| 摘要 |
PURPOSE:To perform an automatic closing of a flow passage of gas in simultaneous with occurrence of earthquake by making such an arrangement in which a motor is driven by falling a bar, a gas supply main plug is rotated and the motor is stopped by rotating the gas supply plug. CONSTITUTION:When an earthquake occurs under a condition in which a limit switch 9 is opened, and a limit switch 10 is closed, a bar 2 abutting against a stopper 4 is fallen from its solid line position to the dotted line position under the vibration of bar 2 so as to close the limit switch 9. Due to this fact, the motor 5 is driven, a change-over lever 7 for the gas supply plug P held by a retainer 8 fitted to the motor rotating shaft 6 is rotated in a direction shown by an arrow to close the gas flow passage. When the change-over lever 7 is rotated in a direction of arrow and moved from its solid line position to its chain line position by about 90 deg., the change-over lever 7 is abutted against the limit switch 10 to operate the switch and then the gas flow passage is completely closed. |
