GB1420284A - Control of gas-fired appliances - Google Patents

Abstract

1420284 Valves PARKINSON COWAN APPLIANCES Ltd 4 June 1974 [13 June 1973] 28063/73 Heading F2V [Also in Division F4] Gas burner control means comprises a manually-operable-valve 10 which can be set in an off position Fig. 4, a maximum flow position, Fig. 1 (not shown), or an intermediate position Figs. 2, 3 (not shown), a by-pass valve having a closure member 32 which provides when open an addition to the flow of gas through valve 10 in its intermediate position, a temperature sensitive device arranged automatically to close member 32, and manually operable means for initially setting closure member 32 in its open position. Manually-rotatable valve 10 has a full flow passage 18, connected to the burner through a passage 19, and a part flow passage 20, 21, the full or part flow passages being selectively connected to a gas main 34 wherein the gas flows to the burner through passage 19, or through passages 16 via an elastomeric pad 22. The by-pass valve is connected to main 34 by passages 33, 31, and to valve 10 by a passage 30, the closure being adapted to be opened by a solenoid 36. In operation, valve 10 is turned from the Fig. 4 off-position with a switch SW1 operated to trip an electric circuit Fig. 5, to an intermediate position, say the Fig. 2 position, which will give a suitable gas supply to provide a hot plate burner simmering state. A button PB1 is pressed so as to set the circuit to energize solenoid 36 which opens closure member 32, so that the gas flow through passages 30, 18, 19 augments the flow through passages 16, and a liquid on the hot plate is heated rapidly. When a desired temperature is reached a thermistor TH1 trips the circuit, solenoid 36 is de-energized and closure member 32 shuts-off the by-pass to reduce the gas flow to the simmering rate. If desired valve 10 can now be controlled manually. The thermistor can be replaced by mechanical or electro-mechanical temperature sensitive means.