Cylinder lock with changeable keyway

A cylinder lock with a changeable keyway, the cylinder lock being of the type having a shell with a longitudinal bore, a plug rotatable within the bore of the shell, the plug having a longitudinal access opening therein for a thin flat key having a blade with a configured side surface and an edge having bits therein, and mechanical stop tumbler means cooperating with the shell and the plug for preventing rotation of the plug unless a properly configured key blade having properly cut bits on the edge of its blade operates the mechanical stop tumbler means, the lock having improvements which provide a changeable keyway, the improvements comprising:

• the longitudinal access opening in the plug having a cross section which is at least in part larger than the cross sectional area of the properly configured key blade, and an elongated interchangeable insert member means having a configuration along at least one side of the elongated portion thereof which conforms to the configuration of only a portion of the side surfaces of the key blade, said portion of the side surfaces including a section with either a groove or a rib and another section void of said groove or rib, the interchangeable insert member means being interchangeably attachable to the plug in the area of the longitudinal access opening in the plug and extending therealong to diminish the cross-sectional area of said access opening and conform such cross-sectional area of said access opening to the desired cross-sectional keyway area of the keyblade.

A cylinder lock with a changeable keyway, the cylinder lock being of the type having a shell with a longitudinal bore, a plug rotatable within the bore of the shell, the plug having a longitudinal access opening therein for a key, and mechanical stop means cooperating with the shell and plug for preventing rotation of the plug unless a properly configured key operates the mechanical stop means, the lock having improvements to provide a changeable keyway comprising:

• the longitudinal access opening in the plug having a cross-sectional area which, in a portion thereof, conforms to a portion of a thin flat blade of a key with the sides of the blade being configured and one edge of the blade having bits, said cross-sectional area of the longitudinal access opening, in another portion thereof, defining longitudinal insert receiving groove means;
• and said lock including at least two elongated keyway defining insert members easily removable and insertable into the insert receiving groove means of the longitudinal access opening and assembled end to end in the plug and extending along the longitudinal access opening to diminish the cross-sectional area of the access opening according to the configuration of each keyway defining insert member and to provide two successive longitudinal separate cross-sectional areas of the access opening of predetermined configurations which correspond to two desired longitudinally spaced cross-sections conforming to respective portions of the configured side surfaces of the blade.