OPERATION INDICATING APPARATUS FOR PILOTTFLAME SAFETY DEVICE

摘要

PURPOSE:To enable to detect operation of a pilot-flame safety device readily, by selecting the time required for a temperature-indicating paint to change its color through heating of an indicating section by the radiant heat of combustion flame to be equal to that required for a solenoid valve in the pilot-flame safety device to complete its self-holding. CONSTITUTION:A thermocouple 4 and an indicating section are heated simultaneously by combustion flame 3. When the thermo-electromotive force of thermocouple 4 becomes greater that the level capable of attracting and self-holding a solenoid valve 5, self-holding of the solenoid valve 5 is completed by thermo-electromotive force. At the same time, indicating section 6 is also heated by the radiant heat of combustion flame 3, so that a temperature indicating paint 6b coated over the surface of heat absorbing material 6a changes its color. Here, by employing such an arrangement that the time required for the solenoid valve 5 to complete its self- holding and that required for the paint 6b to change its color are substantially equal to each other, the user can detect completion of self-holding of solenoid valve 5 from the change of color of indicating section 6 and can detach his hand from an ignition knob 12 at an appropriate time.