Electric fence security device

p0001The present invention relates to electrical network security devices in water, to detect attempts to break through a wall or in a chamber provided with said safety device.

p0002Following the increase in crime and theft and break-ins, we had to develop the means to reliably detect the tampering or attempted unauthorized penetration through a wall or in a secure enclosure.

p0003We developed such devices for example in the field of transport funds, designing pregnant or CIT bags whose walls are provided with a grid safety device in water, embedded in the wall of the pregnant or funds carrying case, and associated with an electronic control device which generates a signal in case of deterioration of the electrical network tablecloth. This signal is then used to trigger a destructive device that destroys the contents of the enclosure or funds carrying case, for example by projecting a liquid or a gas marker that marks the banknotes to make them unusable.

p0004Such a device is thus likely to deter thieves, who are no longer any interest in capturing the capital carrying case, to the extent that they then can not open or cut without destroying the contents of the suitcase.

p0005Document US 6,215,397 B1 proposes a laminated structure made of a single thread arranged in network and took double as a stretch and a return stretch, both ends of the thread being connected to two inputs of an electronic device control adapted to detect the rupture of the thread.

p0006DE 28 56 819 A1 proposes to make it more difficult to achieve a bridge for a break, multiply son conductors forming a composite wire with two security son embedded in an insulator around which layer son reinforcing themselves are surrounded by an insulating coating.

p0007The DE 30 06 999 A1 proposes, for the same reason, to use a composite yarn comprising at its center two round trips a common thread, coated in a layer of insulation, with also other son and a final insulating layer.

p0008FR 2564681 A1 proposes, for the same reason, to use a composite yarn comprising a central conductive core surrounded by an insulating sheath itself surrounded by six drivers and contiguous strands.

p0009For such a safety device works and gives the expected effect of deterrence, it must be really impossible to open or cut the bag having previously destroyed, inhibited or neutralized the destructive device.

p0010This requires make impossible any attempt to drill the wall by a sharp tool or partial cut by a cutting tool, a disc. It should also prevent the possibility to destroy or neutralize destructive devices by a violent attack such as an ax, a guillotine, a gun shot. It should also prevent any attempt to penetration by heat fusion. It should also make unenforceable any fresh aggression and intelligent such as local melting of the insulation of electrical son for electrical bypass which then allows impunity pierce a wall portion between the branch points to destroy or neutralize the then destruction device.

p0011So far, power grids ribbon incorporated into a wall to be secured, as described in the documents cited above are associated with an electronic control device which detects the breakage of the wire constituting the electric network web. But it remains possible, with such a provision, melting or gently use the material in the vicinity of two remote areas of the electrical conductor to expose two corresponding sections of the driver, and then establish, by welding an outer conductor , an electrical lead which then inhibits all the lead portion between the two branch points. It is then easy to break through the wall in the area and concealed, without triggering the destruction device. Once pierced, the wall enables to introduce a means which neutralises the destruction device, for example a curable foam which then prevents the spread of the liquid or of the tracer gas and the wall or enclosure may then be opened by any means.

p0012The problem addressed by the present invention is to design a new security device structure grid ribbon that makes impossible any attempt to inhibition of a web area, so as to reliably detect intrusion attempts in a wall provided with such a device.

p0013In particular, the invention aims to prevent any possibility of establishing an electrical shunt between two successive zones of an electrical circuit ribbon.

p0014Another object of the invention is to design such a device structure which is relatively simple to manufacture, to be produced at a reasonable cost.

p0015Another object of the invention is to design a device that is used according to all forms usually necessary for the walls or safety cabinet, that is to say, shapes that may be flat, but also forms angulated with relatively small radii of curvature.

p0016To achieve these objects and others, the invention provides a security device for detecting unauthorized intrusion attempts through a wall, comprising at least one composite arranged sheathed wire in an electrical network web which develops according the whole extent of the wall with elementary intervening gaps below a certain minimum surface and which is electrically connected to a control electronic device which produces an output signal in case of failure of the electrical network; according to the invention, the composite covered wire comprises at least two elementary electrical son isolated from each other by an insulating means and assembled with each other into a composite yarn itself wrapped; the composite yarn is held mechanically in place in the wall by mechanical means; each of the two insulated electrical elementary son is individually connected to a respective pair of inputs of the electronic control device, itself adapted to detect both the failure of one at least of the elementary electric son that the setting of mutual contact at least two elementary electric son with each other, and producing said output signal in the event of such detection of breakage or mutual contact.

p0017Thanks to the presence of at least two elementary electrical son assembled to one another into a composite clad wire, it becomes very difficult to isolate one of the elementary electric son without deteriorating the other elementary wire, for then return to the same elementary wire in another area to perform an electrical bypass, and make this derivation by welding without damaging the other elementary wire.

