Patent ID: 8312749

Claim:
A lock mechanism comprising: a cylinder housing having an aperture extending along a first axis of the cylinder housing and having a plurality of pin chambers in the cylinder housing aligned along the first axis and extending transverse to the first axis; a cylinder plug positioned within the aperture and selectively rotatable therein about the first axis, the cylinder plug having a plurality of pin chambers aligned along the first axis and extending transverse to the first axis, the cylinder plug pin chambers being moved into alignment with corresponding ones of the cylinder housing pin chambers at which the lock mechanism is locked, the cylinder plug having a keyway passage extending along the first axis; a key pin sized to slideably fit within each of the cylinder plug pin chambers, the key pins each having first and second ends and a selected length with at least some of the key pins having different lengths; a driver pin sized to slideably fit within each of the cylinder housing pin chambers and extending into the corresponding ones of the cylinder plug pin chambers when the lock mechanism is locked, the driver pins abutting the first end of the respective key pin; a spring sized to fit within each of the cylinder housing pin chambers and abut the respective driver pin to thereby resiliently urge the respective driver pin and the respective key pin toward the keyway passage; an extension member extending at least partially into the keyway passage, the extension member forming a resting surface for the key pin second end, the key pins being in a resting position in abutment with the resting surface when the lock mechanism is locked to thereby prevent the key pin second ends from entering the keyway passage; and a key having a size and shape to permit insertion into the keyway passage, the key having a first end for insertion into the keyway passage and a plurality of activation portions along a longitudinal axis of the key corresponding to a respective pin chamber when the key is fully inserted to thereby align the first end portions of the key pins and permit rotation of the cylinder plug by rotation of the key, the key having a sloped leading edge for engagement with the key pins and an activation element at the key first end proximate the leading edge and configured to sequentially engage the key pins as the key is inserted into the keyway passage to thereby move the key pin from its resting position in abutment with the extension member resting surface to thereby expose the second end of the key pin in the keyway passage for engagement with the sloped leading edge of the key.