Abstract: A lock with a stator and a rotor having a key slot or channel for receiving a flat key has four tumbler rows with pin tumblers, the rows extending in the axial direction of the rotor. The planes containing two of the tumbler rows are inclined by identical angles on opposite sides of the median longitudinal plane of the key and intersect a narrow edge surface of the key adjacent the corners so that the recesses in the key to receive the pin tumblers open on both the narrow side and the flat side key, making it possible to reduce the constructional size of cylinder lock.

Abstract: There is disclosed an emergency key mechanism on a cylinder lock with a double locking cylinder and a locking coupling axially moveably fitted thereon.