones, MP3 players, laptops, tablets, but also containers e.g. for cosmetic products.

It goes without saying that the invention can be used not only for the arrangement of a single gemstone in a recess of a shell, but also for a plurality of gemstones, which are arranged in each case a recess of a shell and ultimately secured.

Fig. 1a-1g

schematische Darstellungen der einzelnen Schritte einer Ausführungsform des erfindungsgemäßen Verfahrens, und

Fig. 2

eine Draufsicht auf einen Teil einer erfindungsgemäßen Hülle.

Further details and advantages of the present invention will be explained in more detail below with reference to the description of the figures with reference to the drawings. It shows:

Fig. 1a-1g

schematic representations of the individual steps of an embodiment of the method according to the invention, and

Fig. 2

a plan view of a part of a casing according to the invention.

In FIG. 1 a is a cross section through a shell 1, in which a recess 2 formed as a through hole is arranged.

In FIG. 1b is shown schematically how the gemstone 3 is arranged in the recess 2. The gemstone 3 is formed in this case as a chaton and has a tip 5, which points in the direction of the interior of the shell 1. The region of the largest cross-sectional dimension of the gem 3 is formed by a Rondiste 4. Just below the Rondiste the gemstone 3 is located on the outer edge of the recess 2 in the contact points 6. If the recess is designed as a slot, there is a contact point 6 on both sides of the recess 2. If the recess 2 has a circular cross-section, the result is approximately a continuous circular contact point 6.

In Figure 1c It is shown how the heat source 7 heats the gemstone 3. This heating can be done by direct contact with the gemstone 3. But it can Also be provided that the heat source 7, which is shown schematically in this figure, is arranged above the gemstone 3.

In Figure 1d is shown how the heat from the heat source 7 according to the arrows schematically shown by the gemstone 3 is forwarded to the shell 1 and therefore after a dependent of the shell material and the specific nature of the gemstone 3 duration and strength of heating to the contact points 6 a range. 9 is formed, in which the shell material is melted and therefore pasty or even molten.

In a further process step, which in Figure 1e is shown, after a molten or molten area 9 could form, pressure according to the arrow P exerted on the gemstone 3. Additionally or alternatively, it can also be provided that a suction device arranged below the casing sucks the gemstone 3 in the direction of the casing interior or a corresponding vacuum device is provided for this purpose.

As a result of the application of pressure, the gemstone 3 is pressed in the direction of the shell interior, wherein the Rondiste is moved down until it is disposed within the shell 1. In this case, the molten or molten casing material is redistributed until it forms a seat 10 around the Rondiste 4. After completion of the pressure application and removal of the heat source 7, the shell 1 cools and the gemstone 3 is held by the also cooled seat 10.

In principle, this method can be used when the gemstone 3 is heated to a higher temperature than the melting temperature of the shell 1. If the gemstone 3 is heated to a much higher temperature than the melting temperature of the shell 1, this causes a faster melting or melting of the shell 1 in the region of the contact points 6. Thus, the processing or setting time for a gemstone 3 can be shortened. This can be achieved, for example, by a high heat emission to the gemstone 3. It should be noted, however, that as a result of rapid heating of the gem 3 and the shell 1, a higher material displacement may occur, which may be disadvantages in terms of visual appearance after cooling the shell 1 can result. The temperature selection and the time for the heat release thus depend on it from which optical quality level is desired. As a general rule applies that at a low temperature, a visually very high quality appearance image is achieved, however, associated with a longer processing time, while at a high temperature, a not so high quality appearance can be achieved with a very short processing time.

The temperature selection and the time for the heat release depend, inter alia, on the thermal expansion of the gem 3, the size of the gem 3 and the material properties of the shell 1 and the size of the heat source 7, e.g. the size of the diameter of a heating pin, from.

