| 摘要 |
PROBLEM TO BE SOLVED: To automatically open a door in case of an earthquake and, at the same time, to prevent the door from being opened when no one is in the house by providing a door lock releasing mechanism acting in correspondence with an earthquake sensor together with a door chain releasing mechanism, and adding a door opening prevention mechanism when no one is in the house. SOLUTION: When an earthquake sensor 1 detects an earthquake exceeding a certain level, a door lock releasing mechanism 2 and a door chain releasing mechanism 3 are operated by an output signal 1a of the sensor, and a door opening mechanism 4 is operated by an operating complete signal 2a of the door lock releasing mechanism 2 to open a door. Those operating mechanisms use form restoring force by heating of a form memory alloy spring or a direct acting actuator. As a door opening prevention mechanism no one is in the house, an inverted switch is operated when a door chain is locked and unlocked by sliding it up and down, and the earthquake sensor 1 is thereby turned ON/ OFF. Accordingly, the door is surely opened in case the earthquake occurs, an evacuation route is ensured and, at the same time, the opening of the door is prevented to secure safety when no one is in the house. |
