| 摘要 |
PROBLEM TO BE SOLVED: To provide a lock for a building having high burglarproofness against an illegal unlocking act such as picking and bypass. SOLUTION: This lock comprises a dead bolt, a dead bolt drive mechanism, a latch bolt, and a lock case storing the latch bolt drive mechanism. A cylinder is installed in the lock case therethrough. By the adoption of this structure, since the lock case has a generally sealed structure, a tool for picking and bypass can be prevented from being inserted into the lock case. In addition, the dead bolt is moved from a locking position to an unlocking position when the rotating cam of the cylinder is turned generally two times. As a result, a necessary operating angle for thumb-turn is increased to provide effectiveness to the illegal unlocking act. COPYRIGHT: (C)2004,JPO
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