Removable cylinder for a lock

Abstract

A removable cylinder for a lock has a shell extending along an axis and holding a pin tumbler unit movable along the axis into and out of the shell, being limited in its movement into the shell by a face plate. A key plug having a keyway in it is mounted in the pin tumbler unit so that the key plug can be rotated about the axis in order to actuate the lock. A stop lever is rotatable about the axis between a first position in axial alignment with an end wall of the shell and a second position clear of the end wall of the shell to hold the pin tumbler unit in the shell and to release it from the shell. There is a rod located between the shell and the pin tumbler unit and extending generally parallel to the axis from a tool access passage in the front of the pin tumbler unit and face plate toward the stop lever. The rod is movable by a tool within the access passage. A clutch lug on the rod in one position is in engagement with the pin tumbler unit and the stop lever and in another position is in engagement with the stop lever and the key plug. A tool inserted through the access passage displaces the rod so that the clutch lug disengages from the pin tumbler unit and engages the plug and the stop lever. Rotation of the key plug by the normal key therein then rotates the stop lever to clear the shell so that the cylinder can be removed. When the cylinder is replaced and the key reversely rotates the plug and stop lever, the stop lever is turned into alignment with the shell, the rod is displaced and the clutch lug is reengaged with the pin tumbler unit.

Dependencies are inferred from the claim text.