Locking devices and keys for use therewith.

Closing device comprising a cylinder type lock, in which the cylinder has a housing (1) in which it rotatably adjusts the body of the cylinder (3), together with a plurality of bolts (8), whose cylinder has a profiled keyhole (10) inside which said bolts (8) extend in the rest position of the cylinder, in which an additional bolt (21) is provided which is mounted to effect a sliding movement in a borehole (22) whose longitudinal axis is parallel but is offset relative to the longitudinal central plane of the keyhole (10), and also in which in the keyhole (10) in the area of ​​the additional bolt (21), but separated from it, a stop (32) is provided, the closing device being suitable for use with a key (12) having a profiled sheet (11) corresponding to the keyhole (10) on which a control element (with transverse sliding movement) is mounted 18) which is pushed by the coupling by contact with the stop (32) to a position in which the opposite end thereof protrudes outward from the opposite side of the lock leaf (11), whose protruding end serves to drive the additional bolt (21), whose closing device is characterized in that the end of the additional bolt (21), to which the control element (18) of the key is coupled, is lengthened longitudinally to the keyhole (10) and has a rise ramp (26) that extends in that direction.