Patent ID: 8276419

Claim:
A cylinder lock comprising: a cylinder housing having a cylinder wall surrounding an axial cylindrical core recess including at least one blocking groove formed therein, the at least one blocking groove extending axially parallel with respect to the cylindrical core recess and opening in a direction thereto; a cylinder core seated within the cylindrical core recess and rotatable about a central longitudinal axis thereof, the cylinder core having an axial key channel and a plurality of chamber slots serially extending behind one another along the longitudinal axis and aligned transversely thereto, wherein the plurality of chamber slots proceed from the axial key channel, a plurality of wall webs for separating the plurality of chamber slots; a plurality of rectangular frame-shaped plate tumblers slidably seated in the plurality of chamber slots and being spring-loaded so as to slide in one common sliding direction, the sliding direction being perpendicular to the longitudinal axis, the plurality of plate tumblers having at least one transverse frame web and two lateral longitudinal frame webs which are configured to form a generally rectangular interior space surrounding the key channel; at least one stationary centering pin projecting into the key channel in a direction perpendicular to the sliding direction and perpendicular to the longitudinal axis and configured to guide and center the flat key as the flat key is inserted into the key channel; wherein the plurality of plate tumblers have a plurality of control steps projecting into the interior space and laterally disposed at both sides in the key channel, each one of the plurality of control steps proceeding from one of the two longitudinal frame webs respectively and extending at right angles thereto; the plurality of control steps being disposed on only one side of a central longitudinal plane encompassing the longitudinal axis, the longitudinal plane lying perpendicular to the longitudinal frame webs and perpendicular to the sliding direction; and wherein at least one control step corresponding to a plate tumbler of the plurality of plate tumblers is differently spaced from the longitudinal plane than the control steps corresponding to the other plate tumblers of the plurality of plate tumblers.