INTRUDER ALARM Russian patent published in 1994 - IPC

FIELD: signalling devices. SUBSTANCE: device has housing with cover 1, axially movable rod 2, support washers 3 and 4, helical spring 5, rotary two-arm lever 7 kinematically coupled with a signal sensor made in the form of scaled-contact reed relay and magnet 13 with magnetic shield 15 interposed between them. Support washers 3 and 4 are freely mounted on rod 2. Support plate 6 is rigidly fixed to the housing. Planar springs 9 and 10 are mounted on different arms of rotary two-arm lever 7 and interact with second support washer 4 and magnetic shield 15, respectively. Rotary two-arm lever 7 is mounted on the housing with the aid of bearing 8. The device is characterized in that mechanical locking of the signal sensor on at unauthorized opening of the object by preventing disconnection of the signal sensor contact upon pressing the rod. EFFECT: enhanced reliability. 2 dwg