GB670999A - Combined thermostat and pilot-burner flame-failure control apparatus for gas-burning appliances - Google Patents

Abstract

670,999. Valves. ROBERTSHAW-FULTON CONTROLS CO. Sept. 23, 1949 [June 11, 1949], No. 24538/49. Class 135 A combined thermostat and pilot-burner flamefailure control apparatus for gas burning appliances, e.g. space heaters, comprises a gas control valve, an electromagnet having an armature biased to the released position and energised by a pilot-burner flame responsive means to attract the armature, holding means for closing the valve when the armature is released but which are ineffective when the armature is attracted, a thermal element reponsive to the temperature of the medium heated by the burners, and a lever operated by the thermal element for opening the valve when the holding means is ineffective. Rotation of the main gas cock handle 28 through a quarter turn brings a land 31 over a button 32 so that on pushing in the handle the button depresses a lever 108 having a projection which opens a valve allowing gas to flow from the inlet 12 to a pilot burner. The lever also pushes an armature 102 against a spring 106 into contact with an electromagnet so that on lighting the pilot a thermocouple energizes the magnet which holds the armature. Another quarter turn of the handle 28 allows gas to flow from the inlet into the chamber 16, past a control valve 58 connected by a spring 110 to the lever 108, and through an outlet 14 to the main burner. The control valve is operated by a thermal feeler 81 and bellows 76 adjustable by a screw 86 and acting through a lever 82, a snap-acting mechanism 70, magnifying levers 68 and an override plunger 64, the lever tending to open the valve due to its loading spring 84. On extinguishment of the pilot, the magnet releases the armature and the spring 106 closes the valve 58. Specification 590,605 is referred to.