Abstract: A key blank, key and master keying system for a twisting tumbler sidebar lock of the type where the sidebar is blocked or unblocked by a selectively positioned longitudinally extending slider, has a key blank with a slider contacting surface on a rib on the blank below the bitting area at one of a plurality of selected predetermined locations. A key with skew cut bittings can be cut on the blank and the blank can be configured with the slider contacting surface at different predetermined locations. The slider contact area on the rib of the key blank can be divided into two horizontal portions at different predetermined locations and the slider itself can have contact surfaces also positioned at different predetermined locations so that a number of different master keying variations are possible.

Abstract: A shell and core interchangeable lock assembly for use in a shell housing. The core includes a rotatable pin plug and the shell includes a substantially cylindrical body with a pin chest therein. A mechanism which captures the shell and core within the shell housing includes an integral retainer ring and lug which is attached to the core. The mechanism allows rapid insertion and removal of the shell and core by the use of a correctly bitted control key. The mechanism additionally has a sub-mechanism for preventing its operation by accident or by tampering without the appropriate control key.

Abstract: A key blank, key and master keying system for a twisting tumbler sidebar lock of the type where the sidebar is blocked or unblocked by a selectively positioned longitudinally extending slider, has a key blank with a slider contacting surface on a rib on the blank below the bitting area at one of a plurality of selected predetermined locations. A key with skew cut bittings can be cut on the blank and the blank can be configured with the slider contacting surface at different predetermined locations. The slider contact area on the rib of the key blank can be divided into two horizontal portions at different predetermined locations and the slider itself can have contact surfaces also positioned at different predetermined locations so that a number of different master keying variations are possible.

Abstract: A shell and core interchangeable lock assembly for use in a shell housing. The core includes a rotatable pin plug and the shell includes a substantially cylindrical body with a pin chest therein. A mechanism which captures the shell and core within the shell housing includes an integral retainer ring and lug which is attached to the core. The mechanism allows rapid insertion and removal of the shell and core by the use of a correctly bitted control key. The mechanism additionally has a sub-mechanism for preventing its operation by accident or by tampering without the appropriate control key.

Abstract: A shell and core interchangeable lock assembly for use in a shell housing. The core includes a rotatable pin plug and the shell includes a substantially cylindrical body with a pin chest therein. A mechanism which captures the shell and core within the shell housing includes an integral retainer ring and lug which is attached to the core. The mechanism allows rapid insertion and removal of the shell and core by the use of a correctly bitted control key. The mechanism additionally has a sub-mechanism for preventing its operation by accident or by tampering without the appropriate control key.

Abstract: A deadbolt latch assembly capable of accommodating both rectangular faceplates and circular faceplates. The latch housing assembly is provided with a semi-permanent rectangular faceplate assembly attached thereto, but which is removable with a prying tool to allow the housing to accommodate an alternative faceplate such as a circular faceplate. The housing is manufactured of a thick walled steel casing to enclose and retain not only the latch but the latch extension as well, to thereby prevent the latch extension from flexing about the latch-extension joint.