| 摘要 |
<p>With an auxiliary lock operated by a built-in battery, it is desired to prevent the door from being kept locked even if the battery dies. The auxiliary lock body is provided with first and second voltage detecting means for detecting that the voltage of the battery has lowered to predetermined voltages. If the first voltage detecting means detects that the voltage of the battery has dropped to a predetermined voltage, the fact is alarmed. Then, if the second voltage detecting means detects that the voltage of the battery has dropped further, the actuator is activated to open the lock by pushing down the bolt inside the lock surface before the battery dies, thereby preventing the door from being kept locked even if the battery dies.</p> |
