Abstract: Attachment device by means of which a safety device can be attached to an article, comprising a hollow sleeve accommodating a screw member through operation of which the attachment device can be attached to an article to be protected, while said sleeve extends beyond the article-averted end of the screw member and being provided with a transverse bore hole provided in the corresponding end, said transverse bore hole being adapted to receive a lock shackle or the like which renders the screw member inaccessible to tools.

Abstract: A detection system comprises at least one gate including transmitter means for forming a magnetic field and receiver means for receiving a signal transmitted by a detecting wafer provided with an oscillating circuit, wherein each gate comprises at least two spatial detection zones.

Abstract: A fastener of the kind in which a pin can be inserted into a closed housing between balls provided in a tapering space within the housing, which balls prevent the subsequent removal of the pin through the exercise of clamping action on the pin upon attempts to remove the pin from the housing, wherein the housing having a chamber housing a substantially freely rotatable body having a tapering cavity therein and a central aperture for the insertion of the pin therethrough, the cavity containing the balls, the balls having linear contact with the wall of said cavity.

Abstract: A detection plate for an identification system, comprising a resonant circuit, a switching device, and coding means, characterized in that the coding means comprises a digital circuit and is arranged to receive, in operation, supply voltage from the resonant circuit via rectifier means.