Removable cylinder lock

Abstract

There is disclosed an improved rotatable cylinder lock of the type formed by a cylindrical housing and a removable elongated lock core, the cylinder housing including a tumbler block positioned within the cylindrical housing and extending inwardly with respect to the cylindrical housing, and a tumbler ledge having an interior peripheral surface mounted within the cylinder housing adjacent the tumbler block and extending circumferentially for a portion of the periphery of the cylinder housing, the lock core including a plurality of lock tumblers and a release tumbler which is positionally carried by the lock core to ride on a shoulder formed by the tumbler ledge throughout the rotational movement of the lock core, except in the unlocked position when the release tumbler is positioned such that it is free of blockage by the tumbler block thereby to permit removal of the lock core from the cylindrical housing, the lock core further including a block restrictor relief section formed therein which accommodates the rotational movement of the tumbler block therein and also accommodates the release of the release tumbler to permit removal of the lock core from the housing. A further improvement of the cylinder lock permits the lock tumblers and the release tumbler to be configured identically thereby eliminating the need for any specially configured release tumbler.