By way of example, a few parameters in which the method according to the invention can be implemented are listed in the following table. Herein, the heating time and the temperature of the heat source 7 are indicated for various types of shell materials and 3 different types of gems 1. material Heating pin diameter Zirconia ø 2mm Glass jewelry stone PP14 Genuine topaz ø 2 mm temperature duration temperature duration temperature duration Polycarbonates (PC) 1 mm 750 ° C 3-10 sec 550 ° C 5-11 sec 700 ° C 3-10 sec Polyvinylchloride (PVC) 1 mm 750 ° C 4-11 sec 550 ° C 6-12 sec 700 ° C 4-11 sec Acrylic butadiene styrene (ABS) 1 mm 750 ° C 2-9 sec 550 ° C 4-10 sec 700 ° C 2-9 sec polymethyl methacrylates 1 mm 750 ° C 2-9 sec 550 ° C 4-10 sec 700 ° C 2-9 sec Polycarbonate / ABS Alloy 1 mm 750 ° C 3-10 sec 550 ° C 5-11 sec 700 ° C 3-10 sec Polypropylene homopolymer (PP) 1 mm 750 ° C 2-9 sec 550 ° C 4-10 sec 700 ° C 2-9 sec Acetate 1 mm 750 ° C 3-10 sec 550 ° C 5-11 sec 700 ° C 3-10 sec tin 1 mm 750 ° C 4-12 sec 550 ° C 6-13 sec 700 ° C 4-12 sec aluminum 1 mm 900 ° C 8-30 sec N / A* 900 ° C 8-30 sec zinc 1 mm 750 ° C 4-12 sec 550 ° C 6-13 sec 700 ° C 4-12 sec NA * = melting temperature of the shell material is higher than the resistance temperature of the glass-stone protective film

In Fig. 2 is a plan view of a portion of a casing 1 according to the invention shown, in which a total of seven gems 3 have been set with a method according to the invention in a shell 1. Visible is the circular seat 6, which has formed around the Rondiste 4 of the gems 3.

Claims (13)

1. A method of fastening at least one gemstone (3) to a case (1) of meltable material, wherein the gemstone (3) is in contact with the case (1) at at least one location (6), wherein the gemstone (3) is heated by a heat source (7) until the case (1) passes into an at least partially melted state in the region of the contact location (6) so that a fixed connection can be made between the gemstone (3) and the case (1) by cooling, characterised in that the case (1) has at least one opening (2) in which the gemstone (3) is arranged.
2. A method according to claim 1 wherein the case (1) to which the gemstone (3) is fastened comprises a meltable, preferably thermoplastic, plastic in the region of the opening (2).
3. A method according to claim 1 wherein the case (1) to which the gemstone (3) is fastened comprises a metal and/or a metallic alloy in the region of the opening (2).
4. A method according to one of claims 1 to 3 wherein the opening (2) in which the gemstone (3) is arranged is in the form of a through hole.
5. A method according to one of claims 1 to 3 wherein the opening (2) in which the gemstone (3) is arranged is in the form of a cavity.
6. A method according to one of claims 1 to 5 wherein the gemstone (3) which is fastened to the case (1) has a tip (5) and is so arranged in the opening (2) that the tip (5) faces from the outside of the case (1) in the direction of the interior of the case (1).
7. A method according to one of claims 1 to 5 wherein the gemstone (3) which is fastened to the case (1) has a tip (5) and is so arranged in the opening (2) that the tip (5) faces from the interior of the case (1) outwardly.
8. A method according to one of claims 1 to 7 wherein the gemstone (3) which is fastened to the case (1) is arranged in the region of its largest cross-sectional dimension on the outside edge of the opening (2) and wherein molten case material is arranged around the region of the largest cross-sectional dimension of the gemstone (3).
9. A method according to one of claims 1 to 8 wherein the gemstone (3) is pressed in the direction of the interior of the case (1) while the case (1) is molten in the region (9) of the contact location (6).
10. A method according to one of claims 1 to 9 wherein at the beginning of the heating operation the gemstone (3) is arranged between the case (1) and the heat source (7).
11. A method according to one of claims 1 to 10 wherein the gemstone (3) is heated by contact with the heat source (7).
12. A method according to one of claims 1 to 11 wherein the largest cross-sectional dimension is arranged beneath the outside surface of the case (1) after the case (1) cools down.
13. A method according to one of claims 1 to 12 wherein the gemstone projects above the outside surface of the case (1) after the case (1) cools down.

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