p0018According to one embodiment, in the composite yarn, the elementary electric son can be assembled so as to be parallel along their length.

p0019Preferably, in the composite yarn, the elementary electric son can be assembled twisted along their length.

p0020According to an advantageous embodiment, the insulating means of the elementary electric son may be a covering, that is to say a double-pitch helical winding of a reversed silk, cotton, nylon or other suitable material having properties electrical insulation. In this way, the insulation is obtained by providing the wire flexible, so that the device is adapted to be shaped according to the most various shapes to follow the contours of the speakers to be secured.

p0021The mechanical means of the composite yarn may include non-extendable flexible lateral connection means. It must indeed prevent any attempt spacing of two successive zones of the composite yarn, which spacing then allow a bore in the wall by a piercing tool. And should preferably allow the deformation by bending of the sheet to follow all types of wall contours.

p0022According to an advantageous embodiment, the lateral connection means may include son or warp tapes of thermoformable material. This gives the device, by a thermoforming operation, inappropriate planar shape for setting into an injection mold for plastics.

p0023Preferably, the lateral connecting means has a melting temperature higher than the melting temperature of the insulating medium of the elementary electric son. Thus, any attempt to fresh aggression by localized melting of a grid area in water, and / or any attempt to weld on an elementary wire leads to the fusion of the insulating medium between elementary electrical son, and causes the intrusion detection and the triggering of the device.

p0024Preferably, according to the invention, the composite yarn is arranged in an arrangement in back and forth parallel strands weaving type, associated with son or warp tapes which provide the lateral connection of the strands.

p0025But we can also, according to the invention, arranging the composite wire mesh provision, buckles or buttons, type knitting or crocheting.

p0026It is understood that the elementary electrical son may advantageously have a small diameter, which further complicates attempts to break. Indeed, basic electrical son of small diameter are particularly fragile and tend to break by triggering the device to any attempted burglary.

p0027The diameter of the elementary electric son may advantageously be between about 0.04 millimeters and about 0.20 millimeters. A good compromise can be achieved with an approximately 0.07 mm diameter wire.

p0028Similarly, elementary intermediate space between the elementary electrical son must be low enough to prohibit drilling a hole used for the injection of a neutralizing product, and we can choose a center distance of about ten times the diameter of elementary electrical son, that is to say between about 0.04 centimeters and 0.1 centimeters, preferably about 0.07 centimeters to about a 0.07 mm diameter wire.

p0029It is advantageous to prevent the grid ribbon directly visible. For this purpose, may advantageously incorporate the electrical network web by overmoulding in the opaque synthetic foam.

p0030The electronic control device may comprise, for detecting the breakdown of at least one elementary electrical son and / or mutually contacting at least two of the elementary electrical son with one another:<ul><li>means for measuring the impedance of each unitary elementary electrical son,</li><li>means for measuring the mutual impedance between the elementary electric son,</li><li>means for comparing said unit and mutual impedances measured at a threshold of maximum unit impedance and a minimum mutual impedance threshold, and producing said output signal in case of exceeding at least one of said impedances measured against said thresholds.</li></ul>

p0031The invention also provides the use of such a safety device as defined above, such as intrusion detection means through a wall or in an enclosure.

p0032According to another aspect, the invention provides a wall or security enclosure comprising at least a safety device as defined above. a wall or enclosure may in particular provide with an electric network ribbon as defined above, or with a plurality of electrical networks in bunk tablecloth.

p0033Preferably, in the wall or safety cabinet, the electric network web of the security device will be integrated in a layer of synthetic foam, which may be associated with at least one rigid inner layer. The rigid inner layer may have an uneven shape, while the electric network web can follow only approximate the contour of the rigid inner layer, the connection of the one and the other being provided by the synthetic foam layer. This facilitates securing speaker whose walls have internal shapes very eventful.

p0034According to another aspect, the invention provides a method of manufacturing a wall or a safety enclosure provided with at least one electrical network security device ribbon as defined above, the method comprising a step thermoforming power grid tablecloth. Thermoforming facilitates the subsequent assembly steps by overmolding.

