US Patent 7369052 Anti-theft alarm tag

An anti-theft alarm tag comprises two parts (10,12) which shall be located on opposite sides of a product (11) with a pin (14) on one part (12) extending through the product and locked together with the other part (10). Said one part forms a housing comprising a bottom (15) and a cover (16) and enclosing an alarm device (20) and a circuit board (18) with an electronic circuit controlling the alarm device. The pin is connected to the cover or the circuit board and extends through the bottom with slide fit, contact means (39) being switched for activating the alarm device by deformation of the cover or the circuit board, respectively, following an attempt to separate the two parts of the alarm tag.