Abstract: The method is disclosed for producing a tamper respondent enclosure (10). A flexible tamper respondent laminate (32) is folded to define an inner enclosure (26) which is then potted within an outer enclosure in the form of a molding (28).

Abstract: A security enclosure (20) includes an inner enclosure defined by a first electrically insulating sheet (60) carrying a layer (56) of electrically responsive material on an outer side, the sheet (60) being folded and having edges (100) in overlapping relation and adhered to one another to define the inner enclosure. A detector (80) is provided for detecting separation of the electrically responsive material (56) from the sheet (60) and is located inside the inner enclosure. An outer enclosure is defined by a second electrically insulating sheet (44) wrapped about and adhered to the inner enclosure and also having edges in overlapping relation.

Abstract: There is disclosed a tubular protective sheath for containing a power transmission conduit, the sheath comprising: first and second flexible elements each helically arranged to form respective inner and outer tubular members. The first element is in the form of a first electrically insulating film having respective first and second layers of electrically conductive low melt material adherent to its opposite surfaces. The second element is in the form of a second electrically insulating film having a third layer of electrically conductive low melt material adherent to one surface.

Abstract: A security enclosure comprises a first layer of an insulating material extending over the whole of the area of the enclosure and carrying a linear electrically responsive element on at least one surface. A low tensile strength layer having lower cohesion than adhesion is located between the first layer of insulating material and the electrically responsive element. A second layer of insulating material is adhered to and covers the electrically responsive element. The element is arranged in a configuration on the surface so dividing the surface that attempted penetration of the enclosure changes an electrical characteristic of the element, the change being detectable by an electrical circuit. An attempt to remove the second layer of insulating material to gain access to the element results in breakup of the low tensile strength layer and thus damage to the element and produces a detectable change in an electrical characteristic of the element.

Abstract: There is disclosed a security enclosure including a folded, flexible, electrically insulating sheet extending over the whole of the area of the enclosure and carrying lines of electrically responsive material on each side, the lines defining a conductor extending over both sides of the sheet, electrical connections between lines on one side of the sheet and respective lines on the other side of the sheet being provided by line connections extending through the sheet and at selected edges of the sheet the line connections being spaced inwardly of the edge and separated from the edges by a respective line-carrying portion of sheet. The enclosure includes a circuit for detecting a change in an electrical characteristic of the conductor caused by an attempt to penetrate the sheet.

Abstract: A security enclosure comprises a flexible sheet of insulating material extending over the whole of the area of the enclosure and carrying lines of electrically-responsive material on each side. The lines on one side of the sheet extend obliquely relative to the lines on the other side of the sheet and are connected thereto at edge portions of the sheet to form a plurality of conductors so dividing the sheet into a number of relatively small areas so that attempted opening of the enclosure changes an electrical characteristic of the conductors. Connectors are provided at an edge portion of the sheet for individually connecting the conductors to a detector for detecting the changes in the electrical characteristic of the lines. The connectors include a switch arrangement which is selectively configured to connect further connectors associated with the detector with selected conductors.

Abstract: A signal-carrying member responsive to the presence of a solvent and suitable for use in a security cable or a liquid leakage detector, comprises a conductive ink 20, consisting of a particulate conductive material and a non-conductive carrier medium, printed on to a non-conductive strip 17 and conductors 16 such that when the printed material is contacted by a solvent to which the carrier medium is sensitive, conductive material will be released from the printed material and can be used to vary a signal passed through the signal-carrying member.

Abstract: A security enclosure is formed from layers of flexible material. One layer carries a flexible semiconductive line arranged to extend over the whole area of the enclosure. Any interruption of the line by unauthorized opening of the enclosure changes the resistance of the line and so can be detected by a monitoring circuit. Further, two layers of semiconductive fibers also cover the whole area of the enclosure and are separated by an insulating layer. The length of the fibers is greater than the thickness of the insulating layer so that if the enclosure is pierced fibers from one layer will be forced into contact with fibers from the other layer. This will change the combined resistance of the layers and this can also be detected by a monitoring circuit. The two measures can be used separately.

Abstract: A certain fuel-soluble nitrogen-hydrocarbyl-substituted nitrogenous composition has been found to display a previously unreported detergency in the internal combustion engine when present in fuels to the extent of 10-4,000 ppm. The nitrogenous composition is composed of a hydrocarbyl group bonded to a nitrogenous substrate. The hydrocarbyl substituent contains from 30 to about 400 carbon atoms, and the nitrogenous substrate is a carbamate, urea or amide.