FIELD: protection and warning facilities. SUBSTANCE: invention can be used to protect premises under lock and key by way of generation of alarm signal if attempt is made by outsider to open lock with standard key. Device comes in the form of lock with rotary drum housing working axial pushing pins contacting working axial spring-loaded locking pins meant for opening and closing of lock. In this case lock has certain number of additional keyholes in which false pairs of pushing and spring-loaded locking pins are located. Spring-loaded locking pins are stepped in shape and body of lock has holes for passage of ends of these pins through them. Way of coding is like that: with loss or theft of key and with insertion of key by outsider into false keyhole false spring-loaded opening pins are moved by pressure on them with protrusions of key via false pushing pins. In this case ends of spring-loaded false opening pins are moved outside limits of body of lock with simultaneous movement of magnetic field and cutting in of magnet- controlled contact with generation of alarm electric signal. EFFECT: enhanced efficiency of protection. 4 cl, 3 dwg
