A key including at least one coding cavity (55) defining a hollow geometry for coding the key. The geometry includes at least one internal undercut (60a, 60b). The lock for validating a key comprises blocking means (21, 22) coupled to a driving part (14) and validating means (25, 26) which are coupled to the blocking means so as to change the state of the blocking means when the key used with the lock has a correct coding. The validating means (25, 26) protrude at least partially into the key cavity of the lock in order to introduce the validating means at least partially into the coding cavity (55) of the key and to sense the inner face of the coding cavity.

A key or a key blank for a disk cylinder having a plurality of rotatably supported disk tumblers has a key shaft having a shaft cross-section that comprises a first end section, a second end section and a connection section along a longitudinal axis, said connection section connecting the first end section and the second end section to one another. The connection section is narrower than the two end sections and has two longitudinal edges that are aligned in parallel with one another and that extend obliquely to the longitudinal axis of the shaft cross-section between the two end sections.

A lock including a set of tumblers preserving their position after contact with a key to permit blocking of the keyhole during the opening process.

A key and a lock cylinder, which are formed such that the guiding the key into the keyhole and the key canal occurs precisely and in a user-friendly manner. The precise placement of the key in relation to the lock cylinder and its parts enables even distribution of the forces directed onto the key and the lock cylinder.

A cylinder locking device is provided in which an inner cylinder is pivotably inserted into a cylinder body, a protector is disposed opposite a rear end of the inner cylinder along an insertion direction of a mechanical key, the protector enabling the mechanical key to be inserted toward the inner cylinder, and a coil-shaped spring is provided between the protector and the inner cylinder or the cylinder body, wherein the spring is formed so as to have a coil portion that extends in the axial direction of the inner cylinder and a bent portion that is bent from at least one end part of the coil portion toward an interior of the coil portion in a direction along an axis of the inner cylinder. This enables deformation of a coil-shaped spring to be prevented.

A disc tumbler cylinder lock has a lock cylinder base, multiple discs, and multiple gaskets. The lock cylinder base has an accommodating space, a position limiting opening, and an accommodating opening. Each of the discs has a position limiting protrusion and a disc notch. Each of the gaskets has a ring body, a position limiting segment, and a rotation limiting segment. The position limiting segment protrudes outward from an outer annular surface of the ring body along a radial direction. The rotation limiting segment protrudes from the position limiting segment along an axial direction of the lock sleeve. The discs and the gaskets are staggeredly accommodated in the accommodating space. A side surface of the position limiting protrusion abuts a side surface of the position limiting opening. Two sides of the position limiting segment abut two opposite sides of the position limiting opening.