Abstract: An improved locking device for a door turnably mounted on a safe or the like apparatus of the type including a numbering lock and a movable plate adapted to carry out locking activity is disclosed. An engagement recess is formed on the lower edge of a movable plate so that a locking bar comes in locking engagement to the recess. The movable plate is operatively connected to a lever plate by way of a slidable pin and a coil spring and the lever plate in turn is operatively connected to an actuating plate adapted to move within a certain extent together with a ratch member turnably supported by the side of the actuating plate under the influence of resilient force of a leaf spring. To allow the ratch member to be projected into the lock case a part of the latter is cut out and a plurality of tumblers are housed in the lock case. One of the tumblers is fitted with an engagement pin to which the ratch member comes in engagement as the actuating plate is displaced in the direction of unlocking.

Abstract: A multiplexed telecommunication system includes two looped transmission lines connecting a plurality of stations. Each station transmits along both looped lines and receives only from the first line. If a fault condition occurs, the station receives only from the second line, by automatically changing the receiving switch.