Ignition and control system for gas burners

Claim 2

In an ignition and control system for gas burners, a burner, first and second biased closed solenoid operated valves arranged in series in a gas supply conduit leading to said burner, a solenoid winding for each of said valves, a glow igniter, and a normally closed sensor switch which opens when said igniter reaches gas ignition temperature and is maintained open thereafter by burner flame, circuit connections series connecting said first valve winding, said glow igniter, and said second valve winding across a power source and circuit connections connecting said sensor switch across said second valve winding, thereby shunting it when said switch is closed, said first valve winding being operative to effect opening of said first valve only when said sensor switch is closed and the current flow through said first valve winding and said series connected igniter is sufficient to heat said glow igniter to gas ignition temperature, and said second valve winding being operative to open said second valve when said sensor switch opens.

Claim 3

The ignition and control device claimed in claim 1 in which the current flow through said first valve winding and said igniter is reduced below that required to open said first valve and below that required to maintain said igniter at ignition temperature when said sensor switch opens, and in which said sensor switch is maintained in open position jointly by burner flame and the heat of said igniter.

Claim 4

In an ignition and control system for gas burners, a burner, first and second biased closed solenoid operated valves arranged in series in a gas supply conduit leading to said burner, a high impedance solenoid winding and a low impedance solenoid winding for said first valve connected in series across a power supply, a solenoid winding for said second valve, a glow igniter, and a normally closed sensor switch which opens when said igniter reaches gas ignition temperature, circuit connections connecting said first valve low impedance winding, said glow igniter, and said second valve winding in series across said power supply and in parallel with said high impedance winding, circuit connections connecting said sensor switch across said second valve winding thereby shunting it when said switch is closed, said series connected high and low impedance windings being jointly capable of opening said first valve only when said sensor switch is closed and when sufficient current is flowing through said low impedance winding and said series connected igniter to heat said igniter to gas ignition temperature, and said second valve being opened when said sensor switch opens, said series connected high and low impedance windings being capable of holding said first valve open when said sensor switch is open, and said sensor switch being maintained in open position by burner flame.

Claim 5

In an ignition and control system for gas burners, a burner, first and second biased closed solenoid operated valves arranged in series in a gas supply conduit leading to said burner, a high impedance solenoid winding and a low impedance solenoid winding for said first valve connected in series across a power supply, a solenoid winding for said second valve, a glow igniter, and a normally closed sensor switch which opens when said igniter reaches gas ignition temperature, circuit connections connecting said first valve low impedance winding, said glow igniter, and said second valve winding in series across said power supply and in parallel with said high impedance winding, circuit connections connecting said sensor switch across said second valve winding thereby shunting it when said switch is closed, said series connected high and low impedance windings being jointly capable of opening said first valve only when said sensor switch is closed and when sufficient current is flowing through said low impedance winding and said series connected igniter to heat said igniter to gas ignition temperature, and said second valve being opened when said sensor switch opens, said series connected high and low impedance windings being capable of holding said first valve open when said sensor switch is open, and said sensor switch being maintained in open position by burner flame.

Claim 6

The ignition and control device claimed in claim 3 in which the total impedance of the series connected first valve low impedance winding, the glow igniter, and the second valve winding is such when said sensor switch opens as to result in a substantial reduction in the temperature of said igniter.

Claim 7

The ignition and control device claimed in claim 3 in which said first valve low impedance winding has relatively few turns and in which the total impedance of the series connected low impedance winding, the glow igniter, and the second valve winding is such when the sensor switch opens that said low impedance winding provides only a relatively small portion of the magnetic force required to hold said first valve open.

Claim 8

In an ignition and control system for gas burners, a burner, an electrical power source, first and second biased closed solenoid operated valves arranged in series in a gas supply conduit leading to said burner, a solenoid winding for each of said valves, a glow igniter, and a normally closed sensor switch which opens when said igniter reaches ignition temperature and is thereafter maintained open by burner flame, circuit connections connecting said first valve winding in series with said glow igniter and with said second valve winding across said power source, and circuit connections connecting said sensor switch across said second valve winding thereby shunting it when said switch is closed, a second solenoid winding for said first valve, said windings for said first valve being series connected across said power source and being jointly operative to effect opening of said first valve only when said sensor switch is closed and when sufficient current is flowing through said igniter to heat it to ignition temperature, and said second valve winding being operative to open said second valve only when said sensor switch opens, the total impedance of said series connected first and second valve windings and said igniter being such when said sensor switch is open that the current flow through said first valve winding is reduced below that required to hold said first valve open and both windings of said first valve being jointly operative to hold said first valve open when sensor switch opens.

Claim 9

In an ignition and control system for gas burners, a burner, an electrical power source, first and second biased closed solenoid operated valves arranged in series in a gas supply conduit leading to said burner, a solenoid winding for each of said valves, a glow igniter, and a normally closed sensor switch which opens when said igniter reaches ignition temperature and is thereafter maintained open by burner flame, circuit connections connecting said first valve winding in series with said glow igniter and with said second valve winding across said power source, and circuit connections connecting said sensor switch across said second valve winding thereby shunting it when said switch is closed, a second solenoid winding for said first valve, said windings for said first valve being series connected across said power source and being jointly operative to effect opening of said first valve only when said sensor switch is closed and when sufficient current is flowing through said igniter to heat it to ignition temperature, and said second valve winding being operative to open said second valve only when said sensor switch opens, the total impedance of said series connected first and second valve windings and said igniter being such when said sensor switch is open that the current flow through said first valve winding is reduced below that required to hold said first valve open and both windings of said first valve being jointly operative to hold said first valve open when sensor switch opens.