| 摘要 |
PURPOSE:To prevent abnormal combustion caused by continuously supplying fuel and air to a flame chamber by an oil feeder, by actuating an alarm means, when a detecting means detects that a level of fuel in an auxiliary tank goes down lower than a predetermined level. CONSTITUTION:A photo emitting element 9 and a photo receiving element 10, composing a detecting means 8, are fitted to the suitable positions of a tank guide 5 respectively, facing to a liquid level gauge 2. When a fuel level in an auxiliary tank 1 is higher than the emitting position of a photo emitting element 9, an emission A from the photo emitting element 9 goes straight through fuel as shown by A', passing through the liquid level gauge 2, so that the photo receiving element 10 can not receive emission from the photo emitting element 9. When the fuel level in the auxiliary tank 1 goes down lower than the photo emitting level of a photo emitting element 9, an emission A from the photo emitting element 9 is refracted as shown by B by the primary prism surface 2' on the liquid level guide 2, and is further refracted by the secondary prism surface 2'' as shown by C, being sensed by the photo receiving element 10. |
