METHOD AND DEVICE FOR ELECTRONICALLY PROTECTING ITEMS AGAINST THEFT

The invention relates to a method and device for electronically protecting items against theft. Said device consists of a security element which is integrated into the item and is excited within a given security area by an interrogation field of a transmitting device to generate a characteristic signal, wherein a receiver device triggers an alarm upon recognition of the characteristic signal. The invention has the aim of providing a method and a device enabling protection of the supply of items made from varying materials. This is done by providing a shape-retaining security element and/or a shape-retaining security element enclosed by shape-retaining casing, and by embedding or integrating said device in the item during manufacturing.

FIG. 1 shows a perspective view of a security element 1 according to the invention. The security element 1 is a strip element 2 , which to improve its stability is provided with a casing 3 . The casing 3 is preferably plastic, which is applied around the strip element 2 in the extrusion process and subsequently encases it entirely. By means of the casing 3 , shape retention of the security element 2 is attained that allows it to be integrated without problems into further processing processes. FIG. 2 shows a plan view on a deactivatable strip element 2 . The strip element 2 comprises a strip of soft magnetic material 4 , on which segments of semihard magnetic or hard magnetic material 5 are disposed. The production materials for the strip elements 2 are relatively expensive. They are therefore made as thin and narrow as absolutely possible. Consequently, in terms of their consistency they can be compared with laminations. Such materials with little shape retentions are difficult to process further; this is true for their inclusion in either automated or manual production processes. This disadvantage can be effectively eliminated by the casing 3 . FIGS. 3 a and 3 b show longitudinal sections through embodiments of an injection molding device 6 for performing the method of the invention. Both embodiments are excellently suited to dividing up strip elements 2 , present in the form of band materials, into individual strip elements 2 and integrating them into the items 14 . The basic design of both injection molding devices 6 is the same. An injection molding device 6 comprises a cylinder 9 , which is supplied via a funnel 7 with raw material 8 . The raw material 8 is melted in the cylinder 9 via heating plates 10 , moved via the worm 11 in the direction of the outlet nozzle 12 , and placed in the injection mold 13 as soon as the injection mold is closed. The device shown in FIG. 3 a functions in detail as follows: From the storage roll 30 , the desired length of one security element 1 (strip element 2 ) is unwound. Since the security element 1 is magnetic, it is held in the desired position inside the injection mold 13 by the magnet 29 . Upon closure of the injection mold 13 , a cutting device 31 is actuated, which severs the strip element 2 in the end region of the injection mold 13 . If the security elements 1 are not strip elements 1 but arbitrary other elements, then once again they are placed individually by a delivery device 27 into the injection mold 13 and held in the desired position by a magnet. The delivery device 28 shown in FIG. 3 b for the security elements 1 —in particular, this device 28 again serves to deliver strip elements 2 present in the form of band material—functions as follows: The delivery device 27 is driven into the opened injection mold 13 and pushes the free end of the band material into the opening of the core puller 28 ; the core puller 28 firmly holds the strip element 2 . A cutting device 31 is integrated with the delivery device 27 and cuts off a portion from the band material that corresponds to the desired length of the strip element 2 . The delivery device 27 is then moved out of the injection mold 13 , the injection mold 13 is closed, and the flowable raw material 8 is placed in the injection mold 13 . After hardening has occurred, the core puller 28 is retracted from the finished item 14 . Once again, the strip element 2 is firmly integrated with the item 14 to be secured. FIG. 4 shows a cross section through a first integrally secured item 14 , which has been produced by the injection molding process. In the instance shown, a strip element 2 with casing 3 is integrated into the item. As already noted, a variant of the method of the invention for producing a device for electronically protecting items proposes that the strip element 2 , which has a casing 3 , be introduced during the assembly process of the item 14 into a fitting part of the item 14 . This variant can be seen in FIG. 5 . The opening 20 for receiving the security element 1 here is already originally present in the item 14 . What is shown here is in particular an applicator for cosmetic products, such as nail polish. A brush 16 is mounted on one end of the shaft 18 , which is hollow on the inside; the strip element 2 , carrying a casing 3 , is then introduced into the hollow shaft 18 ; next, the still-open end of the shaft 18 is closed by means of the cap piece 17 . The applicator is placed in a nail polish bottle, which is closed by means of the cap piece 17 . The cosmetic product is subsequently integrally protected against any kind of improper manipulation. FIG. 6 shows a cross section through a third integrally secured item 14 . A bore 19 is made in the item 14 , and the security element 1 is introduced into the bore. The bore 19 is subsequently sealed off from the outside. In FIGS. 7 and 8 , two further features of the security elements 1 can be seen in exploded views. Once again, these can be integrated in the manner described above with the items 14 to be protected. As already described for the case of the strip element 2 , both the resonant frequency security element 24 ( FIG. 4 ) and the magnetoacoustic security element 25 ( FIG. 8 ) can be provided with a sheath or casing 3 before they are introduced into the item 14 and joined inseparably to it. It should be noted here that the adhesive 26 used to join the individual parts of the security elements 24 , 25 together has a melting temperature which is above the temperatures that occur in the extrusion process or the injection molding process. n. 9 shows a plan view on a CD (compact disc) 14 secured by means of a CD ring 22 . The CD ring 22 is a ring of so-called thin-film material 21 . Thin-film material 21 is presented in detail in EP 0 295 028 B1. During the manufacture of the basic body of the cd 14 , the cd ring 22 of thin-film material 21 is placed around the center opening 23 of the cd 14 —which is preferably again done with the aid of a magnet 29 —and embedded into the plastic material. After that, the security element 1 is again inseparably joined to the item 14 . 1 List of Reference Numerals 1 Security element 2 Strip element 3 Casing 4 Soft magnetic material 5 Semihard magnetic or hard magnetic material 6 Injection molding device 7 Funnel 8 Raw material 9 Cylinder 10 Heating strip 11 Worm 12 Outlet nozzle 13 Injection mold 14 Item 15 Applicator 16 Brush 17 Closure cap 18 Shaft 19 Bore 20 Opening 21 Thin-film material 22 CD ring 23 Center opening 24 Resonant frequency security element 25 Magnetoacoustic security element 26 Adhesive 27 Delivery device 28 Core puller 29 Cutting device 30 Storage roll 31 Magnet