Patent ID: 8166784

Claim:
A lock mechanism comprising: a cylinder housing having a plurality of pin chambers sized to receive a pin assembly, the pin chambers including one or more threaded pin chambers having an internal threaded portion; a cover plate removably positionable on the cylinder housing over the plurality of pin chambers, the cover plate including an aperture aligned with at least one threaded pin chamber; and a pin assembly cap having a body portion sized to fit within a corresponding aperture of the cover plate and including an external threaded portion for threaded engagement with the internal threaded portion of a corresponding threaded pin chamber, the body portion further including an internal cavity sized for receiving at least a portion of a corresponding pin assembly, the pin assembly cap further including a head portion sized to prevent passage through the corresponding aperture of the cover plate wherein the internal cavity of the pin assembly cap has a depth such that the dimensions of the plurality of pin chambers are substantially the same when the cover plate and pin assembly caps is installed on the cylinder housing.