p0035Other objects, features and advantages of the present invention appear from the following description of particular embodiments, given with reference to the appended figures, in which:<ul><li>Figure 1 is a schematic view of a security device according to an embodiment of the present invention;</li><li>Figure 2 is a schematic perspective view of a composite yarn according to one embodiment of the invention;</li><li>Figure 3 is a schematic perspective view of a composite yarn according to a second embodiment of the invention;</li><li>Figure 4 is a schematic perspective view of a composite wire according to a third embodiment of the present invention;</li><li>Figure 5 is a schematic view illustrating an electronic control device according to an embodiment of the invention;</li><li>6 illustrates a grid of surface structure according to one embodiment woven according to the invention;</li><li>7 illustrates a grid fabric according knitted embodiment of the present invention;</li><li>Figure 8 is a sectional view of a speaker enclosure or part incorporating a safety device according to the present invention; and</li><li>Figure 9 is a partial view on a larger scale of detail A of Figure 8.</li></ul>

p0036In the embodiment illustrated in Figure 1 a according to the invention the safety device comprises an electrical network 1 in ply electrically connected to an electronic control device 2 adapted to generate an output signal at an output 3 for failure electrical network 1.

p0037The power grid 1 comprises at least two elementary electrical son 4 and 5, insulated from each other by an insulating medium and assembled with each other into a composite wire 6.

p0038The composite wire 6 is held mechanically in sheet form by mechanical holding means 7, and is arranged to cover the required area, that is to say the surface of a wall that one wants to secure, with elemental intervening gaps 8 of size less than a predetermined minimum area.

p0039Elemental electric wire 4 is connected individually to a respective pair of inputs 2a and 2b of the electronic control device 2. Also, the elementary wire 5 is connected individually to a respective pair of inputs 2c and 2d of the electronic device 2 control.

p0040The 2 electronic control device itself is adapted to detect both the rupture of at least one elementary electrical son 4 or 5 that the mutual contacting of two basic electrical son 4 and 5 the with each other, and to produce said output signal at the output 3 in the event of such detection.

p0041In the embodiment illustrated in Figure 1, the composite yarn 6 is formed of two elementary electrical son 4 and 5. However, according to the invention can be designed composite son 6 comprising more than two elementary electrical son 4 and 5, by example three or four son, isolated from each other by an insulating means and assembled with each other in the same sheath.

p0042According to a first embodiment illustrated in Figure 2, the elementary electric son 4 and 5 are assembled so as to be parallel along their length. Are distinguished, in this figure, the insulating peripheral layers 4a and 5a, which constitute the insulating means providing mutual isolation of the elementary electric son 4 and 5 relative to each other, and simultaneously providing a screw-in insulation -vis the outside.

p0043To ensure good flexibility of the elementary electric son 4 and 5 isolated, it is possible the isolation by an insulating means such as a wrapping, that is to say a double helical winding reversed using a wire insulation around the conductor wire 4 or 5.

p00443 illustrates another embodiment in which the composite yarn 6 is formed of two elementary electrical son 4 and 5 assembled twisted along their length. The advantage of a provision twisted as 3 is to make even more difficult the separation of elementary electrical son 4 and 5 with respect to the other for any specific welding a branch conductor.

p0045In Figure 4, there is illustrated another embodiment of u n composite yarn 6 embodiment in which the elementary electric son 4 and 5 are insulated from each other by one or two insulating layers 4a and 5a, the assembly being sheathed with a sheath 6a. For example, the cladding of the composite wire 6 can be achieved by wrapping.

p0046The elementary electric son may advantageously be chosen with a diameter of between approximately 0.04 millimeters and 0.20 millimeters. A good compromise can be achieved with an approximately 0.07 mm diameter wire.

p0047Preferably, the elemental intermediate nip 8 between the axis of the elementary electric son 4 and 5 has a size of about ten times the diameter of the elementary electric son, that is to say between about 0.04 centimeters and 0.1 centimeters, preferably about 0.07 centimeters to about a 0.07 mm diameter wire.

p0048In Figure 1, the mechanical retention means 7 of the composite yarn 6 comprise inextensible flexible lateral connection means such as son or warp tapes of inextensible flexible material.

p0049Advantageously, the son or warp tapes 7 can be of thermoformable material for thermoforming of the electric network in a sheet for insertion into a non-planar wall.

p0050Advantageously, the lateral connecting means 7 may have a melting temperature higher than the melting temperature of the insulating means 4a or 5a of the elementary electrical son 4 and 5, so that the merger of the lateral connecting means 7 for separating or removing them elementary electrical son 4 and 5 involves the prior destruction of the insulating medium, which then causes the mutual contact of elementary electrical son 4 and 5 with each other and the immediate operation of the device.

p0051It is considered the embodiment of Figure 6, which shows the layout of the composite wire 6 with round trips to parallel strands, type of weave on son or strip line 7.

p0052Figure 7 illustrates another arrangement of the invention, wherein the composite wire 6 is arranged in an arrangement in mesh-type loops or eyelets 7a knitting or crocheting.

