Cylinder lock--key--combination

Disc cylinder lock-key-combination, comprising a cylinder housing (1) and inside thereof, a turnable inner cylinder (2) enclosing a stack of discs including a number of locking discs (3,4) provided with peripheral notches (20), a locking bar (10), which in its locking position together with the locking discs (3,4) prevents turning of the inner cylinder (2) with regard to the cylinder housing (1), whereby the locking discs (3,4) are turnable by means of the key (12) of the lock into a releasing position of the lock mechanism, and a guiding element (14) in a key channel formed jointly by key openings (6,7) of the discs (3,4) included in the stack of discs, extending longitudinally over the stack of discs and arranged to turn continuously with the key (12) when the key is turned in the lock, the improvement being therein that the stack of discs includes a number of locking discs (3,4), the key opening (6,7) of which is so formed that it comprises at least one protrusion (21) extending towards the central part of the key opening (6,7) and the adjacent sides of which being substantially perpendicular with regard to each other, whereby one side of the protrusion (21) forms a combination surface (22) arranged to cooperate with a corresponding combination surface (27) in the key (12) for determining the turning movement of the locking disc (3,4) with regard to the inner cylinder (2) when the key (12) is turned in the opening direction of the lock mechanism, and the other side of the protrusion (21) respectively forms a return surface (23) for the locking disc (3,4) on which the key (12) is arranged to act by means of the guiding element (14) for returning the locking disc (3,4) into a locking position of the lock mechanism corresponding to the initial inserting position of the key (12).