| 摘要 |
PROBLEM TO BE SOLVED: To provide a device to prevent a door from being opened by picking and inform us thereof before the door is opened, and protect one's life and property. SOLUTION: A microswitch is mounted in the part of disc tumblers by making use of the movement that a key (foreign matter) vertically or laterally moves in the disc tumblers when inserted, so that a switch is turned on to emit a sound before unlocking.
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