Alarm switches, especially for burglar alarm installations, which are automatically switched on when the lock of a lockable room is closed and which are automatically switched off again when the lock is opened, a contact part of the alarm switch being arranged in an electrically non-conductive part which moves against a conductive part on closing such that, when the door is locked, the alarm installation circuit is completed. In an embodiment suitable for apartment doors, the non-conductive part is a spring-operated push button which is pushed in by a lock piston which can be moved in a lock sleeve. In another embodiment, suitable for car doors, the non-conductive annular part (21), which holds a contact part (25), is placed on the cylindrical part (20) of a lock housing (15) in such a manner that the rotational movement of the lock cylinder (This abstract incomplete) IMAGE
展开▼
