| 摘要 |
PURPOSE:To distinguish an earthquake and at the same time, eliminate the malfunction resulting from shocking vibrations, by introducing a pendulum so as to tilt a saucer selectively. CONSTITUTION:When the trembling of a weight 21 resulting from the repeated vibrations by an earthquake becomes large so that said weight 21 starts to collide with the inner wall of a cylinder 18, a force to tilt a saucer 16 is readily generated. Therefore, the saucer 16 is readily tilted about the center 23 of a ball body 17 as an imaginary fulcrum by the rotational force. Accordingly, the ball body 17, which cannot support any more the inertia force that the earthquake is applying thereto, removes from the saucer 16. The ball body 17 removed from the saucer 16 by the earthquake drops toward into a guide groove 25, pushing down a movable plate 26 and actuating a lever 13 to close a valve 3. |
