Patent ID: 7240526

Claim:
A lock comprising: a cylinder assembly comprising a cylinder having an inner space, multiple outer pin holes and a cylinder keyhole communicating with the inner space; a cylinder plug assembly rotatably mounted in the inner space and comprising a cylinder plug rotatably mounted in the inner space and having an exterior surface; a through passage extending an entire length of the lock and defining said cylinder keyhole at a first end of the lock, said through passage defining a through hole at a second opposing end of the lock; a dummy keyhole and a cylinder plug keyhole defined coaxially completely through the cylinder plug, communicated with each other and selectively aligned with the cylinder keyhole, said dummy keyhole and said cylinder plug keyhole being in direct communication with said through passage; multiple inner pin holes defined completely through the exterior surface of the cylinder plug to communicate with the cylinder plug keyhole, and the inner pin holes aligned respectively with the outer pin holes in the cylinder; a locking pin assembly mounted in the cylinder and the cylinder plug and comprising multiple outer locking pins, and each of the outer locking pins being slidably held in a respective one of the outer pin holes; multiple inner locking pins, and each of the inner locking pins being slidably held in a respective one of the inner pin holes and partially held in the aligned cylinder plug keyhole; and multiple biasing elements, and each of the biasing elements being held in a respective one of the outer pin holes to press the corresponding outer locking pin; and a latch assembly connected to and rotated by the cylinder plug, said through hole being formed in a portion of said latch assembly.