GB739738A - Combination controls for fluid fuel burning appliances - Google Patents

Abstract

739,738. Thermally-actuated valves. ROBERTSHAW-FULTON CONTROLS CO. Sept. 14, 1953, No. 25373/53. Class 135. A combination control for a fluid fuel buiner comprises a main valve 94, Fig. 2, and auxiliary valve 60, Fig. 5, biased to close, first thermal means for opening the main valve, e.g. the rod and tube 112, 114 acting through lever 116 having a fulcrum adjustable for temperature setting by the screw 118, a snap-acting mechanism 102-104 and an over-ride mechanism 84-92; operating means, e.g. the spring-loaded pin 148 acting on lever 140, movable to active position to hold the main valve closed irrespective of the thermal means; manual means 22, 38 for moving the operating means to inactive position for freeing the main valve for opening; means associated with the operating means for opening the auxiliary valve in the inactive position of the operating means, e.g. the lateral projection 162 on the lever 140 engaging the auxiliary valve stem 78; and a detent 160 movable by a second, e.g. diaphragm, thermal element 126 for holding the operating means in its inactive position or allowing it to move to its active position. The knob 22 is rotated to its " pilot " position and depressed so that a cam pushes in pin 38 to depress lever 140 and pin 148 so that the auxiliary valve 60 opens. Gas flows from the inlet 12 through a cock boie 20 and passage 54, filter 48, passage 56, valve 60, adjusting screw 72 and passage 70 to a pilot burner where it heats a mercury phial 123 to expand diaphragm 126 and move the lever detent 160 to hold the pin 148 in its depressed position. The knob and cock are turned to " on " position so that gas now passes to the pilot burner and through the chamber 16 and the main valve, if opened by the rod and tube, to the main burner outlet 14. Should the pilotburner fail, the pin is released upwardly to close both auxiliary and main valves through lever 140.