p0053We now consider Figures 8 and 9 which illustrate an application of the safety device according to the invention by integration in a wall 9 of a housing 10 secured.

p0054As best seen in Figure 9, the wall 9 of the enclosure 10 comprises a rigid inner layer 11, and the web 1 in electrical network security device is an integrated intermediate layer in a synthetic foam layer 12, by example in charged polyurethane. Include, in this embodiment, the composite yarn 6 seen in cross section and composed of elementary electrical son 4 and 5 in a sheath 6a. mechanical strength of the means are in this embodiment constituted by the foam 12 itself is compact enough.

p0055We see in Figure 8, the electric network web 1 follows faithfully the curvatures of the rigid inner layer 11 to the desired shape of the enclosure 10, thanks to the flexibility of composites son 6 constituting the grid ribbon 1.

p0056When enclosure manufacturing 10 can advantageously provide a device according to the invention wherein the lateral link means comprise son or warp tapes 7 of thermoformable material in order to thermoform the electrical network web 1 before available in a mold against the rigid inner layer 11 and then molding the foam 12.

p0057Turning now to Figure 5, which illustrates a possible embodiment of the invention for the electronic control device 2.

p0058Found in this figure, the composite thread 6 consisting of elementary electrical son 4 and 5, and which is connected the end terminals to the electronic control device 2.

p00592 electronic control device comprises, in this embodiment, a first impedance control circuit 20 capable of controlling the impedance of the first elementary wire 4. For this, the two ends of the first elemental wire 4 are connected to inputs 20a and 20b of the first impedance control circuit 20. the structure of the first impedance control circuit 20 can be of any type within the reach of the skilled person, for example a serial current generator with a current sensor and means for the connection between the generator voltage and the measured current and to deduce therefrom the value of the impedance of the elementary wire. 20c the output of the first impedance control circuit 20 is connected to a first comparator 21 which compares the value of the measured impedance to a threshold of maximum allowable impedance value unit for the first elementary wire 4. The comparator 21 produces on its output 21a a signal when the measured impedance exceeds the threshold for maximum unit impedance, and this signal is sent to an OR circuit 22 whose output is connected to the output 3 of the control device 2.

p00602 the control device further comprises, similarly, a second impedance control circuit 23, similar to the first impedance control circuit 20, whose inputs 23a and 23b are respectively connected to both ends of the second wire elemental 5. the second impedance control circuit 23 is adapted to measure the impedance of the second elementary electric wire 5, which measurement is then compared to a threshold of maximum allowable impedance unit by a second comparator 24, which generates on its output 24a a signal to the OR circuit 22.

p0061Similarly, the 2 control device comprises a third impedance control circuit 25, similar to the impedance control circuits 20 and 23, whose inputs 25a and 25b are respectively connected to the first elementary wire 4 and second elementary electric wire 5. the third impedance control circuit 25 is adapted to measure the mutual impedance between the elementary electric son 4 and 5, the thus measured value being sent to a third comparator 26 which compares this measured value of mutual impedance with a minimum permissible mutual impedance threshold and produces on its output a signal when the mutual impedance is less than the minimum mutual impedance threshold, the signal being sent to the OR circuit 22.

p0062OR circuit 22 produces on output 3 a signal when at least one of the comparators 21, 24 and 26 transmits a signal indicating that at least one of the elementary electric son 4 and 5 is too much impedance, e.g. infinite impedance resulting from cutting the thread, or when the elementary electrical son 4 and 5 are in contact one another so that their mutual impedance detected by the third impedance control circuit 25 and the comparator 26 is less than the minimum mutual impedance threshold.

p0063According to an advantageous use, signal or output signal, controls the triggering of an alarm generator or destructive device capable of unusable content protected by the wall 9 or the enclosure 10.

p0064In all embodiments, the basic electrical son 4 and 5 are mechanically assembled with each other in a composite wire 6, so it is very difficult, practically impossible, to remove them relative to another without destroying them. Available in low-mesh sheet, that is to say with elementary intervening gaps 8 Small-scale prohibits drilling a hole sufficient size through the web without damaging one or other of son elementary electrical.

p0065Curl retention or parallel strands of composite yarn 6 by inextensible lateral connecting means prevents the spacing of the loops or strands parallel to each other to increase the size of an individual intermediate gap 8 and thus enable the piercing 'a hole.

p0066An attempted merger or welding degrades the insulating medium between elementary electrical son, and causes the immediate triggering of the device.

p0067It is understood that the signal at the output 3 of 2 control device may control an alarm or destructive device that destroys or renders unusable commercially contents of a pregnant 10.

p0068The present invention is not limited to the embodiments that have been explicitly described, but includes variants and generalizations thereof within the scope of the claims below.